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Speculative
Terms modified by Speculative Selected AbstractsMacular oedema with associated uveitis and cataract following presentation of Type 1 diabetes mellitus in severe ketoacidosisDIABETIC MEDICINE, Issue 4 2000D. Gordon Abstract We present a case of cystoid macular oedema presenting in a newly diagnosed diabetic teenager. She had developed anterior uveitis prior to diabetes and whether this contributed to the subsequent ocular complications remains speculative. The macular changes resolved spontaneously over 6 months without the use of grid laser photocoagulation. [source] The effect of information and communication technologies on urban structureECONOMIC POLICY, Issue 54 2008Yannis M. Ioannides SUMMARY Cities This paper examines the effects of information and communication technologies (ICT) on urban structure. Improvements in ICT may lead to changes in urban structure, for example, because they reduce the costs of communicating ideas from a distance. Hence, they may weaken local agglomeration forces and thus provide incentives for economic activity to relocate to smaller urban centres. We use international data on city size distributions in different countries and on country-level characteristics to test the effect of ICT. We find robust evidence that increases in the number of telephone lines per capita encourage the spatial dispersion of population in that they lead to a more concentrated distribution of city sizes. So far the evidence on internet usage is more speculative, although it goes in the same direction. We argue that the internet is likely to have similar, or even larger, effects on urban structures once its use has spread more thoroughly through different economies. , Yannis M. Ioannides, Henry G. Overman, Esteban Rossi-Hansberg and Kurt Schmidheiny [source] GENETIC VARIATION IN MALE EFFECTS ON FEMALE REPRODUCTION AND THE GENETIC COVARIANCE BETWEEN THE SEXESEVOLUTION, Issue 6 2003MARY ELLEN CZESAK Abstract., Males of many insect species increase the fecundity and/or egg size of their mates through the amount or composition of their nuptial gifts or ejaculate. The genetic bases of such male effects on fecundity or egg size are generally unknown, and thus their ability to evolve remains speculative. Likewise, the genetic relationship between male and female investment into reproduction in dioecious species, which is expected to be positive if effects on fecundity are controlled by at least some of the same genes in males and females, is also unknown. Males of the seed beetle Stator limbatus contribute large ejaculates to females during mating, and the amount of donated ejaculate is positively correlated with male body mass. Females mated to large males lay more eggs in their lifetime than females mated to small males. We describe an experiment in which we quantify genetic variation in the number of eggs sired by males (mated to a single female) and found that a significant proportion of the phenotypic variance in the number of eggs sired by males was explained by their genotype. Additionally, the number of eggs sired by a male was highly positively genetically correlated with his body mass. The between-sex genetic correlation, that is, the genetic correlation between the number of eggs sired by males and the number of eggs laid by females, was highly positive when eggs were laid on Acacia greggii seeds. This indicates that males that sire many eggs have sisters that lay many eggs. Thus, some of the genes that control male ejaculate size (or some other fecundity-enhancing factor) when expressed in males appear to control fecundity when expressed in females. We found no significant interaction between male and female genotype on fecundity. [source] A 3.5 ka record of paleoenvironments and human occupation at Angkor Borei, Mekong Delta, southern CambodiaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2003Paul Bishop Microfossil and sedimentological data from a 3.1 m core extracted from a reservoir (baray) at the ancient Cambodian settlement of Angkor Borei in the Mekong Delta have provided a continuous record of sedimentation and paleoenvironments dating from about 2000 cal yr B.C. Palynological data indicate that for much of the cal. 1st and 2nd millennia B.C. mangroves dominated the regional vegetation, while extensively and regularly burnt grasslands dominated the local vegetation. Turbid, nutrient-rich standing water characterized the core locality, perhaps suggesting a connection with rivers in the area. An abrupt change during the cal. 5th to 6th centuries A.D. involved a dramatic reduction in grasslands and the expansion of secondary forest or re-growth taxa. These changes are synchronous with an abrupt decline in the concentration of microscopic charcoal particles in the sediments, and the colonization of the core locality by swamp forest plants. These changes are taken to indicate a shift in land-use strategies or, possibly, a period of land abandonment. The age for the construction of the baray is interpreted to be in the 17th,19th centuries, but this dating remains speculative. Construction of the Angkor Borei baray exploited a preexisting body of standing water, so its construction was fundamentally different from the methods used at the Angkorian capital in northern Cambodia. © 2003 Wiley Periodicals, Inc. [source] "THE FARTHER REACHES OF HUMAN TIME": RETROSPECT ON CARL SAUER AS PREHISTORIAN,GEOGRAPHICAL REVIEW, Issue 4 2002DAVID R. HARRIS ABSTRACT. Carl Ortwin Sauer (1889,1975) is widely regarded as one of the most influential geographers of the twentieth century, admired particularly for his studies in cultural and historical geography. His contribution to the study of prehistory is less widely acknowledged, but, between 1944 and 1962, he published a series of speculative yet scholarly papers that contain many prescient insights into humanity's remote past and the relationships of our ancestors to the environments they occupied,and modified. In this essay, based on the Carl O. Sauer Memorial Lecture given at the University of California, Berkeley, in October 2001, I reflect on Sauer's contribution to the science of prehistory by examining, in the light of recent advances in knowledge, two major themes of Sauer's work: the early dispersal of Homo sapiens in the Old World, and the origins and prehistoric spread of agriculture. [source] Impact of past and present land-management on the C-balance of a grassland in the Swiss AlpsGLOBAL CHANGE BIOLOGY, Issue 11 2008NELE ROGIERS Abstract Grasslands cover about 40% of the ice-free global terrestrial surface, but their quantitative importance in global carbon exchange with the atmosphere is still highly uncertain, and thus their potential for carbon sequestration remains speculative. Here, we report on CO2 exchange of an extensively used mountain hay meadow and pasture in the Swiss pre-Alps on high-organic soils (7,45% C by mass) over a 3-year period (18 May 2002,20 September 2005), including the European summer 2003 heat-wave period. During all 3 years, the ecosystem was a net source of CO2 (116,256 g C m,2 yr,1). Harvests and grazing cows (mostly via C export in milk) further increased these C losses, which were estimated at 355 g C m,2 yr,1 during 2003 (95% confidence interval 257,454 g C m,2 yr,1). Although annual carbon losses varied considerably among years, the CO2 budget during summer 2003 was not very different from the other two summers. However, and much more importantly, the winter that followed the warm summer of 2003 observed a significantly higher carbon loss when there was snow (133±6 g C m,2) than under comparable conditions during the other two winters (73±5 and 70±4 g C m,2, respectively). The continued annual C losses can most likely be attributed to the long-term effects of drainage and peat exploitation that began 119 years ago, with the last significant drainage activities during the Second World War around 1940. The most realistic estimate based on depth profiles of ash content after combustion suggests that there is an 500,910 g C m,2 yr,1 loss associated with the decomposition of organic matter. Our results clearly suggest that putting efforts into preserving still existing carbon stocks may be more successful than attempts to increase sequestration rates in such high-organic mountain grassland soils. [source] Sleep apnea and dialysis therapies: Things that go bump in the night?HEMODIALYSIS INTERNATIONAL, Issue 4 2007Mark L. UNRUH Abstract Sleep apnea has been linked to excessive daytime sleepiness, depressed mood, hypertension, and cardiovascular disease in the general population. The prevalence of severe sleep apnea in the conventional thrice-weekly hemodialysis population has been estimated to be more than 50%. Sleep apnea leads to repetitive episodes of hypoxemia, hypercapnia, sleep disruption, and activation of the sympathetic nervous system. The hypoxemia, arousals, and intrathoracic pressure changes associated with sleep apnea lead to sympathetic activation, endothelial dysfunction, oxidative stress, and inflammation. Because sleep apnea has been shown to be widespread in the conventional dialysis population, it may be that sleep apnea contributes substantially to the sleepiness, poor quality of life, and cardiovascular disease found in this population. The causal links between conventional dialysis and sleep apnea remain speculative, but there are likely multiple factors related to volume status and azotemia that contribute to the high rate of severe sleep apnea in dialysis patients. Both nocturnal automated peritoneal dialysis and nocturnal hemodialysis have been associated with reduced severity of sleep apnea. Nocturnal dialysis modalities may provide tools to increase our understanding of the uremic sleep apnea and may also provide therapeutic alternatives for end-stage renal disease patients with severe sleep apnea. In conclusion, sleep apnea is an important, but overlooked, public health problem for the dialysis population. The impact of sleep apnea treatment in this high-risk population may include reduced sleepiness, better mood and blood pressure, and lowered risk of cardiovascular disease. [source] International competition and pay, working time and employment: exploring the processes of adjustmentINDUSTRIAL RELATIONS JOURNAL, Issue 2 2001James Arrowsmith The internationalisation of markets, competition and regulation is increasingly recognised. So far, however, debate about the effects has been largely speculative. This article examines the UK engineering industry. Survey evidence suggests that international comparisons are relatively unimportant, little benchmarking is going on and that stability characterises pay and working time arrangements. Further interview evidence explains that this is because pay and working time are set with employee expectations in mind, whereas it is the treatment of unit costs that reflects international pressures. As a consequence there has been substantial reductions in employment as well as some important changes in work organisation, even if there has been little change in pay or working time systems. In effect, it suggests that there is a form of ,implicit contract' taking place. A wider implication is that the main impetus for the ,Europeanisation' of industrial relations is likely to come from the growing convergence of costs rather than pressures for wage parity. [source] Comparative analysis of colonic gene expression of three experimental colitis models mimicking inflammatory bowel diseaseINFLAMMATORY BOWEL DISEASES, Issue 3 2007Anje A. te Velde PhD Abstract Background: Mouse models of inflammatory bowel diseases (IBD) are used to unravel the pathophysiology of IBD and to study new treatment modalities, but their relationship to Crohn's disease (CD) or ulcerative colitis (UC) is speculative. Methods: Using Agilent mouse TOX oligonucleotide microarrays, we analyzed colonic gene expression profiles in three widely used models of experimental colitis. In 2 of the models (TNBS and DSS-induced colitis), exogenous agents induce the colitis. In the third model the colitis is induced after transfer of a T-cell population (CD4+CD45RBhigh T cells) that lacks regulatory cells into an immunodeficient host. Results: Compared with control mice, in DSS, TNBS, and the CD45RB transfer colitis mice, 387, 21, and 582 genes were more than 2-fold upregulated in the intestinal mucosa. Analyses of exclusively shared gene expression profiles between the different models revealed that DSS/transfer colitis share 69 concordantly upregulated genes, DSS/TNBS 6, and TNBS/transfer colitis 1. Seven genes were upregulated in all three models. The CD45RB transfer model expression profile included the most genes that are known to be upregulated in IBD. Of 32 genes that are known to change transcriptional activity in IBD (TNF, IFN -,, Lt,, IL - 6, IL - 16, IL - 18R1, IL - 22, CCR2, 7, CCL2, 3, 4, 5, 7, 11, 17, 20, CXCR3, CXCL1, 5, 10, Mmp3, 7,9, 14, Timp1, Reg3,, and Pap, S - 100a8, S - 100a9, Abcb1, and Ptgs2), 2/32 are upregulated in TNBS, 15/32 are upregulated or downregulated in DSS and 30/32 are upregulated or downregulated in the CD45RB transfer colitis. Conclusion: The pattern of gene expression in the CD45RB transfer model most closely reflects altered gene expression in IBD. (Inflamm Bowel Dis 2007) [source] Libraries in transition to a marketing orientation: are librarians' attitudes a barrier?INTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 4 2007Richard Parker This study examines librarians' attitudes toward the marketing of library services, as libraries continue their transition to a marketing orientation. Although prior studies had observed misunderstandings and hostility to marketing among librarians, most previous discussions of this topic were either speculative or based on extremely small samples. In order to provide more evidence in this matter, a large-scale survey of members of the New Jersey Library Association (NJLA) was conducted. A ,Pro Marketing' scale was introduced and used to segment participants with respect to their attitudes. The findings indicate that most respondents expressed relatively positive attitudes toward marketing, but that more positive attitudes were expressed by public librarians than school or college/university librarians, and by administrators as opposed to reference and technical services librarians. Illustrative respondent comments and implications for library management are included. Copyright © 2007 John Wiley & Sons, Ltd. [source] Role of the Clinical Breast Examination in Breast Cancer ScreeningJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2001Does This Patient Have Breast Cancer? QUESTION: The authors, in an article for the JAMA section on the rational clinical examination, consider the evidence on whether and how to use clinical breast examination as a cancer screening technique. BACKGROUND: Breast cancer is a common disease, particularly in older women. The authors note that by age 70 the annual incidence of breast cancer is one in 200 women. Breast cancer survival is strongly influenced by the stage of the disease at the time of diagnosis. As a result, it is important to consider how best to screen for this disease. In recent years there has been considerable attention in the clinical literature and in the popular media paid to the screening strategies of breast self-examination and of screening mammography, but somewhat less to the potential role of the breast examination by the healthcare provider. In actual clinical practice, the same woman may be the recipient of any, none, or all of these screening modalities. The best way to combine these screening strategies, particularly in the case of the older woman, remains a subject of some uncertainty and controversy. DATA SOURCES: Data were obtained from a MEDLINE search of the English-language literature for 1966 through 1997 and additional articles as identified by the authors. STUDY SELECTION CRITERIA: In their evaluation of the effectiveness of clinical breast examination, the authors included both controlled trials and case-controlled studies in which clinical breast examination was used as a component of the screening. Study of breast examination technique considered both clinical studies and studies using silicone breast models. DATA EXTRACTION: The combined data from the trials included information on approximately 200,000 women who received a breast cancer screening intervention (mammography and/or clinical breast examination). However, none of the studies made the direct comparison of a group receiving clinical breast examination as a sole intervention with a control group that did not receive any screening. Data on the utility of clinical breast examination were partially derived from studies where that screening modality was used in combination with mammography. MAIN RESULTS: A number of trials of cancer screening have demonstrated a reduction in mortality from the use of mammography and clinical breast examination as combined screening strategies compared with no screening, with the inference that the reduction in mortality comes from the earlier detection of breast cancer. The percentage of the detected cancers that are detected in the trials by clinical breast examination despite having been missed on mammography varies across the trials from a low of 3% of the detected cancers to a high of 45%. It is speculative whether the marginal contribution of clinical breast examination to the mortality reduction in these screening trials corresponds to the percentage of cancers detected by clinical breast examination alone. In most of the clinical trials, the technique of breast examination reportedly was not well described. It is unclear therefore how much the technique of breast examination used varied within and among the clinical trials. Data from studies using examinations of breast models made of silicone demonstrated that test performance accuracy correlated with a lengthier breast examination, better breast examination technique, and perhaps with examiner experience. The report includes data from six comparator studies and from two demonstration projects. Of the six comparator studies, four compared a screened population with an unscreened population and two compared different intensities of screening strategies. None of the eight clinical trials was directed to a geriatric population and in fact older women were excluded by upper age entry criteria from the six comparator studies. (The upper age limit for study entry in the six comparator studies varied from 49 to 64.) CONCLUSION: The authors drew on the pooled results of these eight studies to conclude that clinical breast examination has a sensitivity of 54% (95% confidence interval, 48.3,59.8) and a specificity of 94% (95% confidence interval, 90.2,96.9). The authors conclude that screening clinical breast examination should be done for women age older than 40. [source] Is Leptin the Link Between Fat and Bone Mass?,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2002Thierry Thomas Ph.D. Abstract Recently, leptin has emerged as a potential candidate responsible for protective effects of fat on bone tissue. However, it remains difficult to draw a clear picture of leptin effects on bone metabolism because published data are sometimes conflicting or apparently contradictory. Beyond differences in models or experimental procedures, it is tempting to hypothesize that leptin exerts dual effects depending on bone tissue, skeletal maturity, and/or signaling pathway. Early in life, leptin could stimulate bone growth and bone size through direct angiogenic and osteogenic effects on stromal precursor cells. Later, it may decrease bone remodeling in the mature skeleton, when trabecular bone turnover is high, by stimulating osteoprotegerin (OPG) expression. Leptin negative effects on bone formation effected through central nervous system pathway could counterbalance these peripheral and positive effects, the latter being predominant when the blood-brain barrier permeability decreases or the serum leptin level rises above a certain threshold. Thus, the sex-dependent specificity of the relationship between leptin and bone mineral density (BMD) in human studies could be, at least in part, caused by serum leptin levels that are two- to threefold higher in women than in men, independent of adiposity. Although these hypotheses remain highly speculative and require further investigations, existing studies consistently support the role of leptin as a link between fat and bone. [source] Low Systemic Vascular Resistance After Cardiopulmonary Bypass: Incidence, Etiology, and Clinical ImportanceJOURNAL OF CARDIAC SURGERY, Issue 5 2000T. Carrel M.D. The etiology is not completely elucidated and the clinical importance remains speculative. Methods: In this prospective clinical trial, we assessed the incidence of postoperative low systemic vascular resistance in 800 consecutive patients undergoing elective coronary artery bypass grafting and/or valve replacement. We have attempted to identify the predictive factors responsible for the presence of low systemic vascular resistance and we have examined the subsequent postoperative outcome of those patients who developed early postoperative vasoplegia. The severity of vasoplegia was divided into three groups according either to the value of systemic resistance and/or the dose of vasoconstrictive agents necessary to correct the hemodynamic. Results: Six hundred twenty-five patients (78.1%) did not develop vasoplegia, 115 patients (14.4%) developed a mild vasoplegia, and 60 patients (7.5%) suffered from severe vasoplegia. Low systemic vascular resistance did not affect hospital mortality but was the cause for delayed extubation and prolonged stay on the intensive care unit IICU). Logistic regression analysis identified temperature and duration of cardiopulmonary bypass, total cardioplegic volume infused, reduced left ventricular function, and preoperative treatment with angiotensin-converting enzyme (ACE)-inhibitors, out of 25 parameters, as predictive factors for early postoperative vasoplegia. Conclusion. The occurrence of low systemic vascular resistance following cardiopulmonary bypass is as high as 21.8%. The etiology of this clinical condition is most probably multifactorial. Mortality is not affected by vasoplegia, but there is a trend to higher morbidity and prolonged stay in the ICU. [source] The challenges of caring in a technological environment: critical care nurses' experiencesJOURNAL OF CLINICAL NURSING, Issue 8 2008ITU cert, Mary McGrath MSc Purpose., This paper presents and discusses the findings from a phenomenological study which illuminated the lived experiences of experienced critical care nurses caring within a technological environment. Background., While nursing practice is interwoven with technology, much of the literature in this area is speculative. Moreover, there is a debate as to whether and how ,high tech' and ,high touch' are reconcilable; this orientation is referred to as the optimism vs. pessimism debate. On a personal level, the motivation for this study came from the author's 13 years' experience in the critical care area. Method., Following ethical approval, 10 experienced nurses from two cardiothoracic critical care units in Ireland participated in the study. A Heideggerian phenomenological methodology was used. Data collection consisted of unstructured interviews. A method of data analysis described by Walters was used. Findings., The findings provide research-based evidence to illuminate further the optimistic/pessimistic debate on technology in nursing. While the study demonstrates that the debate is far from resolved, it reveals a new finding: life-saving technology that supports the lives of critically ill patients can bring experienced nurses very close to their patients/families. The three main themes that emerged: ,alien environment', ,pulling together' and ,sharing the journey' were linked by a common thread of caring. Conclusion., Experienced critical care nurses are able to transcend the obtrusive nature of technology to deliver expert caring to their patients. However, the journey to proficiency in technology is very demanding and novice nurses have difficulty in caring with technology. Relevance to clinical practice., It is recommended that more emphasis be placed on supporting, assisting and educating inexperienced nurses in the critical care area and that the use of technology in nursing be given serious consideration. [source] Dynamics of mucosal dimensions after root coverage with a bioresorbable membraneJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2000Hans-Peter Müller Abstract Background: So far, the clinical effects of the placement of a resorbable membrane for guided tissue regeneration have not been studied in humans in great detail. The dynamics of the resorptive processes, in particular, appear to be rather speculative. In the present longitudinal study, specific alterations of the dimensions of the dentogingival mucosa were explored after surgical root coverage by using a bioresorbable membrane and a coronally-repositioned flap. Methods: The study population consisted of 14 patients with a total of 31 predominantly shallow, Miller class I, II or III recessions. The thickness of the masticatory and lining mucosa before and after surgical intervention was measured with an ultrasonic device. Results: Mean (±sd) recession depth and width were 2.85±1.29 and 4.46±1.14 mm, respectively. After 12 months, 51±29% of the recession depth (p<0.001) and 13±35% of its width (n.s.) were covered. Root coverage seems to be rather defect-type sensitive with best results obtained at canines with relatively shallow recessions. Mucosal thickness was considerably increased after surgery with a gradual decrease during the following 9 months. Thus, thickness of the marginal tissue rose from 0.82±0.27 mm to 1.49±0.54 mm 3 months after placement of the membrane (p<0.001). After 12 months, a mean thickness of 1.03±0.40 mm was observed (p<0.001). Even more pronounced alterations were noted for the alveolar lining mucosa with a threefold increase of thickness 3 months after surgery and a gradual decrease to about 1 mm after 12 months. Conclusions: The present results point to the considerable space making capacity of the bioresorbable membrane which probably allows for the ingrowth of a granulation tissue derived from the underlying structures. The gradual decline in mucosal thickness between months 6 and 9 after surgery may be paralleled by the maturation of the granulation tissue while complete resorption of the membrane had been accomplished. [source] Does service failure influence customer loyalty?JOURNAL OF CONSUMER BEHAVIOUR, Issue 3 2002Francis Buttle Abstract There is a general consensus that customer loyalty to service providers is not solely dependent upon their level of satisfaction or dissatisfaction. However, the identified antecedents of loyalty remain, at best, highly speculative. The aim of this extensive literature review is to give some understanding of the nature of customer loyalty and the antecedent effects of service dissatisfaction. The research reviewed suggests that customer loyalty is an attitudinal state, reflecting value, trust and commitment within supplier,customer relationships. Satisfaction is one of several antecedents of loyalty. A key influence on loyalty is the offer of unique value-delivering advantages not provided by competitors. Thus firms need to develop positive value-based exit barriers to achieve loyalty. When service failures occur, the recovery process is likely to have a greater impact on loyalty than the original service failure. The key to successful recoveries was found to be the customer's perception of ,fairness'. Recovery programmes must get it right first time. Customers who remain dissatisfied after a complaint has been handled are more dissatisfied than if no recovery attempt had been made. Dissatisfaction and customer satiation are major causes of a customer's exit. The solution to customer satiation is dynamic value creation. Collection and monitoring of customer data is needed for success and two-way communication is vital. Copyright © 2002 Henry Stewart Publications. [source] Eccentric target sign in cerebral toxoplasmosis: Neuropathological correlate to the imaging feature,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2010G.G. Sharath Kumar MD Abstract Cerebral toxoplasmosis remains one of the most common focal brain lesions in patients with acquired immune deficiency syndrome (AIDS). Diagnosis is a challenge because on cranial imaging it closely mimics central nervous system lymphoma, primary and metastatic central nervous system (CNS) tumors, or other intracranial infections like tuberculoma or abscesses. A magnetic resonance imaging (MRI) feature on postcontrast T1-weighted sequences considered pathognomonic of toxoplasmosis is the "eccentric target sign." The pathological correlate of this imaging sign has been speculative. Herein we correlate the underlying histopathology to the MR feature of eccentric target sign in a patient with autopsy-proven HIV/AIDS-related cerebral toxoplasmosis. The central enhancing core of the target seen on MRI was produced by a leash of inflamed vessels extending down the length of the sulcus that was surrounded by concentric zones of necrosis and a wall composed of histiocytes and proliferating blood vessels, with impaired permeability producing the peripheral enhancing rim. J. Magn. Reson. Imaging 2010;31:1469,1472. © 2010 Wiley-Liss, Inc. [source] Functions and pathophysiological roles of phospholipase D in the brainJOURNAL OF NEUROCHEMISTRY, Issue 6 2005Jochen Klein Abstract Ten years after the isoforms of mammalian phospholipase D (PLD), PLD1 and 2, were cloned, their roles in the brain remain speculative but several lines of evidence now implicate these enzymes in basic cell functions such as vesicular trafficking as well as in brain development. Many mitogenic factors, including neurotransmitters and growth factors, activate PLD in neurons and astrocytes. Activation of PLD downstream of protein kinase C seems to be a required step for astroglial proliferation. The characteristic disruption of the PLD signaling pathway by ethanol probably contributes to the delay of brain growth in fetal alcohol syndrome. The post-natal increase of PLD activities concurs with synapto- and myelinogenesis in the brain and PLD is apparently involved in neurite formation. In the adult and aging brain, PLD activity has antiapoptotic properties suppressing ceramide formation. Increased PLD activities in acute and chronic neurodegeneration as well as in inflammatory processes are evidently due to astrogliosis and may be associated with protective responses of tissue repair and remodeling. ARF-regulated PLD participates in receptor endocytosis as well as in exocytosis of neurotransmitters where PLD seems to favor vesicle fusion by modifications of the shape and charge of lipid membranes. Finally, PLD activities contribute free choline for the synthesis of acetylcholine in the brain. Novel tools such as RNA interference should help to further elucidate the roles of PLD isoforms in brain physiology and pathology. [source] THE CYANOTOXINS-BIOACTIVE METABOLITES OF CYANOBACTERIA: OCCURRENCE, ECOLOGICAL ROLE, TAXONOMIC CONCERNS AND EFFECTS ON HUMANSJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Carmichael, W. W. Department of Biological Sciences, Wright State University, Dayton, Ohio 45435 USA Cyanobacteria toxins (cyanotoxins) include cytotoxins and biotoxins with cytotoxins including about 60 compounds ranging from phytoalexins to animicrobials to enzyme inhibitors to compounds that can reverse multidrug resistance. Producer organisms include marine/brackish water Cystoseira, Hormothamnin, Lyngbya, Nodularia and Synechocystis, and the freshwater/terrestrial genera Anabaena, Dichotrix, Fischerella, Hapalosiphon, Lyngbya, Microcystis, Nostoc, Oscillatoria, Planktothrix, Phormidium, Schizothrix, Scytonema, Spirulina, Stigonema and Symploca. Since many of these compounds have been identified, not during ecological studies, but during drug discovery investigations, their ecological role is only speculative. Biotoxins are responsible for acute lethal, acute, chronic and sub-chronic poisonings of wild/domestic animals and humans. They include the neurotoxins; anatoxin-a, anatoxin-a(s) and saxitoxins plus the hepatotoxins; microcystins, nodularins and cylindrospermopsin. These compounds are included when referencing harmful algal blooms (HAB's) such as the more predominate marine PSP (paralytic shellfish poisoning), DSP (diarrhetic shellfish poisoning), NSP (neurotoxic shellfish poisoning), ASP (amnesic shellfish poisoning) and EAS (estuary associated syndrome). The CTP (cyanobacteria toxin poisoning) organisms occur in freshwater lakes, ponds, rivers and reservoirs throughout the world. Organisms responsible for CTP's are Anabaena, Aphanizomenon, Cylindrosperm- opsis, Microcystis, Nodularia, Nostoc Oscillatoria (Planktothrix), Trichodesmium and certain picoplanktic genera. Concern for animal and human health impairments arises from animal poisonings, associated with cyanobacteria waterblooms, beginning with the later part of the 1800's. It was not until the 1950's that we began to understand that cyanobacteria could indeed produce highly toxic compounds. A recent 1998 compilation of all available information on toxic cyanobacteria was published by the World Health Organization. This increasing focus on the role of cyanobacteria metabolites in chemical ecology, drug discovery and toxinology has placed new importance on using correct taxonomy for communication of responsible organisms. [source] Exploring the role of intertextuality in concept construction: Urban second graders make sense of evaporation, boiling, and condensation,JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 7 2006Maria Varelas The study explores urban second graders' thinking and talking about the concepts of evaporation, boiling, and condensation that emerged in the context of intertextuality within an integrated science-literacy unit on the topic of States of Matter, which emphasized the water cycle. In that unit, children and teacher engaged in a variety of activities (reading information books, doing hands-on explorations, writing, drawing, discussing) in a dialogically oriented way where teacher and children shared the power and the burden of making meaning. The three qualitative interrelated analyses showed children who initiated or continued productive links to texts, broadly defined, that gave them spaces to grapple with complex ideas and ways of expressing them. Although some children showed preference for a certain way of thinking about evaporation, boiling, and condensation, the data do not point toward a definite conclusion relative to whether children subscribe or not to a particular conceptual position. Children had multiple, complex, and often speculative, tentative, and emergent ways of accessing and interpreting these phenomena, and their conceptions were contextually based,different contexts offered opportunities for students to theorize about different aspects of the phenomena (along with some similar aspects). Children also theorized about aspects of the same phenomena in different ways. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 637,666, 2006 [source] Cognitive Efficiency in Stimulant Abusers With and Without Alcohol DependenceALCOHOLISM, Issue 3 2003Andrea Lawton-Craddock Background: Although previous studies have found stimulant (i.e., cocaine, methamphetamine) abusers and alcoholics to have neuropsychological deficits, research examining which cognitive abilities are most affected by concurrent exposure to these substances is lacking. To address this issue, detoxified men and women who met criteria for dependence of (a) alcohol only (ALC) (n= 15); (b) stimulants only (STIM) (n= 15); and (c) both alcohol and stimulants (A/STIM) (n= 15) were compared with age- and education-matched community controls (n= 15). Methods: Tasks that measured visual spatial skills, problem-solving and abstraction, short-term memory, cognitive flexibility, and gross motor speed were administered to participants. For each test, both speed and accuracy were assessed and an efficiency ratio (accuracy/time) was derived. Based on an average of these efficiency ratios, an overall performance index of cognitive efficiency was obtained. Results: Overall, controls performed more efficiently than all other groups. However, they were statistically significantly better only in relation to the A/STIM and STIM groups (p < 0.01). Individual comparisons revealed that the ALC group performed significantly better than the STIM group, although the ALC group did not differ from either the control or A/STIM groups (p, 0.05). This pattern of results was relatively consistent across the individual subtests of problem-solving/abstraction, short-term memory, and cognitive flexibility. Conclusions: As expected, substance abuse was associated with cognitive inefficiency. More importantly, these findings suggest that the cognitive effects of chronic stimulant abuse are not additive with those of alcohol abuse. That is, singly addicted stimulant abusers demonstrated similar or greater neurocognitive impairments than individuals who abuse alcohol and stimulants concurrently. The reason for this pattern is speculative but may be attributed to alcohol's opposing actions on cerebrovascular effects brought on by stimulant abuse. [source] Use of oseltamivir in the treatment of canine parvoviral enteritisJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 1 2010DACVECC, Michelle R. Savigny DVM Abstract Objective , To determine if oseltamivir with standard therapy for canine parvoviral enteritis ameliorates disease morbidity, mortality, or both; to document significant adverse effects associated with its use. Design , Prospective, randomized, blinded, placebo-controlled clinical trial. Setting , University veterinary teaching hospital. Animals , Thirty-five dogs. Interventions , Standard therapy was administered to all dogs. Treatment dogs also received oseltamivir, while control dogs received an equivalent volume of placebo. Measurements and Main Results , Dogs were monitored daily according to a clinical scoring system, physical parameters, and diagnostic evaluations. Dogs in the treatment group gained a significant percentage of weight during hospitalization (mean, +2.6%; SD, 7.1%) versus the control dogs (mean, ,4.5%; SD, 6.9%) (P=0.006). Treatment dogs did not have any significant changes in their white blood cell (WBC) count, while control dogs experienced a significant drop in their WBC counts during their initial stay. In addition, it did not appear that oseltamivir use was associated with any major adverse clinical effects. Conclusions , While a clear advantage to the use of oseltamivir was not established, a significant weight loss during hospitalization, as well as a significant decrease in WBC count were documented in the control group. No major adverse effects were identified that could be associated with oseltamivir administration. Based on these results, the true role of oseltamivir in the treatment of parvoviral enteritis remains speculative, although it is believed that further investigation is warranted. [source] Salt glands in a Tithonian metriorhynchid crocodyliform and their physiological significanceLETHAIA, Issue 4 2000Marta Fernández Our knowledge of Mesozoic tetrapods is based mainly on osteological evidence. The discussion of the evolution of any homeostatic system is highly speculative because direct non-osteological evidence is uncommon. Here we report an extraordinarily well-preserved cast of a pair of lobulated protuberances in the skull of the marine metriorhynchid crocodiliform Geosaurus from the Tithonian (Jurassic) of Patagonia (Argentina). These protuberances are interpreted as representing salt glands. Based on their topology, these glands are identified as the nasals. Optimization of this character on a phylogenetic tree permits us to infer the ancestral condition for archosaurs. The relationship between salt gland and diet is also analysed. The presence of hypertrophied salt glands in the skull of Geosaurus suggests that as early as 140 million years ago, some Mesozoic marine reptiles had evolved an extra-renal osmoregulatory system. This achievement was an important clue in the successful colonization of marine environments. Salt glands preclude the risk of lethal dehydration and allow marine reptiles to include an important amount of invertebrates in their diet. [source] Creativity through a rhetorical lens: implications for schooling, literacy and media educationLITERACY, Issue 2 2007Shakuntala Banaji Abstract This article, which is speculative in outlook and emerges from an extended literature review on this subject, takes as its basic premise the notion that the idea of ,creativity', whether in relation to literacy, schooling or the economy, is constructed as a series of rhetorical claims. These rhetorics of creativity emerge from the contexts of research, theory, policy and practice. Initially, we distinguish 10 rhetorics, which are described in relation to the philosophical or political traditions from which they spring. The discussion then focuses on four rhetorics , play, technology, politics/democracy and the creative classroom , which have most relevance for understandings of literacies and the way in which these are nurtured, encouraged and expressed in different social settings. This article aims to summarise the rhetorics and their major concerns, while considering how selected ones might apply to an instance of media literacy. Key questions addressed in this article ask whether creativity is more usefully understood as an internal cognitive function or an external cultural phenomenon; whether it is a ubiquitous human activity or a special faculty; whether it is necessarily ,pro-social' or should be dissident; and what the implications of a culturalist social psychological approach to creativity might be for analyses of the media literacy of children and young people. [source] Conservation status and causes of decline of the threatened New Zealand Long-tailed Bat Chalinolobus tuberculatus (Chiroptera: Vespertilionidae)MAMMAL REVIEW, Issue 2 2000Colin F. J. O'Donnell ABSTRACT Historical anecdotes and preliminary monitoring since 1990 indicate that New Zealand Long-tailed Bats (Chalinolobus tuberculatus, Vespertilionidae) are now rare or absent at many sites where formerly they were common. Chalinolobus tuberculatus appeared to be common throughout New Zealand in the 1800s but by 1900,30 it was becoming scarce in many districts. Formal surveys in the South Island since 1990 either failed to find C. tuberculatus, or recorded bats in low numbers. Of eight sites where transect counts were undertaken, bats were recorded frequently at two sites (45,66% of counts; Eglinton and Dart Valleys), rarely at four sites (2.4,10.7% of counts), and were not recorded at the remaining two sites despite considerable survey effort. Of 10 sites where stationary counts using automatic detector units were used, no C. tuberculatus were recorded in three areas (153 nights combined), they were found rarely at six sites (2.1,21.0% of nights; 461 nights combined) and were recorded commonly only in the Eglinton Valley (85% of 120 nights). Assertions that C. tuberculatus are ,common' and that the conservation status is ,secure' are questionable and this review supports suggestions that the species should be classed as ,Vulnerable'. Possible causes of decline have been suggested including clearance and logging of lowland forests, predation by introduced mammals and owls, competition for roost sites by introduced mammals, birds and wasps, and human interference and disturbance at roosting sites. However, authors' claims have all been speculative and unsubstantiated. There has been no research undertaken to quantify these claims, and this is required urgently. The results of these preliminary surveys provide a new baseline against which future population trends might be compared. Increased effort using standardized monitoring techniques, applied at a national level, is required to confirm the possible trends and to help identify the best sites where conservation managers may attempt to restore the population level. [source] Kierkegaard's Socrates: a Venture in Evolutionary TheoryMODERN THEOLOGY, Issue 4 2001Mary-Jane Rubenstein This essay explores the shifts in Kierkegaard's conceptions of Socrates, looking to produce a more nuanced reading of Kierkegaardian indirect communication, faith, and subjectivity. Entirely bound up with his increasingly troubled view of Hegel and Hegelianism, Kierkegaard's relationship to Socrates can be traced through three of his major texts: The Concept of Irony, Philosophical Fragments, and The Concluding Unscientific Postscript. By examining these three works, this essay charts a path from a critique of the Socratic as un -speculative, through a deep resentment of the Socratic as proto -speculative, to admiration and imitation of the Socratic as anti -speculative. Ultimately, it is argued, Kierkegaard and the pseudonyms rely upon Socrates to rehabilitate subjectivity out of the undifferentiated totality of nineteenth century idealism. [source] Evidence based guidelines and current practice for physiotherapy management of knee osteoarthritisMUSCULOSKELETAL CARE, Issue 1 2009Nicola E. Walsh MSc MCSP Abstract Objectives:,To document physiotherapy provision for patients with knee osteoarthritis (OA) in relation to the United Kingdom (UK) recently published National Institute of health and Clinical Excellence (NICE) guidelines for osteoarthritis. Design:,Questionnaire survey of chartered physiotherapists. Method:,300 postal questionnaires were distributed to Physiotherapy Departments requesting information regarding source of referrals, treatment aims, preferred methods of treatment and service delivery. Results:,Responses were received from 83 physiotherapists (28 %), predominantly working in the UK National Health Service. Approximately equal numbers of referrals came from primary and secondary care. Aims of physiotherapy management were to; encourage self-management; increase strength and range of movement; reduce pain; and improve function. To achieve these, exercise was utilised by 100% of practitioners, often supplemented with electrotherapeutic modalities (66%), manual therapy (64%) and acupuncture (60%). The majority of patients received individual treatment for a total contact time of 1,2 hours, whilst most group interventions lasted 5,6 hours. Approximately half (54%) of respondents reported using outcome measures to determine treatment efficacy. Conclusions:,Although knee OA is usually managed in primary care, the similar number of referrals from primary and secondary care may suggest a deviation from evidence-based management guidelines. The guidelines' recommendations of exercise, patient education and self-management are observed by physiotherapists, but other modalities are often used despite poor or no research evidence supporting their efficacy. Whether any of these interventions are clinically beneficial is speculative as treatment outcomes were frequently under-evaluated. Copyright © 2008 John Wiley & Sons, Ltd. [source] 9.,Human Rights: Historical Learning in the Shadow of ViolenceAMERICAN JOURNAL OF ECONOMICS AND SOCIOLOGY, Issue 1 2009Article first published online: 18 FEB 200, Richard T. Peterson This paper emphasizes the historical dimension of human rights understood as a social ethic. Rather than timeless principles, human rights and the universality proper to them emerge in a process of suffering, conflict, political assertion, and institutional change. We can understand them as historical yet also universal by seeing that human rights arise in processes of social learning that take place in an increasingly globalized world. Such learning often has advanced in the face of dramatic violence, for example, the bombing of Hiroshima. But the demands on a global social ethic today are not only a matter of responding to threats and acts of dramatic violence in isolation. Attention to the example of Hiroshima suggests that the problem of violence is bound up with other questions about the regulation of emerging technical powers in a context of inequality and social conflict. To what extent can an ethic centered on human rights provide an ethics that can inform effective responses to these problems? To consider the promise of human rights, we look more closely at the kind of social learning they involve and explore in particular the role of social movements in forging new identities and reciprocities along with normative claims proper to a global public sphere (the anti-apartheid movement provides an example). We go on to see that these political experiences can inform interpretations of historical experience that can inform a widened sense of historical possibilities, both those missed in the past and those that confront us today. While this argument may thicken our sense of the promise of a human rights ethic, it remains speculative, not least because of the limited effectiveness of these norms in practice today. We close with the suggestion that nonetheless a coherent ethical response is possible, one that in the wealthy parts of the globe might take the form of an ethic of democratic responsibility. This would both represent a distinctive kind of learning and perhaps contribute to a wider advance of human rights. [source] Upper and Lower Common Pathways in Atrioventricular Nodal Reentrant Tachycardia:PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2007Refutation of a Legend? The concepts of upper and lower common pathways represent long-standing controversies of atrioventricular nodal reentrant tachycardia (AVNRT). Over the last years there has been considerable evidence against the presence of a lower and, especially, an upper common pathway as distinct entities that can be identified in most patients with atrioventricular reentrant tachycardia. The mechanism and relevance of these concepts remain speculative. [source] The effects of objective feedback on performance when individuals receive fixed and individual incentive payPERFORMANCE IMPROVEMENT QUARTERLY, Issue 3-4 2008Douglas A. Johnson We examined whether objective feedback would enhance performance when individuals were paid monetary incentives. A two-by-two factorial design was used, with 123 college students assigned to incentive pay without feedback, incentive pay with feedback, fixed pay without feedback, or fixed pay with feedback. Participants attended six sessions and entered the cash value of simulated bank checks presented on a computer. Two-factor ANCOVAs were used to determine whether the number of checks completed correctly and time spent working differed. The number of checks completed correctly during a pretest was used as the covariate to control for keyboard proficiency. Incentives increased the number of checks completed correctly by 34 percent (p<.001, standardized effect size=.91); however, feedback had no effect (p=1.00). The incentives increased the time spent working by 31 percent (p<.001, standardized effect size=1.13); however, again feedback had no effect (p=1.00). Although speculative, the results imply that feedback per se, absent evaluation, is unlikely to increase performance even when correlated with performance-contingent rewards. [source] | ||||||||||||||||||||||||||||