Muhammad: A Prophet for Our Time by Karen Amstrong | Download Free E-Book

Muhammad was born in 570 CE, and over the following sixty years built a thriving spiritual community, laying the foundations of a religion that changed the course of world history. There is more historical data on his life than on that of the founder of any other major faith, and yet his story is little known. Karen Armstrong's immaculately researched new biography of Muhammad will enable readers to understand the true origins and spirituality of a faith that is all too often misrepresented as cruel, intolerant, and inherently violent. An acclaimed authority on religious and spiritual issues, Armstrong offers a balanced, in-depth portrait, revealing the man at the heart of Islam by dismantling centuries of misconceptions. Armstrong demonstrates that Muhammad's life--a pivot point in history--has genuine relevance to the global crises we face today.

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Musculoskeletal Tissue Regeneration: Biological Materials and Methods (Orthopedic Biology and Medicine) | Ricardo Side

The repair of musculoskeletal tissue is a vital concern of all surgical specialties, orthopedics and related disciplines. Written by recognized experts in their field, Musculoskeletal Tissue Regeneration: Biological Materials and Methods aims to provide both basic and advanced knowledge of the newer methodologies being developed and introduced to the clinical arena. On the cusp of a revolution, musculoskeletal repair is based on new tools that have recently become available or are about to emerge into clinical practice. By their very nature, these tools require an interdisciplinary approach, utilizing teams comprised of surgeons, engineers, and scientists in collaboration between industry and academia. A valuable resource for researchers, developers, and clinicians, Musculoskeletal Tissue Regeneration: Biological Materials and Methods presents a foundation to propel the technology and integration of the current state of knowledge into the twenty-first century.

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It’s Worse Being Green

In It’s Not Easy Being Grue, I argued for skepticism — or at least incredulity — towards any inductive inference made solely by appealing to a posteriori evidence. Two hypotheses, as long as they have a logical content greater than the evidence and are not yet refuted are, as a matter of following the rules of logic, necessarily equally favored by the evidence. Even if one should appeal to one of the two hypotheses having a natural property, this problem still stands, since it cannot be uncovered through a posteriori investigation. Of course, more than two hypotheses fit this criteria — any number of empirically adequate hypotheses with greater logical content than the evidence may be constructed. In sum, favoring one hypothesis over another, even with an a prior warrant, cannot be determined from a posteriori evidence at all.

Jessica is different than James. She sees the failure of his program and preemptively seeks out some a priori warrant for favoring some inductive inferences over others. Is there an a priori warrant that would allow Jessica to favor one hypothesis over another? For the time assume that such a warrant exists. Assume that if Jessica finds this warrant, the problem is solved. I will not go into the other problems that face Jessica — whether or not she can know that she has the warrant, whether or not she can know that she knows that she has a warrant, &c.

Some predicates, such as ‘green’ intuitively (so it is said) fit the list of natural properties while others, such as ‘grue’, intuitively do not. Call those grue-like properties ‘ill-behaved’ properties for now. What metaphysical standard sets natural properties apart from ‘ill-behaved’ properties?

We might say that it is solely intuition that guides us; we reject ‘ill-behaved’ predicates like ‘grue’ because they are disjunctive: they involve spatio-temporal properties that, like a cat that turns into a dog after whistling, cannot function within our commonsense ontology. If we assume that we are warranted in rejecting disjunctive predicates due to our intuition, this does not solve the problem, since it begs the question as to why our intuitions are warranted. How then can we give warrant to our intuitions? But first, some historical case-studies:

1. We can take ‘leopard’ as not having spots before a certain time, and having spots after that time. Any other ‘Just-So’ story by Kipling is an example of a possible variation on English (call it ‘Kipling-English‘) that takes a number of animals as having a ‘ill-behaved’ list of properties.
2. Christians take transubstantiation, the transformation of bread and wine into the literal body and blood of Christ after a specific incantation by a priest, very seriously. The term ‘Eucharist’ is then an ‘ill-behaved’ property that has been ingrained into the English lexicon and the Western mind for almost one thousand years.
3. Aristotle took elements to be of two classes: the worldly elements would move linearly towards their natural place unless acted upon, while the heavenly element, known as ‘æther’, was incapable of change other than rotation. Natural motion was then for hundreds of years an ‘ill-behaved’ property as well: just in some cases linear, but in others rotational. It took the work of Newton and others, through imagination, scientific investigation, and questioning Aristotle’s metaphysics, to link these two classes under one unifying force.

Thus, the English language already has several well-established ‘ill-behaved’ spatio-temporal properties in its lexicon. Of course, they are few and far between, so this is far from a convincing argument. It might be said that they’re works of fiction, or strange imaginings, and do not belong to commonsense talk. However, the predicate ‘grue’ is a disjunctive predicate only according to the colors expressed in standard English. If there was an alternative history where all colors were expressed in predicates that are ‘ill-behaved’ in English (call it ‘Engrish’), the predicate ‘grue’ would not be disjunctive or ‘ill-behaved’ in that language; we could not say the same about the predicates ‘green’ and ‘blue’ in Engrish.

It is plausible that, had Engrish been the lingua franca today, we would intuit that any ‘ill-behaved’ property according to English was a natural property, since it did not express a spatio-temporal property, while any natural property according to English was ‘ill-behaved’. Imagine that Jessica and James both decided to base their favoring of one hypothesis over another on their list of (supposed) natural properties. As it so happens, Jessica speaks Engrish and James speaks English. Both Jessica and James see X number of emeralds. Jessica and James both look to their intuitions, and each of them decides that the emeralds are ‘grue’ and ‘green’, respectfully. Each claims that the other is adopting a language that functions with ‘ill-behaved’ properties. How can we decide?

We cannot say that our list of natural properties is obviously true, and choose between Jessica and James on the basis of this list. We are not an outsider with privileged access to the list of natural properties. This would immediately assume the solution to the problem at hand, since like Jessica, we could have been raised speaking Engrish and not English. An accident of birth, rather than a strong metaphysical or epistemological argument, is (as I see it) the only thing that leads to favoring one unfalsified hypothesis over the other.

Why Afternoon May Be the Best Time to Exercise

By GRETCHEN REYNOLDS

 

 

Does exercise influence the body’s internal clock? Few of us may be conscious of it, but our bodies, and in turn our health, are ruled by rhythms. “The heart, the liver, the brain — all are controlled by an endogenous circadian rhythm,” says Christopher Colwell, a professor of psychiatry at the University of California, Los Angeles’s Brain Research Institute, who led a series of new experiments on how exercise affects the body’s internal clock. The studies were conducted in mice, but the findings suggest that exercise does affect our circadian rhythms, and the effect may be most beneficial if the exercise is undertaken midday.
For the study, which appears in the December Journal of Physiology, the researchers gathered several types of mice. Most of the animals were young and healthy. But some had been bred to have a malfunctioning internal clock, or pacemaker, which involves, among other body parts, a cluster of cells inside the brain “whose job it is to tell the time of day,” Dr. Colwell says.
These pacemaker cells receive signals from light sources or darkness that set off a cascade of molecular effects. Certain genes fire, expressing proteins, which are released into the body, where they migrate to the heart, neurons, liver and elsewhere, choreographing those organs to pulse in tune with the rest of the body. We sleep, wake and function physiologically according to the dictates of our body’s internal clock.
But, Dr. Colwell says, that clock can become discombobulated. It is easily confused, for instance, by viewing artificial light in the evening, he says, when the internal clock expects darkness. Aging also worsens the clock’s functioning, he says. “By middle age, most of us start to have trouble falling asleep and staying asleep,” he says. “Then we have trouble staying awake the next day.”
The consequences of clock disruptions extend beyond sleepiness. Recent research has linked out-of-sync circadian rhythm in people to an increased risk for diabetes, obesity, certain types of cancer, memory loss and mood disorders, including depression.
“We believe there are serious potential health consequences” to problems with circadian rhythm, Dr. Colwell says. Which is why he and his colleagues set out to determine whether exercise, which is so potent physiologically, might “fix” a broken clock, and if so, whether exercising in the morning or later in the day is more effective in terms of regulating circadian rhythm.
They began by letting healthy mice run, an activity the animals enjoy. Some of the mice ran whenever they wanted. Others were given access to running wheels only in the early portion of their waking time (mice are active at night) or in the later stages, the equivalent of the afternoon for us.
After several weeks of running, the exercising mice, no matter when they ran, were found to be producing more proteins in their internal-clock cells than the sedentary animals. But the difference was slight in these healthy animals, which all had normal circadian rhythms to start with.
So the scientists turned to mice unable to produce a critical internal clock protein. Signals from these animals’ internal clocks rarely reach the rest of the body.
But after several weeks of running, the animals’ internal clocks were sturdier. Messages now traveled to these animals’ hearts and livers far more frequently than in their sedentary counterparts.
The beneficial effect was especially pronounced in those animals that exercised in the afternoon (or mouse equivalent).
That finding, Dr. Colwell says, “was a pretty big surprise.” He and his colleagues had expected to see the greatest effects from morning exercise, a popular workout time for many athletes.
But the animals that ran later produced more clock proteins and pumped the protein more efficiently to the rest of the body than animals that ran early in their day.
What all of this means for people isn’t clear, Dr. Colwell says. “It is evident that exercise will help to regulate” our bodily clocks and circadian rhythms, he says, especially as we enter middle age.
But whether we should opt for an afternoon jog over one in the morning “is impossible to say yet,” he says.
Late-night exercise, meanwhile, is probably inadvisable, he continues. Unpublished results from his lab show that healthy mice running at the animal equivalent of 11 p.m. or so developed significant disruptions in their circadian rhythm. Among other effects, they slept poorly.
“What we know, right now,” he says, “is that exercise is a good idea” if you wish to sleep well and avoid the physical ailments associated with an aging or clumsy circadian rhythm. And it is possible, although not yet proven, that afternoon sessions may produce more robust results.
“But any exercise is likely to be better than none,” he concludes. “And if you like morning exercise, which I do, great. Keep it up.”

The Earliest Dinosaur, or Maybe Its Closest Kin

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Mark Witton/Natural History Museum

Researchers may have discovered the earliest dinosaur yet, or at least its closest relative.

The creature, named Nyasasaurus parringtoni, was the size of a Labrador retriever but with a five-foot-long tail. It roamed the earth about 243 million years ago, 10 million years before other early dinosaurs, like Eoraptor and Herrerasaurus.

“We’re being cautious about saying it’s the earliest dinosaur,” said Sarah Werning a paleontologist at the University of California, Berkeley, and an author of the study, which appears in the journal Biology Letters. “But if it’s not, it’s the closest cousin found to dinosaurs so far.”

The fossilized bones of Nyasasaurus parringtoni were excavated in the 1930s in Tanzania and reside in the Natural History Museum of London. The bones include one humerus, or upper arm bone, and six vertebrae.

The researchers found that the fossilized bones had an abundance of bone cells and blood vessels.

“We only see that many in animals that grow really fast,” Ms. Werning said. “It was growing about as fast as other early dinosaurs.”

The upper arm bone also has an enlarged crest, to anchor upper arm muscles — another feature common in early dinosaurs.

The fossils were first described in the 1950s by the paleontologist Alan J. Charig in his doctoral dissertation.

Dr. Charig, who died in 1997, is named as a co-author of the paper.

Are Doctors Too Wary of Drug Companies?

Not long ago, I asked a colleague for advice on a patient. He offered up a couple of treatment options, then stopped to show me a new medical app on his electronic tablet. With a few swipes of his finger, he summoned a compilation of research articles, synopses and even entire textbooks that, printed and bound, would have filled shelves in a library.

Dr. Pauline Chen on medical care.

“But do you know what the best part is?” he asked with a twinkle in his eye. I thought of the exhaustive reference material and the seemingly endless scroll of diagnoses that were all so easy to access on the small screen balanced on his knees.

“The best part is that none of this is sponsored by Pharma!” he said with a broad smile. “There’s no bias.”

My colleague is not the only doctor who feels that way, according to a recent study published in The New England Journal of Medicine.

For years, most doctors have had a predictable, if not close, relationship with the pharmaceutical industry. Companies handed out office tchotchkes, paid for staff lunches and distributed drug samples for patients. More significantly, drug companies were important sources of biomedical research money, particularly during periods when federal support wavered. It was understood that the companies providing funding would leave the researchers alone to design and conduct the study, analyze the data and write up the results.

That understanding began to fray about a decade ago when doctors, and patients, began to realize that drug companies were becoming too involved with the research they were supporting. For example, one major pharmaceutical firm manipulated data and underestimated the risk of heart attacks, strokes and deaths in a large study of a drug for arthritis. The drug was eventually withdrawn from the market, but not before 80 million patients had used it, with annual sales topping $2.5 billion.

The case highlighted the dangers of industry sponsorship of research into new drugs, and the public became eager to expose any potential conflict of interest, particularly for doctors. Within a few years, a new standard of transparency in medicine emerged. Brightly labeled drug company pens became an embarrassment; lunches on the drug company tab and sponsored conferences turned suspect; and editors at numerous medical journals published lengthy screeds detailing their disclosure requirements.

The new skepticism and transparency were no doubt good for patients and doctors, but this recent study reveals that in our zeal to single out the pharmaceutical industry’s biases, we may have become blind to our own.

The researchers created several hypothetical drug studies, then asked a group of practicing physicians to rate the “studies” and the likelihood they would prescribe the new “drug.” The researchers purposefully varied the quality of the studies and the disclosures – some of the made-up studies disclosed that they had received pharmaceutical company funding, others said they’d received support from the National Institutes of Health, and the rest listed no funding disclosures at all.

Most of the doctors were able to assess the quality of the research pretty accurately. After reading the less rigorous studies, the ones that weren’t designed, conducted or analyzed well, the doctors were hesitant to prescribe the new drugs under study; seeing the more rigorous studies, they were more willing to do so.

But the researchers also found that the doctors were also unduly swayed by any mention of industry funding. Regardless of the quality, if a study was supported by a pharmaceutical company, doctors were less willing to consider prescribing the studied drug and less likely to assess the quality of the research with accuracy.

“Some amount of skepticism is warranted,” said Dr. Aaron S. Kesselheim, lead author of the study and an assistant professor of medicine in the division of pharmacoepidemiology and pharmacoeconomics at the Brigham and Women’s Hospital in Boston. “But ultimately it should be the quality of the study and the impact of the results that determine your confidence about using a new drug, not who was funding it.”

Being overly skeptical has serious implications for patient care. The pharmaceutical industry, along with medical device and biotechnology firms, continues to finance a majority of current research. In 2007, for example, industry was responsible for nearly 60 percent of the more than $100 billion spent on research. Much industry-supported research focuses on the side effects of new drugs. By writing off such research, doctors risk overlooking findings that may have important treatment implications for their patients, like a new cholesterol-lowering drug that is found to have less of an effect on energy and blood sugar levels than other similar medications.

Dr. Kesselheim and his collaborators believe what is needed in biomedical research is even greater transparency. Such openness would include more independent third-party statistical reviews to ensure that data is not being manipulated or misleading and wider use of public Web sites like ClinicalTrials.gov, regardless of the source of funding.

ClinicalTrials.gov lists study details like objectives, design and data gathered, providing doctors and patients alike with a way to confirm that no data is being selectively reported or distorted. But participation on the site is voluntary, and pharmaceutical, medical device and biomedical companies are often hesitant to share what they consider proprietary data, choosing instead to list only selective details, or no information at all.

Until full transparency is achieved and such details are available to all on the Web or for independent statistical reviews, Dr. Kesselheim and his collaborators suggest that both doctors and patients remain alert to potential biases — Big Pharma’s, and also their own.

“Excessive skepticism,” Dr. Kesselheim observed, “is as much a bad thing as naïveté.”

Source:nyt

A Brief History of Time-Stephen Hawking

A Brief History of Time attempts to explain a range of subjects in cosmology, including the Big Bang, black holes and light cones, to the nonspecialist reader. Its main goal is to give an overview of the subject but, unusual for a popular science book, it also attempts to explain some complex mathematics. The 1996 edition of the book and subsequent editions discuss the possibility of time travel and wormholes and explore the possibility of having a universe without a quantum singularity at the beginning of time.

The author notes that an editor warned him that for every equation in the book the readership would be halved, hence it includes only a single equation: E = mc². Early in 1983, Hawking approached Simon Mitton, the editor in charge of astronomy books at Cambridge University Press, with his ideas for a popular book on cosmology. Mitton was doubtful about all the equations in the draft manuscript, which he felt would put off the buyers in airport bookshops that Hawking wished to reach. It was with some difficulty that he persuaded Hawking to drop all but one equation.^[4] In addition to Hawking's notable abstention from presenting equations, the book also simplifies matters by means of illustrations throughout the text, depicting.

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The Meaning of Relativity - Albert Eistein

in 1921, five years after the appearance of his comprehensive paper on general relativity and twelve years before he left Europe permanently to join the Institute for Advanced Study, Albert Einstein visited Princeton University, where he delivered the Stafford Little Lectures for that year. These four lectures constituted an overview of his then controversial theory of relativity. Princeton University Press made the lectures available under the title The Meaning of Relativity, the first book by Einstein to be produced by an American publisher. As subsequent editions were brought out by the Press, Einstein included new material amplifying the theory. A revised version of the appendix "Relativistic Theory of the Non-Symmetric Field," added to the posthumous edition of 1956, was Einstein's last scientific paper.

Review:

"A condensed unified presentation intended for one who has already gone through a standard text and digested the mechanics of tensor theory and the physical basis of relativity. Einstein's little book then serves as an excellent tying-together of loose ends and as a broad survey of the subject."--Physics Today

Table of Contents:

Introduction by Brian Greene vii

A Note on the Fifth Edition xxv

SPACE AND TIME IN PRE-RELATIVITY PHYSICS 1

THE THEORY OF SPECIAL RELATIVITY 24

THE GENERAL THEORY OF RELATIVITY 55

THE GENERAL THEORY OF RELATIVITY (CONTINUED) 79

APPENDIX FOR THE SECOND EDITION 109

APPENDIX II. RELATIVISTIC THEORY OF THE

NON-SYMMETRIC FIELD 133

Index 167

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Roberto Mancini hails 'incredible' Joe Hart after Manchester City draw

• The Guardian, Thursday 4 October 2012

Joe Hart, the Manchester City and England goalkeeper, pulls off a save in the 1-1 draw with Borussia Dortmund. Photograph: Laurence Griffiths/Bongarts/Getty Images

Roberto Mancini hailed an "incredible" performance from Joe Hart after the England goalkeeper produced a string of exceptional saves to keep Manchester City's Champions League hopes alive on a night when the Italian conceded his side were fortunate to pick up a point against an excellent Borussia Dortmund team.
Mario Balotelli's late penalty, awarded harshly after Neven Subotic was penalised for handling Sergio Agüero's close-range shot, earned City a 1-1 draw that Mancini believes could be vital come the end of the group.
Yet it was Hart, rather than the Italy striker, who was hailed as City's saviour, after the 25-year-old made eight superb saves in a pulsating game that had chances from the first minute to the last. Hart denied Mario Götze on three occasions in the first half alone and, at times, it felt as though he was single-handedly keeping Dortmund at bay. He was so impressive that there was even acclaim from Old Trafford. "Have to say Joe Hart has been incredible. For me best keeper in the world," tweeted Wayne Rooney.
Mancini had expressed his frustration with Hart less than a fortnight ago, after the goalkeeper criticised his team-mates for allowing a 2-1 lead to slip over Real Madrid. On this occasion, however, there was only praise from Mancini, who recognised that he was indebted to Hart for preventing Dortmund from being out of sight by the time Balotelli scored in the 90th minute to cancel out Marco Reus's opener. "Joe Hart is incredible because he saved everything and we should say thank you to him," Mancini said. "He did a fantastic performance. I don't know if it's the best performance in football history but he did very well."
Hart admitted that he could not recall being so busy in goal before. "It could have been 10-all tonight. I thought their keeper was fantastic," he said, acknowledging the contribution that Roman Weidenfeller made in the first half, when the Dortmund keeper made a hat-trick of saves to thwart Agüero. "Off the top of my head, I can't remember making as many saves before. I thought Dortmund were different class tonight. It took a good defensive effort by us to keep it to just one. I hope this result is important and that it is not a waste of effort."
It remains to be seen whether that will be the case, although City will clearly have to play much better if they are to have a chance of reaching the knockout phase and avoid a repeat of last year's elimination at the group stage. Third in Group D with one point from two games, they have not kept a clean sheet since the penultimate game of last season and there was little doubt that Dortmund were going to extend that record on an evening when City never got the balance right between attack and defence.
"The Champions League is totally different from every championship," Mancini said. "When you play, you play against the best players, so when you have a chance you have to score. If you don't score, and after you concede, like we conceded this evening, it's difficult that we can win.
"First half we had three or four incredible chances and I don't know why we didn't score but this can happen. The problem was our performance. This is the problem. In the Champions League we can't play with all players that attack. We need to defend with all players. If you don't defend, if you don't run like Borussia Dortmund did this evening, it's difficult."
City lost Javi García to a thigh strain in the first half and it seems certain that the midfielder will miss Saturday's league game at home to Sunderland. Yaya Touré also appeared to be struggling and was well off the pace in the second half in particular, although Mancini claimed there was nothing wrong with the Ivorian's fitness. "Yaya didn't play well. He is not injured. But it was not only Yaya; all the team played a poor game. We didn't play well. We didn't deserve to take this point, but in the end it could be important. Borussia Dortmund played better than us and at this moment they are a better side."