616 research outputs found
Crop Yields: Stripper Header Technology vs. Conventional Header Technology
The purpose of this paper is to compare crop yields on acres where stripper header technology was used to those where conventional header technology was used in a dryland cropping system. The results are based on experimental data collected at the USDA-ARS Central Great Plains Research Station, and include information on Northeastern Colorado wheat, millet, and sorghum yields. This analysis is important to demonstrate the benefits of using stripper header technology in a dryland cropping system. In the next section, the approaches and major findings of the previous literature are reviewed
Coagulation and fragmentation processes with evolving size and shape profiles : a semigroup approach
We investigate a class of bivariate coagulation-fragmentation equations. These equations describe the evolution of a system of particles that are characterised not only by a discrete size variable but also by a shape variable which can be either discrete or continuous. Existence and uniqueness of strong solutions to the associated abstract Cauchy problems are established by using the theory of substochastic semigroups of operators
Borderline Aggregation Kinetics in ``Dry'' and ``Wet'' Environments
We investigate the kinetics of constant-kernel aggregation which is augmented
by either: (a) evaporation of monomers from finite-mass clusters, or (b)
continuous cluster growth -- \ie, condensation. The rate equations for these
two processes are analyzed using both exact and asymptotic methods. In
aggregation-evaporation, if the evaporation is mass conserving, \ie, the
monomers which evaporate remain in the system and continue to be reactive, the
competition between evaporation and aggregation leads to several asymptotic
outcomes. For weak evaporation, the kinetics is similar to that of aggregation
with no evaporation, while equilibrium is quickly reached in the opposite case.
At a critical evaporation rate, the cluster mass distribution decays as
, where is the mass, while the typical cluster mass grows with
time as . In aggregation-condensation, we consider the process with a
growth rate for clusters of mass , , which is: (i) independent of ,
(ii) proportional to , and (iii) proportional to , with . In
the first case, the mass distribution attains a conventional scaling form, but
with the typical cluster mass growing as . When , the
typical mass grows exponentially in time, while the mass distribution again
scales. In the intermediate case of , scaling generally
applies, with the typical mass growing as . We also give an
exact solution for the linear growth model, , in one dimension.Comment: plain TeX, 17 pages, no figures, macro file prepende
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Pan-active imidazolopiperazine antimalarials target the Plasmodium falciparum intracellular secretory pathway.
A promising new compound class for treating human malaria is the imidazolopiperazines (IZP) class. IZP compounds KAF156 (Ganaplacide) and GNF179 are effective against Plasmodium symptomatic asexual blood-stage infections, and are able to prevent transmission and block infection in animal models. But despite the identification of resistance mechanisms in P. falciparum, the mode of action of IZPs remains unknown. To investigate, we here combine in vitro evolution and genome analysis in Saccharomyces cerevisiae with molecular, metabolomic, and chemogenomic methods in P. falciparum. Our findings reveal that IZP-resistant S. cerevisiae clones carry mutations in genes involved in Endoplasmic Reticulum (ER)-based lipid homeostasis and autophagy. In Plasmodium, IZPs inhibit protein trafficking, block the establishment of new permeation pathways, and cause ER expansion. Our data highlight a mechanism for blocking parasite development that is distinct from those of standard compounds used to treat malaria, and demonstrate the potential of IZPs for studying ER-dependent protein processing
The regulatory subunit of PKA-I remains partially structured and undergoes β-aggregation upon thermal denaturation
Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIα and a truncated RIα(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIα proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly α-helical spectrum at 25°C with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212-216 nm, characteristic of β-structure. A similar α→β transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-β-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIα leads to partial loss of native packing with exposure of aggregation-prone motifs, such as the B' helices in the phosphate-binding cassettes of both CNB domains. The topology of the β-sandwiches in these domains favors inter-molecular β-aggregation, which is suppressed in the ligand-bound states of RIα under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heat-denaturation. © 2011 Dao et al
D-cycloserine augmentation of exposure-based cognitive behavior therapy for anxiety, obsessive-compulsive, and posttraumatic stress disorders: a systematic review and meta-analysis of individual participant data
Importance: Whether and under which conditions D-cycloserine (DCS) augments the effects of exposure-based cognitive behavior therapy for anxiety, obsessive-compulsive, and posttraumatic stress disorders is unclear. Objective: To clarify whether DCS is superior to placebo in augmenting the effects of cognitive behavior therapy for anxiety, obsessive-compulsive, and posttraumatic stress disorders and to evaluate whether antidepressants interact with DCS and the effect of potential moderating variables. Data Sources: PubMed, EMBASE, and PsycINFO were searched from inception to February 10, 2016. Reference lists of previous reviews and meta-analyses and reports of randomized clinical trials were also checked. Study Selection: Studies were eligible for inclusion if they were (1) double-blind randomized clinical trials of DCS as an augmentation strategy for exposure-based cognitive behavior therapy and (2) conducted in humans diagnosed as having specific phobia, social anxiety disorder, panic disorder with or without agoraphobia, obsessive-compulsive disorder, or posttraumatic stress disorder. Data Extraction and Synthesis: Raw data were obtained from the authors and quality controlled. Data were ranked to ensure a consistent metric across studies (score range, 0-100). We used a 3-level multilevel model nesting repeated measures of outcomes within participants, who were nested within studies. Results: Individual participant data were obtained for 21 of 22 eligible trials, representing 1047 of 1073 eligible participants. When controlling for antidepressant use, participants receiving DCS showed greater improvement from pretreatment to posttreatment (mean difference, -3.62; 95% CI, -0.81 to -6.43; P = .01; d = -0.25) but not from pretreatment to midtreatment (mean difference, -1.66; 95% CI, -4.92 to 1.60; P = .32; d = -0.14) or from pretreatment to follow-up (mean difference, -2.98, 95% CI, -5.99 to 0.03; P = .05; d = -0.19). Additional analyses showed that participants assigned to DCS were associated with lower symptom severity than those assigned to placebo at posttreatment and at follow-up. Antidepressants did not moderate the effects of DCS. None of the prespecified patient-level or study-level moderators was associated with outcomes. Conclusions and Relevance: D-cycloserine is associated with a small augmentation effect on exposure-based therapy. This effect is not moderated by the concurrent use of antidepressants. Further research is needed to identify patient and/or therapy characteristics associated with DCS response.2018-05-0
Confronting gang membership and youth violence: Intervention challenges and potential futures
Evaluation of approaches and psychological obstacles to tackling youth gang involvement
X-ray and IR Point Source Identification and Characteristics in the Embedded, Massive Star-Forming Region RCW 108
We report on the results of an approximately 90 ks Chandra observation of a
complex region that hosts multiple sites of recent and active star formation in
ARA OB1a. The field is centered on the embedded cluster RCW 108-IR and includes
and a large portion of the open cluster NGC 6193. We detect over 420 X-ray
sources in the field and combined these data with deep near-IR, Spitzer/IRAC
and MSX mid-IR data. We find about 360 of the X-ray sources have near--IR
counterparts. We divide the region into 5 parts based on the X-ray point source
characteristics and extended 8 micron emission. The most clearly defined
regions are the central region - identified by embedded sources with high
luminosities in the both the near-IR and X-ray as well as high X-ray
temperatures (about 3 keV) and the eastern region - identified by low
extinction and 1 keV X-ray temperatures. Other regions, identified by their
directional relationship to RCW 108-IR are less uniform - representing
combinations of the first two regions, independent star formation epochs, or
both. Over 18% percent of the cluster members with over 100 counts exhibit
flares. Overall about 50% of the stars appear to have optically thick disks
when IRAC data are employed. The largest fraction of X-ray sources are best
described as possessing some disk material via a more detailed extinction
fitting. We estimate that the total number of pre--main sequence stars in the
field is about 1600. Approximately 800 are confined to (1.1 pc) central region.Comment: 63 pages including 18 figures, and 15 tables. Tables 1,2,5,7,10,and
11 have been stubbed in the text and included as ancillary files. Accepted by
the Astronomical Journa
Determinants of Fatigue after First-Ever Ischemic Stroke during Acute Phase
© 2014 The Authors. Published by PLOS. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1371/journal.pone.0110037
A correction to the article was made on 19/12/2012: https://doi.org/10.1371/journal.pone.011646
The Rise and Fall of "Respectable" Spanish Liberalism, 1808-1923: An Explanatory Framework
The article focuses on the reasons behind both the consolidation of what I have termed “respectable” liberalism between the 1830s and the 1840s and its subsequent decline and fall between 1900 and 1923. In understanding both processes I study the links established between “respectable” liberals and propertied elites, the monarchy, and the Church. In the first phase these links served to consolidate the liberal polity. However, they also meant that many tenets of liberal ideology were compromised. Free elections were undermined by the operation of caciquismo, monarchs established a powerful position, and despite the Church hierarchy working with liberalism, the doctrine espoused by much of the Church was still shaped by the Counter-Reformation. Hence, “respectable” liberalism failed to achieve a popular social base. And the liberal order was increasingly denigrated as part of the corrupt “oligarchy” that ruled Spain. Worse still, between 1916 and 1923 the Church, monarch, and the propertied elite increasingly abandoned the liberal Monarchist Restoration. Hence when General Primo de Rivera launched his coup the rug was pulled from under the liberals’ feet and there was no one to cushion the fall
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