562 research outputs found
Evaluation of bone excision on occipital area of simulated human skull
Surgical effects of bone and soft tissue tumours,
whether for biopsy or full excision have been
researched from as early as the 1970’s [1]. These
researches though have as main focus the biological
(histological) rather the mechanical aspects of the
effects [2]. With technological advances in biomedical
and biomechanical modelling, a plethora of researchers
have been exploring the possibilities of understanding
[3] or even predicting musculoskeletal behaviour under
different loading conditions [4]. This research is
seeking to bridge these two different facets by looking
into the mechanical effects bone tumour surgery might
have to the structural rigidity of a simulated human
skull
Comparison of Two Detailed Models of Aedes aegypti Population Dynamics
The success of control programs for mosquito-borne diseases can be enhanced by crucial information provided by models of the mosquito populations. Models, however, can differ in their structure, complexity, and biological assumptions, and these differences impact their predictions. Unfortunately, it is typically difficult to determine why two complex models make different predictions because we lack structured side-by-side comparisons of models using comparable parameterization. Here, we present a detailed comparison of two complex, spatially explicit, stochastic models of the population dynamics of Aedes aegypti, the main vector of dengue, yellow fever, chikungunya, and Zika viruses. Both models describe the mosquito?s biological and ecological characteristics, but differ in complexity and specific assumptions. We compare the predictions of these models in two selected climatic settings: a tropical and weakly seasonal climate in Iquitos, Peru, and a temperate and strongly seasonal climate in Buenos Aires, Argentina. Both models were calibrated to operate at identical average densities in unperturbedconditions in both settings, by adjusting parameters regulating densities in each model (number of larval development sites and amount of nutritional resources). We show that the models differ in their sensitivityto environmental conditions (temperature and rainfall) and trace differences to specific model assumptions.Temporal dynamics of the Ae. aegypti populations predicted by the two models differ more markedly under strongly seasonal Buenos Aires conditions. We use both models to simulate killing of larvae and/or adults with insecticides in selected areas. We show that predictions of population recovery by the models differ substantially, an effect likely related to model assumptions regarding larval development and (director delayed) density dependence. Our methodical comparison provides important guidance for model improvement by identifying key areas of Ae. aegypti ecology that substantially affect model predictions, and revealing the impact of model assumptions on population dynamics predictions in unperturbed and perturbed conditions.Fil: Legros, Mathieu. University of North Carolina; Estados UnidosFil: Otero, Marcelo Javier. Universidad de Buenos Aires; ArgentinaFil: Romeo Aznar, Victoria Teresa. Universidad de Buenos Aires; ArgentinaFil: Solari, Hernan Gustavo. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Gould, Fred. National Institutes of Health; Estados UnidosFil: Lloyd, Alun L.. National Institutes of Health; Estados Unido
Evaluation of Activated Carbon from Fluted Pumpkin Stem Waste for Phenol and Chlorophenol Adsorption in a Fixed \u2013Bed Micro-Column
Fluted pumpkin stem waste, which is both a waste and pollutant, was
chemically modified with ortho-phosphoric acid and used to adsorb
phenol and chlorophenol in fixed bed micro column It was found that the
carbon bed sorption capacity for phenol and chlorophenol (77.20 and
80.0 mg/g) were higher than the equilibrium sorption studies. The
critical bed depth increased with increasing phenol and chlorophenol
concentrations. An increase in phenol and chlorophenol concentration
from 100 to 200mg/l increased the rate constant, critical bed depth
(Do) and bed sorption capacity, for phenol 77.20 to 160.00mg/g and
chlorophenol 80.00 to 173.20mg/g. The breakthrough time, exhaustion
time, uptake capacity decreased as the flow rate increased.
Chlorophenol and phenol uptake capacity increased with increase in bed
height. Experimental data for the change in concentration were
correlated using the bed depth service time (BDST) model. In all
parameters determined chlorophenol had better adsorption than phenol.
Fluted pumpkin is the largest consumed vegetable in the West African
sub region and therefore, creates one of the major agro waste problems
in Nigeria. Preliminary investigations showed that several tons of
these waste are produced daily in market places around the country but
scarcely useful and therefore create environmental nuisance. The
results obtained could be useful for the application of agricultural
wastes for phenol and chlorophenol removal from industrial wastewate
Facile technique for the removal of metal contamination from graphene
Metal contamination deposited on few-layer graphene (3 ± 1 monolayers) grown on SiC(0001) was successfully removed from the surface, using low cost adhesive tape. More than 99% of deposited silver contamination was removed from the surface via peeling, causing minimal damage to the graphene. A small change in the adhesion of graphene to the SiC(0001) substrate was indicated by changes observed in pleat defects on the surface; however, atomic resolution images show the graphene lattice remains pristine. Thin layers of contamination deposited via an electron gun during Auger electron spectroscopy/low energy electron diffraction measurements were also found to be removable by this technique. This contamination showed similarities to “roughened” graphene previously reported in the literature
Neurosurgical team acceptability of brain-computer interfaces: a two-stage international cross-sectional survey
OBJECTIVE:
Invasive brain-computer interfaces (BCIs) require neurosurgical implantation, which confers a range of risks. Despite this, no studies have assessed the acceptability of invasive BCIs amongst the neurosurgical team. This study aims to establish baseline knowledge of BCIs within the neurosurgical team and identify attitudes towards different applications of invasive BCI.
METHOD:
A two-stage cross-sectional international survey of the neurosurgical team (neurosurgeons, anaesthetists, and operating room nurses) was conducted. Results from the first, qualitative, survey were used to guide the second stage quantitative survey, which assessed acceptability of invasive BCI applications. 5-part Likert Scales were used to collect quantitative data. Surveys were distributed internationally via social media and collaborators.
RESULTS:
108 qualitative responses were collected. Themes included the promise of BCIs positively impacting disease targets, concerns regarding stability, and an overall positive emotional reaction to BCI technology. The quantitative survey generated 538 responses from 32 countries. Baseline knowledge of BCI technology was poor, with 9% claiming to have a ‘good’ or ‘expert’ knowledge of BCIs. Acceptability of invasive BCI for rehabilitative purposes was >80%. Invasive BCI for augmentation in healthy populations divided opinion.
CONCLUSION:
The neurosurgical team’s view of the acceptability of BCI was divided across a range of indications. Some applications (for example stroke rehabilitation) were viewed as more appropriate than other applications (such as augmentation for military use). This range in views highlights the need for stakeholder consultation on acceptable use cases along with regulation and guidance to govern initial BCI implantations if patients are to realise the potential benefits
Fungi in a Warmer World: Fungal Diversity in the Tropical Miocene Climate Optimum of the Clarkia Region of Idaho, USA
A knowledge gap associated with how fungal communities change in response to climate was identified in the 2018 State of the World Fungi report (Willis, 2018). While it is virtually impossible to test in the present, fungal assemblage changes can be studied in sediments from a warmer-than-present period such as the Miocene Climate Optimum (MCO) (Romero et al. 2021; O’Keefe 2017). The Fungi in a Warmer World project aims to generate and analyze a global-scale data set of fungal biodiversity, ecology, and associated flora from MCO sediments. This dataset will be used to model past fungal assemblage changes across the MCO and forecast future changes in line with IPCC RCP 4.5-8.5 warming.https://scholarworks.moreheadstate.edu/celebration_posters_2022/1003/thumbnail.jp
The effect of Food Assistance on Adherence to Antiretroviral Therapy among HIV/AIDS Patients in Sofala Province, in Mozambique: A Retrospective Study
Contains fulltext :
117779.pdf (publisher's version ) (Open Access
Troponin elevation pattern and subsequent cardiac and non-cardiac outcomes: Implementing the Fourth Universal Definition of Myocardial Infarction and high-sensitivity troponin at a population level
Background: The Fourth Universal Definition of Myocardial Infarction (MI) differentiates MI from myocardial injury. We characterised the temporal course of cardiac and non-cardiac outcomes associated with MI, acute and chronic myocardial injury. Methods: We included all patients presenting to public emergency departments in South Australia between June 2011–Sept 2019. Episodes of care (EOCs) were classified into 5 groups based on high-sensitivity troponin-T (hs-cTnT) and diagnostic codes: 1) Acute MI [rise/fall in hs-cTnT and primary diagnosis of acute coronary syndrome], 2) Acute myocardial injury with coronary artery disease (CAD) [rise/fall in hs-cTnT and diagnosis of CAD], 3) Acute myocardial injury without CAD [rise/fall in hs-cTnT without diagnosis of CAD], 4) Chronic myocardial injury [elevated hs-cTnT without rise/fall], and 5) No myocardial injury. Multivariable flexible parametric models were used to characterize the temporal hazard of death, MI, heart failure (HF), and ventricular arrhythmia. Results: 372,310 EOCs (218,878 individuals) were included: acute MI (19,052 [5.12%]), acute myocardial injury with CAD (6,928 [1.86%]), acute myocardial injury without CAD (32,231 [8.66%]), chronic myocardial injury (55,056 [14.79%]), and no myocardial injury (259,043 [69.58%]). We observed an early hazard of MI and HF after acute MI and acute myocardial injury with CAD. In contrast, subsequent MI risk was lower and more constant in patients with acute injury without CAD or chronic injury. All patterns of myocardial injury were associated with significantly higher risk of all-cause mortality and ventricular arrhythmia. Conclusions: Different patterns of myocardial injury were associated with divergent profiles of subsequent cardiac and non-cardiac risk. The therapeutic approach and modifiability of such excess risks require further research
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