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Grip
Kinds of Grip Terms modified by Grip Selected AbstractsGlucose-responsive insulin-producing cells from stem cellsDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2002David J. Kaczorowski Abstract Recent success with immunosuppression following islet cell transplantation offers hope that a cell transplantation treatment for type 1 (juvenile) diabetes may be possible if sufficient quantities of safe and effective cells can be produced. For the treatment of type 1 diabetes, the two therapeutically essential functions are the ability to monitor blood glucose levels and the production of corresponding and sufficient levels of mature insulin to maintain glycemic control. Stem cells can replicate themselves and produce cells that take on more specialized functions. If a source of stem cells capable of yielding glucose-responsive insulin-producing (GRIP) cells can be identified, then transplantation-based treatment for type 1 diabetes may become widely available. Currently, stem cells from embryonic and adult sources are being investigated for their ability to proliferate and differentiate into cells with GRIP function. Human embryonic pluripotent stem cells, commonly referred to as embryonic stem (ES) cells and embryonic germ (EG) cells, have received significant attention owing to their broad capacity to differentiate and ability to proliferate well in culture. Their application to diabetes research is of particular promise, as it has been demonstrated that mouse ES cells are capable of producing cells able to normalize glucose levels of diabetic mice, and human ES cells can differentiate into cells capable of insulin production. Cells with GRIP function have also been derived from stem cells residing in adult organisms, here referred to as endogenous stem cell sources. Independent of source, stem cells capable of producing cells with GRIP function may provide a widely available cell transplantation treatment for type 1 diabetes. Copyright © 2002 John Wiley & Sons, Ltd. [source] Oxygen isotope and palaeotemperature records from six Greenland ice-core stations: Camp Century, Dye-3, GRIP, GISP2, Renland and NorthGRIPJOURNAL OF QUATERNARY SCIENCE, Issue 4 2001Sigfus J. Johnsen Abstract Oxygen isotope variations spanning the last glacial cycle and the Holocene derived from ice-core records for six sites in Greenland (Camp Century, Dye-3, GRIP, GISP2, Renland and NorthGRIP) show strong similarities. This suggests that the dominant influence on oxygen isotope variations reflected in the ice-sheet records was regional climatic change. Differences in detail between the records probably reflect the effects of basal deformation in the ice as well as geographical gradients in atmospheric isotope ratios. Palaeotemperature estimates have been obtained from the records using three approaches: (i) inferences based on the measured relationship between mean annual ,18O of snow and of mean annual surface temperature over Greenland; (ii) modelled inversion of the borehole temperature profile constrained either by the dated isotopic profile, or (iii) by using Monte Carlo simulation techniques. The third of these approaches was adopted to reconstruct Holocene temperature variations for the Dye 3 and GRIP temperature profiles, which yields remarkably compatible results. A new record of Holocene isotope variations obtained from the NorthGRIP ice-core matches the GRIP short-term isotope record, and also shows similar long-term trends to the Dye-3 and GRIP inverted temperature data. The NorthGRIP isotope record reflects: (i) a generally stronger isotopic signal than is found in the GRIP record; (ii) several short-lived temperature fluctuations during the first 1500 yr of the Holocene; (iii) a marked cold event at ca. 8.2 ka (the ,8.2 ka event'); (iv) optimum temperatures for the Holocene between ca. 8.6 and 4.3 ka, a signal that is 0.6, stronger than for the GRIP profile; (v) a clear signal for the Little Ice Age; and (vi) a clear signal of climate warming during the last century. These data suggest that the NorthGRIP stable isotope record responded in a sensitive manner to temperature fluctuations during the Holocene. Copyright © 2001 John Wiley & Sons, Ltd. [source] Modeling the deglaciation of the Green Bay Lobe of the southern Laurentide Ice SheetBOREAS, Issue 1 2004CORNELIA WINGUTH We use a time-dependent two-dimensional ice-flow model to explore the development of the Green Bay Lobe, an outlet glacier of the southern Laurentide Ice Sheet, leading up to the time of maximum ice extent and during subsequent deglaciation (c. 30 to 8 cal. ka BP). We focus on conditions at the ice-bed interface in order to evaluate their possible impact on glacial landscape evolution. Air temperatures for model input have been reconstructed using the GRIP ,8O record calibrated to speleothem records from Missouri that cover the time periods of c. 65 to 30 cal. ka BP and 13.25 to 12.4 cal. ka BP. Using that input, the known ice extents during maximum glaciation and early deglaciation can be reproduced reasonably well. The model fails, however, to reproduce short-term ice margin retreat and readvance events during later stages of deglaciation. Model results indicate that the area exposed after the retreat of the Green Bay Lobe was characterized by permafrost until at least 14 cal. ka BP. The extensive drumlin zones that formed behind the ice margins of the outermost Johnstown phase and the later Green Lake phase are associated with modeled ice margins that were stable for at least 1000 years, high basal shear stresses (c. 100 kPa) and permafrost depths of 80,200 m. During deglaciation, basal meltwater and sliding became more important. [source] 10Be dating of Younger Dryas Salpausselkä I formation in FinlandBOREAS, Issue 4 2000SILVIO TSCHUDI Boulders of the Younger Dryas Salpausselkä I (Ss I) formation west of Lahti, southern Finland, were sampled for surface exposure dating. The 10Be concentrations, determined by accelerator mass spectrometry, yield minimum exposure ages of 11 930 ± 950, 11 220 ± 890, 11 050 ± 910 and 11 540 ± 990 years, using recently published production rates scaled for latitude and elevation. This includes a correction to the production rate resulting from postglacial uplift of the Fennoscandian lithosphere (i.e. changing elevation) during the time of exposure. The error-weighted mean exposure age of 11 420 ± 470 years of the analysed boulders agrees with previous varve dates of Ss I, which range from 11 680 to 11 430 calendar years BP. However, erosion has to be taken into account as a process affecting rock surfaces and therefore influencing exposure ages. Available information suggests an erosion rate of 5 mm/kyr, which increases the error-weighted mean exposure age to a value of 11 610 ± 470 years. Within the errors, the formation of Ss I in the Vesala area west of Lahti falls into the Younger Dryas time bracket, as defined by the GRIP and GISP 2 ice core (Greenland). [source] The applicability of the GRIPS geobarometry in metapelitic assemblagesJOURNAL OF METAMORPHIC GEOLOGY, Issue 4 2006C.-M. WU Abstract Although the garnet-rutile-ilmenite-plagioclase-silica (quartz) (GRIPS) geobarometer has been experimentally calibrated and widely applied, its applicability to metapelitic rocks has not yet been discussed carefully. In this paper, this barometer was recalibrated by fitting the available reversed-phase equilibrium data incorporating different combinations of activity models of garnet, plagioclase and ilmenite. The resultant GRIPS barometer formalisms reproduce the experimental pressures well within ±0.2 kbar. The GRIPS and garnet-aluminium silicate-plagioclase-quartz (GASP) barometer values are concordant within ±1 kbar for pressures above ,6 kbar for natural metapelites, but the difference of pressure determinations between these two barometers becomes larger when pressure and/or the grossular content of garnet decrease. However, the pressure difference is independent of either temperature, or almandine in garnet, or anorthite in plagioclase, or iron content in ilmenite. After testing and application of the GRIPS barometer to aluminosilicate-bearing metapelites and metapelitic assemblages within limited geographical areas as well as within contact thermal aureoles, it is concluded that this barometer may be applied to low- to high-grade, medium- to high-pressure metapelites. The application of the GRIPS barometer to metapelites is not advocated in situations where calcium is deficient in garnet ( < 0.05) or plagioclase ( < 0.17), or for pressures below ,6 kbar. [source] Impaired SDF1/CXCR4 signaling in glial progenitors derived from SOD1G93A miceJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2007Yongquan Luo Abstract Mutations in the superoxide dismutase 1 (SOD1) gene are associated with familial amyotrophic lateral sclerosis (ALS), and the SOD1G93A transgenic mouse has been widely used as one animal model for studies of this neurodegenerative disorder. Recently, several reports have shown that abnormalities in neuronal development in other models of neurodegeneration occur much earlier than previously thought. To study the role of mutant SOD1 in glial progenitor biology, we immortalized glial restricted precursors (GRIPs) derived from mouse E11.5 neural tubes of wild-type and SOD1G93A mutant mice. Immunocytochemistry using cell lineage markers shows that these cell lines can be maintained as glial progenitors, because they continue to express A2B5, with very low levels of glial fibrillary acidic protein (astrocyte), ,III-tubulin (neuron), and undetected GalC (oligodendrocyte) markers. RT-PCR and immunoblot analyses indicate that the chemokine receptor CXCR4 is reduced in SOD1G93A GRIPs. Subsequently, SOD1G93A GRIPs are unable to respond to SDF1, to activate ERK1/2 enzymes and the transcription factor CREB. This may be one pathway leading to a reduction in SOD1G93A cell migration. These data indicate that the abnormalities in SOD1G93A glial progenitor expression of CXCR4 and its mediated signaling and function occur during spinal cord development and highlight nonneuronal (glial) abnormalities in this ALS model. © 2007 Wiley-Liss, Inc. [source] Burundi: In the Grip of DroughtAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 2 2010Article first published online: 1 APR 2010 No abstract is available for this article. [source] Titelbild: Beton- und Stahlbetonbau 3/2008BETON- UND STAHLBETONBAU, Issue 3 2008Article first published online: 22 FEB 200 Die Rheinbrücke Wesel hat eine Gesamtlänge von ca. 773 m sowie eine maximale Spannweite von 335 m und wird nach ihrer Fertigstellung die drittgrößte Schrägseilbrücke Deutschlands sein. Nach der 2. Strelasundquerung werden hier zum zweiten Mal in Deutschland die von der DYWIDAG entwickelten Parallellitzenbündel eingesetzt. Sie bestehen in der freien Seillänge aus einzeln korrosionsgeschützten, zueinander parallel in einem Hüllrohr geführten Schrägseillitzen. Die DYNA Grip®-Verankerung bietet die Möglichkeit, einzelne Litzen eines Seiles auszuwechseln und zu inspizieren. (Foto: Donges Stahlbau GmbH) [source] Feminism in the Grips of a Pincer Attack,Traditionalism, liberalism, and globalismINTERNATIONAL JOURNAL OF JAPANESE SOCIOLOGY, Issue 1 2005Yumiko Ehara Abstract:, The dichotomy of individualism versus collectivism is one of the pivots around which political ideologies in postwar Japanese society can be broken down. Many people had thought that what postwar Japan needed was the development of modern individuals who represented a departure from feudalistic thinking. Against the backdrop of uncertainties related to employment and life in general engendered by a prolonged economic stagnation and globalism, Japanese society in the twenty-first century is being pounded by a tempest of neoliberalism and neoconservatism. In the midst of this storm, ideas advocating social policies that promote gender equality are being dismantled by both of these forces. This is because the power of traditionalism as a force for asserting a revisionist ideology in modern Japanese society primarily constitutes the power of neoconservatism, which embraces neoliberalism with a view to revitalizing the free economy through the elimination of social welfare and the intensification of free competition. In order to establish formidable economic competitiveness, neoliberalism and neoconservatism (neoliberalism = neoconservatism) reject domestic systems geared towards labor protection (deregulation) and extol familism and nationalism as means to bringing social unrest under control through the mobilization of the labor force (traditionalism). However, the habitual way of thinking that places traditionalism and liberalism in a dichotomous pivot remains ingrained within us even now. Because globalization reinforces social mobility, these two positions will continue to gain strength even as they conflict with each other. With feminism in the grips of a pincer attack, the movement will struggle to maintain its breath. [source] Stroke volume decreases during mild dynamic and static exercise in supine humansACTA PHYSIOLOGICA, Issue 2 2009M. Elstad Abstract Aim:, The contributions of cardiac output (CO) and total peripheral resistance to changes in arterial blood pressure are debated and differ between dynamic and static exercise. We studied the role stroke volume (SV) has in mild supine exercise. Methods:, We investigated 10 healthy, supine volunteers by continuous measurement of heart rate (HR), mean arterial blood pressure, SV (ultrasound Doppler) and femoral beat volume (ultrasound Doppler) during both dynamic mild leg exercise and static forearm exercise. This made it possible to study CO, femoral flow (FF) and both total and femoral peripheral resistance beat-by-beat. Results:, During a countdown period immediately prior to exercise, HR and mean arterial pressure increased, while SV decreased. During mild supine exercise, SV decreased by 5,8%, and most of this was explained by increased mean arterial pressure. Dynamic leg exercise doubled femoral beat volume, while static hand grip decreased femoral beat volume by 18%. FF is tightly regulated according to metabolic demand during both dynamic leg exercise and static forearm exercise. Conclusion:, Our three major findings are, firstly, that SV decreases during both dynamic and static mild supine exercise due to an increase in mean arterial pressure. Secondly, femoral beat volume decreases during static hand grip, but FF is unchanged due to the increase in HR. Finally, anticipatory responses to exercise are apparent prior to both dynamic and static exercise. SV changes contribute to CO changes and should be included in studies of central haemodynamics during exercise. [source] St Columba and the convention at Druimm Cete: peace and politics at seventh-century IonaEARLY MEDIEVAL EUROPE, Issue 3 2007James E. Fraser Attendance at the ,convention of kings' at Druimm Cete in north-east Ireland is one of the most famous episodes in the career of St Columba or Colum Cille, who died in 597. Discussion of the significance of this shadowy summit, largely informed by unreliable late evidence, has hitherto focused upon what (may have) transpired there between kings based in Ireland and Scotland. The result has been the neglect of the hagiographical dimension of the presentation of Druimm Cete in our principal source, Adomnán's Vita Sancti Columbae, composed c.700. Analysis of this material shows that Adomnán's information about the convention came from his principal source, composed some sixty years earlier. It reveals moreover that Druimm Cete assumed prominence within the Columban dossier in the 640s for what it represented, rather than because of what actually happened there. Once the hagiographical agenda of Vita Sancti Columbae and its principal source is restored to its rightful place in evaluating the text, it emerges that several of its best-known stories , including the story of Columba's ordination of a Scottish king , are much more problematic as witnesses to sixth-century history than is conventionally supposed. As scholars begin to lose their grip upon the historical Columba, however, they grow better able to grasp seventh-century political history in north-east Ireland and Gaelic Scotland. [source] Alcohol and Russian mortality: a continuing crisisADDICTION, Issue 10 2009David A. Leon ABSTRACT Background Russia remains in the grip of a mortality crisis in which alcohol plays a central role. In 2007, male life expectancy at birth was 61 years, while for females it was 74 years. Alcohol is implicated particularly in deaths among working-age men. Aims To review the current state of knowledge about the contribution of alcohol to the continuing very high mortality seen among Russian adults Results Conservative estimates attribute 31,43% of deaths among working-age men to alcohol. This latter estimate would imply a minimum of 170 000 excess deaths due to hazardous alcohol consumption in Russia per year. Men drink appreciably more than women in Russia. Hazardous drinking is most prevalent among people with low levels of education and those who are economically disadvantaged, partly because some of the available sources of ethanol are very cheap and easy to obtain. The best estimates available suggest that per capita consumption among adults is 15,18 litres of pure ethanol per year. However, reliable estimation of the total volume of alcohol consumed per capita in Russia is very difficult because of the diversity of sources of ethanol that are available, for many of which data do not exist. These include both illegal spirits, as well as legal non-beverage alcohols (such as medicinal tinctures). In 2006 regulations were introduced aimed at reducing the production and sale of non-beverage alcohols that are commonly drunk. These appear to have been only partially successful. Conclusion There is convincing evidence that alcohol plays an important role in explaining high mortality in Russia, in particular among working age men. However, there remain important uncertainties about the precise scale of the problem and about the health effects of the distinctive pattern of alcohol consumption that is prevalent in Russia today. While there is a need for further research, enough is known to justify the development of a comprehensive inter-sectoral alcohol control strategy. The recent fall in life expectancy in Russia should give a renewed urgency to attempts to move the policy agenda forward. [source] Differential cortical activity for precision and whole-hand visually guided grasping in humansEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2007Chiara Begliomini Abstract Effective grasping involves the remarkable ability to implement multiple grasp configurations such as precision grip (PG; opposition between the index finger and thumb) and whole-hand grasp (WHG), depending on the properties of the object grasped (e.g. size, shape and weight). In the monkey brain, different groups of cells in the anterior,lateral bank of the intraparietal sulcus (area AIP) are differentially active for various hand configurations during grasping of differently shaped objects. Visually guided grasping studies in humans suggest the anterior intraparietal sulcus (aIPS) as the homologue of macaque area AIP, but leave unresolved the question of whether activity in human aIPS reflects the relationship between object size and grasp configuration, as in macaques. To address this issue, a human fMRI study was conducted in which objects were grasped with the right hand while object size was varied. The results indicated that the left aIPS was active when the subjects naturally adopted a PG to grasp the small object but showed a much weaker response when subjects naturally adopted a WHG to grasp the large object. The primary motor cortex and somatosensory cortices were active for both PG and WHG. Our results suggest that, in humans, the aIPS is centrally involved in determining the type of grasp. [source] Predictive and reactive co-ordination of grip and load forces in bimanual lifting in manEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2003R. Martyn Bracewell Abstract We investigated the intra- and inter-manual coordination of grip force (GF) and load force (LF) during bimanual lifting and holding of a single object. In a voluntary task involving lifting a predictable load (Experiment 1), we showed scaling of GF to LF generated by either hand, similar to effects seen in previous unimanual studies. Moreover, the GF rates generated by the two hands were correlated. In part this correlation was due to the correlation between the LF rates. However, the GF rates remained correlated when the effects of the correlation in LF rates were partialled out. This novel finding suggests an additional co-ordinative constraint at the level of specification of GFs. As a contrast to the predictable loading in the first experiment, in the second experiment loading was temporally unpredictable and elicited reactive increases in GF. In Experiment 2, the intermanual correlation of GF rates was stronger than in Experiment 1. We speculate that this result reflects greater degrees of co-ordinative constraint at lower levels in the motor control hierarchy. [source] The Origins of the ,Nonmarket Economy': Ideas, Pluralism & Power in EC Anti-dumping Law about ChinaEUROPEAN LAW JOURNAL, Issue 4 2001Francis Snyder ,Market' and ,market economy' exercise a powerful, even magnetic grip on our collective imagination. But what do we mean by ,market economy'? Does it make sense to speak of a ,nonmarket economy', and if so, what does it mean? How are the ideas of ,market economy' and ,nonmarket economy' related? Focusing on EC anti-dumping law, this article seeks to answer these questions. It argues that the legal concept of ,nonmarket economy' in EC anti-dumping law has been socially constructed, by means of relations among a plurality of institutional and normative sites, as part of a changing configuration of legal ideas in specific historical circumstances, and in contexts of political, economic, social, and symbolic power. This argument is articulated in three parts. First, the concept of ,nonmarket economy' in EC anti-dumping law, though drawing on earlier elements, had its main roots in the early Cold War. Second, starting in the 1960s, the GATT multilateral negotiating rounds began to define more specific international rules of the game, but a variety of more localised processes played essential roles as forces of change. Of special importance were, first, the tension between legislative rules and administrative discretion in the United States, and, second, the Europeanisation of foreign trade law in the course of European integration. Third, the EC law concept of ,nonmarket economy' was born in the late 1970s. The main reasons were changes in the international anti-dumping law repertoire, specific ideas in Europe about comparative economic systems, and the perceived emergence of new economic threats, including exports from China. [source] Central State Power and its Limits in Bulpitt's Territory and PowerGOVERNMENT AND OPPOSITION, Issue 3 2010Peter John This article assesses Bulpitt's treatment of the centre or central state. It begins by reviewing Bulpitt's argument that the UK centre elite developed a detached style of territorial management and recognized the limits to the state's power. The argument is that the elite at the centre sought to avoid the costs of intervention in the periphery so it could retain its autonomy over decisions affecting the economy and international affairs. The article then assesses Bulpitt's claims against extant evidence from the study of UK politics. It concludes that, in spite of Bulpitt's failure to appreciate the interest of the centre in the detail of local administration, the account holds up surprisingly well and could be adopted as a comparative framework for analysing how central elites seek to keep their grip on power by managing territorial politics successfully. [source] Direct-to-consumer advertising of pharmaceuticals: developed countries experiences and TurkeyHEALTH EXPECTATIONS, Issue 1 2007Semih Semin MD PhD Abstract While several major problems concerning drugs occur in the world, the attempts to direct-to-consumer advertising (DTCA) has gained a considerable impetus lately in both developed and developing countries. DTCA has increasingly become an appealing advertising alternative for the pharmaceutical industry as drug companies have come to wrestle with such problems as the expansion of the drug market; the decline of the medical representatives' work efficiency; drug reimbursement restrictions; and the escalating role of the Internet in the consumer market. Some of the main disadvantages of the DTCA are: increasing drug expenditures, unnecessary drug consumption and adverse effect risks. Even though the influence of pharmaceuticals on health services and the economy hold the same importance in the developed and developing countries, its negative consequences have increased by encompassing developing countries in its grip. Therefore, in this review, using Turkey as an example, the situation of direct-to-consumer advertisements in developing countries is analysed in relation with developed countries. [source] Cruelty, Horror, and the Will to RedemptionHYPATIA, Issue 2 2003Lynne S. Arnault Americans cherish the idea that good eventually triumphs over evil. After briefly arguing that a proper understanding of the moral harm of cruelty calls into question the credibility of popular American idioms of redemption, I argue that the epistemic dynamics of horror help account for the commanding grip of this rhetoric on the popular imagination, and I suggest that this idiom has morally problematic features that warrant the attention of feminists. [source] Canal shapes produced sequentially during instrumentation with Quantec SC rotary nickel,titanium instruments: a study in simulated canalsINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2001I. T. Griffiths Abstract Aim The aim of this study was to determine the shaping ability of Quantec SC nickel,titanium rotary instruments in simulated root canals. Methodology Forty simulated canals consisting of four different shapes in terms of angle and position of curvature were prepared with Quantec SC instruments. Sequential still images were taken of the canals using a video camera attached to a computer with image analysis software. Images were taken preoperatively, and then after instrument 7 (Size 25, 0.05 taper), instrument 8 (size 25, 0.06 taper), and instrument 10 (size 45, 0.02 taper) were taken to length. Each sequential postoperative image was superimposed individually over the preoperative image in order to highlight the amount and position of material removed during preparation. Results Overall, the mean preparation time to size 10 was 3.6 min with 12 mm canals taking on average less time than 8 mm canals. There was a highly significant difference between the canal types (P < 0.0001). No instruments fractured within the canal or deformed, although one instrument separated from the latch grip. All canals remained patent. Following preparation to size 10, 19 canals (48%) retained their length, eight (20%) lost length, and 13 (32%) gained length; the magnitude of the change in length was always 0.5 mm or below. Following preparation to size 7 instruments all canals showed aberrant shapes. Excess removal of material along the outer aspect of the curve between the beginning of the curve and the end-point (outer widening) was found in 26 canals (65%) after instrument 7. At the same stage of preparation six canals (15%) had zips, three (8%) had ledges and five (13%) had perforations. Following preparation to size 10, 27 (68%) canals were perforated. Conclusions Under the conditions of the study, Quantec SC instruments consistently produced aberrations when canals were enlarged to size 7 (size 25, 0.05 taper) or above. Care should be exercised when using these instruments in real teeth. [source] The Spiritual Turn and the Decline of Tradition: The Spread of Post-Christian Spirituality in 14 Western Countries, 1981,2000JOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 3 2007DICK HOUTMAN This article uses data from the World Values Survey to study the spread of post-Christian spirituality ("New Age") in 14 Western countries (1981,2000, N = 61,352). It demonstrates that this type of spirituality, characterized by a sacralization of the self, has become more widespread during the period 1981,2000 in most of these countries. It has advanced farthest in France, Great Britain, the Netherlands, and Sweden. This spiritual turn proves a byproduct of the decline of traditional moral values and hence driven by cohort replacement. Spirituality's popularity among the well educated also emerges from the latter's low levels of traditionalism. These findings confirm the theory of detraditionalization, according to which a weakening of the grip of tradition on individual selves stimulates a spiritual turn to the deeper layers of the self. [source] Allostatic Load and Frailty in Older AdultsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2009Tara L. Gruenewald PhD OBJECTIVES: To examine the association between allostatic load (AL), an index of multisystem physiological dysregulation, and frailty development over a 3-year follow-up in a sample of older adults. DESIGN: Longitudinal cohort study. SETTING: Community. PARTICIPANTS: High-functioning men and women aged 70 to 79 at study entry. MEASUREMENTS: Multisystem physiological dysregulation, or AL, was assessed according to 13 biomarkers of cardiovascular, endocrine, immune, and metabolic function. An AL score was computed as the total number of biomarkers for which participant values fell into high-risk biomarker quartiles. Frailty status (not frail, intermediate frail, frail) was determined according to the total number of five indicators of frailty: weight loss, exhaustion, weak grip, slow gait, and low physical activity. The association between level of AL at baseline and frailty status 3 years later was examined using ordinal logistic regression in 803 participants not frail at baseline. RESULTS: In a multivariable model adjusting for sociodemographic, health, and behavioral characteristics, each 1-unit increase in AL at baseline was associated with a 10% greater likelihood of frailty at the 3-year follow-up (cumulative adjusted odds ratio=1.10, 95% confidence interval=1.03,1.19). CONCLUSION: These findings support the hypothesis that dysregulation across multiple physiological systems is associated with greater risk of frailty. Greater levels of multisystem physiological dysregulation may serve as a warning sign of frailty development in later life. [source] Association Between Changes in Habitual Physical Activity and Changes in Bone Density, Muscle Strength, and Functional Performance in Elderly Men and WomenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 12 2008Robin M. Daly PhD OBJECTIVES: To investigate the long-term effects of habitual physical activity on changes in musculoskeletal health, functional performance, and fracture risk in elderly men and women. DESIGN: Ten-year prospective population-based study. SETTING: Malmö-Sjöbo Prospective Study, Sweden. PARTICIPANTS: Participants were 152 men and 206 women aged 50, 60, 70, and 80 who were followed for 10 years. MEASUREMENTS: Distal radius bone mineral density (BMD) (single photon absorptiometry), upper limb muscle (grip) strength, balance, gait velocity, occupational and leisure-time activity, and fractures (interview-administered questionnaire) were reassessed after 10 years. Annual changes for all measures were compared between participants with varying habitual physical activity histories at baseline and follow-up: inactive,inactive (n=202), active,inactive (n=47), inactive,active (n=49), and active,active (n=60). Data for men and women were pooled, because there were no sex-by-activity group interactions. To detect possible differences in fracture incidence between the varying habitual activity groups, participants were classified into two activity groups based on their activity classification at baseline and follow-up: inactive:less active versus active:more active. RESULTS: The annual rate of bone loss was 0.6% per year less in individuals classified as active at both time points than in those classified as inactive at both time points (P<.01). Similar results were observed for balance, but there was no effect of varying habitual activity on changes in muscle strength or gait velocity. There were also no differences in fracture incidence between individuals categorized as active:more active and those categorized as inactive:less active during the follow-up (adjusted hazard ratio=0.90, 95% confidence interval (CI)=0.42,1.90). CONCLUSION: This study showed that elderly men and women who maintained a habitually active lifestyle over 10 years had lower bone loss and retained better balance than those who remained habitually inactive. [source] Associations Between Lower Extremity Ischemia, Upper and Lower Extremity Strength, and Functional Impairment with Peripheral Arterial DiseaseJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2008Mary M. McDermott MD OBJECTIVES: To identify associations between lower extremity ischemia and leg strength, leg power, and hand grip in persons with and without lower extremity peripheral arterial disease (PAD). To determine whether poorer strength may mediate poorer lower extremity performance in persons with lower arterial brachial index (ABI) levels. DESIGN: Cross-sectional. SETTING: Academic medical centers. PARTICIPANTS: Four hundred twenty-four persons with PAD and 271 without PAD. MEASUREMENTS: Isometric knee extension and plantarflexion strength and handgrip strength were measured using a computer-linked strength chair. Knee extension power was measured using the Nottingham leg rig. ABI, 6-minute walk, and usual and fastest 4-m walking velocity were measured. Results were adjusted for potential confounders. RESULTS: Lower ABI values were associated with lower plantarflexion strength (P trend=.04) and lower knee extension power (P trend <.001). There were no significant associations between ABI and handgrip or knee extension isometric strength. Significant associations between ABI and measures of lower extremity performance were attenuated after additional adjustment for measures of strength. CONCLUSION: These results are consistent with the hypothesis that lower extremity ischemia impairs strength specifically in distal lower extremity muscles. Associations between lower extremity ischemia and impaired lower extremity strength may mediate associations between lower ABI values and greater functional impairment. [source] Effects of Aging on Hand FunctionJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2001Vinoth K. Ranganathan MSE OBJECTIVES: The purpose of this study was to quantify age-induced changes in handgrip and finger-pinch strength, ability to maintain a steady submaximal finger pinch force and pinch posture, speed in relocating small objects with finger grip, and ability to discriminate two identical mechanical stimuli applied to the finger tip. DESIGN: A cross-sectional study. SETTINGS: Greater Cleveland area of Ohio. PARTICIPANTS: Healthy, independent, young (n = 27, range 20,35 years) and older (n = 28, range 65,79 years) subjects. MEASUREMENTS: Handgrip strength, maximum pinch force (MPF), ability to maintain a steady pinch force at three relative force levels (5%, 10%, and 20% MPF) and three absolute force levels (2.5 Newtons (N), 4 N, and 8 N), ability to maintain a precision pinch posture, speed in relocating pegs from a nearby location onto the pegboard, and the shortest distance for discriminating two stimuli were measured in both young and older groups. RESULTS: Compared with young subjects, the older group's handgrip force was 30% weaker (P < .001), MPF was 26% lower (P < .05), and ability to maintain steady submaximal pinch force and a precision pinch posture was significantly less (P < .05). The time taken to relocate the pegs and the distance needed to discriminate two identical stimuli increased significantly with age (P < .01). The decrease in the ability to maintain steady submaximal pinch force was more pronounced in women than men. CONCLUSION: Aging has a degenerative effect on hand function, including declines in hand and finger strength and ability to control submaximal pinch force and maintain a steady precision pinch posture, manual speed, and hand sensation. [source] Morphology and function of the forelimb in arboreal frogs: specializations for grasping ability?JOURNAL OF ANATOMY, Issue 3 2008Adriana S. Manzano Abstract Frogs are characterized by a unique morphology associated with their saltatory lifestyle. Although variation in the form and function of the pelvic girdle and associated appendicular system related to specialized locomotor modes such as swimming or burrowing has been documented, the forelimbs have typically been viewed as relatively unspecialized. Yet, previous authors have noted versatility in forelimb function among arboreal frogs associated with feeding. Here we study the morphology and function of the forelimb and hand during locomotion in two species of arboreal frogs (Litoria caerulea and Phyllomedusa bicolor). Our data show a complex arrangement of the distal forelimb and hand musculature with some notable differences between species. Analyses of high-speed video and video fluoroscopy recordings show that forelimbs are used in alternating fashion in a diagonal sequence footfall pattern and that the position of the hand is adjusted when walking on substrates of different diameters. Electromyographic recordings show that the flexors of the hand are active during substrate contact, suggesting the use of gripping to generate a stabilizing torque. Measurements of grasping forces in vivo and during stimulation experiments show that both species, are capable of executing a so-called power grip but also indicates marked differences between species, in the magnitude of forces generated. Stimulation experiments showed an increased control of digit flexion in the more specialized of the two species, allowing it to execute a precision grip paralleled only by that seen in primates. [source] Self-Deception and Responsibility for AddictionJOURNAL OF APPLIED PHILOSOPHY, Issue 2 2003Neil Levy ABSTRACT We frequently accuse heavy drinkers and drug users of self-deception if they refuse to admit that they are addicted. However, given the ways in which we usually conceptualize it, acknowledging addiction merely involves swapping one form of self-deception for another. We ask addicts to see themselves as in the grip of an irresistible desire, and to accept that addiction is an essentially physiological process. To the extent this is so, we, as much as the addicts, suffer from self-deception, and the responsibility for their state is in part ours. Conversely, since addicts are compelled to accept a self-deceptive image of themselves, they are at least partially excused from blame for their self-deception. [source] Automatic guidance of a four-wheel-steering mobile robot for accurate field operationsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 6-7 2009Christophe Cariou As world population growth requires an increasing level of farm production at the same time that environmental preservation is a priority, the development of new agricultural tools and methods is required. In this framework, the development of robotic devices can provide an attractive solution, particularly in the field of autonomous vehicles. Accurate automatic guidance of mobile robots in farming constitutes a challenging problem for researchers, mainly due to the low grip conditions usually found in such a context. From assisted-steering systems to agricultural robotics, numerous control algorithms have been studied to achieve high-precision path tracking and have reached an accuracy within ±10 cm, whatever the ground configuration and the path to be followed. However, most existing approaches consider classical two-wheel-steering vehicles. Unfortunately, by using such a steering system, only the lateral deviation with respect to the path to be followed can be satisfactorily controlled. Indeed, the heading of the vehicle remains dependent on the grip conditions, and crabwise motions, for example, are systematically observed on a slippery slope, leading to inaccurate field operations. To tackle this drawback, a four-wheel-steering (4WS) mobile robot is considered, enabling servo of both lateral and angular deviations with respect to a desired trajectory. The path tracking control is designed using an extended kinematic representation, allowing account to be taken online of wheel skidding, while a backstepping approach permits management of the 4WS structure. The result is an approach taking advantage of both rear and front steering actuations to fully compensate for sliding effects during path tracking. Moreover, a predictive algorithm is developed in order to address delays induced by steering actuators, compensating for transient overshoots in curves. Experimental results demonstrate that despite sliding phenomena, the mobile robot is able to automatically and accurately achieve a desired path, with lateral and angular errors, respectively, within ±10 cm and ±2 deg, whatever its shape and whatever the terrain conditions. This constitutes a promising result in efforts to define efficient tools with which to tackle tomorrow's agriculture challenge. © 2009 Wiley Periodicals, Inc. [source] Neural network approach to firm grip in the presence of small slipsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 6 2001A. M. Al-Fahed Nuseirat This paper presents a two stage method for constructing a firm grip that can tolerate small slips of the fingertips. The fingers are assumed to be of frictionless contact type. The first stage was to formulate the interaction in the gripper,object system as a linear complementarity problem (LCP). Then it was solved using a special neural network to find minimal fingers forces. The second stage was to use the obtained results in the first stage as a static mapping in training another neural network. The second neural network training included emulating the slips by random noise in the form of changes in the positions of the contact points relative to the reference coordinate system. This noisy training increased robustness against unexpected changes in fingers positions. Genetic algorithms were used in training the second neural network as global optimization techniques. The resulting neural network is a robust, reliable, and stable controller for rigid bodies that can be handled by a robot gripper. © 2001 John Wiley & Sons, Inc. [source] Musculoskeletal underpinnings to differences in killing behavior between North American accipiters (Falconiformes: Accipitridae) and falcons (Falconidae)JOURNAL OF MORPHOLOGY, Issue 3 2008Diego Sustaita Abstract Accipiters (Accipiter spp.) and falcons (Falco spp.) both use their feet to seize prey, but falcons kill primarily with their beaks, whereas accipiters kill with their feet. This study examines the mechanistic basis to differences in their modes of dispatching prey, by focusing on the myology and biomechanics of the jaws, digits, and distal hindlimb. Bite, grip, and distal hindlimb flexion forces were estimated from measurements of physiological cross-sectional area (PCSA) and indices of mechanical advantage (MA) for the major jaw adductors, and digit and tarsometatarsal flexors. Estimated bite force, total jaw adductor PCSA, and jaw MA (averaged over adductors) tended to be relatively and absolutely greater in falcons, reflecting their emphasis on biting for dispatching their prey. Differences between genera in estimated grip force, total digit flexor PCSA, and digit MA (averaged over inter-phalangeal joints and digits) were not as clear-cut; each of these parameters scaled positively allometric in accipiters, which may reflect the scaling of both prey size, and the proportion of mammalian prey consumed by this lineage with increasing body size. Estimated tarsometatarsal force was greater in falcons than in accipiters, due to their greater MA, which may reflect selection for incurring greater forces during prey strikes. Conversely, the comparatively lower tarsometatarsal MA in accipiters reflects their capacity for greater foot speed potentially necessary for grasping elusive prey. Thus, this study elucidates how differences in jaw and hindlimb musculoskeletal morphology of accipiters and falcons are reflected in differences in their killing modes, and through differences in their force-generating capacities. J. Morphol., 2008. © 2007 Wiley-Liss, Inc. [source] Upper limb muscle imbalance in tennis elbow: A functional and electromyographic assessmentJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 12 2007Omid Alizadehkhaiyat Abstract The purpose of this study was to investigate strength, fatigability, and activity of upper limb musculature to elucidate the role of muscular imbalance in the pathophysiology of tennis elbow. Sixteen patients clinically diagnosed with tennis elbow, recruited from a university hospital upper limb orthopedic clinic, were compared with 16 control subjects with no history of upper limb musculoskeletal problem, recruited from university students and staff. Muscle strength was measured for grip, metacarpophalangeal, wrist, and shoulder on both sides. Electromyographic activity (RMS amplitude) and fatigue characteristics (median frequency slope) of five forearm and two shoulder muscles were measured during isometric contraction at 50% maximum voluntary contraction. All strength measurements showed dominance difference in C, but none in TE. In tennis elbow compared to controls, hand/wrist and shoulder strength and extensor carpi radialis (ECR) activity were reduced (p,<,0.05), while fatigue was normal. A global upper limb weakness exists in tennis elbow. This may be due to disuse and deconditioning syndrome caused by fear avoidance, and needs to be addressed in prevention and treatment. Activation imbalance among forearm muscles (reduced extensor carpi radialis activity) in tennis elbow, probably due to protective pain-related inhibition, could lead to a widespread upper limb muscle imbalance. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1651,1657, 2007 [source] | |||||||||||||||||||||||||||||||