Vital Role (vital + role)

Distribution by Scientific Domains
Distribution within Medical Sciences

Selected Abstracts

Vital role of the itch,scratch response in development of spontaneous dermatitis in NC/Nga mice

K. Mihara
Summary Background, The itch sensation and the resultant response, scratching, are important symptoms of atopic dermatitis (AD) and have a significant impact on the quality of life of affected patients. However, the influence of the itch,scratch response on the pathology of AD has not been precisely elucidated. Objectives, To investigate the role of scratching behaviour in the development of spontaneous dermatitis using conventionally raised NC/Nga mice (Conv-NC mice), which are known to be an animal model for human AD. Methods, Capsaicin-sensitive sensory nerves of the mice were ablated by neonatal capsaicin treatment (Cap-NC mice), and the development of spontaneous dermatitis in the Cap-NC mice was compared chronologically with that in Conv-NC mice. Results, Scratching behaviour was almost completely prevented in Cap-NC mice raised for 84 days under conventional conditions, and the development of dermatitis and elevation of the serum IgE level were significantly suppressed. Histological analysis revealed that the numbers of infiltrating eosinophils and mast cells in the lesional skin of Cap-NC mice were lower than those in Conv-NC mice. Immunological studies showed that the capability of spleen T cells to produce both T-helper (Th) 1 (interferon-,) and Th2 [interleukin (IL)-5 and IL-13] cytokines was diminished in Cap-NC mice. Furthermore, serum levels of IL-18 were approximately twice higher in Conv-NC mice than in Cap-NC mice. Conclusions, These observations suggest that scratching behaviour contributes to the development of dermatitis by enhancing various immunological responses in the murine AD model, implying that prevention of the itch sensation and/or itch-associated scratching behaviour is an effective treatment for AD. [source]

Investigation of prolonged neonatal jaundice

S Hannam
Jaundice persisting beyond 14 d of age (prolonged jaundice) can be a sign of serious underlying liver disease. Protocols for investigating prolonged jaundice vary in complexity and the yield from screening has not been assessed. In order to address these issues, we carried out a prospective study of term infants referred to our neonatal unit with prolonged jaundice over an 18 mo period. Infants were examined by a paediatrician and had the following investigations: a total and conjugated serum bilirubin, liver function tests, full blood count, packed cell volume, group and Coombs' test, thyroid function tests, glucose-6-phosphate dehydrogenase levels and urine for culture. One-hundred-and-fifty-four infants were referred with prolonged jaundice out of 7139 live births during the study period. Nine infants were referred to other paediatric specialties. One infant had a conjugated hyperbilirubinaemia, giving an incidence of conjugated hyperbilirubinaemia of 0.14 per 1000 live births. Diagnoses included: giant cell hepatitis (n= 1), hepatoblastoma (n= 1), trisomy 9p (n= 1), urinary tract infections (n= 2), glucose-6-phosphate dehydrogenase deficiency (n= 3) and failure to regain birthweight (n= 1). Conclusions: In conclusion, a large number of infants referred to hospital for prolonged jaundice screening had detectable problems. The number of investigations may safely be reduced to: a total and conjugated bilirubin, packed cell volume, glucose-6-phosphate dehydrogenase level (where appropriate), a urine for culture and inspection of a recent stool sample for bile pigmentation. Clinical examination by a paediatrician has a vital role in the screening process. [source]

AMPK activators , potential therapeutics for metabolic and other diseases

G. Zhou
Abstract AMP-activated protein kinase (AMPK)-mediated cellular metabolic responses to tissue-specific and whole-body stimuli play a vital role in the control of energy homeostasis. As a cellular energy-sensing mechanism, AMPK activation stimulates glucose uptake and fat oxidation, while it suppresses lipogenesis and gluconeogenesis. The cumulative effects of AMPK activation lead to beneficial metabolic states in liver, muscle and other peripheral tissues that are critical in the pathogenesis of obesity, type 2 diabetes and related metabolic disorders. Activators of AMPK that target selected tissues hold potential as novel therapeutics for diseases in which altered energy metabolism contributes to aetiology. [source]

Communication and Context: Collective Tacit Knowledge and Practice in Japan's Workplace ba

Tim Ray
In contrast to Schumpeter's "perennial gale of creative destruction" (Schumpeter 1976: 84), government,coordinated economic development in post,1945 Japan has owed more to informal (but binding) "rules of the game" (North 1990) that situate working, learning and innovation within the spaces delineated by tightly bounded company,as,family workplace organisations or ,ba' (which roughly means ,place' or ,interaction field'). Horizontal keiretsu groupings, together with fixed trading,patterns in supply and distribution chains, continue to support an interlocking ,steady state' economic structure in which new technologies tend to emerge from existing organisations. Shared experience within workplace ba generates tacit knowledge that is held in common by colleagues and retained as a potent tool for shaping future practice. It plays a vital role in facilitating ,friction free' communication amongst insiders, who can act as a group to ostracise and retaliate against agents who break their code. Long,term obligations link salaried male employees to their workplace ba. Consequently, autonomous boundary,spanning communities of practice, together with industry,university collaboration and other transient associations with outsiders, lack legitimacy. Cook and Brown's (1999) pluralist epistemology is used to compare Western interpretations of Mode 1 and Mode 2 knowledge (Gibbons et al 1994) with the privileged role that Japan's workplace ba accord to insider collective,tacit knowledge, which we tentatively call ,Mode 3' knowledge. [source]

Debridement and wound bed preparation

Anna F. Falabella
ABSTRACT:, Debridement can play a vital role in wound bed preparation and the removal of barriers that impair wound healing. In accordance with the TIME principles, debridement can help remove nonviable tissue, control inflammation or infection, decrease excess moisture, and stimulate a nonadvancing wound edge. There are many types of debridement, each with a set of advantages and disadvantages that must be clearly understood by the healthcare team. Failure to use the correct debridement method for a given type of wound may lead to further delays in healing, increase patient suffering, and unnecessarily increase the cost of care. This review article discusses the various methods of debridement, describes currently available debriding agents, evaluates the clinical data regarding their efficacy and safety, and describes strategies for the management of problematic nonhealing wounds. [source]

Dopamine and sensory tissue development in Drosophila melanogaster

Wendi Neckameyer
Abstract Dopamine is an important signaling molecule in the nervous system; it also plays a vital role in the development of diverse non-neuronal tissues in the fruit fly Drosophila melanogaster. The current study demonstrates that males depleted of dopamine as third instar larvae (via inhibition of the biosynthetic enzyme tyrosine hydroxylase) demonstrated abnormalities in courtship behavior as adults. These defects were suggestive of abnormalities in sensory perception and/or processing. Electroretinograms (ERGs) of eyes from adults depleted of dopamine for 1 day as third instar larvae revealed diminished or absent on- and off-transients. These sensory defects were rescued by the addition of L -DOPA in conjunction with tyrosine hydroxylase inhibition during the larval stage. Depletion of dopamine in the first or second larval instar was lethal, but this was not due to a general inhibition of proliferative cells. To establish that dopamine was synthesized in tissues destined to become part of the adult sensory apparatus, transgenic lines were generated containing 1 or 4 kb of 5, upstream sequences from the Drosophila tyrosine hydroxylase gene (DTH) fused to the E. coli ,-galactosidase reporter. The DTH promoters directed expression of the reporter gene in discrete and consistent patterns within the imaginal discs, in addition to the expected expression in gonadal, brain, and cuticular tissues. The ,-galactosidase expression colocalized with tyrosine hydroxylase protein. These results are consistent with a developmental requirement for dopamine in the normal physiology of adult sensory tissues. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 280,294, 2001 [source]

Insulin resistance, diabetes and cardiovascular risk: approaches to treatment

Daniel E. Rosenberg
Abstract:, The prevalence of diabetes is increasing worldwide. Insulin resistance and diabetes mellitus are major predictors of cardiovascular ischaemic disease. Other risk factors for cardiovascular death including hypertension, dyslipidaemia, smoking and visceral obesity are especially lethal in diabetics. C-reactive protein, plasminogen activator inhibitor-1, matrix metalloproteinases and other emerging risk factors and their roles are continually being researched and discovered. Treatment of this syndrome must be aimed at lifestyle modification, glycaemic control and management of concomitant risk factors. Diet and exercise play a vital role in the treatment of diabetes and the metabolic syndrome. Weight reduction and increased physical activity will improve insulin resistance, hyperglycaemia, hypertension and dyslipidaemia. Hypertension management has been shown to be especially important in diabetics to prevent cardiovascular events. Likewise, multiple clinical trials show that reduction of cholesterol is even more vital in diabetics than the general population for risk reduction of coronary disease. There is a great deal of evidence that tight control of glycaemia is essential to treatment of this condition. There are a variety of available pharmacological agents available including metformin, insulin secretagogues, alpha-glucosidase inhibitors, thiazolidinediones and insulin. The mechanisms and side effects of these medications are discussed. As macrovascular disease is the major cause of morbidity and mortality, an early, aggressive, multi-factorial approach to treatment of the metabolic syndrome and diabetes is vital to prevent adverse cardiac outcomes. [source]

Diabetes: insulin resistance and derangements in lipid metabolism.

Cure through intervention in fat transport, storage
Abstract We present multiple findings on derangements in lipid metabolism in type 2 diabetes. The increase in the intracellular deposition of triglycerides (TG) in muscles, liver and pancreas in subjects prone to diabetes is well documented and demonstrated to attenuate glucose metabolism by interfering with insulin signaling and insulin secretion. The obesity often associated with type 2 diabetes is mainly central, resulting in the overload of abdominal adipocytes with TG and reducing fat depot capacity to protect other tissues from utilizing a large proportion of dietary fat. In contrast to subcutaneous adipocytes, the central adipocytes exhibit a high rate of basal lipolysis and are highly sensitive to fat mobilizing hormones, but respond poorly to lipolysis restraining insulin. The enlarged visceral adipocytes are flooding the portal circulation with free fatty acids (FFA) at metabolically inappropriate time, when FFA should be oxidized, thus exposing nonadipose tissues to fat excess. This leads to ectopic TG accumulation in muscles, liver and pancreatic beta-cells, resulting in insulin resistance and beta-cell dysfunction. This situation, based on a large number of observations in humans and experimental animals, confirms that peripheral adipose tissue is closely regulated, performing a vital role of buffering fluxes of FFA in the circulation. The central adipose tissues tend to upset this balance by releasing large amounts of FFA. To reduce the excessive fat outflow from the abdominal depots and prevent the ectopic fat deposition it is important to decrease the volume of central fat stores or increase the peripheral fat stores. One possibility is to downregulate the activity of lipoprotein lipase, which is overexpressed in abdominal relatively to subcutaneous fat stores. This can be achieved by gastrointestinal bypass or gastroplasty, which decrease dietary fat absorption, or by direct means that include surgical removal of mesenteric fat. Indirect treatment consists of the compliant application of drastic lifestyle change comprising both diet and exercise and pharmacotherapy that reduces mesenteric fat mass and activity. The first step should be an attempt to effectively induce a lifestyle change. Next comes pharmacotherapy including acarbose, metformin, PPAR,, or PPAR,, agonists, statins and orlistat, estrogens in postmenopausal women or testosterone in men. Among surgical procedures, gastric bypass has been proven to produce beneficial results in advance of other surgical techniques, the evidence basis of which still needs strengthening. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Daniel T. Griswold
Lord Bauer understood that the human freedom of movement plays a vital role in development. Today, internal and cross-border migration generates hard-currency remittances that raise living standards and capital investment in the country of origin, promotes greater trade and investment ties between destination and origin countries, and raises a country's stock of human and physical capital when migrants return with new skills and investment funds. Immigration can also stimulate political and social reform when migrants return or foreign-born immigrants arrive with new ideas and experiences. Relaxing the pervasive controls on the international movement of people remains a huge piece of unfinished business on the market-driven development agenda. [source]

Commercial aviation in-flight emergencies and the physician

Robert Cocks
Abstract Commercial aviation in-flight emergencies are relatively common, so it is likely that a doctor travelling frequently by air will receive a call for help at some stage in their career. These events are stressful, even for experienced physicians. The present paper reviews what is known about the incidence and types of in-flight emergencies that are likely to be encountered, the international regulations governing medical kits and drugs, and the liability, fitness and indemnity issues facing ,Good Samaritan' medical volunteers. The medical and aviation literature was searched, and information was collated from airlines and other sources regarding medical equipment available on board commercial aircraft. Figures for the incidence of significant in-flight emergencies are approximately 1 per 10,40 000 passengers, with one death occurring per 3,5 million passengers. Medically related diversion of an aircraft following an in-flight emergency may occur in up to 7,13% of cases, but passenger prescreening, online medical advice and on-board medical assistance from volunteers reduce this rate. Medical volunteers may find assisting with an in-flight emergency stressful, but should acknowledge that they play a vital role in successful outcomes. The medico-legal liability risk is extremely small, and various laws and industry indemnity practices offer additional protection to the volunteer. In addition, cabin crew receive training in a number of emergency skills, including automated defibrillation, and are one of several sources of help available to the medical volunteer, who is not expected to work alone. [source]

Halotaxis of cyanobacteria in an intertidal hypersaline microbial mat

Katharina Kohls
Summary An intertidal hypersaline cyanobacterial mat from Abu Dhabi (United Arab Emirates) exhibited a reversible change in its surface colour within several hours upon changes in salinity of the overlying water. The mat surface was orange-reddish at salinities above 15% and turned dark green at lower salinities. We investigated this phenomenon using a polyphasic approach that included denaturing gradient gel electrophoresis, microscopy, high-performance liquid chromatography, hyperspectral imaging, absorption spectroscopy, oxygen microsensor measurements and modelling of salinity dynamics. Filaments of Microcoleus chthonoplastes, identified based on 16S rRNA sequencing and morphology, were found to migrate up and down when salinity was decreased below or increased above 15%, respectively, causing the colour change of the mat uppermost layer. Migration occurred in light and in the dark, and could be induced by different salts, not only NaCl. The influence of salinity-dependent and independent physico-chemical parameters, such as water activity, oxygen solubility, H2S, gravity and light, was excluded, indicating that the observed migration was due to a direct response to salt stress. We propose to term this salinity-driven cyanobacterial migration as ,halotaxis', a process that might play a vital role in the survival of cyanobacteria in environments exposed to continuous salinity fluctuations such as intertidal flats. [source]

Cardiovascular Regulation through Hypothalamic GABAA Receptors in a Genetic Absence Epilepsy Model in Rat

EPILEPSIA, Issue 2 2002
Rezzan Gülhan Aker
Summary: ,Purpose: ,-Aminobutyric acid (GABA) plays a vital role in both central cardiovascular homeostasis and pathogenesis of epilepsy. Epilepsy affects autonomic nervous system functions. In this study, we aimed to clarify the role of GABAA receptors in hypothalamic cardiovascular regulation in a genetically determined animal model of absence epilepsy. Methods: Nonepileptic Wistar rats and genetic absence epilepsy rats from Strasbourg (GAERS) were instrumented with a guide cannula for drug injection and extradural electrodes for EEG recording. After a recovery period, iliac arterial catheters were inserted for direct measurement of mean arterial pressure and heart rate. Bicuculline, a GABAA -receptor antagonist, was injected into the dorsomedial (DMH) or posterior (PH) hypothalamic nuclei of nonepileptic control rats or GAERS. Blood pressure, heart rate, and EEG recordings were performed in conscious unrestrained animals. Results: Bicuculline injections into the hypothalamus produced increases in blood pressure and heart rate of both control rats and GAERS. The DMH group of GAERS showed a twofold increase in the blood pressure and the heart rate compared with those of control rats. Pressor responses to bicuculline, when microinjected into the PH, were similar in the nonepileptic animals and GAERS. Conversely, the amplitude of tachycardic responses to the administration of bicuculline into the PH was significantly higher in GAERS compared with those of control rats. Conclusions: The bicuculline-induced increases in blood pressure and heart rate were more prominent when given in the DMH of GAERS. These results indicate an increased GABAA receptor,mediated cardiovascular response through the DMH in conscious rats with absence epilepsy. [source]

The Effect of Male Incubation Feeding, Food and Temperature on the Incubation Behaviour of New Zealand Robins

ETHOLOGY, Issue 6 2010
Rebecca L. Boulton
Because of finite resources, organisms face conflict between their own self-care and reproduction. This conflict is especially apparent in avian species with female-only incubation, where females face a trade-off between time allocated to their own self-maintenance and the thermal requirements of developing embryos. We recorded incubation behaviour of the New Zealand robin (Petroica longipes), a species with female-only incubation, male incubation feeding and high nest predation rates. We examined how male incubation feeding, ambient temperature and food availability (invertebrate biomass) affected the different components of females' incubation behaviour and whether incubation behaviour explained variation in nest survival. Our results suggest that male incubation feeding rates of 2.8 per hour affect the female's incubation rhythm by reducing both on- and off-bout duration, resulting in no effect on female nest attentiveness, thus no support for the female-nutritional hypothesis. The incubation behaviours that we measured did not explain nest survival, despite high nest predation rates. Increased ambient temperature caused an increase in off-bout duration, whereas increased food availability increased on-bout duration. While males play a vital role in influencing incubation behaviour, female robins attempt to resolve the trade-off between their own foraging needs and the thermal requirements of their developing embryos via alternating their incubation rhythm in relation to both food and temperature. [source]

Surface Physiochemistry Affects Protein Adsorption to Stoichiometric and Silicate-Substituted Microporous Hydroxyapatites,

Katharina Guth
An important factor in the bioactivity and success of a bone-graft substitute is the nature of the adsorbed protein layer, which plays a vital role in orchestrating cell attachment and development through the presence of adhesion proteins such as fibronectin (Fn) and vitronectin (Vn). In this study, microporous hydroxyapatite (HA) and silicate-substituted hydroxyapatite (SA) discs with matched porosity and surface morphology are developed to mimic the topography found in commercial bone-graft substitutes in order to identify whether the introduction of microporosity and associated surface roughness eliminates the beneficial effect that silicate substitution has on protein adsorption. The introduction of microporosity does not abolish the relative enrichment of the protein layer that is adsorbed to the microporous SA discs, as opposed to HA, but appears to accelerate it. Fibronectin and Vn adsorption in a range of competitive environments at physiological temperatures confirm that the microporous SA discs have a greater affinity for Fn and Vn compared with HA, suggesting differences in the mechanisms behind the surface affinity to SA. Thus, development of a surface protein layer on SA and HA is likely to be dependent on the nature of the local protein environment and a combination of factors that are associated with the addition of silicate: the surface charge, the nature of the ionic species at the interface and the resultant hydrophilicity of the surface. Total protein adsorption is not found to be a good indicator of potential implant performance, particularly at early time points. [source]

Colours and Metallic Sheen in Beetle Shells , A Biomimetic Search for Material Structuring Principles Causing Light Interference,

T. Lenau
Abstract Visual aesthetic has always played a vital role for the success of many products. This includes colours and glossiness and metal appearance which is often achieved using surface coatings. Present coating techniques do, however, have limitations. It is difficult to reach very bright and brilliant colours, colours tend to fade over time and many of the materials and coating technologies pollute and have other environmental problems. Beetles in nature have many of the desired properties: They have appealing brilliant colours and some even with metallic appearance. It is noticeable that the colours are long lasting as some of the beetles we have studied at the zoological museum are more than 200 years old and have colours and brightness as if they were still alive. Furthermore, the beetles in nature are part of sustainable ecosystems, which means that they are made from renewable materials that are broken down and recycled when the beetle dies. Beetles also possess another and very attractive property: Their metallic look originates from structures in organic materials which is both electrically and thermal insulating. The industrial perspective is to be able to manufacture products with attractive metallic surfaces that do not feel so cold to touch as their metallic counterparts and that do not represent an electrical shock hazard. [source]

Analysis of 25 Years of Technology Research as Reported in Two Professional Journals: Journal of Family and Consumer Sciences and Family and Consumer Sciences Research Journal

Amy J. Leahy
During the past 25 years, the evaluation and exploration of technological advances within family and consumer sciences (FCS) have played a vital role in the evolution of the discipline. The goal of this investigation was to provide an historical perspective of the reporting of technology or technological innovations within the field of FCS. Titles of articles published in the Journal of Family and Consumer Sciences and the Family and Consumer Sciences Research Journal as well as theses and dissertations completed as listed in the Family and Consumer Sciences Research Journal were examined from 1982 to 2007. Items were included in this analysis if technology or technological content was included in the title. This study provides an analysis of various areas of interest, including geographic location of the author, FCS area, and individual focus or topic of the article, theses, or dissertation. [source]

Dration Models to Analyze Dating Relationships: The Controversial Role of Gift Giving

Ming-Hui Huang
Gifts are proclaimed to play a vital role in making dating relationships last. In this article, however, the authors look at not only the beneficial but also the detrimental effects of gift giving in relationships. To explore the double-edged effects of gifts, this study conceptualizes gift giving in dating relationships as including three aspects: self-gift, interpersonal gift exchange, and jointgift possession. Econometric duration models are used to suggest implications for individuals. It is found that using gifts to enhance the self, express love, and announce relationships,at the proper level of frequency,helps to ensure that a relationship will be successful and lasting. When used too frequently or too rarely, gifts can result in self-depreciation, create anxiety, and spoil relationships. Individuals are advised not to consume gifts indiscriminately and thereby induce negative effects. [source]

Structural modeling and mutational analysis of yeast eukaryotic translation initiation factor 5A reveal new critical residues and reinforce its involvement in protein synthesis

FEBS JOURNAL, Issue 8 2008
Camila A. O. Dias
Eukaryotic translation initiation factor 5A (eIF5A) is a protein that is highly conserved and essential for cell viability. This factor is the only protein known to contain the unique and essential amino acid residue hypusine. This work focused on the structural and functional characterization of Saccharomyces cerevisiae eIF5A. The tertiary structure of yeast eIF5A was modeled based on the structure of its Leishmania mexicana homologue and this model was used to predict the structural localization of new site-directed and randomly generated mutations. Most of the 40 new mutants exhibited phenotypes that resulted from eIF-5A protein-folding defects. Our data provided evidence that the C-terminal ,-helix present in yeast eIF5A is an essential structural element, whereas the eIF5A N-terminal 10 amino acid extension not present in archaeal eIF5A homologs, is not. Moreover, the mutants containing substitutions at or in the vicinity of the hypusine modification site displayed nonviable or temperature-sensitive phenotypes and were defective in hypusine modification. Interestingly, two of the temperature-sensitive strains produced stable mutant eIF5A proteins , eIF5AK56A and eIF5AQ22H,L93F, and showed defects in protein synthesis at the restrictive temperature. Our data revealed important structural features of eIF5A that are required for its vital role in cell viability and underscored an essential function of eIF5A in the translation step of gene expression. [source]

Institutional Environment and Sovereign Credit Ratings

Alexander W. Butler
We use a sample of 86 counties to examine the cross-sectional determinants of sovereign credit ratings. We find that the quality of a country's legal and political institutions plays a vital role in determining these ratings. A one-standard-deviation increase in our legal environment index results in an average credit rating increase of 0.466 standard deviations, even when we control for obvious factors such as GDP per capita, inflation, foreign debt per GDP, previous defaults, and general development. Although part of this effect is due to the legal environment's endogeneity, its relative importance is robust to endogeneity concerns. [source]

Post-return experiences and transnational belonging of return migrants: a Dutch,Moroccan case study

Abstract In this article we explore the links between return migration, belonging and transnationalism among migrants who returned from the Netherlands to northeast Morocco. While transnationalism is commonly discussed from the perspective of a receiving country, this study shows that transnationalism also plays a vital role in reconstructing post-return belonging. Return migration is not simply a matter of ,going home', as feelings of belonging need to be renegotiated upon return. While returnees generally feel a strong need to maintain various transnational practices, the meanings they attach to these practices depend on motivations for return, gender and age. For former (male) labour migrants, transnational practices are essential for establishing post-return belonging, whereas such practices are less important for their spouses. Those who returned as children generally feel uprooted, notwithstanding the transnational practices they maintain. The amount of agency migrants are able to exert in the return decision-making process is a key factor in determining the extent to which returnees can create a post-return transnational sense of home. [source]

Bone marrow and tumour stroma: an intimate relationship

Natalie C Direkze
Abstract In recent years the bone marrow has become recognized as a potential source of cells for non-haematopoietic wound healing, in some instances demonstrating surprising plasticity in providing new epithelial cells. On the other hand, the contribution of bone marrow derived cells to fibrosis and blood vessel formation is more widely acknowledged. Tumour stroma has a vital role to play in determining cancer growth and spread, and there is a growing realization that the bone marrow has a significant input into this desmoplastic response. This review focuses on the contribution of bone marrow cells to tumour stroma, highlighting the bone marrow as a potential new portal through which to direct anti-tumour therapies. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Extending Gregory VII's ,Friendship Network': Social Contacts in Late Eleventh-Century France

HISTORY, Issue 312 2008
In the last quarter of the eleventh century, the Roman Church had a capable ruler and defender in Pope Gregory VII (1073,85). Despite his otherwise charismatic authority, however, Gregory's ability to extend his influence beyond the papacy's more immediate control of Rome and the Campagna was limited. Filling this administrative and legal gap was the emerging office of legation, developing ad hoc under Gregory VII in matters of reform and law. Papal legates such as the French representative, Bishop Hugh of Die (later archbishop of Lyons), became crucial figures in the machinery of papal government. They assumed a vital role in the transmission of reforming legislation north of the Alps while effectively widening Gregory VII's ,friendship network' to encompass influential members of the local and regional clerical and lay elite. With the assistance of this ecclesiastical office, moreover, the papacy significantly enhanced its opportunity for social contacts, thereby strengthening its hold on the more distant provinces of Western Christendom. By focusing on existing and growing social networks in late eleventh-century France, this article examines Hugh of Die's role as an instrument of church reform, and assesses this legate's impact on the larger papal reform initiative in France. [source]

Surgical management of hepatolithiasis

HPB, Issue 3 2009
Sujit Vijay Sakpal
Abstract Background:, Globalization and intercontinental migration have not just changed the socioeconomic status of regions, but have also altered disease dynamics across the globe. Hepatolithiasis, although still rare, is becoming increasingly evident in the West because of immigration from the Asia-Pacific region, where the disease prevails in endemic proportions. Such rare but emerging diseases pose a therapeutic challenge to doctors. Methods:, Here, we briefly introduce the topic of hepatolithiasis and describe features of intrahepatic stones, the aetiology of hepatolithiasis and the symptoms and sequelae of the condition. We then provide a comprehensive review of the various management modalities currently in use to treat hepatolithiasis. Conclusions:, In our opinion, and as is evident from the literature, surgery remains the definitive treatment for hepatolithiasis. However, non-surgical procedures such as cholangiography, although limited in their therapeutic capabilities, play a vital role in diagnosis and preoperative evaluation. [source]

Evaluation of best system performance: Human, automated, and hybrid inspection systems

Xiaochun Jiang
Recently, 100% inspection with automated systems has seen more frequent application than traditional sampling inspection with human inspectors. Nevertheless, humans still outperform machines in most attribute inspection tasks. Because neither humans nor automation can achieve superior inspection system performance, hybrid inspection systems where humans work cooperatively with machines merit study. In response to this situation, this research was conducted to evaluate three of the following different inspection systems: (1) a human inspection system, (2) a computer search/human decision-making inspection system, and (3) a human/computer share search/decision-making inspection system. Results from this study showed that the human/computer share search/decision-making system achieve the best system performance, suggesting that both should be used in the inspection tasks rather than either alone. Furthermore, this study looked at the interaction between human inspectors and computers, specifically the effect of system response bias on inspection quality performance. These results revealed that the risky system was the best in terms of accuracy measures. Although this study demonstrated how recent advances in computer technology have modified previously prescribed notions about function allocation alternatives in a hybrid inspection environment, the adaptability of humans was again demonstrated, indicating that they will continue to play a vital role in future hybrid systems. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 137,152, 2003. [source]

Heaven-Appointed Educators of Mind: Catharine Beecher and the Moral Power of Women

HYPATIA, Issue 2 2004
CATHERINE VILLANUEVA GARDNERArticle first published online: 9 JAN 200
Catharine Beecher held that women possessed a moral power that could allow them to play a vital role in the moral and social progress of nineteenth century America. Problematically, this power could only be obtained through their subordination to the greatest social happiness. I wish to argue that this notion of subordination, properly framed within her ethico-religious system, can in fact lead to economic independence for women and a surprisingly robust conception of moral power. [source]

Serum lipids regulate dendritic cell CD1 expression and function

IMMUNOLOGY, Issue 3 2008
David S. Leslie
Summary Dendritic cells (DCs) are highly potent antigen-presenting cells (APCs) and play a vital role in stimulating naïve T cells. Treatment of human blood monocytes with the cytokines granulocyte,macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 stimulates them to develop into immature dendritic cells (iDCs) in vitro. DCs generated by this pathway have a high capacity to prime and activate resting T cells and prominently express CD1 antigen-presenting molecules on the cell surface. The presence of human serum during the differentiation of iDCs from monocytes inhibits the expression of CD1a, CD1b and CD1c, but not CD1d. Correspondingly, T cells that are restricted by CD1c showed poor responses to DCs that were generated in the presence of human serum, while the responses of CD1d-restricted T cells were enhanced. We chemically fractionated human serum to isolate the bioactive factors that modulate surface expression of CD1 proteins during monocyte to DC differentiation. The human serum components that affected CD1 expression partitioned with polar organic soluble fractions. Lysophosphatidic acid and cardiolipin were identified as lipids present in normal human serum that potently modulate CD1 expression. Control of CD1 expression was mediated at the level of gene transcription and correlated with activation of the peroxisome proliferator-activated receptor (PPAR) nuclear hormone receptors. These findings indicate that the ability of human DCs to present lipid antigens to T cells through expression of CD1 molecules is sensitively regulated by lysophosphatidic acid and cardiolipin in serum, which are ligands that can activate PPAR transcription factors. [source]

Single-Crystalline V2O5 Ultralong Nanoribbon Waveguides

Bin Yan
High-aspect-ratio V2O5 nanoribbons are synthesized by thermal vapor deposition technique. Our results reveal that the nanoribbons can serve as effective active optical waveguides. In addition, the observation of strong Raman signals collected at the end of the ribbon indicate that the unique nanostructure could play a vital role in Raman amplifers and other nonlinear photonic components. [source]

Prospering in a transition economy through information technology-supported organizational learning

Marius Janson
Abstract., This paper presents the findings of a longitudinal study of the Slovenian company Sava during its 1995,2004 transition period when it adapted to and prospered in a free market economy. The company is particularly interesting because of its successful transition from a socialist company operating in a protected market to a privatized company operating in a capitalist global market, as well as the pivotal role of information technology (IT)-supported organizational learning that brought about radical change and successful transition. Our investigation of Sava's experiences demonstrates how the company's increasing attention to organizational learning, integration of working and learning, and its constant innovation of products and processes created new needs for IT support that motivated the adoption of new IT systems (such as Lotus Notes, document management systems, SAP), which in turn increased Sava's capacity to learn. Furthermore, our study reveals how the role of IT systems in organizational learning depends on the nature of learning (single-loop, double-loop or triple-loop learning) and the organizational level at which learning takes place (individual, group/department or organization). By providing insight into the emergence of distinct types of IT-supported learning and their vital role in Sava's successful transition, the paper contributes to a deeper understanding of the relationship between IT and organizational learning that is relevant and inspiring to other companies, especially those operating in transition economies. [source]

Occurrence of oxidative impairments, response of antioxidant defences and associated biochemical perturbations in male reproductive milieu in the Streptozotocin-diabetic rat

B. Shrilatha
Summary Oxidative stress is implicated to play a vital role in the pathogenesis of various diabetic complications. While reproductive dysfunction is a well recognized consequence of diabetes mellitus, the underlying mechanisms are poorly understood. The present study aims to obtain insights into the incidence, extent and progression of oxidative impairments in testis and epididymal sperm (ES) in streptozotocin (STZ)-induced diabetic rat during early and progressive phase. Adult rats (CFT-Wistar strain) rendered diabetic by an acute dose of STZ (60 mg/kg bw, i.p.) were examined for induction of hyperglycaemia at 72 h, followed by the assessment of oxidative impairments in testis and ES over a 6-week period. Oxidative damage was ascertained by measuring the malondialdehyde levels, reactive oxygen species (ROS) generation, alterations in antioxidant defences and extent of protein oxidation. STZ induced a significant (2.5-fold) increase in blood glucose levels. In diabetic rats, both testis and ES showed enhanced status of lipid peroxidation measured as increased TBARS and ROS from week 2 onwards. These impairments in testis were consistent, progressive and accompanied by marked alterations in antioxidant defences and elevated protein carbonyls. Varying degree of reduction in the specific activities of antioxidant enzymes was evident in testis and ES, while the activity of glutathione- S -transferase (GST) was significantly elevated. Reduced glutathione (GSH) and vitamin E levels were consistently reduced in testis. Lipid dysmetabolism measured in terms of increased cholesterol, triglycerides and phospholipids was evident only beyond week 2 in diabetic testis. Taken together, these results indicate that the testis and ES are indeed subjected to significant oxidative stress in the STZ-diabetic rat both during early as well as progressive phase. It is hypothesized that oxidative impairments in testis which develop over time may at least in part contribute towards the development of testicular dysfunction eventually leading to testicular degeneration which culminates in reduced fertility during the progressive phase of STZ-induced diabetes in adult rats. [source]

Service based CAC with QoS guarantee in mobile wireless cellular networks

Robert G. Fry
Abstract The increasing variety and complexity of traffic in today's mobile wireless networks means that there are more restrictions placed on a network in order to guarantee the individual requirements of the different traffic types and users. Call admission control (CAC) plays a vital role in achieving this. In this paper, we propose a CAC scheme for multiple service systems where the predicted call usage of each service is used to make the admission decision. Our scheme enables real-time traffic to be transmitted using shared bandwidth without quality of service (QoS) requirements being exceeded. This ensures that the utilization of the available wireless bandwidth is maximized. Information about the channel usage of each service is used to estimate the capacity of the cell in terms of the number of users that can achieve a certain bit error rate (BER). Priorities assigned to each service are used to allocate the network capacity. An expression for the handoff dropping probability is derived, and the maximum acceptance rate for each service that results in the estimated dropping probability not exceeding its QoS requirements is calculated. Each call is then accepted with equal probability throughout the duration of a control period. Achieved QoS during the previous control period is used to update the new call acceptance rates thus ensuring the dropping probability remains below the specified threshold. Simulations conducted in a wideband CDMA environment with conversational, streaming, interactive and background sources show that the proposed CAC can successfully meet the hard restraint on the dropping probability and guarantee the required BER for multiple services. Copyright © 2005 John Wiley & Sons, Ltd. [source]