bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strouhal numbers and optimization of swimming by odontocete cetaceans
Authors: Rohr Jim J. , Fish Frank E. 
Published: April 2004

SUMMARY
Swimming efficiencies of fish and cetaceans have been related to a certain synchrony between stroke cycle frequency, peak-to-peak tail/fluke amplitude and mean swimming speed. These kinematic parameters form a non-dimensional wake parameter, referred to as a Strouhal number, which for the range between 0.20 and 0.40 has been associated with enhanced swimming efficiency for fish and cetaceans. Yet to date there has been no direct experimental substantiation of what Strouhal numbers are preferred by swimming cetaceans. To address this lack of data, a total of 248 Strouhal numbers were calculated for the captive odontocete cetaceans Tursiops truncatus, Pseudorca crassidens, Orcinus orca, Globicephala melaena, Lagenorhynchus obliquidens and Stenella frontalis. Although the average Strouhal number calculated for each species is within the accepted range, considerable scatter is found in the data both within species and among individuals. A greater proportion of Strouhal values occur between 0.20 and 0.30 (74%) than the 0.25–0.35(55%) range predicted for maximum swimming efficiency. Within 0.05 Strouhal increments, the greatest number of Strouhal values was found between 0.225 and 0.275 (44%). Where propulsive efficiency data were available (Tursiops truncatus, Pseudorca crassidens, Orcinus orca), peak swimming efficiency corresponded to this same Strouhal range. The odontocete cetacean data show that, besides being generally limited to a range of Strouhal numbers between 0.20 and 0.40, the kinematic parameters comprising the Strouhal number provide additional constraints. Fluke-beat frequency normalized by the ratio of swimming speed to body length was generally restricted from 1 to 2, whereas peak-to-peak fluke amplitude normalized by body length occurred predominantly between 0.15 and 0.25. The results indicate that the kinematics of the propulsive flukes of odontocete cetaceans are not solely dependent on Strouhal number, and the Strouhal number range for odontocete cetaceans occurs at slightly (∼20%) lower values than previously predicted for maximum swimming efficiency.
Visual acuity of fly photoreceptors in natural conditions - dependence on UV sensitizing pigment and light-controlling pupil
Authors: Stavenga Doekele G. 
Published: April 2004

SUMMARY
The effect of the UV-absorbing sensitizing pigment of fly photoreceptors on absolute, spectral and angular sensitivity was investigated with a wave-optics model for the facet lens-rhabdomere system. When sky light was used as a UV-rich light source, one sensitizing pigment molecule per rhodopsin increased the photoreceptor absorption by 14-18% with respect to pure rhodopsin, whilst two sensitizing pigment molecules per rhodopsin increased the absorption by 20-27%. Upon light adaptation, when the pupil mechanism is activated,photoreceptor absorption decreases; in the housefly, Musca, by up to 6-fold. The fully light-adapted pupil diminishes the photoreceptor's acceptance angle by a factor of ∼0.6 due to selective absorption of higher order waveguide modes. Spatial acuity of dark-adapted photoreceptors is more or less constant throughout the visual wavelength range, including the UV,because the waveguide optics of the rhabdomere compromise acuity least at wavelengths most limited by diffraction of the facet lens. Diffraction is not the general limiting factor causative for UV sensitivity of insect eyes. Visual acuity is governed by diffraction only with a fully light-adapted pupil, which absorbs higher waveguide modes. Closure of the blue-absorbing pupil causes a UV-peaking spectral sensitivity of fly photoreceptors. The sensitizing pigment does not play an appreciable role in modifying spatial acuity, neither in the dark- nor the light-adapted state, due to the dominant contribution of green light in natural light sources.
Expression and polarity reversal of V-type H+-ATPase during the mineralization–demineralization cycle in Porcellio scabersternal epithelial cells
Authors: Ziegler Andreas , Weihrauch Dirk , Hagedorn Monica , Towle David W. , Bleher Reiner 
Published: April 2004

SUMMARY
The formation and resorption of CaCO3 by epithelial cell layers require epithelial transport of protons. We used the anterior sternal epithelium of the terrestrial isopod Porcellio scaber as a model to study the expression pattern and immunolocalization of a V-type H+-ATPase during the mineralization and demineralization of intermittent CaCO3 deposits. Semiquantitative RT-PCR revealed that the expression of the V-type H+-ATPase increases from non Ca2+-transporting control stages to the stages of CaCO3deposit formation and resorption. In the Ca2+-transporting stages the expression was larger in the anterior than in the posterior sternal epithelium, which is not involved in deposit formation and transports just moderate amounts of CaCO3. Immunocytochemistry of the B-subunit of the V-type H+-ATPase in the anterior sternal epithelium reveals an increase in the abundance of the protein within the basolateral membrane, from undetectable to strong signals in the control stage to the stages of CaCO3 deposit formation, respectively. From the stage of CaCO3 deposit formation to that of CaCO3 resorption the signal decreased within the basolateral plasma membrane and increased within the apical plasma membrane. For the first time the results indicate a contribution of a V-type H+-ATPase to CaCO3 deposition and a reversal of its polarity from the basolateral to the apical plasma membrane compartment within the same cells.
Variation in activity rates of consultant surgeons and the influence of reward structures in the English NHS
Authors: Bloor Karen , Maynard Alan , Freemantle Nick 
Published: April 2004

Objectives: To explore variation in the National Health Service (NHS) activity rates of consultant surgeons, and examine whether activity is dependent upon the type of contract held and/or bonus payments, after accounting for age and other consultant and hospital characteristics. Methods: NHS Hospital Episode Statistics (HES) for England were used in combination with workforce data in five surgical specialties in 1998/99 and 1999/2000. Descriptive statistics were used to explore variation in activity rates. A multi-level model was used to analyse the relationship between NHS contract and bonus payments, and activity. Results: There is considerable variation in activity rates of English NHS consultant surgeons, with and without adjustment for casemix. Interquartile variation shows that the top 25% of consultants have activity rates 60 to 85% higher than the bottom 25%. A multi-level model indicates that consultant surgeons with a 'maximum part-time' contract have significantly higher activity rates than those with a full time contract (129 more finished consultant episodes (FCEs) per year, 95% CI 97-160). Consultant surgeons who hold discretionary salary points undertake significantly more activity than those without (95 FCEs, 95% CI 62-128). Those with a distinction award (a type of bonus payment) have a tendency towards higher activity rates, but this does not reach statistical significance (48 FCEs, 95% CI -4 to 103). Conclusions: 'Maximum part-time contract' status is associated with higher absolute activity rates among NHS surgeons. Rich data sources like HES merit careful exploration and increased use as an essential first step in measuring and managing variations in specialists' performance.
Use of, and attitudes to, clinical priority assessment criteria in elective surgery in New Zealand
Authors: McLeod Deborah , Morgan Sonya , McKinlay Eileen , Dew Kevin , Cumming Jackie , Dowell Anthony , Love Tom 
Published: April 2004

Objectives: To describe the ways patients access elective surgery in New Zealand, and to understand the use of, and attitudes to, clinical priority assessment criteria (CPAC) in determining access to publicly funded elective surgery. Methods: A qualitative study in selected New Zealand localities. A purposive sample of general practitioners, surgeons and administrators in publicly funded hospitals were interviewed. Data were analysed by a process of thematic analysis. Results: Sixty-five interviews were completed. General practitioners had a key role in determining which patients were seen in the public sector and, by utilising strategies to actively advocate for patients, influenced both waiting times for first assessment by surgeons and for surgery. CPAC had been developed as decision support guides with the intention that they would provide transparency and equity in determining access. However, there was variation in the way CPAC were being used both in score construction and in the influence of the score on access to surgery. The management of the hospital system also limited the extent to which CPAC could be used to prioritise patients for surgery. Conclusions: Variability in the use of CPAC tools meant that at the time of the study they did not provide a transparent and equitable method of determining access to surgery. This highlights the difficulties in developing and implementing CPAC and suggests that further development is difficult in the absence of evidence to identify patients who will benefit the most from surgery.
Counting in-hospital deaths in England: a comparison of hospital computer systems and mortuary registers
Authors: Mohammed Mohammed , Raftery James , LeatherBarrow Martin , Harley Mike , Marshall Tom 
Published: April 2004

Objectives: In-hospital death counts derived from hospital computer systems have been used in England by an independent company, 'Dr Foster', to rank the quality of care of hospitals, but the validity of the underlying data remains unclear. This study compares counts of in-hospital deaths using two different sources - the hospital computer system and the mortuary register - to determine: whether the counts of in-hospital deaths from these two sources differed; qualitative explanations for possible sources of discrepancy; the direction and magnitude of any differences; and the possible impact of any differences on the Dr Foster rankings. Methods: The four highest and the four lowest National Health Service (NHS) hospitals in the West Midlands, as ranked by Dr Foster, participated. Each hospital was asked to compare the monthly counts of in-hospital deaths from the hospital computer system and the hospital mortuary register for the fiscal year 1999/2000. Results: One hospital, with a computerised mortuary register, had identical counts of in-hospital deaths. Two hospitals reported 4-5% more deaths and four hospitals reported fewer deaths (0.4-7%) from their hospital computer system than from their mortuary register. These differences were not large enough to change their Dr Foster rankings. Wide discrepancies were noted on a monthly basis (range: -13.9% to +15.9%). Discussion: The differences between the two sources of in-hospital death counts were not large enough to influence the Dr Foster ranks but were sufficient to raise concern about the validity and completeness of mortality data in the NHS.
Comparison of Drug-Related Problems in Different Patient Groups
Authors: Viktil Kirsten K , Blix Hege S , Reikvam Aasmund , Moger Tron A , Hjemaas Bodil J , Walseth Elspeth K , Vraalsen Tine F , Pretsch Piia , Jorgensen Frank 
Published: April 2004

BACKGROUND: There is a lack of knowledge concerning how drug-related problems (DRPs) vary in different patient groups. Possible dissimilarities need to be taken into consideration when guidelines for detecting and preventing DRPs are compiled. OBJECTIVE: To characterize and compare the frequency and categories of DRPs in different groups of hospitalized patients. METHODS: Patients admitted to 4 different types of departments at 5 hospitals in Norway were included consecutively. Medical records and information acquired at multidisciplinary morning meetings were sources for assessing the patients' DRPs. RESULTS: A total of 827 patients were included. Mean age was 70.8 years, 58.6% were female, and 81% had at least one DRP. An average of 1.9, 2.0, 2.1, and 2.3 DRPs per patient were found in the departments of cardiology, geriatrics, respiratory medicine, and rheumatology, respectively. Significant differences in the type of DRPs between the patient groups were found. The most frequent DRPs and the patient group in which they most often occurred were nonoptimal dose (cardiology, respiratory, geriatric) and need for additional drug (rheumatology). CONCLUSIONS: DRPs occurred in the majority of the patients in all departments. The type of DRP differed markedly between the patient groups. Knowledge of these differences is clinically valuable by enabling us to guide efforts toward prevention of DRPs. Antithrombotic agents, loop diuretics, angiotensin-converting enzyme inhibitors, penicillins, antiinflammatory drugs, and opioid analgesics commonly caused DRPs, even in departments where knowledge of these drugs is assumed to be extensive.
Props, not pictures, are worth a thousand words: verbal accessibility of early memories under different conditions of contextual support
Authors: Bauer Patricia J. , van Abbema Dana L. , Wiebe Sandra A. , Cary Mari Strand , Phill Christina , Burch Melissa M. 
Published: April 2004

AbstractWhen they are tested nonverbally, even young children demonstrate long‐term recall. There have been few studies of whether early memories later are verbally accessible; the results of those that exist are mixed. Inconsistencies may be due to differences in the contextual cues provided at the time of recall. In two experiments, children 13–20 months were exposed to multi‐step sequences and tested for nonverbal recall after 3–6 months. At age 3 years, they were tested verbally, under varying conditions of contextual support: in the original laboratory with event‐related props versus at home with photographs of the props (Experiment 1), and at home with props (Experiment 2). Children younger than 20 months at initial experience of the events did not demonstrate verbal recall. Children who were 20 months at the initial exposure recalled verbally, as long as they had physical props as cues, regardless of whether testing took place at home or in the laboratory. This research informs the conditions under which memories from very early childhood later can be recalled verbally. Copyright © 2004 John Wiley & Sons, Ltd.
What US judges know and believe about eyewitness testimony
Authors: Wise Richard A. , Safer Martin A. 
Published: April 2004

AbstractIn a survey, 160 US judges indicated their knowledge and beliefs about eyewitness testimony. Although correct on some issues, judges were often wrong on important issues such as whether at trial eyewitness confidence is a good indicator of eyewitness accuracy, and if jurors can distinguish accurate from inaccurate witnesses. Increased knowledge was associated with: a willingness to permit legal safeguards, including expert testimony at trial; a belief that jurors have limited knowledge of eyewitness factors; a reluctance to convict defendants solely from eyewitness testimony; a more accurate estimate of the extent to which wrongful convictions result from eyewitness error; and a belief that judges need more eyewitness training. Additional training about factors and procedures that affect eyewitness accuracy may help judges reduce the number of wrongful convictions. Copyright © 2004 John Wiley & Sons, Ltd.
Memory for common objects: brief intentional study is sufficient to overcome poor recall of US coin features
Authors: Marmie William R. , Healy Alice F. 
Published: April 2004

AbstractPrior studies have explained the very poor recall for the features of a coin in terms of visual characteristics. Two experiments compared incidental exposure and intentional study of US coins on recall of their features. In Experiment 1, recall performance for a rarely seen Mercury dime after a 1‐min study period was better than that for an unstudied penny, even when the test on the dime was delayed 1 week. In Experiment 2, participants studied the dime for 15, 30, 45, or 60 s. Recall of the dime was greater than that of the unstudied penny even with the shortest study interval. Thus, a high level of recall of a coin's features can be obtained with brief intentional study, and that level can be maintained across a long delay interval. These findings suggest that poor retention of coin features is due to incidental exposure rather than to visual characteristics. Copyright © 2004 John Wiley & Sons, Ltd.
Fabrication deflation? The mixed effects of lying on memory
Authors: Polage Danielle C. 
Published: April 2004

AbstractThis study explored what happens when participants lie in order to convince others that false stories are true. Participants' memories were assessed by comparing their likelihood ratings for the events before and after lying about them. Results showed that most participants rated the events as less likely to have happened after lying about them. Therefore, the most common result of lying seems to be a strengthening of, not a distortion of, the truth. This decrease in likelihood rating for the statement lied about is termed ‘fabrication deflation’. In both studies, however, there were 10–16% of the participants who indicated maximum belief that the lie item was true. Whether this increase in likelihood rating for a lied about event is evidence of memory creation or the triggering of an actual memory is discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Sequential processing in comprehension of hierarchical graphs
Authors: Körner Christof 
Published: April 2004

AbstractHierarchical graphs represent the relationships between non‐numerical entities or concepts (like computer file systems, family trees, etc). Graph nodes represent the concepts and interconnecting lines represent the relationships. We recorded participants' eye movements while viewing such graphs to test two possible models of graph comprehension. Graph readers had to answer interpretive questions, which required comparisons between two graph nodes. One model postulates a search and a combined search‐reasoning stage of graph comprehension (two‐stage model), whereas the second model predicts three stages, two stages devoted to the search of the relevant graph nodes and a separate reasoning stage. A detailed analysis of the eye movement data provided clear support for the three‐stage model. This is in line with recent studies, which suggest that participants serialize problem solving tasks in order to minimize the overall processing load. Copyright © 2004 John Wiley & Sons, Ltd.
A Simple, Efficient and General Procedure for Acetalization of Carbonyl Compounds and Deprotection of Acetals under the Catalysis of Indium(III) Chloride
Authors: Ranu Brindaban C. , Jana Ranjan , Samanta Sampak 
Published: April 2004

AbstractIndium(III) chloride efficiently catalyzes the protection of a variety of aldehydes and ketones to their corresponding 1,3‐dioxolanes and dialkyl acetals in refluxing cyclohexane. On the other hand, deprotection of acetals is also achieved in refluxing aqueous methanol under the catalysis of indium(III) chloride.
Detailed Mechanistic Studies using in situ Spectroscopic Analysis: A Look at Little‐Known Regions of the Heck Reaction
Authors: Rothenberg Gadi , Cruz Susana C. , van Strijdonck Gino P. F. , Hoefsloot Huub C. J. 
Published: April 2004

AbstractThe mechanism of the Heck reaction using palladium complexes with large phosphoramidite ligands is investigated. The catalyst precursor is an inactive dimer that equilibrates with the active monomeric species. A series of kinetic models is introduced and compared with concentration profiles obtained from FT‐NIR spectroscopy. First, an analytical solution of the differential equations for a simplified mechanism is considered. This fits well at low conversions but deviates at higher conversions with increasing deactivation. Formation of palladium clusters and palladium black is then included, with the simplification that all the deactivation processes are represented by a single first‐order process. This results in a five‐step mechanism that describes the dimer‐monomer equilibrium, the Pd(II)/Pd(0) catalytic cycle, and the catalyst deactivation process. The model can be used to monitor the transient concentrations of the virtual Pd(0), Pd(II), and dimer catalyst species, and helps to explain the effects of water. The high resolution of the measurements and low error levels of the models render this approach a powerful tool for mechanistic studies in homogeneous catalysis.
Versatile Phosphite Ligands Based on Silsesquioxane Backbones
Authors: van der Vlugt Jarl Ivar , Ackerstaff Jens , Dijkstra Tessa W. , Mills Allison M. , Kooijman Huub , Spek Anthony L. , Meetsma Auke , Abbenhuis Hendrikus C. L. , Vogt Dieter 
Published: April 2004

AbstractSilsesquioxanes are employed as ligand backbones for the synthesis of novel phosphite compounds with 3,3′‐5,5′‐tetrakis(tert‐butyl)‐2,2′‐dioxa‐1,1′‐biphenyl substituents. Both mono‐ and bidentate phosphites are prepared in good yields. Two types of silsesquioxanes are employed as starting materials. The monophosphinite 1 and the monophosphite 2 are prepared from the thallium silsesquioxide derived from a completely condensed silsesquioxane framework (c‐C5H9)7Si7O12SiOTl. The diphosphite 3 is synthesized starting with the incompletely condensed monosilylated disilanol (c‐C5H9)7Si7O9(OSiMePh2)(OH)2. For monophosphite 2, the corresponding trans‐[PtCl2(2)] complex 4 is characterized by NMR spectroscopy as well as by X‐ray crystallography, as the first example of a completely condensed oxo‐functionalized silsesquioxane framework. The coordination of the bidentate ligand 3 towards Pd, Mo and Rh is studied, both by NMR spectroscopy as well as by X‐ray crystallography. Various modes of coordination are shown to be possible. The molecular structures for the complexes trans‐[PdCl2(3)] (5), cis‐[Mo(CO)4(3)] (6) and the dinuclear complex [{Rh(μ‐Cl)(CO)}2(κ2‐3)] (7) have been determined. In the rhodium‐catalyzed hydroformylation of 1‐octene high activities, with turnover frequencies of up to 6800 h−1, are obtained with these new nanosized phosphorus ligands.
Gold Catalysis: Mild Conditions for the Transformation of Alkynyl Epoxides to Furans
Authors: Hashmi A. Stephen K. , Sinha Pradipta 
Published: April 2004

AbstractGold(III) chloride catalyzes the isomerization of alkynyl epoxides to furans under mild conditions. Additional functional groups like hydroxy groups or aryl bromides do not need to be protected.
Effect of distribution tabs on mass transfer of artificial kidney
Authors: Ding Weiping , He Liqun , Zhao Gang , Luo Xiaodong , Zhou Min , Gao Dayong 
Published: April 2004

AbstractThe configuration of the dialysate inlet and outlet is one of the main factors that affect the mass transfer performance of the artificial kidney. The effect of the distribution tabs at the dialysate inlet and outlet on mass transfer is investigated qualitatively by means of three‐dimensional (3‐D) flow field numerical simulation. The nonporous tabs are designed to be the porous tabs. Then the variation of the artificial kidney's clearance is studied with the porous tabs' Darcy permeability decreasing from +∞ to 0. The results show that the clearance first increases slightly, and then rises sharply; after arriving at a maximum, the clearance falls sharply and then decreases steadily. From the results, the optimal Darcy permeability of the porous tabs is found, corresponding to which the maximal clearance is about 4.5% higher than the current artificial kidney's clearance under the same conditions. The results are very significant for designers to improve the artificial kidney. 2004 American Institute of Chemical Engineers AIChE J, 50: 786–790, 2004