Ethylene evolution and sensitivity in cut orchid flowers

The effects of ethylene and the rate of ethylene production were studied in several orchid flowers. Orchid flowers showed a wide range of sensitivity to ethylene; Vanda ‘Miss Joaquim’ was most sensitive, Cattleya, Cymbidium and Paphiopedilum were less sensitive, while Dendrobium and Oncidium were not sensitive. Ethylene production in opened flowers was low, less than 1 nl/flower/h. In Cattleya, a peak in ethylene production was observed at the onset of senescence. Emasculated and/or pollinated flowers of Vanda, Cattleya and Paphiopedilum produced high levels of ethylene; Dendrobium did not react to these treatments in ethylene production.The anionic silver-thiosulfate complex (STS) was partially inhibitory to ethylene production in emasculated Cymbidium flowers, but appeared to stimulate the process in pollinated flowers. It was, however, effective in decreasing anthocyanin synthesis in both emasculated and pollinated Cymbidium flowers. In Cattleya, aminoxyacetic acid (AOA) and STS had no effect on longevity of cut flowers.     

Administration of acidified drinking water to finishing pigs in order to prevent Salmonella infections

The aim of the study was to test whether acidified drinking water, with two millilitres of an acid mixture per litre, was able to reduce the number of Salmonella infections in finishing pig herds. In each compartment, half of the pens were supplied with acidified water and the other pens served as negative control. In three herds the required dose was not applied to the pigs as a result of various practical problems. In another herd, all pigs remained seronegative throughout the study. Analysis of the remaining three herds showed a large and significant treatment effect in one herd (P<0.001). As a result of the small number of observations and the overall lower seroprevalence in the control groups, the other two herds only showed a statistical trend to a treatment effect (0.10相似文献   

Microbial community shifts in Pythium ultimum-inoculated suppressive substrates

In this study, the role of compost amendments for the biocontrol of Pythium ultimum was evaluated in bioassays with cucumber (Cucumis sativa L. variety “Chinesische Schlangen”). The addition of compost to the peat-based growing substrates resulted in a significant reduction of disease symptoms of cucumber plants in the presence of P. ultimum compared to pure substrate. Microbial community composition of compost-amended substrates and with different levels of P. ultimum inoculum (0, 5‰) was analyzed by polymerase-chain-reaction-based techniques. To detect and compare dominant bacterial and fungal representatives of suppressive substrate mixes with different pathogen inoculum, 16S and 18S rRNA clone libraries were established. Phylogenetic analysis of the 16S rRNA clones revealed Actinobacteria and α-Proteobacteria to be the prominent classes in the presence of P. ultimum, which are not part of the dominant microflora in the mixes without the pathogen. 18S rRNA sequences for the Pythium-inoculated compost supplemented samples were dominated by Chytridiomycota and Sordariomycetes, whereas in uncontaminated soil–compost mixes, a large part of the sequences were related to Homobasidiomycetes. Thus, it is assumed that the presence of P. ultimum induces distinct shifts in microbial communities favoring to groups known to comprise potential biocontrol agents.     

Conditional cooperation and costly monitoring explain success in forest commons management

Recent evidence suggests that prosocial behaviors like conditional cooperation and costly norm enforcement can stabilize large-scale cooperation for commons management. However, field evidence on the extent to which variation in these behaviors among actual commons users accounts for natural commons outcomes is altogether missing. Here, we combine experimental measures of conditional cooperation and survey measures on costly monitoring among 49 forest user groups in Ethiopia with measures of natural forest commons outcomes to show that (i) groups vary in conditional cooperator share, (ii) groups with larger conditional cooperator share are more successful in forest commons management, and (iii) costly monitoring is a key instrument with which conditional cooperators enforce cooperation. Our findings are consistent with models of gene-culture coevolution on human cooperation and provide external validity to laboratory experiments on social dilemmas.     

Treatment of feline mammary tumours using chemotherapy,surgery and a COX‐2 inhibitor drug (meloxicam): a retrospective study of 23 cases (2002–2007)*

The efficacy of a treatment combination of a COX‐2 inhibitor (meloxicam), chemotherapy and surgery in 23 cats with histologically confirmed mammary gland adenocarcinoma was evaluated. All of the cases underwent an aggressive surgery with concurrent doxorubicin‐based chemotherapy. Meloxicam was given orally starting the day after surgery and was continued indefinitely. Serum renal parameters were measured every 3–5 months. Three cats developed azotemia, whereas in four other renal parameters increased but remained within normal limit. The Kaplan–Meier median survival time was 460 days. The Kaplan–Meier median disease free interval was 269 days. The survival times are similar to other studies, not supporting the use of this treatment combination. Prospective studies with a higher number of cases are warranted to investigate the utility of this multimodality protocol for the treatment of feline mammary tumours.     

Histochemical phosphorylase activity in regenerating muscle fibers from myophosphorylase-deficient patients

Fresh frozen sections of mature skeletal muscle fibers from patients with genetically determined "absence" of skeletal muscle phosphorylase (McArdle's disease) have no histochemical phosphorylase activity. That regenerating muscle fibers, in vitro and in vivo, from such patients do have histochemical phosphorylase activity present suggests a loss of enzyme activity with fiber maturity.     

miRNA and piRNA expression profiles of breeder cock testes detected by next‐generation sequencing

miRNAs are small non‐coding regulatory RNAs that play key roles in diverse biological processes. In this study, we used the Solexa sequencing technique to profile miRNAs in breeder cock testes to illustrate their functions. A total of 663 co‐expressed miRNAs and 3,180 co‐expressed piRNAs were detected in three libraries. Based on Mir‐X^? miRNA qRT‐PCR, three miRNAs representing low, medium and high expression levels according to the sequencing results were selected randomly to validate the miRNAs' expression profiles. Results suggested that the miRNA expression profiles data could represent actual miRNA expression levels. Moreover, target genes prediction of the co‐expressed miRNAs and further Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed, which revealed that some candidate miRNAs were involved in the regulation of the spermatogenesis process, spermatozoa function and testicular metabolism. In conclusion, we provided a useful resource for further elucidation of the miRNAs' regulatory role in spermatogenesis, contributing to a preliminary database for functional and molecular mechanistic studies in testicular metabolism, spermatogenesis and other testes functions.     

Skin disease affecting the conservation of the western swamp tortoise (Pseudemydura umbrina)

Objective To review the present position of the western swamp tortoise ( Pseudemydura umbrina ) as an endangered species and significant health issues affecting efforts to save it from extinction.
Procedure A retrospective analysis of the husbandry, hospital and pathology records of the western swamp tortoise captive breeding program at Perth Zoo.
Results In 1987 a captive breeding project was developed to prevent the extinction of the western swamp tortoise but an outbreak of a necrotising dermatitis in 1989 threatened the survival of the captive bred hatchlings. Less severe outbreaks occurred in 1990 and 1993, with isolated cases in between. Of 283 tortoises that were born in captivity or came into captivity from the wild, 37 (13.1%) were affected, comprising 37% of all males, 26% of all females and 13% of animals of unknown gender. Of the affected animals, 70% were less than 2 years of age and 29% were older. Males were 1.6 times more likely to be infected than females but this difference was not statistically significant (P = 0.27). Culture of the lesions consistently yielded unidentified Pseudomonas sp.
Conclusion Improved husbandry, such as strict maintenance of water quality and temperature conditions similar to that of the animal's natural habitat, and monitoring the health of individual tortoises have successfully controlled skin disease in the captive breeding of the western swamp tortoise.     

Patterns of seroconversion to Aujeszky's disease virus in unvaccinated chronically infected Swedish weaner pig-producing herds

This study was carried out in nine unvaccinated Swedish weaner pig-producing herds, ranging in size from 20 to 134 breeding animals, which had experienced a previous outbreak of Aujeszky's disease (AD) and in which seropositive sows were still present. The objective was to quantify the seroconversion rate to Aujeszky's disease virus (ADV) in breeding animals and to find out whether unvaccinated herds could become free from ADV by using only seronegative animals for replacement. Serum samples were initially obtained from all adult pigs in the herds. Animals testing negative, as well as replacement animals, were subsequently tested every second or third month and the herds were followed for 10-28 months. The herd owners were advised to keep seropositive and seronegative animals separate whenever possible and to implement sanitary measures against the reintroduction of the virus into the herds. All herds experienced long consecutive periods (> or = 4 months, median 9 months) without seroconversion. Three herds became free from ADV during the serological study; in two of these herds no seroconversion was observed. In those seven herds where seroconversion occurred, between 9 and 86% of the susceptible pigs became infected. The reinfection was indicative of the reactivation of latent virus in all herds but two, where the reintroduction of the virus was most likely. The pattern of seroconversion was either sporadic, involving not more than three animals at a time, or epidemic, involving a large proportion of the susceptible animals in the herd. Severe clinical outbreaks hit the two largest herds and these only became ADV-free after the conclusion of the study when vaccine was used, which reduced the incidence of seroconversion to zero. The results from the present study show that it is possible for smaller herds to achieve freedom from ADV without any radical control methods, provided that only ADV-free replacement animals are used and the virus is not reintroduced. Moreover, the finding that long periods can elapse without transmission suggests that when infection is discovered in a herd, the risk of massive spread is not necessarily imminent.