Search

This paper presents the results of hypoeutectic 226 grade alloy as well as prepared on its basis Al-Si alloy containing Cr, V and Mo. The additives tested were added as AlCr15, AlV10 and AlMo8 master alloys. Alloys tested were poured into DTA sampler as well as using pressure die casting. An amount of Cr, V and Mo additives in alloy poured into DTA sampler comprised within the range approximately 0.05-0.35%. Alloys to pressure die casting contained 0.05-0.20% Cr, V and Mo. The crystallization process was examined using the derivative thermal analysis (DTA). The microstructure of castings made in the DTA sampler as well as castings made with use of pressure die casting were examined. The basic mechanical properties of castings made using pressure die casting were defined too. It has been shown in the DTA curves of Al-Si alloy containing approximately 0.30 and 0.35% Cr, Mo, and V there is an additional thermal effect probably caused by a peritectic crystallization of intermetallic phases containing the aforementioned additives. These phases have a morphology similar to the walled and a relatively large size. The analogous phases also occur in pressure die casting alloys containing 0.10% or more additions of Cr, V and Mo. The appearance of these phases in pressure die casting Al-Si alloys coincides with a decrease in the value of the tensile strength Rm and the elongation A. It has been shown die castings made of Al-Si alloys containing the aforementioned additives have a higher Rm and A than 226 alloy.

Trichomonas gypaetinii was detected in 117 (88%) of 133 Bald Eagles (Haliaeetus leucocephalus) and in 0/7 Golden Eagles (Aquila chrysaetos) in the USA, with no sex or age prevalence difference. All eagles lacked associated lesions. This study indicated that T. gypaetinii is common and widespread in Bald Eagles, but rarely associated with disease., (© Wildlife Disease Association 2024.)

Following the detection of novel highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b in Newfoundland, Canada, in late 2021, avian influenza virus (AIV) surveillance in wild birds was scaled up across Canada. Herein, we present the results of Canada's Interagency Surveillance Program for Avian Influenza in Wild Birds during the first year (November 2021-November 2022) following the incursions of HPAIV from Eurasia. The key objectives of the surveillance program were to (i) identify the presence, distribution, and spread of HPAIV and other AIVs; (ii) identify wild bird morbidity and mortality associated with HPAIV; (iii) identify the range of wild bird species infected by HPAIV; and (iv) genetically characterize detected AIV. A total of 6,246 sick and dead wild birds were tested, of which 27.4% were HPAIV positive across 12 taxonomic orders and 80 species. Geographically, HPAIV detections occurred in all Canadian provinces and territories, with the highest numbers in the Atlantic and Central Flyways. Temporally, peak detections differed across flyways, though the national peak occurred in April 2022. In an additional 11,295 asymptomatic harvested or live-captured wild birds, 5.2% were HPAIV positive across 3 taxonomic orders and 19 species. Whole-genome sequencing identified HPAIV of Eurasian origin as most prevalent in the Atlantic Flyway, along with multiple reassortants of mixed Eurasian and North American origins distributed across Canada, with moderate structuring at the flyway scale. Wild birds were victims and reservoirs of HPAIV H5N1 2.3.4.4b, underscoring the importance of surveillance encompassing samples from sick and dead, as well as live and harvested birds, to provide insights into the dynamics and potential impacts of the HPAIV H5N1 outbreak. This dramatic shift in the presence and distribution of HPAIV in wild birds in Canada highlights a need for sustained investment in wild bird surveillance and collaboration across interagency partners., Importance: We present the results of Canada's Interagency Surveillance Program for Avian Influenza in Wild Birds in the year following the first detection of highly pathogenic avian influenza virus (HPAIV) H5N1 on the continent. The surveillance program tested over 17,000 wild birds, both sick and apparently healthy, which revealed spatiotemporal and taxonomic patterns in HPAIV prevalence and mortality across Canada. The significant shift in the presence and distribution of HPAIV in Canada's wild birds underscores the need for sustained investment in wild bird surveillance and collaboration across One Health partners., Competing Interests: The authors declare no conflict of interest.

Wild turkeys (Meleagris gallopavo) are an important game species throughout the geographic range. Populations throughout multiple regions of the US have been declining, including in Kentucky, US, raising concerns among managers and resource users. To better understand the overall population health, we performed postmortem examinations and targeted pathogen, mineral, and toxicant testing on 36 adult male, apparently healthy, wild turkeys that were hunter harvested in western Kentucky during April 2018. We found that birds were in fair to good nutritional condition with no significant gross or microscopic lesions. Ticks (Amblyomma spp.) and lice (three species) were present on 94 and 31% of birds, respectively. We commonly detected intestinal nematodes and cestodes and found coccidian oocysts in 39% and capillarid eggs in 6% of birds. The prevalences of lymphoproliferative disease virus and reticuloendotheliosis virus were 39 and 11%, respectively. Spleen samples tested with PCR were positive for Borrelia burgdorferi, Haemoproteus sp., and Leucocytozoon sp. in 11, 83, and 3%, respectively. Based on a subjective histologic assessment of testis tissues, most birds had widespread and abundant sperm present. Mineral analysis and broad toxicant screening on liver samples from 32 turkeys were unremarkable. Further work is needed to assess potential population risk factors and to determine individual- and population-level impacts of pathogens on adults and poults., (© Wildlife Disease Association 2024.)

A Eurasian lineage highly pathogenic avian influenza virus (HPAIV) of the clade 2.3.4.4b (Goose/Guangdong lineage) was detected in migratory bird populations in North America in December 2021, and it, along with its reassortants, have since caused wild and domestic bird outbreaks across the continent. Relative to previous outbreaks, HPAIV cases among wild birds in 2022 exhibited wider geographic extent within North America and higher levels of mortality, suggesting the potential for population-level impacts. Given the possible conservation implications of HPAIV in wild birds, natural resource managers have sought guidance on actions that may mitigate negative effects of disease among North American bird populations, including modification of existing management practices. Banding of waterfowl is a critical tool for population management for several harvested species in North America, but some banding techniques, such as bait trapping, can lead to increased congregation of waterfowl, potentially altering HPAIV transmission. We used an expert opinion exercise to assess how bait trapping of dabbling ducks in Canada may influence HPAIV transmission and wild bird health. The expert group found that it is moderately likely that bait trapping of dabbling ducks in wetlands will significantly increase the transmission of HPAIV among individual ducks, but there is a low probability that this will result in significant population-level effects on North American dabbling ducks. Considering the lack of empirical work studying how capture and handling methods may change transmission of HPAIV among waterfowl, as well as the importance of bait trapping for waterfowl management in North America, future work should focus on filling knowledge gaps pertaining to the influence of baiting on HPAIV occurrence to better inform banding procedures and management decision making., (© Wildlife Disease Association 2023.)

The salamander chytrid fungus (Batrachochytrium salamandrivorans [Bsal]) is causing massive mortality of salamanders in Europe. The potential for spread via international trade into North America and the high diversity of salamanders has catalyzed concern about Bsal in the U.S. Surveillance programs for invading pathogens must initially meet challenges that include low rates of occurrence on the landscape, low prevalence at a site, and imperfect detection of the diagnostic tests. We implemented a large-scale survey to determine if Bsal was present in North America designed to target taxa and localities where Bsal was determined highest risk to be present based on species susceptibility and geography. Our analysis included a Bayesian model to estimate the probability of occurrence of Bsal given our prior knowledge of the occurrence and prevalence of the pathogen. We failed to detect Bsal in any of 11,189 samples from 594 sites in 223 counties within 35 U.S. states and one site in Mexico. Our modeling indicates that Bsal is highly unlikely to occur within wild amphibians in the U.S. and suggests that the best proactive response is to continue mitigation efforts against the introduction and establishment of the disease and to develop plans to reduce impacts should Bsal establish.