301 research outputs found

    interface trap state characterization of metal insulator semiconductor structures based on photosensitive organic materials

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    Abstract Flexible organic and printed electronics has led in the last years to exciting applications, especially for what concerns devices incorporating photosensitive materials. Among the latter, organic field-effect phototransistors are a promising technology because of the high light-sensitivity and the possibility of being integrated within more complex systems. Nevertheless, their optimization has not been thoroughly investigated and considerable variations are often observed in their behavior. In this framework, the most critical aspect is represented by the interface formed between the organic semiconductor and the employed dielectric layer. In our contribution, we have fabricated metal-insulator-semiconductor (MIS) structures based on the archetypal photosensitive organic materials poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PC 61 BM) on Silicon/SiO 2 substrates, exploiting their blend in a bulk heterojunction configuration. The MIS structures have been characterized by means of admittance spectroscopy to study the properties of the trap distribution at the interface between the organic semiconductors and the silicon oxide insulating layer. The complex behavior of the capacitance and loss diagrams has been interpreted with a simple electrical model to extract the density of the traps at the interface between the insulator and the semiconductor. It is shown that in the blend-based MIS device several peaks arise in the loss diagram with respect to the only P3HT MIS device. This could be attributed to a different interaction between the single species in the bulk heterojunction and the silicon oxide layer. Furthermore, the reported values of trap densities result in the range of those determined for analogous structures and materials

    Behavioral and psychological symptoms of dementia: The effects of physical activity at adult day service centers

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    Adult day services (ADS) are an increasingly popular option for caregivers of people with dementia, but there is little research on the effects of activities on the behavior and mood of the client. This study examines participation by 94 individuals in different types of adult day-care activities and their association with changes in behavior and psychological symptoms of dementia (BPSD) for the client during a three-month span. Three domains of BPSD were examined: restless behaviors, mood behaviors, and positive behaviors. Using growth curve modeling, results show that the restless and mood behavior domains, on average, were stable over three months, whereas positive behaviors increased. For all three behavior domains there were individual differences in average level of BPSD. Average rate of change for individuals also varied from the mean for restless and mood behaviors. Physical activities, social activities, engaging activities, and watching and listening activities, along with a day-care dosage variable, were used as covariates to explain these individual differences in change. Engaging activities explained some of the individual variance for restless behaviors; as individuals increased one increment in engaging activities, they had fewer restless behavior problems over time. These results suggest that some features of programming may be related to improvements in restless behavior

    Exploration of Cardiology Patient Hospital Presentations, Health Care Utilisation and Cardiovascular Risk Factors During the COVID-19 Pandemic

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    Objectives: COVID-19 and the lockdowns have affected health care provision internationally, including medical procedures and methods of consultation. We aimed to assess the impact of COVID-19 at two Australian hospitals, focussing on cardiovascular hospital admissions, the use of community resources and cardiovascular risk factor control through a mixed methods approach. Methods: Admissions data from the quaternary referral hospital were analysed, and 299 patients were interviewed from July 2020 to December 2021. With the admissions data, the number, complexity and mortality of cardiology hospital admissions, prior to the first COVID-19 lockdown (T0=February 2018–July 2019) were compared to after the introduction of COVID-19 lockdowns (T1=February 2020–July 2021). During interviews, we asked patients about hospital and community health resource use, and their control of cardiovascular risk factors from the first lockdown. Results: Admission data showed a reduction in hospital presentations (T0=138,099 vs T1=128,030) and cardiology admissions after the lockdown period began (T0=4,951 vs T1=4,390). After the COVID-19-related lockdowns began, there was an increased complexity of cardiology admissions (T0=18.7%, 95% CI 17.7%–19.9% vs T1=20.3%, 95% CI 19.1%–21.5%, chi-square test: 4,158.658, p<0.001) and in-hospital mortality (T0=2.3% of total cardiology admissions 95% CI 1.9%–2.8% vs T1=2.8%, 95% CI 2.3%–3.3%, chi-square test: 4,060.217, p<0.001). In addition, 27% of patients delayed presentation due to fears of COVID-19 while several patients reported reducing their general practitioner or pathology/imaging appointments (27% and 11% respectively). Overall, 19% reported more difficulty accessing medical care during the lockdown periods. Patients described changes in their cardiovascular risk factors, including 25% reporting reductions in physical activity. Conclusion: We found a decrease in hospital presentations but with increased complexity after the introduction of COVID-19 lockdowns. Patients reported being fearful about presenting to hospital and experiencing difficulty in accessing community health services

    Reduction of colonic inflammation in HLA-B27 transgenic rats by feeding Marie Ménard apples, rich in polyphenols

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    Inflammatory bowel diseases (IBD) are immunomediated ailments affecting millions of individuals. Although diet is regarded as an important factor influencing IBD, there are no accepted dietary recommendations presently available. We administered 7.6 % lyophilised apples obtained from two cultivars (Golden Delicious and Marie Ménard, low and high in polyphenols, respectively) to HLA-B27 transgenic rats which develop spontaneous IBD. After 3 months feeding, rats fed Marie Ménard apples had reduced myeloperoxidase activity (3.6 (sem 0.3) v. 2.2 (sem 0.2) U/g tissue; P <0.05) and reduced cyclo-oxygenase-2 (P <0.05) and inducible NO synthase gene expression (P <0.01) in the colon mucosa and significantly less diarrhoea (P <0.05), compared with control rats. Cell proliferation in the colon mucosa was reduced significantly by feeding Golden Delicious apples, with a borderline effect of Marie Ménard apples. Gene expression profiling of the colon mucosa, analysed using the Whole Rat Genome 4 x 44 K Agilent Arrays, revealed a down-regulation of the pathways of PG synthesis, mitogen-activated protein kinase (MAPK) signalling and TNFalpha-NF-kappaB in Marie Ménard-fed rats. In the stools of the animals of this group we also measured a significant reduction of bacteria of the Bacteriodes fragilis group. In conclusion, the administration of Marie Ménard apples, rich in polyphenols and used at present only in the manufacturing of cider, ameliorates colon inflammation in transgenic rats developing spontaneous intestinal inflammation, suggesting the possible use of these and other apple varieties to control inflammation in IBD patient

    The effect of HIV and antiretroviral therapy on characteristics of pulmonary tuberculosis in northern Malawi: a cross-sectional study.

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    BACKGROUND: HIV infection reduces the likelihood that individuals with pulmonary tuberculosis are smear positive and that they have cavitatory disease. Antiretroviral therapy (ART) may shift the pattern of disease to be more similar to that of HIV negative patients. This would aid diagnosis--which often depends on sputum smears--but would also increase infectiousness. We assessed the effect of HIV and ART on smear positivity and cavitatory disease in laboratory-confirmed pulmonary TB patients. METHODS: Three sputum samples were collected per pulmonary TB suspect and were examined using microscopy and culture. Chest radiographs were available for a subset of patients as part of another study. The effect of HIV and ART status on sputum smear positivity and lung cavitation were evaluated using multivariable logistic regression. RESULTS: Of 1024 laboratory-confirmed pulmonary TB patients who were identified between January 2005 and December 2011, 766 had HIV and ART status available. Positive sputum smears were significantly more common among HIV negative individuals than HIV positive individuals (adjusted OR = 2.91, 95% CI 1.53-5.55). Compared to those HIV positive but not on ART, patients on ART were more likely to be smear positive (adjusted OR = 2.33, 95% CI 1.01-5.39) if they had been on ART ≤ 6 months, but only slightly more likely to be smear positive (adjusted OR = 1.43, 95% CI 0.68-2.99) if they were on ART > 6 months. HIV negative patients were more likely than HIV positive patients to have cavitatory disease (adjusted OR = 1.97, 95% CI 1.20-3.23). Patients on ART > 6 months had a slight increase in cavitatory disease compared to HIV positive patients not on ART (adjusted OR = 1.68, CI 0.78-3.63). CONCLUSIONS: HIV infection is associated with less smear positivity and cavitation in pulmonary TB patients. Among HIV positive patients, the use of ART shifts the presentation of disease towards that seen in HIV-negative individuals, which facilitates diagnosis but which also could increase infectiousness

    (2-Hydroxy­phenyl­imido-κN)(methano­lato-κO)[2-(2-oxidobenzyl­ideneamino)phenolato-κ2 O,N,O′](triphenyl­phosphine-κP)rhenium(V)

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    In the neutral title compound, [Re(C6H5NO)(C13H9NO2)(CH3O)(C18H15P)], an 18-valence-electron complex, the ReV ion lies in an octa­hedral coordination geometry with the tridentate dianionic Schiff base 2-(2-oxidobenzyl­idene­amino)phenolate ligand occupying three equatorial coordination sites, and with the triphenyl­phosphine ligand situated trans to the imine N atom. The ReV coordination is completed with a methano­late ligand and a 2-hydroxy­phenyl­imido(2-) ligand. There are two molecules in the asymmetric unit. The crystal structure involves O—H⋯O and C—H⋯O hydrogen bonds. One N and one C atom are disordered over two positions; the site occupancy factors are ca 0.7 and 0.3

    Agricultural and food security impacts from the 2010 Russia flash drought

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    The flash drought and its associated heat wave that affected western Russia in the summer of 2010 had significant cascading agricultural and socioeconomic impacts. Drought indicators sensitive to soil moisture and evapotranspiration (ET) showed that the flash drought began in June 2010, then intensified rapidly and expanded to cover much of western Russia. By early July, almost all of the major wheat producing regions of Russia were experiencing extreme water stress to the winter and spring wheat crops. The timing of the onset of the flash drought was particularly devastating as the period of most rapid intensification overlapped with the flowering stage for both the winter and spring wheat crops. As a result, wheat yields in Russia were reduced by over 70 percent in top wheat producing oblasts and total wheat production was reduced by 20 million metric tons (MT) compared to the previous seasons. In fulfillment of its recently adopted Food Security Doctrine, the Russian government banned the export of wheat in early August 2010 to preserve wheat for its own consumption. Further compounding matters on a global scale, the significant reduction in wheat production in Russia coincided with wheat production issues in places like western Australia, which led to a large drop in global wheat stocks. The sharp drop in global wheat stocks coincided with a rapid increase in wheat prices across the globe. The rapid increase in wheat prices, partly resulting from the rapid intensification of drought in Russia, led to increased prices for wheat flour and bread in many countries throughout the world. This ultimately led to an increase in poverty and civil unrest in countries like Mozambique and Egypt with a history of inequality and poverty

    Epistemic freedom and education

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    First of all, I define the concept of epistemic freedom in the light of the changing nature of educational practice that prioritise over-prescriptive conceptions of learning. I defend the ‘reality’ of this freedom against possible determinist-related criticisms. I do this by stressing the concept of agency as characterised by ‘becoming’. I also discuss briefly some of the technical literature on the subject. I then move on to discuss Gramsci’s concept of hegemony and Foucault’s idea of ‘productive power’: I argue for the need of a counter-narrative of freedom that takes the form of a genealogy. Finally I discuss in more detail the nature of epistemic freedom and briefly discuss the ethical implications of the concept

    The ACTN3 R577X Polymorphism across Three Groups of Elite Male European Athletes

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    The ACTN3 R577X polymorphism (rs1815739) is a strong candidate to influence elite athletic performance. Yet, controversy exists in the literature owing to between-studies differences in the ethnic background and sample size of the cohorts, the latter being usually low, which makes comparisons difficult. In this case:control genetic study we determined the association between elite athletic status and the ACTN3 R577X polymorphism within three cohorts of European Caucasian men, i.e. Spanish, Polish and Russian [633 cases (278 elite endurance and 355 power athletes), and 808 non-athletic controls]. The odds ratio (OR) of a power athlete harbouring the XX versus the RR genotype compared with sedentary controls was 0.54 [95% confidence interval (CI): 0.34–0.48; P = 0.006]. We also observed that the OR of an endurance athlete having the XX versus the RR genotype compared with power athletes was 1.88 (95%CI: 1.07–3.31; P = 0.028). In endurance athletes, the OR of a “world-class” competitor having the XX genotype versus the RR+RX genotype was 3.74 (95%CI: 1.08–12.94; P = 0.038) compared with those of a lower (“national”) competition level. No association (P>0.1) was noted between the ACTN3 R577X polymorphism and competition level (world-class versus national-level) in power athletes. Our data provide comprehensive support for the influence of the ACTN3 R577X polymorphism on elite athletic performance

    Turning collegial governance on its head : symbolic violence, hegemony and the academic board

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    This article draws on Bourdieu&rsquo;s theorisation of domination and Gramsci&rsquo;s notions of hegemony within the context of a larger empirical study of Australian university academic governance, and of academic boards (also known as academic senates or faculty senates) in particular. Reporting data that suggest a continued but radically altered form of collegial governance in which hegemony is exercised by management rather than by the professor, it theorises the domination of academic boards within western democratic universities. However, traditional collegial governance is also dependent upon a community of scholars, a role historically played by the academic board. In view of the suggested transition in collegial governance and the resultant convergence of academic work and management, the article concludes with questions about whether academic boards can continue to serve as communities of scholars in future
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