As calcium plays an important role in regulating a great variety of neuronal processes, there is a strong interest to generate gadolinium complexes which can act as calcium-sensors in magnetic resonance imaging (MRI). Here we report a new series of potential CAs based on DO3A, having alkylaminobis(methylenephosphonate) side chains (propyl L1, butyl L2, pentyl L3 or hexyl L4). The high complexation efficiency towards the biologically important metal ions of the aminopolyphosphonic acids could be used for the sensing of the extracellular (...) calcium in the brain. On the other hand the introduction of negatively charged phosphonate groups into common Gd3+-based CAs increases their r1 which is important to improve the MR signal especially in high field magnets. The paramagnetic response of the complexes GdL1-GdL4 to Ca2+ was studied by means of relaxometric titrations. The initial relaxivities of the complexes found to be higher than usually reported for the DO3A type ligands at high field magnets (9.4T). r1 values of 6.92, 7.43, 6.70 and 5.76 mM-1s-1 were determined for GdL1, GdL2, GdL3, and GdL4 respectively. Interestingly complexes exhibit unusual properties in the presence of Ca2+. In contrast to previously reported probes the longitudinal relaxivities decrease upon addition of Ca2+. This is favourable for novel fMRI techniques as it could allow transforming the real in vivo decrease in Ca2+ concentration into a positive contrast during physiological processes. The sensitivity of the complexes towards Ca2+ increases with the extension of the aliphatic side chain. No changes in r1 of GdL1 were found over the whole span of Ca2+ concentration. In the case of GdL2, a moderate decrease of r1 was observed on addition of Ca2+, whereas the r1 of the GdL3 and GdL4 solutions showed a strong dependency on the calcium concentration resulting in the decrease to 66% and 61% of the initial r1 values, respectively. (shrink)
At the UN, important projects laying down transnational corporations' (TNCs) human rights responsibilities have been launched without ever clarifying the relevant theoretical foundations. One of the consequences is that the human rights principles in projects like the 2000 UN Global Compact and the 2003 Norms on the Responsibilities of Transnational Corporations and Other Business Enterprises with Regard to Human Rights can be understood in different ways, which should not cause surprise given that their authors come from diverse backgrounds, including economics (...) and public policy. An examination of these projects and the views of their authors reveals that, although they are superficially linked to international human rights law, they go well beyond it and attempt to deal with corporate social responsibility issues in ways that elude neat classification as fitting neatly in either legal or non-legal categories. Too little attention has been paid to how in the course of developing these projects the legal and ethical dimensions have become entwined and how lines have gotten blurred. Meanwhile, there has been recognition that these UN projects have emerged simply as ad hoc responses to practical concerns about the sustainability of globalization. The lack of any foundational theory or normative framework should be addressed; it is time to bring together specialists from different fields concerned with the human rights responsibilities of corporations to see if it is possible to define a coherent overarching theory for these UN projects. (shrink)
: Feminist affiliation has long been suspect among Native American women whose memories survive the dishonor of colonialism. The idea of common struggles is simultaneously repugnant and alluring. Sadly, this has led to much confusion and rejection between Aboriginal women. I suggest "a return to reciprocity" to understand and come to terms with feminist rejection or affiliation. If we cannot come together, the fracturing that began with European ideology will continue to fragment and destroy the fabric of Native cultures.
Data mining occurs because most economic hypotheses do not have a unique empirical interpretation but allow the econometrician much leeway in selecting conditioning variables, lags, functional forms, and sometimes the sample. The resulting problems are of interest not only to methodologists and philosophers concerned with how hypotheses are validated in the presence of some inevitable ad hocery but, also to readers of economics journals who have no interest in methodology but need to know whether to believe what they read. Since (...) I focus on such mundane problems I make no claim of contributing to the deeper epistemological problems of relating empirical evidence to theory, and to the meaning of confirmation and disconfirmation when, say five of the eight specifications tested are consistent with the hypothesis and, three are not. Instead, I deal with a practical problem confronting a researcher who wants to persuade his readers but does not want to deceive them. He has fitted many regressions with varying results. How should he decide how many and which ones to report? This paper is therefore more about a problem in communicating results than about a problem in the philosophy of science. Hence, I use some common-sense notions, even though I cannot provide rigorous definitions for them. (shrink)
Several cortical regions are reported to vary in meditation practitioners. However, since prior analyses were focused on examining gray matter or cortical thickness, additional effects with respect to other cortical features might have remained undetected. Gyrification (the pattern and degree of cortical folding) is an important cerebral characteristic related to the geometry of the brain’s surface. Cortical folding occurs early in development and might be linked to behavioral traits. Thus, exploring cortical gyrification in long-term meditators may provide additional clues with (...) respect to the underlying anatomical correlates of meditation. This study examined cortical gyrification in a large sample (n=100) of meditators and controls, carefully matched for sex and age. Cortical gyrification was established via calculating mean curvature across thousands of vertices on individual cortical surface models. Pronounced group differences indicating larger gyrification in meditators were evident within the left precentral gyrus, right fusiform gyrus, right cuneus, as well as left and right anterior dorsal insula (the latter representing the global significance maximum). Although the exact functional implications of larger cortical gyrification remain to be established, these findings suggest the insula to be a key structure involved in aspects of meditation. For example, variations in insular complexity could affect the regulation of well-known distractions in the process of meditation, such as daydreaming, mind-wandering, and projections into past or future. Moreover, given that meditators are masters in introspection, awareness, and emotional control, increased insular gyrification may reflect an ideal integration of autonomic, affective, and cognitive processes. Due to the cross-sectional nature of this study, further research is necessary determine the relative contribution of nature and nurture to links between cortical gyrification and meditation. (shrink)
The introduction of genetically modified (GM) crops and foods into Europe has generated considerable controversy. Despite a risk assessment system that is intended to beprecautionary in nature, the decisions thathave been taken have not gathered publicconfidence. Key attributes of a precautionaryappraisal system include humility,completeness, assessing benefits andjustifications, making comparisons, allowingfor public participation, transparency,diversity, and the ``mapping'' of alternativeviews rather than the prescription of singlesolutions. A comparison of the European GMregulatory system with a different (moreprecautionary) approach using a ``multi-criteriamapping'' technique reveals (...) a number ofproblems. These include the narrow framing ofthe established risk assessment system (therebyexcluding many issues of public concern), alack of public involvement in the process, anda failure to include appropriate comparisons ora diversity of options. Recent changes to theEuropean regulatory system only go part of theway to addressing these issues. Furthercontroversy may therefore be expected. However,practical ways of undertaking a morebroad-based precautionary approach are nowavailable (including the multi-criteria mappingmethod). These new approaches to technologyassessment offer a means for decision making toearn greater public confidence in this complexand difficult area. (shrink)
Criteria distinguishing the professions from ordinary occupations have traditionally stressed the notion of commitment to a service ethic which implies social responsibility. In this survey of 223 students and faculty of three university professional schools in Canada (Business, Engineering, and Forestry), the extent to which students exhibit awareness of the ethical component in their future work is examined. Particular attention is paid to the structural contradictions inherent in the work context of the salaried professions, especially the ethical dilemmas that (...) arise out of bureaucratic demands to serve organizational goals rather than broader social ends. (shrink)
How justified is the charge that ideology strongly influences the allegedly objective opinions of economists? An analysis of a new survey of AEA members and of surveys of labour economists and public economists shows that value judgments and judgments about the government's efficacy have some influence on the way economists think about what should be purely economic issues. But such influence is not strong enough to explain much of the disagreement among economists.
Business leaders are increasingly responsible for the societal and environmental impacts of their actions. Yet conceptual views on responsible leadership differ in their definitions and theoretical foundations. This study attempts to reconcile these diverse views and uncover the phenomenon from a business leader’s point of view. Based on rational egoism theory, this article proposes a formal mathematical model of responsible leadership that considers different types of incentives for stakeholder engagement. The analyses reveal that monetary and instrumental incentives are neither sufficient (...) nor necessary for business leaders to consider societal and environmental stakeholder needs. Non-monetary and non-instrumental incentives, such as leaders’ values and authenticity, as well as their planning horizons, counterbalance pure monetary and instrumental orientations. The model in this article complements the growing body of research on responsible leadership by reconciling its various conceptual views and providing a foundation for future theory development and testing. (shrink)