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Selected AbstractsHyporheic and total transient storage in small, sand-bed streamsHYDROLOGICAL PROCESSES, Issue 12 2008John M. Stofleth Abstract Key processes in stream ecosystems are linked to hydraulic retention, which is the departure of stream flow from ideal ,plug flow', and reflects fluid movement through surface and hyporheic storage zones. Most existing information about hyporheic exchange is based on flume studies or field measurements in relatively steep streams with beds coarser than sand. Stream tracer studies may be used to quantify overall hydraulic retention, but disaggregation of surface and hyporheic retention remains difficult. A stream tracer approach was used to compute the rates at which stream water is exchanged with water in storage zones (total storage) in short reaches of two small, sand-bed streams under free and obstructed flow conditions. Tracer curves were fit to the one-dimensional transport with inflow storage model OTIS-P. Networks of piezometers were used to measure specific discharge between the stream and the groundwater. In the sand-bed streams studied, parameters describing total retention were in the upper 50% of data compiled from the literature, most of which represented streams with beds coarser than sand. However, hyporheic storage was an insignificant component of total hydraulic retention, representing only 0·01,0·49% of total exchange, and this fraction did not increase after installation of flow obstructions. Total retention did not vary systematically with bed material size, but increased 50,100% following flow obstruction. Removal of roughness elements, such as large wood and debris dams, is detrimental to processes dependent upon transient storage in small, sand-bed streams. Copyright © 2007 John Wiley & Sons, Ltd. [source] Indoor Air Quality in the 21st Century: Search for ExcellenceINDOOR AIR, Issue 2 2000P. OLE FANGER Abstract Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from sick building syndrome (SBS) symptoms, even though existing standards and guidelines are met. The reason is that the requirements specified in these standards are rather low, allowing a substantial group of people to become dissatisfied and to be adversely affected. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in the 21st century. Based on existing information and on new research results, five principles are suggested as elements behind a new philosophy of excellence: 1) better indoor air quality increases productivity and decreases SBS symptoms; 2) unnecessary indoor pollution sources should be avoided; 3) the air should be served cool and dry to the occupants; 4) "personalized air", i.e. a small amount of clean air, should be served gently, close to the breathing zone of each individual; and 5) individual control of the thermal environment should be provided. These principles of excellence are compatible with energy efficiency and sustainability. [source] A conceptual selenium management modelINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 3 2009Peter M Chapman Abstract We describe herein a conceptual selenium (Se) management model, directed toward coal mining in western Canada, but which can be applied to other coal mines and, with appropriate modification, to other industrial sources of Se to aquatic and terrestrial environments. This conceptual model provides a transparent means to integrate and synthesize existing information that can be used to provide an adaptive approach for managing ecological exposures and associated risk. It is particularly useful for visualizing and subsequently developing management interventions for Se control and risk reduction. The model provides a structured process by which critical information needs can be identified and addressed. It effectively provides the foundation for making management decisions related to Se discharges to aquatic and terrestrial environments by showing interrelationships of the various media and receptors as well as primary sources, release mechanisms, secondary sources, and exposure pathways. [source] Unsteady free convection,radiation flow over a vertical wall embedded in a porous mediumINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 11 2008Joaquín Zueco Abstract A numerical solution for the transient two-dimensional free convection flow of viscous dissipative fluid over an infinite vertical plate through a porous medium bounded, taking into account the thermal radiation, is analysed. The fluid is grey, and acts as a radiation emitting and absorbing (but non-scattering) medium. The influence of the non-dimensional parameters such as the Forchheimer coefficient (Fo), the permeability parameter (P), the Eckert number (Ec) and the radiation parameter (R) on the velocity, temperature, Nusselt number and on the time taken to reach the steady state is studied. The possibility of non-Darcy flow is also analysed. The numerical method employed, network simulation method, is based on an electro-thermal analogy and permits the direct visualization and evolution of the local and/or integrated transport variables (velocities, temperatures and fluxes) at any point or section of the medium. The numerical solutions of this work have been compared with the existing information in the literature with good agreement. Copyright © 2007 John Wiley & Sons, Ltd. [source] 147 Controlling Harmful Algal Blooms Through Clay FlocculationJOURNAL OF PHYCOLOGY, Issue 2003M. R. Sengco The potential use of clays to control harmful algal blooms (HABs) has been explored in East Asia, Australia, the United States, and Sweden. In Japan and South Korea, minerals such as montmorillonite, kaolinite, and yellow loess, have already been used in the field effectively, to protect fish mariculture from Cochlodinium spp. and other blooms. Cell removal occurs through the flocculation of algal and mineral particles, leading to the formation of larger aggregates (i.e. marine snow), which rapidly settle and further entrain cells during their descent. In the U.S., several clays and clay-rich sediments have shown high removal abilities (e.g. >80% cell removal efficiency) against Karenia brevis, Heterosigma akashiwo, Pfiesteria piscicida and Aureococcus anophagefferens. In some cases, the removal ability of certain clays was further enhanced with chemical flocculants, such as polyaluminum chloride (PAC), to increase their adhesiveness. However, cell removal was also affected by bloom concentration, salinity, and mixing. Cell mortality was observed after clay addition, and increased with increasing clay concentration, and prolonged exposure to clays in the settled layer. Mesocosm, field enclosure, and flume experiments were also conducted to address cell removal with increasing scale and flow, water-column impacts, and the possible benthic effects from clay addition. Results from these studies will be presented, especially those in regards to water quality, seawater chemistry, bottom erodibility and faunal impacts in the benthos. At this time, clay dispersal continues to be a promising method for controlling HABs and mitigating their impacts based on existing information and experimental data. [source] The significance of organic-anion exudation for the aluminum resistance of primary triticale derived from wheat and rye parents differing in aluminum resistanceJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2008Angelika Stass Abstract Eight primary octoploid triticale genotypes (xTriticosecale Wittmack) derived from four wheat cultivars (Triticum aestivum L.) and two rye inbred lines (Secale cereale L.) differing in aluminum (Al) resistance were investigated with respect to their response to Al supply. Aluminum-induced inhibition of root elongation (48 h, 25 µM Al supply), callose formation, and the accumulation of Al in root tips (4 h, 25 µM Al supply) were used as parameters to assess Al resistance. Using these parameters, the existing information on Al resistance of the wheat and rye cultivars was generally confirmed. The triticale cultivars showed a wide range of Al resistance amongst the Al-sensitive wheat and the Al-resistant rye cultivars. The rye parents and the Al-resistant wheat parent Carazinho were characterized by Al-induced exudation particularly of citrate but also of malate from whole root systems of 14 d old seedlings (8 h, 50 µM Al supply). Regression analysis revealed that the degree of Al resistance of the triticale genotypes was closely related to the Al-induced citrate exudation, which was mainly controlled by the Al resistance of the wheat parent. [source] British Association of Critical Care Nurses position statement on prescribing in critical careNURSING IN CRITICAL CARE, Issue 5 2009Kate Bray ABSTRACT Background: Nurses in the UK are now one group of non-medical staff who can prescribe. This practice is evolving for critical care nursing staff who care for critically ill patients during their stay in hospital through ward and outpatient follow-up after admission to critical care. Aim: The purposes of this paper were to present existing information regarding prescribing to support nurses in critical care currently prescribing and to inform those who are intending to prescribe. Methods: To develop the position statement, a search of the literature was conducted using key databases. To ascertain the current level and type of prescribing in critical care, a short questionnaire was sent by email to British Association of Critical Care Nursing members, and the results of this are presented in Appendix A. Outcomes/Results: Evidence was found in relation to the history, context in critical care, educational requirements and issues of consent related to non-medical prescribing. Conclusions: The position statement is based upon evidence from the literature, National Health Service policy and the Nursing and Midwifery Council regulations. It takes account of the critical care patient pathway before, during and after an admission to critical care. [source] How pediatricians manage asthma in ThailandPEDIATRIC PULMONOLOGY, Issue 2 2001Pakit Vichyanond MD Abstract Currently, there is no existing information regarding prescribing practices for the management of childhood asthma among pediatricians in Thailand. In order to evaluate the management standards for childhood asthma in Thailand, 400 self-administered questionnaires were randomly mailed to nonacademic pediatricians throughout Thailand, asking questions about their preferences in the treatment of childhood asthma. One hundred and seventy-four of these 400 questionnaires were returned (a response rate of 43.5%). Data were analyzed using the descriptive module of the Epi-info 6 program. For acute asthma, 17% of the respondents used objective measures such as peak flow meters in assessing asthma severity and severity of acute asthma attacks. The drug of first choice for treating acute attacks was a nebulized beta-agonist q 20 min (81.8%). Although 93% indicated that they had used theophylline for treating acute attacks, most would reserve the drug for patients with severe symptoms. Corticosteroids were reserved for those with severe attacks (91.7% both for clinic and for in-hospital settings). Hydrocortisone was the most preferred corticosteroid preparation (59.8%). Ninety-seven percent used antibiotics in treating acute asthma, but only with appropriate indications. For chronic asthma, a strong preference was observed for oral beta-agonists as the bronchodilator of choice (88%). For moderately severe asthmatics, theophylline was still preferred by 41% of the responders. Among prophylactic agents, ketotifen was the most favored drug (90.4%), whereas inhaled steroids and cromolyn were chosen by 9.6% and 2.4%, respectively. Eighty-five percent indicated that they would prescribe prophylactic agents for 1 year or less. Forty-two percent never considered allergy evaluation as a part of a workup for childhood asthma. Certain prescribing practices of childhood asthma management in Thailand were observed among pediatricians, i.e., 1) low frequency of using objective measures in assessing asthma severity among pediatricians; 2) frequent use of theophylline and antibiotics in the treatment of acute asthma; 3) late introduction of corticosteroids in treating acute asthma; 4) preference for oral bronchodilators; and 5) preference of ketotifen as the prophylactic drug of choice. This survey provides baseline data and will aid in the evaluation of management guidelines for childhood asthma in Thailand. Pediatr Pulmonol. 2001; 32:109,114. © 2001 Wiley-Liss, Inc. [source] Mitochondrial Responses of Normal and Injured Human Skin Fibroblasts Following Low Level Laser Irradiation,An In Vitro StudyPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2009Innocent L. Zungu Laser irradiation has proved to be very efficient in speeding and improving the quality of healing in pathological conditions of diverse etiologies. However, the mechanisms by which the beneficial effects are attained are not clear. Mitochondria are the primary phototargets during irradiation. The study aimed to establish if laser irradiation had an effect on hypoxic and acidotic cells. The study also aimed to use existing information regarding the possible mechanism of action (established in wounded cells) and apply these principles to acidic and hypoxic irradiated cells to determine whether laser has a stimulatory or inhibitory effect. Cell cultures were modified to simulate conditions of hypoxia (hypoxic gas mixture 95% N2 and 5% O2) and acidosis (pH 6.7) whereas the central scratch model was used to simulate a wound. Cells were irradiated with a helium,neon (632.8 nm, 3 mW cm,2) laser using 5 or 16 J cm,2 on days 1 and 4. Mitochondrial responses were measured 1 or 24 h after laser irradiation by assessing changes in mitochondrial membrane potential (MMP), cyclic AMP, intracellular Ca2+ and adenosine triphosphate (ATP) cell viability. Hypoxia and acidosis significantly reduced MMP when compared with normal nonirradiated control cells. Wounded, hypoxic and acidotic cells irradiated with 5 J cm,2 showed an increase in mitochondrial responses when compared with nonirradiated cells while 16 J cm,2 showed a significant decrease. The study confirmed that laser irradiation with 5 J cm,2 stimulated an increase in intracellular Ca2+ which resulted in an increase in MMP, ATP and cAMP, which ultimately results in photobiomodulation to restore homeostasis of injured cells. [source] Mitochondrial DNA HVRI variation in Balearic populationsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2005A. Picornell Abstract The Balearic archipelago (Majorca, Minorca, and Ibiza islands and the Chuetas, a small and inbred community of descendants of Sephardic Jews) and Valencia were studied by means of the sequencing of a 404-bp segment of hypervariable region I (HVRI) mtDNA in 231 individuals. In total, 127 different haplotypes defined by 92 variable positions were identified. The incidence of unique haplotypes was very low, especially in Ibiza and the Chuetas. A remarkable observation in the Chueta community was the high frequency (23%) of preHV-1, a Middle Eastern lineage that is closely related, though not identical, to many others found at high frequencies in different Jewish populations. The presence of this haplogroup convincingly supported the Jewish origin of the Chueta community. The studied populations showed a reduced African contribution, and no individuals were detected with North African haplogroup U6, indicating a lack of maternal contribution from the Moslem settlement to these populations. Only Ibiza showed a lower diversity, indicating a possible genetic drift effect, also supported by the historical information known about this island. The variability in the sequence of mtDNA hypervariable region I correlated well with the existing information from the populations, with the exception of that of the Y-chromosome, which could indicate a differential contribution of the maternal and paternal lineages to the genetic pool of the Balearic Islands. The phylogenetic trees showed the intermediate position of the Chueta population between the Middle Eastern and Majorcan samples, confirming the Jewish origin of this population and their Spanish admixture. Am J Phys Anthropol 128:119-130, 2005. © 2005 Wiley-Liss, Inc. [source] Evaluation of a Navigation System for ENT with Surgical Efficiency Criteria,THE LARYNGOSCOPE, Issue 4 2006Gero Strau MD Abstract The aim of this study is the evaluation of a navigation system (NaviBase) for ENT surgery. For this purpose, a new methodology for the evaluation of surgical and ergonomic system properties has been developed. The practicability of the evaluation instruments will be examined using the example of the overall assessment of the system in comparison with the current surgical standard and with other systems using clinical efficiency criteria. The evaluation is based on 102 ENT surgical applications; of these, 89 were functional endoscopic sinus surgeries (FESS). The evaluation of surgical and ergonomic performance factors was performed by seven ENT surgeons. To evaluate surgical system properties, the Level of Quality (LOQ) in 89 cases of the FESS was determined. It compares the existing information of the surgeon with that of the navigation system on a scale of 0 to 100 and with a mean value of 50 and places it in a relationship to the clinical impact. The intraoperative change of the planned surgical strategy (Change of Surgical Strategy) was documented. The ergonomic factors of the system with the categories of Overall Confidence (Trust), awareness of the situation (Situation Awareness), influence on the operating team, requirements for specific skills (Skill Set Requirement), and cognitive load (Workload Shift) were recorded for all surgical procedures as Level of Reliance (LOR). In the evaluation of the surgical system properties, an average evaluation of the quality of the information, as an LOQ of 63.59, resulted. Every second application of the navigation system (47.9%), on average, led to a change in the surgical strategy. An extension/enhancement of the indication of the endonasal approach through the use of the navigation system was shown in 7 of 102 (6.8%) cases. The completion of the resection in the FESS was rated by 74% of group I and 11% of group II as better in comparison with the standard approach. Total confidence shows a positive evaluation of 3.35 in the LOR. To supplement the evaluation of the navigation system, the technical parameters were included. The maximum deviation, Amax, of the displayed position of the reference value amounted to 1.93 mm. The average deviation was at 1.29 mm with an SD above all values, sd, of 0.29. The subsequent economic evaluation resulted in an effective average extra expenditure of time of 1.35 minutes per case. The overall evaluation of the system imparts application-relevant information beyond the technical details and permits comparability between different assistance systems. [source] Detecting Tropical Forests' Responses to Global Climatic and Atmospheric Change: Current Challenges and a Way ForwardBIOTROPICA, Issue 1 2007Deborah A. ClarkArticle first published online: 21 DEC 200 ABSTRACT Because of tropical forests' disproportionate importance for world biodiversity and for the global carbon cycle, we urgently need to understand any effects on these ecosystems from the ongoing changes in climate and atmosphere. This review, intended to complement existing data reviews on this topic, focuses on three major classes of challenges that we currently face when trying to detect and interpret directional changes in tropical forests. One is the very limited existing information on the historical context of study sites. Lasting effects from past climate, natural disturbances, and/or human activities could be significantly affecting current-day processes in tropical forests and need to be investigated for all active field sites. Second, while progress has been made in recent years on standardizing and refining research approaches, a number of methods- and data-limitations continue to affect efforts both to detect within-forest changes and to relate them to ongoing environmental change. Important outstanding needs are improved sampling designs, longer time-series of observations, filling key data gaps, and data access. Finally, forest responses to ongoing environmental change are complex. The effects of many simultaneously changing environmental factors are integrated by the plants, and their responses can involve significant lags, carryovers, and non-linearities. Specifying effects of individual environmental changes, however, is required for accurate ecosystem-process models and thus for projecting future impacts on these forests. After discussing these several types of challenges and ways to address them, I conclude with a priority agenda for this critical area of research. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp. RESUMEN Debido a la importancia desproporcionada de los bosques tropicales para la biodiversidad mundial y para el ciclo global del carbono, es urgente identificar los impactos sobre estos ecosistemas provocados por los cambios actuales en el clima y en la atmósfera. Este artículo de revisión, escrito con el propósito de complementar otras revisiones recientes, se enfoca en tres principales clases de retos que enfrentamos actualmente en la detección e interpretación de cambios direccionales en los bosques tropicales. Primero es la gran escasez de información histórica acerca de los sitios de estudio. Los procesos actuales en los bosques tropicales pueden reflejar los efectos prolongados del pasado climático, las perturbaciones naturales y/o las actividades humanas, por lo que deben de ser investigados en todos los sitios actuales de estudio. Segundo, a pesar de avances recientes en la estandarización y el refinamiento de los métodos de investigación, nuestra habilidad para detectar cambios en los bosques y ligarlos a los grandes cambios ambientales sigue siendo limitada. Para garantizar avances en el área se requiere mejorar los diseños de muestreo, extender las series de observación en el tiempo a plazos mayores, llenar ciertos vacíos claves en el conocimiento, y facilitar el acceso a los datos existentes. Por último, se requiere de enfoques que tomen en cuenta la complejidad de las respuestas de los bosques a los cambios ambientales. Las plantas integran los efectos de cambios simultáneos en múltiples factores ambientales, y sus respuestas pueden ser no lineales e incluir efectos de retraso y acarreo. No obstante, es importante también especificar los efectos individuales de los diferentes cambios ambientales para afinar los modelos de procesos a nivel del ecosistema, y así poder proyectar los impactos futuros sobre estos bosques. Después de discutir dichos retos y estrategias para enfrentarlos, concluyo con una agenda de prioridades para esta área crítica de investigación. [source] Gene expression profiling of human promyelocytic cells in response to infection with Anaplasma phagocytophilumCELLULAR MICROBIOLOGY, Issue 4 2005José De La Fuente Summary Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae) causes human, equine and canine granulocytic anaplasmosis and tick-borne fever of ruminants. The rickettsia parasitizes granulocytes and bone marrow progenitor cells, and can be propagated in human promyelocytic and tick cell lines. In this study, microarrays of synthetic polynucleotides of 21 329 human genes were used to identify genes that are differentially expressed in HL-60 human promyelocytic cells in response to infection with A. phagocytophilum. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) of selected genes confirmed the results of the microarray analysis. Six genes in the A. phagocytophilum -infected cells were found to be upregulated greater than 30-fold, while expression of downregulated genes most often did not change more than sixfold. Genes that were found to be differentially regulated in infected cells were those essential for cellular mechanisms including growth and differentiation, cell transport, signalling and communication and protective response against infection, some of which are most likely necessary for infection and multiplication of A. phagocytophilum in host cells. The differentially regulated genes described herein provide new information on the gene expression profiles in A. phagocytophilum -infected HL-60 cells, thus expanding in a global manner the existing information on the response of mammalian cells to A. phagocytophilum infection. [source] | ||||||||||||||||