175 research outputs found

    Somatic localization of a specific large-conductance calcium-activated potassium channel subtype controls compartmentalized ethanol sensitivity in the nucleus accumbens

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    Alcohol is an addictive drug that targets a variety of ion channels and receptors. To address whether the effects of alcohol are compartment specific (soma vs dendrite), we examined the effects of ethanol (EtOH) on large-conductance calcium-activated potassium channels (BK) in cell bodies and dendrites of freshly isolated neurons from the rat nucleus accumbens (NAcc), a region known to be critical for the development of addiction. Compartment-specific drug action was indeed observed. Clinically relevant concentrations of EtOH increased somatic but not dendritic BK channel open probability. Electrophysiological single-channel recordings and pharmacological analysis of the BK channel in excised patches from each region indicated a number of differences, suggestive of a compartment-specific expression of the beta4 subunit of the BK channel, that might explain the differential alcohol sensitivity. These parameters included activation kinetics, calcium dependency, and toxin blockade. Reverse transcription-PCR showed that both BK channel beta1 and beta4 subunit mRNAs are found in the NAcc, although the signal for beta1 is significantly weaker. Immunohistochemistry revealed that beta1 subunits were found in both soma and dendrites, whereas beta4 appeared restricted to the soma. These findings suggest that the beta4 subunit may confer EtOH sensitivity to somatic BK channels, whereas the absence of beta4 in the dendrite results in insensitivity to the drug. Consistent with this idea, acute EtOH potentiated alphabeta4 BK currents in transfected human embryonic kidney cells, whereas it failed to alter alphabeta1 BK channel-mediated currents. Finally, an EtOH concentration (50 mm) that increased BK channel open probability strongly decreased the duration of somatic-generated action potential in NAcc neurons

    The Promise and Perils of Private Voluntary Regulation: Labor Standards and Work Organization in Two Mexican Garment Factories

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    This paper is part of a larger project on globalization and labor standards organized by Professor Richard Locke of M.I.T.. In addition to the results presented in this paper (some of which appear as well in Monica Romis, "Beneath Corporate Codes of Conduct: What Drives Compliance in Two Mexican Garment Factories," (Masters Thesis, Dept. of Urban Studies and Planning, M.I.T., 2005)), the project entailed field research in China, Turkey, Europe and the United States as well as systematic analysis of Nike’s factory audits of working conditions in over 800 factories in 51 countries.What role can private voluntary regulation play in improving labor standards and working conditions in global supply chain factories? How does this system relate to and interact with other systems of labor regulation and work organization? This paper seeks to address these questions through a structured comparison of two factories supplying Nike, the world’s largest athletic footwear and apparel company. These two factories have many similarities - both are in Mexico, both are in the apparel industry, both produce more or less the same products for Nike (and other brands) and both are subject to the same code of conduct. On the surface, both factories appear to have similar employment (i.e., recruitment, training, remuneration) practices and they receive comparable scores when audited by Nike’s compliance staff. However, underlying (and somewhat obscured by) these apparent similarities, significant differences in actual labor conditions exist between these two factories. What drives these differences in working conditions? What does this imply for traditional systems of monitoring and codes of conduct? Field research conducted at these two factories reveals that beneath the code of conduct and various monitoring efforts aimed at enforcing it, workplace conditions and labor standards are shaped by very different patterns of work organization and human resource management policies

    A Kir6.2 mutation causing severe functional effects in vitro produces neonatal diabetes without the expected neurological complications

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    AIMS/HYPOTHESIS: Heterozygous activating mutations in the pancreatic ATP-sensitive K+ channel cause permanent neonatal diabetes mellitus (PNDM). This results from a decrease in the ability of ATP to close the channel, which thereby suppresses insulin secretion. PNDM mutations that cause a severe reduction in ATP inhibition may produce additional symptoms such as developmental delay and epilepsy. We identified a heterozygous mutation (L164P) in the pore-forming (Kir6.2) subunit of the channel in three unrelated patients and examined its functional effects. METHODS: The patients (currently aged 2, 8 and 20 years) developed diabetes shortly after birth. The two younger patients attempted transfer to sulfonylurea therapy but were unsuccessful (up to 1.1 mg kg(-1) day(-1)). They remain insulin dependent. None of the patients displayed neurological symptoms. Functional properties of wild-type and mutant channels were examined by electrophysiology in Xenopus oocytes. RESULTS: Heterozygous (het) and homozygous L164P K(ATP) channels showed a marked reduction in channel inhibition by ATP. Consistent with its predicted location within the pore, L164P enhanced the channel open state, which explains the reduction in ATP sensitivity. HetL164P currents exhibited greatly increased whole-cell currents that were unaffected by sulfonylureas. This explains the inability of sulfonylureas to ameliorate the diabetes of affected patients. CONCLUSIONS/INTERPRETATION: Our results provide the first demonstration that mutations such as L164P, which produce a severe reduction in ATP sensitivity, do not inevitably cause developmental delay or neurological problems. However, the neonatal diabetes of these patients is unresponsive to sulfonylurea therapy. Functional analysis of PNDM mutations can predict the sulfonylurea response

    Higher ethical objective (Maqasid al-Shari'ah) augmented framework for Islamic banks : assessing the ethical performance and exploring its determinants.

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    This study utilises higher objectives postulated in Islamic moral economy or the maqasid al-Shari’ah theoretical framework’s novel approach in evaluating the ethical, social, environmental and financial performance of Islamic banks. Maqasid al-Shari’ah is interpreted as achieving social good as a consequence in addition to well-being and, hence, it goes beyond traditional (voluntary) social responsibility. This study also explores the major determinants that affect maqasid performance as expressed through disclosure analysis. By expanding the traditional maqasid al-Shari’ah,, we develop a comprehensive evaluation framework in the form of a maqasid index, which is subjected to a rigorous disclosure analysis. Furthermore, in identifying the main determinants of the maqasid disclosure performance, panel data analysis is used by including several key variables alongside political and socio-economic environment, ownership structures, and corporate and Shari’ah governance-related factors. The sample includes 33 full-fledged Islamic banks from 12 countries for the period of 2008–2016. The findings show that although during the nine-year period the disclosure of maqasid performance of the sampled Islamic banks has improved, this is still short of ‘best practices’. Through panel data analysis, this study finds that the Muslim population indicator, CEO duality, Shari’ah governance, and leverage variables positively impact the disclosure of maqasid performance. However, the effect of GDP, financial development and human development index of the country, its political and civil rights, institutional ownership, and a higher share of independent directors have an overall negative impact on the maqasid performance. The findings reported in this study identify complex and multi-faceted relations between external market realities, corporate and Shari’ah governance mechanisms, and maqasid performance

    Towards the Development of an Empirical Model for Islamic Corporate Social Responsibility: Evidence from the Middle East

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    Academic research suggests that variances in contextual dynamics, and more specifically religion, may lead to disparate perceptions and practices of corporate social responsibility (CSR). Driven by the increased geopolitical and economic importance of the Middle East and identified gaps in knowledge, the study aims to examine if indeed there is a divergent form of CSR exercised in the region. The study identifies unique CSR dimensions and constructs presented through an empirical framework in order to outline the practice and perception of CSR in a context with strong Islamic beliefs. The framework goes beyond the platform of mere Islamic philanthropy and is based on CSR-stakeholder management practices. Following an exploratory research design and collecting interview data from representatives of 63 organisations from Saudi Arabia, the United Arab Emirates and Oman, the study offers a snapshot of the CSR reality from the perspective of those living the phenomenon. The results suggest that the practice and perception of CSR in the examined context are largely grounded in the areas of social and altruistic actions but they cannot be examined in isolation from the religious context of CSR operation. This focus is mainly attributed to the dominant role of Islam in the examined sample, which leads to forms of non-structured or semi-structured approaches to CSR. Apart from the theoretical advancements offered to the CSR literature, the study also provides contributions for practitioners and policy makers.</p

    The economic case for prioritizing governance over financial incentives in REDD+

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    This article contributes to the ongoing debate on the role of public policies and financial incentives in Reducing Emissions from Deforestation and forest Degradation (REDD+). It argues that the subordination of policies to results-based payments for emission reductions causes severe economic inefficiencies affecting the opportunity cost, transaction cost and economic rent of the programme. Such problems can be addressed by establishing sound procedural, land and financial governance at the national level, before REDD+ economic incentives are delivered at scale. Consideration is given to each governance dimension, the entry points for policy intervention and the impact on costs. International support must consider the financial and political cost of governance reforms, and use a pay-for-results ethos based on output and outcome indicators. This can be done in the readiness process but only if the latter’s legal force, scope, magnitude and time horizon are adequately reconsidered. In sum, the paper provides ammunition for the institutionalist argument that UNFCCC Parties must prioritise governance reform between now and the entry into force of the new climate agreement in 2020, and specific recommendations about how this can be done: only by doing so will they create the basis for the programme’s financial sustainability
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