Experimental indication of interaction between viscoelastic and mechano-sorptive creep

Summary This paper describes the study of possible interactions between the viscoelastic and mechano-sorptive creep inPinus sylvestris. When two periods of constant-moisture creep were separated by a period of mechano-sorptive creep, the expected creep rate during the second viscoelastic period was decreased. A similar effect was observed during creep recovery. These results were taken to indicate an interaction between the two types of creep, although not necessarily a common mechanism. During recovery with uniform moisture cycling, the effects of one extra low and one extra high humidity were observed. The low humidity showed no significant effect, but the high humidity significantly increased the recovery. This was attributed to a parallel effect to that of creep: namely, the creep acceleration that occurs at a higher moisture level than has previously been reached during the test.     

Macroinvertebrate-Inferred Stream-Water Acidity in North Eastern Finland Along a Sulphur Deposition Gradient

Recently developed weighted averaging (WA) models and widely used tolerance-limit approaches for inferring stream minimum pH from macroinvertebrates were tested in northeastern Finnish Lapland. Surface waters there are threatened by large sulphur emissions in the Russian Kola Peninsula. The modelled sulphur deposition increases from west to east approximately parallel to longitude. The effect of deposition on stream minimum pH was assessed by relating the macroinvertebrate-inferred stream minimum pH to longitude. In a test set of 17 streams, the minimum pH inferred from pooled invertebrate samples of three seasons by WA models showed a strong correlation (r = 0.67–0.72) with the minimum pH (range 6.3–7.1) observed during the spring snow-melt period. The relationship was slightly weaker (r = 0.59–0.69) using autumn samples only. The tolerance-limit approaches assigned the streams into the correct acidity class, but the inferred pH was not related to the observed minimum pH. This further demonstrates the superiority of the WA approach, especially in detecting early signs of acidification. The minimum pH inferred by WA from autumn assemblages of 37 streams along the deposition gradient showed a significant negative correlation with longitude, suggesting that the emissions from the Kola region contribute to low pH events in streams of northeastern Finnish Lapland. The results demonstrate the potential of bioassessment and monitoring using invertebrates in detecting impacts and changes that could remain unnoticed by conventional water quality-analyses.     

Economic and policy considerations regarding hydropower and migratory fish

Environmental standards have rarely been applied for promoting the joint production of hydropower and migratory fish. The objective of this study was to review existing research results on the effectiveness and costs of alternative measures improving fish migration, which are necessary for the development of environmental standards. The ranking of alternative measures indicates that cost‐effective combinations of measures are case‐specific and highly dependent on measure design, implementation and maintenance. In addition to tailored ex ante cost‐effectiveness analyses, other preconditions for cost savings include effective and affordable monitoring and enforcement, and cooperation among power companies that share water‐use rights within a river basin as well as among other stakeholders, such as the local community, fishermen and recreational users.     

Road culvert restoration expands the habitat connectivity and production area of juvenile Atlantic salmon in a large subarctic river system

The effects of restoration of impassable road culverts on the distribution of juvenile Atlantic salmon, Salmo salar L., were evaluated in seven small tributaries of the subarctic River Teno system, northernmost Finland/Norway. Restoration enabled the passage of juvenile salmon through the culverts and increased the distribution area of salmon parr in the seven streams by tens or hundreds of metres, depending on the natural slope of the tributary with a total of ≈1 km new area for ascending juveniles. Areas upstream of the culverts were colonised after varying number of years, mostly 2–3, following restoration. Age‐1 and age‐2 parr were the first salmon age groups entering the new territory after removal of the migration barrier. Although the restoration measures were conducted at the downstream outlet area of the culverts only, the connectivity was improved and increased the production area accessible to juvenile salmon. Such removal of migration barriers and securing habitat connectivity by passable culverts should be taken into account in environmental management strategies of river systems safeguarding the essential habitats of salmonid fish.     

Das Sammeln von Raff- und Leseholz in den Staatswaldungen

Ohne Zusammenfassung     

Comparison of milk antitrypsin,albumin, n-acetyl-β-d-glucosaminidase,somatic cells and bacteriological analysis as indicators of bovine subclinical mastitis

Thirty-two quarters, five of which harbored subclinical mastitis, were examined daily for one month. The usefulness of milk antitrypsin, BSA (bovine serum albumin), NAGase, somatic cells and bacteriological analysis in differentiating the inflamed quarters from the healthy control quarters was analysed. Inter-quarter evaluation clearly improved each indirect mastitis parameter; NAGase and antitrypsin were better indicators of differences between infected and non-infected quarters than BSA or the somatic cell count.     

Sonography in pleural effusion of horses

Pleural effusion in the horse can be caused by diseases such as pneumonia, trauma, pulmonary abscesses and thoracic neoplasms. Besides clinical (auscultation, percussion) and radiographic diagnostic procedures, the ultrasonic examination represents a method that supplies detailed information on quantity and location of fluid in the pleural space. By means of ultrasonic examination the most favourable position for a thoracentesis can be determined. Control of thoracentesis' efficiency as well as exact supervision of the disease's course are made feasible by repeated sonographic examinations.     

A critique of the Texas A&M model when used to simulate beef cattle grazing pasture

This paper describes the experiences of the authors with the Texas A&M University model when used to simulate the production of beef cattle in a grazing system. Problems associated with the lack of interaction between pasture and animals, including the monthly time interval, supplementation and an input parameter (weight at maturity), are discussed.     

Animal consumption of antibiotics and chemotherapeutic drugs in Sweden during 1980, 1982 and 1984

The total animal consumption of antibiotic and chemotherapeutic drugs in Sweden during 1980, 1982 and 1984 has been studied. The study also included coccidiostatic, antiparasitic and antimycotic drugs. The total animal consumption during the years mentioned was 66.1, 68.8 and 72.6 tons of active substance, respectively, and the amount of antibacterial drugs for therapy was 28.7 (43.4%), 29.1 (42.5%) and 34.1 (47.0%) tons, respectively. Tetracycline, penicillin, sulphonamide and aminoglycoside were the four major groups of antibiotics used for therapy of bacterial infections in animals. The consumption was related to the metabolic bodyweights of animals which were the potential consumers. A comparison was also made with the corresponding human consumption during 1980. The data on antibiotic consumption can be divided by county and compared to the animal population and disease situation in each county. This study thus offers a good base for further investigations on different aspects of the use of antibiotics.