17,256 research outputs found

    A study of the Tyrone-Mount Union lineament by remote sensing techniques and field methods

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    The author has identified the following significant results. This study has shown that subtle variations in fold axes, fold form, and stratigraphic thickness can be delineated. Many of the conclusions were based on extrapolation in similitude to different scales. A conceptual model was derived for the Tyrone-Mount Union lineament. In this model, the lineament the morphological expression of a zone of fracture concentrations which penetrated basement rocks and may have acted as a curtain to regional stresses or as a domain boundary between uncoupled adjacent crustal blocks

    Longitudinal distribution of cosmic rays in the heliosphere

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    The longitudinal distribution of cosmic ray intensity was examined during the years 1974-1976 when the persistent high speed solar wind stream structures produced a well ordered inner heliosphere. Solar wind velocity is mapped back to the Sun and compared with cosmic ray intensity which is represented relative to the solar rotation average. Low solar wind velocity is observed to be a necessary, but not sufficient, condition for the occurrence of higher cosmic ray intensities at 1 AU. These relative enhancements cover a restricted range of heliographic longitudes and persist for several solar rotations. The observed solar wind and cosmic ray intensity relationships are consistent with a simple model suggested here in which cosmic ray modulation is very weak in the inner heliosphere, sunward of the first shock crossing on each field line and more intense in the outer heliosphere

    The surface geometry of inherited joint and fracture trace patterns resulting from active and passive deformation

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    Hypothetical models are considered for detecting subsurface structure from the fracture or joint pattern, which may be influenced by the structure and propagated to the surface. Various patterns of an initially orthogonal fracture grid are modeled according to active and passive deformation mechanisms. In the active periclinal structure with a vertical axis, fracture frequency increased both over the dome and basin, and remained constant with decreasing depth to the structure. For passive periclinal features such as a reef or sand body, fracture frequency is determined by the arc of curvature and showed a reduction over the reefmound and increased over the basin

    The early expansion and evolutionary dynamics of POU class genes.

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    The POU genes represent a diverse class of animal-specific transcription factors that play important roles in neurogenesis, pluripotency, and cell-type specification. Although previous attempts have been made to reconstruct the evolution of the POU class, these studies have been limited by a small number of representative taxa, and a lack of sequences from basally branching organisms. In this study, we performed comparative analyses on available genomes and sequences recovered through "gene fishing" to better resolve the topology of the POU gene tree. We then used ancestral state reconstruction to map the most likely changes in amino acid evolution for the conserved domains. Our work suggests that four of the six POU families evolved before the last common ancestor of living animals-doubling previous estimates-and were followed by extensive clade-specific gene loss. Amino acid changes are distributed unequally across the gene tree, consistent with a neofunctionalization model of protein evolution. We consider our results in the context of early animal evolution, and the role of POU5 genes in maintaining stem cell pluripotency

    Code extraction algorithms which unify slicing and concept assignment

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    One approach to reverse engineering is to partially automate subcomponent extraction, improvement and subsequent recombination. Two previously proposed automated techniques for supporting this activity are slicing and concept assignment. However, neither is directly applicable in isolation; slicing criteria (sets of program variables) are simply too low level in many cases, while concept assignment typically fails to produce executable subcomponents. This paper introduces a unification of slicing and concept assignment which exploits their combined advantages, while overcoming their individual weaknesses. Our 'concept slices' are extracted using high level criteria, while producing executable subprograms. The paper introduces three ways of combining slicing, and concept assignment and algorithms for each. The application of the concept slicing algorithms is illustrated with a case study from a large financial organisation

    Cyclotron resonance photoconductivity of a two-dimensional electron gas in HgTe quantum wells

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    Far-infrared cyclotron resonance photoconductivity (CRP) is investigated in HgTe quantum wells (QWs) of various widths grown on (013) oriented GaAs substrates. It is shown that CRP is caused by the heating of two-dimensional electron gas (2DEG). From the resonance magnetic field strength effective masses and their dependence on the carrier concentration is obtained. We found that the effective mass in each sample slightly increases from the value (0.0260 \pm 0.0005)m_0 at N_s = 2.2x10^11 cm^(-2) to (0.0335 \pm 0.0005)m_0 at N_s = 9.6x10^11 cm^(-2). Compared to determination of effective masses by the temperature dependence of magnitudes of the Shubnikov-de Haas (SdH) oscillations used so far in this material our measurements demonstrate that the CRP provides a more accurate (about few percents) tool. Combining optical methods with transport measurements we found that the transport time substantially exceeds the cyclotron resonance lifetime as well as the quantum lifetime which is the shortest.Comment: 3 pages, 2 figure

    Perceptions, experiences and opportunities for occupational safety and health professionals arising out of the COVID-19 Pandemic

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    This study explored perceptions, experiences and opportunities for the occupational safety and health professional (OSHP) as a result of COVID-19. Using qualitative methods, interviews took place with OSHPs in two organisations to understand how their role developed during the pandemic. Additionally, seven focus groups were organised and met virtually, using the Zoom platform, each addressing a different topic identified by the researchers. Participants (n = 45) from 10 different countries were distributed among the focus groups. Topics were separated into four themes: impact on the workplace; the psychosocial dynamic; medical and health issues and occupational safety and health (OSH) issues. Results were subsequently divided into seven action categories and compared with the findings from the organisational interviews. Comparison pointed to an expanded role for the OSHP including business continuity, resilience and wellbeing in addition to assessing and controlling risks emerging during the pandemic. There is also the need for a means to adequately disseminate trustworthy information. Results indicated that there was no single ‘average’ role of the OSHP, demonstrating essential contributions as a member of the management team. Results also stressed that the pandemic carried three health-related co-morbidities, stress, Post-Traumatic Stress Disorder and burnout. Directions for future research included: the education of the OSHP to support a move away from compliance towards risk management; determining how mental health issues in organisations should be managed; expanded roles for OSHPs within business; and implications for professional bodies, membership institutions and academia in supporting the above-mentioned emerging roles

    Examining the role of the occupational safety and health professional in supporting the control of the risks of multiple psychosocial stressors generated during the COVID-19 pandemic

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    Abstract: COVID-19 created challenges at work with increased risks of multiple interrelated psychosocial stressors, surfacing as a comorbidity of COVID-19. The roles of many Occupational Safety and Health Practitioners (OSHPs) included helping to recognise, prevent and mitigate these risks, especially for essential and front-line workers. The rationale for this study was to investigate potential competency gaps amongst OSHPs on their lack of priority or inability to understand the scope of the negative synergistic effects of these stressors and provide support where and when appropriate. Drawing on the International Labour Office (ILO) SOLVE methodology, eight psychosocial stressors were identified and a seminar was developed to raise the awareness of the comorbidity of COVID-19 and psychosocial stressors with the target audience of OSHPs, who would potentially further disseminate this information to a broader workforce. The membership network of the Institution of Occupational Safety and Health (IOSH) was used to implement the intervention through organising Zoom-based seminars globally. Participants were followed-up with during the seminar and through a one-year post-seminar survey to determine retention of the presented material and to what extent it was put to use. An information sheet was designed and made available to participants for further dissemination. The information sheet can be used by all industries at all levels as a tool to raise awareness and to signpost participants on where to seek help if needed. Twenty-five seminars were held with 2483 participants. Feedback revealed that participants grasped the presented concepts as many of the questions raised during and after the session focused on the implementation of the presented measures. We concluded that, given the correct knowledge, OHSPs are an invaluable resource to lead workforce engagement in this area. Due to UK General Data Protection Regulations (GDPR), there were difficulties undertaking the follow-up survey. Those who could be contacted indicated that where they could influence an intervention, there were improvements in the workplace. It is recommended that participant data be controlled by the research team with qualitative data recorded. Further studies are needed to review both competencies and existing job descriptions of OSHPs and the challenges around expanding responsibilities to lead psychosocial interventions at work

    Relation of lineaments to sulfide deposits: Bald Eagle Mountain, Centre County, Pennsylvania

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    The author has identified the following significant results. Discrete areas of finely-fractured and brecciated sandstone float are present along the crest of Bald Mountain and are commonly sites of sulfide mineralization, as evidenced by the presence of barite and limonite gossans. The frequency distributions of the brecciated float as the negative binomial distribution supports the interpretation of a separate population of intensely fractured material. Such zones of concentrated breccia float have an average width of one kilometer with a range from 0.4 to 1.6 kilometers and were observed in a quarry face to have subvertical dips. Direct spatial correlation of the Landsat-derived lineaments to the fractured areas on the ridge is low; however, the mineralized and fracture zones are commonly assymetrical to the lineament positions. Such a systematic dislocation might result from an inherent bias in the float population or could be the product of the relative erosional resistance of the silicified material in the mineralized areas in relation to the erosionally weak material at the stream gaps

    Analysis and application of ERTS-1 data for regional geological mapping

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    Combined visual and digital techniques of analysing ERTS-1 data for geologic information have been tried on selected areas in Pennsylvania. The major physiolographic and structural provinces show up well. Supervised mapping, following the imaged expression of known geologic features on ERTS band 5 enlargements (1:250,000) of parts of eastern Pennsylvania, delimited the Diabase Sills and the Precambrian rocks of the Reading Prong with remarkable accuracy. From unsupervised mapping, transgressive linear features are apparent in unexpected density, and exhibit strong control over river valley and stream channel directions. They are unaffected by bedrock type, age, or primary structural boundaries, which suggests they are either rejuvenated basement joint directions on different scales, or they are a recently impressed structure possibly associated with a drifting North American plate. With ground mapping and underflight data, 6 scales of linear features have been recognized
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