757 research outputs found
The Noncommutative Harmonic Oscillator based in Simplectic Representation of Galilei Group
In this work we study symplectic unitary representations for the Galilei
group. As a consequence the Schr\"odinger equation is derived in phase space.
The formalism is based on the non-commutative structure of the star-product,
and using the group theory approach as a guide a physical consistent theory in
phase space is constructed. The state is described by a quasi-probability
amplitude that is in association with the Wigner function. The 3D harmonic
oscillator and the noncommutative oscillator are studied in phase space as an
application, and the Wigner function associated to both cases are determined.Comment: 7 pages,no figure
TonEBP/NFAT5 promotes obesity and insulin resistance by epigenetic suppression of white adipose tissue beiging
Tonicity-responsive enhancer binding protein (TonEBP or NFAT5) is a regulator of cellular adaptation to hypertonicity, macrophage activation and T-cell development. Here we report that TonEBP is an epigenetic regulator of thermogenesis and obesity. In mouse subcutaneous adipocytes, TonEBP expression increases > 50-fold in response to high-fat diet (HFD) feeding. Mice with TonEBP haplo-deficiency or adipocyte-specific TonEBP deficiency are resistant to HFD-induced obesity and metabolic defects (hyperglycemia, hyperlipidemia, and hyperinsulinemia). They also display increased oxygen consumption, resistance to hypothermia, and beiging of subcutaneous fat tissues. TonEBP suppresses the promoter of beta 3-adrenoreceptor gene, a critical regulator of lipolysis and thermogenesis, in ex vivo and cultured adipocytes. This involves recruitment of DNMT1 DNA methylase and methylation of the promoter. In human subcutaneous adipocytes TonEBP expression displays a correlation with body mass index but an inverse correlation with beta 3-adrenoreceptor expression. Thus, TonEBP is an attractive therapeutic target for obesity, insulin resistance, and hyperlipidemia
P20-08. Glycosylation: an important factor in Env diversity
Supported by a CAVD Grant from the Bill and Melinda Gates Foundation
Heritable symbionts in a world of varying temperature
Heritable microbes represent an important component of the biology, ecology and evolution of many plants, animals and fungi, acting as both parasites and partners. In this review, we examine how heritable symbiont–host interactions may alter host thermal tolerance, and how the dynamics of these interactions may more generally be altered by thermal environment. Obligate symbionts, those required by their host, are considered to represent a thermally sensitive weak point for their host, associated with accumulation of deleterious mutations. As such, these symbionts may represent an important determinant of host thermal envelope and spatial distribution. We then examine the varied relationship between thermal environment and the frequency of facultative symbionts that provide ecologically contingent benefits or act as parasites. We note that some facultative symbionts directly alter host thermotolerance. We outline how thermal environment will alter the benefits/costs of infection more widely, and additionally modulate vertical transmission efficiency. Multiple patterns are observed, with symbionts being cold sensitive in some species and heat sensitive in others, with varying and non-coincident thresholds at which phenotype and transmission are ablated. Nevertheless, it is clear that studies aiming to predict ecological and evolutionary dynamics of symbiont–host interactions need to examine the interaction across a range of thermal environments. Finally, we discuss the importance of thermal sensitivity in predicting the success/failure of symbionts to spread into novel species following natural/engineered introduction
Short-Lived Trace Gases in the Surface Ocean and the Atmosphere
The two-way exchange of trace gases between the ocean and the atmosphere is important for both the chemistry and physics of the atmosphere and the biogeochemistry of the oceans, including the global cycling of elements. Here we review these exchanges and their importance for a range of gases whose lifetimes are generally short compared to the main greenhouse gases and which are, in most cases, more reactive than them. Gases considered include sulphur and related compounds, organohalogens, non-methane hydrocarbons, ozone, ammonia and related compounds, hydrogen and carbon monoxide. Finally, we stress the interactivity of the system, the importance of process understanding for modeling, the need for more extensive field measurements and their better seasonal coverage, the importance of inter-calibration exercises and finally the need to show the importance of air-sea exchanges for global cycling and how the field fits into the broader context of Earth System Science
Structural rearrangements maintain the Glycan Shield of an HIV-1 envelope trimer after the loss of a glycan
The HIV-1 envelope (Env) glycoprotein is the primary target of the humoral immune response and a
critical vaccine candidate. However, Env is densely glycosylated and thereby substantially protected
from neutralisation. Importantly, glycan N301 shields V3 loop and CD4 binding site epitopes from
neutralising antibodies. Here, we use molecular dynamics techniques to evaluate the structural
rearrangements that maintain the protective qualities of the glycan shield after the loss of glycan
N301. We examined a naturally occurring subtype C isolate and its N301A mutant; the mutant not
only remained protected against neutralising antibodies targeting underlying epitopes, but also
exhibited an increased resistance to the VRC01 class of broadly neutralising antibodies. Analysis
of this mutant revealed several glycans that were responsible, independently or through synergy,
for the neutralisation resistance of the mutant. These data provide detailed insight into the glycan
shield’s ability to compensate for the loss of a glycan, as well as the cascade of glycan movements on
a protomer, starting at the point mutation, that affects the integrity of an antibody epitope located at
the edge of the diminishing effect. These results present key, previously overlooked, considerations for
HIV-1 Env glycan research and related vaccine studies.IS
The ISoP CommSIG for Improving Medicinal Product Risk Communication: A New Special Interest Group of the International Society of Pharmacovigilance
Prediction of gastrointestinal disease with over-the-counter diarrheal remedy sales records in the San Francisco Bay Area
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