486 resultados para swing conveyor


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BACKGROUND Joint hypermobility is known to be associated with joint and muscle pain, joint instability and osteoarthritis. Previous work suggested that those individuals present an altered neuromuscular behavior during activities such as level walking. Therefore, the aim of this study was to explore the differences in ground reaction forces, temporal parameters and muscle activation patterns during gait between normomobile and hypermobile women, including symptomatic and asymptomatic hypermobile individuals. METHODS A total of 195 women were included in this cross-sectional study, including 67 normomobile (mean 24.8 [SD 5.4] years) and 128 hypermobile (mean 25.8 [SD 5.4] years), of which 56 were further classified as symptomatic and 47 as asymptomatic. The remaining 25 subjects could not be further classified. Ground reaction forces and muscle activation from six leg muscles were measured while the subjects walked at a self-selected speed on an instrumented walkway. Temporal parameters were derived from ground reaction forces and a foot accelerometer. The normomobile and hypermobile groups were compared using independent samples t-tests, whereas the normomobile, symptomatic and asymptomatic hypermobile groups were compared using one-way ANOVAs with Tukey post-hoc tests (significance level=0.05). FINDINGS Swing phase duration was higher among hypermobile (P=0.005) and symptomatic hypermobile (P=0.018) compared to normomobile women. The vastus medialis (P=0.049) and lateralis (P=0.030) and medial gastrocnemius (P=0.011) muscles showed higher mean activation levels during stance in the hypermobile compared to the normomobile group. INTERPRETATION Hypermobile women might alter their gait pattern in order to stabilize their knee joint.

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The Quiet Eye (QE; Vickers 1996) has been shown to underpin successful performance, differentiating both expertise (inter-individual) and proficiency (intra-individual), with experts and successful attempts characterised by longer QE durations. The QE is proposed to reflect the time needed to organise and fine tune the parameters of movement (e.g. force and direction). In order to examine this prediction and build upon previous research we experimentally manipulated the difficulty of a golf putting task; we hypothesised that if the QE is related to motor programming then a more difficult task should be associated with longer QE durations. 33 golfers (M age= 21.16, SD= 3.98) with an average handicap of 6.5 (SD= 6.02) performed putts in 4 conditions of increasing difficulty. We manipulated the length of the golf putt (short-4ft, long-8ft) and the contact point of the putter head (large-1.7cm, small-0.5cm,) giving increasingly difficult putting conditions of short-large [1], short-small [2], long-large [3] and long-small [4]. We measured performance (radial error from hole in cm) and QE (in ms) for 10 putts in each condition. A repeated measures ANOVA was performed on the performance and QE data. The performance data suggest that we were successful in increasing the difficulty of the task (F (3,93) = 26.46. p = .000), with the best performance in condition [1] (8.57cm), followed by [2] (9.10cm) followed by [3] (16.11cm) and finally the worst performance was in condition [4] (23.40cm). The QE data suggest that, in keeping with our hypothesis, the QE was lengthened as task difficulty increased (F (3,87) = 11.91, p = .043). The QE was shortest in condition [1] (1787.85ms) and increased to condition [2] (1939.78ms) and condition [3] (2076.51ms), with the longest QE in condition [4] (2164.08ms). More detailed analysis of the QE reveal that it was the proportion of the QE that occurred before movement initiation (pre-QE) which increased with shot difficulty, rather than the proportion that occurred during the swing (Online-QE; see Vine et al., 2013). Results support the notion that more complex tasks are associated with a longer QE duration, specifically participants appear to spend longer fixating the target prior to movement. This likely reflects the time needed to process visual information gathered in a pre-performance routine, to inhibit external distraction, and to pre-programme the increasingly difficult parameters of the movement. Vickers, J.N. (1996). Visual control when aiming at a far target. Journal of Experimental Psychology: Human Perception and Performance, 22, 342-354. Vine, S.J. et al. (2013). Quiet eye and choking: Online control breaks down at the point of performance failure. Medicine and Science in Sports and Exercise, 45, 1988-1994.

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On 9 February 2014, the Swiss people accepted the popular initiative “against mass immigration” launched by the national-conservative Swiss People’s Party (SVP). This voting outcome has triggered wide-ranging debates about both the policy on immigrants as well as the future of Switzerland within the European context. Against this background, we evaluate attitudes toward immigration in Switzerland. Using hitherto unexplored survey data of MOSAiCH, our empirical analyses show that already in the year 2013, before the debate about the initiative on mass immigration was in full swing, roughly 53 percent of the 1011 interviewed Swiss citizens stated that immigration should be reduced. Moreover, our estimations indicate that the threats and fears induced by immigration and the will to maintain sovereignty and autonomy are particularly relevant for attitudes toward immigration. By contrast, education and national or personal economic conditions are only weakly related to the immigration issue.

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A safety door for the discharge opening of a selfunloading wagon is disclosed herein. The wagon includes a material receiving box having a first conveyor therein for conveying the material towards one end thereof. A cross conveyor is mounted at the one end of the box for conveying the material outwardly from the box through the lower end of a discharge opening formed in the side of the box. A material beater means is rotatably mounted in the box above the cross conveyor. The safety door extends across the discharge opening to prevent the operator from reaching inwardly through the discharge opening. The safety door is self-closing and is opened by the material being discharged outwardly through the discharge opening.

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En la Argentina tuvo lugar entre 1924 y 1930 una polémica literario–política centrada en las revistas Martín Fierro, por un lado y Los Pensadores y Claridad por el otro, referente al objetivo de la literatura y su papel en la sociedad, aspectos que ejemplifican posiciones diferentes frente a lo real, la literatura como tarea y la obra como comunicación y portadora de significado. Los dos grupos intentaron legitimar sus objetivos frente a lo canónico: Florida atacó los modelos modernista, realista y los residuos románticos, y Boedo trató de ampliar la noción de público literario. Sin embargo, la disputa motivó más leyendas que vanguardias. En esta oportunidad nos interesa analizar, desde la perspectiva de la historia de la ideas y centrados en Los Pensadores, la mencionada polémica como expresión propia de la época.

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A benthic isotope record has been measured for core SO75-26KL from the upper Portuguese margin (1099 m water depth) to monitor the response of thermohaline overturn in the North Atlantic during Heinrich events. Evaluating benthic delta18O in TS diagrams in conjunction with equilibrium deltac fractionation implies that advection of Mediterranean outflow water (MOW) to the upper Portuguese margin was significantly reduced during the last glacial (< 15% compared to 30% today). The benthic isotope record along core SO75-26KL therefore primarily monitors variability of glacial North Atlantic conveyor circulation. The 14C-accelerator mass spectrometry ages of 13.54±.07 and 20.46±.12 ka for two ice-rafted detritus (IRD) layers in the upper core section and an interpolated age of 36.1 ka for a third IRD layer deeper in the core are in the range of published 14C ages for Heinrich events H1, H2, and H4. Marked depletion of benthic delta13C by 0.7-1.1 per mil during the Heinrich events suggests reduced thermohaline overturn in the North Atlantic during these events. Close similarity between meltwater patterns (inferred from planktonic delta18O) at Site 609 and ventilation patterns (inferred from benthic delta13C) in core SO75-26KL implies coupling between thermohaline overturn and surface forcing, as is also suggested by ocean circulation models. Benthic delta13C starts to decrease 1.5-2.5 kyr before Heinrich events Hl and H4, fully increased values are reached 1.5-3 kyr after the events, indicating a successive slowdown of thermohaline circulation well before the events and resumption of the conveyor's full strength well after the events. Benthic delta13C changes in the course of the Heinrich events show subtle maxima and minima suggesting oscillatory behavior of thermohaline circulation, a distinct feature of thermohaline instability in numerical models. Inferrred gradual spin-up of thermohaline circulation after Hl and H4 is in contrast to abrupt wanning in the North Atlantic region that is indicated by sudden increases in Greenland ice core delta18O and in marine faunal records from the northern North Atlantic. From this we infer that thermohaline circulation can explain only in part the rapid climatic oscillations seen in glacial sections of the Greenland ice core record.

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El presente artículo analiza las políticas públicas de fomento para la creación y fortalecimiento de organismos intermunicipales desarrolladas por niveles superiores de gobierno en Argentina y España. Dado el desarrollo incipiente de este tipo de experiencias en Iberoamérica, se propone un análisis comparado de las políticas públicas de fomento del asociativismo municipal en la Provincia de Mendaza (Argentina) y la Provincia de Sevilla (España), dos entidades gubernamentales intermedias que poseen características demográficas y económicas semejantes en el contexto de sus respectivos países y donde la creación de estas entidades locales se encuentra en plena actividad. En función de estos desarrollos, reflexionaremos en torno a las restricciones institucionales más relevantes que dificultan la ejecución de proyectos articulativos intermunicipales.

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Because zooplankton feces represent a potentially important transport pathway of surface-derived organic carbon in the ocean, we must understand the patterns of fecal pellet abundance and carbon mobilization over a variety of spatial and temporal scales. To assess depth-specific water column variations of fecal pellets on a seasonal scale, vertical fluxes of zooplankton fecal pellets were quantified and their contribution to mass and particulate carbon were computed during 1990 at 200, 500, 1000, and 2000 m depths in the open northwestern Mediterranean Sea as part of the French-JGOFS DYFAMED Program. Depth-averaged daily fecal pellet flux was temporally variable, ranging from 3.04 * 10**4 pellets m**2/d in May to a low of 6.98 * 10**2 pellets m**2/d in September. The peak flux accounted for 50% of the integrated annual flux of fecal pellets and 62% of pellet carbon during only two months in mid-spring (April and May). Highest numerical fluxes were encountered at 1000 m, suggesting fecal pellet generation well below the euphotic zone. However, there was a trend toward lower pellet carbon with increasing depth, suggesting bacterial degradation or in situ repackaging as pellets sink through the water column. At 500 m, both the lowest pellet numerical abundance and carbon flux were evident during the spring peak. Combined with data indicating that numerical and carbon fluxes are dominated at 500 m by a distinct type of pellet found uniquely at this depth, these trends suggest the presence of an undescribed mid-water macro-zooplankton or micro-nekton community. Fecal pellet carbon flux was highest at 200 m and varied with depth independently of overall particulate carbon, which was greatest at 500 m. Morphologically distinct types of pellets dominated the numerical and carbon fluxes. Small elliptical and spherical pellets accounted for 88% of the numerical flux, while larger cylindrical pellets, although relatively rare (<10%), accounted for almost 40% of the overall pellet carbon flux. Cylindrical pellets dominated the pellet carbon flux at all depths except 500 m, where a large subtype of elliptical pellet, found only at that depth, was responsible for the majority of pellet carbon flux. Overall during 1990, fecal pellets were responsible for a depth-integrated annual average flux of 1.03 mgC/m**2/d, representing 18% of the total carbon flux. The proportion of vertical carbon flux attributed to fecal pellets varied from 3 to 35%, with higher values occurring during periods when the water column was vertically mixed. Especially during these times, fecal pellets are a critical conveyor of carbon to the deep sea in this region.

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High-resolution sediment records from the South China Sea reveal a winter monsoon dominated glacial regime and a summer monsoon dominated Holocene regime during the last glacial cycle. A fundamental change between regimes occurred during deglaciation through a series of millennial reoccurrences of century-scale changes in the East Asian monsoon (EAM) climate. These abrupt events centered at 17.0, 15.9, 15.5, 14.7, 13.5, 13.9, 13.3, 12.1, 11.5, and 10.7 14C ka correlate well with the millennial-scale events in the Santa Barbara Basin and the Arabian Sea, i.e. a relationship between EAM and El Niño/Southern Oscillation systems. The abrupt increases in summer monsoon imply enhanced heat transport from low-latitude sea area to the midlatitude/high-latitude land area. The phase relationship between events of EAM and ice sheet may reflect a faster EAM response and a slower ice sheet response to the insolation change. A far-reaching conclusion is that the EAM might have triggered the Northern Hemisphere deglaciation.

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Planktonic foraminiferal assemblages from the upper Pleistocene part of Hole 1087A (0 to 12.1 meters below seafloor) are investigated to assess the role of global and local climate changes on surface circulation in the southern Benguela region. The benthic stable isotope record indicates that the studied interval is representative of the last four climatic cycles, that is, down to marine isotope Stage (MIS) 12. The species assemblages bear a clear transitional to subpolar character, with Neogloboquadrina pachyderma (d), Globorotalia inflata, and Globigerina bulloides, in order of decreasing abundance, as the dominant taxa. This species association presently characterizes the mixing domain of old upwelled and open ocean waters, seaward of the Benguela upwelling cells. Abundance variation of the dominant foraminiferal species roughly follows a glacial-interglacial pattern down to MIS 8, suggesting an alternation of upwelling strength and associated seaward extension of the belt of upwelled water as a response to global climate changes. This pattern is interrupted from ~250 ka down to MIS 12, where the phase relationship with global climate is ill defined and might be interpreted as a local response of the southern Benguela region to the mid-Brunhes event. Of particular interest is a single pulse of newly upwelled waters at the location of Site 1087 during early MIS 9 as indicated by a peak abundance of sinistral N. pachyderma (s). Variable input of warm, salty Indian Ocean thermocline waters into the southeast Atlantic, a key component of the Atlantic heat conveyor, is indicated by abundance changes of the tropical taxon Globorotalia menardii. From this tracer, we suggest that interocean exchange was hardly interrupted throughout the last 460 k.y., but was most effective at glacial terminations, particularly during Terminations I and II, as well as during the upper part of MIS 12. This maximum input of Indian Ocean waters around the southern tip of Africa is associated with the reseeding of G. menardii in the tropical Atlantic.

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During Leg 177 of the Ocean Drilling Program (ODP), well-preserved Middle Miocene to Pleistocene carbonate-rich sediment records were recovered on a north-south transect through the south-eastern Atlantic sector of the Southern Ocean at Site 1088 on the Agulhas Ridge and Site 1092 on Meteor Rise. Both sites were dominated by the deposition of calcareous nannofossil oozes through the Miocene, indicating low biological productivity in warm to temperate surface waters. A continuous increase in the proportions of foraminifera since the latest Miocene (6.5 Ma) points to enhanced nutrient supply, possibly related to the global 'biogenic bloom' event across the Miocene-Pliocene boundary. Since the Late Pliocene, different styles of biological productivity developed between the sites. Enhanced deposition of biosiliceous constituents at the southern Site 1092, particularly in the Early Pleistocene, is consistent with the formation of the Circum-Antarctic Opal Belt since 2.5 Ma in a setting near the Polar Front, whereas carbonate deposition still prevailed at the northern Site 1088 situated near the Subtropical Front. Clay-mineral tracers of water-mass advection together with the pattern of sedimentation rates and hiatuses reflect distinct pulses in the development of regional ocean circulation between 14 and 12 Ma, around 8 Ma and since 2.8 Ma. These pulses can be related to Antarctic ice-sheet extension that mediates the production and flow of southern source water, and stepwise increases in North Atlantic Deep Water production that drives global conveyor circulation. At Site 1088, illite chemistry and silt/clay ratios of the terrigenous sediment fraction reflect the history of terrestrial climate in southern Africa, with humid conditions prior to the Early Late Miocene (9.7 Ma), followed by a dry episode until 7.7 Ma. The latest Miocene and Early Pliocene were characterized by a humid episode until modern aridity was established in the Late Pliocene between 4.0 and 2.8 Ma. These climate changes were related to the latitudinal migration of climate belts in response to tectonically caused reorganizations in atmospheric and ocean circulation.

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Foraminiferal assemblages were studied in northern Barents Sea core ASV 880 along with oxygen and carbon isotope measurements in planktonic (N. pachyderma sin.) and benthic (E. clavatum) species. AMS C-14 measurements performed on molluscs Yoldiella spp. show that this core provides a detailed and undisturbed record of Holocene climatic changes over the last 10000 calendar years. Surface and deep waters were very cold (<0°C) at the beginning of the Holocene. C. reniforme dominated the highly diverse benthic foraminiferal assemblage. From 10 to 7.8 cal. ka BP, a warming trend culminated in a temperature optimum, which developed between 7.8 and 6.8 cal. ka BP. During this optimum, the input of Atlantic water to the Barents Sea reached its maximum. The Atlantic water mass invaded the whole Franz Victoria Trough and was present from subsurface to the bottom. No bottom water, which would form through rejection of brine during winter, was present at the core depth (388 m). The water stratification was therefore greatly reduced as compared to the present. An increase in percentage of I. helenae/norcrossi points to long seasonal ice-free conditions. The temperature optimum ended rather abruptly, with the return of cold polar waters into the trough within a few centuries. This was accompanied by a dramatic reduction of the abundance of C. reniforme. During the upper Holocene, the more opportunistic species E. clavatum became progressively dominant and the water column was more stratified. Deep water in Franz Victoria Trough contained a significant amount of cold Barents Sea bottom water as it does today, while subsurface water warmed progressively until about 3.7 cal. ka BP and reached temperatures similar to those of today. These long-term climatic changes were cut by several cold events of short duration, in particular one in the middle of the temperature optimum and another, which coincides most probably with the 8.2 ka BP cold event. Both long- and short-term climatic changes in the Barents Sea are associated with changes in the flow of Atlantic waters and the oceanic conveyor belt.

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Paleomagnetic inclination, declination and relative paleointensity were reconstructed from the sediments of Laguna Potrok Aike in the framework of the International Continental scientific Drilling Program (ICDP) Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO). Here we present the u-channel-based full vector paleomagnetic field reconstruction since 51.2 ka cal BP. The relative paleointensity proxy (RPI) was built by normalising the natural remanent magnetisation with the anhysteretic remanent magnetisation using the average ratio at 4 demagnetisation steps part of the ChRM interval (NRM/ARM10e40 mT). A grain size influence on the RPI was removed using a correction based on the linear relationship between the RPI and the median destructive field of the natural remanent magnetisation (MDFNRM). The new record is compared with other lacustrine and marine records and stacks from the mid- to high-latitudes of the Southern Hemisphere, revealing consistent millennial-scale variability, the identification of the Laschamp and possibly the Mono Lake geomagnetic excursions, and a direction swing possibly associated to the Hilina Pali excursion at 20 ka cal BP. Nonetheless, a global-scale comparison with other high-resolution records located on the opposite side of the Earth and with various dipole field references hint at a different behaviour of the geomagnetic field around southern South America at 46 ka cal BP.

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Stable isotopic measurements of G. sacculifer and C. wuellerstorfi in a core from the western equatorial Atlantic imply that there are parallel, suborbital oscillations in surface water hydrography and deep water circulation occurring during oxygen isotope stages 2 and 3. Low values of G. sacculifer delta18O accompany high values of C. wuellerstorfi delta13C, linking warmer sea surface temperatures (SSTs) in the tropics with increased production of lower North Atlantic Deep Water (NADW). The amplitude of the delta18O oscillations is 0.6 per mil (or 2°-3°C), which is superimposed on a glacial/interglacial amplitude of about 2.1per mil. Using the G. sacculifer delta18O data, we calculate that surface waters were colder during stage 2 than calculated by CLIMAP [1976, 1981]. The longer-period (>2 kyr) oscillations in air temperature recorded in the Greenland and Antarctic ice cores appear to correlate with oscillations in sea surface temperature in the equatorial Atlantic. The magnitude of these oscillations in tropical SST is too large to have resulted from changes in meridional heat transport caused by the global conveyor alone. The apparent synchroneity of equatorial SST and polar air temperature changes, as well as the amplitude of the SST changes at the equator, are consistent with the climate effects expected from changes in the atmosphere's greenhouse gas content (H2Ovapor, CO2, and CH4).

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Marine snow (MS) distribution from the surface to 1000 m depth was determined in the equatorial Pacific using the underwater video profiler during the Etude du Broutage en Zone Equatoriale cruise in fall 1996. The latitudinal transect was carried out at 17 stations along the 180° meridian from 8°S to 8°N during a cold phase of El Niño-Southern Oscillation. Higher MS concentrations were found below the equatorial zone than poleward. At the equator the estimated integrated MS carbon/m**2 in the upper kilometer was 5.7 g/m**2, while both southward and northward (between 1° and 8°) the mean integrated MS carbon was about 2.7 g/m**2. In the upper 50 m the MS carbon was twofold lower than the combined carbon of autotrophic and heterotrophic protists and four times lower than the mesozooplankton carbon biomass, both measured concurrently during the cruise. Different water bodies had different MS content. The highest concentrations were found in the South Equatorial Current, the South Equatorial Counter Current, and the North Equatorial Countercurrent. Tropical waters at the south in the South Subsurface Countercurrents and the warm northern superficial waters had the lowest MS biomass. Mechanistically, a latitudinal "conveyor belt", a poleward divergence of upwelled waters that return to the equator after being downwelled at north and south convergent zones, may partially explain the vertical distribution of particulate matter observed during the studied period.