Plane geometry topics with the software geogebra: proposal of didactic sequences

According to the reality of the schools that I have worked the teaching of plane geometry is deficient, causing students to forget certain facility settings and properties. A source that can (and should) be used is the proposal of the present dissertation: an educational software for the study of plane geometry. To be more explicit, we propose the use of the GeoGebra software, which is free, to show some topics of plane geometry. The idea is to bring the student to assimilate definitions and properties through geometric constructions, using didactic sequences in GeoGebra. These didactic sequences may be used in any term of high school, once the main goal of the project is to support students, regardless the series that they are attending. The first sequences are intended to show some features of the software and the other, geometric constructions and properties involved.De acordo com a realidade das escolas em que trabalho, o ensino da geometria plana está deficitário, fazendo com que os alunos esqueçam com facilidade certas definições e propriedades. Um recurso que pode (e deve) ser usado é o que essa dissertação propõe: softwares educacionais para o estudo da geometria plana. Para ser mais objetiva é proposto o uso do software GeoGebra, que é gratuito, para mostrar alguns tópicos da geometria plana. A ideia é levar cada aluno a assimilação de definições e propriedades através de construções geométricas, usando-se o GeoGebra em sequências didáticas. Estas sequências didáticas poderão ser usadas inclusive em qualquer série do Ensino Médio, pois um dos objetivos do projeto é dar suporte para os alunos, independentemente da série que estão cursando. As primeiras sequências têm o objetivo de mostrar alguns recursos do software e as demais, construções geométricas e propriedades envolvidas

Salmonella typhimurium's transthyretin-like protein is a host-specific factor important in fecal survival in chickens.

The transthyretin-like protein (TLP) from Salmonella enterica subspecies I is a periplasmic protein with high level structural similarity to a protein found in mammals and fish. In humans, the protein homologue, transthyretin, binds and carries retinol and thyroxine, and a series of other, unrelated aromatic compounds. Here we show that the amino acid sequence of the TLP from different species, subspecies and serovars of the Salmonella genus is highly conserved and demonstrate that the TLP gene is constitutively expressed in S. Typhimurium and that copper and other divalent metal ions severely inhibit enzyme activity of the TLP, a cyclic amidohydrolase that hydrolyses 5-hydroxyisourate (5-HIU). In order to determine the in vivo role of the S. Typhimurium TLP, we constructed a strain of mouse-virulent S. Typhimurium SL1344 bearing a mutation in the TLP gene (SL1344 ΔyedX). We assessed the virulence of this strain via oral inoculation of mice and chickens. Whilst SL1344 ΔyedX induced a systemic infection in both organisms, the bacterial load detected in the faeces of infected chickens was significantly reduced when compared to the load of S. Typhimurium SL1344. These data demonstrate that the TLP gene is required for survival of S. Typhimurium in a high uric acid environment such as chicken faeces, and that metabolic traits of Salmonellae in natural and contrived hosts may be fundamentally different. Our data also highlight the importance of using appropriate animal models for the study of bacterial pathogenesis especially where host-specific virulence factors or traits are the subject of the study

Hormone affinity and fibril formation of piscine transthyretin: the role of the N-terminal

Transthyretin (TTR) transports thyroid hormones (THs), thyroxine (T4) and triiodothyronine (T3) in the blood of vertebrates. TH-binding sites are highly conserved in vertebrate TTR however, piscine TTR has a longer N-terminus which is thought to influence TH-binding affinity and may influence TTR stability. We produced recombinant wild-type sea bream TTR (sbTTRWT) plus two mutants in which six (sbTTRM6) and twelve (sbTTRM12) N-terminal residues were removed. Ligandbinding studies revealed similar affinities for T3 (Kd=10.6±1.7nM) and T4 (Kd=9.8±0.97nM) binding to sbTTRWT. Affinity for THs was unaltered in sbTTRM12 but sbTTRM6 had poorer affinity for T4 (Kd=252.3±15.8nM) implying that some residues in the N-terminus can influence T4 binding. sbTTRM6 inhibited acid-mediated fibril formation in vitro as shown by fluorometric measurements using thioflavine-T.In contrast, fibril formation by sbTTRM12 was significant, probably due to decreased stability of the tetramer. Such studies also suggested that sbTTRWT is more resistant to fibril formation than human TTR

Temporary migration programmes: the cause or antidote for migrant worker exploitation in UK agriculture

The referendum result in Britain in 2016 and the potential loss of EU labour in the advent of a “hard Brexit” has raised pressing questions for sectors that rely on EU labour, such as agriculture. Coupled with the closure of the long-standing Seasonal Agricultural Scheme in 2013, policymakers are grappling with how to satisfy one the one hand employer demands for mobility schemes, and on the other public demands for restrictive immigration policies. Labour shortages in agriculture transcend the immigration debate, raising questions for food security, the future of automation and ultimately what labour market the UK hopes to build. Temporary Migration programmes have been heralded as achieving a triple win, yet they are rightly criticized for breeding bonded labour and exploitation. In lieu of a dedicated EU labour force agricultural employers are calling for the establishment of a new seasonal scheme. In this paper we explore whether the absence of a temporary migration programme resolves the potential exploitation of migrant workers. We argue that the absence of a TMP is not an antidote to migrant exploitation, and that a socially just TMP which is built around migrant agency may be the most palpable solution

Effects of COVID-19 pandemic restrictions on an Australian neonatal and paediatric retrieval service

First published: 28 February 2022Aim: The COVID-19 pandemic and associated travel and social distancing restrictions have reduced paediatric intensive care unit admissions for respiratory illnesses. The effects on retrieval (transport) services remain unquantified. Our study examined the utility of statistical process control in assessing the impact of the COVID-19 pandemic on the number of neonatal and paediatric transfers in an Australian retrieval service. Methods: Data collected prospectively from the SA Ambulance Service MedSTAR Emergency Retrieval database in South Australia were analysed from January 2015 to June 2021. Statistical process control methodology, a combination of a time series analysis and assessment for common and special cause variation, was used to assess the impact of the COVID-19 pandemic on retrieval workload (primary outcome of interest). Results: A total of 5659 neonatal and paediatric transfers occurred during the study period and were included. A significant decrease in paediatric transfers occurred after the initial lockdown measures in March 2020 were announced in South Australia (special cause variation). However, a similar reduction was not observed for neonatal transfers (common cause variation). Conclusion: Our study demonstrates that statistical process control may be effectively used to understand the effects of external events and processes on usual activity patterns in the retrieval setting. We found a reduction in retrieval numbers for paediatric transfers but no effect on neonatal transfer numbers. The decline in paediatric transfers was primarily attributed to reduced respiratory cases.Amy Keir, Jeffrey Dutschke, Bron Hennebry, Kate Kerin and John Crave

Culprit-Vessel Percutaneous Coronary Intervention Followed by Contralateral Angiography Versus Complete Angiography in Patients With St-Elevation Myocardial Infarction

In patients with ST-elevation myocardial infarction, delay in door-to-balloon time strongly increases mortality rates. To our knowledge, no randomized studies to date have focused on reducing delays within the catheterization laboratory. We performed a retrospective analysis of all patients who presented with ST-elevation myocardial infarction at our institution from July 2006 through June 2010, looking primarily at time differences between percutaneous coronary intervention in the culprit vessel on the basis of ECG criteria, followed by contralateral angiography (Group 1), versus complete coronary angiography followed by culprit-vessel percutaneous intervention (Group 2). There were 49 patients in Group 1 and 57 patients in Group 2. No major differences in baseline characteristics were observed between the groups, except a higher prevalence of diabetes mellitus in Group 2. There was a statistically significant difference between Groups 1 and 2 in door-to-balloon time (median and interquartile range, 75 min [61–89] vs 87 min [70–115], P=0.03, respectively) and access-to-balloon time (12 min [9–18] vs 21 min [11–33], P=0.0006, respectively). Five Group 1 patients (10%) with inferior myocardial infarction had a contralateral culprit vessel. There were no differences in mortality rate or ejection fraction at the median 1-year follow-up. Four patients in Group 1 and 3 patients in Group 2 were referred for coronary artery bypass grafting after percutaneous intervention. This study suggests that performing culprit-vessel percutaneous intervention on the basis of electrocardiographic criteria, followed by angiography in patients with anterior ST-elevation myocardial infarction, might be the preferred approach, given the door-to-balloon time that is saved

Effects of new polymorphisms in the bovine myocyte enhancer factor 2D (MEF2D) gene on the expression rates of the longissimus dorsi muscle

Myocyte enhancer factor 2D (MEF2D), a product of the MEF2D gene, belongs to the myocyte enhancer factor 2 (MEF2) protein family which is involved in vertebrate skeletal muscle development and differentiation during myogenesis. The aim of the present study was to search for polymorphisms in the bovine MEF2D gene and to analyze their effect on MEF2D mRNA and on protein expression levels in the longissimus dorsi muscle of Polish Holstein–Friesian cattle. Overall, three novel variations, namely, insertion/deletion g.−818_−814AGCCG and g.−211C<A transversion in the promoter region as well as g.7C<T transition in the 5′untranslated region (5′UTR), were identified by DNA sequencing. A total, 375 unrelated bulls belonging to six different cattle breeds were genotyped, and three combined genotypes (Ins-C-C/Ins-C-C, Del-A-T/Del-A-T and Ins-C-C/Del-A-T) were determined. The frequency of the combined genotype Ins-C-C/Ins-C-C and Del-A-T/Del-A-T was varied between the breeds and the average frequency was 0.521 and 0.037, respectively. Expression analysis showed that the MEF2D variants were highly correlated with MEF2D mRNA and protein levels in the longissimus dorsi muscle of Polish Holstein–Friesian bulls carrying the three different combined genotypes. The highest MEF2D mRNA and protein levels were estimated in the muscle of bulls with the Ins-C-C/Ins-C-C homozygous genotype as compared to the Del-A-T/Del-A-T homozygotes (P < 0.01) and Ins-C-C/Del-A-T heterozygotes (P < 0.05). A preliminary association study showed no significant differences in the carcass quality traits between bulls with various MEF2D combined genotypes in the investigated population of Polish Holstein–Friesian cattle

Be our guest/worker: reciprocal dependency and expressions of hospitality in Ni-Vanuatu overseas labour migration

Whilst there has been renewed interest in the development potential of temporary migration programmes, such schemes have long been criticized for creating conditions for exploitation and fostering dependence. In this article, which is based on a case study of Ni-Vanuatu seasonal workers employed in New Zealand’s horticultural industry, I show how workers and employers alike actively cultivate and maintain relations of reciprocal dependence and often describe their relation in familial terms of kinship and hospitality. Nevertheless, workers often feel estranged both in the Marxian sense of being subordinated to a regime of time-discipline, and in the intersubjective sense of feeling disrespected or treated unkindly. I show how attention to the ‘non-contractual element’ in the work contract, including expressions of hospitality, can contribute to anthropological debates surrounding work, migration, and dependence, and to interdisciplinary understandings of the justice of labour migration.ESRC scholarship (project reference ES/H034943/1

The genome, transcriptome, and proteome of the nematode Steinernema carpocapsae: Evolutionary signatures of a pathogenic lifestyle

The entomopathogenic nematode Steinernema carpocapsae has been widely used for the biological control of insect pests. It shares a symbiotic relationship with the bacterium Xenorhabdus nematophila, and is emerging as a genetic model to study symbiosis and pathogenesis. We obtained a high-quality draft of the nematode’s genome comprising 84,613,633 bp in 347 scaffolds, with an N50 of 1.24 Mb. To improve annotation, we sequenced both short and long RNA and conducted shotgun proteomic analyses. S. carpocapsae shares orthologous genes with other parasitic nematodes that are absent in the free-living nematode C. elegans, it has ncRNA families that are enriched in parasites, and expresses proteins putatively associated with parasitism and pathogenesis, suggesting an active role for the nematode during the pathogenic process. Host and parasites might engage in a co-evolutionary arms-race dynamic with genes participating in their interaction showing signatures of positive selection. Our analyses indicate that the consequence of this arms race is better characterized by positive selection altering specific functions instead of just increasing the number of positively selected genes, adding a new perspective to these co-evolutionary theories. We identified a protein, ATAD-3, that suggests a relevant role for mitochondrial function in the evolution and mechanisms of nematode parasitism