4,291 research outputs found
340 years of atmospheric circulation characteristics reconstructed from an eastern Antarctic Peninsula ice core
Copyright @ 2006 American Geophysical Union (AGU)Precipitation delivery mechanisms for Dolleman Island (DI), located off the east coast of the Antarctic Peninsula, are investigated using reanalysis and back trajectory data. The Southern Annular Mode (SAM) and ENSO are both shown to influence precipitation delivery and event size. Precipitation delivery variability is compared against the interannual variation of chemical data from two DI ice cores. Nitrate concentration in the cores is strongly linked with the ratio of easterly to westerly back trajectories arriving at DI, as described by a Cross-Peninsula Index (CPI) defined in this paper. This CPI is used subsequently to reconstruct the atmospheric circulation characteristics for the 340-year ice core record. The analysis highlights a period of increased easterlies during 1720–1780 and an increase in westerlies for 1950–1980, the latter concomitant with a positive SAM trend and western Peninsula warming. The reconstruction also reveals periods when polynyas may have been present in the Weddell Sea
Genetic improvement of aphid resistance, protein, and elemental composition in soybean
Yield Drag Associated with the Aphid Resistance Gene Rag2 from PI 200538
The soybean aphid (Aphis glycines Matsumura) is an important pest of soybean [Glycine max (L.) Merr.] that was first identified in North American during 2000. The pest can be controlled by the resistance genes Rag1 and Rag2, which have been introgressed into Midwestern adapted soybean lines. In previous studies, the Rag2 resistance allele was shown to be associated with a seed yield reduction. The objective of this study was to confirm the reduction in yield associated with Rag2 and determine its cause. This was done by testing a population of lines with all combinations of resistance and susceptibility alleles at Rag1 and Rag2 to further discern the effect of the Rag2 gene on agronomic traits, and by evaluating the introgressed genetic region surrounding Rag2 in populations of near isogenic lines to localize quantitative trait loci (QTL) causing yield drag associated with the Rag2 gene. The populations were tested in multiple environments across three years with little or no aphid infestation. Yield tests of the population segregating for Rag1 and Rag2 showed that Rag2 was associated with a yield reduction across environments, but Rag1 was not. Results from the tests of the Rag2 genetic region populations indicate that one or more QTL(s) causing yield drag are located within a 6.5 Mbp region approximately 1.6 Mbp from Rag2. This information can be used to break the linkage between the yield reduction QTL(s) and Rag2, ultimately providing higher yielding aphid resistant cultivars.
Fine Mapping of the Soybean Seed Protein QTL cqSeed protein-003
Soybean is a widely grown, important source of protein and oil for both animal and human consumption. In this study, the previously identified protein QTL cqSeed protein-003 on chromosome 20 (formerly linkage group I) was fine mapped to further delineate the candidate gene region of the QTL. Fine mapping was conducted using a population of near isogenic lines (NILs) segregating for cqSeed protein-003 developed through five backcrosses (BC5) using PI468916 as the donor parent and A81-356022 as a recurrent parent. Genetic marker analysis of the BC5 populations placed the QTL in a 77.8 kb region on chromosome 20, based on the Glyma.Wm82.a2 (Gmax2.0) map assembly. This narrowed candidate gene region can help facilitate gene cloning which ultimately can result in the identification of the causal gene(s) for one of the most widely studied, large effect protein QTL in soybean.
Mapping of Ionomic QTL in a Soybean Nested Association Mapping Population
It is estimated that nearly half of the world’s population suffers from nutrition deficiencies. With the world’s population projected to reach 9.3 billion people by 2050, there will be a need not only for more food, but also more nutritious food to alleviate nutritional deficiencies. More land will likely be used by agriculture to meet the increasing food demand, often coming from land contaminated with heavy metals or high levels of unwanted nutrients. To produce crops with increased concentration of beneficial nutrients and fewer toxic metals, one must have an understanding of the genetic control of mineral accumulation in plant tissue which can be studied through ionomic analysis. Therefore, the objective of this study was to map QTL controlling the elemental composition of soybean seed. The ionome of seed samples from two environments (Illinois 2012 and Nebraska 2012) of the soybean nested association mapping (NAM) project were analyzed for elemental concentration of 20 traits. These data were then analyzed with 4,312 SNPs in a joint linkage analysis to identify QTL from both growing environments. In total, 88 QTL were identified, including a previously identified QTL for calcium. This information can be used in additional studies to gain more knowledge of the genetic architecture of elemental accumulation in soybean, but also in marker-assisted selection and genomic prediction models. This study provides an important first step in that process which will ultimately result in biofortification of beneficial elements, and sequestration of heavy metals in crops
Reliability and Validity of Self-Reported Questionnaires Related to Adolescent Violence and Consequences, Thailand
Copyright © 2013 Wongtonkam et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.In Thailand physical violence among male adolescents is considered a significant public health issue, although there has been little published research into the aetiology and functions of violence in Thai youth. Research in this area has been hampered by a lack of psychometrically sound tools that have been validated to assess problem behaviours in Asian youth. The purpose of this paper is to provide validity and reliability data on an instrument to measure violence in Thai youth. In this study, reliability and validity data for a sample of adolescent Thai youth are reported for the Communities That Care Youth Survey (CTC-YS), a measure of risk and protective factors for violent behaviour, and the STAXI-II, a measure of angry experience and expression. The findings showed overall high internal consistency for both questionnaires, and there was evidence of construct validity. It is concluded that these measures are appropriate for use in research that seeks to investigate youth violence among adolescents in Thailand
Combined tissue and fluid proteomics with Tandem Mass Tags to identify low-abundance protein biomarkers of disease in peripheral body fluid: An Alzheimer's Disease case study
RATIONALE:
Ideal biomarkers are present in readily accessible samples including plasma and cerebrospinal fluid (CSF), and are directly derived from diseased tissue, therefore likely to be of relatively low abundance. Traditional unbiased proteomic approaches for biomarker discovery have struggled to detect low-abundance markers due to the high dynamic range of proteins, the predominance of hyper-abundant proteins, and the use of data-dependent acquisition mass spectrometry (MS). To overcome these limitations and improve biomarker discovery in peripheral fluids, we have developed TMTcalibrator™; a novel MS workflow combining isobarically labelled diseased tissue digests in parallel with an appropriate set of labelled body fluids to increase the chance of identifying low-abundance, tissue-derived biomarkers.
METHODS:
A disease relevant cell line was labelled with TMT® in a range of concentrations generating a multi-point calibration curve. Peripheral biofluid samples were labelled with the remaining tags and quantitative analysis was performed using an Orbitrap Fusion Tribrid mass spectrometer with a Top10 CID-HCD MS3 synchronous precursor selection (SPS) method. SPS allowed direct analysis of non-depleted, unfractionated CSF samples with complete profiling of six individual samples requiring only 15 hours of MS time, equivalent to 1.5 h per sample.
RESULTS:
Using the TMTcalibrator™ workflow allowed the identification of several markers of microglia activation that are differentially quantified in the CSF of patients with Alzheimer's disease (AD). We report peptides from 41 proteins that have not previously been detected in the CSF, that appear to be regulated by at least 60% in AD.
CONCLUSIONS:
This study has demonstrated the benefits of the new TMTcalibrator™ workflow and the results suggest this is a suitable and efficient method of detecting low-abundance peptides within biological fluids. The use of TMTcalibrator™ in further biomarker discovery studies should be considered to overcome some of the limitations commonly associated with more conventional approaches
Radial dyssynchrony assessed by cardiovascular magnetic resonance in relation to left ventricular function, myocardial scarring and QRS duration in patients with heart failure
Radial dyssynchrony is almost universal in patients with heart failure. This vies against the notion that a lack of response to CRT is related to a lack of dyssynchrony
Children\u27s Understanding of the Concept of Physical Activity
This study evaluated 4th-grade students\u27 understanding of the concept of physical activity and assessed the effects of two interventions to enhance the students\u27 understanding of this concept. Students were randomly assigned to 1 of 3 conditions: the video group (n=40) watched a 5-min video describing physical activity; the verbal group (n=42) listened to a generic description of physical activity; the control group received no instruction (n=45). Students completed a 17-item checklist testing their understanding of the concept of physical activity. Compared to controls, students in the verbal and video group demonstrated significantly higher checklist scores, with the video group scoring significantly higher than the verbal group. Only 35.6% of the controls compared to 52.4% and 70.0% of the verbal and video group respectively, could classify \u3e 15 of the checklist items correctly. The results indicate that, without intervention, children have a limited understanding of the concept of physical activity
G-CSF does not influence C2C12 myogenesis despite receptor expression in healthy and dystrophic skeletal muscle
Granulocyte-colony stimulating factor (G-CSF) increases recovery of rodent skeletal muscles after injury, and increases muscle function in rodent models of neuromuscular disease. However, the mechanisms by which G-CSF mediates these effects are poorly understood. G-CSF acts by binding to the membrane spanning G-CSFR and activating multiple intracellular signaling pathways. Expression of the G-CSFR within the haematopoietic system is well known, but more recently it has been demonstrated to be expressed in other tissues. However, comprehensive characterization of G-CSFR expression in healthy and diseased skeletal muscle, imperative before implementing G-CSF as a therapeutic agent for skeletal muscle conditions, has been lacking. Here we show that the G-CSFR is expressed in proliferating C2C12 myoblasts, differentiated C2C12 myotubes, human primary skeletal muscle cell cultures and in mouse and human skeletal muscle. In mdx mice, a model of human Duchenne muscular dystrophy (DMD), G-CSF mRNA and protein was down-regulated in limb and diaphragm muscle, but circulating G-CSF ligand levels were elevated. G-CSFR mRNA in the muscles of mdx mice was up-regulated however steady-state levels of the protein were down-regulated. We show that G-CSF does not influence C2C12 myoblast proliferation, differentiation or phosphorylation of Akt, STAT3, and Erk1/2. Media change alone was sufficient to elicit increases in Akt, STAT3, and Erk1/2 phosphorylation in C2C12 muscle cells and suggest previous observations showing a G-CSF increase in phosphoprotein signaling be viewed with caution. These results suggest that the actions of G-CSF may require the interaction with other cytokines and growth factors in vivo, however these data provides preliminary evidence supporting the investigation of G-CSF for the management of muscular dystrophy
A New Rodent Model to Assess Blood Stage Immunity to the Plasmodium falciparum Antigen Merozoite Surface Protein 119 Reveals a Protective Role for Invasion Inhibitory Antibodies
Antibodies capable of inhibiting the invasion of Plasmodium merozoites into erythrocytes are present in individuals that are clinically immune to the malaria parasite. Those targeting the 19-kD COOH-terminal domain of the major merozoite surface protein (MSP)-119 are a major component of this inhibitory activity. However, it has been difficult to assess the overall relevance of such antibodies to antiparasite immunity. Here we use an allelic replacement approach to generate a rodent malaria parasite (Plasmodium berghei) that expresses a human malaria (Plasmodium falciparum) form of MSP-119. We show that mice made semi-immune to this parasite line generate high levels of merozoite inhibitory antibodies that are specific for P. falciparum MSP-119. Importantly, protection from homologous blood stage challenge in these mice correlated with levels of P. falciparum MSP-119–specific inhibitory antibodies, but not with titres of total MSP-119–specific immunoglobulins. We conclude that merozoite inhibitory antibodies generated in response to infection can play a significant role in suppressing parasitemia in vivo. This study provides a strong impetus for the development of blood stage vaccines designed to generate invasion inhibitory antibodies and offers a new animal model to trial P. falciparum MSP-119 vaccines
Confidence does not mediate a relationship between owner experience and likelihood of using weight management approaches for native ponies
Funding: This study was funded by Mars Petcare and is part of a PhD studentship funded by the Scottish Funding Council Research Excellence Grant (REG). Authors WR and MN receive salary support from the Rural and Environment Science and Analytical Services Division (RESAS). With the exception of PH (employed by the funding organization), the funding organization did not have any additional role in the conceptualization, methodology, investigation, data curation, formal analysis, decision to publish, or preparation of the manuscript. PH was involved in study design, data interpretation, and manuscript preparation.Peer reviewedPublisher PD
Do Physical Activity Facilities near Schools Affect Physical Activity in High School Girls?
Objective - To investigate associations between the number of physical activity facilities within walking distance of school and physical activity behavior in 12th grade girls during after-school hours.
Methods - Girls (N=1394) from 22 schools completed a self-report to determine physical activity after 3:00 pm. The number of physical activity facilities within a 0.75-mile buffer of the school was counted with a Geographic Information System. Associations between the number of facilities and girls\u27 physical activity were examined using linear mixed-model analysis of variance.
Results - Overall, girls who attended schools with ≥ 5 facilities within the buffer reported more physical activity per day than girls in schools with \u3c 5 facilities. In addition, girls who attended rural schools with ≥ 5 facilities reported ~12% more physical activity per day than girls who attended rural schools with \u3c 5 facilities. No difference existed for girls in urban/suburban schools with ≥ 5 vs. \u3c 5 facilities.
Conclusion - When school siting decisions are made, the number of physical activity facilities surrounding the school should be considered to encourage physical activity in 12th grade girls
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