bluuebunny/crossref_metadata_2025 huggingface dataset:
Organization and seasonal quantification of the intertubular compartment in the bat Molossus molossus (Pallas, 1776) testis
Authors: Morais Danielle Barbosa , De Oliveira Luciana Coutinho , Carmo Cupertino Marli Do , De Freitas Karine Moura , De Freitas Mariella Bontempo Duca , De Paula Tarcízio Antônio Rêgo , Da Matta Sérgio Luis Pinto
Published: October 2012

Environmental factors can influence the reproductive rates in bats, and since morphometric information of bats testis is scarce, we aimed to compare the organization and quantification of the intertubular components in the testes of the bat Molossus molossus, collected in different seasons. Testicular histological sections were evaluated using light and electron microscopy. The intertubular compartment occupied an average 10% of the testes, being predominately constituted of Leydig cells (LC). The percentages of the testes occupied by the intertubular compartment and by LC were significantly higher in summer, while the other intertubular components did not vary significantly among the seasons. As suspected under light microscopy, the ultrastructural analysis confirmed the existence of multinucleated LC during winter. The increase in the nuclear percentage of LC in winter seems to have caused the decrease of the cytoplasmatic measurements in that season, as well as in the volume of LC. The highest cytoplasmatic values and volume of LC registered in the spring, summer, and fall can be related to greater activity of this cell in these seasons. The higher investment in intertubular tissue and in LC observed in summer, compared to winter; suggest an increase in the steroidogenic capacity of this bat during summer. The analyses correlating testicular morphometry and abiotic environmental factors in this study confirm the influence of climatic factors on the reproduction of M. molossus. Microsc. Res. Tech., 2013. © 2012 Wiley Periodicals, Inc.
Design and evaluation of an external high‐current target for production of 211At
Authors: Gagnon K. , Risler R. , Pal S. , Hamlin D. , Orzechowski J. , Pavan R. , Zeisler S. , Wilbur D. S.
Published: October 2012

This report presents the design and testing of an external target system for clinical‐scale production of 211At on the Scanditronix MC‐50 cyclotron at the University of Washington Medical Center. While other 211At production sites have typically employed an internal target, an external target setup was deemed necessary at our facility since the cyclotron's main application is for cancer patient treatment via fast neutron therapy. The challenge was that previous external 211At targets demonstrated reduced yields when compared to internal target systems. The target developed in this study has been used in more than 100 irradiations. From those irradiations 211At saturated yields of 181 ± 16 MBq/μA and 241 ± 17 MBq/μA at 28.0 and 29.0 MeV, respectively, were obtained. Importantly, consistent yields were observed over the 25–60 μA range of irradiation currents evaluated. With a recent production in excess of 4 GBq 211At for a 29.0 MeV, 58 μA, 4‐hour irradiation, this external target system has demonstrated its potential for producing clinically relevant quantities of 211At.
Spatial learning‐related changes in metabolic activity of limbic structures at different posttask delays
Authors: Méndez‐López M. , Méndez M. , Sampedro‐Piquero P. , Arias J.L.
Published: October 2012

The aim of this study was to assess the functional contribution of brain limbic system regions at different moments after the acquisition of a short‐term spatial memory task performed in the Morris water maze. Adult male Wistar rats were submitted to a matching‐to‐sample procedure with a hidden platform. The trials were made up of two daily identical visits to the platform, sample (swim‐1) and retention (swim‐2). To study oxidative metabolic activity, we applied cytochrome oxidase (COx) histochemistry. Densitometric measurements were taken at 1.5, 6, 24, and 48 hr posttask. An untrained group was added to explore the COx changes not specific to the learning process. The brain regions studied showed a different pattern of metabolic activity at different time points after the spatial memory task. Specifically, a significant increase of COx was found in the septal dentate gyrus, anteromedial thalamus, medial mammillary nucleus, and entorhinal cortex at early moments after learning. The entorhinal cortex maintained an increase of COx at later stages of the posttask period. In addition, an increase of COx activity was found in the supramammillary nucleus and the retrosplenial, perirhinal, and parietal cortices a long time after learning. These findings suggest that diencephalic and cortical regions are involved in this spatial learning and contribute at different moments to process this information. © 2012 Wiley Periodicals, Inc.
Downregulation of L1 perturbs neuronal migration and alters the expression of transcription factors in murine neocortex
Authors: Kishimoto Tomokazu , Itoh Kyoko , Umekage Masafumi , Tonosaki Madoka , Yaoi Takeshi , Fukui Kenji , Lemmon Vance P. , Fushiki Shinji
Published: October 2012

L1 is a cell adhesion molecule associated with a spectrum of human neurological diseases, the most well‐known being X‐linked hydrocephalus. L1 knockout (L1‐KO) mice have revealed a variety of functions of L1 that were crucial in brain development in different brain regions. However; the function of L1 in neuronal migration during cortical histogenesis remains to be clarified. We therefore investigated the corticogenesis of mouse embryos in which L1 molecules were knocked down in selected neurons, by employing in utero electroporation with shRNAs targeting L1 (L1 shRNA). Although more than 50% of the cells transfected with no small hairpin RNA (shRNA; monster green fluorescent protein: MGFP only) vector at embryonic day 13 (E13) reached the cortical plate at E16, significantly fewer (27%) cells transfected with L1 shRNA migrated to the same extent. At E17, 22% of cells transfected with the MGFP‐only vector were found in the intermediate zone, and significantly more (34%) cells transfected with L1 shRNA remained in the same zone. Furthermore, the directions of the leading process of neurons transfected with L1 shRNA became more dispersed compared with cells with the MGFP‐only vector. In addition, two transcription factors expressed in the neurons, Satb2 and Tbr1, were shown to be reduced or aberrantly expressed in neurons transfected with L1 shRNA. These observations suggest that L1 plays an important role in regulating the locomotion and orientation of migrating neurons and the expression of transcription factors during neocortical development that might partially be responsible for the abnormal tract formation seen in L1‐KO mice. © 2012 Wiley Periodicals, Inc.
Provenance investigations of amber jewelry excavated in Lower Silesia (Poland) and dated back to Early Iron Age
Authors: Łydżba‐Kopczyńska Barbara I. , Gediga Bogusław , Chojcan Jan , Sachanbiński Michał
Published: October 2012

The aim of presented work was to establish the provenance of unique amber jewelry dated back to Early Iron Age discovered in burial chambers of archeological excavations in Domasław, Lower Silesia (Poland). To assess the origin of the archeological amber objects, there was performed a comparative analysis of over 100 artifacts and reference material originated from amber sources within reasonable proximity to the axcavations. Succinite (Baltic amber) from tertiary deposit at the seashore from North Harbor in Gdansk (Poland) and Sambian Penisula, Yantarny near Kaliningrad (Russia) valchovite or/and neudorfite from Valchov in Moravy (Czech Republic) dated back to Upper Cretaceous and amber originating from Lower Silesia (cenoman from Boleslawiec, Poland) were used as a reference material. Raman and positron annihilation spectroscopies have been previously successfully applied in provenance studies of archeological amber jewelry, and both techniques were accepted as a method of choice in current investigation. All Raman measurements of valuable amber objects were performed in situ. Raman spectra collected for analyzed artifacts confirmed their Baltic origin. The study showed that annihilation positron spectroscopy is effective toll in the provenance investigations of raw amber material but can be misleading in analysis of previously processed material. Copyright © 2012 John Wiley & Sons, Ltd.
Pharmacological Secondary Prevention of PTSD in Youth: Challenges and Opportunities for Advancement
Authors: Maccani Matthew A. , Delahanty Douglas L. , Nugent Nicole R. , Berkowitz Steven J.
Published: October 2012

Child and adolescent posttraumatic stress disorder (PTSD) is associated with an increased risk for a number of deleterious mental and physical health outcomes that if untreated may persist throughout the life course. Efficacious interventions applied soon after trauma exposure have the potential to reduce or prevent the development of PTSD symptoms and their associated impact on behavior and physical health. We review extant research related to treatment‐modifiable peritraumatic predictors of pediatric PTSD, which have informed an emerging field of pharmacologic secondary prevention (i.e., occurring shortly following trauma exposure) of PTSD. Challenges and opportunities for early posttrauma PTSD prevention are described. Finally, we offer new models for biologically informed integration of pharmacologic and psychosocial secondary prevention intervention strategies for children and adolescents.
Modeling PTSD Symptom Clusters, Alcohol Misuse, Anger, and Depression as They Relate to Aggression and Suicidality in Returning U.S. Veterans
Authors: Hellmuth Julianne C. , Stappenbeck Cynthia A. , Hoerster Katherine D. , Jakupcak Matthew
Published: October 2012

Suicidal ideation and aggression are common correlates of posttraumatic stress disorder (PTSD) among U.S. Iraq and Afghanistan war veterans. The existing literature has established a strong link between these factors, but a more nuanced understanding of how PTSD influences them is needed. The current study examined the direct and indirect relationships between PTSD symptom clusters and suicidal ideation in general aggression (without a specified target) regarding depression, alcohol misuse, and trait anger. Participants were 359 (92% male) U.S. Iraq/Afghanistan war veterans. Path analysis results suggested that the PTSD numbing cluster was directly (β = .28, p < .01) and indirectly (β = .17, p = .001) related through depression. The PTSD hyperarousal cluster was indirectly related to suicidal ideation through depression (β = .13, p < .001). The PTSD reexperiencing cluster was directly related to aggression (β = .17, p < .05), whereas the PTSD numbing and hyperarousal clusters were indirectly related to aggression through trait anger (β = .05, p < .05; β = .20, p < .001). These findings indicate that adjunct treatments aimed at stabilizing anger, depression, and alcohol misuse may help clinicians ameliorate the maladaptive patterns often observed in veterans. These results also point to specific manifestations of PTSD and co‐occurring conditions that may inform clinicians in their attempts to identify at risk veterans and facilitate preventative interventions.
Rumination Moderates the Associations Between PTSD and Depressive Symptoms and Risky Behaviors in U. S. Veterans
Authors: Borders Ashley , McAndrew Lisa M. , Quigley Karen S. , Chandler Helena K.
Published: October 2012

Risky behaviors, including unsafe sex, aggression, rule breaking, self‐injury, and dangerous substance use have become a growing issue for U.S. veterans returning from combat deployments. Evidence in nonveteran samples suggests that risky behaviors reflect efforts to cope with and alleviate depressive and/or anxious symptoms, particularly for individuals with poor emotion‐regulation skills. These associations have not been studied in veterans. Rumination, or repeated thoughts about negative feelings and past events, is a coping strategy that is associated with several psychopathologies common in veterans. In this cross‐sectional study, 91 recently returned veterans completed measures of trait rumination, self‐reported risky behaviors, and symptoms of posttraumatic stress disorder (PTSD) and depression. Analyses revealed that veterans with more depressive and PTSD symptoms reported more risky behaviors. Moreover, rumination significantly interacted with PTSD symptoms and depressive symptoms (both β = .21, p < .05), such that psychiatric symptoms were associated with risky behaviors only for veterans with moderate to high levels of rumination. Although cross‐sectional, these findings support theory that individuals with poor coping skills may be particularly likely to respond to negative mood states by engaging in risky behaviors. Implications include using rumination‐focused interventions with veterans in order to prevent engagement in risky behaviors.
Changes in Social Adjustment With Cognitive Processing Therapy: Effects of Treatment and Association With PTSD Symptom Change
Authors: Monson Candice M. , Macdonald Alexandra , Vorstenbosch Valerie , Shnaider Philippe , Goldstein Elizabeth S. R. , Ferrier‐Auerbach Amanda G. , Mocciola Katharine E.
Published: October 2012

The current study sought to determine if different spheres of social adjustment, social and leisure, family, and work and income improved immediately following a course of cognitive processing therapy (CPT) when compared with those on a waiting list in a sample of 46 U.S. veterans diagnosed with posttraumatic stress disorder (PTSD). We also sought to determine whether changes in different PTSD symptom clusters were associated with changes in these spheres of social adjustment. Overall social adjustment, extended family relationships, and housework completion significantly improved in the CPT versus waiting‐list condition, η2 = .08 to .11. Hierarchical multiple regression analyses revealed that improvements in total clinician‐rated PTSD symptoms were associated with improvements in overall social and housework adjustment. When changes in reexperiencing, avoidance, emotional numbing, and hyperarousal were all in the model accounting for changes in total social adjustment, improvements in emotional numbing symptoms were associated with improvements in overall social, extended family, and housework adjustment (β = .38 to .55). In addition, improvements in avoidance symptoms were associated with improvements in housework adjustment (β = .30), but associated with declines in extended family adjustment (β = −.34). Results suggest that it is important to consider the extent to which PTSD treatments effectively reduce specific types of symptoms, particularly emotional numbing and avoidance, to generally improve social adjustment.
Treatment Improves Symptoms Shared by PTSD and Disordered Eating
Authors: Mitchell Karen S. , Wells Stephanie Y. , Mendes Adell , Resick Patricia A.
Published: October 2012

Eating disorders and posttraumatic stress disorder (PTSD) are debilitating conditions that frequently co‐occur. Although the two disorders have different clinical presentations, they share associated features, including cognitive disturbances, emotion dysregulation, dissociation, and impulsivity. We hypothesized that reductions in PTSD symptoms following cognitive processing therapy (CPT) and its treatment components (CPT without the written account or the written account only) would be associated with improvements in symptoms common to PTSD and eating disorders. Participants in the current investigation included women with PTSD (N = 65) who reported a history of rape or physical assault, were in a randomized dismantling study of CPT, and completed the Eating Disorder Inventory‐2 (EDI‐2) at pre‐ and posttreatment. Latent growth modeling results indicated that decreases in PTSD symptom scores were significantly associated with reductions in the Impulse Regulation, Interoceptive Awareness, Interpersonal Distrust, Ineffectiveness, and Maturity Fears subscales of the EDI‐2. Thus, PTSD treatment affected symptoms shared by PTSD and eating disorders. Currently, there are no clear guidelines for treatment of comorbid PTSD and eating disorders. Traditional CPT may impact symptoms common to both, but additional therapy may be needed for specific disordered eating attitudes and behaviors.
Posttraumatic Growth Following Cancer: Links to Quality of Life
Authors: Tomich Patricia L. , Helgeson Vicki S.
Published: October 2012

This study examined the linkage of posttraumatic growth (PTG) to quality of life (QOL) among individuals newly diagnosed with cancer. Individuals (26 men, 36 women) reported PTG 3 months postdiagnosis (T1) and 3 months later (T2). Cross‐sectional analyses revealed a linear association between PTG and QOL—more PTG was related toworsemental health at T1 (β = −.28). PTG, however, revealed a quadratic relationship with depressive symptoms at T1 and physical health at T2: Individuals with high or low levels of PTG had fewer depressive symptoms and better QOL than those with moderate levels. Longitudinal analyses revealed a linear association between PTG and QOL; more PTG at T1 predicted better physical health at T2. There were no longitudinal curvilinear associations. Although the linear links of PTG to QOL were contradictory within this study, both of the curvilinear relations, although not robust, confirm previous research. Further analyses differentiated low, medium, and high PTG groups in terms of perceiving cancer as stressful, intrusive thoughts, and coping strategies. Overall, relations of PTG to adjustment may be more complex and dynamic than previously assumed. Clinicians should consider the notion that more growth may sometimes, but not always, be better.
Fluorescent Polymeric Micelles with Tetraphenylethylene Moieties and Their Application for the Selective Detection of Glucose
Authors: Shen Xiang , Shi Yi , Peng Bo , Li Kan , Xiang Junfeng , Zhang Guanxin , Liu Zitong , Chen Yongming , Zhang Deqing
Published: October 2012

By linking TPE moieties that exhibit aggregation‐induced (enhanced) emission to the amphiphilic copolymer 1, fluorescent micelles are prepared and characterized. The polymeric micelles exhibit relatively strong fluorescence which can be tuned by heating and cooling. By combining cascaded enzymatic (oxidation of D‐glucose with GOx) and chemical (oxidation of I– by H2O2) reactions, the fluorescent micelles of copolymer 1 are successfully utilized for the selective detection of D‐glucose in aqueous solution. The influences of proteins (e.g., bovine serum albumin) and reductants (e.g., ascorbic acid) on this fluorescence detection of D‐glucose are also discussed.

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One‐Step Preparation and pH‐Tunable Self‐Aggregation of Amphoteric Aliphatic Polycarbonates Bearing Plenty of Amine and Carboxyl Groups
Authors: Wang Hua‐Fen , Jia Hui‐Zhen , Zhu Jing‐Yi , Chu Yan‐Feng , Feng Jun , Zhang Xian‐Zheng , Zhuo Ren‐Xi
Published: October 2012

This paper reports a novel amphoteric aliphatic polycarbonate bearing both amine and carboxyl groups. In the absence of protection‐deprotection chemistry, the multi‐functionalized copolymer is synthesized by one‐step enzymatic copolymerization. The influences of the reaction conditions including monomer feed ratio and polymerization time are explored. The simultaneous incorporation of amine and carboxyl functionalities provides the copolymer with a pH‐tunable self‐aggregation feature, leading to various aggregation states including precipitated agglomerate, well‐dispersed positively or negatively charged nanoparticles in a controlled manner. The copolymer displays minimal cytotoxicity to 293T and HeLa cells.

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Schatten‐Herz class Toeplitz operators on harmonic Bergman spaces of smooth domains in Rn
Authors: Lv Xiaofen , Hu Zhangjian
Published: October 2012

On the setting of the bounded domain Ω in \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\textbf R}^n$\end{document} with C∞ boundary, we introduce the Schatten‐Herz classes Toeplitz operators. And in term of averaging functions and Berezin transforms, we characterize those finite positive Borel measures μ on Ω for which the induced Toeplitz operators are in Shatten‐Herz classes. As some preliminary results, we obtain the sharp estimate of integral means for the harmonic Bergman kernel on the level surface and the boundedness of the Berezin transform on the Herz spaces.
Grothendieck‐Lidskiǐ theorem for subspaces of Lp‐spaces
Authors: Reinov Oleg , Latif Qaisar
Published: October 2012

In 1955, A. Grothendieck has shown that if the linear operator T in a Banach subspace of an L∞‐space is 2/3‐nuclear then the trace of T is well defined and is equal to the sum of all eigenvalues {μk(T)} of T. Lidskiǐ, in 1959, proved his famous theorem on the coincidence of the trace of the S1‐operator in L2(ν) with its spectral trace \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\sum _{k=1}^\infty \mu _k(T)$\end{document}. We show that for p ∈ [1, ∞] and s ∈ (0, 1] with 1/s = 1 + |1/2 − 1/p|, and for every s‐nuclear operator T in every subspace of any Lp(ν)‐space the trace of T is well defined and equals the sum of all eigenvalues of T. Note that for p = 2 one has s = 1, and for p = ∞ one has s = 2/3.
Analysis of parametric histogram from dynamic contrast‐enhanced MRI: application in evaluating brain tumor response to radiotherapy
Authors: Peng Shin‐Lei , Chen Chih‐Feng , Liu Ho‐Ling , Lui Chun‐Chung , Huang Yu‐Jie , Lee Tsung‐Han , Chang Chiung‐Chih , Wang Fu‐Nien
Published: October 2012

Dynamic contrast‐enhanced MRI (DCE MRI) has been used to study tumor response to treatment for many years. In this study, the modified full width at half‐maximum (mFWHM), calculated from the wash‐in slope histogram, is proposed as a parameter for the evaluation of changes in tumor heterogeneity which respond to radiotherapy. Twenty‐five patients with brain tumors were evaluated and divided into the nonresponder group (n = 11) and the responder group (n = 14) according to the Response Evaluation Criteria in Solid Tumors (RECIST). All selected tumors were evaluated by mFWHM ratios of post‐ to pre‐therapy (the ratio was defined as the therapeutic mFWHM ratio, TMR). The changes in kurtosis of the histograms and the averaged Ktrans within a tumor were also calculated for comparison. The receiver operating characteristic analysis and Kaplan–Meier curves were used to examine the diagnosis ability. The TMR values were significantly higher in nonresponders than in responders (p < 0.001). When compared with the other two parameters, the proposed method also demonstrated better sensitivity and specificity. When adopting the TMR for the estimation of prognosis after therapy, there was a significant difference between the population survival curves. In conclusion, the derived mFWHM reflects tumor heterogeneity, and the ability to depict patient survival probability from TMR corresponds well with that from RECIST. The results reveal that, in brain tumors, progression may be exhibited not only by tumor size, but also by tumor heterogeneity. Copyright © 2012 John Wiley & Sons, Ltd.
Two‐dimensional and three‐dimensional Doppler assessment of fetal growth restriction with different severity and onset
Authors: Luria Oded , Barnea Ofer , Shalev Josef , Barkat Jonathan , Kovo Michal , Golan Abraham , Bar Jacob
Published: October 2012

Objectives

To investigate the role of three‐dimensional (3D) power Doppler ultrasonography in the assessment of fetal growth‐restriction (FGR) with various degrees of severity and onset, and compare the results with the analysis of two‐dimensional (2D) Doppler.

Study design

Vascular indices extracted from 3D Doppler measurements of the placenta were compared with indices of flow‐velocity waveforms extracted from 2D Doppler measurements of the major sites of the fetal circulation between FGR (study group) and uncomplicated pregnancies (control group) from 25 to 38 weeks’ gestation.

Results

Three‐dimensional indices were significantly lower in pregnancies complicated by FGR compared with uncomplicated pregnancies. When measured in placental periphery, vascularization index was 9.4 ± 9.6 in FGR pregnancies compared with 16 ± 14.7, P = 0.04. Flow index was 33.9 ± 6.9 compared with 38.7 ± 4.9, P = 0.03 and the vascularization‐flow index was 3.8 ± 4.3 compared with 6.5 ± 6, respectively, P = 0.03. Among the conventional 2D indices, umbilical artery and middle cerebral artery pulsatility indices were not significantly different between the FGR and control groups. Higher rate of maternal or fetal compartment vascular lesions were detected in the FGR group.

Conclusions

Three‐dimensional Doppler was found to be more strongly associated with placental vascular compromise than conventional 2D Doppler, regardless of severity and onset of fetal growth restriction. © 2012 John Wiley & Sons, Ltd.
Algorithm for the evaluation of therapeutic failure reports—proposal and pilot analysis
Authors: González Claudia Patricia Vaca , Martínez Roxana Patricia De las salas , Gutiérrez José Julián López , Pedraza Ricardo Sánchez , Figueras Albert
Published: October 2012

Purpose

To propose and validate an algorithm to analyze the reports of suspected therapeutic failure (TF) received in pharmacovigilance programs.

Methods

A Delphi consensus method with a group of 12 international experts was used to identify the different causes that prompt TF and to propose an algorithm to analyze reports of suspected lack of efficacy of medicines. A pilot analysis of 50 reports was the basis to evaluate the interrater and intrarater validity of the algorithm.

Results

A 10‐question algorithm was proposed. The evaluation of 50 reports of suspected TF showed that only 8% could be actually attributed to a manufacturing quality problem, whereas the real reason underlying the alleged TF was the inappropriate use of the prescribed drug in 28%. Minimum information to attribute the cause to a TF was lacking in 31% of these reports. The interrater reliability was “moderate” (kappa coefficient = 0.55), and the intrarater reliability ranged from 0.732 to 0.908 (“substantial” to “almost perfect”).

Conclusions

The proposed TF algorithm is a valid, reliable, and reproducible analysis tool that can help to disentangle the frequent and complex reports of suspected TF. Copyright © 2012 John Wiley & Sons, Ltd.
Polymer coating of carboxylic acid functionalized multiwalled carbon nanotubes via reversible addition‐fragmentation chain transfer mediated emulsion polymerization
Authors: Nguyen Duc , Such Chris H. , Hawkett Brian S.
Published: October 2012

In this work, successful polymer coating of COOH‐functionalized multiwalled carbon nanotubes (MWCNTs) via reversible addition fragmentation chain transfer (RAFT) mediated emulsion polymerization is reported. The method used amphiphilic macro‐RAFT copolymers as stabilizers for MWCNT dispersions, followed by their subsequent coating with poly(methyl methacrylate‐co‐butyl acrylate). Poly(allylamine hydrochloride) was initially used to change the charge on the surface of the MWCNTs to facilitate adsorption of negatively charged macro‐RAFT copolymer onto their surface via electrostatic interactions. After polymerization, the resultant latex was found to contain uniform polymer‐coated MWCNTs where polymer layer thickness could be controlled by the amount of monomer fed into the reaction. The polymer‐coated MWCNTs were demonstrated to be dispersible in both polar and nonpolar solvents. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
High‐Resolution Mapping of Wet Terrain within Discontinuous Permafrost using LiDAR Intensity
Authors: Stevens Christopher W. , Wolfe Stephen A.
Published: October 2012

Surface hydrology is an important aspect of northern environments on account of the thermal influence of water on permafrost. In this study, we demonstrate the ability of light detection and ranging (LiDAR) to map wet terrain within an area of discontinuous permafrost adjacent to the Northwest Territories Highway 3, located west of Yellowknife, Canada. Wet terrain was identified from LiDAR intensity measurements beneath forest canopies and across vegetated surfaces, including peatlands, fens, flooded black spruce and birch forests, and terrain adjacent to the highway embankment. Surface water pathways representing hydrological connections between water bodies and wet terrain were also identified at locations otherwise indiscernible from optical imagery. Statistical separability between terrain types, and thus the ability to map them, was improved by integrating LiDAR all‐return and bare‐earth intensity with colour orthophotos. The average classification accuracy for wet terrain was 93 per cent. These results indicate that LiDAR intensity can be used for local‐scale mapping of wet terrain, as required by northern engineers and scientists. Future integration of LiDAR intensity and elevation measurements may be used to assess changes in surface hydrological conditions impacting permafrost. Copyright © Her Majesty the Queen in Right of Canada 2012.
U‐calculation of the LSDA + U functional using the hybrid B3LYP and HSE functionals
Authors: Andriotis Antonis N. , Mpourmpakis Giannis , Lisenkov Sergey , Sheetz R. Michael , Menon Madhu
Published: October 2012

We generalize the DFT/SGGA + U (density functional theory (DFT) at the spin polarized generalized gradient approximation (SGGA) and the Hubbard‐U approximation) functional with a view to bring the calculated electronic band structures in agreement with experiment in an efficient way. We show the necessity of incorporating the different components of U, namely the Us/p/d‐terms, for the s, p, and d orbitals, to achieve this objective. The proposed generalization requires the knowledge of a few specific spectral features to which we fit the results of the DFT/SGGA + U calculations. In the absence of experimental data we use results obtained by more accurate ab initio calculations such as, the Becke 3‐parameter Lee Yang Parr (B3LYP) and the Heyd‐Scuseria‐Ernzerhof (HSE06) ones for fitting purposes. Application of the method to select materials shows it to be a relatively inexpensive and promising approach for obtaining excitation spectra of materials.
Effect of weak magnetic field on terahertz radiation of hot electrons in n‐Ge
Authors: Bondar V. M. , Tomchuk P. M. , Shepelskii G. A.
Published: October 2012

We present results of experimental studies of the effect of weak magnetic field (H = 300 Oe) on the intensity of terahertz radiation (λ = 100 µm) of hot electrons from n‐Ge at the near liquid helium temperatures (T ≈ 5 K) when both electric and magnetic fields are oriented along the same direction. Strong effect of the weak magnetic field (reduction of the radiation intensity by a factor of 3–10) is observed to occur under relatively weak electric fields (5–15 V/cm), thus demonstrating a switch‐like effect. We show experimentally that this strong effect is due to sharp decrease of the free carrier concentration by means of suppression of the donor ionization by the magnetic field. Much less reduction of the radiation intensity (up to 20% of the initial value) caused by the weak magnetic field is reliably detected under stronger electric fields (100–200 V/cm) when all donors are ionized and the influence of the magnetic field on the carrier concentration is expected to be absent. We propose a theoretical model to explain the subtle effect of the weak magnetic field on the THz hot electron radiation at stronger electric fields which reveals through the longitudinal magnetoresistance. The longitudinal magnetoesistance is shown to become essential due to anisotropy of the electron energy dispersion law and due to strong modification of the electron velocity distribution function by stronger electric fields. Our theoretical estimations well agree with our experimental results.
Cytotoxic Action of Brazilian Propolis In Vitro on Canine Osteosarcoma Cells
Authors: Cinegaglia N. C. , Bersano P. R. O. , Búfalo M. C. , Sforcin J. M.
Published: October 2012

Osteosarcoma (OSA) is a primary bone neoplasm frequently diagnosed in dogs. The biology of OSA in pet dogs is identical to that of pediatric patients, and it has been considered an excellent model in vivo to study human OSA. Since the individual response to chemotherapy is unpredictable and considering that propolis is a natural product with several biological properties, this work evaluated the cytotoxic action of propolis on canine OSA cells. The primary cell culture of canine OSA was obtained from the tumor of a dog with OSA. Cell viability was assessed after incubation with propolis, 70% ethanol (propolis solvent), and carboplatin after 6, 24, 48, and 72 h. Cell viability was analyzed by the crystal violet method. Data showed that canine OSA cells were sensitive to propolis in a dose‐ and time‐dependent manner and had a distinct morphology compared to control. Its solvent (70% ethanol) had no effect on cell viability, suggesting that the cytotoxic action was exclusively due to propolis. Our propolis sample exerted a cytotoxic effect on canine OSA cells, and its introduction as a possible therapeutic agent in vivo could be investigated, providing a new contribution to OSA treatment. Copyright © 2012 John Wiley & Sons, Ltd.
Static anti‐windup design for a class of nonlinear systems
Authors: da Silva J.M.Gomes , Oliveira M.Z. , Coutinho D. , Tarbouriech S.
Published: October 2012

This paper focuses on the problem of static anti‐windup design for a class of multivariable nonlinear systems subject to actuator saturation. The considered class regards all systems that are rational on the states or that can be conveniently represented by a rational system with algebraic constraints considering some variable changes. More precisely, a method is proposed to compute a static anti‐windup gain which ensures regional stability for the closed‐loop system assuming that a dynamic output feedback controller is previously designed to stabilize the nonlinear system. The results are based on a differential algebraic representation of rational systems. The control saturation effects are taken into account by the application of a generalized sector bound condition. From these elements, LMI‐based conditions are devised to compute an anti‐windup gain with the aim of enlarging the closed‐loop region of attraction. Several numerical examples are provided to illustrate the application of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.
Solid‐State Nanopore Detection of Protein Complexes: Applications in Healthcare and Protein Kinetics
Authors: Freedman Kevin J. , Bastian Arangassery R. , Chaiken Irwin , Kim Min Jun
Published: October 2012

Protein conjugation provides a unique look into many biological phenomena and has been used for decades for molecular recognition purposes. In this study, the use of solid‐state nanopores for the detection of gp120‐associated complexes are investigated. They exhibit monovalent and multivalent binding to anti‐gp120 antibody monomer and dimers. In order to investigate the feasibility of many practical applications related to nanopores, detection of specific protein complexes is attempted within a heterogeneous protein sample, and the role of voltage on complexed proteins is researched. It is found that the electric field within the pore can result in unbinding of a freely translocating protein complex within the transient event durations measured experimentally. The strong dependence of the unbinding time with voltage can be used to improve the detection capability of the nanopore system by adding an additional level of specificity that can be probed. These data provide a strong framework for future protein‐specific detection schemes, which are shown to be feasible in the realm of a ‘real‐world’ sample and an automated multidimensional method of detecting events.
Antimicrobial polymers as synthetic mimics of host‐defense peptides
Authors: Kuroda Kenichi , Caputo Gregory A.
Published: October 2012

Antibiotic‐resistant bacteria ‘superbugs’ are an emerging threat to public health due to the decrease in effective antibiotics as well as the slowed pace of development of new antibiotics to replace those that become ineffective. The need for new antimicrobial agents is a well‐documented issue relating to world health. Tremendous efforts have been given to developing compounds that not only show high efficacy, but also those that are less susceptible to resistance development in the bacteria. However, the development of newer, stronger antibiotics which can overcome these acquired resistances is still a scientific challenge because a new mode of antimicrobial action is likely required. To that end, amphiphilic, cationic polymers have emerged as a promising candidate for further development as an antimicrobial agent with decreased potential for resistance development. These polymers are designed to mimic naturally occurring host‐defense antimicrobial peptides which act on bacterial cell walls or membranes. Antimicrobial‐peptide mimetic polymers display antibacterial activity against a broad spectrum of bacteria including drug‐resistant strains and are less susceptible to resistance development in bacteria. These polymers also showed selective activity to bacteria over mammalian cells. Antimicrobial polymers provide a new molecular framework for chemical modification and adaptation to tune their biological functions. The peptide‐mimetic design of antimicrobial polymers will be versatile, generating a new generation of antibiotics toward implementation of polymers in biomedical applications. WIREs Nanomed Nanobiotechnol 2013, 5:49–66. doi: 10.1002/wnan.1199

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease

Biology-Inspired Nanomaterials > Peptide-Based Structures
Color-kinematics duality and double-copy construction for amplitudes from higher-dimension operators
Authors: Broedel Johannes , Dixon Lance J.
Published: October 2012

Abstract

We investigate color-kinematics duality for gauge-theory amplitudes produced by the pure nonabelian Yang-Mills action deformed by higher-dimension operators. For the operator denoted by F
3, the product of three field strengths, the existence of color-kinematic dual representations follows from string-theory monodromy relations. We provide explicit dual representations, and show how the double-copy construction of gravity amplitudes based on them is consistent with the Kawai-Lewellen-Tye relations. It leads to the amplitudes produced by Einstein gravity coupled to a dilaton field ϕ, and deformed by operators of the form ϕR
2 and R
3. For operators with higher dimensions than F
3, such as F
4-type operators appearing at the next order in the low-energy expansion of bosonic and superstring theory, the situation is more complex. The color structure of some of the F
4 operators is incompatible with a simple color-kinematics duality based on structure constants f
abc, but even the color-compatible F
4 operators do not admit the duality. In contrast, the next term in the α′ expansion of the superstring effective action — a particular linear combination of D
2
F
4 and F
5-type operators — does admit the duality, at least for amplitudes with up to six external gluons.
Universal contributions to scalar masses from five dimensional supergravity
Authors: Dudas Emilian , von Gersdorff Gero
Published: October 2012

Abstract

We compute the effective Kahler potential for matter fields in warped compactifications, starting from five dimensional gauged supergravity, as a function of the matter fields localization. We show that truncation to zero modes is inconsistent and the tree-level exchange of the massive gravitational multiplet is needed for consistency of the four-dimensional theory. In addition to the standard Kahler coming from dimensional reduction, we find the quartic correction coming from integrating out the gravity multiplet. We apply our result to the computation of scalar masses, by assuming that the SUSY breaking field is a bulk hypermultiplet. In the limit of extreme opposite localization of the matter and the spurion fields, we find zero scalar masses, consistent with sequestering arguments. Surprisingly enough, for all the other cases the scalar masses are tachyonic. This suggests the holographic interpretation that a CFT sector always generates operators contributing in a tachyonic way to scalar masses. Viability of warped supersymmetric compactifications necessarily asks then for additional contributions. We discuss the case of additional bulk vector multiplets with mixed boundary conditions, which is a particularly simple and attractive way to generate large positive scalar masses. We show that in this case successful fermion mass matrices implies highly degenerate scalar masses for the first two generations of squarks and sleptons.
Spectral action for Robertson-Walker metrics
Authors: Chamseddine Ali H. , Connes Alain
Published: October 2012

Abstract

We use the Euler-Maclaurin formula and the Feynman-Kac formula to extend our previous method of computation of the spectral action based on the Poisson summation formula. We show how to compute directly the spectral action for the general case of Robertson-Walker metrics. We check the terms of the expansion up to a
6 against the known universal formulas of Gilkey and compute the expansion up to a
10 using our direct method.
Emergent spacetime and holographic CFTs
Authors: El-Showk Sheer , Papadodimas Kyriakos
Published: October 2012

Abstract

We discuss universal properties of conformal field theories with holographic duals. A central feature of these theories is the existence of a low-lying sector of operators whose correlators factorize. We demonstrate that factorization can only hold in the large central charge limit. Using conformal invariance and factorization we argue that these operators are naturally represented as fields in AdS as this makes the underlying linearity of the system manifest. In this class of CFTs the solution of the conformal bootstrap conditions can be naturally organized in structures which coincide with Witten diagrams in the bulk. The large value of the central charge suggests that the theory must include a large number of new operators not captured by the factorized sector. Consequently we may think of the AdS hologram as an effective representation of a small sector of the CFT, which is embedded inside a much larger Hilbert space corresponding to the black hole microstates.
Cost‐Effectiveness of Ingunial Hernia Surgery in Northwestern Ecuador
Authors: Shillcutt Samuel D. , Sanders David L. , Teresa Butrón‐Vila M. , Kingsnorth Andrew N.
Published: October 2012

Background

Cost‐effectiveness of tension‐free inguinal hernia repair at a private 20‐bed rural hospital in Esmeraldas Province, Ecuador, was calculated relative to no treatment.

Methods

Lichtenstein repair using mosquito net or polypropylene commercial mesh was provided to patients with inguinal hernia by surgeons from Europe and North America. Prospective data were collected from provider, patient, and societal perspectives, with component costs collected on site and from local supply companies or published literature. Patient outcomes were forecasted using disability adjusted life years (DALYs) averted. Uncertainty in patient‐level data was evaluated with Monte–Carlo simulation.

Results:

Surgery was provided to 102 patients with inguinal hernias of various sizes. Local anesthesia was used for 80 % of operations during the first mission, and spinal anesthesia was used for 89 % in the second mission. Few complications were observed. An average 6.39 DALYs (3,0) were averted per patient (95 % confidence interval: 6.22–6.84). The average cost per patient was US$499.33 (95 % CI: US$490.19–$526.03) from a provider perspective, US$118.79 (95 % CI: US$110.28–$143.72) from a patient perspective, and US$615.46 (95 % CI: US$603.39–$650.40) from a societal perspective. Mean cost‐effectiveness from a provider perspective was US$78.18/DALY averted (95 % CI: US$75.86–$85.78) according to DALYs (3,0) averted using the West Life Table level 26, well below the Ecuadorian per‐capita Gross National Income (US$3,850). Results were robust to all sensitivity analyses.

Conclusions

Inguinal hernia repair was cost‐effective in western Ecuador through international collaboration.
Preoperative Prediction of Central Lymph Node Metastasis in Thyroid Papillary Microcarcinoma Using Clinicopathologic and Sonographic Features
Authors: Kim Kyung‐Eun , Kim Eun‐Kyung , Yoon Jung Hyun , Han Kyung Hwa , Moon Hee Jung , Kwak Jin Young
Published: October 2012

Background

The purpose of the present study was to evaluate the clinicopathologic factors and ultrasound (US) features predictive of central lymph node metastasis (LNM) in patients diagnosed with papillary thyroid microcarcinoma (PTMC).

Methods

From March 2008 to August 2008, the clinicopathologic features and preoperative US features of 483 patients who were diagnosed with conventional PTMC were included. Medical records, US features, and pathology reports of all patients were retrospectively reviewed. Univariate and multivariate analysis was performed to identify clinicopathological prognostic factors associated with central LNM. Odds ratios (OR) with relative 95 % confidence intervals (95 % CI) were calculated to determine the relevance of all potential predictors of central LNM.

Results

Among the 483 patients with PTMC, 139 (28.8 %) patients had central LNM. The OR of significant independent factors were 2.055 (95 % CI, 1.137–3.716), 2.075 (95 % CI, 1.27–3.39), 1.71 (95 % CI, 1.073–2.724), and 15.897 (95 % CI, 4.173–60.569), respectively, for bilaterality, larger tumor size (>5 mm), extracapsular invasion, and lateral LNM. No significant association was seen among the US features of PTMC with central LNM.

Conclusions

Central lymph node metastasis in patients with PTMC was significantly associated with various clinicopathological factors, including larger tumor size (>5 mm), bilaterality, extracapsular invasion, and lateral LNM. When these features are detected on preoperative US, selective central compartment dissection may be helpful in patients diagnosed with PTMC.