Identifying Undergraduate Student\u27s Motivation to Attend Tutoring for General Chemistry Courses

General Chemistry II is a common chemistry course that is required for professional school such as, medical, dental, optometry schooling. Considering that it historically has a high drop, fail, withdrawal rate, it is surprising that less than 10% of students in chemistry II attend tutoring at the Student Academic Resource Center (SARC). In this tutoring center, sessions are led by students who have excelled previously in that specific course. The objective of this research is to investigate the relationship between student motivation and attendance in SARC peer tutoring sessions for chemistry II. More precisely, to better understand the connection between those who have a motivation of getting a good grade and learning the material and those who attend tutoring. In order to gain insight on a student’s motivation to attend sessions in SARC, a survey was distributed to those taking the class currently. Two modes were used including paper survey and online. Findings from this investigation will lead to suggestions to increase SARC chemistry tutoring attendance which could positively impact the success of STEM students on UCF\u27s campus

Set up of a methodology for participatory plant breeding in bread wheat in France

In Organic Agriculture, cultivation environments and agronomic practices are very diverse. This diversity can be handled with decentralized selection based on the knowledge of farmers and scientists. A collaborative work between associations from Réseau Semences Paysannes and the DEAP team from INRA du Moulon set up an innovative breeding approach on farm based on decentralization and participation of farmers. This approach makes it possible to (i) create new population varieties of bread wheat locally adapted (genetic innovation) (ii) set up an organizational scheme based on decentralization and co construction between actors (societal innovation) and (iii) develop experimental designs, create statistical and data management tools which stimulate these genetic and societal innovations

Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium.</p> <p>Methods</p> <p>3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis.</p> <p>Results</p> <p>The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86.</p> <p>Conclusions</p> <p>Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.</p

Bioavailable iron in the Southern Ocean: the significance of the iceberg conveyor belt

Productivity in the Southern Oceans is iron-limited, and the supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine reservoir. Glacial sediment sources of iron have rarely been considered, as the iron has been assumed to be inert and non-bioavailable. This study demonstrates the presence of potentially bioavailable Fe as ferrihydrite and goethite in nanoparticulate clusters, in sediments collected from icebergs in the Southern Ocean and glaciers on the Antarctic landmass. Nanoparticles in ice can be transported by icebergs away from coastal regions in the Southern Ocean, enabling melting to release bioavailable Fe to the open ocean. The abundance of nanoparticulate iron has been measured by an ascorbate extraction. This data indicates that the fluxes of bioavailable iron supplied to the Southern Ocean from aeolian dust (0.01–0.13 Tg yr-1) and icebergs (0.06–0.12 Tg yr-1) are comparable. Increases in iceberg production thus have the capacity to increase productivity and this newly identified negative feedback may help to mitigate fossil fuel emissions

SUR QUELQUES PREMIERES PREMOLAIRES ANORMALEMENT VOLUMINEUSES OBSERVEES CHEZ DES INDIVIDUS DE NOTRE EPOQUE

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Real-Time Experimental Assessment of Hill Climbing MPPT Algorithm Enhanced by Estimating a Duty Cycle for PV System

Better functioning of maximum power point tracking (MPPT) can significantly increase the energy efficiency of photovoltaic systems. This process is provided by MPPT algorithms. Such as fractional open-circuit voltage, perturb and observe, fractional short-circuit current, hill climbing, incremental conductance, fuzzy logic controller, neural network controller, just to name a few. The hill climbing algorithm uses the duty cycle of the boot converter as a retraction parameter when the MPPT task is performed. However, this technique has disadvantages in terms of the stability of the system during periods of constant radiation. To overcome this disadvantage, A MPPT technique based on the estimation of the boost converter duty cycle associated with the conventional hill climbing, fractional open-circuit voltage and fractional short-circuit current algorithm is proposed. A comprehensive description of the experimental implementation hardware and software platforms is presented. On the basis of the measured data, the enhanced algorithm was compared to the conventional hill climbing MPPT technique according to various criteria, showing the disadvantages and advantages of each. Experimental results show advantage of the enhanced algorithm compared to the conventional hill climbing MPPT technique in time response attenuation (0.25s versus 0.6s), little oscillations (0.5 W versus 2.5 W), power loss reductions and better maximum power point tracking accuracy (98.45 W versus 92.75 W) of the enhanced algorithm compared to the conventional hill climbing MPPT technique

L'Intermédiaire des mathematiciens.

Editors: v. 1-27, C.A. Laisant, E. Lemoine.Mode of access: Internet

Hyperpolarization without persistent radicals for in vivo real-time metabolic imaging

Hyperpolarized substrates prepared via dissolution dynamic nuclear polarization have been proposed as magnetic resonance imaging (MRI) agents for cancer or cardiac failure diagnosis and therapy monitoring through the detection of metabolic impairments in vivo. The use of potentially toxic persistent radicals to hyperpolarize substrates was hitherto required. We demonstrate that by shining UV light for an hour on a frozen pure endogenous substance, namely the glucose metabolic product pyruvic acid, it is possible to generate a concentration of photo-induced radicals that is large enough to highly enhance the (13)C polarization of the substance via dynamic nuclear polarization. These radicals recombine upon dissolution and a solution composed of purely endogenous products is obtained for performing in vivo metabolic hyperpolarized (13)C MRI with high spatial resolution. Our method opens the way to safe and straightforward preclinical and clinical applications of hyperpolarized MRI because the filtering procedure mandatory for clinical applications and the associated pharmacological tests necessary to prevent contamination are eliminated, concurrently allowing a decrease in the delay between preparation and injection of the imaging agents for improved in vivo sensitivity

Incorporating geomicrobial processes in subsurface reactive transport models

info:eu-repo/semantics/publishe