OPTIMAL HARVESTING OF MOOSE IN ALBERTA

We developed a stage/sex matrix model for quota-harvest management of moose (Al­ces alces) populations in Alberta, and believe that the model structure has general applicability for harvesting of large mammal populations. The model includes density dependence in stage/sex-based vital rates and allows for estimation of carrying capacity and herd composition at carrying capacity from limited population survey data and harvest data. The model allows a biologist to evaluate optimal harvest strategies with the aim to optimize either the yield of the number of bulls harvested (goal B) or the yield of the total number of moose harvested (goal TY). The model predicted that to optimize yield of bulls, hunting of calves should be avoided because male calves recruit into the bull population the following year. If optimizing total yield, calves should be subject to intense harvest; harvesting for calves was predicted to be more intense than for bulls if female harvesting was not allowed, other­wise less intense. Bull harvest was less intense when trying to optimize yield of bulls than optimiz­ing total yield. Small quotas of females could increase optimal yield substantially. The model also predicted that predation on calves and females reduced long-term optimal harvest intensity and calf predation reduced optimal total yield more than it influenced the optimal harvest of bulls. Reductions in moose abundance caused by predation and stochastic weather events can potentially cause severe consequences to harvest policy, challenging wildlife managers who must balance moose conservation, predator control, and hunter harvests. We believe that our model can facilitate harvest management, but vigilant monitoring of herd population size and composition will be necessary to ensure balance between predation and hunter harvests

C/EBPα is an essential collaborator in Hoxa9/Meis1-mediated leukemogenesis

Homeobox A9 (HOXA9) is a homeodomain-containing transcription factor that plays a key role in hematopoietic stem cell expansion and is commonly deregulated in human acute leukemias. A variety of upstream genetic alterations in acute myeloid leukemia (AML) lead to overexpression of HOXA9, almost always in association with overexpression of its cofactor meis homeobox 1 (MEIS1) . A wide range of data suggests that HOXA9 and MEIS1 play a synergistic causative role in AML, although the molecular mechanisms leading to transformation by HOXA9 and MEIS1 remain elusive. In this study, we identify CCAAT/enhancer binding protein alpha (C/EBPα) as a critical collaborator required for Hoxa9/Meis1-mediated leukemogenesis. We show that C/EBPα is required for the proliferation of Hoxa9/Meis1-transformed cells in culture and that loss of C/EBPα greatly improves survival in both primary and secondary murine models of Hoxa9/Meis1-induced leukemia. Over 50% of Hoxa9 genome-wide binding sites are cobound by C/EBPα, which coregulates a number of downstream target genes involved in the regulation of cell proliferation and differentiation. Finally, we show that Hoxa9 represses the locus of the cyclin-dependent kinase inhibitors Cdkn2a/b in concert with C/EBPα to overcome a block in G1 cell cycle progression. Together, our results suggest a previously unidentified role for C/EBPα in maintaining the proliferation required for Hoxa9/Meis1-mediated leukemogenesis

INCREASE IN CANDIDA PARAPSILOSIS CANDIDEMIA IN CANCER PATIENTS

Background: This study aimed to identify the risk factors of candidemia and asses possible clinically significant differences between Candida parapsilosis and other candida species among cancer patients. Methods: A retrospective study was conducted in a Chinese tertiary cancer center over a 6-year period. A total of 323 cancer patients were enrolled and analyzed from 2012 to 2018. Data about demographic characteristics, underlying diseases, and risk factors of candidemia were collected. Univariate and multivariate logistic regression models were used to identify the risk factors associated with the development of candidemia. Results: Among the isolates, the species most frequently isolated was C. parapsilosis (37.15%, 120/323), and C. albicans only accounted for 34.37%. Based on statistical analysis, when candidemia patients who had C. parapsilosis were compared with other Candida spp., the following factors were found to be significantly associated with C. parapsilosis fungemia: parenteral nutrition (p < 0.001), neutropenia (p < 0.001), receipt of chemotherapy (p = 0.002), and previous antifungal use (p < 0.001). Parenteral nutrition was a factor that independently predicted C. parapsilosis candidemia (OR, 0.183; 95% CI, 0.098–0.340; p < 0.001). Conclusions: In short, C. parapsilosis as the leading non-albicans Candida spp. isolates in candidemia is posing a major threat for cancer patients. The study highlights the urgent need to evaluate the possibility of development of C. parapsilosis candidemia in cancer patients exposed to these risk factors effective and prevention strategies against this causative agent transmitted through nosocomial route should be implemented

Long-Term Continental Changes in Wing Length, but Not Bill Length, of a Long-Distance Migratory Shorebird

We compiled a &gt;50‐year record of morphometrics for semipalmated sandpipers (Calidris pusilla), a shorebird species with a Nearctic breeding distribution and intercontinental migration to South America. Our data included &gt;57,000 individuals captured 1972–2015 at five breeding locations and three major stopover sites, plus 139 museum specimens collected in earlier decades. Wing length increased by ca. 1.5 mm (&gt;1%) prior to 1980, followed by a decrease of 3.85 mm (nearly 4%) over the subsequent 35 years. This can account for previously reported changes in metrics at a migratory stopover site from 1985 to 2006. Wing length decreased at a rate of 1,098 darwins, or 0.176 haldanes, within the ranges of other field studies of phenotypic change. Bill length, in contrast, showed no consistent change over the full period of our study. Decreased body size as a universal response of animal populations to climate warming, and several other potential mechanisms, are unable to account for the increasing and decreasing wing length pattern observed. We propose that the post‐WWII near‐extirpation of falcon populations and their post‐1973 recovery driven by the widespread use and subsequent limitation on DDT in North America selected initially for greater flight efficiency and latterly for greater agility. This predation danger hypothesis accounts for many features of the morphometric data and deserves further investigation in this and other species

Distamycin A Inhibits HMGA1-Binding to the P-Selectin Promoter and Attenuates Lung and Liver Inflammation during Murine Endotoxemia

Background: The architectural transcription factor High Mobility Group-A1 (HMGA1) binds to the minor groove of AT-rich DNA and forms transcription factor complexes (“enhanceosomes”) that upregulate expression of select genes within the inflammatory cascade during critical illness syndromes such as acute lung injury (ALI). AT-rich regions of DNA surround transcription factor binding sites in genes critical for the inflammatory response. Minor groove binding drugs (MGBs), such as Distamycin A (Dist A), interfere with AT-rich region DNA binding in a sequence and conformation-specific manner, and HMGA1 is one of the few transcription factors whose binding is inhibited by MGBs. Objectives: To determine whether MGBs exert beneficial effects during endotoxemia through attenuating tissue inflammation via interfering with HMGA1-DNA binding and modulating expression of adhesion molecules. Methodology/Principal Findings: Administration of Dist A significantly decreased lung and liver inflammation during murine endotoxemia. In intravital microscopy studies, Dist A attenuated neutrophil-endothelial interactions in vivo following an inflammatory stimulus. Endotoxin induction of P-selectin expression in lung and liver tissue and promoter activity in endothelial cells was significantly reduced by Dist A, while E-selectin induction was not significantly affected. Moreover, Dist A disrupted formation of an inducible complex containing NF-κB that binds an AT-rich region of the P-selectin promoter. Transfection studies demonstrated a critical role for HMGA1 in facilitating cytokine and NF-κB induction of P-selectin promoter activity, and Dist A inhibited binding of HMGA1 to this AT-rich region of the P-selectin promoter in vivo. Conclusions/Significance: We describe a novel targeted approach in modulating lung and liver inflammation in vivo during murine endotoxemia through decreasing binding of HMGA1 to a distinct AT-rich region of the P-selectin promoter. These studies highlight the ability of MGBs to function as molecular tools for dissecting transcriptional mechanisms in vivo and suggest alternative treatment approaches for critical illness

Harvesting in seasonal environments

Most harvest theory is based on an assumption of a constant or stochastic environment, yet most populations experience some form of environmental seasonality. Assuming that a population follows logistic growth we investigate harvesting in seasonal environments, focusing on maximum annual yield (M.A.Y.) and population persistence under five commonly used harvest strategies. We show that the optimal strategy depends dramatically on the intrinsic growth rate of population and the magnitude of seasonality. The ordered effectiveness of these alternative harvest strategies is given for different combinations of intrinsic growth rate and seasonality. Also, for piecewise continuous-time harvest strategies (i.e., open / closed harvest, and pulse harvest) harvest timing is of crucial importance to annual yield. Optimal timing for harvests coincides with maximal rate of decline in the seasonally fluctuating carrying capacity. For large intrinsic growth rate and small environmental variability several strategies (i.e., constant exploitation rate, linear exploitation rate, and time-dependent harvest) are so effective that M.A.Y. is very close to maximum sustainable yield (M.S.Y.). M.A.Y. of pulse harvest can be even larger than M.S.Y. because in seasonal environments population size varies substantially during the course of the year and how it varies relative to the carrying capacity is what determines the value relative to optimal harvest rate. However, for populations with small intrinsic growth rate but subject to large seasonality none of these strategies is particularly effective with M.A.Y. much lower than M.S.Y. Finding an optimal harvest strategy for this case and to explore harvesting in populations that follow other growth models (e.g., involving predation or age structure) will be an interesting but challenging problem

Forecasting spatially structured populations: the role of dispersal and scale

We forecasted spatially structured population models with complex dynamics. focusing on the effect of dispersal and spatial scale on the predictive capability of nonlinear forecasting (NLF). Dispersal influences NLF ability by its influence on population dynamics. For simple 2-cell models, when dispersal is small, our ability to predict abundance in subpopulations decreased and then increased with increasing dispersal. Spatial heterogeneity, dispersal manner. and environmental noise did not qualitatively change this result. But results are not clear for complex spatial configurations because of complicated dispersal interactions across subpopulations. Populations undergoing periodic fluctuations could be forecasted perfectly for all deterministic cases that we studied, but less reliably when environmental noise was incorporated. More importantly, for all models that we have examined, NLF was much worse at larger spatial scales as a consequence of the asynchronous dynamics of subpopulations when the dispersal rate was below some critical value. The only difference among models was the critical value of dispersal rate. which varied with growth rate, carrying capacity, mode of dispersal, and spatial configuration. These results were robust even when environmental noise was incorporated. Intermittency, common in the dynamics of spatially structured populations, lowered the predictive capability of NLF. Forecasting population behaviour is of obvious value in resource exploitation and conservation. We suggest: that forecasting at local scales holds promise, whereas forecasting abundance at regional scales may yield poor results. Improved understanding of dispersal can enhance the management and conservation of natural resources. and may help is to understand resource-exploitation strategies employed by local indigenous humans

Forecasting spatially structured populations: the role of dispersal and scale

We forecasted spatially structured population models with complex dynamics, focusing on the effect of dispersal and spatial scale on the predictive capability of nonlinear forecasting (NLF). Dispersal influences NLF ability by its influence on population dynamics. For simple 2-cell models, when dispersal is small, our ability to predict abundance in subpopulations decreased and then increased with increasing dispersal. Spatial heterogeneity, dispersal manner, and environmental noise did not qualitatively change this result. But results are not clear for complex spatial configurations because of complicated dispersal interactions across subpopulations. Populations undergoing periodic fluctuations could be forecasted perfectly for all deterministic cases that we studied, but less reliably when environmental noise was incorporated. More importantly, for all models that we have examined, NLF was much worse at larger spatial scales as a consequence of the asynchronous dynamics of subpopulations when the dispersal rate was below some critical value. The only difference among models was the critical value of dispersal rate, which varied with growth rate, carrying capacity, mode of dispersal, and spatial configuration. These results were robust even when environmental noise was incorporated. Intermittency, common in the dynamics of spatially structured populations, lowered the predictive capability of NLF. Forecasting population behaviour is of obvious value in resource exploitation and conservation. We suggest that forecasting at local scales holds promise, whereas forecasting abundance at regional scales may yield poor results. Improved understanding of dispersal can enhance the management and conservation of natural resources, and may help us to understand resource-exploitation strategies employed by local indigenous humans

Forecasting spatially structured populations: the role of dispersal and scale

We forecasted spatially structured population models with complex dynamics. focusing on the effect of dispersal and spatial scale on the predictive capability of nonlinear forecasting (NLF). Dispersal influences NLF ability by its influence on population dynamics. For simple 2-cell models, when dispersal is small, our ability to predict abundance in subpopulations decreased and then increased with increasing dispersal. Spatial heterogeneity, dispersal manner. and environmental noise did not qualitatively change this result. But results are not clear for complex spatial configurations because of complicated dispersal interactions across subpopulations. Populations undergoing periodic fluctuations could be forecasted perfectly for all deterministic cases that we studied, but less reliably when environmental noise was incorporated. More importantly, for all models that we have examined, NLF was much worse at larger spatial scales as a consequence of the asynchronous dynamics of subpopulations when the dispersal rate was below some critical value. The only difference among models was the critical value of dispersal rate. which varied with growth rate, carrying capacity, mode of dispersal, and spatial configuration. These results were robust even when environmental noise was incorporated. Intermittency, common in the dynamics of spatially structured populations, lowered the predictive capability of NLF. Forecasting population behaviour is of obvious value in resource exploitation and conservation. We suggest: that forecasting at local scales holds promise, whereas forecasting abundance at regional scales may yield poor results. Improved understanding of dispersal can enhance the management and conservation of natural resources. and may help is to understand resource-exploitation strategies employed by local indigenous humans

Factors affecting the primary patency of native arteriovenous fistulas after ultrasound-guided percutaneous transluminal angioplasty

AbstractObjective By analyzing the clinical history, laboratory test indexes, and intraoperative ultrasound imaging data of patients receiving ultrasound-guided percutaneous transluminal angioplasty (UG-PTA) for the first time, the application value of UG-PTA in the treatment of peripheral stenosis of autogenous arteriovenous fistula (AVF) and the related factors affecting postoperative patency were investigated.Methods A total of 381 patients with dysfunction of radio-cephalic AVF were treated with UG-PTA from June 2017 to September 2019. According to the inclusion and exclusion criteria, 199 patients were included in this study. Baseline characteristics of patients, including demographic, clinical, and laboratory data, were collected. Kaplan–Meier’s survival curve was used to demonstrate the cumulative primary patency rate of UG-PTA. Univariate and multivariate Cox regression analysis was performed on clinical, anatomic, biochemical, and medication variables to identify the predictors of postintervention primary patency.Results The early technical success rate of UG-PTA was 98.4% (375/381). One hundred and ninety-nine patients, with an average age of 52.9 years, were analyzed, 97 of whom were males (48.7%). The median follow-up duration was 21 months. No major complication was observed. Postintervention primary patency rates were 87.7%, 75.8%, and 60.0% at 6, 12, and 24 months, respectively. A previously failed AVF (HR, 1.935, 95% CI 1.071–3.494; p = .029) and an increased level of parathyroid hormone (HR per 100 pg/mL increase, 1.105; 95% CI 1.014–1.203; p = .004) were identified as independent negative predictors of primary patency of UG-PTA.Conclusions UG-PTA is a safe and effective method for the treatment of peripheral stenosis of AVF. Previously failed AVF and elevated parathyroid hormone levels are associated with lower primary patency rate