What Science Knows And How It Knows It,What Science Say About: 09/03/14

Wednesday, 3 September 2014

Astrophotography 101

Welcome to Astrophotography 101: A Lesson Series on Photographing the Milky Way.

What is Astrophotography?

There are many different genres of photography. Portrait photography, street photography, landscape, nature, macro… the list goes on. If portrait photography is the art of making photos of people, astrophotography is the art of making photos of the night sky. Astrophotography isn’t a new genre of photography but until recently, it has been a rather obscure one. It used to be confined to a subset of the astronomy community. So, when most people think of astrophotography, they used to think of a camera pointed through an expensive telescope, maybe on a computer controlled mount with an autoguider, and hours and hours of exposure data. It used to be a form of photography that was only possible with expensive equipment and technical expertise.

Now astrophotography is more accessible than ever. The technology has improved, the equipment is cheaper and the community has grown. To get started all you really need is a decent digital camera with manual controls and a tripod. Making your first images of the Milky Way may forever change the way you look at photography and the universe around you. Astrophotography is about capturing the beauty of the vast and mysterious universe we are a part of from the comfort of the precious planet that we all share. Few experiences have impacted my life as much as astrophotography and I want to hopefully share a little bit of that experience with you here.

What is Astrophotography 101?

Astrophotography 101 is a class for everyone. It is series of online posts and video lessons on how photograph the Milky Way without expensive equipment. If you already own a digital SLR and a tripod, you already have the most expensive things you’ll need for this class. We’ll cover everything that you will need to make your very first astrophotos and then we’ll dive deeper into the finer (and funner) techniques to make some truly amazing photographs. Building from my originalHow to Photograph the Milky Way post, Astrophotography 101 will provide a more complete and detailed guide on astrophotography with a special emphasis on helping beginners and seasoned photographers alike.

Free for Everyone

Over-the-counter pain reliever may restore immune function in old age

Date:

September 2, 2014

Source:

Federation of American Societies for Experimental Biology

Summary:

New research involving mice suggests that the key to more youthful immune function might already be in your medicine cabinet. Scientists have shown that macrophages from the lungs of old mice had different responses to Mycobacterium tuberculosis than macrophages from young mice, but these changes were reversed by ibuprofen.

New research published in the Journal of Leukocyte Biology suggests that macrophages from the lungs of old mice responded differently to infections than those of young mice, ibuprofen reversed these changes.

New research involving mice suggests that the key to more youthful immune function might already be in your medicine cabinet. In a report published in theJournal of Leukocyte Biology scientists show that macrophages from the lungs of old mice had different responses to Mycobacterium tuberculosis than macrophages from young mice, but these changes were reversed by ibuprofen.

"Inflammation in old age can have significant consequences on immune function," said Joanne Turner, Ph.D., a researcher involved in the work from the Department of Microbial Infection and Immunity and Center for Microbial Interface Biology at The Ohio State University in Columbus, Ohio. "With this knowledge, it may be possible to reduce or prevent some diseases in the elderly by decreasing inflammation with diet, exercise and/or drugs."

To make this discovery, scientists measured inflammatory markers in the total lung or within purified macrophage populations of young healthy mice and of old healthy mice. Inflammatory markers were elevated in old mice, and isolated macrophages from both old and young healthy mice responded differentially to infection with Mycobacterium tuberculosis in vitro. This suggests that the altered interactions with M. tuberculosiswere linked to inflammation in old age. The researchers then placed a group of old, but healthy, mice on an ibuprofen supplemented diet, and this reduced inflammation and restored immune function to that of young healthy mice.

"This may give new meaning to the phrase 'take two aspirins and call me in the morning,'" said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology. "The report may not be about aspirin, but it does show that over-the-counter remedies may broader value that usually appreciated, including by affecting immune functions that change with age."

Aging gracefully: Diving seabirds shed light on declines with age

Date:

September 2, 2014

Source:

Wiley

Summary:

Scientists who studied long-lived diving birds, which represent valuable models to examine aging in the wild, found that blood oxygen stores, resting metabolism and thyroid hormone levels all declined with age, although diving performance did not. Apparently, physiological changes do occur with age in long-lived species, but they may have no detectable effect on behavioral performance.

Bird in study. Physiological changes do occur with age in long-lived species, but they may have no detectable effect on behavioral performance, scientists have found.

The Functional Ecology findings suggest that reductions in metabolism with age can be viewed as strategic restraint on the part of individuals who are likely to encounter energy-related senescence.

"As a graduate student, it was humbling to study seabirds older than me. Despite expending more energy for their body size when flying than any other animal, living in cold, harsh Arctic environments, diving over 100 meters in depth, and having to search for unpredictable food, even old birds return year after year to rear their chicks with no discernible change in their performance," said lead author Dr. Kyle Elliott. "By understanding how seabirds can cope with high metabolic demands with no effect on longevity, we may learn how old humans can reduce their chance of being impacted by metabolic diseases."

Bar code devised for bacteria that causes tuberculosis

Date:
September 2, 2014
Source:
London School of Hygiene & Tropical Medicine
Summary:
Doctors and researchers will be able to easily identify different types of tuberculosis (TB) thanks to a new genetic barcode devised by scientists. To help identify the different origins and map how tuberculosis moves around the world, spreading from person to person through the air, the research team studied over 90,000 genetic mutations.

The bacteria that cause the deadly respiratory disease have evolved into families of strains, or lineages, which may affect people differently.

To help identify the different origins and map how tuberculosis moves around the world, spreading from person to person through the air, the research team studied over 90,000 genetic mutations.

According to the study -- published in Nature Communications -- the researchers found that just 62 mutations are needed to code the global family of strains.

Dr Taane Clark, Reader in Genetic Epidemiology and Statistical Genomics at the London School of Hygiene & Tropical Medicine, who led the study, said: "There is increasing interest in new technologies that can assist those treating tuberculosis patients.

"This new barcode can be easily implemented and used to determine the strain-type that is a surrogate for virulence.

"We are making this information available to the doctors and scientists working with tuberculosis so that they can more easily know what strains they are dealing with."

Dr Ruth McNerney, TB expert and Senior Lecturer in Pathogen Biology and Diagnostics at the School, who was also part of the study, said: "New technology is making it easier to track mutations but genomes are very complicated and we hope this simple bar code will help people with their research."

Tuberculosis is a bacterial disease that often involves the lungs but can affect any part of the body. Untreated it is often fatal and TB kills an estimated 1.3 million people every year.

The World Health Organization estimates there are 12 million TB patients in the world and in the UK nearly 9,000 new cases are diagnosed every year. The disease can be carried around the world by people unaware they are infected. The bacterium that causes TB is called Mycobacterium tuberculosis.

Spinach extract decreases cravings, aids weight loss

Date:

September 2, 2014

Source:

Lund University

Summary:

A spinach extract containing green leaf membranes called thylakoids decreases hedonic hunger with up to 95 percent -- and increases weight loss with 43 percent, research concludes.

Aspinach extract containing green leaf membranes called thylakoids decreases hedonic hunger with up to 95% -- and increases weight loss with 43%. This has been shown in a recently published long-term human study at Lund University in Sweden.

Hedonic hunger is another term for the cravings many people experience for unhealthy foods such as sweets or fast food, a common cause of obesity and unhealthy eating habits. The study shows that taking thylakoids reinforces the body's production of satiety hormones and suppresses hedonic hunger, which leads to better appetite control, healthier eating habits and increased weight loss.

"Our analyses show that having a drink containing thylakoids before breakfast reduces cravings and keeps you feeling more satisfied all day," says Charlotte Erlanson-Albertsson, Professor of Medicine and Physiological Chemistry at Lund University.

The study involved 38 overweight women and ran for three months. Every morning before breakfast the participants had a green drink. Half of the women were given 5 grams of spinach extract and the other half, the control group, were given a placebo. The participants did not know which group they belonged to -- the only instructions they received were to eat a balanced diet including three meals a day and not to go on any other diet.

"In the study, the control group lost an average of 3.5 kg while the group that was given thylakoids lost 5 kg. The thylakoid group also found that it was easier to stick to three meals a day -- and they did not experience any cravings," said Charlotte Erlanson-Albertsson.

The key is the feeling of satiety and suppression of hedonic hunger, vs homeostatic hunger that deals with our basic energy needs. Modern processed food is broken down so quickly that the hormones in the intestines that send satiety signals to the brain and suppress cravings cannot keep up. The green leaf membranes slow down the digestion process, giving the intestinal hormones time to be released and communicate to the brain that we are satisfied.

"It is about making use of the time it takes to digest our food. There is nothing wrong with our digestive system, but it doesn't work well with the modern 'pre-chewed' food. The thylakoids extend digestion, producing a feeling of satiety. This means that we are able to stick to the diet we are meant for without snacks and unnecessary foods like sweets, crisps and such," says Charlotte Erlanson-Albertsson.

Understanding, improving body's fight against pathogens

Date:
September 2, 2014
Source:
A*Star Agency for Science, Technology and Research
Summary:
The crucial role of two signalling molecules, DOK3 and SHP1, in the development and production of plasma cells has been uncovered by researchers. These discoveries advance the understanding of plasma cells and the antibody response, and may lead to optimization of vaccine development and improved treatment for patients with autoimmune diseases such as lupus and tumors such as multiple myeloma.

Significant reductions in the number of plasma cells in the spleen and bone marrow were observed in the absence of DOK3. Each dot in the figure represents one plasma cell detected.

Scientists from A*STAR's Bioprocessing Technology Institute (BTI) have uncovered the crucial role of two signalling molecules, DOK3 and SHP1, in the development and production of plasma cells. These discoveries, published in two journals PNAS and Nature Communications, advance the understanding of plasma cells and the antibody response, and may lead to optimisation of vaccine development and improved treatment for patients with autoimmune diseases such as lupus and tumours such as multiple myeloma.

While they exist in small populations in humans, the large amounts of antibodies secreted by plasma cells make them key to the body's immune system and its ability to defend itself against pathogens, such as bacteria and viruses. Proper maintenance of a pool of plasma cells is also critical for the establishment of lifelong immunity elicited by vaccination.

Dysregulation of plasma cell production and maintenance could lead to autoimmune diseases and multiple myeloma. Autoimmune diseases occur when the immune system does not distinguish between healthy tissue and antigens, which are found in pathogens. This results in expansion of plasma cells which produce excessive amounts of antibodies leading to destruction of one's own healthy tissue. The discoveries by scientists in BTI's Immunology Group have improved understanding of the mechanism by which plasma cells are developed from a major class of white blood cells called B cells.

For the first time, the molecule DOK3 was found to play an important role in formation of plasma cells. While calcium signalling typically controls a wide range of cellular processes that allow cells to adapt to changing environments, it was found to inhibit the expression of the membrane proteins essential for plasma cell formation. These membrane proteins include PDL1 and PDL2, and represent some of the key targets for the development of immunotherapy by pharmaceutical companies. DOK3 was able to promote the production of plasma cells by reducing the effects of calcium signalling on these membrane proteins. The absence of DOK3 would thus result in defective plasma cell formation.

In another study, BTI scientists discovered the importance of SHP1 signalling to the long term survival of plasma cells. While the molecule SHP1 has a proven role in prevention of autoimmune diseases, it was found that the absence of SHP1 would result in the failure of plasma cells to migrate from the spleen where they are generated to the bone marrow, a survival niche where they are able to survive for much longer periods. This could result in a reduction of the body's immune response and thus, an increased susceptibility to infections and diseases. The scientists in this study also successfully rectified the defective immune response caused by an absence of SHP1 by applying antibody injections, which might advance the development of therapeutics. On the other hand, targeting SHP1 might be a strategy to treat multiple myeloma where the accumulation of cancerous plasma cells in the bone marrow survival niches is undesirable.

Findings hold potential for improved treatment

The discovery of these new targets for modulating the antibody response allows the development of novel therapeutic strategies for patients with autoimmune diseases and cancer.Understanding the mechanism that governs plasma cell differentiation is also critical for the optimal design of vaccines and adjuvants, which are added to vaccines to boost the body's immune response.

Prof Lam Kong Peng, Executive Director of BTI, said, "These findings allow better understanding of plasma cells and their role in the immune system. The identification of these targets not only paves the way for development of therapeutics for those with autoimmune diseases and multiple myeloma, but also impacts the development of immunological agents for combating infections."

Oil spills and marine snow: Changing microbial dynamics in the wake of the Macondo blowout

Date:

September 2, 2014

Source:

American Institute of Biological Sciences

Summary:

Following the oil spill caused by the blowout at the Macondo wellhead in 2010, Gulf of Mexico microbial population dynamics shifted rapidly as numbers of oil degraders quickly increased. In addition, the spill provided an opportunity to study the newly described phenomenon of microbe-derived marine snow.

In an article in the September issue of BioScience, Samantha Joye and colleagues describe Gulf of Mexico microbial communities in the aftermath of the 2010 Macondo blowout. The authors describe revealing population-level responses of hydrocarbon-degrading microbes to the unprecedented deepwater oil plume.

The spill provided a unique opportunity to study the responses of indigenous microbial communities to a substantial injection of hydrocarbons. Surveys of genetic identifiers within cells known as ribosomal RNA and analyses relying on modern techniques including metagenomics, metatranscriptomics, and other methods revealed quickly changing population sizes and community structures. The presence of oil-degrading microbes, which was determined through the use of ribosomal RNA signatures, was found even after the dissipation of the initial plume, which provides evidence that seed populations persist and may be maintained by natural oil seepage or small accidental leaks.

Perhaps one of the most striking features of the microbial response to the blowout was the rapid formation of large flocs of marine "snow." The flocs were initially observed in the upper water column and constituted the precursors to a massive pulse of oil-derived sediment that settled near the wellhead in the weeks following the accident. The rapid movement of oil to the seafloor in the form of microbe-induced marine snow represents a previously unrecognized outcome for marine hydrocarbons that may have far-reaching implications. The authors performed laboratory simulations of marine oil snow formation and identified several possible microbial mechanisms for the formation of the snow, including the creation of mucus webs through the action of bacterial oil degraders. As a result of their findings, Joye and her colleagues call for the inclusion of marine snow in the federal oil budget, which is intended to describe the fate of discharged oil.

The authors close with a call for additional research. Further study is needed both to increase the understanding of oil-degrading microbes and to quantify the rates at which they may degrade spilled oil.

Ancient metal workers were not slaves but highly regarded craftsmen

Date:

August 28, 2014

Source:

American Friends of Tel Aviv University

Summary:

In the course of ongoing excavations at Timna Valley, archaeologists analyzed remnants of food eaten by copper smelters 3,000 years ago. This analysis indicates that the laborers operating the furnaces were in fact skilled craftsmen who enjoyed high social status and adulation. They believe their discovery may have ramifications for similar sites across the region.

Iron Age copper smelters were respected leaders with sophisticated skills, say Tel Aviv University archaeologists.In 1934, merican archaeologist Nelson Glueck named one of the largest known copper production sites of the Levant "Slaves' Hill." This hilltop station, located deep in Israel's Arava Valley, seemed to bear all the marks of an Iron Age slave camp -- fiery furnaces, harsh desert conditions, and a massive barrier preventing escape. New evidence uncovered by Tel Aviv University archaeologists, however, overturns this entire narrative.

In the course of ongoing excavations at Timna Valley, Dr. Erez Ben-Yosef and Dr. Lidar Sapir-Hen of TAU's Department of Archaeology and Near Eastern Cultures analyzed remnants of food eaten by copper smelters 3,000 years ago. The result of this analysis, published in the journal Antiquity, indicates that the laborers operating the furnaces were in fact skilled craftsmen who enjoyed high social status and adulation. They believe their discovery may have ramifications for similar sites across the region.

"What we found represents a general trend or reality related to metal workers in antiquity," said Dr. Ben-Yosef. "They had a very unique role in society, and we can demonstrate this by looking at Timna."

Examining ancient leftovers

The rare arid conditions of Timna have resulted in unparalleled preservation of organic materials usually destroyed by the march of time: bones, seeds, fruits, and even fabric dating back to the 10th century B.C. Using a technique called "wet sieving," the archaeologists found miniscule animal and fish bones, evidence of a rich and diverse diet.

"The copper smelters were given the better cuts of meat -- the meatiest parts of the animals," said Dr. Sapir-Hen. "Someone took great care to give the people working in the furnaces the best of everything. They also enjoyed fish, which must have been brought from the Mediterranean hundreds of kilometers away. This was not the diet of slaves but of highly-regarded, maybe even worshipped, craftsmen."

Copper, used at the time to produce tools and weapons, was the most valuable resource in ancient societies. According to Dr. Ben-Yosef, the smelters needed to be well-versed in the sophisticated technology required to turn stone into usable copper. This knowledge was so advanced for the time it may have been considered magical or supernatural.

"Like oil today, copper was a source of great power," said Dr. Ben-Yosef. "If a person had the exceptional knowledge to 'create copper,' it is not surprising he would have been treated well. In comparing our findings to current ethnographic accounts from Africa, we see smelters worshipped and even honored with animal sacrifices."

Copper production is a complex operation requiring many levels of expertise. Ancient mine workers at Timna may have indeed been slaves or prisoners, because theirs was a simple task performed under severe conditions. However, the act of smelting, turning stone into metal, required an enormous amount of skill and leadership. The smelter had to build a furnace out of clay in precise dimensions, provide the right amount of oxygen and charcoal, maintain a 1,200 degree (Celsius) heat, connect bellow pipes, blow a fixed amount of air, and add an exact mixture of minerals. All told, the smelter had to manage some 30-40 variables in order to produce the coveted copper ingots.

Reconstructing social diversity

According to Dr. Sapir-Hen, an expert on early complex societies, the food remains reflect the social stratification of different laborers at the site. "By studying the remains of domesticated food animals, we reveal differential access to meat that may indicate different levels of specialization among workers at the same site. This allowed us to reconstruct social diversity at the site," said Dr. Sapir-Hen.

The remains of the wall found at the Timna site, once considered a barrier used to contain slave laborers, apparently played a different role as well. "We now know it was a wall used to defend the sophisticated technology and its most precious product -- the ingot, the result of the complex copper smelting process," said Dr. Ben-Yosef.

Flapping baby birds give clues to origin of flight

Date:

August 28, 2014

Source:

University of California - Berkeley

Summary:

The origin of flight is a contentious issue: some argue that tree-climbing dinosaurs learned to fly in order to avoid hard falls. Others favor the story that theropod dinosaurs ran along the ground and pumped their forelimbs to gain lift, eventually talking off. New evidence showing the early development of aerial righting in birds favors the tree-dweller hypothesis.

How did the earliest birds take wing? Did they fall from trees and learn to flap their forelimbs to avoid crashing? Or did they run along the ground and pump their "arms" to get aloft?

The answer is buried 150 million years in the past, but a new University of California, Berkeley, study provides a new piece of evidence -- birds have an innate ability to maneuver in midair, a talent that could have helped their ancestors learn to fly rather than fall from a perch.
The study looked at how baby birds, in this case chukar partridges, pheasant-like game birds from Eurasia, react when they fall upside down.
The researchers, Dennis Evangelista, now a postdoctoral researcher at the University of North Carolina, Chapel Hill, and Robert Dudley, UC Berkeley professor of integrative biology, found that even ungainly, day-old baby birds successfully use their flapping wings to right themselves when they fall from a nest, a skill that improves with age until they become coordinated and graceful flyers.
"From day one, post-hatching, 25 percent of these birds can basically roll in midair and land on their feet when you drop them," said Dudley, who also is affiliated with the Smithsonian Tropical Research Institute in Balboa, Panama. "This suggests that even rudimentary wings can serve a very useful aerodynamic purpose."
Flapping and rolling
The nestlings right themselves by pumping their wings asymmetrically to flip or roll. By nine days after hatching, 100 percent of the birds in the study had developed coordinated or symmetric flapping, plus body pitch control to right themselves.
"These abilities develop very quickly after hatching, and occur before other previously described uses of the wings, such as for weight support during wing-assisted incline running," said Evangelista, who emphasized that no chukar chicks were injured in the process. "The results highlight the importance of maneuvering and control in development and evolution of flight in birds."
The researchers' study appeared Aug. 27 in the online journal Biology Letters, published by the Royal Society.
Dudley has argued for a decade that midair maneuverability preceded the development of flapping flight and allowed the ancestors of today's birds to effectively use their forelimbs as rudimentary wings. The new study shows that aerial righting using uncoordinated, asymmetric wing flapping is a very early development.
Righting behavior probably evolved because "nobody wants to be upside down, and it's particularly dangerous if you're falling in midair," Dudley said. "But once animals without wings have this innate aerial righting behavior, when wings came along it became easier, quicker and more efficient."
Dudley noted that some scientists hypothesize that true powered flight originated in the theropod dinosaurs, the ancestors to birds, when they used symmetric wing flapping while running up an incline, a behavior known as wing-assisted incline running, or WAIR. WAIR proponents argue that the wings assist running by providing lift, like the spoiler on a race car, and that the ability to steer or maneuver is absent early in evolution.
Falling, gliding and flying
Such activity has never been regularly observed in nature, however, and Dudley favors the scenario that flight developed in tree-dwelling animals falling and eventually evolving the ability to glide and fly. He has documented many ways that animals in the wild, from lizards and lemurs to ants, use various parts of their bodies to avoid hard landings on the ground. Practically every animal that has been tested is able to turn upright, and a great many, even ones that do not look like fliers, have some ability to steer or maneuver in the air.
Contrary to WAIR, maneuvering is very important at all stages of flight evolution and must have been present early, Evangelista said. Seeing it develop first in very young chicks indirectly supports this idea.
"Symmetric flapping while running is certainly one possible context in which rudimentary wings could have been used, but it kicks in rather late in development relative to asymmetric flapping," Dudley added. "This experiment illustrates that there is a much broader range of aerodynamic capacity available for animals with these tiny, tiny wings than has been previously realized."
The researchers also tested the young chicks to see if they flapped their wings while running up an incline. None did.

Plant life forms in the fossil record: When did the first canopy flowers appear?

Date:
September 1, 2014
Source:
Geological Society of America
Summary:
Most plant fossils are isolated organs, making it difficult to reconstruct the type of plant life or its ecosystem structure. Botanists have now used leaf vein density, a trait visible on leaf compression fossils, to document the occurrence of stratified forests with a canopy dominated by flowering plants.

Most plant fossils are isolated organs, making it difficult to reconstruct the type of plant life or its ecosystem structure. In their study forGeology, published online on 28 Aug. 2014, researchers Camilla Crifò and colleagues used leaf vein density, a trait visible on leaf compression fossils, to document the occurrence of stratified forests with a canopy dominated by flowering plants.

Using a 40-meter-tall canopy crane equipped with a gondola, they were able to collect leaves from the very top of trees in Panama and the United States. They measured leaf vein density in 132 species from two Panamanian tropical forests and one temperate forest in Maryland (USA). The team also compared the leaf vein values of canopy-top and forest-bottom leaves (i.e., leaf litter on the forest floor).

The authors show that venation density, like plant metabolism (i.e., transpiration and photosynthesis), is higher in the leaves located in the forest canopy and decreases in leaves at lower levels. Furthermore, they found that leaves from the forest floor, which are the closest analog to fossil floras, preserve this pattern.

The team also reanalyzed vein density data from the literature from the Early Cretaceous (132.5 million years ago) to the Paleocene (58 million years ago) to determine when flowering plants became part of the upper forest canopy. Vein density values similar to present ones appeared about 58 million years ago, indicating that the emergence of flowering plants in the canopy occurred by the Paleocene.

From silk tunics to relics: Development of early relic worship

Date:

September 2, 2014

Source:

Universität Bonn

Summary:

Archaeologists working with restorers are preserving and studying 4th-century tunics ascribed to St. Ambrose. In the course of examining these valuable silk garments, they have made surprising scholarly discoveries regarding the development of early relic worship.

In Milan’s Basilica of Sant’Ambrogio: Prof. Dr. Sabine Schrenk (r.) of the University of Bonn and Cologne textile restorer Ulrike Reichert with the valuable tunics.

Archaeologist from the University of Bonn, working with restorers, are preserving and studying 4th-century tunics ascribed to St. Ambrose. In the course of examining these valuable silk garments, they have made surprising scholarly discoveries regarding the development of early relic worship. In a few days they will return to Milan with a mobile lab to continue the project at the Basilica of Sant'Ambrogio.

Saint Ambrose is the patron saint of grocers, beekeepers, and gingerbread bakers. He is also the patron saint of study, which explains why his attributes include the book and the flagellum, in addition to the beehive. What is more, Ambrose (339-397) is also the patron saint of Milan, where his bones rest in the Basilica that bears his name, Sant'Ambrogio. Born in Trier, Germany, he began his career as a politician, becoming elected, in 374, the influential Bishop of the emperor's residenceof Milan. He enacted relic worship, and would become frequently quoted in the catechism. The Ambrosian chants are associated with him, and he is honored as a Doctor of the Church. Surprisingly though, the tunics at Sant'Ambrogio, which are associated with the saint and worshipped as relics, are little known.

"These are marvelously beautiful vestments of sumptuous silk that have been ascribed to the saint," says Professor Dr. Sabine Schrenk of the department of Christian Archaeology at the University of Bonn. One of them has intricate depictions of hunting scenes with trees and leopards, while the other valuable textile is keptrather simple. There is yet no conclusive proof that these tunics date to the late 4th century, though they certainly cannot be dated very much later. Hence they are very significant testimony for the Late Antique and Early Christian periods.

In the course of many centuries, time took its toll on these famous textiles. "If these fragile silk threads are to be preserved for a long time to come, it is critical to remove harmful layers of dust," says Cologne textile restorer Ulrike Reichert, who has headed her own restoration workshop in the Dellbrück neighborhood for many years, specializing in preserving early silk textiles. The cloth is painstakingly cleaned with a tiny vacuum cleaner and delicate brushes. "For this we have had to carefully free the material from the protective glass that had been laid over it," says Professor Schrenk's colleague Katharina Neuser. Rescue Project:

The Mobile Lab

Professor Schrenk and the team of restorers have taken their mobile lab to Milan several times in the last two years, with support from the Gielen-Leyendecker Foundation, to learn more about the origin and history of these textiles beyond the restoration works. "These pieces were revered as the tunics of St. Ambrose probably by the 11th century," says Professor Schrenk. Aribert, the Archbishop of Milan, arranged for the placement of a textile band on the site where the tunics were kept. "It's a kind of woven museum label indicating the significance of the relics," says the Bonn scholar. Presumably, however, a red cross had already been sewn onto one of the vestments much earlier, as an indicator of their significance for the Church.

These tunics have been kept and exhibited in various ways over the centuries. For a while they were stored packed in a chest, sandwich-like, between two other layers of fabric. Until the Second World War, the relics were kept in a frame mounted to an altar in the Basilica of Sant'Ambrogio; they then got new glass frames in the Basilica's museum, where they remained until a few years ago. To protect them from the light they were then placed in storage drawers. "The pressure of heavy glass plates only aggravated the effect of many centuries of deterioration," says Professor Schrenk. So the decision to have these valuable silks restored was made.

While the project's researchers and restorers have already made tremendous progress, they will still have their hands full in the coming years. "Based on the textiles, the Ambrose project reveals the evolution of early relic worship in a surprising way," says Professor Schrenk. The project will also shed new light on the economic history of Late Antiquity. It is well known that silk was not yet produced in 4th-century Europe and Asia Minor; the expensive thread was imported from China. However, Professor Schrenk is skeptical about the scholarly consensus that all silks of the time were woven in the eastern Mediterranean, primarily in Syria. "Milan at the time, being the emperor's residence, had access to ample patronage, and used silk in grand fashion. I would be very surprised if there had not been silk workshops there at the time," says the archaeologist.

Exceptionally well preserved insect fossils from the Rhône Valley found

Date:

September 2, 2014

Source:

PeerJ

Summary:

In Bavaria, the Tithonian Konservat-Lagerstätte of lithographic limestone is well known as a result of numerous discoveries of emblematic fossils from that area (for example, Archaeopteryx). Now, for the first time, researchers have found fossil insects in the French equivalent of these outcrops -- discoveries which include a new species representing the oldest known water treader.

Despite the abundance of fossils in the equivalent Bavarian outcrops, fewer fossils have been obtained from the Late Kimmeridgian equivalents of these rocks in the departments of Ain and Rhône in France. Many outcrops are recorded (for example Cerin and Orbagnoux), but the fauna found there is essentially of marine origin, being made up of crustaceans and fishes. Some layers have provided dinosaur footprints, but until today's announcement the only known terrestrial organisms were plant remains transported into the ancient lagoons.

During the course of two field expeditions in 2012 and 2013 French researchers working with the help of two active teams of amateur scientists (Société des Naturalistes et Archéologues de l'Ain and the Group 'Sympetrum Recherche et Protection des Libellules') discovered the first insects from the Orbagnoux outcrop, together with traces of activities of these organisms on leaves and in the sediment.

The newly discovered insect was described today, in the open access journal PeerJ. The bug was 6 mm long and is the oldest record of the aquatic bug lineage of the Gerromorpha which comprises the water striders and the water measurers. This is the oldest known water treader (Mesoveliidae), the sister group of all other gerromorphan lineages. In a similar manner to some of its recent relatives, this aquatic bug could have lived in brackish environments.

In addition, traces of insect activity on plants were found, comprising surface feeding traces on Zamites leaves. Such traces are quite rare in the fossil record and in this situation they demonstrate the presence of strictly terrestrial insects on the emerged lands that were surrounded by these Jurassic lagoons.

The exquisite quality of preservation of the fossils suggests that these rocks are likely to provide new fossil insects of crucial importance for the knowledge of the Upper Jurassic insect fauna, an important transition period in the evolution of the terrestrial environments towards the Lower Cretaceous diversification of the flowering plants.

Modern population boom traced to pre-industrial roots

Date:

September 2, 2014

Source:

Emory Health Sciences

Summary:

The foundation of the human population explosion, commonly attributed to a sudden surge in industrialization and public health during the 18th and 19th centuries, was actually laid as far back as 2,000 years ago, suggests an extended model of detailed demographic and archeological data.

Image Modern population boom traced to pre-industrial roots

Ancient Colosseum in Rome (stock image). By the end of the Roman Empire, humanity had crossed a critical threshold of social organization that allowed more people to take advantage of economies of scale, says anthropologist Aaron Stutz.

The Public Library of Science One (PLOS ONE)recently published the analytical framework developed by Aaron Stutz, an associate professor of anthropology at Emory's Oxford College.

"The industrial revolution and public health improvements were proximate reasons that more people lived longer," Stutz says. "If you dig further in the past, however, the data suggest that a critical threshold of political and economic organization set the stage 1,500 to 2,000 years ago, around the start of the Common Era. The resulting political-economic balance was the tipping point for economies of scale: It created a range of opportunities enabling more people to get resources, form successful families, and generate enough capital to transfer to the next generation."

Population dynamics have been a hot topic since 1798, when English scholar Thomas Robert Malthus published his controversial essay that population booms in times of plenty will inevitably be checked by famine and disease. "The power of population is indefinitely greater than the power in Earth to produce subsistence for man," he wrote. The so-called Malthusian Catastrophe theory was penned just prior to the global census size reaching one billion.

While it took hundreds of thousands of years for humans to reach that one billion milestone, it took only another 120 years for humanity to double to two billion. And during the past 50 years, the human population has surged to near eight billion.

"It's mind-boggling," Stutz says. "The human population has not behaved like any other animal population. We haven't stayed in any kind of equilibrium with what we would consider a typical ecological niche."

Economic historians and demographers have focused on societal changes that occurred during the Industrial Revolution as the explanation for this super-exponential population growth. An archeologist by training, Stutz wanted to explore further back in time.

"Archeologists are interested in looking at much earlier changes in human society," Stutz says. "In addition to looking at data, we dig up things like people's houses, community courtyards, agricultural fields, harbors and so on. That gives us this sort of holistic view of how human society and the environment influence one another over time."

His analysis found that that the potential for the human population to burgeon despite environmental degradation, conflict and disease could be traced to a subtle interaction between competition and organization. At a certain tipping point, this interaction created opportunities for individuals to gain more control over their lives and prosper, opening the door to economies of scale.

Stutz cites the Roman Empire, which spanned 500 years, from just before the Common Era to 476 CE, as a classic example of passing through this threshold. One of the largest and most prosperous empires in history, it is noteworthy for economic and political organization, literature, and advances in architecture and engineering. And yet, on an individual level, life was not necessarily so grand. Farm laborers and miners were ground into short, miserable lives to produce all those surplus goods for trading and empire building. And large numbers of young males had to serve in the military to ward off rebellions.

"The vast majority of people who lived under Roman rule had a life expectancy into their late 20s or early 30s," Stutz says. "A huge swath of the population was feeding, quite literally, the dynamism that was taking place in terms of economic and political development. Their labor increased the potential for providing more democracy and competition on the smaller scale. That, in turn, led to a more complex, inter-generational dynamic, making it possible to better care for offspring and even transfer resources to them."

The tipping point had been reached, Stutz says, and the trend continued despite the collapse of the Roman Empire. "The increasingly complex and decentralized economic and political entities that were built up around the world from the beginning of the Common Era to 1500 CE created enough opportunities for individuals, states and massive powers like England, France and China to take advantage of the potential for economies of scale," Stutz says.

This revised framework for the underpinnings of human population dynamics could lead to better understanding of how economic and political organization is affecting modern-day society, he adds.

"We might wind up being back in a situation where a growing part of the population is basically providing labor to sustain a minority," Stutz says. "You could certainly point to the sweat shops in the developing world. Another potential example is the growing income inequality that's been well-documented in the United States over the last couple of decades."

Cockatoos go to carpentry school

Date:

September 2, 2014

Source:

University of Oxford

Summary:

Goffin's cockatoos can learn how to make and use wooden tools from each other, a new study has found. The discovery is thought to be the first controlled experimental evidence for the social transmission of tool use in any bird species.

Cockatoos can learn how to make tools from each other, scientists from Oxford University, the University of Vienna, and the Max Planck Institute at Seewiesen, have found. Image: after watching another bird demonstrate Kiwi manufactures a tool.

Goffin's cockatoos can learn how to make and use wooden tools from each other, a new study has found.

The discovery, made by scientists from Oxford University, the University of Vienna, and the Max Planck Institute at Seewiesen, is thought to be the first controlled experimental evidence for the social transmission of tool use in any bird species.

Goffin's cockatoo (Cacatua goffini) is a curious species of Indonesian parrot not known to use tools in the wild. At a laboratory in Austria the researchers had observed a captive adult male Goffin's cockatoo named 'Figaro' spontaneously start to sculpt stick tools out of wooden aviary beams to use them for raking in nuts out of his reach. To investigate if such individual invention could be passed on to other cockatoos the team used Figaro as a 'role model', exposing other birds to tool use demonstrations, some with Figaro as 'teacher' and others without his 'students' seeing him at work.

In the experiments one cockatoo group was allowed to observe Figaro skilfully employing a ready-made stick tool, while another could see what researchers called 'ghost demonstrations' -- either seeing the tools displacing the nuts by themselves, while being controlled by magnets hidden under a table, or seeing the nuts moving towards Figaro without his intervention, again using magnets to displace the food. The birds were all then placed in front of an identical problem, with a ready-made tool lying on the ground nearby.

Three males and three females that saw Figaro's complete demonstration interacted much more with potential tools and other components of the problem than those seeing ghost demos. They picked up sticks more than the ghost demo control groups and generally seemed more interested in achieving the result. Remarkably, all three males in this group acquired proficient tool use, while neither the females in the same group nor males and females in the ghost demo groups did.

A report of the research is published in the journal Proceedings of the Royal Society B.

'This is the first controlled evidence for the social transmission of an original tool use event in any bird so far,' says Stefan Weber, a student from the University of Vienna, who was involved in the data collection.

The successful birds did not just imitate Figaro's movements: their tool-use techniques were themselves new. Figaro held tools by their tips, inserted them through the cage grid at different heights and raked the nuts towards him while adjusting the tool's position as the target moved closer. The successful observers, instead, laid the sticks on the ground and propelled the nuts into their reach by a quick ballistic flipping movement. The latter technique was arguably more efficient for the test circumstances, which differed from those in which Figaro had made his first discovery; the pupils in this sense surpassed the teacher's performance.

'This means that although watching Figaro was necessary for their success they did not imitate his exact motor activities. Successful observers seemed to attend to the result of Figaro's interaction with the tool but developed their own strategies for reaching the same result, rather than copying his actions. This is typical of what psychologists would call emulation learning,' explains Dr Alice Auersperg who led the study at the Goffin Lab at the University of Vienna.

'The importance of them needing an active live demonstrator is that they seem to be sensitive to 'agency' -- the existence of a subject whose goal they share. This can act through paying more attention to the task, or some more demanding process such as empathising with the actor, but this is not known yet,' said co-author Professor Alex Kacelnik from Oxford University's Department of Zoology.

Two of the successful observers were later tested in the absence of ready-made tools, but offering them suitable tool-making material. One of them spontaneously started to make his own tools out of a wooden block, while the other initially failed, but then did so after a single demonstration session watching Figaro carve tools out of a block. Whilst inconclusive, this shows that learning to use tools may in itself stimulate the acquisition of tool-making, which is more distant from the target behaviour and closer to behavioural planning.

Professor Alex Kacelnik of Oxford University said: 'There is a substantial difference between repeating a teacher's behaviour and emulating his or her achievements while creating one's own methods. The latter implies a creative process stimulated by a social interaction, while the former could, at least potentially, rely on simpler imitation. The cockatoos seem to emulate and surpass their teacher, which is what all good professors hope for from their best students.'

Extinctions during human era one thousand times more than before

Date:

September 2, 2014

Source:

Brown University

Summary:

The gravity of the world's current extinction rate becomes clearer upon knowing what it was before people came along. A new estimate finds that species die off as much as 1,000 times more frequently nowadays than they used to. That's 10 times worse than the old estimate of 100 times.

The gravity of the world's current extinction rate becomes clearer upon knowing what it was before people came along. A new estimate finds that species die off as much as 1,000 times more frequently nowadays than they used to. That's 10 times worse than the old estimate of 100 times.

It's hard to comprehend how bad the current rate of species extinction around the world has become without knowing what it was before people came along. The newest estimate is that the pre-human rate was 10 times lower than scientists had thought, which means that the current level is 10 times worse.

Extinctions are about 1,000 times more frequent now than in the 60 million years before people came along. The explanation from lead author Jurriaan de Vos, a Brown University postdoctoral researcher, senior author Stuart Pimm, a Duke University professor, and their team appears online in the journalConservation Biology.

"This reinforces the urgency to conserve what is left and to try to reduce our impacts," said de Vos, who began the work while at the University of Zurich. "It was very, very different before humans entered the scene."

In absolute, albeit rough, terms the paper calculates a "normal background rate" of extinction of 0.1 extinctions per million species per year. That revises the figure of 1 extinction per million species per year that Pimm estimated in prior work in the 1990s. By contrast, the current extinction rate is more on the order of 100 extinctions per million species per year.

Orders of magnitude, rather than precise numbers are about the best any method can do for a global extinction rate, de Vos said. "That's just being honest about the uncertainty there is in these type of analyses."

From fossils to genetics

The new estimate improves markedly on prior ones mostly because it goes beyond the fossil record. Fossils are helpful sources of information, but their shortcomings include disproportionate representation of hard-bodied sea animals and the problem that they often only allow identification of the animal or plant's genus, but not its exact species.

What the fossils do show clearly is that apart from a few cataclysms over geological periods -- such as the one that eliminated the dinosaurs -- biodiversity has slowly increased.

The new study next examined evidence from the evolutionary family trees -- phylogenies -- of numerous plant and animal species. Phylogenies, constructed by studying DNA, trace how groups of species have changed over time, adding new genetic lineages and losing unsuccessful ones. They provide rich details of how species have diversified over time.

"The diversification rate is the speciation rate minus the extinction rate," said co-author Lucas Joppa, a scientist at Microsoft Research in Redmond, Wash. "The total number of species on earth has not been declining in recent geological history. It is either constant or increasing. Therefore, the average rate at which groups grew in their numbers of species must have been similar to or higher than the rate at which other groups lost species through extinction."

The work compiled scores of studies of molecular phylogenies on how fast species diversified.

For a third approach, de Vos noted that the exponential climb of species diversity should take a steeper upward turn in the current era because the newest species haven't gone extinct yet.

"It's rather like your bank account on the day you get paid," he said. "It gets a burst of funds -- akin to new species -- that will quickly become extinct as you pay your bills."

By comparing that rise of the number of species from the as-yet unchecked speciation rate with the historical trend (it was "log-linear") evident in the phylogenies, he could therefore create a predictive model of what the counteracting historical extinction rate must have been.

The researchers honed their models by testing them with simulated data for which they knew an actual extinction rate. The final models yielded accurate results. They tested the models to see how they performed when certain key assumptions were wrong and on average the models remained correct (in the aggregate, if not always for every species group).

All three data approaches together yielded a normal background extinction rate squarely in the order of 0.1 extinctions per million species per year.

A human role

There is little doubt among the scientists that humans are not merely witnesses to the current elevated extinction rate. This paper follows a recent one in Science, authored by Pimm, Joppa, and other colleagues, that tracks where species are threatened or confined to small ranges around the globe. In most cases, the main cause of extinctions is human population growth and per capita consumption, although the paper also notes how humans have been able to promote conservation.

The new study, Pimm said, emphasizes that the current extinction rate is a more severe crisis than previously understood.

"We've known for 20 years that current rates of species extinctions are exceptionally high," said Pimm, president of the conservation nonprofit organization SavingSpecies. "This new study comes up with a better estimate of the normal background rate -- how fast species would go extinct were it not for human actions. It's lower than we thought, meaning that the current extinction crisis is much worse by comparison."

Other authors on the paper are John Gittleman and Patrick Stephens of the University of Georgia.