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Selected AbstractsA Cross-Atlantic Dialogue: The Progress of Research and Theory in the Study of International MigrationINTERNATIONAL MIGRATION REVIEW, Issue 3 2004Alejandro Portes The articles included in this issue were originally presented at a conference on Conceptual and Methodological Developments in the Study of International Migration held at Princeton University in May 2003. The conference was jointly sponsored by the Committee on International Migration of the Social Science Research Council (SSRC), the Center for Migration and Development (CMD) at Princeton, and this journal. Its purpose was to review recent innovations in this field, both in theory and empirical research, across both sides of the Atlantic. The conference was deliberately organized as a sequel to a similar event convened by the SSRC on Sanibel Island in January 1996 in order to assess the state of international migration studies within the United States from an inter-disciplinary perspective. A selection of articles from that conference was published as a special issue of International Migration Review (Vol. 31, No. 4, Winter), and the full set of articles was published as the Handbook of International Migration: The American Experience (Hirschman, Kasinitz and DeWind, 1999). [source] Neuro-mesodermal patterns in artificially deformed embryonic explants: A role for mechano-geometry in tissue differentiationDEVELOPMENTAL DYNAMICS, Issue 3 2010E.S. Kornikova Abstract The mutual arrangement of neural and mesodermal rudiments in artificially bent double explants of Xenopus laevis suprablastoporal areas was compared with that of intact explants. While some of the bent explants straightened or became spherical, most retained and actively reinforced the imposed curvature, creating folds on their concave sides and expanding convex surfaces. In the intact explants, the arrangement of neural and mesodermal rudiments exhibited a distinct antero-posterior polarity, with some variability. In the bent explants, this polarity was lost: the neural rudiments were shifted towards concave while the mesodermal tissues moved towards the convex side, embracing the neural rudiments in a horseshoe-shaped manner. We associate these drastic changes in neuro-mesodermal patterning with the active extension and contraction of the convex and concave sides, respectively, triggered by the imposed deformations. We speculate that similar events are responsible for the establishment of neuro-mesodermal patterns during normal development. Developmental Dynamics 239:885,896, 2010. © 2010 Wiley-Liss, Inc. [source] A stress survival response in retinal cells mediated through inhibition of the serine,/,threonine phosphatase PP2AEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2010Sorcha Finnegan Abstract Cell survival signalling involving the PI3K/Akt survival pathway can be negatively regulated by several phosphatases including PP2A. When retinal-derived 661W cells were subjected to trophic factor deprivation this initiated a survival response through inhibition of the activity of PP2A and subsequent upregulation of the Erk and Akt survival pathways. We show this survival response via inhibition of PP2A activity was due in part to increased reactive oxygen species production when retinal cells were deprived of trophic factors. Inhibition of PP2A activity was mediated by a rapid and transient increase in phosphorylation at Tyr307, accompanied by an increase in demethylation and a decrease in the methylated form. Pre-treatment with N -acetyl- l -cysteine, which is involved in scavenging reactive oxygen species, prevented PP2A inhibition and subsequent upregulation of survival pathways. Pre-treatment with the Src family kinase inhibitor PP2 resulted in approximately 50% reduction in cellular levels of phospho-PP2A in trophic factor-deprived 661W cells, suggesting an Src tyrosine kinase had a role to play in this redox regulation of cell survival. We observed similar events in the rd10 mouse retina where there was an increased survival response prior to retinal cell death mediated through an increase in both phospho-PP2A and phospho-Gsk. Together, these results demonstrate that when retinal cells are stressed there is an initial struggle to survive, mediated through inhibition of PP2A and subsequent upregulation of survival pathways, and that these events occur simultaneously with production of reactive oxygen species, thus suggesting an important cell-signalling role for reactive oxygen species. [source] THE ,LITTLE ICE AGE': RE-EVALUATION OF AN EVOLVING CONCEPTGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 1 2005JOHN A. MATTHEWS ABSTRACT. This review focuses on the development of the ,Little Ice Age' as a glaciological and climatic concept, and evaluates its current usefulness in the light of new data on the glacier and climatic variations of the last millennium and of the Holocene. ,Little Ice Age' glacierization occurred over about 650 years and can be defined most precisely in the European Alps (c. AD 1300,1950) when extended glaciers were larger than before or since. ,Little Ice Age' climate is defined as a shorter time interval of about 330 years (c. AD 1570,1900) when Northern Hemisphere summer temperatures (land areas north of 20°N) fell significantly below the AD 1961,1990 mean. This climatic definition overlaps the times when the Alpine glaciers attained their latest two highstands (AD 1650 and 1850). It is emphasized, however, that ,Little Ice Age' glacierization was highly dependent on winter precipitation and that ,Little Ice Age' climate was not simply a matter of summer temperatures. Both the glacier-centred and the climate-centred concepts necessarily encompass considerable spatial and temporal variability, which are investigated using maps of mean summer temperature variations over the Northern Hemisphere at 30-year intervals from AD 1571 to 1900. ,Little Ice Age'-type events occurred earlier in the Holocene as exemplified by at least seven glacier expansion episodes that have been identified in southern Norway. Such events provide a broader context and renewed relevance for the ,Little Ice Age', which may be viewed as a ,modern analogue' for the earlier events; and the likelihood that similar events will occur in the future has implications for climatic change in the twenty-first century. It is concluded that the concept of a ,Little Ice Age' will remain useful only by (1) continuing to incorporate the temporal and spatial complexities of glacier and climatic variations as they become better known, and (2) by reflecting improved understanding of the Earth-atmosphere-ocean system and its forcing factors through the interaction of palaeoclimatic reconstruction with climate modelling. [source] September 11, Anti-Terror Laws and Civil Liberties: Britain, France and Germany Compared1GOVERNMENT AND OPPOSITION, Issue 1 2003Dirk Haubrich The attacks on the United States of America in September 2001 have spurred a rapid implementation of new Anti-Terrorism legislation around the world. In an effort to, ostensibly, safeguard against the repetition of similar events on their own territories, many democracies have taken far-reaching legislative steps that might threaten the ideal of liberty on which their societies have traditionally been built. This article examines the laws introduced in Britain, France and Germany to establish the extent to which civil liberties in eight different categories have been curtailed. It concludes that, despite the otherwise similar characteristics of the countries studied, the legal provisions differ significantly in scope and depth, a fact that might be explained by: the different levels of threat perception; Britain's history of anti-terror legislation; and the respective power balances between judiciaries and legislatures. [source] Fuel sensing and the central nervous system (CNS): implications for the regulation of energy balance and the treatment for obesityOBESITY REVIEWS, Issue 3 2005R. J. Seeley Summary This review describes the product of the 3-day International Association for the Study of Obesity (IASO) Stock Conference held in March 2004 and sponsored by Abbott Laboratories. The conference was focused on how the mechanisms by which individual cells sense their own fuel status might influence the energy balance of the entire organism. Whether you are a single-celled organism or a sophisticated mammal with a large cerebral cortex, it is critical that cellular activity be matched to the available fuel necessary for that activity. Rapid progress has been made in the last decade in our understanding of the critical metabolic events that cells monitor to accomplish this critical task. More recent developments have begun to apply this understanding to how critical populations of neurones may monitor similar events to control both food intake and energy expenditure. The picture that emerges is that numerous peripheral fuel sensors communicate to the central nervous system (CNS) via neural and humoral routes. Moreover, it has been known for decades that specific populations of neurones sense changes in ambient glucose levels and adjust their firing rate in response and changes in neuronal glucose metabolism can influence energy balance. The CNS, however, does not just sense glucose but rather appears to be sensitive to a wide range of metabolic perturbations associated with fuel availability. This information is used to adjust both caloric intake and the disposition of fuels in the periphery. Increased understanding of these CNS fuel-sensing mechanisms may lead to novel therapeutic targets for obesity. [source] Perception of a cetacean mass stranding in Italy: the emergence of compassionAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 6 2010Giovanni Bearzi Abstract 1The view that whales are malicious monsters has been pervasive throughout history. Conversely, the idea that these animals experience suffering has emerged only recently. One way of investigating perceptual, as well as behavioural, shifts is assessing general public reactions to mortality events involving wild, rare and charismatic animals. 2Here, the responses of 118 individuals to questions regarding the mass stranding of seven sperm whales (Physeter macrocephalus) along the Adriatic Sea coast of Italy in December 2009 are reported through interviews taken at the stranding site and in the direct proximity of the dead animals. 3When asked why the whales were stranded, 44.1% of the respondents suggested anthropogenic causes and 21.2% non-anthropogenic. The remaining 34.7% mentioned a generic ,disorientation' or stated they did not know. When asked how they felt about the whales, 68.6% expressed feelings of compassion or care towards the animals. Clearly non-compassionate attitudes accounted for only 4.1% of the sample. Finally, 21.2% expressed feelings that were ambiguous in terms of being suggestive of compassionate or non-compassionate attitudes, including 11.9% amazement, 4.2% deprecation and 5.1% powerlessness. 4These results are in stark contrast with information obtained from accounts of similar events that have occurred in historical times, up until the first half of the 20th century. For centuries, responses to cetacean live strandings,typically including killing and harming of the animals,were either utilitarian or characterized by feelings including fear and a desire to ,subjugate the beast', with no apparent concern for their suffering and death. 5It is concluded that attitudes towards whales,today strikingly revolving around sadness, compassion and a sense of loss,have changed dramatically over time, with a steep turnaround in the 1970/1980s. Full appreciation of the ongoing evolution in public perception can channel marine conservation efforts and assist in the design of response strategies to marine mammal strandings. Copyright © 2010 John Wiley & Sons, Ltd. [source] | |||||||||||||