bluuebunny/crossref_metadata_2025 huggingface dataset:
Higher Serum Levels of Interleukin 10 Occur at Onset of Acute Otitis Media Caused by Streptococcus Pneumoniae Compared to Haemophilus Influenzae and Moraxella Catarrhalis
Authors: Liu Keyi , Kaur Ravinder , Almudevar Anthony , Pichichero Michael E.
Published: February 2013

Objectives/Hypothesis

Acute otitis media (AOM) involves an inflammatory response to microbes in the middle ear that facilitates clearance of otopathogens. Clinically, Streptococcus pneumoniae (Spn) infections of the respiratory tract are characterized by greater inflammatory responses than nontypeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis (Mcat). Interleukin 10 (IL‐10) plays an important role in down‐regulating the inflammatory response. We compared serum IL‐10 levels in children before onset, at onset, and after recovery from AOM caused by Spn, NTHi, and Mcat. We sought to determine if IL‐10 could serve as a biomarker to distinguish AOM caused by Spn versus NTHi and Mcat.

Study Design

Prospective, longitudinal study in a primary care pediatric practice in Rochester, NY.

Methods

Participants were 54 children, 6 to 30 months of age. Outcomes measured were serum IL‐10 levels when healthy, at onset of AOM, and after recovery from AOM.

Results

Serum IL‐10 was elevated when children developed AOM (P=0.013) due to infections caused by Spn (P=0.011) but not AOM caused by NTHi or Mcat. Middle ear fluid levels of IL‐10 mirrored those seen in serum but were 10‐fold higher (P=0.02). Other effector cytokines in serum: IL‐4, IFN‐γ, and TNF‐alpha, did not show the same increases as IL‐10 at onset of AOM.

Conclusion

Our study indicates that AOM caused by Spn elicits a significantly higher IL‐10 response compared to NTHi and Mcat and may prove to be a biomarker of AOM infections by Spn.

Level of Evidence

4.
Investigating Interfacial Contributions on the Layer‐Thickness‐Dependent Mechanical Response of Confined Self‐Assembly via Forced Assembly
Authors: Burt Tiffani M. , Jordan Alex M. , Korley LaShanda T. J.
Published: February 2013

Understanding block copolymer (BCP) self‐assembly under confinement via conventional melt extrusion is advantageous as technology moves towards thin film applications. Previous research has revealed that confining elastomeric BCPs in thin films with polystyrene (PS) via microlayering results in an increase in ductility with decreasing layer thickness and that the interfacial region dramatically influences the elastic modulus. This contribution investigated the role of interfacial width and layer thickness on deformation mechanics by comparing poly(methyl methacrylate) (PMMA) and PS as wetting layers in confined multilayers. The interfacial region was found to be crucial to tailoring the mechanical response of composite materials.

magnified image
Collapse of Cylindrical Brushes with 2‐Isopropyloxazoline Side Chains Close to the Phase Boundary
Authors: Bühler Jasmin , Muth Sandra , Fischer Karl , Schmidt Manfred
Published: February 2013

A high‐molar‐mass cylindrical brush polymer with a main chain degree of polymerization of Pw = 1047 is synthesized by free‐radical polymerization of a poly‐2‐isopropyloxazoline macromonomer with Pn = 28. The polymerization is conducted above the lower phase transition temperature of the macromonomer, i.e., in the phase‐separated regime, which provides a sufficiently concentrated macromonomer phase mandatory to obtain high‐molar‐mass cylindrical brushes. Upon heating to the phase transition temperature, the hydrodynamic radius is observed to shrink from 34 to 27 nm. Further increase in temperature resulted in aggregated chains which were observed to coexist with single chains until eventually only aggregates of μm size were detectable.

magnified image
An economic model of Parkinson's disease: Implications for slowing progression in the United States
Authors: Johnson Scott J. , Diener Melissa D. , Kaltenboeck Anna , Birnbaum Howard G. , Siderowf Andrew D.
Published: February 2013

Multiple studies describe progression, dementia rates, direct and indirect costs, and health utility by Hoehn and Yahr (H&Y) stage, but research has not incorporated these data into a model to evaluate possible economic consequences of slowing progression. This study aimed to model the course of Parkinson's disease (PD) and describe the economic consequences of slower rates of progression. A Markov model was developed to show the net monetary benefits of slower rates of progression. Four scenarios assuming hypothetical slower rates of progression were compared to a base case scenario. A systematic literature review identified published longitudinal H&Y progression rates. Direct and indirect excess costs (i.e., healthcare costs beyond what similar patients without PD would incur), mortality rates, dementia rates, and health utility were derived from the literature. Ten publications (N = 3,318) were used to model longitudinal H&Y progression. Base case results indicate average excess direct costs of $303,754, life‐years of 12.8 years and quality‐adjusted life‐years of 6.96. A scenario where PD progressed 20% slower than the base case resulted in net monetary benefits of $60,657 ($75,891 including lost income) per patient. The net monetary benefit comes from a $37,927 decrease in direct medical costs, 0.45 increase in quality‐adjusted life‐years, and $15,235 decrease in lost income. The scenario where PD progression was arrested resulted in net monetary benefits of $442,429 per patient. Reducing progression rates could produce significant economic benefit. This benefit is strongly dependent on the degree to which progression is slowed. © 2013 Movement Disorder Society
The heat transfer problem for inhomogeneous materials in photoacoustic applications and spectral parameter power series
Authors: Khmelnytskaya Kira V. , Serroukh Ibrahim
Published: February 2013

A method for studying the one‐dimensional heat transfer process within an inhomogeneous spatially bounded medium in the presence of an external heat source is presented. It is based on a recently introduced technique for solving problems related to Sturm–Liouville equations that consists in the representation of solutions in the form of a spectral parameter power series. We consider a heat transfer model linked to photoacoustic and show that the introduced method, besides its relative simplicity and analytical nature, offers an efficient numerical algorithm as well as a convenient way to work separately with different physically meaningful components of the temperature distribution function. Detailed explanations and numerical examples are given. Copyright © 2013 John Wiley & Sons, Ltd.
Late Quaternary climatic and oceanographic changes in the Northeast Pacific as recorded by dinoflagellate cysts from Guaymas Basin, Gulf of California (Mexico)
Authors: Price Andrea M. , Mertens Kenneth N. , Pospelova Vera , Pedersen Thomas F. , Ganeshram Raja S.
Published: February 2013

A high‐resolution record of organic‐walled dinoflagellate cyst production in Guaymas Basin, Gulf of California (Mexico) reveals a complex paleoceanographic history over the last ~40 ka. Guaymas Basin is an excellent location to perform high resolution studies of changes in late Quaternary climate and paleo‐productivity because it is characterized by high primary productivity, high sedimentation rates, and low oxygen bottom waters. These factors contribute to the deposition and preservation of laminated sediments throughout large portions of the core MD02‐2515. In this study, we document dinoflagellate cyst production at a centennial to millennial scale throughout the late Quaternary. Based on the cyst assemblages, three dinoflagellate cyst zones were established and roughly correspond to Marine Isotope Stages (MISs) 1 to 3. MISs 1 and 3 are dominated by cysts of heterotrophic dinoflagellates, whereas MIS 2 is characterized by enhanced variability and a greater proportion of cysts produced by autotrophic taxa. The most dominant dinoflagellate cyst taxa found throughout the core were Brigantedinium spp. and Operculodinium centrocarpum. Dansgaard‐Oeschger event 8 is observed in the dinoflagellate cyst record where it is characterized by an increase in warm taxa, such as Spiniferites pachydermus. Other intervals of interest are the Younger Dryas where warmer conditions are recorded and the Holocene which is characterized by the consistent presence of tropical species Stelladinium reidii, Tuberculodinidum vancampoae, Bitectatodinium spongium, and an increase in Quinquecuspis concreta. Changes in cyst assemblages, concentrations, and species diversity, along with geochemical data reflect major orbital to millennial‐scale climatic and oceanographic changes.
The impact of a managed transition of care upon psychosocial characteristics and patient satisfaction in a cohort of adult survivors of childhood cancer
Authors: van Laar M. , Glaser A. , Phillips R. S. , Feltbower R. G. , Stark D. P.
Published: February 2013

Objective

Many adult survivors of childhood cancer receive care in paediatric departments, despite national policy to transition their care to adult services. When long‐term follow‐up care for survivors of childhood cancer in our region moved from a paediatric to an adult environment in 2009, we prospectively assessed the impact of this change on patient satisfaction.

Methods

Questionnaire data were collected in paediatric and adult clinical environments regarding the level of satisfaction with care and potential mediators: quality of life, psychological health and social difficulties. Predictors of satisfaction and optimum longitudinal risk‐based care were described using path analysis and compared with previously described models.

Results

There was no significant difference in satisfaction between the paediatric and adult settings. Short waiting times and increased understanding of the purpose of follow‐up were significantly associated with increased satisfaction. Those with a higher perception of health problems and those that were older were more likely to not attend all of their clinic appointments.

Conclusions

Within our service, transition to adult care did not impact significantly upon patient satisfaction. Shorter waits and knowing why participants were attending the clinic increased satisfaction. Joint working between adult and paediatric cancer professionals enabled adult survivors of childhood cancer to receive highly satisfactory care in adult services. Copyright © 2013 John Wiley & Sons, Ltd.
The Morphology Evolution of Nickel Phosphite Hexagonal Polyhedrons and Their Primary Electrochemical Capacitor Applications
Authors: Pang Huan , Yan Zhenzhen , Wei Yuanyuan , Li Xuexue , Li Juan , Zhang Li , Chen Jing , Zhang Jiangshan , Zheng Honghe
Published: February 2013

Nickel posphite (Ni11(HPO3)8(OH)6) hexagonal polyhedrons are successfully synthesized under hydrothermal conditions. The effect of surfactants on the growth mechanism of Ni11(HPO3)8(OH)6 are also explored. More importantly, Ni11(HPO3)8(OH)6 hexagonal polyhedrons are successfully applied as electrochemical supercapacitor electrode materials, which have a good specific capacitance (295 F g−1 at 0.625 A g−1), good rate capability, and cycling properties (maintained about 99.3% at 0.625 A g−1 after 1000 cycles).
Influence of protein immobilization on protein–protein interaction measured by scanning force spectroscopy
Authors: Rösch Christina , Huber Christina , Müller Christine , Umanskaya Natalia , Hannig Matthias , Ziegler Christiane
Published: February 2013

For a better understanding of biofilm establishment, adhesion forces of proteins on immobilized protein layers were investigated by scanning force spectroscopy (SFS). For this purpose the experimental setup to immobilize protein layers on the surface is important. The influence of the method chosen to immobilize the proteins on the surface was examined and afterwards the effect of variations in pH and contact time on the measured adhesion forces in protein–protein interaction was analyzed. The adsorption of bovine serum albumin (BSA) on BSA‐coated silicon was used here as a model system. To coat the substrate, free adsorption, crosslinking with glutaraldehyde, and covalent protein binding to the surface after silanization were used. For the latter different deposition methods of the silane were compared. Depending on the immobilization method the measured protein–protein interactions show distinct differences. Covalent attachment of proteins is a promising approach to attain stable, pre‐adsorbed protein layers for SFS measurements. The adhesion forces of a BSA‐coated cantilever on such layers seem to be dominated by electrostatic interactions of the molecules.
Highly enhanced luminescence of SrSi2O2N2:Eu2+ phosphors by Mg2+ substitution and their application in pc‐LED
Authors: Lee Sun‐Hee , Kim Kwang‐Bok , Kim Jong‐Moon , Jeong Yong‐Kwang , Kang Jun‐Gill
Published: February 2013

The effect of substitution of Sr2+ by Mg2+ on the luminescence properties of (Sr0.9 − xMgx)Si2O2N2:0.1Eu2+ were investigated as a function of the concentration of Mg2+(x). The peak position of the yellowish green emission from (Sr0.9 − xMgx)Si2O2N2:0.1Eu2+ was invariant with x. However, the luminescence intensity was significantly affected by x. With increasing Mg2+ concentration, the intensity increased to a maximum at x = 0.1. Partial substitution of Sr2+ by Mg2+ enhanced the intensity 1.8‐fold. The Eu2+ concentration affected the peak positions of both luminescence and excitation. With increasing Eu2+ concentration, the red‐shifting and enhancement of the luminescence were associated with the nephelauxetic effect. Concentration quenching of the luminescence occurred above y = 0.07 in the (Sr0.8 − yMg0.1)Si2O2N2:yEu2+. Above the critical concentration of Eu2+, non‐radiative transitions between adjacent Eu2+ ions were more effective than the nephelauxetic effect. Optimized (Sr0.83Mg0.1)Si2O2N2:0.07Eu2+ phosphors were fabricated with blue GaN LED and the chromaticity index of the phosphor‐formulated GaN LED was investigated as a function of the wt% of the optimized phosphor.
Evaluation of reagentless pH modification for in situ ocean analysis: determination of dissolved inorganic carbon using mass spectrometry
Authors: Cardenas‐Valencia Andres M. , Adornato Lori R. , Bell Ryan J. , Byrne Robert H. , Short R. Timothy
Published: February 2013

RATIONALE

In situ analytical techniques that require the storage and delivery of reagents (e.g., acidic or basic solutions) have inherent durability limitations. The reagentless electrolytic technique for pH modification presented here was developed primarily to ease and to extend the longevity of dissolved inorganic carbon (DIC) determinations in seawater, but can also be used for other analytical methods. DIC, a primary carbon dioxide (CO2) system variable along with alkalinity, controls seawater pH, carbonate saturation state, and CO2 fugacity. Determinations of these parameters are central to an understanding of ocean acidification and global climate change.

METHODS

Electrodes fabricated with electroactive materials, including manganese(III) oxide (Mn2O3) and palladium (Pd), were examined for potential use in electrolytic acidification. In‐line acidification techniques were evaluated using a bench‐top membrane introduction mass spectrometry (MIMS) setup to determine the DIC content of artificial seawater. Linear least‐squares (LLSQ) calibrations for DIC concentration determinations over a range between 1650 and 2400 µmol kg–1 were obtained, using both the novel electrolytic and conventional acid addition techniques.

RESULTS

At sample rates of 4.5 mL min–1, electrodes clad with Mn2O3 and Pd were able to change seawater pH from 7.6 to 2.8 with a power consumption of less than 3 W. Although calibration curves were influenced by sampling rates at a flow of 4.5 mL min–1, the 1σ measurement precision for DIC was of the order of ±20 µmol kg–1.

CONCLUSIONS

Calibrations obtained with the novel reagentless technique and the in‐line addition of strong acid showed similar capabilities for DIC quantification. However, calculations of power savings for the reagentless technique relative to the mechanical delivery of stored acid demonstrated substantial advantages of the electrolytic technique for long‐term deployments (>1 year). Copyright © 2013 John Wiley & Sons, Ltd.
Background effects on Faraday collectors in gas‐source mass spectrometry and implications for clumped isotope measurements
Authors: Bernasconi Stefano M. , Hu Bin , Wacker Ulrike , Fiebig Jens , Breitenbach Sebastian F. M. , Rutz Tanja
Published: February 2013

RATIONALE

The measurement of the abundances of minor isotopologues by mass spectrometry requires correction of subtle non‐linearities in the mass spectrometer that cause deviations in the relationship between actual and measured isotope ratios. Here we show that negative backgrounds on the Faraday cups recording the minor ion beams are the cause of the observed non‐linearities in the measurement of CO2 isotopologues, and propose a new correction procedure for clumped isotope measurements.

METHODS

We carefully investigated the cause of non‐linearity effects in the measurement of the abundance of 13C18O16O, a minor isotopologue of CO2 with m/z 47, on two different mass spectrometers. By using gases of different composition with close to stochastic and with non‐random distribution of isotopes we demonstrate that the apparent dependence of the excess abundance of the isotopologue of m/z 47 on the bulk isotopic composition of CO2 is due to a background interference that is linearly dependent on the partial pressure of the gas in the source of the mass spectrometer.

CONCLUSIONS

Background determination with gas flowing into the source of the mass spectrometer is necessary for accurate clumped isotope measurements of CO2. Background corrections can be performed accurately if the slit width of the m/z 44 Faraday cup significantly exceeds that of the one for m/z 47, using a correlation between m/z 44 signal intensity and the corresponding minimum in m/z 47 background. We propose two new correction schemes that reduce the time‐consuming measurement of gases of different bulk isotopic compositions. These findings may also be relevant for the measurement of other rare isotopologues by mass spectrometry. Copyright © 2013 John Wiley & Sons, Ltd.
Teachers’ Nature of Science Implementation Practices 2–5 Years After Having Completed an Intensive Science Education Program
Authors: HERMAN BENJAMIN C. , CLOUGH MICHAEL P. , OLSON JOANNE K.
Published: February 2013

Few, if any, studies have examined the impact of nature of science (NOS) instruction on science teachers’ practices 2 or more years after completing a science teacher education program. Extant studies on preservice and first‐year teachers’ NOS teaching practices have had disappointing results, with few teachers valuing NOS as a cognitive objective or teaching it in ways consistent with literature regarding effective NOS instruction. In addition, little is known about teachers’ specific NOS practices due to a lack of observation protocols to assess teachers’ NOS instruction. This study examined teachers’ NOS instructional practices 2–5 years after completing an intensive secondary science education program that included a NOS course and attention to NOS instruction throughout all other science education coursework. Twelve of the 13 study participants explicitly taught NOS, and 9 of the 13 did so at moderate to high levels. This paper also presents a NOS Classroom Observation Protocol (NOS‐COP) designed to make evident many facets of teachers’ NOS implementation practices that have not always been clear in prior research. This study raises important issues about achieving the goal of NOS instruction. Accurate and effective NOS instruction appears achievable, but may require far more effort than found in typical science teacher education programs. © 2013 Wiley Periodicals, Inc. Sci Ed 97:271–309, 2013
Becoming Researchers: The Participation of Undergraduate and Graduate Students in Scientific Research Groups
Authors: FELDMAN ALLAN , DIVOLL KENT A. , ROGAN‐KLYVE ALLYSON
Published: February 2013

This study sought to understand how graduate and undergraduate students learn to do science by participating in research groups. A phenomenological approach was used to illuminate the experiences of the students. The results provide evidence that the students were in the role of apprentices, although this was not made explicit. As apprentices they learned by doing as legitimate peripheral participants in the groups. Mentoring was distributed among the group, with more advanced students providing much of it. The groups were both communities of practice and epistemic communities in which students gained methodological and intellectual proficiency. Finally, student learning in research groups can be conceptualized as learning trajectories that enter the group, traverse characteristics of communities of practice and epistemic communities, and leave with the students as novice researchers, proficient technicians, or knowledge producers. The implications for K‐12 science education are that it is unrealistic to expect teachers to achieve the proficiency in traditional short‐term research experiences that would prepare them to teach their students how to engage in authentic scientific research, and that these experiences should be structured so that the teachers are placed in tightly organized research groups with mentors who explicitly teach them how to do science. © 2013 Wiley Periodicals, Inc. Sci Ed 97:218–243, 2013
Proportional‐odds models for repeated composite and long ordinal outcome scales
Authors: Parsons Nick R.
Published: February 2013

In many medical studies, researchers widely use composite or long ordinal scores, that is, scores that have a large number of categories and a natural ordering often resulting from the sum of a number of short ordinal scores, to assess function or quality of life. Typically, we analyse these using unjustified assumptions of normality for the outcome measure, which are unlikely to be even approximately true. Scores of this type are better analysed using methods reserved for more conventional (short) ordinal scores, such as the proportional‐odds model. We can avoid the need for a large number of cut‐point parameters that define the divisions between the score categories for long ordinal scores in the proportional‐odds model by the inclusion of orthogonal polynomial contrasts. We introduce the repeated measures proportional‐odds logistic regression model and describe for long ordinal outcomes modifications to the generalized estimating equation methodology used for parameter estimation. We introduce data from a trial assessing two surgical interventions, briefly describe and re‐analyse these using the new model and compare inferences from the new analysis with previously published results for the primary outcome measure (hip function at 12 months postoperatively). We use a simulation study to illustrate how this model also has more general application for conventional short ordinal scores, to select amongst competing models of varying complexity for the cut‐point parameters. Copyright © 2013 John Wiley & Sons, Ltd.
AdS field theory from conformal field theory
Authors: Fitzpatrick A. Liam , Kaplan Jared
Published: February 2013

Abstract

We provide necessary and sufficient conditions for a Conformal Field Theory to have a description in terms of a perturbative Effective Field Theory in AdS. The first two conditions are well-known: the existence of a perturbative ‘1/N ’ expansion and an approximate Fock space of states generated by a finite number of low-dimension operators. We add a third condition, that the Mellin amplitudes of the CFT correlators must be well- approximated by functions that are bounded by a polynomial at infinity in Mellin space, or in other words, that the Mellin amplitudes have an effective theory-type expansion. We explain the relationship between our conditions and unitarity, and provide an analogy with scattering amplitudes that becomes exact in the flat space limit of AdS. The analysis also yields a simple connection between conformal blocks and AdS diagrams, providing a new calculational tool very much in the spirit of the S-Matrix program.

We also begin to explore the potential pathologies associated with higher spin fields in AdS by generalizing Weinberg’s soft theorems to AdS/CFT. The AdS analog of Weinberg’s argument constrains the interactions of conserved currents in CFTs, but there are potential loopholes that are unavailable to theories of massless higher spin particles in flat spacetime.
Liberian Surgical and Anesthesia Infrastructure: A Survey of County Hospitals
Authors: Knowlton Lisa Marie , Chackungal Smita , Dahn Bernice , LeBrun Drake , Nickerson Jason , McQueen Kelly
Published: February 2013

Background

There is a significant burden of disease in low‐income countries that can benefit from surgical intervention. The goal of this survey was to evaluate the current ability of the Liberian health care system to provide safe surgical care and to identify unmet needs in regard to trained personnel, equipment, infrastructure, and outcomes measurement.

Methods

A comprehensive survey tool was developed to assess physical infrastructure of operative facilities, education and training for surgical and anesthesia providers, equipment and medications, and the capacity of the surgical system to collect and evaluate surgical outcomes at district‐level hospitals in Africa. This tool was implemented in a sampling of 11 county hospitals in Liberia (January 2011). Data were obtained from the Ministry of Health and by direct government‐affiliated hospital site visits.

Results

The total catchment area of the 11 hospitals surveyed was 2,313,429—equivalent to roughly 67 % of the population of Liberia (3,476,608). There were 13 major operating rooms and 34 (1.5 per 100,000 population) physicians delivering surgical, obstetric, or anesthesia care including 2 (0.1 per 100,000 population) who had completed formal postgraduate training programs in these specialty areas. The total number of surgical cases for 2010 was 7,654, with approximately 43 % of them being elective procedures. Among the facilities that tracked outcomes in 2010, a total of 11 intraoperative deaths (145 per 100,000 operative cases) were recorded for 2009. The 30‐day postoperative mortality at hospitals providing data was 44 (1,359 per 100,000 operative cases). Metrics were also used to evaluate surgical output, safety of anesthesia, and the burden of obstetric disease.

Conclusions

A significant volume of surgical care is being delivered at county hospitals throughout Liberia. The density and quality of appropriately trained personnel and infrastructure remain critically low. There is strong evidence for continued development of emergency and essential surgical services, as well as improved surgical outcomes tracking, at county hospitals in Liberia. These results serve to inform the international community and donors of the ongoing global surgical and anesthesia crisis.
Laparoscopic Surgical Skills are Significantly Improved by the Use of a Portable Laparoscopic Simulator: Results of a Randomized Controlled Trial
Authors: Johnston T. J. , Tang B. , Alijani A. , Tait I. , Steele R. J. , Ker J. , Nabi G. ,   Surgical Simulation Group at the University of Dundee
Published: February 2013

Background

There is growing evidence that training on virtual reality simulators leads to improved performance in the animate and human operating room. However, they are expensive, have a limited availability, and involve complex systems. Portable simulators are significantly cheaper, more user‐friendly, and are flexible systems that are more suited to a surgical trainee’s busy schedule. The use of portable surgical simulators to train skills and reduce errors has never been evaluated in prospective, randomized clinical settings. The objective of this study was to determine if training on the portable Integrated Laparoscopic Simulator leads to improved performance of core laparoscopic skills.

Methods

Core laparoscopic skills were identified by five experienced laparoscopic surgeons and modeled into two exercises and three basic tasks. Twenty surgically naive medical students had baseline laparoscopic skills assessed on a fixed simulator. Participants were randomized to either 14 h training on a portable laparoscopic simulator over a 3 week period, or control with no training. At 3 weeks two expert laparoscopic surgeons blinded to the allocation of participants assessed their pre‐ and post‐intervention performances recorded on a CD‐ROM. The outcome measures included time to complete and global rating scores of clipping and dissection tasks.

Results

No differences were observed in baseline skills level between the two groups. The intervention group had better quality of scissors dissection (p = 0.0038) and improved clipping skills (p = 0.0051), and they took less time to accomplish the tasks (p = 0.0099) in comparison to control.

Conclusions

Training on the portable Integrated Laparoscopic Simulator significantly improved core laparoscopic skills in medical students with no prior experience.
Remittances in the Republic of Georgia: Correlates, Economic Impact, and Social Capital Formation
Authors: Gerber Theodore P. , Torosyan Karine
Published: February 2013

The economic impact of remittances on migrant-sending countries has been a subject of debate in the scholarly literature on migration. We consider the topic using a household-level approach. We use a new survey, “Georgia on the Move,” to examine migrant-level, household-level, and contextual variables associated with the probability that a household in the Republic of Georgia receives remittances. We then apply propensity score matching to estimate how remittances affect particular types of household expenditures, savings, labor supply, health, and other measures of well-being. Separate analysis of the subsample of households with a migrant currently abroad distinguishes the effects of remittances from the effects of migration as such. In Georgia, remittances improve household economic well-being without, for the most part, producing the negative consequences often suggested in the literature. We find evidence for an important aspect that has not been widely discussed in prior studies: remittances foster the formation of social capital by increasing the amount of money that households give as gifts to other households.
[18F]T807, a novel tau positron emission tomography imaging agent for Alzheimer's disease
Authors: Xia Chun‐Fang , Arteaga Janna , Chen Gang , Gangadharmath Umesh , Gomez Luis F. , Kasi Dhanalakshmi , Lam Chung , Liang Qianwa , Liu Changhui , Mocharla Vani P. , Mu Fanrong , Sinha Anjana , Su Helen , Szardenings A. Katrin , Walsh Joseph C. , Wang Eric , Yu Chul , Zhang Wei , Zhao Tieming , Kolb Hartmuth C.
Published: February 2013

Objective

We wished to develop a highly selective positron emission tomography (PET) imaging agent targeting PHF‐tau in human Alzheimer's disease (AD) brains.

Methods

To screen potential tau binders, human AD brain sections were used as a source of native paired helical filament (PHF)‐tau and Aβ rather than synthetic tau aggregates or Aβ fibrils generated in vitro to measure the affinity and selectivity of [18F]T807 to tau and Aβ. Brain uptake and biodistribution of [18F]T807 in mice were also tested.

Results

In vitro autoradiography results show that [18F]T807 exhibits strong binding to PHF‐tau‐positive human brain sections. A dissociation constant (Kd) of [18F]T807 (14.6 nM) was measured using brain sections from the frontal lobe of AD patients. A comparison of autoradiography and double immunohistochemical staining of PHF‐tau and Aβ on adjacent sections demonstrated that [18F]T807 binding colocalized with immunoreactive PHF‐tau pathology, but did not highlight Aβ plaques. In vivo studies in mice demonstrated that [18F]T807 was able to cross the blood–brain barrier and washed out quickly.

Conclusions

[18F]T807 demonstrates high affinity and selectivity to PHF‐tau as well as favorable in vivo properties, making this a promising candidate as an imaging agent for AD.
Can we prevent Alzheimer's disease? Secondary “prevention” trials in Alzheimer's disease
Authors: Carrillo Maria C. , Brashear H. Robert , Logovinsky Veronika , Ryan J. Michael , Feldman Howard H. , Siemers Eric R. , Abushakra Susan , Hartley Dean M. , Petersen Ronald C. , Khachaturian Ara S. , Sperling Reisa A.
Published: February 2013

Current research including the basic biology of Alzheimer's disease (AD) provides a foundation to explore whether our current state of knowledge is sufficient to initiate prevention studies and allow us to believe prevention of AD is possible. Current research and recently revised criteria for the diagnosis of AD by the National Institutes on Aging and the Alzheimer's Association suggest a continuum of disease from preclinical asymptomatic to symptomatic Alzheimer's dementia. In light of these revised criteria, the possibility of secondary prevention and even primary prevention is under discussion. The Alzheimer's Association Research Roundtable convened a meeting to discuss the rationale and feasibility of conducting secondary prevention trials in AD.
The British Aesthetic Tradition
Authors: Costelloe Timothy M.
Published: February 2013

The British Aesthetic Tradition: From Shaftesbury to Wittgenstein is the first single volume to offer readers a comprehensive and systematic history of aesthetics in Britain from its inception in the early eighteenth century to major developments in Britain and beyond in the late twentieth century. The book consists of an introduction and eight chapters, and is divided into three parts. The first part, The Age of Taste, covers the eighteenth-century approaches of internal sense theorists, imagination theorists and associationists. The second, The Age of Romanticism, takes readers from debates over the picturesque through British Romanticism to late Victorian criticism. The third, The Age of Analysis, covers early twentieth-century theories of Formalism and Expressionism to conclude with Wittgenstein and a number of views inspired by his thought.
Positron sound waves and nonlinear Landau damping of intense transverse EM waves in an isotropic EPI plasma
Authors: TSINTSADZE N. L. , CHAUDHARY R. , RASHEED A.
Published: February 2013

Relativistically hot electron–positron–ion (EPI) plasmas in the presence of relativistic intense electromagnetic (EM) radiation that are not in thermal equilibrium are studied by following a modified plasma particle distribution function. By means of a kinetic description, soliton solution is obtained for a small amplitude EM wave, whereas for large amplitude EM waves a cusp soliton solution is obtained. A general expression of positron density oscillations is obtained for long wavelength in comparison with the Debye length of electrons, and is discussed for special cases. Dispersion relations for a new type of longitudinal waves with slow damping is formulated as a consequence of resonant wave–particle interaction, and the necessary conditions for the existence of positron sound waves are obtained. Furthermore, for ultrarelativistic electrons and non-relativistic positrons, quasi positron sound waves dispersion relation in the intermediate wave range is obtained. It is shown that the modulation of amplitude of relativistic EM waves leads to instability for the rare plasma. Finally, we have obtained the relativistic kinetic nonlinear Schrödinger equation (KNLS) with local and non-local nonlinearities. The KNLS equation depicts nonlinear Landau damping rates for intense EM waves, and these damping rates are also examined.
The Busemann–Petty problem in the complex hyperbolic space
Authors: DANN SUSANNA
Published: February 2013

The Busemann–Petty problem asks whether origin-symmetric convex bodies in ℝn with smaller central hyperplane sections necessarily have smaller volume. The answer is affirmative if n ≤ 4 and negative if n ≥ 5. We study this problem in the complex hyperbolic n-space ℍnℂ and prove that the answer is affirmative for n ≤ 2 and negative for n ≥ 3.
Integrally closed rings in birational extensions of two-dimensional regular local rings
Authors: OLBERDING BRUCE , TARTARONE FRANCESCA
Published: February 2013

Let D be an integrally closed local Noetherian domain of Krull dimension 2, and let f be a nonzero element of D such that fD has prime radical. We consider when an integrally closed ring H between D and Df is determined locally by finitely many valuation overrings of D. We show such a local determination is equivalent to a statement about the exceptional prime divisors of normalized blow-ups of D and, when D is analytically normal, this property holds for D if and only if it holds for the completion of D. This latter fact, along with MacLane's notion of key polynomials, allows us to prove that in some central cases where D is a regular local ring and f is a regular parameter of D, then H is determined locally by a single valuation. As a consequence, we show that if H is also the integral closure of a finitely generated D-algebra, then the exceptional prime ideals of the extension H/D are comaximal. Geometrically, this translates into a statement about intersections of irreducible components in the closed fiber of the normalization of a proper birational morphism.
Foetal aortic valvuloplasty: experience of five cases
Authors: Marantz Pablo , Aiello Horacio , Grinenco Sofía , Izbizky Gustavo , Peña Gabriela , Trentacoste Luis , Granja Miguel , Otaño Lucas
Published: February 2013

Objectives

Foetal aortic valvuloplasty has been proposed as a strategy to improve left heart growth and function in foetuses with severe aortic stenosis at risk of progression to hypoplastic left heart syndrome. We report our experience with this intervention.

Methods and results

Between 2005 and 2010, five foetuses with aortic stenosis and at risk of progression to hypoplastic left heart syndrome underwent ultrasound-guided percutaneous foetal aortic valvuloplasty. There were no associated maternal complications or foetal demise. In one case, the pregnancy was terminated a couple of weeks after the intervention, one foetus evolved to hypoplastic left heart syndrome, and three did not.

Conclusions

Foetal aortic valvuloplasty seems to be a safe and feasible procedure. It has been reported that it has the potential to prevent progression to hypoplastic left heart syndrome in selected foetuses with severe aortic stenosis. Further investigation regarding physiological and clinical aspects of this disease both prenatally and postnatally will probably allow to improve therapeutic strategies and clinical outcome.
Heart rate variability in β-thalassaemia major with or without cardiac siderosis
Authors: Alp A. , Ozdogan O. , Guloglu C.C. , Turker M. , Atabay B.
Published: February 2013

Objectives

Iron cardiomyopathy remains the major cause of death in β-thalassaemia major. Excessive iron loading could lead to cardiac dysfunction and arrhythmias. Reduced heart rate variability is associated with a higher risk of arrhythmia and sudden death after myocardial infarction and heart failure. Previous data have reported on reduced heart rate variability in patients with marked cardiac iron accumulation. In this study, we compared heart rate variability among β-thalassaemia major (TM) patients with or without cardiac siderosis.

Methods

Out of 70 β-thalassaemia major patients with preserved ejection fractions, 38 patients with cardiac T2* magnetic resonance imaging assessment were included in our study. Time domain heart rate variability parameters were analysed from 24-hour recorded electrocardiograms and were compared with the control group.

Results

The mean T2* magnetic resonance imaging value was 22.9 ± 13.3 (4.7–47.5). In 21 patients with β-thalassaemia major, the T2* magnetic resonance imaging values were greater than 20 ms and these patients were considered to be in the early stage of the disease. When we compare these patients with control subjects, the standard deviation of all NN intervals was still significantly lower (133.0 ± 32.2 versus 162.8 ± 32.9, p = 0.001) in β-thalassaemia major patients despite normal T2* magnetic resonance imaging values. On the contrary, the standard deviation of all NN intervals was not correlated with haemoglobin levels in these patients (p > 0.05).

Conclusions

Heart rate variability parameters were reduced even in β-thalassaemia major patients without evident cardiac siderosis, as specified by magnetic resonance imaging data. The results of this study show that reduction of heart rate variability may start before cardiac iron loading is demonstrated by T2* magnetic resonance imaging in β-thalassaemia major.
What are neuroimaging meta-analytic procedures?
Authors: Cortese S. , Castellanos F.X. , Eickhoff S.B.
Published: February 2013

Activation likelihood estimation (ALE) meta-analyses allow investigators to integrate the results of multiple neuroimaging studies, potentially yielding novel results that may not have been evident in the individual studies. Here, we provide a brief, introductory description of ALE methods for readers without extensive expertise in neuroimaging.
Mitochondrially localised MUL1 is a novel modulator of antiviral signaling
Authors: Jenkins Kristie , Khoo Jing Jing , Sadler Anthony , Piganis Rebecca , Wang Die , Borg Natalie A , Hjerrild Kathryn , Gould Jodee , Thomas Belinda J , Nagley Phillip , Hertzog Paul J , Mansell Ashley
Published: February 2013

The innate immune response to virus must be balanced to eliminate infection yet limit damaging inflammation. A critical arm of the antiviral response is launched by the retinoic acid‐inducible‐gene I (RIG‐I) protein. RIG‐I is activated by viral RNA then associates with the mitochondrial antiviral signaling (MAVS) protein to subsequently induce potent inflammatory cytokines. Here, we demonstrate the mitochondrial E3 ubiquitin protein ligase 1 (MUL1) is a crucial moderator of RIG‐I signaling. MUL1 is localized to the mitochondria where it interacts with MAVS and catalyzes RIG‐I post‐translational modifications that inhibit RIG‐I‐dependent cell signaling. Accordingly, depletion of MUL1 potentiated RIG‐I mediated nuclear factor‐kappa B (NF‐κB) and interferon (IFN) β reporter activity. Moreover, depletion of MUL1 boosted the antiviral response and increased proinflammatory cytokines following challenge with the RNA mimetic poly I:C and Sendai virus. We therefore submit that MUL1 is a novel regulator of the RIG‐I‐like receptor‐dependent antiviral response, that otherwise functions to limit inflammation.
The Perception of the Relationship Between Affective Prosody and the Emotional Content in Utterances in Children With Autism Spectrum Disorders
Authors: Kjelgaard Margaret M. , Tager-Flusberg Helen
Published: February 2013

Children with autism spectrum disorders (ASD) were compared to children with specific language impairment (SLI) and typically developing (TD) children and adults in their ability to perceive and judge the emotional information conveyed by happy, neutral, and sad prosody. Authors found that high-functioning verbal children with ASD have an implicit sensitivity to emotional prosody, but are unable to explicitly judge the emotion of the same prosody. Children with SLI showed they were better able to judge the emotional prosody, similar to TD children, although not as well as adults. The findings indicate that, unique to the children with ASD, there is a disconnect between the implicit processing of emotional prosody and the explicit labeling of the emotion in prosody. This is promising for interventions aimed at facilitating the abilities of ASD children in their everyday understanding of emotional prosody in conversation.
Nanomechanical properties of lipid bilayer: Asymmetric modulation of lateral pressure and surface tension due to protein insertion in one leaflet of a bilayer
Authors: Maftouni Negin , Amininasab Mehriar , Ejtehadi Mohammad Reza , Kowsari Farshad , Dastvan Reza
Published: February 2013

The lipid membranes of living cells form an integral part of biological systems, and the mechanical properties of these membranes play an important role in biophysical investigations. One interesting problem to be evaluated is the effect of protein insertion in one leaflet of a bilayer on the physical properties of lipid membrane. In the present study, an all atom (fine-grained) molecular dynamics simulation is used to investigate the binding of cytotoxin A3 (CTX A3), a cytotoxin from snake venom, to a phosphatidylcholine lipid bilayer. Then, a 5-microsecond coarse-grained molecular dynamics simulation is carried out to compute the pressure tensor, lateral pressure, surface tension, and first moment of lateral pressure in each monolayer. Our simulations reveal that the insertion of CTX A3 into one monolayer results in an asymmetrical change in the lateral pressure and corresponding spatial distribution of surface tension of the individual bilayer leaflets. The relative variation in the surface tension of the two monolayers as a result of a change in the contribution of the various intermolecular forces may potentially be expressed morphologically.
A quantum cascade laser absorption spectrometer devoted to the in situ measurement of atmospheric N2O and CH4 emission fluxes
Authors: Mappé I. , Joly L. , Durry G. , Thomas X. , Decarpenterie T. , Cousin J. , Dumelie N. , Roth E. , Chakir A. , Grillon P. G.
Published: February 2013

This paper describes a Quantum Cascade Laser Absorption Spectrometer, called “QCLAS” that was developed to monitor in situ greenhouse gases like N2O and CH4, at high temporal resolution and with a high accuracy. The design of the laser sensor is reported as well as its performances in terms of precision error and field deployment capabilities. Finally, to demonstrate the efficiency and the robustness of QCLAS and its suitability for gas emission monitoring and for the determination of fluxes, we report the results from a field campaign, that took place in the Wallis and Futuna Islands in 2011, to investigate the impact of environmental intensive pig farming.
Multiscale model for phonon-assisted band-to-band tunneling in semiconductors
Authors: Ajoy Arvind , Laux S. E. , Murali Kota V. R. M. , Karmalkar Shreepad
Published: February 2013

We present a TCAD (Technology Computer Aided Design) compatible multiscale model of phonon-assisted band-to-band tunneling in semiconductors, which incorporates the non-parabolic nature of complex bands within the bandgap of the material. This model is shown capture the measured current-voltage data in silicon, for current transport along the [100], [110], and [111] directions. Our model will be useful to predict band-to-band tunneling phenomena to quantify on and off currents in tunnel FETs and in small geometry MOSFETs and FINFETs.