9,838 research outputs found
Fasting and Postprandial Glucose Levels after a Single Resistance Training Event in Mexican-Americans
TACSM Abstract
Fasting and Postprandial Glucose Levels after a Single Resistance Training Event in Mexican-Americans
Lopez I, Kendrick KH, and Smith JD
Health & Human Performance Laboratory; Department of Health & Kinesiology; Texas A&M University-San Antonio; San Antonio, TX
Category: Masters
Advisor / Mentor: Kendrick, K. ([email protected])
ABSTRACT
The number of Mexican-Americans diagnosed with diabetes has increased, with 10.2% diagnosed in 2010. Physical activity is an important component to help maintain healthy body weight and composition, and prevent diseases. Previous research has shown that a single event of resistance training can have a positive effect on glucose levels, but little is known about exercise’s effect in the Mexican-American population. Therefore, the purpose of this study is to analyze the fasting and postprandial glucose levels after a single resistance training event in Mexican-Americans. IRB approval was granted by Texas A&M University-San Antonio for this study. Fifteen subjects (Age=25.9±3.3 yrs, Ht=165.0±7.7 cm, Wt=71.2±13.5 kg) of Mexican-American ethnicity were recruited at Texas A&M University-San Antonio. A pre-trial training day occurred so that subjects could become familiar with the resistance training procedure. All exercises were completed using the Raptor series stack weights by ProMaxima or the ProMaxima leg sled; abdominal crunches were completed as described by the Fitnessgram®. All subjects completed both a resistance training event (RT) in which subjects completed 8 exercises (3 sets of 8-12 reps, one minute rest between sets, resistance determined at pre-trial) and a non-training event (NT). The order of trials was randomly selected for a counter-balanced design. After the RT, subjects reported to the Human performance lab approximately 14 hours later, having fasted for at least 8 hours. Finger-sticks were used to collect blood samples for glucose analysis. A Cardio Check professional grade meter was used to perform glucose analyses. Subjects were then served a high carbohydrate (1.5 g/kg body weight), high fat (0.25 g/kg body weight) breakfast to consume prior blood sample collection. The NT was performed as described above except subjects did not take part in the resistance protocol prior to the specimen collection, breakfast, and subsequent specimen collection. Glucose area under the curve (AUC) was calculated using a trapezoidal calculation for each subject, for each the RT and NT events. A paired t-test was used to compare the means of the NT to the RT glucose AUC. Resistance training AUC (11,960±1,961 mg/dL/min) was significantly less than NT AUC (12,885±1,993 mg/dL/min), t(14)=-2.193,
All-angle negative refraction of highly squeezed plasmon and phonon polaritons in graphene-boron nitride heterostructures
A fundamental building block for nanophotonics is the ability to achieve
negative refraction of polaritons, because this could enable the demonstration
of many unique nanoscale applications such as deep-subwavelength imaging,
superlens, and novel guiding. However, to achieve negative refraction of highly
squeezed polaritons, such as plasmon polaritons in graphene and phonon
polaritons in boron nitride (BN) with their wavelengths squeezed by a factor
over 100, requires the ability to flip the sign of their group velocity at
will, which is challenging. Here we reveal that the strong coupling between
plasmon and phonon polaritons in graphene-BN heterostructures can be used to
flip the sign of the group velocity of the resulting hybrid
(plasmon-phonon-polariton) modes. We predict all-angle negative refraction
between plasmon and phonon polaritons, and even more surprisingly, between
hybrid graphene plasmons, and between hybrid phonon polaritons. Graphene-BN
heterostructures thus provide a versatile platform for the design of
nano-metasurfaces and nano-imaging elements.Comment: 16 pages; 3 figure
Do school preferences differ between mothers and fathers? International evidence from PISA
A sizeable literature – spanning education, sociology and economics – has investigated the issue of parental school preferences and school choice. A notable gap in the existing evidence base is an exploration of how such preferences differ between mothers and fathers. We present new cross-national findings on this matter, drawing on survey data collected from more than 300,000 parents across 25 countries. Our findings suggest that mothers rate the school environment – whether the school is safe and has a pleasant atmosphere – to be more important than fathers. Differences are also observed with respect to the school’s reputation and whether it has a high level of achievement. Clearer evidence of such differences emerges for industrialised Western nations than for countries that are not members of the OECD. In most countries, mothers’ and fathers’ preferences do not vary substantially between sons and daughters.This work has been partly supported by FEDER funding (under Research Project PY20-00228-R); Ministerio de Ciencia e Innovación (under Research Project PID2020-119471RB-I00); by the Andalusian Regional Government (SEJ-645) and the Universidad de Málaga under Research Project B1-2022_23
Substrate-Independent Light Confinement in Bioinspired All-Dielectric Surface Resonators
Traditionally, photonic crystal slabs can support resonances that are strongly confined to the slab but also couple to external radiation. However, when a photonic crystal slab is placed on a substrate, the resonance modes become less confined, and as the index contrast between slab and substrate decreases, they eventually disappear. Using the scale structure of the Dione juno butterfly wing as an inspiration, we present a low-index zigzag surface structure that supports resonance modes even without index contrast with the substrate. The zigzag structure supports resonances that are contained away from the substrate, which reduces the interaction between the resonance and the substrate. We experimentally verify the existence of substrate-independent resonances in the visible wavelength regime. Potential applications include substrate-independent structural color and light guiding.United States. Army Research Office (W911NF-13-D-0001)Solid-State Solar-Thermal Energy Conversion Center (DE-SC0001299)National Science Foundation (U.S.) (1122374
Downregulation of 26S proteasome catalytic activity promotes epithelial-mesenchymal transition.
The epithelial-mesenchymal transition (EMT) endows carcinoma cells with phenotypic plasticity that can facilitate the formation of cancer stem cells (CSCs) and contribute to the metastatic cascade. While there is substantial support for the role of EMT in driving cancer cell dissemination, less is known about the intracellular molecular mechanisms that govern formation of CSCs via EMT. Here we show that β2 and β5 proteasome subunit activity is downregulated during EMT in immortalized human mammary epithelial cells. Moreover, selective proteasome inhibition enabled mammary epithelial cells to acquire certain morphologic and functional characteristics reminiscent of cancer stem cells, including CD44 expression, self-renewal, and tumor formation. Transcriptomic analyses suggested that proteasome-inhibited cells share gene expression signatures with cells that have undergone EMT, in part, through modulation of the TGF-β signaling pathway. These findings suggest that selective downregulation of proteasome activity in mammary epithelial cells can initiate the EMT program and acquisition of a cancer stem cell-like phenotype. As proteasome inhibitors become increasingly used in cancer treatment, our findings highlight a potential risk of these therapeutic strategies and suggest a possible mechanism by which carcinoma cells may escape from proteasome inhibitor-based therapy
Z(2)-Singlino Dark Matter in a Portal-Like Extension of the Minimal Supersymmetric Standard Model.
We propose a Z2-stabilized singlino () as a dark matter candidate in extended and R-parity violating versions of the supersymmetric standard model. interacts with visible matter via a heavy messenger field S, which results in a supersymmetric version of the Higgs portal interaction. The relic abundance of can account for cold dark matter if the messenger mass satisfies GeV. Our model can be implemented in many realistic supersymmetric models such as the next-to-minimal supersymmetric (SUSY) standard model and nearly minimal SUSY standard model
Spanish version of the Oral Health Impact Profile (OHIP-Sp)
BACKGROUND: The need for appraisal of oral health-related quality of life has been increasingly recognized over the last decades. The aims of this study were to develop a Spanish version (OHIP-Sp) of the Oral Health Impact Profile and to evaluate its convergent and discriminative validity, and its internal consistency. METHODS: The original 49-items OHIP was translated to Spanish, revised for understanding and semantics by two independent dentists, and then translated back to English by an independent bilingual dentist. The data originated in a cross sectional study conducted among high school students from the Province of Santiago, Chile. The study group was sampled using a multistage random cluster procedure yielding 9,203 students aged 12–21 years. All selected students were invited to participate and all filled a questionnaire with information on socio-demographic factors; oral health related behaviors; and self-reported oral health status (good, fair or poor). From this group, 9,163 students also accepted to fill a detailed questionnaire on socio-economic indicators and to receive a clinical examination comprising direct recordings of clinical attachment levels (CAL) in molars and incisors, tooth loss, and the presence of necrotizing ulcerative gingival lesions. RESULTS: The participation rate and the questionnaire completeness were high with OHIP-Sp total scores being computed for 9,133 subjects. Self-perceived oral health status was associated with the total OHIP-Sp score and all its domains (Spearman rank correlation). The OHIP-Sp total score was also directly associated with the 4 dental outcomes investigated (Mann-Whitney test) and the largest impact was found for the outcomes, 'tooth loss' with a mean OHIP-Sp score = 13.5 and 'CAL >= 3 mm' with a mean OHIP-Sp score = 13.0. CONCLUSION: The OHIP-Sp revealed suitable convergent and discriminative validity and appropriate internal consistency (Cronbach's α). Further studies on OHIP-Sp warrant the inclusion of populations with a higher disease burden; and the use of test-retest reliability exercises to evaluate the stability of the test
Ethanol and Caffeine Effects on Social Interaction and Recognition in Mice: Involvement of Adenosine A2A and A1 Receptors
Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A1/A2A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A1 and A2A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg) increasing social contact and higher doses (1.0-1.5 g/kg) reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0-60.0 mg/kg), and even blocked social preference at higher doses (30.0-60.0 mg/kg). The A1 antagonist Cyclopentyltheophylline (CPT; 3-9 mg/kg) did not modify social contact or preference on its own, and the A2A antagonist MSX-3 (1.5-6 mg/kg) increased social interaction at all doses. Ethanol at intermediate doses (0.5-1.0 g/kg) was able to reverse the reduction in social exploration induced by caffeine (15.0-30.0 mg/kg). Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol impairs the formation of social memories, and A2A adenosine antagonists can prevent the amnestic effects of ethanol, so that animals can recognize familiar conspecifics. On the other hand, ethanol can counteract the social withdrawal induced by caffeine, a non-selective adenosine A1/A2A receptor antagonist. These results show the complex set of interactions between ethanol and caffeine, some of which could be the result of the opposing effects they have in modulating the adenosine system
Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States
Widespread efforts to abate ozone (O3) smog have significantly reduced emissions of nitrogen oxides (NOx) over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July–August 2004), SENEX (June–July 2013), and SEAC4RS (August–September 2013) and long-term ground measurement networks alongside a global chemistry–climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON) and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy) in both 2004 and 2013. Among the major RON species, nitric acid (HNO3) is dominant (∼ 42–45%), followed by NOx (31%), total peroxy nitrates (ΣPNs; 14%), and total alkyl nitrates (ΣANs; 9–12%) on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOxemissions will lead to a continued decline in surface ozone and less frequent high-ozone events
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