Leaf-mining insects destroyed with the dinosaurs, others quickly appeared

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After the asteroid impact at the end of the Cretaceous period that triggered the dinosaurs’ extinction and ushered in the Paleocene, leaf-mining insects in the western United States completely disappeared. Only a million years later, at Mexican Hat, in southeastern Montana, fossil leaves show diverse leaf-mining traces from new insects that were not present during the Cretaceous, according to paleontologists.”Our results indicate both that leaf-mining diversity at Mexican Hat is even higher than previously recognized, and equally importantly, that none of the Mexican Hat mines can be linked back to the local Cretaceous mining fauna,” said Michael Donovan, graduate student in geosciences, Penn State.Insects that eat leaves produce very specific types of damage. One type is from leaf miners — insect larvae that live in the leaves and tunnel for food, leaving distinctive feeding paths and patterns of droppings.Donovan, Peter Wilf, professor of geosciences, Penn State, and colleagues looked at 1,073 leaf fossils from Mexican Hat for mines. They compared these with more than 9,000 leaves from the end of the Cretaceous, 65 million years ago, from the Hell Creek Formation in southwestern North Dakota, and with more than 9,000 Paleocene leaves from the Fort Union Formation in North Dakota, Montana and Wyoming. The researchers present their results in today’s (July 24) issue of PLOS ONE.”We decided to focus on leaf miners because they are typically host specific, feeding on only a few plant species each,” said Donovan. “Each miner also leaves an identifiable mining pattern.”The researchers found nine different mine-damage types at Mexican Hat attributable to the larvae of moths, wasps and flies, and six of these damage types were unique to the site.The researchers were unsure whether the high diversity of leaf miners at Mexican Hat compared to other early Paleocene sites, where there is little or no leaf mining, was caused by insects that survived the extinction event in refugia — areas where organisms persist during adverse conditions — or were due to range expansions of insects from somewhere else during the early Paleocene.However, with further study, the researchers found no evidence of the survival of any leaf miners over the Cretaceous-Paleocene boundary, suggesting an even more total collapse of terrestrial food webs than has been recognized previously.”These results show that the high insect damage diversity at Mexican Hat represents an influx of novel insect herbivores during the early Paleocene and not a refugium for Cretaceous leaf miners,” said Wilf. “The new herbivores included a startling diversity for any time period, and especially for the classic post-extinction disaster interval.”Insect extinction across the Cretaceous-Paleocene boundary may have been directly caused by catastrophic conditions after the asteroid impact and by the disappearance of host plant species. While insect herbivores constantly need leaves to survive, plants can remain dormant as seeds in the ground until more auspicious circumstances occur.The low-diversity flora at Mexican Hat is typical for the area in the early Paleocene, so what caused the high insect damage diversity?Insect outbreaks are associated with a rapid population increase of a single insect species, so the high diversity of mining damage seen in the Mexican Hat fossils makes the possibility of an outbreak improbable.The researchers hypothesized that the leaf miners that are seen in the Mexican Hat fossils appeared in that area because of a transient warming event, a number of which occurred during the early Paleocene.”Previous studies have shown a correlation between temperature and insect damage diversity in the fossil record, possibly caused by evolutionary radiations or range shifts in response to a warmer climate,” said Donovan. “Current evidence suggests that insect herbivore extinction decreased with increasing distance from the asteroid impact site in Mexico, so pools of surviving insects would have existed elsewhere that could have provided a source for the insect influx that we observed at Mexican Hat.”Story Source:The above story is based on materials provided by Penn State. The original article was written by A’ndrea Eluse Messer. …


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#Cretaceous, #Current, #Donovan, #Formation, #Health, #Mexican, #North-Dakota, #Paleocene, #Professor, #Union

The number of tumor cells spread to sentinel lymph nodes affects melanoma prognosis

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Cancer cell spread to the sentinel node — the lymph node to which cancer cells are most likely to spread from a primary tumor — is a risk factor for melanoma death. According to a study published in this week’s PLOS Medicine by Anja Ulmer, Christoph Klein and colleagues from the Universities of Tbingen and Regensburg, Germany, the prognosis of a patient largely depends on the number of disseminated cancer cells per million lymphocytes in the sentinel node. Even very low numbers were found to be predictive for reduced survival.The leading cause of death from skin disease is melanoma, which is the most dangerous type of skin cancer. When melanoma metastasizes and spreads to other parts of the body, treatment options become limited and the prognosis is poor. Melanoma staging (and prognosis) is currently focused on the primary tumor itself, with characteristics like tumor thickness, mitotic rate, and ulceration (break in the skin caused by the tumor) indicating the likelihood that the tumor has started to spread. Looking for tumor cells in the sentinel nodes is done for patients who are at increased risk for spread, but standard procedures for how to measure spread to the nodes and how to integrate this information with the tumor histology are needed. Since melanoma is one of the deadliest cancers, better predictors of prognosis for melanoma patients are needed for patient information and to determine treatment options.The researchers prospectively collected a large number of samples for this relatively rare cancer: 1,834 sentinel lymph nodes from 1,027 patients with melanoma who had been followed for 5 years after the samples were taken. They labelled disseminated cancer cells (DCCs) in the lymph nodes through the use of a marker for melanoma cells, counted them, and calculated DCC density. They then asked whether DCC density was related to a patient’s survival. They found that patients with high DCC density in the lymph nodes were more likely to die from melanoma within 5 years. …


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#Agriculture, #Alzheimer, #Body, #Christophklein, #Current, #Disease, #Health, #King, #Medicine, #Plos, #Standard, #Tbingen

New depression treatments reported

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New insights into the physiological causes of depression are leading to treatments beyond common antidepressants such as Prozac and Zoloft, according to an evidence-based report in the journal Current Psychiatry.Depression treatments on the horizon include new medications, electrical and magnetic stimulation of the brain and long-term cognitive behavioral therapy for stress management.Authors are Murali Rao, MD, and Julie M. Alderson, DO. Rao is professor and chair of the Department of Psychiatry and Behavioral Neurosciences at Loyola University Chicago Stritch School of Medicine, and Alderson is a resident at East Liverpool City Hospital in East Liverpool, Ohio.For more than 50 years, depression has been studied and understood as a deficiency of chemical messengers, called neurotransmitters, that carry signals between brain cells. Commonly used antidepressants are designed to either increase the release or block the degradation of three neurotransmitters — dopamine, norepinephrine and serotonin.But drugs that target neurotransmitters, such as Prozac, Zoloft and Paxil, succeed in inducing the remission of depression in fewer than half of patients. This has prompted researchers “to look beyond neurotransmitters for an understanding of depressive disorders,” Rao and Alderson write.New theories of depression are focusing on differences in neuron density in various regions of the brain; on the effect of stress on the birth and death of brain cells; on the alteration of feedback pathways in the brain and on the role of inflammation evoked by the stress response.Chronic stress is believed to be the leading cause of depression, the authors write. Long-term stress harms cells in the brain and body. Stressful experiences are believed to be closely associated with the development of psychological alterations and, thus, neuropsychiatric disorders. In conditions of chronic stress exposure, nerve cells in the hippocampus begin to atrophy. (The hippocampus is a part of the brain involved with emotions, learning and memory formation.)The new depression theories “should not be viewed as separate entities because they are highly interconnected,” Rao and Alderson write. “Integrating them provides for a more expansive understanding of the pathophysiology of depression and biomarkers that are involved.”Such biomarkers are molecules in the body that can be indicators of depression. …


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#Alderson, #Alternative-Medicine, #Alzheimer, #Cancer, #Chemical, #Current, #Insights, #Zoloft

Brain"s "sweet spot" for love found in neurological patient

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A region deep inside the brain controls how quickly people make decisions about love, according to new research at the University of Chicago.The finding, made in an examination of a 48-year-old man who suffered a stroke, provides the first causal clinical evidence that an area of the brain called the anterior insula “plays an instrumental role in love,” said UChicago neuroscientist Stephanie Cacioppo, lead author of the study.In an earlier paper that analyzed research on the topic, Cacioppo and colleagues defined love as “an intentional state for intense [and long-term] longing for union with another” while lust, or sexual desire, is characterized by an intentional state for a short-term, pleasurable goal.In this study, the patient made decisions normally about lust but showed slower reaction times when making decisions about love, in contrast to neurologically typical participants matched on age, gender and ethnicity. The findings are presented in a paper, “Selective Decision-Making Deficit in Love Following Damage to the Anterior Insula,” published in the journal Current Trends in Neurology.”This distinction has been interpreted to mean that desire is a relatively concrete representation of sensory experiences, while love is a more abstract representation of those experiences,” said Cacioppo, a research associate and assistant professor in psychology. The new data suggest that the posterior insula, which affects sensation and motor control, is implicated in feelings of lust or desire, while the anterior insula has a role in the more abstract representations involved in love.In the earlier paper, “The Common Neural Bases Between Sexual Desire and Love: A Multilevel Kernel Density fMRI Analysis,” Cacioppo and colleagues examined a number of studies of brain scans that looked at differences between love and lust.The studies showed consistently that the anterior insula was associated with love, and the posterior insula was associated with lust. However, as in all fMRI studies, the findings were correlational.”We reasoned that if the anterior insula was the origin of the love response, we would find evidence for that in brain scans of someone whose anterior insula was damaged,” she said.In the study, researchers examined a 48-year-old heterosexual male in Argentina, who had suffered a stroke that damaged the function of his anterior insula. He was matched with a control group of seven Argentinian heterosexual men of the same age who had healthy anterior insula.The patient and the control group were shown 40 photographs at random of attractive, young women dressed in appealing, short and long dresses and asked whether these women were objects of sexual desire or love. The patient with the damaged anterior insula showed a much slower response when asked if the women in the photos could be objects of love.”The current work makes it possible to disentangle love from other biological drives,” the authors wrote. Such studies also could help researchers examine feelings of love by studying neurological activity rather than subjective questionnaires.The full article can be found online at: https://hpenlaboratory.uchicago.edu/sites/caciopponeurolab.uchicago.edu/files/uploads/Cacioppo%20et%20al_Current%20Trends%20in%20Neurology%202013.pdfStory Source:The above story is based on materials provided by University of Chicago. Note: Materials may be edited for content and length.


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#Analysis, #Cacioppo, #Cancer, #Common, #Control, #Current, #Journal, #Mri, #Neurology, #Professor, #Sexual, #Women

Eucalypt in Ethiopian highlands: Increasing productivity of important tree

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Researchers at the UPM are collaborating in a eucalypts breeding program in the Ethiopian highlands which will increase this species productivity.This program is developed by the research group of Forest Physiology and Genetics and the cooperative group of Support to Forestry Development of the Universidad Politcnica de Madrid (UPM). Also, it is supported by several national and international institutions that will contribute to satisfy the demand of woody biomass and other financial needs of Ethiopian farmers.For years, these two research groups have been collaborating with Forestry Research Center and the St. Mary’s College and supported by Ence and the Council of Alcorcn. Also, they are working on providing the Ethiopian highlands with tools and knowledge for better forestry management. This could constitute a valuable tool to achieve sustainability when using and supplying natural resources. The main project consists of a eucalypt breeding program that will result in improvements in many areas.The great demand for forest products to use for agriculture by the population of the Ethiopian highlands has resulted in the deforestation of a region with the lowest human development rate in the world. The eucalypt is the species with the highest demand among Ethiopian farmers and has an important environmental and socioeconomic key role in the highlands area. The consumption of eucalypt is been boosted because of its compatibility with the grazing system and its high yields even in marginal agricultural soils of abandoned lands. However, farmers are lacking of start materials and the current techniques make production difficult.Within the improvement program, the researchers established an experimental test with eucalypt plants from Ethiopia and Spain in order to compare their potential productivity in local conditions. The Spanish plant, that had a certain rate of improvement, showed a growth and survival rate between 27% and 35%, a rate higher than the Ethiopian plants. …


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#Current, #Ecology, #Ethiopian, #Health, #Physiology, #Politcnica, #Research, #Result, #Science, #Species, #Universidad

New live-cell printing technology works like ancient Chinese woodblocking

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HOUSTON — ( Feb. 6, 2014 ) — With a nod to 3rd century Chinese woodblock printing and children’s rubber stamp toys, researchers in Houston have developed a way to print living cells onto any surface, in virtually any shape. Unlike recent, similar work using inkjet printing approaches, almost all cells survive the process, scientists report in this week’s Proceedings of the National Academy of Sciences.The researchers, led by Houston Methodist Research Institute nanomedicine faculty member Lidong Qin, Ph.D., say their approach produces 2-D cell arrays in as little as half an hour, prints the cells as close together as 5 micrometers (most animal cells are 10 to 30 micrometers wide), and allows the use of many different cell types. They’ve named the technology Block-Cell-Printing, or BloC-Printing.”We feel the current technologies are inadequate,” Qin said. “Inkjet-based cell printing leaves many of the cells damaged or dead. We wanted to see if we could invent a tool that helps researchers obtain arrays of cells that are alive and still have full activity.”Recent work to print cells in two and three dimensions using electricity-gated inkjet technology have been largely successful, but sometimes only half of the printed cells survive the printing process — a source of frustration for many laboratory scientists.”Cell printing is used in so many different ways now — for drug development and in studies of tissue regeneration, cell function, and cell-cell communication,” Qin said. “Such things can only be done when cells are alive and active. A survival rate of 50 to 80 percent is typical as cells exit the inkjet nozzles. By comparison, we are seeing close to 100 percent of cells in BloC-Printing survive the printing process.”BloC-Printing manipulates microfluidic physics to guide living cells into hook-like traps in the silicone mold. Cells flow down a column in the mold, past trapped cells to the next available slot, eventually creating a line of cells (in a grid of such lines). …


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#Cancer, #Current, #Health, #Houston, #Houstonmethodist, #Inkjetbased, #Market, #Printing, #Research, #Science, #Sciences

Massive neutrinos solve a cosmological conundrum

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Scientists have solved a major problem with the current standard model of cosmology identified by combining results from the Planck spacecraft and measurements of gravitational lensing in order to deduce the mass of ghostly sub-atomic particles called neutrinos.The team, from the universities of Manchester and Nottingham, used observations of the Big Bang and the curvature of space-time to accurately measure the mass of these elementary particles for the first time.The recent Planck spacecraft observations of the Cosmic Microwave Background (CMB) — the fading glow of the Big Bang — highlighted a discrepancy between these cosmological results and the predictions from other types of observations.The CMB is the oldest light in the Universe, and its study has allowed scientists to accurately measure cosmological parameters, such as the amount of matter in the Universe and its age. But an inconsistency arises when large-scale structures of the Universe, such as the distribution of galaxies, are observed.Professor Richard Battye, from The University of Manchester School of Physics and Astronomy, said: “We observe fewer galaxy clusters than we would expect from the Planck results and there is a weaker signal from gravitational lensing of galaxies than the CMB would suggest.”A possible way of resolving this discrepancy is for neutrinos to have mass. The effect of these massive neutrinos would be to suppress the growth of dense structures that lead to the formation of clusters of galaxies.”Neutrinos interact very weakly with matter and so are extremely hard to study. They were originally thought to be massless but particle physics experiments have shown that neutrinos do indeed have mass and that there are several types, known as flavours by particle physicists. The sum of the masses of these different types has previously been suggested to lie above 0.06 eV (much less than a billionth of the mass of a proton).In this paper, Professor Battye and co-author Dr Adam Moss, from the University of Nottingham, have combined the data from Planck with gravitational lensing observations in which images of galaxies are warped by the curvature of space-time. They conclude that the current discrepancies can be resolved if massive neutrinos are included in the standard cosmological model. They estimate that the sum of masses of neutrinos is 0.320 +/- 0.081 eV (assuming active neutrinos with three flavours).Dr Moss said: “If this result is borne out by further analysis, it not only adds significantly to our understanding of the sub-atomic world studied by particle physicists, but it would also be an important extension to the standard model of cosmology which has been developed over the last decade.”The paper is published in Physical Review Letters and has been selected as an Editor’s choice.Story Source:The above story is based on materials provided by University of Manchester. Note: Materials may be edited for content and length.


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#Atomic, #Cosmology, #Current, #Model, #Nottingham, #Particles, #Physics, #Planck, #Spacecraft