3,398 research outputs found

    Sbf/MTMR13 coordinates PI(3)P and Rab21 regulation in endocytic control of cellular remodeling.

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    Cells rely on the coordinated regulation of lipid phosphoinositides and Rab GTPases to define membrane compartment fates along distinct trafficking routes. The family of disease-related myotubularin (MTM) phosphoinositide phosphatases includes catalytically inactive members, or pseudophosphatases, with poorly understood functions. We found that Drosophila MTM pseudophosphatase Sbf coordinates both phosphatidylinositol 3-phosphate (PI(3)P) turnover and Rab21 GTPase activation in an endosomal pathway that controls macrophage remodeling. Sbf dynamically interacts with class II phosphatidylinositol 3-kinase and stably recruits Mtm to promote turnover of a PI(3)P subpool essential for endosomal trafficking. Sbf also functions as a guanine nucleotide exchange factor that promotes Rab21 GTPase activation associated with PI(3)P endosomes. Of importance, Sbf, Mtm, and Rab21 function together, along with Rab11-mediated endosomal trafficking, to control macrophage protrusion formation. This identifies Sbf as a critical coordinator of PI(3)P and Rab21 regulation, which specifies an endosomal pathway and cortical control

    Experimental evaluation of foot-and-mouth disease vaccines for emergency use in ruminants and pigs: a review

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    Changes to foot-and-mouth disease (FMD) control policies since 2001 mean that emergency vaccination must be considered more readily as a control measure in the future. Since field application of vaccine for emergency use has only rarely been applied, the effectiveness of single dose administration, as a control measure in an outbreak situation, is poorly understood. In this review we consider all the available experimental data from studies utilizing either experimental or readily available, commercially produced vaccines, in order to assess their likely effectiveness as an additional means of controlling FMD transmission and spread in an emergency. Overall it is concluded that such vaccines offer an additional and valuable means of FMD control for both ruminants and pigs. They are able to reduce clinical disease, sub-clinical infection and excretion and onward transmission of virus. However, to be most effective, vaccination should be rapidly applied to give maximum opportunity for immunity to develop. We also identify areas for future research and emphasize the importance of vaccine efficacy studies in providing data for models that can help to predict the efficacy of differing FMD control strategies

    Optical Tweezers as an Effective Tool for Spermatozoa Isolation from Mixed Forensic Samples

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    A single focus optical tweezer is formed when a laser beam is launched through a high numerical aperture immersion objective. This objective focuses the beam down to a diffraction-limited spot, which creates an optical trap where cells suspended in aqueous solutions can be held fixed. Spermatozoa, an often probative cell type in forensic investigations, can be captured inside this optical trap and dragged one by one across millimeter-length distances in order to create a cluster of cells which can be subsequently drawn up into a capillary for collection. Sperm cells are then ejected onto a sterile cover slip, counted, and transferred to a tube for DNA analysis workflow. The objective of this research was to optimize sperm cell collection for maximum DNA yield, and to determine the number of trapped sperm cells necessary to produce a full STR profile. A varying number of sperm cells from both a single-source semen sample and a mock sexual assault sample were isolated utilizing optical tweezers and processed using conventional STR analysis methods. Results demonstrated that approximately 50 trapped spermatozoa were required to obtain a consistently full DNA profile. A complete, single-source DNA profile was also achieved by isolating sperm cells via optical trapping from a mixture of sperm and vaginal epithelial cells. Based on these results, optical tweezers are a viable option for forensic applications such as separation of mixed populations of cells in forensic evidence

    High Resolution 8 mm and 1 cm Polarization of IRAS 4A from the VLA Nascent Disk and Multiplicity (VANDAM) Survey

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    Magnetic fields can regulate disk formation, accretion and jet launching. Until recently, it has been difficult to obtain high resolution observations of the magnetic fields of the youngest protostars in the critical region near the protostar. The VANDAM survey is observing all known protostars in the Perseus Molecular Cloud. Here we present the polarization data of IRAS 4A. We find that with ~ 0.2'' (50 AU) resolution at {\lambda} = 8.1 and 10.3 mm, the inferred magnetic field is consistent with a circular morphology, in marked contrast with the hourglass morphology seen on larger scales. This morphology is consistent with frozen-in field lines that were dragged in by rotating material entering the infall region. The field morphology is reminiscent of rotating circumstellar material near the protostar. This is the first polarization detection of a protostar at these wavelengths. We conclude from our observations that the dust emission is optically thin with {\beta} ~ 1.3, suggesting that mm/cm-sized grains have grown and survived in the short lifetime of the protostar.Comment: Accepted to ApJL. 13 pages, 4 figure

    The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Perseus Protostars. VI. Characterizing the Formation Mechanism for Close Multiple Systems

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    We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of multiple protostar systems in the Perseus molecular cloud previously detected by the Karl G. Jansky Very Large Array (VLA). We observed 17 close (<<600~AU separation) multiple systems at 1.3~mm in continuum and five molecular lines (i.e., \twco, \cateo, \thco, H2_2CO, SO) to characterize the circum-multiple environments in which these systems are forming. We detect at least one component in the continuum for the 17 multiple systems. In three systems, one companion is not detected, and for two systems the companions are unresolved at our observed resolution. We also detect circum-multiple dust emission toward 8 out of 9 Class 0 multiples. Circum-multiple dust emission is not detected toward any of the 8 Class I multiples. Twelve systems are detected in the dense gas tracers toward their disks/inner envelopes. For these 12 systems, we use the dense gas observations to characterize their formation mechanism. The velocity gradients in the circum-multiple gas are clearly orthogonal to the outflow directions in 8 out of the 12 systems, consistent with disk fragmentation. Moreover, only two systems with separations <<200~AU are \textit{inconsistent} with disk fragmentation, in addition to the two widest systems (>>500~AU). Our results suggest that disk fragmentation via gravitational instability is an important formation mechanism for close multiple systems, but further statistics are needed to better determine the relative fraction formed via this method.Comment: 48 Pages, 26 Figures, 7 Tables, Accepted by Ap

    Evaluation of soil carbon simulation in CMIP6 Earth system models

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    The response of soil carbon represents one of the key uncertainties in future climate change. The ability of Earth system models (ESMs) to simulate present-day soil carbon is therefore vital for reliably estimating global carbon budgets required for Paris Agreement targets. In this study CMIP6 ESMs are evaluated against empirical datasets to assess the ability of each model to simulate soil carbon and related controls: net primary productivity (NPP) and soil carbon turnover time (τs). Comparing CMIP6 with the previous generation of models (CMIP5), a lack of consistency in modelled soil carbon remains, particularly the underestimation of northern high-latitude soil carbon stocks. There is a robust improvement in the simulation of NPP in CMIP6 compared with CMIP5; however, an unrealistically high correlation with soil carbon stocks remains, suggesting the potential for an overestimation of the long-term terrestrial carbon sink. Additionally, the same improvements are not seen in the simulation of τs. These results suggest that much of the uncertainty associated with modelled soil carbon stocks can be attributed to the simulation of below-ground processes, and greater emphasis is required on improving the representation of below-ground soil processes in future developments of models. These improvements would help to reduce the uncertainty in projected carbon release from global soils under climate change and to increase confidence in the carbon budgets associated with different levels of global warming.</p

    Exploring Citizen Psych-Science and the Motivations of Errordiary Volunteers

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    Although virtual citizen science projects have the potential to engage large networks of people in science research, seeding and maintaining such networks can be difficult. A feature of successful projects is that they have well-motivated volunteers. What makes volunteers motivated rather than apathetic? In this paper we focus on projects that contribute to psychology research, which we term ‘citizen psych-science’. This differs from typical citizen science because volunteers are asked to contribute themselves as data. We describe research studies that we conducted with Errordiary — a citizen psych-science project where volunteers tweet about their everyday experiences of human error. These studies were: (1) an interview study, to explore the motivations of eight Errordiary volunteers; and (2) three focus groups, to explore the potential of attracting new communities to Errordiary. We found that the personal nature of the data can influence participation in positive and negative ways. We suggest several factors that scientists need to consider when encouraging citizen psych-science volunteers to contribute their personal experiences towards research

    Formation of pH‐Resistant Monodispersed Polymer–Lipid Nanodiscs

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    Polymer lipid nanodiscs are an invaluable system for structural and functional studies of membrane proteins in their near‐native environment. Despite the recent advances in the development and usage of polymer lipid nanodisc systems, lack of control over size and poor tolerance to pH and divalent metal ions are major limitations for further applications. A facile modification of a low‐molecular‐weight styrene maleic acid copolymer is demonstrated to form monodispersed lipid bilayer nanodiscs that show ultra‐stability towards divalent metal ion concentration over a pH range of 2.5 to 10. The macro‐nanodiscs (>20 nm diameter) show magnetic alignment properties that can be exploited for high‐resolution structural studies of membrane proteins and amyloid proteins using solid‐state NMR techniques. The new polymer, SMA‐QA, nanodisc is a robust membrane mimetic tool that offers significant advantages over currently reported nanodisc systems.All under control: A poor tolerance to pH and divalent metal ions and a lack of control over size are major limitations of polymer nanodiscs. A modified styrene maleimide based polymer is demonstrated to form monodispersed nanodiscs with ultrahigh stability towards divalent metal ions over a pH range of 2.5 to 10.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141640/1/anie201712017_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141640/2/anie201712017-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141640/3/anie201712017.pd

    The Young Lady\u27s Guide

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    Contents Papers for thoughtful girls, by Sarah Tytler. A woman’s thoughts about women, by the author of John Halifax, gentleman . Fashion, from Mrs. Sydney Cox’s Friendly counsel for girls . Novel-reading, from the Greyson letters, by Henry Rogers. From Daughters and Women of England, by Sarah S. Ellis. From Hannah More.--From The young ladies’ mentor , by a lady. The social position and culture due to woman, by W. R. Williams.--Education of the heart, woman’s best, by Sarah S. Ellis. From The young woman’s friend , by J. A. James
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