Asynchrony in shoot and root phenological relationships in hybrid walnut

New Forests - Understanding the processes driving plant phenology is crucial for assessing how shifts in climate affect plant productivity and species’ distribution. Despite the key role of...     

Enzyme-induced gelation of extensively hydrolyzed whey proteins by alcalase: comparison with the plastein reaction and characterization of interactions

Extensive hydrolysis of whey protein isolate by Alcalase 2.4L produces a gel. The objectives of this study were to compare enzyme-induced gelation with the plastein reaction by determining the types of interactions involved in gelation. The average chain length of the peptides did not increase during hydrolysis and reached a plateau after 30 min to be approximately 4 residues, suggesting that the gel was formed by small molecular weight peptides held together by non-covalent interactions. The enzyme-induced gel network was stable over a wide range of pH and ionic strength and, therefore, showed some similarities with the plastein reaction. Disulfide bonds were not involved in the gel network. The gelation seems to be caused by physical aggregation, mainly via hydrophobic interactions with hydrogen bonding and electrostatic interactions playing a minor role.     

Antioxidant vitamins in barley green biomass

Two malting hulled varieties (Sebastian, Malz) and one nonmalting hull-less variety (AF Lucius) were used to assess vitamins C and E in the green biomass of young plants of spring barley ( Hordeum vulgare L.) in three stages of growth and development (BBCH 29, 31, 32-33). The samples from sampling I (BBCH 29) had statistically significantly higher vitamin C content and vitamin E activity compared to sampling I (BBCH 31). The highest average vitamin content was determined in the malting variety Sebastian (vitamin C, 520 mg 100 g(-1) DM; vitamin E, 73.06 mg kg(-1) DM) compared to the varieties Malz (501 mg 100 g(-1) DM; 61.84 mg kg(-1) DM) and AF Lucius (508 mg 100 g(-1) DM; 67.81 mg 100 g(-1) DM). The locality Krome?r?i?z? (Czech Republic, CR), with vitamin C and E contents of 524 mg 100 g(-1) DM and 68.74 mg kg(-1) DM, respectively, proved to be more suitable for growing green biomass compared to the locality Z?abc?ice (CR) (content of vitamins C and E, 477 mg 100 g(-1) DM and 66.39 mg kg(-1) DM, respectively). During the research period (2005-2007), it was determined that the green mass of young plants of spring barley was a significant source of vitamins C and E in the growth stage BBCH 29; in later samplings (BBCH 32-33) the vitamin levels dropped (by as much as 48%). These vitamins are important antioxidants for human health. Therefore, "green barley" can be recommended for the preparation of natural dietary supplements and is preferred to synthetic vitamin preparations.     

Effect of glucocorticoid administration on adrenal gland size and sonographic appearance in beagle dogs

Our aim was to evaluate the influence of glucocorticoids on the adrenal gland using ultrasonography. Eleven healthy beagles were used in a prospective placebo-controlled study. All dogs received hydrocortisone at 10 mg/kg twice a day per os for 4 months or a gelatin capsule twice a day per os as a placebo. Clinical and endocrinologic examination of the dogs and ultrasonographic evaluation of adrenal echogenicity, shape, and measurement of the length and height of the cranial and caudal pole were performed at baseline (TO), at 1 (T1) and 4 months (T4) after the beginning of treatment, and 2 months after the end of the treatment including 1 month of tapering and 1 month without treatment (T6). The dogs were assigned randomly to the glucocorticoid (n = 6) and placebo groups (n = 5). At T1, the difference between the two groups for the height of the cranial and caudal pole was not ultrasonographically remarkable despite a statistically significant difference (P = 0.0165 and P = 0.0206). Decreased height and length of entire gland were observed at T4 (P < 0.0001, P = 0.0015, and P = 0.0035, respectively). Percentages of atrophy were variable between dogs. Both adrenal glands regained normal size and shape 1 month after cessation of glucocorticoid administration. As not all dogs developed marked adrenal gland atrophy and the degree of atrophy varied widely between individuals, ultrasonography cannot be the technique of choice to detect iatrogenic hypercortisolism. Ultrasonographic changes are reversible within 1 month after the end of glucocorticoid administration.     

Alopecia areata and humpy-back syndrome in suckling piglets

This report describes an uncommon variant of humpy-back syndrome associated with multiple rib fractures and multisystemic vasculitis in several nursing piglets and, for the first time, a skin disease in swine consistent with alopecia areata. Both conditions were observed concurrently on the farm and occasionally in the same piglets.     

Epidemiological investigations in regard to porcine reproductive and respiratory syndrome (PRRS) in Quebec, Canada. Part 1: biosecurity practices and their geographical distribution in two areas of different swine density

Porcine reproductive and respiratory syndrome virus (PRRSV) is a considerable threat to the swine industry and implementing biosecurity measures is essential for the control of its transmission. The aims of this study were: (1) to describe biosecurity practices in production sites located in a moderate density (MD) and a high density (HD) pig area according to production type; (2) to group sites in different patterns according to their biosecurity practices; and (3) to determine the geographical distribution of sites according to biosecurity patterns. Biosecurity practices were selected based on PRRS epidemiology. A questionnaire was completed on 125 breeding sites (MD=54; HD=71) and 120 growing (HD) sites, between 2005 and 2008. Depending on area and production type, the frequency of biosecurity practices used ranged from 0 to 2% for barrier at site entrance, 0 to 19% for use of shower, 25 to 35% for washing truck between loads of pigs, 51 to 57% for absence of rendering or rendering without access to the site, and 26 to 51% for absence of gilt purchase or purchase with quarantine. Better practices pertaining to entrance protocol (i.e. "no-entry" sign, shower, ≥24 h downtime) were reported more frequently on breeding sites in the MD than the HD area (P<0.05). In the HD area, growing sites had in general a lower level of biosecurity than breeding sites. Using a two-step clustering procedure performed separately for breeding and growing sites, two different patterns were obtained for each production type, which corresponded to a high and low level of biosecurity. For breeding sites, a higher biosecurity level was observed at sites located away from other pig sites, set at more than 300 m from the public road, having higher sow inventory, or being part of an integrated production (P<0.05). Spatial clusters of sites for each biosecurity pattern were detected. This study identified some shortcomings regarding biosecurity that should be addressed before implementing any PRRSV regional control. Vicinity of sites with different biosecurity levels also suggests difficulties in planning priorities of intervention based on geographical distribution of sites.     

Allelic variation for the rust resistance gene <Emphasis Type="Italic">Lr34</Emphasis>/<Emphasis Type="Italic">Yr18</Emphasis> in Canadian wheat cultivars

The wheat (Triticum aestivum L.) gene Lr34/Yr18 conditions resistance to leaf rust, stripe rust, and stem rust, along with other diseases such as powdery mildew. This makes it one of the most important genes in wheat. In Canada, Lr34 has provided effective leaf rust resistance since it was first incorporated into the cultivar Glenlea, registered in 1972. Recently, molecular markers were discovered that are either closely linked to this locus, or contained within the gene. Canadian wheat cultivars released from 1900 to 2007, breeding lines and related parental lines, were tested for sequence based markers caSNP12, caIND11, caIND10, caSNP4, microsatellite markers wms1220, cam11, csLVMS1, swm10, csLV34, and insertion site based polymorphism marker caISBP1. Thirty different molecular marker haplotypes were found among the 375 lines tested; 5 haplotypes had the resistance allele for Lr34, and 25 haplotypes had a susceptibility allele at this locus. The numbers of lines in each haplotype group varied from 1 to 140. The largest group was represented by the leaf rust susceptible cultivar “Thatcher” and many lines derived from “Thatcher”. The 5 haplotypes that had the resistance allele for Lr34 were identical for the markers tested within the coding region of the gene but differed in the linked markers wms1220, caISBP1, cam11, and csLV34. The presence of the resistance or susceptibility allele at the Lr34 locus was tracked through the ancestries of the Canadian wheat classes, revealing that the resistance allele was present in many cultivars released since the 1970s, but not generally in the older cultivars.     

Vaccination of Full‐sib Channel Catfish Families Against Enteric Septicemia of Catfish with an Oral Live Attenuated Edwardsiella ictaluri Vaccine

This study evaluated the efficacy of an oral live attenuated Edwardsiella ictaluri vaccine against enteric septicemia of catfish in 20 full‐sib fingerling channel catfish families. The vaccine was delivered orally by feeding fish a diet coated with an attenuated E. ictaluri isolate. Sixty‐nine days postvaccination, control and vaccinated fish were challenged with virulent E. ictaluri and mortality was examined for 21 d postchallenge. Vaccinated fish had significantly lower mortality than nonvaccinated fish following challenge (P < 0.001). Mortality of vaccinated fish was 1.7 ± 1.4% as opposed to 47.8 ± 28.7% in nonvaccinated fish. Relative percent survival ranged from 87.7 to 100% with an average of 95.2 ± 4.0% (±SE) among the 20 families of fish. There were significant differences in mortality among families in nonvaccinated fish (P < 0.01) while there were no differences among vaccinated families of fish. Results indicate that the live attenuated E. ictaluri vaccine is effective at reducing mortality in channel catfish exposed to virulent E. ictaluri. These data demonstrate that genetic differences among healthy families of channel catfish are not major considerations in developing an effective vaccination program utilizing the oral vaccination platform described in this study.