Ecology of a landscape-scale deer assemblage

This thesis investigates the ecology of a multi-species ungulate assemblage and their impacts to inform management in commercial forestry (Thetford Forest, eastern England, 195km2). The aims were to analyse environmental factors influencing deer densities, to identify the species causing the greatest damage to young crop plantings, and to analyse how habitat, landscape context and intra- and inter-specific competition affect roe deer performance. Local roe and muntjac densities (collected in 2018) were related to habitat, landscape context and recreation. Roe deer densities were higher in young (0-5 since planting) stands and lower closer to grasslands and in areas of high recreational activity. Muntjac densities were higher in mature (≥46 years) stands, on calcareous soils, and with high recreation, while being lower closer to grasslands. Effects of local species-specific densities (from 2018 to 2020) of muntjac, roe, fallow deer and large deer (comprising fallow and red deer) on scots pine (Pinus sylvestris) leader browsing were assessed while controlling for hares presence and ground vegetation. More pine leaders were browsed in localities with higher densities of fallow or ‘large’ deer. Using a long-term dataset (2002-2015) we analysed effects of habitat and landscape context on roe deer fertility and body mass. Yearling and adult roe deer were more fertile when heavier; adult body mass was higher closer to arable lands, however, adult fertility was lower closer to arable. Relative importance of intra- and interspecific competition of fallow deer and muntjac on the condition and fertility of adult roe deer was tested using data from 2011-2016. Densities of muntjac were negatively related to fallow deer densities. Roe deer fertility was lower at higher muntjac densities, while being higher at higher roe deer densities. Roe deer are, therefore, subject to inter-specific competition from muntjac while intra-specific competition wasn’t detected. This is among the first studies showing effects of inter-specific competition of introduced species on reproductive output of a native vertebrate. Deer management should focus on reducing large deer and introduced species numbers to reduce impacts on regeneration and alleviate interspecific competition on native roe

Relation of pine crop damage to species-specific density in a multi-ungulate assemblage

Deer management in forest ecosystems requires information on deer densities and impacts to inform culling decisions with a known target density for acceptable damage levels. In multi-ungulate assemblages, managers need knowledge of relative impacts by different species or guilds. In an extensive (195 km2) conifer forest in eastern England, we related Scots pine (Pinus sylvestris) leader damage (% dominant shoots browsed) in 48 restocked stands (1–3 years growth) over multiple years (n = 79 observations) to species-specific annual muntjac (Muntiacus reevesi), roe (Capreolus capreolus), fallow (Dama dama) and “large deer” densities (composite of annual fallow and multi-year mean red deer Cervus elaphus) using generalized mixed effects models. Forest-wide density surface models were calibrated through intensive annual thermal imaging distance transects and local densities around stands resampled within confidence bounds. Models also examined effects of ground vegetation and hare presence (Lepus europaeus). More pine leaders were browsed at higher fallow or large deer densities (22% and 18%, respectively, increased leader damage across inter-quartile range). Leader damage intensity was not influenced by ground vegetation, hares, muntjac (across the range 8.3–41.6 individuals km−2) or roe deer density (1.7–19.4 individuals km−2). To reduce pine crop damage to economically acceptable levels, managers need to reduce fallow deer to a density as low as 0.6 individuals km−2 (CI = 0.06–1.44, which is considered impractical) or reduce combined large deer density to 2.3 (CI = 1.18–3.46) individuals km−2. Reducing muntjac or roe abundance would minimally affect leader damage in this system, but may be important for other tree species. Multi-species deer management requires species-specific understanding of impacts and robust density estimates

Right heart echocardiographic variables and prediction of clinical severity in dogs with pulmonary stenosis

Background: Pulmonary stenosis (PS) usually is evaluated using echocardiography. A multiparametric approach, in addition to the maximum pressure gradient (PG), might be indicated to better characterize PS severity and address its management. Hypothesis/objectives: Our hypothesis was that right heart size and function are associated with echocardiographic and clinical severity of pulmonary stenosis in dogs. Animals: Client-owned dogs with PS. Methods: Prospective, multicenter, observational study. Enrolled dogs underwent complete echocardiographic examination. Associations among right heart echocardiographic variables, PS transvalvular PG >80 mm Hg and presence of clinical signs (exercise intolerance, syncope, right-sided congestive failure, or some combination of these) were assessed using logistic regression analysis. Results: Eighty-eight dogs with PS. Twenty-eight dogs were symptomatic. Increased right ventricular end-diastolic free wall thickness (odds ratio [OR] > 100; 95% confidence interval [95%CI], 50- > 100; P = .01) and decreased aorta-to-pulmonary artery velocity time integral ratio (OR, 80 mm Hg. Decreased tricuspid annular plane systolic excursion (OR, 0.35; 95%CI, 0.15-0.77; P = .01) and increased right ventricular end-diastolic area (OR, 1.4; 95%CI, 1.08-2.02; P = .01) were independently associated with clinical severity. Conclusion and clinical importance: Structural and functional right heart echocardiographic variables are associated with echocardiographic and clinical severity in dogs with PS. A multiparametric approach is advised to better assess PS severity

The sternum reconstruction: Present and future perspectives

Sternectomy is a procedure mainly used for removing tumor masses infiltrating the sternum or treating infections. Moreover, the removal of the sternum involves the additional challenge of performing a functional reconstruction. Fortunately, various approaches have been proposed for improving the operation and outcome of reconstruction, including allograft transplantation, using novel materials, and developing innovative surgical approaches, which promise to enhance the quality of life for the patient. This review will highlight the surgical approaches to sternum reconstruction and the new perspectives in the current literature

Histological evaluation of the distribution of systemic AA-amyloidosis in nine domestic shorthair cats.

Amyloidosis is a group of protein-misfolding disorders characterized by the accumulation of amyloid in organs, both in humans and animals. AA-amyloidosis is considered a reactive type of amyloidosis and in humans is characterized by the deposition of AA-amyloid fibrils in one or more organs. In domestic shorthair cats, AA-amyloidosis was recently reported to be frequent in shelters. To better characterize this pathology, we report the distribution of amyloid deposits and associated histological lesions in the organs of shelter cats with systemic AA-amyloidosis. AA-amyloid deposits were identified with Congo Red staining and immunofluorescence. AA-amyloid deposits were then described and scored, and associated histological lesions were reported. Based on Congo Red staining and immunofluorescence nine shelter cats presented systemic AA-amyloidosis. The kidney (9/9), the spleen (8/8), the adrenal glands (8/8), the small intestine (7/7) and the liver (8/9) were the organs most involved by amyloid deposits, with multifocal to diffuse and from moderate to severe deposits, both in the organ parenchyma and/or in the vascular compartment. The lung (2/9) and the skin (1/8) were the least frequently involved organs and deposits were mainly focal to multifocal, mild, vascular and perivascular. Interestingly, among the organs with fibril deposition, the stomach (7/9), the gallbladder (6/6), the urinary bladder (3/9), and the heart (6/7) were reported for the first time in cats. All eye, brain and skeletal muscle samples had no amyloid deposits. An inflammatory condition was identified in 8/9 cats, with chronic enteritis and chronic nephritis being the most common. Except for secondary cell compression, other lesions were not associated to amyloid deposits. To conclude, this study gives new insights into the distribution of AA-amyloid deposits in cats. A concurrent chronic inflammation was present in almost all cases, possibly suggesting a relationship with AA-amyloidosis

Histological evaluation of the distribution of systemic AA-amyloidosis in nine domestic shorthair cats

Amyloidosis is a group of protein-misfolding disorders characterized by the accumulation of amyloid in organs, both in humans and animals. AA-amyloidosis is considered a reactive type of amyloidosis and in humans is characterized by the deposition of AA-amyloid fibrils in one or more organs. In domestic shorthair cats, AA-amyloidosis was recently reported to be frequent in shelters. To better characterize this pathology, we report the distribution of amyloid deposits and associated histological lesions in the organs of shelter cats with systemic AA-amyloidosis. AA-amyloid deposits were identified with Congo Red staining and immunofluorescence. AA-amyloid deposits were then described and scored, and associated histological lesions were reported. Based on Congo Red staining and immunofluorescence nine shelter cats presented systemic AA-amyloidosis. The kidney (9/9), the spleen (8/8), the adrenal glands (8/8), the small intestine (7/7) and the liver (8/9) were the organs most involved by amyloid deposits, with multifocal to diffuse and from moderate to severe deposits, both in the organ parenchyma and/or in the vascular compartment. The lung (2/9) and the skin (1/8) were the least frequently involved organs and deposits were mainly focal to multifocal, mild, vascular and perivascular. Interestingly, among the organs with fibril deposition, the stomach (7/9), the gallbladder (6/6), the urinary bladder (3/9), and the heart (6/7) were reported for the first time in cats. All eye, brain and skeletal muscle samples had no amyloid deposits. An inflammatory condition was identified in 8/9 cats, with chronic enteritis and chronic nephritis being the most common. Except for secondary cell compression, other lesions were not associated to amyloid deposits. To conclude, this study gives new insights into the distribution of AA-amyloid deposits in cats. A concurrent chronic inflammation was present in almost all cases, possibly suggesting a relationship with AA-amyloidosis

miR-382-5p Controls Hematopoietic Stem Cell Differentiation Through the Downregulation of MXD1

microRNAs are key regulators of gene expression that control stem cell fate by posttranscriptional downregulation of hundreds of target genes through seed pairing in their 3' untranslated region. In fact, miRNAs tightly regulate fundamental stem cell processes, like self-renewal, proliferation, and differentiation; therefore, miRNA deregulation may contribute to the development of solid tumors and hematological malignancies. miR-382-5p has been found to be upregulated in patients with myeloid neoplasms, but its role in normal hematopoiesis is still unknown. In this study, we demonstrated that miR-382-5p overexpression in CD34(+) hematopoietic stem/progenitor cells (HSPCs) leads to a significant decrease of megakaryocyte precursors coupled to increase of granulocyte ones. Furthermore, by means of a computational analysis using different prediction algorithms, we identified several putative mRNA targets of miR-382-5p that are downregulated upon miRNA overexpression (ie, FLI1, GATA2, MAF, MXD1, RUNX1, and SGK1). Among these, we validated MXD1 as real target of miR-382-5p by luciferase reporter assay. Finally, we showed that MXD1 knockdown mimics the effects of miR-382-5p overexpression on granulocyte and megakaryocyte differentiation of CD34(+) cells. Overall, our results demonstrated that miR-382-5p expression favors the expansion of granulocyte lineage and impairs megakaryocyte commitment through MXD1 downregulation. Therefore, our data showed for the first time that the miR-382-5p/MXD1 axis plays a critical role in myelopoiesis by affecting the lineage choice of CD34(+) HSPCs

Human and environmental associates of local species-specific abundance in a multi-species deer assemblage

Understanding how habitat, landscape context, and human disturbance influence local species-specific deer density provides evidence informing strategic management of increasing deer populations. Across an extensive (187 km 2) heterogeneous forest-mosaic landscape in eastern England, spatially explicit density surface models of roe deer Capreolus capreolus and introduced muntjac Muntiacus reevesi were calibrated by thermal imaging distance sampling (recording 1590 and 400 muntjac and roe deer groups, respectively, on 567 km of driven transects). Models related deer density to local habitat composition, recreational intensity, and deer density (roe deer models controlled for muntjac density and vice versa) at a local grain across 1162 composite transect segments, incorporating geographical coordinates accounting for spatial autocorrelation. Abundance of both species was lower in localities with more grasslands (inter-quartile, IQ, effect size: roe −2.9 deer/km 2; muntjac −2.9 deer/km 2). Roe abundance (mean = 7 deer/km 2, SD = 6) was greater in localities with more young stands (IQ effect size, + 1.3 deer/km 2) and lower at localities with more recreationists (−1.1 deer/km 2). Muntjac density (mean = 21 deer/km 2, SD = 10) was greater in localities with more recreationists (+ 2.4 deer/km 2), with more mature (≥ 46 years) stands (+ 1.5 deer/km 2), or calcareous soil (+ 7.1 deer/km 2). Comparison of models incorporating candidate variables and models comprising geographical coordinates only shows candidate variables to be weak predictors of deer densities. Adapting forest management to manipulate habitat and recreational access may influence local deer densities, but only subtly: effect sizes are not sufficient to mitigate deer impacts through planting vulnerable tree crops in areas avoided by deer. Effective culling remains the most viable management option

Co-culture of hematopoietic stem/progenitor cells with human osteblasts favours mono/macrophage differentiation at the expense of the erythroid lineage

Hematopoietic stem cells (HSCs) are located in the bone marrow in a specific microenvironment referred as the hematopoietic stem cell niche, where HSCs interact with a variety of stromal cells. Though several components of the stem cell niche have been identified, the regulatory mechanisms through which such components regulate the stem cell fate are still unknown. In order to address this issue, we investigated how osteoblasts (OBs) can affect the molecular and functional phenotype of Hematopoietic Stem/Progenitor Cells (HSPCs) and vice versa. For this purpose, human CD34+ cells were cultured in direct contact with primary human OBs. Our data showed that CD34+ cells cultured with OBs give rise to higher total cell numbers, produce more CFUs and maintain a higher percentage of CD34+CD38- cells compared to control culture. Moreover, clonogenic assay and long-term culture results showed that co-culture with OBs induces a strong increase in mono/macrophage precursors coupled to a decrease in the erythroid ones. Finally, gene expression profiling (GEP) allowed us to study which signalling pathways were activated in the hematopoietic cell fraction and in the stromal cell compartment after coculture. Such analysis allowed us to identify several cytokine-receptor networks, such as WNT pathway, and transcription factors, as TWIST1 and FOXC1, that could be activated by co-culture with OBs and could be responsible for the biological effects reported above. Altogether our results indicate that OBs are able to affect HPSCs on 2 different levels: on one side, they increase the immature progenitor pool in vitro, on the other side, they favor the expansion of the mono/macrophage precursors at the expense of the erythroid lineage

Do examinations prepare students for higher education? A lesson from the Covid-19 lockdown

The COVID-19 pandemic caused severe disruption to education in the UK in 2020, with most of the school teaching moving online and national school examinations being cancelled. This was particularly disruptive for those taking end of school examinations in preparation for higher education. Biological science courses require students to absorb a lot of new vocabulary and concepts, with examinations traditionally focusing on content recall rather than reasoning. Students who had entered university in September 2019 were compared with those arriving in September 2020 with respect to their knowledge of bioscience vocabulary and understanding of key concepts. Results showed no significant difference between those who had gone through the examination process in 2019 relative to those who had not, in 2020. This suggests the cramming of information for examinations has no detectable effect on the knowledge and understanding of biology that students take with them to university