Occupancy pattern of a long-horned beetle in a variegated forest landscape: linkages between tree quality and forest cover across spatial scales     

Pablo M. Vergara  Luis O. Meneses  Audrey A. Grez  Madelaine S. Quiroz  Gerardo E. Soto  Christian G. Pérez-Hernández  Paola A. Diaz  Ingo J. Hahn  Andrés Fierro 《Landscape Ecology》2017,32(2):279-293

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Application of urease inhibitor improves protein composition and bread‐baking quality of urea fertilized winter wheat     

Azin Rekowski  Monika A. Wimmer  Bernd Hitzmann  Bernhard Hermannseder  Heike Hahn  Christian Zrb 《植物养料与土壤学杂志》2020,183(2):260-270

Background: Nitrogen losses is an economic problem for wheat production and a high risk to the environment. Therefore, improved N fertilizer management is a key to increasing the N efficiency and minimizing N losses. To increase N efficiency, enhanced fertilizers such as urea combined with urease inhibitor can be used. Aims: The aim of present study was to evaluate the effects of different N forms on grain storage protein subunits in winter wheat and to examine whether the observed changes correlate with parameters of baking quality. Methods: The investigation was performed over two consecutive years at two locations in Germany. Protein subunits were analyzed by SDS‐PAGE. Results: Protein concentrations were similarly increased after fertilization with ammonium nitrate and urea + urease inhibitor. Analysis of the individual storage protein fractions indicated that both fertilizers specifically enhanced ω‐gliadins and HMW glutenins, but the effect was more pronounced in the ammonium nitrate treatment. Application of urea + urease inhibitor had greater influence on the protein composition and resulted in higher specific baking volume as well as the best fresh keeping ability, in comparison with urea treatment. Conclusion: Considering that the urea + urease inhibitor treatment resulted in almost comparable improvements of NUE and baking quality, with the additional benefit of reduced N losses in combination with easy handling, urea + urease inhibitor can be recommended as a viable alternative to both urea alone and ammonium nitrate treatments. This opens up an opportunity for the reduction of N loss in wheat production when use of urea is preferred.  相似文献   

Allometric and ontogenetic patterns related to feeding of a neotropical fish, Satanoperca pappaterra (Perciformes, Cichlidae)     

F. A. S. Cassemiro  T. F. L. V. B. Rangel  F. M. Pelicice  N. S. Hahn 《Ecology of Freshwater Fish》2008,17(1):155-164

Abstract –  This study aims to analyse whether Satanoperca pappaterra changes its feeding habit throughout ontogenetic development, and whether morphological ontogenetic patterns are related to its feeding habit and food capture. We collected 258 individuals in the Cuiabá river basin (Brazil) for analyses. There was a weak relationship between diet and body size, as evidenced by size class and multivariate analyses, and niche breadth did not vary strongly during ontogenetic development. Eight morphometric variables were measured in each individual. We found an isometric relationship for mouth height and width, and for head length. We found positive allometry for snout length and body height in relation to body length, whereas this relationship for intestine length and eye diameter showed negative allometry. These results suggest that morphology and consequently diet vary weakly during ontogenetic development of S. pappaterra .  相似文献   

Immunizing against salmonella infections with live and inactivated vaccines]     

E Vielitz  C Conrad  M Voss  U L?hren  J Bachmeier  I Hahn 《DTW. Deutsche tier?rztliche Wochenschrift》1992,99(12):483-485

A live attenuated auxotrophic S. typhimurium (S. tm.)-mutant was used by orally administration via drinking water several times during rearing, combined with 1- or 2-times parenteral injection of an autogenous S. enteritidis (S. e.)/S. tm.-oil emulsion vaccine. In a 8-month period, more than 500,000 birds were vaccinated. The vaccine was safe. Challenge test showed protection in the vaccinates and their offspring. The number of isolates in the farms detected by regular monitoring decreased. The protection of the live-culture mutant lasted about only 8 to 10 weeks. A. S. tm.-mutant more potent for chickens will be tested now. We consider vaccinations as one important factor in a salmonella control program, especially for commercial layers and broiler breeders.  相似文献   

Brunstsynchronisation bei der Ziege     

Von G.M. Wani  H. Geldermann  J. Hahn 《Reproduction in domestic animals》1985,20(4):247-250

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Peripheral concentrations of cortisol as an indicator of stress in the pig   总被引：5，自引：0，他引：5  

B A Becker  J A Nienaber  R K Christenson  R C Manak  J A DeShazer  G L Hahn 《American journal of veterinary research》1985,46(5):1034-1038

Twenty-four crossbred gilts (7 to 9 months old) were exposed to 3 different stressors to evaluate changes in peripheral concentrations of the adrenal hormone cortisol. Gilts were confined in a box for 1 hour, electrically stimulated for 6 minutes, or heat-stressed for 6 hours; these stressors were imposed for 3 consecutive days. Blood samples were collected repeatedly, and serum cortisol concentrations were determined by radioimmunoassay. Peak cortisol concentrations for pigs in the box, electrically stimulated, and heat-stressed were 67.8 +/- 9.9 ng/ml (mean +/- SEM), 43.2 +/- 5.8 ng/ml, and 25.2 +/- 3.0 ng/ml greater than the control concentrations. The times at which these peaks occurred varied with each stressor. Overall serum cortisol concentrations decreased from day 1 to day 3, but the response to a given stressor was not diminished. Our data substantiate the use of cortisol as an indicator of stress in swine and emphasize consideration for the interval between exposures to stressors.  相似文献   

Effect of fasting and transportation on various physiological parameters and meat quality of slaughter hogs     

B A Becker  H F Mayes  G L Hahn  J A Nienaber  G W Jesse  M E Anderson  H Heymann  H B Hedrick 《Journal of animal science》1989,67(2):334-341

Forty-nine slaughter hogs were transported and fasted or fasted with no transport for 0 (no transport), 24, 48 and 72 h. Blood samples were taken before treatments were imposed and again prior to slaughter. Soft tissues of the ham were chemically analyzed and loin samples were evaluated by a sensory panel. Fasting and transportation decreased plasma triiodothyronine and hematocrit and increased plasma osmolality. Preslaughter treatment did not affect juiciness or desirability of cooked chops or percentage of fat in the ham soft tissues. These data suggest that although fasting and transporting of slaughter hogs may disrupt homeostasis of pigs, such physiological changes do not negatively affect meat quality.  相似文献   

Results of in vitro fertilization experiments with rabbit ova. B. The effects of the ovum's age after ovulation on the development of the ovum]     

J Hahn  H Sulzer  U Schneider 《Zuchthygiene》1975,10(1):24-28

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Recurrent somatic embryogenesis and plant regeneration in Coriandrum sativum L.     

H.N. Murthy  E.J. Hahn  K.Y. Paek 《Scientia Horticulturae》2008

An efficient method of repetitive somatic embryogenesis and plant regeneration was established in Coriandrum sativum L. Embryogenic callus was induced from cotyledon and hypocotyl segments on Murashige and Skoog (MS) medium with 4.52 μM 2,4-dichlorophenoxy acetic acid (2,4-D), upon subculturing on medium having same level of 2,4-D at an interval of 3 weeks developed somatic embryos, which progressed to cotyledonary stage through early developmental stages of somatic embryogenesis. The transfer of somatic embryos at an early cotyledonary and cotyledonary stage in clumps in succession to fresh 4.52 μM 2,4-D supplemented medium developed embryos in a cyclic manner. Upon transferal to embryogenic clumps (cotyledonary embryos) to modified MS medium (4 g l⁻¹ KNO₃, 0.29 g l⁻¹ NH₄NO₃, 3 mg l⁻¹ thiamine HCl, 0.5 mg l⁻¹ pyridoxine HCl, and 5 mg l⁻¹ nicotinic acid), the embryos irrespective of the cycles underwent maturation and germination. Germinating embryos transferred to half-strength MS medium favored healthy growth of plantlets. The system of recurrent somatic embryogenesis in coriander offers a system for genes transfer and also scale-up production of modified plants.  相似文献   

Assessment of survey radiography as a method of diagnosing bilateral laryngeal paralysis in dogs     

Chloe Touzet  Harriet Hahn  Eymeric Gomes  Camille Bismuth  Kevin Le Boedec 《Veterinary radiology & ultrasound》2023,64(2):183-193

The gold standard for diagnosis of laryngeal paralysis is laryngoscopy under light anesthesia. This prospective analytical cross-sectional study aimed to determine whether a radiographic assessment of the larynx could be used as a non-invasive screening tool for diagnosing laryngeal paralysis in non-sedated animals, as the laryngeal ventricles may appear wider in affected animals. The laryngeal ventricles of 18 dogs with bilateral laryngeal paralysis composing the affected group and 25 non-sedated dogs presenting no respiratory abnormality composing the control group were evaluated using right lateral radiography of the larynx. Three observers measured the ratios of the maximal ventricular length and surface to the body length of the third cervical vertebra (MVL/LC3 and VS/LC3, respectively). They also subjectively assessed the ventricular shape as either normal or rounded. The most accurate criterion was found to be MVL/LC3, as the respective areas under the ROC curves were 0.96 (95% confidence interval [CI]: 0.95–0.97), 0.89 (95% CI: 0.87–0.91), 0.80 (95% CI: 0.65–0.95) for MVL/LC3, VS/LC3, and ventricular shape evaluation, respectively. Based on ROC curve analysis, two thresholds of clinical interest were set for the MVL/LC3; bilateral laryngeal paralysis was very unlikely for values < 0.3 and very likely for values > 0.5. The findings of this study support the use of lateral laryngeal radiography as a screening tool for diagnosing bilateral laryngeal paralysis. However, further diagnostic tests remain required if MVL/LC3 lies between these threshold values or if clinically indicated. Further studies are warranted to explore the use of laryngeal radiography in unilateral paralysis and other laryngeal or oropharyngeal diseases.  相似文献