Late biological effects of heavy charged particles: Cataracts, vascular injury and life shortening in mice

Risks associated with extended habitation in a space environment, particularly hazards to space workers that might result from exposure to high energy heavy ion particles (HZE), were studied. Biological effects of HZE were investigated in mice to assess their potential adverse health hazards. The potential effects of HZE particles on the crystalline lens of the eye and the carcinogenic effects and blood vessel (vascular) damage from radiation were evaluated by a risk assessment. Animal experiments to evaluate dose response relationships for tumor induction/promotion and for vascular injury were introduced. Cataract productions and preliminary results on cacinogenic and vascular effects are presented for perspective

Pengaruh Kepuasan Kerja Dan Organizational Citizenship Behavior Terhadap Stres Kerja Dan Retensi Karyawan Di PT Multi Auto Intrawahana Pekanbaru

The research was conducted at PT. Multi Auto Intrawahana Pekanbaru. The purpose of this study was to determine the effect of job satisfaction and Organizational Citizenship Behavior (OCB) against work stress and its impact on the retention of employees at PT. Multi Auto Intrawahana Pekanbaru. Total population in this study were 53 employees and a sample is taken from the entire population of 53 employees. The determination of the sample using census method or technique of total sampling is a sampling technique that is done by taking the entire population. The results of the study of job satisfaction significant positive effect on employee retention, Organizational Citizenship Behavior (OCB) has no effect on employee retention, job stress significant negative effect on employee retention, job satisfaction significant negative effect on job stress of employees and Organizational Citizenship Behavior (OCB) negative effect significantly to the stress of employees of PT Multi Auto Intrawahana Pekanbaru. Advice can be given that the leaders should provide equitable opportunities for all employees in career development, to employees in order to always maintain good communication and continue to think positively with each other and the company should be able to pass training on cooperation and responsibility to cultivate an attitude and awareness of responsibility and cooperation on the employee

Biological implications of high-energy cosmic ray induced muon flux in the extragalactic shock model

A ~ 62 My periodicity in fossil biodiversity has been observed in independent studies of paleontology databases over ~0.5Gy. The period and phase of this biodiversity cycle coincides with the oscillation of our solar system normal to the galactic disk with an amplitude ~70 parsecs and a period ~64 My. Our Galaxy is falling toward the Virgo cluster, forming a galactic shock at the north end of our galaxy due to this motion, capable of accelerating particles and exposing our galaxy's northern side to a higher flux of cosmic rays. These high-energy particles strike the Earth's atmosphere initiating extensive air showers, ionizing the atmosphere by producing charged secondary particles. Secondary particles such as muons produced as a result of nuclear interactions are able to reach the ground and enhance the biological radiation dose. Using a Monte Carlo simulation package CORSIKA, we compute the biological dose resulting from enhanced muon exposure from cosmic rays and discuss their implications for terrestrial biodiversity variations.Comment: Accepted for publication in Geophysical Research Letter

Astrophysical Ionizing Radiation and the Earth: A Brief Review and Census of Intermittent Intense Sources

Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere: on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. We enumerate the known sources of radiation and characterize their intensities at the Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval", our best estimate of how often a major extinction-level event is probable given the current state of knowledge; we base these estimates on computed or expected depletion of stratospheric ozone. In general, moderate level events are dominated by the Sun, but the far more severe infrequent events are probably dominated by gamma-ray bursts and supernovae. We note for the first time that so-called "short-hard" gamma-ray bursts are a substantial threat, comparable in magnitude to supernovae and greater than that of the higher-luminosity long bursts considered in most past work. Given their precursors, short bursts may come with little or no warning.Comment: to be published in Astrobiolog

Atmospheric Consequences of Cosmic Ray Variability in the Extragalactic Shock Model II: Revised ionization levels and their consequences

It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic ray exposure as the solar system oscillates perpendicular to the galactic plane. Here we investigate a mechanism by which cosmic rays might affect terrestrial biodiversity, ionization and dissociation in the atmosphere, resulting in depletion of ozone and a resulting increase in the dangerous solar UVB flux on the ground, with an improved ionization background computation averaged over a massive ensemble (about 7 x 10^5) shower simulations. We study minimal and full exposure to the postulated extragalactic background. The atmospheric effects are greater than with our earlier, simplified ionization model. At the lower end of the range effects are too small to be of serious consequence. At the upper end of the range, ~6 % global average loss of ozone column density exceeds that currently experienced due to effects such as accumulated chlorofluorocarbons. The intensity is less than a nearby supernova or galactic gamma-ray burst, but the duration would be about 10^6 times longer. Present UVB enhancement from current ozone depletion ~3% is a documented stress on the biosphere, but a depletion of the magnitude found at the upper end of our range would double the global average UVB flux. For estimates at the upper end of the range of the cosmic ray variability over geologic time, the mechanism of atmospheric ozone depletion may provide a major biological stress, which could easily bring about major loss of biodiversity. Future high energy astrophysical observations will resolve the question of whether such depletion is likely.Comment: 22 pages, 5 figures, to be published in Journal of Geophysical Research--Planets. This is an update and replacement for our 2008 paper, with a much more extensive simulation of air shower ionization. Ionization effects and ozone depletion are somewhat large

Critical success factors of the Norwegian offshore support vessel industry

Since the middle of the 1960s, the Norwegian oil industry has been a major source of investments, earnings, and value creation for the whole country. Operating in the upstream logistics of the sector, offshore support vessels (OSVs) are essential for supporting installations throughout the Norwegian continental shelf. This assignment looks at Norwegian OSV companies which are involved in this industry. Fifteen such companies were found after thorough searches and cooperation with industry workers. Using a mixed-methods approach, the study looks into critical success factors (CSFs) in the Norwegian OSV industry. After a thorough document review, 27 CSFs were identified and placed into 11 major categories. These included strategic management, reputation, regulatory, supplier management, bidding process, workforce, innovation, competitiveness, operations, financial, and environment. The study highlighted how important it is to uphold strict operational standards, with the highest priority going to operational quality. Qualified staff, risk reduction, cost effectiveness, and sustainability initiatives were further important variables. Even while some criteria, such as environmental licensing fees and collaboration with universities, were considered relevant, their immediate influence was restricted, therefore they were ranked lower. All things considered, these results highlight how important it is for maritime companies to put safety, effectiveness, and trustworthiness first in order to secure long-term success in the offshore support vessel industry

Tingkat percaya diri dan keterampilan micro teaching

The purpose of this study was to see the level of student confidence in micro teaching learning for students of Physical Education Health and Recreation, Univeritas Islam Riau. This type of research is a quantitative descriptive study. The population in this study were all students of Physical Education for Health and Recreation Semester VI of the 2019/2020 Academic Year who had completed the micro teaching course which received 211 people. The research sampling technique used total sampling. The research was conducted by applying a questionnaire to students. Based on the results of the research analysis, the findings obtained were 34.59% of self-competence results in the "sufficient" category and 35.07% of micro teaching skills in the "sufficient" category. This proves that Health and Recreation Physical Education students must be able to hone their ability to practice speaking skills so that they can become more competent prospective teachers in their fields

LITERATURE REVIEW STUDY: IN OBSERVING JOB SATISFACTION OF PHYSICAL EDUCATION TEACHERS

The purpose of this literature review is to review the scientific literature on physical education teacher job satisfaction research. One database (google schoolar) was used to select articles containing information on physical education teacher job satisfaction. The search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After exclusion criteria, only 10 articles were categorized. The results show that the types of research used in physical education teacher job satisfaction research are diverse, namely; quantitative, qualitative research, and descriptive. On average, the study used questionnaires and interviews in data collection. Several limitations inherent in the review have been noted. In summarizing the results of the study, it can be seen that physical education teacher job satisfaction is influenced by various variables and contexts, including language, geography, and pandemic conditions

Kontribusi Kekuatan Otot Lengan Terhadap Hasil Servis Bawah Bolavoli di SMP Negeri 2 Rambah Samo Kabupaten Rokan Hulu

Penelitian ini berpangkal dari beberapa permasalahan yang ditemukan peneliti di lapangan, yang telah dilakukan di SMP Negeri 2 Rambah Samo Kabupaten Rokan Hulu pada saat melakukan servis bawah, sikap awal berdiri sudah terlihat kesalahan yang menonjol, kaki yang dirapatkan sehingga tidak leluasa untuk bergerak dalam melakukan servis bawah. Sikap badan yang tidak merunduk saat melakukan servis bawah sehingga siswa terlihat kaku. Terkadang bola dilambung terlalu tinggi pada saat melakukan servis bawah, sehingga perkenaan kontak tangan dengan bola kurang tepat. Pandangan ke arah bola tidak diseimbangkan dengan ayunan lengan tangan terhadap bola. sehingga bola tidak dapat diarahkan sesuai dengan yang diharapkan. Pada sikap perkenaan, masih terdapat kesalahan yaitu, siswa belum bisa secara maksimal menyesuaikan ketepatan tangan saat menyentuh bola. Kemudian pada sikap akhir dalam servis bawah, ada siswa tidak kembali pada posisi awal setelah melakukan servis bawah. Tujuan penelitian ini adalah untuk mengetahui kontribusi kekuatan otot lengan terhadap kemampuan servis bawah bolavoli siswa SMP Negeri 2 Rambah Samo Kabupaten Rokan Hulu. Jenis penelitian ini merupakan korelasi. Semua populasi diambil sebagai sampel, teknik ini disebut dengan total sampling. Jadi populasi dan sampel di penelitian ini adalah siswa kelas VIII SMP Negeri 2 Rambah Samo Kabupaten Rokan Hulu sebanyak 40 orang. Pengumpulan data ini dilakukan dengan test push-up dan tes servis bawah bolavoli. Berdasarkan hasil pengolahan data diperoleh rhitungsebesar 84.03 sedangkan rtabel pada taraf signifikan 5% adalah 0.304, dari data tersebut, maka uraian tersebut dapat ditarik asumsinya bahwa rhitung≥ rtabelatau 84.03 ≥ 0.304. Dengan demikian dapat disimpulkan bahwa terdapat kontribusi 7.06% dan terdapat signifikan antara kekuatan otot lengan terhadap hasil servis bawah bolavoli siswa SMP Negeri 2 Rambah Samo Kabupaten Rokan Hulu