bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of immature platelet fraction and immature reticulocyte fraction as predictors of engraftment after hematopoietic stem cell transplantation
Authors: Morkis I. V. C. , Farias M. G. , Rigoni L. D. C. , Scotti L. , Gregianin L. J. , Daudt L. E. , Silla L. M. da R. , Paz A. A.
Published: July 2014

Introduction

Engraftment is a critical milestone of the hematopoietic stem cell transplantation (HSCT) process. The immature platelet fraction (IPF) and immature reticulocyte fraction (IRF) are considered early indicators of bone marrow recovery. The objective of this study was to assess these parameters as predictors of HSCT engraftment.

Methods

Neutrophil and platelet engraftment were defined as the first of three consecutive days with an absolute neutrophil count >0.5 × 109/L or platelet count >20 × 109/L, respectively. The IRF cutoff was 12%. Two IPF cutoffs were used: >6.2% and >10%.

Results

The study sample comprised 44 patients, of whom 24 had undergone autologous HSCT and 20 had undergone allogeneic HSCT. Absolute neutrophil counts >0.5 × 109/L were preceded by IRF >12% in 86% of patients (38 of 44). Platelet counts >20 × 109/L were preceded by an IPF >6.2% in 90% of patients (37 of 41) and by an IPF >10% in 63% of patients (26 of 41).

Conclusion

The results show that IRF and IPF are engraftment predictors. Peak in IPF was observed before rise in platelet count, while IRF rises before absolute neutrophil count (ANC) and persists increased. This indicates that IRF and IPF can be considered as new tools for hematopoietic assessment after HSCT.
Risk factors for chronic pelvic pain: hospital‐based case–control study from Turkey
Authors: Gokyildiz Sule , Beji Nezihe K , Avcibay Burcu , Ozgunen Fatma T
Published: July 2014

Chronic pelvic pain (CPP) is a complicated condition that can have a large impact on life. The aetiology of CPP is often unclear and the origin appears to be multifactorial. This study aims to identify risk factors associated with CPP complaint in women. The study is a descriptive case–control study in nature. The study was conducted in one university and one state hospital. Women with CPP (n = 134) composed the case group while those who consulted to the polyclinics with other problems formed the control group (n = 383). The data were collected through a questionnaire which was prepared in light of the related literature and the ‘Pelvic Pain Assessment Form’ developed by the International Pelvic Pain Society. Women in the case and control groups were found to have similar socio‐demographical features. This study has detected that CPP is associated with factors such as having a relative with recurrent pelvic pain complaint, having cancer or CPP history, having pain during menstruation, feeling of fullness in the abdominal region and stool consistency, recurrent urinary tract infections, having a diagnosed woman's disease (ovarian cyst, genital tract infection, prolapsus and menstrual irregularity), having had an abdominal operation, taking vaginal showers after sexual intercourse or for any other reason, falling down from height or having an accident that caused back damage, experiencing a sad event during childhood, being exposed to physical violence or forced to sexual intercourse. In Conclusion, this study has found that reproduction, urinary, gastrointestinal, musculoskeletal systems and psychological factors affect women with chronic pelvic pain.
Factors influencing cardiometabolic monitoring practices in an adult community mental health service
Authors: Millar Freyja , Sands Natisha , Elsom Stephen
Published: July 2014

People with serious mental illness are reported to live up to 25 years less than the general population. Cardiovascular disease and diabetes risk factors, as well as mental health, treatment, lifestyle, service provision, and socioeconomic factors, all contribute to this health inequity. Cardiometabolic monitoring (CMM) is one strategy used to attend to some cardiometabolic risk factors. The present study aimed to explore factors that influence decisions to undertake CMM in an Australian adult community mental health service. A CMM audit tool was designed to capture demographic, clinical, and care‐provision factors. A 6‐month retrospective file audit from the total population of consumers of an adult community mental health service was undertaken, where no existing CMM guidelines or practices were in place. The study findings confirmed a higher prevalence of cardiometabolic disorders in the study population compared to the general population. Complete CMM occurred in 24% of the study population (n = 94). No consumer demographic, socioeconomic, or clinical characteristics, or care‐provision factors, were found to be predictors of complete CMM. The random manner in which CMM was observed to occur in the study highlights the need for standardized CMM guidelines and capacity‐building strategies to improve current CMM practices.
Examining the use of telehealth in community nursing: identifying the factors affecting frontline staff acceptance and telehealth adoption
Authors: Taylor Johanna , Coates Elizabeth , Brewster Liz , Mountain Gail , Wessels Bridgette , Hawley Mark S.
Published: July 2014

Aims

To examine frontline staff acceptance of telehealth and identify barriers to and enablers of successful adoption of remote monitoring for patients with Chronic Obstructive Pulmonary Disease and Chronic Heart Failure.

Background

The use of telehealth in the UK has not developed at the pace and scale anticipated by policy. Many existing studies report frontline staff acceptance as a key barrier, however data are limited and there is little evidence of the adoption of telehealth in routine practice.

Design

Case studies of four community health services in England that use telehealth to monitor patients with Chronic Obstructive Pulmonary Disease and Chronic Heart Failure.

Methods

Thematic analysis of qualitative interviews with 84 nursing and other frontline staff; and 21 managers and key stakeholders; data collected May 2012–June 2013.

Findings

Staff attitudes ranged from resistance to enthusiasm, with varied opinions about the motives for investing in telehealth and the potential impact on nursing roles. Having reliable and flexible technology and dedicated resources for telehealth work were identified as essential in helping to overcome early barriers to acceptance, along with appropriate staff training and a partnership approach to implementation. Early successes were also important, encouraging staff to use telehealth and facilitating clinical learning and increased adoption.

Conclusions

The mainstreaming of telehealth hinges on clinical ‘buy‐in’. Where barriers to successful implementation exist, clinicians can lose faith in using technology to perform tasks traditionally delivered in person. Addressing barriers is therefore crucial if clinicians are to adopt telehealth into routine practice.
Obesity Does Not Increase Complication Rate of Percutaneous Epicardial Access
Authors: WAN SIU‐HIN , KILLU AMMAR M. , HODGE DAVID O. , PACKER DOUGLAS L. , MULPURU SIVA , ASIRVATHAM SAMUEL J. , MUNGER THOMAS M. , FRIEDMAN PAUL A.
Published: July 2014

Epicardial Access and Obesity

Introduction

Percutaneous epicardial access for ablative therapies is an increasingly common technique utilized for refractory ventricular arrhythmias. There are, however few known data on obesity and complication rates associated with this procedure.

Methods and Results

We retrospectively reviewed the charts of subjects undergoing epicardial access at Mayo Clinic between January 2004 and June 2013. Baseline clinical and echocardiographic data were collected for each subject, who was then classified into body mass index (BMI) categories as underweight, normal weight, overweight, and obese based on a BMI of <18.5, 18.5–24.99, 25–29.99, and ≥30, respectively. Events and complications were recorded, and procedural and clinical success rates were determined.

There was no statistically significant difference in access approach, procedural or clinical outcomes, or complications among the BMI categories. Note that 95.1%, 91.7%, and 93.1% derived procedural success among the normal weight, overweight, and obese categories, respectively (P value = 0.81). Similarly, there was no difference in clinical outcomes with success rates of 68.3%, 66.7%, and 75.9% between the respective groups (P value = 0.54). At 5 years, there was a trend toward increased mortality among obese individuals (28.8%) compared to normal weight (8.8%) and overweight (9.8%) patients (P value = 0.139).

Conclusion

Percutaneous epicardial access, mapping, and ablation can be performed in obese individuals with similar outcomes to those of lower weight category. Obesity should not preclude the use of percutaneous epicardial access when clinically indicated.
Striatal serotonin 2C receptors decrease nigrostriatal dopamine release by increasing GABA‐A receptor tone in the substantia nigra
Authors: Burke Mary V. , Nocjar Christine , Sonneborn Alex J. , McCreary Andrew C. , Pehek Elizabeth A.
Published: July 2014

Drugs acting at the serotonin‐2C (5‐HT2C) receptor subtype have shown promise as therapeutics in multiple syndromes including obesity, depression, and Parkinson's disease. While it is established that 5‐HT2C receptor stimulation inhibits DA release, the neural circuits and the localization of the relevant 5‐HT2C receptors remain unknown. This study used dual‐probe in vivo microdialysis to investigate the relative contributions of 5‐HT2C receptors localized in the rat substantia nigra (SN) and caudate‐putamen (CP) in the control of nigrostriatal DA release. Systemic administration (3.0 mg/kg) of the 5‐HT2C receptor selective agonist Ro 60‐0175 [(αS)‐6‐Chloro‐5‐fluoro‐α‐methyl‐1H‐indole‐1‐ethanamine fumarate] decreased, whereas intrastriatal infusions of the selective 5‐HT2C antagonist SB 242084 [6‐Chloro‐2,3‐dihydro‐5‐methyl‐N‐[6‐[(2‐methyl‐3‐pyridinyl)oxy]‐3‐pyridinyl]‐1H‐indole‐1‐carboxyamide; 1.0 μM] increased, basal DA in the CP. Depending on the site within the SN pars reticulata (SNpr), infusions of SB 242084 had more modest but significant effects. Moreover, infusions of the GABA‐A receptor agonist muscimol (10 μM) into the SNpr completely reversed the increases in striatal DA release produced by intrastriatal infusions of SB 242084. These findings suggest a role for 5‐HT2C receptors regulating striatal DA release that is highly localized. 5‐HT2C receptors localized in the striatum may represent a primary site of action that is mediated by the actions on GABAergic activity in the SN.

image

Dopamine (DA) neurons in the substantia nigra pars compacta (SNpc) project to the caudate‐putamen (CP; striatum). This circuitry is implicated in numerous pathologies including Parkinson's disease. Using in vivo microdialysis, we demonstrated that blockade of serotonin (5‐HT) 2C receptors in the CP increased nigrostriatal DA release. Infusions of a GABA‐A agonist into the substantia nigra pars reticulata (SNpr) blocked this increase. This work indicates that striatal serotonin 2C receptors regulate GABAergic tone in the SNpr, which in turn regulates nigrostriatal DA release.
The effect of a non‐surgical orthopaedic physician on wait times to see a paediatric orthopaedic surgeon
Authors: Bowman Matthew , Mackey Anna , Wilson Nichola , Stott Ngaire Susan
Published: July 2014

Aims

High referral volumes to paediatric orthopaedic surgeons create long clinic waiting lists. The use of extended scope roles for doctors and health professionals is one strategy to address these wait times. We completed a 6‐month trial of a non‐surgical paediatric orthopaedic physician role (NSP) to help manage non‐urgent referrals to our service from local general practitioners (GPs).

Methods

For a 6‐month period, the majority of non‐urgent GP referrals were assessed by a US‐trained NSP. Wait times were compared between this period and the same time period in the previous year. Family and referrer satisfaction was determined through postal surveys.

Results

Over the trial period, the NSP saw a total of 155 new patient referrals, which represented 49% of all non‐urgent GP referrals for the period. Before the trial, only 75% of non‐urgent referrals were seen within 131 days (19 weeks) with 10% waiting more than 215 days (31 weeks). By the end of the trial, 75% of referrals were seen within 55 days (8 weeks) and 90% within 61 days (9 weeks). The most common outcome was discharge with management advice. 12% of patients were referred on to an orthopaedic surgeon but only 1% went on to a surgical wait list. Families and referrers reported high levels of satisfaction and only three patients discharged by the NSP were referred back for orthopaedic surgeon review.

Conclusion

The NSP role was effective at reducing clinic wait times for patients with non‐urgent paediatric orthopaedic conditions, while maintaining family and referrer satisfaction.
Beneficial effects of melatonin on bovine oocytes maturation: a mechanistic approach
Authors: Tian XiuZhi , Wang Feng , He ChangJiu , Zhang Lu , Tan DunXian , Reiter Russel J. , Xu Jing , Ji PengYun , Liu GuoShi
Published: July 2014

This study was performed to investigate the effect of melatonin on bovine oocyte maturation and subsequent embryonic development in vitro. The endogenous melatonin concentration in bovine follicular fluid is approximately 10−11 m. To examine the potential beneficial effects of melatonin on bovine oocyte maturation in vitro, germinal vesicle (GV) oocytes were incubated with different concentrations of melatonin (10−11, 10−9, 10−7, 10−5, 10−3 m). Melatonin supplementation at suitable concentrations significantly promoted oocyte maturation. The development of embryos and the mean cell number/blastocyst produced after in vitro fertilization were remarkably improved. The most effective melatonin concentrations obtained from the studies ranged from 10−9 to 10−7 m. The expression of melatonin receptor MT1 and MT2 genes was identified in cumulus cells, granulosa cells, and oocytes using reverse transcription PCR, immunofluorescence, and Western blot. The mechanistic studies show that the beneficial effects of melatonin on bovine oocyte maturation are mediated via melatonin membrane receptors as the melatonin receptor agonist (IIK7) promotes this effect while the melatonin receptor antagonist (luzindole) blocks this action. Mechanistic explorations revealed that melatonin supplementation during bovine oocyte maturation significantly up‐regulated the expressions of oocyte maturation‐associated genes (GDF9, MARF1, and DNMT1a) and cumulus cells expansion‐related gene (PTX3, HAS1/2) and that LHR1/2, EGFR are involved in signal transduction and epigenetic reprogramming. The results obtained from the studies provide new information regarding the mechanisms by which melatonin promotes bovine oocyte maturation in vitro and provide an important reference for in vitro embryo production of bovine and the human‐assisted reproductive technology.
Black and white with some shades of grey: the diverse responses of inducible metabolic pathways inEscherichia coli
Authors: Rao Christopher V. , Koirala Santosh
Published: July 2014

The metabolic pathways for many sugars are inducible. This process has been extensively studied in the case ofEscherichia colilactose metabolism. It has long been known that gratuitous induction of thelacoperon with non‐metabolizable lactose analogues generates an all‐or‐nothing response, where some cells express thelacgenes at a maximal rate and others not at all. However, the response to lactose itself is graded, where all cells express thelacgenes in proportion to lactose concentrations. The mechanisms generating these distinct behaviours in lactose metabolism have been a topic of many studies. Despite this large body of work, little is known about how other pathways respond to their cognate sugars. An article ofMolecular Microbiologyinvestigated the response of eight metabolic pathways inE. colito their cognate sugars at single‐cell resolution. The authors demonstrate that these pathways exhibit diverse responses, ranging from graded to all‐or‐nothing responses and combinations thereof. Remarkably, they were able to interpret these responses using a simple mathematical model and identify the mechanisms likely giving rise to each.
Somali Piracy Negotiations: Resolving the Paradoxes of Extortionate Transactions
Authors: Donohue William A. , Pugh Franziska , Sabrie Sharmaake
Published: July 2014

This article examines the negotiation process within piracy hijackings that occur around Somalia. Access was provided to two Somali pirates who were interviewed about their roles: a financier and a navigator. This article views these hostage negotiations as extortionate transactions, which requires negotiators to confront five paradoxes in the course of forging an outcome. The interviews with the two pirates reveal how the pirates and the ship owners who do the negotiations manage these paradoxes in the settling on a ransom. The interviews reveal how the hijackings are organized and financed, how the negotiations are organized logistically, how the ransoms are paid, and what happens when negotiations reach sticking points. The article concludes with a discussion of how the negotiations are shaped by the paradoxes as each side crafts its position.
Multidisciplinary care improves clinical outcome and reduces medical costs for pre‐end‐stage renal disease in Taiwan
Authors: Chen Yue‐Ren , Yang Yu , Wang Shu‐Chuan , Chou Wen‐Yu , Chiu Ping‐Fang , Lin Ching‐Yuang , Tsai Wen‐Chen , Chang Jer‐Ming , Chen Tzen‐Wen , Ferng Shyang‐Hwa , Lin Chun‐Liang
Published: July 2014

Aim

Multidisciplinary care (MDC) for patients with chronic kidney disease (CKD) may help to optimize disease care and improve clinical outcomes. Our study aimed to evaluate the effectiveness of pre‐end‐stage renal disease (ESRD) patients under MDC and usual care in Taiwan.

Method

In this 3‐year retrospective observational study, we recruited 822 ESRD subjects, aged 18 years and older, initiating maintenance dialysis more than 3 months from five cooperating hospitals. The MDC (n = 391) group was cared for by a nephrologists‐based team and the usual care group (n = 431) was cared for by sub‐specialists or nephrologists alone more than 90 days before dialysis initiation. Patient characteristics, dialysis modality, hospital utilization, hospitalization at dialysis initiation, mortality and medical cost were evaluated. Medical costs were further divided into in‐hospital, emergency services and outpatient visits.

Results

The MDC group had a better prevalence in peritoneal dialysis (PD) selection, less temporary catheter use, a lower hospitalization rate at dialysis initiation and 15% reduction in the risk of hospitalization (P < 0.05). After adjusting for gender, age and Charlson Comorbidity Index score, there were lower in‐hospital and higher outpatient costs in the MDC group during 3 months before dialysis initiation (P < 0.05). In contrast, medical costs (NT$ 146 038 vs 79 022) and hospitalization days (22.4 vs 15.5 days) at dialysis initiation were higher in the usual care group. Estimated medical costs during 3 months before dialysis till dialysis initiation, the MDC group yielded a reduction of NT$ 59 251 for each patient (P < 0.001). Patient mortality was not significantly different.

Conclusion

Multidisciplinary care intervention for pre‐ESRD patients could not only significantly improve the quality of disease care and clinical outcome, but also reduce medical costs.
Uranium and cadmium provoke different oxidative stress responses in Lemna minor L.
Authors: Horemans N. , Van Hees M. , Van Hoeck A. , Saenen E. , De Meutter T. , Nauts R. , Blust R. , Vandenhove H.
Published: July 2014

Common duckweed (Lemna minor L.) is ideally suited to test the impact of metals on freshwater vascular plants. Literature on cadmium (Cd) and uranium (U) oxidative responses in L. minor are sparse or, for U, non‐existent. It was hypothesised that both metals impose concentration‐dependent oxidative stress and growth retardation on L. minor. Using a standardised 7‐day growth inhibition test, the adverse impact of these metals on L. minor growth was confirmed, with EC50 values for Cd and U of 24.1 ± 2.8 and 29.5 ± 1.9 μm, respectively, and EC10 values of 1.5 ± 0.2 and 6.5 ± 0.9 μm, respectively. The metal‐induced oxidative stress response was compared through assessing the activity of different antioxidative enzymes [catalase, glutathione reductase, superoxide dismutase (SOD), ascorbate peroxidase (APOD), guaiacol peroxidase (GPOD) and syringaldizyne peroxidase (SPOD)]. Significant changes in almost all antioxidative enzymes indicated their importance in counteracting the U‐ and Cd‐imposed oxidative burden. However, some striking differences were also observed. For activity of APODs and SODs, a biphasic but opposite response at low Cd compared to U concentrations was found. In addition, Cd (0.5–20 μm) strongly enhanced plant GPOD activity, whereas U inhibited it. Finally, in contrast to Cd, U up to 10 μm increased the level of chlorophyll a and b and carotenoids. In conclusion, although U and Cd induce similar growth arrest in L. minor, the U‐induced oxidative stress responses, studied here for the first time, differ greatly from those of Cd.
Prophylactic red blood cell exchange may be beneficial in the management of sickle cell disease in pregnancy
Authors: Asma Suheyl , Kozanoglu Ilknur , Tarım Ebru , Sarıturk Cagla , Gereklioglu Cigdem , Akdeniz Aydan , Kasar Mutlu , Turgut Nurhilal H. , Yeral Mahmut , Kandemir Fatih , Boga Can , Ozdogu Hakan
Published: July 2014

Background

Sickle cell disease (SCD) is associated with chronic hemolysis and painful episodes. Pregnancy accelerates sickle cell complications, including prepartum and postpartum vasoocclusive crisis, pulmonary complications, and preeclampsia or eclampsia. Fetal complications include preterm birth and its associated risks, intrauterine growth restriction, and a high rate of perinatal mortality. The purpose of this study was to evaluate pregnancy outcomes in patients with SCD who underwent planned preventive red blood cell exchange (RBCX).

Study Design and Methods

We retrospectively evaluated the complications of SCD in 37 pregnant patients. Patients with SCD who had undergone prophylactic RBCX were compared with a control group who had not undergone RBCX during pregnancy.

Results

Forty‐three exchange procedures were performed in 24 patients. The control group comprised 13 patients with a mean age of 27.4 ± 3.3 years who had not undergone RBCX during pregnancy. Four of the five patients who developed a vasoocclusive crisis died. There was a significant difference in maternal mortality between the study and control groups (p = 0.011). There was also a significant difference in the incidence of vasoocclusive crisis between the study and control groups. One fetal death occurred in the 20th gestational week in a patient in the control group, although there were no postpartum complications in either the babies or the mothers in the control group.

Conclusion

This study has demonstrated that prophylactic RBCX during pregnancy is a feasible and safe procedure for prevention of complications. Given the decrease in the risks of transfusion, RBCX warrants further study.
Radioresistance of cancer stem‐like cell derived from canine tumours
Authors: Tanabe A. , Deguchi T. , Sato T. , Nemoto Y. , Maruo T. , Madarame H. , Shida T. , Naya Y. , Ogihara K. , Sahara H.
Published: July 2014

Cancer stem‐like cells (CSCs)/cancer‐initiating cells (CICs) are a small subpopulation of cancer cells that are responsible for the initiation, recurrence and metastasis of cancer. We previously demonstrated that, using the Hoechst 33342 dye‐based side population technique, CSCs/CICs in canine lung adenocarcinoma cell line exist. In this study, as CSCs/CICs are known to form spheres in anchorage‐independent environment in vitro, we evaluated the stemness of spheroid cells derived from canine lung adenocarcinoma and osteosarcoma cells by expression of stemness markers, and investigated radioresistance. Spheroid cells showed greater expression of stemness markers Oct‐4 and CD133 gene than those of adherent‐cultured cells. In nude mouse xenograft models, spheroid cells showed higher tumourigenic ability than adherent‐cultured cells. In addition, spheroid cells showed significantly resistant against radioactivity as compared with adherent‐cultured cells. These results suggest that spheroid cells could possess stemness and provide a CSCs/CICs research tool to investigate CSCs/CICs of canine tumour cells.
Effects of Maxwell Stress on Interfacial Crack Between Two Dissimilar Piezoelectric Solids
Authors: Wang Yi-Ze
Published: July 2014

In this study, the effects of the Maxwell stress on the interfacial crack between two dissimilar piezoelectric solids are investigated. With the Stroh form and Muskhelishvili theory, the explicit expressions of generalized stresses are presented and the closed forms of the stress and electric displacement intensity factors are derived. Results show that the generalized stress field has singularities and oscillatory properties near the crack tip and the Maxwell stress has influences on the fracture characteristics. For the piezoelectric composites with the Maxwell stress, the normalized stress intensity factor KI* can be changed by both the remote stress and electric load. Such phenomenon cannot be found for the piezoelectric system without the Maxwell stress. Furthermore, the electric displacement intensity factor is more sensitive to the electric load than that to the remote stress.
Optimization-Aided Forced Response Analysis of a Mistuned Compressor Blisk
Authors: Beirow Bernd , Giersch Thomas , Kühhorn Arnold , Nipkau Jens
Published: July 2014

The forced response of the first rotor of an engine 3E (technology program) (E3E)-type high pressure compressor (HPC) blisk is analyzed with regard to varying mistuning, varying engine order (EO) excitations and the consideration of aero-elastic effects. For that purpose, subset of nominal system modes (SNM)-based reduced order models are used in which the disk remains unchanged while the Young's modulus of each blade is used to define experimentally adjusted as well as intentional mistuning patterns. The aerodynamic influence coefficient (AIC) technique is employed to model aero-elastic interactions. Furthermore, based on optimization analyses and depending on the exciting EO and aerodynamic influences it is searched for the worst as well as the best mistuning distributions with respect to the maximum blade displacement. Genetic algorithms using blade stiffness variations as vector of design variables and the maximum blade displacement as objective function are applied. An allowed limit of the blades' Young's modulus standard deviation is formulated as secondary condition. In particular, the question is addressed if and how far the aero-elastic impact, mainly causing aerodynamic damping, combined with mistuning can even yield a reduction of the forced response compared to the ideally tuned blisk. It is shown that the strong dependence of the aerodynamic damping on the interblade phase angle is the main driver for a possible response attenuation considering the fundamental blade mode. The results of the optimization analyses are compared to the forced response due to real, experimentally determined frequency mistuning as well as intentional mistuning.
Inputs for Subject-Specific Computational Fluid Dynamics Simulation of Blood Flow in the Mouse Aorta
Authors: Van Doormaal Mark , Zhou Yu-Qing , Zhang Xiaoli , Steinman David A. , Mark Henkelman R.
Published: July 2014

Mouse models are an important way for exploring relationships between blood hemodynamics and eventual plaque formation. We have developed a mouse model of aortic regurgitation (AR) that produces large changes in plaque burden with charges in hemodynamics [Zhou et al., 2010, "Aortic Regurgitation Dramatically Alters the Distribution of Atherosclerotic Lesions and Enhances Atherogenesis in Mice," Arterioscler. Thromb. Vasc. Biol., 30(6), pp. 1181–1188]. In this paper, we explore the amount of detail needed for realistic computational fluid dynamics (CFD) calculations in this experimental model. The CFD calculations use inputs based on experimental measurements from ultrasound (US), micro computed tomography (CT), and both anatomical magnetic resonance imaging (MRI) and phase contrast MRI (PC-MRI). The adequacy of five different levels of model complexity (a) subject-specific CT data from a single mouse; (b) subject-specific CT centerlines with radii from US; (c) same as (b) but with MRI derived centerlines; (d) average CT centerlines and averaged vessel radius and branching vessels; and (e) same as (d) but with averaged MRI centerlines) is evaluated by demonstrating their impact on relative residence time (RRT) outputs. The paper concludes by demonstrating the necessity of subject-specific geometry and recommends for inputs the use of CT or anatomical MRI for establishing the aortic centerlines, M-mode US for scaling the aortic diameters, and a combination of PC-MRI and Doppler US for estimating the spatial and temporal characteristics of the input wave forms.
Blood Damage Through a Bileaflet Mechanical Heart Valve: A Quantitative Computational Study Using a Multiscale Suspension Flow Solver
Authors: Min Yun B. , Aidun Cyrus K. , Yoganathan Ajit P.
Published: July 2014

Bileaflet mechanical heart valves (BMHVs) are among the most popular prostheses to replace defective native valves. However, complex flow phenomena caused by the prosthesis are thought to induce serious thromboembolic complications. This study aims at employing a novel multiscale numerical method that models realistic sized suspended platelets for assessing blood damage potential in flow through BMHVs. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow through a 23 mm St. Jude Medical (SJM) Regent™ valve in the aortic position at very high spatiotemporal resolution with the presence of thousands of suspended platelets. Platelet damage is modeled for both the systolic and diastolic phases of the cardiac cycle. No platelets exceed activation thresholds for any of the simulations. Platelet damage is determined to be particularly high for suspended elements trapped in recirculation zones, which suggests a shift of focus in blood damage studies away from instantaneous flow fields and toward high flow mixing regions. In the diastolic phase, leakage flow through the b-datum gap is shown to cause highest damage to platelets. This multiscale numerical method may be used as a generic solver for evaluating blood damage in other cardiovascular flows and devices.
Experimental Comparison of Axial Turbine Performance Under Steady and Pulsating Flows
Authors: George A. St. , Driscoll R. , Gutmark E. , Munday D.
Published: July 2014

The performance of an axial turbine is studied under close-coupled, out-of-phase, multiple-admission pulsed air flow to approximate turbine behavior under pulsed detonation inflow. The operating range has been mapped for four frequencies and compared using multiple averaging approaches and five formulations of efficiency. Steady performance data for full and partial admission are presented as a basis for comparison to the pulsed flow cases. While time-averaged methods are found to be unsuitable, mass-averaged, work-averaged, and integrated instantaneous methods yield physically meaningful values and comparable trends for all frequencies. Peak work-averaged efficiency for pulsed flow cases is within 5% of the peak steady, full admission values for all frequencies, in contrast to the roughly 15–20% performance deficit experienced under steady, 50% partial admission conditions. Turbine efficiency is found to be a strong function of corrected flow rate and mass-averaged rotor incidence angle, but only weakly dependent on frequency.
Relationship between Ceftolozane-Tazobactam Exposure and Selection for Pseudomonas aeruginosa Resistance in a Hollow-Fiber Infection Model
Authors: VanScoy Brian D. , Mendes Rodrigo E. , Castanheira Mariana , McCauley Jennifer , Bhavnani Sujata M. , Jones Ronald N. , Friedrich Lawrence V. , Steenbergen Judith N. , Ambrose Paul G.
Published: July 2014

It is important to understand the relationship between antibiotic exposure and the selection of drug resistance in the context of therapy exposure. We sought to identify the ceftolozane-tazobactam exposure necessary to prevent the amplification of drug-resistant bacterial subpopulations in a hollow-fiber infection model. Two
Pseudomonas aeruginosa
challenge isolates were selected for study, a wild-type ATCC strain (ceftolozane-tazobactam MIC, 0.5 mg/liter) and a clinical isolate (ceftolozane-tazobactam MIC, 4 mg/liter). The experiment duration was 10 days, and the ceftolozane-tazobactam dose ratio (2:1) and dosing interval (every 8 h) were selected to approximate those expected to be used clinically. The studied ceftolozane-tazobactam dosing regimens ranged from 62.5/31.25 to 2,000/1,000 mg per dose in step fold dilutions. Negative-control arms included no treatment and tazobactam at 500 mg every 8 h. Positive-control arms included ceftolozane at 1 g every 8 h and piperacillin-tazobactam dosed at 4.5 g every 6 h. For the wild-type ATCC strain, resistance was not selected by any ceftolozane-tazobactam regimen evaluated. For the clinical isolate, an inverted-U-shaped function best described the relationship between the amplification of a drug-resistant subpopulation and drug exposure. The least (62.5/31.25 mg) and most (2,000/1,000 mg) intensive ceftolozane-tazobactam dosing regimens did not select for drug resistance. Drug resistance selection was observed with intermediately intensive dosing regimens (125/62.5 through 1,000/500 mg). For the intermediately intensive ceftolozane-tazobactam dosing regimens, the duration until the selection for drug resistance increased with dose regimen intensity. These data support the selection of ceftolozane-tazobactam dosing regimens that minimize the potential for on-therapy drug resistance selection.
Staphylococcus aureus Hyaluronidase Is a CodY-Regulated Virulence Factor
Authors: Ibberson Carolyn B. , Jones Crystal L. , Singh Shweta , Wise Matthew C. , Hart Mark E. , Zurawski Daniel V. , Horswill Alexander R.
Published: July 2014

Staphylococcus aureus
is a Gram-positive pathogen that causes a diverse range of bacterial infections. Invasive
S. aureus
strains secrete an extensive arsenal of hemolysins, immunomodulators, and exoenzymes to cause disease. Our studies have focused on the secreted enzyme hyaluronidase (HysA), which cleaves the hyaluronic acid polymer at the β-1,4 glycosidic bond. In the study described in this report, we have investigated the regulation and contribution of this enzyme to
S. aureus
pathogenesis. Using the Nebraska Transposon Mutant Library (NTML), we identified eight insertions that modulate extracellular levels of HysA activity. Insertions in the
sigB
operon, as well as in genes encoding the global regulators SarA and CodY, significantly increased HysA protein levels and activity. By altering the availability of branched-chain amino acids, we further demonstrated CodY-dependent repression of HysA activity. Additionally, through mutation of the CodY binding box upstream of
hysA
, the repression of HysA production was lost, suggesting that CodY is a direct repressor of
hysA
expression. To determine whether HysA is a virulence factor, a Δ
hysA
mutant of a community-associated methicillin-resistant
S. aureus
(CA-MRSA) USA300 strain was constructed and found to be attenuated in a neutropenic, murine model of pulmonary infection. Mice infected with this mutant strain exhibited a 4-log-unit reduction in bacterial burden in their lungs, as well as reduced lung pathology and increased levels of pulmonary hyaluronic acid, compared to mice infected with the wild-type, parent strain. Taken together, these results indicate that
S. aureus
hyaluronidase is a CodY-regulated virulence factor.
Epithelial Anion Transporter Pendrin Contributes to Inflammatory Lung Pathology in Mouse Models of Bordetella pertussis Infection
Authors: Scanlon Karen M. , Gau Yael , Zhu Jingsong , Skerry Ciaran , Wall Susan M. , Soleimani Manoocher , Carbonetti Nicholas H.
Published: July 2014

Pertussis disease, characterized by severe and prolonged coughing episodes, can progress to a critical stage with pulmonary inflammation and death in young infants. However, there are currently no effective treatments for pertussis. We previously studied the role of pertussis toxin (PT), an important
Bordetella pertussis
virulence factor, in lung transcriptional responses to
B. pertussis
infection in mouse models. One of the genes most highly upregulated in a PT-dependent manner encodes an epithelial transporter of bicarbonate, chloride, and thiocyanate, named pendrin, that contributes to asthma pathology. In this study, we found that pendrin expression is upregulated at both gene and protein levels in the lungs of
B. pertussis
-infected mice. Pendrin upregulation is associated with PT production by the bacteria and with interleukin-17A (IL-17A) production by the host.
B. pertussis
-infected pendrin knockout (KO) mice had higher lung bacterial loads than infected pendrin-expressing mice but had significantly reduced levels of lung inflammatory pathology. However, reduced pathology did not correlate with reduced inflammatory cytokine expression. Infected pendrin KO mice had higher levels of inflammatory cytokines and chemokines than infected pendrin-expressing mice, suggesting that these inflammatory mediators are less active in the airways in the absence of pendrin. In addition, treatment of
B. pertussis
-infected mice with the carbonic anhydrase inhibitor acetazolamide reduced lung inflammatory pathology without affecting pendrin synthesis or bacterial loads. Together these data suggest that PT contributes to pertussis pathology through the upregulation of pendrin, which promotes conditions favoring inflammatory pathology. Therefore, pendrin may represent a novel therapeutic target for treatment of pertussis disease.
Near-band-gap luminescence from TiO2 nanograss–nanotube hierarchical membranes
Authors: Liu Lijia , Li Jun , Sham Tsun-Kong
Published: July 2014

Freestanding TiO2 nanograss–nanotube hierarchical membranes are synthesized from a Ti metal foil by electrochemical anodization. It is found that the two nanostructures exhibit different luminescence properties, which are also affected by the crystal phases upon phase transformation. An unusual near-UV luminescence is observed from the amorphous nanograss, which is found to be excitation element specific. The amorphous nanotube shows no luminescence. Upon calcination, both nanograss and nanotubes are crystalized into the anatase phase with some rutile phase present, and both structures emit visible green luminescence at slightly different energies. The luminescence mechanism is explored using UV–vis spectroscopy, X-ray absorption near-edge structures (XANES), and X-ray excited optical luminescence (XEOL), and its implications are presented.
Solutions of the multiconfiguration Dirac–Fock equations
Authors: Levitt Antoine
Published: July 2014

The multiconfiguration Dirac–Fock (MCDF) model uses a linear combination of Slater determinants to approximate the electronic N-body wave function of a relativistic molecular system, resulting in a coupled system of nonlinear eigenvalue equations, the MCDF equations. In this paper, we prove the existence of solutions of these equations in the weakly relativistic regime. First, using a new variational principle as well as the results of Lewin on the multiconfiguration non-relativistic model, and Esteban and Séré on the single-configuration relativistic model, we prove the existence of critical points for the associated energy functional, under the constraint that the occupation numbers are not too small. Then, this constraint can be removed in the weakly relativistic regime, and we obtain non-constrained critical points, i.e. solutions of the multiconfiguration Dirac–Fock equations.
PATTERN RECOGNITION SYSTEMS UNDER ATTACK: DESIGN ISSUES AND RESEARCH CHALLENGES
Authors: BIGGIO BATTISTA , FUMERA GIORGIO , ROLI FABIO
Published: July 2014

We analyze the problem of designing pattern recognition systems in adversarial settings, under an engineering viewpoint, motivated by their increasing exploitation in security-sensitive applications like spam and malware detection, despite their vulnerability to potential attacks has not yet been deeply understood. We first review previous work and report examples of how a complex system may be evaded either by leveraging on trivial vulnerabilities of its untrained components, e.g. parsing errors in the pre-processing steps, or by exploiting more subtle vulnerabilities of learning algorithms. We then discuss the need of exploiting both reactive and proactive security paradigms complementarily to improve the security by design. Our ultimate goal is to provide some useful guidelines for improving the security of pattern recognition in adversarial settings, and to suggest related open issues to foster research in this area.
A SEGMENTATION FRAMEWORK FOR PHASE CONTRAST AND FLUORESCENCE MICROSCOPY IMAGES
Authors: ALIOSCHA-PEREZ MITCHEL , WILLAERT RONNIE , SAHLI HICHEM
Published: July 2014

The noninvasive imaging of unstained living cells is a widely used technique in biotechnology for determining biological and biochemical role of proteins, since it allows studying living specimens without altering them. Usually, fluorescence and contrast (or transmission) images are both used complementarily, as their combination allows possible better outcomes. However, segmentation of contrast images is particularly difficult due to the presence of defocused scans, lighting/shade-off artifacts and cells overlapping. In this work, we investigate the optical properties intervening during the image formation process, and propose different segmentation strategies that can benefit from these properties. The proposed scheme (i) combines the estimated phase and the fluorescence information in order to obtain initial markers for a latter segmentation stage; and (ii) use the shear oriented polar snakes, an active contour model that implicitly involves phase information on its energy functional. The obtained contour can be used as region of interest estimation, as data for a latter shape-fitting process, or as smart markers for a more detailed segmentation process (i.e. watershed). Experimental results provide a comparison of the different segmentation schemes, and confirm the suitability of the proposed strategy and model for cell images segmentation.
NUMERICAL SIMULATION OF TORTUOSITY FOR FLUID FLOW IN TWO-DIMENSIONAL PORE FRACTAL MODELS OF POROUS MEDIA
Authors: LUO LIANG , YU BOMING , CAI JIANCHAO , ZENG XIANGFENG
Published: July 2014

The tortuosity is a very important parameter for description of fluid flow in porous media, and it has been shown that porous media in nature have the fractal characteristics. The Sierpinski carpet is an exactly self-similar fractal model, which is often used to simulate fractal porous media. In this work, the tortuosity of different generations of Sierpinski carpet is calculated and analyzed by the finite volume method. A simple linear relation between the generations and tortuosity in pore fractal model of porous media is obtained. The results are compared with the available conclusions and show a more realistic tortuosity predication for fluid flow in the two-dimensional pore fractal models of porous media.
BINARY MARKETS UNDER TRANSACTION COSTS
Authors: CORDERO FERNANDO , KLEIN IRENE , PEREZ-OSTAFE LAVINIA
Published: July 2014

The goal of this work is to study binary market models with transaction costs, and to characterize their arbitrage opportunities. It has been already shown that the absence of arbitrage is related to the existence of λ-consistent price systems (λ-CPS), and, for this reason, we aim to provide conditions under which such systems exist. More precisely, we give a characterization for the smallest transaction cost λc (called "critical" λ) starting from which one can construct a λ-CPS. We also provide an expression for the set [Formula: see text] of all probability measures inducing λ-CPS. We show in particular that in the transition phase "λ = λc" these sets are empty if and only if the frictionless market admits arbitrage opportunities. As an application, we obtain an explicit formula for λc depending only on the parameters of the model for homogeneous and also for some semi-homogeneous binary markets.
Facilitative and rememberative
Authors: Garg Vaibhav , Adams Emily K. , Husted Nathaniel , Brown James
Published: July 2014

The traditional approaches to encourage gamers to exercise have been two-fold: incorporating in-game incentives and designing games that are based on exercise. We discuss the drawbacks of these approaches and introduce two new design constructs: facilitative and rememberative. A facilitative design introduces external interaction mechanisms that reward physical exertion with an increase of control over the utility and entertainment value of a game. The rememberative approach leverages "ambient" design artifacts embedded into the gaming experience reminding the gamer to exercise. We propose to explore the use of these design constructs in existing games and discuss two prototypes based on them.
Our responsibility to manage evaluative diversity
Authors: Santos-Lang Christopher
Published: July 2014

The ecosystem approach to computer system development is similar to management of biodiversity. Instead of modeling machines after a successful individual, it models machines after successful teams. It includes measuring the evaluative diversity of human teams (i.e. the disparity in ways members conduct the evaluative aspect of decision-making), adding similarly diverse machines to those teams, and monitoring the impact on evaluative balance. This article reviews new research relevant to this approach, especially the validation of a survey instrument for measuring computational evaluative differences in humans (the GRINSQ). The research confirms the existence of all four known machine types among humans.
Electrical Control of Epilepsy
Authors: Mogul David J. , van Drongelen Wim
Published: July 2014

Epilepsy afflicts approximately 1–2% of the world's population. The mainstay therapy for treating the chronic recurrent seizures that are emblematic of epilepsy are drugs that manipulate levels of neuronal excitability in the brain. However, approximately one-third of all epilepsy patients get little to no clinical relief from this therapeutic regimen. The use of electrical stimulation in many forms to treat drug-refractory epilepsy has grown markedly over the past few decades, with some devices and protocols being increasingly used as standard clinical treatment. This article seeks to review the fundamental modes of applying electrical stimulation—from the noninvasive to the nominally invasive to deep brain stimulation—for the control of seizures in epileptic patients. Therapeutic practices from the commonly deployed clinically to the experimental are discussed to provide an overview of the innovative neural engineering approaches being explored to treat this difficult disease.
Electrical Stimuli in the Central Nervous System Microenvironment
Authors: Thompson Deanna M. , Koppes Abigail N. , Hardy John G. , Schmidt Christine E.
Published: July 2014

Electrical stimulation to manipulate the central nervous system (CNS) has been applied as early as the 1750s to produce visual sensations of light. Deep brain stimulation (DBS), cochlear implants, visual prosthetics, and functional electrical stimulation (FES) are being applied in the clinic to treat a wide array of neurological diseases, disorders, and injuries. This review describes the history of electrical stimulation of the CNS microenvironment; recent advances in electrical stimulation of the CNS, including DBS to treat essential tremor, Parkinson's disease, and depression; FES for the treatment of spinal cord injuries; and alternative electrical devices to restore vision and hearing via neuroprosthetics (retinal and cochlear implants). It also discusses the role of electrical cues during development and following injury and, importantly, manipulation of these endogenous cues to support regeneration of neural tissue.