2,127 research outputs found
New Insight into Metformin Mechanism of Action and Clinical Application
Metformin is the first-line medication for Type 2 diabetes (T2D) treatment, and it is the only US FDA approved oral antidiabetic medication for pediatric patients with T2D 10 years and older. Metformin is also used to treat polycystic ovary syndrome (PCOS), another condition with underlying insulin resistance. The clinical applications of metformin are continuing to expand into other fields including cancer, aging, cardiovascular diseases, and neurodegenerative diseases. Metformin modulates multiple biological pathways. Its novel properties and effects continue to evolve; however, its molecular mechanism of action remains incompletely understood. In this chapter, we focus on the recent translational research and clinical data on the molecular action of metformin and the evidence linking the effects of metformin on insulin resistance, prediabetes, diabetes, aging, cancer, PCOS, cardiovascular diseases, and neurodegenerative diseases
Partial cold treatment of citrus fruit for export risk mitigation for Thaumatotibia leucotreta (Lepidoptera: Tortricidae) as part of a systems approach
Some of South Africa’s citrus export markets require mandatory postharvest cold treatment of citrus fruit as a phytosanitary risk mitigation treatment for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). An alternative to this may be partial cold treatment as one of the final steps in a systems approach to mitigate phytosanitary risk. Consequently, the efficacy of such partial cold treatments was evaluated. It was first determined that a 2C cold treatment was significantly more effective against fourth and fifth instars (the most cold-tolerant instars) than treatments at 3C and 4C for a duration of 18 d. Secondly, it was determined that 2C for 18 d and 1C for 16 d were similarly effective, but both treatments were significantly more effective than 1C for 14 d. Mean mortality of fourth and fifth instars treated with 2C for 18 d in seven replicates from four trials was 99.94%. Finally, it was determined that the inability of the majority of surviving larvae to develop to adulthood would further increase the efficacy of a 2C for 18 d treatment to 99.96%. Inclusion of reproductive nonviability of survivors increased mortality to 99.99%
Theory of Circle Maps and the Problem of One-Dimensional Optical Resonator with a Periodically Moving Wall
We consider the electromagnetic field in a cavity with a periodically
oscillating perfectly reflecting boundary and show that the mathematical theory
of circle maps leads to several physical predictions. Notably, well-known
results in the theory of circle maps (which we review briefly) imply that there
are intervals of parameters where the waves in the cavity get concentrated in
wave packets whose energy grows exponentially. Even if these intervals are
dense for typical motions of the reflecting boundary, in the complement there
is a positive measure set of parameters where the energy remains bounded.Comment: 34 pages LaTeX (revtex) with eps figures, PACS: 02.30.Jr, 42.15.-i,
42.60.Da, 42.65.Y
Fructose Intake: Metabolism and Role in Diseases
Fructose consumption has dramatically increased worldwide over the past decades. There are numerous clinical, experimental, and epidemiological studies evidenced that increased consumption of fructose negatively impacts carbohydrate metabolism and lactate formed from fructose can also affect whole-body energy balance. Excessive fructose intake stimulates endogenous glucose production and lipid synthesis in the liver. Currently fructose is believed to be a major contributing factor to chronic metabolic diseases, including obesity, insulin resistance, hypertriglyceridemia, and non-alcoholic fatty liver disease, hyperglycemia, type 2 diabetes, and cancer. These new findings bring challenges to researchers today because of what is still to be discovered, and how to apply what has been discovered to modern health. Further investigation should seek to analyze and understand specific mechanistic effects of fructose in metabolic pathways, and how to apply this knowledge to our daily lives. Conducting this monosaccharide research is important to improve the diet of the general population and to attenuate the epidemics of metabolic disease and associated diseases. Here, we focus on the mechanism and role of fructose in diseases as well as its potential as a dietary interventional target
Data Assimilation Enhancements to Air Force Weathers Land Information System
The United States Air Force (USAF) has a proud and storied tradition of enabling significant advancements in the area of characterizing and modeling land state information. 557th Weather Wing (557 WW; DoDs Executive Agent for Land Information) provides routine geospatial intelligence information to warfighters, planners, and decision makers at all echelons and services of the U.S. military, government and intelligence community. 557 WW and its predecessors have been home to the DoDs only operational regional and global land data analysis systems since January 1958. As a trusted partner since 2005, Air Force Weather (AFW) has relied on the Hydrological Sciences Laboratory at NASA/GSFC to lead the interagency scientific collaboration known as the Land Information System (LIS). LIS is an advanced software framework for high performance land surface modeling and data assimilation of geospatial intelligence (GEOINT) information
Search for Electroweak Production of Single Top Quarks in ppbar Collisions
We present a search for electroweak production of single top quarks in the
electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of
data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with
the DZero detector between 1992 and 1995. We use events that include a tagging
muon, implying the presence of a b jet, to set an upper limit at the 95%
confidence level on the cross section for the s-channel process ppbar->tb+X of
39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb.Comment: 11 pages, 2 figures. This is the published versio
A Quasi-Model-Independent Search for New Physics at Large Transverse Momentum
We apply a quasi-model-independent strategy ("Sleuth") to search for new high
p_T physics in approximately 100 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV
collected by the DZero experiment during 1992-1996 at the Fermilab Tevatron.
Over thirty-two e mu X, W+jets-like, Z+jets-like, and 3(lepton/photon)X
exclusive final states are systematically analyzed for hints of physics beyond
the standard model. Simultaneous sensitivity to a variety of models predicting
new phenomena at the electroweak scale is demonstrated by testing the method on
a particular signature in each set of final states. No evidence of new high p_T
physics is observed in the course of this search, and we find that 89% of an
ensemble of hypothetical similar experimental runs would have produced a final
state with a candidate signal more interesting than the most interesting
observed in these data.Comment: 28 pages, 17 figures. Submitted to Physical Review
Search for R-parity Violating Supersymmetry in Dimuon and Four-Jets Channel
We present results of a search for R-parity-violating decay of the neutralino
chi_1^0, taken to be the Lightest Supersymmetric Particle. It is assumed that
this decay proceeds through one of the lepton-number violating couplings
lambda-prime_2jk (j=1,2; k=1,2,3). This search is based on 77.5 pb-1 of data,
collected by the D0 experiment at the Fermilab Tevatron in ppbar collisions at
a center of mass energy of 1.8 TeV in 1992-1995.Comment: 10 pages, 3 figure
Search for New Physics Using Quaero: A General Interface to D0 Event Data
We describe Quaero, a method that i) enables the automatic optimization of
searches for physics beyond the standard model, and ii) provides a mechanism
for making high energy collider data generally available. We apply Quaero to
searches for standard model WW, ZZ, and ttbar production, and to searches for
these objects produced through a new heavy resonance. Through this interface,
we make three data sets collected by the D0 experiment at sqrt(s)=1.8 TeV
publicly available.Comment: 7 pages, submitted to Physical Review Letter
Direct Search for Charged Higgs Bosons in Decays of Top Quarks
We present a search for charged Higgs bosons in decays of pair-produced top
quarks in pbar p collisions at sqrt(s) = 1.8 TeV using 62.2 pb^-1 of data
recorded by the D0 detector at the Fermilab Tevatron collider. No evidence is
found for signal, and we exclude at 95% confidence most regions of the (M
higgs, tan beta) parameter space where the decay t->H b has a branching
fraction greater than 0.36 and B(H -> tau nu) is large.Comment: 11 pages, 4 figures, submitted to Phys. Rev. Let
- …