638 research outputs found
Temperature-dependent Hall scattering factor and drift mobility in remotely doped Si:B/SiGe/Si heterostructures
Hall-and-Strip measurements on modulation-doped SiGe heterostructures and combined Hall and capacitance–voltage measurements on metal-oxide-semiconductor (MOS)-gated enhancement mode structures have been used to deduce Hall scattering factors, rH, in the Si1 – xGex two-dimensional hole gas. At 300 K, rH was found to be equal to 0.4 for x = 0.2 and x = 0.3. Knowing rH, it is possible to calculate the 300 K drift mobilities in the modulation-doped structures which are found to be 400 cm2 V – 1 s – 1 at a carrier density of 3.3 × 1011 cm – 2 for x = 0.2 and 300 cm2 V – 1 s – 1 at 6.3 × 1011 cm – 2 for x = 0.3, factors of between 1.5 and 2.0 greater than a Si pMOS control
Factors that support Indigenous involvement in multi-actor environmental stewardship
Regional, multi-actor environmental collaborations bring together diverse parties to achieve environmental protection and stewardship outcomes. Involving a range of participants helps involve alternative forms of knowledge, expertise, and perspectives; it may also present greater challenges in reaching agreements, particularly when both Indigenous and non-Indigenous parties are involved. The authors conduct a cross-case study of 39 regional partnerships involving Indigenous nations from the Great Lakes basin of North America with the aim of determining the factors that enable Indigenous partners to remain engaged in multi-actor collaborations. Six characteristics influenced Indigenous nations’ willingness to remain engaged: respect for Indigenous knowledges, control of knowledge mobilization, intergenerational involvement, self-determination, continuous cross-cultural education, and early involvement. Being attentive of these factors can help partnerships achieve their environmental goals by keeping important partners at the table
High Resolution MEMS Accelerometers to Estimate VO2 and Compare Running Mechanics between Highly Trained Inter-Collegiate and Untrained Runners
BACKGROUND: The purposes of this study were to determine the validity and reliability of high resolution accelerometers (HRA) relative to VO(2) and speed, and compare putative differences in HRA signal between trained (T) and untrained (UT) runners during treadmill locomotion. METHODOLOGY: Runners performed 2 incremental VO(2max) trials while wearing HRA. RMS of high frequency signal from three axes (VT, ML, AP) and the Euclidean resultant (RES) were compared to VO(2) to determine validity and reliability. Additionally, axial rms relative to speed, and ratio of axial accelerations to RES were compared between T and UT to determine if differences in running mechanics could be identified between the two groups. PRINCIPAL FINDINGS: Regression of RES was strongly related to VO(2), but T was different than UT (r = 0.96 vs 0.92; p<.001) for walking and running. During walking, only the ratio of ML and AP to RES were different between groups. For running, nearly all acceleration parameters were lower for T than UT, the exception being ratio of VT to RES, which was higher in T than UT. All of these differences during running were despite higher VO(2), O(2) cost, and lower RER in T vs UT, which resulted in no significant difference in energy expenditure between groups. CONCLUSIONS/SIGNFICANCE: These results indicate that HRA can accurately and reliably estimate VO(2) during treadmill locomotion, but differences exist between T and UT that should be considered when estimating energy expenditure. Differences in running mechanics between T and UT were identified, yet the importance of these differences remains to be determined
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A Search for H 2 O Maser Emission in Southern Active Galactic Nuclei and Star‐forming Galaxies: Discovery of a Maser in the Edge‐on Galaxy IRAS F01063?8034
We report the cumulative results of five surveys for H2O maser emission at 1.35 cm wavelength in 131 active galactic nuclei (AGNs) and star-forming galaxies, conducted at the Parkes Observatory between 1993 and 1998. We detected one new maser, in the edge-on galaxy IRAS F01063-8034, which exhibits a single, ∼ 0.1 Jy spectral feature at 4282 ± 6 km s−1 (heliocentric) with an unusually large 54 ±16 km s−1 half-power full width. The centroid velocity of the emission increased to 4319.6 ±0.6 km s−1 (38 ±2 km s−1 width) over the 13 days between discovery and confirmation of the detection. A similarly broad linewidth and large change in velocity has been noted for the maser in NGC 1052, wherein jet activity excites the emission. Neither optical spectroscopy, radio-infrared correlations, nor infrared colors provide compelling evidence of unusual activity in the nucleus of IRAS F01063-8034. Since the galaxy appears to be outwardly normal at optical and infrared wavelengths, detection of an H2O maser therein is unique. The maser emission is evidence that the galaxy harbors an AGN that is probably obscured by the edge-on galactic disk. The detection highlights the possibility that undetected AGNs could be hidden in other relatively nearby galaxies. No other maser emission features have been identified at velocities between 3084 km s−1 and 6181 km s−1.AstronomyPhysic
Readout System for Arrays of Frisch-Ring CdZnTe Detectors.
Frisch-ring CdZnTe detectors have demonstrated good energy resolution for identifying isotopes, <1% FWHM at 662 keV, and good efficiency for detecting gamma rays. We will fabricate and test at Brookhaven National Laboratory an integrated module of a 64-element array of 6 x 6 x 12 mm{sup 3} Frisch-ring detectors, coupled with a readout electronics system. It supports 64 readout channels, and includes front-end electronics, signal processing circuit, USB interface and high-voltage power supply. The data-acquisition software is used to process the data stream, which includes amplitude and timing information for each detected event. This paper describes the design and assembly of the detector modules, readout electronics, and a conceptual prototype system. Some test results are also reported
Potential effects of oilseed rape expressing oryzacystatin-1 (OC-1) and of purified insecticidal proteins on larvae of the solitary bee Osmia bicornis
Despite their importance as pollinators in crops and wild plants, solitary bees have not previously been included in non-target testing of insect-resistant transgenic crop plants. Larvae of many solitary bees feed almost exclusively on pollen and thus could be highly exposed to transgene products expressed in the pollen. The potential effects of pollen from oilseed rape expressing the cysteine protease inhibitor oryzacystatin-1 (OC-1) were investigated on larvae of the solitary bee Osmia bicornis (= O. rufa). Furthermore, recombinant OC-1 (rOC-1), the Bt toxin Cry1Ab and the snowdrop lectin Galanthus nivalis agglutinin (GNA) were evaluated for effects on the life history parameters of this important pollinator. Pollen provisions from transgenic OC-1 oilseed rape did not affect overall development. Similarly, high doses of rOC-1 and Cry1Ab as well as a low dose of GNA failed to cause any significant effects. However, a high dose of GNA (0.1%) in the larval diet resulted in significantly increased development time and reduced efficiency in conversion of pollen food into larval body weight. Our results suggest that OC-1 and Cry1Ab expressing transgenic crops would pose a negligible risk for O. bicornis larvae, whereas GNA expressing plants could cause detrimental effects, but only if bees were exposed to high levels of the protein. The described bioassay with bee brood is not only suitable for early tier non-target tests of transgenic plants, but also has broader applicability to other crop protection products
Public preferences for vaccination campaigns in the COVID-19 endemic phase:insights from the VaxPref database
Objective: Despite widespread perceptions that SARS-CoV-2 (COVID-19) is no longer a significant threat, the virus continues to loom, and new variants may require renewed efforts to control its spread. Understanding how individual preferences and attitudes influence vaccination behaviour and policy compliance in light of the endemic phase is crucial in preparation for this scenario. Method: This paper presents descriptive data from a global stated choice survey conducted in 22 countries across 6 different continents between July 2022 and August 2023, and reports the methodological work developed to address the need for comparable data. Results: This study included 50,242 respondents. Findings indicated significant heterogeneity across countries in terms of vaccination status and willingness to accept boosters. Vaccine hesitancy and refusal were driven by lower trust in public health bodies, younger age, and lower educational levels. Refusers and hesitant people reported lower willingness to take risks compared to those fully vaccinated (p<0.05). Lower mental health levels were found for the hesitant cohort (p<0.05). Conclusions: Insights from this database can help public health authorities to gain a new understanding of the vaccine hesitancy phenomenon, support them in managing the transition from the pandemic to the endemic phase, and favour a new stream of research to maximise behavioural response to vaccination programs in preparation of future pandemics.</p
Public preferences for vaccination campaigns in the COVID-19 endemic phase:insights from the VaxPref database
Objective: Despite widespread perceptions that SARS-CoV-2 (COVID-19) is no longer a significant threat, the virus continues to loom, and new variants may require renewed efforts to control its spread. Understanding how individual preferences and attitudes influence vaccination behaviour and policy compliance in light of the endemic phase is crucial in preparation for this scenario. Method: This paper presents descriptive data from a global stated choice survey conducted in 22 countries across 6 different continents between July 2022 and August 2023, and reports the methodological work developed to address the need for comparable data. Results: This study included 50,242 respondents. Findings indicated significant heterogeneity across countries in terms of vaccination status and willingness to accept boosters. Vaccine hesitancy and refusal were driven by lower trust in public health bodies, younger age, and lower educational levels. Refusers and hesitant people reported lower willingness to take risks compared to those fully vaccinated (p<0.05). Lower mental health levels were found for the hesitant cohort (p<0.05). Conclusions: Insights from this database can help public health authorities to gain a new understanding of the vaccine hesitancy phenomenon, support them in managing the transition from the pandemic to the endemic phase, and favour a new stream of research to maximise behavioural response to vaccination programs in preparation of future pandemics.</p
Public preferences for vaccination campaigns in the COVID-19 endemic phase: insights from the VaxPref database
Objective Despite widespread perceptions that SARS-CoV-2 (COVID-19) is no longer a significant threat, the virus continues to loom, and new variants may require renewed efforts to control its spread. Understanding how individual preferences and attitudes influence vaccination behaviour and policy compliance in light of the endemic phase is crucial in preparation for this scenario. Method This paper presents descriptive data from a global stated choice survey conducted in 22 countries across 6 different continents between July 2022 and August 2023, and reports the methodological work developed to address the need for comparable data. Results This study included 50,242 respondents. Findings indicated significant heterogeneity across countries in terms of vaccination status and willingness to accept boosters. Vaccine hesitancy and refusal were driven by lower trust in public health bodies, younger age, and lower educational levels. Refusers and hesitant people reported lower willingness to take risks compared to those fully vaccinated (p<0.05). Lower mental health levels were found for the hesitant cohort (p<0.05). Conclusions Insights from this database can help public health authorities to gain a new understanding of the vaccine hesitancy phenomenon, support them in managing the transition from the pandemic to the endemic phase, and favour a new stream of research to maximise behavioural response to vaccination programs in preparation of future pandemics
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