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Tide
Kinds of Tide Terms modified by Tide Selected AbstractsTHE ROLE OF CALCIUM IN FLOW-STIMULATED BIOLUMINESCENCE OF THE RED TIDE DINOFLAGELLATE LINGULODINIUM POLYEDRUMJOURNAL OF PHYCOLOGY, Issue 2000P. Von Dassow Many marine planktonic dinoflagellates emit flashes of light in response to either laminar or turbulent flows as well as direct mechanical stimulation. The production of a flash of light is known to be mediated by a proton-mediated action potential across the vacuolar membrane; the mechanotransduction process initiating this action potential is unknown. Here we report on an investigation into the role of Ca+2 in the mechanotransduction process regulating bioluminescence in the red tide dinoflagellate Lingulodinium polyedrum. Calcium ionophores and low concentrations of the membrane-disrupting agent digitonin stimulated bioluminescence only when calcium was present in the media or added with the agent, indicating that the flash-triggering vacuolar action potential is specifically stimulated by a calcium influx. A variety of known calcium channel blockers or antagonists inhibited mechanically stimulated bioluminescence but did not affect cellular bioluminescent capacity. In many cases the inhibitory affect occurred after only a brief exposure. In addition, gadolinium (Gd+3), a blocker of many stretch-activated ion channels, caused potent inhibition of mechanically stimulated bioluminescence. The order of potency of the transition metals tested was La+3 > Gd+3 > Co+2 > Mn+2 > Ni+2, similar to their potency as blockers of known calcium channels. Experiments with a quantified shear flow demonstrated that flow-stimulated bioluminescence depended on the level of extracellular calcium. Future work will elucidate the signaling pathway involving calcium-mediated flow-stimulated mechanotransduction. Our goal is to use bioluminescence as a proxy for the initial cellular mechanotransduction events triggered by fluid flow. [source] Against the Tide: Gendered Prejudice and Disadvantage in EngineeringGENDER, WORK & ORGANISATION, Issue 2 2007Fatma Küskü Although a balance has been achieved in the overall numbers of female and male students in higher education in the industrialized countries, vertical sex segregation has remained high as male academics and students continued to outnumber their female counterparts internationally. Gender representation is only one façade of gendered disadvantage in engineering, as complex forms of gendered disadvantage occur in social, cultural, psychological and economic layers of life, where women engineering students find themselves swimming against the tide of prejudice. This article draws on comparative and historical data, and a qualitative study with interviews and a questionnaire survey which generated 603 completed responses from female and male engineering students in Turkey. It seeks to reveal the complex and layered nature of gendered prejudice levelled against female engineering students. The findings suggest that linear formulations of gendered prejudice and disadvantage in engineering study are insufficient to account for the complexity of influences on career choice and their concomitant gendered outcomes. [source] Democracy: Rising Tide or Mirage?MIDDLE EAST POLICY, Issue 2 2005Marina S. Ottaway The following is an edited transcript of the thirty-ninth in a series of Capitol Hill conferences convened by the Middle East Policy Council. The meeting was held on April 22, 2005, in the Hart Senate Office Building, with Chas. W. Freeman, Jr., moderating. [source] Going Against the Tide: Sabah and the 2008 Malaysian General ElectionASIAN POLITICS AND POLICY, Issue 2 2010James Chin In the 2008 Malaysian general election, the ruling Barisan Nasional (BN or National Front) lost its two-thirds majority for the first time since independence. BN performed poorly in West Malaysia (Peninsular Malaysia) but was saved by a strong showing in the East Malaysian states of Sabah and Sarawak. Understandably, these two states are expected to play a key role in helping BN stay in power in the next general elections. In this article, we shall examine the reasons why BN did well in Sabah. In the main, Sabah politics is still primarily driven by local factors due to its unique history and geographical location. As such, national issues, such as the Anwar Ibrahim sodomy case, do not connect with voters in Sabah. [source] King Canute and the ,Problem' of Structure and Agency: On Times, Tides and HerestheticsPOLITICAL STUDIES, Issue 2 2009Colin Hay The story of King Canute (Cnut) is well known. Indeed, in perhaps its most familiar form it exists as an oral historical tradition passed from generation to generation. In this almost legendary account, King Canute is depicted as an arrogant ruler, so confident as to his own omnipotence that he takes on the forces of nature, pitting his own powers against those of the rising tide , his wet robes paying testament to his powerlessness in the face of potent material forces and to the triumph of (natural) structures over (human) agency. Or so it might seem. In this article I suggest that even in this, the simplest depiction of the story of Canute, the relationship between structure and agency is more complex and involved than it appears. This complexity is only accentuated if we turn from the legend to the historical evidence. Moreover, by reflecting on Canute's practical negotiation of the ,problem' of structure and agency we can not only gain an interesting political analytical purchase on a seemingly familiar tale, but we can also generate a series of valuable and more general insights into our understanding of the structure,agency relationship. In particular, the (various) stories of King Canute and the waves alert us to the need: (1) to maintain a clear distinction between the empirical and the ontological; (2) to resist the temptation to attempt an empirical adjudication of ontological issues (or, indeed, an ontological adjudication of empirical issues); (3) to differentiate clearly between the capacities of agents with respect to material/physical structures on the one hand, and social/political structures on the other; (4) to acknowledge the significance of unintended consequences; (5) to attend to the ,performative' dimensions of agency; and (6) to recognise the dangers inherent in an overly instrumental view of actors' motivations and intentions. [source] Atmospheric tides over the Pyrenees: observational study and numerical simulationTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 650 2010J. Díaz de Argandoña Abstract Barometric tides around the Pyrenees mountain range are analyzed by means of synoptic surface-station data recorded during one year, surface data from the Pyrenees Experiment (PYREX) and the CRA/LA Very High Frequency (VHF) wind profiler installed in the north of the range. Tides are decomposed into their diurnal and semi-diurnal components. Diurnal tides show a strong non-migrating component and are very dependent on local conditions. Semi-diurnal tides are more homogeneous and present a north,south asymmetry, also noted in the Alps. This cross-range asymmetry could be related to some interference effect caused by the mountain range in the migrating semi-diurnal tide wave. The asymmetry of the diurnal component presents a very strong seasonal variation, probably related to local diabatic effects. A three-month long simulation has been carried out with the National Center for Atmospheric Research's Weather Research and Forecasting (WRF) limited-area model to try to reproduce the tide structure. The validation of the results with wind-profiler data shows reasonable agreement with the observed diurnal tide and poorer results for the semi-diurnal component. At surface level, however, the model reproduces some of the features of the observed semi-diurnal tide, and especially the cross-range asymmetry. Copyright © 2010 Royal Meteorological Society [source] Mexico's Community-Managed Forests as a Global Model for Sustainable LandscapesCONSERVATION BIOLOGY, Issue 3 2003David Barton Bray On the other hand, conservationists have declared that the only way to stem the tide of deforestation is to place as many tracts as possible under strict protection. In this context, Mexico presents a national laboratory for studying the social and ecological benefits of delivering forests to local people. As a little-noticed result of the Mexican Revolution in the second decade of the twentieth century, well over half of the forests of Mexico were placed in community-held lands. In historic struggles that passed through several phases, most of these communities have now gained substantial control over the use of their forests. Because of the substantial degree of social capital in rural forms of organization in Mexico, this control of forest resources has led to an estimated 290,479 community forest enterprises ( CFEs ), through which communities are producing timber on their own lands. New studies are beginning to suggest that important gains in both social and economic justice, good forest management, and biodiversity protection are resulting from the actions of these CFEs. As more forests globally are being devolved to local communities, it is important to carry out more research on the Mexican model of community forest management for timber production. Resumen: Investigadores preocupados por el manejo sostenible de bosques en los trópicos han argumentado que el camino para una custodia mas efectiva de los recursos forestales es la transferencia de la responsabilidad a las comunidades locales que obtienen sustento de ellos. Por otro lado, conservacionistas han declarado que la única manera de detener la ola de deforestación es colocar bajo protección estricta tantas regiones como sea posible. En este contexto, México representa un laboratorio para el estudio de los beneficios sociales y ecológicos de entregar los bosques a los habitantes locales. Como un resultado poco conocido de la Revolución Mexicana, en la segunda década del siglo veinte, más de la mitad de los bosques de México se ubicaban en tierras que estaban en manos de las comunidades. Las comunidades forestales han atravesado por distintas etapas de conflicto, tras la cuáles han obtendio un control sustancial de los usos de sus bosques. Debido al nivel considerable de capital social en formas de organización rural en México, este control de los recursos forestales ha conducido a la integración de entre 290,479 empresas forestales comunitarias ( EFC ), en las que las comunidades están produciendo madera en sus propias tierras. Nuevos estudios están comenzando a sugerir que se están produciendo ganancias importantes en las acciones de estas EFC están generando beneficios importantes, tanto en lo que se refiere a justicia social como económica, la administración correcta de bosques y la protección de la biodiversidad. A medida en que se deleguen mayores extensiones de bosques a comunidades locales, es importante llevar a cabo más investigación sobre el modelo mexicano de manejo comunitario de bosques para la producción de forestal maderable. [source] Backshore coarsening processes triggered by wave-induced sand transport: the critical role of storm events,EARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2010Keiko Udo Abstract Spatial backshore processes were investigated through field observations of topography and median sand grain size at a sandy beach facing the Pacific Ocean in Japan. A comparison of the backshore profile and cross-shore distribution of the median sand grain size in 1999 and 2004 revealed an unusual sedimentary process in which sand was coarsened in a depositional area in the 5-year period, although sediment is generally coarsened in erosional areas. In support of these observations, monthly spatial field analyses carried out in 2004 demonstrated a remarkable backshore coarsening process triggered by sedimentation in the seaward part of the backshore during a storm event. In order to elucidate mechanisms involved in the backshore coarsening process, thresholds of movable sand grain size under wave and wind actions (a uniform parameter for both these cases) in the onshore and offshore directions were estimated using wave, tide, and wind data. The cross-shore distributions of the estimated thresholds provided reasonable values and demonstrated a coarsening mechanism involving the intermediate zone around the shoreline under alternating wave and wind actions as a result of which coarse sand was transported toward the seaward part of the backshore by large waves during storms and then toward the landward part by strong onshore winds. The 5-year backshore coarsening is most certainly explained by repetition of short-term coarsening mechanisms caused by wave-induced sand transport occurring from the nearshore to the intermediate zone. Copyright © 2010 John Wiley & Sons, Ltd [source] Microhabitat and rhythmic behavior of tiger beetle Callytron yuasai okinawense larvae in a mangrove forest in JapanENTOMOLOGICAL SCIENCE, Issue 3 2007Aya SATOH Abstract Mangrove forests are regularly flooded by tides at intervals of approximately 12.4 h (tidal rhythm). Larvae of the tiger beetle Callytron yuasai okinawense in a mangrove forest made shallow burrows in mounds up to 1 m in height constructed by the mud lobster Thalassina anomala. No larval burrows were observed on the forest floor, which was very muddy even during low tide. Some larvae plugged the burrow openings before they were submerged at high tide. The mean interval between consecutive burrow plugging events was 12.37 h, which is similar to the period of tidal cycles. Nine out of 30 larvae plugged the burrow openings even when the burrows did not become submerged. Plugging behavior may be governed by an endogenous biological clock, or may be a response to exogenous information about tidal level (e.g. moisture seeping through the ground). [source] Thermal habitat of striped bass (Morone saxatilis) in coastal waters of northern Massachusetts, USA, during summerFISHERIES OCEANOGRAPHY, Issue 5 2010GARY A. NELSON Abstract Striped bass, Morone saxatilis, were captured and released with temperature-measuring data storage tags in Salem Sound, Massachusetts, to collect data on their thermal preferences in coastal and marine waters and to identify environmental factors that may influence temperatures experienced during their summer residence. Striped bass recaptured during summer of 2006 (21 of 151 releases) experienced a wide range of temperatures (6.5,28.0°C) while at-large for 1,53 days. Overall mean temperature and standard deviation selected by striped bass recaptured in Salem Sound during the longest commonly-shared duration of time (3,12 July) were 17.8 and 3.57°C, respectively. Comparison of temperature data between fish and 13 vertical arrays in Salem Sound revealed that striped bass experienced higher and more variable temperatures, and that daily changes in temperature actually experienced were unrelated to daily changes in surrounding ambient temperature. Regular cyclical changes in temperature of all striped bass and vertical arrays were identified as influences of the local tide, which contributed about a 2°C change in temperature, on average, over the complete cycle. Most striped bass appeared to limit their activities to depths shallower than the lower limit of the thermocline, above which temperatures generally exceed 9.0°C in Salem Sound. Therefore, it is likely that the vertical distribution of striped bass is restricted by the low temperatures below this depth. An implication of this finding is that the spatial distribution of striped bass may be defined coarsely by knowledge of the distribution of temperature in coastal areas. [source] Flow-field observations of a tidally driven island wake used by marine mammals in the Bay of Fundy, CanadaFISHERIES OCEANOGRAPHY, Issue 5 2007D. W. JOHNSTON Abstract Correlations between fine-scale oceanographic features and aggregations of marine mammals are frequently reported, but the physical forces shaping these relationships are rarely explored. We conducted a series of oceanographic observations and remote sensing surveys of an oceanographic feature near Grand Manan Island known to attract marine mammals on flood tides. We tracked drift drogues from cliff-top with a theodolite and conducted box-type surveys with an acoustic Doppler current profiler (ADCP) to assess flow patterns within the oceanographic feature. The feature was also visualized with Synthetic Aperture Radar (SAR) scenes. Drift drogues were advected towards a shear line originating near the northern tip of the island and entrained in one or more eddies downstream. ADCP surveys confirmed the presence of the shear line between rapid easterly flow and slower return flow. As the tide progressed, the shear line extended and manifested a single anti-cyclonic eddy at its distal end. As the flood tide progressed, northerly flow along the eastern shore of the island intensified and deflected the shear line northwards, shedding the eddy at slack high water. SAR images confirmed the presence of the shearline and eddy system, illustrating the evolution of a wake behind the island on flood tides. Profiles of flow direction and acoustic backscatter revealed secondary flows within the wake consistent with models and observations of other wakes. Oceanographic and remote sensing observations confirm that an island wake is generated by tidal flow past Grand Manan Island and provide an ecological context for the predictable aggregations of odontocete and mysticete cetaceans observed foraging within this region. [source] Key factors influencing transport of white shrimp (Litopenaeus setiferus) post-larvae into the Ossabaw Sound system, Georgia, USAFISHERIES OCEANOGRAPHY, Issue 3 2005E. L. WENNER Abstract We examined conditions under which white shrimp (Litopenaeus setiferus) post-larvae enter an estuarine channel receiving high freshwater discharge and one receiving negligible discharge in the Ossabaw Sound system of Georgia, USA, during 1997 and 1998. We used surface nets to collect plankton over several 14-day periods, during which consecutive tows were made at night against the flooding current at stations in the inlet channels. During these sampling periods, additional intensive periods of around-the-clock surface and near-bottom (using a bottom sled) plankton tows were made. Data on oceanographic conditions were obtained from moored instrument arrays and shipboard sampling. We identified three key factors that influenced the densities of post-larval white shrimp in time and space within the Ossabaw inlet system. The first factor was a critical minimum temperature of coastal waters of 27,28°C. Once the threshold temperature was reached, lunar tidal stage became a key factor when the full duration of the flood tide coincided with darkness during peak ingress. This peak also coincided with an increase in water level within the system by more than 0.2 m, which induced an additional influx of water that reinforces the flood current over the ingress period. Our results suggest that the direction of subtidal currents (into or out of the system) becomes a significant factor in post-larval ingress when influx of water coincides with the time of favorable temperature conditions and nighttime flood tides. [source] Temporal dynamics of dissolved oxygen in a floating,leaved macrophyte bedFRESHWATER BIOLOGY, Issue 8 2008KARA GOODWIN Summary 1. Oxygen concentrations in shallow vegetated areas of aquatic systems can be extremely dynamic. In these waters, characterizing the average oxygen content or frequency of low oxygen events (hypoxia) may require high frequency measurements that span seasons and even years. In this study, moored sondes were used to collect 15-min interval dissolved oxygen (DO) readings in an embayment of the tidal Hudson River with dense coverage by an invasive floating leaved plant (Trapa natans) and in adjacent open waters. Measurements were made from late spring to summer over a 2-year period (2005, 2006). 2. Oxygen concentrations were far more dynamic in the vegetated embayment than in the adjacent open waters and while hypoxic conditions never occurred in the open waters, they occurred frequently in the vegetated site. Overall the vegetated site was hypoxic (DO < 2.5 mg L,1) 30% of the time and had an average oxygen concentration of 5.1 mg L,1. Oxygen concentration was significantly (P < 0.0001, anova) related to season, year and tide. Low tide periods during summer of 2006 had the lowest average oxygen concentration and the highest frequency of hypoxia. 3. The greater hypoxia in summer than spring is related to changes in plant morphology. In the spring and early summer when plants are submersed hypoxia occurs at lower frequency and duration than in the summer when dense floating vegetation covers the water. The tidal pattern in oxygen is related to hydrologic exchange with the non-vegetated open waters. Year-to-year variation may be related to relatively small changes in plant biomass between years. 4. Oxygen concentrations in aquatic systems can be critical to habitat quality and can have cascading impacts on redox sensitive nutrient and metal cycling. For some systems with dynamic oxygen patterns neither weekly spot sampling nor short-duration, high-frequency measurements may be sufficient to characterize oxygen conditions of the system. [source] Against the Tide: Gendered Prejudice and Disadvantage in EngineeringGENDER, WORK & ORGANISATION, Issue 2 2007Fatma Küskü Although a balance has been achieved in the overall numbers of female and male students in higher education in the industrialized countries, vertical sex segregation has remained high as male academics and students continued to outnumber their female counterparts internationally. Gender representation is only one façade of gendered disadvantage in engineering, as complex forms of gendered disadvantage occur in social, cultural, psychological and economic layers of life, where women engineering students find themselves swimming against the tide of prejudice. This article draws on comparative and historical data, and a qualitative study with interviews and a questionnaire survey which generated 603 completed responses from female and male engineering students in Turkey. It seeks to reveal the complex and layered nature of gendered prejudice levelled against female engineering students. The findings suggest that linear formulations of gendered prejudice and disadvantage in engineering study are insufficient to account for the complexity of influences on career choice and their concomitant gendered outcomes. [source] Tidal Effects on Ground Water Discharge Through a Sandy Marine BeachGROUND WATER, Issue 7 2004Daniel W. Urish Tidal fluctuations along the salt water boundary of a sandy beach affect the magnitude, location, timing, and salinity of both subaerial and submarine ground water discharge. Detailed studies of shoreline discharge from an unconfined aquifer at two sites in an embayment on the Cape Cod, Massachusetts, coastline provide insight into the highly dynamic spatial and temporal nature of discharge along sandy beaches affected by the tide. The constantly moving tidal boundary over a sloping beach results in a shoreline-perpendicular discharge zone of 10 to 20 m, with ,35% to 55% of the discharge being submarine discharge. The distribution of fresh ground water through a beach face varies greatly, depending primarily on the tidal cycle and range, the heterogeneous characteristics of the beach sediments, and the beach geometry. The estimated relative volume of discharge varies temporally with tidal fluctuations, with the greatest discharge occurring during early to mid ebbing tide and location of greatest estimated discharge moving seaward during ebbing tide. This is determined using net hydraulic head calculations in monitoring wells set in a shoreline-perpendicular transect in the beach. The salinity of discharge varies temporally from near fresh water values of 1 part per thousand (ppt) to near coastal salt water values of 30 ppt, being saltiest at the start of discharge as the tide ebbs and freshest during a low tide period of ,2 h. Of the discharge volume, ,65% to 85% is estimated to be from salt water that infiltrates during high tide episodes. This study highlights the complexity of the dynamic coastal ground water discharge phenomenon and provides insight into the hydraulic mechanisms involved. While there is a general pattern to sandy beach discharge, comparison of results from beaches studied at Cape Cod indicates that the temporal and spatial details of the discharge is very site-specific. [source] Swimming against the tide: Outward staffing flows from multinational subsidiariesHUMAN RESOURCE MANAGEMENT, Issue 4 2010David G. Collings Abstract Studying the flows of parent country nationals in multinational enterprises (MNEs) to subsidiary operations has a relatively long tradition. Studying flows of subsidiary employees to other subsidiaries, as third country nationals, and to the corporate headquarters, as inpatriates, however, has empirically much less pedigree. Drawing on a large-scale empirical study of MNEs in Ireland, this paper provides a benchmark of outward flows of international assignees from the Irish subsidiaries of foreign-owned MNEs to both corporate headquarters and other worldwide operations. Building on insights from the resource-based view and neo-institutional theory, we develop and test a theoretical model to explain outward staffing flows. The results show that almost half of all MNEs use some form of outward staffing flows from their Irish operations. Although the impact of specific variables in explaining inter-organization variation differs between the utilization of inpatriate and third country national assignments, overall we find that a number of headquarters, subsidiary, structural, and human resource systems factors emerge as strong predictors of outward staffing flows. © 2010 Wiley Periodicals, Inc. [source] A two-dimensional analytical solution for groundwater flow in a leaky confined aquifer system near open tidal waterHYDROLOGICAL PROCESSES, Issue 4 2001Zhonghua Tang Abstract Groundwater in coastal areas is commonly disturbed by tidal fluctuations. A two-dimensional analytical solution is derived to describe the groundwater fluctuation in a leaky confined aquifer system near open tidal water under the assumption that the groundwater head in the confined aquifer fluctuates in response to sea tide whereas that of the overlying unconfined aquifer remains constant. The analytical solution presented here is an extension of the solution by Sun for two-dimensional groundwater flow in a confined aquifer and the solution by Jiao and Tang for one-dimensional groundwater flow in a leaky confined aquifer. The analytical solution is compared with a two-dimensional finite difference solution. On the basis of the analytical solution, the groundwater head distribution in a leaky confined aquifer in response to tidal boundaries is examined and the influence of leakage on groundwater fluctuation is discussed. Copyright © 2001 John Wiley & Sons, Ltd. [source] A vertically moving grid finite-element modelling of tidal flow in the Changjiang Estuary, ChinaINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 2 2003Z. Shi Abstract An estuarine two-dimensional vertical finite-element model of tidal flow has been established by laterally integrating Navier,Stokes equation. To this end, a moving grid finite-element method has been used. An arbitrarily shaped quadrilateral element has been selected. This model has been validated by using field data from two monitoring stations at the North Passage of the Changjiang Estuary. Using this numerical model, two types of modelled results were obtained: (1) vertical distributions of tidal current velocities at the North Passage of the Changjiang Estuary; (2) longitudinal distributions of tidal current velocities at maximum flood tide, at high slack water, at maximum ebb tide and at low slack water tide at the North Passage of the Changjiang Estuary. The conclusion is that the model provides a reasonable agreement with observed data. Copyright © 2003 John Wiley & Sons, Ltd. [source] Dependence between extreme sea surge, river flow and precipitation in eastern BritainINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2002Cecilia Svensson Abstract Flooding in estuaries may be caused by both high river flows and by high sea levels. In order to investigate whether these tend to occur simultaneously in eastern Britain, the dependence between high sea surge (observed sea level minus predicted astronomical tide), river flow and precipitation was studied using a measure of dependence specially developed for extremal dependence. Extreme events were interpreted using meteorological maps. This new analysis found that the strongest flow,surge dependence occurs between river flow on the north shore of the Firth of Forth and sea surge at Aberdeen, Wick and Lerwick. In contrast to most other catchments in eastern Britain, the area to the north of the Firth of Forth is not sheltered from south-westerly winds by any major topographical barrier. Therefore, precipitation from this direction may be orographically enhanced as it encounters the hills on the northern side of the firth, and high river flows may ensue. Events resulting in both high river flow and surge in the northern part of the study area were found to be caused by cyclones travelling north-eastward to the north of Scotland. High surge events, only, were associated with similar storm tracks, but without much precipitation from the fronts. High river flows, only, were associated with rain-bearing east,west-directed fronts over northern Britain, with slow-moving depressions located over or to the west of the British Isles where they are unable to generate a strong surge in the North Sea. The dependence between river flow and surge was found to be stronger during winter than summer, and a lagged analysis revealed that the dependence is strongest when flow and surge occur on the same day, but was also strong for lags of plus and minus 1 day. For precipitation, the dependence with both flow and surge is strongest when precipitation precedes them by 1 day. Copyright © 2002 Royal Meteorological Society. [source] Crosscurrents: against cultural narration in nursingJOURNAL OF ADVANCED NURSING, Issue 2 2000Dawn Freshwater PhD BA RNT RN Crosscurrents: against cultural narration in nursing Nurses, like other groups throughout history, have been described as an oppressed group. Writers who describe nurses as lacking in self-esteem, autonomy, accountability and power support this view in the literature. Indeed the cultural narration of nursing is for nurses to be subordinate. This article explores the emergence of horizontal violence within nursing and suggests that it is a result of unexpressed conflict within an oppressed group. The author aims to raise the awareness of horizontal violence in nursing so that practitioners come to understand how this in itself can be an expression of power. Drawing upon theories of reflective practice, the article examines how the educational system in nursing may have contributed to the felt oppression within the group by colluding with the cultural narrative. The crosscurrents of cultural narration are strong and it is argued here that the nurse needs to feel empowered in order to take action to swim against the tide. The author proposes that a model of transformatory learning based upon critical theory creates the possibility of emancipatory action in nursing, both locally and globally. [source] Vegetable and animal food sorts found in the gastric content of Sardinian Wild Boar (Sus scrofa meridionalis)JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5-6 2007W. Pinna Summary Authors report results emerging from gastric content analysis from n. 96 wild boars hunted in Sardinia isle, during the hunting tide (2001,2005), from November to January. Mean pH of the gastric content was 3.77 ± 0.69. Mean total capacity (TC) of each stomach was 1702 ± 680 g. Mean Stuff ratio (CW/TC) between the content weight (CW) and stomachs TC was 0.45. Food categories found in animal stomachs were: 19 categories of vegetal species (Allium spp., Arbutus unedo, Arisarum vulgare, Avena fatua, Avena sativa, Castanea sativa, Ceratonia siliqua, Chamaerops umilis, Cichorium intybus, Hordeum sativum, Juniperus oxycedrus, Myrtus communis, Olea europea, Pirus amygdaliformis, Pistacia lentiscus, Quercus spp., Rhamnus alaternus, Triticum durum, Zea mais); 11 categories of animal species (Agriotes lineatus, Apodemus sylvaticus dicrurus, Chalcides chalcides, Chalcides ocellatus tiligugu, Crematogaster scutellaris, Forficula auricularia, Helix aspersa, Lumbricus terrestris, Ovis aries, Podarcis tiliguerta tiliguerta, Scolopendra cingulata); three categories were identified in general terms (insects larvae, hairs of mammals, feathers of birds). Food categories found in the stomach contents of Sus scrofa meridionalis confirm observations by other researchers who report the prevalence of vegetables in spite of animal food sorts in the wild boar diet in Italian regions. [source] Cytotoxic action mode of a novel porphyrin derivative isolated from harmful red tide dinoflagellate Heterocapsa circularisquamaJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2008Daekyung Kim Abstract Heterocapsa circularisquama is known to cause lethal effect on bivalves, but toxic effect on fish has not been reported yet. Recently, we have found that H. circularisquama has potent light-dependent hemolytic toxins. Based on the chemical structural analysis, one of the hemolytic toxins named H2-a was found to be a novel porphyrin derivative with similar structure to pyropheophorbide a methyl ester (PME), a well-known photoactive hemolytic agent (Miyazaki et al., Aquatic Toxicol. 2005;73:382--393). To clarify the cytotoxic action mode of H2-a, we examined the effects of H2-a on HeLa cells in comparison with PME. The cytotoxicities of both reagents were strictly light dependent, and no significant cytotoxic effects including cellular morphological changes were induced without light illumination. The dose response curves revealed that H2-a showed stronger cytotoxicity to HeLa cells than PME. Fluorescence microscopic observation suggested that H2-a tends to accumulate in the plasma membrane, whereas PME seems to distribute entire cytoplasm. Although PME induced typical apoptotic nuclear morphological changes and DNA fragmentation in HeLa cells, no such apoptosis-inducing ability of H2-a was observed. Among the radical scavengers, histidine significantly inhibited the cytotoxic activity of H2-a, suggesting the involvement of singlet oxygen in the cytotoxicity. These results suggest that the cytotoxic mechanism of H2-a is necrotic rather than apoptosis differing from PME, even though these are structurally quite similar to each other. The relatively high affinity of H2-a to the plasma membrane might result in the potent and quick cytotoxicity without induction of apoptotic signal transduction. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:158,165, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20216 [source] Incidence and severity of marine borer attack at different depths at Mtongwe Jetty Pontoon Mombasa, KenyaAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009P. K. Sirmah Abstract The activity of marine borers was investigated at Mtongwe Jetty Pontoon, Mombasa, Kilindini harbour using untreated panels of Pinus patula (Schlecht) submerged to different depths. Twenty test panels replicated over 7 months were each strung in three ladder-like frames using nylon twine and suspended vertically, in such a way that the top most panels were 25 cm below the water surface at low and high tide. Monthly observations were made between January and July for the vertical incidence and extent of marine borer attack following the technique of Bobat (1995). Marine borers were collected from test panels, identified and counted. In addition, the percentage weight loss for panels at different depths was determined at the end of 7 months. Teredo fulleri (Clapp) was dominant on panels near water surface while Martesia striata (Linne) and Lyrodus pedicellatus (Quatrefages) were predominant at the bottom. The results showed that attack began within the first month of exposure and was severest by the seventh month. The vertical incidence and extent of attack decreased with increasing depth of panel exposure and was negatively correlated with depth. This is attributed to changes in hydrographic conditions. Résumé L'activité des foreurs marins a étéétudiée dans le Ponton de Mtongwe Jetty, Mombasa, dans le port de Kilindini, en utilisant des panneaux de Pinus patula (Schlecht) non traités, plongés à différentes profondeurs. Vingt panneaux tests identiques ont été attachés avec des cordes de nylon pour former trois cadres ressemblant à des échelles et suspendus pendant sept mois verticalement de façon à ce que les panneaux supérieurs se trouvent à 25 cm sous la surface à marée basse et haute. L'on a fait des observations mensuelles entre janvier et juillet de l'occurrence verticale et l'étendue de l'attaque des foreurs marins en utilisant la technique de Bobat (1995). Les foreurs marins ont été collectés sur les panneaux tests, identifiés et comptés. De plus, on a déterminé le pourcentage de la perte de poids des panneaux aux différentes profondeurs à la fin des sept mois. Teredo fulleri (Clapp) était dominant sur les panneaux situés près de la surface de l'eau alors que Martesia striata (Linné) et Lyrodus pedicellatus (Quatrefages) étaient prédominants en profondeur. Les résultats ont montré que l'attaque a commencé dès le premier mois et que c'est alors qu'elle fut la plus sévère. L'occurrence verticale et l'étendue de l'attaque diminuaient quand le panneau était plus profond et étaient négativement liées à la profondeur. Cela est attribué aux changements des conditions hydrographiques. [source] Fighting costly health care fraudJOURNAL OF CORPORATE ACCOUNTING & FINANCE, Issue 4 2005Stephen R. Goldberg There is a rising tide of health care fraud in this country. And it is costing all of us upwards of $100 billion each year, adding to already skyrocketing medical costs. Many companies do not have adequate internal controls over their health care system. And even when they do, monitoring or auditing is lax. The authors explore the scope of these problems and offer practical advice on stemming the tide. © 2005 Wiley Periodicals, Inc. [source] Population trends and habitat use of Harlequin Ducks in Rhode IslandJOURNAL OF FIELD ORNITHOLOGY, Issue 3 2007Christine M. Caron ABSTRACT To assess population trends of Harlequin Ducks (Histrionicus histrionicus) in Rhode Island (U.S.A.), we analyzed Christmas Bird Counts and other historical surveys and also conducted surveys during the winter of 2005,2006. We estimated sex and age ratios, evaluated the effects of tidal regime and time of day on survey precision, and quantified habitat use. The population in Rhode Island experienced logistic growth from 1976 to 2004, with approximately 150 birds now wintering at three primary sites in the state. We estimated that the current ratio of males to females in the region was 1.6:1 (62% males) and that 13% of males were first-winter birds. Most Harlequin Ducks were observed in rocky habitats within 50 m of the shore or offshore islands. We detected the greatest numbers of birds, with the least amount of variation, during morning surveys at low tide, suggesting that this may be the most appropriate time for population monitoring. Increases in the Rhode Island population and male-biased sex ratios may indicate a local population recovery resulting from a hunting ban initiated in 1990. Although most Harlequin Ducks in eastern North America winter in Maine, the population in Rhode Island represents one of the largest in the southern part of their range. SINOPSIS Para determinar las tendencias poblacionales de arlequines (Histrionicus histrionicus), en Rhode Island, analizamos los conteos navideños, otros censos históricos y además llevamos a cabos censos durante el invierno de 2005,2006. Cuantificamos el uso de habitat, estimamos la tasa de edad y sexos y evaluamos el efecto del régimen de mareas y la hora del dia en la presición de los censos. La población de patos arlequines experimentó un crecimiento logístico de 1976,2004, con unos 150 patos pasando el invierno en tres localidades primarias, del estado. Estimamos una tasa de 1.6:1 de machos a hembras (62% de machos), siendo un 13% de los machos individuos de primer invierno. La mayoría de las aves fueron observadas en hábitats rocosos a unos 50 m de la playa o en islas cerca de la playa. Detectamos el mayor número de aves, con la menor variación, en los censos que se llevaron a cabo durante la marea baja, lo que sugiere que este es el momento más apropiado para monitorear sus poblaciones. El aumento de estas aves en Rhode Island, el sesgo en su sexo, hacia mayor cantidad de machos, pudiera indicar, de un recobro poblacional como resultado la prohibición de su cacería a partir de 1990. Aunque la mayoría de los arlequines de la parte este de los EUA pasan el invierno en Maine, la población de Rhode Island representa una de las mayores en la parte sur de su distribución. [source] Migratory behaviour and survival rates of wild northern Atlantic salmon Salmo salar post-smolts: effects of environmental factorsJOURNAL OF FISH BIOLOGY, Issue 7 2009J. G. Davidsen To study smolt behaviour and survival of a northern Atlantic salmon Salmo salar population during river descent, sea entry and fjord migration, 120 wild S. salar were tagged with acoustic tags and registered at four automatic listening station arrays in the mouth of the north Norwegian River Alta and throughout the Alta Fjord. An estimated 75% of the post-smolts survived from the river mouth, through the estuary and the first 17 km of the fjord. Survival rates in the fjord varied with fork length (LF), and ranged from 97·0 to 99·5% km,1. On average, the post-smolts spent 1·5 days (36 h, range 11,365 h) travelling from the river mouth to the last fjord array, 31 km from the river mouth. The migratory speed was slower (1·8 LF s,1) in the first 4 km after sea entry compared with the next 27 km (3·0 LF s,1). Post-smolts entered the fjord more often during the high or ebbing tide (70%). There was no clear diurnal migration pattern within the river and fjord, but most of the post-smolts entered the fjord at night (66%, 2000,0800 hours), despite the 24 h daylight at this latitude. The tidal cycle, wind-induced currents and the smolts' own movements seemed to influence migratory speeds and routes in different parts of the fjord. A large variation in migration patterns, both in the river and fjord, might indicate that individuals in stochastic estuarine and marine environments are exposed to highly variable selection regimes, resulting in different responses to environmental factors on both temporal and spatial scales. Post-smolts in the northern Alta Fjord had similar early marine survival rates to those observed previously in southern fjords; however, fjord residency in the north was shorter. [source] Recruitment of Anguilla spp. glass eels in the Waikato River, New Zealand.JOURNAL OF FISH BIOLOGY, Issue 9 2009Evidence of declining migrations? The timing of Anguilla spp. glass eel recruitment into the Waikato River, North Island, New Zealand, was studied over a 2 year period (2004,2005). While glass eels of both the shortfin eel Anguilla australis and the endemic longfin eel Anguilla dieffenbachii were caught, the former comprised >97% of the species composition. There was a positive correlation of glass eel migrations with spring tides, with peak migration periods typically occurring within a few hours of the peak of high tide, and between 2 and 4 days after the day of spring tide. Both water temperature and discharge had significant inverse relationships with glass eel catches, with temperature explaining >30% of the variance in catch periodicity. Comparison of catch data 30 years apart showed that main migration periods appear to occur several weeks earlier today than previously. Reduced catch per unit effort and duration of runs from recent years' sampling (compared with the 1970s) indicate that a reduction in recruitment may also have occurred during this period, something recorded in other temperate species of Anguilla. [source] Movement patterns of the round stingray Urobatis halleri(Cooper) near a thermal outfallJOURNAL OF FISH BIOLOGY, Issue 6 2006J. J. Vaudo Fine-scale movements and site fidelity of round stingrays Urobatis halleri at Seal Beach California, U.S.A., were examined using acoustic telemetry. Actively tracked fish generally exhibited limited nearshore movement, with greater distances travelled at night when the tide was ebbing than during the day with ebbing tides. Increases in round stingray activity were associated with increases in ambient temperature. Passively tracked fish showed seasonal patterns in their presence at Seal Beach. Males left Seal Beach during the autumn, returned the following spring, and remained in the area until the following autumn. Females spent far less time at Seal Beach, remaining in the area for a few weeks during June and July. Passively tracked round stingrays were recorded more often in the warm waters of the San Gabriel River mouth (the location of a thermal outfall from an electric-generating station) than adjacent beaches, with fish often returning to Seal Beach after periods of absence. Anthropogenic effects resulting from coastal development may have created environmental conditions (i.e. warmer water and finer sediments) that influence the movements and site fidelity of round stingrays. [source] Factors affecting recruitment of glass eels into the Grey River, New ZealandJOURNAL OF FISH BIOLOGY, Issue 5 2003D. J. Jellyman The arrival pattern of glass eels of the shortfin eel Anguilla australis and longfin eel Anguilla dieffenbachii was studied over a two successive migration seasons in the Grey River, South Island, New Zealand. Fishing was carried out on selected nights during September to November, for 3 h per night during 2000 and 2001. The number of shortfin glass eels exceeded longfins in both years; earliest glass eels (September) were larger than later glass eels (November), and longfins larger than shortfins, but there were significant differences in size between years for both species. Environmental variables affecting recruitment differed between years, but common variables for both years were sampling date, time after high tide (incoming tide preferred), time after sunset and moon phase; the influence of moon phase appeared to be expressed both through tides (spring tides preferred) and moonlight. During the year of higher discharge variability, both increasing discharge and increased turbidity were also important. [source] A novel artificial habitat collection device for studying resettlement patterns in anguillid glass eelsJOURNAL OF FISH BIOLOGY, Issue 5 2001V. Silberschneider The number of glass eels Anguilla australis and A. reinhardtii caught in artificial habitat collectors, made from a PVC base and polyethylene split rope fibres, was related to the number of rope fibre tufts attached to each collector rather than collector area directly. Ageing of collectors in situ to promote algal growth enhanced the catch of glass eels. Glass eels entered the collectors at night primarily during the flood tide, and did not move into the collectors during daylight hours. Glass eel abundance increased with increasing distance from the freshwater drain located in the causeway. The artificial habitat collectors are effective for assessing relative numbers of resettling glass eels and may be useful for studying recruitment and settlement patterns of other anguillid eel species, as well as identifying areas and habitats within a catchment that provide important shelter for glass eels. Sampling glass eels can be carried out with maximum effect and minimum effort using compact, aged artificial habitat collectors on the night time flood tide when low tide coincides with dusk. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||