28 research outputs found

    Corticotropin-releasing factor-like diuretic hormone acts as a gonad-inhibiting hormone in adult female, Rhodnius prolixus

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    Within insects, corticotropin-releasing factor/diuretic hormones (CRF/DHs) are responsible for the modulation of a range of physiological and behavioural processes such as feeding, diuresis, and reproduction. Rhopr-CRF/DH plays a key role in feeding and diuresis in Rhodnius prolixus, a blood-gorging insect and a vector for human Chagas disease. Here, we extend our understanding on the role of this neurohormone in reproduction in adult female R. prolixus. Double-label immunohistochemistry displays co-localized staining of CRF-like and the glycoprotein hormone (GPA2/GPB5) subunit GPB5-like immunoreactivity in the same neurosecretory cells (NSCs) in the mesothoracic ganglionic mass (MTGM) and in their neurohemal sites in adult female R. prolixus, suggesting these peptides could work together to regulate physiological processes. qPCR analysis reveals that the transcript for Rhopr-CRF/DH receptor 2 (Rhopr-CRF/DH-R2) is expressed in reproductive tissues and fat body (FB) in adult female R. prolixus, and its expression increases post blood meal (PBM), a stimulus that triggers diuresis and reproduction. Using RNA interference, transcript expression of Rhopr-CRF/DH-R2 was knocked down, and egg production monitored by examining the major yolk protein, vitellogenin (Vg), the number and quality of eggs laid, and their hatching ratio. Injection of dsCRFR2 into adult females reduces Rhopr-CRF/DH-R2 transcript expression, accelerates oogenesis, increases the number of eggs produced, and reduces hatching rate in female R. prolixus. Downregulation of Rhopr-CRF/DH-R2 leads to an increase in the transcript expression of RhoprVg1 in the fat body and ovaries, and increases the transcript level for the Vg receptor, RhoprVgR, in the ovaries. A significant increase in Vg content in the fat body and in the hemolymph is also observed. Incubation of isolated tissues with Rhopr-CRF/DH leads to a significant decrease in transcript expression of RhoprVg1 in the fat body and RhoprVg1 in the ovaries. In addition, Rhopr-CRF/DH reduces transcript expression of the ecdysteroid biosynthetic enzymes and reduces ecdysteroid titer in the culture medium containing isolated ovaries. These results suggest the involvement of the CRF-signaling pathway in reproduction, and that Rhopr-CRF/DH acts as a gonad-inhibiting hormone in the adult female R. prolixus, as previously shown for the colocalized glycoprotein, GPA2/GPB5

    Food sustainability education as a route to healthier eating: Evaluation of a multi-component school programme in English primary schools

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    Promising approaches to the promotion of healthier eating among children in primary school settings include the opportunity to practise practical cooking and growing, promoting the take up of healthier school meals and nutritional education. However, less is known about the potential for strategies that integrate approaches through a focus on food sustainability issues - such as the promotion of awareness about local, seasonal, organic, fair trade and higher animal welfare foods. This paper presents an evaluation of the Food for Life Partnership, a multi-component programme that sought to address both the health and sustainability aspects of food. The study consisted of a two-stage cross-sectional survey of Years 5 and 6 students (ages 9-11) in 30 primary schools at enrolment and after 18-24 months, combined with an analysis of programme delivery. Higher self-reported fruit and vegetable consumption in the second stage survey was associated with a range of indicators of school participation in the programme. These included the reform of school meal procurement and preparation; experiential food growing, cooking and farm-based education and improved opportunities for stakeholder engagement. The study therefore develops a case for multilevel programmes that incorporate sustainability issues alongside experiential food education in primary school settings. © 2011 The Author. Published by Oxford University Press. All rights reserved

    Attitudes and perceptions regarding entrepreneurship around the world : a cluster analysis approach

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    Nowadays it is believed that entrepreneurship could be a driving force in growth and development. For the achievement of a relevant national entrepreneurship rate the social and economic business environment can be crucial. However, despite the international attention given to entrepreneurship, it is not known if it is a global phenomenon or if there are particular regions where the entrepreneurial activity is specially recognized by society. Applying cluster analysis statistical techniques to a dataset gathered by the Global Entrepreneurship Monitor (GEM) and that includes, in 2010, 59 countries this paper intends to identify groups of countries with the same population attitude and perception regarding entrepreneurship

    Attitudes and perceptions regarding entrepreneurship around the world : a cluster analysis approach

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    Nowadays it is believed that entrepreneurship could be a driving force in growth and develop-ment. For the achievement of a relevant national entrepreneurship rate the social and economic business environment can be crucial. However, despite the international attention given to entrepreneurship, it is not known if it is a global phenomenon or if there are particular regions where the entrepreneurial activity is specially recognized by society. Applying cluster analysis statistical techniques to a dataset gathered by the Global Entrepreneurship Monitor (GEM) and that includes, in 2010, 59 countries this paper intends to identify groups of countries with the same population attitude and perception regarding entrepreneurship

    International project finance: review and implications for international finance and international business

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    The Impact of Cataract Surgery on Depression in Elderly Iranian Patients: A Case–Control Study

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    Background: Cataract-related vision impairment is clearly associated with depressive symptoms in old age. This study aimed to evaluate the effect of Cataract surgery on depression among elderly Iranian patients. Methods: In this case–control study, a total of 113 elderly patients with and without Cataract who were admitted to Buali-Sina Hospital in Sari, Mazandaran, Iran were evaluated. Ophthalmological examinations were first performed at the beginning of the study and then four months later; demographic and clinical characteristics were obtained for all patients. Additionally, depression was assessed using the Hospital Anxiety and Depression Scale (HADS) for all patients during the study period. Results: A statistically significant difference was found between the mean depression score in patients without Cataract (3.28), patients with Cataract surgery (3.74), and patients without Cataract surgery (5.60) (P = 0.024). On the other hand, there was no statistically significant differences between the mean depression score in patients with Cataract surgery and patients without Cataract (P = 0.582). However, a statistically significant difference was observed between the mean depression score after Cataract surgery in men (1.70) and women (4.94) (P < 0.001). Visual function improved in all bilateral Cataract patients who had surgery in one eye. Also, the results of this study showed that in all unilateral Cataract patients who had eye surgery, visual function in the left and right eyes improved. Conclusion: We conclude that depression is more prevalent in patients with Cataract compared to those without Cataract. In addition, Cataract surgery seems to be associated with reduced depression and better visual acuity in elderly patients with Cataract

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