1,923 research outputs found
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Bombardier Enables Delivery of Short-Form Bomanins in the Drosophila Toll Response.
Toll mediates a robust and effective innate immune response across vertebrates and invertebrates. In Drosophila melanogaster, activation of Toll by systemic infection drives the accumulation of a rich repertoire of immune effectors in hemolymph, including the recently characterized Bomanins, as well as the classical antimicrobial peptides (AMPs). Here we report the functional characterization of a Toll-induced hemolymph protein encoded by the bombardier (CG18067) gene. Using the CRISPR/Cas9 system to generate a precise deletion of the bombardier transcriptional unit, we found that Bombardier is required for Toll-mediated defense against fungi and Gram-positive bacteria. Assaying cell-free hemolymph, we found that the Bomanin-dependent candidacidal activity is also dependent on Bombardier, but is independent of the antifungal AMPs Drosomycin and Metchnikowin. Using mass spectrometry, we demonstrated that deletion of bombardier results in the specific absence of short-form Bomanins from hemolymph. In addition, flies lacking Bombardier exhibited a defect in pathogen tolerance that we trace to an aberrant condition triggered by Toll activation. These results lead us to a model in which the presence of Bombardier in wild-type flies enables the proper folding, secretion, or intermolecular associations of short-form Bomanins, and the absence of Bombardier disrupts one or more of these steps, resulting in defects in both immune resistance and tolerance
Scaling of dynamical susceptibility at the onset of rigidity for disordered viscoelastic matter
The onset of rigidity in interacting liquids, as they undergo a transition to
a disordered solid, is associated with a dramatic rearrangement of the
low-frequency vibrational spectrum. In this letter, we derive scaling forms for
the singular dynamical response of disordered viscoelastic networks near both
jamming and rigidity percolation. Using effective-medium theory, we extract
critical exponents, invariant scaling combinations and analytical formulas for
universal scaling functions near these transitions. Our scaling forms describe
the behavior in space and time near the various onsets of rigidity, for rigid
and floppy phases and the crossover region, including diverging length and time
scales at the transitions. We expect that these behaviors can be measured in
systems ranging from colloidal suspensions to anomalous charge-density
fluctuations of "strange" metals.Comment: 6 pages, 3 figure
Amount of Time to Eat Lunch Is Associated with Children’s Selection and Consumption of School Meal Entrée, Fruits, Vegetables, and Milk
Background
There are currently no national standards for school lunch period length and little is known about the association between the amount of time students have to eat and school food selection and consumption.
Objective Our aim was to examine plate-waste measurements from students in the control arm of the Modifying Eating and Lifestyles at School study (2011 to 2012 school year) to determine the association between amount of time to eat and school meal selection and consumption.
Design We used a prospective study design using up to six repeated measures among students during the school year.
Participants/setting One thousand and one students in grades 3 to 8 attending six participating elementary and middle schools in an urban, low-income school district where lunch period lengths varied from 20 to 30 minutes were included.
Main outcome measures School food selection and consumption were collected using plate-waste methodology.
Statistical analyses performed Logistic regression and mixed-model analysis of variance was used to examine food selection and consumption.
Results
Compared with meal-component selection when students had at least 25 minutes to eat, students were significantly less likely to select a fruit (44% vs 57%; PPPP
Conclusions During the school year, a substantial number of students had insufficient time to eat, which was associated with significantly decreased entrée, milk, and vegetable consumption compared with students who had more time to eat. School policies that encourage lunches with at least 25 minutes of seated time might reduce food waste and improve dietary intake
Anomalous diffusion and Tsallis statistics in an optical lattice
We point out a connection between anomalous quantum transport in an optical
lattice and Tsallis' generalized thermostatistics. Specifically, we show that
the momentum equation for the semiclassical Wigner function that describes
atomic motion in the optical potential, belongs to a class of transport
equations recently studied by Borland [PLA 245, 67 (1998)]. The important
property of these ordinary linear Fokker--Planck equations is that their
stationary solutions are exactly given by Tsallis distributions. Dissipative
optical lattices are therefore new systems in which Tsallis statistics can be
experimentally studied.Comment: 4 pages, 1 figur
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A Toolbox for Spatiotemporal Analysis of Voltage-Sensitive Dye Imaging Data in Brain Slices
Voltage-sensitive dye imaging (VSDI) can simultaneously monitor the spatiotemporal electrical dynamics of thousands of neurons and is often used to identify functional differences in models of neurological disease. While the chief advantage of VSDI is the ability to record spatiotemporal activity, there are no tools available to visualize and statistically compare activity across the full spatiotemporal range of the VSDI dataset. Investigators commonly analyze only a subset of the data, and a majority of the dataset is routinely excluded from analysis. We have developed a software toolbox that simplifies visual inspection of VSDI data, and permits unaided statistical comparison across spatial and temporal dimensions. First, the three-dimensional VSDI dataset (x,y,time) is geometrically transformed into a two-dimensional spatiotemporal map of activity. Second, statistical comparison between groups is performed using a non-parametric permutation test. The result is a 2D map of all significant differences in both space and time. Here, we used the toolbox to identify functional differences in activity in VSDI data from acute hippocampal slices obtained from epileptic Arx conditional knock-out and control mice. Maps of spatiotemporal activity were produced and analyzed to identify differences in the activity evoked by stimulation of each of two axonal inputs to the hippocampus: the perforant pathway and the temporoammonic pathway. In mutant hippocampal slices, the toolbox identified a widespread decrease in spatiotemporal activity evoked by the temporoammonic pathway. No significant differences were observed in the activity evoked by the perforant pathway. The VSDI toolbox permitted us to visualize and statistically compare activity across the spatiotemporal scope of the VSDI dataset. Sampling error was minimized because the representation of the data is standardized by the toolbox. Statistical comparisons were conducted quickly, across the spatiotemporal scope of the data, without a priori knowledge of the character of the responses or the likely differences between them
Tracing the Orphan Stream to 55 kpc with RR Lyrae Stars
We report positions, velocities and metallicities of 50 ab-type RR Lyrae
(RRab) stars observed in the vicinity of the Orphan stellar stream. Using about
30 RRab stars classified as being likely members of the Orphan stream, we study
the metallicity and the spatial extent of the stream. We find that RRab stars
in the Orphan stream have a wide range of metallicities, from -1.5 dex to -2.7
dex. The average metallicity of the stream is -2.1 dex, identical to the value
obtained by Newberg et al. (2010) using blue horizontal branch stars. We find
that the most distant parts of the stream (40-50 kpc from the Sun) are about
0.3 dex more metal-poor than the closer parts (within ~30 kpc), suggesting a
possible metallicity gradient along the stream's length. We have extended the
previous studies and have mapped the stream up to 55 kpc from the Sun. Even
after a careful search, we did not identify any more distant RRab stars that
could plausibly be members of the Orphan stream. If confirmed with other
tracers, this result would indicate a detection of the end of the leading arm
of the stream. We have compared the distances of Orphan stream RRab stars with
the best-fit orbits obtained by Newberg et al. (2010). We find that model 6 of
Newberg et al. (2010) cannot explain the distances of the most remote Orphan
stream RRab stars, and conclude that the best fit to distances of Orphan stream
RRab stars and to the local circular velocity is provided by potentials where
the total mass of the Galaxy within 60 kpc is M_{60}~2.7x10^{11} Msun, or about
60% of the mass found by previous studies. More extensive modelling that would
consider non-spherical potentials and the possibility of misalignment between
the stream and the orbit, is highly encouraged.Comment: Submitted to ApJ, 15 pages in emulateapj format, three tables in
machine-readable format (download "Source" from "Other formats"
Early Glycemic Control in Critically Ill Emergency Department Patients: Pilot Trial
Objective: Glycemic control in the critically ill intensive care unit (ICU) patient has been shown to improve morbidity and mortality. We sought to investigate the effect of early glycemic control in critically ill emergency department (ED) patients in a small pilot trial.Methods: Adult non-trauma, non-pregnant ED patients presenting to a university tertiary referral center and identified as critically ill were eligible for enrollment on a convenience basis. Critical illness was determined upon assignment for ICU admission. Patients were randomized to either ED standard care or glycemic control. Glycemic control involved use of an insulin drip to maintain blood glucose levels between 80-140 mg/dL. Glycemic control continued until ED discharge. Standard patients were managed at ED attending physician discretion. We assessed severity of illness by calculation of APACHE II score. The primary endpoint was in-hospital mortality. Secondary endpoints included vasopressor requirement, hospital length of stay, and mechanical ventilation requirement.Results: Fifty patients were randomized, 24 to the glycemic group and 26 to the standard care cohort. Four of the 24 patients (17%) in the treatment arm did not receive insulin despite protocol requirements. While receiving insulin, three of 24 patients (13%) had an episode of hypoglycemia. By chance, the patients in the treatment group had a trend toward higher acuity by APACHE II scores. Patient mortality and morbidity were similar despite the acuity difference.Conclusion: There was no difference in morbidity and mortality between the two groups. The benefit of glycemic control may be subject to source of illness and to degree of glycemic control, or have no effect. Such questions bear future investigation. [West J Emerg Med. 2010; 11(1):20-23]
Enhancement of piezoelectricity in a mixed ferroelectric
We use first-principles density-functional total energy and polarization
calculations to calculate the piezoelectric tensor at zero temperature for both
cubic and simple tetragonal ordered supercells of Pb_3GeTe_4. The largest
piezoelectric coefficient for the tetragonal configuration is enhanced by a
factor of about three with respect to that of the cubic configuration. This can
be attributed to both the larger strain-induced motion of cations relative to
anions and higher Born effective charges in the tetragonal case. A normal mode
decomposition shows that both cation ordering and local relaxation weaken the
ferroelectric instability, enhancing piezoelectricity.Comment: 5 pages, revtex, 2 eps figure
Clinical Decision-Making Following Disasters: Efficient Identification of PTSD Risk in Adolescents
The present study aimed to utilize a Receiver Operating Characteristic (ROC) approach in order to improve clinical decision-making for adolescents at risk for the development of psychopathology in the aftermath of a natural disaster. Specifically we assessed theoretically-driven individual, interpersonal, and event-related vulnerability factors to determine which indices were most accurate in forecasting PTSD. Furthermore, we aimed to translate these etiological findings by identifying clinical cut-off recommendations for relevant vulnerability factors. Our study consisted of structured phone-based clinical interviews with 2,000 adolescent-parent dyads living within a 5-mile radius of tornados that devastated Joplin, MO, and northern Alabama in Spring 2011. Demographics, tornado incident characteristics, prior trauma, mental health, and family support and conflict were assessed. A subset of youth completed two behavioral assessment tasks online to assess distress tolerance and risk taking behavior. ROC analyses indicated four variables that significantly improved PTSD diagnostic efficiency: Lifetime depression (AUC=.90), trauma history (AUC=.76), social support (AUC=.70), and family conflict (AUC=.72). Youth were 2–3 times more likely to have PTSD if they had elevated scores on any of these variables. Of note, event-related characteristics (e.g., property damage) were not related to PTSD diagnostic status. The present study adds to the literature by making specific recommendations for empirically-based, efficient disaster-related PTSD assessment for adolescents following a natural disaster. Implications for practice and future trauma-related developmental psychopathology research are discussed
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