Evaluation of isotopic dilution method for measuring N2 fixation in Azolla: Comparison with other methods 1

An isotopic dilution method that overcomes the drawbacks of commonly used methods for measuring N₂ fixation by aquatic N‐fixers such as Azolla pinnata‐Anabaena azollae association (Azolla) is presented. The method was compared with ¹⁵N₂ gas (while maintaining CO₂) and the difference methods of measuring N₂ fixation. The isotopic dilution method was used for two conditions: a. For ¹⁵N‐free growth medium, Azolla was pre‐enriched with ¹⁵N, and N₂ fixation was determined by measuring the dilution of ¹⁵N in the tissue. b. For the growth medium containing N, N₂ fixation was determined by providing ¹⁵N enriched ammonium sulfate in the growth medium and measuring ¹⁵N to ¹⁴N ratio in the tissue. An airtight chamber, necessary for ¹⁵N₂ gas and acetylene reduction methods, was not representative of the growing environment of Azolla. Temperature in the airtight chamber was far from uniform and CO₂ was rapidly depleted. The isotopic dilution method is simpler, relatively inexpensive, subject to fewer errors and applicable to more diverse conditions, and yet was as accurate as ¹⁵N₂‐gas method.     

Some characteristics of vaginal prolapse in Nepali buffaloes

Prolapse of vagina is one of the important maternal abnormalities during pregnancy in cattle and buffaloes. A field investigation was carried out on 26 Murrah graded buffaloes to study clinical characteristics of vaginal prolapse in buffaloes in Nepal. Fifty-seven percent of the 26 buffaloes with vaginal prolapse were either heifers or in first lactation. Sixty-five percent of the cases were in seventh month of pregnancy or later. About three quarters of the cases occurred between June and October. Twelve cases (63%) of the 19 animals excluding 7 heifers had a history of vaginal prolapse in previous gestations. A half of the buffaloes were showing prolapse of the vagina even when they were in standing position and showing moderate or vigorous straining. After the conventional treatments, twenty-three buffaloes retained the replaced vagina and calved normally. One animal aborted although the vagina was retained. Two buffaloes had severest degree of vaginal prolapse complicated with edema, injury and cyanosis, and they did not respond to the treatment. The two buffaloes had frequently recurrent prolapse and subsequently died. Early detection and prompt treatment may be imperative to control the vaginal prolapse in buffaloes.     

Identification of windbreaks in Kansas using object-based image analysis,GIS techniques and field survey

Windbreaks are valuable resources in conserving soils and providing crop protection in Great Plains states in the US. Currently, Kansas has no up-to date inventory of windbreaks. The goal of this project was to assist foresters with future windbreak renovation planning and reporting, by outlining a series of semi-automated digital image processing methods that rapidly identify windbreak locations. There were two specific objectives of this research. First, to develop semi-automated methods to identify the location of windbreaks in Kansas, this can be applied to other regions in Kansas and the Great Plains. We used a remote sensing technique known as object-based image analysis (OBIA) to classify windbreaks visible in the color aerial imagery of National Agriculture Imagery Program. We also combined GIS techniques and field survey to complement OBIA in generating windbreak inventory. The techniques successfully located more than 4500, windbreaks covering an approximate area of 2500, hectares in 14 Kansas counties. The second purpose of this research is to determine how well the results of the automated classification schemes match with other available windbreak data and the selected sample collected in the field. The overall accuracy of OBIA method was 58.97 %. OBIA combined with ‘heads up’ digitizing and field survey method yielded better result in identifying and locating windbreaks in the studied counties with overall accuracy of 96 %.     

Comparative Disposition Kinetics of Albendazole in Sheep Following Oral and Intraruminal Administration

The pharmacokinetics of albendazole was studied in sheep following single oral and intraruminal administration at nematocidal dose rates. The disposition curves of its metabolites indicated increased uptake of the drug in sheep following intraruminal as compared to oral dosing (p<0.05). The increased bioavailability of benzimidazole anthelmintics given by the intraruminal route could be exploited for optimizing the use of anthelmintic for sustained parasite control in small ruminants.     

Response of Chickens to Infection with Newcastle Disease Virus Isolated from a Guinea Fowl

An isolate of Newcastle disease virus obtained from a guinea fowl was characterized as a viscerotropic velogenic strain based upon pathogenicity index studies. Following inoculation of the viral isolate oronasally into 3-week-old chickens, clinical signs appeared after an incubation period of 4–5 days and included dullness, depression, dyspnoea, diarrhoea and leg paralysis. The virus caused a mortality of 56% with haemorrhages at the tip of the glands of the proventriculus and caecal tonsil. Histopathological changes were prominent in the lymphoid organs, being characterized by depletion, degeneration and necrosis of the lymphoid tissues. The brain was the first organ affected, with changes being noticed 3 days after infection. Isolation of virus from various organs was more frequent from 5 to 10 days after infection, but the virus persisted in some of the organs until 21 days after infection. In spite of the high mortality, a good immune response was elicited by the isolate, as was evident from the antibody titre.     

Septicemic proteus infection in Japanese quail chicks (Coturnix coturnix japonica)

Proteus infection was incriminated as the cause of severe depression, coma, and high mortality in successive broods of quail chicks. The pathological lesions comprised congestion of lungs, liver, and kidneys and mucus exudation in the trachea. The organism, isolated from the heart blood and lungs of affected chicks, was identified on biochemical tests as Proteus mirabilis. Pathogenicity of the isolate was tested in young albino mice and week-old quail chicks, which succumbed to infection within 48 hours of inoculation. Association of P. mirabilis with septicemic disease in Japanese quails has apparently been demonstrated for the first time.     

Impact of Buckwheat Flavonoids on In Vitro Starch Digestibility and Noodle‐Making Properties

The effects of various buckwheat materials (buckwheat flour [BF], dietary fiber extract [DE], flavonoids extract [FE], and rutin‐enhanced flavonoids extract [REFE]) on starch digestibility and noodle‐making properties were evaluated. When FE and REFE were incorporated into noodles, the amount of rapidly digestible starch and the predicted glycemic index (pGI) were reduced. However, BF and DE did not significantly decrease the pGI value of noodles. When assessing noodle properties, hardness was increased with increasing content of buckwheat materials, whereas other texture parameters were not significantly affected by buckwheat addition. All noodles were similar in regard to water absorption and swelling index, but cooking loss was slightly increased in FE and REFE noodles. FE and REFE demonstrated higher flavonoid stability during noodle making and, additionally, were more effective at reducing starch digestibility than BF and DE. REFE, specifically, does not generate quercetin (the cause of a bitter taste), and, therefore, REFE was effective in suppressing the hydrolysis of starch in the noodles, lowering the pGI.     

Tonic activation of NMDA receptors by ambient glutamate enhances excitability of neurons

Voltage clamp recordings and noise analysis from pyramidal cells in hippocampal slices indicate that N-methyl-D-aspartate (NMDA) receptors are tonically active. On the basis of the known concentration of glutamate in the extracellular fluid, this tonic action is likely caused by the ambient glutamate level. NMDA receptors are voltage-sensitive, thus background activation of these receptors imparts a regenerative electrical property to pyramidal cells, which facilitates the coupling between dendritic excitatory synaptic input and somatic action potential discharge in these neurons.