bluuebunny/crossref_metadata_2025 huggingface dataset:
Limited Dose-Effect Relationship of Adenosine for Detection of Atrioventricular Nodal Duality in Patients with Supraventricular Tachycardias
Authors: Schernthaner Christiana , Pichler Maximilian , Strohmer Bernhard
Published: August 2007

Objective: The purpose of the study was to test the dose-effect relationship of adenosine for the diagnosis of dual atrioventricular (AV) nodal physiology in patients presenting with supraventricular tachycardia. Subjects and Methods: The study population consisted of 57 patients (mean age 50 ± 14 years; 36 females, 21 males) with palpitations related to supraventricular tachycardia. Adenosine was injected as bolus during sinus rhythm at rest in order to unmask dual AV nodal physiology by a PR jump on surface ECG (defined as a sudden increase by ≧50 ms measured from the onset of the P-wave to the R-wave between two consecutive sinus beats). According to a stepwise clinical approach, adenosine was administered as bolus in incremental dosages (6 mg followed by 12 mg, if necessary up to 18 mg). Once a PR jump ≧50 ms or a high-grade AV block was noted on surface ECG, the injection was stopped at that dose. Results: A significant PR jump was noted after injection of 6 mg (n = 21, 99 ± 30 ms) or 12 mg (n = 13, 94 ± 35 ms), but not after 18 mg (n = 4, 35 ± 10 ms) adenosine. Provocation of temporary first-grade AV block (n = 13) was associated with the longest increment of PR interval, whereas high-grade AV block (n = 36) produced a significantly shorter PR jump (105 ± 35 vs. 65 ± 40 ms, p = 0.0024). Electrophysiological study and ablation were performed in 37 highly symptomatic patients. AV nodal reentrant tachycardia was diagnosed in 33 patients and orthodromic AV reentrant tachycardia in 4 patients. Conclusion: The adenosine test was characterized by a reverse dose-effect relationship as far as identification of AV nodal duality was concerned.
Therapeutic Drug Monitoring of Gentamicin: Evaluation of Five Nomograms for Initial Dosing at Al-Amiri Hospital in Kuwait
Authors: Al-Lanqawi Yousef , Capps Phillip , Abdel-hamid Mohamed , Abulmalek Kefaya , Phillips Dotun , Matar Kamal , Sharma Prem , Thusu Anil
Published: August 2007

Objective: To compare five published nomograms (Thomson guidelines, Mawer nomogram, rule of eights, Hull-Sarubbi table and Dettli method) for calculating the initial gentamicin dosage regimen in a Kuwaiti population. Materials and Methods: Based on measured peak and trough gentamicin concentrations, the elimination rate constant and volume of distribution of gentamicin were calculated for each patient (n = 56), using a modified two-point Sawchuk-Zaske method. The calculated individual set of pharmacokinetic parameters and the initial dose regimen recommended by each of the five methods were used to predict the steady-state peak and trough of gentamicin concentrations. Results: The Thomson guidelines produced consistent results in predicting gentamicin concentrations within the target ranges of peak plus trough, peak only and trough only (63, 75 and 75%, respectively). The Mawer nomogram, Hull-Sarubbi table and Dettli methods achieved similar percentages of patients (46–50%) within the target ranges (5–10 mg · l–1 for peak and 0.5–2 for trough), whereas empirical dosing and the rule of eights showed the lowest percentages of patients within the peak plus trough target range (25 and 37%, respectively). However, with respect to the underdosing target range (predicted concentration <5 mg · l–1), the Thomson guidelines showed that 21% of patients were underdosed. Conclusion: The results show that a large number of patients (37–63%) were outside the target ranges in all initial gentamicin dosing methods evaluated in this study. Therefore, serum concentration measurement can be advised to assist in the optimization of gentamicin dose selection.
Bioavailability Assessment of Vitamin A Self-Nanoemulsified Drug Delivery Systems in Rats: A Comparative Study
Authors: Taha Ehab , Ghorab Dalia , Zaghloul Abdel-azim
Published: August 2007

Objectives: To assess and compare the bioavailability of three different oral dosage forms of vitamin A in rats. The formulations included vitamin A self-nanoemulsified drug delivery (SNEDD) optimized formulation-filled capsule (F1), vitamin A SNEDD optimized formulation compressed tablet (F2) and vitamin A oily solution-filled capsules without any additives (control, F3). Materials and Methods: Bioavailability was assessed after a single oral dose of the three formulations using three groups of rats, each group comprising 6 rats. Blood samples were collected at baseline and over the next 8 h. Plasma was separated and extracted to obtain the drug, which was measured by HPLC. Statistical data analysis was performed using the Student t test and ANOVA with p < 0.05 as the minimal level of significance. Results: From the pharmacokinetic parameters, both F1 and F2 showed improved bioavailability compared to F3. The values of AUC ± SD were 3,080.7 ± 190.2, 2,137.1 ± 130.5 and 1,485.2 ± 80.1 ng·h/ml for F1, F2 and F3, respectively. The Tmax was 1 h in case of F1 and F2 as compared to 1.5 h for F3. The Cmax ± SD was 799.5 ± 48.5, 656.2 ± 64.4 and 425.8 ± 33.1 for F1, F2 and F3, respectively. The increase in AUC, Cmax and Tmax was significant (p < 0.05). The bioavailability calculated from the AUC for F1 and F2 relative to F3 was 207.4 and 143.8%, respectively. The bioavailability increased almost twofold and 1.4 times for F1 and F2, respectively. Conclusions: The study showed that the newly developed vitamin A SNEDD formulations increased the rate and extent of drug absorption compared to the oily drug solution. The present investigation demonstrated that vitamin A SNEDD optimized formulations, either as filled capsules or as compressed tablets, were superior to its oily solution with regard to their biopharmaceutical characteristics.
Serum Cholesteryl Ester Transfer Protein Concentrations Are Associated with Serum Levels of Total Cholesterol, Beta-Lipoprotein and Apoproteins in Patients with Type 2 Diabetes Mellitus
Authors: Inukai Y. , Ito K. , Hara K. , Yamazaki A. , Takebayashi K. , Aso Y. , Inukai T.
Published: August 2007

Objective: To investigate the role of serum cholesterol ester transfer protein (CETP) and the metabolism of various lipids including apoproteins in patients with type 2 diabetes. Materials and Methods: The relationships between serum concentrations of CETP and various lipids and apoproteins were investigated in 193 patients with type 2 diabetes mellitus and 68 age-matched healthy subjects. Serum CETP concentrations were measured by an enzyme-linked immunosorbent assay. Results: Serum CETP values were lower in diabetic patients than in healthy controls (p < 0.01). Female diabetic patients had significantly higher CETP concentrations than male patients. Serum CETP concentrations exhibited a significant positive correlation with serum concentrations of cholesterol (TC) and β-lipoproteins in diabetic patients (r = 0.485, p = 0.013). Patients with relatively high serum concentrations of high-density lipoprotein cholesterol (HDL-C) tended to have much lower CETP concentrations than patients with lower HDL-C concentrations. Serum CETP concentrations showed significant positive correlations with those of apoproteins B (Apo B; r = 0.384, p = 0.024) and E (Apo E; r = 0.341, p = 0.035). Conclusion: The data indicate that serum CETP is closely involved in the metabolism of TC, β-lipoprotein, Apo B and Apo E in type 2 diabetic patients.
Total Hip Arthroplasty in Acetabular Deficiency: Experience in Al Razi Hospital, Kuwait
Authors: Pospula Wieslaw , Noor Tarek Abu
Published: August 2007

Objective: To report clinical and radiological outcomes of cemented and cementless total hip arthroplasty for primary and secondary osteoarthritis with a deficiency of acetabular bone stock. Subject and Methods: Thirty-seven patients (16 male and 21 female) having 41 hips affected by primary and secondary acetabular bone stock defect that were operated using cemented (n = 25) and cementless (n = 16) hip replacement were followed for an average period of 37 (range 12–100) months. Bone defect was classified according to American Academy of Orthopedic Surgery criteria. Different types of bone graft techniques and metal reinforcements were used. Merle d’Aubigné clinical score was used to calculate clinical outcomes. Geometrical position of the acetabular component, cup integration, hip center and graft integration were assessed. Results: The mean clinical score improved significantly from 10.6 patients preoperatively to 16.7 patients postoperatively; 95% of the cups were in the desired position and were considered integrated and the bone graft remodeled in most cases. There were 2 deep infections, 1 dislocation and 2 cases of transient neurological deficit. No significant differences in final clinical and radiological outcomes, rate of loosening and rate of complications were found between cemented and cementless acetabular replacements.Conclusion: The results show that reconstruction of acetabular bone deficiency can be accomplished with few complications using either a cemented or cementless acetabular component with or without grafting according to the clinical situation.
Can Spirometry, Pulse Oximetry and Dyspnea Scoring Reflect Respiratory Failure in Patients with Chronic Obstructive Pulmonary Disease Exacerbation?
Authors: Güryay Melek Sedef , Ceylan Emel , Günay Türkan , Karaduman Sevilay , Bengi Fecri , Parlak İsmet , Çiçek Metin , Cımrın Arif H.
Published: August 2007

Objective: To evaluate the extent to which oximetry, spirometry and dyspnea scoring can reflect hypoxemia and hypercapnia among patients admitted to the emergency department (ED) with acute exacerbations of chronic obstructive pulmonary disease. Subjects and Methods: Spirometry, oxygen saturation by pulse oximetry (SpO2), arterial blood gas analysis and dyspnea scoring assessments were made in the ED. Correlations of these parameters were evaluated by means of Pearson’s test. Pulse oximetry cutoff values to express hypoxemia were demonstrated by receiver operating characteristic (ROC) curves. Results: 76 patients with a mean age of 68.0 years were included in the study. Mean spirometric values, expressed as percentages of predicted values, were forced expiratory volume in 1 s (FEV1) = 23.1 ± 9%; forced vital capacity (FVC) = 32.8 ± 11%, and mean FEV1/FVC = 72.4 ± 21.6%. While there was a positive correlation between the SpO2,SaO2 and PaO2 values (r = 0.91 and 0.80, respectively), a negative correlation (r = –0.74) was observed between PaCO2 and SpO2. In determining hypoxemia, both SpO2 and FEV1 were sensitive (83.9 and 90.3%, respectively) while dyspnea scoring was the most sensitive (93.5%). In the evaluation by means of an ROC curve, a saturation of 88.5% for the pulse oximeter was the best cutoff value to reflect hypoxemia (sensitivity 95.6%, specificity 80.6%). Conclusion: SpO2 alone appears to be as highly specific as a combination of other tests in the evaluation of hypoxemia. A cutoff value for SpO2 of ≤88.5% is proposed as a criterion in screening for hypoxemia.
Physiological Falls Risk Assessment in Older People with Alzheimer’s Disease
Authors: Lorbach Edwina R. , Webster Kate E. , Menz Hylton B. , Wittwer Joanne E. , Merory John R.
Published: August 2007

Background: Falls are common in people with Alzheimer’s disease (AD). There is some evidence that deficits in vision, peripheral sensation, strength, reaction time and balance may be partly responsible for this increased risk. Aims: To determine the feasibility and test-retest reliability of a physiological test battery designed to assess falls risk [the Physiological Profile Assessment (PPA)] in people with AD, and to compare their PPA scores to age- and sex-matched controls. Methods: Twenty-one community-dwelling people with probable, mild to moderate AD aged 63–91 years, and 21 age- and sex-matched controls underwent the PPA tests and the Mini-Mental State Examination. All tests were then repeated in the AD group to determine test-retest reliability. Results: Most of the PPA tests could be successfully administered to participants with AD. The AD group had a significantly higher overall falls risk score (t40 = –2.41, p < 0.02), slower hand (t40 = –4.86, p < 0.01) and foot reaction time (t40 = –2.26, p < 0.05) and worse coordinated stability (t40 = –2.40, p < 0.05) than the controls. Conclusion: Physiological falls risk assessment is feasible in older people with mild to moderate AD. Older people with AD demonstrate significant impairments in several physiological domains, particularly reaction time, compared to controls.
Dietary Fish or Seafood Consumption Is Not Related to Cerebrovascular Disease Risk in Twin Veterans
Authors: Bravata Dawn M. , Wells Carolyn K. , Brass Lawrence M. , Morgan Thomas , Lichtman Judith H. , Concato John
Published: August 2007

Background/Aims: The results of studies about dietary fish consumption and stroke risk have been conflicting. We sought to examine the relationship between dietary fish and seafood consumption and the risk of stroke or transient ischemic attack (TIA). Methods: We used data from the National Academy of Sciences-National Research Council Twin Registry, a prospective cohort of white male twins born in the US (1917–1927). Participants were asked about fish and seafood consumption in 1972 and 1985. Self-report or death-certificate report of stroke or TIA was obtained in 1996–1998. Results: Among 5,355 participants, 579 (10.8%) had a stroke or TIA. In unmatched analyses, dietary fish and seafood consumption was not associated with stroke or TIA: 10.4% (91/872) of frequent fish or seafood consumers had a stroke or TIA versus 10.9% (488/4,483) of infrequent consumers, p = 0.70. In an analysis of matched twin pairs, frequent fish or seafood consumption was also not associated with stroke or TIA: hazard ratio 0.89, 95% CI 0.59–1.36. Conclusions: These data, from a prospective cohort of white male twins, do not support an association between dietary fish and seafood consumption and stroke or TIA.
Serotonin, 5-HT1A Serotonin Receptors and Proliferation of Lymphocytes in Major Depression Patients
Authors: González Alfonso , Fazzino Fili , Castillo Mirta , Mata Salvador , Lima Lucimey
Published: August 2007

Serotonin receptors are present in lymphocytes and might be related to the functionality of these cells in health and in pathology. The serotonergic system is affected in the brain and in peripheral immune cells of depressed patients. The objectives of this work were to evaluate the basal proliferation of lymphocytes, the response to the mitogen concanavalin A, and the role of serotonin 5-HT1A receptors. Twenty-nine patients, 19–52 years old, were diagnosed for a major depression episode with the Statistical and Diagnostic Manual-IV of the American Psychiatric Association, approved by ethic committees and gave written consent. The Hamilton depression score was 30.60 ± 2.65. An apparently healthy group without a family history of psychiatric illness was included. Blood peripheral lymphocytes were isolated by density gradients with Ficoll/Hypaque and differential adhesion to plastic, cultured in 96-well plaques with RPMI-1640 medium with or without 4 µg/ml of concanavalin A. 8-Hydroxy-2-(di-n-propylamino)tetralin (5–40 nM) and WAY-100,478 (0.1–100 µM), agonist and antagonist of 5-HT1A receptors, serotonin (12.5–100 nM) or imipramine (0.1–100 µM) were also added. Proliferation was evaluated at 72 h with 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyltetrazolium bromide, and the optical density was 570 nm. Basal proliferation was three times higher in depressed patients than in controls, whereas no response to mitogen was obtained, and 5-HT1A receptors significantly reacted to the agonist, with increases of about 31–54% at 10, 20 and 40 nM of the specific agonist, indicating initial activation probably in relation to autoimmunity and overreactivity of these receptors in depression. The antagonist reduced proliferation in mitogen-stimulated lymphocytes, 50% in controls and 70% in depressed patients, with a differential concentration dependency; probably, these receptors are more sensitive in depression due to increased 5-HT1A receptor transduction. The antagonist also reduced the stimulation produced by the 5-HT1A agonist. Imipramine caused biphasic effects according to concentrations, showing a possible dual role for serotonin, although all values were significantly higher in depressed subjects. The described alterations might be of relevance in the pathophysiology of depression.
Nitric Oxide and TNFα Effects in Experimental Autoimmune Encephalomyelitis Demyelination
Authors: Farias Alessandro S. , de la Hoz Cristiane , Castro Fabiano R. , Oliveira Elaine C. , Ribeiro dos Reis Jose R. , Silva João S. , Langone Francesco , Santos Leonilda M.B.
Published: August 2007

The involvement of inducible nitric oxide synthase (iNOS), which plays various roles in the progression of autoimmune diseases, was studied in iNOS knockout (KO) mice and wild-type (WT) controls with respect to experimental autoimmune encephalomyelitis (EAE). The iNOS (KO) mice presented a less severe form of the disease than the WT control mice. Although the levels of TNFα decreased in the periphery in both groups, an increase in the number of TNFα-positive cells was detected in the central nervous system during the acute phase of EAE in the WT mice, but not in the KO mice. These findings suggest that NO and TNFα contribute to the pathogenesis of acute EAE.
Effect of an Instantaneous Controlled Pressure Drop on in vitro Allergenicity to Lupins (Lupinus albus var Multolupa)
Authors: Guillamón Eva , Burbano Carmen , Cuadrado Carmen , Muzquiz Mercedes , Pedrosa Mercedes M. , Sánchez Mónica , Cabanillas Beatriz , Crespo Jesus F. , Rodriguez Julia , Haddad Joshep , Allaf Karin
Published: August 2007

Background: Lupin seed flour has been reported as a causative agent of allergic reactions, especially in patients with allergy to peanut. Previous studies have demonstrated that autoclave treatment can considerably reduce the allergenicity of lupins. Aims: The aim of this work was to evaluate the effect of instantaneous controlled pressure drop (détente instantanée contrôlée, DIC) treatment on lupin in vitro allergenicity. Methods: Lupin cotyledons were subjected to instantaneous controlled pressure drop at several pressure and time conditions (3, 4.5 and 6 bar for 1, 2 and 3 min, respectively). Immunoreactivity to raw and DIC-treated extracts was evaluated by Western blot using a serum pool from 19 sensitized patients. Results: Depending on the operating parameters used during DIC treatment, a reduction in protein solubility of lupin seed was observed. Moreover, drastic modifications in protein profiles were observed after DIC treatment by SDS-PAGE analysis. Western blot experiments showed that the decreases in IgE binding to lupin proteins were associated with the increases in steam pressure and time treatment, and binding was completely abolished by DIC at 6 bar for 3 min. Conclusions: The results suggest that DIC treatment could produce a reduction in lupin allergenicity.
ACE Inhibitor-Based, Directly Observed Therapy for Hypertension in Hemodialysis Patients
Authors: Zheng Sijie , Nath Vijay , Coyne Daniel W.
Published: August 2007

Background: Hypertension is present in nearly 80% of dialysis patients yet adequately controlled in less than half. We designed a stepped antihypertensive regimen using long-acting antihypertensives (trandolapril, atenolol and amlodipine) administered thrice a week (TIW) after each hemodialysis, and compared blood pressure (BP) control, medication cost and pill burden to each patient’s prior daily antihypertensive prescriptions. Methods: Patients were continued on their daily medications, pre-dialysis sitting BP was measured and a 44-hour interdialytic ambulatory BP monitoring (ABPM) was obtained. Then, their medications were stopped and replaced with trandolapril (2 mg TIW). Atenolol and/or amlodipine were also given TIW if the patients had any member of these classes of drugs as part of their daily regimen. Medications were titrated every 2 weeks to achieve a pre-dialysis mean arterial pressure (MAP) of <107 mm Hg. After 2 consecutive weeks with a pre-dialysis MAP of <107 mm Hg, a second 44-hour ABPM was obtained. Results: Ten patients completed the study. A persistent MAP of <107 was maintained in all 10 patients after conversion to TIW dosing. The systolic BP decreased from 122.2 ± 7.1 to 116.4 ± 11.6, and the diastolic BP decreased from 75.3 ± 10.4 to 70.4 ± 11.4 mm Hg. Pill burden and cost of medications were also significantly less. Conclusions: This pilot study found that ACE inhibitor-based, directly observed TIW therapy to be effective in hemodialysis patients with mild to moderate hypertension. Larger trials of directly observed therapy for hypertension in dialysis patients are warranted.
Randomized Trial of Intraarterial Infusion of Urokinase Within 6 Hours of Middle Cerebral Artery Stroke
Authors: Ogawa Akira , Mori Etsuro , Minematsu Kazuo , Taki Waro , Takahashi Akira , Nemoto Shigeru , Miyamoto Susumu , Sasaki Makoto , Inoue Takashi
Published: August 2007

Background and Purpose—

The Middle Cerebral Artery Embolism Local Fibrinolytic Intervention Trial (MELT) Japan was organized to determine the safety and clinical efficacy of intraarterial infusion of urokinase (UK) in patients with stroke within 6 hours of onset.

Methods—

Patients with ischemic stroke presenting within 6 hours of onset and displaying occlusions of the M1 or M2 portion of the middle cerebral artery on carotid angiography were randomized to the UK or control groups. Clinical outcome was assessed by the modified Rankin Scale, National Institutes of Health Stroke Scale, and Barthel Index.

Results—

The Independent Monitoring Committee recommended stopping the trial after approval of intravenous infusion of recombinant tissue plasminogen activator in Japan. A total of 114 patients underwent randomization, 57 patients in each group. Background characteristics were comparable between the 2 groups. The primary end point of favorable outcome (modified Rankin Scale 0 to 2) at 90 days was somewhat more frequent in the UK group than in the control group (49.1% and 38.6%, OR: 1.54, 95% CI: 0.73 to 3.23) but did not reach a significant level (
P
=0.345). However, excellent functional outcome (modified Rankin Scale 0 to 1) at 90 days, a preplanned secondary end point, was more frequent in the UK group than in the control group (42.1% and 22.8%,
P
=0.045, OR: 2.46, 95% CI: 1.09 to 5.54). There were significantly more patients with National Institutes of Health Stroke Scale 0 or 1 at 90 days in the UK group than the control group (
P
=0.017). The 90-day cumulative mortality was 5.3% in the UK group and 3.5% in the control group (
P
=1.000), and intracerebral hemorrhage within 24 hours of treatment occurred in 9% and 2%, respectively (
P
=0.206).

Conclusions—

The trial was aborted prematurely and the primary end point did not reach statistical significance. Nevertheless, the secondary analyses suggested that intraarterial fibrinolysis has the potential to increase the likelihood of excellent functional outcome.
Classifying Non-Sentential Utterances in Dialogue: A Machine Learning Approach
Authors: Fernández Raquel , Ginzburg Jonathan , Lappin Shalom
Published: August 2007

In this article we use well-known machine learning methods to tackle a novel task, namely the classification of non-sentential utterances (NSUs) in dialogue. We introduce a fine-grained taxonomy of NSU classes based on corpus work, and then report on the results of several machine learning experiments. First, we present a pilot study focused on one of the NSU classes in the taxonomy—bare wh-phrases or “sluices”—and explore the task of disambiguating between the different readings that sluices can convey. We then extend the approach to classify the full range of NSU classes, obtaining results of around an 87% weighted F-score. Thus our experiments show that, for the taxonomy adopted, the task of identifying the right NSU class can be successfully learned, and hence provide a very encouraging basis for the more general enterprise of fully processing NSUs.
Covariant Genetic Dynamics
Authors: Chryssomalakos Chryssomalis , Stephens Christopher R.
Published: August 2007

We present a covariant form for the dynamics of a canonical GA of arbitrary cardinality, showing how each genetic operator can be uniquely represented by a mathematical object — a tensor — that transforms simply under a general linear coordinate transformation. For mutation and recombination these tensors can be written as tensor products of the analogous tensors for one-bit strings thus giving a greatly simplified formulation of the dynamics. We analyze the three most well known coordinate systems — string, Walsh and Building Block — discussing their relative advantages and disadvantages with respect to the different operators, showing how one may transform from one to the other, and that the associated coordinate transformation matrices can be written as a tensor product of the corresponding one-bit matrices. We also show that in the Building Block basis the dynamical equations for all Building Blocks can be generated from the equation for the most fine-grained block (string) by a certain projection (“zapping”).
Crossover and Evolutionary Stability in the Prisoner's Dilemma
Authors: Thibert-Plante Xavier , Charbonneau Paul
Published: August 2007

We examine the role played by crossover in a series of genetic algorithm-based evolutionary simulations of the iterated prisoner's dilemma. The simulations are characterized by extended periods of stability, during which evolutionarily meta-stable strategies remain more or less fixed in the population, interrupted by transient, unstable episodes triggered by the appearance of adaptively targeted predators. This leads to a global evolutionary pattern whereby the population shifts from one of a few evolutionarily metastable strategies to another to evade emerging predator strategies. While crossover is not particularly helpful in producing better average scores, it markedly enhances overall evolutionary stability. We show that crossover achieves this by (1) impeding the appearance and spread of targeted predator strategies during stable phases, and (2) greatly reducing the duration of unstable epochs, presumably by efficient recombination of building blocks to rediscover prior metastable strategies. We also speculate that during stable phases, crossover's operation on the persistently heterogeneous gene pool enhances the survival of useful building blocks, thus sustaining long-range temporal correlations in the evolving population. Empirical support for this conjecture is found in the extended tails of probability distribution functions for stable phase lifetimes.
A Graph-Based Evolutionary Algorithm: Genetic Network Programming (GNP) and Its Extension Using Reinforcement Learning
Authors: Mabu Shingo , Hirasawa Kotaro , Hu Jinglu
Published: August 2007

This paper proposes a graph-based evolutionary algorithm called Genetic Network Programming (GNP). Our goal is to develop GNP, which can deal with dynamic environments efficiently and effectively, based on the distinguished expression ability of the graph (network) structure. The characteristics of GNP are as follows. 1) GNP programs are composed of a number of nodes which execute simple judgment/processing, and these nodes are connected by directed links to each other. 2) The graph structure enables GNP to re-use nodes, thus the structure can be very compact. 3) The node transition of GNP is executed according to its node connections without any terminal nodes, thus the past history of the node transition affects the current node to be used and this characteristic works as an implicit memory function. These structural characteristics are useful for dealing with dynamic environments. Furthermore, we propose an extended algorithm, “GNP with Reinforcement Learning (GNPRL)” which combines evolution and reinforcement learning in order to create effective graph structures and obtain better results in dynamic environments. In this paper, we applied GNP to the problem of determining agents' behavior to evaluate its effectiveness. Tileworld was used as the simulation environment. The results show some advantages for GNP over conventional methods.
Widowhood Strategies in Preindustrial Society
Authors: Dribe Martin , Lundh Christer , Nystedt Paul
Published: August 2007

In preindustrial society, the loss of a spouse usually impelled the surviving party to adapt quickly by choosing between certain strategies: to remain the head of the household, to remarry, to enter a household headed by a child or the spouse of child, to dissolve the household and enter into an unrelated person's household, or to migrate out of the parish. The use of competing-risk hazard models and longitudinal microlevel data shows that demographic, socioeconomic, and gender-related factors interacted in determining the choice of strategy in a rural area of southern Sweden during the nineteenth century.
Sensitivity of Australian Rainfall to Inter–El Niño Variations
Authors: Wang Guomin , Hendon Harry H.
Published: August 2007

Australia typically experiences drought during El Niño, especially across the eastern two-thirds of the continent during austral spring (September–November). There have, however, been some interesting departures from this paradigm. For instance, the near-record-strength El Niño of 1997 was associated with near-normal rainfall. In contrast, eastern Australia experienced near-record drought during the modest El Niño of 2002. This stark contrast raises the issue of how the magnitude of the drought is related to the character and magnitude of El Niño, for instance as measured by the broadscale sea surface temperature (SST) anomaly in the equatorial eastern Pacific. Internal (unpredictable) atmospheric noise is one plausible explanation for this contrasting behavior during these El Niño events. Here, the authors suggest that Australian rainfall is sensitive to the zonal distribution of SST anomalies during El Niño and, in particular, the greatest sensitivity is to the SST variations on the eastern edge of the Pacific warm pool rather than in the eastern Pacific where El Niño variations are typically largest. Positive SST anomalies maximized near the date line in 2002, but in 1997 maximum anomalies were shifted well into the eastern Pacific, where their influence on Australian rainfall appears to be less. These findings provide a plausible physical basis for the view that forecasting the strength of El Niño is not sufficient to accurately predict rainfall variations across Australia during El Niño.
Influence of the Madden–Julian Oscillation on Southern African Summer Rainfall
Authors: Pohl B. , Richard Y. , Fauchereau N.
Published: August 2007

Composite maps of outgoing longwave radiation (OLR) anomalies over the Madden–Julian oscillation (MJO) cycle show marked intraseasonal fluctuations over southern Africa (south of 15°S). Large-scale convective clusters are seen to propagate eastward and then northward over the continent, mainly between 10° and 20°S. The corresponding response of the rainfall field presents the alternation, over the cycle, of dry and humid phases, which are both significant. Moisture flux anomalies indicate an intraseasonal modulation of the midtropospheric easterly flow over the Congo basin at 700 hPa; these fluctuations are coupled to meridional flux anomalies that extend from the tropical to the subtropical austral latitudes, and favor occurrences of wet or dry conditions over the domain. Though statistically significant, the influence of the MJO on southern Africa is however not homogeneous spatially, and only the tropical areas exhibit sharp periodicities in the 30–60-day period range.

The OLR dipole observed in previous studies at the interannual and synoptic time scales between the hinterland parts of southern Africa and the southwestern Indian Ocean in the north of Madagascar is investigated next, as it also shows strong fluctuations at the intraseasonal time scale. The study points out that the dipole is partly influenced by the MJO, though the strongest periodicities are found for slightly longer periods (35–80 days) than those typically associated with the oscillation. The forcing of the MJO on the OLR dipole, though significant, remains thus partial.
Spatiotemporal Stochastic Simulation of Monthly Rainfall Patterns in the United Kingdom (1980–87)
Authors: Ekström Marie , Kyriakidis Phaedon C. , Chappell Adrian , Jones Philip D.
Published: August 2007

With few exceptions, spatial estimation of rainfall typically relies on information in the spatial domain only. In this paper, a method that utilizes information in time and space and provides an assessment of estimate uncertainty is used to create a gridded monthly rainfall dataset for the United Kingdom over the period 1980–87. Observed rainfall profiles within the region were regarded as the sum of a deterministic temporal trend and a stochastic residual component. The parameters of the temporal trend components established at the rain gauges were interpolated in space, accounting for their auto- and cross correlation, and for relationships with ancillary spatial variables. Stochastic Gaussian simulation was then employed to generate alternative realizations of the spatiotemporal residual component, which were added to the estimated trend component to yield realizations of rainfall (after distributional corrections). In total, 40 realizations of rainfall were generated for each month of the 8-yr period. The methodology resulted in reasonably accurate estimates of rainfall but underestimated in northwest and north Scotland and northwest England. The cause for the underestimation was identified as a weak relationship between local rainfall and the spatial area average rainfall, used to estimate the temporal trend model in these regions, and suggestions were made for improvement. The strengths of this method are the utilization of information from the time and space domain, and the assessment of spatial uncertainty in the estimated rainfall values.
A Synthesis of Antarctic Temperatures
Authors: Chapman William L. , Walsh John E.
Published: August 2007

Monthly surface air temperatures from land surface stations, automatic weather stations, and ship/buoy observations from the high-latitude Southern Hemisphere are synthesized into gridded analyses at a resolution appropriate for applications ranging from spatial trend analyses to climate change impact assessments. Correlation length scales are used to enhance information content while limiting the spatial extent of influence of the sparse data in the Antarctic region. The correlation length scales are generally largest in summer and over the Antarctic continent, while they are shortest over the winter sea ice. Gridded analyses of temperature anomalies, limited to regions within a correlation length scale of at least one observation, are constructed and validated against observed temperature anomalies in single-station-out experiments. Trends calculated for the 1958–2002 period suggest modest warming over much of the 60°–90°S domain. All seasons show warming, with winter trends being the largest at +0.172°C decade−1 while summer warming rates are only +0.045°C decade−1. The 45-yr temperature trend for the annual means is +0.082°C decade−1 corresponding to a +0.371°C temperature change over the 1958–2002 period of record. Trends computed using these analyses show considerable sensitivity to start and end dates, with trends calculated using start dates prior to 1965 showing overall warming, while those using start dates from 1966 to 1982 show net cooling over the region. Because of the large interannual variability of temperatures over the continental Antarctic, most of the continental trends are not statistically significant. However, the statistically significant warming over the Antarctic Peninsula is the strongest and most seasonally robust in the spatial patterns of temperature change.

Composite (11-model) global climate model (GCM) simulations for 1958–2002 with forcing from historic aerosol and greenhouse gas concentrations show warming patterns and magnitudes similar to the corresponding observed trends for the 45-yr period. GCM projections for the rest of the twenty-first century, however, discontinue the pattern of strongest warming over the Antarctic Peninsula, but instead show the strongest warming over the Antarctic continent.
Assessment of Dynamic Downscaling of the Continental U.S. Regional Climate Using the Eta/SSiB Regional Climate Model
Authors: Xue Yongkang , Vasic Ratko , Janjic Zavisa , Mesinger Fedor , Mitchell Kenneth E.
Published: August 2007

This study investigates the capability of the dynamic downscaling method (DDM) in a North American regional climate study using the Eta/Simplified Simple Biosphere (SSiB) Regional Climate Model (RCM). The main objective is to understand whether the Eta/SSiB RCM is capable of simulating North American regional climate features, mainly precipitation, at different scales under imposed boundary conditions. The summer of 1998 was selected for this study and the summers of 1993 and 1995 were used to confirm the 1998 results. The observed precipitation, NCEP–NCAR Global Reanalysis (NNGR), and North American Regional Reanalysis (NARR) were used for evaluation of the model’s simulations and/or as lateral boundary conditions (LBCs). A spectral analysis was applied to quantitatively examine the RCM’s downscaling ability at different scales.

The simulations indicated that choice of domain size, LBCs, and grid spacing were crucial for the DDM. Several tests with different domain sizes indicated that the model in the North American climate simulation was particularly sensitive to its southern boundary position because of the importance of moisture transport by the southerly low-level jet (LLJ) in summer precipitation. Among these tests, only the RCM with 32-km resolution and NNGR LBC or with 80-km resolution and NARR LBC, in conjunction with appropriate domain sizes, was able to properly simulate precipitation and other atmospheric variables—especially humidity over the southeastern United States—during all three summer months—and produce a better spectral power distribution than that associated with the imposed LBC (for the 32-km case) and retain spectral power for large wavelengths (for the 80-km case). The analysis suggests that there might be strong atmospheric components of high-frequency variability over the Gulf of Mexico and the southeastern United States.
A Lethal Threat to U.S. Teacher Education
Authors: Weiner Lois
Published: August 2007

Dramatic changes are being made to teacher education internationally and in the United States. Some of the alterations have been recognized as threatening university-based teacher preparation, for instance, the growth of alternate route programs. Many other phenomena that have an impact on teacher education have not been analyzed as such, including for-profit corporations' development of professional development services linked to raising students' standardized test scores and the entry of private, for-profit institutions into the market for higher education. The challenge to teacher education's commitment to social justice has been debated, but its relationship to the other alterations being made to public education has not been explored. Moreover, the common origins of these phenomena and their synergistic impact have been inadequately studied, as have the implications of this synergy for university-based teacher education in the near future.
The dynamics of ensemble: the case for flamenco
Authors: Maduell Mariana , Wing Alan M.
Published: August 2007

We provide behavioural and quantitative analyses of coordination and synchronization in ensemble performance, using flamenco as a case study. The concept of ensemble is introduced and developed with the aid of connected network models, then applied to the flamenco ensemble. Flamenco performance is described in terms of ensemble interaction, including both the types of rhythmical accompaniment used by the individual classes of performer participating in the ensemble and the main sociocultural factors governing control of rhythm and cuing changes. These factors involve hierarchies relating to the degree to which each performer commands audience attention (focus) and the status of ensemble members within the company. We describe an observational approach to ensemble coordination with an event-based video analysis of a four-member ensemble performing a flamenco piece and a correlation-based motion analysis of two-person performance of simple rhythm.
The prevalence and nature of imagined music in the everyday lives of music students
Authors: Bailes Freya
Published: August 2007

`Musical imagery' is the experience of imagining music in the `mind's ear'. A study was conducted to explore the prevalence and nature of musical imagery for music students in everyday life, using experience-sampling methods (ESM). As a group, music students reported that imagining music was a very frequent form of musical experience. Participants reported individual variation in their imagery experience but also common differences between the strength of imagery for different musical dimensions. For instance, melody and lyrics were rated as being more vivid components of the image than timbre and expression. Another clear pattern was the influence of hearing music on musical imagination, one indicator being that 58 percent of sampled episodes described having heard or performed the music recently as a possible reason for currently imagining it.
15-Year Follow-up of Neuromuscular Function in Patients with Unilateral Nonreconstructed Anterior Cruciate Ligament Injury Initially Treated with Rehabilitation and Activity Modification
Authors: Ageberg Eva , Pettersson Annika , Fridén Thomas
Published: August 2007

Background

It has been suggested that neuromuscular function is of importance in the overall outcome after anterior cruciate ligament (ACL) injury.

Hypothesis

Good neuromuscular function can be achieved and maintained over time in subjects with ACL injury treated with rehabilitation and activity modification but without reconstructive surgery.

Study Design

Case series; Level of evidence, 4.

Methods

One hundred consecutive patients (42 women and 58 men) with acute ACL injury at a nonprofessional, recreational or competitive activity level were assessed 1, 3, and 15 years after injury. Their mean age at inclusion was 26 years (range, 15-43 years). All patients initially underwent rehabilitation and were advised to modify their activity level, especially by avoiding contact sports. Patients with recurrent giving-way episodes or secondary meniscal injuries that required fixation were subsequently excluded and underwent reconstruction of the ACL. Sixty-seven patients (71% of those available for follow-up) with unilateral nonreconstructed injury remained at the 15-year follow-up. Fifty-six of these 67 patients were examined with the single-legged hop test for distance and knee muscle strength. The limb symmetry index (LSI), calculated by dividing the result for the injured leg by that of the uninjured leg and multiplying by 100, was used for comparisons over time (paired t test).

Results

The LSI for the single-legged hop test was higher at the 3-year follow-up (mean, 98.5%; standard deviation [SD], 7.6%) than at the 15-year follow-up (mean, 94.8%; SD, 10.5%) (mean difference, —3.7%; 95% confidence interval [CI], —6.1% to —1.2%; P = .004). The LSI for isometric extension was higher at the 15-year follow-up (mean, 97.2%; SD, 13.7%) than at the 1-year follow-up (mean, 88.2%; SD, 15.4%) (mean difference, 9.0%; 95% CI, 3.7% to 14.4%; P = .001). At the 15-year follow-up, between 69% and 85% of the patients had an LSI ≥90%.

Conclusions

Good functional performance and knee muscle strength can be achieved and maintained over time in the majority of patients with ACL injury treated with rehabilitation and early activity modification but without reconstructive surgery.
Revision Hip Arthroscopy
Authors: Philippon Marc J. , Schenker Mara L. , Briggs Karen K. , Kuppersmith David A. , Maxwell R. Brian , Stubbs Allston J.
Published: August 2007

Background

Hip arthroscopy has become increasingly popular; however, little is known about revision hip arthroscopy.

Hypothesis

Revision hip arthroscopy is associated with unaddressed femoroacetabular impingement. The purpose of this study was to describe reasons for revision hip arthroscopy.

Study Design

Case series; Level of evidence, 4.

Methods

Between March 2005 and March 2006, 37 revision hip arthroscopies were performed by the senior author. Data were collected through retrospective review of clinical and operative notes.

Results

All patients required revision surgery because of persistent hip pain. There were 25 women and 12 men with an average age of 33 years (range, 16-53 years). The average time from prior surgery to revision was 20.5 months (range, 2.9-84 months). Common findings among patients needing revision were hip pain, decreased range of motion, and functional disability. The average modified Harris Hip Score was 53 (range, 22-99). Thirty-six patients had radiographic evidence of femoroacetabular impingement at the time of revision. Revision procedures included 34 (95%) for femoroacetabular impingement, 32 (87%) for labral lesions, 26 (70%) for a chondral defect, 23 (62%) for lysis of adhesions, and 13 (35%) for previously unaddressed instability. Two patients had total hip arthroplasty after revision, and 3 patients required further revision. Of the remaining 32 patients, early follow-up was obtained on 27 (84%) at an average of 12.7 months postoperatively (range, 6-19 months). Outcomes showed patients regained some of their lost function within the first year.

Conclusion

Patients commonly required revision hip arthroscopy because of persistent impingement.
Pubic Magnetic Resonance Imaging Findings in Surgically and Conservatively Treated Athletes with Osteitis Pubis Compared to Asymptomatic Athletes during Heavy Training
Authors: Paajanen Hannu , Hermunen Heikki , Karonen Jari
Published: August 2007

Background

Osteitis pubis is characterized by diffuse pain, inflammation, and bony changes in the pubic symphysis. Bone marrow edema in magnetic resonance imaging is associated with stress injury and osteitis of the pubic bone.

Hypothesis

Laparoscopic mesh repair decreases inflammation and pain in the pubic periosteum. The presence of extensive bone marrow edema may correlate with the severity of symptoms and may guide the surgical treatment of osteitis pubis.

Study Design

Case control study; Level of evidence, 4.

Methods

Surgery (n = 8) was performed by placement of totally extraperitoneal endoscopic mesh behind the symphysis. Nonoperative treatment (n = 8) included physical therapy and corticosteroids. Preoperative and postoperative pain was measured by the visual analog scale. Athletes were followed up from 1 to 6 years (mean, 2.7 years). All magnetic resonance imaging scans were analyzed blindly by 2 radiologists. Twenty asymptomatic ice hockey or soccer players served as controls in magnetic resonance imaging.

Results

The patients treated surgically had higher preoperative pain scores than did the patients treated conservatively. Seven of 8 athletes (88%) treated surgically returned to sport activities after 2 months of convalescence. No complications were associated with surgery. In the nonoperative group, 4 patients (50%) still had disabling symptoms after 1 year of follow-up, and they stopped their elite sports during 3 years of follow-up. The presence of bone marrow edema was distributed in the surgical (100%), nonoperative (88%), and asymptomatic athletes (65%) with no statistical difference between the groups.

Conclusion

This study indicated that the placement of retropubic mesh was an efficient method for the treatment of severe pubic enthesopathy in athletes. Abnormal magnetic resonance imaging findings were also common in asymptomatic athletes, which decreases the value of magnetic resonance imaging in surgical decision-making.