7,393 research outputs found
Enhancing Ocean Literacy Using Real-Time Data
Ocean literacy is the understanding of our relationship with the ocean and the crucial services that the ocean provides to society and other living organisms (Cava et al., 2005). In 2004, a number of ocean science and educational communities adopted seven essential ocean literacy principles1 (Cava et al., 2005). These principles were further broken down into concepts, which were designed to teach science standards using an ocean orientation. Most state science standards do not specifically address these ocean principles but they have been categorized according to the National Science Educational Standards by discipline and overlap with the other traditional science disciplines. Hoffman and Barstow (2007) noted that no state addresses more than 20 of the 35 fundamental ocean concepts. Ten of the 35 concepts that were more biology focused were not included in their study. They also noted that more research needs to be conducted to evaluate whether students learn core science concepts and process skills using ocean literacy as the primary curriculum
Investigating Coastal Processes and Nitrate Levels in the Elkhorn Slough Using Real-Time Data
The primary objective of this activity is to predict how coastal processes, such as tides, affect salinity, temperature, and nitrate levels in a type of estuary, called a slough. Real-time data from the Elkhorn Slough National Estuarine Research Reserve in Monterey, California, will be used to test predictions. In addition to collecting, graphing, and interpreting real-time data, students will learn how nitrates enter the estuary, and they will gain a better understanding of the interconnectedness of all bodies of water, especially estuaries
Evaluation of Microcosms for Determining the Fate and Effect of Benz(a)anthracene in Aquatic Systems
Small scale, three-phase microcosms were used to study the aquatic fate and effect of a polycyclic aromatic hydrocarbon (PAH), benz(a)anthracene. This compound was chosen as a model for carcinogenic PAH because it is a typical constituent of petro-chemical effluents and has middle-of-the-range physical and chamical characteristics. In a series of experiments, techniques were established for monitoring the behavior and for assessing the biological response to the pollutant. Results indicate taht benz(a)anthracene has no acute effect on aquatic organisms as indicated by the parameters used to measure community structure and function (gas productivity, nutrient utilization, biomass accumulation, and species composition). Gas chromatograph/mass spectral analysis of benz(a)anthracene and metabolites in the medium sediment, and biota made it possible to trace the fate of the compound. At the end of one 60 day experiment, 76 percent remained in the sediment, 17 percent had been recovered in the medium, 1 percent was associated with the biota. Of the remaining 5 percent, a portion photodegraded. There was no evidence of metabolism
AFM-BASED TESTING AND MEASUREMENTS OF CONTACT AND STICTION IN A MICROMECHANICAL SWITCH
ABSTRACT Cycling of a micromechanical switch with gold-on-gold contacts demonstrates that the contact resistance decreases and the adherence force increases. An experimental setup using a Scanning Probe Microscope (SPM) is allowing the fundamental physics of this behavior to be better understood. The setup includes two side-by-side cantilevers -one of high stiffness which applies the repeated loading and the other a standard profiling cantilever allowing in-situ measurements of topographical changes. INTRODUCTION MEMS switches are smaller and can switch faster than the smallest existing mechanical relays (reed relays). They also have lower on-resistance and lower parasitic capacitances than transistor switches. Electrostatically actuated MEMS switches consume practically zero steady-state power. Potential uses of MEMS switches include RF applications such as in cell phones, phase shifters and smart antennas (Rebeiz and Muldavin, [1]), as well as relay-replacements in Automatic Test Equipment (ATE) and industrial and medical instrumentation
Reliability and Criterion Validity of the Assess2Perform Bar Sensei
The Assess2Perform Bar Sensei is a device used to measure barbell velocity for velocity-based training that has not yet been validated. The purpose of this study was to determine criterion validity and reliability of the Assess2Perform Bar Sensei in barbell back squats by comparing it against the GymAware PowerTool, a previously validated instrument. Sixteen injury-free, resistance-trained subjects (eleven males and five females) were recruited. Subjects were tested for their back squat one repetition maximum (1RM). Then, on two separate days, subjects performed two sets of three repetitions at loads of 45%, 60% and 75% 1RM. The GymAware PowerTool and Bar Sensei were attached to the barbell in similar locations for concurrent collection of mean concentric velocity (MCV) and peak concentric velocity (PCV). The Bar Sensei and PowerTool showed generally fair to poor agreement for MCV and PCV when subjects lifted 45% of 1RM (intraclass correlation;ICC 0.4–0.59), and they showed poor agreement when subjects lifted 60% and 75% of 1RM (ICC 0.3–0.4). Inter-repetition/within-set reliability for the Bar Sensei ranged between ICC = 0.273–0.451 for MCV and PCV compared to the far more reliable PowerTool (ICC = 0.651–0.793). Currently, the Bar Sensei is not a reliable or valid tool for measuring barbell velocity in back squats
The charged-hadron/pion ratio at the Relativistic Heavy Ion Collider
The hadron/pion ratio is calculated in 200 GeV AuAu collisions at
midrapidity, applying pQCD and non-universal transverse-momentum broadening.
Arguments are presented for such non-universality, and the idea is implemented
in a model, which explains the enhancement of the hadron/pion ratio in central
AuAu collisions. The model also describes the qualitative difference between
the recently-measured dAu nuclear enhancement factors for pions and charged
hadrons.Comment: 4 pages, 3 figure
Conformational control of structure and guest uptake by a tripeptide-based porous material
Chemical processes often rely on the selective sorting and transformation of molecules according to their size, shape and chemical functionality. For example, porous materials such as zeolites achieve the required selectivity through the constrained pore dimensions of a single structure.1 In contrast, proteins function by navigating between multiple metastable structures using bond rotations of the polypeptide,2,3 where each structure lies in one of the minima of a conformational energy landscape and can be selected according to the chemistry of the molecules interacting with the protein.3 Here we show that rotation about covalent bonds in a peptide linker can change a flexible metal-organic framework (MOF) to afford nine distinct crystal structures, revealing a conformational energy landscape characterised by multiple structural minima. The uptake of small molecule guests by the MOF can be chemically triggered by inducing peptide conformational change. This change transforms the material from a minimum on the landscape that is inactive for guest sorption to an active one. Chemical control of the conformation of a flexible organic linker offers a route to modify the pore geometry and internal surface chemistry and thus the function of open-framework materials
Pro-Apoptotic Apoptosis Protease–Activating Factor 1 (Apaf-1) Has a Cytoplasmic Localization Distinct from Bcl-2 or Bcl-XL
How Bcl-2 and its pro-survival relatives prevent activation of the caspases that mediate apoptosis is unknown, but they appear to act through the caspase activator apoptosis protease–activating factor 1 (Apaf-1). According to the apoptosome model, the Bcl-2–like proteins preclude Apaf-1 activity by sequestering the protein. To explore Apaf-1 function and to test this model, we generated monoclonal antibodies to Apaf-1 and used them to determine its localization within diverse cells by subcellular fractionation and confocal laser scanning microscopy. Whereas Bcl-2 and Bcl-xL were prominent on organelle membranes, endogenous Apaf-1 was cytosolic and did not colocalize with them, even when these pro-survival proteins were overexpressed or after apoptosis was induced. Immunogold electron microscopy confirmed that Apaf-1 was dispersed in the cytoplasm and not on mitochondria or other organelles. After the death stimuli, Bcl-2 and Bcl-xL precluded the release of the Apaf-1 cofactor cytochrome c from mitochondria and the formation of larger Apaf-1 complexes, which are steps that presage apoptosis. However, neither Bcl-2 nor Bcl-xL could prevent the in vitro activation of Apaf-1 induced by the addition of exogenous cytochrome c. Hence, rather than sequestering Apaf-1 as proposed by the apoptosome model, Bcl-2–like proteins probably regulate Apaf-1 indirectly by controlling upstream events critical for its activation
The effectiveness of lifestyle adaptation for the prevention of prediabetes in adults: a systematic review
Diabetes prevalence is increasing exceptionally worldwide and with this come associated healthcare costs. The primary outcome of this systematic review was to assess glycaemic control and incidence of Type 2 diabetes mellitus (T2DM) diagnosis after exercise and dietary intervention (measured with any validated scale). The secondary outcome assessed body mass index change, weight change, and physical exercise capacity after diet and exercise intervention (measured with any validated scale). 1,780 studies were identified from searching electronic databases. Relevant studies went through a selection process. The inclusion criteria for all studies were people with prediabetes diagnosed by either impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). Lifestyle adaptation reduced the incidence of diabetes development more than standard treatment. Furthermore, better glycaemic control, improved physical exercise capacity, and increased weight reduction were observed with lifestyle intervention over standard treatment. Finally, improvements over the long term deteriorated, highlighting problems with long-term adherence to lifestyle changes. Overall, cumulative incidence of diabetes is drastically reduced in the intervention groups compared to control groups (standard care). Furthermore, glycaemic control was improved in the short term, with many participants reverting to normoglycaemia
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