Automated tester permits precise calibration of pressure transducers from 0 to 1050 psi

Automated portable checker allows last-minute calibration of pressure transducers before testing. It uses a pressure console and equipment that can produce test pressures of 0-1050 psi. The console can be connected to other apparatus for measurement and visual display of the electrical output

High Temperature Behavior and Long-term Stability of Lithium Drifted Silicon Surface-barrier Detectors

High temperature behavior and long-term stability of lithium drifted silicon surface barrier charged particle detector

Comparing Soil Boundaries Delineated by Digital Analysis of Multispectral Scanner Data from High and Low Spatial Resolution Systems

Aircraft and Landsat data were used with computer-aided techniques to delineate soils patterns of a field of 40 ha in a transition zone between soils developed under deciduous forest and those developed under prairie vegetation. Two computer-aided classification techniques, supervised and nonsupervised, were employed in classifying soils of the study area. The means and covariance matrix statistics were obtained for every cluster or soil class through the statistics algorithm. Each cluster of aircraft and Landsat data was identified and assigned to a specific soil type by correlating the cluster soil patterns with a standard soils map of the test site which was prepared as a part of the ground observation task. A sampling grid plan was used to select a training set for a supervised classification of the aircraft MSS data. The spectral soil patterns revealed in the classifications from aircraft and satellite MSS data resembled the general patterns of the soils of the conventionally prepared soil map. The spatial resolution of the aircraft scanner was adequate to recognize each soil type boundary in the test site. However, the limited spatial resolution of the satellite scanner made it difficult to delineate those soil features with widths less than the spatial resolution of the scanner. On the contrary those soil patterns which were broad enough to exceed the spatial resolution of the Landsat scanner were delineated very well

Perspective on integrating machine learning into computational chemistry and materials science

Machine learning (ML) methods are being used in almost every conceivable area of electronic structure theory and molecular simulation. In particular, ML has become firmly established in the construction of high-dimensional interatomic potentials. Not a day goes by without another proof of principle being published on how ML methods can represent and predict quantum mechanical properties – be they observable, such as molecular polarizabilities, or not, such as atomic charges. As ML is becoming pervasive in electronic structure theory and molecular simulation, we provide an overview of how atomistic computational modeling is being transformed by the incorporation of ML approaches. From the perspective of the practitioner in the field, we assess how common workflows to predict structure, dynamics, and spectroscopy are affected by ML. Finally, we discuss how a tighter and lasting integration of ML methods with computational chemistry and materials science can be achieved and what it will mean for research practice, software development, and postgraduate training

Generation of EMIC Waves and Effects on Particle Precipitation During a Solar Wind Pressure Intensification With Bz>0.

During geomagnetic storms, some fraction of the solar wind energy is coupled via reconnection at the dayside magnetopause, a process that requires a southward interplanetary magnetic field Bz. Through a complex sequence of events, some of this energy ultimately drives the generation of electromagnetic ion cyclotron (EMIC) waves, which can then scatter energetic electrons and ions from the radiation belts. In the event described in this paper, the interplanetary magnetic field remained northward throughout the event, a condition unfavorable for solar wind energy coupling through low‐latitude reconnection. While this resulted in SYM/H remaining positive throughout the event (so this may not be considered a storm, in spite of the very high solar wind densities), pressure fluctuations were directly transferred into and then propagated throughout the magnetosphere, generating EMIC waves on global scales. The generation mechanism presumably involved the development of temperature anisotropies via perpendicular pressure perturbations, as evidenced by strong correlations between the pressure variations and the intensifications of the waves globally. Electron precipitation was recorded by the Balloon Array for RBSP Relativistic Electron Losses balloons, although it did not have the same widespread signatures as the waves and, in fact, appears to have been quite patchy in character. Observations from Van Allen Probe A satellite (at postmidnight local time) showed clear butterfly distributions, and it may be possible that the EMIC waves contributed to the development of these distribution functions. Ion precipitation was also recorded by the Polar‐orbiting Operational Environmental Satellite satellites, though tended to be confined to the dawn‐dusk meridians

Challenges in Nigeria’s education sector and the migration of Nigerian postgraduate students to South African universities

Education remains the weapon for upward stratification, social and economic development of any nation but the Nigerian government has not shown enough commitment to the educational sector. The manifestation could be seen in the shrinking government funding on education, decaying and lack of infrastructure in Nigeria’s universities which have led to demoralization of the academia. A major consequence of this is the frustration experienced by postgraduate students who are pursuing higher education and having to spend longer period than expected record time. This frustration in pursuing higher educational qualification often leads to stunted career progression. This has led to an alternative decision to migrate in search of higher education abroad. Consequently, in recent times, Nigerian postgraduate students have migrated more than ever before to South African Universities that are believed to have modern facilities for training and ensuring completion of programmes in record time. This study employed the use of structured questionnaire to investigate the determinants of this form of migration. Among other findings, this study found that the decision to migrate and pursue postgraduate student abroad is informed by the demoralization and frustration suffered in attaining postgraduate education in Nigeria. The study also found that many Nigerian postgraduate migrant students that desired to stay back in South Africa after the programme were discouraged from doing so because of the frequent hostilities between the bulging South African youths. Their hostility is associated with the shrinking capacity of the host government (South Africa) to create new jobs for them. In addition, the belief of the agitating South African youth that the migrant postgraduates are responsible for their unemployed status, by taking up their jobs especially in those areas where required skills among the South African are lacking further gingers hostilities. This study, therefore, suggests among others that the home country should increase budgetary allocation to improve the education sector as well as monitor such allocation to ensure that it is prudently utilized. It is also recommended that institutional processes and procedures to monitor and evaluate postgraduate studies in Nigerian universities be institutionalized

Insights into congenital stationary night blindness based on the structure of G90D rhodopsin

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102109/1/embr201344.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102109/2/embr201344.reviewer_comments.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102109/3/embr201344-sup-0001.pd

Antibiotic and Antiinflammatory Therapy Transiently Reduces Inflammation and Hypercoagulation in Acutely SIV-Infected Pigtailed Macaques

Increased chronic immune activation and inflammation are hallmarks of HIV/SIV infection and are highly correlated with progression to AIDS and development of non-AIDS comorbidities, such as hypercoagulability and cardiovascular disease. Intestinal dysfunction resulting in microbial translocation has been proposed as a lead cause of systemic immune activation and hypercoagulability in HIV/SIV infection. Our goal was to assess the biological and clinical impact of a therapeutic strategy designed to reduce microbial translocation through reduction of the microbial content of the intestine (Rifaximin-RFX) and of gut inflammation (Sulfasalazine-SFZ). RFX is an intraluminal antibiotic that was successfully used in patients with hepatic encephalopathy. SFZ is an antiinflammatory drug successfully used in patients with mild to moderate inflammatory bowel disease. Both these clinical conditions are associated with increased microbial translocation, similar to HIV-infected patients. Treatment was administered for 90 days to five acutely SIV-infected pigtailed macaques (PTMs) starting at the time of infection; seven untreated SIVsab-infected PTMs were used as controls. RFX+SFZ were also administered for 90 days to three chronically SIVsab-infected PTMs. RFX+SFZ administration during acute SIVsab infection of PTMs resulted in: significantly lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and significantly lower levels of hypercoagulation biomarkers. This effect was clear during the first 40 days of treatment and was lost during the last stages of treatment. Administration of RFX+SFZ to chronically SIVsab–infected PTMs had no discernible effect on infection. Our data thus indicate that early RFX+SFZ administration transiently improves the natural history of acute and postacute SIV infection, but has no effect during chronic infection

The Temperature, Electron, and Pressure Characteristics of Switchbacks: Parker Solar Probe Observations

Parker Solar Probe (PSP) observes unexpectedly prevalent switchbacks, which are rapid magnetic field reversals that last from seconds to hours, in the inner heliosphere, posing new challenges to understanding their nature, origin, and evolution. In this work, we investigate the thermal states, electron pitch angle distributions, and pressure signatures of both inside and outside switchbacks, separating a switchback into spike, transition region (TR), and quiet period (QP). Based on our analysis, we find that the proton temperature anisotropies in TRs seem to show an intermediate state between spike and QP plasmas. The proton temperatures are more enhanced in spike than in TR and QP, but the alpha temperatures and alpha-to-proton temperature ratios show the opposite trends, implying that the preferential heating mechanisms of protons and alphas are competing in different regions of switchbacks. Moreover, our results suggest that the electron integrated intensities are almost the same across the switchbacks but the electron pitch angle distributions are more isotropic inside than outside switchbacks, implying switchbacks are intact structures but strong scattering of electrons happens inside switchbacks. In addition, the examination of pressures reveals that the total pressures are comparable through a switchback, confirming switchbacks are pressure-balanced structures. These characteristics could further our understanding of ion heating, electron scattering, and the structure of switchbacks.Comment: submitted to Ap