Home About us Contact
|
Home About us Contact | ||
|
|
||
Retention
Kinds of Retention Terms modified by Retention Selected AbstractsEFFECTS OF COOKING METHODS ON SENSORY QUALITIES AND CAROTENOID RETENTION IN SELECTED VEGETABLES,JOURNAL OF FOOD QUALITY, Issue 5 2006MONIQUE D. NUNN ABSTRACT The effects of induction boiling, conventional boiling and microwave steaming on the sensory qualities and carotenoid retention of broccoli, carrots, green beans and sweet potatoes were investigated. Significantly higher cooking yields were obtained for vegetables that were induction and conventionally boiled. No differences in the retentions of alpha-carotene (, -carotene), beta-carotene (, -carotene) and lutein/zeaxanthin were observed for vegetables by the cooking method, with the exception of , -carotene retention in broccoli and sweet potatoes where retentions were higher for those that were induction boiled (90.3 and 86.1%, respectively) than those that were microwave steamed (62.2 and 66.4%, respectively). A trained panel judged the color scores of three vegetables by the cooking method as similar. The mean flavor scores (1 = extremely bland; 9 = extremely intense) for three vegetables that were conventional (4.7,5.4) and induction (5.3,5.5) boiled were lower than those that were microwave steamed (5.9,7.0). The mean texture scores (1 = extremely mushy/tender; 9 = extremely firm/tough) for all induction-boiled (5.0,6.0) vegetables were higher than those that were conventionally boiled (3.4,5.2) and lower than those that were microwave steamed (5.1,6.6). [source] THE ROLE OF PERIPHYTON IN PHOSPHORUS RETENTION IN SHALLOW FRESHWATER AQUATIC SYSTEMSJOURNAL OF PHYCOLOGY, Issue 5 2003Article first published online: 26 SEP 200, Walter K. Dodds Eutrophication caused by phosphorus (P) leads to water quality problems in aquatic systems, particularly freshwaters, worldwide. Processing of nutrients in shallow habitats removes P from water naturally and periphyton influences P removal from the water column in flowing waters and wetlands. Periphyton plays several roles in removing P from the water column, including P uptake and deposition, filtering particulate P from the water, and attenuating flow, which decreases advective transport of particulate and dissolved P from sediments. Furthermore, periphyton photosynthesis locally increases pH by up to 1 unit, which can lead to increased precipitation of calcium phosphate, concurrent deposition of carbonate-phosphate complexes, and long-term burial of P. Actively photosynthesizing periphyton can cause super-saturated O2 concentrations near the sediment surface encouraging deposition of metal phosphates. However, anoxia associated with periphyton respiration at night may offset this effect. Linking the small-scale functional role of periphyton to ecosystem-level P retention will require more detailed studies in a variety of ecosystems or large mesocosms. A case study from the Everglades illustrates the importance of considering the role of periphyton in P removal from wetlands. In general, periphyton tends to increase P retention and deposition. In pilot-scale constructed periphyton-dominated wetlands in South Florida, about half of the inflowing total P was removed. [source] RACIAL DIFFERENCES IN EMPLOYEE RETENTION: ARE DIVERSITY CLIMATE PERCEPTIONS THE KEY?PERSONNEL PSYCHOLOGY, Issue 1 2007PATRICK F. McKAY Given considerable racial differences in voluntary turnover (Bureau of Labor Statistics, 2006, Table 28), the present study examined the influence of diversity climate perceptions on turnover intentions among managerial employees in a national retail organization. The authors hypothesized that pro-diversity work climate perceptions would correlate most negatively with turnover intentions among Blacks, followed in order of strength by Hispanics and Whites (Hypothesis 1), and that organizational commitment would mediate these interactive effects of race and diversity climate perceptions on turnover intentions (Hypothesis 2). Results from a sample of 5,370 managers partially supported both hypotheses, as findings were strongest among Blacks. Contrary to the hypotheses, however, White men and women exhibited slightly stronger effects than Hispanic personnel. [source] FACTORS AFFECTING IMPLANT RETENTION IN INFECTED JOINT REPLACEMENTSANZ JOURNAL OF SURGERY, Issue 10 2007Jean-Claude Theis Background: There is no standard treatment for infected joint replacements. The options available are varied, and treatment choices may pose problems in relation to both efficacy and cost-effectiveness. Methods: A retrospective review of 73 patient records identified in our departmental audit database as infected joint replacements treated at Dunedin Hospital between 1990 and 2000 was carried out. The findings were analysed in terms of outcome of primary treatment, final outcome including prosthesis retention and bacteriology. Results: Of the 73 patients (50 hips and 20 knees), the majority (69%) were managed by primary surgical debridement followed by intravenous antibiotics but about one-third (34%) lost their implants because of infection. Retention of implants was higher in acute infections (85,100%) as opposed to late infections (20,50%). The microbiological analysis showed that Staphylococcus and Streptococcus caused the majority (76%) of infections. Conclusion: In our series, a patient with an infected joint replacement had an approximately similar 30% chance of retaining the original prosthesis, undergoing a successful revision and having no implants in situ at the end of treatment. [source] CENTRAL AUSTRALIAN NURSE MANAGEMENT MODEL (CAN MODEL): A STRATEGIC APPROACH TO THE RECRUITMENT AND RETENTION OF REMOTE-AREA NURSESAUSTRALIAN JOURNAL OF RURAL HEALTH, Issue 1 2000Melanie Van Haaren This paper introduces a new strategic approach, the Central Australian Nurse Management Model (CAN Model), to manage remote area nursing services. Central Australia is home to approximately 45 000 people, of whom 30% are Aborigines with a health status that is markedly lower than the rest of the population. While the Federal, State and Territory governments have policies in place to address health inequities, improvement has been hindered by the difficulty in recruiting and retaining suitable nursing staff in remote areas. Implementation of the three key initiatives that comprise the CAN Model has succeeded in attracting, stabilising and skilling a remote area nursing workforce, fundamental to achieving better health outcomes in Aboriginal populations. [source] Dependency of Tritium Retention in Graphite on Temperature Control of Molecular DynamicsCONTRIBUTIONS TO PLASMA PHYSICS, Issue 3-5 2010A. Ito Abstract We have investigated the carbon plasma facing material and hydrogen atom interaction by the use of molecular dynamics simulation to clarify chemical erosion processes on divertor plate. The present paper is our first try at elucidation of temperature dependence by the molecular dynamics. Temperature was controlled by using Langevin thermostat method. As a result, the retention of hydrogen atom achieve steady state, and the CH4 was generated, which was not found MD simulations without a temperature control method. About 30 percent of injected hydrogen atoms are retained. CH4 yields has a peak at 600 K, which accords with experimental results. A dominant path of CH4 generation found by the present molecular dynamics simulation is as follows: a CH is detached from eroded surface and then it grows into CH4 adsorbing hydrogen atoms via CH2 and CH3. In addition, we propose the problem that the hydrogen atom retention and CH,, yields depend on the thermal relaxation time in MD simulation using temperature control methods (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Pregabalin, tiapride and lorazepam in alcohol withdrawal syndrome: a multi-centre, randomized, single-blind comparison trialADDICTION, Issue 2 2010Giovanni Martinotti ABSTRACT Introduction The aim of this trial was to compare lorazepam with non-benzodiazepine medications such as pregabalin and tiapride in the treatment of alcohol withdrawal syndrome (AWS). These drugs were chosen for their inhibitorial effects on the hypersecretion of neurotransmitters usually observed in AWS. Craving reduction and improvement of psychiatric symptoms were the secondary end-points. Methods One hundred and ninety subjects affected by current alcohol dependence were considered consecutively: 111 were enrolled and divided into three groups of 37 subjects each. Within a treatment duration of 14 days, medication was given up to the following maximum doses (pregabalin 450 mg/day; tiapride 800 mg/day; lorazepam 10 mg/day). Withdrawal (CIWA-Ar), craving [visual analogue scale (VAS); Obsessive and Compulsive Drinking Scale (OCDS)], psychiatric symptoms [Symptom Check List 90 Revised (SCL-90-R)] and quality of life (QL-index) rating scales were applied. Results On the CIWA-Ar score, all the groups showed a significant reduction between times (P < 0.001) with a higher reduction for the pregabalin group (P < 0.01) on items regarding headache and orientation. Retention in treatment was lower in the tiapride group (P < 0.05), while the number of subjects remaining alcohol free was higher in the pregabalin group (P < 0.05). Significant reduction between baseline and the end of the treatment was found in all the groups at the OCDS and the VAS for craving, at the SCL-90-R and QL-index (P < 0.001). Discussion All the medications in the trial showed evidence of safety and efficacy in the treatment of uncomplicated forms of AWS, with some particular differences. The efficacy of pregabalin was superior to that of tiapride, used largely in research trials and, for some measures, to that of the ,gold standard', lorazepam. Accordingly, pregabalin may be considered as a potentially useful new drug for treatment of AWS, deserving further investigation. [source] Opioid agonist pharmacotherapy in New South Wales from 1985 to 2006: patient characteristics and patterns and predictors of treatment retentionADDICTION, Issue 8 2009Lucy Burns ABSTRACT Aims The aims of this study were to: examine the number and characteristics of patients entering and re-entering opioid replacement treatment between 1985 and 2006, to examine select demographic and treatment correlates of leaving treatment between 1985 and 2000, and to compare retention rates in methadone and buprenorphine maintenance treatment from 2001 to 2006. Design A retrospective cohort study using register data from the Pharmaceutical Drugs of Addiction System. Setting Opioid substitution treatment in New South Wales (NSW), Australia. Participants A total of n = 42 690 individuals prescribed opioid replacement treatment between 1985 and 2006 in NSW. Measurements Client characteristics over time, retention in days in first treatment episode, number of episodes of treatment and proportion switching medication. Findings Overall, younger individuals were significantly more likely to leave their first treatment episode than older individuals. In 2001,06, after controlling for age, sex and first administration point, the hazard of leaving treatment was 1.9 times for those on buprenorphine relative to those on methadone. Retention in treatment varied somewhat across historical time, with those entering during 1995,2000 more likely to leave at an earlier stage than those who entered before that time. Conclusions Retention in treatment appears to fluctuate in inverse proportion to the availability of heroin. Individuals in contemporary treatment are older users with a lengthy treatment history. This study has provided population-level evidence to suggest that retention in methadone and buprenorphine differ in routine clinical practice. Future work might investigate ways in which patient adherence and retention may be improved. [source] Cellulose dimethylphenylcarbamate-immobilized zirconia for chiral separation in reversed-phase CECELECTROPHORESIS, Issue 22 2009Jurim Gwon Abstract Cellulose dimethylphenylcarbamate (CDMPC)-immobilized zirconia (CDMPCZ) was used as a chiral stationary phase for enantioseparation of a set of nine racemic compounds in reversed-phase CEC. Influences of the type and composition of organic modifier and the applied voltage on enantioseparation were examined. Separation data on CDMPCZ were also compared with those on CDMPC-immobilized silica (CDMPCS). Enantiomers of the analytes investigated are well separated in ACN/phosphate buffer mobile phases. Better enantioselectivity and resolution were obtained with ACN than MeOH as the organic modifier. Retention was longer but better enantioselectivity and resolution were obtained on CDMPCZ than CDMPCS. [source] Retention of proteins and metalloproteins in open tubular capillary electrochromatography with etched chemically modified columns,ELECTROPHORESIS, Issue 18 2008Joseph J. Pesek Abstract Etched chemically modified capillaries with two different bonded groups (pentyl and octadecyl) are compared for their migration behavior of several common proteins and metalloproteins as well as metalloproteinases. Migration times, efficiency and peak shape are evaluated over the pH range of 2.1,8.1 to determine any effects of the bonded group on the electrochromatographic behavior of these compounds. One goal was to determine if the relative hydrophobicity of the stationary phase has a significant effect on proteins in the open tubular format of capillary electrochromatography as it does in HPLC. Reproducibility of the migration times is also investigated. [source] Comparing retention in treatment and mortality in people after initial entry to methadone and buprenorphine treatmentADDICTION, Issue 7 2009James Bell ABSTRACT Aim To compare retention in treatment and mortality among people entering methadone and buprenorphine treatment for opioid dependence. Data sources The Pharmaceutical Drugs of Abuse System (PHDAS) database records start- and end-dates of all episodes of methadone and buprenorphine treatment in New South Wales, and the National Death Index (NDI) records all reported deaths. Methods Data linkage study. First entrants to treatment between June 2002 and June 2006 were identified from the PHDAS database. Retention in treatment was compared between methadone and buprenorphine. Names were linked to the NDI database, and ,good matches' were identified. Deaths were classified as occurring during induction, maintenance and either post-methadone or post-buprenorphine, depending on the latest episode of treatment prior to death. The numbers of inductions into treatment, of total person-years spent in each treatment, and person-years post-methadone or buprenorphine, were calculated. Risk of death in different periods, and different treatments, was analysed using Poisson regression. Results A total of 5992 people entered their first episode of treatment,3349 (56%) on buprenorphine, 2643 on methadone. Median retention was significantly longer in methadone (271 days) than buprenorphine (40 days). During induction, the risk of death was lower for buprenorphine (relative risk = 0.114, 95% confidence interval = 0.002,0.938, P = 0.02, Fisher's exact test). Risk of death was lowest during treatment, significantly higher in the first 12 months after leaving both methadone and buprenorphine. Beyond 12 months after leaving treatment, risk of death was non-significantly higher than during treatment. Conclusions Buprenorphine was safer during induction. Despite shorter retention in treatment, buprenorphine maintenance was not associated with higher risk of death. [source] Cyclical electrical field flow fractionationELECTROPHORESIS, Issue 9 2005Bruce K. Gale Abstract Cyclical electrical field flow fractionation (Cy/ElFFF) is demonstrated in a standard electrical field flow fractionation (ElFFF) channel for the first time. Motivation for the use of alternating current (AC) fields in a traditionally direct current (DC) technique are discussed. The function of the system over a wide range of operating conditions is explored and challenges associated with various operating conditions reported. Retention of polystyrene nanoparticle standards is accomplished and the effect of varying parameters of the applied field, such as voltage and frequency, are explored. The first separations using this technique are demonstrated. The experimental results are compared to analytical models previously reported in the literature. The general trend of the experimental results is similar to those predicted in theoretical models and possible reasons for discrepancies are elucidated. Suggestions are made for improving the separation and analysis method, and possible applications explored. [source] Retention in methadone maintenance drug treatment for prescription-type opioid primary users compared to heroin usersADDICTION, Issue 5 2009Caleb J. Banta-Green ABSTRACT Aims To assess retention in methadone maintenance treatment for prescription-type opioid primary (PTOP) users compared to heroin users. Design and participants A retrospective cohort study was carried out to examine the association between opiate types used on 12-month retention. The study population consisted of adults admitted to one of 11 not-for-profit methadone maintenance clinics in 2004 and 2005 throughout Washington State (n = 2308). Logistic regression analyses with fixed effects for treatment agencies were conducted. Measurements Opiate use type in past 30 days: any heroin use or primary prescription opioid without heroin use. Demographics, other drugs used, self-reported medical and psychiatric concerns, social, familial and legal issues, public assistance type and housing stability were documented at intake using a comprehensive biopsychosocial instrument, the Treatment and Assessment Reports Generation Tool. Findings The odds of being retained in treatment for PTOP compared to heroin users not adjusting for other factors was 1.33 (95% confidence interval [CI], 1.03, 1.71). In the final logistic regression model the odds of retention for PTOP compared to heroin users was 1.25 (95% CI, 0.93, 1.67), indicating that there was no statistically significant difference in treatment retention by opiate type after adjusting for demographics, treatment agencies, other drug use, public assistance type, medical, psychiatric, social, legal and familial factors. Conclusion The findings of this study suggest that PTOP can be treated at methadone maintenance treatment facilities at least as effectively as heroin users in terms of treatment retention. [source] Persistent or not persistent?ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2009Polychlorinated biphenyls are readily depurated by grizzly bears (Ursus arctos horribilis) Abstract Major pharmacokinetic processes influencing polychlorinated biphenyl (PCB) accumulation in mammals include uptake, biotransformation, respiration, and excretion. We characterized some of the factors underlying PCB accumulation/loss by evaluating PCB concentrations and patterns in pre- and posthibernation grizzly bears (Ursus arctos horribilis) and their prey. The PCB congeners with vicinal meta - and para -chlorine unsubstituted hydrogen positions consistently showed loss both before and during hibernation, supporting the idea of a dominant role for biotransformation. Retention of all other studied congeners relative to that of PCB 194 varied widely (from <1 to 100%) and was highly correlated with log octanol--water partition coefficient (p < 0.0001). A lack of loss for most of these other congeners during hibernation supports the notion that excretion (e.g., fecal or urinary) or lack of uptake during the feeding season underlies their lack of accumulation, because hibernating bears do not eat or excrete. We estimate that grizzly bears retain less than 10% of total PCBs taken up from their diet. Our results suggest that for grizzly bears, depuration of PCBs via biotransformation is important (explaining ,40% of loss), but that nonbiotransformation processes, such as excretion, may be more important (explaining ,60% of loss). These findings, together with the approximately 91% loss of the persistent PCB 153 congener relative to PCB 194 in grizzly bears, raise important questions about how one defines persistence of PCBs in wildlife and may have bearing on the interpretation of food-web biomagnification studies. [source] Efficacy of maintenance treatment with naltrexone for opioid dependence: a meta-analytical reviewADDICTION, Issue 4 2006Björn Axel Johansson ABSTRACT Aims To determine the efficacy of naltrexone in reducing illicit opioid use and the potential moderating role of treatment retention. ,Design First, randomized controlled trials (RCTs) comparing the regimens of treatment using the opioid antagonist, naltrexone, with controls were analysed by meta-analysis for treatment effect with regard to a range of outcome criteria. The degree of heterogeneity was also determined. The moderating effect of other interventions during naltrexone maintenance was then estimated, particularly with regard to their effect on treatment retention. Participants Fifteen studies involving 1071 patients were found. Measurements All available outcomes were analysed in 10 studies of naltrexone versus control (seven placebo) and six studies of randomized psychosocial/psychopharmacological interventions. Findings Significant heterogeneity was found in the efficacy of naltrexone. Level of retention in treatment was found to be a moderator, explaining most of the heterogeneity found. Overall, naltrexone was significantly better than control conditions in reducing the number of opioid-positive urines. This effect was only present in the high retention subgroup for differences in retention. Contingency management (CM) increased retention and naltrexone use, resulting in a reduced number of opioid-positive urines. Conclusion Retention is important to the effect of naltrexone in treating opioid dependence. Contingency management is a promising method of increasing retention. [source] Prognostic Factors Affecting Long-Term Retention of Topiramate in Patients with Chronic EpilepsyEPILEPSIA, Issue 3 2000S. D. Lhatoo Summary: Purpose: To determine the long-term retention rate of topiramate (TPM) therapy in patients with chronic epilepsy and to identify the relevant prognostic factors that influence retention. Methods: All patients with chronic epilepsy (n = 393) prescribed TPM between October 1, 1995, and December 31, 1998, at a tertiary referral centre for epilepsy were analysed. The retention rate for TPM was calculated by using Kaplan-Meier survival analysis, and the prognostic factors influencing retention were analysed by using Cox regression. Results: Of patients prescribed TPM, 30% continued taking the drug beyond 3 years. Discontinuation was mainly due to adverse events and lack of efficacy. Use of more than one new concurrent antiepileptic drug (AED) and lower maximal daily doses were more likely to result in treatment discontinuation due to adverse events. Older age at onset of epilepsy, a history of having previously taken more than one new AED [lamotrigine (LTG), gabapentin (GBP), or vigabatrin (VGB)], and lower maximal daily doses were more likely to lead to discontinuation due to lack of efficacy. Conclusions: A third of patients with chronic epilepsy started on TPM therapy will continue on treatment for >3 years. Absence of learning disabilities, late age at onset of seizures, previous use of more than one new AED, two or more concurrent AED use, and low maximal daily doses of TPM are more likely to result in discontinuation of medication. These factors should be taken into account when considering the use of TPM for the treatment of chronic epilepsy. [source] Side-Chain Retention During Lithiation of 4-Picoline and 3,4-Lutidine: Easy Access to Molecular Diversity in Pyridine SeriesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2003Thomas Kaminski Abstract The first direct ring-selective lithiation of 4-picoline and 3,4-lutidine has been achieved through the use of BuLi/LiDMAE aggregates to prevent the usual side-chain metallation. Several functionalities have been introduced at the C-2, C-6 and C-5 positions by ring-selective sequential lithiation, opening a simple and fast route to polysubstituted pyridine building blocks. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Physicochemical factors controlling the release of dissolved organic carbon from columns of forest subsoilsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2002J.-M. Münch Summary Retention of dissolved organic carbon in soil depends on the chemical and physical environment. We studied the release of organic carbon from three carbonate-free forest subsoil materials (Bs1, Bs2, Bg) in unsaturated column experiments as influenced by (i) variations of the flow regime and (ii) varied chemical properties of the irrigation solution. We investigated the effect of flow initiation, constant irrigation, interruptions to flow, and variation in the effective pore water velocity on the release of organic C. The influence of ionic strength and cation valence in the irrigation solution was studied by stepped pulses of NaCl and CaCl2. The release of C from all materials was characterized by an initial large output and a decline to constant concentrations under long-term irrigation. Interrupting the flow increased its release when flow was resumed. The release from the Bs1 material was not related to the duration of the interruption. The Bs2 material, in contrast, released organic carbon in a way that was successfully described by a kinetic first-order model. Increased pore water velocity decreased the concentrations of C in the effluent from it. The pH of the irrigation solution had negligible effects on the mobilization of C. Increased ionic strength reduced the release, whereas rinsing with distilled water increased the concentrations of C in the effluent. The response of dissolved C to pulses of weak solutions, however, was sensitive to the type of cation in the previous step with strong solutions. The results suggest that the release of organic matter in the soils depends on its colloidal properties. [source] Retention of the duplicated cellular retinoic acid-binding protein 1 genes (crabp1a and crabp1b) in the zebrafish genome by subfunctionalization of tissue-specific expressionFEBS JOURNAL, Issue 14 2005Rong-Zong Liu The cellular retinoic acid-binding protein type I (CRABPI) is encoded by a single gene in mammals. We have characterized two crabp1 genes in zebrafish, designated crabp1a and crabp1b. These two crabp1 genes share the same gene structure as the mammalian CRABP1 genes and encode proteins that show the highest amino acid sequence identity to mammalian CRABPIs. The zebrafish crabp1a and crabp1b were assigned to linkage groups 25 and 7, respectively. Both linkage groups show conserved syntenies to a segment of the human chromosome 15 harboring the CRABP1 locus. Phylogenetic analysis suggests that the zebrafish crabp1a and crabp1b are orthologs of the mammalian CRABP1 genes that likely arose from a teleost fish lineage-specific genome duplication. Embryonic whole mount in situ hybridization detected zebrafish crabp1b transcripts in the posterior hindbrain and spinal cord from early stages of embryogenesis. crabp1a mRNA was detected in the forebrain and midbrain at later developmental stages. In adult zebrafish, crabp1a mRNA was localized to the optic tectum, whereas crabp1b mRNA was detected in several tissues by RT-PCR but not by tissue section in situ hybridization. The differential and complementary expression patterns of the zebrafish crabp1a and crabp1b genes imply that subfunctionalization may be the mechanism for the retention of both crabp1 duplicated genes in the zebrafish genome. [source] Graphite Oxides Obtained from Porous Graphite: The Role of Surface Chemistry and Texture in Ammonia Retention at Ambient ConditionsADVANCED FUNCTIONAL MATERIALS, Issue 10 2010Mykola Seredych Abstract Graphite oxides (GO) synthesized using Brodie and Hummers methods are tested for ammonia adsorption at ambient conditions with different contents of water in the system. Surface characterization before and after exposure to ammonia is performed using XRD, FTIR spectroscopy, potentiometric titration, thermal analysis, adsorption of nitrogen, and XPS. Oxidation of the same porous graphite using two methods results in materials with different textural and chemical features. On GO obtained using the Brodie method mainly epoxy and carboxylic groups are present whereas on the GO obtained using the Hummers method chemisorbed oxygen is also found. The contribution of the carboxylic groups in the latter material is greater. It also contains sulfur either in sulfones or as residual sulfuric acid. Ammonia is adsorbed either via reaction with surface groups or dissolution in water. The former is responsible for strong adsorption. The evidence of the catalytic effect of the carbon surface on activation of oxygen leading to surface oxidation is also observed. [source] Computer-Assisted Reading: The Effect of Glossing Format on Comprehension and Vocabulary RetentionFOREIGN LANGUAGE ANNALS, Issue 2 2001Serafima Gettys Two glossing methods are compared. The first method provides readers with sentence-level translation equivalents of the second-language (L2) words. The second method connects the words with their meanings through basic dictionary forms. The main purpose of the study was to determine which of the two glossing formats is more beneficial for text comprehension and vocabulary retention. The results of the study show that retention of lexical items is better aided by reading the text with dictionary-form equivalents of the L2 words, because it involves a deeper level of cognitive processing. The situation is less clear-cut regarding the effect of the two glossing formats on global comprehension. The pedagogical implications of the data obtained are discussed. [source] Enhanced Adsorption of Ammonia on Metal-Organic Framework/Graphite Oxide Composites: Analysis of Surface InteractionsADVANCED FUNCTIONAL MATERIALS, Issue 1 2010Camille Petit Abstract Composites of the metal-organic framework (MOF), MOF-5, and graphite oxide (GO) with different ratios of the two components are prepared and tested in ammonia removal under dry conditions. The parent and composite materials are characterized before and after exposure to ammonia by sorption of N2, X-ray diffraction, thermal analyses, and FT-IR spectroscopy. The results show a synergetic effect resulting in an increase in the ammonia uptake compared to the parent materials. It is linked to enhanced dispersive forces in the pore space of the composites. Additionally, ammonia interacts with zinc oxide tetrahedra via hydrogen bonding and is intercalated between the layers of GO. Retention of a large quantity of ammonia eventually leads to a collapse of the MOF-5 structure in the composites. The effect resembles that observed when MOF-5 is exposed to water. Taking into account the similarity of ammonia and water molecules, it is hypothesized that ammonia causes a destruction of the MOF-5 and composite structure as a result of its hydrogen bonding with the zinc oxide clusters. [source] Formation of Highly Luminescent Supramolecular Architectures Possessing Columnar Order from Octupolar Oxadiazole Derivatives: Hierarchical Self-Assembly from Nanospheres to Fibrous Gels,ADVANCED FUNCTIONAL MATERIALS, Issue 13 2009Shinto Varghese Abstract The synthesis and study of the liquid crystalline, photophysical, and aggregation behavior of novel octupolar oxadiazole derivatives are reported. These molecules formed columnar mesophases at elevated temperatures which transformed into a glassy state at ambient temperatures wherein the columnar order was retained. Their spontaneous concentration dependent hierarchical self-assembly from spheres to fibrous gels has been investigated using TEM, SEM, and XRD. Retention of the hexagonal columnar (Colh) order was also observed in the fibrous aggregates. Concentration dependent luminescence spectral studies indicated that the change in morphology from spheres to fibrous aggregates was associated with a shift in chromophore packing from predominantly H -type to J -type aggregates. Time resolved anisotropic investigations revealed that the columnar stacking of molecules in the aggregated state provided a pathway for excitation energy migration to the lower energy J -traps. [source] Managing Environmental Impacts of Recreation and Tourism in Rainforests of the Wet Tropics of Queensland World Heritage AreaGEOGRAPHICAL RESEARCH, Issue 2 2005Stephen M. Turton Abstract This paper describes environmental impacts of tourism and recreation activities in the world heritage listed rainforests of northeast Australia and presents management strategies for sustainable visitor use of the protected area. Tropical rainforests are characterised by their low resistance and moderate to high resilience to impacts associated with human visitation. Visitor use in the World Heritage Area is mostly associated with walking tracks, camping areas, day use areas and off-road vehicle use of old forestry roads and tracks. Adverse environmental impacts range from vegetation trampling, soil compaction, water contamination and soil erosion at the local scale through to spread of weeds, feral animals and soil pathogens along extensive networks of old forestry roads and tracks at the regional scale. Concentration of visitor use is the most desirable management strategy for controlling adverse impacts at most World Heritage Area visitor nodes and sites, and includes methods such as site hardening and shielding to contain impacts. For dispersed visitor activities, such as off-road vehicle driving and long-distance walking, application of best practice methods by the tourist industry and recreational users such as removal of mud and soils from vehicle tyres and hiking boots before entering pathogen-free catchments, together with seasonal closure of roads and tracks, are the preferred management strategies. Retention of canopy cover at camping areas and day use areas, as well as along walking tracks and forestry roads is a simple, yet effective, management strategy for reduction of a range of adverse impacts, including dispersal of weeds and feral animals, edge effects, soil erosion and nutrient loss, road kill and linear barrier effects on rainforest fauna. [source] Humus/Mineral Interactions Affect Retention of Some Soil Pollutants: Waterlink/Barnebey Sutcliffe Expands Carbon Service NetworkGROUND WATER MONITORING & REMEDIATION, Issue 2 2000Article first published online: 22 FEB 200 No abstract is available for this article. [source] Superhydrophobic Coatings: The Salvinia Paradox: Superhydrophobic Surfaces with Hydrophilic Pins for Air Retention Under Water (Adv. Mater.ADVANCED MATERIALS, Issue 21 201021/2010) The cover shows the sophisticated surface design of the floating water fern Salvinia. The unique surface architecture is composed of complex hydrophobic eggbeater-shaped hairs with hydrophilic terminal cells. The evenly distributed hydrophilic patches stabilize the air layer by pinning the air/water interface in place. The paradox combination of hydrophilic patches on superhydrophobic surfaces (the "Salvinia Effect") provides an innovative concept for smart biomimetic surfaces in maritime coatings and underwater applications, as reported by Wilhelm Barthlott, Thomas Schimmel, and co-workers on p. 2325. [source] The Salvinia Paradox: Superhydrophobic Surfaces with Hydrophilic Pins for Air Retention Under WaterADVANCED MATERIALS, Issue 21 2010Wilhelm Barthlott A novel mechanism for long-term air retention under water is found in the sophisticated surface design of the water fern Salvinia. Its floating leaves are evenly covered with complex hydrophobic hairs retaining a layer of air when submerged under water. Surprisingly the terminal cells of the hairs are hydrophilic. These hydrophilic patches stabilize the air layer by pinning the air,water interface. This "Salvinia Effect" provides an innovative concept to develop biomimetic surfaces with long-term air-retention capabilities for under water applications. [source] Retention of chloride in soil and cycling of organic matter-bound chlorineHYDROLOGICAL PROCESSES, Issue 11 2005G. Öberg Abstract Chloride (Clinorg) is generally considered to be a hydrologically and chemically inert substance. Past research suggests that Clinorg participates in a complex biogeochemical cycle involving the formation of organically bound chlorine (Clorg). The present study examines whether Clorg cycling is sufficiently extensive as to influence the geochemical cycling of Clinorg. Undisturbed soil cores were collected in a coniferous forest soil in SE Sweden. The cores were stored in climate chambers for three months, irrigated with artificial rain, and the leachate was collected and analysed. The water balance of the lysimeters could be well described, and we found that 20,50% of the chlorine leached from the lysimeters was organically bound and that the amounts lost did not decrease with time. This strongly suggests that a substantial amount of Clorg forms in topsoil, and that subsequent leaching to deeper layers causes a considerable withdrawal of Clinorg. The concentration of both organic carbon and Clorg in the leachate was considerably higher than concentrations observed in the runoff in the actual catchment, suggesting that organic matter precipitates or is mineralized on its way through the soil. Copyright © 2005 John Wiley & Sons, Ltd. [source] Unionization, Compensation, and Voice Effects on Quits and RetentionINDUSTRIAL RELATIONS, Issue 4 2000John E. Delery This study explores the relationships among unionization, compensation practices, and employee attachment (quit rates and tenure) among trucking companies to assess the applicability of Freeman and Medoff's exit/voice argument. Unionization was associated with lower quit rates, higher tenure, a better compensation package, and stronger voice mechanisms. The relationship of unionization to quit rates and tenure becomes nonsignificant after accounting for compensation (pay and benefits), and voice mechanisms do not add explanatory variance. [source] Fast Mapping but Poor Retention by 24-Month-Old InfantsINFANCY, Issue 2 2008Jessica S. Horst Four experiments explored the processes that bridge between referent selection and word learning. Twenty-four-month-old infants were presented with several novel names during a referent selection task that included both familiar and novel objects and tested for retention after a 5-min delay. The 5-min delay ensured that word learning was based on retrieval from long-term memory. Moreover, the relative familiarity of objects used during the retention test was explicitly controlled. Across experiments, infants were excellent at referent selection, but very poor at retention. Although the highly controlled retention test was clearly challenging, infants were able to demonstrate retention of the first 4 novel names presented in the session when referent selection was augmented with ostensive naming. These results suggest that fast mapping is robust for reference selection but might be more transient than previously reported for lexical retention. The relations between reference selection and retention are discussed in terms of competitive processes on 2 timescales: competition among objects on individual referent selection trials and competition among multiple novel name,object mappings made across an experimental session. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||