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  • 1
    Digitale Medien
    Digitale Medien
    SOURCES OF RELATIVISTIC JETS IN THE GALAXY (1999)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 37 (1999), S. 409-443 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract Black holes of stellar mass and neutron stars in binary systems are first detected as hard X-ray sources using high-energy space telescopes. Relativistic jets in some of these compact sources are found by means of multiwavelength observations with ground-based telescopes. The X-ray emission probes the inner accretion disk and immediate surroundings of the compact object, whereas the synchrotron emission from the jets is observed in the radio and infrared bands, and in the future could be detected at even shorter wavelengths. Black-hole X-ray binaries with relativistic jets mimic, on a much smaller scale, many of the phenomena seen in quasars and are thus called microquasars. Because of their proximity, their study opens the way for a better understanding of the relativistic jets seen elsewhere in the Universe. From the observation of two-sided moving jets it is inferred that the ejecta in microquasars move with relativistic speeds similar to those believed to be present in quasars. The simultaneous multiwavelength approach to microquasars reveals in short timescales the close connection between instabilities in the accretion disk seen in the X-rays, and the ejection of relativistic clouds of plasma observed as synchrotron emission at longer wavelengths. Besides contributing to a deeper understanding of accretion disks and jets, microquasars may serve in the future to determine the distances of jet sources using constraints from special relativity, and the spin of black holes using general relativity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.37.1.409
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  • 2
    Digitale Medien
    Digitale Medien
    Risk factors for inflammatory bowel disease in the general population (2005)
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 22 (2005), S. 0 
    Details
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background:  The aetiology of inflammatory bowel disease remains largely unknown.Aim:  We performed a comprehensive assessment of potential risk factors associated with the occurrence of inflammatory bowel disease.Methods:  We identified a cohort of patients 20–84 years old between 1995 and 1997 registered in the General Practitioner Research Database in the UK. A total of 444 incident cases of IBD were ascertained and validated with the general practitioner. We performed a nested case–control analysis using all cases and a random sample of 10 000 frequency-matched controls.Results:  Incidence rates for ulcerative colitis, Crohn's disease, and indeterminate colitis were 11, 8, and 2 cases per 100 000 person-years, respectively. Among women, we found that long-term users of oral contraceptives were at increased risk of developing UC (OR: 2.35; 95% CI: 0.89–6.22) and CD (OR: 3.15; 95% CI: 1.24–7.99). Similarly, long-term users of HRT had an increased risk of CD (OR: 2.60; 95% CI: 1.04–6.49) but not UC. Current smokers experienced a reduced risk of UC along with an increased risk of CD. Prior appendectomy was associated with a decreased the risk of UC (OR: 0.37; 95% CI: 0.14–1.00).Conclusions:  Our results support the hypothesis of an increased risk of inflammatory bowel disease associated with oral contraceptives use and suggest a similar effect of hormone replacement therapy on CD. We also confirmed the effects of smoking and appendectomy on inflammatory bowel disease.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2036.2005.02564.x
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  • 3
    Digitale Medien
    Digitale Medien
    One-year follow-up of newly diagnosed irritable bowel syndrome patients (1999)
    Oxford UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 13 (1999), S. 0 
    Details
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: : Irritable bowel syndrome is the most common functional gastrointestinal disorder seen by general physicians.〈section xml:id="abs1-2"〉〈title type="main"〉Methods: We followed up a population-based cohort of newly diagnosed irritable bowel syndrome patients aged 20–79 years, to examine patterns of treatment, comorbidity and healthcare utilization. We used the UK General Practice Research Database as the source population. Individuals with other gastrointestinal diseases, cancer and pregnant women were not included. There were 2956 patients in our final cohort.〈section xml:id="abs1-3"〉〈title type="main"〉Results: Irritable bowel syndrome patients were mainly young and middle-aged; only 12% were 60 years or older. The majority of patients were women (74%). There were no marked differences in terms of use of healthcare services or comorbidity status in the year before irritable bowel syndrome diagnosis as compared to the year after. Fourteen per cent of irritable bowel syndrome patients received no drug treatment at all. Among those treated, the first choice was an antispasmodic. Elderly patients (〉 60 years old) were more likely to receive drug treatment. Females had a slightly higher probability of being treated than men, except for the category of anti-diarrhoeal drugs.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusion: This study has shown that irritable bowel syndrome patients are mainly young and female. We also found that treatment pattern varied according to age and gender. Elderly patients and females were at a higher risk of receiving drug treatment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2036.1999.00576.x
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  • 4
    Digitale Medien
    Digitale Medien
    Carbon dioxide laser treatment of erythroplasia of Queyrat: a revisited treatment to this condition (2005)
    Oxford, UK : Blackwell Science Ltd
    Journal of the European Academy of Dermatology and Venereology 19 (2005), S. 0 
    Details
    ISSN: 1468-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1468-3083.2005.01217.x
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  • 5
    Digitale Medien
    Digitale Medien
    Hafnia alvei as an opportunistic pathogen causing mortality in brown trout, Salmo trutta L. (1998)
    Oxford, UK : Blackwell Science Ltd
    Journal of fish diseases 21 (1998), S. 0 
    Details
    ISSN: 1365-2761
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie , Medizin
    Notizen: Strains of Hafnia alvei caused mortalities in brown trout, Salmo trutta L., following intraperitoneal injection with LD50 values ranging between 1.3 × 104 and 2.5 × 107 bacteria fish−−1. These values are considered to represent a high to moderate degree of virulence. Virulent strains were isolated from non-fish sources. Fish surviving the LD50 values continued to harbour the organism in the kidney, suggesting the establishment of a carrier state.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2761.1998.00116.x
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  • 6
    Digitale Medien
    Digitale Medien
    Group coancestry-controlled selection in a Pinus sylvestris L. breeding program (1999)
    Springer
    Theoretical and applied genetics 99 (1999), S. 73-80 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Key words Breeding program ; Coancestry ; Genetic diversity ; Group coancestry ; Integer linear programming ; Selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Integer Linear Programming was used to maximize genetic gain from selection at a given level of relatedness. Variances and breeding values for total height were available for 296 plus-trees of Pinus sylvestris which had been evaluated by open-pollinated progeny testing at a single test site in northern Sweden. Second-generation breeding and selection scenarios for this breeding population were evaluated using simulated data derived deterministically from normal distributions of estimated breeding values of progeny around mid-parent family means. The study considered two mating designs, assortative and non-assortative single-pair mating, and two selection criteria, individual phenotype and performance of half-sib progeny. Relatedness (group coancestry) was restricted to a level equivalent to that given by within-family selection of 2 trees per family from each of 25 families (the current standard in Sweden). Selection that allows the best-performing families to contribute a greater number of progeny was superior, both when the breeding population size was limited to 50 individuals and when it was allowed to be larger. The selected set giving the greatest average breeding value under restricted group coancestry included the best individual from families that would have been rejected under application of standard within-family selection. We made a comparison of the present value on retrieved gain between phenotypic selection and evaluation by progeny testing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s001220051210
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  • 7
    Digitale Medien
    Digitale Medien
    Influence of food quantity and temperature on development and growth of the marine copepod Calanus chilensis from northern Chile (1997)
    Springer
    Marine biology 128 (1997), S. 281-288 
    Details
    ISSN: 1432-1793
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An experiment under laboratory conditions was conducted to test the hypothesis that development and growth of copepodite stages in Calanus chilensis are temperature-dependent and not subject to food shortage in the upwelling area of the Humboldt Current, northern Chile. Field data obtained from June 1994 to May 1995 in Bahía Mejillones (23°S) were used to define four combinations of temperature and food under which copepodites were reared from Stage CIII to adulthood. The high temperature was 18.1 °C and the low temperature 13.1 °C, whereas the high food level was in the range of 6.8 to 24.8 μg l−1 chlorophyll a and the low level 1.0 to 6.8 μg l−1 chlorophyll a. As food a mixture of three unknown species of phytoflagellates and the diatom Navicula cryptocephala was used. This phytoplankton was initially obtained from the same sampling sites as copepods and kept in f/2 media at stable levels and composition throughout the experiment. The development rate (1/t), estimated from the time (t) elapsing between Stage CIV and adult, was significantly affected by both temperature and food, although low-food effects were much more remarkable. Low-food conditions also significantly reduced body length and “structural” (lipid-discounted) body mass at adulthood, while temperature only affected body length. The weight-specific growth rate was also affected by food and temperature, but again food effects were much more drastic. The results indicate that C. chilensis is a highly sensitive species to lack of food, and is possibly subject to food shortage during its annual cycle in the coastal upwelling area of northern Chile. Food limitation may help explain the seasonal pattern of adult size reported by previous studies in the area and the lack of consistence between the number of generations predictable from a temperature-dependent model and that observed in the field during the annual cycle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002270050093
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  • 8
    Digitale Medien
    Digitale Medien
    Microquasars in our Galaxy (1998)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 392 (1998), S. 673-676 
    Details
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Microquasars are stellar-mass black holes in our Galaxy that mimic, on a smaller scale, many of the phenomena seen in quasars. Their discovery opens the way for a new understanding of the connection between the accretion of matter onto black holes and the origin of the relativistic jets observed in ...
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1038/33603
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  • 9
    Digitale Medien
    Digitale Medien
    Compact protoplanetary disks around the stars of a young binary system (1998)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 395 (1998), S. 355-357 
    Details
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Planet formation is believed to occur in the disks of gas and dust that surround young solar-type stars. Most stars, however, form in multiple systems, where the presence of a close companion could affect the structure of the disk and perhaps interfere with planet formation. It has been ...
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1038/26421
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  • 10
    Digitale Medien
    Digitale Medien
    Bone Mineral Content and Density in Professional Tennis Players (1998)
    Springer
    Calcified tissue international 62 (1998), S. 491-496 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Key words: DXA — Bone mass — Body composition — Osteoporosis — Tennis.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. Total and regional bone mineral content (BMC) as well as lean and fat mass were measured in nine male professional tennis players (TPs) and 17 nonactive subjects; dual-energy X-ray absorptiometry (DXA) was used for measuring. The mean (±SD) age, body mass, and height were 26 ± 6 and 24 ± 3 years, 77 ± 10 and 74 ± 9 kg, and 180 ± 6 and 178 ± 6 cm for the TP and the control group (CG), respectively. The whole body composition for BMC, lean mass, and fat of the TP was similar to that observed in the CG. The tissue composition of the arms and legs was determined from the regional analysis of the whole-body DXA scan. The arm region included the hand, forearm, and arm, and was separated from the trunk by an inclined line crossing the scapulo-humeral joint. In the TP, the arm tissue mass (BMC + fat + lean mass) was about 20% greater in the dominant compared with the contralateral arm because of a greater lean (3772 ± 500 versus 3148 ± 380 g, P 〈 0.001) and BMC (229.0 ± 43.5 versus 188.2 ± 31.9 g, P 〈 0.001). In contrast, no significant differences were observed either in BMC or BMD between arms in the CG. Total mass, lean mass, and BMC were greater in the dominant arm of the TP than in the CG (all P 〈 0.05). In the TP, BMD was similar in both legs whereas in the CG, BMD was greater in the right leg. Lumbar spine (L2–L4) BMD, adjusted for body mass and height, was 15% greater in the TP than in the CG (P 〈 0.05). Femoral neck BMDs (femoral neck, Ward's triangle, greater trochanter, and intertrochanteric regions) adjusted for body mass and height were 10–15% greater in the TP (all P 〈 0.05). Ward's triangle BMD was correlated with the maximal leg extension isometric strength (r = 0.77, P 〈 0.05) even when adjusted for body mass (r = 0.76, P 〈 0.05) and height (r = 0.77, P 〈 0.05). In summary, the participation in tennis is associated with increased BMD in the lumbar spine and femoral neck. These results may have implications for devising exercise strategies in young and middle-aged persons to prevent involutional osteoporosis later in life.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002239900467
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