682 research outputs found
GROWING RESILIENCE WITH MOBILE TECHNOLOGY: “USMC CONNECT” AND RESILIENCE IN THE MARINE CORPS RESERVE FORCES
The aim of this study was to quantitatively analyze the introduction and use of resilience interventions with the USMC Connect application in order to develop possible structured ways to introduce consistent resilience training to the Marines, while also examining USMC Connect’s effectiveness in individuals learning its material. Four USMC Reserve units participated in the field study. One unit received resilience interventions in the form of regular nudge or push notifications which appeared on their phones like a text message. Another had access to the mobile application but did not have nudge notifications for interventions from the researchers. A third group served as a control group and did not have access to the application. The fourth control group did not receive access to the application but received resilience interventions. Each group was assessed for resilience and other factors before and after the intervention period. Measures of resilience and other related instruments were used to assess changes in resilience and what we expect affects those changes. However, due to low participation in the second survey, the study turned to reporting and analyzing resilience scores from each unit’s initial survey results to examine resilience measurements and its associated key factors.Major, United States Marine CorpsApproved for public release. Distribution is unlimited
Cognitive Function and Atrial Fibrillation: From the Strength of Relationship to the Dark Side of Prevention. Is There a Contribution from Sinus Rhythm Restoration and Maintenance?
Atrial fibrillation (AF) is the most common chronic cardiac arrhythmia with an increasing prevalence over time mainly because of population aging. It is well established that the presence of AF increases the risk of stroke, heart failure, sudden death, and cardiovascular morbidity. In the last two decades several reports have shown an association between AF and cognitive function, ranging from impairment to dementia. Ischemic stroke linked to AF is a well-known risk factor and predictor of cognitive decline. In this clinical scenario, the risk of stroke might be reduced by oral anticoagulation. However, recent data suggest that AF may be a predictor of cognitive impairment and dementia also in the absence of stroke. Cerebral hypoperfusion, reduced brain volume, microbleeds, white matter hyperintensity, neuroinflammation, and genetic factors have been considered as potential mechanisms involved in the pathogenesis of AF-related cognitive dysfunction. However, a cause-effect relationship remains still controversial. Consequently, no therapeutic strategies are available to prevent AF-related cognitive decline in stroke-free patients. This review will analyze the potential mechanisms leading to cognitive dysfunction in AF patients and examine the available data on the impact of a sinus rhythm restoration and maintenance strategy in reducing the risk of cognitive decline
Grapevine leafroll-associated virus 3.
Grapevine leafroll disease (GLD) is one of the most important grapevine viral diseases affecting grapevines worldwide. The impact on vine health, crop yield, and quality is difficult to assess due to a high number of variables, but significant economic losses are consistently reported over the lifespan of a vineyard if intervention strategies are not implemented. Several viruses from the family Closteroviridae are associated with GLD. However, Grapevine leafroll-associated virus 3 (GLRaV-3), the type species for the genus Ampelovirus, is regarded as the most important causative agent. Here we provide a general overview on various aspects of GLRaV-3, with an emphasis on the latest advances in the characterization of the genome. The full genome of several isolates have recently been sequenced and annotated, revealing the existence of several genetic variants. The classification of these variants, based on their genome sequence, will be discussed and a guideline is presented to facilitate future comparative studies. The characterization of sgRNAs produced during the infection cycle of GLRaV-3 has given some insight into the replication strategy and the putative functionality of the ORFs. The latest nucleotide sequence based molecular diagnostic techniques were shown to be more sensitive than conventional serological assays and although ELISA is not as sensitive it remains valuable for high-throughput screening and complementary to molecular diagnostics. The application of next-generation sequencing is proving to be a valuable tool to study the complexity of viral infection as well as plant pathogen interaction. Next-generation sequencing data can provide information regarding disease complexes, variants of viral species, and abundance of particular viruses. This information can be used to develop more accurate diagnostic assays. Reliable virus screening in support of robust grapevine certification programs remains the cornerstone of GLD management
Unusual sesquiterpene glucosides from Amaranthus retroflexus
Abstract—Implementing the phytochemical study of the weed Amaranthus retroflexus, four new sesquiterpene glucosides were isolated
from the methanolic extract of the plant. The structures of these metabolites are determined on the basis of the mass spectrometry, and 1D
and 2D NMR spectroscopies (DQ-COSY, TOCSY, HSQC, HSQC–TOCSY, HMBC, and NOESY). Two compounds are characterized by
a new aglycone and differed from the site of glucosylation. The other two compounds are dimeric diastereoisomers.
All the glucoside sesquiterpenes were tested on the wild species Taraxacum officinale to evaluate the role of this weed in the habitat and on the seed of A. retroflexus to verify the potential autotoxic effect of the plant
Dimensionality assessment in bifactor structures with multiple general factors: a network psychometrics approach
The accuracy of factor retention methods for structures with one or more general
factors, like the ones typically encountered in fields like intelligence, personality,
and psychopathology, has often been overlooked in dimensionality research. To
address this issue, we compared the performance of several factor retention methods
in this context, including a network psychometrics approach developed in this
study. For estimating the number of group factors, these methods were the Kaiser
criterion, empirical Kaiser criterion, parallel analysis with principal components
(PAPCA) or principal axis, and exploratory graph analysis with Louvain clustering
(EGALV). We then estimated the number of general factors using the factor
scores of the first-order solution suggested by the best two methods, yielding a
“second-order” version of PAPCA (PAPCA-FS) and EGALV (EGALV-FS). Additionally,
we examined the direct multilevel solution provided by EGALV. All the methods
were evaluated in an extensive simulation manipulating nine variables of interest,
including population error. The results indicated that EGALV and PAPCA displayed
the best overall performance in retrieving the true number of group factors, the
former being more sensitive to high cross-loadings, and the latter to weak group
factors and small samples. Regarding the estimation of the number of general
factors, both PAPCA-FS and EGALV-FS showed a close to perfect accuracy across all
the conditions, while EGALV was inaccurate. The methods based on EGA were
robust to the conditions most likely to be encountered in practice. Therefore, we
highlight the particular usefulness of EGALV (group factors) and EGALV-FS (general
factors) for assessing bi-factor structures with multiple general factorsThis research was supported by Grant PSI2017-85022-P (Ministerio
de Ciencia, InnovaciĂłn y Universidades, Spain) and the UAM IIC Chair
Psychometric Models and Applications. Luis Eduardo Garrido is supported by
Grant 2018-2019-1D2-085 from the Fondo Nacional de InnovaciĂłn Desarrollo
CientĂfico y TecnolĂłgico (FONDOCYT) of the Dominican Republic. The results
of this work were presented in the XVII Congress of the Spanish Association of
Methodology for the Social Sciences (AEMCCO XVII) and the manuscript was
published as a preprint in the psyarxiv repository at https://psyarxiv.com/2ujdk
Engineering a detect and destroy skin probiotic to combat methicillin-resistant Staphylococcus aureus.
The prevalence and virulence of pathogens such as methicillin-resistant Staphylococcus (S.) aureus (MRSA), which can cause recurrent skin infections, are of significant clinical concern. Prolonged antibiotic exposure to treat or decolonize S. aureus contributes to development of antibiotic resistance, as well as depletion of the microbiome, and its numerous beneficial functions. We hypothesized an engineered skin probiotic with the ability to selectively deliver antimicrobials only in the presence of the target organism could provide local bioremediation of pathogen colonization. We constructed a biosensing S. epidermidis capable of detecting the presence of S. aureus quorum sensing autoinducer peptide and producing lysostaphin in response. Here, we demonstrate in vitro activity of this biosensor and present and discuss challenges to deployment of this and other engineered topical skin probiotics
A Markovian Entropy Measure for the Analysis of Calcium Activity Time Series
Methods to analyze the dynamics of calcium activity often rely on visually distinguishable features in time series data such as spikes, waves, or oscillations. However, systems such as the developing nervous system display a complex, irregular type of calcium activity which makes the use of such methods less appropriate. Instead, for such systems there exists a class of methods (including information theoretic, power spectral, and fractal analysis approaches) which use more fundamental properties of the time series to analyze the observed calcium dynamics. We present a new analysis method in this class, the Markovian Entropy measure, which is an easily implementable calcium time series analysis method which represents the observed calcium activity as a realization of a Markov Process and describes its dynamics in terms of the level of predictability underlying the transitions between the states of the process. We applied our and other commonly used calcium analysis methods on a dataset from Xenopus laevis neural progenitors which displays irregular calcium activity and a dataset from murine synaptic neurons which displays activity time series that are well-described by visually-distinguishable features. We find that the Markovian Entropy measure is able to distinguish between biologically distinct populations in both datasets, and that it can separate biologically distinct populations to a greater extent than other methods in the dataset exhibiting irregular calcium activity. These results support the benefit of using the Markovian Entropy measure to analyze calcium dynamics, particularly for studies using time series data which do not exhibit easily distinguishable features
Serotonin Antagonism Improves Platelet Inhibition in Clopidogrel Low-Responders after Coronary Stent Placement: An In Vitro Pilot Study
Increased residual platelet reactivity remains a burden for coronary artery disease (CAD) patients who received a coronary stent and do not respond sufficiently to treatment with acetylsalicylic acid and clopidogrel. We hypothesized that serotonin antagonism reduces high on-treatment platelet reactivity. Whole blood impedance aggregometry was performed with arachidonic acid (AA, 0.5 mM) and adenosine diphosphate (ADP, 6.5 µM) in addition to different concentrations of serotonin (1–100 µM) in whole blood from 42 CAD patients after coronary stent placement and 10 healthy subjects. Serotonin increased aggregation dose-dependently in CAD patients who responded to clopidogrel treatment: After activation with ADP, aggregation increased from 33.7±1.3% to 40.9±2.0% in the presence of 50 µM serotonin (p<0.05) and to 48.2±2.0% with 100 µM serotonin (p<0.001). The platelet serotonin receptor antagonist ketanserin decreased ADP-induced aggregation significantly in clopidogrel low-responders (from 59.9±3.1% to 37.4±3.5, p<0.01), but not in clopidogrel responders. These results were confirmed with light transmission aggregometry in platelet-rich plasma in a subset of patients. Serotonin hence increased residual platelet reactivity in patients who respond to clopidogrel after coronary stent placement. In clopidogrel low-responders, serotonin receptor antagonism improved platelet inhibition, almost reaching responder levels. This may justify further investigation of triple antiplatelet therapy with anti-serotonergic agents
Unique Variable Analysis of Redundancy in ADHD Items from the Conners Teacher Rating Scale - Revised: Short.
peer reviewedAttention deficit hyperactivity disorder (ADHD) is a neuropsychiatric disorder interfering with the normal development of the child. The disorder can be screened at school with the Conners Teacher Rating Scale Revised Short (CTRS-R:S). This scale goes beyond the disorder itself and covers a wider construct, that of abnormal child behavior. This can be understood as a complex system of mutually influencing entities. We analyzed a data set of 525 children in French-speaking primary schools from Belgium, and estimated a network structure, as well as to determine the local dependence of items through Unique Variable Analysis. A reduced network was computed including 15 non-locally dependent items. The structural consistency of the network was not affected by redundant items and was structurally sound. The reduction of the number of variables in network studies is important to improve the investigation of network structures as well as better interpret results from inference measures
Monitoring multiple myeloma by idiotype-specific peptide binders of tumor-derived exosomes.
Abstract Tumor-derived exosomes (TDEs) play a pivotal role in tumor establishment and progression, and are emerging biomarkers for tumor diagnosis in personalized medicine. To date, there is a lack of efficient technology platforms for exosome isolation and characterization. Multiple myeloma (MM) is an incurable B-cell malignancy due to the rapid development of drug-resistance. MM-released exosomes express the immunoglobulin B-cell receptor (Ig-BCR) of the tumor B-cells, which can be targeted by Idiotype-binding peptides (Id-peptides). In this study, we analyzed the production of MM-released exosomes in the murine 5T33MM multiple myeloma model as biomarkers of tumor growth. To this end, we selected Id-peptides by screening a phage display library using as bait the Ig-BCR expressed by 5T33MM cells. By FACS, the FITC-conjugated Id-peptides detected the MM-released exosomes in the serum of 5T33MM-engrafted mice, levels of which are correlated with tumor progression at an earlier time point compared to serum paraprotein. These results indicate that Id-peptide-based recognition of MM-released exosomes may represent a very sensitive diagnostic approach for clinical evaluation of disease progression
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