bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capacity, consent, and selection bias in a study of delirium
Authors: Adamis D , Martin F C , Treloar A , Macdonald A J D 
Published: February 2005

Objectives:To investigate whether different methods of obtaining informed consent affected recruitment to a study of delirium in older, medically ill hospital inpatients.Design:Open randomised study.Setting:Acute medical service for older people in an inner city teaching hospital.Participants:Patients 70 years or older admitted to the unit within three days of hospital admission randomised into two groups.Intervention:Attempted recruitment of subjects to a study of the natural history of delirium. This was done by either (a) a formal test of capacity, followed by either a request for consent or an attempt at obtaining assent from a proxy, or (b) a combined informal capacity/consent process.Main outcome measures:Prevalence and severity of delirium, and, as case mix measures, length of hospital stay and destination on discharge.Results:Recruitment of subjects through establishing formal capacity and then informed consent was less successful (43.9%v74% of those approached) and, compared with those recruited through the usual combined capacity/consent approach, yielded a sample with less cognitive impairment, lower severity of delirium, lower probability of case note diagnosis of delirium and lower rate of entering a care home.Conclusions:Methods of obtaining informed consent may significantly influence the case mix of subjects recruited to a study of delirium. Stringent testing of capacity may exclude patients with delirium from studies, thus rendering findings less generalisable. A different method is necessary to achieve an ethical balance between respecting autonomy through obtaining adequate informed consent and avoiding sample bias.
Physicians’ evaluations of patients’ decisions to refuse oncological treatment
Authors: van Kleffens T , van Leeuwen E 
Published: February 2005

Objective:To gain insight into the standards of rationality that physicians use when evaluating patients’ treatment refusals.Design of the study:Qualitative design with indepth interviews.Participants:The study sample included 30 patients with cancer and 16 physicians (oncologists and general practitioners). All patients had refused a recommended oncological treatment.Results:Patients base their treatment refusals mainly on personal values and/or experience. Physicians mainly emphasise the medical perspective when evaluating patients’ treatment refusals. From a medical perspective, a patient’s treatment refusal based on personal values and experience is generally evaluated as irrational and difficult to accept, especially when it concerns a curative treatment. Physicians have a different attitude towards non-curative treatments and have less difficulty accepting a patient’s refusal of these treatments. Thus, an important factor in the physician’s evaluation of a treatment refusal is whether the treatment refused is curative or non-curative.Conclusion:Physicians mainly use goal oriented and patients mainly value oriented rationality, but in the case of non-curative treatment refusal, physicians give more emphasis to value oriented rationality. A consensus between the value oriented approaches of patient and physician may then emerge, leading to the patient’s decision being understood and accepted by the physician. The physician’s acceptance is crucial to his or her attitude towards the patient. It contributes to the patient’s feeling free to decide, and being understood and respected, and thus to a better physician–patient relationship.
North Atlantic Winter SLP Anomalies Based on the Autumn ENSO State
Authors: Pozo-Vázquez D. , Gámiz-Fortis S. R. , Tovar-Pescador J. , Esteban-Parra M. J. , Castro-DÍez Y. 
Published: February 2005

Abstract
The winter sea level pressure (SLP) anomalies in the Northern Hemisphere have been analyzed over the period 1873–2000 based on the ENSO state during the previous autumn. First, a set of extreme cold and warm ENSO events and periods that may be regarded as normal is selected using the SST data of the Niño-3 region. This selection is carried out for autumn and with the constraint that the ENSO event is well developed. For the winters following these selected autumn events, composites of Northern Hemisphere SLP anomalies have been obtained and compared to each other. A study of the consistency among events of the relationship between ENSO and SLP anomalies was also carried out. Results show the preference for a positive NAO-like SLP anomaly pattern in the North Atlantic region during the winters following autumns of strong cold ENSO events and, thus, suggest the existence of a potential source of predictability for the North Atlantic climate. An additional analysis of the winter North Atlantic Oscillation (NAO) index confirms this finding. The possible physical basis of this source of predictability for the North Atlantic climate is discussed.
Importance of the Salinity Barrier Layer for the Buildup of El Niño
Authors: Maes Christophe , Picaut Joël , Belamari Sophie 
Published: February 2005

Abstract
Several studies using sea level observations and coupled models have shown that heat buildup in the western equatorial Pacific is a necessary condition for a major El Niño to develop. However, none of these studies has considered the potential influence of the vertical salinity stratification on the heat buildup and thus on El Niño. In the warm pool, this stratification results in the presence of a barrier layer that controls the base of the ocean mixed layer. Analyses of in situ and TOPEX/Poseidon data, associated with indirect estimates of the vertical salinity stratification, reveal the concomitant presence of heat buildup and a significant barrier layer in the western equatorial Pacific. This relationship occurs during periods of about one year prior to the mature phase of El Niño events over the period 1993–2002. Analyses from a coupled ocean–atmosphere general circulation model suggest that this relationship is statistically robust. The ability of the coupled model to reproduce a realistic El Niño together with heat buildup, westerly wind bursts, and a salinity barrier layer suggests further investigations of the nature of this relationship. In order to remove the barrier layer, modifications to the vertical ocean mixing scheme are applied in the equatorial warm pool and during the 1-yr period of the heat buildup. At the bottom of the ocean mixed layer, the heat buildup is locally attenuated, as expected from switching on the entrainment cooling. At the surface, the coupled response over the warm pool increases the fetch of westerly winds and favors the displacement of the atmospheric deep convection toward the central equatorial Pacific. These westerly winds generate a series of downwelling equatorial Kelvin waves whose associated eastward currents drain the heat buildup toward the eastern Pacific Ocean. The overall reduction of the heat buildup before the onset of El Niño results in the failure of El Niño. These coupled model analyses confirm that the buildup is a necessary condition for El Niño development and show that the barrier layer in the western equatorial Pacific is important for maintaining the heat buildup.
The Semidirect Aerosol Effect: Comparison of a Single-Column Model with Large Eddy Simulation for Marine Stratocumulus
Authors: Johnson B. T. 
Published: February 2005

Abstract
Large eddy simulations (LES) show that the presence of black carbon aerosols in marine boundary layers leads to a marked reduction of stratocumulus liquid water path (LWP) by heating the cloud layer and suppressing convection in the boundary layer. The reduction of LWP leads to a positive radiative forcing known as the semidirect effect. In this study LES results are compared with results from the National Center for Atmospheric Research (NCAR) Single-Column Community Climate Model (SCCM). The SCCM represents clouds and boundary layer processes through simple parameterization schemes that are typical of general circulation models (GCMs) used for climate experiments. In a case study in which black carbon aerosols were introduced in a stratocumulus-capped boundary layer the SCCM gave a semidirect aerosol radiative forcing that was a factor of 5 smaller than the value obtained from the LES. The cloud response to absorbing aerosols was underestimated because of the way that cloud cover and cloud radiative properties were parameterized in the SCCM. Furthermore, the SCCM gave a poor representation of processes, such as entrainment and boundary layer decoupling, that are crucial to determining stratocumulus LWP. This study shows that GCMs may not include all the physical processes necessary to adequately capture the semidirect aerosol effect. Previous GCM estimates of the semidirect effect that have incorporated simple cloud parameterizations should, therefore, be treated with some caution.
The Variability of Seasonality
Authors: Pezzulli S. , Stephenson D. B. , Hannachi A. 
Published: February 2005

AbstractSeasons are the complex nonlinear response of the physical climate system to regular annual solar forcing. There is no a priori reason why they should remain fixed/invariant from year to year, as is often assumed in climate studies when extracting the seasonal component. The widely used econometric variant of Census Method II Seasonal Adjustment Program (X-11), which allows for year-to-year variations in seasonal shape, is shown here to have some advantages for diagnosing climate variability. The X-11 procedure is applied to the monthly mean Niño-3.4 sea surface temperature (SST) index and global gridded NCEP–NCAR reanalyses of 2-m surface air temperature. The resulting seasonal component shows statistically significant interannual variations over many parts of the globe. By taking these variations in seasonality into account, it is shown that one can define less ambiguous ENSO indices. Furthermore, using the X-11 seasonal adjustment approach, it is shown that the three cold ENSO episodes after 1998 are due to an increase in amplitude of seasonality rather than being three distinct La Niña events. Globally, variations in the seasonal component represent a substantial fraction of the year-to-year variability in monthly mean temperatures. In addition, strong teleconnections can be discerned between the magnitude of seasonal variations across the globe. It might be possible to exploit such relationships to improve the skill of seasonal climate forecasts.
Spatial and Temporal Variability of Canadian Seasonal Streamflows
Authors: Coulibaly Paulin , Burn Donald H. 
Published: February 2005

Abstract
Wavelet and cross-wavelet analysis are used to identify and describe spatial and temporal variability in Canadian seasonal streamflows, and to gain insights into the dynamical relationship between the seasonal streamflows and the dominant modes of climate variability in the Northern Hemisphere. Results from applying continuous wavelet transform to mean seasonal streamflows from 79 rivers selected from the Canadian Reference Hydrometric Basin Network (RHBN) reveal striking climate-related features before and after the 1950s. The span of available observations, 1911–99, allows for depicting variance and covariance for periods up to 12 yr. Scale-averaged wavelet power spectra are used to simultaneously assess the temporal and spatial variability in each set of 79 seasonal streamflow time series. The most striking feature, in the 2–3-yr period and in the 3–6-yr period—the 6–12-yr period is dominated by white noise and is not considered further—is a net distinction between the timing and intensity of the temporal variability in autumn, winter, and spring–summer streamflows. It is found that the autumn season exhibits the most intense activity (or variance) in both the 2–3- and the 3–6-yr periods. The spring–summer season corresponds to the least intense activity for the 2–3-yr period, but it exhibits more activity than winter for the 3–6-yr period.
Cross-wavelet analysis is provided between the seasonal streamflows and three selected climatic indices: the Pacific–North America (PNA), the North Atlantic Oscillation (NAO), and the sea surface temperature series over the Niño-3 region (ENSO3). The wavelet cross-spectra reveal strong climate–streamflow activity (or covariance) in the 2–6-yr period starting after 1950 whatever the climatic index and the season. Prior to 1950, local and weaker 2–6-yr activity is revealed in central and western Canada essentially in winter and autumn, but overall a non-significant streamflow–climate relationship is observed prior to 1950. Correlation analysis in the 2–6-yr band between the seasonal streamflow and the selected climatic indices revealed strong positive correlations with the ENSO in the spring–summer and winter seasons for the post-1950 period for both eastern and western Canada. A similar correlation pattern is revealed in the west with the NAO, while in the east moderate negative NAO correlations are observed only in the autumn season prior to 1950. After 1950 strong NAO correlations emerge for all the seasons. The cross-wavelet spectra and the correlation analysis in the 2–6-yr band suggest the presence of a change point around 1950 in the east and west seasonal streamflows.
Gridded Area-Averaged Daily Precipitation via Conditional Interpolation
Authors: Hewitson B. C. , Crane R. G. 
Published: February 2005

Abstract
A growing need for gridded observational datasets of area-average values to support research, specifically in relation to climate models, raises questions about the adequacy of traditional interpolation techniques. Conventional interpolation techniques (particularly for precipitation) suffer from not recognizing the changing spatial representivity of stations as a function of the driving synoptic state, nor the bounded nature of the precipitation field—that the precipitation field is spatially discontinuous. Further, many interpolation techniques explicitly estimate new point location values, and do not directly address the need arising from climate modeling for area-average values.
A new procedure, termed conditional interpolation, is presented to estimate daily gridded area-average precipitation from station observations. The approach explicitly recognizes that the point observations represent a mixture of synoptic forcing shared in common with surrounding stations, and a response that is unique to the station. Consequently the spatial representivity of a station is conditional on the synoptic forcing and is a function of the radial direction from the station. The conditional interpolation accommodates this in a two-stage process through conditioning the interpolation parameters as a function of the synoptic state. First, the spatial pattern of wet/dry conditions is estimated, following which the magnitude of the precipitation is derived for those locations determined as “wet.” In a test based on a high-resolution dataset for South Africa the conditional interpolation is very effective in defining the spatial extent of the precipitation field. It then derives gridded values that are representative of the area average. In comparison, both these characteristics appear to be significantly overestimated by one of the commonly used interpolation schemes (Cressman interpolation). Overall the interpolation conditioned by the synoptic state appears to better estimate realistic gridded area-average values.
Comparison of TRMM Precipitation Retrievals with Rain Gauge Data from Ocean Buoys
Authors: Bowman Kenneth P. 
Published: February 2005

Abstract
Four years of precipitation retrievals from the Tropical Rainfall Measuring Mission (TRMM) satellite are compared with data from 25 surface rain gauges on the National Oceanic and Atmospheric Administration/Pacific Marine Environment Laboratory (NOAA/PMEL) Tropical Atmosphere–Ocean Array/Triangle Trans-Ocean Buoy Network TAO/TRITON buoy array in the tropical Pacific. The buoy gauges have a significant advantage over island-based gauges for this purpose because they represent open-ocean conditions and are not affected by island orography or surface heating. Because precipitation is correlated with itself in both space and time, comparisons between the two data sources can be improved by properly averaging in space and/or time. When comparing gauges with individual satellite overpasses, the optimal averaging time for the gauge (centered on the satellite overpass time) depends on the area over which the satellite data are averaged. For 1° × 1° areas there is a broad maximum in the correlation for gauge-averaging periods of ∼2 to 10 h. Maximum correlations r are in the range 0.6 to 0.7. For larger satellite averaging areas, correlations with the gauges are smaller (because a single gauge becomes less representative of the precipitation in the box) and the optimum gauge-averaging time is longer. For individual satellite overpasses averaged over a 1° × 1° box, the relative rms difference with respect to a rain gauge centered in the box is ∼200% to 300%. For 32-day time means over 1° × 1° boxes, the relative rms difference between the satellite data and a gauge is in the range of 40% to 70%. The bias between the gauges and the satellite retrievals is estimated by correlating the long-term time-mean precipitation estimates across the set of gauges. The TRMM Microwave Imager (TMI) gives an r2 of 0.97 and a slope of 0.970, indicating very little bias with respect to the gauges. For the Precipitation Radar (PR) the comparable numbers are 0.92 and 0.699. The results of this study are consistent with the sampling error estimates from the statistical model of Bell and Kundu.
Azithromycin in bronchiolitis obliterans complicating bone marrow transplantation: a preliminary study
Authors: Khalid M. , Al Saghir A. , Saleemi S. , Al Dammas S. , Zeitouni M. , Al Mobeireek A. , Chaudhry N. , Sahovic E. 
Published: February 2005

Bronchiolitis obliterans (BO) is a serious noninfectious pulmonary complication following allogeneic bone marrow transplantation (BMT). Azithromycin, a macrolide antibiotic, may have a beneficial effect in BO through its anti-inflammatory effect. The aim of the current study was to investigate the potential effect of azithromycin on pulmonary function tests (PFTs) in BO complicating BMT.PFTs of 153 post-BMT patients were followed; eight patients out of 153 (12%) developed obstructive airway disease on their PFTs, along with characteristic findings of BO on high-resolution computed tomography of the chest. These patients were given azithromycin 500 mgq.d.for 3 days, followed by 250 mg three times a week for 12 weeks.Clinically significant improvements were achieved both in forced vital capacity, where the mean (95% confidence interval) increase reported was 410 mL (0.16–0.65), which was an average improvement of 21.57%, and in the forced expiratory volume in one second, where the mean increase noticed was 280 mL (0.10–0.44), which was an average improvement of 20.58%.In conclusion, the potential role of azithromycin in the treatment of bronchiolitis obliterans is intriguing and it warrants further testing.
Determinants of airway responsiveness to histamine in children
Authors: Turner S. W. , Palmer L. J. , Rye P. J. , Gibson N. A. , Young S. , Goldblatt J. , Landau L. I. , Le Souëf P. N. 
Published: February 2005

Increased airway responsiveness (AR) is associated with asthma, but not all individuals with increased AR have asthma. The aim of this study was to identify factors, other than physician-diagnosed asthma (PDA), which are associated with increased AR.In a longitudinal study, data were collected on atopy and lower respiratory tract illness (LRTI) in infancy, and AR (expressed as dose–response slope (DRS)), atopy, tobacco-smoke exposure and PDA in childhood.At age 6 yrs, DRS was assessed in 102 children, of whom 22 (22%) had PDA; the corresponding figures at 11 yrs of age were 176 and 29 (15%). At age 6 yrs, DRS was significantly associated with PDA, current atopy and parental smoking (n = 83). At age 11 yrs, DRS was significantly associated with PDA, current atopy and LRTI in the first six months (n = 75). There was a significant positive interaction between atopy at age 12 months and PDA age 11 yrs.In conclusion, these data suggest that factors other than asthma or atopy may determine the level of airway responsiveness in children. In children with asthma, airway responsiveness may be influenced by the early onset of atopy. The current findings may explain the inconsistent relationship between airway responsiveness and asthma.
All-cause mortality in males with sleep apnoea syndrome: declining mortality rates with age
Authors: Lavie P. , Lavie L. , Herer P. 
Published: February 2005

The objective of this study was to assess whether an increasing severity of sleep apnoea is associated with increased all-cause mortality hazards and to assess whether the syndrome is associated with excess mortality, in comparison with the general population.Participants included 14,589 adult males, aged 20–93 yrs, referred to the sleep clinics with suspected sleep apnoea or diagnosed with sleep apnoea.Altogether, 372 deaths were recorded after a median follow-up of 4.6 yrs. The crude all-cause mortality rate was 5.55/1,000 patient yrs, increasing with apnoea severity. Cox proportional analysis revealed that both respiratory disturbance index (RDI) and body mass index significantly influenced all-cause mortality hazard but there was no interaction between them. Males with respiratory disturbance index >30 had a significantly higher mortality hazard rate than the reference group of males with RDI ≤10. Comparing mortality rates of males with moderate/severe sleep apnoea to the general population revealed that only males aged <50 yrs showed an excess mortality rate.The hazard of mortality in sleep apnoea increases with apnoea severity as indexed by respiratory disturbance index. Moderate and severe levels of sleep apnoea are moderately associated with an increased risk of all-cause mortality, in comparison with the general population, particularly in males aged <50 yrs. The lack of information about possible confounders and treatment effects should be taken into consideration in the interpretation of these results.
Skeletal muscle microbiopsy: a validation study of a minimally invasive technique
Authors: Hayot M. , Michaud A. , Koechlin C. , Caron M-A. , LeBlanc P. , Préfaut C. , Maltais F. 
Published: February 2005

The study of the peripheral skeletal muscle function in patients with chronic obstructive pulmonary disease (COPD) is of growing interest, but often requires biopsies, usually with the Bergström technique. The current study was designed to test the validity of a minimally invasive technique: the microbiopsy.In 17 patients with COPD and four normal subjects, two specimens of the vastus lateralis were taken percutaneously under local anaesthesia, one with a 16-gauge needle (microbiopsy) and the other with the Bergström needle. The enzymatic activity of citrate synthase (CS) and phosphofructokinase (PFK), and the myosin heavy chain (MyoHC) composition were measured for both techniques.The subjects reported no pain or much less with the microbiopsy compared with the Bergström biopsy. The microbiopsy sample weight reached 55±17 mg. The two techniques showed excellent agreement for CS activity and MyoHC composition. The PFK activity did not differ statistically between the techniques, but the agreement was moderate. The agreement between both biopsy techniques was stable over time. The median (range) fibre number within the microbiopsy specimens was 144 (38–286).In conclusion, the current study shows the feasibility and validity of a minimally invasive muscle biopsy technique that appears more comfortable for subjects, compared with the Bergström technique.