Investigation of interference from canine anti‐mouse antibodies in hormone immunoassays     

Daniel Bergman  Anders Larsson  Helene Hansson‐Hamlin  Bodil Strm Holst 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2019,48(Z1):59-69

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Marine migrations in anadromous brown trout (Salmo trutta). Fjord residency as a possible alternative in the continuum of migration to the open sea     

Diego del Villar‐Guerra  Kim Aarestrup  Christian Skov  Anders Koed 《Ecology of Freshwater Fish》2014,23(4):594-603

Partial migration is a common phenomenon in many fish species. Trout (Salmo trutta) is a partially migratory species where some part of the population migrate to the marine environment, while another remains in freshwater. In the years 2008 and 2009, a total of 159 wild sea trout smolts were tagged with acoustic and PIT‐tags in the river Villestrup (Denmark) to study the initial postsmolt marine behaviour within a fjord system. We found that the strategies of the sea migrants vary: some stay in the fjord, while others migrate to the sea, suggesting that partial migration occurs even in the marine environments. Overall, a total of 53% of the tagged smolts migrated from the fjord to the sea, and 47% stayed (or potentially died) in the fjord. The ratios of fjord‐resident versus sea‐migrating postsmolts were consistent at the study times, and no differences between the early and late migration periods of the smolts were observed. The individual's size or body condition at the time of tagging did not affect survival or the migratory decisions in the fjord. High overall initial survival (74%) was found 30 days after the fjord entry. We suggest that within a continuum of migration to sea, there is a migratory decision point when sea trout postsmolts encounter a fjord system. At this point, postsmolts will assess the possibility of migration versus the alternative of fjord residency.  相似文献   

Migration of eels tagged in the Baltic Sea and Lake Mälaren—in the context of the stocking question          下载免费PDF全文

Niklas B. Sjöberg  Håkan Wickström  Anders Asp  Erik Petersson 《Ecology of Freshwater Fish》2017,26(4):517-532

Eels (Anguilla spp.) are in decline worldwide, and the signs of reduced recruitment have been observed in continental Europe since the early 1970s. To aid recovery of the European eel, stocking is used by many European countries as a management option. In this study, tagging experiments were conducted to follow eel migration from Lake Mälaren and four sites along the Swedish east coast in the Baltic Sea. The recaptured tagged eels were retrieved from fishermen, allowing for the opportunity to investigate their origin (brackish water, stocked in freshwater or a mix in between) by otolith microchemistry and to assess for morphological differences after tagging. Several changes took place; for example, eye index increased while weight and condition decreased with migrated distance and time until recapture. In Lake Mälaren, the majority of tagged eels did not migrate out of the outlets, irrespective of their origin. Most of them were caught in the opposite direction and continued to be caught in the lake 1–3 years after tagging, with significant weight losses. Overall, overwintering is suggested to be an inferior option, but it is uncertain whether this is a natural behaviour or a result of translocation and restocking. For coastal eels, origin had no effect on migratory behaviour; a majority of the tagged eels migrated towards the outlet of the Baltic Sea. Interestingly, a minority of the recaptured eels originated from stocked fish. Instead, recaptures were dominated by natural immigrants that had spent most of their lives in brackish waters.  相似文献   

Farm-related Factors Influencing the Adoption of Short-rotation Willow Coppice Production Among Swedish Farmers     

Anders Roos  Håkan Rosenqvist  Erik Ling  Bo Hektor 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(1):28-34

The area of short-rotation willow coppice energy plantations on Swedish farmland increased quickly in the early 1990s because of subsidies for energy crop production, an increased CO₂ tax on fossil fuel and an already existing biofuel market in the country. In this study farm-related determinants for the adoption of short-rotation willow coppice production among Swedish farmers are identified and estimated. A Tobit model is applied to cross-sectional data on Swedish farmers in 1995. The results show that the decision to plant willow and the areas planted depend positively on arable land area, forest land area, the area of other land types, leasing out of arable land and tractor ownership. Negative factors are pasture area, tenancy and animal production. Differences in willow growing between ownership types, age groups and geographical regions are also important. The policy implications of the results are discussed.  相似文献   

Effect of intermittent drought on grain yield and quality of rice (Oryza sativa L.) grown in Rwanda     

Alphonsine Mukamuhirwa  Helena Persson Hovmalm  Rodomiro Ortiz  Obedi Nyamangyoku  Maria Luisa Prieto–Linde  Anders Ekholm  Eva Johansson 《Journal of Agronomy and Crop Science》2020,206(2):252-262

The climate change will contribute drought and temperature extremes to rice growing systems, especially when cultivated in equatorial regions. To evaluate opportunities to cultivate and breed drought-tolerant rice, seven rice cultivars were evaluated in Rwanda for recurring morphological drought scores, grain yield and components, and quality characteristics. The cultivation conditions, that is site and drought treatment, impacted morphological drought scores, growth and yield attributes, while cultivar affected quality attributes. Thus, site showed a higher impact on grain yield and components than drought and cultivar, with generally a reduced grain yield at the low-temperature site, as a result of low spikelet fertility. Morphological drought scores were generally increased by drought, while drought at the reproductive stage at the high-temperature site was negative for yield and its components. The cultivars “Intsindagirabigega” and “Jyambere” were adapted to high-temperature site conditions. The cultivar “Intsindagirabigega” had the highest amylose content, and “Mpembuke,” the highest antioxidant capacity. Thus, climate change with increased temperature and drought extremes may increase rice productivity in cool areas, while especially drought at reproductive stage will be detrimental in low altitude areas with high temperature. Cultivar variation indicated opportunities for selection and breeding of climate change tolerant rice cultivars which should be of immediate priority.  相似文献   

Otolith size differences during early life of dwarf and cannibal Arctic char (Salvelinus alpinus)          下载免费PDF全文

Bjørn Florø‐Larsen  Anders G. Finstad  Ole K. Berg  Per H. Olsen 《Ecology of Freshwater Fish》2016,25(2):203-210

In Arctic and alpine lakes, Arctic char [Salvelinus alpinus (L.)] often form two distinct morphs: invertebrate feeders (‘dwarfs’) and piscivores (‘giant or cannibals’). Here, we test for early life history growth variation in dimorphic Arctic char as a proximate explanation for the observed life history variation between the two forms. Char were sampled in 11 alpine and Arctic Norwegian lakes. Dwarfs (defined as sexually mature char less than 15 cm long; N = 304) had a mean total length of 105 mm, whereas the typical cannibal (body length above 20 cm; N = 153) was 388 mm long. A positive correlation between egg size and otolith hatching ring were ascertained in a separate hatching experiment with brown trout (Salmo trutta) and it is assumed that this relationship also is valid for Arctic char, and otolith size was used as a proxy for length. Otolith hatching ring from Arctic char cannibals was larger (mean ± SD; 187 ± 24 μm) than those from dwarfs (mean ± SD; 164 ± 23 μm). There were only minor size differences between dwarfs and cannibals during the next three years, after which dwarfs usually matured. Two mutually nonexclusive, proximate explanations for the differentiation into separate morphs (dwarfs and cannibals) are therefore maternal effects and/or genetic based differentiation. The high catchability of large piscivorous char and low production in alpine and Arctic lake ecosystems may make these stocks particularly vulnerable to overexploitation.  相似文献   

An integrative insight into the synsacral canal of fossil and extant Antarctic penguins     

Piotr JADWISZCZAK  Anders SVENSSON-MARCIAL  Thomas MÖRS 《Integrative zoology》2023,18(2):237-253

The lumbosacral-canal system in birds most likely operates as a sense organ involved in the control of balanced walking and perching, but our knowledge of it is superficial. Penguins constitute interesting objects for the study of this system due to their upright walking, but only the Humboldt penguin, Spheniscus humboldti, and some incomplete fossil penguin synsacra have been studied in this respect. Here, we give an integrative comparative insight into the synsacral canal of extant Emperor penguin, Aptenodytes forsteri, Adelie penguin, Pygoscelis adeliae, and Eocene giant Anthropornis and/or Palaeeudyptes Antarctic penguins, using computed tomography imaging and associated data-extraction methodologies, complemented by analytical approaches ranging from geometric morphometrics to modularity, curvature, and wavelet analyses. We document that the variability in the number of synsacro-lumbar vertebrae is evolutionarily conserved, and all studied synsacra possess osteological correlates of the lumbosacral-canal system. We also found that Eocene and extant Antarctic penguins were separable on the basis of the main direction of the shape-related (size-independent) variability within said system, and A. forsteri was unique in the entire studied set in terms of the relative cranial shift of this compound structure. Moreover, we suggest that the evolutionary processes, shaping both the terrestrial posture and gait, were responsible, in extant penguins, for the increased simplicity and stability of the synsacral canal cross-sectional periodic patterns, as well as pave the way for the lumbosacral-canal system modularity characterized by reduced atomization/complexity.  相似文献   

Rundschau     

Erwin Schimitschek  Ing H. Anders 《Journal of pest science》1956,29(9):148-150

Ohne Zusammenfassung  相似文献   

Quantitative structure-activity relationships of pine weevil antifeedants, a multivariate approach     

Sunnerheim K  Nordqvist A  Nordlander G  Borg-Karlson AK  Unelius CR  Bohman B  Nordenhem H  Hellqvist C  Karlén A 《Journal of agricultural and food chemistry》2007,55(23):9365-9372

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Scientific description can imperil species     

Stuart BL  Rhodin AG  Grismer LL  Hansel T 《Science (New York, N.Y.)》2006,312(5777):1137

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