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11.
J. Bootsma 《摩擦学汇刊》2013,56(4):287-296
The load capacity and power loss of spiral groove bearings, lubricated with a Newtonian, incompressible liquid with a viscosity depending on temperature only, are determined by solving the continuity and momentum equations analytically and the energy equation for the grooves and ridges numerically. It is assumed that the total flow perpendicular to the relative velocity of the bearing parts is zero. This implies that the generated heat is discharged by conduction to the bearing parts only. The effect of the “thermal entrance region” is investigated. 相似文献
12.
IM Spivak NM Pleskach VM Mikhel'son D Bootsma A Kolman 《Canadian Metallurgical Quarterly》1997,39(6):420-434
The action of ionizing radiation and chemical mutagens--epoxides (ethylene oxide, propylene oxide, epichlorohydrin)--upon survival and repair processes in xeroderma pigmentosum (XP2SP) and Cockayne syndrome (CS1SP) patients' cells was studied, compared to healthy donor's cells VH-10 and C5RO. Ionizing radiation was demonstrated to enhance significantly higher survival decrease of XP2SP and CS1SP fibroblasts, compared to healthy donor's cells, according to the cloning efficiency criterion. In contrast to this, no significant difference between XP2SP and healthy donor's cells was found, according to cells' ability to replicative DNA synthesis after gamma irradiation. Differences in survival of mutant cells and healthy donor's cells after treatment by epoxides were found significant only following XP2SP being treated by ethylene oxide. DNA single-string breaks in XP2SP and in CS1SP cells treated by mutagens studied were proved to occur with the same frequency as in the DNA of the control cells; however the DNA repair according to this criterion was significantly suppressed in mutant cells. 相似文献
13.
The role of G. Stanley Hall as cofounder of American psychology of religion and helmsperson of the Clark School of Religious Psychology is examined. Background ingredients include Hall's religious biography, his definition of religion, and his genetic psychology. Elements of the Clark School of Religious Psychology abstracted here include Hall's courses and plans for the library, the writings of his students, the 7 volumes of the Journal of Religious Psychology, and religious articles in other Clark journals. Hall's major religious contribution, Jesus, the Christ, in the Light of Psychology, serves as a focal point. Other contributions briefly examined include Hall's sexual theory of conversion and his approach to religious education and missionary work. Reasons are offered for Hall's relatively swift obscurity as a religious psychologist. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
15.
Milk fatty acid (FA) profile is a dynamic pattern influenced by lactational stage, energy balance and dietary composition. In the first part of this study, effects of the energy balance during the proceeding lactation [weeks 1-21 post partum (pp)] on milk FA profile of 30 dairy cows were evaluated under a constant feeding regimen. In the second part, effects of a negative energy balance (NEB) induced by feed restriction on milk FA profile were studied in 40 multiparous dairy cows (20 feed-restricted and 20 control). Feed restriction (energy balance of -63 MJ NEL/d, restriction of 49 % of energy requirements) lasted 3 weeks starting at around 100 days in milk. Milk FA profile changed markedly from week 1 pp up to week 12 pp and remained unchanged thereafter. The proportion of saturated FA (predominantly 10:0, 12:0, 14:0 and 16:0) increased from week 1 pp up to week 12 pp, whereas monounsaturated FA, predominantly the proportion of 18:1,9c decreased as NEB in early lactation became less severe. During the induced NEB, milk FA profile showed a similarly directed pattern as during the NEB in early lactation, although changes were less marked for most FA. Milk FA composition changed rapidly within one week after initiation of feed restriction and tended to adjust to the initial composition despite maintenance of a high NEB. C18:1,9c was increased significantly during the induced NEB indicating mobilization of a considerable amount of adipose tissue. Besides 18:1,9c, changes in saturated FA, monounsaturated FA, de-novo synthesized and preformed FA (sum of FA >C16) reflected energy status in dairy cows and indicated the NEB in early lactation as well as the induced NEB by feed restriction. 相似文献
16.
Human sewage contamination of surface waters is a major human health concern. We found urban stormwater systems that collect and convey runoff from impervious surfaces act as a conduit for sewage originating from breeches in sanitary sewer infrastructure. A total of 828 samples at 45 stormwater outfalls were collected over a four-year period and assessed by culture based methods, PCR, and quantitative PCR (qPCR) to test for traditional and alternative indicators of fecal pollution. All outfalls had the HF183 (human) Bacteroides genetic marker detected in at least one sample, suggesting sewage contamination is nearly ubiquitous in the urban environment. However, most outfalls were intermittently positive, ranging from detection in 11%-100% of the samples. Positive results did not correlate with seasonality, rainfall amounts, or days since previous rainfall. Approximately two-thirds of the outfalls had high (>5000 copy number, i.e. CN, per 100 ml) or moderate levels (1000-5000 CN per 100 ml) of the human Bacteroides genetic marker. Escherichia coli (E. coli) and enterococci levels did not correlate to human Bacteroides. A total of 66% of all outfall samples had standard fecal indicator levels above 10,000 CFU per 100 ml. A tiered assessment using this benchmark to identify high priority sites would have failed to flag 35% of the samples that had evidence of sewage contamination. In addition, high fecal indicators would have flagged 33% of samples as priority that had low or no evidence of sewage. Enteric virus levels in one outfall with high levels of the human Bacteroides genetic marker were similar to untreated wastewater, which illustrates stormwater can serve as a pathway for pathogen contamination. The major source of fecal pollution at four of five river sites that receive stormwater discharge appeared to be from sewage sources rather than non-human sources based on the ratios of human Bacteroides to total Bacteroides spp. This study shows the feasibility and benefits of employing molecular methods to test for alternative indicators of fecal pollution to identify sewage sources and potential health risks and for prioritization of remediation efforts. 相似文献
17.
Robert E. Hecky Harvey A. Bootsma Eric O. Odada 《Lakes & Reservoirs: Research and Management》2006,11(4):203-213
There is a global dimension to lake management in Africa and elsewhere that will require a concerted action not only from individual riparian states, but also from regional, continental and global communities. The current global lake threats arise from climate change, regional land degradation and semivolatile contaminants, and share the common feature that the atmosphere is the vector that spreads their impacts over large areas and to many lakes. The Great Lakes of Africa (Malawi, Victoria and Tanganyika) are particularly sensitive to these problems because of their enormous surface areas, slow water flushing rates, and the importance of direct rainfall in their water budgets. Their response times might be slow to yield a detectable change and, unfortunately, their recovery times might also be slow. It is possible for atmospheric effects to act antagonistically to the impacts of catchment change, but antagonistic effects could become synergistic in the future. Improved understanding of the physical dynamics of these lakes, and development of models linking their physical and biogeochemical behaviour to regional, mesoscale climate models, will be necessary to guide lake managers. 相似文献
18.
Gosse A. Bootsma 《化学,工程师,技术》1974,46(19):819-819
19.
Discusses the phenomenon of postpartum depression from a transgenerational perspective. The concept of symbiosis is taken from the mother's point of view as well as from the baby's. Symbiosis is defined as a delusional 2-person fantasy of mutual dependence rather than as a normal phase of development. Analysis of a case of postnatal depression is presented to illustrate the clinical and theoretical implications of this viewpoint and how it was applied in treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
20.
Martin C. J. Bootsma Marjan W. M. Wassenberg Pieter Trapman Marc J. M. Bonten 《Journal of the Royal Society Interface》2011,8(57):578-584
The global epidemiology of meticillin-resistant Staphylococcus aureus (MRSA) is characterized by different clonal lineages with different epidemiological behaviour. There are pandemic hospital clones (hospital-associated (HA-)MRSA), clones mainly causing community-acquired infections (community-associated (CA-)MRSA, mainly USA300) and an animal-associated clone (ST398) emerging in European and American livestock with subsequent spread to humans. Nosocomial transmission capacities (RA) of these different MRSA types have never been quantified. Using two large datasets from MRSA outbreaks in Dutch hospitals (dataset 1, the UMC Utrecht for 144 months; dataset 2, 51 hospitals for six months) and a recently developed mathematical model, we determined the genotype-specific RA for ST398 and non-ST398 isolates (categorized as HA-MRSA), using observational data, the detection rate of MRSA carriage and the discharge rate from hospital as the input. After detection of 42 MRSA index cases in dataset 1 (all non-ST398 MRSA) 5076 people were screened, yielding 30 secondary cases. In dataset 2, 75 index cases (51 non-ST398 MRSA and 24 ST398) resulted in 7892 screened individuals and 56 and three secondary cases for non-ST398 MRSA and ST398, respectively. The ratio between discharge and the detection rate was 2.7. RA values (95% confidence interval (CI)) were 0.68 (0.47–0.95) for non-ST398 MRSA in dataset 1, 0.93 (0.71–1.21) for non-ST398 MRSA in dataset 2 and 0.16 (0.04–0.40) for ST398. The RA ratio between non-ST398 MRSA and ST398 was 5.90 (95% CI 2.24–23.81). ST398 is 5.9 times less transmissible than non-ST398 MRSA in Dutch hospitals, which may allow less stringent transmission-control measures for ST398 MRSA. 相似文献