bluuebunny/crossref_metadata_2025 huggingface dataset:
Proposals for Sample Size Calculation Programs
Authors: Heinzl H. , Benner A. , Ittrich C. , Mittlböck M.
Published: November 2007

Objectives
: Numerous sample size calculation programs are available nowadays. They include both commercial products as well as public domain and open source applications. We propose modifications for these programs in order to even better support statistical consultation during the planning stage of a two-armed clinical trial.

Methods
: Directional two-sided tests are commonly used for two-armed clinical trials. This may lead to a non-negligible Type III error risk in a severely underpowered study. In the case of a reasonably sized study the question for the so-called auxiliary alternative may evolve.

Results
: We propose that sample size calculation programs should be able to compute i) Type III errors and the so-called (q-values, ii) minimum sample sizes required to keep the (q-values below pre-specified levels, and iii) detectable effect sizes of the so-called auxiliary alternatives.

Conclusions
: Proposals iand ii are intended to help prevent irresponsibly underpowered clinical trials, whereas the proposal iii is meant as additional assistance for the planning of reasonably sized clinical trials.
Requirements Analysis of Information Services for Patients on a General Practitioner's Website
Authors: Abu-Hanna A. , Prins A. H.
Published: November 2007

Objective
: To elicit and analyze information needs of patients and primary care physicians (GPs) regarding the information services (static and functional) that a GP's practice website should provide.

Methods
: To find candidate information services, we conducted a literature search and examined primary care physicians' websites, especially Dutch websites. Semi-structured depth interviews with the stakeholders, Dutch patients and GPs, were done to arrive at a final checklist. We then conducted a survey to elicit the level of importance associated with each service on the checklist. The data underwent statistical analysis and relevant requirements were formulated. The requirements were then validated by interviews. General website quality and usability aspects were elicited from the literature.

Results
: The research resulted in a checklist of 38 selected information services including their priority ratings for patients and GPs; a discrepancy list between GP and patient priorities; and a requirements document containing information services (14 static and 6 functional), and general quality and usability aspects (8 and 5).

Conclusion
: The following items occurred in the top 10 of both user groups: general practice information, information of local public health institutions, self-help information, repeat prescription, links to health websites. At the bottom on both priority lists were: links to journals, tests and forums. Dutch GPs are much more selective in terms of which information services to provide on-line. Discrepancy between the two groups concerns on-line services that seem to require a change to the GP's workflow, or those services that are not recognized for reimbursing the GP. Although the Dutch patients' requirements seem to generalize to other patients, the conflict list might depend on the primary care system.
Supporting Medical Planning by Mitigating Cognitive Load
Authors: Oettinger A. , Smith-Spark J. H. , Castillo F. D. , Monaghan V. E. L. , Fox J. , Glasspool D. W.
Published: November 2007

Objectives
: Developing a care plan for a patient is a complex task, requiring an understanding of interactions and dependencies between procedures and of their possible outcomes for an individual patient. Decision support for planning has broader requirements than are typically considered in medical informatics applications. We consider the appropriate design of software to assist medical planning.

Methods
: The likely cognitive loads imposed by planning tasks were assessed with a view to directly supporting these via software.

Results
: Five types of cognitive load are likely to be important. A planning support system, REACT, was designed to ameliorate these cognitive loads by providing targeted dynamic feedback during planning. An initial evaluation study in genetic counselling indicates that the approach is successful in that role.

Conclusions
: The approach provides the basis of a general aid for visualizing, customizing and evaluating care plans.
User Acceptance of a Picture Archiving and Communication System
Authors: Pynoo B. , Devolder P. , Voet T. , Adang L. , Vercruysse J. , Duyck P.
Published: November 2007

Objective:
The aim of this study is to gain insight into the individual user acceptance of PACS by the radiology department staff of the Ghent University Hospital. Hereto a basic – direct effects only – form of UTAUT was assessed.

Methods:
Ninety-four questionnaires were distributed and 56 usable questionnaires were returned (19 radiologists – 37 technologists). The questionnaire consisted of scales of Venkatesh et al. [13] for performance expectancy (PE), effort expectancy (EE), facilitating conditions (FC), social influence (SI), self-efficacy (SE), attitude (ATT), anxiety (ANX) and behavioral intention (BI), and a scale of Moore et al. [22] to assess the perceived voluntariness of PACS-use.

Results:
The reliability of all scales, except FC and voluntariness, was acceptable to good. The voluntariness scale was divided into a mandatoriness (MAN) and a voluntariness (VOL) measure. Both radiologists and technologists seem to welcome PACS, with radiologists having higher ratings on PE, EE, ATT, VOL and BI. Only PE and FC were salient for predicting BI, while EE and SI were not salient. Variance explained in behavioral intention to use PACS was 48%.

Conclusion:
Both radiologists and technologists were positive towards PACS and had strong intentions to use PACS. As other healthcare professionals, they appear to make their technology acceptance decision independent from their superiors, hereby focusing on usefulness rather than on ease of use. It is also important that support is supplied. Basic UTAUT is an adequate model to assess technology acceptance in a radiological setting.
Causes of death and case fatality rates among infants with down syndrome in metropolitan Atlanta
Authors: Shin Mikyong , Kucik James E. , Correa Adolfo
Published: November 2007

BACKGROUND:

There is limited population‐based information on the extent of underreporting of congenital heart defects (CHD) as a cause of death among infants with Down syndrome (DS) and on the variation in case fatality by presence of CHD and age at death.

METHODS:

Using data from the Metropolitan Atlanta Congenital Defects Program (MACDP), we identified infants with DS born 1979–2003. We used data from Georgia death certificates and the National Death Index to determine vital status and identify causes of death. Using MACDP records as a reference, we calculated the sensitivity and positive predictive value of reports of CHD as any cause of death or contributing condition in death certificates. We calculated race‐specific case fatality rate by infant's age at death and presence of CHD.

RESULTS:

CHD was the most frequently reported cause of death from death certificates; however, a review of causes of death and birth defects data indicated a potentially greater impact of CHD among DS infant deaths than could be determined from the reported cause of death. The case fatality rate among infants with DS was significantly higher among blacks than whites, with the greatest racial disparity observed among infants without CHD who died in the post‐neonatal period.

CONCLUSIONS:

Efforts are needed to improve reporting of causes of death related to CHD among infants with DS that would allow for a clearer assessment of determinants of case fatality among DS infants and identification of possible ways to reduce the racial disparities. Birth Defects Research (Part A) 79:775–780, 2007. © 2007 Wiley‐Liss, Inc.
Synchrotron X‐Ray Charge‐Density Study of Coordination Polymer [Mn(HCOO)2(H2O)2]∞
Authors: Poulsen Rasmus D. , Jørgensen Mads R. V. , Overgaard Jacob , Larsen Finn K. , Morgenroth Wolfgang , Graber Timothy , Chen Yu‐Sheng , Iversen Bo B.
Published: November 2007

Three high‐quality single‐crystal X‐ray diffraction data sets have been measured under very different conditions on a structurally simple, but magnetically complex, coordination polymer, [Mn(HCOO)2(H2O)2]∞(1). The first data set is a conventional 100(2) K MoKαdata set, the second is a very high resolution 100(2) K data set measured on a second‐generation synchrotron source, while the third data set was measured with a tiny crystal on a high brilliance third‐generation synchrotron source at 16(2) K. Furthermore, the magnetic susceptibility (χ) and the heat capacity (Cp) have been measured from 2 to 300 K on pressed powder. The charge density of1was determined from multipole modeling of the experimental structure factors, and overall there is good agreement between the densities obtained separately from the three data sets. When considering the fine density features, the two 100 K data sets agree well with each other, but show small differences to the 16 K data set. Comparison with ab initio theory suggests that the 16 K APS data set provides the most accurate density. Topological analysis of the metal–ligand bonding, experimental 3d orbital populations on the Mn atoms, and Bader atomic charges indicate quite ionic, high‐spin metal atoms. This picture is supported by the effective moment estimated from the magnetization measurements (5.840(2) μB), but it is at variance with earlier spin density measurements from polarized neutron diffraction. The magnetic ordering originates from superexchange involving covalent interactions with the ligands, and non‐ionic effects are observed in the static deformation density maps as well as in plots of the valence shell charge concentrations. Overall, the present study provides a benchmark charge density that can be used in comparison with future metal formate dihydrate charge densities.
Intramolecular Alkyl Phosphine Dehydrogenation in Cationic Rhodium Complexes of Tris(cyclopentylphosphine)
Authors: Douglas Thomas M. , Brayshaw Simon K. , Dallanegra Romaeo , Kociok‐Köhn Gabriele , Macgregor Stuart A. , Moxham Gemma L. , Weller Andrew S. , Wondimagegn Tebikie , Vadivelu Prabha
Published: November 2007

[Rh(nbd)(PCyp3)2][BArF4] (1) [nbd = norbornadiene, ArF = C6H3(CF3)2, PCyp3 = tris(cyclopentylphosphine)] spontaneously undergoes dehydrogenation of each PCyp3 ligand in CH2Cl2 solution to form an equilibrium mixture of cis‐[Rh{PCyp2(η2‐C5H7)}2][BArF4] (2 a) and trans‐[Rh{PCyp2(η2‐C5H7)}2][BArF4] (2 b), which have hybrid phosphine–alkene ligands. In this reaction nbd acts as a sequential acceptor of hydrogen to eventually give norbornane. Complex 2 b is distorted in the solid‐state away from square planar. DFT calculations have been used to rationalise this distortion. Addition of H2 to 2 a/b hydrogenates the phosphine–alkene ligand and forms the bisdihydrogen/dihydride complex [Rh(PCyp3)2(H)2(η2‐H2)2][BArF4] (5) which has been identified spectroscopically. Addition of the hydrogen acceptor tert‐butylethene (tbe) to 5 eventually regenerates 2 a/b, passing through an intermediate which has undergone dehydrogenation of only one PCyp3 ligand, which can be trapped by addition of MeCN to form trans‐[Rh{PCyp2(η2‐C5H7)}(PCyp3)(NCMe)][BArF4] (6). Dehydrogenation of a PCyp3 ligand also occurs on addition of Na[BArF4] to [RhCl(nbd)(PCyp3)] in presence of arene (benzene, fluorobenzene) to give [Rh(η6‐C6H5X){PCyp2(η2‐C5H7)}][BArF4] (7: X = F, 8: X = H). The related complex [Rh(nbd){PCyp2(η2‐C5H7)}][BArF4] 9 is also reported. Rapid (≈5 minutes) acceptorless dehydrogenation occurs on treatment of [RhCl(dppe)(PCyp3)] with Na[BArF4] to give [Rh(dppe){PCyp2(η2‐C5H7)}][BArF4] (10), which reacts with H2 to afford the dihydride/dihydrogen complex [Rh(dppe)(PCyp3)(H)2(η2‐H2)][BArF4] (11). Competition experiments using the new mixed alkyl phosphine ligand PCy2(Cyp) show that [RhCl(nbd){PCy2(Cyp)}] undergoes dehydrogenation exclusively at the cyclopentyl group to give [Rh(η6‐C6H5X){PCy2(η2‐C5H7)}][BArF4] (17: X = F, 18: X = H). The underlying reasons behind this preference have been probed using DFT calculations. All the complexes have been characterised by multinuclear NMR spectroscopy, and for 2 a/b, 4, 6, 7, 8, 9 and 17 also by single crystal X‐ray diffraction.
Fractionation, Characterization and Speciation of Heavy Metals in Composts and Compost‐Amended Soils
Authors: Iwegbue C. M. A. , Emuh F. N. , Isirimah N. O. , Egun A. C.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Effect of soybean proteins on gluten depolymerization during mixing and resting
Authors: Pérez Gabriela T , Ribotta Pablo D , Steffolani María E , León Alberto E
Published: November 2007

BACKGROUND: Gluten and soy proteins interact as a consequence of dough mixing; however, there is no evidence of the effect of soy protein on gluten depolymerization. The aim of this study was to assess the depolymerizing effect of soy protein on gluten network after mixing and resting of mixed doughs. Therefore, the changes in glutenin macropolymer (GMP) content, protein composition and free sulfhydryl content were evaluated.

RESULTS: The protein profile from gluten–soybean blends, obtained by multistacking SDS‐PAGE, showed differences when compared to gluten profile. Soy and gluten proteins were extracted together with SDS buffer, which showed that soy proteins remained associated to insoluble wheat proteins even after hand‐washing the dough to obtain gluten. GMP content was determined to analyze the effect of soy protein on GMP gel formation. Protein content of GMP obtained from flour mixes and doughs was increased by inactive soy flour because soy proteins became insoluble and precipitated together with GMP. Active soy flour decreased GMP content due to gluten depolymerization.

CONCLUSION: Soy proteins were associated to wheat protein through physical interaction and covalent and non‐covalent bonds during mixing and resting. These interactions produced large and medium‐size polymers. This fact increased SDS solubility of insoluble gluten proteins, producing a weakening of the gluten network. Physicochemical status of soy protein in the product had a great influence on how wheat–soy proteins interact. Copyright © 2007 Society of Chemical Industry
The Kneser relation and the Hilbert pairing in multidimensional local field
Authors: Lai K. F. , Vostokov S. V.
Published: November 2007

We generalize the Kneser relation to multidimensional local fields and use it to obtain an explicit formula for the Hilbert pairing of multidimensional local fields directly from the definition of the pairing. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Topological Electronegativity Index and Its Application 2. Enthalpies of Formation for Monosubstituted Alkanes RX
Authors: Cao Chenzhong
Published: November 2007

The enthalpy of formation of monosubstituted alkane RX was divided into three contributions of alkyl group R, substituent X, and the interaction between the R and X. The Topological Electronegativity Index (TEI) of alkyl group R and the electronegativity χx of substituent X were used to quantify the interaction between the R and X. Combining this interaction with other parameters proposed by Cao (J. Mol. Struct. Theochem. 2005, 728, 85–92), a new general expression for estimating the enthalpy of formation of the monosubstituted alkane RX in gas phase (where, X=Cl, Br, I, OH, SH, NO2, CN, NH2, CHO, and COOH) was established. The expression can be used to predict the enthalpy of formation well for the RX with the correlation coefficient r=0.9999 and the standard deviation s=2.59 kJ/mol, and its estimation accuracy is better than that of preceding reported methods. Using the obtained equation, the enthalpies of formation of other sorts of compounds, such as ROMe, RSMe, RCOMe, and RCOOMe, were predicted, and the predicted values are in good agreement with the experimental ones.
(+)‐Methamphetamine increases corticosterone in plasma and BDNF in brain more than forced swim or isolation in neonatal rats
Authors: Grace Curtis E. , Schaefer Tori L. , Herring Nicole R. , Skelton Matthew R. , McCrea Anne E. , Vorhees Charles V. , Williams Michael T.
Published: November 2007

(+)‐Methamphetamine (MA) administered on postnatal days (P) 11–15 (four times/day) results in increased corticosterone that overlaps the stress hyporesponsive period (SHRP; P2–14) and leads to later learning and memory deficits. Elevated corticosterone during the SHRP results in neurotrophin changes and long‐term effects on learning. We determined whether two known stressors could mimic the effects of MA [10 (mg/kg)/dose] administration in neonatal rats. Stressors were four 15‐min sessions of forced swim or isolation (confinement in forced swim tubes without water). Saline and weighed‐only controls were included and all five treatments were represented within each litter. Corticosterone in plasma and brain‐derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in neostriatum and hippocampus were examined after one or four treatments on P11 or P15 (0.5, 1.75, 6.5, or 24 h after first dose). MA increased corticosterone and BDNF; forced swim and isolation also increased corticosterone, but to a lesser extent than MA, and neither stressor increased BDNF. NGF was unaffected by saline treatment, but there was a minor reduction in NGF in the forced swim group compared with the weighed‐only group. The data show that MA is more potent at releasing corticosterone and increasing BDNF than short‐term, repeated episodes of forced swim or isolation. The possible relationship between these changes and the long‐term cognitive effects of developmental MA administration are discussed. Synapse 62:110–121, 2008. © 2008 Wiley‐Liss, Inc.
Impact of Three‐Dimensional Vision in Laparoscopic Training
Authors: Votanopoulos Konstantinos , Brunicardi F. Charles , Thornby John , Bellows Charles F.
Published: November 2007

Background

Simulators are being used to teach laparoscopic skills before residents get to the operating room. It is unknown whether the use of three‐dimensional (3D) vision will facilitate laparoscopic training. Therefore, our objective was to compare the effectiveness of using 3D imaging over the traditional two‐dimensional (2D) imaging to teach laparoscopic simulator skills to novice individuals and assess whether 3D imaging ameliorates laparoscopic performance for surgeons who have already adapted to working within a 2D surgical environment.

Methods

This prospective study involved 36 surgical residents and students. Inexperienced participants included medical students and first‐ and second‐year surgical residents (n = 25). Experienced participants included third‐ and fifth‐year surgical residents (n = 11). Participants were tested on six laparoscopic skills using 2D or 3D imaging systems and then retested about 3 months later using the opposing imaging system. Evaluation of performance was based on the time elapsed to task completion and the errors committed during that time.

Results

The experienced participants performed better than the inexperienced participants regardless of the imaging system. Inexperienced participants initially tested using 2D imaging required significantly more time and/or made more errors to complete five of the six laparoscopic tasks compared to those initially tested using 3D imaging (p < 0.05). After initial testing on 3D imaging, inexperienced participants retested using 2D imaging performed significantly better on five of six tasks compared to the scores of inexperienced participants initially tested on 2D imaging (p < 0.05). In contrast, the inexperienced participants’ retested on 3D after initial 2D imaging did not improve on any laparoscopic task compared to the scores of inexperienced participants initially tested on 3D imaging. Among the experienced participants, no significant difference in time or errors to task completion was observed under 2D imaging compared to 3D imaging during the first or second testing session.

Conclusions

Our study indicates that 3D imaging offers significant advantages in the teaching of laparoscopic skills to inexperienced individuals.
Outcomes of Surgical Management of Total Colonic Aganglionosis
Authors: Choe E. K. , Moon S. B. , Kim H. Y. , Lee S. C. , Park K. W. , Jung S. E.
Published: November 2007

Purpose

The purpose of this study was to assess the long‐term clinical outcomes and bowel function of patients with total colonic aganglionosis (TCA) after surgery.

Methods

The hospital records of 17 TCA patients treated surgically during 1985 to 2004 were reviewed. Long‐term follow‐up was done by telephone interviews with the parents.

Results

Primary enterostomy was performed in 13 (76%) patients. In three (17%) patients, TCA was not suspected initially. They underwent conservative surgery primarily, which required a second operation soon after. One had transverse colectomy with ileostomy. By pathologic review, nine (53%) patients had small bowel involvement of aganglionosis. Six (35%) patients died before corrective surgery. They all had extensive small bowel involvement. Among 11 patients who had a corrective operation, 10 were treated with Martin’s procedure. Long‐term (mean 74 months) follow‐up was available in seven patients, and the mean weight‐for‐age percentiles was 27.1% (range 5–50%), the frequency of defecation was three to five times a day in four patients (57%), one or two times a day in two patients (28%), and more than five times a day in one patient (15%).

Conclusions

TCA is difficult to diagnose; but once it is diagnosed correctly and treated by corrective surgery, outcomes seem promising. Martin’s operation brought about a good outcome and enabled patients to have acceptable bowel habits. The prognosis is highly dependent on the extent of aganglionosis.
Can Local Secretion of Prostaglandin E2, Thromboxane B2, and Interleukin‐6 Play a Role in Ruptured Abdominal Aortic Aneurysm?
Authors: Cheuk Bernice L. Y. , Cheng Stephen W. K.
Published: November 2007

Background

Our laboratory has previously shown that the levels of secreted prostaglandin E2 (PGE2), Thromboxane B2 (TxB2), and interleukin‐6 (IL‐6) by aortic explant cultures were high in patients with ruptured abdominal aortic aneurysm (AAA). In the present study, we sought to examine the secretory levels of these inflammatory mediators in aortic explant cultured from a group of AAAs rupturing at a certain size and a group that did not rupture at that size. It was thought that such a comparison might reveal the contribution of those inflammatory mediators to the risk of AAA rupture.

Materials and methods

All subjects had abdominal computed tomography (CT) scans to determine the size of the aneurysm, and surgical aortic tissue was collected from both nonruptured AAAs (18 with a mean size of 6 + 0.5 cm [range: 5–7 cm] and 12 with a mean size of 8 + 0.1 cm [range: 7.01–10 cm]) and ruptured AAAs (10 with a mean size of 5.8 + 0.3 cm [range: 5–7 cm] and 10 with a mean size of 7.8 + 0.1 cm [range: 7.01–10 cm]). Aortic explant cultures from different sizes of aneurysms were immediately established and the culture media were collected 72 h later.

Results

The levels of PGE2, TxB2, and IL‐6 secreted in the cultured medium were quantified by specific enzyme‐linked immunosorbent assays (ELISA). The secretary levels of PGE2, TxB2, and IL‐6 were significantly higher in ruptured AAAs than in nonruptured AAAs of similar diameter. However, there was no correlation between these three inflammatory mediators and the size of AAA.

Conclusions

This study shows that these inflammatory mediators may play a role in the progression toward rupture but may not be responsible for the expansion of AAA.
The role of specialist parasites in structuring host communities
Authors: Fenton Andy , Brockhurst Michael A.
Published: November 2007

Natural enemies can be a powerful force when structuring natural communities, and in facilitating or preventing species coexistence depending on the nature of the trophic interaction. In particular, “keystone” predators can promote species coexistence, provided they preferentially attack the competitively dominant species. However, it is not clear whether parasites can play a similar structuring role; parasites typically form chronic associations with their victims, reducing their fitness (i.e., fecundity) rather than survival, and allowing infected hosts to remain viable competitors within the community. Therefore the density‐dependent suppression of the host is likely to be more subtle than that due to predation. Using a series of simple population‐dynamic models we show that specialist parasites can facilitate species coexistence, although possibly less so than predators. These results contrast with those typically found with models of generalist parasites, which can reduce the likelihood of species coexistence through apparent competition. In addition, we show that the likelihood of parasite‐facilitated species coexistence depends greatly on the specific type of parasite. In particular, macroparasites (e.g., parasitic helminths) may be less likely to facilitate species coexistence than microparasites (e.g., viruses or bacteria) due to their typically highly aggregated distribution amongst their hosts. Furthermore, species coexistence is more likely if the parasite is relatively benign to its host. Parasitism by apparently “harmless” specialist parasites may provide an important but overlooked factor in the maintenance of species diversity, facilitating species invasions into new communities and the emergence of novel infectious diseases.
Adherence, adaptation and acceptance of elderly chronic heart failure patients to receiving healthcare via telephone‐monitoring
Authors: Clark Robyn A. , Yallop Julie J. , Piterman Leon , Croucher Joanne , Tonkin Andrew , Stewart Simon , Krum Henry ,   CHAT Study Team
Published: November 2007

Background

Although the potential to reduce hospitalisation and mortality in chronic heart failure (CHF) is well reported, the feasibility of receiving healthcare by structured telephone support or telemonitoring is not.

Aims

To determine; adherence, adaptation and acceptability to a national nurse‐coordinated telephone‐monitoring CHF management strategy. The Chronic Heart Failure Assistance by Telephone Study (CHAT).

Methods

Triangulation of descriptive statistics, feedback surveys and qualitative analysis of clinical notes. Cohort comprised of standard care plus intervention (SC+I) participants who completed the first year of the study.

Results

30 GPs (70% rural) randomised to SC+I recruited 79 eligible participants, of whom 60 (76%) completed the full 12month follow‐up period. During this time 3619 calls were made into the CHAT system (mean 45.81 SD±79.26, range 0−369), Overall there was an adherence to the study protocol of 65.8% (95% CI 0.54−0.75; p=0.001) however, of the 60 participants who completed the 12month follow‐up period the adherence was significantly higher at 92.3% (95% CI 0.82−0.97, p≤0.001). Only 3% of this elderly group (mean age 74.7±9.3years) were unable to learn or competently use the technology. Participants rated CHAT with a total acceptability rate of 76.45%.

Conclusion

This study shows that elderly CHF patients can adapt quickly, find telephone‐monitoring an acceptable part of their healthcare routine, and are able to maintain good adherence for a least 12months.
Mechanistic insight into the functional and toxic effects of Strophanthidin in the failing human myocardium
Authors: von Lewinski Dirk , Bisping Egbert , Elgner Andreas , Kockskämper Jens , Pieske Burkert
Published: November 2007

Background

Cardiac glycosides are characterized by a narrow therapeutic range with Ca2+‐overload and arrhythmias occurring at higher concentrations. Data on cardiac glycosides in isolated failing human myocardium are scarce and the frequency‐dependent actions and toxicity of Strophanthidin have not yet been characterized.

Aims

To determine inotropic responses and toxicity of Strophanthidin in failing human myocardium.

Methods and results

Experiments were performed in trabeculae from 64 end‐stage failing hearts. Developed force, and intracellular [Ca2+]i and [Na+]i were recorded with Strophanthidin (0.01 to 1 μmol/L; 37°C, 1 Hz) and compared to interventions with distinct mechanisms of action (elevated [Ca2+]o, Isoproterenol, and EMD57033). The effects of Strophanthidin on force–frequency behaviour were also assessed.

Strophanthidin exerted concentration‐dependent positive inotropic effects. These were paralleled by increases in intracellular [Na+] as well as increasing [Ca2+]i‐transients and SR‐Ca2+‐load. At high concentrations (>0.5 μmol/L), Strophanthidin caused afterglimmers and aftercontractions, with declining developed force despite further increasing [Ca2+]i‐transients. The force–frequency‐relationship and diastolic function at higher pacing rates was worsened by Strophanthidin in a concentration‐dependent manner.

Conclusions

Strophanthidin toxicity was dependent on concentration, calcium load, beating rate and β‐adrenergic receptor activation. Our data support the view that low doses, heart rate control and additional β‐adrenergic receptor blockade are essential in the use of cardiac glycosides in heart failure.
Comparison of the beneficial effect of beta‐blockers on mortality in patients with ischaemic or non‐ischaemic systolic heart failure: A meta‐analysis of randomised controlled trials
Authors: Fauchier Laurent , Pierre Bertrand , de Labriolle Axel , Babuty Dominique
Published: November 2007

Mechanisms by which beta‐blockers bring benefit may differ according to the aetiology of heart failure (HF). It is uncertain whether the magnitude of the benefit of beta‐blockers is the same in ischaemic or non‐ischaemic HF.

Methods

We performed a systematic review of all randomised, placebo‐controlled, parallel‐design trials of beta‐blockers in HF that collected data on mortality during follow‐up.

Results

Among 26 randomised trials comparing beta‐blockers with placebo in HF, 4 studies with 7250 patients provided information on the number of patients who died during follow‐up in subgroups of ischaemic and non‐ischaemic aetiology of HF. Two studies were performed with bisoprolol, one with carvedilol and one with metoprolol. HF was associated with ischaemic aetiology in 4746/7250 patients (65%) and non‐ischaemic aetiology in 2504/7250 patients (35%). Mortality occurred in 301 patients. The risk ratio (RR) for beta‐blockers versus placebo was 0.62 (95% confidence interval [CI] 0.52−0.75, p<0.00001) in ischaemic HF, compared with a RR of 0.62 (95% CI 0.45−0.84, p=0.002) in the presence of non‐ischaemic HF.

Conclusion

The magnitude of the prognostic benefit conferred by beta‐blockers for overall mortality in non‐ischaemic HF appears to be very similar to that in ischaemic HF.
EARLY COLONIAL INDIA BEYOND EMPIRE
Authors: WILSON JON E.
Published: November 2007

Since 1947, the relationship between Indian society and the British empire has provided the most important frame of reference for scholars writing about the history of modern India. India is often treated merely as an exemplar of the colonial condition. As a result, scholars have failed properly to examine modern India's participation in global processes of historical change, and been reluctant adequately to ‘provincialize’ Europe. This review argues that historians need to move beyond this imperial frame of reference if they are to explain the transition to, or characteristics of, British rule in the subcontinent. Placing modern India in a broader comparative context allows one to see how the colonial subcontinent participated in an uneven but broadly comparative set of processes which occurred across Asia as well as Europe in the eighteenth and nineteenth centuries. There are, for example, important parallels between the process of active state-, economy-, and culture-formation occurring in France, Germany, and India in the nineteenth century, for example. This comparative approach would not denigrate the importance of ‘colonialism’ as an analytical category. It might, though, allow historians to produce a more satisfying interpretation of the difference between colonial and non-colonial states and societies.
Specific effects of ecstasy and other illicit drugs on cognition in poly-substance users
Authors: Schilt T. , Win M. M. L. de , Jager G. , Koeter M. W. , Ramsey N. F. , Schmand B. , van den Brink W.
Published: November 2007

Background

A large number of studies, reviews and meta-analyses have reported cognitive deficits in ecstasy users. However most ecstasy users are polydrug users, and therefore it cannot be excluded that these deficits are (partly) the result of drugs other than ecstasy. The current study, part of the Netherlands XTC Toxicity (NeXT) study, investigates the specific sustained effects of ecstasy relative to amphetamine, cocaine and cannabis on the brain using neuropsychological examination.

Method

A stratified sample of 67 subjects with such a variation in type and amount of drug use was included that correlations between the consumption of the various drugs were relatively low allowing stepwise linear multiple regression analyses to differentiate between the effects of ecstasy and those of other substances. Subjects were assessed with neuropsychological tests measuring attention, working memory, verbal and visuospatial memory, and visuospatial ability.

Results

Ecstasy use [mean 327 (s.d.=364) tablets in lifetime] had a specific significant dose-related negative effect on verbal delayed recall after adjusting for the use of other drugs.

Conclusions

These findings strongly suggest a specific sustained negative effect of ecstasy use on verbal memory. The clinical relevance is not immediately clear, because test performance generally remained within the normal range. However the magnitude of the effect is substantial (d>0.5) and long-term consequences cannot be excluded.
Rotavirus infections and climate variability in Dhaka, Bangladesh: a time-series analysis
Authors: HASHIZUME M. , ARMSTRONG B. , WAGATSUMA Y. , FARUQUE A. S. G. , HAYASHI T. , SACK D. A.
Published: November 2007

Attempts to explain the clear seasonality of rotavirus infections have been made by relating disease incidence to climate factors; however, few studies have disentangled the effects of weather from other factors that might cause seasonality. We investigated the relationships between hospital visits for rotavirus diarrhoea and temperature, humidity and river level, in Dhaka, Bangladesh, using time-series analysis adjusting for other confounding seasonal factors. There was strong evidence for an increase in rotavirus diarrhoea at high temperatures, by 40·2% for each 1°C increase above a threshold (29°C). Relative humidity had a linear inverse relationship with the number of cases of rotavirus diarrhoea. River level, above a threshold (4·8 m), was associated with an increase in cases of rotavirus diarrhoea, by 5·5% per 10-cm river-level rise. Our findings provide evidence that factors associated with high temperature, low humidity and high river-level increase the incidence of rotavirus diarrhoea in Dhaka.
Prevalence of antibodies against Rift Valley fever virus in Kenyan wildlife
Authors: EVANS A. , GAKUYA F. , PAWESKA J. T. , ROSTAL M. , AKOOLO L. , VAN VUREN P. J. , MANYIBE T. , MACHARIA J. M. , KSIAZEK T. G. , FEIKIN D. R. , BREIMAN R. F. , KARIUKI NJENGA M.
Published: November 2007

Rift Valley fever virus (RVFV) is an arbovirus associated with periodic outbreaks, mostly on the African continent, of febrile disease accompanied by abortion in livestock, and a severe, fatal haemorrhagic syndrome in humans. However, the maintenance of the virus during the inter-epidemic period (IEP) when there is low or no disease activity detected in livestock or humans has not been determined. This study report prevalence of RVFV-neutralizing antibodies in sera (n=896) collected from 16 Kenyan wildlife species including at least 35% that were born during the 1999–2006 IEP. Specimens from seven species had detectable neutralizing antibodies against RVFV, including African buffalo, black rhino, lesser kudu, impala, African elephant, kongoni, and waterbuck. High RVFV antibody prevalence (>15%) was observed in black rhinos and ruminants (kudu, impala, buffalo, and waterbuck) with the highest titres (up to 1:1280) observed mostly in buffalo, including animals born during the IEP. All lions, giraffes, plains zebras, and warthogs tested were either negative or less than two animals in each species had low (⩽1:16) titres of RVFV antibodies. Of 249 sera collected from five wildlife species during the 2006–2007 outbreak, 16 out of 19 (84%) of the ruminant (gerenuk, waterbuck, and eland) specimens had RVFV-neutralizing titres ⩾1:80. These data provide evidence that wild ruminants are infected by RVFV but further studies are required to determine whether these animals play a role in the virus maintenance between outbreaks and virus amplification prior to a noticeable outbreak.
Performance of an interferon-gamma release assay for diagnosing latent tuberculosis infection in children
Authors: OKADA K. , MAO T. E. , MORI T. , MIURA T. , SUGIYAMA T. , YOSHIYAMA T. , MITARAI S. , ONOZAKI I. , HARADA N. , SAINT S. , KONG K. S. , CHHOUR Y. M.
Published: November 2007

Newly developed interferon-gamma release assays have become commercially available to detect tuberculosis (TB) infection in adults. However, little is known about their performance in children. We compared test results between the QuantiFERON-TB® Gold test (QFT) and tuberculin skin test (TST) in young children living with pulmonary TB patients in Cambodia. Of 195 children tested with both QFT and TST, the TST-positive rate of 24% was significantly higher than the QFT-positive rate of 17%. The agreement between the test results was considerable (κ-coefficient 0·63). Positive rates increased from 6% to 32% for QFT and from 15% to 43% for TST, according to the sputum smear grades of the index cases. The presence of Bacille Calmette-Guérin (BCG) scars did not significantly affect the results of TST or QFT in a logistic regression analysis. In conclusion, QFT can be a substitute for TST in detecting latent TB infection in childhood contacts aged ⩽5 years, especially in those who may have a false-positive TST due to BCG vaccination or non-tuberculous mycobacterial infection.
BUBBLES IN FOREIGN EXCHANGE MARKETS
Authors: KIRMAN ALAN , RICCIOTTI ROMAIN FABIO , TOPOL RICHARD LÉON
Published: November 2007

We consider a model in which foreign and domestic traders buy the assets of both of two countries. Speculators in both countries use chartist or fundamentalist rules for forecasting the exchange rate. Demand for the assets of each country is determined by these forecasts. Perceptions of the fundamentals in each country are not necessarily the same. Rules are used with a certain probability depending on an agent's previous experience with them. The demands of the fundamentalist and chartist agents in the two countries determine the temporary equilibrium exchange rate at each point in time. This is unique under certain assumptions. With traders of both nationalities there is no need, as in other models, for an exogenous supply of foreign exchange. The model produces realistic features of the equilibrium exchange rate series. Periods in which the exchange rate tracks the fundamentals of one of the countries alternate with others in which bubbles appear.
Model of successive granite sheet emplacement in transtensional setting: Integrated microstructural and anisotropy of magnetic susceptibility study
Authors: Kratinová Zuzana , Schulmann Karel , Edel Jean‐Bernard , Ježek Josef , Schaltegger Urs
Published: November 2007

This study presents a model of successive emplacement of three granite plutons in transtensional deformation regime controlled by the preextensional synconvergent history of the lower and middle crust in the central Vosges Mountains (France). The complex compressional orogenic structure recorded a vertical exhumation‐related fabric in midcrustal levels which was overprinted by the regional extension. Three successively emplaced granite sheets exploited the inherited vertical anisotropy obliquely oriented with respect to the applied tensile stress. This progressive opening of original steep fabric leads to the sequential generation of free spaces toward the south, and emplacement and deformation of granite sheets. Repeated granite intrusions are responsible for reheating of southern margins of the already partially solidified granites, which became reactivated under lower ambient thermal conditions related to overall ∼6 Ma cooling of rapidly exhumed crust. The results of anisotropy of magnetic susceptibility (AMS) fabric modeling suggest a highly partitioned oblique extension divided into pure shear‐dominated deformation close to the central and northern margins of intrusions and wrench‐dominated shear along the southern margins. The AMS modeling suggests the importance of overprinting of the intrusive fabrics by the transtensional deformation.
Ocean response to Typhoon Ketsana traveling over the northwest Pacific and a numerical model approach
Authors: Yin Xiaobin , Wang Zhenzhan , Liu Yuguang , Xu Yi
Published: November 2007

Recent satellite data of sea surface temperature and chlorophyll‐a concentration are presented in investigating the ocean response to Typhoon Ketsana traveling over the Northwest Pacific in October 2003. A significant characteristic is that the surface chlorophyll‐a concentration triggered by the typhoon increased 10 times on average during its five‐day stay. Characteristics of ocean response to the typhoon are simulated by the Regional Oceanic Modeling System (ROMS). The simulations indicate that when QuikSCAT wind data are used to force the ROMS, the model outputs of sea surface temperature, chlorophyll‐a concentration in cold pool are underestimated compared with satellite data. However, more accurate wind data under strong wind and heavy rain condition can be derived from the angular momentum model. When those wind data are used to force the ROMS, the model output fits the satellite data much better. At last, it is confirmed that the Regional Oceanic Modeling System with strong wind data from the angular momentum model of wind and moderate wind data from QuikSCAT can correctly simulate both the biochemical and physical responses of the ocean to Typhoon Ketsana traveling over the Northwest Pacific.
Timing of Sexual Reproduction and Reproductive Success in the High‐Mountain Plant Saxifraga bryoides L.
Authors: Ladinig U. , Wagner J.
Published: November 2007

Abstract: Saxifraga bryoides L. is one of the plant species reaching the upper limits of distribution for flowering plants in the European Alps. Because of its abundance in the subnival and nival zones, we expected S. bryoides to reproduce efficiently in the highly stochastic climate at higher altitudes. Investigations were carried out at two subnival sites (2650 m and 2880 m a.s.l.) in the Austrian Alps. We studied flowering phenology, dynamics of seed development, and reproductive success in the climatically different years from 2001 ‐ 2004. For a nival plant species, S. bryoides showed a particularly long prefloration period (6 ‐ 9 weeks). From onset of anthesis until seed maturity took an individual flower another 6 ‐ 7 weeks and all individuals at a site 9 ‐ 10 weeks. The length of the prefloration period and seed histogenesis was temperature‐dependent, whereas seed maturation seemed to be endogenously controlled. Only in the exceptionally long and warm growing season of 2003 did all fruits mature at a site. In the other years, the onset of winter conditions halted development in many fruits before maturity. The seed/ovule ratio of mature fruits was around 0.7 in all years. The relative reproductive success (RRS) ranged from zero to 0.7, depending on the site and year. In conclusion, S. bryoides needs an unexpectedly long time to undergo reproductive development. Though fruit maturation is uncertain, the high S/O ratio of single intact fruits results in at least a small seed crop in most years. This seems to be sufficient to assure the spread and maintenance of S. bryoides at higher altitudes. As a seed‐risk strategist (Molau, 1993), S. bryoides would clearly benefit from a prolonged growing season, which might occur more often if climate warming continues.
Variation in Sexual Expression in the Monoecious Shrub Buxus balearica at Different Scales
Authors: Lázaro A. , Méndez M.
Published: November 2007

Abstract: Monoecy allows high plasticity in gender expression because the production of separate female and male flowers increases the ability to respond to specific environmental circumstances. We studied variation in sexual expression and its correlates in the monoecious shrub Buxus balearica, for two years, in six populations in the Balearic Islands and four in the Iberian Peninsula. Phenotypic gender varied among populations; while island populations showed slight variations around an average gender, mainland populations showed a broad range of variation in gender among individuals, always biased towards increasing maleness compared with the other populations. Within populations, gender was not related to plant size. Between‐year changes were slight and mainly consisted of an increase in relative maleness in the mast year. Reproduction did not affect gender in the next year, as assessed by either observational or experimental methods. Most variation in gender expression occurred among individuals within populations (83.6 %), followed by variation among populations (13.6 %) and years (2.8 %). Our results suggest that male‐biased gender at population and plant levels was related to stressful conditions and resource limitation, because: (1) maleness was higher in mainland populations, where summer drought was stronger; (2) maleness increased with elevation; (3) fruit set was positively correlated with femaleness; (4) the percentage of male inflorescences increased over the flowering period; and (5) male inflorescences were preferentially in lower parts of the branch nodes. Higher maleness in mast years, however, could be related to increased male success under synchronic flowering.
Cell Suspension as a Tool to Study the Biosynthesis of Pilocarpine in Jaborandi
Authors: Abreu I. N. , Andreazza N. L. , Sawaya A. C. H. F. , Eberlin M. N. , Mazzafera P.
Published: November 2007

Abstract: Jaborandi (Pilocarpus microphyllus) is a species that naturally occurs in the North and Northeast of Brazil, whose leaves produce pilocarpine (an imidazole alkaloid that has been used to treat glaucoma and xerostomy), the biosynthesis of which is still uncertain. The aim of this work was to establish cell lineages and select them according to an alkaloid profile similar to the one from Jaborandi leaves. The induction of callus was done in different culture media and growth regulators. Calluses from primary cultures or those subcultured several times were used as explants for the obtainment of six cell lineages. Alkaloids content analyses and growth curves showed that lines obtained from primary cultures produced more alkaloids and a better development. Cell lines from 12 subcultures presented a decrease in pilocarpine and pilosine production. After 24 subcultures, the production of alkaloids remained constant. ESI‐MS analysis showed that cell culture extracts have the same alkaloid composition as extracts made from leaves. The results indicate that cell suspensions can be used as a model to study the biosynthesis of the imidazole alkaloid in P. microphyllus.