bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting success of endoscopic third ventriculostomy: validation of the ETV Success Score in a mixed population of adult and pediatric patients
Authors: Labidi Moujahed , Lavoie Pascale , Lapointe Geneviève , Obaid Sami , Weil Alexander G. , Bojanowski Michel W. , Turmel André
Published: July 2015

OBJECT

Endoscopic third ventriculostomy (ETV) has become the first line of treatment in obstructive hydrocephalus. The Toronto group (Kulkarni et al.) developed the ETV Success Score (ETVSS) to predict the clinical response following ETV based on age, previous shunt, and cause of hydrocephalus in a pediatric population. However, the use of the ETVSS has not been validated for a population comprising adults. The objective of this study was to validate the ETVSS in a “closed-skull” population, including patients 2 years of age and older.

METHODS

In this retrospective observational study, medical charts of all consecutive cases of ETV performed in two university hospitals were reviewed. The primary outcome, the success of ETV, was defined as the absence of reoperation or death attributable to hydrocephalus at 6 months. The ETVSS was calculated for all patients. Discriminative properties along with calibration of the ETVSS were established for the study population. The secondary outcome is the reoperation-free survival.

RESULTS

This study included 168 primary ETVs. The mean age was 40 years (range 3–85 years). ETV was successful at 6 months in 126 patients (75%) compared with a mean ETVSS of 82.4%. The area under the receiver operating characteristic curve was 0.61, revealing insufficient discrimination from the ETVSS in this population. In contrast, calibration of the ETVSS was excellent (calibration slope = 1.01), although the expected low numbers were obtained for scores < 70. Decision curve analyses demonstrate that ETVSS is marginally beneficial in clinical decision-making, a reduction of 4 and 2 avoidable ETVs per 100 cases if the threshold used on the ETVSS is set at 70 and 60, respectively. However, the use of the ETVSS showed inferior net benefit when compared with the strategy of not recommending ETV at all as a surgical option for thresholds set at 80 and 90.

In this cohort, neither age nor previous shunt were significantly associated with unsuccessful ETV. However, better outcomes were achieved in patients with aqueductal stenosis, tectal compressions, and other tumor-associated hydrocephalus than in cases secondary to myelomeningocele, infection, or hemorrhage (p = 0.03).

CONCLUSIONS

The ETVSS did not show adequate discrimination but demonstrated excellent calibration in this population of patients 2 years and older. According to decision-curve analyses, the ETVSS is marginally useful in clinical scenarios in which 60% or 70% success rates are the thresholds for preferring ETV to CSF shunt. Previous history of CSF shunt and age were not associated with worse outcomes, whereas posthemorrhagic and postinfectious causes of the hydrocephalus were significantly associated with reduced success rates following ETV.
Publication misrepresentation among neurosurgery residency applicants: an increasing problem
Authors: Kistka Heather M. , Nayeri Arash , Wang Li , Dow Jamie , Chandrasekhar Rameela , Chambless Lola B.
Published: July 2015

OBJECT

Misrepresentation of scholarly achievements is a recognized phenomenon, well documented in numerous fields, yet the accuracy of reporting remains dependent on the honor principle. Therefore, honest self-reporting is of paramount importance to maintain scientific integrity in neurosurgery. The authors had observed a trend toward increasing numbers of publications among applicants for neurosurgery residency at Vanderbilt University and undertook this study to determine whether this change was a result of increased academic productivity, inflated reporting, or both. They also aimed to identify application variables associated with inaccurate citations.

METHODS

The authors retrospectively reviewed the residency applications submitted to their neurosurgery department in 2006 (n = 148) and 2012 (n = 194). The applications from 2006 were made via SF Match and those from 2012 were made using the Electronic Residency Application Service. Publications reported as “accepted” or “in press” were verified via online search of Google Scholar, PubMed, journal websites, and direct journal contact. Works were considered misrepresented if they did not exist, incorrectly listed the applicant as first author, or were incorrectly listed as peer reviewed or published in a printed journal rather than an online only or non-peer-reviewed publication. Demographic data were collected, including applicant sex, medical school ranking and country, advanced degrees, Alpha Omega Alpha membership, and USMLE Step 1 score. Zero-inflated negative binomial regression was used to identify predictors of misrepresentation.

RESULTS

Using univariate analysis, between 2006 and 2012 the percentage of applicants reporting published works increased significantly (47% vs 97%, p < 0.001). However, the percentage of applicants with misrepresentations (33% vs 45%) also increased. In 2012, applicants with a greater total of reported works (p < 0.001) and applicants from unranked US medical schools (those not ranked by US News & World Report) were more likely to have erroneous citations (p = 0.038).

CONCLUSIONS

The incidence of legitimate and misrepresented scholarly works reported by applicants to the authors’ neurosurgery residency program increased during the past 6 years. Misrepresentation is more common in applicants from unranked US medical schools and those with a greater number of reported works on their application. This trend is concerning in a profession where trustworthiness is vital. To preserve integrity in the field, programs should consider verifying citations prior to submitting their rank lists.
Assessment and classification of subsidence after lateral interbody fusion using serial computed tomography
Authors: Malham Gregory M. , Parker Rhiannon M. , Blecher Carl M. , Seex Kevin A.
Published: July 2015

OBJECT

Intervertebral cage settling during bone remodeling after lumbar lateral interbody fusion (LIF) is a common occurrence during the normal healing process. Progression of this settling with endplate collapse is defined as subsidence. The purposes of this study were to 1) assess the rate of subsidence after minimally invasive (MIS) LIF by CT, 2) distinguish between early cage subsidence (ECS) and delayed cage subsidence (DCS), 3) propose a descriptive method for classifying the types of subsidence, and 4) discuss techniques for mitigating the risk of subsidence after MIS LIF.

METHODS

A total of 128 consecutive patients (with 178 treated levels in total) underwent MIS LIF performed by a single surgeon. The subsidence was deemed to be ECS if it was evident on postoperative Day 2 CT images and was therefore the result of an intraoperative vertebral endplate injury and deemed DCS if it was detected on subsequent CT scans (≥ 6 months postoperatively). Endplate breaches were categorized as caudal (superior endplate) and/or cranial (inferior endplate), and as ipsilateral, contralateral, or bilateral with respect to the side of cage insertion. Subsidence seen in CT images (radiographic subsidence) was measured from the vertebral endplate to the caudal or cranial margin of the cage (in millimeters). Patient-reported outcome measures included visual analog scale, Oswestry Disability Index, and 36-Item Short Form Health Survey physical and mental component summary scores.

RESULTS

Four patients had ECS in a total of 4 levels. The radiographic subsidence (DCS) rates were 10% (13 of 128 patients) and 8% (14 of 178 levels), with 3% of patients (4 of 128) exhibiting clinical subsidence. In the DCS levels, 3 types of subsidence were evident on coronal and sagittal CT scans: Type 1, caudal contralateral, in 14% (2 of 14), Type 2, caudal bilateral with anterior cage tilt, in 64% (9 of 14), and Type 3, both endplates bilaterally, in 21% (3 of 14). The mean subsidence in the DCS levels was 3.2 mm. There was no significant difference between the numbers of patients in the subsidence (DCS) and no-subsidence groups who received clinical benefit from the surgical procedure, based on the minimum clinically important difference (p > 0.05). There was a significant difference between the fusion rates at 6 months (p = 0.0195); however, by 12 months, the difference was not significant (p = 0.2049).

CONCLUSIONS

The authors distinguished between ECS and DCS. Radiographic subsidence (DCS) was categorized using descriptors for the location and severity of the subsidence. Neither interbody fusion rates nor clinical outcomes were affected by radiographic subsidence. To protect patients from subsidence after MIS LIF, the surgeon needs to take care with the caudal endplate during cage insertion. If a caudal bilateral (Type 2) endplate breach is detected, supplemental posterior fixation to arrest progression and facilitate fusion is recommended.
Feasibility of CT-based intraoperative 3D stereotactic image-guided navigation in the upper cervical spine of children 10 years of age or younger: initial experience
Authors: Kovanda Timothy J. , Ansari Shaheryar F. , Qaiser Rabia , Fulkerson Daniel H.
Published: July 2015

OBJECT

Rigid screw fixation may be technically difficult in the upper cervical spine of young children. Intraoperative stereotactic navigation may potentially assist a surgeon in precise placement of screws in anatomically challenging locations. Navigation may also assist in defining abnormal anatomy. The object of this study was to evaluate the authors’ initial experience with the feasibility and accuracy of this technique, both for resection and for screw placement in the upper cervical spine in younger children.

METHODS

Eight consecutive pediatric patients 10 years of age or younger underwent upper cervical spine surgery aided by image-guided navigation. The demographic, surgical, and clinical data were recorded. Screw position was evaluated with either an intraoperative or immediately postoperative CT scan.

RESULTS

One patient underwent navigation purely for guidance of bony resection. A total of 14 navigated screws were placed in the other 7 patients, including 5 C-2 pedicle screws. All 14 screws were properly positioned, defined as the screw completely contained within the cortical bone in the expected trajectory. There were no immediate complications associated with navigation.

CONCLUSIONS

Image-guided navigation is feasible within the pediatric cervical spine and may be a useful surgical tool for placing screws in a patient with small, often difficult bony anatomy. The authors describe their experience with their first 8 pediatric patients who underwent navigation in cervical spine surgery. The authors highlight differences in technique compared with similar navigation in adults.
Long-term developmental follow-up in children with nonsyndromic craniosynostosis
Authors: Bellew Maggie , Chumas Paul
Published: July 2015

OBJECT

The aim of this study was to determine the distribution of Full Scale IQ (FSIQ) by type of craniosynostosis and to verify the finding that at long-term follow-up, verbal IQ (VIQ) is significantly higher than performance IQ (PIQ) in patients with single-suture sagittal synostosis (SS) despite falling within the “average” range for intelligence. Whether this also occurs in other types of craniosynostosis and whether surgery and sex are relevant were also determined. The relationship between age at time of surgery and later IQ was ascertained.

METHODS

The data for 91 children with craniosynostosis (47 sagittal, 15 unicoronal, 13 metopic, 9 multisuture, and 7 bicoronal) were collected at their routine, 10 years of age IQ assessment (mean age 123.8 months). The patients included 61 males and 30 females; 62 patients had undergone surgery and 29 had not.

RESULTS

The mean FSIQ for all types of craniosynostosis combined (96.2) fell within the average range for the general population. Some variation was evident across the different types of craniosynostosis: the SS group showed the highest FSIQs and a “normal” distribution of bandings; the other types had a higher proportion of FSIQs in the lower bandings. The data confirmed the finding that VIQ is greater than PIQ despite falling within the average range for intelligence, with a difference of 5.0 for all types of craniosynostosis combined (p = 0.001), 7.6 for the SS group (p = 0.001), and 6.9 for the unicoronal group (p = 0.029). This VIQ > PIQ effect was not found with multisuture craniosynostosis. The VIQ > PIQ discrepancy occurred regardless of whether the patient had undergone surgery and occurred more often in males than females. In the SS group and the bicoronal group, FSIQ (p = 0.036 and p = 0.046, respectively) and PIQ (p = 0.012 and p = 0.017, respectively), though not VIQ, were higher when surgery had been performed early.

CONCLUSIONS

The study confirms that at long-term follow-up, although children with nonsyndromic craniosynostosis fall within the normal range for intelligence, there is a VIQ > PIQ discrepancy above what would be expected in the normal population, which may be indicative of more subtle difficulties in achievement. This discrepancy is affected by type of craniosynostosis, sex, and age at time of surgery.
Descending transtentorial herniation, a rare complication of the treatment of trapped fourth ventricle: case report
Authors: Frassanito Paolo , Markogiannakis Georgios , Di Bonaventura Rina , Massimi Luca , Tamburrini Gianpiero , Caldarelli Massimo
Published: July 2015

Descending transtentorial herniation (DTH) is a complication of raised pressure in the supratentorial compartment, usually resulting from mass lesion of several etiologies. The authors report an exceptional case of DTH complicating the implant of a CSF shunting device in the trapped fourth ventricle of a 17-year-old boy in whom a second CSF shunting device had been implanted for neonatal posthemorrhagic and postinfectious hydrocephalus. The insidious clinical and radiological presentation of DTH, mimicking a malfunction of the supratentorial shunt, is documented. Ultimately, the treatment consisted of removal of the infratentorial shunt and endoscopic acqueductoplasty with stenting. The absence of supratentorial mass lesion and other described etiologies of DTH prompted the authors to speculate on the hydrodynamic pathogenesis of DTH in the present case.
Effect of Additives and Fuel Blending on Emissions and Ash-Related Problems from Small-Scale Combustion of Reed Canary Grass
Authors: Fournel Sébastien , Palacios Joahnn , Godbout Stéphane , Heitz Michèle
Published: July 2015

Agricultural producers are interested in using biomass available on farms to substitute fossil fuels for heat production. However, energy crops like reed canary grass contain high nitrogen (N), sulfur (S), potassium (K) and other ash-forming elements which lead to increased emissions of gases and particulate matter (PM) and ash-related operational problems (e.g., melting) during combustion. To address these problematic behaviors, reed canary grass was blended with wood (50 wt%) and fuel additives (3 wt%) such as aluminum silicates (sewage sludge), calcium (limestone) and sulfur (lignosulfonate) based additives. When burned in a top-feed pellet boiler (29 kW), the four blends resulted in a 17%–29% decrease of PM concentrations compared to pure reed canary grass probably because of a reduction of K release to flue gas. Nitrogen oxides (NOx) and sulfur dioxide (SO2) emissions varied according to fuel N and S contents. This explains the lower NOx and SO2 levels obtained with wood based products and the higher SO2 generation with the grass/lignosulfonate blend. The proportion of clinkers found in combustion ash was greatly lessened (27%–98%) with the use of additives, except for lignosulfonate. The positive effects of some additives may allow agricultural fuels to become viable alternatives.
Antimicrobial Stewardship Intervention and Feedback to Infectious Disease Specialists: A Case Study in High-Dose Daptomycin
Authors: Ross Jennifer , Rankin Shannon , Marshik Patricia , Mercier Renée-Claude , Brett Meghan , Walraven Carla
Published: July 2015

Infectious Diseases specialists have used high-dose daptomycin (≥6 mg/kg/day) in select patients with difficult to treat methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) infections to optimize outcomes. Antimicrobial stewardship programs enforce antimicrobial formulary restrictions; however, interventions specifically aimed at Infectious Disease specialists can be particularly challenging. The purpose of this study was to create a high-dose daptomycin algorithm for Infectious Disease specialists that are consistent with best-practices. Daptomycin prescribing habits pre- and post-daptomycin algorithm implementation were evaluated using a quasi-experimental study design. Patients were included if ≥18 years of age and received daptomycin for ≥48 h. Patients were excluded if daptomycin was initiated on an outpatient setting. During the 12-month pre-intervention phase, 112 patients were included, with 73 patients in the 12-month post-intervention phase. A statistically significant decrease in the mean daptomycin dose from 9.01 mg/kg to 7.51 mg/kg (p < 0.005) was observed, resulting in an annual drug cost-savings of over $75,000 without adversely affecting readmission rates due to infection. Creation of a daptomycin algorithm with consideration of pathogen, disease state, and prior treatment, is an effective means of influencing prescribing habits of Infectious Disease specialists.
Topography and Data Mining Based Methods for Improving Satellite Precipitation in Mountainous Areas of China
Authors: Xia Ting , Wang Zhong-Jing , Zheng Hang
Published: July 2015

Topography is a significant factor influencing the spatial distribution of precipitation. This study developed a new methodology to evaluate and calibrate the Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA) products by merging geographic and topographic information. In the proposed method, firstly, the consistency rule was introduced to evaluate the fitness of satellite rainfall with measurements on the grids with and without ground gauges. Secondly, in order to improve the consistency rate of satellite rainfall, genetic programming was introduced to mine the relationship between the gauge rainfall and location, elevation and TMPA rainfall. The proof experiment and analysis for the mean annual satellite precipitation from 2001–2012, 3B43 (V7) of TMPA rainfall product, was carried out in eight mountainous areas of China. The result shows that the proposed method is significant and efficient both for the assessment and improvement of satellite precipitation. It is found that the satellite rainfall consistency rates in the gauged and ungauged grids are different in the study area. In addition, the mined correlation of location-elevation-TMPA rainfall can noticeably improve the satellite precipitation, both in the context of the new criterion of the consistency rate and the existing criteria such as Bias and RMSD. The proposed method is also efficient for correcting the monthly and mean monthly rainfall of 3B43 and 3B42RT.
Scaling Flux Tower Observations of Sensible Heat Flux Using Weighted Area-to-Area Regression Kriging
Authors: Hu Maogui , Wang Jianghao , Ge Yong , Liu Mengxiao , Liu Shaomin , Xu Ziwei , Xu Tongren
Published: July 2015

Sensible heat flux (H) plays an important role in characterizations of land surface water and heat balance. There are various types of H measurement methods that depend on observation scale, from local-area-scale eddy covariance (EC) to regional-scale large aperture scintillometer (LAS) and remote sensing (RS) products. However, methods of converting one H scale to another to validate RS products are still open for question. A previous area-to-area regression kriging-based scaling method performed well in converting EC-scale H to LAS-scale H. However, the method does not consider the path-weighting function in the EC- to LAS-scale kriging with the regression residue, which inevitably brought about a bias estimation. In this study, a weighted area-to-area regression kriging (WATA RK) model is proposed to convert EC-scale H to LAS-scale H. It involves path-weighting functions of EC and LAS source areas in both regression and area kriging stages. Results show that WATA RK outperforms traditional methods in most cases, improving estimation accuracy. The method is considered to provide an efficient validation of RS H flux products.
Influence of Virtual Photon Process on the Generation of Squeezed Light from Atoms in an Optical Cavity
Authors: Bhattacherjee Aranya
Published: July 2015

We show that a collection of two-level atoms in an optical cavity beyond the rotating wave approximation and in the dispersive-adiabatic and non-dispersive adiabatic regime constitutes a nonlinear medium and is capable of generating squeezed state of light. It is found that squeezing produced in the non-dispersive adiabatic regime is significantly high compared to that produced in the dispersive-adiabatic limit. On the other hand, we also show that it could be possible to observe the Dicke superradiant quantum phase transition in the dispersive-adiabatic regime where the Ã2 term is negligible. Such a system can be an essential component of a larger quantum-communication system.
Galectin Binding to Neo-Glycoproteins: LacDiNAc Conjugated BSA as Ligand for Human Galectin-3
Authors: Böcker Sophia , Laaf Dominic , Elling Lothar
Published: July 2015

Carbohydrate-lectin interactions are relatively weak. As they play an important role in biological recognition processes, multivalent glycan ligands are designed to enhance binding affinity and inhibitory potency. We here report on novel neo-glycoproteins based on bovine serum albumin as scaffold for multivalent presentation of ligands for galectins. We prepared two kinds of tetrasaccharides (N-acetyllactosamine and N,N-diacetyllactosamine terminated) by multi-step chemo-enzymatic synthesis utilizing recombinant glycosyltransferases. Subsequent conjugation of these glycans to lysine groups of bovine serum albumin via squaric acid diethyl ester yielded a set of 22 different neo-glycoproteins with tuned ligand density. The neo-glycoproteins were analyzed by biochemical and chromatographic methods proving various modification degrees. The neo-glycoproteins were used for binding and inhibition studies with human galectin-3 showing high affinity. Binding strength and inhibition potency are closely related to modification density and show binding enhancement by multivalent ligand presentation. At galectin-3 concentrations comparable to serum levels of cancer patients, we detect the highest avidities. Selectivity of N,N-diacetyllactosamine terminated structures towards galectin-3 in comparison to galectin-1 is demonstrated. Moreover, we also see strong inhibitory potency of our scaffolds towards galectin-3 binding. These novel neo-glycoproteins may therefore serve as selective and strong galectin-3 ligands in cancer related biomedical research.
Pre-mRNA Splicing in Plants: In Vivo Functions of RNA-Binding Proteins Implicated in the Splicing Process
Authors: Meyer Katja , Koester Tino , Staiger Dorothee
Published: July 2015

Alternative pre-messenger RNA splicing in higher plants emerges as an important layer of regulation upon exposure to exogenous and endogenous cues. Accordingly, mutants defective in RNA-binding proteins predicted to function in the splicing process show severe phenotypic alterations. Among those are developmental defects, impaired responses to pathogen threat or abiotic stress factors, and misregulation of the circadian timing system. A suite of splicing factors has been identified in the model plant Arabidopsis thaliana. Here we summarize recent insights on how defects in these splicing factors impair plant performance.
Carbon Nanotubes-Based Potentiometric Bio-Sensors for Determination of Urea
Authors: Jaworska Ewa , Maksymiuk Krzysztof , Michalska Agata
Published: July 2015

The possibility of using disposable plastic-carbon potentiometric sensors as enzyme biosensors was examined. Urease enzyme was immobilized on poly(vinyl chloride) based H+- or NH4+-selective membranes using cellulose acetate. This approach has resulted in a potentiometric response on changing the pH of the solution or NH4+ ion content due to an enzymatic reaction that occurs between urease and urea. Both types of potentiometric biosensors for urea were characterized by good analytical parameters as high sensitivity and fast response time.
Information-Theoretic Characterization and Undersampling Ratio Determination for Compressive Radar Imaging in a Simulated Environment
Authors: Zhang Jingxiong , Yang Ke , Liu Fengzhu , Zhang Ying
Published: July 2015

Assuming sparsity or compressibility of the underlying signals, compressed sensing or compressive sampling (CS) exploits the informational efficiency of under-sampled measurements for increased efficiency yet acceptable accuracy in information gathering, transmission and processing, though it often incurs extra computational cost in signal reconstruction. Shannon information quantities and theorems, such as source rate-distortion, trans-information and rate distortion theorem concerning lossy data compression, provide a coherent framework, which is complementary to classic CS theory, for analyzing informational quantities and for determining the necessary number of measurements in CS. While there exists some information-theoretic research in the past on CS in general and compressive radar imaging in particular, systematic research is needed to handle issues related to scene description in cluttered environments and trans-information quantification in complex sparsity-clutter-sampling-noise settings. The novelty of this paper lies in furnishing a general strategy for information-theoretic analysis of scene compressibility, trans-information of radar echo data about the scene and the targets of interest, respectively, and limits to undersampling ratios necessary for scene reconstruction subject to distortion given sparsity-clutter-noise constraints. A computational experiment was performed to demonstrate informational analysis regarding the scene-sampling-reconstruction process and to generate phase transition diagrams showing relations between undersampling ratios and sparsity-clutter-noise-distortion constraints. The strategy proposed in this paper is valuable for information-theoretic analysis and undersampling theorem developments in compressive radar imaging and other computational imaging applications.
Impact of National Smoke-Free Legislation on Educational Disparities in Smoke-Free Homes: Findings from the SIDRIAT Longitudinal Study
Authors: Gorini Giuseppe , Carreras Giulia , Cortini Barbara , Verdi Simona , Petronio Maria , Sestini Piersante , Chellini Elisabetta
Published: July 2015

Families with lower socioeconomic status are less likely to adopt household smoking bans (HSB). The aim of this study was to determine whether socioeconomic disparities in HSB prevalence in Italy decreased 7–9 years after the introduction of the Italian ban on smoking in public places. A longitudinal, 12-year, two-wave study was conducted on a sample of 3091 youths aged 6–14 years in 2002; 1763 (57%) were re-interviewed in 2012–2014. A Poisson regression with a robust error variance was used to assess the association between socioeconomic disparities and HSB prevalence. The adoption of HSBs significantly increased from 60% in 2002 to 75% in 2012–2014, with the increase recorded in youths with ≥1 smoking parent only (from 22% at baseline to 46% at follow-up). The presence of HSBs at baseline was more likely in families with ≥1 graduate parent compared to those with no graduate parents (prevalence ratio (PR) = 1.34, 95% confidence interval (CI) = 1.15–1.57), either in families with ≥1 smoking parent (PR = 1.36, 95% CI = 1.17–1.58) or in families with non-smoking parents (PR = 1.61, 95% CI = 1.01–2.56). Conversely, at follow-up socioeconomic disparities dropped since families with no graduate parents were 1.5-fold more likely to introduce a HSB between the two waves. The Italian ban on smoking in public places may have increased the adoption of smoke-free homes in families with smoking and non-graduate parents, causing the drop of the socioeconomic gap in smoke-free homes.
Long-Term Effectiveness of Antiretroviral Therapy in China: An Observational Cohort Study from 2003–2014
Authors: Huang Peng , Tan Jingguang , Ma Wenzhe , Zheng Hui , Lu Yan , Wang Ning , Peng Zhihang , Yu Rongbin
Published: July 2015

In order to assess the effectiveness of the Chinese government’s expanded access program, a cohort study on all adult HIV patients in Shenzhen was conducted from December 2003 to February 2014 to estimate the effects of antiretroviral therapy (ART) on mortality, tuberculosis and CD4 cell counts. Marginal structural regression models adjusted for baseline and time-varying covariates. Of the 6897 patients enrolled and followed up for a maximum of 178 months, 44.92% received ART. Among patients who commenced receiving ART during the study, there were 98 deaths and 59 new tuberculosis diagnoses, while there were 410 deaths and 201 new tuberculosis diagnoses among those without ART. ART was associated with both lower mortality (hazard ratio [HR] = 0.18; 95% confidence interval [CI] = 0.11–0.27) and the presence of tuberculosis (HR = 0.27; 95% CI = 0.19–0.37). Each month of ART was associated with an average increase in CD4 cell count of 6.52 cells/µL (95% CI = 6.08–7.12 cells/µL). In conclusions, the effectiveness of ART provided by China government health services is the same as that in higher-income countries. Accounting to higher mortality rates from the delay of starting ART, faster expansion and timely imitation of ART are urgent.
Observations and Predictions of Wave Runup, Extreme Water Levels, and Medium-Term Dune Erosion during Storm Conditions
Authors: Suanez Serge , Cancouët Romain , Floc'h France , Blaise Emmanuel , Ardhuin Fabrice , Filipot Jean-François , Cariolet Jean-Marie , Delacourt Christophe
Published: July 2015

Monitoring of dune erosion and accretion on the high-energy macrotidal Vougot beach in North Brittany (France) over the past decade (2004–2014) has revealed significant morphological changes. Dune toe erosion/accretion records have been compared with extreme water level measurements, defined as the sum of (i) astronomic tide; (ii) storm surge; and (iii) vertical wave runup. Runup parameterization was conducted using swash limits, beach profiles, and hydrodynamic (Hm0, Tm0,–1, and high tide water level—HTWL) data sets obtained from high frequency field surveys. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes [1] runup formula. In addition, an empirical equation based on observed tidal water level and offshore wave height was produced to estimate extreme water levels over the whole period of dune morphological change monitoring. A good correlation between this empirical equation (1.01Hmoξo) and field runup measurements (Rmax) was obtained (R2 85%). The goodness of fit given by the RMSE was about 0.29 m. A good relationship was noticed between dune erosion and high water levels when the water levels exceeded the dune foot elevation. In contrast, when extreme water levels were below the height of the toe of the dune sediment budget increased, inducing foredune recovery. These erosion and accretion phases may be related to the North Atlantic Oscillation Index.
Influence of Wind Pressure on the Carbonation of Concrete
Authors: Zou Dujian , Liu Tiejun , Du Chengcheng , Teng Jun
Published: July 2015

Carbonation is one of the major deteriorations that accelerate steel corrosion in reinforced concrete structures. Many mathematical/numerical models of the carbonation process, primarily diffusion-reaction models, have been established to predict the carbonation depth. However, the mass transfer of carbon dioxide in porous concrete includes molecular diffusion and convection mass transfer. In particular, the convection mass transfer induced by pressure difference is called penetration mass transfer. This paper presents the influence of penetration mass transfer on the carbonation. A penetration-reaction carbonation model was constructed and validated by accelerated test results under high pressure. Then the characteristics of wind pressure on the carbonation were investigated through finite element analysis considering steady and fluctuating wind flows. The results indicate that the wind pressure on the surface of concrete buildings results in deeper carbonation depth than that just considering the diffusion of carbon dioxide. In addition, the influence of wind pressure on carbonation tends to increase significantly with carbonation depth.
Investigation of the InAs/GaAs Quantum Dots’ Size: Dependence on the Strain Reducing Layer’s Position
Authors: Souaf Manel , Baira Mourad , Nasr Olfa , Alouane Mohamed , Maaref Hassen , Sfaxi Larbi , Ilahi Bouraoui
Published: July 2015

This work reports on theoretical and experimental investigation of the impact of InAs quantum dots (QDs) position with respect to InGaAs strain reducing layer (SRL). The investigated samples are grown by molecular beam epitaxy and characterized by photoluminescence spectroscopy (PL). The QDs optical transition energies have been calculated by solving the three dimensional Schrödinger equation using the finite element methods and taking into account the strain induced by the lattice mismatch. We have considered a lens shaped InAs QDs in a pure GaAs matrix and either with InGaAs strain reducing cap layer or underlying layer. The correlation between numerical calculation and PL measurements allowed us to track the mean buried QDs size evolution with respect to the surrounding matrix composition. The simulations reveal that the buried QDs’ realistic size is less than that experimentally driven from atomic force microscopy observation. Furthermore, the average size is found to be slightly increased for InGaAs capped QDs and dramatically decreased for QDs with InGaAs under layer.
Cold-Active, Heterotrophic Bacteria from the Highly Oligotrophic Waters of Lake Vanda, Antarctica
Authors: Vander Schaaf Nicole , Cunningham Anna , Cluff Brandon , Kraemer CodyJo , Reeves Chelsea , Riester Carli , Slater Lauren , Madigan Michael , Sattley W.
Published: July 2015

The permanently ice-covered lakes of the McMurdo Dry Valleys, Antarctica are distinctive ecosystems that consist strictly of microbial communities. In this study, water samples were collected from Lake Vanda, a stratified Dry Valley lake whose upper waters (from just below the ice cover to nearly 60 m) are highly oligotrophic, and used to establish enrichment cultures. Six strains of psychrotolerant, heterotrophic bacteria were isolated from lake water samples from a depth of 50 or 55 m. Phylogenetic analyses showed the Lake Vanda strains to be species of Nocardiaceae, Caulobacteraceae, Sphingomonadaceae, and Bradyrhizobiaceae. All Lake Vanda strains grew at temperatures near or below 0 °C, but optimal growth occurred from 18 to 24 °C. Some strains showed significant halotolerance, but no strains required NaCl for growth. The isolates described herein include cold-active species not previously reported from Dry Valley lakes, and their physiological and phylogenetic characterization broadens our understanding of these limnologically unique lakes.
Toxicological Studies of 212Pb Intravenously or Intraperitoneally Injected into Mice for a Phase 1 Trial
Authors: Milenic Diane , Molinolo Alfredo , Solivella María , Banaga Eileen , Torgue Julien , Besnainou Sarah , Brechbiel Martin , Baidoo Kwamena
Published: July 2015

Faced with the novelty of a 212Pb-labeled monoclonal antibody (mAb) for clinical translation, concerns were expressed by the Food and Drug Administration (FDA) regarding 212Pb prematurely released from the mAb-chelate conjugate. The objective of this study was to simulate the worst case scenario of such a failure. Groups of Balb/c mice (n = 9–20) were administered 212Pb by intraperitoneal (0.0925–1.85 MBq) or intravenous (0.0925–1.11 MBq) injection and then euthanized at 7 or 90 days to assess acute or chronic effects. Weights were recorded prior to injection of the 212Pb and at the end of the observation periods. Blood samples were collected for clinical chemistry and blood cell analysis. Thirty tissues were harvested and formalin fixed for histopathological examination. Treatment related effects of the 212Pb were observed in the bone marrow, spleen, kidneys and the liver. Histological alterations in these organs were considered mild to moderate, indicating low grade toxicity, and not considered severe enough to affect function. This data was presented to the FDA and determined to be acceptable. The clinical trial with 212Pb-TCMC-trastuzumab was approved in January 2011 and the trial opened at the University of Alabama at Birmingham (UAB) in July.
Life Insurance Cash Flows with Policyholder Behavior
Authors: Buchardt Kristian , Møller Thomas
Published: July 2015

The problem of the valuation of life insurance payments with policyholder behavior is studied. First, a simple survival model is considered, and it is shown how cash flows without policyholder behavior can be modified to include surrender and free policy behavior by calculation of simple integrals. In the second part, a more general disability model with recovery is studied. Here, cash flows are determined by solving a modified Kolmogorov forward differential equation. We conclude the paper with numerical examples illustrating the methods proposed and the impact of policyholder behavior.
PEG Functionalization of Whispering Gallery Mode Optical Microresonator Biosensors to Minimize Non-Specific Adsorption during Targeted, Label-Free Sensing
Authors: Wang Fanyongjing , Anderson Mark , Bernards Matthew , Hunt Heather
Published: July 2015

Whispering Gallery Mode (WGM) optical microresonator biosensors are a powerful tool for targeted detection of analytes at extremely low concentrations. However, in complex environments, non-specific adsorption can significantly reduce their signal to noise ratio, limiting their accuracy. To overcome this, poly(ethylene glycol) (PEG) can be employed in conjunction with appropriate recognition elements to create a nonfouling surface capable of detecting targeted analytes. This paper investigates a general route for the addition of nonfouling elements to WGM optical biosensors to reduce non-specific adsorption, while also retaining high sensitivity. We use the avidin-biotin analyte-recognition element system, in conjunction with PEG nonfouling elements, as a proof-of-concept, and explore the extent of non-specific adsorption of lysozyme and fibrinogen at multiple concentrations, as well as the ability to detect avidin in a concentration-dependent fashion. Ellipsometry, contact angle measurement, fluorescence microscopy, and optical resonator characterization methods were used to study non-specific adsorption, the quality of the functionalized surface, and the biosensor’s performance. Using a recognition element ratio to nonfouling element ratio of 1:1, we showed that non-specific adsorption could be significantly reduced over the controls, and that high sensitivity could be maintained. Due to the frequent use of biotin-avidin-biotin sandwich complexes in functionalizing sensor surfaces with biotin-labeled recognition elements, this chemistry could provide a common basis for creating a non-fouling surface capable of targeted detection. This should improve the ability of WGM optical biosensors to operate in complex environments, extending their application towards real-world detection.
A Micro-Preconcentrator Combined Olfactory Sensing System with a Micromechanical Cantilever Sensor for Detecting 2,4-Dinitrotoluene Gas Vapor
Authors: Chae Myung-Sic , Kim Jinsik , Yoo Yong , Kang Ji , Lee Jeong , Hwang Kyo
Published: July 2015

Preventing unexpected explosive attacks and tracing explosion-related molecules require the development of highly sensitive gas-vapor detection systems. For that purpose, a micromechanical cantilever-based olfactory sensing system including a sample preconcentrator was developed to detect 2,4-dinitrotoluene (2,4-DNT), which is a well-known by-product of the explosive molecule trinitrotoluene (TNT) and exists in concentrations on the order of parts per billion in the atmosphere at room temperature. A peptide receptor (His-Pro-Asn-Phe-Ser-Lys-Tyr-Ile-Leu-His-Gln-Arg) that has high binding affinity for 2,4-DNT was immobilized on the surface of the cantilever sensors to detect 2,4-DNT vapor for highly selective detection. A micro-preconcentrator (µPC) was developed using Tenax-TA adsorbent to produce higher concentrations of 2,4-DNT molecules. The preconcentration was achieved via adsorption and thermal desorption phenomena occurring between target molecules and the adsorbent. The µPC directly integrated with a cantilever sensor and enhanced the sensitivity of the cantilever sensor as a pretreatment tool for the target vapor. The response was rapidly saturated within 5 min and sustained for more than 10 min when the concentrated vapor was introduced. By calculating preconcentration factor values, we verified that the cantilever sensor provides up to an eightfold improvement in sensing performance.
Twenty Years of Rad-Hard K14 SPAD in Space Projects
Authors: Michálek Vojtěch , Procházka Ivan , Blažej Josef
Published: July 2015

During last two decades, several photon counting detectors have been developed in our laboratory. One of the most promising detector coming from our group silicon K14 Single Photon Avalanche Diode (SPAD) is presented with its valuable features and space applications. Based on the control electronics, it can be operated in both gated and non-gated mode. Although it was designed for photon counting detection, it can be employed for multiphoton detection as well. With respect to control electronics employed, the timing jitter can be as low as 20 ps RMS. Detection efficiency is about 40%in range of 500 nm to 800 nm. The detector including gating and quenching circuitry has outstanding timing stability. Due to its radiation resistivity, the diode withstands 100 krad gamma ray dose without parameters degradation. Single photon detectors based on K14 SPAD were used for planetary altimeter and atmospheric lidar in MARS92/96 and Mars Surveyor ’98 space projects, respectively. Recent space applications of K14 SPAD comprises LIDAR and mainly time transfer between ground stations and artificial satellites. These include Laser Time Transfer, Time Transfer by Laser Link, and European Laser Timing projects.
Colorimetric Sensor Array for White Wine Tasting
Authors: Chung Soo , Park Tu , Park Soo , Kim Joon , Park Seongmin , Son Daesik , Bae Young , Cho Seong
Published: July 2015

A colorimetric sensor array was developed to characterize and quantify the taste of white wines. A charge-coupled device (CCD) camera captured images of the sensor array from 23 different white wine samples, and the change in the R, G, B color components from the control were analyzed by principal component analysis. Additionally, high performance liquid chromatography (HPLC) was used to analyze the chemical components of each wine sample responsible for its taste. A two-dimensional score plot was created with 23 data points. It revealed clusters created from the same type of grape, and trends of sweetness, sourness, and astringency were mapped. An artificial neural network model was developed to predict the degree of sweetness, sourness, and astringency of the white wines. The coefficients of determination (R2) for the HPLC results and the sweetness, sourness, and astringency were 0.96, 0.95, and 0.83, respectively. This research could provide a simple and low-cost but sensitive taste prediction system, and, by helping consumer selection, will be able to have a positive effect on the wine industry.
Eco-Industrial Parks Development and Integrated Management Challenges: Findings from Italy
Authors: Tessitore Sara , Daddi Tiberio , Iraldo Fabio
Published: July 2015

The evolution of Eco Industrial Parks (EIPs) in Italy is a development opportunity for many territories and companies. Starting from the initial experiences in the 1980s, the Eco Industrial Parks model has spread throughout many of the central and northern regions of the country. The key element of Italian Eco Industrial Parks is the management body, an entity provided by national legislation to manage and coordinate companies and to develop more environmentally sustainable production practices. The survey results describe the role and activities of the management bodies concerning the actions implemented, the interaction with the main stakeholders and the resources and investments. The following research introduces an important environmental management experience implemented in Italy.
GIS Based Measurement and Regulatory Zoning of Urban Ecological Vulnerability
Authors: Zhang Xiaorui , Wang Zhenbo , Lin Jing
Published: July 2015

Urban ecological vulnerability is measured on the basis of ecological sensitivity and resilience based on the concept analysis of vulnerability. GIS-based multicriteria decision analysis (GIS-MCDA) methods are used, supported by the spatial analysis tools of GIS, to define different levels of vulnerability for areas of the urban ecology. These areas are further classified into different types of regulatory zones. Taking the city of Hefei in China as the empirical research site, this study uses GIS-MCDA, including the index system, index weights and overlay rules, to measure the degree of its ecological vulnerability on the GIS platform. There are eight indices in the system. Raking and analytical hierarchy process (AHP) methods are used to calculate index weights according to the characteristics of the index system. The integrated overlay rule, including selection of the maximum value, and weighted linear combination (WLC) are applied as the overlay rules. In this way, five types of vulnerability areas have been classified as follows: very low vulnerability, low vulnerability, medium vulnerability, high vulnerability and very high vulnerability. They can be further grouped into three types of regulatory zone of ecological green line, ecological grey line and ecological red line. The study demonstrates that ecological green line areas are the largest (53.61% of the total study area) and can be intensively developed; ecological grey line areas (19.59% of the total area) can serve as the ecological buffer zone, and ecological red line areas (26.80%) cannot be developed and must be protected. The results indicate that ecological green line areas may provide sufficient room for future urban development in Hefei city. Finally, the respective regulatory countermeasures are put forward. This research provides a scientific basis for decision-making around urban ecological protection, construction and sustainable development. It also provides theoretical method references for future research into urban ecological vulnerability, including the introduction of GIS-MCDA methods into the field of urban ecological vulnerability, which expands the application for these techniques.