257 research outputs found
A comparison of manifest refractions, cycloplegic refractions and retinoscopy on the RMA-3000 autorefractometer in children aged 3 to 15 years
T Rotsos,1 D Grigoriou,2 A Kokkolaki,2 N Manios21Moorfields eye hospital, London, UK; 2Department of Ophthalmology, General Children’s Hospital, Penteli, Athens, GreecePurpose: The study was conducted to compare the accuracy of readings of the RMA-3000 autorefractometer (Topcon, Tokyo, Japan) with traditional retinoscopy as a means of determining the approximate subjective refraction in children after cycloplegia.Methods: 142 children aged 3 to 15 years were included. All children had their refractive status measured with the RMA-3000 autorefractometer (noncycloplegic autorefraction [AR]). Subsequently all children underwent cycloplegia and the refractive status was estimated again with the autorefractometer (cycloplegic autorefraction [ARC]) and traditional retinoscopy (RC) by examiners who were unaware of the results from the other techniques.Results: From 69 right eyes with negative sphere we observed that the sphere power was significantly higher (more than 0.5 diopters) in AR than in ARC (P = 0.0001) and RC (P = 0.0001). From the 73 normal and hyperopic right eyes we observed that the sphere power was significantly lower (more than 0.5 diopters) in AR than in ARC (P = 0.0001) and RC (P = 0.0001). Conclusions: The use of the autorefractometer in children (in whom accommodation is more active than older patients) without cycloplegia may underestimate the actual hyperopia and overestimate the actual myopia. Manual retinoscopy is still the most accurate technique to estimate refractive status in children.Keywords: refractometer, cycloplegia, retinoscopy, myopia, hyperopia, astigmatis
Pre-plant release enhanced the earlier establishment of Nesidiocoris tenuis in open field tomato
Ο εχθρός της τομάτας, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) που εισέβαλε στη χώρα μας, πολύ σύντομα έγινε σημαντικός εχθρός τόσο των υπαίθριων όσο και των θερμοκηπιακών καλλιεργειών. Η εξαπόλυση του αρπακτικού Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) στο φυτώριο έχει βρεθεί ότι μπορεί να συμβάλει στην αντιμετώπιση του T. absoluta σε καλλιέργειες τομάτας στο θερμοκήπιο. Ο στόχος της παρούσας μελέτης είναι να αξιολογηθεί κατά πόσο σε υπαίθρια καλλιέργεια τομάτας, η εξαπόλυση του N. Tenuis στο φυτώριο μπορεί να συμβάλει στην έγκαιρη εγκατάστασή του. Συμπερασματικά, η εξαπόλυση του N. tenuis συνέβαλε ουσιαστικά στην έγκαιρη αποίκηση της καλλιέργειας σε σύγκριση με τα τεμάχια του μάρτυρα. Επίσης, ο ρόλος του ιθαγενούς πληθυσμού του M. pygmaeus πρέπει να λαμβάνεται σοβαρά υπόψη στα προγράμματα ολοκληρωμένης αντιμετώπισης. Η μέθοδος αυτή είναι αποτελεσματική στην πιο έγκαιρη εγκατάσταση του N. tenuis και θα πρέπει να αξιολογηθεί περαιτέρω η συμβολή της στην αντιμετώπιση του Τ. absoluta.The invasive pest of the tomato crops, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), soon after its establishment became a major problem of outdoor and greenhouse tomato crops across the Mediterranean countries. The pre-plant release of the predator Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) has been found to substantially contribute to its establishment on the crop and efficient control of T. absoluta in greenhouses. The aim of the current study was to assess whether the pre-plant release of N. tenuis could contribute to its earlier establishment. It was concluded that the release of N. tenuis in the nursery contributed substantially in the earlier increase of its numbers in the field in comparison to the control plots. The native populations of M. pygmaeus appeared on the tomato plants before the native populations of N. tenuis. Thus, the conservation of both predators should be taken into consideration in the integrated management strategies against T. absoluta. Therefore, the application of this method in open field tomato crop enhances the earlier establishment of N. tenuis and should be further evaluated in the control of T. absoluta
Pre-plant release enhanced the earlier establishment of Nesidiocoris tenuis in open field tomato
Ο εχθρός της τομάτας, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) που εισέβαλε στη χώρα μας, πολύ σύντομα έγινε σημαντικός εχθρός τόσο των υπαίθριων όσο και των θερμοκηπιακών καλλιεργειών. Η εξαπόλυση του αρπακτικού Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) στο φυτώριο έχει βρεθεί ότι μπορεί να συμβάλει στην αντιμετώπιση του T. absoluta σε καλλιέργειες τομάτας στο θερμοκήπιο. Ο στόχος της παρούσας μελέτης είναι να αξιολογηθεί κατά πόσο σε υπαίθρια καλλιέργεια τομάτας, η εξαπόλυση του N. Tenuis στο φυτώριο μπορεί να συμβάλει στην έγκαιρη εγκατάστασή του. Συμπερασματικά, η εξαπόλυση του N. tenuis συνέβαλε ουσιαστικά στην έγκαιρη αποίκηση της καλλιέργειας σε σύγκριση με τα τεμάχια του μάρτυρα. Επίσης, ο ρόλος του ιθαγενούς πληθυσμού του M. pygmaeus πρέπει να λαμβάνεται σοβαρά υπόψη στα προγράμματα ολοκληρωμένης αντιμετώπισης. Η μέθοδος αυτή είναι αποτελεσματική στην πιο έγκαιρη εγκατάσταση του N. tenuis και θα πρέπει να αξιολογηθεί περαιτέρω η συμβολή της στην αντιμετώπιση του Τ. absoluta.The invasive pest of the tomato crops, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), soon after its establishment became a major problem of outdoor and greenhouse tomato crops across the Mediterranean countries. The pre-plant release of the predator Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) has been found to substantially contribute to its establishment on the crop and efficient control of T. absoluta in greenhouses. The aim of the current study was to assess whether the pre-plant release of N. tenuis could contribute to its earlier establishment. It was concluded that the release of N. tenuis in the nursery contributed substantially in the earlier increase of its numbers in the field in comparison to the control plots. The native populations of M. pygmaeus appeared on the tomato plants before the native populations of N. tenuis. Thus, the conservation of both predators should be taken into consideration in the integrated management strategies against T. absoluta. Therefore, the application of this method in open field tomato crop enhances the earlier establishment of N. tenuis and should be further evaluated in the control of T. absoluta
Who’s more vulnerable? A generational investigation of COVID-19 perceptions’ effect on Organisational citizenship Behaviours in the MENA region: job insecurity, burnout and job satisfaction as mediators
Background
This paper is an empirical investigation that examines a path model linking COVID-19 perceptions to organisational citizenship behaviour (OCBs) via three mediators: job insecurity, burnout, and job satisfaction. The research examines the path model invariance spanning Generations X, Y, and Z. Three countries in the Middle East and North Africa (MENA) were the focus of the study.
Methods
The data was collected from a sample of employees in service companies (n = 578). We used a Partial Least Square Structural Equation Modelling (PLS-SEM) to analyse the data.
Results
Our findings reveal that COVID-19 perceptions positively predict job insecurity, which positively impacts burnout levels. Burnout negatively predicts job satisfaction. The findings established that job satisfaction positively predicts OCBs. The mediation analysis determined that job insecurity, burnout and job satisfaction convey the indirect effects of COVID-19 perceptions onto OCBs. Finally, our hypothesised model is non-equivalent across Generations X, Y and Z. In that regard, our multi-group analysis revealed that the indirect effects of COVID-19 perceptions on OCBs were only valid amongst younger generations, i.e., Generation Y and Generation Z. Specifically, younger generations are substantially more vulnerable to the indirect effects of COVID-19 perceptions on their engagement in OCBs than Generation X whose job satisfaction blocks the effects of COVID-19 perceptions on OCBs.
Conclusions
The present study extends our knowledge of workplace generational differences in responding to the perceptions of crises or pandemics. It offers evidence that suggests that burnout, job attitudes and organisational outcomes change differently across generations in pandemic times
GLOBAL CLIMATE CHANGE AND SECURITY THREATS
Climate change and the associated particularly pronounced warming of the Earth today represent a serious global environmental threat. The paper presents the issues of climate change as a source of threat to not only the environment but also a source of current security threats. The aim is to point out to climate change, which some forecasts with a negative impact on the environment are now actually happening. The paper focuses on the detection of gradual climate changes that culminate in the final verdict of the IPCC, to the impacts of climate change on the most serious ecosystems with reference to possible security threats such climate changes that may significantly affect the quality or safety of a person or existence of life on Earth
Pandemic pains to Instagram gains! COVID-19 perceptions effects on behaviours towards fashion brands on Instagram in Sub-Saharan Africa: Tech-native vs non-native generations
This study represents a novel attempt to investigate the cascading effects of COVID-19 perceptions onto behavioural patterns towards fashion brands on Instagram and across two generations tech-native vs tech non-native) in a Sub-Saharan African context. We drew our study on a sample of 338 Instagram users that experienced fashion brands on Instagram in two Sub-Saharan African countries: Uganda and Nigeria. We used partial least square structural equation modelling (PLS-SEM) to test the hypothetical model. We found that COVID-19 perception positively predicted enjoyment and usefulness, leading to more satisfaction with fashion brand accounts on Instagram and hence greater intention to follow and recommend those accounts. Finally, running a multigroup analysis (MGA), we found the effects of COVID-19 perceptions pronounced into both intentions to follow and intention to recommend via the sequence of mediators: enjoyment and satisfaction were only valid amongst the tech-native generational cohort. Our research suggested a new generational categorisation based on technology nativity – offering a new direction of generational studies in digital marketing communications
Investigation of intracellular signals generated by γ-interferon and IL-4 leading to the induction of class II antigen expression
Signal transduction plays a vital role in cellular behaviour as cells respond to various stimuli in different ways and utilize diverse pathways for accomplishing their task. Determination of the pathway followed by various cytokines can be achieved using specific inhibitors which include theophylline (TPH), TMB-8 and W7 that hinder calmodulin binding to Ca2+; sphingosine (SPH), H7 and staurosporine that inhibit protein kinase C (PKC) activation; and mevalonate (MEV) or the anti-p21ras antibody which block G-proteins. This study shows that the immunologically important class II antigens in human cells are up-regulated predominately via the same pathway after gamma-interferon (γ-IFN) treatment, whereas murine cells are activated by other signalling routes. Thus, the calcium/calmodulin (Ca2+/Cam) pathway is preferentially selected for human cells whereas the PKC pathway is more often chosen for murine cells. These findings are firmly supported by other reports and show, in addition, a unique action exerted by γ-IFN, since IL-4, another inducer of class II antigen expression, uses different pathways. This diversity of activation reveals the existence of a previously unknown complicated network of intracellular interactions able to regulate the same phenotype or cellular event. As major histocompatibility complex antigens (MHC) or human leukocyte antigens (HLA), are important in immune recognition and response, the results show that for human cells a more coherent method of HLA-DR antigen induction is followed after γ-IFN administration, as calcium participation seems to be the first step in signal transduction. The same T-cell derived lymphokine, however, follows a totally different route when applied to murine cells
Email is Evil! Behavioural Responses towards Permission-based Direct Email Marketing and Gender Differences
Purpose
This study aims to assess consumers’ beliefs in three Middle Eastern Arab countries regarding attitudinal and behavioural responses towards permission-based direct email marketing (hereafter DEM) and the moderating role of gender in the hypothesised path model.
Design/methodology/approach
Structural equation modelling was used to test the hypothesised path model by using data collected from 829 respondents.
Findings
The findings show that attitude was found to fully mediate the relationship between beliefs and behavioural responses towards permission-based DEM. Gender moderates the relationship between beliefs and attitudes and responses to permission-based DEM. Notably, female respondents were found to react more actively when exposed to permission-based DEM.
Research limitations/implications
Further qualitative research is needed to learn more about how and why individuals develop behavioural intentions in certain ways towards opt-in DEM. In addition, neuropsychology approaches such as eye-tracking are endorsed for future research to gain more insights and conquer biases associated with self-reporting procedures in countries where such technologies are deemed as legal and ethical to be used with human subjects.
Practical implications
Advertisers promoting products and services in the Middle Eastern Arab context should take further steps to enhance the quality of information (including cultural sensitiveness) and the perceived entertainment value that could be delivered to consumers through permission-based DEM, especially for female internet users. Additionally, this study highly recommends the double opt-in approach to permission-based DEM.
Originality/value
To the best of the authors’ knowledge, this is the first attempt to address the gender role as a moderator of the path depicting the effectiveness of permission-based DEM approach in the Middle East (Arab counties) from beliefs to behavioural responses via attitudes
Can being gay provide a boost in the hiring process? Maybe if the boss is female
Purpose – The purpose of this study was to investigate whether men and women differentially prefer hiring gay and lesbian job applicants relative to equally qualified heterosexual job applicants.
Design/methodology/approach – Data were collected from two samples of non-student participants. Each participant evaluated the perceived hirability of an ostensibly real job applicant by reviewing the applicant’s resume. In reality, all participants were randomly assigned to evaluate the same fictitious resume that differed only in the gender and sexual orientation of the applicant.
Findings – We find that men perceived gay and lesbian job applicants as less hirable, while women perceived gay and lesbian job applicants as more hirable than heterosexual job applicants. Additionally, we show perceptions of hirability are mediated by perceptions of gay and lesbian job applicants’ competence.
Implications – These results show that bias against gays and lesbians is much more nuanced than previous work suggests. One implication is that placing more women in selection roles within organizations could be a catalyst for the inclusion of gay and lesbian employees. Additionally, these results could influence when and how gays and lesbians disclose their gay identities at work.
Originality/value –These studies are the first to identify a positive bias in favor of gay and lesbian job applicants. As attitudes toward gays and lesbians become more positive, results like these are important to document as they signal a shift in intergroup relations. These results will also help managers and organizations design selection processes to minimize bias towards applicants.
Keywords: gender, sexual orientation, selection, bia
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