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Search Results: 1 - 10 of 213623 matches for " Sarah L. Pallas "
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Cross-Modal Plasticity Results in Increased Inhibition in Primary Auditory Cortical Areas
Yu-Ting Mao,Sarah L. Pallas
Neural Plasticity , 2013, DOI: 10.1155/2013/530651
Abstract: Loss of sensory input from peripheral organ damage, sensory deprivation, or brain damage can result in adaptive or maladaptive changes in sensory cortex. In previous research, we found that auditory cortical tuning and tonotopy were impaired by cross-modal invasion of visual inputs. Sensory deprivation is typically associated with a loss of inhibition. To determine whether inhibitory plasticity is responsible for this process, we measured pre- and postsynaptic changes in inhibitory connectivity in ferret auditory cortex (AC) after cross-modal plasticity. We found that blocking GABAA receptors increased responsiveness and broadened sound frequency tuning in the cross-modal group more than in the normal group. Furthermore, expression levels of glutamic acid decarboxylase (GAD) protein were increased in the cross-modal group. We also found that blocking inhibition unmasked visual responses of some auditory neurons in cross-modal AC. Overall, our data suggest a role for increased inhibition in reducing the effectiveness of the abnormal visual inputs and argue that decreased inhibition is not responsible for compromised auditory cortical function after cross-modal invasion. Our findings imply that inhibitory plasticity may play a role in reorganizing sensory cortex after cross-modal invasion, suggesting clinical strategies for recovery after brain injury or sensory deprivation. 1. Introduction Loss of sensory drive as a result of deprivation or deafferentation can lead to a compensatory plastic reorganization of the affected sensory cortex. For example, a homeostatic downregulation of inhibition makes cortical neurons more sensitive to any remaining inputs (see [1], for review). Although the plastic response to the loss of drive can be limited to a single modality, sprouting of inputs responding to other sensory modalities into the deafferented area often results in cross-modal plasticity. For example, in deaf and blind subjects, the spared sensory cortex can be taken over by sensory inputs from other sensory modalities [2–4]. Such cross-modal inputs replace the lost inputs to some extent; thus the mechanisms of recovery might be different from recovery from manipulations affecting a single modality [5]. Because sensory inputs have been changed rather than lost entirely, the loss of inhibition seen after unimodal deprivation may be mitigated. It is important to understand whether cross-modal plasticity has similar or different effects on inhibition than within-modality plasticity because of the prevalence of cross-modal plasticity in patients suffering from
Technology paternalism – wider implications of ubiquitous computing
Sarah Spiekermann,Frank Pallas
Poiesis & Praxis , 2006, DOI: 10.1007/s10202-005-0010-3
Abstract: Die Technologien des “Ubiquitous Computing” werden weit gehende Auswirkungen auf unser t gliches Leben haben. Derzeit bewegen sich die meisten Debatten zu den sozialen Auswirkungen haupts chlich in den Gebieten des Datenschutzes und der Datensicherheit. Dennoch vertreten die Autoren dieses Artikels die Auffassung, dass auch weitere Aspekte aus der sozialen Perspektive betrachtet werden müssen. Insbesondere wird die Frage aufgeworfen, wie Menschen in einer Umgebung, die immer weiter autamatisiert sein soll, weiterhin die Kontrolle behalten k nnen. Unter Hinweis auf die M glichkeit, dass Menschen von autonom agierenden Maschinen kontrolliert werden k nnten, führen wir Autoren den Begriff des Technologiepaternalismus ein. Wir entwickeln hierzu eine Arbeitsdefinition und illustrieren das Konzept anhand bereits existierender wie auch m glicher zukünftiger Technologien. Wir gehen zudem auf die Beziehung zwischen Allgegenw rtigkeit und Kontrolle ein und schlagen stellen Ans tze zur Sicherstellung einer angemessenen Balance unterschiedlicher Interessen vor. Einer dieser Vorschl ge ist ein generelles “Recht auf das letzte Wort”.
Revolutionary, advocate, agent, or authority: context-based assessment of the democratic legitimacy of transnational civil society actors
Christopher L. Pallas
Ethics & Global Politics , 2010, DOI: 10.3402/egp.v3i3.4882
Abstract: The literature on transnational civil society encompasses a number of conflicting views regarding civil society organizations’ (CSOs) behavior and impacts and the desirability of civil society involvement in international policymaking. This piece suggests that this lack of consensus arises from the diverse range of contexts in which CSOs operate and the wide variety of activities in which they engage. This article seeks to organize and analyze the disparate data on civil society by developing a context-based standard of democratic legitimacy for CSOs. The article disaggregates democracy into input, throughput, and output components, and shows how CSOs must support or manifest different aspects of democracy in order to be democratically legitimate in a given context. Applying this standard to existing works, the article identifies several problems in current research, including a failure to recognize ways the democratic imperatives of transnational advocacy differ from national advocacy, and the potential for international civil society interventions to undermine local democratic processes.
A Digital Atlas to Characterize the Mouse Brain Transcriptome
James P Carson ,Tao Ju,Hui-Chen Lu,Christina Thaller,Mei Xu,Sarah L Pallas,Michael C Crair,Joe Warren,Wah Chiu,Gregor Eichele
PLOS Computational Biology , 2005, DOI: 10.1371/journal.pcbi.0010041
Abstract: Massive amounts of data are being generated in an effort to represent for the brain the expression of all genes at cellular resolution. Critical to exploiting this effort is the ability to place these data into a common frame of reference. Here we have developed a computational method for annotating gene expression patterns in the context of a digital atlas to facilitate custom user queries and comparisons of this type of data. This procedure has been applied to 200 genes in the postnatal mouse brain. As an illustration of utility, we identify candidate genes that may be related to Parkinson disease by using the expression of a dopamine transporter in the substantia nigra as a search query pattern. In addition, we discover that transcription factor Rorb is down-regulated in the barrelless mutant relative to control mice by quantitative comparison of expression patterns in layer IV somatosensory cortex. The semi-automated annotation method developed here is applicable to a broad spectrum of complex tissues and data modalities.
Individual and community level socioeconomic inequalities in contraceptive use in 10 Newly Independent States: a multilevel cross-sectional analysis
Janevic Teresa,Sarah Pallas W,Leyla Ismayilova,Elizabeth Bradley H
International Journal for Equity in Health , 2012, DOI: 10.1186/1475-9276-11-69
Abstract: Introduction Little is known regarding the association between socioeconomic factors and contraceptive use in the Newly Independent States (NIS), countries that have experienced profound changes in reproductive health services during the transition from socialism to a market economy. Methods Using 2005–2006 data from Demographic Health Surveys (Armenia, Azerbaijan, and Moldova) and Multiple Indicator Cluster Surveys (Belarus, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan, Ukraine, and Uzbekistan), we examined associations between individual and community socioeconomic status with current modern contraceptive use (MCU) among N = 55,204 women aged 15–49 married or in a union. Individual socioeconomic status was measured using quintiles of wealth index and education level (higher than secondary school, secondary school or less). Community socioeconomic status was measured as the percentage of households in the poorest quintile of the nationals household wealth index (0%, 0–25%, or greater than 25%). We used multilevel logistic regression to estimate associations adjusted for age, number of children, urban/rural, and socioeconomic variables. Results MCU varied by country from 14% (in Azerbaijan) to 62% (in Belarus). Overall, women living in the poorest communities were less likely than those in the richest to use modern contraceptives (adjusted odds ratio (aOR) = 0.82, 95% Confidence Interval = 0.76, 0.89). Similarly, there was an increasing odds of MCU with increasing individual-level wealth. Women with a lower level of education also had lower odds of MCU than those with a higher level of education (aOR = .75, 95%CI = 0.71, 0.79). In country-specific analyses, community-level socioeconomic inequalities were apparent in 4 of 10 countries; in contrast, inequalities by individual-level wealth were apparent in 7 countries and by education in 8 countries. All countries in which community-level socioeconomic status was associated with MCU were in Central Asia, whereas at the individual-level inequalities of the largest magnitude were found in the Caucasus. There were no distinct patterns found in Eastern European countries. Conclusions Community-level socioeconomic inequalities in MCU were most pronounced in Central Asian countries, whereas individual-level socioeconomic inequalities in MCU were most pronounced in the Caucasus. It is important to consider multilevel contextual determinants of modern contraceptive use in the development of reproductive health and family planning programs.
Economics of Households in Pacific Island Countries: A Case Study of Vanuatu and Tuvalu  [PDF]
Ranjila Devi Singh, Sarah L. Hemstock
Theoretical Economics Letters (TEL) , 2013, DOI: 10.4236/tel.2013.35A3001
Abstract:

The source of livelihood varies amongst the Pacific Island Countries and also within a country; between urban and rural areas. Most Pacific Island Countries (PICs) and their households rely on subsistence activities and agriculture for their livelihood. This research was based on surveys conducted in Piliura and Tassiriki villages in Vanuatu and Vaiaku, Senala and Tumaseu villages in Tuvalu, which involved developing a methodology for household surveys to elucidate issues linked to livelihood. The analysis revealed that the major source of household income in Vanuatu study sites was from the sale of products, while in Funafuti (Tuvalu) households earned the majority of their income from wages/salaries. However, in Tumaseu village (Tuvalu) the households generated their source of income from both wages and sale of products. In all the study sites, food was the major household expense. This study was aimed at allowing researchers and decision makers a better understanding of the economic realities for households in PICs.

Biology of recently discovered cytokines: Interleukin-17 – a unique inflammatory cytokine with roles in bone biology and arthritis
Sarah L Gaffen
Arthritis Research & Therapy , 2004, DOI: 10.1186/ar1444
Abstract: The cytokine IL-17, originally termed CTLA-8, was isolated as a CD4-specific transcript from a rodent cDNA library [1]. Shortly thereafter, IL-17 was discovered in humans, and its receptor (IL-17R) was cloned and characterized [2-4]. The most striking feature of both IL-17 and IL-17R is that they are distinct in sequence from previously described cytokine/receptor families. However, they are highly homologous among mice, rats, and humans. In addition, an IL-17R homolog in zebrafish (termed SEF [similar expression of FGF genes]) has been described that functions in embryonic development [5], and mammalian homologs of SEF were also recently identified [6,7]. Consequently, IL-17 and IL-17R are now recognized to be the founding members of an emerging new family that, in mammals, contains at least six cytokines and five receptors (Table 1[8,9]). This review focuses primarily on the original IL-17 cytokine (also known as IL-17A), because its roles in bone physiology and arthritis are most clearly defined, but the biology of the remaining family members promises to be a fascinating emerging story within the field of 'high numbered' cytokines.Even though IL-17 and IL-17R have been recognized for many years, there is still much to learn about their respective structures and functions. IL-17 is secreted primarily by CD4+ T cells in a mix of both nonglycosylated and N-glycosylated forms, which migrate in SDS-PAGE at 28 kDa and 33 kDa, respectively [2]. Secreted IL-17 apparently exists as a homodimer, but the specific contact points between IL-17 subunits or between IL-17 and IL-17R have never been defined [2,10]. IL-17B and IL-17F also exist as dimers [10,11]. While the amino acid sequence of IL-17 did not permit it to be classified as a member of any known cytokine families, X-ray crystallographic studies of IL-17F – its closest homolog – have been performed. Interestingly, the three-dimensional structure of IL-17F takes on a 'cystine knot fold', and hence resembles the neuro
Palaeolithic-Mesolithic Day Meeting, British Museum, 17th March 1995
Sarah L. R. Mason
Papers from the Institute of Archaeology , 1995, DOI: 10.5334/pia.71
Abstract:
Neolithic Studies Group Autumn Meeting: Domestic Settlement and the Landscape, British Museum, 14th November 1994
Sarah L. R. Mason
Papers from the Institute of Archaeology , 1995, DOI: 10.5334/pia.75
Abstract:
Vitamin K: food composition and dietary intakes
Sarah L. Booth
Food & Nutrition Research , 2012, DOI: 10.3402/fnr.v56i0.5505
Abstract: Vitamin K is present in the diet in the forms of phylloquinone and menaquinones. Phylloquinone, which is the major dietary source, is concentrated in leafy plants and is the vitamin K form best characterized in terms of food composition and dietary intakes. In contrast, menaquinones are the product of bacterial production or conversion from dietary phylloquinone. Food composition databases are limited for menaquinones and their presence in foods varies by region. Dietary intakes of all forms of vitamin K vary widely among age groups and population subgroups. Similarly, the utilization of vitamin K from different forms and food sources appear to vary, although our understanding of vitamin K is still rudimentary in light of new developments regarding the menaquinones.
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