Over the last 1000 years, temperature differences between the Northern and Southern Hemispheres were larger than previously thought. Using new data from the Southern Hemisphere, researchers have shown that climate model simulations overestimate the links between the climate variations across Earth with implications for regional predictions.These findings are demonstrated in a new international study coordinated by Raphael Neukom from the Oeschger Centre of the University of Bern and the Swiss Federal Research Institute WSL and are published today in the journal Nature Climate Change.The Southern Hemisphere is a challenging place for climate scientists. Its vast oceans, Antarctic ice, and deserts make it particularly difficult to collect information about present climate and, even more so, about past climate. However, multi-centennial reconstructions of past climate from so-called proxy archives such as tree-rings, lake sediments, corals, and ice-cores are required to understand the mechanisms of the climate system. Until now, these long-term estimates were almost entirely based on data from the Northern Hemisphere.Over the past few years, an international research team has made a coordinated effort to develop and analyse new records that provide clues about climate variation across the Southern Hemisphere. Climate scientists from Australia, Antarctic-experts, as well as data specialists and climate modellers from South and North America and Europe participated in the project. They compiled climate data from over 300 different locations and applied a range of methods to estimate Southern Hemisphere temperatures over the past 1000 years. In 99.7 percent of the results, the warmest decade of the millennium occurs after 1970.Surprisingly, only twice over the entire last millennium have both hemispheres simultaneously shown extreme temperatures. One of these occasions was a global cold period in the 17th century; the other one was the current warming phase, with uninterrupted global warm extremes since the 1970s. “The ‘Medieval Warm Period’, as identified in some European chronicles, was a regional phenomenon,” says Raphael Neukom. …Read more
Yesterday morning we were up early 4.30am and left home with the car packed at 5.30am – headed to Port Melbourne where the beautiful car ferry Spirit Of Tasmania was docked. We arrived there at 6.30am and got in the line of waiting cars and caravans to load onto the ferry once we were all cleared through customs. We eventually parked our car on the ferry at 8am and set sail by 9am. A good calm crossing arriving in Devonport Tasmania around 6.15pm. While on the ferry we had an ocean recliner at the back of the ship and were able to rest there, have a cuppa, read the newspaper and look out to sea and enjoy the views of passing thru the heads about an hr out …Read more
Oct. 10, 2013 — How can biodiversity be preserved in a world in which traditional ecosystems are increasingly being displaced by “human-made nature”? Biologists at the TU Darmstadt and ETH Zurich have developed a new concept for conservation measures that incorporates current landscapes formerly considered ecologically “of little value.” Numerous experiences from islands have shown that this concept has a positive effect on biodiversity. Now the authors are proposing applying these lessons learned to other landscapes.In a human-dominated world that contains only little “historical” nature, the term ecosystem can no longer be a synonym for unspoilt nature. The term “novel ecosystems” was coined a few years ago to describe disturbed ecosystems in which biodiversity has been significantly altered as the result of human intervention. “In our new conservation framework we argue that this strict distinction between historic and novel ecosystems should be reconsidered to aid conservation,” pollination biologist Dr. Christopher Kaiser-Bunbury describes the approach, which is not without controversy.On continents with vast natural parks, such as the USA and Africa, critics fear that the new concept could weaken the protection of historic nature by, for instance, redirecting financial resources towards more active intervention and design of ecosystems. The team of Darmstadt and Zurich biologists, however, propagates a reconciling approach. “Our framework combines strategies that were, until now, considered incompatible. Not only historic wildlands are worth protecting, but also designed cultural landscapes. …Read more
Sep. 2, 2013 — The HI virus is feared, not least, because of its great adaptability. If the virus mutates at precisely the point targeted by a drug, it is able to neutralise the attack and the treatment fails. To minimise these viral defence mechanisms, doctors treat patients with modern combination therapies involving the simultaneous administration of several drugs. This approach forces the virus to run through a series of mutations before it becomes immune to the drugs.Share This:Sequential nature of mutations”It is not easy to decide which of the over 30 combination therapies is best suited to a patient,” says Huldrych Günthard from Zurich University Hospital, president of the Swiss HIV Cohort Study. The decision is based on the prospects of success and therefore on the genetic make-up of a particular virus. The established prediction models already consider the genetics of the virus but they neglect that the virus continuously evolves through sequential mutations.Choosing the right therapy for each patientIn cooperation with the Swiss HIV Cohort Study, Niko Beerenwinkel and his team from ETH Zurich have now developed a more accurate prediction model based on a probabilistic method. This model calculates the possible evolutionary paths of the virus and yields a new predictive measure for the development of resistances: the so-called individualised genetic barrier. When applied retrospectively to 2185 patients of the HIV Cohort, the new approach made it possible to predict treatment success more accurately compared to the existing models. “We are now introducing the individualised genetic barrier in a pilot project and hope that it will help us in the future to identify the best therapy for each patient,” says Günthard.The Swiss HIV Cohort StudyEstablished in 1988, the Cohort Study aims to generate knowledge about HIV infection and AIDS as well as to improve the care given to patients. …Read more
Aug. 19, 2013 — Reservoirs of silica-rich magma — the kind that causes the most explosive volcanic eruptions — can persist in Earth’s upper crust for hundreds of thousands of years without triggering an eruption, according to new University of Washington modeling research.That means an area known to have experienced a massive volcanic eruption in the past, such as Yellowstone National Park, could have a large pool of magma festering beneath it and still not be close to going off as it did 600,000 years ago.”You might expect to see a stewing magma chamber for a long period of time and it doesn’t necessarily mean an eruption is imminent,” said Sarah Gelman, a UW doctoral student in Earth and space sciences.Recent research models have suggested that reservoirs of silica-rich magma, or molten rock, form on and survive for geologically short time scales — in the tens of thousands of years — in the Earth’s cold upper crust before they solidify. They also suggested that the magma had to be injected into the Earth’s crust at a high rate to reach a large enough volume and pressure to cause an eruption.But Gelman and her collaborators took the models further, incorporating changes in the crystallization behavior of silica-rich magma in the upper crust and temperature-dependent heat conductivity. They found that the magma could accumulate more slowly and remain molten for a much longer period than the models previously suggested.Gelman is the lead author of a paper explaining the research published in the July edition of Geology. Co-authors are Francisco Gutiérrez, a former UW doctoral student now with Universidad de Chile in Santiago, and Olivier Bachmann, a former UW faculty member now with the Swiss Federal Institute of Technology in Zurich.There are two different kinds of magma and their relationship to one another is unclear. Plutonic magma freezes in the Earth’s crust and never erupts, but rather becomes a craggy granite formation like those commonly seen in Yosemite National Park. Volcanic magma is associated with eruptions, whether continuous “oozing” types of eruption such as Hawaii’s Kilauea Volcano or more explosive eruptions such as Mount Pinatubo in the Philippines or Mount St. Helens in Washington state.Some scientists have suggested that plutonic formations are what remain in the crust after major eruptions eject volcanic material. Gelman believes it is possible that magma chambers in the Earth’s crust could consist of a core of partially molten material feeding volcanoes surrounded by more crystalline regions that ultimately turn into plutonic rock. It is also possible the two rock types develop independently, but those questions remain to be answered, she said.The new work suggests that molten magma reservoirs in the crust can persist for far longer than some scientists believe. …Read more
Aug. 13, 2013 — Swiss researchers report an increase risk of inflammatory bowel disease (IBD) relapse in patients during heat wave periods. The study published in The American Journal of Gastroenterology also found an increase of infectious gastroenteritis during heat waves, with the strongest impact following a 7 day lag time after the heat wave.Share This:The authors noted, “There is evidence for an increase of IBD hospital admissions by 4-6 percent for each additional day within a heat wave period. Presence of a heat wave was estimated to increase the risk of infectious gastroenteritis by 4-7 percent for every additional day within a heat way period. In the control group there was no evidence for a heat wave effect.”Researchers from Zurich, Switzerland studied the data of 738 IBD and 786 IG patients admitted to the University Hospital of Zurich over a 5-year period (2001-2005) and compared data with other non-infectious chronic intestinal inflammations, as the control. The Swiss Federal Office for Meteorology and Climatology provided the climate data. A total of 17 heat waves were identified during that period.”The evidence of patients with IBD having a significant increase risk of flare ups compared to the control group shows a cause and effect between the climate and the disease,” said lead author Christine N. Manser, MD. “This study ties heat stress to digestive symptoms supporting the observed seasonal variation in the clinical course of inflammatory bowel disease and suggests that microbial infections of the gut might be additionally influenced by climate changes.”Some people with IBD may experience flare ups during significant weather changes. “Heat waves are known to cause physical stress as evident from increased frequencies of other stress dependent health events such as heart attacks. …Read more
Aug. 8, 2013 — A little-studied factor known as the Little Elongation Complex (LEC) plays a critical and previously unknown role in the transcription of small nuclear RNAs (snRNA), according to a new study led by scientists at the Stowers Institute for Medical Research and published in the Aug. 22, 2013, issue of the journal Molecular Cell.”We have found that LEC not only has a role in this process — it is like the “Swiss Army knife” of snRNA transcription,” says Stowers Investigator Ali Shilatifard, senior author of the study. “LEC does it all.” The findings shed new light on the mystery of snRNA transcription, which is vitally important to gene expression and regulation but has been poorly understood until now.”As biologists we are very much interested in defining the molecular machineries involved in life, and snRNA are very important in life,” Shilatifard says. “DNA is a suitcase with all this information in it, and you need specific machinery to identify the right information to perform the exact process that’s needed. Now we understand another piece of that machinery.”Understanding LEC and the machinery of snRNA transcription may also have implications for the treatment of disease. It could, for example, open the door to novel approaches for treating diseases that are associated with defective snRNA function and splicing, such as spinal muscular atrophy and Prader-Willi syndrome, or attacking cancer cells, whose proteins may also undergo splicing. But first, more mysteries must be solved, Shilatifard says.Shilatifard and his colleagues have spent decades studying the factors that facilitate transcription, the process by which information encoded in DNA is converted into various forms of RNA, including messenger RNA, which carries protein-making instructions, and snRNAs, which partner with proteins to form small nuclear ribonucleoproteins (snRNPs). In particular, they have focused their work on a family of factors called ELL (for “Eleven-nineteen lysine-rich leukemia gene”), which speed up the rate at which genes are expressed to help the transcription process along. In a recent study in fruit flies, Edwin Smith, Ph.D., a research scientist in Shilatifard’s lab, identified the Little Elongation Complex as a complex that contains ELL. …Read more
June 19, 2013 — Many proteins work like Swiss Army knives, fitting multiple functions into their elaborately folded structures. A bit mysteriously, some proteins manage to multitask even with structures that are unfolded and floppy — “intrinsically disordered.” In this week’s issue of Nature, scientists at The Scripps Research Institute (TSRI) report their discovery of an important trick that a well-known intrinsically disordered protein (IDP) uses to expand and control its functionality.”We’ve found what is probably a general mechanism by which IDPs modulate their activities,” said TSRI Professor Peter E. Wright, who is Cecil H. and Ida M. Green Investigator in Biomedical Research and member of TSRI’s Skaggs Institute for Chemical Biology. Wright was a senior investigator for the study, along with TSRI Associate Professor Ashok A. Deniz.The study focused on an IDP known as the adenovirus “early region 1A oncoprotein” (E1A). An adenovirus starts producing copies of E1A shortly after it infects a cell. E1A proteins interact with a variety of key cellular molecules to quickly subvert the cell’s replication machinery for the benefit of the virus.Links to DiseaseE1A is worth studying not just because it facilitates adenovirus infections, but also because it’s a prime example of an IDP. Such proteins frequently play outsized roles in cells, as crucial “molecular hubs” within very large protein-interaction networks. …Read more
June 12, 2013 — The consequences of high blood pressure are one of the most common causes of death worldwide. Despite this, according to the World Health Organization WHO, fewer than one in two of those affected measures their blood pressure regularly. The main reason for this is that regular measurements are costly or inconvenient. An innovative wrist sensor should now change that.Measuring and monitoring blood pressure is a tedious business for patients. It usually involves a cuff which is activated every 15 minutes over several hours and compresses the upper arm, a cumbersome measuring device on the body, or in some cases even invasive monitoring, in which a catheter is inserted into the artery. It is no wonder that those affected avoid this procedure if at all possible.A new sensor hardly bigger than a wristwatch should soon offer a more pleasant method for measuring blood pressure. The company STBL Medical Research AG (STBL) has developed a device that can be worn comfortably on the wrist and records the blood pressure continuously — with no pressure cuff or invasive procedure. The measurement is carried out by several sensors which simultaneously measure the contact pressure, pulse and blood flow on the surface of the skin in the vicinity of the wrist. Michael Tschudin, co-founder of STBL, sees great potential for the device: “This measuring device can be used for medical purposes, for example as a precaution for high-risk patients or for treating high blood pressure, but also as a blood pressure and heart rate monitor for leisure activities and sports as well as for monitoring fitness in high-level sports.”Empa sensor greatly increases measuring accuracyEngineers had one particular obstacle to overcome in this new technology: the pressure of the device on the skin changes constantly, meaning that highly sensitive correctional measurements are necessary. Empa’s Laboratory for High Performance Ceramics sought a suitable solution to this problem within the scope of a CTI project. …Read more
June 5, 2013 — Scientists are reporting development and successful lab tests on the first potential drug to pack a lethal one-two punch against melanoma skin cancer cells. Hit number one destroys cells in the main tumor, and the second hit blocks the spread of the cancer to other sites in the body, according to their report in the journal ACS Chemical Biology.Share This:Nathan Luedtke and colleagues explain that the spread of melanoma and other forms of cancer beyond the original location — a process called metastasis — makes cancer such a serious disease. Photodynamic therapy (PDT), which involves administering a drug that kills cancer cells when exposed to light, already is available. But PDT works only on the main tumor and has other drawbacks. Luedtke’s team set out to find an improved approach to PDT.The scientists describe successful tests in laboratory mice of one compound they synthesized that not only killed melanoma cells, but also stopped them from metastasizing by blocking a key signal inside the tumor cells. The compound “provides the first example of a preclinical candidate possessing both of these properties,” the scientists state.The authors acknowledge funding from the Swiss National Science Foundation.Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is reprinted from materials provided by American Chemical Society. Note: Materials may be edited for content and length. For further information, please contact the source cited above. Journal Reference:Balayeshwanth R. Vummidi, Faiza Noreen, Jawad Alzeer, Karin Moelling, Nathan W. …Read more
May 29, 2013 — EPFL researchers have detected microplastic pollution in one of Western Europe’s largest lakes, Lake Geneva, in large enough quantities to raise concern. While studies in the ocean have shown that these small bits of plastic can be harmful to fish and birds that feed on plankton or other small waterborne organisms, the full extent of their consequences in lakes and rivers is only now being investigated.
The study, which is being extending under a mandate by the Swiss Federal Office for the Environment, was published in the latest issue of the journal Archives des Sciences.
“We were surprised to find such high concentrations of microplastics, especially in an environmentally aware country like Switzerland,” says first author Florian Faure from EPFL. Faure’s study focused on Lake Geneva, where both beaches and lake water were shown to contain significant amounts of microplastic contamination — pieces of plastic waste up to 5 mm in diameter. The study is one of the first of its kind to focus on a continental freshwater lake. And according to Faure, given the massive efforts put into protecting the lakes shores over the past decades, both on its French and the Swiss shores, the situation is likely to be representative of fresh water bodies around the world.
Microplastics in continental waters may be the main source of microplastic pollution in oceans, where huge hotspots containing high concentrations of these pollutants have formed. Scientists estimate that only around 20 percent of oceanic microplastics are dumped straight into the sea. The remaining 80 percent are estimated to originate from terrestrial sources, such as waste dumps, street litter, and sewage.
Microplastic pollution is also a strain to lake and river ecosystems, threatening the animals that inhabit these aquatic ecosystems both physically and chemically. When inadvertently swallowed by aquatic birds and fish, the tiny bits of plastic can wind up stuck in the animals’ intestines, where they obstruct their digestive tracts, or cause them to suffocate by blocking their airways. Ingested plastics may also leach toxic additives and other pollutants stuck to their surface into the animals that swallow them, such as bisphenol A (BPA) and phthalates, two carcinogenic agents used in transparent plastics, or other hydrophobic water pollutants, such as PCBs.
Like counting needles in a haystack
Florian Faure and his collaborators used a variety of approaches to quantify plastic and microplastic pollution in and around the lake, from combing beaches along Lake Geneva for plastic litter to dissecting animals, fishes (pikes, roaches and breams) and birds from the aquatic environment, and observing bird droppings around the lake.
To measure the concentration of microplastics in the water, Faure worked in collaboration with Oceaneye, a Geneva-based non-profit organization. Using an approach developed to study plastic pollution in the Mediterranean Sea, they pulled a manta trawl — a floating thin-meshed net — behind a boat in Lake Geneva to pick up any solid matter in the top layer of the water. The samples were then sorted out, dried and the solid compounds were analyzed for their composition.
“We found plastic in every sample we took from the beaches,” says Faure. Polystyrene beads were the most common culprits, but hard plastics, plastic membranes, and bits of fishing line were also widespread. In this preliminary study, the amount of debris caught in Lake Geneva using the manta trawl was comparable to measurements made in the Mediterranean Sea.
The scientists are now extending their focus to lakes and rivers across the country, backed by a mandate from the Swiss Federal Office for the Environment. According to the lab’s director, Luiz Felippe de Alencastro, this will involve studying microplastic pollution in lakes, rivers, and biota across the country, as well as the associated micropollutants, such as PCBs, which have already been found stuck on microplastics from Lake Geneva in significant concentrations.Read more