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Marked Shift (marked + shift)
Selected AbstractsCallosal contribution to ocular dominance in rat primary visual cortexEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2010Chiara Cerri Abstract Ocular dominance (OD) plasticity triggered by monocular eyelid suture is a classic paradigm for studying experience-dependent changes in neural connectivity. Recently, rodents have become the most popular model for studies of OD plasticity. It is therefore important to determine how OD is determined in the rodent primary visual cortex. In particular, cortical cells receive considerable inputs from the contralateral hemisphere via callosal axons, but the role of these connections in controlling eye preference remains controversial. Here we have examined the role of callosal connections in binocularity of the visual cortex in naïve young rats. We recorded cortical responses evoked by stimulation of each eye before and after acute silencing, via stereotaxic tetrodotoxin (TTX) injection, of the lateral geniculate nucleus ipsilateral to the recording site. This protocol allowed us to isolate visual responses transmitted via the corpus callosum. Cortical binocularity was assessed by visual evoked potential (VEP) and single-unit recordings. We found that acute silencing of afferent geniculocortical input produced a very significant reduction in the contralateral-to-ipsilateral (C/I) VEP ratio, and a marked shift towards the ipsilateral eye in the OD distribution of cortical cells. Analysis of absolute strength of each eye indicated a dramatic decrease in contralateral eye responses following TTX, while those of the ipsilateral eye were reduced but maintained a more evident input. We conclude that callosal connections contribute to normal OD mainly by carrying visual input from the ipsilateral eye. These data have important implications for the interpretation of OD plasticity following alterations of visual experience. [source] POSTFIRE SUCCESSION IN AN ADIRONDACK FOREST,GEOGRAPHICAL REVIEW, Issue 4 2007Susy Svatek Ziegler ABSTRACT. Landscape diversity has increased with the surprising postfire establishment of aspen at upper elevations (700,945 meters above sea level) in the High Peaks of Adirondack Park in upstate New York. Tree seedlings returned quickly to the charred slopes west of Noonmark Mountain after an accidental fire consumed the forest in 1999. Aspen stands have replaced the spruce-fir-birch forests in the burned area even though mountain paper birch is expected to colonize burned sites at these elevations. Environmental conditions, historical events, and unique circumstances help explain why quaking aspen and bigtooth aspen rather than paper birch blanket the burned mountainside. Climate change over the past century to warmer, wetter conditions may have fostered this marked shift in species composition. In the unburned firebreak that people cleared to contain the flames, pin cherry has regenerated from seeds stored in the soil for nearly a century. The history of pin cherry on the site suggests that large fires or severe windthrow may have been more common in the region than was previously documented. [source] Alteration of the food web along the Antarctic Peninsula in response to a regional warming trendGLOBAL CHANGE BIOLOGY, Issue 12 2004Mark A. Moline Abstract In the nearshore coastal waters along the Antarctic Peninsula, a recurrent shift in phytoplankton community structure, from diatoms to cryptophytes, has been documented. The shift was observed in consecutive years (1991,1996) during the austral summer and was correlated in time and space with glacial melt-water runoff and reduced surface water salinities. Elevated temperatures along the Peninsula will increase the extent of coastal melt-water zones and the seasonal prevalence of cryptophytes. This is significant because a change from diatoms to cryptophytes represents a marked shift in the size distribution of the phytoplankton community, which will, in turn, impact the zooplankton assemblage. Cryptophytes, because of their small size, are not grazed efficiently by Antarctic krill, a keystone species in the food web. An increase in the abundance and relative proportion of cryptophytes in coastal waters along the Peninsula will likely cause a shift in the spatial distribution of krill and may allow also for the rapid asexual proliferation of carbon poor gelatinous zooplankton, salps in particular. This scenario may account for the reported increase in the frequency of occurrence and abundance of large swarms of salps within the region. Salps are not a preferred food source for organisms that occupy higher trophic levels in the food web, specifically penguins and seals, and thus negative feedbacks to the ecology of these consumers can be anticipated as a consequence of shifts in phytoplankton community composition. [source] Religion and the secularisation of health careJOURNAL OF CLINICAL NURSING, Issue 14 2009John Paley Aims and objectives., To assess the claim that conceptualisations of religion and spirituality should be grounded in theology, and acknowledge the global resurgence of religion. Background., Although there is widespread agreement in the nursing literature that ,spirituality' is a broader concept than ,religion,' and should be understood generically, this approximate consensus has occasionally been challenged. A recent paper by Barbara Pesut and colleagues argues that the generic view not only empties spirituality of powerful religious symbols and narratives, but underestimates the continuing social influence of religion, and its resurgence on a global scale. Accordingly, these authors suggest three principles for conceptualising spirituality and religion in health care, one of which is that conceptualisations should be grounded in philosophical and theological thinking, and should not ignore the global resurgence of religion. Method., Critical review. Conclusion., The Pesut principle privileges theology, disregarding other disciplines which theorise religion. Arguably, it privileges specifically Christian theology, the history of which suggests a politics of orthodoxy and an epistemology of authority and obedience. The global resurgence of religion is not, in fact, global, as the industrialised countries have experienced a marked shift towards secular-rational values; and the postindustrial phase of development is associated with self-expression values, which represent a challenge not merely to religious institutions (arguably an affirmation of ,spirituality') but to traditional elites and structures of all kinds. Finally, religion ,resurgent' is not an attractive model for health care, since many of its most obvious manifestations are incompatible with the ideology of health professionals. Relevance to clinical practice., In the secular societies of Europe, if not North America, there should be no expectation that nurses provide spiritual care. It is a requirement of the great separation between civil order and religion that the health services, as a public space, should remain thoroughly secular. [source] Egg cannibalism in Barents Sea capelin in relation to a narrow spawning distributionJOURNAL OF FISH BIOLOGY, Issue 1 2006A. Slotte The spawning distribution of Barents Sea capelin Mallotus villosus off northern Norway in 2002 was restricted to a narrow area at the easternmost spawning grounds. There was an increase in abundance and a marked shift in aggregation area from east towards west during 11 March to 4 April, as the capelin went from prespawning through spawning to spent stages. The capelin stomachs were either empty or contained capelin eggs, often mixed with sand. Both the occurrence of cannibals and stomach fullness increased with stage of maturity, being highest in spent fish, and higher in males than in females. No differences were found between cannibals and non-cannibals of the same sex when adjusted for total length (LT), age, LT at age and condition factor. At similar stomach fullness, the females had consumed more eggs than the males. This was attributed to a higher proportion of empty and broken eggs and less sand in females compared to males. In the full stomachs, the mean consumption in females and males was 623 and 334 eggs, respectively, whereas the respective maximum egg consumption was 871 and 683 eggs. The minimum estimates (given no digestion) of mean ± 95% CL egg consumption in spent females and males were 75·4 ± 6·9 and 58·4 ± 12·0 eggs, respectively, implying a minimum mortality of 1,2% of the total egg production caused by cannibalism. [source] United States vital statistics and the measurement of gestational agePAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2007Joyce A. Martin Summary Estimates of the gestational age of the newborn based on US Birth Certificate data are extensively used to monitor trends in infant and maternal health and to improve our understanding of adverse pregnancy outcome. Two measures of gestational age, the ,date of the last normal menses' (LMP) and the ,clinical estimate of gestation' (CE), have been available from birth certificate data since 1989. Reporting irregularities with the LMP-based measure are well-documented, and important questions remain regarding the derivation of the CE. Changes in perinatal medicine and in vital statistics reporting in recent years may have importantly altered gestational age data based on vital statistics. This study describes how gestational age measures are collected and edited in US national vital statistics, and examines changes in the reporting of these measures by race and Hispanic origin between 1990 and 2002. Data are drawn from the National Center for Health Statistics' restricted use US birth files for 1990,2002. Bivariable statistics are used. The percentage of records with missing LMP dates declined markedly over the study period, overall, and for each racial/Hispanic origin group studied. A marked shift in the distribution of the CE of gestational age was also observed, suggesting changes both in the true distribution of age at birth, and in the derivation of this measure. Agreement between the LMP-based and CE estimates increased over the study period, especially among preterm births. However, a high proportion of LMP dates continue to be missing or invalid and the derivation of the CE is still uncertain. In sum, although the reporting of gestational age measures in vital statistics appears to have improved between 1990 and 2002, substantial concerns with both the LMP-based and the CE persist. Efforts to identify approaches to further improve upon the quality of these data are needed. [source] The influence of masticatory loading on craniofacial morphology: A test case across technological transitions in the Ohio valleyAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Carolina Paschetta Abstract Masticatory loading is one of the main environmental stimuli that generate craniofacial variation among recent humans. Experimental studies on a wide variety of mammals, including those with retrognathic postcanine teeth, predict that responses to masticatory loading will be greater in the occlusal plane, the inferior rostrum, and regions associated with the attachments of the temporalis and masseter muscles. Here we test these experimentally-derived predictions on an extinct human population from the middle and upper Ohio valley that underwent a marked shift from hunting-gathering to extensive farming during the last 3,000 years and for which we have good archaeological evidence about diet and food processing technology. Geometric morphometric methods were used to detect and measure the putative effect of diet changes on cranial shape independent of size. Our results partially confirm only some of the experimental predictions. The effect of softer and/or less tough diets on craniofacial shape seem to be concentrated in the relative reduction of the temporal fossa and in a displacement of the attachment of the temporal muscle. However, there were few differences in craniofacial shape in regions closer to the occlusal plane. These results highlight the utility of exploring specific localized morphological shifts using a hierarchical model of craniofacial integration. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] Changes in biological anthropology: Results of the 1998 American Association of Physical Anthropology Membership SurveyAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2002Trudy R. Turner Abstract In response to the results of the 1996 survey of the membership of the American Association of Physical Anthropology (AAPA), the Executive Committee of the Association sponsored a follow-up survey designed to assess gender and specialty differences in training, employment, academic status, mentoring, and research support. A total of 993 questionnaires was analyzed, representing approximately 62% of the 1998 membership of the Association. There has been a marked shift in the number of males and females in the discipline from the 1960s to the 1990s. While 51.2% of all respondents are female and 48.8% are male, 70% of the students are female. Chi-square tests indicate significant differences between males and females by highest degree, age, status, obtaining a tenure-track position, receiving tenure, and taking nontenure-track employment before receiving a tenure-track position. In recent years, there has been an increasing number of females in the ranks of assistant and associate professors; however, this is not true for the rank of professor. There are also significant differences between males and females by specialty within the discipline: researchers in primatology, human biological variation, skeletal biology, and paleopathology are primarily female, while researchers in human and primate evolution are increasingly female. Am J Phys Anthropol 118:111,116, 2002. © 2002 Wiley-Liss, Inc. [source] It's a long way to Auchterarder! ,Negotiated management' and mismanagement in the policing of G8 protests1THE BRITISH JOURNAL OF SOCIOLOGY, Issue 2 2008Hugo Gorringe Abstract Recent analyses of protest policing in Western democracies argue that there has been a marked shift away from oppressive or coercive approaches to an emphasis on consensus based negotiation. King and Waddington (2005) amongst others, however, suggest that the policing of international summits may be an exception to this rule. This paper examines protest policing in relation to the 2005 G8 summit in Gleneagles, Scotland. We argue that ,negotiated management' cannot be imported wholesale as a policing strategy. Rather it is mediated by local history, forms of police knowledge and modes of engagement. Drawing on interviews and participant observation we show that ,negotiated management' works best when both sides are committed to negotiation and that police stereotyping or protestor intransigence can lead to the escalation of any given event. In closing we note the new challenges posed by forms of ,global' protest and consider the implications for future policing of protest. [source] International Conflict and the Tenure of Leaders: Is War Still Ex Post Inefficient?AMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 3 2004Giacomo Chiozza Recent work in comparative politics and international relations has shown a marked shift toward leaders as the theoretical unit of analysis. In most of the new theoretical models a core assumption is that leaders act to stay in power. There exists, however, remarkably little systematic empirical knowledge about the factors that affect the tenure of leaders. To provide a baseline of empirical results we explore how a broad range of domestic and international factors affects the tenure of leaders. We focus in particular on the effect of conflict and its outcome. We find that political institutions fundamentally mediate the costs and benefits of international conflict and that war is not necessarilyex postinefficient for leaders. This suggests that the assumption that war isex postinefficient for unitary rational actors can not be simply extended to leaders. Therefore, a focus on leaders may yield important new rationalist explanations for war. [source] Regulation of secondary metabolism by the carbon,nitrogen status in tobacco: nitrate inhibits large sectors of phenylpropanoid metabolismTHE PLANT JOURNAL, Issue 4 2006Christina Fritz Summary Interactions between nitrogen and carbon metabolism modulate many aspects of the metabolism, physiology and development of plants. This paper investigates the contribution of nitrate and nitrogen metabolism to the regulation of phenylpropanoid and nicotine synthesis. Wild-type tobacco was grown on 12 or 0.2 mm nitrate and compared with a nitrate reductase-deficient mutant [Nia30(145)] growing on 12 mm nitrate. Nitrate-deficient wild-type plants accumulate high levels of a range of phenylpropanoids including chlorogenic acid, contain high levels of rutin, are highly lignified, but contain less nicotine than nitrogen-replete wild-type tobacco. Nia30(145) resembles nitrate-deficient wild-type plants with respect to the levels of amino acids, but accumulates large amounts of nitrate. The levels of phenylpropanoids, rutin and lignin resemble those in nitrogen-replete wild-type plants, whereas the level of nicotine resembles that in nitrate-deficient wild-type plants. Expression arrays and real time RT-PCR revealed that a set of genes required for phenylpropanoid metabolism including PAL, 4CL and HQT are induced in nitrogen-deficient wild-type plants but not in Nia30(145). It is concluded that nitrogen deficiency leads to a marked shift from the nitrogen-containing alkaloid nicotine to carbon-rich phenylpropanoids. The stimulation of phenylpropanoid metabolism is triggered by changes of nitrate, rather than downstream nitrogen metabolites, and is mediated by induction of a set of enzymes in the early steps of the phenylpropanoid biosynthetic pathway. [source] | ||||||||||||||||