Absence of synaptic regulation by phosducin in retinal slices.

Phosducin is an abundant photoreceptor protein that binds G-protein βγ subunits and plays a role in modulating synaptic transmission at photoreceptor synapses under both dark-adapted and light-adapted conditions in vivo. To examine the role of phosducin at the rod-to-rod bipolar cell (RBC) synapse, we used whole-cell voltage clamp recordings to measure the light-evoked currents from both wild-type (WT) and phosducin knockout (Pd(-/-)) RBCs, in dark- and light-adapted retinal slices. Pd(-/-) RBCs showed smaller dim flash responses and steeper intensity-response relationships than WT RBCs, consistent with the smaller rod responses being selectively filtered out by the non-linear threshold at the rod-to-rod bipolar synapse. In addition, Pd(-/-) RBCs showed a marked delay in the onset of the light-evoked currents, similar to that of a WT response to an effectively dimmer flash. Comparison of the changes in flash sensitivity in the presence of steady adapting light revealed that Pd(-/-) RBCs desensitized less than WT RBCs to the same intensity. These results are quantitatively consistent with the smaller single photon responses of Pd(-/-) rods, owing to the known reduction in rod G-protein expression levels in this line. The absence of an additional synaptic phenotype in these experiments suggests that the function of phosducin at the photoreceptor synapse is abolished by the conditions of retinal slice recordings

Leading interactions in the β\beta-SrV6O15Sr V_6 O_{15} compound

The present study shows that the electronic structure of the $\beta$-$AV\_6O\_{15}$ family of compounds ($A = Sr, Ca, Na ...$) is based on weakly interacting two-leg ladders, in contrast with the zig-zag chain model one could expect from their crystal structure. Spin dimer analysis, based on extended H\"{u}ckel tight-binding calculations, was performed to determine the structure of the dominant transfer and magnetic interactions in the room temperature $\beta$-$SrV\_6O\_{15}$ phase. Two different two-legs ladders, associated with different charge/spin orders are proposed to describe these one-dimensional $\beta$-type systems. The antiferromagnetic ladders are packed in an 'IPN' geometry and coupled to each other through weak antiferromagnetic interactions. This arrangement of the dominant interactions explains the otherwise surprising similarities of the optical conductivity and Raman spectra for the one-dimensional $\beta$-type phases and the two-dimensional $\alpha$-type ones such as the well-known $\alpha^\prime$-$NaV\_2O\_5$ system

Diagonals of rational functions, pullbacked 2F1 hypergeometric functions and modular forms (unabrigded version)

We recall that diagonals of rational functions naturally occur in lattice statistical mechanics and enumerative combinatorics. We find that a seven-parameter rational function of three variables with a numerator equal to one (reciprocal of a polynomial of degree two at most) can be expressed as a pullbacked 2F1 hypergeometric function. This result can be seen as the simplest non-trivial family of diagonals of rational functions. We focus on some subcases such that the diagonals of the corresponding rational functions can be written as a pullbacked 2F1 hypergeometric function with two possible rational functions pullbacks algebraically related by modular equations, thus showing explicitely that the diagonal is a modular form. We then generalise this result to eight, nine and ten parameters families adding some selected cubic terms at the denominator of the rational function defining the diagonal. We finally show that each of these previous rational functions yields an infinite number of rational functions whose diagonals are also pullbacked 2F1 hypergeometric functions and modular forms.Comment: 39 page

Alien Registration- Dallaire, Marie Y. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29595/thumbnail.jp

Alien Registration- Rison, Marie Y. (Auburn, Androscoggin County)

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Alien Registration- Arpin, Marie Y. (Portland, Cumberland County)

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Homeworking, telecommuting and journey to workplaces - Are differences among genders and professions varying over space?

The aim of this paper is to assess differences on homeworking and teleworking behaviour among genders considering age groups, professional statuses, household structures and car access. The analysis is based on a sample of more than 30,000 workers responding to the 2001 origin-destination (O-D) survey data in Quebec City (Canada). Moreover, this paper puts specific emphasis on linking those differences in behaviour to the location of workplaces related to living places of the respondents. During the O-D survey, every worker was asked to disclose the frequency of homeworking and teleworking he/she was experiencing during the preceding weeks. Answers were later aggregated into six categories: never working at home (88.4% of respondents), working at home 1 day per two weeks or less (4.8%), 1 day per week (1.7%), 2 or 3 days per week (1.2%), 4 days or more per week (0.7%), always working at home (3.2% – homeworkers). However, those patterns show significant differences among genders (higher proportion of females are working entirely at home; higher proportion of males are occasionally working at home), age groups (younger workers seldom work at home and the proportion of teleworker increases with age – about 16% among the 55-64 years old and 27% among the elderly) and professional status (proportion of teleworkers is strongly related to qualifications and decisional status of the person, yielding higher levels of teleworking for managers, self-employed persons, professors and lawyers than for office clerks, technicians and non-qualified workers). This last relationship is very strong suggesting that job empowerment (especially ability to control time schedule) is of paramount importance for the development of teleworking. However, having higher family constraints, lone parents are seeking more flexibility on their work agenda: 12% are experiencing some level of teleworking on top of 3% of them which are homeworkers. Again, the difference appears more significant among male than among female workers, suggesting again a better control of the first group on their work schedule. Moreover, owning a driver license or holding a bus pass does not have the expected effect on teleworking: car drivers are working at home more frequently than other people; conversely 92% of bus users are going to their work place every weekday, leaving a mere 8% to teleworking and homeworking. Significant differences appear when considering workplaces and home locations within the city. People working near the city centre are more willing than others to consider teleworking, people living in the suburban areas show higher levels of homeworking. Finally, significant differences of travel time from home to work were found among various categories of teleworkers and homeworkers. Preliminary results suggest that the development of teleworking could be highly rooted to labour market and household structures as well as to the urban form. Urban sprawl is probably impeding development of teleworking, at least for Quebec City.

Can Emergency Physicians Perform Carotid Artery Point-of-Care Ultrasound to Detect Stenosis in Patients with TIA and Stroke? A Pilot Study

Introduction: Patients with severe, symptomatic carotid stenosis can have their subsequent stroke risk reduced by surgical intervention if performed soon after a transient ischemic attack (TIA) or stroke. Patients presenting to an emergency department (ED) without computed tomography angiography (CTA) with TIA/stroke, may require transfer to another hospital for imaging to rule out carotid artery stenosis. The objective of this study was to determine the test characteristics of carotid artery point-of-care ultrasound (POCUS) in detecting greater than 50% stenosis in patients presenting with TIA/stroke.Methods: We conducted a prospective cohort study on a convenience sample of adult patients presenting to a comprehensive stroke centre with TIA or stroke between June–October 2017. Carotid POCUS was performed. Primary outcome measure, stenosis ≥ 50%, was determined by the final radiology report of CTA. A blinded POCUS expert separately reviewed the archived carotid POCUS scans. We calculated sensitivity and specificity for stenosis ≥ 50%.Results: We conducted POCUS on 75 patients, of which 70 were included in our analyses. Of those 70, 14.3% were diagnosed with greater than 50% stenosis. Carotid POCUS performed as follows: sensitivity 70.0% (95% confidence interval [CI], 34.8%-93.3%); specificity 86.7% (95% CI, 75.4%-94.1%); positive likelihood ratio (LR +) 5.3 (95% CI, 1.2-9.3); negative likelihood ratio (LR -) 0.4 (95% CI, 0.0-0.7). The inter-rater reliability between POCUS performer interpretation and expert interpretation had moderate agreement (k = 0.68). Scans took a mean 6.2 ± 2.2 minutes to complete.Conclusion: Carotid POCUS has low to moderate association with CTA for detection of carotid artery stenosis ≥ 50%. Further research and investigation is needed prior to widespread use of carotid POCUS in patients with acute cerebral ischemia. Additionally, external validity is likely affected by availability of training, maintenance of competency, and experience in more rural centres