79 research outputs found

    A statistical approach to quantitative data validation focused on the assessment of students' perceptions about biotechnology

    Get PDF
    Student awareness levels are frequently used to evaluate the effectiveness of educational policies to promote scientific literacy. Over the last years several studies have been developed to assess students' perceptions towards science and technology, which usually rely on quantitative methods to achieve broad characterizations, and obtain quantifiable and comparable data. Although the usefulness of this information depends on its validity and reliability, validation is frequently neglected by researchers with limited background in statistics. In this context, we propose a guideline to implement a statistical approach to questionnaire validation, combining exploratory factor analysis and reliability analysis. The work focuses on the psychometric analysis of data provided by a questionnaire assessing 1196 elementary and high school students' perceptions about biotechnology. Procedural guidelines to enhance the efficiency of quantitative inquiry surveys are given, by discussing essential methodological aspects and relevant criteria to integrate theory into practice.The authors are grateful to all the participant teachers and students that contributed to gather the data presented and to Catarina L. Santos for useful comments and suggestions on the manuscript. Maria Joao Fonseca was supported by the FCT fellowship SFRH/BD/37389/2007 and this work was sponsored by a research grant (PTDC/AGR-PRO/111857/2009) from Fundacao para a Ciencia e Tecnologia (FCT, Portugal)

    High recombination rates and hotspots in a Plasmodium falciparum genetic cross

    Get PDF
    Using the universal P2/P8 primers, we were able to obtain the gene segments of chromo-helicase-DNA binding protein (CHD)-Z and CHD-W from ten species of ardeid birds including Chinese egret (Egretta eulophotes), little egret (E. garzetta), eastern reef egret (E. sacra), great egret (Ardea alba), grey heron (A. cinerea), Chinese pond-heron (Ardeola bacchus), cattle egret (Bubulcus ibis), black-crowned night-heron (Nycticorax nycticorax), cinnamon bittern (Ixobrychus cinnamomeus) and yellow bittern (I. sinensis). Based on conserved regions inside the P2/P8-derived sequences, we designed new PCR primers for sex identification in these ardeid species. Using agarose gel electrophoresis, the PCR products showed two bands for females (140 bp derived from CHD-W and the other 250 bp from CHD-ZW), whereas the males showed only the 250 bp band. The results indicated that our new primers could be used for accurate and convenient sex identification in ardeid species.National Natural Science Foundation of China[30970380, 40876077]; Fujian Natural Science Foundation of China[2008S0007, 2009J01195

    The recording and characteristics of pulmonary rehabilitation in patients with COPD using The Health Information Network (THIN) primary care database

    Get PDF
    Pulmonary rehabilitation is recommended for patients with COPD to improve physical function, breathlessness and quality of life. Using The Health Information Network (THIN) primary care database in UK, we compared the demographic and clinical parameters of patients with COPD in relation to coding of pulmonary rehabilitation, and to investigate whether there is a survival benefit from pulmonary rehabilitation. We identified patients with COPD, diagnosed from 2004 and extracted information on demographics, pulmonary rehabilitation and clinical parameters using the relevant Read codes. Thirty six thousand one hundred and eighty nine patients diagnosed with COPD were included with a mean (SD) age of 67 (11) years, 53% were male and only 9.8% had a code related to either being assessed, referred, or completing pulmonary rehabilitation ever. Younger age at diagnosis, better socioeconomic status, worse dyspnoea score, current smoking, and higher comorbidities level are more likely to have a record of pulmonary rehabilitation. Of those with a recorded MRC of 3 or worse, only 2057 (21%) had a code of pulmonary rehabilitation. Survival analysis revealed that patients with coding for pulmonary rehabilitation were 22% (95% CI 0.69–0.88) less likely to die than those who had no coding. In UK THIN records, a substantial proportion of eligible patients with COPD have not had a coded pulmonary rehabilitation record. Survival was improved in those with PR record but coding for other COPD treatments were also better in this group. GP practices need to improve the coding for PR to highlight any unmet need locally

    An examination of the factorial and convergent validity of four measures of conspiracist ideation, with recommendations for researchers

    Get PDF
    A number scales have been developed to measure conspiracist ideation, but little attention has been paid to the factorial validity of these scales. We reassessed the psychometric properties of four widely-used scales, namely the Belief in Conspiracy Theories Inventory (BCTI), the Conspiracy Mentality Questionnaire (CMQ), the Generic Conspiracist Beliefs Scale (GCBS), and the One-Item Conspiracy Measure (OICM). Eight-hundred-and-three U. S. adults completed all measures, along with measures of endorsement of 9/11 and anti- vaccination conspiracy theories. Through both exploratory and confirmatory factor analysis, we found that only the BCTI had acceptable factorial validity. We failed to confirm the factor structures of the CMQ and the GBCS, suggesting these measures had poor factorial valid- ity. Indices of convergent validity were acceptable for the BCTI, but weaker for the other measures. Based on these findings, we provide suggestions for the future refinement in the measurement of conspiracist ideation

    Prospect theory and the effects of bankruptcy laws on entrepreneurial aspirations

    Get PDF
    We apply prospect theory to explain how personal and corporate bankruptcy laws affect risk perceptions of entrepreneurs at time of entry and therefore their growth ambitions. Previous theories have reached ambiguous conclusions as to whether countries with more debtor-friendly bankruptcy laws (i.e. laws that are more forgiving towards debtors in bankruptcy proceedings) are likely to have more entrepreneurs, or whether, creditorfriendly regimes have positive effects on new ventures via enhanced incentives for the supply of credit to entrepreneurs. Responding to this ambiguity, we apply prospect theory to propose that entrepreneurs do not attach the same significance to different elements of bankruptcy codes—and to explain which aspects of debtor-friendly bankruptcy laws matter more to entrepreneurs. Based on this, we derive and confirm hypotheses about the impact of aspects of bankruptcy codes on entrepreneurial activity using the Global Entrepreneurship Monitor combined with data on both personal and corporate bankruptcyregulations for 15 developed OECD countries. We use multilevel random coefficient logistic regressions to take account of the hierarchical nature of the data (country and individual levels). Because entrepreneurs and creditors are sensitive to different elements of the codes, there is scope for optimisation of the legal design of bankruptcy law to achieve both an adequate supply of credit and to encourage high-ambition entrepreneurship

    Inflammatory responses to acute exercise during pulmonary rehabilitation in patients with COPD

    Get PDF
    Objective Pulmonary rehabilitation is a cornerstone treatment in the management of chronic obstructive pulmonary disease (COPD). Acute bouts of exercise can lead to short bursts of inflammation in healthy individuals. However, it is unclear how COPD patients respond to acute bouts of exercise. This study assessed inflammatory responses to exercise in COPD patients at the start (phase 1) and end (phase 2) of pulmonary rehabilitation. Methods Blood samples were collected before and after an acute exercise bout at the start (phase 1, n = 40) and end (phase 2, n = 27) of pulmonary rehabilitation. The primary outcome was change in fibrinogen concentrations. Secondary outcomes were changes in CRP concentrations, total/differential leukocyte counts, markers of neutrophil activation (CD11b, CD62L and CD66b), and neutrophil subsets (mature, suppressive, immature, progenitor). Results Acute exercise (phase 1) did not induce significant changes in fibrinogen (p = 0.242) or CRP (p = 0.476). Total leukocyte count [mean difference (MD), 0.5 ± 1.1 (109 L−1); p = 0.004], neutrophil count [MD, 0.4 ± 0.8 (109 L−1); p < 0.001], and immature neutrophils (MD, 0.6 ± 0.8%; p < 0.001) increased post-exercise. Neutrophil activation markers, CD11b (p = 0.470), CD66b (p = 0.334), and CD62L (p = 0.352) were not significantly altered post-exercise. In comparison to the start of pulmonary rehabilitation (phase 2), acute exercise at the end of pulmonary rehabilitation led to a greater fibrinogen response (MD, 84 mg/dL (95% CI − 14, 182); p = 0.045). Conclusion An acute bout of exercise does not appear to induce significant alterations in the concentrations of inflammatory mediators but can increase white blood cell subsets post-exercise. A greater fibrinogen response to acute exercise is seen at the end of pulmonary rehabilitation when compared to the start. Further research is required to understand the clinical context of these acute inflammatory responses to exercise

    Toxoplasma Effector MAF1 Mediates Recruitment of Host Mitochondria and Impacts the Host Response

    Get PDF
    Recent information has revealed the functional diversity and importance of mitochondria in many cellular processes including orchestrating the innate immune response. Intriguingly, several infectious agents, such as Toxoplasma, Legionella, and Chlamydia, have been reported to grow within vacuoles surrounded by host mitochondria. Although many hypotheses have been proposed for the existence of host mitochondrial association (HMA), the causes and biological consequences of HMA have remained unanswered. Here we show that HMA is present in type I and III strains of Toxoplasma but missing in type II strains, both in vitro and in vivo. Analysis of F1 progeny from a type II×III cross revealed that HMA is a Mendelian trait that we could map. We use bioinformatics to select potential candidates and experimentally identify the polymorphic parasite protein involved, mitochondrial association factor 1 (MAF1). We show that introducing the type I (HMA+) MAF1 allele into type II (HMA-) parasites results in conversion to HMA+ and deletion of MAF1 in type I parasites results in a loss of HMA. We observe that the loss and gain of HMA are associated with alterations in the transcription of host cell immune genes and the in vivo cytokine response during murine infection. Lastly, we use exogenous expression of MAF1 to show that it binds host mitochondria and thus MAF1 is the parasite protein directly responsible for HMA. Our findings suggest that association with host mitochondria may represent a novel means by which Toxoplasma tachyzoites manipulate the host. The existence of naturally occurring HMA+ and HMA- strains of Toxoplasma, Legionella, and Chlamydia indicates the existence of evolutionary niches where HMA is either advantageous or disadvantageous, likely reflecting tradeoffs in metabolism, immune regulation, and other functions of mitochondria. © 2014 Pernas et al
    • …
    corecore