113 resultados para Wild animal collecting


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis has made a significant contribution to future chlamydial research by uncovering the chlamydial pathogenic mechanisms which will potentially help in the development of targeted vaccine against the pathogen. This thesis has made important new contributions to our understanding of Chlamydia pneumoniae specific adaptations to stress responses and has provided new perspectives on the survival of this successful pathogen. This thesis has used two well established microbial stressors and has identified major differences in stress responses between human and animal Chlamydia pneumoniae isolates.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A successful translocation involves many complex factors, including a genetically appropriate source population that can sustain harvest, social and governmental support, assessment of disease transmission risk and a release site with appropriately secure habitat that can support population establishment and persistance. This information is typically discussed during staturory approval processes and can take considerable time. However, following approval, for translocations of most fauna, the initial critical step involves the inherently stressful process of capture, holding, transportation and release. This process is unpredictable and novel, and is especially challenging for wild animals when they are confined in close proximity to conspecifics and humans. In contrast, captive-reared animals have to cope with the unfamiliar challenges of finding food and shelter, along with coping with competition and predation. Little has been written in the scientific literature about the translocation process. This is unsurprising because this process has usually been the realm of skilled practioners, often with animal husbandry backgrounds, rather than research scientists. Highly skilled intuition, observation and the translocation practioner's equivalent of a 'green thumb' often guides the way. However, theory and experimentation, particularly on the effects of stress, is available and this work is invaluable for a successful translocation. Here, we provide a brief description of the translocation process, and discussion of what stress is and how it can be managed. We then provide practical guidelines for the successful translocation of invertebrates, lizards, turtles, passerine birds, marsupials and bats, using examples from Australia and New Zealand.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We aimed to identify genetic variants associated with cortical bone thickness (CBT) and bone mineral density (BMD) by performing two separate genome-wide association study (GWAS) meta-analyses for CBT in 3 cohorts comprising 5,878 European subjects and for BMD in 5 cohorts comprising 5,672 individuals. We then assessed selected single-nucleotide polymorphisms (SNPs) for osteoporotic fracture in 2,023 cases and 3,740 controls. Association with CBT and forearm BMD was tested for ~2.5 million SNPs in each cohort separately, and results were meta-analyzed using fixed effect meta-analysis. We identified a missense SNP (Thr>Ile; rs2707466) located in the WNT16 gene (7q31), associated with CBT (effect size of -0.11 standard deviations [SD] per C allele, P = 6.2×10-9). This SNP, as well as another nonsynonymous SNP rs2908004 (Gly>Arg), also had genome-wide significant association with forearm BMD (-0.14 SD per C allele, P = 2.3×10-12, and -0.16 SD per G allele, P = 1.2×10-15, respectively). Four genome-wide significant SNPs arising from BMD meta-analysis were tested for association with forearm fracture. SNP rs7776725 in FAM3C, a gene adjacent to WNT16, was associated with a genome-wide significant increased risk of forearm fracture (OR = 1.33, P = 7.3×10-9), with genome-wide suggestive signals from the two missense variants in WNT16 (rs2908004: OR = 1.22, P = 4.9×10-6 and rs2707466: OR = 1.22, P = 7.2×10-6). We next generated a homozygous mouse with targeted disruption of Wnt16. Female Wnt16-/- mice had 27% (P<0.001) thinner cortical bones at the femur midshaft, and bone strength measures were reduced between 43%-61% (6.5×10-13<P<5.9×10-4) at both femur and tibia, compared with their wild-type littermates. Natural variation in humans and targeted disruption in mice demonstrate that WNT16 is an important determinant of CBT, BMD, bone strength, and risk of fracture. © 2012 Zheng et al.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mutations of UDP-N-acetyl-alpha-D-galactosamine polypeptide N-acetyl galactosaminyl transferase 3 (GALNT3) result in familial tumoural calcinosis (FTC) and the hyperostosis-hyperphosphataemia syndrome (HHS), which are autosomal recessive disorders characterised by soft-tissue calcification and hyperphosphataemia. To facilitate in vivo studies of these heritable disorders of phosphate homeostasis, we embarked on establishing a mouse model by assessing progeny of mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU), and identified a mutant mouse, TCAL, with autosomal recessive inheritance of ectopic calcification, which involved multiple tissues, and hyperphosphataemia; the phenotype was designated TCAL and the locus, Tcal. TCAL males were infertile with loss of Sertoli cells and spermatozoa, and increased testicular apoptosis. Genetic mapping localized Tcal to chromosome 2 (62.64-71.11 Mb) which contained the Galnt3. DNA sequence analysis identified a Galnt3 missense mutation (Trp589Arg) in TCAL mice. Transient transfection of wild-type and mutant Galnt3-enhanced green fluorescent protein (EGFP) constructs in COS-7 cells revealed endoplasmic reticulum retention of the Trp589Arg mutant and Western blot analysis of kidney homogenates demonstrated defective glycosylation of Galnt3 in Tcal/Tcal mice. Tcal/Tcal mice had normal plasma calcium and parathyroid hormone concentrations; decreased alkaline phosphatase activity and intact Fgf23 concentrations; and elevation of circulating 1,25-dihydroxyvitamin D. Quantitative reverse transcriptase-PCR (qRT-PCR) revealed that Tcal/Tcal mice had increased expression of Galnt3 and Fgf23 in bone, but that renal expression of Klotho, 25-hydroxyvitamin D-1α-hydroxylase (Cyp27b1), and the sodium-phosphate co-transporters type-IIa and -IIc was similar to that in wild-type mice. Thus, TCAL mice have the phenotypic features of FTC and HHS, and provide a model for these disorders of phosphate metabolism. © 2012 Esapa et al.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper investigates communication protocols for relaying sensor data from animal tracking applications back to base stations. While Delay Tolerant Networks (DTNs) are well suited to such challenging environments, most existing protocols do not consider the available energy that is particularly important when tracking devices can harvest energy. This limits both the network lifetime and delivery probability in energy-constrained applications to the point when routing performance becomes worse than using no routing at all. Our work shows that substantial improvement in data yields can be achieved through simple yet efficient energy-aware strategies. Conceptually, there is need for balancing the energy spent on sensing, data mulling, and delivery of direct packets to destination. We use empirical traces collected in a flying fox (fruit bat) tracking project and show that simple threshold-based energy-aware strategies yield up to 20% higher delivery rates. Furthermore, these results generalize well for a wide range of operating conditions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective Spondyloarthritides (SpA) occur in 1% of the population and include ankylosing spondylitis (AS) and arthropathy of inflammatory bowel disease (IBD), with characteristic spondylitis, arthritis, enthesitis, and IBD. Genetic studies implicate interleukin-23 (IL-23) receptor signaling in the development of SpA and IBD, and IL-23 overexpression in mice is sufficient for enthesitis, driven by entheseal-resident T cells. However, in genetically prone individuals, it is not clear where IL-23 is produced and how it drives the SpA syndrome, including IBD or subclinical gut inflammation of AS. Moreover, it is unclear why specific tissue involvement varies between patients with SpA. We undertook this study to determine the location of IL-23 production and its role in SpA pathogenesis in BALB/c ZAP-70W163C-mutant (SKG) mice injected intraperitoneally with β-1,3-glucan (curdlan). Methods Eight weeks after curdlan injection in wild-type or IL-17A-/- SKG or BALB/c mice, pathology was scored in tissue sections. Mice were treated with anti-IL-23 or anti-IL-22. Cytokine production and endoplasmic reticulum (ER) stress were determined in affected organs. Results In curdlan-treated SKG mice, arthritis, enthesitis, and ileitis were IL-23 dependent. Enthesitis was specifically dependent on IL-17A and IL-22. IL-23 was induced in the ileum, where it amplified ER stress, goblet cell dysfunction, and proinflammatory cytokine production. IL-17A was pathogenic, while IL-22 was protective against ileitis. IL-22+CD3- innate-like cells were increased in lamina propria mononuclear cells of ileitis-resistant BALB/c mice, which developed ileitis after curdlan injection and anti-IL-22. Conclusion In response to systemic β-1,3-glucan, intestinal IL-23 provokes local mucosal dysregulation and cytokines driving the SpA syndrome, including IL-17/IL-22-dependent enthesitis. Innate IL-22 production promotes ileal tolerance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Our understanding of the origin and fate of the IgE-switched B cell has been markedly improved by studies in mouse models. The immediate precursor of the IgE-switched B cell is either a relatively naive nonswitched B cell or a mature IgG-switched B cell. These 2 routes are referred to as the direct and indirect pathways, respectively. IgE responses derived from each pathway differ significantly, largely reflecting the difference in time spent in a germinal center and thus time for clonal expansion, somatic hypermutation, affinity maturation, and acquisition of a memory phenotype. The clinical and therapeutic implications for IgE responses in human subjects are still a matter of debate, largely because the immunization procedures used in the animal models are significantly different from classical atopic sensitization to allergens from pollen and mites. On the basis of the limited information available, it seems likely that these atopic IgE responses are characterized by a relatively low IgG/IgE ratio, low B-cell memory, and modest affinity maturation, which fits well with the direct switching pathway. It is still unresolved how the IgE response evolves to cover a wide epitope repertoire involving many epitopes per allergen, as well as many different allergens from a single allergen source. © 2013 American Academy of Allergy, Asthma & Immunology.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ross River (RR) virus is an alphavirus endemic to Australia and New Guinea and is the aetiological agent of epidemic polyarthritis or RR virus disease. Here we provide evidence that RR virus uses the collagen-binding α1β1 integrin as a cellular receptor. Infection could be inhibited by collagen IV and antibodies specific for the β1 and α1 integrin proteins, and fibroblasts from α1-integrin-/- mice were less efficiently infected than wild-type fibroblasts. Soluble α1β1 integrin bound immobilized RR virus, and peptides representing the α1β1 integrin binding-site on collagen IV inhibited virus binding to cells. We speculate that two highly conserved regions within the cell-receptor binding domain of E2 mimic collagen and provide access to cellular collagen-binding receptors.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Genital tract carriage of group B streptococcus (GBS) is prevalent among adult women; however, the dynamics of chronic GBS genital tract carriage, including how GBS persists in this immunologically active host niche long term, are not well defined. To our knowledge, in this study, we report the first animal model of chronic GBS genital tract colonization using female mice synchronized into estrus by delivery of 17β-estradiol prior to intravaginal challenge with wild-type GBS 874391. Cervicovaginal swabs, which were used to measure bacterial persistence, showed that GBS colonized the vaginal mucosa of mice at high numbers (106–107 CFU/swab) for at least 90 d. Cellular and histological analyses showed that chronic GBS colonization of the murine genital tract caused significant lymphocyte and PMN cell infiltrates, which were localized to the vaginal mucosal surface. Long-term colonization was independent of regular hormone cycling. Immunological analyses of 23 soluble proteins related to chemotaxis and inflammation showed that the host response to GBS in the genital tract comprised markers of innate immune activation including cytokines such as GM-CSF and TNF-α. A nonhemolytic isogenic mutant of GBS 874391, Δcyle9, was impaired for colonization and was associated with amplified local PMN responses. Induction of DNA neutrophil extracellular traps, which was observed in GBS-infected human PMNs in vitro in a hemolysin-dependent manner, appeared to be part of this response. Overall, this study defines key infection dynamics in a novel murine model of chronic GBS genital tract colonization and establishes previously unknown cellular and soluble defense responses to GBS in the female genital tract.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background The growing awareness of transfusion-associated morbidity and mortality necessitates investigations into the underlying mechanisms. Small animals have been the dominant transfusion model but have associated limitations. This study aimed to develop a comprehensive large animal (ovine) model of transfusion encompassing: blood collection, processing and storage, compatibility testing right through to post-transfusion outcomes. Materials and methods Two units of blood were collected from each of 12 adult male Merino sheep and processed into 24 ovine-packed red blood cell (PRBC) units. Baseline haematological parameters of ovine blood and PRBC cells were analysed. Biochemical changes in ovine PRBCs were characterized during the 42-day storage period. Immunological compatibility of the blood was confirmed with sera from potential recipient sheep, using a saline and albumin agglutination cross-match. Following confirmation of compatibility, each recipient sheep (n = 12) was transfused with two units of ovine PRBC. Results Procedures for collecting, processing, cross-matching and transfusing ovine blood were established. Although ovine red blood cells are smaller and higher in number, their mean cell haemoglobin concentration is similar to human red blood cells. Ovine PRBC showed improved storage properties in saline–adenine–glucose–mannitol (SAG-M) compared with previous human PRBC studies. Seventy-six compatibility tests were performed and 17·1% were incompatible. Only cross-match compatible ovine PRBC were transfused and no adverse reactions were observed. Conclusion These findings demonstrate the utility of the ovine model for future blood transfusion studies and highlight the importance of compatibility testing in animal models involving homologous transfusions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cushing's syndrome, which is characterized by excessive circulating glucocorticoid concentrations, maybe due to ACTH-dependent or -independent causes that include anterior pituitary and adrenal cortical tumors, respectively. ACTH secretion is stimulated by CRH, and we report a mouse model for Cushing's syndrome due to an N-ethyl-N-nitrosourea (ENU) induced Crh mutation at -120 bp of the promoter region, which significantly increased luciferase reporter activity and was thus a gain-of-function mutation. Crh -120/+ mice, when compared with wild-type littermates, had obesity, muscle wasting, thin skin, hair loss, and elevated plasma and urinary concentrations of corticosterone. In addition, Crh-120/+ mice had hyperglycemia, hyperfructosaminemia, hyperinsulinemia, hypercholesterolemia, hypertriglyceridemia, and hyperleptinemia but normal adiponectin. Crh -120/+ mice also had low bone mineral density, hypercalcemia, hypercalciuria, and decreased concentrations of plasma PTH and osteocalcin. Bone histomorphometry revealed Crh-120/+ mice to have significant reductions in mineralizing surface area, mineral apposition, bone formation rates, osteoblast number, and the percentage of corticoendosteal bone covered by osteoblasts, which was accompanied by an increase in adipocytes in the bone marrow. Thus, a mouse model for Cushing's syndrome has been established, and this will help in further elucidating the pathophysiological effects of glucocorticoid excess and in evaluating treatments for corticosteroid-induced osteoporosis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bone diseases such as rickets and osteoporosis cause significant reduction in bone quantity and quality, which leads to mechanical abnormalities. However, the precise ultrastructural mechanism by which altered bone quality affects mechanical properties is not clearly understood. Here we demonstrate the functional link between altered bone quality (reduced mineralization) and abnormal fibrillar-level mechanics using a novel, real-time synchrotron X-ray nanomechanical imaging method to study a mouse model with rickets due to reduced extrafibrillar mineralization. A previously unreported N-ethyl-N-nitrosourea (ENU) mouse model for hypophosphatemic rickets (Hpr), as a result of missense Trp314Arg mutation of the phosphate regulating gene with homologies to endopeptidase on the X chromosome (Phex) and with features consistent with X-linked hypophosphatemic rickets (XLHR) in man, was investigated using in situ synchrotron small angle X-ray scattering to measure real-time changes in axial periodicity of the nanoscale mineralized fibrils in bone during tensile loading. These determine nanomechanical parameters including fibril elastic modulus and maximum fibril strain. Mineral content was estimated using backscattered electron imaging. A significant reduction of effective fibril modulus and enhancement of maximum fibril strain was found in Hpr mice. Effective fibril modulus and maximum fibril strain in the elastic region increased consistently with age in Hpr and wild-type mice. However, the mean mineral content was ∼21% lower in Hpr mice and was more heterogeneous in its distribution. Our results are consistent with a nanostructural mechanism in which incompletely mineralized fibrils show greater extensibility and lower stiffness, leading to macroscopic outcomes such as greater bone flexibility. Our study demonstrates the value of in situ X-ray nanomechanical imaging in linking the alterations in bone nanostructure to nanoscale mechanical deterioration in a metabolic bone disease. Copyright

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Progeny of mice treated with the mutagen N-ethyl-N-nitrosourea (ENU) revealed a mouse, designated Longpockets (Lpk), with short humeri, abnormal vertebrae, and disorganized growth plates, features consistent with spondyloepiphyseal dysplasia congenita (SEDC). The Lpk phenotype was inherited as an autosomal dominant trait. Lpk/+ mice were viable and fertile and Lpk/Lpk mice died perinatally. Lpk was mapped to chromosome 15 and mutational analysis of likely candidates from the interval revealed a Col2a1 missense Ser1386Pro mutation. Transient transfection of wild-type and Ser1386Pro mutant Col2a1 c-Myc constructs in COS-7 cells and CH8 chondrocytes demonstrated abnormal processing and endoplasmic reticulum retention of the mutant protein. Histology revealed growth plate disorganization in 14-day-old Lpk/+ mice and embryonic cartilage from Lpk/+ and Lpk/Lpk mice had reduced safranin-O and type-II collagen staining in the extracellular matrix. The wild-type and Lpk/+ embryos had vertical columns of proliferating chondrocytes, whereas those in Lpk/Lpk mice were perpendicular to the direction of bone growth. Electron microscopy of cartilage from 18.5 dpc wild-type, Lpk/+, and Lpk/Lpk embryos revealed fewer and less elaborate collagen fibrils in the mutants, with enlarged vacuoles in the endoplasmic reticulum that contained amorphous inclusions. Micro-computed tomography (CT) scans of 12-week-old Lpk/+ mice revealed them to have decreased bone mineral density, and total bone volume, with erosions and osteophytes at the joints. Thus, an ENU mouse model with a Ser1386Pro mutation of the Col2a1 C-propeptide domain that results in abnormal collagen processing and phenotypic features consistent with SEDC and secondary osteoarthritis has been established.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article elaborates the impact that crises of authority provoked by animal magnetism, mesmerism, and hypnosis in the 19th century had for field formation in American education. Four layers of analysis elucidate how curriculum history’s repetitive focus on public school policy and classroom practice became possible. First, the article surveys external conditions of possibility for the enactment of compulsory public schooling. Second, “internal” conditions of possibility for the formation of educational objects (e.g., types of children) are documented via the processes of différance that were generated from within the experiences of confinement. Third, the article maps how these were interpenetrated by animal magnetic debates that were lustered and planished in education’s emerging field, including impact upon behavior management practices, the contouring of expertise and authority, the role of Will in intelligence testing and child development theories, and the redefinition of public and private. Last, the article examines implications for curriculum history, whether policy- or practice-oriented, especially around the question of influence, the theorization of child mind, and philosophies of Being.