Seasonal and diurnal variation of downstream fish movement at four small-scale hydropower plants     

Josef Knott  Melanie Mueller  Joachim Pander  Juergen Geist 《Ecology of Freshwater Fish》2020,29(1):74-88

Hydropower structures hinder the movement and migration of fishes, impairing their life cycles. Additionally, downstream moving fish are often at risk of being injured during turbine passage. To improve hydropower production towards more fish-friendly techniques and management, knowledge on timing and extent of natural patterns of fish downstream movement is necessary. So far, migration behaviour of long-distance migrators such as eel or salmon has been well studied, but little is known about seasonal and diurnal movement patterns of nonmigratory species or medium-distance migrators. In this study, movement patterns of 39 fish species captured by stownets while transiting hydropower facilities in four impounded rivers were assessed and compared with the fish community composition directly upstream of the hydropower plants assessed by electrofishing. Strong differences between the fish community composition inhabiting the upstream sides of the dams and the fish detected in downstream passage were evident. In each study river, the downstream moving fish community composition differed significantly between spring and autumn. On average, significantly more fish were caught during the night (2.9 fish/hr) than during the day (1.3 fish/hr). Topmouth gudgeon, European grayling and pike-perch mostly moved downstream during the night, whereas roach, spirlin and bleak were the most frequent downstream moving fish during daytime. Downstream fish movement was positively related with turbidity, water temperature and discharge. The strong differences in seasonal and diurnal fish movement patterns suggest that fish damage can be strongly reduced by adaptive turbine and corridor management, for example by shutting down turbines at peak movements.  相似文献   

Comparison of Tensile Strength and Early Healing of Acute Repeat Celiotomy Through a Ventral Median or a Right Ventral Paramedian Approach     

Lindsey Helms Boone DVM  PhD  Kira Epstein DMV  Diplomate ACVS & ACVECC  Jeanette Cremer Dr. Med. Vet  Diplomate ACVA  Andrew Rogers BS  Tim Foutz PhD  Jane Quandt DVM  Diplomate ACVA & ACVECC  Elizabeth Howerth DVM  PhD  Diplomate ACVP  P.O. Eric Mueller DVM  PhD  Diplomate ACVS 《Veterinary surgery : VS》2014,43(6):741-749

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Pet Obesity Management : Beyond Nutrition     

Deborah Linder  Megan Mueller 《Veterinary Clinics of North America: Small Animal Practice》2014

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Endoscopically Visualized Lesions,Histologic Findings,and Bacterial Invasion in the Gastrointestinal Mucosa of Dogs with Acute Hemorrhagic Diarrhea Syndrome     

S. Unterer  K. Busch  M. Leipig  W. Hermanns  G. Wolf  R.K. Straubinger  R.S. Mueller  K. Hartmann 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(1):52-58

Background

Etiology of hemorrhagic gastroenteritis (HGE) syndrome in dogs is unknown and histopathologic and microbial investigations have only been performed post mortem.

Objective

To identify characteristic intra vitam endoscopic and histologic mucosal lesions, as well as bacterial species, within the mucosa of dogs with HGE.

Animals

Ten dogs diagnosed with HGE were included. Eleven dogs with gastroduodenoscopy and different intestinal diseases were used as controls for microbial changes. Dogs pretreated with antibiotics or diagnosed with any disease known to cause bloody diarrhea were excluded from the study.

Methods

In this prospective study, gastrointestinal biopsies were collected from 10 dogs with HGE. Endoscopic and histologic changes were assessed according to WSAVA guidelines. Biopsies from the stomach, duodenum, ileum, and colon were investigated by histology and by immunohistochemistry for the presence of Clostridium spp. and parvovirus. The first duodenal biopsy taken with a sterile forceps was submitted for bacterial culture.

Results

Acute mucosal lesions were only found in the intestines, not in the stomach. Clostridium spp., identified as Clostridium perfringens in 6/9 cases, were detected on the small intestinal mucosa in all dogs with HGE, either by culture or immunohistopathology. In the control group, C. perfringens could only be cultured in one of 11 dogs.

Conclusions and Clinical Importance

The results of this study demonstrate an apparent association between C. perfringens and the occurrence of acute hemorrhagic diarrhea. The term “HGE,” which implies the involvement of the stomach, should be renamed as “acute hemorrhagic diarrhea syndrome.”  相似文献   

Intensive Intravenous Infusion of Insulin in Diabetic Cats     

M. Hafner  S. Dietiker‐Moretti  K. Kaufmann  C. Mueller  T.A. Lutz  C.E. Reusch  E. Zini 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(6):1753-1759

Background

Remission occurs in 10–50% of cats with diabetes mellitus (DM). It is assumed that intensive treatment improves β‐cell function and increases remission rates.

Hypothesis

Initial intravenous infusion of insulin that achieves tight glycemic control decreases subsequent insulin requirements and increases remission rate in diabetic cats.

Animals

Thirty cats with newly diagnosed DM.

Methods

Prospective study. Cats were randomly assigned to one of 2 groups. Cats in group 1 (n = 15) received intravenous infusion of insulin with the goal of maintaining blood glucose concentrations at 90–180 mg/dL, for 6 days. Cats in group 2 (n = 15) received subcutaneous injections of insulin glargine (cats ≤4 kg: 0.5–1.0 IU, q12h; >4 kg 1.5–2.0 IU, q12h), for 6 days. Thereafter, all cats were treated with subcutaneous injections of insulin glargine and followed up for 6 months. Cats were considered in remission when euglycemia occurred for ≥4 weeks without the administration of insulin. Nonparametric tests were used for statistical analysis.

Results

In groups 1 and 2, remission was achieved in 10/15 and in 7/14 cats (P = .46), and good metabolic control was achieved in 3/5 and in 1/7 cats (P = .22), respectively. Overall, good metabolic control or remission occurred in 13/15 cats of group 1 and in 8/14 cats of group 2. In group 1, the median insulin dosage given during the 6‐month follow‐up was significantly lower than in group 2 (group 1: 0.32 IU/kg/day, group 2: 0.51 IU/kg/day; P = .013).

Conclusions and Clinical Importance

Initial intravenous infusion of insulin for tight glycemic control in cats with DM decreases insulin requirements during the subsequent 6 months.  相似文献   

Evolutionary history of the symbiosis between fungus-growing ants and their fungi     

Chapela IH  Rehner SA  Schultz TR  Mueller UG 《Science (New York, N.Y.)》1994,266(5191):1691-1694

The evolutionary history of the symbiosis between fungus-growing ants (Attini) and their fungi was elucidated by comparing phylogenies of both symbionts. The fungal phylogeny based on cladistic analyses of nuclear 28S ribosomal DNA indicates that, in contrast with the monophyly of the ants, the attine fungi are polyphyletic. Most cultivated fungi belong to the basidiomycete family Lepiotaceae; however, one ant genus, Apterostigma, has acquired a distantly related basidiomycete lineage. Phylogenetic patterns suggest that some primitive attines may have repeatedly acquired lepiotaceous symbionts. In contrast, the most derived attines have clonally propagated the same fungal lineage for at least 23 million years.  相似文献   

Strange magnetism and the anapole structure of the proton     

Hasty R  Hawthorne-Allen AM  Averett T  Barkhuff D  Beck DH  Beise EJ  Blake A  Breuer H  Carr R  Covrig S  Danagoulian A  Dodson G  Dow K  Farkhondeh M  Filippone BW  Gao J  Herda MC  Ito TM  Jones CE  Korsch W  Kramer K  Kowalski S  Lee P  McKeown RD  Mueller B  Pitt M 《Science (New York, N.Y.)》2000,290(5499):2117-2119

The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.  相似文献   

Solar Availability for Winter Space Heating: An Analysis of SOLMET Data, 1953 to 1975     

Asbury JG  Maslowski C  Mueller RO 《Science (New York, N.Y.)》1979,206(4419):679-681

Solar availability for space heating on coldest-weather days has been determined from an analysis of SOLMET data tapes. The tapes contain hourly readings of insolation and ambient temperature over the period from 1953 through 1975. Scatter diagrams of insolation versus heating degree-days, compiled on a daily basis, indicate a wide variation in the insolation level, even during coldest-weather periods. For all but one of the eight sites studied, the peak-day backup energy requirement of the solar system was in excess of 85 percent of the peak-day energy requirement of the conventional (nonsolar) heating system.  相似文献   

The evolution of agriculture in ants     

UG Mueller  SA Rehner  TR Schultz 《Science (New York, N.Y.)》1998,281(5385):2034-2038

Cultivation of fungi for food by fungus-growing ants (Attini: Formicidae) originated about 50 million years ago. The subsequent evolutionary history of this agricultural symbiosis was inferred from phylogenetic and population-genetic patterns of 553 cultivars isolated from gardens of "primitive" fungus-growing ants. These patterns indicate that fungus-growing ants succeeded at domesticating multiple cultivars, that the ants are capable of switching to novel cultivars, that single ant species farm a diversity of cultivars, and that cultivars are shared occasionally between distantly related ant species, probably by lateral transfer between ant colonies.  相似文献   

Lipoperoxidation of lung lipids in rats exposed to nitrogen dioxide   总被引：8，自引：0，他引：8  

H V Thomas  P K Mueller  R L Lyman 《Science (New York, N.Y.)》1968,159(814):532-534

Absorption spectra characteristic of diene conjugation and typical for peroxidized polyenoic fatty acids can be induced in rat lung lipids after the rats have been exposed to a scant amount of nitrogen dioxide (1 part per million) for 4 hours. The peroxidative changes do not occur immediately but appear to reach a maximum between 24 and 48 hours after exposure. The prooxidant effect of this atmospheric pollutant in rat lung lipids may be partially prevented by prior treatment of the animal with large doses of alpha-tocopherol.  相似文献