Single-slice dynamic computed tomographic determination of glomerular filtration rate by use of Patlak plot analysis in anesthetized pigs

OBJECTIVE: To compare glomerular filtration rate (GFR) as estimated from Patlak plot analysis by use of single-slice computed tomography (CT) with that obtained from clearance of plasma inulin in pigs. ANIMALS: 8 healthy anesthetized juvenile pigs. PROCEDURES: All pigs underwent precontrast, whole-kidney, helical CT; postcontrast single-slice dynamic CT; and postcontrast, whole-kidney CT for volume determination. On dynamic images, corrected Hounsfield unit values were determined for each kidney and the aorta. A Patlak plot for each kidney was generated, and plasma clearance per unit volume was multiplied by renal volume to obtain whole-animal contrast clearance. Mean GFR determined via inulin clearance (Inu-GFR) was measured from each kidney and correlated to mean GFR determined via CT (CT-GFR) for the left kidney, right kidney, and both kidneys by use of linear regression and Bland-Altman analyses. RESULTS: CT-GFR results from 7 pigs were valid. Total and right kidney Inu-GFR were correlated with total and right kidney CT-GFR (total, R(2) = 0.85; right kidney, R(2) = 0.86). However, left kidney CT-GFR was poorly correlated with left kidney Inu-GFR (R(2) = 0.47). Bland-Altman analysis revealed no significant bias between Inu-GFR and CT-GFR for the left kidney, right kidney, or both kidneys. CONCLUSIONS AND CLINICAL RELEVANCE: CT-GFR as determined by use of a single-slice acquisition technique, low-dose of iohexol, and Patlak plot analysis correlated without bias with Inu-GFR for the right kidney and both kidneys (combined). This technique has promise as an accurate CT-GFR method that can be combined with renal morphologic evaluation.     

Draft Genome Sequence of Potato Dry Rot Pathogen <Emphasis Type="Italic">Fusarium sambucinum</Emphasis> Fckl. F-4

Fusarium sambucinum is one of the most important causal agents that not only cause the dry rot disease of potato tubers in fields and stores worldwide but also capable of producing secondary metabolites toxic for people and animals. Here we present the first draft genome sequence of the strain (F-4) estimated to be around appx. 42.0 Mb. The genome has 12,845 protein coding genes with more than 35,900 exons and gene density of 3.13 per 10Kb. F. sambucinum is evolutionary more close to the F. graminearum among the Fusarium species complex. The genome sequence represents a valuable resource for understanding the pathogenecity and virulence factors, and their evolution within the complex and highly plastic genus Fusarium.     

Genome-wide QTL analysis for pre-harvest sprouting tolerance in bread wheat

A framework linkage map comprising 214 molecular marker (SSR, AFLP, SAMPL) loci was prepared using an intervarietal recombinant inbred line (RIL) mapping population of bread wheat. The RIL population that was developed from the cross SPR8198 (red-grained and PHS tolerant genotype) × HD2329 (white-grained and PHS susceptible genotype) following single seed descent segregated for pre-harvest sprouting (PHS). The RIL population and parental genotypes were evaluated in six different environments and the data on PHS were collected. Using the linkage map and PHS data, genome-wide single-locus and two-locus QTL analyses were conducted for PHS tolerance (PHST). Single-locus analysis following composite interval mapping (CIM) detected a total of seven QTL, located on specific arms of five different chromosome (1AS, 2AL, 2DL, 3AL and 3BL). These seven QTL included two major QTL one each on 2AL and 3AL. Two of these seven QTL were also detected following two-locus analysis, which resolved a total of four main-effect QTL (M-QTL), and 12 epistatic QTL (E-QTL), the latter involved in 7 QTL × QTL interactions. Interestingly, none of these M-QTL and E-QTL detected by two-locus analysis was involved in Q × E and Q × Q × E interactions, supporting the results of ANOVA, where genotype × environment interaction were non-significant. The QTL for PHS detected in the present study may be efficiently utilized for marker-aided selection for enhancing PHST in bread wheat.     

Increasing water productivity with improved N fertilizer management

There is continuing debate about the role of water productivity and the potential to increase it in response to significantly increased water demand to meet the future needs for food—estimated to be roughly double that of today by 2050. The debate centers round the relative potential benefits of enhancing rainfed agriculture, improving irrigation and expanding areas of both. All expansion and intensification options will require significantly more water to be used, often in places where the ecosystem impacts of agriculture are already severe. Improvement in water productivity can result from improving the provision and management of the other factor inputs of crop production. There is considerable debate on the ability of other inputs—typically nitrogen—to substitute for water. This paper describes a set of simulations undertaken with well calibrated maize (Zea mays L.) crop model in Decision Support System for Agro-technology Transfer (DSSAT). The simulations investigate the response to nitrogen under rainfed conditions in Florida, and show that neither the transpiration ratio nor the harvest index are constant in practice, and that fertilizer use can enhance water productivity, even in quite high yield conditions and that the transpiration ratio can be increased by N fertilizer application at low levels of crop water use.     

Linseed oil in boar's diet improved in vivo fertility and antioxidant status

The reactive oxygen species (ROS) which are produced during storage of boar semen are causing oxidative stress and leads to poor fertility. Also, tropical and sub-tropical weather condition adversely impacts the physicomorphological quality and fertility of boar sperm. The aim of this study was to examine the effects of feeding linseed oil to boar on its seminal attributes, sperm kinetics, biomarkers of antioxidant, fatty acid profile of seminal plasma (SP) and sperm and in vivo fertility. Six Hampshire crossbreed boars were fed with 90 ml linseed oil (LIN) whereas six Hampshire crossbreed boars were fed 90 ml canola oil (CON) for 16 weeks. Sperm quality was evaluated (60 ejaculates for each group; a total of 120 ejaculates) for motility, livability, abnormal morphology, acrosomal membrane integrity, hypo-osmotic swelling test (HOST) and sperm kinetic parameters by computer assisted semen analysis (CASA) at 0 h and at 72 h of storage at 17°C. Biomarkers of antioxidant (glutathione peroxidase; GPx, catalase; CAT, total antioxidant capacity; TAC) and malondialdehyde (MDA) were measured in SP and serum. Gas chromatography–mass spectrometry (GC–MS) was used for the estimation of fatty acid composition of SP and sperm. Boars fed with linseed oil had higher semen volume (p < .01) and more total sperm numbers (p < .01). Feeding linseed oil to boar enhanced seminal attributes (p < .05) at 0 h as well as at 72 h of storage. Linseed oil feeding (p < .01) improved biomarkers of antioxidants and significantly (p < .01) lowered the lipid peroxidation in serum and SP. Linseed oil feeding (p < .05) increased the proportion of alpha linolenic (ALA), arachidonic and docosahexaenoic (DHA) fatty acids in SP. The ratio of n-6 to n-3 fatty acids in sperm increased significantly (p < .01) in treatment group. Farrowing rate was significantly (p < .05) higher in treatment group. In conclusion, feeding linseed oil to boar improved the in vivo fertility, enhanced antioxidant capacity and increased the DHA content of SP and sperm.     

Transgressive segregation for yield traits in Oryza sativa IR58025B X Oryza meridionalis Ng. Bc2F3population under irrigated and aerobic conditions

Wild species of the genus Oryza are a good source of beneficial alleles for enhancing rice yield under normal and adverse conditions. BC₂F₃ population was derived from a cross between Oryza sativa IR58025B and Oryza meridionalis Ng. (2n = 24, AA) a heat tolerant wild species to evaluate 12 yield traits under irrigated and aerobic conditions. Analysis of variance and genetic estimates indicated there is substantial genetic variation among progenies under both conditions. Grain yield had high heritability (61.9%) and genetic advance (36.4%) under irrigated conditions but moderate heritability (49.6%) and genetic advance (13.3%) under aerobic conditions indicating that selection for yield will be effective under both conditions. Panicle number, grain number, spikelet fertility, and test weight showed significant positive correlation with grain yield under both conditions. Families out-performing IR58025B for yield under both conditions were obtained providing evidence that phenotypically inferior O. meridionalis contributed to yield increase. This species can be a novel source of natural genetic variation for the improvement of rice under irrigated as well as under aerobic condition.     

Biodiversity in the barnyard millet (<Emphasis Type="Italic">Echinochloa frumentacea</Emphasis> Link,Poaceae) germplasm in India

One hundred ninety four accessions of barnyard millet collected from different eco-geographical regions of India were evaluated for 14 quantitative traits during kharif 2003 and 2005. These accessions were grouped into 5 groups on the basis of place of collection. These groups differed significantly in their mean values for quantitative traits and magnitude of correlation among traits indicates origin based association. The group ‘C’ (source of origin is unknown) was found most diverse group (mean coefficient of variation 17.67%), while rest of the groups recorded mean coefficient of variation between 12 and 13%. Correlation studies indicate that flag leaf width, number of racemes along with internode length should be considered while performing selection in segregating generations. The plotting of first and second principal component axes scores suggests that presence of three distinct morphotypes in the present study. These morphotypes are quite similar to three botanical varieties viz., var. robusta, var. intermedia and var. stolonifera in their morphological traits, while botanical variety laxa (endemic to Sikkim area of India) was completely absent from the present study.     

Effects of water temperature on mortality in Megalocytivirus‐infected rock bream Oplegnathus fasciatus (Temminck et Schlegel) and development of protective immunity

Rock bream iridovirus (RBIV) causes huge losses, especially in rock bream Oplegnathus fasciatus. Rock bream injected with RBIV and held at 29, 26, 23 or 20 °C had 100% mortality. Conversely, all infected fish held at 17 °C survived even after the temperature was progressively increased to 26 °C at 100 dpi. Rock bream exposed to virus and held for 2, 4 and 7 days at 23/26 °C before the temperature was reduced to 17 °C had mortality rates of 26.6/73.2%, 66.6/100% and 93.4/100%, respectively, through 100 dpi. When surviving fish had the water temperature increased from 17 to 26 °C at 100 dpi, they did not exhibit signs of disease and had low virus copy numbers (below 10³). To investigate the development of a protective immune, rock bream were infected with RBIV and held at 23 °C before shifting the water temperature to 17 °C at 4 dpi. All injected fish survived until 120 dpi. While 100% of the previously unexposed fish died, 80.2% of the previously infected fish survived. When the survivors were rechallenged again at 160 dpi, no further mortality occurred. The high survival rate of fish following rechallenge with RBIV indicates that protective immunity was established in the surviving rock bream.     

Isolation and characterization of lipopolysaccharides from different rhizobial isolates

Formation of nodules on roots or in stems (in some cases) of leguminous plants is the unique ability of gram-negative bacteria, Rhizobia, which converts atmospheric nitrogen into usable forms by the host plant. Lipopolysaccharide (LPS) is the outer membrane component of the gram-negative bacteria, known to be an essential factor in host recognition, specificity, and initial infection processes. In the present study, we extracted lipopolysaccharides from different rhizobial isolates by a modified phenol-water method and partially characterized by polyacrylamide gel electrophoresis with silver staining. The results showed two separate banding regions, LPS-I and LPS-II. The high molecular weight and electrophoretic mobility of LPS-I region resembles that of lysozyme, used as a standard marker. The LPS-II region has a low molecular weight and electrophoretic mobility greater than that of lysozyme. The LPS-II region was due to incomplete LPS, which either lacks the entire O-antigen repeating unit or contains only one or two repeating units. The banding patterns of LPS vary among the different rhizobial isolates. Results revealed that the type of LPS structure and banding regions greatly facilitate the further characterization of the LPS modifications required for symbiosis.