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Abu al-Wafa al-Buzjanî « Muslim Heritage

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Abu al-Wafa al-Buzjanî « Muslim Heritage





Abu al-Wafa al-Buzjanî

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Muḥammad Abūʾl-Wafāʾ al-Būzjānī (10 June 940–997 or 998) was a distinguished Muslim astronomer and mathematician, who made important contributions to the development of trigonometry. He worked in a private observatory in Baghdad, where he made observations to determine, among other astronomical parameters, the obliquity of the ecliptic, the length of the seasons, and the latitude of the city. In honour of his astronomical work, a crater on the Moon was named for him. His 1073th anniversary falls this June 10th....
Fig 1. Artistic depiction of Muhammad Abu al-Wafa in a Spanish stam. (Source).
​Abu al-Wafa (or Abu al-Wafa’) al-Būzjānī was one of the leading astronomers and mathematicians of the Islamic scientific tradition, with significant contributions in observational astronomy. His achievements in trigonometry paved the way for more precise astronomical calculations. He was born Born in Būzjān or Būzhgān (Khurāsān, Iran) on 10 June 940, in the region of Nīshāpūr, located now in Khurāsān, Iran. He was from an educated and well‐established family.
Abu al-Wafa flourished in an age of great political upheavals. The Būyids (reigned from 945 to 1055), a family originally from the highlands of Daylam in northern Iran, had established a new dynasty that soon extended its rule over Iraq, the heart of the ʿAbbāsid caliphate, reducing the caliph’s rule to a mere formality. Under the Būyids, who were great patrons of science and the arts, many scientists and scholars were attracted to Baghdad to enjoy the benefits of the new rulers’ patronage. The change in the political climate had brought with it a great cultural revival in the eastern Islamic lands, promoting literary, scientific, and philosophical activities on a large scale.
At the age of 20, Abu al-Wafa moved to Baghdad where he soon rose to prominence as a leading astronomer and mathematician at the Būyid court, conducting observations and research in the Bāb alTibn observatory. The decade following 975 seems to have been his most active years in astronomy, during which he conducted most of his observations. Later, to comply with the wishes of the Būyid regent Sharaf al‐Dawla, who was himself a learned man with keen interest in astronomy, Al-Būzjānī became actively involved in the construction of a new observatory in Baghdad. His collaborator was Al-Kūhī, another celebrated astronomer, who excellent in mathematics, physics and in making astronomical instruments. The astronomical work of Al-Būzjānī and his colleagues in Baghdad mark the revival of the “Baghdad school,” a tradition with much vitality in the preceding century.
Fig 3.‘Google Doodles’ celebrates Abu al-Wafa’ al-Buzjani’s 1075th Birthday – June 10, 2015
“Today’s doodle honors this man, an innovator whose contributions to science include one of the first known introductions to negative numbers, and the development of the first quadrant, a tool used by astronomers to examine the sky. His pioneering work in spherical trigonometry was hugely influential for both mathematics and astronomy…”
www.google.com/doodles/abu-al-wafa-al-buzjanis-1075th-birthday
Abu al-Rayhan al-Bīrūnī, the renowned astronomer and scientist living at that time in Kath (in central Asia), tells us of his correspondence with Al-Būzjānī, who was in Baghdad. In 997, the two astronomers prearranged to make a joint astronomical observation of a lunar eclipse to establish the difference in local time between their respective localities. The result showed a difference of approximately one hour between the two longitudes, very close to present‐day calculations. Al-Biruni made numerous references to Al-Būzjānī’s measurements in his various works.
Al-Būzjānī’s principal astronomical work, and his sole extant writing on the subject, is Kitāb alMajisī, which was edited and translated in 2010 by Ali Musa. The book consists of three chapters: trigonometry, application of spherical trigonometry to astronomy, and planetary theory. Although Kitab alMajisī did not introduce considerable theoretical novelties, it contains observational data that were used by many later astronomers. Its section on trigonometry was a comprehensive study of the subject, introducing proofs in a masterly way for the most important formulas in both plane and spherical trigonometry. Abu al-Wafa’s approach, at least in some instances, bears a striking resemblance to modern presentations.
Fig 3. Page of the manuscript of Kitab al-majisti by Abu al-Wafa. (Source).
In this book, Al-Būzjānī introduced for the first time the tangent function and hence facilitated the solutions to problems of the spherical right‐angled triangle in his astronomical calculations. He also devised a new method for constructing the sine tables, which made his tables for sin 30′ more precise than those of his predecessors. This was an important advance, since the precision of astronomical calculations depends upon the precision of the sine tables. The sine table in Al-Būzjānī’s Almagest was compiled at 15′ intervals and given to four sexagesimal places. In the sixth chapter of the book, Al-Būzjānī defines the terms tangent, cotangent, sine, sine of the complement (cosine), secant and cosecant, establishing all the elementary relations between them.
In mathematics, Abu al-Wafa’s contributions cover both theoretical and practical aspects of this science. His practical textbook on geometry, A Book on Those Geometric Constructions Which Are Necessary for a Craftsman (Kitab fima yahtaju ilayhi al-sani’ min ‘ilm al-handasa), is unparalleled among the geometrical works of its kind written in the Islamic world. He wrote also a practical textbook on arithmetic, the Book on What Is Necessary from the Science of Arithmetic for Scribes and Businessmen (Kitab fima yahtaju ilayhi al-‘ummal wa-‘l-kuttab min ‘ilm al-hisab).
On the basis of works attributed to him, Al-Būzjānī seems to have been a prolific scholar. He is said to have written 22 books and treatises. These include works on astronomy, arithmetic, and geometry, as well as translations and commentaries on the algebraic works of past masters like Diophantus and Al-Khwārizmī, and a commentary on Euclid’s Elements. Of all these works, however, we know of only eight which have survived. Of his astronomical works, references were made to a Zīj ali, an influential work that is no longer extant.
Historical evidence, as well as the judgments of Būzjānī’s colleagues and generations of scholars who came after him, all attest to the fact that he was one of the greatest astronomers of his age. He was also said to have been a man with great moral virtues who dedicated his life to astronomy and mathematics. His endeavors in the domain of science did not die with him. In fact, the data he had gathered from his observations were used by astronomers centuries after him. Furthermore, the science of trigonometry as it is today is much indebted to him for his work.

Selected References

Fig 4. Front cover of Majisti Abi al-Wafa’ al-Buzgani by Ali Musa, Beirut: Markaz dirasat al-wahda al-‘arabiyya, 2010.
– Al‐Qifṭī, Jamāl al‐Dīn (1903). Taʾrīkh al‐ḥukamāʾ, edited by J. Lippert. Leipzig: Theodor Weicher.
– Carra de Vaux (May–June 1892). “L’Almageste d’Abū ʾl Wéfā Alboūzdjānī.” Journal asiatique, 8th ser., vol. 19: pp. 408–471.
– Debarnot, Marie‐Thérèse (1996). “Trigonometry.” In Encyclopedia of the History of Arabic Science, edited by Roshdi Rashed. Vol. 2, pp. 495–538. London: Routledge.
– Ghorbani, A. and M. A. Sheykhan (1992). Buzdjānī Nāmeh: The Biography and a Survey of Buzdjānī’s Mathematical Works. Tehran: Enqelab‐e Eslami Publishing and Educational Organization.
– Hashemipour, Behnaz, “Al-Būzjānī,” in Thomas Hockey et al. (eds.). The Biographical Encyclopedia of AstronomersSpringer Reference. New York: Springer, 2007, pp. 188-189.
– Ibn al‐Nadīm (1970). The Fihrist of alNadīm: A TenthCentury Survey of Muslim Culture, edited and translated by Bayard Dodge. 2 Vols., Vol. 1, p. 83. New York: Columbia University Press.
– Kennedy, E. S. (1984). “Applied Mathematics in the Tenth Century: Abu ʾl‐Wafāʾ Calculates the Distance Baghdad–Mecca.” Historia Mathematica 11: 193–206.
– Kennedy, E. S. and Mustafa Mawaldi (1979). “Abū al‐Wafāʾ and the Heron Theorems.” Journal of the History of Arabic Science 3: 19–30.
– Medovoi, M. I. (1960). “On the Arithmetic Treatise of Abū ʾl‐Wafāʾ.” Studies in the History of Mathematics, vol. 13: pp. 253–324.
– Saidan, Ahmad S. (1974). “The Arithmetic of Abū ʾl‐Wafāʾ.” Isis, vol. 65: pp. 367–375.
– Sesiano, Jacques (1998). “Le traité d’Abū ʾl‐Wafāʾ sur les carrés magiques.” Geschichte der ArabischIslamischen Wissenschaften, vol. 12: pp. 121–244.
– Suter, H. (1960). “Abu ʾl‐Wafāʾ al‐Būzadjānī.” In Encyclopaedia of Islam. 2nd ed. Vol. 1, p. 159. Leiden: E. J. Brill.
– Youschkevitch, A. P. (1970). “Abū ʾl‐Wafāʾ al‐Būzjānī.” In Dictionary of Scientific Biography, edited by Charles Coulston Gillispie. Vol. 1, pp. 39–43. New York: Charles Scribner’s Sons.

An Infrared View of the M81 Galaxy | NASA

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An Infrared View of the M81 Galaxy | NASA



An Infrared View of 

the M81 Galaxy

M81 Galaxy


Located in the northern constellation of Ursa Major, which also includes the Big Dipper, nearby galaxy Messier 81 is easily visible through binoculars or a small telescope. M81 is located at a distance of 12 million light-years.
M81 was one of the first publicly released datasets soon after the launch of the Spitzer Space Telescope in August 2003. On the occasion of Spitzer's 16th anniversary this new image revisits this iconic object with extended observations and improved processing.
This Spitzer infrared image is a composite mosaic combining data from the Infrared Array Camera (IRAC) at wavelengths of 3.6/4.5 microns (blue/cyan) and 8 microns (green) with data from the Multiband Imaging Photometer (MIPS) at 24 microns (red).
The 3.6-micron near-infrared data (blue) traces the distribution of stars, although the Spitzer image is virtually unaffected by obscuring dust and reveals a very smooth stellar mass distribution, with the spiral arms relatively subdued.
As one moves to longer wavelengths, the spiral arms become the dominant feature of the galaxy. The 8-micron emission (green) is dominated by infrared light radiated by hot dust that has been heated by nearby luminous stars. Dust in the galaxy is bathed by ultraviolet and visible light from nearby stars. Upon absorbing an ultraviolet or visible-light photon, a dust grain is heated and re-emits the energy at longer infrared wavelengths. The dust particles are composed of silicates (chemically similar to beach sand), carbonaceous grains and polycyclic aromatic hydrocarbons and trace the gas distribution in the galaxy. The well-mixed gas (which is best detected at radio wavelengths) and dust provide a reservoir of raw materials for future star formation.
Image Credit: NASA/JPL-Caltech
Last Updated: Sept. 4, 2019
Editor: Yvette Smith

NASA Selects Proposals to Advance Understanding of Space Weather | NASA

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NASA Selects Proposals to Advance Understanding of Space Weather | NASA



NASA Selects Proposals 

to Advance Understanding 

of Space Weather

auroras, as seen in this image captured by the International Space Station on Aug. 6, 2017.
NASA has chosen three mission proposals for concept studies to help us better understand the dynamic space weather system driven by the Sun that manifests near Earth. One proposal will focus on auroras, as seen in this image captured by the International Space Station on Aug. 6, 2017.
Credits: NASA
NASA has selected three proposals for concept studies of missions that could help us better understand the dynamic space weather system driven by the Sun that manifests near Earth. The proposals examine what drives different parts of that system and ultimately could help us predict and mitigate its effects on spacecraft and astronauts, as NASA’s Artemis program looks to send the first woman and the next man to the Moon by 2024.
“NASA’s research to understand the space we travel through relies on exploring key details about a vast system from the Sun, to Earth, to the edges of the solar system,” said Peg Luce, deputy director for heliophysics in the Science Mission Directorate at NASA Headquarters in Washington. “Each of these proposals could add a significant tool from a unique vantage point to help us understand that system.”
Each of these Heliophysics Mission of Opportunity proposals will receive $400,000 to conduct a nine-month mission concept study. After the study period, NASA will choose one proposal to go forward to launch. Each potential mission has a separate launch opportunity and time frame.
The proposals were selected based on potential science value and feasibility of development plans. The total cost for the mission ultimately chosen will be capped at $55 million and is funded by NASA’s Heliophysics Explorers’ program. 
The selected proposals are:
Extreme Ultraviolet High-Throughput Spectroscopic Telescope (EUVST) Epsilon Mission
EUVST would aim to provide an answer to a fundamental question in solar physics: How does the interplay of solar material – a hot plasma – and magnetic fields drive solar activity and eruptions, such as solar flares and coronal mass ejections? The mission would launch with the Japan Aerospace Exploration Agency’s Solar-C mission, planned for 2025. EUVST would observe simultaneously, for the first time and over a wide range of the lower solar atmosphere, how magnetic fields and plasma interact. Those observations could help us learn more about how the two systems contribute to the dynamic atmosphere around the Sun. The principal investigator for EUVST is Clarence Korendyke at the U.S. Naval Research Laboratory in Washington.
Aeronomy at Earth: Tools for Heliophysics Exploration and Research (AETHER)
AETHER would explore the ionosphere-thermosphere system and its response to geomagnetic storms. From a position aboard the International Space Station, it could gather observations of the ionosphere – the area of our atmosphere that overlaps with the lower regions of space. These observations would be complemented by ground observations of electrons in the same region. The mission would provide information on how the neutral, terrestrial-weather-driven thermosphere interacts with the ionosphere’s charged particles. Understanding how the neutral atmosphere affects the ions and vice versa is key to better understanding the complex space weather system surrounding our planet, which affects spacecraft and astronauts flying through it. The launch of AETHER would be no later than 2024. The principal investigator for AETHER is James Clemmons at the University of New Hampshire in Durham.
Electrojet Zeeman Imaging Explorer (EZIE)
EZIE would focus on an electric current known as the auroral electrojet, which circles through the atmosphere around 60 to 90 miles above Earth, near the poles. Using three SmallSats to measure magnetic fields, EZIE would observe the structure of electrojets and explore what causes them and how they evolve. Electrojets are part of a larger space weather system that can lead to oscillations in Earth’s magnetic fields, creating geomagnetic storms that can interfere with spacecraft and – at their most intense – utility grids on the ground. Knowing how electrojets form and grow could contribute to ultimately predicting such storms. EZIE would launch as part of the agency’s CubeSat Launch Initiative. EZIE also would launch no later than 2024. The principal investigator for EZIE is Jeng-Hwa Yee at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
For information about NASA and space science, visit:
-end-
Grey Hautaluoma / Karen Fox
Headquarters, Washington
202-358-0668 / 301-286-6284
grey.hautaluoma@nasa.gov / karen.fox@nasa.gov
Last Updated: Sept. 3, 2019
Editor: Karen Northon

Las mujeres mantienen mejor el rendimiento en las pruebas de conocimiento / Noticias / SINC

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Las mujeres mantienen mejor el rendimiento en las pruebas de conocimiento / Noticias / SINC

SINC - Servicio de información y noticias científicas

Las mujeres mantienen mejor el rendimiento en las pruebas de conocimiento



Un nuevo estudio confirma que ante una prueba de conocimiento, aunque los varones obtengan mejores resultados en matemáticas o ciencias, las mujeres obtendrían los mismos o mejores resultados que ellos, si el examen se alarga.

SINC |  | 04 septiembre 2019 15:00
<p>Un estudio señala que las mujeres tienen mejor rendimiento durante una prueba cognitiva. / Pixabay</p>
Un estudio señala que las mujeres tienen mejor rendimiento durante una prueba cognitiva. / Pixabay
Los resultados de las pruebas PISA revelan que las mujeres superan a los hombres en rendimiento, independientemente del tipo de prueba, según investigadores de la Universidad de las Islas Baleares y de la Universidad Erasmo de Róterdam (Holanda).
Las mujeres superaban a los hombres en pruebas de lectura y los varones a las mujeres en las de matemáticas y ciencias
La brecha de género favorece a las mujeres cuando se trata del rendimiento en el transcurso de la realización de pruebas de conocimientos. Así lo pone de manifiesto un trabajo publicado recientemente en la revista Nature Communications por los investigadores Pau Balart, del departamento de Economía de la Empresa de la Universidad de las Islas Baleares, y Matthijs Oosterveen, del departamento de Economía de la Universidad Erasmo de Róterdam.
En el marco de este trabajo, los investigadores han llevado a cabo dos estudios para investigar el rendimiento durante el transcurso de las pruebas de conocimientos y sus implicaciones en las brechas de género.

Diferencias por materias 

En el primer estudio, utilizaron datos de las pruebas PISA, una prueba estandarizada internacional que se hace cada tres años para evaluar el rendimiento de los alumnos de 15 años en materias como matemáticas, ciencias y lectura.
Utilizando datos de las pruebas realizadas en 2006, 2009, 2012 y 2015, Balart y Oosterveen observaron que, al empezar la prueba, las mujeres superaron los hombres en las pruebas de lectura, mientras que los hombres superaron las mujeres en las pruebas de matemáticas y ciencias, lo cual arrecia los estudios previos.
Para más del 20 % de los países, la brecha de género en matemáticas y ciencias quedó compensada o se revirtió después de dos horas de examen
Sin embargo, independientemente del tipo de prueba, las mujeres mostraron más capacidad para sostener el rendimiento durante la prueba. Así, para más del 20 % de los países incluidos en el estudio, la brecha de género en matemáticas y ciencias quedó compensada o se revirtió después de dos horas de examen.

Disparidad en el rendimiento 

En un segundo estudio, los autores analizaron un conjunto de datos provenientes de 441 pruebas de matemáticas de una duración variable. En este caso, los resultados obtenidos mostraron que las pruebas más largas se asociaron con una brecha de género más estrecha. Es decir, cuanto más larga era la prueba, menos diferencias había en los resultados entre hombres y mujeres, a pesar de las diferencias detectadas en esta asignatura en el primer estudio.
La implicación más notable del estudio consiste a subrayar que las mujeres tienen más habilidad a la hora de sostener el rendimiento durante una prueba cognitiva, una fortaleza que merece visibilidad y reconocimiento.
Además, si bien el tamaño y la relevancia estadística de los resultados logrados varían de un país a otro, vistos los resultados, los investigadores consideran razonable señalar que esta diferencia de género es evidente en la mayoría de los países de los cuales se  tienen datos, aunque presenten características y pertenezcan a culturas muy diferentes.


Referencia bibliográfica:
Balart, P.; Oosterveen, M. "Females show more sustained performance during test-taking than males". Nature Communications 10:3798 (2019) doi: 10.1038/s41467-019-11691-y

La retroalimentación entre suelo y atmósfera impulsa la sequía / Noticias / SINC

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La retroalimentación entre suelo y atmósfera impulsa la sequía / Noticias / SINC

SINC - Servicio de información y noticias científicas



La retroalimentación entre suelo y atmósfera impulsa la sequía



Un nuevo estudio indica que la Tierra experimentará sequías cada vez más frecuentes y extremas que las que han tenido lugar hasta ahora. Esta situación se agravará tanto por el cambio climático como por los flujos entre la superficie de la tierra y la atmósfera, lo que planteará grandes riesgos para el planeta y la vida humana.



SINC |  | 03 septiembre 2019 17:35
<p>Las altas temperaturas y la baja humedad atmosférica son dos factores de riesgo que provocan una mortalidad generalizada de la vegetación. / Pixabay</p>
Las altas temperaturas y la baja humedad atmosférica son dos factores de riesgo que provocan una mortalidad generalizada de la vegetación. / Pixabay
Hasta ahora, la mayoría de los estudios habían analizado cómo los procesos atmosféricos y oceánicos provocaban climas extremos. La interpretación que se hacía era que estos fenómenos son el resultado de la circulación atmosférica a gran escala y de las alteraciones de la temperatura del mar.
“Hay una relación más fuerte entre sequía y sequedad atmosférica que entre sequía y olas de calor”
Sin embargo, recientemente se ha demostrado que los periodos con baja humedad en el suelo y déficit de presión de vapor en la atmósferasuelen coexistir de manera simultánea, y se prevé que estos eventos sean más frecuentes e intensos en el futuro, lo que limitaría en gran medida la capacidad de los continentes para actuar como sumideros de carbono.
El estudio de la simultaneidad de estos fenómenos ha venido de la mano de un equipo de científicos de la Universidad de Columbia (EE.UU). Estos han indicado que la retroalimentación entre tierra y atmósfera, que se inicia por las alteraciones en la humedad del suelo, puede modificar el calor de la superficie y promover, al mismo tiempo, anomalías en la circulación atmosférica a gran escala.
Los expertos comenzaron a estudiar esta relación porque se percataron de que la sequía y la sequedad atmosférica tenían un impacto más fuerte en el ciclo del carbono.
“La mayoría de los grupos han evaluado la simultaneidad entre las sequías y olas de calor pero nosotros estamos encontrando una relación más fuerte entre sequía y sequedad atmosférica que entre sequía y olas de calor”, dice Sha Zhou, autor principal del estudio que publica la revista PNAS.
Su equipo demostró que estos fenómenos se produce en gran medida por los cambios en los flujos entre tierra y atmósfera y en los circuitos de retroalimentación.

Altas temperaturas y baja humedad atmosférica

Si el suelo se seca debido a una escasa evapotranspiración (cantidad de agua del suelo que vuelve a la atmósfera como consecuencia de la evaporación y de la transpiración de las plantas) puede reducirse la humedad atmosférica. A su vez, si hay mucho déficit de presión de vapor atmosférico, aumentará la demanda evaporativa de la atmósfera, lo que puede exacerbar el agotamiento de la humedad del suelo.
El aumento de esta retroalimentación podría dar lugar a eventos simultáneos como este cada vez más frecuentes y ocasionar más sequía y aridez en la atmósfera.
Esta investigación indica que una combinación de altas temperaturas y baja humedad atmosférica son dos factores de riesgo que provocan una mortalidad generalizada de la vegetación y una reducción de la absorción de carbono terrestre.

Revisar los datos y modelos anteriores

Para extraer las conclusiones, los investigadores trabajaron sobre estudios previos y volvieron a analizar los datos existentes. Además, utilizaron modelos climáticos y métodos estadísticos para evaluar cómo los ciclos de la tierra y la atmósfera afectarían al clima futuro.
Las altas temperaturas y la baja humedad atmosférica son dos factores de riesgo que provocan una mortalidad generalizada de la vegetación
Su mayor obstáculo era aislar esta retroalimentación y para ello los expertos trabajaron con un proyecto previo del Instituto de Ciencias Atmosféricas y Climáticas de ETH Zurich (Suiza), denominado GLACE-CMIP5, y utilizaron sus experimentos modelo.
Pierre Gentine, profesor asociado de ingeniería terrestre y ambiental de este instituto, fue el primero en aislar este fenómeno y se sorprendió de que su trabajo produjera resultados tan dramáticos.
Las simulaciones del CMIP5 sugieren que la retroalimentación que se da entre tierra y atmósfera aumentará aún más la frecuencia e intensidad de la sequía y la aridez en el siglo XXI, con impactos humanos y ecológicos potencialmente grandes.
“La simultaneidad de la sequía del suelo y la sequedad atmosférica tienen impactos dramáticos en la vegetación natural, la agricultura, la industria y la salud pública”, dice Pierre Gentine. “La intensificación en el futuro de la sequía sería desastrosa para los ecosistemas y tendría un gran impacto en todos los aspectos de nuestras vidas”, confirma.
El estudio destaca la importancia de la variabilidad de la humedad del suelo para permitir una serie de procesos y circuitos de retroalimentación que afectan al clima de la Tierra.
Según Gentine, “es fundamental que cuantifiquemos y evaluemos mejor estos procesos en nuestros modelos climáticos. La representación exacta de la variabilidad de la humedad del suelo y de la retroalimentación asociada es crucial si queremos proporcionar simulaciones fiables de la frecuencia, duración e intensidad de los eventos de aridez y sequedad atmosférica y de sus cambios en un clima más cálido”.


Referencia bibliográfica:
Sha Zhou et. Al. "Land–atmosphere feedbacks exacerbate concurrent soil drought and atmospheric aridity". PNAS. DOI: 10.1073/pnas.1904955116

Este es el fósil de un animal que reptaba hace 550 millones de años / Noticias / SINC

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Este es el fósil de un animal que reptaba hace 550 millones de años / Noticias / SINC

SINC - Servicio de información y noticias científicas

Los primeros surcos de un animal en la Tierra

Este es el fósil de un animal que reptaba hace 550 millones de años



El fósil de un animal parecido a un milpiés, que vivió hace entre 551 a 539 millones de años, indica que los animales móviles evolucionaron a finales del período Ediacárico. El hallazgo proporciona una evidencia directa porque los restos están conectados con el rastro que hizo al desplazarse.

SINC |  | 04 septiembre 2019 19:00
<p>Rastro fosilizado del animal <em>Yilingia spiciformis</em>, que data de hace 550 millones de años. El rastro fue encontrado en China. / Virginia Tech College of Science</p>
Rastro fosilizado del animal Yilingia spiciformis, que data de hace 550 millones de años. El rastro fue encontrado en China. / Virginia Tech College of Science
Los científicos estimaban que los animales móviles y segmentados con simetría bilateral evolucionaron durante el período Ediacárico (hace entre 635 y 542 millones de años), mucho antes de la edad de los dinosaurios o incluso del supercontinente Pangea. Sin embargo, no existían evidencias convincentes que corroboraran estas estimaciones. Solo se conocían trazas fósiles de senderos, caminos y madrigueras que, salvo excepciones, eran huellas de seres vivos desconocidos.
Este descubrimiento demuestra que los animales segmentados y móviles evolucionaron hace 550 millones de años
Un estudio publicado hoy en la revista Nature describe detalles del rastro producido por un animal parecido a un gusano poco antes de su muerte, lo que indica que esta especie era móvil. Este ser fósil, al que han denominado Yilingia spiciformis, habría vivido hace entre 551 y 539 millones de años en lo que hoy es la Formación Dengying, en el área de las Gargantas de Yangtze (China). El descubrimiento es vital porque el animal y la señal que produjo justo antes de su muerte se conservan juntos.
“Este descubrimiento demuestra que los animales segmentados móviles evolucionaron hace 550 millones de años. La movilidad hizo posible que estos trazaran una huella inconfundible en la Tierra, tanto literal como metafóricamente”, afirma Shuhai Xiao, geocientífico de la Virgina Tech (EE UU) e investigador principal del estudio. “Esas son las características que se encuentran en un grupo denominado bilateral, que incluye a los humanos y a la mayoría de los animales”, añade.


Los autores de este trabajo recogieron 35 fósiles de la especie y estimaron que el animal tenía alrededor de entre 5 mm a 26 mm de ancho y hasta 27 cm de largo, con aproximadamente 50 segmentos. También hallaron otros 13 restos fósiles, incluido un rastro que estaba directamente conectado a uno de los fósiles. Las características del rastro, de 25 mm, indican que lo dejó el animal Yilingia al moverse, lo que lo convierte en el signo más convincente de la antigua movilidad animal.
El origen de los animales bilateralmente simétricos, con cuerpos segmentados y movilidad direccional es un evento fundamental en la evolución animal temprana

Un ser parecido a un milpiés

Yilingia spiciformis, debe su nombre a un insecto puntiagudo Yiling que es, a su vez, el nombre de una ciudad china cercana al yacimiento. El animal era una criatura parecida a un milpiés que arrastraba alternativamente su cuerpo a través del suelo fangoso del océano y descansaba a lo largo del camino. Su forma era alargada y angosta, con un lado izquierdo y derecho y una cabeza y una cola.
El origen de los animales bilateralmente simétricos, con cuerpos segmentados y movilidad direccional es un evento fundamental en la evolución animal temprana.
El hallazgo también marca lo que puede ser la primera señal de toma de decisiones entre los animales. “Los senderos sugieren un esfuerzo para moverse hacia algo o para alejarse, tal vez bajo la dirección de un sistema nervioso central sofisticado”, dice Xiao.
La movilidad de los animales provocó impactos ambientales y ecológicos en el sistema de superficie de la Tierra y, en última instancia, causó el sustrato cámbrico o las revoluciones agronómicas.
“Somos el animal con más impacto sobre la Tierra. Imprimimos una gran huella, no solo por la locomoción, sino por muchas otras actividades con mayor impacto relacionadas con nuestra capacidad de movimiento. Cuándo y cómo evolucionó la locomoción animal define un importante contexto geológico y evolutivo de las consecuencias antropogénicas en la superficie de la Tierra”, enfatiza el científico.
Rachel Wood, profesora de la Facultad de Geociencias de la Universidad de Edimburgo en Escocia, que no participó en el estudio, concluye: “Este es un hallazgo notable de fósiles muy significativos. Ahora tenemos evidencia de que animales segmentados estaban presentes y tenían la capacidad para moverse en el fondo marino antes del Cámbrico. Podemos vincular al responsable real del rastro con sus huellas. Tal preservación es inusual y proporciona una visión considerable de un paso importante en la evolución de los animales”.


Referencia bibliográfica:
Zhe Chen, Chuanming Zhou, Xunlai Yuan y Shuhai Xiao. “Death march of a segmented and trilobate bilaterian elucidates early animal evolution” Nature 4 de septiembre de 2019. https://doi.org/10.1038/s41586-019-1522-7

Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express

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Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express

Matilda by Roald Dahl

Matilda is one of Roald Dahl’s most famous book. (Source: Amazon.in)


The story of the extraordinarily talented Matilda is well-known, so is her dysfunctional relationship with her family. But the story also remains memorable for the lovely relationship she shared with the kindergarten teacher, Miss Honey. The teacher not only gives the young girl all the attention she deserves but also helps her to evolve, emotionally and academically.

Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express


Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express

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Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express

To Sir, with Love by E R Braithwaite

This 1959 autobiographical novel remains an enduring book on teachers and their relationship with students. (Source: Amazon.in)


This 1959 autobiographical novel is a compelling take on how Ricky Braithwaite, an engineer from British Guiana, won over a class full of unmotivated and unruly children. In many ways, the novel, which was later made into a film, serves as a precursor to Dead Poet’s Society for the way Braithwaite departs from the traditional forms of teaching and forges an intimate relationship with the students.

Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express

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Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express

Dead Poets Society by Nancy H Kleinbaum

Dead Poets Society is an engaging novel that narrates the story of an English teacher John Keating and his unique methods. (Source: Amazon.in)


Most famously known as the 1989 film starring Robbin Williams, Dead Poets Society is an engaging novel that narrates the story of an English teacher John Keating and his insistence to his students for them to break away from norms. Carpe Diem, seize the moment, he said and the students followed.

Teachers’ Day 2019: Books that uphold the bond teachers and students share | Lifestyle News, The Indian Express

How German photographer Peter Lindbergh kicked off the supermodel era | Lifestyle News, The Indian Express

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How German photographer Peter Lindbergh kicked off the supermodel era | Lifestyle News, The Indian Express

Published: September 5, 2019 4:47:13 pm

How German photographer Peter Lindbergh kicked off the supermodel era

Star photographer Peter Lindbergh, who overturned the glossy standards of fashion photography, and who was seen as the "father" of supermodels such as Cindy Crawford and Naomi Campbell, has died at the age of 74.

Peter Lindbergh created in 1988 a series of portraits of new models together on a beach in Malibu, all dressed in white shirts and in a natural look. (Source: Peter Lindbergh/ DW)


Considered one of the most influential fashion photographers of the past 40 years, Peter Lindbergh has died aged 74, his studio in Paris confirmed on Wednesday. The circumstances of his death were not provided.

Actor Rohit Roy on playing a cop, a sleaze and a shrink in the horror play, Ovee | Lifestyle News, The Indian Express

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Actor Rohit Roy on playing a cop, a sleaze and a shrink in the horror play, Ovee | Lifestyle News, The Indian Express

New Delhi |Updated: September 5, 2019 8:47:20 am

Actor Rohit Roy on playing a cop, a sleaze and a shrink in the horror play, Ovee

This weekend, Rohit Roy leads a star cast in the play, Ovee, a horror play, directed by Aniket Patil, about a teenage girl, who has been sent to an orphanage by her paternal uncle after her parents die.

Rohit Roy ensured that his voice modulation and dialogue delivery were different for each character


I am an actor by accident. My foray into films was when I was 21. Theatre is a more recent phenomenon,” says Rohit Roy. A famous face on the big and small screens, Roy first acted on stage around 10 years ago in Unfaithful with Cyrus Broacha and Perizad Zorabian. This weekend, he leads a star cast in the play, Ovee, a horror play, directed by Aniket Patil, about a teenage girl, who has been sent to an orphanage by her paternal uncle after her parents die. Soon, paranormal activities start taking place and she must confront her fears. Excerpts from an interview with Roy:

Exhibits at a new gallery in Delhi’s Purana Qila tell stories of their solitary journeys | Lifestyle News, The Indian Express

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Exhibits at a new gallery in Delhi’s Purana Qila tell stories of their solitary journeys | Lifestyle News, The Indian Express

Written by Divya A |New Delhi |Updated: September 5, 2019 8:44:22 am

Exhibits at a new gallery in Delhi’s Purana Qila tell stories of their solitary journeys

The exhibit also sensitises visitors about the illegal trade of precious heritage artefacts and the process of receiving them.

The Standing Buddha statue (Express Photo by Praveen Khanna)


Last week, Gallery of Confiscated and Retrieved Antiquities at Delhi’s Purana Qila opened its doors to visitors. Curated by the Archaeological Survey of India (ASI), the gallery is located in one of the arched cells at the fort and displays as many as 190 antiques that were stolen from India and have now been recovered. The exhibit also sensitises visitors about the illegal trade of precious heritage artefacts and the process of receiving them. The gallery has two parallel narratives — one, establishing the importance of these artworks, laws governing heritage and the theft and trafficking of these items, and the other is the display, which ranges from 2nd century to 19th century stone and metal sculptures, coins, paintings, terracotta, ivory and copper artefacts, and architectural panels. A look at some of the iconic exhibits, how we lost them, and how we brought them home:

The Wheelchair as an Actor | Lifestyle News, The Indian Express

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The Wheelchair as an Actor | Lifestyle News, The Indian Express

Written by Dipanita Nath |Updated: September 5, 2019 4:15:45 am



The Wheelchair as an Actor

Divya Arora plays the titular role in Mahesh Dattani’s Tara and draws attention to the discrimination against women and specially-abled individuals.

Divya Arora during rehearsals. (Express Photo by Praveen Khanna)


She can kill with a smile, she can wound with her eyes,” croons Billy Joel in the ringtone of Mumbai-based theatre actor Divya Arora. “I have always liked this song because it helped me become the woman I am. On stage or in life, I always do the main role. I don’t like to accept the second place,” she says.

30 years on, Tara’s messages on gender discrimination, disability still resonate | Lifestyle News, The Indian Express

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30 years on, Tara’s messages on gender discrimination, disability still resonate | Lifestyle News, The Indian Express

30 years on, Tara’s messages on gender discrimination, disability still resonate

Written about 30 years ago by noted English playwright Mahesh Dattani, the story deals with the emotional separation of two conjoined twins (at the hip) - Tara and Chandan.

Divya Arora, Tara Play, Tara, indianexpress.com, indianexpress, sohaila kapur, mahesh dattani, gender based discrimination, India patriarchy, disability rights, male child preference, society settings,
Sohaila Kapur and Divya Arora are co-directors of the play Tara. (Source: Habitat Learning Centre, IHC)


As the preference for a male child, female foeticide, gender discrimination as well as discrimination against People with Disabilities (PwDs) remain rampant, exploring these aspects is a play titled Tara that will be performed in the national capital soon.

Happy Teachers' Day 2019: Wishes Images Download, Quotes, Status, Greeting Card, HD Wallpapers, Messages, SMS, Photos, GIF Pics, and Pictures

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Happy Teachers' Day 2019: Wishes Images Download, Quotes, Status, Greeting Card, HD Wallpapers, Messages, SMS, Photos, GIF Pics, and Pictures

By Lifestyle Desk |New Delhi |Updated: September 5, 2019 7:00:34 pm



Happy Teachers’ Day 2019: Wishes Images, Quotes, Status, Greeting Card, Wallpaper, SMS, Messages, Photos, Pics, and Pictures

Happy Teachers' Day 2019 Wishes Images, Quotes, Status, Greeting Card, Messages, SMS, Photos: Every year, the birthday of Dr Sarvapalli Radhakrishnan, one of the most prominent statesman and teacher, is celebrated as Teachers' Day on September 5.

Teachers Day 2019, teachers day, happy teachers day, teachers day images, happy teachers day 2019, teachers day images hd, teachers day images download, happy teachers day card, teachers day card, happy teachers day card, happy teachers day quotes, happy teachers day status, happy teachers day pics, happy teachers day images download, happy teachers day greetings card, happy teachers day messages, happy teachers day photos, happy teachers day pictures, teachers day pictures, teachers day quotes, teachers day images hd download, teachers day status
Happy Teacher’s Day 2019 Wishes Images, Quotes: (Photo: Getty Images/Thinkstock’ Designed by Gargi Singh)


Happy Teacher‘s Day 2019 Wishes Images, Quotes, Status, Greeting Card, Messages, SMS: Whether a school teacher, a mentor or a guide, there is no denying that teachers play a huge role in shaping one’s life. To honour their immense contribution, the birthday of Dr Sarvapalli Radhakrishnan, one of the most prominent statesman, is celebrated as Teachers’ Day. Celebrated on September 5 every year, on this day, many schools and educational institutions dedicate various events and performances to teachers.

Happy Teachers' Day 2019: Wishes Images Download, Quotes, Status, Greeting Card, HD Wallpapers, Messages, SMS, Photos, GIF Pics, and Pictures

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Happy Teachers' Day 2019: Wishes Images Download, Quotes, Status, Greeting Card, HD Wallpapers, Messages, SMS, Photos, GIF Pics, and Pictures

So, if you are looking to wish your favourite teachers and mentors, we have curated a list of wishes and messages for you.
Teachers Day 2019, teachers day, happy teachers day, teachers day images, happy teachers day 2019, teachers day images hd, teachers day images download, happy teachers day card, teachers day card, happy teachers day card, happy teachers day quotes, happy teachers day status, happy teachers day pics, happy teachers day images download, happy teachers day greetings card, happy teachers day messages, happy teachers day photos, happy teachers day pictures, teachers day pictures, teachers day quotes, teachers day images hd download, teachers day status
Happy Teacher’s Day 2019 Wishes Images, Quotes: Wish your favourite one. (Designed by Gargi Singh)


*You are not only our teacher
You are our friend, philosopher and guide
All molded into one person
We will always be grateful for your support
Happy Teachers’ Day!

Happy Teachers' Day 2019: Wishes Images Download, Quotes, Status, Greeting Card, HD Wallpapers, Messages, SMS, Photos, GIF Pics, and Pictures

Happy Teachers' Day 2019: Wishes Images Download, Quotes, Status, Greeting Card, HD Wallpapers, Messages, SMS, Photos, GIF Pics, and Pictures

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