Saturday, March 28, 2015

2699 - AMICOR 17

Alimentos Regionais Brasileiros

Aloyzio AchuttiemAMICOR - Há 13 minutos
From: Profa. *Cristianne Maria Famer Rocha* [image: Alimentos Regionais Brasileiros] *TÍTULO:*Alimentos Regionais Brasileiros*TIPO DE DOCUMENTO:*Livro*AUTOR:*Ministério da Saúde*ANO:*2015*EDITORA:*Ministério da Saúde*PALAVRAS-CHAVE:*Politica Nacional de Alimentação e Nutrição; Frutas; Hortaliças; Leguminosas*CATEGORIA E SUB CATEGORIA:*Promoção da Alimentação Adequada; Educação Alimentar Nutricional *ACESSO AO DOCUMENTO:*Clique aqui para realizar o download*LINK PRA BVS:*- *REFERÊNCIA:*Brasil. Ministério da Saúde. Secretaria de Atenção à Saúde. Departamento de Atenção Básica. Alimentos... mais »

KURZWEIL Newsletter

Aloyzio AchuttiemAMICOR - Há 10 horas
*KURZWEIL NEWSLETTER* [image: Ask Ray | Question about molecular assembler]

Família Achutti, primeiro encontro em 1985

Aloyzio AchuttiemAMICOR EXTENSION - Há um dia
Com a ajuda da *Sonia Chiarlo*, filha de meu saudoseo primo* João Rechden*, identificamos parentes em foto de mais de 3 décadas, durante o 1o. encontro da Família ACHUTTI, realizado aqui em Porto Alegre Foi na antiga sede da Sociedade Libanesa em 16 de março de 1985, e minha irmã Lia que identificou a Soninha na foto. sonia ciarlo 11:16 (Há 7 minutos) *Oi Aloyzio* *Que foto linda! Mas não tenho nem idéia de onde estou com esta criançada. Mas reconheço alguns sim, a menina de saia xadrez, à minha frente, é a Fernanda (hoje com 34 anos), e a de sainha verde é a Carla (hoje com 37), mi... mais »

Richard III e Thomas More

Aloyzio AchuttiemAMICOR - Há um dia
[image: Torin Weston, 4, in Leicester, England, on Thursday.]WORLD | LEICESTER JOURNALRichard III Gets a Kingly Burial, on Second Try By JOHN F. BURNS The archbishop of Canterbury presided over the service on Thursday, but critics said the notorious monarch should not have been given such honors.

factor XII-driven contact system in AD

Aloyzio AchuttiemAMICOR - Há um dia
Changes in a blood-based molecular pathway identified in Alzheimer’s disease [image: Changes in a blood-based molecular pathway identified in Alzheimer’s diseaseBy the time most people receive a diagnosis of Alzheimer’s disease — based on clinical signs of mental decline — their brains have already suffered a decade or more of damage. But although the mechanisms that spur the destruction of neurons in Alzheimer’s disease are not yet fully understood, two well-documented signs of the condition are accumulation of the amyloid-β peptide (the main component of plaques found in Alzheimer’... mais »

Complexity

Aloyzio AchuttiemAMICOR - Há um dia
Science 27 March 2015: Vol. 347 no. 6229 p. 1426 DOI: 10.1126/science.aaa5153 - BOOKS ET AL. COMPLEXITY Seeing the forest for the trees 1. Sybil Derrible The Art of Insight in Science and Engineering: Mastering Complexity *Sanjoy Mahajan* MIT Press, 2014. 408 pp. 1. The reviewer is at the Complex and Sustainable Urban Networks (CSUN) Laboratory, University of Illinois at Chicago, Chicago, IL 60607, USA. 1. E-mail: derrible@uic.edu [image: Figure] View larger version: - In this page - In a new window - Download PowerPoint Slide for Teaching We now... mais »

Declaração do Panamá

Aloyzio AchuttiemAMICOR - Há 2 dias
26 Governments Sign 'Declaration of Panama' to Eliminate Health Inequalities in Latin America & Caribbean - *SM2015 among the international agencies signing the Declaration* *Panama City (10 Sept. 2013). - *26 Ministers of Health from Latin America and the Caribbean and seven international partners –the Salud Mesoamérica 2015 Initiative (SM2015) among them– signed the ‘Declaration of Panama’, a pledge to end all preventable child and maternal deaths by 2035. The Declaration of Panama, signed during the ‘ Promise Renewed for the Americas conference, is a call-to-action for... mais »

POA 243

Aloyzio AchuttiemAMICOR - Há 2 dias
Porto Alegre faz 243 anos: veja como artistas retratam a cidadeGaleria virtual criada por Zero Hora apresenta trabalhos de poetas, fotógrafos e artistas visuais sobre Porto Alegre, que completa 243 anos nesta quinta-feira por Francisco Dalcol 26/03/2015 | 08h34 [image: Porto Alegre faz 243 anos: veja como artistas retratam a cidade Reprodução/Reprodução] Foto de Fernanda ChemaleFoto: Reprodução / Reprodução *Qual é o seu olhar sobre Porto Alegre?* Provocados por essa pergunta, poetas, fotógrafos e artistas visuais contemporâneos foram convidados pelo 2º Caderno de ZH a apresentar trab... mais »

zeptoseconds and yoctoseconds Delanceyplace.com

Aloyzio AchuttiemAMICOR - Há 2 dias
Comprei o livro pela Amazon Today's *encore* selection -- from *The Canon: A Whirligig Tour of the Beautiful Basics of Science by Natalie Angier*. Fractions of a second: "What happens ... in subsections of seconds? In a tenth of a second, we find the proverbial 'blink of an eye' for that's how long the act takes. In a hundredth of a second, a hummingbird can beat its wings once. ... A millisecond, 10-3 seconds is thetime it takes a typical camera strobe to flash. Five-thousandths of a second is also the time it takes ... a Mexican salamander ... to snag its prey./.../

Global Agewatch

Aloyzio AchuttiemAMICOR - Há 2 dias
http://www.helpage.org/global-agewatch/Infographic [image: Click to view full Global AgeWatch Index 2014 infographic]

Global Footprint Network

Aloyzio AchuttiemAMICOR - Há 2 dias
*2015 National Footprint Accounts Launch* Earlier this month, Global Footprint Network released the 2015 Edition of the National Footprint Accounts with several methodological improvements; a new, more open licensing structure; and country risk data for the finance community. Global Footprint is excited to offer the 2015 National Footprint Accounts for non-commercial use through a free, easily downloadable "Public Data Package," which features the latest (2011) Footprint and biocapacity results per capita by land type for 182 countries in a highly sortable spreadsheet. Based on calc... mais »

Hubble 25 years old

Aloyzio AchuttiemAMICOR - Há 2 dias
Hubble Telescope at 25 [image: Picture of the Pillars of Creation] Hubble’s Greatest HitsPictures from the space telescope have dazzled us for 25 years. By Timothy Ferris Photograph above by NASA; ESA; Hubble Heritage Team, STScI/AURA. Colorized Composite/Mosaic It didn’t amount to much at first. Launched into orbit aboard the space shuttle *Discovery* on April 24, 1990, amid flurries of hope and hype, the Hubble Space Telescope promptly faltered. Rather than remaining locked on its celestial targets, it trembled and shook, quaking like a photophobic vampire whenever sunlight struck it... mais »

Universe Extra Dimensions

Aloyzio AchuttiemAMICOR - Há 2 dias
Physics Letters B Volume 743, 9 April 2015, Pages 295–300 [image: Cover image] Absence of black holes at LHC due to gravity's rainbow - Ahmed Farag Alia, b, c, , , - Mir Faizald, , - Mohammed M. Khalile, , Open Access funded by SCOAP³ - Sponsoring Consortium for Open Access Publishing in Particle PhysicsUnder a Creative Commons license Show more Open Access ------------------------------ Abstract In this paper, we investigate the effect of Planckian deformation of quantum gravity on the production of black holes at colliders using the framework of gravity's rainbow. ... mais »

Salt a World History

Aloyzio AchuttiemAMICOR - Há 3 dias
Salt, the state, and the private sector -- 3/25/15 [image: delanceyplace | www.delanceyplace.com]Today's selection -- from *Salt* by Mark Kurlansky. Until very recently, salt was one of civilization's rarest and most precious commodities. Wars were fought to gain access to salt mines, it was sometimes used as money, and states often formed salt monopolies as the underpinning of their economies. This first occurred with the Emperor Qin of China in the third century BC, and with it began the perennial debate regarding the role of the state versus the private sector: "[In the third ... mais »

Monoclonal in Alzheimer's

Aloyzio AchuttiemAMICOR - Há 4 dias
*Finally, a Big Win for a Monoclonal in Alzheimer's* Medscape Medical News > Conference News Finally, a Big Win for a Monoclonal in Alzheimer's Daniel M. Keller, PhD March 23, 2015 - 4 comments EDITORS' RECOMMENDATIONS - Trial of Antiamyloid Agent in Prodromal Alzheimer's Halted - More Good News for Solanezumab in Alzheimer's - Second Bapineuzumab Trial Fails in Alzheimer's - NICE, France — After years of disappointing trials of monoclonal antibodies directed against forms of β-amyloid for the treatment of Alzheimer's disease (AD), one appears to have hit the mark,... mais »

Saúde Urbana

Aloyzio AchuttiemAMICOR - Há 4 dias
Da AMICOR Maria Ines Azambuja 11:11 (Há 3 minutos) Além de já estar no site do Programa Saúde Urbana o material do PNUD apresentado no Seminário do dia 31/1 sobre a Restinga (ver aba-restinga), está agora também um link para um documento de acesso facilitado aos relatórios sobre indicadores demográficos e sociais produzidos pelo PNUD para 335 microáreas de Porto Alegre. Junto disponibilizamos figuras com a distribuição de alguns indicadores (renda per capita, mortalidade infantil, longevidade) nestas 335 áreas, para permitir que, de posse do relatório de sua micro-área, a comunidad... mais »

Inequality

Aloyzio AchuttiemAMICOR - Há 4 dias
Da revista Science 16 anexos Visualizar o anexo Science of inequality - Editorial - Inevitable inequality.pdf Science of inequality - Editorial - Inevitable inequality.pdf Visualizar o anexo Science of inequality - Editor note - a new look on inequality.pdf Science of inequality - Editor note - a new look on inequality.pdf Visualizar o anexo Science of inequality - on the psychology of poverty.pdf Science of inequality - on the psychology of poverty.pdf Visualizar o anexo Science of inequality - The intergenerational transmission of inequality - material disadvantage and health at b... mais »

Exodo Rural na China

Aloyzio AchuttiemAMICOR - Há 4 dias
Do Professor Antônio Padula Área de anexos Visualizar o anexo Exudo Rural e Urbanização na China.pdf Exudo Rural e Urbanização na China.pdf

coorte ELSA e DM

Aloyzio AchuttiemAMICOR - Há 4 dias
Mensagem dos Prof. Bruce Duncan e Maria Inês Schmit ARTIGOS: - https://drive.google.com/file/d/0B3-0JjscwhtpNjA3VERJMmNLdnRZamEwRExmcHNfMlVqMklB/view?usp=sharing - - https://drive.google.com/file/d/0B3-0JjscwhtpZmtpVWFaODBiMTBxTmc0QVQzTE9mN3E1azFB/view?usp=sharing - - https://drive.google.com/file/d/0B3-0JjscwhtpcUE3cHFqSnd3N1JDcm8xZzNDcXF2MmxScjhN/view?usp=sharing Nosso estudo de coorte ELSA está começando mostrar sua relevância e força. Encaminho 2 artigos recentes do ELSA sobre diabetes – O primeiro mostra a alta prevalência da doença no ELSA quando se f... mais »

keeping smokers ignorant

Aloyzio AchuttiemAMICOR - Há 4 dias
[image: Banner] The Shame Of America's "Public Health" By Gil Ross | March 20th 2015 02:32 PM | 10 comments | Print | E-mail | Track Comments [image: User pic.] Gil Ross Our nation’s most influential, respected and powerful public health officials and academics are engaged in a vast,corrupt and fraudulent conspiracy to keep desperate smokers ignorant of the facts about how reduced-harm devices (such as e-cigarettes) are likely to help them quit smoking. /.../

Water, Water

Aloyzio AchuttiemAMICOR - Há 4 dias
‘Water, Water Everywhere’ In The Solar System Avaneesh Pandey Posted with permission from International Business Times

O Maravilhoso Mundo Novo...

Aloyzio AchuttiemAMICOR - Há 4 dias
*Está chegando o Maravilhoso Mundo Novo (Aldous Huxley). Não precisamos mais de políticos, nem de propina ou compra de parceiros e votos. Basta um comprimido de "soma" ou de colocar na água potável...* There Could Soon Be a Pill to Make Us More Compassionate - Alice Park @aliceparkny March 21, 2015 How brain chemistry influences compassion Biology may have a lot to do with our behavior, especially in social situations. And that means our social interactions could be manipulated by a pill. That’s what a new study, published in the journal *Current Biology*, suggests. A group led... mais »

The 'intraterrestrials'

Aloyzio AchuttiemAMICOR - Há 4 dias
The 'intraterrestrials': New viruses discovered in ocean depths [image: Graphic of viruses attempting to dock on a microbial mat, using the tips of their tails.] The intraterrestrials, they might be called. Strange creatures live in the deep sea, but few are odder than the viruses that inhabit deep ocean methane seeps and prey on single-celled microorganisms called archaea. The least understood of life's three primary domains, archaea thrive in the most extreme environments on the planet: near hot ocean rift vents, in acid mine drainage, in the saltiest of evaporation ponds and in pet... mais »

Autismo e Resperidona

Aloyzio AchuttiemAMICOR - Há 4 dias
ESPERANÇA CONTRA O AUTISMOESTUDO ERA SOBRE potencial tratamento oncológico, mas, de forma incidental, levou cientistas a resultados promissores para pacientes que sofrem de transtornos neuropsiquiátricos de desenvolvimento Um achado incidental em uma pesquisa relacionada ao câncer se transformou em esperança para as famílias de autistas. Em curso há três anos no Hospital de Clínicas de Porto Alegre (HCPA), o estudo – inicialmente destinado a avaliar uma nova e potencial estratégia de tratamento oncológico – levou os cientistas a tomar o caminho de outras áreas da medicina, alcançando... mais »

The hunger vital sign

Aloyzio AchuttiemAMICOR - Há 5 dias
CHILDREN’S HEALTH WATCH Policy Action Brief The Hunger Vital Sign: A New Standard of Care for Preventive Health Nathan Goldman, Policy Intern; Richard Sheward, MPP, Senior Policy Analyst; Stephanie Ettinger de Cuba, MPH, Research and Policy Director; Maureen M. Black, PhD, Principal Investigator; Megan Sandel, MD, MPH, Principal Investigator; John Cook, PhD, MAEd, Principal Investigator; and Sharon Coleman, MS, MPH, Statistical AnalystMay 16, 2014Children's HealthWatch Policy Action Brief Drs. Erin Hager and Anna Quigg and the Children’s HealthWatch team developed the Hunger Vital S... mais »

Alimentos Regionais Brasileiros

From: Profa. Cristianne Maria Famer Rocha

Alimentos Regionais Brasileiros
Alimentos Regionais BrasileirosLivroMinistério da Saúde2015Ministério da SaúdePolitica Nacional de Alimentação e Nutrição; Frutas; Hortaliças; LeguminosasPromoção da Alimentação Adequada; Educação Alimentar Nutricional
Clique aqui para realizar o download-Brasil. Ministério da Saúde. Secretaria de Atenção à Saúde. Departamento de Atenção Básica. Alimentos regionais brasileiros / Ministério da Saúde, Secretaria de Atenção à Saúde, Departamento de Atenção Básica. – 2. ed. – Brasília : Ministério da Saúde, 2015.A nova edição desta publicação tem como propósito favorecer o conhecimento a cerca das mais variadas espécies de frutas, hortaliças, leguminosas, tubérculos, cereais, ervas, entre outras, existentes em nosso país, além de contribuir para divulgar a variedade de alimentos em todas as regiões, orientar seu uso em preparações culinárias e resgatar, valorizar e fortalecer a cultura alimentar brasileira. O resgate, o reconhecimento e a incorporação desses alimentos no cotidiano das práticas alimentares representa importante iniciativa de melhoria do padrão alimentar e nutricional, contribuindo para a garantia do direito humano à alimentação adequada e saudável e da Segurança Alimentar e Nutricional da população brasileira. Além disso, constitui um instrumento de educação alimentar e nutricional que pode ser utilizado por profissionais de saúde, educação, assistência social, entre outros, buscando a valorização dos alimentos existentes em nosso país.

KURZWEIL Newsletter

KURZWEIL NEWSLETTER
Ask Ray | Question about molecular assembler

Friday, March 27, 2015

Richard III e Thomas More


Torin Weston, 4, in Leicester, England, on Thursday.

WORLD | LEICESTER JOURNAL

Richard III Gets a Kingly Burial, on Second Try

By JOHN F. BURNS

The archbishop of Canterbury presided over the service on Thursday, but critics said the notorious monarch should not have been given such honors.

Thursday, March 26, 2015

factor XII-driven contact system in AD

Changes in a blood-based molecular pathway identified in Alzheimer’s disease

Changes in a blood-based molecular pathway identified in Alzheimer’s diseaseBy the time most people receive a diagnosis of Alzheimer’s disease — based on clinical signs of mental decline — their brains have already suffered a decade or more of damage. But although the mechanisms that 
spur the destruction of neurons in Alzheimer’s disease
 are not yet fully understood, two well-documented signs of the 
condition are accumulation of the amyloid-β peptide (the main component 
of plaques found in Alzheimer’s patient brains) and chronic 
inflammation. New research from Rockefeller University, published March 
16 in the Proceedings of the National Academy of Sciences, 
identifies a bridge between the two. That bridge, a molecular cascade 
known as the contact system, may provide opportunities for early 
diagnosis of the disease through simple blood tests.“People have been looking for a long time for markers for Alzheimer’s disease,” says Sidney Strickland, head of the Patricia and John Rosenwald Laboratory of Neurobiology and Genetics.
 But current diagnostic tests for pre-symptomatic Alzheimer’s leave much
 to be desired. Evaluating the level of amyloid-β in the cerebral spinal
 fluid, for instance, requires an invasive spinal tap procedure.“Finding a blood biomarker that would let us know through a simple 
test whether someone is on their way to developing the disease would be a
 significant advance,” says first author Daria Zamolodchikov, a 
postdoctoral associate in the Strickland lab.The new study grew from the lab’s ongoing work
 that looks at how the vascular system is involved in Alzheimer’s 
disease. It has been shown that amyloid-β can activate a protein in 
plasma called factor XII, the first step in a pathway known as the 
contact system. When activated, this system leads to the release of a 
small peptide called bradykinin, a molecule known to promote potentially
 damaging inflammation. Although some studies have found these molecules
 in the cerebral spinal fluid and brain tissue of Alzheimer’s patients, 
no one had studied them in Alzheimer’s patient plasma.Using plasma from people with and without diagnosed Alzheimer’s 
disease, the researchers measured the activation levels of the contact 
system. They found increased activation of this system in the plasma of 
Alzheimer’s patients, potentially implicating it in the inflammatory 
pathology of the disease. Moreover, in a subset of patients whose 
amyloid-β levels in the cerebral spinal fluid were known, the 
researchers demonstrated a positive correlation between activation of 
the contact system and changes in cerebral spinal fluid amyloid-β 
levels, which as mentioned above are correlated with the development of 
Alzheimer’s.The researchers found similar activation of the contact system in 
mouse models of Alzheimer’s, which are genetically modified to 
overproduce amyloid-β. They then conducted a follow-up experiment with 
healthy mice. “We went one step further and took completely normal 
wild-type mice and injected them with amyloid-β. We found that on its 
own, injection with amyloid-β can activate this system. It’s a proof of 
principle in a complex environment,” says Zamolodchikov.These findings will need to be supported by studies in larger patient
 populations and longitudinal studies, but they could eventually open 
the door to diagnosis of pre-symptomatic Alzheimer’s based on blood 
levels of these molecules.The contact system may also offer a new approach to therapies for 
Alzheimer’s disease, since inhibition of the pathway could blunt some of
 the inflammatory aspects of the disease. One concern is that the 
contact system is also involved in blood clotting and inhibition might 
carry a risk of bleeding. However, people with a defect in this system 
do not have hemophilia. Thus, inhibition of this pathway might slow 
progression of the disease without increasing the risk of hemorrhage.
By the time most people receive a diagnosis of Alzheimer’s disease — based on clinical signs of mental decline — their brains have already suffered a decade or more of damage. But although the mechanisms that spur the destruction of neurons inAlzheimer’s disease are not yet fully understood, two well-documented signs of the condition are accumulation of the amyloid-β peptide (the main component of plaques found in Alzheimer’s patient brains) and chronic inflammation. New research from Rockefeller University, published March 16 in the Proceedings of the National Academy of Sciences, identifies a bridge between the two. That bridge, a molecular cascade known as the contact system, may provide opportunities for early diagnosis of the disease through simple blood tests.
“People have been looking for a long time for markers for Alzheimer’s disease,” says Sidney Strickland, head of the Patricia and John Rosenwald Laboratory of Neurobiology and Genetics. But current diagnostic tests for pre-symptomatic Alzheimer’s leave much to be desired. Evaluating the level of amyloid-β in the cerebral spinal fluid, for instance, requires an invasive spinal tap procedure.
“Finding a blood biomarker that would let us know through a simple test whether someone is on their way to developing the disease would be a significant advance,” says first author Daria Zamolodchikov, a postdoctoral associate in the Strickland lab.
The new study grew from the lab’s ongoing work that looks at how the vascular system is involved in Alzheimer’s disease. It has been shown that amyloid-β can activate a protein in plasma called factor XII, the first step in a pathway known as the contact system. When activated, this system leads to the release of a small peptide called bradykinin, a molecule known to promote potentially damaging inflammation. Although some studies have found these molecules in the cerebral spinal fluid and brain tissue of Alzheimer’s patients, no one had studied them in Alzheimer’s patient plasma.
Using plasma from people with and without diagnosed Alzheimer’s disease, the researchers measured the activation levels of the contact system. They found increased activation of this system in the plasma of Alzheimer’s patients, potentially implicating it in the inflammatory pathology of the disease. Moreover, in a subset of patients whose amyloid-β levels in the cerebral spinal fluid were known, the researchers demonstrated a positive correlation between activation of the contact system and changes in cerebral spinal fluid amyloid-β levels, which as mentioned above are correlated with the development of Alzheimer’s.
The researchers found similar activation of the contact system in mouse models of Alzheimer’s, which are genetically modified to overproduce amyloid-β. They then conducted a follow-up experiment with healthy mice. “We went one step further and took completely normal wild-type mice and injected them with amyloid-β. We found that on its own, injection with amyloid-β can activate this system. It’s a proof of principle in a complex environment,” says Zamolodchikov.
These findings will need to be supported by studies in larger patient populations and longitudinal studies, but they could eventually open the door to diagnosis of pre-symptomatic Alzheimer’s based on blood levels of these molecules.
The contact system may also offer a new approach to therapies for Alzheimer’s disease, since inhibition of the pathway could blunt some of the inflammatory aspects of the disease. One concern is that the contact system is also involved in blood clotting and inhibition might carry a risk of bleeding. However, people with a defect in this system do not have hemophilia. Thus, inhibition of this pathway might slow progression of the disease without increasing the risk of hemorrhage.
PNASProceedings of the National Academy of Sciences online: March 16, 2015
Activation of the factor XII-driven contact system in Alzheimer’s disease patient and mouse model plasma
Daria Zamolodchikov, Zu-Lin Chen, Brooke A. Conti, Thomas Renné, and Sidney Strickland
Tags: 

Complexity

Science
Vol. 347 no. 6229 p. 1426 
DOI: 10.1126/science.aaa5153
  • BOOKS ET AL.
COMPLEXITY

Seeing the forest for the trees

  1. Sybil Derrible
The Art of Insight in Science and Engineering: Mastering Complexity Sanjoy Mahajan MIT Press, 2014. 408 pp.
  1. The reviewer is at the Complex and Sustainable Urban Networks (CSUN) Laboratory, University of Illinois at Chicago, Chicago, IL 60607, USA.
  1. E-mail: derrible@uic.edu
We now live in a world obsessed with data, in which paper and pencil have been traded for code and algorithms. As a result, we often spend less time getting a feel for problems we are tackling than we would have 35 years ago. It was therefore very refreshing to read a book that encourages the reader to do just that.
The Art of Insight in Science and Engineering acts as a step-by-step guide that enables the reader to tackle fundamental scientific problems through simple back-of-the-envelope calculations. The main objective of the book is not to promote a thorough understanding of an underlying theory or to allow us to come to an exact solution but rather to encourage us to use our instincts and knowledge of the fundamental concepts to come to an approximate and reasonable solution. “Approximate first, and worry later,” says the book's author, Sanjoy Mahajan. “Otherwise you never start, and you can never learn that the approximations would have been accurate enough—if only you had gathered the courage to make them.”
To gain insight into a variety of problems, Mahajan has devised a series of reasoning tools. He uses real-life examples to illustrate each tool's utility, showing the reader how to calculate everything from the energy needed for a plane to take off to the time needed to cook a fish to perfection (which is about 10 minutes, for those interested). Each is also cleverly illustrated by practical exercises that reinforce our understanding of the concepts.
The tools in the first section of the book enable us to make a problem more manageable. The divide-and-conquer strategy, for instance, tells us to divide a problem into subparts that can be solved or approximated easily and then aggregated back to the main answer (e.g., mass = density × volume).
In the second section, the reader is encouraged to simplify a problem by combining some of its elements. One way this can be done is by looking at a problem's symmetry. Here, Mahajan recalls the story of the German mathematician Carl Friedrich Gauss, who managed to calculate the sum 1 + 2 + … + 100 quickly when he was only 3 years old by using symmetry.
The final section has tools to help us discard some elements of complexity and purposefully omit information to reach a conclusion, using techniques including probabilistic analysis and what Mahajan refers to as “lumping.” As an example, instead of integrating complex velocity and acceleration profiles to estimate the airborne time of a falling object, Mahajan suggests lumping the profiles into rectangles and computing their areas to generate rough approximations.
Naturally, the book is not perfect. Mahajan clearly comes from a physics background, and he relies mostly on physics problems. The traditional electrical and spring models are used extensively, and so are the fundamentals of fluid mechanics. Moreover, toward the end of the book, Mahajan tackles much more complex problems, looking at sound, light, and gravitational radiation, for instance, which may be difficult for nonphysicists to appreciate. Nevertheless, these more advanced examples show that the overall approach is also applicable and even pertinent to more complex problems.
Senior undergraduate and graduate students will likely enjoy the book because it encourages them to think beyond the equation, and it may help build mental connections between many concepts learned in classes. Researchers and other professionals stand to benefit from it as well, because it may encourage them to think about their own problems in a slightly different way. Teachers will undoubtedly enjoy the book because it should equip them with a battery of techniques to improve their classes. Whichever applies to you, this book is definitely worth adding to your reading list.