Similar Time Frames Research Articles

Statistical and Spatial Analysis of Land Cover Impact on Selected Metro Vancouver, British Columbia Watersheds

The Greater Vancouver area has undergone significant land use and land cover (LULC) change over the past several decades, often adversely affecting stream health and water quality, particularly in those areas that have undergone the most urbanization. In this study 30 years of historical LULC and water quality data were examined using GIS and statistical analysis to better understand these impacts and to help build a broader understanding of cause and effect relationships of changing LULC, especially since urbanization is increasingly occurring within sensitive watersheds at greater distances from the City of Vancouver. Urban, agriculture, and disturbed LULC data from 1976, 1986, and 2000 were examined within a number of watersheds and related to historical water quality data sampled from streams during similar time frames. Additional higher resolution 2006 LULC data from a smaller number of watersheds were then examined and compared to stream health data to investigate the sensitivity of LULC data resolution on monitoring watershed impact. While LULC impact can be clearly seen at both high and lower resolutions, issues of ambiguous land cover and land use designations can potentially affect the magnitude of the relationship.

Identifying unidirectional and dynamic habitat filters to faunal recolonisation in restored mine‐pits

Summary1. There is increasing evidence that passive faunal recolonisation of restored areas can take decades or even centuries, reducing benefits to biodiversity from restoration. Thus, there is a need to develop restoration and management strategies that facilitate and accelerate faunal recolonisation. This requires identification of habitat features that act as filters to slow or prevent recolonisation and whether those filters are temporally unidirectional or dynamic.2. We investigated successional patterns of reptiles and mammals in restored mine‐pits in south‐western Australia to identify potential filters to faunal recolonisation. We sampled reptiles and small mammals using 30 trapping grids across each of four restoration ages (4, 8, 12 and 17‐years old) and unmined forest and assessed vegetation structure to identify animal–habitat relationships.3. Mammal communities in restored areas converged on unmined forest communities as restoration matured, and all species recolonised rapidly, indicating there were no filters to mammal recolonisation. In contrast, reptile communities did not converge in the same way, indicating there were filters that slowed or prevented reptile recolonisation. We identified three reptile species that were slow, or failed, to recolonise restored areas and a fourth species that rapidly recolonised but disappeared as restoration matured. We identified low coarse woody debris (CWD) volumes and high overstorey stem densities as likely filters; the former is a unidirectional filter that will decrease gradually over long time frames, possibly centuries, while the latter is a dynamic filter that fluctuates in its intensity over short time frames of years.4. Synthesis and applications. Our study adds to growing evidence that filters to faunal recolonisation may be widespread in restored areas, with important implications for restoration practices. Firstly, examining individual species may more effectively identify filters than examining community successional patterns. Secondly, filters can persist over long time frames, possibly centuries, so management, such as the provision and accelerated development of CWD, may need to occur over similar time frames. Lastly, filters can be dynamic and repeated management interventions, such as thinning, may be required to overcome these filters. The growing evidence for filters suggests that facilitating faunal recolonisation is more complex than simply returning vegetation to restoration sites.

The Effect of Completing a Surrogacy Information and Decision-Making Tool upon Admission to an Intensive Care Unit on Length of Stay and Charges

Many critically ill patients in intensive care units (ICUs) are unable to communicate their wishes about goals of care, particularly about the use of life-sustaining treatments. Surrogates and clinicians struggle with medical decisions because of a lack of clarity regarding patients' preferences, leading to prolonged hospitalizations and increased costs. This project focused on the development and implementation of a tool to facilitate a better communication process by (1) assuring the early identification of a surrogate if indicated on admission and (2) clarifying the decision-making standards that the surrogate was to use when participating in decision making. Before introducing the tool into the admissions routine, the staff were educated about its use and value to the decision-making process. PROJECT AND METHODS: The study was to determine if early use of a simple method of identifying a patient's surrogate and treatment preferences might impact length of stay (LOS) and total hospital charges. A pre- and post-intervention study design was used. Nurses completed the surrogacy information tool for all patients upon admission to the neuroscience ICU. Subjects (total N = 203) were critically ill patients who had been on a mechanical ventilator for 96 hours or longer, or in the ICU for seven days or longer.The project included staff education on biomedical ethics, critical communication skills, early identification of families and staff in crisis, and use of a simple tool to document patients' surrogates and previously expressed care wishes. Data on hospital LOS and hospital charges were collected through a retrospective review of medical records for similar four-month time frames pre- and post-implementation of the assessment tool. Significant differences were found between pre- and post-groups in terms of hospital LOS (F = 6.39, p = .01) and total hospital charges (F = 7.03, p = .009). Project findings indicate that the use of a simple admission assessment tool, supported by staff education about its completion, use, and available resources, can decrease LOS and lower total hospital charges. The reasons for the difference between the pre- and post-intervention groups remain unclear. Further research is needed to evaluate if the quality of communications between patients, their legally authorized representatives, and clinicians--as suggested in the literature--may have played a role in decreasing LOS and total hospital charges.

Insurance accounting: a new era?

AbstractInsurance accounting has for many years proved a challenging topic for standard setters, preparers and users, often described as a “black box”. Will recent developments, in particular the July 2010 Insurance Contracts Exposure Draft, herald a new era?This paper reviews these developments, setting out key issues and implications. It concentrates on issues relevant to life insurers, although much of the content is also relevant to non-life insurers.The paper compares certain IFRS and Solvency II developments, recognising that UK insurers face challenges in implementing new financial and regulatory reporting requirements in similar timeframes. The paper considers resulting external disclosure requirements and a possible future role for supplementary information.

Dissolution and precipitation dynamics during dedolomitization

We simulate the processes of dedolomitization and calcium carbonate precipitation using particle tracking. The study is stimulated by the results of a laboratory experiment that examined reactive transport of injected CaCl2/HCl, into a column of sucrosic dolomite particles, with a constant flow field. The injected fluid supplies Ca2+ and H+. Dedolomitization is a protonation reaction yielding carbonic acid; a subsequent deprotonation reaction yields , and reaction with the abundant Ca2+ forms the precipitate CaCO3. The dedolomitization and precipitation processes involve multistep, multispecies chemical reactions, with both irreversible and reversible stages. The particle tracking is governed by spatial and temporal distributions within a continuous time random walk framework. This accounts for the effects of disorder of heterogeneous media (leading to non‐Fickian transport) and includes the option of treating purely advective‐dispersive (Fickian) transport. The dynamics of dedolomitization are examined for different flow conditions and reaction rates. The fluctuations in the local velocity distributions, due to porosity changes, create conditions for positive feedbacks leading to development of preferential pathways, large‐scale nonlinearity, and precipitation banding. These features have been observed in the laboratory experiments and are now accounted for by the simulation results at similar time frames, velocities, and pH levels.

Pregnancy outcome after in utero exposure to angiotensin converting enzyme inhibitors or angiotensin receptor blockers

Objective To examine first trimester safety of angiotensin-converting-enzyme-inhibitors (ACEIs) or angiotensin-receptor-blockers (ARBs). Study design Prospective observational cohort regarding pregnancy ACEI/ARBs-exposure including contacts to two Teratology Information Services in Israel (1994–2007) and Italy (1990–2008), with two comparison groups: (1) exposed to other antihypertensives (OAH) (2) after non-teratogenic exposure (NTE) in similar time frames. Results 252 ACEI/ARBs-exposed, 256 OAH-exposed and 495 NTE-exposed pregnancies were followed-up. The rate of major congenital anomalies was comparable between the groups (8/190, 4.2%, ACEI/ARB; 9/212, 4.2%, OAH; 18/471, 3.8% NTE; p = 0.954) among first trimester exposed pregnancies. The median gestational age at delivery was two weeks earlier, rate of preterm deliveries more than 2-fold higher, and median birth weight more than 200 g lower in the ACEI/ARB and OAH groups compared to the NTE group. Conclusion The present study suggests that ACEI/ARBs are not major teratogens when used in the first trimester, and can reassure women with similar exposures.

Anaerobic biodegradation of iso-butanol and ethanol and their relative effects on BTEX biodegradation in aquifer materials

Biologically produced iso-butanol is currently being considered as an additive in gasoline blends. To evaluate its potential environmental fate in groundwater aquifers, a laboratory microcosm study was performed to evaluate iso-butanol biodegradation under various anaerobic conditions (nitrate-reducing, sulfate-reducing and methanogenic). The impacts of iso-butanol on benzene, toluene, ethylbenzene, and total xylenes (BTEX) biodegradation were also assessed, and microcosms prepared using ethanol instead of iso-butanol were evaluated to provide a basis for comparison. Iso-butanol was biodegraded under all conditions studied, with an observed apparent first-order rate constant ranging from approximately 0.2 d −1 (nitrate-reducing) to approximately 0.02 d −1 (sulfate-reducing). Iso-butanol typically was degraded in a time frame that was shorter than or similar to BTEX compounds. Iso-butyric acid and trace levels of iso-butylaldehyde were identified as transient intermediates, and both of these compounds were subsequently degraded within the time frame of the experiments. Iso-butanol and ethanol were biodegraded in similar time frames under methanogenic conditions. Under sulfate-reducing conditions, iso-butanol biodegradation initially proceeded more slowly than ethanol, and then increased to a rate greater than that observed for ethanol; this observation likely was due to the growth of iso-butanol degrading bacteria. Iso-butanol generally exhibited less adverse impacts on BTEX biodegradations than ethanol under the anaerobic conditions studied. In some cases, addition of iso-butanol enhanced the rate of TEX biodegradation.

Field‐Scale Evaluation of Bioaugmentation Dosage for Treating Chlorinated Ethenes

A field demonstration was performed to evaluate the impacts of bioaugmentation dosage for treatment of chlorinated ethenes in a sandy‐to‐silty shallow aquifer. Specifically, bioaugmentation using a commercially available Dehalococcoides (DHC)‐containing culture was performed in three separate groundwater recirculation loops, with one loop bioaugmented with 3.9 × 1011 DHC, the second loop bioaugmented with 3.9 × 1012 DHC, and the third loop bioaugmented with 3.9 × 1013 DHC. Groundwater monitoring was performed to evaluate DHC growth and migration, dechlorination rates, and aquifer geochemistry. The loop inoculated with 3.9 × 1012 DHC showed slower dechlorination rates and DHC migration/growth compared with the other loops. This relatively poor performance was attributed to low pH conditions. Results for the loops inoculated with 3.9 × 1011 and 3.9 × 1013 DHC showed similar timeframes for dechlorination, as evaluated at a monitoring well approximately 10 feet downgradient of the DHC injection well. Application of a recently developed one‐dimensional bioaugmentation fate and transport screening model provided a reasonable prediction of the data in these two loops. Overall, these results suggest that increasing bioaugmentation dosage does not necessarily result in decreased dechlorination timeframes in the field. The ability to predict results suggests that modeling potentially can serve as an effective tool for determining bioaugmentation dosage and predicting overall remedial timeframes.

Rapid cooling triggers forisome dispersion just before phloem transport stops

Phloem transport stops transiently within dicot stems that are cooled rapidly, but the cause remains unknown. Now it is known that (1) rapid cooling depolarizes cell membranes giving a transient increase in cytoplasmic Ca(2+), and (2) a rise of free calcium triggers dispersion of forisomes, which then occlude sieve elements (SEs) of fabacean plants. Therefore, we compared the effects of rapid chilling on SE electrophysiology, phloem transport and forisomes in Vicia faba. Forisomes dispersed after rapid cooling with a delay that was longer for slower cooling rates. Phloem transport stopped about 20 s after forisome dispersion, and then transport resumed and forisomes re-condensed within similar time frames. Transport interruption and forisome dispersion showed parallel behaviour--a cooling rate-dependent response, transience and desensitization. Chilling induced both a fast and a slow depolarization of SE membranes, the electrical signature suggesting strongly that the cause of forisome dispersion was the transient promotion of SE free calcium. This apparent block of SEs by dispersed forisomes may be assisted by other Ca(2+)-dependent sealing proteins that are present in all dicots.

Do atmospheric pressure changes influence seizure occurrence in the epilepsy monitoring unit?

In a prior study of epilepsy and atmospheric pressure, we were able to show a small association between changes in atmospheric pressure and increased seizure frequency in consecutive patients with epilepsy undergoing video telemetry. In this study, we used a larger data set of similar patients undergoing telemetry at another Seattle institution, and examined the possible impact of atmospheric pressure (AP) changes on seizure onset in subtypes of seizures (focal, generalized, and nonepileptic). Comparisons were made between AP score at time of seizure onset and AP score at selected time ranges prior to the event (hour of seizure and 3, 6, and 24 hours prior) and a random sample of AP scores collected over similar time frames using nonparametric testing with correction for multiple comparisons. We could find no evidence to suggest atmospheric pressure changes made seizure occurrence more likely in any of the seizure groups across any of the time periods.

The use of tablet PCs to access an electronic portfolio in the clinical setting: A pilot study using undergraduate nursing students

In 2006, a digitalised clinical portfolio was introduced into an undergraduate nursing program. The use of a tablet personal computer (PC) with wireless broadband access could overcome issues around computer access in the clinical setting enhancing authenticity and timeliness of assessment. In July 2007, a Hewlett-Packard TC 4400 tablet PC was issued to three participating students. A focus group utilising a semi-structured interview and a survey collected data from the students at the end of the trial to determine the effectiveness of the strategy. Participants used tablet PCs to access their portfolios. However, lack of space, busy wards and concerns about the security of the PCs limited their use in the clinical setting. The majority of their journal entries were made at home and within similar time frames to those prior to access to tablet PCs. Participants also used the PCs to provide education to other students and staff but were reluctant to use them in front of patients. Barriers limiting the use of tablet PCs in the clinical setting may be overcome with greater proficiency in their utility and increased portability of the technology. Tablet PCs offer advantages related to and beyond portfolio use in the clinical setting.

The Many “Small COPDs”: COPD Should Be an Orphan Disease

The Many “Small COPDs”: COPD Should Be an Orphan Disease

Has enhanced folate status during pregnancy altered natural selection and possibly Autism prevalence? A closer look at a possible link

The inverse association between maternal folate status and incidence of infants born with neural tube defects (NTD's) was recognized over twenty years ago and led the US health agencies in the early 1990s to recommend that women of childbearing age consume 400 microg of folic acid each day. The FDA followed by mandating that certain foods be fortified with folic acid and this has resulted in a significant enhancement of maternal folate status to levels that are often difficult to otherwise achieve naturally. At least one study indicates that this has decreased the incidence of NTD's. However, this same time period directly coincides with what many feel is the apparent beginning and continuous increase in the prevalence of Autism and related Autism Spectrum Disorders (ASD's) in the US. Are these similar time frames of changes in maternal folate status and possible Autism prevalence a random event or has improved maternal (and fetal) folate status during pregnancy played a role? It is not only plausible but highly likely. A particular polymorphic form to a key enzyme required to activate folate for methylation in neurodevelopment, 5-methylenetetrahydrofolate reductase (MTHFR), demonstrates reduced activity under low or normal folate levels but normal activity under conditions of higher folate nutritional status. A consequence of the presence of the polymorphic form of this enzyme during normal or reduced folate status are higher plasma homocysteine levels than noncarriers and the combination of these factors have been shown in several studies to result in an increase rate of miscarriage via thrombotic events. However, the incidence of hyperhomocysteinemia in the presence of the polymorphism is reduced under the common condition of enhanced folate status and thereby masks the latent adverse effects of the presence of this enzyme form during pregnancy. Of great importance is that this polymorphism, although common in the normal population, is found in significantly higher frequency in Autisic individuals. It is hypothesized here that the enhancement of maternal folate status before and during pregnancy in the last 15 years has altered natural selection by increasing survival rates during pregnancy of infants possessing the MTHFR C677T polymorphism, via reduction in hyperhomocysteinemia associated with this genotype and thereby miscarriage rates. This also points directly to an increased rate of births of infants with higher postnatal requirements for folic acid needed for normal methylation during this critical neurodevelopmental period. If these numbers have increased then so have the absolute number of infants that after birth fail to maintain the higher folate status experienced in utero thus leading to an increased number of cases of developmental disorders such as Autism. Detection of the C677T polymorphism as well as other methionine cycle enzymes related to folate metabolism and methylation at birth as part of newborn screening programs could determine which newborns need be monitored and maintained on diets or supplements that ensure adequate folate status during this critical postnatal neurodevelopment period.

Psychosis and Place

One important line of epidemiologic inquiry implicating social context in the etiology of psychosis is the examination of spatial variation in the distribution of psychotic illness. The authors conducted a systematic review of evidence from urbanicity and neighborhood studies regarding spatial variation in the incidence of psychosis in developed countries since 1950. A total of 44 studies (20 of urbanicity and 24 of neighborhood) were culled from three databases with similar time frames: Medline (1950-2007), PsychInfo (1950-2007), and Sociological Abstracts (1952-2007). With a special emphasis on social factors potentially relevant to etiology, the authors elucidated contributions, limitations, and issues related to study design, measurement, and theory. Evidence from both arenas supports a possible etiologic role for social context. Studies of urbanicity indicate that early-life exposure may be important; dose-response relations, spatial patterning of schizophrenia, and interactions with other factors may exist. Neighborhood studies indicate heterogeneity in rates, hint at spatial patterning of schizophrenia, and offer intriguing evidence implying more proximal social (as opposed to physical) exposures. The authors encourage the exploration of social pathways engaging theory, methodological advances, and the life-course perspective. They also propose a conceptual shift from studies of spatial variation in outcomes to research addressing the etiologic effect of exposures shaped by place as a reservoir of risk or resilience.

Benefits of the NEC ECC form of contract: A New Zealand case study

This paper examines by means of a case study the effectiveness of the project and process method detailed in the NEC Engineering and Construction Contract (ECC), as developed and published by the Institute of Civil Engineers (ICE), and makes recommendations regarding its future use. The performance of the ECC with that of a conventional form of contract delivered by two separate contractors to the same employer on the same site in similar timeframes in New Zealand provided a unique opportunity for comparison. The objective was to determine if the benefits claimed by the proponents of the NEC ECC were realised, to understand the factors which need to be considered to ensure successful use of this form of contract and to understand if any changes are needed to make the contract more effective in the NZ environment. Qualitative data were gathered by way of a series of semi-structured interviews with the project management teams of the employer and with both contractors, supplemented by secondary quantitative data extracted from project records. It is concluded that use of ECC does deliver business benefits. Minor changes are recommended for alignment with NZ statutes. It is considered that the findings will be of interest to project managers for larger and complex engineering and construction projects in any country.

Reaching a consensus on management practices and vaccine development targets for mitigation of infectious diarrhoea among deployed US military forces

This study is part of a research effort to identify and quantify factors related to the cost-effectiveness of a vaccine acquisition strategy to reduce the burden of infectious diarrhoea on US military personnel deployed overseas. Where evidence is lacking in the scientific literature, or considerable uncertainty exists, it is often necessary to develop best estimates with ranges of certainty. To this end, a modified 'Delphi' survey technique to obtain the best estimates for uncertain parameters including clinical care-seeking behaviour for acute diarrhoea, routine diarrhoea management in a deployed setting, and vaccine development time frames and costs were developed from a diverse panel of experts. The study was conducted in three survey iterations. During each iteration, participants were contacted and given 2-3 weeks to complete a web-based survey designed to ascertain estimates, ranges of variability, and level of certainty for these estimates. In all, 25 of 43 solicited experts agreed to participate in the study. These included three (12%) experts who identified themselves primarily as being currently involved in Vaccine Industry, six (24%) Academic/Military Diarrheal Vaccine Development, five (20%) Military Product Acquisition, five (20%) Military Preventive Medicine, two (8%) Tropical/Travel Medicine and four (16%) Military Clinical Infectious Disease. Management practices in deployed military populations (for both provider and self-treatment) were consistent with recently published literature. Similar target time frames for vaccine licensure were established for Enterotoxigenic E. coli, Campylobacter, Shigella and Norovirus of around 9-11 years. Targets for vaccine efficacy appear to be lower than currently licensed travel vaccines (60-80%), and there was consensus on more conservative adverse event rates. These data should prove useful to researchers and policy makers working in the area of vaccine acquisition for the US military and provide continued information on the gap in optimal travellers' diarrhoea management practices in a deployed setting.

Growth chart curves do not describe individual growth biology

Growth reference tables present statistical distributions of size for age of individuals within a sample or population. As summaries of phenotypic variability at the group level, they document that individuals grow by different rates during similar time frames. The data are commonly fitted by mathematical functions to produce the convex curves of percentile distributions useful for infant and childhood growth monitoring. In this form, the growth chart appears to be a frame of reference for judging how well an individual infant/child is progressing through time by comparison with peers across ages. This has led to the assumption that individuals should track in these channels during growth. The interpolated lines between the statistical distributions of size for age at the level of the population do not, however, represent how individuals grow. Growing is an individual process characterized by nonlinear episodic saltatory increments that result in shifting size relationships among similarly aged peers over short time intervals. Data from a prospective, longitudinal study of infants illustrate the poor performance of growth chart curves as representations of individual growth. Clarification of the paradigms supporting perceptions of normal growth patterns is useful both practically and theoretically: growth chart patterns have important clinical sequelae when this informs feeding recommendations. Further characterization of individual growth patterns will contribute to increased understanding of both individual growth biology and the nature of adaptability.

Growth rate of Holocene reefal microbialites ? implications for use as environmental proxies, Heron Reef southern Great Barrier Reef

Microbialites are important constituents of reefrock in modern coral reefs, and they have proven to be reliable proxies for some aspects of seawater geochemistry. We used radiocarbon dating to evaluate their potential use as environmental archives by establishing their growth rates and temporal relationship with associated coral-algal communities. At Heron Reef, southern Great Barrier Reef, microbialites occupy ~7 % of framework volume, having formed in low-light settings in framework cavities within two metres below the reef flat. Microbialite growth generally was initiated within a few 100?s of years of the death of the surface-dwelling coral or clam substrates upon which they grew after those substrates had been incorporated into the framework by successive framework growth. Microbialites accreted at a mean rate of 2.9 mm/100 yrs and grew for only a few 100?s of years, presumably while conditions were optimal. Hence, microbialites represent ecological factors in reef growth, operating over similar time frames to associated coral-algal communities, but offset in time by as much as hundreds of years, compared to immediately adjacent skeletal framework. Therefore, microbialites can serve as proxies for marine geochemistry over averaged century-scale time frames, but they lack the temporal resolution afforded by, for example, scleractinian corals.

End‐user requesting – trail‐blazing, Kiwi style

PurposeEnd‐user requesting in New Zealand remains a relatively new phenomenon. The National Library of New Zealand has conducted two separate pilot projects with different institutions. This paper aims to consider the differences between the two projects and looks at the trends that emerged.Design/methodology/approachThe pilot projects occurred over similar timeframes, 12 months apart. Each used a different interface from which end‐users submitted their requests. The projects aimed to test workflow processes and ascertain the impacts for end‐users and library staff. System impacts and maintenance requirements, how the results would feed into best practice guidelines, and recommend future developments were also considered.FindingsThis paper details the different user responses elicited during the evaluation processes. A large proportion of end‐users in both projects confirmed that they would use this method of request creation again. The results confirm that end‐user requesting does work in a utility environment.Practical implicationsBoth projects continue in production with differing levels of involvement. The Lincoln University project continues following a redevelopment of the request screens based on what end‐users identified as important to them. The Landcare Research project continues with a more low key approach as the National Library of New Zealand considers the future developments required to enhance the end‐user experience and product up‐take in New Zealand.Originality/valueThis paper is of value to interloan librarians and especially those in an academic environment. It provides a compact case study where a national electronic utility provides the main platform for interlending and document supply in one country.

Trends in numbers and survival of Black-browed (Thalassarche melanophrys) and Grey-headed (T. chrysostoma) Albatrosses breeding on Macquarie Island

Black-browed (Thalassarche melanophrys) and Grey-headed (T. chrysostoma) Albatrosses are globally threatened seabirds that breed on remote subantarctic islands. Population trends of Black-browed and Grey-headed Albatrosses breeding on Macquarie Island were described using historical data combined with data from a more intensive 10-year monitoring program. Survival estimates were also calculated for both species over similar time frames. Breeding numbers and survival rates of Black-browed and Grey-headed Albatrosses appear to have remained stable since the mid-1970s. There was no conclusive evidence of survival varying over time and it is unlikely that mortality owing to fisheries’ activities has had a significant impact on these populations. This is in contrast to most other subantarctic populations of these species and may be attributed to their foraging ranges not overlapping significantly with areas of high fishing effort. However, both species forage in areas of new and expanding legal and illegal fishery operations. Owing to their extremely small size, these populations remain chronically vulnerable to any elevated levels of mortality.