820 research outputs found
Preschool children’s biophilia and attitudes toward nature: The effect of personal experiences
Regular engagement outside may promote healthy physical and psychological development as well as a respect and appreciation for nature. This exploratory study compared biophilia and attitudes toward nature between young children living in an urban area to those in a rural area. Urban and rural areas may offer different opportunities for exposure and engagement with elements such as water, plants, and animals. A comparison between young children in these settings may determine if experience in these different environments affects their attitudes and biophilia. Thirty-six children (urban n = 27; rural n = 9) participated in one-on-one structured interviews about their attitudes toward and being in nature. Results revealed no significant difference in biophilia between children by geographical area. Common themes in children’s attitudes emerged: 1) young children define nature by identifying specific elements; 2) young children are aware that their actions have consequences for the condition of the natural environment; and 3) children understood that the expectations guiding behavior in the natural environment apply to everyone. Preschool children’s level of cognitive maturity and individual preferences may be better predictors of biophilia and attitude than location alone. Authors suggest implications for teachers and parents
Light Ions Response of Silicon Carbide Detectors
Silicon carbide (SiC) Schottky diodes 21 mum thick with small surfaces and
high N-dopant concentration have been used to detect alpha particles and low
energy light ions. In particular 12C and 16O beams at incident energies between
5 and 18 MeV were used. The diode active-region depletion-thickness, the
linearity of the response, energy resolution and signal rise-time were measured
for different values of the applied reverse bias. Moreover the radiation damage
on SiC diodes irradiated with 53 MeV 16O beam has been explored. The data show
that SiC material is radiation harder than silicon but at least one order of
magnitude less hard than epitaxial silicon diodes. An inversion in the signal
was found at a fluence of 10^15 ions/cm^2.Comment: 20 pages, 16 figures, submitted for publication to Nuclear
Instruments and Methods in Physics Research
Preschool children’s biophilia and attitudes toward nature: The effect of personal experiences
Regular engagement outside may promote healthy physical and psychological development as well as a respect and appreciation for nature. This exploratory study compared biophilia and attitudes toward nature between young children living in an urban area to those in a rural area. Urban and rural areas may offer different opportunities for exposure and engagement with elements such as water, plants, and animals. A comparison between young children in these settings may determine if experience in these different environments affects their attitudes and biophilia. Thirty-six children (urban n = 27; rural n = 9) participated in one-on-one structured interviews about their attitudes toward and being in nature. Results revealed no significant difference in biophilia between children by geographical area. Common themes in children’s attitudes emerged: 1) young children define nature by identifying specific elements; 2) young children are aware that their actions have consequences for the condition of the natural environment; and 3) children understood that the expectations guiding behavior in the natural environment apply to everyone. Preschool children’s level of cognitive maturity and individual preferences may be better predictors of biophilia and attitude than location alone. Authors suggest implications for teachers and parents
Preparing students for university studies and beyond: a micro-credential trial that delivers academic integrity awareness
Micro-credentials are making an impact on the university course curriculums. Industry partners have increasingly indicated that students exit university with inadequate 'soft skills' such as team work, leadership and digital literacy skills. Micro-credentials are now being viewed favourably as a platform to address this deficit in workplace skills. Universities are now expending considerable time identifying industry skill gaps to provide students with the attributes that will serve for a successful transition to the world of work. This article addresses the development of an academic integrity awareness micro-credential for new student entrants to university. The trial of this micro-credential provides students with foundational skills in understanding the academic world, subsequently providing the advantage required for a successful transition to industry
Piston-ring film thickness: theory and experiment compared
A review of the published literature has demonstrated a large variability and discrepancies in the measured and predicted values of piston-ring lubricating film thickness in internal combustion engines. Only 2 papers have been found that compare experiments in firing engines directly with outputs from sophisticated ring-pack lubrication models. The agreement between theory and experiment in these comparisons was limited, possibly because of inadequacies in the models and/ or inaccuracies of measurement. This paper seeks to contribute to the literature by comparing accurately calibrated experimental measurements of piston-ring film thickness in a firing engine with predictions from an advanced, commercial software package alongside details of the systematic analysis of the measurement errors in this process. Suggestions on how measurement accuracy could be further improved are also given. Measurements of oil film thickness with an error (standard deviation) of +/-15% have been achieved. It is shown that this error can be reduced further, by changes in the design and installation of the sensors.
Detailed experimental measurements of film thickness under the top compression ring in a firing petrol engine have been made and compared with the predictions from a commercial, state-of-the art modelling package. The agreement between theory and experiment is excellent throughout the stroke in most cases, but some significant differences are observed at the lower load conditions. These differences are as yet unexplained, but may be due to the sensor topography influencing the hydrodynamic lubrication, lubricant availability, out-of-roundness in the cylinder, or squeeze effects. This a topic that requires further stud
Multiple technology approach based on stable isotope ratio analysis, Fourier transform infrared spectrometry and thermogravimetric analysis to ensure the fungal origin of the chitosan
Chitosan is a natural polysaccharide which has been authorized for oenological practices for the treatment of musts and wines. This authorization is limited to chitosan of fungal origin while that of crustacean origin is prohibited. To guarantee its origin, a method based on the measurement of the stable isotope ratios (SIR) of carbon δ13C, nitrogen δ15N, oxygen δ18O and hydrogen δ2H of chitosan has been recently proposed without indicating the threshold authenticity limits of these parameters which, for the first time, were estimated in this paper. In addition, on part of the samples analysed through SIR, Fourier transform infrared spectrometry (FTIR) and thermogravimetric analysis (TGA) were performed as simple and rapid discrimination methods due to limited technological resources. Samples having δ13C values above -14.2‱ and below -125.1‱ can be considered as authentic fungal chitosan without needing to analyse other parameters. If the δ13C value falls between -25.1‱ and -24.9‱, it is necessary to proceed further with the evaluation of the parameter δ15N, which must be above +2.7‱. Samples having δ18O values lower than +25.3‱ can be considered as authentic fungal chitosan. The combination of maximum degradation temperatures (obtained using TGA) and peak areas of Amide I and NH2/Amide II (obtained using FTIR) also allows the discrimination between the two origins of the polysaccharide. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) based on TGA, FTIR and SIR data successfully distributed the tested samples into informative clusters. Therefore, we present the technologies described as part of a robust analytical strategy for the correct identification of chitosan samples from crustaceans or fung
A stem cell strategy identifies glycophorin C as a major erythrocyte receptor for the rodent malaria parasite Plasmodium berghei
The clinical complications of malaria are caused by the parasite expansion in the blood. Invasion of erythrocytes is a complex process that depends on multiple receptor-ligand interactions. Identification of host receptors is paramount for fighting the disease as it could reveal new intervention targets, but the enucleated nature of erythrocytes makes genetic approaches impossible and many receptors remain unknown. Host-parasite interactions evolve rapidly and are therefore likely to be species-specific. As a results, understanding of invasion receptors outside the major human pathogen Plasmodium falciparum is very limited. Here we use mouse embryonic stem cells (mESCs) that can be genetically engineered and differentiated into erythrocytes to identify receptors for the rodent malaria parasite Plasmodium berghei. Two proteins previously implicated in human malaria infection: glycophorin C (GYPC) and Band-3 (Slc4a1) were deleted in mESCs to generate stable cell lines, which were differentiated towards erythropoiesis. In vitro infection assays revealed that while deletion of Band-3 has no effect, absence of GYPC results in a dramatic decrease in invasion, demonstrating the crucial role of this protein for P. berghei infection. This stem cell approach offers the possibility of targeting genes that may be essential and therefore difficult to disrupt in whole organisms and has the potential to be applied to a variety of parasites in diverse host cell types
Influence of Castor canadensis on northern lower Michigan forest succession
General EcologyForests undergo a natural progression, called ecological succession, in which they experience a gradual change in community species composition (Luken 1990). As the tree community cycles through each stage of succession, the surrounding habitat cycles and transforms with it (Barnes and Wagner 2004). Our study focuses on how Castor canadensis (North American beaver) affects the direction of forest succession in northern lower Michigan. We counted, identified, and measured the diameter of standing and felled trees at four known beaver sites in the vicinity of Pellston, MI. In addition, we counted and identified 50 randomly selected juvenile trees at each site. Our results showed that C. Canadensis have a preference for Populus tremuloides (trembling aspen) (chi-square: p=0.008) and early successional tree species (chi-square: p=0.000) and show no foraging preference based on tree diameter (Mann-Whitney U: p=0.109). By comparing adult tree species to juvenile tree species, we also found that the species composition prior to and during beaver interference differs significantly from future forest species composition (chi-square: p=0.016). Given these results, we conclude that the foraging preferences of C. canadensis caused a premature progression of forest succession.http://deepblue.lib.umich.edu/bitstream/2027.42/78379/1/Breyer_Ruddy_Silver_2010.pd
Novel stem cell technologies are powerful tools to understand the impact of human factors on Plasmodium falciparum malaria
© 2023 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Plasmodium falciparum parasites have a complex life cycle, but the most clinically relevant stage of the disease is the invasion of erythrocytes and the proliferation of the parasite in the blood. The influence of human genetic traits on malaria has been known for a long time, however understanding the role of the proteins involved is hampered by the a nuclear nature of erythrocytes that makes them inaccessible to genetic tools. Here we overcome this limitation using stem cells to generate erythroid cells with an in-vitro differentiation protocol and assess parasite invasion with an adaptation of flow cytometry to detect parasite hemozoin. We combine this strategy with reprogramming of patient cells to Induced Pluripotent Stem Cells and genome editing to understand the role of key genes and human traits in malaria infection. We show that deletion of basigin ablates invasion while deletion of ATP2B4 has a minor effect and that erythroid cells from reprogrammed patient-derived HbBart α-thalassemia samples poorly support infection. The possibility to obtain patient-secific and genetically modifed erythoid cells offers an unparalleled opportunity to study the role of human genes and polymorphisms in malaria allowing preservation of the genomic background to demonstrate their function and understand their mechanisms.Peer reviewe
- …