Effects of salinity on osmoregulation,growth and survival in Asian swamp eel (Monopterus albus) (Zuiew 1793)     

Pil Birkefeldt Møller Pedersen  Kasper Hansen  Do Thi Thanh Houng  Mark Bayley  Tobias Wang 《Aquaculture Research》2014,45(3):427-438

The Asian swamp eel Monopterus albus is normally considered a freshwater species, but can also occasionally be found in brackish water. It is an obligate air‐breather with highly reduced gills, making its osmoregulation physiology interesting because the gills normally represent the primary site of osmoregulation in teleosts. Being a popular fish for human consumption, the swamp eel is cultured extensively in freshwater ponds in the Mekong Delta of Vietnam. However, very little is known about its salinity tolerance, which is becoming topical due to the increasing salt‐water intrusions into tropical deltas. We therefore studied how increased salinity affects survival, growth, blood pressure, heart rate, blood osmolality and plasma ions. All eels survived prolonged exposure to 5 and 10 g L^?1, although plasma osmolality increased significantly at 10 g L^?1. Further elevation to 15 and 20 g L^?1 was associated with significantly elevated mortality, with a corresponding increase in plasma osmolality and ion con‐centrations. Our results show that swamp eels thrive in 0–10 g L^?1 with an optimum growth between 0 and 9 g L^?1, indicating that utilization of low saline brackish waters for aquaculture is possible.  相似文献   

Molecular genetic characterization of Central European soybean breeding germplasm     

Volker Hahn  Tobias Würschum 《Plant Breeding》2014,133(6):748-755

Soybean is the most important oilseed and protein crop worldwide, but in Europe, the acreage is comparably low. Thus, Europe strongly depends on imports of soy products and consequently recent efforts aim at expanding the acreage of soybean, particularly in Central Europe. The aim of this study was, therefore, to assist these breeding efforts by characterizing Central European soybean germplasm, employing a genotyping‐by‐sequencing approach yielding 7741 genomewide distributed markers. Our analysis on genetic diversity and population structure revealed that the Central European lines are most closely related to Swiss and Canadian lines and somewhat more distant from the investigated Chinese and US lines. In addition, we analysed patterns of allelic diversity and the extent of linkage disequilibrium. Collectively, our results can assist breeding of Central European soybean and suggest that further progress can be made by crosses among adapted material but a long‐term success also requires introgression of alleles from non‐European germplasm to further broaden the genetic diversity and incorporate novel traits.  相似文献   

Comparison of critical limits for crop plant growth based on different indicators for the state of soil compaction     

Manfred Kaufmann  Silvia Tobias  Rainer Schulin 《植物养料与土壤学杂志》2010,173(4):573-583

Soil compaction affects physical soil condition, in particular aeration, soil strength, and water availability and has adverse effects on plant growth. Bulk density is the most frequently used indicator to describe the state of compaction of a soil. However, this parameter lacks a direct functional relationship with plant growth. Various indicators have been proposed to simultaneously characterize the state of compaction of agricultural soil and its suitability for plant growth. This paper examines and compares the critical limits for crop plant growth based on three of these indicators: packing density, least limiting water range, and S parameter (the latter is the slope of the soil water‐retention curve in the inflexion point). In a first step, we reviewed the literature for published optimum and limiting values of bulk density and found that these values were highly dependent on clay and silt content. Converting them into corresponding values of packing density (composite index of bulk density and clay content), a value of 1.70 was found to effectively distinguish between optimum and limiting soil conditions for plant growth. In a second step, the packing density of 59 soil horizons sampled in N Switzerland was compared with the least limiting water range and the S parameter of these soil horizons (both determined by means of pedotransfer functions taken from the literature). A linear relationship between the three parameters was found, which allowed for a comparison of the published critical limits for plant growth based on these parameters. The critical limits of the three indicators, which had been postulated independently of each other in the literature, were found to agree well with each other. This means that all of them could equally be used to describe the compaction state of a soil and its physical suitability for plant growth. However, the proposed critical limits of packing density, least limiting water range, and S parameter still need further validation by field studies relating plant growth to soil compaction.  相似文献   

Removal of short‐range‐order minerals prior to grain‐size analysis of volcanic ash soils     

Andre Velescu  Tobias Meßmer  Thomas Scholten  Peter Kühn 《植物养料与土壤学杂志》2010,173(6):799-804

Incomplete dispersion of aggregates is a well‐known difficulty when analyzing soil texture of Andosols, particularly if no fresh soil material is available. To facilitate such investigations, several dispersion procedures were carried out on air‐dried samples rich in short‐range‐order minerals, originating from selected Andosol profiles (S Mexico). As a result, we propose an improved method based on a sequential chemical treatment with K oxalate, NH₄ oxalate, and oxalic acid that reliably removes cementing agents and allows for a stable dispersion of soil particles after addition of Na pyrophosphate. This method was proved to be well reproducible and highly reliable for routine grain‐size determinations. The potential error caused by the inherent risk of dissolving primary minerals or fresh volcanic glass remains far beyond the analytical error resulting from the incomplete and irreproducible dispersion of highly resistant aggregates by other commonly used techniques.  相似文献   

How pollution legacies and land use histories shape post-communist forest cover trends in the Western Carpathians     

Magdalena Main-Knorn  Patrick Hostert  Jacek Kozak  Tobias Kuemmerle 《Forest Ecology and Management》2009

Forests that encompass the border triangle of Poland, the Czech Republic and Slovakia currently suffer from centuries of inadequate forest management strategies, including overexploitation during the countries’ respective communist regimes and high stress levels due to airborne emissions from heavy industry. Since the fall of the Iron Curtain, each country has approached forest monitoring, protection and the improvement of forest conditions in its own way. Spaceborne remote sensing of forest changes across country borders offers great potential for better understanding the underlying drivers of change and for developing comparable indicators between countries.  相似文献   

Static site indices from different national forest inventories: harmonization and prediction from site conditions     

Susanne Brandl  Tobias Mette  Wolfgang Falk  Patrick Vallet  Thomas Rötzer  Hans Pretzsch 《Annals of Forest Science》2018,75(2):56

  相似文献   

COMPARISONS AMONG COMPUTED TOMOGRAPHIC FEATURES OF ADIPOSE MASSES IN DOGS AND CATS          下载免费PDF全文

Elisa Spoldi  Tobias Schwarz  Silvia Sabattini  Massimo Vignoli  Simona Cancedda  Federica Rossi 《Veterinary radiology & ultrasound》2017,58(1):29-37

A better understanding of the CT features of different forms of canine and feline adipose tumors would be valuable for improving patient management and treatment. The purpose of this retrospective, cross‐sectional study was to describe and compare the CT features of pathologically confirmed lipomas, infiltrative lipomas, and liposarcomas in a sample of canine and feline patients. A total of 50 animals (46 dogs, four cats) and a total of 60 lesions (23 lipomas, 20 infiltrative lipomas, and 17 liposarcomas) were included in the study. Lipomas appeared as round to oval‐shaped (n = 21), well‐marginated (n = 20) fat‐attenuating lesions. Infiltrative lipomas appeared as homogeneous, fat‐attenuating masses but, unlike lipomas, they were most commonly characterized by an irregular shape (75%; P < 0.001), and linear components, hyperattenuating relative to the surrounding fat (100%; P < 0.05). Liposarcomas were represented exclusively by heterogeneous lesions with soft tissue attenuating components with a multinodular appearance (76.5%; P < 0.05). Regional lymphadenopathy (n = 10) and amorphous mineralization (n = 4) were also observed in association with liposarcomas. Computed tomography can provide useful information regarding disease location, extent, and involvement of the adjacent structures. Tumor definition and shape were the most useful parameters to differentiate between lipomas and infiltrative lipomas. The presence of a heterogeneous mass, with a multinodular soft tissue component and associated regional lymphadenopathy and mineralization, were features favoring a diagnosis of liposarcoma.  相似文献   

Human guanylate-binding protein 1 as a model system investigated by several surface techniques     

Kerstan A  Ladnorg T  Grunwald C  Vöpel T  Zacher D  Herrmann C  Wöll C 《Biointerphases》2010,5(4):131-138

In medical technologies concerning the surface immobilization of proteins in a defined orientation, maintaining their activity is a critical aspect. Therefore, in this study, the authors have investigated the activity of an elongated protein attached to a self-assembled monolayer supported streptavidin layer for different relative orientations of the protein with regard to the surface. Several mutants of this protein, human guanylate-binding protein 1 (hGBP1) showing GTPase catalytic activity, have been furnished with either one or two biotin anchors. Various independent methods that are based on different biophysical properties such as surface plasmon resonance, atomic force microscopy, and quartz crystal microbalance have been used to determine the orientation of the hGBP1 variants after anchoring them via a streptavidin-linker to a biotinylated surface. The activity of guanosine-triphosphate hydrolysis of hGBP1 monomers bound on the surface is found to depend on their orientation relative to the substrate, relating to their ability to form dimers with other neighboring anchored mutants; the maximum activity is lower than that observed in solutions, as might be expected from diffusion limitations at the solid/liquid interface on the one hand and prevention from homodimer formation due to immobilization on the other hand.  相似文献   

Prediction of early race starts in Norwegian-Swedish Coldblooded Trotters     

Tobias Revold  Stig Larsen  Carl F Ihler 《Acta veterinaria Scandinavica》2010,52(1):53

Background

Less than a third of Norwegian-Swedish Coldblooded Trotters (NSCTs) have started racing as three year olds since the year 2000 despite the fact that large sums are paid out as price-money in the three year season. Recruitment races are arranged by the Norwegian Trotting Association (NTA) to stimulate early training. The management of young horses varies considerably and a large majority is reared by amateurs. The aim of the present study was to identify predictors of early race starts in young NSCT horses under field conditions.

Methods

Of the 801 registered NSCT horses born in 2005, 144 were randomly selected by stratified sampling with gender and paternal progeny as stratification factors. All horses were examined clinically. Further data were collected from NTA and by interviews of breeders, owners and trainers. The set of dependent variables consisted of "passed recruitment race", "start in regular race by the end of the three year season" and "start in regular race by the end of October in the four year season". Univariate and logistic regression analyses were performed.

Results

Genetic performance potential, as indicated by best linear unbiased prediction (BLUP) indices, was the major predictor of the three dependent variables despite large variation in management. Dam''s index was a better predictor than sire''s index. However, the probability of early race starts in a horse with a low genetic performance potential can be increased by a favourable management. Examples of advantageous management factors in the present study were a flat pasture the first summer and early training. Nearly all horses racing in the three or four year seasons had passed a recruitment race in the two year season.

Conclusions

The results confirm the value of the published BLUP index as an important tool for the NSCT breeding program. Recruitment races stimulate early training.  相似文献   

Evaluation of the Swedish breeding program for cavalier King Charles spaniels     

Tobias Lundin  Clarence Kvart 《Acta veterinaria Scandinavica》2010,52(1):54

A breeding program with the aim of reducing the prevalence of mitral regurgitation (MR) caused by myxomatous mitral valve disease (MMVD) in Cavalier King Charles Spaniels (CKCS) is currently ongoing in Sweden. In this investigation 353 CKCS were selected as a sample of the population and 150 were examined by auscultation for heart murmurs when they reached the age of six years in 2007 and 2009. The aim with this investigation was to study the prevalence of heart murmurs in six-year-old CKCS and to estimate if prevalence has decreased since the breeding program was introduced 2001. The effect of the breeding program was evaluated by comparing the prevalence of heart murmurs in the two groups. In 2007, the prevalence of heart murmurs was 52% (50% for females and 54% for males) and in 2009, the prevalence was 55% (44% for females and 67% for males). No significant difference was found in the prevalence of heart murmurs between 2007 and 2009 (P = 0.8). For all six-year-old CKCS, the prevalence of heart murmur was 53% (females 46% and males 61%), which is higher than previous Swedish investigations.  相似文献