2,967 research outputs found
Quantitative estimation of plant characteristics using spectral measurement: A survey of the literature
There are no author-identified significant results in this report
Exploring Factors that Contribute to STEM Transfer Student Sense of Belonging
There is an ongoing disconnect between the number of students who enter college intending to earn a STEM degree and the number of students who persist to degree, this is particularly true for transfer students. Sense of belonging has been named as a STEM persistence factor, yet how that belonging develops for transfer students is largely unknown. Here we used a mixed-methods design to explore the experiences of STEM transfer students at PSU (n=38). Participants completed a survey prior to participating in an interview. The survey and interviews explored their science identity, sense of belonging, and involvement in STEM-related activities. Interviews were transcribed verbatim and de-identified. We leveraged a framework: Core Elements of Sense of Belonging to iteratively code student interviews and identify overarching themes. Preliminary results reveal that engaging in multiple STEM programs facilitate a dosage effect that reflects their perspective on community; communal support through faculty and peers allows students to be more motivated to succeed. This research contributes to the literature on STEM transfer student belonging and can inform future programming and structures to better support these students to graduation
Proving Craig and Lyndon Interpolation Using Labelled Sequent Calculi
We have recently presented a general method of proving the fundamental
logical properties of Craig and Lyndon Interpolation (IPs) by induction on
derivations in a wide class of internal sequent calculi, including sequents,
hypersequents, and nested sequents. Here we adapt the method to a more general
external formalism of labelled sequents and provide sufficient criteria on the
Kripke-frame characterization of a logic that guarantee the IPs. In particular,
we show that classes of frames definable by quantifier-free Horn formulas
correspond to logics with the IPs. These criteria capture the modal cube and
the infinite family of transitive Geach logics
Three-Dimensional Myocardial Perfusion Maps by Contrast Echocardiography
We evaluated the clinical applicability of a system for three-dimensional (3-D) display of a perfusion map following myocardial contrast echocardiography (MCE). The system was used in 12 patients (9 males and 3 females, mean age 52 ± 10 years) undergoing interventional treatment of chronic total coronary occlusion. In each patient three standard apical views were acquired at baseline with sonicated IopamidolR injections into the left coronary artery (LCA) and into the right coronary artery (RCA). Following successful recanalization of the occluded artery MCE was repeated. The patients tolerated the procedure well. Acquisition of three standard apical views provided sufficient information for the reconstruction of 3-D perfusion maps containing the 16 standard left ventricular (LV) segments. Side-by-side display of the perfusion maps obtained following LCA and RCA echocontrast injections allowed us to classify the myocardial segments (192) into three groups: (1) those supplied by one major artery (124); (2) those supplied by collaterals from contralateral or both major arteries (58); and (3) segments supplied by none of the major arteries (10). Decreased opacification was observed in 50 segme
Food cost and availability in a rural setting in Australia
Introduction: The burden of chronic diseases is rapidly increasing worldwide. In Australia rural populations have a greater burden of disease. Chronic diseases are largely preventable with diet as a key risk factor. With respect to diet-related chronic disease, dietary risk may be due to poor food access, namely, poor availability and/or the high cost of healthy food. It is likely that poor food access is an issue in rural areas. Objective: To assess food access in rural south-west (SW) Victoria, Australia.Methods: A total of 53 supermarkets and grocery stores in 42 towns participated in a survey of food cost and availability in the rural area of SW Victoria. The survey assessed availability and cost of a Healthy Food Access Basket (HFAB) which was designed to meet the nutritional needs of a family of 6 for 2 weeks.Results: Seventy-two percent of the eligible shops in SW Victoria were surveyed. The study found that the complete HFAB was significantly more likely to be available in a town with a chain-owned store (p<0.00). The complete HFAB was less likely to be available from an independently owned store in a town with only one grocery shop (p<0.004). The average cost of the HFAB across SW Victoria was AU380.30 ± 25.10 (mean ± SD). There was a mean range in difference of cost of the HFAB of $36.92. In particular, high variability was found in the cost of fruits and vegetables.Conclusions: Cost and availability of healthy food may be compromised in rural areas. Implications: Improvements in food access in rural areas could reduce the high burden of disease suffered by rural communities.<br /
Preliminary evaluation of spectral, normal and meteorological crop stage estimation approaches
Several of the projects in the AgRISTARS program require crop phenology information, including classification, acreage and yield estimation, and detection of episodal events. This study evaluates several crop calendar estimation techniques for their potential use in the program. The techniques, although generic in approach, were developed and tested on spring wheat data collected in 1978. There are three basic approaches to crop stage estimation: historical averages for an area (normal crop calendars), agrometeorological modeling of known crop-weather relationships agrometeorological (agromet) crop calendars, and interpretation of spectral signatures (spectral crop calendars). In all, 10 combinations of planting and biostage estimation models were evaluated. Dates of stage occurrence are estimated with biases between -4 and +4 days while root mean square errors range from 10 to 15 days. Results are inconclusive as to the superiority of any of the models and further evaluation of the models with the 1979 data set is recommended
Assessing the Impact of Groundwater Pollution from Marine Caves on Nearshore Seagrass Beds in Bermuda
This investigation characterized karstic and nearshore environments of Bermuda
to describe 1) behavior and periodicity of cave springs; 2) submarine spring water
quality; and 3) nearshore marine seagrass density. Caves can be conduits for
groundwater pollution where terrestrial anthropogenic processes leach nutrient enriched
water into marine caves springs that flow directly into coastal waters. Seagrass may
serve as an environmental indicator due to its susceptibility to anthropogenic pollution.
In 2007, environmental water monitoring devices were moored at the entrance of
coastal cave springs throughout Bermuda to retrieve data on water quality, flow
volume, velocity and direction. Nutrients (nitrate, phosphate, nitrite, and ammonium)
and fecal bacteria (Enterococcus spp. and Escherichia coli) were measured in each cave.
To qualify a link between terrestrial pollution and the nearshore environment, seagrass
density within 100 m from cave entrances were measured.
Bermuda caves were tidally influenced. Caves in Harrington Sound showed a
delayed tidal flux with smaller ranges due to the restricted tidal inlet. Four caves
exhibited a 1:1 in:out flow ratio. Caves with an imbalance flow ratio could be influenced
by additional entrances, connection to an alternate water body, or cave geometry. Cave
water was similar between caves. Environmental parameters and nutrients changed
together, excluding seasonal variations in temperature (17.89 to 22.94 degrees C). Higher
nutrients and fecal coliforms within caves indicated sewage may be leaching into the
subsurface ground water system. Three seagrass species were evenly distributed within patchy meadows. Densities
ranged from 0.91 to 4.5 (on a Braun-Blanket Scale). Higher mean densities in
Harrington Sound, suggested the enclosed, protected nature of the sound allowed for
reduced wave and current action. Syringodium filiforme decreased in density towards the
ocean signifying a direct influence of cave water on seagrass beds. Tidal in and out-flux
allowed for a constantly changing environment suitable for a mixture of seagrass
species. Higher dissolved inorganic nutrient concentrations were associated with
locations lacking seagrass.
This study found 1) cave springs connected groundwater and nearshore seagrass
ecosystems; and 2) components associated with terrestrial sewage pollution (DIN,
HPO4=, and Enterococcus spp.) were higher within caves than nearshore waters
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