224 research outputs found
Early Life Depression: Social Moderation of the Influences of Neurotransmitter Candidate Genes and Physical Attractiveness
Understanding the social determinants of depression has remained a primary concern in the mental health literature for decades. Investigation into the topic has been productive, yielding a number of robust empirical findings and organizing theoretical frameworks. Thus, social scientists have made substantial progress in elucidating how social factors including stressful events, social support and socio-economic status influence depression over the life course. However, it is also clear that there are considerable individual differences in the impact of social factors, with some individuals showing greater vulnerability than others. This fact suggests that much of the variance in depression is due to interactions between social factors and personal characteristics not typically examined in social science research. This dissertation elaborates this line of reasoning, investigating social moderation of the influence of five neurotransmitter candidate genes and physical attractiveness on depression using data from the National Longitudinal Study of Adolescent Health. In the first empirical chapter, the direct and interactive influences of candidate genes and various dimensions of social environmental risk on depression are examined. Using false discovery rate (FDR) methods to account for multiple testing, evidence suggests possible interactions between the MAOA VNTR promoter polymorphism, particularly the 2 repeat and 3.5/4 repeat variants, and social support among females. In the second empirical chapter, temporal variation in the influence of neurotransmitter candidate genes across early life is examined. Again using FDR methods to account for multiple testing, results indicate temporal variation in the effects of the DRD4 dopamine receptor gene (5 repeat variant) for the full sample, and the MAOA VNTR promoter polymorphism (3.5 repeat) among males. The final substantive chapter examines the depressogenic influence of another source of individual differences rarely considered by social scientists--physical attractiveness. Results indicate that attractiveness becomes increasingly influential on depression as individuals age through adolescence and young adulthood, and that less attractive individuals are more resilient to the effects of eventful stress than their more attractive counterparts. Overall, this research demonstrates that, in addition to their main effects on depression, social factors represent important moderators of the influence of genetic variation and physical attractiveness
Nucleon-Nucleon Scattering under Spin-Isospin Reversal in Large-N_c QCD
The spin-flavor structure of certain nucleon-nucleon scattering observables
derived from the large N_c limit of QCD in the kinematical regime where
time-dependent mean-field theory is valid is discussed. In previous work, this
regime was taken to be where the external momentum was of order N_c which
precluded the study of differential cross sections in elastic scattering. Here
it is shown that the regime extends down to order N_c^{1/2} which includes the
higher end of the elastic regime. The prediction is that in the large N_c
limit, observables describable via mean-field theory are unchanged when the
spin and isospin of either nucleon are both flipped. This prediction is tested
for proton-proton and neutron-proton elastic scattering data and found to fail
badly. We argue that this failure can be traced to a lack of a clear separation
of scales between momentum of order N_c^{1/2} and N_c^1 when N_c is as small as
three. The situation is compounded by an anomalously low particle production
threshold due to approximate chiral symmetry.Comment: 5 pages, 1 figur
Pathways to the all-volunteer military*
The present study investigates the role of a disadvantaged background, the lack of social connectedness, and behavioral problems in channeling young men to the opportunities of the all-volunteer military instead of to college and the labor market
Technologies and Approaches to Elucidate and Model the Virulence Program of Salmonella
Salmonella is a primary cause of enteric diseases in a variety of animals. During its evolution into a pathogenic bacterium, Salmonella acquired an elaborate regulatory network that responds to multiple environmental stimuli within host animals and integrates them resulting in fine regulation of the virulence program. The coordinated action by this regulatory network involves numerous virulence regulators, necessitating genome-wide profiling analysis to assess and combine efforts from multiple regulons. In this review we discuss recent high-throughput analytic approaches used to understand the regulatory network of Salmonella that controls virulence processes. Application of high-throughput analyses have generated large amounts of data and necessitated the development of computational approaches for data integration. Therefore, we also cover computer-aided network analyses to infer regulatory networks, and demonstrate how genome-scale data can be used to construct regulatory and metabolic systems models of Salmonella pathogenesis. Genes that are coordinately controlled by multiple virulence regulators under infectious conditions are more likely to be important for pathogenesis. Thus, reconstructing the global regulatory network during infection or, at the very least, under conditions that mimic the host cellular environment not only provides a bird's eye view of Salmonella survival strategy in response to hostile host environments but also serves as an efficient means to identify novel virulence factors that are essential for Salmonella to accomplish systemic infection in the host
A systematic method for estimating individual responses to treatment with antipsychotics in CATIE
In addition to comparing drug treatment groups, the wealth of genetic and clinical data collected in the Clinical Antipsychotic Trials of Intervention Effectiveness study offers tremendous opportunities to study individual differences in response to treatment with antipsychotics. A major challenge, however, is how to estimate the individual responses to treatments. For this purpose, we propose a systematic method that condenses all information collected during the trials in an optimal, empirical fashion
Excited Baryon Decay Widths in Large N_c QCD
We study excited baryon decay widths in large N_c QCD. It was suggested
previously that some spin-flavor mixed-symmetric baryon states have strong
couplings of O(N_c^{-1/2}) to nucleons [implying narrow widths of O(1/N_c)], as
opposed to the generic expectation based on Witten's counting rules of an
O(N_c^0) coupling. The calculation obtaining these narrow widths was performed
in the context of a simple quark-shell model. This paper addresses the question
of whether the existence of such narrow states is a general property of large
N_c QCD. We show that a general large N_c QCD analysis does not predict such
narrow states; rather they are a consequence of the extreme simplicity of the
quark model.Comment: 9 page
The influence of five monoamine genes on trajectories of depressive symptoms across adolescence and young adulthood
The influence of five monoamine candidate genes on depressive symptom trajectories in adolescence and young adulthood were examined in the Add Health genetic sample. Results indicated that, for all respondents, carriers of the DRD4 5-repeat allele were characterized by distinct depressive symptom trajectories across adolescence and early adulthood. Similarly, for males, individuals with the MAOA 3.5-repeat allele exhibited unique depressive symptom trajectories. Specifically, the trajectories of those with the DRD4 5-repeat allele were characterized by rising levels in the transition to adulthood, while their peers were experiencing a normative drop in depressive symptom frequency. Conversely, males with the MAOA 3.5-repeat allele were shown to experience increased distress in late adolescence. An empirical method for examining a wide array of allelic combinations was employed, and false discovery rate methods were used to control the risk of false positives due to multiple testing. Special attention was given to thoroughly interrogate the robustness of the putative genetic effects. These results demonstrate the value of combining dynamic developmental perspectives with statistical genetic methods to optimize the search for genetic influences on psychopathology across the life course
A randomized phase 2 study of temsirolimus and cetuximab versus temsirolimus alone in recurrent/metastatic, cetuximab‐resistant head and neck cancer: The MAESTRO study
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155947/1/cncr32929_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155947/2/cncr32929.pd
Prospects for Pentaquark Production at Meson Factories
Following Rosner [hep-ph/0312269], we consider B-decay production channels
for the exotic I=0 and pentaquarks that have been recently reported. We
also discuss new search channels for isovector pentaquarks, such as the
, that are generically present in chiral soliton
models but were not observed in recent experiments. Futhermore, we argue that
weak decays of charmed baryons, such as the and ,
provide another clean way of detecting exotic baryons made of light quarks
only. We also discuss discovery channels for charmed pentaquarks, such as the
isosinglet , in weak decays of bottom mesons and
baryons. Finally, we discuss prospects for inclusive production of pentaquarks
in collisions, with associated production of particles carrying the
opposite baryon number.Comment: 15 pages, LaTeX; v2,v3: minor corrections, references added; v4:
minor modifications, the version published in Physics Letters
Omic data from evolved E. coli are consistent with computed optimal growth from genome-scale models
Proteomic and transcriptomic data from wild-type and laboratory-evolved strains of Escherichia coli are consistent with predicted pathway usage from optimal growth rate solutions.In laboratory-evolved strains, there is an upregulation of the pathways in the computed optimal growth states, and downregulation of non-functional pathways.Known regulatory mechanisms are only partially responsible for altered metabolic pathway activity
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