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#1 Re: Ganesh's Puzzles » Oral puzzles » Today 00:51:47


#3886. Five cards - the ten, jack, queen, king, and the ace of diamonds, are well-shuffled with their face downwards. One card is then picked up at random.
(i) What is the probability of the card is the queen?
(ii) If the queen is drawn and put aside, what is the probability of the second card picked up is (a) an ace? (b) a queen?

#2 Re: Ganesh's Puzzles » 10 second questions » Today 00:38:28


#6323. Obtain the zeroes of the polynomial

, if two of its zeroes are -2 and -1.

#3 Re: Dark Discussions at Cafe Infinity » crème de la crème » Today 00:22:15

264) Jimmy Wales

Jimmy is an internet entrepreneur best known for founding the open-content reference site Wikipedia.


Jimmy Wales was born in Huntsville, Alabama, on August 7, 1966. Wales attended graduate school for finance before dropping out to pursue business ventures. In 2001, Wales founded the open-content internet resource Wikipedia, which became the world's largest encyclopedia. Wales also founded the for-profit web-hosting company Wikia, and has advised governments and universities.

Early Life

Jimmy Donal Wales was born in Huntsville, Alabama, on August 7, 1966. He attended a one-room school run by his mother and grandmother through the eighth grade. An intellectually curious child whose education proceeded according to the Montessori system, Wales spent considerable amounts of time reading encyclopedias. He credits this self-directed upbringing with his ability to think creatively.

Wales attended the Randolph preparatory school and studied finance at Auburn University. After graduating, he began a doctoral program in finance at the University of Alabama. Wales transferred to Indiana University before dropping out of school to take a job in a financial services firm.


Wales had been interested in the internet from its earliest days. In 1996, he left his job at the firm to cofound a startup called Bornis. Although the venture was not successful, it motivated Wales to pursue his vision of creating an online encyclopedia. In March 2000, he launched Nupedia—an open-content, peer-moderated reference site. He hired an academic, Larry Sanger, to serve as editor-in-chief.

Sanger learned about wikis in 2001 and Wales agreed to adopt the model. Wikipedia and Nupedia co-existed for a short time, with Wikipedia attracting much more traffic and participation. Without the funding to continue his position, Sanger resigned from both organizations in 2002. Sanger and Wales would later spar publicly over Sanger's role at Wikipedia. While Sanger considers himself a co-founder, Wales claims total conceptual ownership of the enterprise.

The non-profit Wikimedia Foundation, founded by Wales, has overseen the development of Wikipedia since 2003.

Other Ventures

In 2004, Wales and colleague Angela Beesley founded a for-profit internet company called Wikia. He stepped down from his position as CEO in 2009.

Wales began advising the British government on potential open access initiatives in 2012. The goal of the project was to make government-funded research available to taxpayers at no cost. In addition to his paid positions, Wales serves on the advisory boards of a number of academic foundations and research centers.

Personal Life

Wales has been married three times and has two daughters. He has received a number of major awards and honorary degrees from institutions, including Amherst College.

Wales is an outspoken atheist and an adherent of Objectivism, a philosophy popularized by author Ayn Rand. Objectivism privileges individualism, capitalism and reason. He identifies as a libertarian though he is not a supporter of the Libertarian Party.


#4 Re: Dark Discussions at Cafe Infinity » crème de la crème » Yesterday 00:36:36

263) Jozef Murgaš

Jozef Murgaš (English Joseph Murgas) (17 February 1864 – 11 May 1929) was a Slovak inventor, architect, botanist, painter, and Roman Catholic priest. He contributed to wireless telegraphy and help develop mobile communications and wireless transmission of information and human voice.

Murgaš was nicknamed the Radio Priest and deemed a Renaissance man.



Murgaš was born in Tajov (Tajó), Kingdom of Hungary, Austrian Empire (now Slovakia). He studied theology in Prešporok (Pressburg, present Bratislava) (1880–82), Esztergom (1882–84), and in Banská Bystrica, where he graduated in 1888. From his youth he was bright, skillful and good at painting and electrotechnology: The vice-head of the school in Esztergom allowed him to use the physics room for experiments, and the Slovak painters B. Klemens and Dominik Skutecký noticed his talent for painting.

After priestly ordination in 1888, Murgaš worked as a curate. On Skutecký's initiative, Murgaš was accepted at a painting school in Budapest, where he studied from 1889–90. He also studied painting in Munich from 1890-93. He attended both schools while working. He painted sacral pieces and Slovak landscapes and Slovak personalities. It was due to his strong patriotism he exhibited during holidays in the 1890s that he was not allowed to finish his painting studies and had to work as a curate in changing places in the Kingdom of Hungary: in Chrenovec (Nyitratormás), Slovenská Ľupča (Zólyomlipcse), Dubová (Cseres) and in Lopej (Lopér). In Lopej, he painted a large sacral picture of St. George, which is still on the church altar of the village. The central altar painting of St. Elisabeth, in the 14th century Church of St. Elizabeth in the main square of Banská Bystrica, is by Murgaš.

United States

Due to permanent conflicts with the bishop's secretary, Murgaš had to emigrate to the United States in 1896, where he was assigned a Slovak parish in the city of Wilkes-Barre, Pennsylvania. Having no possibility for painting, he started to deal with natural sciences again, especially electrotechnology. He established a laboratory in Wilkes-Barre, in which he primarily investigated radiotelegraphy. His article in the Tovaryšstvo magazine of 1900 shows that his radiotelegraphy studies had achieved a high level. In 1904, he received his first two US patents: the Apparatus for wireless telegraphy and The way of transmitted messages by wireless telegraphy. Further 15 patents followed between 1907 and 1916 (see below). Based on the first two patents, he created the Universal Aether Telegraph Co., which organized a public test of Murgaš's transmitting and receiving facilities in September 1905. The test was successful, but a storm destroyed the antenna masts three month later, which led to a dissolution of the company.

Murgaš's primary concern in Wilkes-Barre, however, were the local Slovaks. He took care of Slovak immigrants, had a new church, library, cemetery, several schools, gymnasium and playgrounds built, all of which are still used by American Slovaks. He was also one of the founders of the Saints Cyril and Methodius community and took care of children and youth. He was very popular among religious people because of his emotional relation to them. He also published a newspaper, in which he published some popular-science articles and verses.

Murgaš was active in the Slovak expatriates movement, wrote articles for their press, was one of the founders of the Slovak League in America, actively supported the creation of the state of Czechoslovakia, organized a money collection (a fund) of American Slovaks for the creation of Czechoslovakia (1,000,000 USD), and was also a writer and a signatory of the Pittsburgh Agreement (1918) between Czechs and Slovaks on establishing Czechoslovakia. As a respected personality, he gained trust and support of the highest authorities in the USA for the establishment of Czechoslovakia.

Murgaš continued to study physics and to do many experiments. He financed his activities by selling his paintings. He also collected mushrooms, plants, minerals and insects. His butterfly collection comprised 9000 pieces from all over the world.

When the United States entered World War I, private radiotelegraphy stations were prohibited, which put an end to Murgaš's pioneer work in this field. After the creation of Czechoslovakia, he returned to Slovakia in 1920, where he taught electrotechnology at a high school, but since he did not find appropriate understanding by the Ministry of Education in Prague, he returned to Wilkes-Barre four months later. He was nominated to be a member of the Federal Radio Commission of the United States in 1925. Murgaš died in Wilkes-Barre four years later.

Importance and primacy conflicts

The most dynamic segments in the area of communications services today are internet services, mobile telephony and convergence of voice and data process. If we go back one hundred years to history we can see that development in this area began with wireless information transmission encoded in telegraphy marks and wireless voice transmission which was made by frequency modulation.

In 1905, Murgaš achieved radio transmission between Wilkes-Barre and Scranton, Pennsylvania, or a distance of 20 miles (30 km).

The tone system is the use of two signals of different frequencies, i.e. Murgaš substituted the "dot" of the Morse code with a higher tone and the "dash" with a lower tone (this is the 1904 patent "The way of transmitted messages by wireless telegraphy").

Thomas Edison paid remarkable attention to Murgaš's experiments and he is said to have informed Guglielmo Marconi of Murgaš's success. Murgaš's lab in Wilkes-Barre was visited by President Theodore Roosevelt in 1905.

Memorials and honors

In Tajov, there is Murgaš's house where he was born, a memorial room, and a symbolic grave with a sepulchral monument of Murgaš at the local cemetery. Jozef Šebo, the founder of the room and monument (now a retired teacher) looks after them very carefully. The memorial room also features originals of pictures, paintings, some unique pieces from his butterfly collection, models of inventions in wireless telegraphy and documents. One can also see there a minimodel of Murgaš's original antenna masts built by company Universal Aether Telegraph Co. in Wilkes-Barre in 1905.

Further objects include:

Jozef Murgaš Monument in Bratislava, Slovakia – the Slovak Telecom building in the Jarošova Street
Jozef Murgaš street in Podbrezová-Lopej, Slovakia
Joseph Murgas Monument in Wilkes-Barre, Pennsylvania
Paintings in a church in Wilkes-Barre in Pennsylvania
Paintings in the Memorial room in Tajov, in some churches in Lopej and Banská Bystrica
Murgas Amateur Radio Club of Wilkes-Barre, PA named after Fr. Murgas in 1975.
Model of Murgas' transmitting station in Wilkes-Barre
Collection of butterflies (9,000 pieces) from all over the world
Liberty ship SS Joseph Murgas in the U.S. state Georgia in 1944
Jozef Murgaš Secondary School of Electrical Engineering in Banská Bystrica, Slovakia
Jozef Murgaš stamp issued by the Ministry of Transport, Communications and Public Works of the Slovak Republic in 1994 (400,000 pieces) on the occasion of 130th birth anniversary (1864) of Jozef Murgaš.

To the memory of Murgaš and to support the development of telecommunications in Slovakia, the Jozef Murgaš Award is awarded annually by the Slovak Electrotechnical Society and Ministry of Transport, Posts and Telecommunications of the Slovak Republic for:

publication of original theoretical contribution supporting development of telecommunication in Slovakia,
utilization of original or foreign theoretical contribution to development of telecommunications and telecommunication industry in Slovakia.


#5 Re: Ganesh's Puzzles » 10 second questions » 2018-01-17 00:51:39



#6322. A train travels 360 kilometers at a uniform speed. If the speed had been 5 kilometers per hour more, it would have taken 1 hour less for the same journey. Find the speed of the train.

#6 Re: Ganesh's Puzzles » Oral puzzles » 2018-01-17 00:42:21


#3885. Find the probability of a number selected from the number 1 to 25 is not a prime number when each of the given numbers is equally likely to be selected.

#7 Re: This is Cool » Miscellany » 2018-01-17 00:28:43

59) Parkinson's Disease


Parkinson's disease is a progressive disorder of the nervous system that affects movement. It develops gradually, sometimes starting with a barely noticeable tremor in just one hand. But while a tremor may be the most well-known sign of Parkinson's disease, the disorder also commonly causes stiffness or slowing of movement.

In the early stages of Parkinson's disease, your face may show little or no expression, or your arms may not swing when you walk. Your speech may become soft or slurred. Parkinson's disease symptoms worsen as your condition progresses over time.

Although Parkinson's disease can't be cured, medications may markedly improve your symptoms. In occasional cases, your doctor may suggest surgery to regulate certain regions of your brain and improve your symptoms.


Parkinson's disease symptoms and signs may vary from person to person. Early signs may be mild and may go unnoticed. Symptoms often begin on one side of your body and usually remain worse on that side, even after symptoms begin to affect both sides.

Parkinson's signs and symptoms may include:

Tremor. A tremor, or shaking, usually begins in a limb, often your hand or fingers. You may notice a back-and-forth rubbing of your thumb and forefinger, known as a pill-rolling tremor. One characteristic of Parkinson's disease is a tremor of your hand when it is relaxed (at rest).
Slowed movement (bradykinesia). Over time, Parkinson's disease may reduce your ability to move and slow your movement, making simple tasks difficult and time-consuming. Your steps may become shorter when you walk, or you may find it difficult to get out of a chair. Also, you may drag your feet as you try to walk, making it difficult to move.

Rigid muscles. Muscle stiffness may occur in any part of your body. The stiff muscles can limit your range of motion and cause you pain.
Impaired posture and balance. Your posture may become stooped, or you may have balance problems as a result of Parkinson's disease.
Loss of automatic movements. In Parkinson's disease, you may have a decreased ability to perform unconscious movements, including blinking, smiling or swinging your arms when you walk.

Speech changes. You may have speech problems as a result of Parkinson's disease. You may speak softly, quickly, slur or hesitate before talking. Your speech may be more of a monotone rather than with the usual inflections.

Writing changes. It may become hard to write, and your writing may appear small.

When to see a doctor

See your doctor if you have any of the symptoms associated with Parkinson's disease — not only to diagnose your condition but also to rule out other causes for your symptoms.


In Parkinson's disease, certain nerve cells (neurons) in the brain gradually break down or die. Many of the symptoms are due to a loss of neurons that produce a chemical messenger in your brain called dopamine. When dopamine levels decrease, it causes abnormal brain activity, leading to signs of Parkinson's disease.

The cause of Parkinson's disease is unknown, but several factors appear to play a role, including:

Your genes. Researchers have identified specific genetic mutations that can cause Parkinson's disease, but these are uncommon except in rare cases with many family members affected by Parkinson's disease.

However, certain gene variations appear to increase the risk of Parkinson's disease but with a relatively small risk of Parkinson's disease for each of these genetic markers.

Environmental triggers. Exposure to certain toxins or environmental factors may increase the risk of later Parkinson's disease, but the risk is relatively small.
Researchers have also noted that many changes occur in the brains of people with Parkinson's disease, although it's not clear why these changes occur. These changes include:

The presence of Lewy bodies. Clumps of specific substances within brain cells are microscopic markers of Parkinson's disease. These are called Lewy bodies, and researchers believe these Lewy bodies hold an important clue to the cause of Parkinson's disease.

Alpha-synuclein is found within Lewy bodies. Although many substances are found within Lewy bodies, scientists believe an important one is the natural and widespread protein called alpha-synuclein (A-synuclein). It's found in all Lewy bodies in a clumped form that cells can't break down. This is currently an important focus among Parkinson's disease researchers.

Risk factors

Risk factors for Parkinson's disease include:

Age. Young adults rarely experience Parkinson's disease. It ordinarily begins in middle or late life, and the risk increases with age. People usually develop the disease around age 60 or older.

Heredity. Having a close relative with Parkinson's disease increases the chances that you'll develop the disease. However, your risks are still small unless you have many relatives in your family with Parkinson's disease.

Physical relation.

Men are more likely to develop Parkinson's disease than are women.

Exposure to toxins. Ongoing exposure to herbicides and pesticides may put you at a slightly increased risk of Parkinson's disease.


Parkinson's disease is often accompanied by these additional problems, which may be treatable:

Thinking difficulties. You may experience cognitive problems (dementia) and thinking difficulties, which usually occur in the later stages of Parkinson's disease. Such cognitive problems aren't very responsive to medications.

Depression and emotional changes.

People with Parkinson's disease may experience depression. Receiving treatment for depression can make it easier to handle the other challenges of Parkinson's disease.

You may also experience other emotional changes, such as fear, anxiety or loss of motivation. Doctors may give you medications to treat these symptoms.

Swallowing problems.

You may develop difficulties with swallowing as your condition progresses. Saliva may accumulate in your mouth due to slowed swallowing, leading to drooling.

Sleep problems and sleep disorders.

People with Parkinson's disease often have sleep problems, including waking up frequently throughout the night, waking up early or falling asleep during the day.

People may also experience rapid eye movement sleep behavior disorder, which involves acting out your dreams. Medications may help your sleep problems.

Bladder problems. Parkinson's disease may cause bladder problems, including being unable to control urine or having difficulty urinating.


Many people with Parkinson's disease develop constipation, mainly due to a slower digestive tract.

You may also experience:

i) Blood pressure changes. You may feel dizzy or lightheaded when you stand due to a sudden drop in blood pressure (orthostatic hypotension).
ii) Smell dysfunction. You may experience problems with your sense of smell. You may have difficulty identifying certain odors or the difference between odors.
iii) Fatigue. Many people with Parkinson's disease lose energy and experience fatigue, and the cause isn't always known.
iv) Pain. Many people with Parkinson's disease experience pain, either in specific areas of their bodies or throughout their bodies.
v) Physical dysfunction. Some people with Parkinson's disease notice a decrease in physical desire or performance.


Because the cause of Parkinson's is unknown, proven ways to prevent the disease also remain a mystery. However, some research has shown that caffeine — which is found in coffee, tea and cola — may reduce the risk of developing Parkinson's disease. Green tea also may reduce the risk of developing Parkinson's disease.

Some research has shown that regular aerobic exercise may reduce the risk of Parkinson's disease.


#8 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2018-01-16 00:18:41

262) John Charles Fields

John Charles Fields, (May 14, 1863 – August 9, 1932) was a Canadian mathematician and the founder of the Fields Medal for outstanding achievement in mathematics. First awarded in 1936, the medal has been awarded since 1950 every four years at the International Congress of Mathematicians to two, three or four recipients under the age of 40.

Life and career

Born in Hamilton, Ontario, to a leather shop owner, Fields graduated from Hamilton Collegiate Institute in 1880 and the University of Toronto in 1884 before leaving for the United States to study at Johns Hopkins University in Baltimore, Maryland. Fields received his Ph.D. in 1887. His thesis, entitled Symbolic Finite Solutions and Solutions by Definite Integrals of the Equation

, was published in the American Journal of Mathematics in 1886.

Fields taught for two years at Johns Hopkins before joining the faculty of Allegheny College in Meadville, Pennsylvania. Disillusioned with the state of mathematical research in North America at the time, he left for Europe in 1891, locating primarily in Berlin, Göttingen and Paris, where he associated with some of the greatest mathematical minds of the time, including Karl Weierstrass, Felix Klein, Ferdinand Georg Frobenius and Max Planck. Fields also began a friendship with Gösta Mittag-Leffler, which would endure their lifetimes. He began publishing papers on a new topic, algebraic functions, which would prove to be the most fruitful research field of his career.

Fields returned to Canada in 1902 to lecture at the University of Toronto. Back in the country of his birth, he worked tirelessly to raise the stature of mathematics within academic and public circles. He successfully lobbied the Ontario Legislature for an annual research grant of $75,000 for the university and helped establish the National Research Council of Canada, and the Ontario Research Foundation. Fields served as president of the Royal Canadian Institute from 1919 until 1925, during which time he aspired to mold the institute into a leading centre of scientific research, although with mixed success. His efforts, however, were pivotal in making Toronto the location of the 1924 International Congress of Mathematicians (ICM). He was an Invited Speaker of the ICM in 1912 at Cambridge, in 1924 at Toronto, and in 1928 at Bologna.

Fields is best known for his development of the Fields Medal, which is considered by some to be the Nobel Prize in Mathematics, although there are differences between the awards. First awarded in 1936, the medal was reintroduced in 1950 and has been awarded every four years since. It is awarded to two to four mathematicians, under the age of 40, who have made important contributions to the field.

Fields began planning the award in the late 1920s but, due to deteriorating health, never saw the implementation of the medal in his lifetime. He died on August 9, 1932 after a three-month illness; in his will, he left $47,000 for the Fields Medal fund.

Fields was elected fellow of the Royal Society of Canada in 1907 and fellow of the Royal Society of London in 1913.

The Fields Institute at the University of Toronto was named in his honour.


#9 Re: Help Me ! » fourier analysis » 2018-01-15 23:57:46

Hi kristijan,

I may not be able to help you fully but this may be of some help.

In mathematics, Fourier analysis is the study of the way general functions may be represented or approximated by sums of simpler trigonometric functions. Fourier analysis grew from the study of Fourier series, and is named after Joseph Fourier, who showed that representing a function as a sum of trigonometric functions greatly simplifies the study of heat transfer.

Today, the subject of Fourier analysis encompasses a vast spectrum of mathematics. In the sciences and engineering, the process of decomposing a function into oscillatory components is often called Fourier analysis, while the operation of rebuilding the function from these pieces is known as Fourier synthesis. For example, determining what component frequencies are present in a musical note would involve computing the Fourier transform of a sampled musical note. One could then re-synthesize the same sound by including the frequency components as revealed in the Fourier analysis. In mathematics, the term Fourier analysis often refers to the study of both operations.

The decomposition process itself is called a Fourier transformation. Its output, the Fourier transform, is often given a more specific name, which depends on the domain and other properties of the function being transformed. Moreover, the original concept of Fourier analysis has been extended over time to apply to more and more abstract and general situations, and the general field is often known as harmonic analysis. Each transform used for analysis has a corresponding inverse transform that can be used for synthesis.


The first three successive partial Fourier series (shown in red) for a square wave (shown in blue). The second half of the course is devoted to Fourier series and Fourier integrals.

#11 Re: This is Cool » Miscellany » 2018-01-15 00:27:21

58) Universal Serial Bus

What does Universal Serial Bus (USB) mean?

A Universal Serial Bus (USB) is a common interface that enables communication between devices and a host controller such as a personal computer (PC). It connects peripheral devices such as digital cameras, mice, keyboards, printers, scanners, media devices, external hard drives and flash drives. Because of its wide variety of uses, including support for electrical power, the USB has replaced a wide range of interfaces like the parallel and serial port.

A USB is intended to enhance plug-and-play and allow hot swapping. Plug-and-play enables the operating system (OS) to spontaneously configure and discover a new peripheral device without having to restart the computer. As well, hot swapping allows removal and replacement of a new peripheral without having to reboot.

Although there are several types of USB connectors, the majority of USB cables are one of two types, type A and type B. The USB 2.0 standard is type A; it has a flat rectangle interface that inserts into a hub or USB host which transmits data and supplies power. A keyboard or mouse are common examples of a type A USB connector. A type B USB connector is square with slanted exterior corners. It is connected to an upstream port that uses a removable cable such as a printer. The type B connector also transmits data and supplies power. Some type B connectors do not have a data connection and are used only as a power connection.

The USB was co-invented and established by Ajay Bhatt, a computer architect who had been working for Intel. In 1994 seven companies that included Intel, Compaq, Microsoft, IBM, Digital Equipment Corporation (DEC), Nortel and NEC Corporation started the development of the USB. Their objective was to make it easier to connect peripheral devices to a PC and eliminate the mass amount of connectors. Factors involved included: creating larger bandwidths, streamlining software configurations and solving utilization problems for current interfaces.

The USB design is standardized by the USB Implementers Forum (USBIF) that is comprised of a group of companies supporting and promoting the USB. The USBIF not only markets the USB but maintains the specifications and upholds the compliance program. Specifications for the USB were created in 2005 with the 2.0 version. The standards were introduced by the USBIF in 2001; these included the older versions of 0.9, 1.0 and 1.1, which are backward compatible.

Universal Serial Bus (USB)

A Universal Serial Bus (USB) is basically a newer port that is used as a common interface to connect several different types of devices such as keyboards, printers, media devices, cameras, scanners, and mice. It is designed for easy installation, faster transfer rates, higher quality cabling and hot swapping. It has conclusively replaced the bulkier and slower serial and parallel ports.

One of the greatest features of the USB is hot swapping. This feature allows a device to be removed or replaced without the past prerequisite of rebooting and interrupting the system. Older ports required that a PC be restarted when adding or removing a new device. Rebooting allowed the device to be reconfigured and prevented electrostatic discharge (ESD), an unwanted electrical current capable of causing serious damage to sensitive electronic equipment such as integrated circuits. Hot swapping is fault tolerant, i.e. able to continue operating despite a hardware failure. However, care should be taken when hot swapping certain devices such as a camera; damage can occur to the port, camera or other devices if a single pin is accidently shorted.

Another USB feature is the use of direct current (DC). In fact, several devises use a USB power line to connect to DC current and do not transfer data. Example devices using a USB connector only for DC current include a set of speakers, an audio jack and power devices like a miniature refrigerator, coffee cup warmer or keyboard lamp.

USB Version 1 allowed for two speeds: 1.5 Mb/s (megabits per second) and 12 Mb/s, which work well for slow I/O devices. USB Version 2 allows up to 480 Mb/s and is backward compatible with slower USB devices. USB supports three.


#12 Re: Ganesh's Puzzles » Oral puzzles » 2018-01-15 00:14:30



#3884. A box contains 90 discs which are numbered from 1 to 90. If one disc are drawn at random from the box, find the probability of it bearing
(i) a two digit number
(ii) a perfect square number
(iii) a number divisible by 5.

#14 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2018-01-14 02:56:37

261) Maryam Mirzakhani

(3 May 1977 – 14 July 2017)

Pioneering mathematician and winner of the Fields Medal.

Maryam Mirzakhani was one of the greatest mathematicians of her generation. She made monumental contributions to the study of the dynamics and geometry of mathematical objects called Riemann surfaces. Just as impressive as her theorems was her ability to push a field in a new direction by always providing a fresh point of view. Her raw talent was rare, even among the most celebrated mathematicians, and she was known for having a taste for difficult problems.

She became an icon without wanting to be. She was the first woman and first Iranian to win the Fields Medal, considered the highest honour in mathematics. For women, Mirzakhani was a role model, pursuing a successful career in a male-dominated field. For Iran, she represented the country's tradition of intellectualism. And for young scientists, she was a calming force that rose above the pressures of academia. She died aged 40 from breast cancer on 14 July.

Mirzakhani was born in May 1977 in Tehran. She attended school there and twice won gold medals for Iran in the International Mathematical Olympiad. Being hailed as a genius allowed her to pursue pure mathematics — not an easy career choice for women in Iran.

Mirzakhani gained a bachelor's degree in mathematics in 1999 from the Sharif University of Technology in Tehran. She left to do doctoral work in the United States and earned her PhD in 2004 from Harvard University in Cambridge, Massachusetts, under the supervision of Curtis McMullen. She turned down a junior fellowship there to become a Clay Mathematics Institute research fellow at Princeton University in New Jersey. She became a full professor at Stanford University in California in 2008, by which time she was considered a leader in the fields of hyperbolic geometry, topology and dynamics. She stayed at Stanford until her death.

Mirzakhani's PhD concerned Riemann surfaces. Picture a surface with several holes in it, like that of a pretzel or two doughnuts stuck together, and then imagine trying to wrap a rubber band around the surface without it overlapping itself. Mirzakhani wanted to work out how many different ways this can be done for a rubber band of a given length.

She realized that she could flip the method. Instead of fixing a surface and counting the number of curves, she could find the average of all such numbers corresponding to points in the 'moduli space' of Riemann surfaces: a 'space', or set, of points, each of which represents one of the shapes a surface can take. Computing such an average requires one to calculate the 'volume', or size, of the space of Riemann surfaces that contain a curve of a certain length. A clever recursive formula for the volumes of various moduli spaces solved the problem. The solution had several stunning ramifications in seemingly distant fields. For example, it offered a new proof of a famous theorem by the Russian–French mathematician Maxim Kontsevich, which had implications in quantum field theory.

In later work, Mirzakhani studied the dynamics of a billiard ball, or point mass, moving in a polygon. A ball moves in a straight line until it hits the edge of the polygon; then it bounces back at the same angle at which it hit. A mathematician could ask several questions about such a system. For instance, is it possible for a ball to move inside a given polygon in such a way that the path it takes is eventually repeated — and, if so, how many such paths are there, and what do they look like? The problem of whether a repeating path exists for a general polygon is still unsolved.

In some cases, it is helpful to embed the space of certain billiard tables in a larger space in which every point is a surface that is locally either flat or cone-shaped. With Alex Eskin, a mathematician at the University of Chicago in Illinois, Mirzakhani used this method to prove, for such spaces, a version of a theorem about a group of symmetric geometric objects known as Lie groups. The theorem was proposed by Marina Ratner, another leading mathematician in the field who also died in July, aged 78. The proof — a monumental work written up in a 200-page paper (A. Eskin and M. Mirzakhani Preprint at; 2013) — tied together disparate fields including geometry, topology and dynamical systems, and spawned a field of its own. It has been dubbed the 'magic wand' theorem because it enabled many previously intractable mathematical problems to be solved.

Despite the fame and attention she received, Mirzakhani remained humble and grounded, always avoiding the spotlight. She listened to the work of other mathematicians with excitement and asked forward-looking questions that hinted at possible new directions. At conferences, she could be found talking with graduate students and Fields medallists alike. She generously shared her ideas with the community and helped others to further their careers.

I visited Maryam in December 2016. We walked from her home in Palo Alto, California, to Stanford's maths department to listen to a lecture by the Russian–French mathematician Mikhail Gromov. Mirzakhani was diagnosed with cancer in 2013 and had already been treated for the illness, but by this time it had returned and spread, and she was in pain. We stopped every few minutes along the walk so that she could lie down on a bench to rest. Maryam told me that she didn't want to take long-term leave from work for her illness and that she would like to continue her responsibilities as an editor of the Journal of the American Mathematical Society. I couldn't resist telling her about the maths problems I was thinking about, and despite all that was going on in her life, she was happy to listen and offer helpful insights.

The mathematics community has lost one of its greatest minds much too early, and I have lost a friend.

Author information
Kasra Rafi is an associate professor in the Department of Mathematics, University of Toronto, Toronto, Canada. He was a friend and collaborator of Maryam Mirzakhani.


#15 Re: This is Cool » Miscellany » 2018-01-13 16:48:10

57) The Grand Canyon

#1 The Grand Canyon reveals 40% of Earths history.

The Grand Canyon contains the metamorphic rock Vishnu schist, and layers of sedimentary rock that date back to 1.75 billion years old — that’s nearly half the age of the Earth  (4.5 billion years old)! That means there are tons of fossils and tracks to help us learn about ancient species.

#2 There are pink snakes!

There are six different types of rattlesnakes that call the Grand Canyon home but one of them sticks out a little more than the others. Or doesn’t stick out, actually, because the pink hue of the snake works as camouflage among the sunlit rocks.

#3 The Grand Canyon encompasses several ecosystems.

As you descend into the Grand Canyon, your surroundings can change rapidly. There are around 70 mammal species, 47 reptile species, 250 species of birds, and over 1,750 plant species. Temperatures have been recorded from -10° to 110° Fahrenheit in various locations of the canyon.

#4 The Grand Canyon is the reason we have the FFA.

Back in the 1950’s, the awe-inspiring view of the canyon was so tempting that there were numerous plane collisions resulting from pilots who decided to take a scenic detour away from their flight path. These tragedies necessitated the in-air regulations we have today, and they’re the reason that, these days, you can safely fly over the Grand Canyon for a unique view.

#5 The Pueblo Indians were the first to call the Grand Canyon home.

More than 3,000 years ago, the Grand Canyon worked well as as a place to provide shelter and store food. Not only this, but the Grand Canyon was believed to be a holy land. We continue to learn more about the Pueblo Indians today, as we find tools and structures that they left behind.

#6 The air at the Grand Canyon is some of the cleanest in the U.S.

As a National Park, the Grand Canyon is well protected. Barring the occasional dust storm or forest fire, chances are good that you’ll be breathing easy. It’s no wonder that over 5 million people a year come to experience this beautiful feat of nature.

#7 It’s still growing

Scientists generally agree that the Grand Canyon is a result of continual erosion by wind, rain, and the powerful Colorado river. The Colorado river still flows today, of course, which means that the Grand Canyon is constantly getting bigger and changing shape. It’s a slow process, but it’s happening nonetheless!

#8 People still live in the Grand Canyon, even today!

While you might think that the Grand Canyon is a beautiful place to visit, many people call this beautiful place home. Records show that some 2,000 people live in the Grand Canyon all year round. The majority of the inhabitants are members of the Havasupai Tribe, but we can’t forget those who keep Phantom Ranch (the only place to stay at the bottom of the canyon) up and running.

#9 Sometimes we start fires in the Grand Canyon on purpose!

This may seem like a destructive act against nature, but its goal is actually to prevent a tragedy. Firefighters strategically start small fires, called prescribed burns, that help refresh forest ecosystems and ensure that larger canopy fires don’t occur, resulting in widespread, tragic losses.

#10 The Grand Canyon is considered to be one of the 7 Wonders of the World.

On average, the canyon is 277 miles long, 18 miles wide, and 1 mile deep.


#16 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2018-01-13 00:53:35

260) Edward Butler

Edward Butler (1862–1940) was an English inventor who produced an early three-wheeled petrol automobile called the Butler Petrol Cycle, which is accepted by many as the first British car.

Butler showed plans for his three-wheeled petrol vehicle at the Stanley Cycle Show in London in 1884, two years earlier than Karl Benz, who is generally recognized as the inventor of the modern automobile. Butler's vehicle was also the first design to be shown at the 1885 Inventions Exhibition, also in London.

Butler Petrol Cycle

Built by the Merryweather Fire Engine company in Greenwich, in 1888, the Butler Petrol Cycle (first recorded use of the term) was a three-wheeled petrol vehicle. The rear wheel was directly driven by a 5/8 hp (466W) 600 cc (40 in³; 2¼×5-inch {57×127-mm}) flat twin four-stroke engine (with magneto ignition replaced by coil and battery), equipped with rotary valves and a float-fed carburettor (five years before Maybach), and Ackermann steering, all of which were state of the art at the time. The engine was liquid-cooled, with a radiator over the rear driving wheel. Speed was controlled by means of a throttle valve lever. The driver was seated between the front wheels.

The vehicle featured in an article in the 14 February 1891 issue of Scientific American, where it was stated that one gallon of fuel in the form of petroleum or benzolene could propel the vehicle for forty miles (5.9 L/100 km) at a speed of 3–10 mph (5–16 km/h).

Butler improved the specifications of his vehicle over the years, but was prevented from adequately testing it due to the 1865 Red Flag Act, which legislated a maximum speed for self-propelled road vehicles of 2 mph (3 km/h) in built up areas and 4 mph (6.5 km/h) in rural areas. Additionally, the vehicle had to be attended by three people, one of whom had to proceed in front of the vehicle waving a red flag.

Butler wrote in the magazine The English Mechanic in 1890, "The authorities do not countenance its use on the roads, and I have abandoned in consequence any further development of it."

Due to general lack of interest, Butler broke up his machine for scrap in 1896, and sold the patent rights to Harry J. Lawson who continued manufacture of the engine for use in motorboats.

Instead, Butler turned to making stationary and marine engines. His motor tricycle was in advance of its better-known contemporaries on several points.

#17 Re: Ganesh's Puzzles » 10 second questions » 2018-01-13 00:18:51


#6320. Find the value of


#19 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2018-01-11 23:38:48

259) Corradino D'Ascanio

General Corradino D'Ascanio (February 1, 1891 in Popoli, Pescara – August 6, 1981 in Pisa) was an Italian aeronautical engineer. D'Ascanio designed the first production helicopter, for Agusta, and designed the first motor scooter for Ferdinando Innocenti. After the two fell out, D'Ascanio helped Enrico Piaggio produce the original Vespa.


D'Ascanio had an early passion for flight and design: by the age of fifteen, after studying flying techniques and the ratio between weight and wingspan of some birds, he built an experimental glider which he would launch from the hills near his home town.

World War I

After graduating in 1914 in mechanical engineering at the Politecnico di Torino, he enlisted in the voluntary division of the Italian Army entitled "weapon of Engineers, Division Battalion Aviatori" in Piedmont, where he was assigned the testing of airplane engines. Appointed sub-lieutenant on March 21, 1915, D'Ascanio was sent to France to choose a rotary engine to be produced in Italy for the Corpo Aeronautico Militare, returning with an agreement to produce the Gnome et Rhône designed Le Rhône.

After a brief pilot training course in Corsica on a Farman MF.7, he returned to engineering, designing a patented forward-facing monitoring device to improve maintenance monitoring within flight squadrons (estimated to have saved fifty lives), and took part in the trials of the first radio equipment installed in Italian aircraft.

In 1916 D'Ascanio was assigned to join Fabbrica Aeroplani Ing. O. Pomilio, engaged in the manufacture of equipment SP2, Type C, D Type and others. Following the end of World War I, the Pomilio brothers sold the company and moved in 1918 with key staff, including D'Ascanio, to Indianapolis in the United States to form the Pomilio Brothers Corporation.

Between the wars

On his return to Italy after a year in 1919, D'Ascanio again settled in Popoli, focused on the control mechanisms for helicopters, through which he derived a number of patents. In 1925 he founded a company with Baron Pietro Trojani, which commissioned by the Ministry dell'Aeronautica produced in 1930 its third prototype, the coaxial D'AT3. This relatively large machine had two double-bladed, counter-rotating rotors, with control achieved by using auxiliary wings or servo-tabs on the trailing edges of the blades, a concept that was later adopted by other helicopter designers, initially by the French Breguet-Dorand Gyroplane Laboratoire in 1935, and still later by designs from both Bleeker and Kaman. Three small propellers mounted on the airframe were used for additional control of pitch, roll, and yaw. Piloted by Marinello Nelli in October 1930 at Ciampino Airport, this machine held modest Fédération Aéronautique Internationale speed and altitude records for the time, including altitude (18 m), duration (8 minutes 45 seconds) and distance flown (1,078 m).[2][3] D'Ascanio's altitude record would be "unofficially" shattered by the Soviet-built, Yuriev-Cheremukhin TsAGI-1EA single-lift rotor helicopter in mid-August 1932, with a 605 meters (1,985 ft) altitude achievement, and also possessed fore-and-aft tubular fuselage structures for similar "anti-torque" stabilization rotors.

However, during the Depression, in which the fascist government of Benito Mussolini concentrated on "standard" production items, the company collapsed in 1932, and D'Ascanio went to work for Enrico Piaggio at his fathers company, designing numerous successful high-speed adjustable pitch propellors for Piaggio Aero. His work was considered so important during World War II, he was promoted to General in the Regia Aeronautica, and restarted helicopter development under instruction from President of Piaggio S. p. A. Enrico Piaggio from 1942.

After the war

Like many Italians, D'Ascanio found himself unemployed - the Piaggio factory was destroyed through Allied bombing. Worse still, Italy was under an agreement not to research or produce military or aerospace technology for a ten-year period, and so he was unemployable in Italy. Approached by pre-war tubing manufacturer Ferdinando Innocenti, who saw the future of cheap private transport and decided to produce a motor scooter – competing on cost and weather protection against the ubiquitous motorcycle.

The Vespa

The main stimulus for the design style of the proposed Lambretta dated back to Pre-WWII Cushman scooters made in Nebraska, USA. These olive green scooters were in Italy in large numbers, ordered originally by the US Government as field transport for the Paratroops and Marines. The US military had used them to get around Nazi defence tactics, destroying roads and bridges during the Battle of Monte Cassino and in the Dolomites and the Austrian border areas.

The motor scooter

Ferdinando Innocenti gave D'Ascanio the job of designing a simple, robust and affordable vehicle. The vehicle had to be easy to ride for both men and women, be able to carry a passenger, and not get its driver's clothes dirty. D'Ascanio, who hated motorcycles, designed a revolutionary vehicle. It was built on a spar-frame with a handlebar gear change, and the engine mounted directly on to the rear wheel. The front protection "shield" kept the rider dry and clean in comparison to the open front end on motorcycles. The pass-through leg area design was geared towards all user groups, including women, whose skirts made riding a motorcycle a challenge. The front fork, like an aircraft's landing gear, allowed for easy wheel changing. The internal mesh transmission eliminated the standard motorcycle chain, a source of oil, dirt, and aesthetic misery. This basic design allowed a series of features to be deployed on the frame, which would later allow quick development of new models.

However, D'Ascanio fell out with Innocenti, who wanted to produce his frame from rolled tubing, rather than a stamped spar frame, thereby allowing him to revive both parts of his pre-war company. General D'Ascanio dissociated himself from Innocenti, and took his design directly to Enrico Piaggio, who produced the spar-framed Vespa from 1946. Innocenti, faced by design problems and production issues surrounding his tube frame, produced the Lambretta from 1947. In the decades of its history, the Vespa scooter has become one of the most famous brand designs worldwide, with 16 million units produced in 130 different models as of 2005.

After Vespa

In 1948 D'Ascanio attended an international congress for the helicopter in Philadelphia, where he was hailed as a true pioneer. He continued to work for Piaggio, tweaking designs for the Piaggio PD 3, and in 1952 the Piaggio PD4. However, restricted legally through neutrality agreements and financially through reconstruction, Piaggio had by now fallen behind the developments of the American Sikorsky Aircraft Corporation, and few of D'Ascanio helicopter designs or aeronautical developments made it beyond the drawing board.

In 1964 D'Ascanio left Piaggio to join the Agusta Group of Cascina Costa, by then the largest Italian manufacturer of helicopters. In 1969 D'Ascanio designed a small training helicopter, the Agusta ADA, which could be modified for agricultural use - but it was not developed, due to Agusta's commitment to re-equipping the Italian military.

Author of numerous scientific publications, published between 1954 and 1980, he was professor of design of machines and projects at the University of Pisa between 1937 (when he was an employee of Piaggio) and 1961. D'Ascanio, for his services to Italy and aeronautical development, was decorated with the Order of Merit of the Italian Republic by the President of the Italian Republic.

Always disappointed by the fact he was publicly recognised for his associations with the Vespa motor scooter over his developments and patents in the world of aviation, D'Ascanio died in Pisa on August 6, 1981.


#20 Re: Ganesh's Puzzles » Oral puzzles » 2018-01-11 23:15:24


#3882. Solve:
152x - 378y = -74,
-378x + 152y = -604.

#21 Re: Ganesh's Puzzles » 10 second questions » 2018-01-11 23:09:16


#6319. A passenger train takes 2 hours less for a journey of 300 kilometers if its speed is increased by 5 kilometers per hour from its usual speed. Find the usual speed of the train.

#22 Re: Jokes » Deft Definitions » 2018-01-11 17:14:52

Deft Definitions

(Some more)

Adder : Mathematically inclined snake.

Babies : Nature's way of showing people what the world looks like at 2 a.m.

Comic books : The opera of the print media.

Drama : What literature does at night.

Ego trip : Something that never gets you anywhere.

Emergency numbers : Police station, fire department, and places that deliver.

Eternity : The first 60 seconds of a blind date.

Fancy Restaurant : One that serves cold soup on purpose.

Fear : Excitement in need of an attitude adjustment.

Great economist : Someone who, tomorrow, is perfectly capable of explaining why what he forecasted yesterday didn't happen today.

Mobile phones : The only subject on which men boast about who's got the smallest.

Net worth : Fisherman's income.

Perfectionist : A person who takes great pains and gives them to others.

Slimming : Living beyond your seams.

#23 Re: This is Cool » Miscellany » 2018-01-11 00:30:49

56) Malic Acid

Malic acid is a component of many of the foods that we eat daily. Although it is found as a naturally occurring organic compound in various fruits, many choose to take malic acid supplements to increase their overall health, as well as treat various maladies. Today, the acid is most commonly used as a food additive and preservative. It is a mild and relatively harmless acid when used in appropriate amounts. As a food supplement, it is generally considered beneficial for health and is present in large amounts in apple juices. As when taking any supplement, however, you should not exceed the recommended amounts for consumption.

Benefits of Malic Acid

Pain Reduction

One of its most commonly touted benefits is its ability to help reduce pain. For this reason, it is frequently used by those who suffer from fibromyalgia and chronic fatigue system. Those who take it for this reason have reported reduced muscle soreness and pain. Although it takes several days of consistent consumption for the supplement to take full effect, it can start to reduce pain as quickly as 48 hours after your first supplement.

Energy Boost

In addition to providing reduced pain, it is also said to provide increased energy. This is another side effect enjoyed by sufferers of chronic fatigue syndrome and fibromyalgia. Those who have it as a supplement to their diet, especially those who suffer from these conditions, have experienced a significant reduction in fatigue, giving them a much-needed boost of energy.

Skin Care Benefits

Not only is this acid used in the form of a food supplement, it is also a common additive to skin care products. Malic acid has long been used in skin products for its exfoliating properties. Furthermore, it is able to penetrate the skin more deeply, due to its chemical composition. As a result, products that employ this great supplement can greatly help in improving skin smoothness, pigmentation and complexion. Its superior ability to penetrate the skin makes it an ideal moisturizer for people who have very sensitive skin that does not benefit form typical moisturizers.

In the majority of products it is used in, it functions largely as a pH adjuster. By raising the pH of the skin, this acid helps to facilitate healthy exfoliating, thereby improving the overall health and appearance of the area that you are targeting.

Side Effects

Although generally regarded as a very safe and effective supplement, there can be some minor side effects. The most common of these, while uncomfortable, are only experienced by a small number of those who use the supplement. The side effects most frequently experienced include muscle pain, nausea, redness, constipation, swollen skin, chest pain and itching. While annoying, these typically dissipate after a couple days.

While most of the side effects are relatively minor, there are also some more serious side effects, which are very rare. These serious side effects are often more serious forms of their minor counterparts, such as extreme chest tightness. This also includes dangerous events such as allergic reaction, which can lead to difficulty breathing or a completely closed throat. If you experience any of these, seek medical help immediately.

Foods Containing Malic Acid

The food that is most well known for its high malic acid content is the apple. Other fruits with a very high concentration of the acid are nectarines, cherries, lychees, bananas, mangoes, peaches, tomatoes and strawbesrries. It can be found, however, in nearly all fruits.

Malic acid is also used as a flavor enhancer for many drinks and candies. It is especially common in diet sodas and other artificially sweetened drinks. This is also true of artificially sweetened candies, such as gum and other gummy candies. Because of its highly versatile nature, especially in masking unnatural flavors, it has become an important part of nearly any food product that contains alternative sweeteners.

One of the greatest things about malic acid as both a food supplement and a skincare agent is the fact that it is a completely natural, organic compound. Rather than relying on man-made products to improve the health of your body and skin, it provides a natural alternative for a variety of purposes. Whether you are treating your chronic fatigue, fibromyalgia or just some dry skin, this acid is a safe and readily available solution. Because of its powerful pain relieving and healing properties, it has become a very popular, and viable solution for many people in the treatment of their various maladies. This has only been amplified by its overall safety.

DL-Malic Acid Background and Benefits

Malic acid is a dicarboxylic acid with the chemical formula C4H6O5, which has two structures known as enantiomers. L-malic acid occurs naturally in all organisms, while D-malic acid must be synthesized in the laboratory. A mixture of D-malic acid and L-malic acid is called a racemic mixture, which is commonly known as DL-malic acid.

The Swedish chemist Carl Wilhelm Scheele first isolated malic acid from apple juice in 1785. Its name comes from “malum,” which is the Latin word for apple. Malic acid is a major contributor to the sourness in apples, although its concentration decreases as the apple ripens. It is also the primary flavor in rhubarb and is used to flavor “salt and vinegar” potato chips.

L-malic acid is often formed in organisms as an intermediate product of metabolic reactions involving pyruvate. It also has many esters and salts known as malates that play critical biological roles. Malates are a source of carbon dioxide in the Calvin cycle, and they are also an intermediate product in the citric acid cycle. D-malic acid is primarily used in health supplements, typically in the form of DL-malic acid.

L-malic acid may be produced commercially by fermenting fumaric acid. Racemic malic acid is typically synthesized by double hydrating maleic anhydride.

Uses of DL-Malic Acid

The uses of DL-malic acid generally relate to the role of malic acid in the production of chemical energy for both aerobic and anaerobic conditions. These uses include the management of discomfort, energy production, oral hygiene and general detoxification.


#24 Re: Help Me ! » Math » 2018-01-10 22:36:01

Hi kayla1dance,

Welcome to the forum!

#25 Re: Jokes » Q & A » 2018-01-10 18:18:19

Q: Did you hear about the astronaut who stepped on chewing gum?
A: He got stuck in Orbit.

Q: What did the penny say to the other penny?
A: We make perfect cents.

Q: Why did the man with one hand cross the road?
A: To get to the second hand shop.

Q: Why did the boy sprinkle sugar on his pillow before he went to sleep?
A: So he could have sweet dreams.

Q: What do you call a nervous javelin thrower?
A: Shakespeare.

Q: Did you hear about the painter who was hospitalized?
A: Reports say it was due to too many strokes.

Q: Why did the robber take a bath?
A: Because he wanted to make a clean getaway.

Q: What do you call a funny mountain?
A: Hill-arious.

Q: What goes up when the rain comes down?
A: An umbrella.

Q: Did you hear about the calendar thief?
A: He got 12 months; they say his days are numbered.

Q: What did one raindrop say to the other?
A: Two's company, three's a cloud.

Q: Why did the balloon burst?
A: Because is saw a lolly pop.

Q: What did the stamp say to the envelope?
A: Stick with me and we will go places!

Q: Who can shave 10 times a day and still have a beard?
A: A barber.

Q: What do you call a horse that can't lose a race
A: Sherbet.

Q: What do you call a dentist in the army?
A: A drill sergeant.

Q: What did the triangle say to the circle?
A: Your pointless!

Q: What's easy to get into but hard to get out of?
A: Trouble.

Q: Did you hear about the guy who died when an axe fell on him?
A: The police are calling it an axe-i-dent.

Q: Why don't you see giraffes in elementary school?
A: Because they're all in High School!

Q: Which month do soldiers hate most?
A: The month of March!

Q: What did the painter say to the wall?
A: One more crack like that and I'll plaster you!

Q: What do you call a magician on a plane?
A: A flying sorcerer!

Q: What do you call a South American girl who is always in a hurry?
A: Urgent Tina.

Q: Why did the man lose his job at the orange juice factory
A: He couldn't concentrate!

Q: Can I tell you a joke about paper.
A: Nah, never mind, its tearable.

Q: How do you repair a broken tomato?
A: Tomato Paste!

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