bluuebunny/crossref_metadata_2025 huggingface dataset:
Suicide Clusters: A Review of Risk Factors and Mechanisms
Authors: Haw Camilla , Hawton Keith , Niedzwiedz Claire , Platt Steve
Published: November 2012

Suicide clusters, although uncommon, cause great concern in the communities in which they occur. We searched the world literature on suicide clusters and describe the risk factors and proposed psychological mechanisms underlying the spatio‐temporal clustering of suicides (point clusters). Potential risk factors include male gender, being an adolescent or young adult, drug or alcohol abuse, and past history of self‐harm. However, the majority of studies lack methodological rigor. Many different psychological mechanisms are described, including contagion, imitation, suggestion, learning, and assortative relating, but supporting empirical evidence is generally lacking. More scientifically rigorous studies are needed to improve understanding of suicide clusters.
Antibacterial action of calcium hydroxide vehicles and calcium hydroxide pastes
Authors: Pacios María Gabriela , Silva Clara , López María Elena , Cecilia Marta
Published: November 2012

Aim

To evaluate the in vitro action of vehicles alone and with calcium hydroxide against different bacterial species.

Methods

Agar plates were inoculated with the microbial suspensions, and wells were made and filled with the calcium hydroxide pastes and the vehicles used to prepare the pastes. The zones of inhibited bacterial growth were recorded, and the resulting measurements were statistically analyzed.

Results

Enterococcus faecalis was the most resistant microorganism to all medicaments. Calcium hydroxide + p‐monochlorophenol; calcium hydroxide + p‐monochlorophenol‐propylene glycol pastes; and p‐monochlorophenol, p‐monochlorophenol‐propylene glycol, and chlorhexidine gluconate gel alone showed the largest zones of inhibition against all the tested microorganisms.

Conclusions

The vehicle used to prepare the calcium hydroxide paste might contribute to its antibacterial action. Chlorhexidine gluconate gel used alone, and camphorated p‐monochlorophenol and camphorated p‐monochlorophenol‐propylene glycol as vehicles of calcium hydroxide, could be recommended, in an antimicrobial sense.
Nonlinear Analysis of Fibrillatory Electrogram Similarity to Optimize the Detection of Complex Fractionated Electrograms During Persistent Atrial Fibrillation
Authors: LIN YENN‐JIANG , LO MEN‐TZUNG , LIN CHEN , CHANG SHIH‐LIN , LO LI‐WEI , HU YU‐FENG , CHAO TZE‐FAN , LI CHENG‐HUNG , CHANG YI‐CHUNG , HSIEH WAN‐HSIN , CHUNG FA‐PO , TSAO HSUAN‐MING , CHANG HUNG‐YU , HUANG NORDEN E. , CHEN SHIH‐ANN
Published: November 2012

Nonlinear Analysis of Atrial Fibrillation. Introduction: Currently, the identification of complex fractionated atrial electrograms (CFEs) in the substrate modification is mostly based on cycle length‐derived algorithms. The characteristics of the fibrillation electrogram morphology and their consistency over time are not clear. The aim of this study was to optimize the detection algorithm of crucial CFEs by using nonlinear measure electrogram similarity.

Methods and Results:
One hundred persistent atrial fibrillation patients that underwent catheter ablation were included. In patients who required CFE ablation (79%), the time‐domain fibrillation signals (6 seconds) were acquired for a linear analysis (mean fractionation interval and dominant frequency [DF]) and nonlinear‐based waveform similarity analysis of the local electrograms, termed the similarity index (SI). Continuous CFEs were targeted with an endpoint of termination. Predictors of the various signal characteristics on the termination and clinical outcome were investigated.

Procedural termination was observed in 39% and long‐term sinus rhythm maintenance in 67% of the patients. The targeted CFEs didn't differ based on the linear analysis modalities between the patients who responded and did not respond to CFE ablation. In contrast, the average SI of the targeted CFEs was higher in termination patients, and they had a better outcome. Multivariate regression analysis showed that a higher SI independently predicted sites of termination (≥0.57; OR = 4.9; 95% CI = 1.33–18.0; P = 0.017).

Conclusions:
In persistent AF patients, a cycle length‐based linear analysis could not differentiate culprit CFEs from bystanders. This study suggested that sites with a high level of fibrillation electrogram similarity at the CFE sites were important for AF maintenance. (J Cardiovasc Electrophysiol, Vol. 24, pp. 280‐289, March 2013)
Analyses of a Glycine max Degradome Library Identify microRNA Targets and MicroRNAs that Trigger Secondary SiRNA Biogenesis
Authors: Hu Zheng , Jiang Qiyan , Ni Zhiyong , Chen Rui , Xu Shuo , Zhang Hui
Published: November 2012

Plant microRNAs (miRNAs) regulate gene expression mainly by guiding cleavage of target mRNAs. In this study, a degradome library constructed from different soybean (Glycine max (L.) Merr.) tissues was deep‐sequenced. 428 potential targets of small interfering RNAs and 25 novel miRNA families were identified. A total of 211 potential miRNA targets, including 174 conserved miRNA targets and 37 soybean‐specific miRNA targets, were identified. Among them, 121 targets were first discovered in soybean. The signature distribution of soybean primary miRNAs (pri‐miRNAs) showed that most pri‐miRNAs had the characteristic pattern of Dicer processing. The biogenesis of TAS3 small interfering RNAs (siRNAs) was conserved in soybean, and nine Auxin Response Factors were identified as TAS3 siRNA targets. Twenty‐three miRNA targets produced secondary small interfering RNAs (siRNAs) in soybean. These targets were guided by five miRNAs: gma‐miR393, gma‐miR1508, gma‐miR1510, gma‐miR1514, and novel‐11. Multiple targets of these secondary siRNAs were detected. These 23 miRNA targets may be the putative novel TAS genes in soybean. Global identification of miRNA targets and potential novel TAS genes will contribute to research on the functions of miRNAs in soybean.
Expression of oral secretory leukocyte protease inhibitor in HIV‐infected subjects with long‐term use of antiretroviral therapy
Authors: Nittayananta Wipawee , Kemapunmanus Marisa , Yangngam Supaporn , Talungchit Sineepat , Sriplung Hutcha
Published: November 2012

Background

The objectives of this study were to determine (i) the expression of oral secretory leukocyte protease inhibitor (SLPI) in HIV‐infected subjects compared with non‐HIV controls, (ii) the oral SLPI expression in HIV‐infected subjects with antiretroviral therapy (ART) compared with those without ART, and (iii) factors associated with the expression of oral SLPI.

Methods

Oral tissues and samples of both un‐stimulated and stimulated saliva were collected from HIV‐infected subjects with and without ART, and non‐HIV individuals. The expression of SLPI mRNA in the tissue was determined by quantitative real‐time PCR. Salivary SLPI protein was detected using ELISA. Chi‐square test and logistic regression analysis were performed to determine the association between HIV/ART status and the expression of oral SLPI.

Results

One hundred and fifty‐seven HIV‐infected subjects were enrolled: 99 on ART (age range, 23–57 years; mean, 39 years), 58 not on ART (age range, 20–59 years; mean, 34 years), and 50 non‐HIV controls (age range, 19–59 years; mean, 36 years). The most common ART regimen was 2NRTIs + 1NNRTI. The expression of oral SLPI in stimulated saliva was significantly decreased with HIV infection (P < 0.001). The expression was also significantly different with respect to ART use (P = 0.007). Smoking, CD4+ cell count, and HIV viral load were the factors associated with the oral SLPI expression.

Conclusion

The expression of oral SLPI is altered by HIV infection and use of ART. Thus, oral SLPI may be the useful biomarker to identify subjects at risk of infections and malignant transformation due to HIV infection and long‐term ART.
Avoidance Goal Pursuit Depletes Self‐Regulatory Resources
Authors: Oertig Daniela , Schüler Julia , Schnelle Jessica , Brandstätter Veronika , Roskes Marieke , Elliot Andrew J.
Published: November 2012

Objective

Research on the strength model of self‐regulation is burgeoning, but little empirical work has focused on the link between distinct types of daily goal pursuit and the depletion of self‐regulatory resources. The authors conducted two studies on the link between avoidance goals and resource depletion.

Method

Study 1 (283 [228 female] Caucasians, ages 18–51) investigated the concurrent and longitudinal relations between avoidance goals and resource depletion over a 1‐month period. Study 2 (132 [93 female] Caucasians, ages 18–49) investigated the concurrent and longitudinal relations between avoidance goals and resource depletion over a 1‐month period and explored resource depletion as a mediator of the avoidance goal to subjective well‐being relation.

Results

Studies 1 and 2 documented both a concurrent and a longitudinal negative relationship between avoidance goals and self‐regulatory resources, and Study 2 additionally showed that self‐regulatory resources mediate the negative link between avoidance goals and subjective well‐being. Ancillary analyses demonstrated that the results observed in the two studies were independent of neuroticism.

Conclusions

These findings advance knowledge in both the resource depletion and avoidance goal literatures, and bolster the view that avoidance goal pursuit over time represents a self‐regulatory vulnerability.
Unifying the Aspects of the Big Five, the Interpersonal Circumplex, and Trait Affiliation
Authors: DeYoung Colin G. , Weisberg Yanna J. , Quilty Lena C. , Peterson Jordan B.
Published: November 2012

Objective

Two dimensions of the Big Five, Extraversion and Agreeableness, are strongly related to interpersonal behavior. Factor analysis has indicated that each of the Big Five contains two separable but related aspects. The present study examined the manner in which the aspects of Extraversion (Assertiveness and Enthusiasm) and Agreeableness (Compassion and Politeness) relate to interpersonal behavior and trait affiliation, with the hypothesis that these four aspects have a structure corresponding to the octants of the interpersonal circumplex. A second hypothesis was that measures of trait affiliation would fall between Enthusiasm and Compassion in the IPC.

Method

These hypotheses were tested in three demographically different samples (N = 469; 294; 409) using both behavioral frequency and trait measures of the interpersonal circumplex, in conjunction with the Big Five Aspect Scales (BFAS) and measures of trait affiliation.

Results

Both hypotheses were strongly supported.

Conclusions

These findings provide a more thorough and precise mapping of the interpersonal traits within the Big Five and support the integration of the Big Five with models of interpersonal behavior and trait affiliation.
Influence of eyewitness age and recall error on mock juror decision‐making
Authors: Bruer Kaila , Pozzulo Joanna D.
Published: November 2012

The purpose of this research was to determine if child eyewitnesses are seen as more or less credible compared with older eyewitnesses and to determine whether the number of descriptive errors made while recalling the appearance of a perpetrator has an influence on perceived credibility of the witness. Mock jurors were given a mock trial that presented a positive identification by an eyewitness where age of the eyewitness (4‐, 12‐, 20‐year‐old) and the number of perpetrator descriptor errors (i.e., 0, 3, 6) made by the eyewitness were manipulated. Perceived levels of credibility, accuracy, and determinations of guilt were compared using a self‐report questionnaire. Results support the hypothesis that mock jurors perceive eyewitnesses who make fewer errors in descriptions with more integrity (i.e., more credible, reliable, and accurate) and perceive the evidence presented by them (i.e., description of perpetrator and description of events) as more reliable. Overall, adult eyewitnesses are perceived with more integrity than child eyewitnesses.
Natural coniferous resin lacquer in treatment of toenail onychomycosis: an observational study
Authors: Sipponen Pentti , Sipponen Arno , Lohi Jouni , Soini Marjo , Tapanainen Riikka , Jokinen Janne J.
Published: November 2012

In in vitro tests, natural coniferous resin from the Norway spruce (Picea abies) is strongly antifungal. In this observational study, we tested the clinical effectiveness of a lacquer composed of spruce resin for topical treatment of onychomycosis. Thirty‐seven patients with clinical diagnosis of onychomycosis were enrolled into the study. All patients used topical resin lacquer treatment daily for 9 months. A mycological culture and potassium hydroxide (KOH) stain were done from nail samples in the beginning and in the end of the study. Treatment was considered effective, if a mycological culture was negative and there was an apparent clinical cure. At study entry, 20 patients (20/37; 54%; 95% CI: 38–70) had a positive mycological culture and/or positive KOH stain for dermatophytes. At study end, the result of 13 patients was negative (13/19; 68%; 95% CI: 48–89). In one case (1/14; 7%; 95% CI: 0–21) the mycological culture was initially negative, but it turned positive during the study period. By 14 compliant patients (14/32; 44%; 95% CI: 27–61), resin lacquer treatment was considered clinically effective: complete healing took place in three cases (9%) and partial healing in 11 cases (85%). The results indicate some evidence of clinical efficacy of the natural coniferous resin used for topical treatment of onychomycosis.
Focal Dermal Hypoplasia Due to a Novel Mutation in a Boy with Klinefelter Syndrome
Authors: Alkindi Said , Battin Malcolm , Aftimos Salim , Purvis Diana
Published: November 2012

A boy was born with multiple anomalies, including right hemifacial microsomia, eye abnormalities, syndactyly, right hand ectrodactyly, hypoplastic nails, omphalocele, bladder exstrophy, renal dilatation, and splayed symphysis pubis. The skin was also abnormal, with atrophic skin plaques and areas of telangiectasia along the lines of Blaschko. The karyotype was 47,XXY (Klinefelter syndrome). He was found to have a heterozygous mutation in the PORCN gene. He exhibited the classical features of focal dermal hypoplasia. Fewer than 15% of reported cases are male when it is thought to be due to postzygotic mutation and thus mosaic. This is the first reported boy to have heterozygous mutation for Goltz syndrome who survived due to the extra X chromosome.
Blood Lead Level Analysis Among Refugee Children Resettled in New Hampshire and Rhode Island
Authors: Raymond Jaime S. , Kennedy Chinaro , Brown Mary Jean
Published: November 2012

Objective

To examine the association between refugee status and elevated blood lead levels (EBLLs) among children living in two U.S. cities and to assess the effect of the Centers for Disease Control and Prevention recommendations for BLL testing of newly emigrated refugee children for EBLLs.

Design and Sample

A longitudinal study was conducted of 1,007 refugee children and 953 nonrefugee children living, when blood testing occurred, in the same buildings in Manchester, New Hampshire and Providence, Rhode Island.

Measures

Surveillance and blood lead data were collected from both sites, including demographic information, BLLs, sample type, refugee status, and age of housing.

Results

Refugee children living in Manchester were statistically significantly more likely to have an EBLL compared with nonrefugee children even after controlling for potential confounders. We did not find this association in Providence. Compared with before enactment, the mean time of refugee children to fall below 10 μg/dL was significantly shorter after the recommendations to test newly emigrated children were enacted.

Conclusions

Refugee children living in Manchester were significantly more likely to have an EBLL compared with nonrefugee children. And among refugee children, we found a statistically significant difference in the mean days to BLL decline <10 μg/dL before and after recommendations to test newly emigrated children.
The effect of ultraviolet radiation from a novel portable fluorescent lamp on serum 25‐hydroxyvitamin D3 levels in healthy adults with Fitzpatrick skin types II and III
Authors: Dabai Nicholas S. , Pramyothin Pornpoj , Holick Michael F.
Published: November 2012

Background/Purpose

Ultraviolet (UV) B irradiation may provide a safe and effective method to treat vitamin D deficiency. The objective of this study was to assess the effectiveness of a novel Sperti D/UV‐Fluorescent lamp in converting 7‐dehydrocholesterol (7‐DHC) to previtamin D3 in vitro and in raising serum 25‐hydroxyvitamin D3 [25(OH)D3] in healthy adults.

Methods

The lamp was assessed in vitro using a 7‐DHC solution and a human skin sample. In a prospective cohort study, five healthy adults with skin types II and III were exposed to a 0.75 minimal erythemal dose of UV radiation over ∼9% of body surface area three times a week for 4 weeks. The main outcomes were percentage of conversion from 7‐DHC to previtamin D3 in vitro and changes in serum 25(OH)D3 after irradiation in vivo.

Results

A dose response between UV irradiation time and conversion of 7‐DHC to previtamin D3 was seen in the 7‐DHC solution and surgically obtained human skin. The subjects had a significant increase in mean 25(OH)D3 from 18.4 ± 8.2 to 27.3 ± 7.6 ng/ml (P < 0.001) after 4 weeks of irradiation. No adverse events occurred.

Conclusion

The Sperti D/UV‐Fluorescent lamp is effective in converting 7‐DHC to previtamin D3 in vitro and in raising serum 25(OH)D3 in healthy adults.
Misclassification of pregnancy‐related deaths in adult mortality surveys: case study in Senegal
Authors: Helleringer Stéphane , Duthé Géraldine , Kanté Almamy Malick , Andro Armelle , Sokhna Cheikh , Trape Jean‐François , Pison Gilles
Published: November 2012

Objective

In countries with limited vital registration data, maternal mortality levels are often estimated using siblings' survival histories (SSH) collected during retrospective adult mortality surveys. We explored how accurately adult deaths can be classified as pregnancy related using such data.

Method

The study was conducted in a rural area of south‐eastern Senegal with high maternal mortality, Bandafassi. We used data from a demographic surveillance system (DSS) in this area to identify deaths of women at reproductive ages between 2003 and 2009 and to locate the surviving adult sisters of the deceased and interview them. Siblings' survival histories were linked at the individual level to death records, and verbal autopsy data obtained by the demographic surveillance system. We compared the classification of adult female deaths as pregnancy related or not in interviews and DSS records.

Results

There were 91 deaths at reproductive ages in the Bandafassi DSS between 2003 and 2009, but only 59 had known surviving sisters. Some deaths were omitted by respondents, or reported as alive or as having occurred during childhood (n = 8). Among deaths reported both in the SSH and DSS data, 94% of deaths classified as pregnancy related in the DSS data were also classified as such by siblings' survival histories. Only 70% of deaths classified as not pregnancy related in the DSS data were also classified as such by siblings' survival histories.

Conclusion

Misclassifications of pregnancy‐related deaths in retrospective adult mortality surveys may affect estimates of pregnancy‐related mortality rates.
Activity profiling of vacuolar processing enzymes reveals a role for VPE during oomycete infection
Authors: Misas‐Villamil Johana C. , Toenges Gerrit , Kolodziejek Izabella , Sadaghiani Amir M. , Kaschani Farnusch , Colby Thomas , Bogyo Matthew , van der Hoorn Renier A.L.
Published: November 2012

Vacuolar processing enzymes (VPEs) are important cysteine proteases that are implicated in the maturation of seed storage proteins, and programmed cell death during plant–microbe interactions and development. Here, we introduce a specific, cell‐permeable, activity‐based probe for VPEs. This probe is highly specific for all four Arabidopsis VPEs, and labeling is activity‐dependent, as illustrated by sensitivity for inhibitors, pH and reducing agents. We show that the probe can be used for in vivo imaging and displays multiple active isoforms of VPEs in various tissues and in both monocot and dicot plant species. Thus, VPE activity profiling is a robust, simple and powerful tool for plant research for a wide range of applications. Using VPE activity profiling, we discovered that VPE activity is increased during infection with the oomycete pathogen Hyaloperonospora arabidopsidis (Hpa). The enhanced VPE activity is host‐derived and EDS1‐independent. Sporulation of Hpa is reduced on vpe mutant plants, demonstrating a role for VPE during compatible interactions that is presumably independent of programmed cell death. Our data indicate that, as an obligate biotroph, Hpa takes advantage of increased VPE activity in the host, e.g. to mediate protein turnover and nutrient release.
Presentation of Phagocytosed Antigens by MHC Class I and II
Authors: Mantegazza Adriana R. , Magalhaes Joao G. , Amigorena Sebastian , Marks Michael S.
Published: November 2012

Phagocytosis provides innate immune cells with a mechanism to take up and destroy pathogenic bacteria, apoptotic cells and other large particles. In some cases, however, peptide antigens from these particles are preserved for presentation in association with major histocompatibility complex (MHC) class I or class II molecules in order to stimulate antigen‐specific T cells. Processing and presentation of antigens from phagosomes presents a number of distinct challenges relative to antigens internalized by other means; while bacterial antigens were among the first discovered to be presented to T cells, analyses of the cellular mechanisms by which peptides from phagocytosed antigens assemble with MHC molecules and by which these complexes are then expressed at the plasma membrane have lagged behind those of conventional model soluble antigens. In this review, we cover recent advances in our understanding of these processes, including the unique cross‐presentation of phagocytosed antigens by MHC class I molecules, and in their control by signaling modalities in phagocytic cells.
The role of fructose transporters in diseases linked to excessive fructose intake
Authors: Douard Veronique , Ferraris Ronaldo P.
Published: November 2012

Fructose intake has increased dramatically since humans were hunter‐gatherers, probably outpacing the capacity of human evolution to make physiologically healthy adaptations. Epidemiological data indicate that this increasing trend continued until recently. Excessive intakes that chronically increase portal and peripheral blood fructose concentrations to >1 and 0.1 mm, respectively, are now associated with numerous diseases and syndromes. The role of the fructose transporters GLUT5 and GLUT2 in causing, contributing to or exacerbating these diseases is not well known. GLUT5 expression seems extremely low in neonatal intestines, and limited absorptive capacities for fructose may explain the high incidence of malabsorption in infants and cause problems in adults unable to upregulate GLUT5 levels to match fructose concentrations in the diet. GLUT5‐ and GLUT2‐mediated fructose effects on intestinal electrolyte transporters, hepatic uric acid metabolism, as well as renal and cardiomyocyte function, may play a role in fructose‐induced hypertension. Likewise, GLUT2 may contribute to the development of non‐alcoholic fatty liver disease by facilitating the uptake of fructose. Finally, GLUT5 may play a role in the atypical growth of certain cancers and fat tissues. We also highlight research areas that should yield information needed to better understand the role of these GLUTs in fructose‐induced diseases.
Generation of striatal projection neurons extends into the neonatal period in the rat brain
Authors: Wright Jordan , Stanic Davor , Thompson Lachlan H.
Published: November 2012

Key points

Studies on postnatal neurogenesis as a constitutive physiological process have largely focused on the adult brain.

This study identifies and characterises a continued period of striatal neurogenesis under normal physiological conditions in the neonatal brain.

Birth‐dating studies show a peak production of striatal projection neuron generation at postnatal day 0 that declines sharply within the first postnatal week.

New striatal projection neurons integrate appropriately into existing circuitry through target‐directed innervation of appropriate sub‐striatal structures.

The results are highly relevant for the development of regenerative strategies for neonatal brain repair.

Abstract Substantial advances have been made in the last decade on our understanding of the basic physiology underlying neurogenesis in the postnatal mammalian brain. The bulk of the work in this area has been based on analysis of the adult brain. Relatively less is known about the capacity for neurogenesis in specific structures within the neonatal brain. Here we report that the production of medium spiny striatal projection neurons extends into the early neonatal period under normal physiological conditions in the rat brain. Birth‐dating of newborn cells with bromodeoxyuridine at postnatal days 0, 2 and 5 showed a peak production close to birth, which sharply declined at the later time‐points. Additionally, there was a low‐level but stable contribution of neurons with interneuron identity over the same time‐period. Importantly, retroviral labelling of new striatal projection neurons with green fluorescent protein showed long‐term survival and terminal differentiation with characteristic morphology, including highly elaborated spiny dendrites, and appropriate axonal targeting of the globus pallidus and midbrain. This latent period of striatal neurogenesis in the early neonatal brain represents an interesting target for regenerative approaches aimed at restoring striatal circuitry in perinatal pathologies, such as hypoxic and ischaemic damage associated with cerebral palsy.
Evaluation of Maintenance Intervals for Spring-Operated Relief Valves Using a Risk-Based Inspection Technique
Authors: Gross Robert E. , Mitchell Emily M. , Harris Stephen P.
Published: November 2012

The Savannah River Site (SRS) spring-operated relief valve (SORV) maintenance intervals were evaluated using the American Petroleum Institute’s (API) inspection updating approach in API RP 581 for Risk-Based Inspection (RBI) technology. In addition, the impact of extending the inspection schedule was evaluated using Monte Carlo simulation (MCS). The API RP 581 approach is characterized as a Weibull analysis with modified Bayesian updating. Initial Weibull parameter estimates were updated using SRS’s historical proof test records contained in the Center for Chemical Process Safety Process Equipment Reliability Database. The API RP 581 methodology was used to estimate the SORV’s probability of failing on demand and the annual expected risk. An illustration of the inspection costs versus the associated risks is provided. Current practices are reviewed, and recommendations are made for extending maintenance intervals. A cost-effective maintenance frequency balancing both financial risk and inspection cost is demonstrated.
Growth of Fe cubical particles on substrates during gas flow sputtering
Authors: Sakuma Hiroshi , Sakamoto Shinichi , Naoi Akimasa , Saito Yusuke , Ishii Kiyoshi
Published: November 2012

The shape of Fe fine particles formed during gas flow sputtering was examined. Simultaneous formation of truncated dodecahedron particles with an average size of 80 nm and small particles with an average size of 20 nm was observed in an Ar gas flow. Truncated dodecahedron particles deposited on a substrate were observed to grow and change their shape as a result of collisions with the small particles. Under conditions of short substrate-target separation or a high gas flow rate, particles with a novel shape and possessing {100} facets of a body-centered-cubic structure and a staircase-like structure on the edges of the cubes were formed. On the other hand, under conditions of long substrate-target separation and a low gas flow rate, aggregated particles, which were almost round particles covered with smaller particles, were formed. This behavior is explained by the kinetic energy of the small particles, termed “gas flow energy” in this paper, which is a function of the velocity of the small particles prior to colliding with the truncated dodecahedron particles on the substrate.
Scintillator high‐gain avalanche rushing photoconductor active‐matrix flat panel imager: Zero‐spatial frequency x‐ray imaging properties of the solid‐state SHARP sensor structure
Authors: Wronski M. , Zhao W. , Tanioka K. , DeCrescenzo G. , Rowlands J. A.
Published: November 2012

Purpose:

The authors are investigating the feasibility of a new type of solid‐state x‐ray imaging sensor with programmable avalanche gain: scintillator high‐gain avalanche rushing photoconductor active matrix flat panel imager (SHARP‐AMFPI). The purpose of the present work is to investigate the inherent x‐ray detection properties of SHARP and demonstrate its wide dynamic range through programmable gain.

Methods:

A distributed resistive layer (DRL) was developed to maintain stable avalanche gain operation in a solid‐state HARP. The signal and noise properties of the HARP‐DRL for optical photon detection were investigated as a function of avalanche gain both theoretically and experimentally, and the results were compared with HARP tube (with electron beam readout) used in previous investigations of zero spatial frequency performance of SHARP. For this new investigation, a solid‐state SHARP x‐ray image sensor was formed by direct optical coupling of the HARP‐DRL with a structured cesium iodide (CsI) scintillator. The x‐ray sensitivity of this sensor was measured as a function of avalanche gain and the results were compared with the sensitivity of HARP‐DRL measured optically. The dynamic range of HARP‐DRL with variable avalanche gain was investigated for the entire exposure range encountered in radiography/fluoroscopy (R/F) applications.

Results:

The signal from HARP‐DRL as a function of electric field showed stable avalanche gain, and the noise associated with the avalanche process agrees well with theory and previous measurements from a HARP tube. This result indicates that when coupled with CsI for x‐ray detection, the additional noise associated with avalanche gain in HARP‐DRL is negligible. The x‐ray sensitivity measurements using the SHARP sensor produced identical avalanche gain dependence on electric field as the optical measurements with HARP‐DRL. Adjusting the avalanche multiplication gain in HARP‐DRL enabled a very wide dynamic range which encompassed all clinically relevant medical x‐ray exposures.

Conclusions:

This work demonstrates that the HARP‐DRL sensor enables the practical implementation of a SHARP solid‐state x‐ray sensor capable of quantum noise limited operation throughout the entire range of clinically relevant x‐ray exposures. This is an important step toward the realization of a SHARP‐AMFPI x‐ray flat‐panel imager.
Chloroplast Rescued by Ubiquitin
Authors: Hurtley Stella M.
Published: November 2012

Protein degradation helps to coordinate the growth of chloroplasts with that of the whole plant.
Improving Risk Assessment
Authors: Dambach Donna M. , Uppal Hirdesh
Published: November 2012

A U.S. government initiative to engineer nonclinical cell-based models that mimic human biology may improve predictions of drug-related adverse events.
Prospective Study of the Wilson Severity-of-Illness Scoring System for Complicated Skin and Skin Structure Infections
Authors: Talbot George H. , O'Neal Tanya , Das Anita F. , Thye Dirk
Published: November 2012

Wilson et al. (Am. J. Surg.
185:
369–375, 2003) developed a disease severity classification system for use in complicated skin and skin structure infections (cSSSI). Two phase 3 trials of ceftaroline fosamil in cSSSI provided the opportunity to evaluate the association between Wilson Severity Risk Class and clinical cure rates. Our analyses did not confirm that an association exists between Wilson Severity Risk Class and clinical cure rate and, thus, did not validate its predictive utility.
A novel ice storm manipulation experiment in a northern hardwood forest
Authors: Rustad Lindsey E. , Campbell John L.
Published: November 2012

Ice storms are an important natural disturbance within forest ecosystems of the northeastern United States. Current models suggest that the frequency and severity of ice storms may increase in the coming decades in response to changes in climate. Because of the stochastic nature of ice storms and difficulties in predicting their occurrence, most past investigations of the ecological effects of ice storms across this region have been based on case studies following major storms. Here we report on a novel alternative approach where a glaze ice event was created experimentally under controlled conditions at the Hubbard Brook Experimental Forest, New Hampshire, USA. Water was sprayed over a northern hardwood forest canopy during February 2011, resulting in 7–12 mm radial ice thickness. Although this is below the minimum cutoff for ice storm warnings (13 mm of ice) issued by the US National Weather Service for the northeastern United States, this glaze ice treatment resulted in significant canopy damage, with 142 and 218 g C·m–2 of fine and coarse woody debris (respectively) deposited on the forest floor, a significant increase in leaf-on canopy openness, and increases in qualitative damage assessments following the treatment. This study demonstrates the feasibility of a relatively simple approach to simulating an ice storm and underscores the potency of this type of extreme event in shaping the future structure and function of northern hardwood forest ecosystems.
Root system response of naturally regenerated Douglas-fir (Pseudotsuga menziesii) after complete overstory removal
Authors: Briggs Nathan A. , Kuehne Christian , Kohnle Ulrich , Bauhus Jürgen
Published: November 2012

Long regeneration periods, which result in two-layered or multilayered forest stands, are an important element of the close-to-nature forest management paradigm in central Europe. Such extended regeneration periods, however, may lead to undesirable development of advance regeneration, specifically in species such as Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) where root growth is strongly curtailed under competition. We hypothesized that root systems of naturally regenerated Douglas-fir that had grown under closed canopy for prolonged periods would be inhibited in their capacity to develop adequate structural root systems following release through removal of the canopy. Complete root systems of six approximately 25-year-old Douglas-fir that had grown for at least 12 years underneath a closed canopy before overstory removal were excavated using subterranean explosives. Root elongation, radial increment of primary lateral and vertical roots, and aboveground stem growth were investigated using retrospective analysis of growth rings. Structural roots of the previously suppressed Douglas-fir were capable of strongly responding to release from competition relative to growth prior to removal, but this response, particularly in the form of root elongation, was delayed. However, since the growth response of roots was not stronger than that above ground, an imbalanced root to shoot ratio, likely developed in trees when grown under the canopy, was not reverted. Generalizing interpretation of the derived findings of this study is limited because of the small sample size and the lack of freely grown control trees. Whether or not previously suppressed trees can develop the same physical stability as open-grown individuals therefore deserves further investigation.
The influence of stand and landscape characteristics on forest tent caterpillar (Malacosoma disstria) defoliation dynamics: the case of the 1999–2002 outbreak in northwestern Quebec
Authors: Charbonneau Daniel , Lorenzetti François , Doyon Frédérik , Mauffette Yves
Published: November 2012

The forest tent caterpillar (Malacosoma disstria Hbn.) is an eruptive forest insect common across North America and an important defoliator of trembling aspen (Populus tremuloides Michx.). Forest stands having suffered severe defoliations by the forest tent caterpillar over multiple years are known to incur reduced tree growth and increased tree mortality. In this study, we developed a predictive model of forest tent caterpillar defoliation dynamics using local and contextual variables expressing forest composition and structure, and their heterogeneity, at different scales. Of all scales considered (500, 1000, 1500, and 2000 m), contextual variables at 1500 m were found to have the greatest effect on defoliation dynamics. At this scale, we found that a greater proportion of preferred host trees in the landscape increased defoliation severity, but duration was modulated by compositional heterogeneity, where persistence was reduced in highly heterogeneous landscapes. Indeed, the likelihood of a single year of defoliation was much greater in highly diverse landscapes than the likelihood of multiple years of defoliation. These findings are consistent with ecological theory. Contrary to the expected result that older trees would be most susceptible, we found that “middle-aged” trees (~50 years) were most likely to be defoliated.
Long-term drought sensitivity of trees in second-growth forests in a humid region
Authors: Pederson Neil , Tackett Kacie , McEwan Ryan W. , Clark Stacy , Cooper Adrienne , Brosi Glade , Eaton Ray , Stockwell R. Drew
Published: November 2012

Classical field methods of reconstructing drought using tree rings in humid, temperate regions typically target old trees from drought-prone sites. This approach limits investigators to a handful of species and excludes large amounts of data that might be useful, especially for coverage gaps in large-scale networks. By sampling in more “typical” forests, network density and species diversity would increase in ways that could potentially improve reconstructions. Ten nonclassical tree-ring chronologies derived from randomly selected trees, trees from logged forests, or both were compared to more classical chronologies and an independent regional drought reconstruction to determine their usefulness for dendrohydroclimatic research. We find that nonclassical chronologies are significantly correlated to classical chronologies and reconstructed drought over the last 2–3 centuries. While nonclassical chronologies have spectral properties similar to those from classical dendroclimatic collections, they do lack spectral power at lower frequencies that are present in the drought reconstruction. Importantly, our results show that tree growth is strongly dependent on moisture availability, even for small, randomly selected trees in cut forests. These results indicate that there could be more data available in areas with few current tree-ring collections for studying climate history and that drought plays an important role in humid forests.
USING NEWTON'S LAW FOR DARK ENERGY
Authors: FRAMPTON PAUL H.
Published: November 2012

A model is introduced in which Newton's law is modified between matter and dark energy corpuscles (DECs). The model predicts that the DEC component is presently decelerating in its expansion at 14% of the magnitude of the matter expansion acceleration. In the future, expansion of the DEC universe will continue to decelerate.
EXPLAINING THE SUPERNOVA DATA WITHOUT ACCELERATING EXPANSION
Authors: STUCKEY W. M. , McDEVITT T. J. , SILBERSTEIN M.
Published: November 2012

The 2011 Nobel Prize in Physics was awarded "for the discovery of the accelerating expansion of the universe through observations of distant supernovae." However, it is not the case that the type Ia supernova data necessitates accelerating expansion. Since we do not have a successful theory of quantum gravity, we should not assume general relativity (GR) will survive unification intact, especially on cosmological scales where tests are scarce. We provide a simple example of how GR cosmology may be modified to produce a decelerating Einstein-de Sitter cosmology (EdS) that accounts for the Union2 Compilation data as well as the accelerating ΛCDM (EdS plus a cosmological constant).
THEORETICAL STUDY OF ONE- AND TWO-PHOTON ABSORPTION PROPERTIES FOR THREE SERIES OF DIPHENYLAMINE AND DIFLUORENYLAMINE SUBSTITUTED CONJUGATED COMPOUNDS
Authors: WANG JIN-YUN , LIN CHEN-SHENG , ZHANG MIN-YI , CHAI GUO-LIANG , CHENG WEN-DAN
Published: November 2012

The one-photon (OPA) and two-photon (TPA) absorption properties of three series of symmetrically substituted quadrupolar compounds with structure of donor-π bridge-donor (D–π–D) were investigated by time-dependent density functional theory (TDDFT) based on the Hartree–Fock (HF)-optimized geometrical structures. These compounds were constructed with either phenyl or fluorenyl groups connected by vinylene unit as the central π-conjugated bridges and either diphenylamine or difluorenylamine groups as terminal electron donors. The calculated OPA spectra are dominated by two strong transitions which are attributed to the charge transfers from the donor groups to central conjugated chains. The OPA and TPA transition strength all increase with the extension of conjugated chain length in each series and the corresponding wavelength shifts red in general. The transition strength in either OPA or TPA process also increases from series one to series two or three by replacing the phenyl groups with fluorenyl groups. The intramolecular charge transfers make significant contributions to the TPA activity. According to the three-state model, the enhanced TPA activity comes from the enhancement of transition moment between states–states as conjugated chain increases.
COMPUTATIONAL STUDIES OF SQUALENE SYNTHASE FROMPANAX GINSENG: HOMOLOGY MODELING, DOCKING STUDY AND VIRTUAL SCREENING FOR A NEW INHIBITOR
Authors: ZHAN DONGLING , ZHANG YU , SONG YAWEI , SUN HANG , LI ZESHENG , HAN WEIWEI , LIU JINGSHENG
Published: November 2012

Through a reductive dimerization of two farnesyl diphosphate (FPP) molecules, Squalene synthase from Panax ginseng (P. ginseng) (PgSS) catalyzes the biosynthesis of squalene, a key cholesterol precutsor, and hence is an attractive site of therapeutic intervention. Thus, the 3D structure of PgSS has been firmly established by homology modeling and was used to relax by MD simulation to get the reliable structure. It is well known that Mg2+plays an important role in substrate binding. Understanding how PgSS recruits the FPP substrate through Mg2+is the first and foremost step toward further mechanistic investigations and the design of effective PgSS inhibitors. Quantum mechanical calculation method is used to determine the Mg2+binding mode. In the first binding motif, the Mg2+ion is coordinated to D77, D81, and one oxygen atom from the α- and β-phosphates of FPP. In order to determine the important residue of the substrate (FPP) binding, we dock the one FPP to the protein. Arg113 may be an important residue because they form a salt bridge with PgSS. After virtual screening technique of PgSS, a novel natural compound (8002215) has been found with the lowest affinity energy. Then we identify that His266 is the most important anchoring residue for binding with 8002215 because it has strong edge-to-face interaction with inhibitor. Leu205 and Gln206 are important residues for they make hydrogen bonds with inhibitor. Our results may be helpful for further experimental investigations.
THEORETICAL STUDY ON CUI-CATALYZED LIGAND-FREE N-ARYLATION OF IMIDAZOLE WITH BROMOBENZENE
Authors: GUO HAN , XUE YING
Published: November 2012

The density functional theory (DFT) is used to investigate the mechanism of ligand-free CuI -catalyzed N -arylation of imidazole with aryl halide. The oxidative addition/reductive elimination mechanism is adopted via two different pathways to form the same Cu(III) intermediate. Comparing two pathways, the path 1 in which the imidazolyl coordination occurs prior to the oxidative addition is more favorable, because the free energy barrier of the rate-limiting step of path 1 is lower than the barrier of the other. In addition, it leads to a relative stable intermediate which can promote the reaction to process via path 1. And the overall free energy barrier of oxidative addition to imidazole-ligated Cu(I) complex is not high enough when comparing with the diamine-promote process, which can further prove that the N -arylation of imidazole is feasible in the absence of additional ligands. Nucleophile coordination and reductive elimination steps are facile, while the oxidative addition is the rate-limiting step.
A NOTE ON BARKER POLYNOMIALS
Authors: BORWEIN PETER , ERDÉLYI TAMÁS
Published: November 2012

We call the polynomial [Formula: see text] a Barker polynomial of degree n-1 if each aj ∈{-1, 1} and [Formula: see text] Properties of Barker polynomials were studied by Turyn and Storer thoroughly in the early sixties, and by Saffari in the late eighties. In the last few years P. Borwein and his collaborators revived interest in the study of Barker polynomials (Barker codes, Barker sequences). In this paper we give a new proof of the fact that there is no Barker polynomial of even degree greater than 12, and hence Barker sequences of odd length greater than 13 do not exist. This is intimately tied to irreducibility questions and proved as a consequence of the following new result.

Theorem.Ifn ≔ 2m + 1 > 13and[Formula: see text]where eachbj ∈{-1, 0, 1}for even values of j, each bj is an integer divisible by 4 for odd values of j, then there is no polynomial[Formula: see text]such that[Formula: see text], where[Formula: see text]and[Formula: see text]denotes the collection of all polynomials of degree 2m with each of their coefficients in {-1, 1}.

A clever usage of Newton's identities plays a central role in our elegant proof.
Anisotropy of magnetic susceptibility and sedimentary cycle data from Permo-Carboniferous rhythmites (Paraná Basin, Brazil): a multiple proxy record of astronomical and millennial scale palaeoclimate change in a glacial setting
Authors: Franco Daniel R. , Hinnov Linda A.
Published: November 2012

In this study we examine glaciogenic rhythmites from the Late Palaeozoic Itararé Group, Paraná Basin, Brazil. We conduct spectral analysis on lithological cycle (‘couplet’) thickness series, and declination of maximum axis of anisotropy of magnetic susceptibility ellipsoidal tensor (K1) data. We tested the efficiency of K1 as a palaeoclimatic proxy. To constrain the timescale of harmonic features in the data, we analysed the couplet thickness spectra, converting the spectra to the time domain using an astronomical calibration based on Milankovitch frequency ratios. Comparison of the two rhythmites provides insights into their sedimentation rate evolution and cyclicity. Millennial-scale mechanisms of climatic origin influenced the deposition of both rhythmites, generating the lithological couplets, and are consistent with millennial-scale variations recognized as triggers for large-scale climatic changes during the Late Pleistocene. The common harmonic features in the couplet thickness and K1 spectra support the view that the azimuth of the K1 axis in sedimentary fabric is a useful palaeoclimatic proxy, reflecting sedimentation processes that were directly influenced by flow-induced, sediment transport, which is linked to external climate factors.