This paper is motivated by the series of research papers that consider parasitoids’ external input upon the host–parasitoid interactions. We explore a class of host–parasitoid models with variable release and constant release of parasitoids. We assume that the host population has a constant rate of increase, but we do not assume any density dependence regulation other than parasitism acting on the host population. We compare the obtained results for constant stocking with the results for proportional stocking. We observe that under a specific condition, the release of a constant number of parasitoids can eventually drive the host population (pests) to extinction. There is always a boundary equilibrium where the host population extinct occurs, and the parasitoid population is stabilized at the constant stocking level. The constant and variable stocking can decrease the host population level in the unique interior equilibrium point; on the other hand, the parasitoid population level stays constant and does not depend on stocking. We prove the existence of Neimark–Sacker bifurcation and compute the approximation of the closed invariant curve. Then we consider a few host–parasitoid models with proportional and constant stocking, where we choose well-known probability functions of parasitism. By using the software package Mathematica we provide numerical simulations to support our study.
This paper is motivated by the series of research papers that consider parasitoids’ external input upon the host–parasitoid interactions. We explore a class of host–parasitoid models with variable release and constant release of parasitoids. We assume that the host population has a constant rate of increase, but we do not assume any density dependence regulation other than parasitism acting on the host population. We compare the obtained results for constant stocking with the results for proportional stocking. We observe that under a specific condition, the release of a constant number of parasitoids can eventually drive the host population (pests) to extinction. There is always a boundary equilibrium where the host population extinct occurs, and the parasitoid population is stabilized at the constant stocking level. The constant and variable stocking can decrease the host population level in the unique interior equilibrium point; on the other hand, the parasitoid population level stays constant and does not depend on stocking. We prove the existence of Neimark–Sacker bifurcation and compute the approximation of the closed invariant curve. Then we consider a few host–parasitoid models with proportional and constant stocking, where we choose well-known probability functions of parasitism. By using the software package Mathematica we provide numerical simulations to support our study.
During the COVID-19 pandemic, the need to provide high-level care for a large number of patients with COVID-19 has affected resourcing for, and limited the routine care of, all other conditions. The impact of this health emergency is particularly relevant in the rare connective tissue diseases (rCTDs) communities, as discussed in this Perspective article by the multi-stakeholder European Reference Network on Rare and Complex Connective Tissue and Musculoskeletal Diseases (ERN ReCONNET). The clinical, organizational and health economic challenges faced by health-care providers, institutions, patients and their families during the SARS-CoV-2 outbreak have demonstrated the importance of ensuring continuity of care in the management of rCTDs, including adequate diagnostics and monitoring protocols, and highlighted the need for a structured emergency strategy. The vulnerability of patients with rCTDs needs to be taken into account when planning future health policies, in preparation for not only the post-COVID era, but also any possible new health emergencies. In this Perspective article, members of the European Reference Network on Rare and Complex Connective Tissue and Musculoskeletal Diseases discuss clinical and organizational challenges in this community caused by the COVID-19 pandemic and what lessons might be learned for the future.
Background Total hip arthroplasty is the traditional treatment for osteoarthritis in the hip joint. Hip resurfacing arthroplasty, with metal on metal bearing, is a modern concept initially developed mainly for young active people. The metal-on-metal hip arthroplasty implant, Articular Surface Replacement (ASR), was implanted in approximately 93,000 patients before it was recalled in 2010 due to a high complication rate. This study aimed to evaluate patients’ own experiences living with an implant that they knew had a high complication rate and had been recalled from the market. Methods A total of 14 patients, still living with the implant, of a cohort of 34 patients were available for follow-up. Qualitative semi-structured interviews were conducted with 14 patients where a majority actively sought for metal-on-metal hip resurfacing arthroplasty (HRA), and subsequently underwent HRA with an ASR prosthesis between 11/21/2006 and 09/28/2009. The responses were analyzed using content analysis described by Graneheim and Lundman to compress text and identify categories and subcategories. Results The results showed that most patients had already decided that they wanted a metal-on-metal HRA implant before meeting the surgeon. They expressed that the implant made it possible to live an active life. A majority did not think about the fact that they had a hip implant, because they lacked subjective pain. Most of the patients were positive about the annual exams at the hospital and wanted them to continue. None of them felt that their trust towards the healthcare system had changed after the implant recall. They expressed a belief that they would need new surgery sooner than they first thought. Conclusions Despite all the attention when the ASR prosthesis was recalled, patients with ASR-HRA did not report themselves negatively affected by the recall in this group of patients where a majority had actively sought for an HRA procedure. The healthcare system has an obligation to continue the annual exams, even if the implant provider does not continue reimbursement.
Changes in the environment as a result of industrialisation and urbanisation impact negatively on plant growth and crop production. Cadmium (Cd) is one of the most dangerous metals that enters the food chain, with toxic effects on plants and human health. This study evaluated the potential of Silene sendtneri as a novel hyperaccumulator and the role of seed priming in tolerance and accumulation rate of Cd. The effect of different priming agents on germination performance, root growth, seedling development, metal uptake and accumulation, antioxidant defences including enzymatic and non-enzymatic antioxidants has been assessed. Seed priming using silicic acid, proline alone or in combination with salicylic acid- enhanced germination, seedling development, and root growth under Cd stress. The same priming treatments induced an increase of water content in shoots and roots when plants were exposed to Cd. The enzymatic antioxidant response was specific for the priming agent used. An increase in ferulic acid and rutin in shoots was related to the increase of Cd concentration in the medium. The concentration of malic and oxalic acid increased significantly in shoots of plants grown on high Cd concentrations compared to low Cd concentrations. Silene sendtneri can accumulate significant levels of Cd with enhanced accumulation rate and tolerance when seeds are primed. The best results are obtained by seed priming using 1% silicic acid, proline and salicylic acid.
During global pandemics, such as coronavirus disease 2019 (COVID-19), crisis communication is indispensable in dispelling fears, uncertainty, and unifying individuals worldwide in a collective fight against health threats. Inadequate crisis communication can bring dire personal and economic consequences. Mounting research shows that seemingly endless newsfeeds related to COVID-19 infection and death rates could considerably increase the risk of mental health problems. Unfortunately, media reports that include infodemics regarding the influence of COVID-19 on mental health may be a source of the adverse psychological effects on individuals. Owing partially to insufficient crisis communication practices, media and news organizations across the globe have played minimal roles in battling COVID-19 infodemics. Common refrains include raging QAnon conspiracies, a false and misleading “Chinese virus” narrative, and the use of disinfectants to “cure” COVID-19. With the potential to deteriorate mental health, infodemics fueled by a kaleidoscopic range of misinformation can be dangerous. Unfortunately, there is a shortage of research on how to improve crisis communication across media and news organization channels. This paper identifies ways that legacy media reports on COVID-19 and how social media-based infodemics can result in mental health concerns. This paper discusses possible crisis communication solutions that media and news organizations can adopt to mitigate the negative influences of COVID-19 related news on mental health. Emphasizing the need for global media entities to forge a fact-based, person-centered, and collaborative response to COVID-19 reporting, this paper encourages media resources to focus on the core issue of how to slow or stop COVID-19 transmission effectively.
Objective: to evaluate the lifestyle of university students of the Nutrition course. Methodology: This is a quantitative research, with a cross-sectional and descriptive approach carried out with 108 students enrolled and frequent in the Nutrition course of two private colleges, in the city of Montes Claros, Minas Gerais. For the data collection, the validated questionnaire was used. The study was approved by the Ethics and Research Committee of SOEBRAS. Results: the majority of university students (44%) have a good lifestyle. By associating the "good", "very good" and "excellent" classifications, 92 university students (85%) achieved a satisfactory lifestyle, 16 of them (15%) obtained a regular classification and none of the evaluated ones scored below 35 points, Measure that indicates need for improvement. Conclusion: academics have an adequate lifestyle. However, lifestyle indicators point to the need for improvements in aspects related mainly to the nutrition, introspection and physical activity component.
Objetivo: Realizar um levantamento bibliografico e relatorios do aumento de casos de Febre Amarela, Chickungunya, Dengue e Zika apos o rompimento das barragens de Mariana e Brumadinho (Minas Gerais). Metodologia: Foi feito um estudo bibliografico, epidemiologico com artigos, reportagens e busca em plataformas academicas e de boletins do Ministerio da Saude com o intuito de associar o aumento dos casos conforme sua localizacao de acordo com o periodo apos o rompimento. Resultados: Houve um aumento evidente nos casos de arboviroses logo apos o rompimento das barragens em areas afetadas com o impacto e proximidades. Isso pode ser resultado da movimentacao de pessoas e animais apos as tragedias, pois com a degradacao da area, pessoas foram afetadas de maneira direta e indireta, as que foram afetadas de maneira direta tiveram suas casas destruidas pela lama e as que foram afetadas de maneira indireta podem ter saido da cidade em busca de alternativas de melhora. Tambem ha uma alteracao na cadeia alimentar local, algumas populacoes elevam e outras diminuem, as populacoes de mosquitos elevam e migram para outras areas mais populosas em busca de alimento, assim sendo um fator da disseminacao de doencas. Conclusao: Observou-se ne que no periodo de 2015 a 2016 os casos de CHIKV foram os que mais cresceram no Brasil, tendo um aumento de quase 10x, de Febre Amarela e Dengue tendo um aumento de mais ou menos 3x. Os casos de Zika comecam a ser notificados em 2015, portanto nao e possivel determinar se houve um aumento significativo.
A review was conducted using PubMed/MEDLINE (published articles) as well as World Wide Web (video material) to determine the frequency of anterior and posterior presentation of the elephant at birth. Of 46 identified cases, 12 were in anterior and 34 in posterior presentation. The Fisher exact test (p=0.682) did not show a statistically significant difference in the distribution of presentations between the Loxodonta africana (2 anterior and 10 posterior presentation) and Elephas maximus (10 anterior and 24 posterior presentation). The ratio between anterior and posterior presentation 6:29 (18.51% versus 81.49%) at birth without knowing dystocia, is significantly different from the distribution anterior and posterior presentation 6:3 (66.7% versus 33.3%) in cases with dystocia (Fisher exact test p = 0.012). Obtained data shows that posterior presentation at birth in elephants is more often present than anterior, while anterior presentation is more often associated with dystocia.
The Vostok ice core data cover 420,000 years indicating the natural regularity of Earth's surface temperature and climate. Here, we consider four major cycles of similar duration, ranging from 86,000 to 128,000 years, comprising 15% of periods for the warming interglacials compared to some 85% of cooling periods. Globally, we are near the peak of a rapid warming period. We perform a detailed frequency analysis of temperature and CO2 cycles, as a primary stage in building a logical Climate Prediction Engine (CPE), illustrated with specific harmonics. This analysis can be repeated for all harmonics and various cycle combinations. Our time correlation estimates the CO2 time lag for temperature at 400-2300 years, depending on the cycle, longer on average than previously concluded. We also perform Fast-Fourier transform analysis, identifying a full harmonic spectrum for each cycle, plus an energy analysis to identify each harmonic amplitude - to achieve further prediction analysis using a Kalman filter harmonic bank. For Vostok data we can use combinations of different cycles compared to the most recent for learning and then the current ongoing cycle for testing. Assuming causal time regularity, more cycles can be employed in training, hence reducing the prediction error for the next cycle. This results in prediction of climate data with both naturally occurring as well as human forced CO2 values. We perform this detailed time and frequency analysis as a basis for improving the quality of our climate prediction methodologies, with particular attention to testing alternative hypotheses of the possible causes of climate change. These include the effect on albedo of suspended dust and increasing water vapor with temperature in initiating interglacial warming, the effect of temperature and pH values of surface water on ambient level of CO2 in the atmosphere and finding a larger latent heat capacity in the atmosphere required to sustain its circulatory motions, leading to friction and turbulent release of heat in boundary layer. All these potentials can be examined in an effective CPE.
Background: Premature ovarian failure (POF) can be found in 1% of women at the age of 35-40, mostly due to unknown causes. PI3K-Akt signaling is associated with both ovarian function and growth of primordial follicles. In this study, we examined the effects of autologous in vitro ovarian activation with stem cells and autologous growth factors on reproductive and endocrine function in patients with ovarian impairment. Materials and Methods: The longitudinal prospective observational study included 50 patients (between 30 and 50 years) with a diagnosis of POF and infertility. This multicenter study was performed at Jevremova Special Hospital in Belgrade, Saint James Hospital (Malta), and Remedica Skoplje Hospital, between 2015 and 2018. All patients went through numerous laboratory testings, including hormonal status. The autologous bone marrow mesenchymal stem cells (BMSCs) and growth factors were used in combination for activation of ovarian tissue before its re-transplantation. The software package SPSS 20.0 was used for statistical analysis of the results. Results: Differences in follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and progesterone (PG) hormone concentrations before and after 3, 6, and 12 months post-transplantation were tested in correlation with the volume of transplanted ovarian tissue. A significant correlation (P=0.029) was found between the change in E2 level after 3 months and the volume of re-transplanted tissues. Also after re-transplantation, 64% of the patients had follicles resulting in aspiration of oocytes in 25% of positive women with follicles. Conclusion: The SEGOVA method could potentially solve many human reproductive problems in the future due to the large number of patients diagnosed with POF, as well as the possibility of delaying menopause, thus improving the quality of life and general health (Registration number: NCT04009473).
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