Abstract
Concerns regarding food safety and animal health require more effective alternatives with the potential to improve health and productivity. High Immune Response (HIR™) technology is a ...patented method to identify animals with inherently more robust, balanced and protective immune responses. This approach has been shown to decrease disease incidence in pigs and dairy cattle by about half. Economic benefits of high immune responder dairy cows are in the range of $240/cow/lactation, including reduced treatment costs. Our research focus is on adapting HIR™ for use in Canadian beef feedlots to decrease economically important diseases such as Bovine Respiratory Disease (BRD). HIR test measures IR to non-replicating test antigens (Ag) to elicit both antibody-mediated IR (AMIR) and cell-mediated IR (CMIR). Results on 170 cows of mixed breeds and 126 of their calves at the university research facility demonstrate that calves as young as 3 weeks of age and mature cattle can be ranked for AMIR and CMIR using the HIR test system. A SAS GLM model was used to evaluate the effects of age of dam, parity, and breed composition (y = mu + age + calf/no-calf + breed + error) on IR rank. Regression analysis was used to examine associations between serum IgG of cows and their calves. Results indicated a slight positive correlation between serum IgG in calves of the same dam (R2 = 0.097) when animals of all parities were evaluated, and a greater association was noted when only heifers were evaluated in their first two parities (R2 = 0.64). However, there was no association between AMIR rank of the dam and serum IgG of the calf. There was slight positive association between CMIR rank of the dam and serum IgG of the calf (R2 = 0.05). More dam-calf pairs will be evaluated in the future.
Concerns regarding food safety and animal health require more effective alternatives with the potential to improve health and productivity. High Immune Response (HIR™) technology is a patented method ...to identify animals with inherently more robust, balanced and protective immune responses. This approach has been shown to decrease disease incidence in pigs and dairy cattle by about half. Economic benefits of high immune responder dairy cows are in the range of $240/cow/lactation, including reduced treatment costs. Our research focus is on adapting HIR™ for use in Canadian beef feedlots to decrease economically important diseases such as Bovine Respiratory Disease (BRD). HIR test measures IR to non-replicating test antigens (Ag) to elicit both antibody-mediated IR (AMIR) and cell-mediated IR (CMIR). Results on 170 cows of mixed breeds and 126 of their calves at the university research facility demonstrate that calves as young as 3 weeks of age and mature cattle can be ranked for AMIR and CMIR using the HIR test system. A SAS GLM model was used to evaluate the effects of age of dam, parity, and breed composition (y = mu + age + calf/no-calf + breed + error) on IR rank. Regression analysis was used to examine associations between serum IgG of cows and their calves. Results indicated a slight positive correlation between serum IgG in calves of the same dam (R2 = 0.097) when animals of all parities were evaluated, and a greater association was noted when only heifers were evaluated in their first two parities (R2 = 0.64). However, there was no association between AMIR rank of the dam and serum IgG of the calf. There was slight positive association between CMIR rank of the dam and serum IgG of the calf (R2 = 0.05). More dam-calf pairs will be evaluated in the future.
Résumé
Les fractures du pilon tibial sont peu fréquentes, elles présentent un haut risque de complications précoces et tardives comme les cals vicieux et les pseudarthroses. Ces deux complications ...sont très mal tolérées, leur prise en charge reste un problème d’actualité en raison de leur mode de correction, de fixation et de difficulté de consolidation. Elles surviennent souvent chez des patients multiopérés avec un mauvais état cutané. Nous rapportons deux cas de cals vicieux supramalléolaires que nous avons traités par le fixateur externe d’Ilizarov dernière génération : le Truelok® et Truelok Hexapodal® assisté par un logiciel de planification préopératoire et de suivi. Le recul actuel est de deux ans.
Vitrification of aqueous cryoprotectant mixtures is essential in cryopreservation of proteins and other biological samples. Systematic measurements of critical cryoprotective agent (CPA) ...concentrations required for vitrification during plunge‐cooling from T = 295 K to T = 77 K in liquid nitrogen are reported. Measurements on fourteen common CPAs, including alcohols (glycerol, methanol, 2‐propanol), sugars (sucrose, xylitol, dextrose, trehalose), polyethylene glycols (ethylene glycol, PEG 200, PEG 2000, PEG 20000), glycols dimethyl sulfoxide (DMSO), 2‐methyl‐2,4‐pentanediol (MPD), and salt (NaCl), were performed for volumes ranging over four orders of magnitude from ∼1 nl to 20 µl, and covering the range of interest in protein crystallography. X‐ray diffraction measurements on aqueous glycerol mixtures confirm that the polycrystalline‐to‐vitreous transition occurs within a span of less than 2% w/v in CPA concentration, and that the form of polycrystalline ice (hexagonal or cubic) depends on CPA concentration and cooling rate. For most of the studied cryoprotectants, the critical concentration decreases strongly with volume in the range from ∼5 µl to ∼0.1 µl, typically by a factor of two. By combining measurements of the critical concentration versus volume with cooling time versus volume, the function of greatest intrinsic physical interest is obtained: the critical CPA concentration versus cooling rate during flash‐cooling. These results provide a basis for more rational design of cryoprotective protocols, and should yield insight into the physics of glass formation in aqueous mixtures.
Pollen morphology of 11 species (6 genera) representing the Tiliaceae and Sterculiaceae in the flora of Egypt was studied using Light Microscope (LM) and Scanning Electron Microscope (SEM). Pollen ...grains are spheroidal to prolate or oblate-spheroidal to spheroidal, tricolporate or trizonoporate. Sculpturing is reticulate-perforate or spiny-perforate. Three pollen types were recorded: Grewia, Hermannia and Melhania types. Pollen morphology in relation to taxonomy of the investigated taxa and their relations to Malvaceae is briefly discussed.
PDF
