Evaluating the Impacts of Forest Management Policies and Community-Level Institutions in the Buffer Zone of Chitwan National Park,Nepal

A Master Plan for Nepal’s Forestry Sector (MPFS), enacted in 1989, and subsequent legislation laid the foundation for modern community-based forest management in Nepal. In 2014, the MPFS reached the end of its 25-yr lifespan, after successfully ushering in significant institutional changes that fundamentally transformed the management of Nepal’s forests, mostly through devolving management and benefits from the national level to local communities. Here, we use the 25-yr anniversary of the MPFS to explore forest cover trends in the buffer zone surrounding Chitwan National Park (CNP). Landsat imagery was used for the years 1989, 2005, and 2013 to compute a normalized difference vegetation index (NDVI) to analyze trends in forest cover for 36 buffer zone village development committees (VDCs). The analysis, covering approximately 1,267 km², found that since the MPFS was enacted, there was first a continued decrease in forest cover, followed by a significant recovery. These data offer insight into the success of modern community-based forest management policies and supporting institutions, and provide a model for other efforts to conserve forest resources in Nepal and elsewhere.     

Response of the dusky wireworm, Agriotes obscurus (Coleoptera: Elateridae), to residual levels of bifenthrin in field soil

To determine if bifenthrin residues elicit morbidity and surfacing behavior in wireworms, larvae of the dusky wireworm, Agriotes obscurus (Coleoptera: Elateridae) were placed in field soil treated with the pyrethroid insecticide bifenthrin ~1 year previous. Morbidity was immediate and lasted as long as wireworms remained in the soil, disappearing quickly after transfer to clean soil. In 2009, field soil treated 336 days previous with bifenthrin at 340 g AI/ha elicited morbidity symptoms similar to that elicited by soil freshly amended with bifenthrin at 100 g AI, and analysis of the field soil confirmed residual levels of bifenthrin exceeding 100 g AI/ha. In 2010, wireworms placed in field soil treated 343 days previous with bifenthrin at 100, 200, and 300 g AI/ha responded as in 2009, with the degree of morbidity increasing with the rate of insecticide, and with wireworms in a non-feeding state more affected than those in a feeding state at each rate. In both 2009 and 2010, moribund wireworms moved to the soil surface within 1 day of placement in the soil containing residual bifenthrin and remained there until reburied, after which they often resurfaced. To confirm that the bifenthrin residues elicited repellency, wireworms were placed in soil window bioassays containing field soil with residual bifenthrin. Wireworms behaved markedly different upon contacting soil containing the residues than when exposed to untreated soil, both in the presence and absence of an attractant, but were less likely to avoid soil containing residual bifenthrin when attracted by wheat seedlings placed inside it.     

Varying dietary levels of wheat pollard and wheat bran in growing pigs: effect on growth and carcass traits

To study the effect of increasing levels of wheat pollard as a replacement for wheat bran on growth and carcass characteristics of growing pigs, 64 crossbred (Landrace?×?Large white Yorkshire) pigs were fed with diets in which wheat pollard was added back to wheat bran in ratios of 15, 30, 45 and 60 %. The pigs were divided into groups of four, balanced for sex, ancestry and body weight. They were then allotted to the dietary treatments in a completely randomised design with four replications. The trial lasted 4 months and data were collected on feed intake and weight gain. A digestibility trial was carried out on eight male pigs per treatment during the growth period. At the end of the growth period, two pigs per replicate in each treatment (n?=?32) were slaughtered for determination of carcass characteristics. There were significant differences in the rate of gain and efficiency of feed utilisation among treatments. Diet significantly affected weights of the liver, lungs and small intestine (P?<?0.05). The availability of nutrients was not a limiting factor for the growing pigs and that substituting wheat bran by wheat pollard at 60 % improved the pig’s average daily gain and feed efficiency.     

An assessment of external biosecurity on southern Ontario swine farms and its application to surveillance on a geographic level

Risk-based surveillance is becoming increasingly important in the veterinary and public health fields. It serves as a means of increasing surveillance sensitivity and improving cost-effectiveness in an increasingly resource-limited environment. Our approach for developing a tool for the risk-based geographical surveillance of contagious diseases of swine incorporates information about animal density and external biosecurity practices within swine herds in southern Ontario. The objectives of this study were to group the sample of herds into discrete biosecurity groups, to develop a map of southern Ontario that can be used as a tool in the risk-based geographical surveillance of contagious swine diseases, and to identify significant predictors of biosecurity group membership. A subset of external biosecurity variables was selected for 2-step cluster analysis and latent class analysis (LCA). It was determined that 4 was the best number of groups to describe the data, using both analytical approaches. The authors named these groups: i) high biosecurity herds that were open with respect to replacement animals; ii) high biosecurity herds that were closed with respect to replacement animals; iii) moderate biosecurity herds; and iv) low biosecurity herds. The risk map was developed using information about the geographic distribution of herds in the biosecurity groups, as well as the density of swine sites and of grower-finisher pigs in the study region. Finally, multinomial logistic regression identified heat production units (HPUs), number of incoming pig shipments per month, and herd type as significant predictors of biosecurity group membership. It was concluded that the ability to identify areas of high and low risk for disease may improve the success of surveillance and eradication projects.     

Structural changes in femoral bone tissue of rats after subchronic peroral exposure to selenium

Background

The role of selenium (Se) on bone microarchitecture is still poorly understood. The present study aims to investigate the macroscopic and microscopic structures of femoral bone tissue in adult male rats after subchronic peroral administration of Se.

Methods

Twenty one-month-old male Wistar rats were randomly divided into two experimental groups. In the first group (Se group) young males were exposed to 5 mg Na₂SeO₃/L in drinking water, for 90 days. Ten one-month-old males without Se administration served as a control group. At the end of the experiment, macroscopic and microscopic structures of the femurs were analysed using analytical scales, sliding instrument, and polarized light microscopy.

Results

The body weight, femoral length and cortical bone thickness were significantly decreased in Se group rats. These rats also displayed different microstructure in the middle part of the femur, both in medial and lateral views, where vascular canals expanded into the central area of the bone while, in control rats, these canals occurred only near the endosteal surfaces. Additionally, a smaller number of primary and secondary osteons was identified in Se group rats. Histomorphometric analyses revealed significant increases for area, perimeter, maximum and minimum diameters of primary osteons’ vascular canals but significant reductions for all measured variables of Haversian canals and secondary osteons.

Conclusions

Se negatively affected the macroscopic and microscopic structures of femoral bone tissue in adult male rats. The results contribute to the knowledge on damaging impact of Se on bone.     

Proceedings of the 2013 Joint JSTP/NTP Satellite Symposium

The first joint Japanese Society of Toxicologic Pathology (JSTP) and National Toxicology Program (NTP) Satellite Symposium, entitled “Pathology Potpourri,” was held on January 29^th at Okura Frontier Hotel in Tsukuba, Ibaraki, Japan, in advance of the JSTP’s 29^th Annual Meeting. The goal of this Symposium was to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers’ presentations, including diagnostic or nomenclature issues that were presented, select images that were used for audience voting or discussion, and the voting results. Some lesions and topics covered during the symposium include: treatment-related atypical hepatocellular foci of cellular alteration in B6C3F1 mice; purulent ventriculoencephalitis in a young BALB/c mouse; a subcutaneous malignant schwannoma in a RccHan:WIST rat; spontaneous nasal septum hyalinosis/eosinophilic substance in B6C3F1 mice; a rare pancreatic ductal cell adenoma in a young Lewis rat; eosinophilic crystalline pneumonia in a transgenic mouse model; hyaline glomerulopathy in two female ddY mice; treatment-related intrahepatic erythrocytes in B6C3F1 mice; treatment-related subendothelial hepatocytes in B6C3F1 mice; spontaneous thyroid follicular cell vacuolar degeneration in a cynomolgus monkey; congenital hepatic fibrosis in a 1-year-old cat; a spontaneous adenocarcinoma of the middle ear in a young Crl:CD(SD) rat; and finally a series of cases illustrating some differences between cholangiofibrosis and cholangiocarcinoma in Sprague Dawley and F344 rats.     

Vaccination with recombinant NetB toxin partially protects broiler chickens from necrotic enteritis

NetB toxin from Clostridium perfringens is a major virulence factor in necrotic enteritis in poultry. In this study the efficacy of NetB as a vaccine antigen to protect chickens from necrotic enteritis was examined. Broiler chickens were immunized subcutaneously with purified recombinant NetB (rNetB), formalin treated bacterin and cell free toxoid with or without rNetB supplementation. Intestinal lesion scores and NetB antibody levels were measured to determine protection after mild oral gavage, moderate in-feed and heavy in-feed challenges with virulent C. perfringens isolates. Birds immunized with rNetB were significantly protected against necrotic enteritis when challenged with a mild oral dose of virulent bacteria, but were not protected when a more robust challenge was used. Bacterin and cell free toxoid without rNetB supplementation did not protect birds from moderate and severe in-feed challenge. Only birds immunized with bacterin and cell free toxoid supplemented with rNetB showed significant protection against moderate and severe in-feed challenge, with the later giving the greatest protection. Higher NetB antibody titres were observed in birds immunized with rNetB compared to those vaccinated with bacterin or toxoid, suggesting that the in vitro levels of NetB produced by virulent C. perfringens isolates are too low to induce the development of a strong immune response. These results suggest that vaccination with NetB alone may not be sufficient to protect birds from necrotic enteritis in the field, but that in combination with other cellular or cell-free antigens it can significantly protect chickens from disease.