90 research outputs found

    BER Performance of IM/DD FSO System with OOK using APD Receiver

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    In this paper, the performance of intensity-modulated with direct detection (IM/DD) free space optical (FSO) system using the on-off keying (OOK) and avalanche photodiode (APD) receiver is observed. The gamma-gamma model is used to describe the effect of atmospheric turbulence since it provides good agreement in the wide range of atmospheric conditions. In addition, the same FSO system with equal gain combining applied at the reception is analyzed. After theoretical derivation of the expression for the bit error rate (BER), the numerical integration with previously specified relative calculation error is performed. Numerical results are presented and confirmed by Monte Carlo simulations. The effects of the FSO link and receiver parameters on the BER performance are discussed. The results illustrate that the optimal APD gain in the minimum BER sense depends considerably on the link distance, atmospheric turbulence strength and receiver temperature. In addition, the value of this optimal gain is slightly different in the case of spatial diversity application compared with single channel reception

    Effect of sensory stimulation on salivary IgA secretion rate in karate players

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    Objectives: Secretory IgA is predominant immunoglobulin in secretions of the mucosal immune system. Low concentration of salivary IgA is associated with a higher risk of respiratory tract infections episodes in athletes during the training season. The purpose of this study was to determine whether orange-flavored whey based drink has beneficial effect on level of IgA in saliva after the training. Methods: Twenty healthy, young karate players participated in this study. They were divided into two groups. One group rinsed a mouth with 20 ml of liquid whey, two times in 30-min period: 15 and 30 min after training. Second group rinsed a mouth with 20 ml of whey based orange flavored soft drink, at the same time. Saliva was collected before the training, just after the training and after application of fluids. Results: We observed decrease in salivary flow after physical activity. The salivary flow was higher after the application of flavored drink compared to salivary flow after the application of whey. The absolute concentration of sIgA and sIgA secretion rate decreased just after exercise compared to pre exercise values. Application of whey elevated sIgA levels on day 1, while application of flavored drink caused increasing in sIgA levels on day 3. In all other cases sIgA level was decreasing even after applied stimuli. Conclusions: The exercise induces decreasing in salivary flow, sIgA absolute concentration and sIgA secretion rate. Application of fluid whey and flavored whey-based drink elevated salivary flow, but had little effect on absolute concentration of sIgA and sIgA secretion rate in young karate players

    Hypericum sp.: essential oil composition and biological activities

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    Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/ 13283/2003

    Incorporating Ecosystems in the Water-Energy-Food Nexus: Current Perspective and Future Directions

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    Integrated approaches for managing natural resources are needed to meet the increasing demand for freshwater, energy and food, while, in parallel, mitigating and adapting to climate change, maintaining the integrity of ecosystems, and ensuring equitable access to resources. The Water-Energy-Food (WEF) Nexus has been proposed as a cross-sectoral approach to understand, analyse, and manage the complex trade-offs and exploit synergies that arise among these resource sectors. Although not initially included as a component of the Nexus, the importance of ecosystems in supporting water, energy and food security is increasingly recognised by the Nexus community of researchers and practitioners. However, attempts to conceptually integrate Ecosystems into the Nexus have yet to converge into a common framework. A group of natural resources management researchers, system thinkers and ecosystem services experts from the European network COST Action CA20138 NEXUSNET have compiled and investigated the various approaches for integrating ecosystems in the WEF Nexus. By combining literature analysis with interdisciplinary workshops – one of which was held in a hybrid format (in person and online) at the University of Oulu, Finland, in September 2022 – we reveal a multiplicity of concepts utilised to represent, partially or fully, ecosystems in the Nexus, namely “natural environment”, “ecosystem services” and “biodiversity”. Disparity was also found in the role attributed to ecosystems in the Nexus framework, being it an underlying layer from which resources for Nexus sectors are extracted or the pillar of an expanded Nexus system – i.e., the WEF-Ecosystems Nexus. Through this collaborative effort, we present possible advantages and disadvantages of adopting differential WEF-Ecosystems Nexus approaches, highlighting their potential complementarity and integration to support future advancement of Nexus research. In the oral presentation, we will show our preliminary findings and encourage the exchange of ideas and feedback from the different scientific disciplines present at the CEMEPE Conference.Tenth International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE) & SECOTOX Conference organized by: Division of Hydraulics and Environmental Engineering, Department of Civil Engineering, Aristotle University of Thessaloniki and Society of Ecotoxicology and Environmental Safety (SECOTOX), Skiathos island, Greece, 2023

    Measuring collective action intention toward gender equality across cultures

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    Collective action is a powerful tool for social change and is fundamental to women and girls’ empowerment on a societal level. Collective action towards gender equality could be understood as intentional and conscious civic behaviors focused on social transformation, questioning power relations, and promoting gender equality through collective efforts. Various instruments to measure collective action intentions have been developed, but to our knowledge none of the published measures were subject to invariance testing. We introduce the gender equality collective action intention (GECAI) scale and examine its psychometric isomorphism and measurement invariance, using data from 60 countries (N = 31,686). Our findings indicate that partial scalar measurement invariance of the GECAI scale permits conditional comparisons of latent mean GECAI scores across countries. Moreover, this metric psychometric isomorphism of the GECAI means we can interpret scores at the country-level (i.e., as a group attribute) conceptually similar to individual attributes. Therefore, our findings add to the growing body of literature on gender based collective action by introducing a methodologically sound tool to measure collective action intentions towards gender equality across cultures

    Measuring collective action intention toward gender equality across cultures

    Get PDF
    Collective action is a powerful tool for social change and is fundamental to women and girls’ empowerment on a societal level. Collective action towards gender equality could be understood as intentional and conscious civic behaviors focused on social transformation, questioning power relations, and promoting gender equality through collective efforts. Various instruments to measure collective action intentions have been developed, but to our knowledge none of the published measures were subject to invariance testing. We introduce the gender equality collective action intention (GECAI) scale and examine its psychometric isomorphism and measurement invariance, using data from 60 countries (N = 31,686). Our findings indicate that partial scalar measurement invariance of the GECAI scale permits conditional comparisons of latent mean GECAI scores across countries. Moreover, this metric psychometric isomorphism of the GECAI means we can interpret scores at the country-level (i.e., as a group attribute) conceptually similar to individual attributes. Therefore, our findings add to the growing body of literature on gender based collective action by introducing a methodologically sound tool to measure collective action intentions towards gender equality across cultures.info:eu-repo/semantics/acceptedVersio

    The psychological science accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    The Psychological Science Accelerator's COVID-19 rapid-response dataset

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    In COVID-19 Health Messaging, Loss Framing Increases Anxiety with Little-to-No Concomitant Benefits: Experimental Evidence from 84 Countries

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    The COVID-19 pandemic (and its aftermath) highlights a critical need to communicate health information effectively to the global public. Given that subtle differences in information framing can have meaningful effects on behavior, behavioral science research highlights a pressing question: Is it more effective to frame COVID-19 health messages in terms of potential losses (e.g., "If you do not practice these steps, you can endanger yourself and others") or potential gains (e.g., "If you practice these steps, you can protect yourself and others")? Collecting data in 48 languages from 15,929 participants in 84 countries, we experimentally tested the effects of message framing on COVID-19-related judgments, intentions, and feelings. Loss- (vs. gain-) framed messages increased self-reported anxiety among participants cross-nationally with little-to-no impact on policy attitudes, behavioral intentions, or information seeking relevant to pandemic risks. These results were consistent across 84 countries, three variations of the message framing wording, and 560 data processing and analytic choices. Thus, results provide an empirical answer to a global communication question and highlight the emotional toll of loss-framed messages. Critically, this work demonstrates the importance of considering unintended affective consequences when evaluating nudge-style interventions

    In search of tools for the use of Country-Image (CI) in the brand

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    Existing country image (CI) literature tends to focus on consumer behaviour. In contrast, this paper approaches CI from the point of view of the firm. In doing so, it seeks to identify the means by which international companies associate a brand with a specific country of origin in order to build brand values. In particular, it looks at the use of CI cues in brand strategies. The paper is based on exploratory research comprising a case study of two contrasting companies from the cosmetics industry, Natura, a domestic company, and the French-owned L’Occitane, both of which draw on images of Brazil to build their brands. Specific elements of CI used in branding are identified, and the extent to which the use of these differs depending on the origin of the owning company is explored. The cases suggest that CI can be exploited in different contexts. Through analysis of the elements used by both companies to build strong brands associated with the Brazilian CI—Natura Cosméticos and L’Occitane au Brésil—six tools are identified that can be combined by firms to deliver brand values, derived from any country, through the use of CI
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