bluuebunny/crossref_metadata_2025 huggingface dataset:
Fetal Intraventricular Bleeding Possibly due to Maternal Vitamin K Deficiency
Authors: Minami Hiroji , Furuhashi Madoka , Minami Kojiro , Miyazaki Ken , Yoshida Kana , Ishikawa Kaoru
Published: October 2008

We report a rare case of fetal intraventricular bleeding possibly due to maternal vitamin K deficiency. A 20-year-old woman was admitted to our hospital due to impending premature delivery and loss of dietary intake at 28 weeks of gestation. Her blood examination showed metabolic alkalosis, prolonged prothrombin time, and extremely high level of plasma des-gamma-carboxyprothrombin (protein induced by vitamin K absence, PIVKA-II). Intraventricular hemorrhage was demonstrated by ultrasonography 6 days after admission. She delivered a 2,288-gram girl infant at 40 weeks of gestation. Cranial computerized tomography and magnetic resonance images obtained postnatally demonstrated a reduced cerebral parenchyma adjacent to the interior side of the right lateral ventricle and the deficit of left cerebellum. The infant’s head control was insufficient and central impaired hearing was noted at 6 months of life.
No Difference in Nitrogen Balance between Standard Prescriptions of Hemodialysis and Peritoneal Dialysis
Authors: Lu Qian , Cheng Lei , Axelsson Jonas , Lindholm Bengt , Wang Tao
Published: October 2008

Background: It has been thought that peritoneal dialysis (PD) may not achieve adequate solute removal after the loss of residual renal function when compared to hemodialysis (HD). However, it should be noted that adequate solute removal depends not only on dialysis dose but also on dietary intake. Therefore, in the present study, we compared, both theoretically and clinically, the dietary protein intake and nitrogen removal between standard HD and PD as currently practiced in China. Methods: The nitrogen removal for both HD and PD was calculated theoretically with defined membrane permeability. For HD, the urea removal was based on a 2-compartment model. We compared the dietary protein intake and the amount of nitrogen removed at dialysis in 38 anuric well-nourished hemodialysis patients and 44 peritoneal dialysis patients. Results: With the theoretical calculation, setting the blood urea level at 21 or 26 mmol/l for both dialysis modalities, with the current practice pattern (4 exchanges of 2 liters of dialysis solution a day for PD and 4 h × 3 per week for HD), HD and PD removed almost identical amounts of nitrogen, and the allowable dietary protein intakes to achieve nitrogen balance for each modality were about 0.9 and 1.0 g/kg/day, respectively. In the 38 HD patients, the peak blood urea concentration was 26.44 ± 3.96 mmol/l, significantly higher than that of PD patients (20.85 ± 4.08 mmol/l). There was no significant difference in the dietary protein intake between the 2 modalities: 1.01 ± 0.29 and 0.91 ± 0.28 g/kg/day for HD patients and PD patients, respectively. Conclusions: Our study suggests that to achieve the same level of blood urea level, the protein intake and nitrogen removal is almost identical between HD and PD with the current practice pattern, indicating PD could provide similar dialysis adequacy to that of HD when patients lose their residual renal function.
Impact of Intravenous Loop Diuretics on Outcomes of Patients Hospitalized with Acute Decompensated Heart Failure: Insights from the ADHERE Registry
Authors: Peacock W. Franklin , Costanzo Maria Rosa , De Marco Teresa , Lopatin Margarita , Wynne Janet , Mills Roger M. , Emerman Charles L.
Published: October 2008

The optimal use of diuretics in decompensated heart failure remains uncertain. We analyzed data from the ADHERE registry to look at the impact of diuretic dosing. 62,866 patients receiving <160 mg and 19,674 patients ≥160 mg of furosemide were analyzed. The patients receiving the lower doses had a lower risk for in-hospital mortality, ICU stay, prolonged hospitalization, or adverse renal effects. These findings suggest that future studies should evaluate strategies for minimizing exposure to high doses of diuretics.
Main-Effects Model Is a Special Kind of Additive Model in the Presence of Linkage Disequilibrium
Authors: Zhang Yulong , Ji Liang
Published: October 2008

Objective: Statistical epistasis refers to a departure from additivity on some scale related to a trait. The implication of it may vary due to the choice of scale. In this paper, we focus on statistical epistasis between two loci for a binary trait and mainly investigate two common scales, the penetrance and the variance of the penetrance. For each scale, the model that keeps additivity is first studied and then the statistical epistatic effect is tested as a deviation from the model. The additive model describes additivity on the penetrance scale and the main-effects model assumes additivity on the variance of the penetrance. These two models have been proved to be equivalent when the loci are in linkage equilibrium (LE). Our goal is to show that they are not equivalent in the presence of linkage disequilibrium (LD) and to reveal that the degrees of deviations from these two models may not be the same. Methods: At first, we prove that the main-effects model is only a special kind of additive model when the loci are in LD. We then use statistics to test the degrees of deviations from these two models, respectively. Results: All statistics were applied to analyze real and simulated data. The results show that an additive model may deviate from the main-effects model significantly in the presence of LD. Conclusions: The results suggest that it is better to test the statistical epistatic effect as a departure from the main-effects model.
Optimal DNA Pooling-Based Two-Stage Designs in Case-Control Association Studies
Authors: Zhao Yihong , Wang Shuang
Published: October 2008

Study cost remains the major limiting factor for genome-wide association studies due to the necessity of genotyping a large number of SNPs for a large number of subjects. Both DNA pooling strategies and two-stage designs have been proposed to reduce genotyping costs. In this study, we propose a cost-effective, two-stage approach with a DNA pooling strategy. During stage I, all markers are evaluated on a subset of individuals using DNA pooling. The most promising set of markers is then evaluated with individual genotyping for all individuals during stage II. The goal is to determine the optimal parameters (πpsample , the proportion of samples used during stage I with DNA pooling; and πpmarker , the proportion of markers evaluated during stage II with individual genotyping) that minimize the cost of a two-stage DNA pooling design while maintaining a desired overall significance level and achieving a level of power similar to that of a one-stage individual genotyping design. We considered the effects of three factors on optimal two-stage DNA pooling designs. Our results suggest that, under most scenarios considered, the optimal two-stage DNA pooling design may be much more cost-effective than the optimal two-stage individual genotyping design, which use individual genotyping during both stages.
An Example of Ovarian Cancer as a ‘Chronic Disease Process’ – 11-Year Survival with Multiple Treatments for Recurrent and Progressive Disease
Authors: Markman Maurie , Malviya Vinay
Published: October 2008

The 11-year survival of a woman with recurrent progressive advanced epithelial ovarian cancer emphasizes the potential for the disease process to be quite ‘chronic’ in nature.
The Prevalence, Correlates and Impact of Dementia in Cuba
Authors: Llibre Rodríguez J. , Valhuerdi A. , Sanchez I.I. , Reyna C. , Guerra M.A. , Copeland J.R.M. , McKeigue P. , Ferri C.P. , Prince M.J.
Published: October 2008

Background: We aimed to estimate the prevalence, correlates and impact of dementia in Havana and Matanzas, Cuba. Methods: A 1-phase catchment area survey of all over 65-year-old residents of 7 catchment areas in Havana and 1 in Matanzas was conducted. Dementia diagnosis was established according to DSM-IV and our own, pre-validated10/66 criteria. The impact of dementia was assessed through associations with needs for care, cutting back on work to care and caregiver psychological morbidity. Results: We interviewed 2,944 older people, a response proportion of 96.4%. The prevalence of DSM-IV dementia was 6.4% and that of 10/66 dementia 10.8%. Both dementia outcomes were associated with older age, less education, a family history of dementia, shorter leg length and smaller skull circumference. Dementia, rather than physical health problems or depression, was the main contributor to needs for care (population-attributable prevalence fraction = 64.6%) and caregiver cutting back on work (population-attributable prevalence fraction = 57.3%). Conclusion: The prevalence of dementia in Cuba is similar to Europe. Among health conditions, dementia is the major contributor to dependency and caregiver economic and psychological strain. More attention needs to be given to it and other chronic diseases associated more with disability than premature mortality.
Role of Kinin B2Receptor Signaling in the Recruitment of Circulating Progenitor Cells With Neovascularization Potential
Authors: Kränkel Nicolle , Katare Rajesh G. , Siragusa Mauro , Barcelos Luciola S. , Campagnolo Paola , Mangialardi Giuseppe , Fortunato Orazio , Spinetti Gaia , Tran Nguyen , Zacharowski Kai , Wojakowski Wojciech , Mroz Iwona , Herman Andrew , Manning Fox Jocelyn E. , MacDonald Patrick E. , Schanstra Joost P. , Bascands Jean Loup , Ascione Raimondo , Angelini Gianni , Emanueli Costanza , Madeddu Paolo
Published: October 2008

Reduced migratory function of circulating angiogenic progenitor cells (CPCs) has been associated with impaired neovascularization in patients with cardiovascular disease (CVD). Previous findings underline the role of the kallikrein-kinin system in angiogenesis. We now demonstrate the involvement of the kinin B2 receptor (B2R) in the recruitment of CPCs to sites of ischemia and in their proangiogenic action. In healthy subjects, B2R was abundantly present on CD133+and CD34+CPCs as well as cultured endothelial progenitor cells (EPCs) derived from blood mononuclear cells (MNCs), whereas kinin B1 receptor expression was barely detectable. In transwell migration assays, bradykinin (BK) exerts a potent chemoattractant activity on CD133+and CD34+CPCs and EPCs via a B2R/phosphoinositide 3-kinase/eNOS-mediated mechanism. Migration toward BK was able to attract an MNC subpopulation enriched in CPCs with in vitro proangiogenic activity, as assessed by Matrigel assay. CPCs from cardiovascular disease patients showed low B2R levels and decreased migratory capacity toward BK. When injected systemically into wild-type mice with unilateral limb ischemia, bone marrow MNCs from syngenicB2R-deficient mice resulted in reduced homing of sca-1+and cKit+flk1+progenitors to ischemic muscles, impaired reparative neovascularization, and delayed perfusion recovery as compared with wild-type MNCs. Similarly, blockade of the B2R by systemic administration of icatibant prevented the beneficial effect of bone marrow MNC transplantation. BK-induced migration represents a novel mechanism mediating homing of circulating angiogenic progenitors. Reduction of BK sensitivity in progenitor cells from cardiovascular disease patients might contribute to impaired neovascularization after ischemic complications.
Cerebral Microemboli and Brain Injury During Carotid Artery Endarterectomy and Stenting
Authors: Skjelland Mona , Krohg-Sørensen Kirsten , Tennøe Bjørn , Bakke Søren J. , Brucher Rainer , Russell David
Published: October 2008

Background and Purpose—

Cerebral microembolic signals detected by transcranial Doppler are frequent during carotid angioplasty with stenting and carotid endarterectomy (CEA). Their potential harmful effects on the brain are, however, unclear. The aim of this study was to relate the frequency and type of per-procedural microembolic signals to procedure-related ipsilateral ischemic strokes and new ipsilateral ischemic lesions on diffusion-weighted cerebral MRI.

Methods—

Eighty-five patients who were prospectively treated with CEA (61) or carotid angioplasty with stenting (30) for high-grade (≥70%) internal carotid artery stenoses were monitored during the procedures using multifrequency transcranial Doppler with embolus detection and differentiation. Pre- and postprocedural cerebral diffusion-weighted cerebral MRIs were performed on a subset of patients.

Results—

Solid and gaseous microemboli were independently associated with procedure-related ipsilateral ischemic strokes (solid:
P
=0.027, gaseous:
P
=0.037) or new ipsilateral diffusion-weighted cerebral MRI lesions (solid:
P
=0.043, gaseous:
P
=0.026). Microembolic signals were detected during all procedures except one (CEA); 17% and 21% of all emboli were solid during carotid angioplasty with stenting and CEA, respectively. Patients undergoing carotid angioplasty with stenting had more solid (
P
<0.001) and gaseous (
P
<0.001) emboli and more new ipsilateral ischemic strokes (
P
=0.033) compared with patients undergoing CEA. Echolucent plaques (
P
=0.020) and preprocedural diffusion-weighted cerebral MRI ischemic lesions (
P
=0.002) were associated with increased numbers of solid emboli.

Conclusions—

Solid and gaseous microemboli were increased in patients with procedure-related ipsilateral ischemic strokes or new diffusion-weighted cerebral MRI lesions, which suggests that both solid and gaseous emboli may be harmful to the brain during CEA and carotid angioplasty with stenting.
Extension of the Thrombolytic Time Window With Minocycline in Experimental Stroke
Authors: Murata Yoshihiro , Rosell Anna , Scannevin Robert H. , Rhodes Kenneth J. , Wang Xiaoying , Lo Eng H.
Published: October 2008

Background and Purpose—

Thrombolysis with tPA is the only FDA-approved therapy for acute ischemic stroke. But its widespread application remains limited by narrow treatment time windows and the related risks of cerebral hemorrhage. In this study, we ask whether minocycline can prevent tPA-associated cerebral hemorrhage and extend the reperfusion window in an experimental stroke model in rats.

Methods—

Spontaneously hypertensive rats were subjected to embolic focal ischemia using homologous clots and treated with: saline at 1 hour; early tPA at 1 hour, delayed tPA at 6 hours; minocycline at 4 hours; combined minocycline at 4 hours plus tPA at 6 hours. Infarct volumes and hemorrhagic transformation were quantified at 24 hours. Gelatin zymography was used to measure blood levels of circulating matrix metalloproteinase-9 (MMP-9).

Results—

Early 1-hour thrombolysis restored perfusion and reduced infarction. Late 6-hour tPA did not decrease infarction but instead worsened hemorrhagic conversion. Combining minocycline with delayed 6-hour tPA decreased plasma MMP-9 levels, reduced infarction, and ameliorated brain hemorrhage. Blood levels of MMP-9 were also significantly correlated with volumes of infarction and hemorrhage.

Conclusion—

Combination therapy with minocycline may extend tPA treatment time windows in ischemic stroke.
Differences in Risk Factors Between Black Caribbean Patients With Stroke in Barbados and South London
Authors: Smeeton Nigel C. , Corbin David O.C. , Hennis Anselm J. , Hambleton Ian R. , Fraser Henry S. , Wolfe Charles D.A. , Heuschmann Peter U.
Published: October 2008

Background and Purpose—

Risk of stroke is higher in black Caribbeans in the United Kingdom compared with black Caribbeans in their country of origin. We investigated if these differences were caused by variations in prior-to-stroke risk factors.

Summary of Report—

Data were collected from the South London Stroke Register (SLSR) and the Barbados Register of Strokes (BROS). Differences in prevalence and management of stroke risk factors were adjusted for age, sex, living conditions prestroke, stroke subtype, and socioeconomic status by multivariable logistic regression. Patients in BROS were on average older (mean difference 4 years) and more likely to have a nonmanual occupation. They were less likely to have a prestroke diagnosis of myocardial infarction (OR, 0.39; 95% CI, 0.19 to 0.77) or diabetes (OR, 0.65; 95% CI, 0.46 to 0.92) and were less likely to report smoking (OR, 0.31; 95% CI, 0.19 to 0.49). They were also more likely to receive appropriate prestroke antihypertensive (OR, 1.88; 95% CI, 1.21 to 2.92) and antidiabetic treatment (OR, 3.33; 95% CI, 1.44 to 7.70) and less likely to receive cholesterol-lowering drugs (OR, 0.19; 95% CI, 0.05 to 0.71).

Conclusions—

The higher risk of stroke in black Caribbeans in the United Kingdom might be caused by a higher prevalence of major prior-to-stroke risk factors, differences in treatment patterns for comorbid conditions, and less healthy lifestyle practices compared with indigenous black Caribbean populations.
Therapy of Acute Basilar Artery Occlusion
Authors: Nagel Simon , Schellinger Peter D. , Hartmann Marius , Juettler Eric , Huttner Hagen B. , Ringleb Peter , Schwab Stefan , Köhrmann Martin
Published: October 2008

Background and Purpose—

While intravenous recombinant tissue plasminogen activator (rt-PA) has been approved for acute stroke therapy within 3 hours, the optimum management of basilar artery occlusion (BAO) is still a matter of debate. We compared intraarterial thrombolysis with the combined bridging approach of intravenous abciximab and intraarterial thrombolysis with rt-PA (bridging therapy) in an observational, longitudinal, monocenter study.

Methods—

Between 1998 and 2006, information for 106 patients with acute BAO were prospectively entered into a local database. Patients eligible for treatment received either intraarterial thrombolysis with rt-PA alone (intraarterial thrombolysis) or were treated with intravenous abciximab and intraarterial rt-PA (bridging therapy). Outcome parameters were recanalization of the basilar artery according to Trial in Myocardial Infarction criteria, survival, and reduction of severe disability and death at 3 months. Logistic regression was used to identify independent predictors for recanalization, survival, and clinical outcome.

Results—

Of a total of 106 patients with confirmed BAO, 87 patients underwent subsequent angiography. Among those, 75 patients were identified who received the full treatment protocol. Patients in the bridging group had a better recanalization rate (83.7% vs 62.5%;
P
=0.03), a higher survival rate (58.1% vs 25%;
P
=0.01), and a better chance for an outcome with no or only mild to moderate disability (modified Rankin Scale score, 0–3; 34.9% vs 12.5%;
P
=0.02). Symptomatic intracerebral hemorrhage rates were comparable in both groups (14% in the bridging group vs 18.8%;
P
=0.41). Independent predictors for recanalization were age (OR, 0.95; 95% CI, 0.91–0.99), atrial fibrillation (OR, 6.53; 95% CI, 1.14–37.49), and bridging therapy (OR, 3.37; 95% CI, 1.02 to 11.18). Independent prognostic factors for outcome were Glasgow coma scale score at presentation (OR, 1.24; 95% CI, 1.03–1.45) and the combination of bridging therapy with successful recanalization (OR, 3.744; 95% CI, 1.04–13.43).

Conclusion—

Bridging therapy for acute BAO with intravenous abciximab and intraarterial rt-PA appears to be safe and yields higher recanalization and improved survival rates, as well as an overall improved chance for a better outcome.
Factor V Leiden and Antiphospholipid Antibodies in Either Mothers or Infants Increase the Risk for Perinatal Arterial Ischemic Stroke
Authors: Simchen Michal J. , Goldstein Gal , Lubetsky Aaron , Strauss Tzipi , Schiff Eyal , Kenet Gili
Published: October 2008

Background and Purpose—

The objective was to investigate the role of infant and maternal thrombophilia in a cohort of mothers and infants presenting with perinatal arterial ischemic stroke.

Methods—

Forty-seven infants with clinically and radiologically confirmed perinatal arterial ischemic stroke underwent thrombophilia workup: factor V Leiden (FVL), PII20210A mutation, Methylene-tetrahydrofolate reductase 677T polymorphism, protein C, protein S, antithrombin, FVIII, and antiphospholipid antibodies. Thrombophilia data were available for 23 mother–infant pairs and compared with control populations to evaluate the risk for PAS.

Results—

Thirty of 47 (64%) infants and 15 of 22 mothers (68%) had evidence of thrombophilia. In 18 of 23 (78%) mother–infant pairs, there was at least 1 thrombophilic risk factor, but 15 pairs were mismatched in pathology. Among infants, FVL, protein C deficiency, and presence of antiphospholipid antibodies prevailed (OR, 4.2; 95% CI, 1.5–11.3; OR, 12.2; 95% CI, 2.5–59.9; OR, 4.1; 95% CI, 1.4–12.2, respectively). Interestingly FVL prevailed in almost one-third of mothers (OR, 8.5; 95% CI, 4.1–17.5) and 18% of mothers had antiphospholipid antibodies (OR, 3.8l; 95% CI, 1.5–10.0).

Conclusions—

Maternal and neonatal thrombophilia, especially presence of FVL or antiphospholipid antibodies, may be important in the pathogenesis of perinatal arterial ischemic stroke. The nature of thrombophilic mother–infant risk potential interactions warrants further investigation.
Complete Stability in Multistable Delayed Neural Networks
Authors: Cheng Chang-Yuan , Shih Chih-Wen
Published: October 2008

We investigate the complete stability for multistable delayed neural networks. A new formulation modified from the previous studies on multistable networks is developed to derive componentwise dynamical property. An iteration argument is then constructed to conclude that every solution of the network converges to a single equilibrium as time tends to infinity. The existence of 3n equilibria and 2n positively invariant sets for the n-neuron system remains valid under the new formulation. The theory is demonstrated by a numerical illustration.
Improving Expressive Writing Skills of Children Rated for ADHD Symptoms
Authors: Re Anna Maria , Caeran Monica , Cornoldi Cesare
Published: October 2008

The present study examines the expressive writing abilities of children described by their teachers as having Attention Deficit Hyperactivity Disorder (ADHD) symptoms and of matched controls and the effects of two types of facilitation. A group of 35 ADHD children and matched controls are given the task of composing a letter either under standard instructions or with facilitation (a guide scheme), preceded by a brief training on how to use the facilitation. Results show that both groups drew benefit from the guide scheme. Despite the fact that differences between groups were maintained after the training for the case of spelling errors, the poorer performance of ADHD children vanished. It is concluded that ADHD children have poor expressive writing skills, but this can be improved through the help of a guide scheme preceded by brief training.
Deconstructing Barriers
Authors: Denhart Hazel
Published: October 2008

This phenomenological study investigated barriers to higher education faced by 11 college students labeled with learning disabilities (LD) using their voice as the primary data. Data were analyzed and interpreted through a disability theory perspective revealing barriers stemmed largely from external social causes rather than individual pathology. Barriers included being misunderstood by faculty, being reluctant to request accommodations for fear of invoking stigma, and having to work considerably longer hours than nonlabeled peers. Findings indicated barriers could be overcome through raising faculty awareness about LD issues, engaging the assistance of the college LD specialist, and participation in a LD democratic empowerment community on campus.
Retromalleolar Groove Impaction for the Treatment of Unstable Peroneal Tendons
Authors: Walther Markus , Morrison Robert , Mayer Bernd
Published: October 2008

Background

Several techniques are published for the treatment of peroneal tendon instability.

Hypothesis

The fibular retromalleolar groove impaction technique is a simple and reliable surgical procedure with low morbidity for the treatment of peroneal tendon instability.

Study Design

Case series; Level of evidence, 4.

Methods

Twenty-three consecutive patients (average age, 34.2 years; range, 16-57 years) with a symptomatic subluxation of the peroneal tendons but no other peroneal tendon injuries were included in the study. All patients were severely limited in sports participation by their symptoms. The mean preoperative American Orthopedic Foot and Ankle Society score was 68.5 (range, 47-78). The reconstruction of the peroneal retromalleolar groove was performed by removing the cancellous bone behind the groove with a 3.5-mm drill. Then the entire peroneal rim was mobilized with small osteotomes at its edges and impacted into the fibula. Using this technique, it was possible to deepen the peroneal retromalleolar groove and to preserve the smooth surface of the peroneal rim at the same time. After the procedure, the patients were kept in a boot cast for 6 weeks with partial weight-bearing of 20 kg. The ankle joint was then mobilized under the supervision of a physical therapist. Linear sports activities were allowed after 7 weeks and unlimited sports after 12 weeks.

Results

No local wound problems were observed, and no further symptomatic subluxation or dislocation of the peroneal tendons was encountered during the 2-year follow-up. The mean American Orthopedic Foot and Ankle Society score improved to 96.3 (range, 85-100).

Conclusion

Groove impaction offers a simple, quickly done procedure with low morbidity, relatively quick return to sports, and successful elimination of peroneal tendon instability.
Pathways to Adult Sexual Revictimization
Authors: Fargo Jamison D.
Published: October 2008

The purpose of this study is to investigate direct and indirect social and behavioral risk factors for adult sexual revictimization. Participants include 147 adult, predominantly African American (88%) women, 59% of whom had a documented history of child sexual abuse. Participants are interviewed in adulthood about adolescent and adult sexual victimization as well as other background and lifestyle characteristics. Structural equation modeling indicates that the relationship between child and adolescent sexual victimization is indirect, mediated by adolescent risk-taking behavior. The relationship between adolescent and adult sexual victimization is also indirect, mediated by risky sexual behavior. The residual effects of early childhood family environment and childhood physical abuse also indirectly predict sexual revictimization. Results provide empirical support for the general supposition that the relationship between child and adult sexual victimization is complex and that many intermediary factors differentially affect risk for a heightened vulnerability to sexual revictimization.
Design and Experimental Parameteric Study of a Fish Robot Actuated by Piezoelectric Actuators
Authors: Wiguna Tedy , Heo Seok , Hoon Cheol Park  , Nam Seo Goo
Published: October 2008

This paper presents the design and experimental parametric study of a biomimetic fish robot actuated by two lightweight piezo-composite actuators. The biomimetic aspects in this work are the mimicking of an oscillating tail-beat motion and the shape of an artificial caudal fin. Artificial caudal fins that resemble the fins of fish propelled by the body-and-caudal fin mode are fabricated for a parametric study of the way caudal fin characteristics affect the production of thrust at an operating frequency range. The observed caudal fin characteristics are the shape, area, and aspect ratio. A caudal fin with a high aspect ratio contributes to the high swimming speed of the present fish platform. A fish robot propelled by an artificial caudal fin shaped like the fin of a thunniform fish, which has a relatively high aspect ratio, produces a swimming speed as high as 2.364 cm/s for a 300 Vpp input voltage excited at 0.9Hz. The thrust performance of the biomimetic fish robot is examined in terms of the Strouhal number, the Froude number, the Reynolds number, and power consumption.
Multi-mode Damage Detection Methods with Piezoelectric Wafer Active Sensors
Authors: Lingyu Yu  , Giurgiutiu Victor
Published: October 2008

PWAS are small and non-invasive transducers that can be easily affixed to a structure to interrogate it at will. Their wideband non-resonant properties make them advantageous candidates for multiple modes structural health monitoring (SHM) and nondestructive evaluation (NDE) simply by changing the driving frequencies. This paper presents research results obtained by using PWAS transducer for SHM/NDE. The results are given in the following directions: (1) PWAS operation principles; (2) PWAS electromechanical impedance measurements; (3) PWAS ultrasonic SHM/NDE; and (4) PWAS multi-mode corrosion detection. The analytical methods and experimental results can be successfully used in the design of active SHM systems to be embedded on operational structures, such as aircraft panels.
Advanced Higher Order Spectra for Classification of Damage in Transient Conditions
Authors: Gelman L. , Lapeña E. , Thompson C.
Published: October 2008

A generalization of the higher order spectra is proposed for damage classification for transient signals with any nonlinear time variation of the instantaneous frequency. The generalized transform is applied for the exponential variation of the instantaneous frequency and compared with partially adapted and non-adapted generalized transforms and the classical higher order spectra. It is shown that in transient conditions the fully adapted generalized transform is more effective for damage classification than the classical higher order spectra, partially adapted and non-adapted generalized transforms.
Improving Academic Achievement, But at What Cost?
Authors: Castagno Angelina E.
Published: October 2008

This case focuses on an urban middle school that has recently seen much improvement in the academic performance of its students and its reputation within the community. These positive changes, however, have come about largely because of what might be perceived as a narrow focus on standardized curricula, pedagogy, and assessment techniques. Readers are asked to consider the relative costs and benefits of this focus; the implications of change for faculty, administrators, students, and the larger community; and what it really means to lead with a goal of social justice or equity in mind given the nuances presented in this case—nuances that are shared by many urban schools across the nation.
Doing All the Right Things
Authors: Brown Kathleen M. , Schainker Stanley A.
Published: October 2008

Teacher retention has become a national crisis. This case study describes one principal's efforts to support new teachers and reduce the turnover rate at her school. Recognizing the problem a few years ago, the principal took what she thought were a number of proactive, decisive steps to resolve the issue—she is doing all the right things. However, instead of improving, her new teacher attrition and migration rates are actually getting worse.
Grades and Graduation
Authors: Salmonowicz Michael J.
Published: October 2008

This case was written for use in courses dealing with school administration, philosophy of education, or ethics in educational leadership. It deals with the ethical dilemma of an assistant principal at a low-performing, urban high school. Caught between a principal and a teacher who have different views on plagiarism, the assistant principal must decide whether to bring to light allegations of illegal grade-changes for two students that could threaten their status as high school graduates. Students reading the case should assume the role of the assistant principal and, considering the perspectives of the opposing parties, resolve the situation in an ethical manner.
Evaluation of human gene variant detection in amplicon pools by the GS-FLX parallel Pyrosequencer
Authors: Bordoni Roberta , Bonnal Raoul , Rizzi Ermanno , Carrera Paola , Benedetti Sara , Cremonesi Laura , Stenirri Stefania , Colombo Alessio , Montrasio Cristina , Bonalumi Sara , Albertini Alberto , Bernardi Luigi Rossi , Ferrari Maurizio , De Bellis Gianluca
Published: October 2008

Background

A new priority in genome research is large-scale resequencing of genes to understand the molecular basis of hereditary disease and cancer. We assessed the ability of massively parallel pyrosequencing to identify sequence variants in pools. From a large collection of human PCR samples we selected 343 PCR products belonging to 16 disease genes and including a large spectrum of sequence variations previously identified by Sanger sequencing. The sequence variants included SNPs and small deletions and insertions (up to 44 bp), in homozygous or heterozygous state.

Results

The DNA was combined in 4 pools containing from 27 to 164 amplicons and from 8,9 to 50,8 Kb to sequence for a total of 110 Kb. Pyrosequencing generated over 80 million base pairs of data. Blind searching for sequence variations with a specifically designed bioinformatics procedure identified 465 putative sequence variants, including 412 true variants, 53 false positives (in or adjacent to homopolymeric tracts), no false negatives. All known variants in positions covered with at least 30× depth were correctly recognized.

Conclusion

Massively parallel pyrosequencing may be used to simplify and speed the search for DNA variations in PCR products. Our results encourage further studies to evaluate molecular diagnostics applications.
Regulatory and structural properties differentiating the chromosomal and the bacteriophage-associated Escherichia coli O157:H7 Cu, Zn Superoxide Dismutases
Authors: D'Orazio Melania , Scotti Raffaella , Nicolini Laura , Cervoni Laura , Rotilio Giuseppe , Battistoni Andrea , Gabbianelli Roberta
Published: October 2008

Background

Highly virulent enterohemorrhagic Escherichia coli O157:H7 strains possess three sodC genes encoding for periplasmic Cu, Zn superoxide dismutases: sodC, which is identical to the gene present in non-pathogenic E. coli strains, and sodC-F1 and sodC-F2, two nearly identical genes located within lambdoid prophage sequences. The significance of this apparent sodC redundancy in E. coli O157:H7 has not yet been investigated.

Results

We report that strains deleted of one or more sodC genes are less resistant than the wild type strain to a challenge with hydrogen peroxide, thus confirming their involvement in the bacterial antioxidant apparatus. To understand if the different sodC genes have truly overlapping functions, we have carried out a comparison of the functional, structural and regulatory properties of the various E. coli O157:H7 SodC enzymes. We have found that the chromosomal and prophagic sodC genes are differentially regulated in vitro. sodC is exclusively expressed in aerobic cultures grown to the stationary phase. In contrast, sodC-F1 and sodC-F2 are expressed also in the logarithmic phase and in anaerobic cultures. Moreover, the abundance of SodC-F1/SodC-F2 increases with respect to that of SodC in bacteria recovered from infected Caco-2 cells, suggesting higher expression/stability of SodC-F1/SodC-F2 in intracellular environments. This observation correlates with the properties of the proteins. In fact, monomeric SodC and dimeric SodC-F1/SodC-F2 are characterized by sharp differences in catalytic activity, metal affinity, protease resistance and stability.

Conclusion

Our data show that the chromosomal and bacteriophage-associated E. coli O157:H7 sodC genes have different regulatory properties and encode for proteins with distinct structural/functional features, suggesting that they likely play distinctive roles in bacterial protection from reactive oxygen species. In particular, dimeric SodC-F1 and SodC-F2 possess physico-chemical properties which make these enzymes more suitable than SodC to resist the harsh environmental conditions which are encountered by bacteria within the infected host.
Genotypic and phenotypic diversity of Bacillus spp. isolated from steel plant waste
Authors: Freitas Dulcecleide B , Reis Mariana P , Lima-Bittencourt Cláudia I , Costa Patrícia S , Assis Paulo S , Chartone-Souza Edmar , Nascimento Andréa MA
Published: October 2008

Background

Molecular studies of Bacillus diversity in various environments have been reported. However, there have been few investigations concerning Bacillus in steel plant environments. In this study, genotypic and phenotypic diversity and phylogenetic relationships among 40 bacterial isolates recovered from steel plant waste were investigated using classical and molecular methods.

Results

16S rDNA partial sequencing assigned all the isolates to the Bacillus genus, with close genetic relatedness to the Bacillus subtilis and Bacillus cereus groups, and to the species Bacillus sphaericus. tDNA-intergenic spacer length polymorphisms and the 16S–23S intergenic transcribed spacer region failed to identify the isolates at the species level. Genomic diversity was investigated by molecular typing with rep (repetitive sequence) based PCR using the primer sets ERIC2 (enterobacterial repetitive intergenic consensus), (GTG)5, and BOXAIR. Genotypic fingerprinting of the isolates reflected high intraspecies and interspecies diversity. Clustering of the isolates using ERIC-PCR fingerprinting was similar to that obtained from the 16S rRNA gene phylogenetic tree, indicating the potential of the former technique as a simple and useful tool for examining relationships among unknown Bacillus spp. Physiological, biochemical and heavy metal susceptibility profiles also indicated considerable phenotypic diversity. Among the heavy metal compounds tested Zn, Pb and Cu were least toxic to the bacterial isolates, whereas Ag inhibited all isolates at 0.001 mM.

Conclusion

Isolates with identical 16S rRNA gene sequences had different genomic fingerprints and differed considerably in their physiological capabilities, so the high levels of phenotypic diversity found in this study are likely to have ecological relevance.
The development of motor coordination in Drosophilaembryos
Authors: Crisp Sarah , Evers Jan Felix , Fiala André , Bate Michael
Published: October 2008

We used non-invasive muscle imaging to study the onset of motor activity and emergence of coordinated movement in Drosophila embryos. Earliest movements are myogenic, and neurally controlled muscle contractions first appear with the onset of bursting activity 17 hours after egg laying. Initial episodes of activity are poorly organised and coordinated crawling sequences only begin to appear after a further hour of bursting. Thus, network performance improves during this first period of activity. The embryo continues to exhibit bursts of crawling-like sequences until shortly before hatching, while other reflexes also mature. Bursting does not begin as a reflex response to sensory input but appears to reflect the onset of spontaneous activity in the motor network. It does not require GABA-mediated transmission, and, by using a light-activated channel to excite the network,we demonstrate activity-dependent depression that may cause burst termination.
Landmark guidance and vector navigation in outbound desert ants
Authors: Merkle Tobias , Wehner Rüdiger
Published: October 2008

This study deals with the influence landmark information has on the foraging behaviour of the desert ant, Cataglyphis fortis, especially with the interaction of such landmark information with the ants' path integration system. We show in the first experiment that desert ants that are captured immediately after leaving their nest and then transferred to a remote test area search for the nest rather than activate their previous path integration vector. In a second experiment, the ants had been trained to a landmark corridor on their way to the feeder. In the critical test situation,they were again captured immediately after they had left the nest and transferred to a test field where they faced one of the following three situations: (1) the same landmark corridor as used during the training phase,(2) no landmarks at all and (3) a landmark corridor rotated by 90 deg. as compared with the training situation. Nearly all ants in test situation (1)eventually followed the landmark corridor but most of them never reached the fictive feeder. In situation (2), the ants searched around the nest entrance. In situation (3), approximately one half of the ants searched for the nest,whereas most of the other ants followed the landmark corridor, i.e. headed in a completely wrong direction. Hence, familiar landmarks do not only influence the foraging behaviour of desert ants, e.g. in making the ants start their foraging runs but can even out-compete the ants' path integration system.
Unlinked anonymous HIV prevalence among New Zealand sexual health clinic attenders: 2005–2006
Authors: McAllister S M , Dickson N P , Sharples K , Reid M R , Morgan J M , MacDonald E J , Coughlan E , Johnston T M , Tanner N A , Paul C
Published: October 2008

This unlinked anonymous study aimed at determining the prevalence of HIV among sexual health clinic attenders having blood samples taken for syphilis and/or hepatitis B serology in six major New Zealand cities over a 12-month period in 2005–2006. Overall, seroprevalence was five per 1000 (47/9439). Among men who have sex with men (MSM), the overall prevalence and that of previously undiagnosed HIV were 44.1 and 20.1 per 1000, respectively. In heterosexual men, the overall prevalence was 1.2 per 1000 and in women 1.4 per 1000. HIV remains to be concentrated among homosexual and bisexual men. Comparison with a previous survey in 1996–1997 suggests an increase in the prevalence of undiagnosed HIV among MSM and also an increase in the number of MSM attending sexual health clinics. The low prevalence of HIV among heterosexuals suggests no extensive spread into the groups identified at risk of other sexually transmitted infections.
Clinical Impact of New Prostate-Specific Antigen WHO Standardization on Biopsy Rates and Cancer Detection
Authors: Jansen F H , Roobol M , Bangma C H , van Schaik R H N
Published: October 2008

Background: Clinicians may be unaware that replacement of the historical total prostate-specific antigen (tPSA) standard with the WHO 96/670 international standard leads to difficulties in interpreting tPSA results. Our aim was to investigate the relationship between the Hybritech and WHO calibrations of the Beckman Coulter tPSA assay, and to assess the impact on prostate cancer (PCa) detection.

Methods: tPSA concentrations were measured in 106 serum samples with both Hybritech and WHO calibrations. The established relationships were used for an in silico experiment with a cohort of 5865 men. Differences in prostate biopsy rates, PCa detection, and characteristics of missed cancers were calculated at biopsy thresholds of 3.0 and 4.0 μg/L.

Results: A linear relationship was observed between the 2 calibrations, with a 20.3% decrease in tPSA values with the WHO standard compared with the Hybritech calibration. Applying the WHO calibration to the cohort of 5865 men yielded a 20% or 19% decrease in prostate biopsies and a 19% or 20% decrease in detected cancers compared with the Hybritech calibration, at a cutoff for biopsy of 3.0 or 4.0 μg/L, respectively. The decrease in detected cancers declined to 9% or 11% if an abnormal result in a digital rectal examination or a transrectal ultrasound evaluation was used as trigger for prostate biopsy (cutoff of 3.0 or 4.0 μg/L, respectively).

Conclusions: Application of the WHO standard for tPSA assays with commonly used tPSA thresholds leads to a significant decrease in PCa detection. Careful assessment of the relationship between the WHO standard and the thresholds used for prostate biopsy is hence necessary.
Automated Measurement of 25-OH Vitamin D3 on the Roche Modular E170 Analyzer
Authors: Leino Aila , Turpeinen Ursula , Koskinen Pertti
Published: October 2008

Background: The first commercial direct automated immunoassay specific for 25-OH vitamin D3 (25-OH-D3) was recently introduced for use on Roche Diagnostics immunoassay analyzers. We assessed the analytical performance of the Elecsys 25-OH-D3 assay on a Roche Modular E 170 analyzer.

Methods: The Elecsys 25-OH-D3 assay is a direct electrochemiluminescence immunoassay for human serum or plasma. It is a competitive assay in which the binding protein of vitamin D is inactivated during incubation. The assay employs a polyclonal antibody directed against 25-OH vitamin D3. We compared the 25-OH-D3 assay to assays performed with RIA, HPLC, and liquid chromatography–tandem mass spectrometry (LC-MS/MS).

Results: At concentrations of 48, 76, and 124 nmol/L, within-run CVs were 5.1%, 3.1%, and 7.1% and total CVs were 12.1%, 7.4%, and 10.6%, respectively. A comparison of Elecsys 25-OH vitamin D3 with RIA yielded the regression equation: Elecsys = 1.114 × RIA – 6.15 (Sy|x = 15.7 nmol/L; n = 163). The corresponding equation with HPLC was: Elecsys = 1.077 × HPLC + 5.442 (Sy|x = 13.9 nmol/L; n = 67) and with LC-MS/MS: Elecsys = 0.887 × LC-MS/MS + 5.046 (Sy|x =12.4 nmol/L; n = 64). Contrary to LC-MS/MS, with the cutoff of 50 nmol/L (deficiency vs normal), approximately 10% of samples were misclassified as normal with RIA and Elecsys. Plasma samples were observed to have markedly higher concentrations than serum samples.

Conclusions: The Elecsys concentrations of 25-OH-D3 were in good overall agreement with those determined with LC-MS/MS and RIA. However, large between-method variation was observed in individual patient samples. Use of serum rather than plasma is preferred owing to the higher results observed with plasma samples.
Assessing the Impact of the Frequency of Quality Control Testing on the Quality of Reported Patient Results
Authors: Parvin Curtis A
Published: October 2008

Background: The traditional measure used to evaluate QC performance is the probability of rejecting an analytical run that contains a critical out-of-control error condition. The probability of rejecting an analytical run, however, is not affected by changes in QC-testing frequency. A different performance measure is necessary to assess the impact of the frequency of QC testing.

Methods: I used a statistical model to define in-control and out-of-control processes, laboratory testing modes, and quality control strategies.

Results: The expected increase in the number of unacceptable patient results reported during the presence of an undetected out-of-control error condition is a performance measure that is affected by changes in QC-testing frequency. I derived this measure for different out-of-control error conditions and laboratory testing modes and showed that a worst-case expected increase in the number of unacceptable patient results reported can be estimated. The laboratory thus has the ability to design QC strategies that limit the expected number of unacceptable patient results reported.

Conclusions: To assess the impact of the frequency of QC testing on QC performance, it is necessary to move beyond thinking in terms of the probability of accepting or rejecting analytical runs. A performance measure based on the expected increase in the number of unacceptable patient results reported has the dual advantage of objectively assessing the impact of changes in QC-testing frequency and putting focus on the quality of reported patient results rather than the quality of laboratory batches.