Poorly crystalline iron and aluminium oxides contribute to the carbon saturation and sorption of dissolved organic carbon in the soil     

Tania Khandakar  Chris Guppy  Sheikh M. F. Rabbi  Heiko Daniel 《Soil Use and Management》2021,37(1):120-125

Soil carbon (C) saturation implies an upper limit to a soil's capacity to store C depending on the contents of silt + clay and poorly crystalline Fe and Al oxides. We hypothesized that the poorly crystalline Fe and Al oxides in silt + clay fraction increased the C saturation and thus reduced the capacity of the soil to sorb additional C input. To test the hypothesis, we studied the sorption of dissolved organic carbon (DOC) on silt + clay fractions (<53 µm) of highly weathered oxic soils, collected from three different land uses (i.e., improved pasture, cropping and forest). Soils with high carbon saturation desorbed 38% more C than soils with low C saturation upon addition of DOC, whereas adsorption of DOC was only observed at higher concentration (>15 g kg^?1). While high Al oxide concentration significantly increased both the saturation and desorption of DOC, the high Fe oxide concentration significantly increased the desorption of DOC, supporting the proposition that both oxides have influence on the DOC sorption in soil. Our findings provide a new insight into the chemical control of stabilization and destabilization of DOC in soil.  相似文献   

Beaver dams,streamflow complexity,and the distribution of a rare minnow,Lepidomeda copei          下载免费PDF全文

Daniel C. Dauwalter  John D. Walrath 《Ecology of Freshwater Fish》2018,27(2):606-616

Freshwater fishes are threatened globally, and often too little is known about threatened species to effectively guide their conservation. Habitat complexity is linked to fish species diversity and persistence, and degraded streams often lack habitat complexity. Beaver Castor spp., in turn, have been used to restore streams and increase habitat complexity. The northern leatherside chub Lepidomeda copei is a rare, small‐bodied, drift‐feeding minnow that has anecdotally been observed to use complex habitats associated with beaver dams in the western United States. To investigate this anecdote, we conducted fish and habitat surveys, the latter focusing on quantifying habitat complexity, in a sub‐basin of the Upper Snake River Basin in the USA. Complementary generalised linear model and path analyses revealed that northern leatherside chub occurred more often at sites with complex streamflows, and streamflows were more complex when beaver dams were present and pools were deeper. Northern leatherside chubs were also more likely to occur when temperatures were warmer, aquatic macrophytes were abundant and stream channels were narrow and deep. The linkage between chubs, complex streamflows and beaver dams needs to be evaluated more broadly to completely understand its role in the rangewide status of the species. However, it does suggests that increased use of beaver reintroductions and dam analogues for stream restoration could be a boon for the northern leatherside chub, but such efforts should be monitored to determine their effectiveness to help adapt beaver‐based restoration approaches to best benefit the species.  相似文献   

Spiro N‐methoxy piperidine ring containing aryldiones for the control of sucking insects and mites: discovery of spiropidion     

Michel Muehlebach  Anke Buchholz  Werner Zambach  Juergen Schaetzer  Miriam Daniels  Ottmar Hueter  Daniel P Kloer  Rob Lind  Peter Maienfisch  Andy Pierce  Thomas Pitterna  Tomas Smejkal  David Stafford  Laura Wildsmith 《Pest management science》2020,76(10):3440-3450

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The effect of feeding a novel multistrain yeast fraction on European seabass (Dicentrachus labrax) intestinal health and growth performance     

Mark D. Rawling  Nicola Pontefract  Ana Rodiles  Ilektra Anagnostara  Eric Leclercq  Marion Schiavone  Mathieu Castex  Daniel L. Merrifield 《Journal of the World Aquaculture Society》2019,50(6):1108-1122

Fish were fed a single‐strain yeast fraction (SsYF; 2 g/kg) or a multistrain yeast fraction (MsYF; 0.8 g/kg) for 10 weeks. The results demonstrated significant (p ≤ 0.03) elevations in weight gain, specific growth rate, protein efficiency ratio, and feed conversion ratio in fish fed the yeast fraction‐supplemented diets. In the distal intestine, a significant elevation in microvilli density was observed after 5 and 10 weeks of dietary supplementation with MsYF and SsYF, respectively, compared to control fed fish (p < 0.001). A significant elevation (p = 0.02) in the perimeter ratio was observed in fish fed diets supplemented with the yeast fractions. After 10 weeks of feeding on the experimental diets, Rt‐qPCR demonstrated a significant downregulation (p < 0.05) in the stress response genes, heat‐shock protein 70 (hsp70) and proliferating cell nuclear antigen (pcna), in fish fed diets supplemented with the yeast fractions. Significant (p < 0.05) elevations in interleukin 1‐beta (il1β) and interleukin‐10 (il10) gene expression were observed in fish fed diets supplemented with the MsYF compared to the other dietary groups. These findings suggest that feeding an MsYF specifically at a lower incorporation rate < 1 g/kg, compared to a commercial SsYF at 2 g/kg, is effective in improving the intestinal health status and growth performance of European seabass.  相似文献   

Comparative effects of technical‐grade and formulated chlorantraniliprole to the survivorship and locomotor activity of the honey bee,Apis mellifera (L.)     

Jennifer R Williams  Daniel R Swale  Troy D Anderson 《Pest management science》2020,76(8):2582-2588

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The ecosystem services concept: a new Esperanto to facilitate participatory planning processes?     

Spyra  Marcin  Kleemann  Janina  Cetin  Nuket Ipek  Vázquez Navarrete  Cesar Jesús  Albert  Christian  Palacios-Agundez  Igone  Ametzaga-Arregi  Ibone  La Rosa  Daniele  Rozas-Vásquez  Daniel  Adem Esmail  Blal  Picchi  Paolo  Geneletti  Davide  König  Hannes J.  Koo  HongMi  Kopperoinen  Leena  Fürst  Christine 《Landscape Ecology》2019,34(7):1715-1735

Landscape Ecology - Several case studies investigated the role of ecosystem services in participatory planning processes. However, no systematic study exists that cuts across a large number of...  相似文献   

Pharmacokinetic evaluation of ceftiofur in serum, tissue chamber fluid and bronchial secretions from healthy beef-bred calves.          下载免费PDF全文

S L Halstead  R D Walker  J C Baker  R E Holland  G E Stein    J G Hauptman 《Canadian journal of veterinary research》1992,56(4):269-274

Ceftiofur is a new broad spectrum cephalosporin marketed for the treatment of acute bovine respiratory disease. In this investigation ceftiofur was administered by intramuscular injection, at 24 h intervals, to healthy beef-bred calves for four days at dosages of 2.2 and 4.4 mg/kg of body weight, with 4 wk intervals between dosing regimens. Serum, tissue chamber fluid (TCF), and bronchial secretion (BS) concentrations of ceftiofur were measured by microbiological assay after the first and fourth dose of each dosing regimen. Peak serum concentrations (Cmax) of 8.8 micrograms/mL and 17.3 micrograms/mL were obtained approximately 2 h (Tmax), the time of mean peak concentration) after single injections of 2.2 mg/kg and 4.4 mg/kg, respectively. The Cmax was increased approximately twofold following multiple doses of 2.2 mg/kg (Cmax = 13.1 micrograms/mL) and 4.4 mg/kg (Cmax = 24.1 micrograms/mL). Ceftiofur accumulated slowly into TCF and peak concentrations were found to be approximately 14% of those observed in serum after the first dose and approximately 24% after multiple dosing. Concentrations of ceftiofur in BS were obtained rapidly with peak concentrations reaching 45% of the serum Cmax after the first dose. After multiple dosing the Cmax for BS was approximately 25% of the serum Cmax. This study found that both the 2.2 mg/kg and 4.4 mg/kg dosing regimens resulted in continuous serum, TCF and BS concentrations of ceftiofur that exceeded the minimal concentration required to inhibit the bacteria most frequently isolated from calves with acute bovine respiratory disease.  相似文献   

A Tremor Syndrome With a Central Axonopathy in Scottish Terriers     

Luc Van  Ham  Marc Vandevelde  Miek Desmidt  Mulenda Tshamala  Luc De  Schaepdrijver Daniel Mattheeuws 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(4):290-292

A central axonopathy in 2 male and 1 female Scottish Terrier puppies from 3 different but related litters is reported. Clinical signs consisting of severe whole-body tremors and ataxia were first detected at the age of 10 to 12 weeks. They worsened with activity and excitement and diminished during rest or sleep. Two dogs also had paraparesis. In 1 dog the neurological deficits progressed over several months. Neuropathological examination revealed widespread axonal changes, vacuolation, and gliosis in the white matter of the central nervous system.  相似文献   

Serum Progesterone Concentrations and Blood Neutrophil Alkaline Phosphatase Activity in Cows Following Normal and Abnormal Parturition     

A.M. Hussain  R.C.W. Daniel 《Reproduction in domestic animals》1992,27(4):229-235

Serum progesterone concentrations and alkaline phosphatase (ALP) activity of blood neutrophils were determined in 3 groups of cows (n = 5 each) on days 1 and 2 and then at 3-day intervals up to 32 days post-partum. Group I cows had a normal delivery, Group II cows had dexamethasone-induced parturition and Group III cows were subjected to a caesarian section. All cows in Group III and 2 cows in Group II retained their fetal membranes. Mean serum progesterone concentrations declined the second day after calving (to < 0.67 ng/ml) and remained at low levels (< 0.54 ng/ml) throughout the observation period, except for the values in Group III, which were elevated on day 16 (0.94 ng/ml), declined again on day 26 (0.46 ng/ml) and peaked (1.05 ng/ml) on day 32 portpartum. Significant (P < 0.01) differences were found between serum progesterone concentrations on day 1 and on each of the other sampling days in Groups I and III. Day X parturition group interaction was significant (P < 0.05) for the progesterone concentrations. No significant differences were found between the overall means of ALP activity of blood neutrophils in the 3 parturition groups nor between days of the experiment. No significant correlation was found between serum progesterone concentrations and ALP activity values of blood PMN during the first 32 days post-partum. Inhalt: Serum Progesteron Konzentrat und Aktivität der alkalischen Phosphatase in neutrophilen Blutzellen bei Küken mit normalem und abnormalen Geburtsverlauf Serum-Progesteronkonzentrationen und alkalische Phosphatase- (ALP) Aktivität von neutrophilen Granulozysten, nach der Abkalbung am Tag 1 und 2 und dann im Abstand von 3 Tagen bis zum 32. Tag p.p. bei Kühen untersucht, die in drei Untersuchungsgruppen (n = 5) eingeteilt waren. Gruppe I kalbte normal ab, in Gruppe II wurde die Geburt durch Dexamethason eingeleitet, und Kälber der Gruppe III wurden via Kaiserschnitt gewonnen. Alle Tiere der Gruppe III und 2 Kühe der Gruppe II wiesen Nachgeburtsverhaltungen auf Der mittlere Serum-Progesterongehalt sank am 2. Tag p.p. auf < 0,67 ng/ml ab und blieb auf niederigem Niveau (< 0,54 ng/ml) während der gesamten Untersuchungs-periode. Lediglich in Gruppe III, mit erhöhten Werten (0,94 ng/ml) an Tag 16 p.p., sanken die Werte wieder an Tag 26 p.p. (0,46 ng/ml) und erreichten einen Maximalwert an Tag 32 p.p. mit 1,05 ng/ml. Signifikante (P 0,01) Unterschiede in der Serum-Progesteronkonrentration wurden zwischen Tag 1 p.p. und allen anderen Untersuchungstagen in den Gruppen I und III gefunden. Interaktionen zwischen den Gruppen für Tag X waren signifikant (P 0,05). Keine signifikanten Unterschiede wurden für den Gesamtmittelwert der ALP-Aktivität in den neutrophilen Granulorysten zwischen den Gruppen und im Vergleich der Untersuchungstage gefunden. Es wurden auch keine signifikanten Korrelationen zwischen den Serum-Progesteronkonzentrationen und der ALP-Aktivität der PMN während der ersten 32 Tage p.p. nachgewiesen.  相似文献   

The effect of exploratory laparotomy on the serum and peritoneal haptoglobin concentrations of the pony.   总被引：1，自引：0，他引：1       下载免费PDF全文

T E Eurell  D A Wilson    G J Baker 《Canadian journal of veterinary research》1993,57(1):42-44

Serum haptoglobin concentration was used as an indicator of the acute phase response in ponies undergoing exploratory laparotomy. Preoperative, 1 h intraoperative, 3 h, 6 h, 12 h and 24 h postoperative blood samples and 48 h postoperative peritoneal fluid samples were obtained for haptoglobin analysis. A spectrophotometric assay based on cyanmethemoglobin binding capacity (CyanBC) was used to determine haptoglobin concentrations. The preoperative reference range for serum haptoglobin concentrations in these ponies was 25-60 mg CyanBC/dL. Intraoperative and 3 h postoperative blood samples had decreased haptoglobin concentrations when compared to preoperative values. Serum haptoglobin concentrations began to rise by the 6 h postoperative sample and were generally elevated above preoperative values by the 24 h postoperative sample. Two of the ten ponies had mild signs of postoperative colic which were associated with twofold elevations in serum haptoglobin concentrations and fivefold elevations in peritoneal fluid haptoglobin concentrations.  相似文献