bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen production and COD elimination rate in a continuous microbial electrolysis cell: The influence of hydraulic retention time and applied voltage
Authors: Escapa A. , Lobato A. , García D.M. , Morán A.
Published: February 2012

The influence of the applied voltage (Vapp) and the hydraulic retention time (HRT) on hydrogen and methane production and the removal rate for chemical oxygen demand (COD) was studied in a membrane‐less microbial electrolysis cell with a Ni‐based cathode. When a synthetic effluent from a dark‐fermentation process was fed continuously into the anodic chamber, an increase in both the Vapp (from 0.6 to 1.0 V) and HRT (from 8 to 12 h) increased the hydrogen production rate from 0.18 to 1.42 L LA−1 d−1 (liters per liter of anode per day) and the COD elimination rate from 46 to 94%. The influences of Vapp and HRT on hydrogen production and the COD removal rate were found to be interdependent. Whereas acetic and butyric acids were easily degraded, propionic acid exhibited pseudo‐recalcitrant behavior. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 263‐268, 2013
Seismic isolation for low‐to‐medium‐rise buildings using granulated rubber–soil mixtures: numerical study
Authors: Tsang Hing‐Ho , Lo S. H. , Xu X. , Neaz Sheikh M.
Published: February 2012

This paper presents the preliminary research works on a potential seismic isolation method that makes use of scrap rubber tires for the protection of low‐to‐medium‐rise buildings. The method involves mixing shredded rubber tire particles with soil materials and placing the mixtures around building foundations, which provides a function similar to that of a cushion. Meanwhile, the stockpiling of scrap tires is a significant threat to our environment, and the engineering community has been looking for long‐term viable solutions to the recycling and reuse of rubber. A finite element program has been developed for modeling the time‐domain dynamic responses of soil–foundation–structure system, by which the effectiveness and robustness of the proposed method have been evaluated. In general, the structural responses, in terms of acceleration and inter‐story drift, can be reduced by 40–60%. Copyright © 2012 John Wiley & Sons, Ltd.
Brief screening for mild cognitive impairment: validation of the Brazilian version of the Montreal cognitive assessment
Authors: Memória Cláudia M. , Yassuda Mônica S. , Nakano Eduardo Y. , Forlenza Orestes V.
Published: February 2012

Background

The Montreal Cognitive Assessment (MoCA) is a brief cognitive schedule that has been developed for the screening of patients with Mild Cognitive Impairment (MCI). MCI is recognized as a high‐risk state for Alzheimer's disease. The aim of the present study is to examine the reliability and validity of the Brazilian version of the MoCA test (MoCA‐BR) in a sample of older individuals with at least 4 years of education.

Methods

The MoCA‐BR was administered to 112 older adults who were classified into three diagnostic groups according to their cognitive state (Alzheimer's disease, n = 28; MCI, n = 43; normal controls, n = 41). This procedure was based on clinical and neuropsychological data. The performance in the MoCA‐BR was compared with the Mini‐mental state examination (MMSE) and the Cambridge Cognitive Examination. Diagnostic accuracy was examined with the receiver operating characteristic (ROC) curve analyses.

Results

Cronbach's alpha for the MoCA‐BR was 0.75. Temporal stability (retesting after 3 months) using intraclass correlation coefficient was 0.75 (p < 0.001). The sensitivity and specificity of the MoCA‐BR for MCI were 81% and 77%, respectively, with a cut‐off score of 25 points. The area under the ROC curve for predicting MCI was 0.82 ± 0.06.

Conclusions

The present results indicate that the MoCA‐BR maintains its core diagnostic properties rendering it a valid and reliable tool for the screening of MCI among older individuals with at least 4 years of education. Copyright © 2012 John Wiley & Sons, Ltd.
Unique effects of apathy and depression signs on cognition and function in amnestic mild cognitive impairment
Authors: Zahodne Laura B. , Tremont Geoffrey
Published: February 2012

Objective

Apathy and depression are the most common neuropsychiatric features in mild cognitive impairment (MCI). These syndromes have been linked to cognitive and functional decline. This study aimed to examine their unique relationships with specific cognitive abilities and daily functioning among MCI patients with memory impairment (amnestic MCI).

Methods

Data from 90 individuals referred for outpatient clinical neuropsychological evaluation and subsequently characterized as having amnestic MCI were obtained from a memory disorders center. MCI was defined using current NIA‐Alzheimer's Association criteria. Variables included caregiver‐reported apathy (Frontal Systems Behavior Scale) and depression (Memory and Behavioral Problems Checklist), scores on neuropsychological measures, and the Lawton–Brody Instrumental Activities of Daily Living Scale. Data were analyzed with multiple regressions controlling for age and education.

Results

Depression was independently associated with composite scores of executive functioning. Neither apathy nor depression was associated with composite scores of attention, memory, or language. With regard to individual measures of executive functioning, depression was independently associated with poorer set‐shifting (i.e., Trails B). Apathy was independently associated with poorer letter fluency (i.e., FAS). Apathy, but not depression, was associated with greater functional impairment.

Conclusions

Apathy and depression are associated with different aspects of executive functioning in amnestic MCI, which may reflect differing patterns of frontal lobe pathology. Apathy exerts a greater impact on daily functioning than depression and may therefore increase reliance on caregivers. Results support the separability of apathy and depression in amnestic MCI. Clinicians should differentiate these neuropsychiatric states during assessment and treatment. Copyright © 2012 John Wiley & Sons, Ltd.
Probing principles of large‐scale object representation: Category preference and location encoding
Authors: Cichy Radoslaw Martin , Sterzer Philipp , Heinzle Jakob , Elliott Lloyd T. , Ramirez Fernando , Haynes John‐Dylan
Published: February 2012

Knowledge about the principles that govern large‐scale neural representations of objects is central to a systematic understanding of object recognition. We used functional magnetic resonance imaging (fMRI) and multivariate pattern classification to investigate two such candidate principles: category preference and location encoding. The former designates the preferential activation of distinct cortical regions by a specific category of objects. The latter refers to information about where in the visual field a particular object is located. Participants viewed exemplars of three object categories (faces, bodies, and scenes) that were presented left or right of fixation. The analysis of fMRI activation patterns revealed the following. Category‐selective regions retained their preference to the same categories in a manner tolerant to changes in object location. However, category preference was not absolute: category‐selective regions also contained location‐tolerant information about nonpreferred categories. Furthermore, location information was present throughout high‐level ventral visual cortex and was distributed systematically across the cortical surface. We found more location information in lateral‐occipital cortex than in ventral‐temporal cortex. Our results provide a systematic account of the extent to which the principles of category preference and location encoding determine the representation of objects in the high‐level ventral visual cortex. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Temporal manipulation of transferrin‐receptor‐1‐dependent iron uptake identifies a sensitive period in mouse hippocampal neurodevelopment
Authors: Fretham S.J.B. , Carlson E.S. , Wobken J. , Tran P.V. , Petryk A. , Georgieff M.K.
Published: February 2012

Iron is a necessary substrate for neuronal function throughout the lifespan, but particularly during development. Early life iron deficiency (ID) in humans (late gestation through 2–3 yr) results in persistent cognitive and behavioral abnormalities despite iron repletion. Animal models of early life ID generated using maternal dietary iron restriction also demonstrate persistent learning and memory deficits, suggesting a critical requirement for iron during hippocampal development. Precise definition of the temporal window for this requirement has been elusive due to anemia and total body and brain ID inherent to previous dietary restriction models. To circumvent these confounds, we developed transgenic mice that express tetracycline transactivator regulated, dominant negative transferrin receptor (DNTfR1) in hippocampal neurons, disrupting TfR1 mediated iron uptake specifically in CA1 pyramidal neurons. Normal iron status was restored by doxycycline administration. We manipulated the duration of ID using this inducible model to examine long‐term effects of early ID on Morris water maze learning, CA1 apical dendrite structure, and defining factors of critical periods including parvalbmin (PV) expression, perineuronal nets (PNN), and brain‐derived neurotrophic factor (BDNF) expression. Ongoing ID impaired spatial memory and resulted in disorganized apical dendrite structure accompanied by altered PV and PNN expression and reduced BDNF levels. Iron repletion at P21, near the end of hippocampal dendritogenesis, restored spatial memory, dendrite structure, and critical period markers in adult mice. However, mice that remained hippocampally iron deficient until P42 continued to have spatial memory deficits, impaired CA1 apical dendrite structure, and persistent alterations in PV and PNN expression and reduced BDNF despite iron repletion. Together, these findings demonstrate that hippocampal iron availability is necessary between P21 and P42 for development of normal spatial learning and memory, and that these effects may reflect disruption of critical period closure by early life ID. © 2012 Wiley Periodicals, Inc.
Voltage dependence of subthreshold resonance frequency in layer ii of medial entorhinal cortex
Authors: Shay Christopher F. , Boardman Ian S. , James Nicholas M. , Hasselmo Michael E.
Published: February 2012

The resonance properties of individual neurons in entorhinal cortex (EC) may contribute to their functional properties in awake, behaving rats. Models propose that entorhinal grid cells could arise from shifts in the intrinsic frequency of neurons caused by changes in membrane potential owing to depolarizing input from neurons coding velocity. To test for potential changes in intrinsic frequency, we measured the resonance properties of neurons at different membrane potentials in neurons in medial and lateral EC. In medial entorhinal neurons, the resonant frequency of individual neurons decreased in a linear manner as the membrane potential was depolarized between −70 and −55 mV. At more hyperpolarized membrane potentials, cells asymptotically approached a maximum resonance frequency. Consistent with the previous studies, near resting potential, the cells of the medial EC possessed a decreasing gradient of resonance frequency along the dorsal to ventral axis, and cells of the lateral EC lacked resonant properties, regardless of membrane potential or position along the medial to lateral axis within lateral EC. Application of 10 μM ZD7288, the H‐channel blocker, abolished all resonant properties in MEC cells, and resulted in physiological properties very similar to lateral EC cells. These results on resonant properties show a clear change in frequency response with depolarization that could contribute to the generation of grid cell firing properties in the medial EC. © 2012 Wiley Periodicals, Inc.
Junior Placement and Community Activities
Authors: SHOTWELL MARY G.
Published: February 2012

Junior counselors in North Carolina are following an interesting program which coordinates the youth‐serving agencies available in a community. The schools, private industry, the National Youth Administration, the State Employment Service are all cooperating in the guidance, training and placement of youth. Some valuable suggestions are offered by the writer.
Training for Public Service
Authors: MOORE LYMAN S.
Published: February 2012

An increasingly large number of jobs in the public service are coming to be regarded as careers. How shall we insure that incumbents in such positions have the requisite training? The author's answer calls for a coordination of facilities which should challenge educators of traditional bent.
First‐principles calculations on the four phases of BaTiO3
Authors: Evarestov Robert A. , Bandura Andrei V.
Published: February 2012

The calculations based on linear combination of atomic orbitals basis functions as implemented in CRYSTAL09 computer code have been performed for cubic, tetragonal, orthorhombic, and rhombohedral modifications of BaTiO3 crystal. Structural and electronic properties as well as phonon frequencies were obtained using local density approximation, generalized gradient approximation, and hybrid exchange‐correlation density functional theory (DFT) functionals for four stable phases of BaTiO3. A comparison was made between the results of different DFT techniques. It is concluded that the hybrid PBE0 [J. P. Perdew, K. Burke, M. Ernzerhof, J. Chem. Phys. 1996, 105, 9982.] functional is able to predict correctly the structural stability and phonon properties both for cubic and ferroelectric phases of BaTiO3. The comparative phonon symmetry analysis in BaTiO3 four phases has been made basing on the site symmetry and irreducible representation indexes for the first time. © 2012 Wiley Periodicals, Inc.
Pediatric observation status: Are we overlooking a growing population in children's hospitals?
Authors: Macy Michelle L. , Hall Matthew , Shah Samir S. , Harding John P. , Del Beccaro Mark A. , Hain Paul D. , Hronek Carla , Alpern Elizabeth R.
Published: February 2012

BACKGROUND:

Inpatient administrative datasets often exclude observation stays, as observation is considered to be outpatient care. The extent to which this status is applied to pediatric hospitalizations is not known.

OBJECTIVE:

To characterize trends in observation status code utilization and 1‐day stays among children admitted from the emergency department (ED), and to compare patient characteristics and outcomes associated with observation versus inpatient stays.

DESIGN:

Retrospective longitudinal analysis of the 2004–2009 Pediatric Health Information System (PHIS).

SETTING:

Sixteen US freestanding children's hospitals contributing outpatient and inpatient data to PHIS.

PATIENTS:

Admissions to observation or inpatient status following ED care in study hospitals.

MEASUREMENTS:

Proportions of observation and 1‐day stays among all admissions from the ED were calculated each year. Top ranking discharge diagnoses and outcomes of observation were determined. Patient characteristics, discharge diagnoses, and return visits were compared for observation and 1‐day stays.

RESULTS:

The proportion of short‐stays (including both observation and 1‐day stays) increased from 37% to 41% between 2004 and 2009. Since 2007, observation stays have outnumbered 1‐day stays. In 2009, more than half of admissions from the ED for 6 of the top 10 ranking discharge diagnoses were short‐stays. Fewer than 25% of observation stays converted to inpatient status. Return visits and readmissions following observation were no more frequent than following 1‐day stays.

CONCLUSIONS:

Children admitted under observation status make up a substantial proportion of acute care hospitalizations. Analyses of inpatient administrative databases that exclude observation stays likely result in an underestimation of hospital resource utilization for children. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
Longitudinal assessment of symptom severity among hospitalized elders diagnosed with cancer, heart failure, and chronic obstructive pulmonary disease
Authors: Pantilat Steven Z. , O'Riordan David L. , Dibble Suzanne L. , Landefeld C. Seth
Published: February 2012

BACKGROUND:

Pain, dyspnea, and anxiety are common among patients with cancer, heart failure (HF), and chronic obstructive pulmonary disease (COPD), yet little is known about the severity of symptoms over time.

OBJECTIVE:

To determine the prevalence, severity, burden, and predictors of symptoms during the course of hospitalization and at 2 weeks after discharge.

DESIGN:

A prospective cohort study.

SETTING:

A large academic university.

PATIENTS:

Patients were 65 years or older with a primary diagnosis of cancer, COPD, or HF.

MEASUREMENTS:

Daily living skills and depression were recorded at enrollment. Symptoms were assessed daily and 2 weeks postdischarge.

RESULTS:

At baseline, most participants reported moderate/severe pain (54%), dyspnea (53%), and anxiety (62%). Almost two‐thirds (64%) had 2 or more symptoms at a moderate/severe level. The prevalence of moderate/severe symptoms decreased at the 24‐hour assessment (pain = 42%, dyspnea = 45%, anxiety = 55%, burden = 55%) and again at follow‐up (pain = 28%, dyspnea = 27%, anxiety = 25%, burden = 30%). While there was no association between primary diagnosis and symptom severity at baseline or 24‐hour assessment, at 2‐week follow‐up, a higher percentage of patients with COPD had moderate/severe pain (54%, χ2 = 22.0, P = 0.001), dyspnea (45%, χ2 = 9.3, P = 0.05), and overall symptom burden (55%, χ2 = 25.9, P = 0.001) than those with cancer (pain = 22%, dyspnea = 16%, symptom burden = 16%) or HF (pain = 25%, dyspnea = 24%, symptom burden = 28%). Predictors of symptom burden at follow‐up were COPD (odds ratio [OR] = 7.5; 95% confidence interval [CI] = 2.0, 27.7) and probable depression (OR = 6.1; 95% CI = 2.1, 17.8).

CONCLUSION:

The majority of inpatients with chronic illness reported high severity of symptoms. Symptoms improved over time but many patients, particularly those with COPD, had high symptom severity at follow‐up. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
Clinical utility of apparent diffusion coefficient values obtained using high b‐value when diagnosing prostate cancer using 3 tesla MRI: Comparison between ultra‐high b‐value (2000 s/mm2) and standard high b‐value (1000 s/mm2)
Authors: Kitajima Kazuhiro , Takahashi Satoru , Ueno Yoshiko , Yoshikawa Takeshi , Ohno Yoshiharu , Obara Makoto , Miyake Hideaki , Fujisawa Masato , Sugimura Kazuro
Published: February 2012

Purpose:

To determine whether the apparent diffusion coefficient (ADC) obtained using b = 2000 s/mm2 upon 3 Tesla (T) diffusion‐weighted MRI is superior to b = 1000 s/mm2 for discriminating malignant from normal prostate tissue and predicting the aggressiveness of prostate cancer, using histopathological findings of radical prostatectomy as a reference.

Materials and Methods:

Eighty prostate cancer patients underwent preoperative 3T MRI including diffusion weighted imaging with b‐values of 0, 1000, and 2000 s/mm2. ADCs were measured for malignant lesions and normal sites on three sets of ADC maps calculated with monoexponential fitting between b = 0 and 1000, 0 and 2000, and 1000 and 2000, respectively. The relationship between the ADC and Gleason score was evaluated.

Results:

The areas under the ROC curves for b = 0,1000, b = 0,2000, and b = 1000,2000 were 0.896, 0.937, and 0.857, respectively, in the peripheral zone (PZ) and 0.877, 0.889, and 0.731, respectively, in the transition zone (TZ). The difference between b = 0,1000 and b = 0,2000 was significant in PZ (P = 0.033), but not in TZ (P = 0.84). Weak but significant negative correlations were identified between ADCs and Gleason score in both PZ and TZ cancer at b = 0,1000 and b = 0,2000 (r = −0.323 to −0.341).

Conclusion:

For 3T MRI, ADCs using b = 0,2000 are more accurate than b = 0,1000 for diagnosing PZ cancer, and as accurate for TZ cancer. J. Magn. Reson. Imaging 2012;36:198–205. © 2012 Wiley Periodicals Inc.
Outcome of surgical treatment of pelvic osteosarcoma
Authors: Guo Wei , Sun Xin , Ji Tao , Tang Xiaodong
Published: February 2012

Background and objectives

Surgical treatment of pelvic osteosarcoma is often challenging. The objective of this study was to assess the oncologic and functional outcome and the operation‐related complications of patients with pelvic osteosarcoma who were treated in a single center in the past decade.

Methods

Nineteen patients underwent surgical procedures between June 2000 and June 2009. There were 11 males and 8 females with a mean age of 30 years. According to Enneking and Dunham pelvic classification system, there were: Type I‐3, Type I + IV‐3, Type I + II‐2, Type II + III‐4, Type I + II + III‐1, Type III‐1, and type I + II + IV‐5. All patients received chemotherapy.

Results

Local recurrence rate was 26.3% (5/19). The 5‐year overall survival rate was 44.9%. Seventeen patients received reconstruction after tumor resection. The average MSTS 93 score was 18 (10–23) for the 11 patients with hemipelvic endoprosthetic reconstruction and 23 (20–25) for 6 patients with rod‐screw reconstruction. Complication was found in 7 of 19 patients (36.8%).

Conclusion

The oncological results of pelvic osteosarcoma are poor at best. Even with a higher complication rate, we believe restoration of pelvic ring continuity and hip joint mobility is reasonable option to achieve favorable functional outcomes in selected patients. J. Surg. Oncol. 2012; 106:406–410. © 2012 Wiley Periodicals, Inc.
Stress‐Whitening of High‐Impact Poly(propylene): Characterization and Analysis
Authors: Liu Xuanbo , Guo Meifang , Wei Wenjun
Published: February 2012

Summary: High‐impact isotactic polypropylene (hiPP) is a multiphase material and hiPP is susceptible to stress‐whitening (or blushing) when exposed to impact, tension etc. Stress‐whitening will influence the quality of the products. The object of this work is to find the factors influencing the resistance of stress whitening. Five reactor‐alloy hiPP samples were used. Stress whitening was characterized by Gardner‐type impact apparatus. Automated PP viscometer and xylence solubles analyzer (CrystEX), tapping mode atomic force microscopy (TMAFM), Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), wide angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC) were used to characterize the samples. The stress‐whitening was found to be related with the following factors: 1.particle size of the dispersion phase (rubber phase), 2.composition of the dispersion phase, 3.crystallization in in the dispersion phase, 4.crystalline form of the matrix (iPP).
Effect of Ethylene‐Propylene Copolymer Composition on Morphology and Surface Properties of Impact Poly(propylene) Copolymer
Authors: Kim Soon‐Deok , Choi Yeonbeom , Choi Wonsook , Choi Changhyun , Chun Yong Sung
Published: February 2012

Summary: Impact poly(propylene) copolymers (IPC) having various ethylene‐propylene rubber (EPR) compositions were prepared using a high activity Ziegler‐Natta catalyst. EPR composition was characterized by temperature rising elution fractionation (TREF) analysis and FT‐IR spectroscopy. Effect of EPR composition on the morphology and surface properties of IPC was investigated by scanning electron microscopy (SEM), 3D profiler, and gloss meter. Composition and amount of amorphous and crystalline EPR were quantified by TREF and found to be dependent on the ethylene content in EPR. From the SEM result, it was found EPR composition has a strong influence on its shape and size. IPCs containing propylene‐rich EPR exhibited a finer dispersion of EPR phase. The surface roughness decreased with decreasing ethylene content in EPR. The comparison of EPR composition and morphology and surface properties exhibited strong correlations.
C6‐substituted purine derivatives: an experimental and theoretical 1H, 13C and 15N NMR study
Authors: Procházková Eliška , Šála Michal , Nencka Radim , Dračínský Martin
Published: February 2012

We measured the 1H, 13 C and 15 N chemical shifts for a series of purine derivatives bearing a norbornane substituent in position 9 and various substituents in position 6. The experimental data were complemented with density functional theory (DFT) calculations. The comparison of the calculated and experimental chemical shifts provided us with information about the tautomer and conformational equilibria of the studied compounds. Copyright © 2012 John Wiley & Sons, Ltd.
Influence of modified natural rubber and structure of carbon black on properties of natural rubber compounds
Authors: Salaeh Subhan , Nakason Charoen
Published: February 2012

Carbon black‐filled natural rubber composites were prepared using various types of natural rubber: unmodified natural rubber, epoxidized natural rubber with two levels of epoxy groups at 25 and 50 mol % [epoxidized natural rubber (ENR)‐25 and ENR‐50], and maleated natural rubber. Two types of carbon black (HAF and ECF) with different structure and surface area were used. The functional groups present in natural rubber and carbon black were characterized by FTIR and1H‐NMR. Furthermore, cure characteristics, mechanical, morphological, and electrical properties of composites and gum rubber compounds were investigated. It was found that the presence of polar functional groups in rubber molecules and the different structures of carbon black significantly affected the cure characteristics and mechanical properties. This is attributed to physical and chemical interactions between carbon black surfaces and rubber molecules. It was also found that natural rubber filled with ECF showed the highest Young's modulus and hardness, which is due to the high‐surface area and structure of the ECF causing an increase in the degree of entanglement between rubber chains and carbon black particles. Frequency dependency of the dielectric constant, loss tangent, and AC conductivity was also investigated. An increase in dielectric constant, loss tangent, and AC conductivity was observed in the ENR/ECF composites. High‐carbon black loading level caused network formation of these conductive particles, increasing the AC conductivity of the composites. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
About RC‐like contacts in deep level transient spectroscopy and Cu(In,Ga)Se2 solar cells
Authors: Lauwaert J. , Callens L. , Khelifi S. , Decock K. , Burgelman M. , Chirila A. , Pianezzi F. , Buecheler S. , Tiwari A. N. , Vrielinck H.
Published: February 2012

The low temperature Deep‐Level Transient Spectroscopy (DLTS) signal of two Cu(In, Ga)Se2 samples on glass with different buffer layers is subjected to a thorough study. A similar signal is observed in the DLTS and admittance spectra of many solar cells and is usually labeled as N1. The standard DLTS theory assumes the investigated device to be a Schottky or p–n diode with an ohmic back contact, and relates the spectral components to capture or emission of free carriers by defect levels in the structure. It is well‐known, though, that Cu(In, Ga)Se2 thin film solar cells deviate from this ideal structure. However, even for a device like this, where advanced numerical modeling is necessary to describe the equilibrium charge distribution as a function of applied bias, a change in the free carrier concentration at a certain position of the device as a result of capture or emission by deep defect levels should satisfy the detailed balance equation. The DLTS experiment performed with conventional and complemental settings for the reverse and pulse bias voltages (Vr < Vp < 0 and Vp < Vr < 0, respectively) exhibit characteristics that cannot be explained using free carrier transfer between deep levels—in the bulk or at an interface—and the conduction (electrons) or valence (holes) band of a semiconductor as a model. On the other hand, we show that for the solar cells studied here, the N1 signals follow the behavior predicted for a non‐ohmic RC‐like contact, as established in our recent paper (J. Lauwaert et al. Journal of Applied Physics 2011) closely. Copyright © 2012 John Wiley & Sons, Ltd.
Total Alkaloids of Sophorea alopecuroides‐induced Down‐regulation of AcrAB‐ToLC Efflux Pump Reverses Susceptibility to Ciprofloxacin in Clinical Multidrug Resistant Escherichia coli isolates
Authors: Zhou Xuezhang , Jia Fang , Liu Xiaoming , Wang Yujiong
Published: February 2012

In this report, total alkaloids extracted from the seeds of Sophorea alopecuroides (TASA) was evaluated against clinical Escherichia coli isolates resistant to four tested antibiotics, ampicillin (AM), amikacin (AN), cefotaxime (CTX) and ciprofloxacin (CIP). The TASA showed an antibacterial activity against the multidrug resistant (MDR) isolates. In combination with TASA, synergistic effects on the tested antibiotics against the MRD isolates were observed. Similarly, the isolates pretreated with a lower dose of TASA yielded increased and stable susceptibilities to CIP by 16–32‐fold determined by a microbroth dilution checkerboard method. Moreover, quantitative reverse transcription–polymerase chain reaction (qRT‐PCR) analysis revealed a constitutive overexpression of the AcrAB‐TolC pump system in the tested MDR isolates. The pretreatment of MDR isolates with TASA resulted in a statistically down‐regulated expression of acrA and acrB genes, and an up‐regulated expression of acrR gene (p < 0.05). But the expression of tolC gene was not significantly altered (p > 0.05). These results suggested that the TASA‐induced reversal resistance to CIP might be partially through a mechanism of inhibition of the AcrAB‐TolC pump activity in these isolates, implying that the TASA can be used as a potential natural source to develop efflux pump inhibitors (EPI) against AcrAB‐TolC pump mediated MDR in E. coli isolates. Copyright © 2012 John Wiley & Sons, Ltd.
Minimally invasive robotically assisted repair of atrial perforation from a pacemaker lead
Authors: Hussain Sara , Adams Corey , Mechulan Alexis , Leong‐Sit Peter , Kiaii Bob
Published: February 2012

Background

We present the first reported case of robotic‐assisted right atrial perforation repair and pacemaker lead extraction.

Methods

A 75‐year‐old female with symptomatic sinus node dysfunction underwent atrial single chamber permanent pacemaker insertion via a persistent left superior vena cava approach. At one week follow‐up a chest radiograph and a computerized dynamic tomography demonstrated that the right atrial lead had perforated the right atrial free wall. The patient remained asymptomatic without signs of pericardial tamponade, however urgent repair was warranted.

Results

Utilizing the da Vinci robotic system (Intuitive Surgical Inc., Sunnyvale, California, USA), the pacer lead perforation was visualized, the lead retracted, and the right atrium repaired. The existing atrial lead was repositioned in the right atrial appendage.

Conclusion

The patient's postoperative convalescence was uneventful, and she was discharged home on the third post‐operative day. This case demonstrates the increasing clinical utilization of robotic‐assisted technology in minimally invasive cardiac surgery. Copyright © 2012 John Wiley & Sons, Ltd.
Transient growth associated with continuous spectra of the Batchelor vortex
Authors: Mao X. , Sherwin S. J.
Published: February 2012

The spectrum of the Batchelor vortex can be broadly split into a discrete spectrum, a potential spectrum and a free-stream spectrum where, since the last two spectra are both continuous, they can also be considered as one continuous spectrum. The discrete spectrum has been extensively studied but the continuous spectrum has received limited attention in the context of vortex flow. A local transient growth study is conducted and the contribution of the discrete spectrum and the continuous spectrum to the transient growth is separated by constructing optimal perturbations on the discrete or continuous sub-eigenspaces separately. It is found that the significant transient growth is mainly due to the non-normality of the continuous eigenmodes/spectrum whilst the discrete eigenmodes/spectrum have little contribution to the transient energy growth. A matrix-free method, which reduces to the local analysis when appropriate periodic boundary conditions are imposed, is also applied to investigate the transient growth in both a plane of constant azimuthal angle and a plane constant axial location. Previously studies by other authors have demonstrated that at zero azimuthal wavenumber the transient growth reaches infinitely large values over infinite time intervals while the optimal perturbations are located far from the vortex core. Therefore we limited our scope to small values of the time horizon so as to obtain reasonably strong transient effects stemming from physically relevant optimal perturbations. Two mechanisms of transient growth are observed: namely a redistribution of the azimuthal velocity to the azimuthal vorticity and interaction between out-of-vortex-core structures with those within the vortex core. A direct numerical simulation (DNS) of the vortex perturbed by optimal perturbations is conducted to investigate the nonlinear development of the optimal perturbations. In the azimuthally constant decomposed case, it is found that the optimal perturbation induces a string of bubble structures to be generated as a consequence of the non-orthogonality of continuous eigenmodes and the breakdown bubble is induced by viscous diffusion, while in the axially constant decomposition transient growth analysis, it is observed that the optimal perturbations associated with the continuous eigenmodes drive the vortex to vibrate around the initial vortex centre before eventually returning to its original position at larger times. This transient effect provides a mechanism for the ‘vortex meandering’ observed in previous experimental and numerical studies. These optimal perturbations associated with the continuous spectrum with out-of-vortex-core structures are observed to be activated by anisotropic inflow perturbations in the potential region.
Sweet buttermilk intake reduces colonisation and translocation ofListeria monocytogenesin rats by inhibiting mucosal pathogen adherence
Authors: Sprong R. Corinne , Hulstein Marco F. E. , Lambers Tim T. , van der Meer Roelof
Published: February 2012

The bovine milk fat globule membrane (MFGM) contains several antimicrobial components with proven efficacyin vitro, butin vivoevidence is scarce. The present study was performed to determine the efficacy of the bovine MFGMin vivo.Rats were fed diets based on bovine skimmed milk powder (low in MFGM) or bovine sweet buttermilk powder (high in MFGM). After dietary adaptation, rats were orally infected withSalmonella enteritidisorListeria monocytogenes.Whereas sweet buttermilk powder did not protect rats against infection withS. enteritidis, it protected againstL. monocytogenes, as shown by a lower colonisation and translocation of this pathogen. Protection coincided with higher listericidal capacity of gastric and caecal contents. The digestion products of phosphoglycerides and sphingomyelin are bactericidalin vitro.To study their role, rats were fed diets containing either 0·1 % phosphatidylcholine or sphingomyelin, or a control diet. After dietary adaptation, rats were infected withL. monocytogenes.SinceListeriacolonisation was not affected by these diets, phosphoglycerides and sphingomyelin are not involved in the protective effect of sweet buttermilk. Additionalin vitroexperiments were performed to further explore the mechanism of the beneficial effects of sweet buttermilk. Inhibition of the adherence ofL. monocytogenesto the intestinal mucosa is the most likely explanation, since sweet buttermilk powder inhibited the binding ofL. monocytogenesin both a haemagglutination assay and a Caco-2 cell adherence assay. In conclusion, sweet buttermilk powder, which is rich in MFGM, protects againstL. monocytogenesinfection in rats, probably by preventing adherence of this pathogen to the intestinal mucosa.
Proteomic study of proteolysis during ripening of Cheddar cheese made from milk over a lactation cycle
Authors: Hinz Katharina , O'Connor Paula M , O'Brien Bernadette , Huppertz Thom , Ross R Paul , Kelly Alan L
Published: February 2012

Milk for cheese production in Ireland is predominantly produced by pasture-fed spring-calving herds. Consequently, there are marked seasonal changes in milk composition, which arise from the interactive lactational, dietary and environmental factors. In this study, Cheddar cheese was manufactured on a laboratory scale from milk taken from a spring calving herd, over a 9-month lactation cycle between early April and early December. Plasmin activity of 6-months-old Cheddar cheese samples generally decreased over ripening time. One-dimensional urea-polyacrylamide gel electrophoresis (PAGE) of cheese samples taken after 6 months of ripening showed an extensive hydrolysis of caseins, with the fastest hydrolysis of αs1-caseins in cheeses made in August. A proteomic comparison between cheeses produced from milk taken in April, August and December showed a reduction in levels of β-casein and appearance of additional products, corresponding to low molecular weight hydrolysis products of the caseins. This study has demonstrated that a seasonal milk supply causes compositional differences in Cheddar cheese, and that proteomic tools are helpful in understanding the impact of those differences.
The generational contract in flux: intergenerational tensions in post-conflict Sierra Leone
Authors: Boersch-Supan Johanna
Published: February 2012

Intergenerational solidarity and reciprocity are fundamental building blocks of any society. Simultaneously, socio-generational groups constantly struggle for influence and authority. In Africa, disproportionately male, gerontocratic and patrimonial systems governing economic, social and political life lend a special explosiveness to the social cleavage of generation. This paper draws on the concept of the generational contract to explore whether Sierra Leone's civil war – labelled a ‘revolt of youth’ – catalysed changes in the power asymmetries between age groups. I argue that youth question fundamental norms of intergenerational relations, and challenge local governance structures demanding changes to the generational contract. Amidst a strong continuity of gerontocratic dominance and counter-strategies from elders, youth draw on organisational forms and a local human rights discourse to create spaces for contestation and negotiation. These openings hold potential for long-term rearrangements of societal relations.
Estimating optimal salinity and temperature of chaetognaths
Authors: Zhang Dong , Xu Zhao-Li
Published: February 2012

Determining optimal temperature and salinity for marine organisms is a challenge for marine ecologists because not every species can be easily maintained in the laboratory for testing the influence of environmental parameters. To find a simple method to estimate the optimal temperature and salinity for marine organisms based on survey data, a reciprocal quadratic yield-density model was used for determining the optimal temperature or salinity from abundance data for six pelagic Chaetognatha species. The data for the modelling were collected in four surveys in the East China Sea (23°30′–33°N 118°30′–128°E) from 1997 to 2000. According to both survey data and results from the models, we analysed qualitatively and quantitatively the ecological characteristics of those species. Estimated optimal temperatures and salinities are 17.3°C and 14.1‰ forSagitta nagae, 20.3°C and 13.8‰ forS. bedoti, 24.9°C and 32.9‰ forS. enflata, 22.5°C and 16.5‰ forS. ferox, 24.5°C and 34.1‰ forS. pacificaand 17.3°C and 14.1‰ forS. pulchra, respectively. Three ecological groups were evident in the East China Sea: the neritic, warm temperate water species (S. nagae); the neritic, warm water species (S. pulchra, S. feroxandS. bedoti); and the oceanic, warm water species (S. enflataandS. pacifica). Our results validate that the model is applicable for describing the relationship between chaetognaths abundance and temperature or salinity.
Distribution and abundance of Darwin’s finches and other land birds on Santa Cruz Island, Galápagos: evidence for declining populations
Authors: Dvorak Michael , Fessl Birgit , Nemeth Erwin , Kleindorfer Sonia , Tebbich Sabine
Published: February 2012

Population monitoring is a vital tool for conservation management and for testing hypotheses about population trends in changing environments. Darwin’s finches on Santa Cruz Island in the Galápagos archipelago have experienced habitat alteration because of human activity, introduced predators, parasites and disease. We used point counts to conduct systematic quantitative surveys of Darwin’s finches and other land birds between 1997 and 2010. The temporal analysis revealed that six of the nine species investigated declined significantly and that this decline was most pronounced at higher elevations in humid native forest and agricultural areas; the highland areas have been most affected by introduced species or direct human impact. Five of the six declining species are insectivorous, which suggests that changes in insect abundance or insect availability are a critical factor in the declines. Further study is required to test this idea. Other factors including habitat alteration and introduced parasites or pathogens may be contributing to the observed declines.
No pay, no care? A case study exploring motivations for participation in payments for ecosystem services in Uganda
Authors: Fisher Janet
Published: February 2012

A key question in the literature on payments for ecosystem services (PES) is how payments incentivize conservation action and, in particular, how they interact with other motivations, including motivations for environmental stewardship. Related to this question are concerns about the temporal sustainability of PES: what happens when payments cease and whether a ‘no pay, no care’ environmental ethic is fostered. I present empirical research from a case study in western Uganda, where forest-adjacent communities are paid in exchange for planting trees on private lands, for carbon sequestration. The study demonstrates the range of values people have for trees in the landscape and the range of motivations for participating in PES schemes. However, the analysis shows that payments are clearly the main motivation for involvement, except in one area where people are more motivated by aesthetic and existence values for trees. Given the widespread importance of money in motivating involvement, I investigate the profitability of participation over time. This profitability analysis, in combination with qualitative data on perceptions of, and plans for, the future, contributes to understanding the temporal sustainability of PES. I draw on various strands of evidence to argue that the way participants prioritize payments may constitute a threat to the long-term maintenance of PES activities, particularly in situations such as in this case study, in which there is a mismatch between payments and contract length.
Divine will/divine command moral theories and the problem of arbitrariness
Authors: CARSON THOMAS L.
Published: February 2012

A well-known objection to divine will/divine command moral theories is that they commit us to the view that God's will is arbitrary. I argue that several versions of divine will/divine command moral theories, including two of Robert Adams's versions of the DCT and my own divine preference theory, can be successfully defended against this objection. I argue that, even if God's preferences are somewhat arbitrary,wehave reasons to conform our wills to them. It is not a fatal objection to divine will/divine command moral theories if they imply that God's will/God's commands is/are arbitrary, to some extent.
Understanding omnipotence
Authors: PEARCE KENNETH L. , PRUSS ALEXANDER R.
Published: February 2012

An omnipotent being would be a being whose power was unlimited. The power of human beings is limited in two distinct ways: we are limited with respect to our freedom of will, and we are limited in our ability to execute what we have willed. These two distinct sources of limitation suggest a simple definition of omnipotence: an omnipotent being is one that has both perfect freedom of will and perfect efficacy of will. In this article we further explicate this definition and show that it escapes the standard objections to divine omnipotence.
The Readings of Apollonius'On the Cutting off of a Ratio
Authors: Vandoulakis Ioannis M.
Published: February 2012

During the second half of the twentieth century an attention of historians of mathematics shifted to mathematics of the Late Antiquity and its subsequent development by mathematicians of the Arabic world. Many critical editions of works of mathematicians of the Hellenistic era have made their appearance, giving rise to a new, more detailed historical picture. Among these are the critical editions of the works of Diophantus, Apollonius, Archimedes, Pappus, Diocles, and others.
A Negative Stain for Electron Microscopic Tomography
Authors: Fera Andrea , Farrington Jane E. , Zimmerberg Joshua , Reese Thomas S.
Published: February 2012

While negative staining can provide detailed, two-dimensional images of biological structures, the potential of combining tomography with negative staining to provide three-dimensional views has yet to be fully realized. Basic requirements of a negative stain for tomography are that the density and atomic number of the stain are optimal, and that the stain does not degrade or rearrange with the intensive electron dose (∼106 e/nm2) needed to collect a full set of tomographic images. A commercially available, tungsten-based stain appears to satisfy these prerequisites. Comparison of the surface structure of negatively stained influenza A virus with previous structural results served to evaluate this negative stain. The combination of many projections of the same structure yielded detailed images of single proteins on the viral surface. Corresponding surface renderings are a good fit to images of the viral surface derived from cryomicroscopy as well as to the shapes of crystallized surface proteins. Negative stain tomography with the appropriate stain yields detailed images of individual molecules in their normal setting on the surface of the influenza A virus.
Highly Reproducible Secondary Electron Imaging under Electron Irradiation Using High-Pass Energy Filtering in Low-Voltage Scanning Electron Microscopy
Authors: Tsurumi Daisuke , Hamada Kotaro , Kawasaki Yuji
Published: February 2012

The reproducibility of contrast in secondary electron (SE) imaging during continuous electron irradiation, which caused surface contamination, was investigated using SE high-pass energy filtering in low-voltage scanning electron microscopy (SEM). According to high-pass energy-filtered imaging, dopant contrast in an indium phosphide remained remarkably stable during continuous electron irradiation although the contrast in unfiltered SE images decreased rapidly as a contamination layer was formed. Charge neutralization and the SE energy distributions indicate that the contamination layer induces a positive charge. This results in a decrease of low-energy SE emissions and reduced dopant contrast in unfiltered SE images. The retention of contrast was also observed in high-pass energy-filtered images of a gold surface. These results suggest that this imaging method can be widely used when SE intensities decrease under continuous electron irradiation in unfiltered SE images. Thus, high-pass energy-filtered SE imaging will be of a great assistance for SEM users in the reproducibility of contrast such as a quantitative dopant mapping in semiconductors.