bluuebunny/crossref_metadata_2025 huggingface dataset:
Dental care utilization among North Carolina rural older adults
Authors: Arcury Thomas A. , Savoca Margaret R. , Anderson Andrea M. , Chen Haiying , Gilbert Gregg H. , Bell Ronny A. , Leng Xiaoyan , Reynolds Teresa , Quandt Sara A.
Published: April 2012

Objectives:This analysis delineates the predisposing, need, and enabling factors that are associated with regular and recent dental care in a multiethnic sample of rural older adults.

Methods:A cross‐sectional, comprehensive, oral‐health survey conducted with a random, multiethnic (African American, American Indian, white) sample of 635 community‐dwelling adults aged 60 years and older was completed in two rural southern counties. Logistic regression models assessed the simultaneous associations of dental care with predisposing, enabling, and need factors.

Results:Almost no edentulous rural older adults received dental care; 27.1 percent of dentate rural older adults had received regular dental care, and 36.7 percent had received recent dental care. Predisposing (less than high‐school education, dental anxiety), enabling (no regular place for dental care), and need factors (no filled teeth) reduced the odds of regular dental, while predisposing (dental anxiety), enabling (no regular place for dental care), and need factors (no filled teeth) reduced the odds of recent dental care. Having excellent, very good, or good self‐rated oral health increased the odds of receiving regular and recent dental care.

Conclusions:Regular and recent dental care are infrequent among rural older adults. Contrary to expectations, those not receiving dental care are those who most need care; this has been referred to as the Paradox of Dental Need. Community access to dental care and the ability of older adults to pay for dental care must be addressed by public‐health policy to improve the health and quality of life of older adults in rural communities.
Reliability and validity testing for the Child Oral Health Impact Profile‐Reduced (COHIP‐SF 19)
Authors: Broder Hillary L. , Wilson‐Genderson Maureen , Sischo Lacey
Published: April 2012

Objectives: This study assessed the reliability and validity of the Child Oral Health Impact Profile–Short Form 19 (COHIP‐SF 19) from the validated 34‐item COHIP.

Methods: Participants included 205 pediatric, 107 orthodontic, and 863 patients with craniofacial anomalies (CFAs). Item level evaluations included examining content overlap, distributional properties, and use of the response set. Confirmatory factor analysis identified potential items for deletion. Scale reliability was assessed with Cronbach's alpha. Discriminant validity of the COHIP‐SF 19 was evaluated as follows: among pediatric participants, scores were compared with varying amounts of decayed and filled surfaces (DFS) and presence of caries on permanent teeth; for orthodontic patients, scores were correlated with anterior tooth spacing/crowding; and for those with CFA, scores were compared with clinicians' ratings of extent of defect (EOD) for nose and lip and/or speech hypernasality. Convergent validity was assessed by examining the partial Spearman correlation between the COHIP scores and a standard Global Health self‐rating. Comparisons between the COHIP and the COHIP‐SF 19 were completed across samples.

Results: The reduced questionnaire consists of 19 items: Oral Health (five items), Functional Well‐Being (four items), and a combined subscale named Socio‐Emotional Well‐Being (10 items). Internal reliability is ≥0.82 for the three samples. Results demonstrate that the COHIP‐SF 19 discriminates within and across treatment groups by EOD and within a community‐based pediatric sample. The measure is associated with the Global Health rating (P < 0.05), thereby indicating convergent validity.

Conclusions: Reliability and validity testing demonstrate that the COHIP‐SF 19 is a psychometrically sound instrument to measure oral health‐related quality of life across school‐aged pediatric populations.
Recent trends in dental emergency department visits in the United States – 1997/1998 to 2007/2008
Authors: Wall Thomas
Published: April 2012

Objective: The author focused on recent national trends in dental emergency department (ED) visits. Patients who presented at an ED for a dental condition are described and the author look at the extent to which these patients have changed over time.

Methods: This study was based on the National Ambulatory Medical Care Survey, a national probability survey of hospital ED visits. A dental ED visit was defined using International Classification of Diseases, Ninth Edition, Clinical Modification diagnostic codes.

Results: Between 1997/1998 and 2007/2008, dental ED visits increased from 1.15 to 1.87 percent of total ED visits. The largest increase in the number of dental ED visits per 1,000 persons was found for young adults 20‐34 years old. Primary payer, a measure of insurance status, suggests that patients from all income levels participated in the increase.

Conclusions: Although dental‐related ED visits account for a relatively small percentage of total ED visits, both the number and the percentage of such visits grew from 1997/1998 to 2007/2008. Young adults 20‐34 years old were most likely to present at an ED with a dental problem.
The association of individual characteristics and neighborhood poverty on the dental care of American adolescents
Authors: Atkins Robert , Sulik Michael J. , Hart Daniel
Published: April 2012

Objective: The purpose of this study was to explore the extent to which neighborhood poverty was associated with the utilization of dental care by American adolescents.

Methods: To accomplish the study goals we conducted multilevel modeling analyses of two nationally representative data sets: National Longitudinal Study of Adolescent Health (Add Health) and the Early Childhood Longitudinal Study, Kindergarten Class of 1998‐1999 (ECLS‐K).

Results: As hypothesized, neighborhood poverty predicted frequency of dental care in both studies (t = 6.06; P < 0.001; t = 2.44; P < 0.05). Even after accounting for individual level predictors such as household income, health insurance, and parental education, adolescents living in poor neighborhoods are less likely than their counterparts in non‐poor neighborhoods to utilize dental care.

Conclusions: The findings from this study indicate that neighborhoods influence dental care utilization patterns in adolescents.
Evaluation of six candidate DNA barcoding loci in Ficus (Moraceae) of China
Authors: LI H.‐Q. , CHEN J.‐Y. , WANG S. , XIONG S.‐Z.
Published: April 2012

Ficus, with about 755 species, diverse habits and complicated co‐evolutionary history with fig wasps, is a notoriously difficult group in taxonomy. DNA barcoding is expected to bring light to the identification of Ficus but needs evaluation of candidate loci. Based on five plastid loci (rbcL, matK, trnH‐psbA, psbK‐psbI, atpF‐atpH) and a nuclear locus [internal transcribed spacer (ITS)], we calculated genetic distances and DNA barcoding gaps individually and in combination and constructed phylogenetic trees to test their ability to distinguish the species of the genus. A total of 228 samples representing 63 putative species in Ficus (Moraceae) of China were included in this study. The results demonstrated that ITS has the most variable sites, greater intra‐ and inter‐specific divergences, the highest species discrimination rate (72%) and higher primer universality among the single loci. It is followed by psbK‐psbI and trnH‐psbA with moderate variation and considerably lower species discrimination rates (about 19%), whereas matK, rbcL and atpF‐atpH could not effectively separate the species. Among the possible combinations of loci, ITS + trnH‐psbA performed best but only marginally improved species resolution over ITS alone (75% vs. 72%). Therefore, we recommend using ITS as a single DNA barcoding locus in Ficus.
Autonomic impairment in rheumatoid arthritis
Authors: Janse van Rensburg Dina C. , Ker James A. , Grant Catharina C. , Fletcher Lizelle
Published: April 2012

Aim

To determine if there is a difference between autonomic cardiac control as measured by heart rate variability (HRV) in women with rheumatoid arthritis (RA) compared to a healthy control group.

Methods

The RA group (45) and control group (39) were matched for age and body mass index (BMI). Three techniques were used: time domain, frequency domain and Poincarè plot analysis. All possible confounding factors were excluded and the test environment strictly regulated.

Results

Basal heart rate was significantly higher in the RA patients. In the supine position significant differences existed between RA patients and controls (P ≤ 0.01). Indicators of parasympathetic activity showed significantly lower variation in the RA group (root mean square of the standard deviation [RMSSD] = 14.70, percentage of successive normal‐to‐normal interval differences larger than 50 ms [pNN50] = 0.50, standard deviation [SD]1 = 10.50, high frequency [HF] (ms2) = 31) compared to controls (RMSSD = 29.40, pNN50 = 7.8, SD1 = 20.9, HF (ms2) = 141.00). Indicators of sympathetic variation were also significantly lower in RA patients (SD2 = 36.70, low frequency [LF] (ms2) = 65) compared to controls (SD2 = 49.50, LF (ms2) = 175). In the standing position eight variables indicated autonomic impairment by significant differences (P ≤ 0.01) between the groups. The response of the RA group to an orthostatic stressor showed less vagal withdrawal, (P‐values for RMSSD = 0.038, pNN50 = 0.022, SD1 = 0.043 and HF [ms2] = 0.008 respectively); and lower sympathetic response (P‐values for SD2 = 0.001 and LF [ms2] < 0.001) when compared to controls.

Conclusions

An inability of the autonomic nervous system to efficiently compensate for internal and external environmental changes may predispose RA patients to arrhythmias, thereby increasing cardiovascular mortality. All three methods used showed the same outcome, implying decreased HRV and thus an increased risk for arrhythmias in RA patients. Evaluating the autonomic nervous system might be critical in planning management of RA patients.
Characterization of the secretion pathway of the collagen adhesin EmaA of Aggregatibacter actinomycetemcomitans
Authors: Jiang X. , Ruiz T. , Mintz K.P.
Published: April 2012

The extracellular matrix protein adhesin A (EmaA) surface antennae‐like structures of the periodontal pathogen Aggregatibacter actinomycetemcomitans are composed of three identical protein monomers. Recently, we have demonstrated that the protein is synthesized with an extended signal peptide of 56 amino acids necessary for membrane targeting and protein translocation. In this study, EmaA secretion was demonstrated to be reliant on a chaperone‐dependent secretion pathway. Deletion of secB partially reduced but did not abolish the amount of EmaA in the membrane. This observation was attributed to an increase in the synthesis of DnaK in the ΔsecB strain. Overexpression of a DnaK substitution mutant (A174T), with diminished activity, in the ΔsecB strain further reduced the amount of EmaA in the membrane. Expression of dnaK A174T in the wild‐type strain did not affect the amount of EmaA in the membrane when grown under optimal growth conditions at 37°C. However, EmaA was found to be reduced when this strain was grown at heat‐shock temperature. A chromosomal deletion of amino acids 16–39 of the EmaA extended signal peptide, transformed with either the wild‐type or dnaK A174T‐expressing plasmid, did not affect the amount of EmaA in the membrane. In addition, the level of EmaA in a ΔsecB/emaA− double mutant strain expressing EmaAΔ16–39 was unchanged when grown at both temperatures. The data suggest that chaperones are required for the targeting of EmaA to the membrane and a specific region of the signal peptide is necessary for secretion under stress conditions.
Stress, coping, and psychological well‐being among forensic health care professionals
Authors: Elliott Katie Ann , Daley David
Published: April 2012

Purpose. Although forensic services are often regarded as highly stressful environments, there has been a surprising lack of research into the phenomena of occupational stress among forensic health care professionals (FHCP) in the United Kingdom. This study investigated stress, coping, and psychological well‐being among FHCP employed within inpatient settings.

Methods. One hundred and thirty‐five FHCP were recruited from four Medium Secure Units in the United Kingdom. A postal research pack was used to collect background information and measures of psychological well‐being, burnout, occupational stress, work satisfaction, and coping.

Results. The study found that a substantial proportion of FHCP experienced elevated levels of occupational stress and psychological distress, while moderate levels of burnout were demonstrated in terms of emotional exhaustion, depersonalization, and reduced personal accomplishment. The findings confirmed that FHCP utilized a range of problem‐focused (e.g., positive), emotion‐focused (e.g., religious, negative, and supported), and palliative coping strategies (e.g., excessive smoking and drinking).

Conclusions. The results appeared to support the commonly held assertion that forensic services are an inherently stressful and dangerous working environment, which can cause FHCP to experience marked levels of psychological distress, burnout, and occupational stress.
Modeling, Force Sensing, and Control of Flexible Cannulas for Microstent Delivery
Authors: Wei Wei , Simaan Nabil
Published: April 2012

This paper presents a kinetostatic modeling framework for flexible cannulas (concentric tubing robots) subject to tip loads. Unlike existing methods that allow fast computation of the beam tip position, this modeling framework provides fast computation of both the tip position and the entire shape of the deflected robot. A method for online force sensing based on inverse kinetostatic solution is also proposed and assistive telemanipulation control methods for microstent delivery are presented. The modeling framework uses polynomial approximation and linear interpolation based on elliptic integral solutions to the deflection of lightweight beams. To date, there are no systems capable of stent delivery in retinal vasculature. The modeling and control frameworks of this paper are validated experimentally on pilot studies for microstent delivery. We believe that the methods presented in this paper open the way for robot-assisted retinal microvascular stenting that may potentially revolutionize the treatment of blinding retinal vasculature diseases.
Adaptive General Predictive Control Using Optimally Scheduled Multiple Models for Parallel-Coursing Utility Units With a Header
Authors: Pan Lei , Shen Jiong , Luh Peter B.
Published: April 2012

An adaptive general predictive control using optimally scheduled multiple models (OSMM-GPC) is presented for improving the load-following capability and economic profits of the system of parallel-coursing utility units with a header (PUUH). OSMM-GPC is a comprehensive control algorithm built on the distributed multiple-model control architecture. It is improved from general predictive control by two novel algorithms. One is the mixed fuzzy recursive least-squares (MFRLS) estimation and the other is the model optimally scheduling algorithm. The MFRLS mixes the local and global online estimations by weighting a dynamic multi-objective cost function on the membership feature of each sampling point. It provides better parameter estimation on the Takagi–Sugeno (TS) fuzzy model of a time-varying system than the local and global recursive least squares, thus, it is proper for building adaptive models for the OSMM-GPC. Based on high-precision adaptive models estimated by the MFRLS, the model optimally scheduling algorithm computes the regulating efficiencies of all control groups and then chooses the optimal one in charge of the multiple-variable general predictive control. Through the model scheduling at each operation point, considerable fuel consumption can be saved; meanwhile, a better control performance is achieved. Besides PUUH, the OSMM-GPC can also work for other distributed multiple-model control applications.
Quantification of Computational Uncertainty for Molecular and Continuum Methods in Thermo-Fluid Sciences
Authors: Drikakis Dimitris , Asproulis Nikolaos
Published: April 2012

This paper presents a review of computational uncertainties in scientific computing, as well as quantification of these uncertainties in the context of numerical simulations for thermo-fluid problems. The need for defining a measure of the numerical error that takes into account errors arising from different numerical building blocks of the simulation methods is discussed. In the above context, the effects of grid resolution, initial and boundary conditions, numerical discretization, and physical modeling constraints are presented.
Coupling Mechanics of Antikythera Gearwheels
Authors: Sorge F.
Published: April 2012

This paper discusses the gear coupling mechanics of the ancient Antikythera mechanism, among whose distinctive characteristics was the triangular shaping of the teeth. The engagement of the tooth pairs is analyzed in detail, estimating the temporal variation of the speed ratio due to the back and forth shifting of the relative instant center. The admissibility of the theoretical contact points is carefully checked, and the magnitude of the successive tooth collisions is calculated together with the energy losses arising from the particular nature of the coupling. Some interesting results are that only one tooth pair turns out to be active at each time instant and the real path may belong only to the approach or to the recess region entirely, or may split into separate subphases, in approach and in recess, or may even straddle both regions. The occurrence of each of these conditions depends on the average speed ratio (tooth ratio) and the assigned clearance between the wheels. It is also found that the speed oscillation is roughly contained in a ±10% range and the efficiency may reach rather high values, despite the presumable crude finishing of the ancient gearwheels due to the rather rudimentary technology used in the construction of the tooth profiles.
Improved characteristics of mesa-type intrinsic Josephson junctions by vacuum cleavage process for Bi2Sr2CaCu2O8+δ/Au contacts
Authors: Ishida Hiroki , Kato Takahiro , Saito Atsushi , Yasui Kanji
Published: April 2012

Improvement in the quality of stacked intrinsic Josephson junctions (IJJs) was attempted using Bi2Sr2CaCu2O8+δ (Bi-2212) single crystals. The introduction of a clean Bi-2212/Au interface reduced contact resistivity (ρc), decreased low frequency noise, and suppressed the drop in the maximum Josephson current (Ic), which are very important factors for applications such as a superconducting quantum interference device. The ρc of samples produced by crystal cleavage in air or vacuum were, respectively, 8.2 × 10−5 and 7.0 × 10−6 Ω cm2 at 300 K and 8.2 × 10−5 and 2.1 × 10−6 Ω cm2 at 77 K. Random-telegraph voltage noise observed with the air-cleaved samples did not occur for the samples cleaved in a vacuum. The degradation of Ic was suppressed for IJJs produced by the vacuum cleavage process.
Quantitative Sequencing of 5-Methylcytosine and 5-Hydroxymethylcytosine at Single-Base Resolution
Authors: Booth Michael J. , Branco Miguel R. , Ficz Gabriella , Oxley David , Krueger Felix , Reik Wolf , Balasubramanian Shankar
Published: April 2012

Distinguishing Epigenetic Marks

Methylation of the cytosine base in eukaryotic DNA (5mC) is an important epigenetic mark involved in gene silencing and genome stability. Methylated cytosine can be enzymatically oxidized to 5-hydroxymethylcytosine (5hmC), which may function as a distinct epigenetic mark—possibly involved in pluripotency—and it may also be an intermediate in active DNA demethylation. To be able to detect 5hmC genome-wide and at single-base resolution,

Booth
et al.

(p.
934
, published online 26 April) developed a 5hmC sequencing chemistry that selectively oxidizes 5hmC to 5-formylcytosine and then to uracil while leaving 5mC unchanged. Using this method, mouse embryonic stem cell genomic DNA was sequenced to reveal that 5hmC is found enriched at intragenic CpG islands and long interspersed nuclear element–1 retrotransposons.
The Crystal Structure of Human Argonaute2
Authors: Schirle Nicole T. , MacRae Ian J.
Published: April 2012

Human Argonaute Revealed

RNA interference (RNAi) is mediated by Argonaute (Ago) proteins, which bind small regulatory RNAs that have sequence complementarity to target RNAs destined to be silenced. The structure of bacterial homologs of the Ago proteins, and fragments of eukaryotic Ago proteins, have provided initial insights into Ago function. Now,
Schirle and MacRae
(p.
1037
, published online 26 April; see the Perspective by

Kaya and Doudna

) have determined the structure of the full-length human Ago protein bound to a single-stranded (ss) guide RNA. Within the bilobed structure, eight nucleotides of the ssRNA are visibly positioned in the RNA-guide, strand-binding site. The “seed” region of the ssRNA has its Watson-and-Crick base edges exposed to solvent, likely aiding target recognition. The location of two free tryptophans in the Piwi domain suggests a possible recruitment site for Ago-interacting proteins.
mTOR Inhibitors Synergize on Regression, Reversal of Gene Expression, and Autophagy in Hepatocellular Carcinoma
Authors: Thomas Hala Elnakat , Mercer Carol A. , Carnevalli Larissa S. , Park Jongsun , Andersen Jesper B. , Conner Elizabeth A. , Tanaka Kazuhiro , Matsutani Tomoo , Iwanami Akio , Aronow Bruce J. , Manway Liu , Maira S. Michel , Thorgeirsson Snorri S. , Mischel Paul S. , Thomas George , Kozma Sara C.
Published: April 2012

Combination therapy causes gene reprogramming, autophagy, and tumor regression in a mouse model approximating human HCC.
Immune Response to Haemophilus influenzae Type b Vaccination in Patients with Chronic Renal Failure
Authors: Hawdon Nicole , Nix Eli B. , Tsang Raymond S. W. , Ferroni Garry , McCready William G. , Ulanova Marina
Published: April 2012

Adult chronic renal failure patients undergoing hemodialysis are at an increased risk of invasiveHaemophilus influenzaetype b (Hib) disease due to the lack of functionally active anti-Hib antibodies. The pediatric Hib polysaccharide-protein conjugate vaccine is highly immunogenic in these patients and can provide protection against invasive Hib infection for at least 1 year.
Biochemical, Serological, and Virulence Characterization of Clinical and Oyster Vibrio parahaemolyticus Isolates
Authors: Jones Jessica L. , Lüdeke Catharina H. M. , Bowers John C. , Garrett Nancy , Fischer Markus , Parsons Michele B. , Bopp Cheryl A. , DePaola Angelo
Published: April 2012

In this study, 77 clinical and 67 oyster
Vibrio parahaemolyticus
isolates from North America were examined for biochemical profiles, serotype, and the presence of potential virulence factors (
tdh
,
trh
, and type III secretion system [T3SS] genes). All isolates were positive for oxidase, indole, and glucose fermentation, consistent with previous reports. The isolates represented 35 different serotypes, 9 of which were shared by clinical and oyster isolates. Serotypes associated with pandemic strains (O1:KUT, O1:K25, O3:K6, and O4:K68) were observed for clinical isolates, and 7 (9%) oyster isolates belonged to serotype O1:KUT. Of the clinical isolates, 27% were negative for
tdh
and
trh
, while 45% contained both genes. Oyster isolates were preferentially selected for the presence of
tdh
and/or
trh
; 34% contained both genes, 42% had
trh
but not
tdh
, and 3% had
tdh
but not
trh
. All but 1 isolate (143/144) had at least three of the four T3SS1 genes examined. The isolates lacking both
tdh
and
trh
contained no T3SS2α or T3SS2β genes. All clinical isolates positive for
tdh
and negative for
trh
possessed all T3SS2α genes, and all isolates negative for
tdh
and positive for
trh
possessed all T3SS2β genes. The two oyster isolates containing
tdh
but not
trh
possessed all but the
vopB2
gene of T3SS2α, as reported previously. In contrast to the findings of previous studies, all strains examined that were positive for both
tdh
and
trh
also carried T3SS2β genes. This report identifies the serotype as the most distinguishing feature between clinical and oyster isolates. Our findings raise concerns about the reliability of the
tdh
,
trh
, and T3SS genes as virulence markers and highlight the need for more-detailed pathogenicity investigations of
V. parahaemolyticus
.
Comparison of Medium, Temperature, and Length of Incubation for Detection of Vancomycin-Resistant Enterococcus
Authors: Nguyen Trang D. Hua , Evans Kaye D. , Goh Rosalinda A. , Tan Grace L. , Peterson Ellena M.
Published: April 2012

Campylobacter
(Campy; BD Diagnostics, Sparks, MD), Spectra VRE (Remel, Lenexa, KS), and bile-esculin-azide-vancomycin (BEAV; Remel) agars were compared for their ability to detect vancomycin-resistant enterococci (VRE) in 750 stool specimens. The media were compared at 24 h and 48 h of incubation at 35°C and 42°C. When incubated for 24 h at 35°C, Campy was the most sensitive (97.8%) and specific (99.9%) but was comparable to Spectra, which has a sensitivity of 95.6% and a specificity of 99.1%, whereas BEAV was significantly less sensitive (90%) and specific (96.1%). Incubation at 42°C or extended incubation at 35°C for 48 h yielded no advantage over incubation at 35°C for 24 h.
An Unusual Foreign Body in the Urinary Bladder Mimicking a Parasitic Worm
Authors: Schmitt Bryan H. , Feder Marc T. , Rokke Denise L. , Moyer Thomas P. , Pritt Bobbi S.
Published: April 2012

We report an unusual case of a foreign body removed from the urinary bladder of a 63-year-old male which mimicked a parasitic worm. The foreign body was identified as an artificial fishing worm by morphological comparison to a similar commercially produced product and by infrared spectrum analysis.
Recovery of Influenza B Virus with the H273Y Point Mutation in the Neuraminidase Active Site from a Human Patient
Authors: Higgins Rachel R. , Beniprashad Melissa , Chong-King Eddie , Li Yan , Bastien Nathalie , Low Donald E. , Gubbay Jonathan B.
Published: April 2012

The H275Y oseltamivir resistance mutation confers high-level resistance to oseltamivir in isolates of human A(H1N1) influenza. We report the recovery and identification of an influenza B virus with the H273Y neuraminidase point mutation directly from a human patient. The H273Y influenza B isolate is resistant to oseltamivir and peramivir but sensitive to zanamivir.
Rapid and Specific Detection of Lassa Virus by Reverse Transcription-PCR Coupled with Oligonucleotide Array Hybridization
Authors: Ölschläger Stephan , Günther Stephan
Published: April 2012

To facilitate sequence-specific detection of DNA amplified in a diagnostic reverse transcription (RT)-PCR for Lassa virus, we developed an array featuring 47 oligonucleotide probes for post-PCR hybridization of the amplicons. The array procedure may be performed with low-tech equipment and does not take longer than agarose gel detection.
Successful Identification of Clinical Dermatophyte and Neoscytalidium Species by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry
Authors: Alshawa Kinda , Beretti Jean-Luc , Lacroix Claire , Feuilhade Martine , Dauphin Brunhilde , Quesne Gilles , Hassouni Noura , Nassif Xavier , Bougnoux Marie-Elisabeth
Published: April 2012

Dermatophytes are keratinolytic fungi responsible for a wide variety of diseases of glabrous skin, nails, and hair. Their identification, currently based on morphological criteria, is hindered by intraspecies morphological variability and the atypical morphology of some clinical isolates. The aim of this study was to evaluate matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) as a routine tool for identifying dermatophyte and
Neoscytalidium
species, both of which cause dermatomycoses. We first developed a spectral database of 12 different species of common and unusual dermatophytes and two molds responsible for dermatomycoses (
Neoscytalidium dimidiatum
and
N. dimidiatum
var.
hyalinum
). We then prospectively tested the performance of the database on 381 clinical dermatophyte and
Neoscytalidium
isolates. Correct identification of the species was obtained for 331/360 dermatophytes (91.9%) and 18/21
Neoscytalidium
isolates (85.7%). The results of MALDI-TOF MS and standard identification disagreed for only 2 isolates. These results suggest that MALDI-TOF MS could be a useful tool for routine and fast identification of dermatophytes and
Neoscytalidium
spp. in clinical mycology laboratories.
Genetic connectivity of the reef fishLutjanus kasmiraat the scale of the western Indian Ocean
Authors: Muths D. , Gouws G. , Mwale M. , Tessier E. , Bourjea J.
Published: April 2012

Examining the genetic structure of species allows an estimate of the level of evolutionary connectivity between localities; this information is important for marine biodiversity protection, in particular, for the delineation of marine protected areas. In this context, a total of 601 Lutjanus kasmira (Forsskål, 1775) were sampled in 16 localities of the western Indian Ocean and analyzed with both mitochondrial cytochrome b sequencing and eight microsatellite loci genotyping. Both genetic markers indicate that differentiation was not significant even between samples separated by more than 4000 km. This absence of genetic differentiation among samples was favored by ecological plasticity of the species and is now ensured by resultant high levels of dispersal. Nevertheless, some significant genetic structure was detected for the areas of Mauritius and Moroni, as well as within populations in all localities, which will have to be explained by additional studies on local processes.
Identifying river of origin for age-0 Scaphirhynchus sturgeons in the Missouri and Mississippi rivers using fin ray microchemistry
Authors: Phelps Quinton E. , Whitledge Gregory W. , Tripp Sara J. , Smith Kurt T. , Garvey James E. , Herzog David P. , Ostendorf David E. , Ridings Joseph W. , Crites Jason W. , Hrabik Robert A. , Doyle Wyatt J. , Hill Tracy D.
Published: April 2012

Understanding linkages between natal and nursery habitats is critical for conservation of riverine fishes. Scaphirhynchus sturgeons inhabiting the middle Mississippi River may originate from the Missouri or Mississippi rivers, although relative importance of these recruitment sources is unknown. We characterized the relationship between water and sturgeon fin ray Sr:Ca, verified shifts in water Sr:Ca are recorded in age-0 sturgeon fin rays, and determined whether age-0 sturgeons from the Mississippi and Missouri rivers exhibited distinct fin ray Sr:Ca signatures. Fin ray Sr:Ca of laboratory-reared fish reflected transfer from water with elevated Sr:Ca to ambient water 1 day posthatch, indicating that short-term residency in environments can be detected. Nine of 30 age-0 fish captured in the middle Mississippi River were Missouri River emigrants. Four of these emigrants originated in the upper portion of the lower Missouri River (≥589 km upstream from its mouth), where water Sr:Ca is higher compared with the lowermost section of the Missouri River and the Mississippi River. Twenty-five of 30 fish collected from the lowermost section of the Missouri River originated within this river segment; the remainder originated upriver. Fin ray Sr:Ca enables identification of natal river segment for age-0 sturgeons and contributions of river segments to sturgeon recruitment.
Hierarchical predation: wolf (Canis lupus) selection along hunt paths and at kill sites
Authors: McPhee Heather M. , Webb Nathan F. , Merrill Evelyn H.
Published: April 2012

Predation is a hierarchical process whereby a predator is constrained to killing prey within the area they select while hunting. We demonstrate the hierarchical nature of predation using movement data from six GPS-collared wolves ( Canis lupus L., 1758) in the Rocky Mountains of Alberta, Canada, by coupling the kill locations of their ungulate prey with their preceding hunt path. Selection of where to hunt constrained the characteristics influencing where wolves killed within hunt paths. Specifically, wolves selected to hunt where prey densities were higher than the mean density for their territories, but prey densities were not related to kill site locations within the selected hunt path. Wolves selected to hunt in open valleys and near habitat edges, where prey may be most predictable, detectable, or vulnerable, which may have been reinforced by a higher likelihood of killing within these characteristics along hunt paths. In contrast, wolves selected to hunt relatively farther from frozen water bodies and closer to well sites than kill site locations, indicating different processes were occurring during the hunting and killing phases. Treating predation as a hierarchical sequence will ensure the role of prey and landscape characteristics on the processes of predation are not over- or under-emphasized by decoupling kill sites from hunt paths, which will lead to a better mechanistic understanding of predation in heterogeneous environments.
Habitat selection and fidelity by White-throated Sparrows (Zonotrichia albicollis): generalist species, specialist individuals?
Authors: Rousseau Patrick , Desrochers André , Hadley Adam S.
Published: April 2012

Individuals from habitat generalist species are often thought to be habitat generalist themselves, but this assumption should be examined in light of mounting evidence for native and phenotypic habitat preference. We experimentally tested whether the White-throated Sparrow ( Zonotrichia albicollis (Gmelin, 1789)) exhibits habitat preferences at the individual level. The White-throated Sparrow was a habitat generalist species in our study area, with high occupancy of clearcuts as well as mature forests. However, males in mature forests whose territories were clear-cut in the winter following their breeding season (n = 14), dispersed twice as far as males from uncut mature forests (n = 21). New territories selected by males after clearcuts contained significantly more mature forest than what remained in the territory that they abandoned, but not as much mature forest as was found in their former territory. Gain in uncut habitat after dispersal was positively correlated with dispersal distance. Clear-cut locations left vacant by dispersing males were colonized by new conspecifics. Our results suggest that individual sparrows use only a subset of their species’ wide range of habitats. We question the assumption that individuals from a generalist species are versatile and unlikely to be affected by habitat disturbance.
Variation in basal metabolic rate and activity in relation to reproductive condition and photoperiod in white-footed mice (Peromyscus leucopus)
Authors: Kaseloo P.A. , Crowell M.G. , Jones J.J. , Heideman P.D.
Published: April 2012

A naturally variable life-history trait with underlying physiological variation is the photoperiodic response of many temperate-zone rodents, including white-footed mice (Peromyscus leucopus (Rafinesque, 1818)). Male P. leucopus were obtained from a short photoperiod responsive (R) line, artificially selected for reproductive suppression in short-day conditions (SD) and a nonresponsive (NR) line selected for reproductive maturity in SD. We tested for variation in metabolic rate between lines in SD and long-day conditions (LD). NR mice consumed 34% more food than R mice, without concomitant increase in body mass in SD. Basal metabolic rate (BMR) was found to be significantly greater in NR than R mice, and NR mice were found to engage in significantly more spontaneous (daily) locomotor activity. Energy-use estimates based on 24 h respirometry matched closely the level of intake reported for individual mice. The increased BMR and average daily metabolic rate in NR mice was correlated with testis size, but not with major central organs or digestibility. No significant difference in BMR or activity was found in mice from the same lines held in LD. Elevated intake in SD mice appears to be associated with differences in fertility and not other aspects of physiology in the respective lines.
WEAK ANNIHILATION TOPOLOGIES AND FINAL STATE INTERACTIONS IN $B^+ \rightarrow D^+_s\phi$ DECAY
Authors: MOHAMMADI BEHNAM , MEHRABAN HOSSEIN
Published: April 2012

In this research, the hadronic decay of [Formula: see text] is analyzed by using "QCD factorization" (QCDF) method and final state interaction (FSI). First, the [Formula: see text] decay is calculated via QCDF method and only the annihilation graphs exist in that method. Then, FSI is considered to solve the [Formula: see text] decay as a sizable correction and the D+*K0, D0*K+ and [Formula: see text] via the exchange of [Formula: see text], K-(*) and [Formula: see text] mesons are chosen for the intermediate states. To estimate the intermediate states amplitudes, QCDF method is again used. These amplitudes are used in the absorptive part of the diagrams. The experimental branching ratio of [Formula: see text] decay is less than 1.9×10-6 and our results according to QCDF method and FSI effects are 0.16×10-6 and 1.86×10-6, respectively.
SYMMETRIES AND ADJUNCTION INEQUALITIES FOR KNOT FLOER HOMOLOGY
Authors: SAHAMIE BIJAN
Published: April 2012

We derive symmetries and adjunction inequalities of the knot Floer homology groups which appear to be especially interesting for homologically essential knots. Furthermore, we obtain an adjunction inequality for cobordism maps in knot Floer homologies. We demonstrate the adjunction inequalities and symmetries in explicit calculations which recover some of the main results from [E. Eftekhary, Longitude Floer homology and the Whitehead double, Algebr. Geom. Topol. 5 (2005) 1389–1418] on longitude Floer homology and also give rise to vanishing results on knot Floer homologies.
MULTIWAVE MEDICAL DEVICE ON THE DIODE PUMPED SOLID STATE LASER FOR THE MICROBE NATURE DISEASE TREATMENT
Authors: KUZMIN G. P. , KUZMINA A. G. , LOVACHEVA O. V. , SIROTKIN A. A.
Published: April 2012

Multiwave laser medical device "Livadia" has been developed for bactericidal and therapeutic impact on the affected organism parts. This device is on the diode pumped solid-state laser and main wavelength radiation conversion 1064 nm into the second harmonic 532 nm and fourth harmonic 266 nm. It has been shown that UV radiation on the wavelength 266 nm on bronchia mucosa with various inflammation types improves regenerative processes in bronchia tissues which decreases treatment deadline.
AQUEOUS-BASED FORMATION OF GOLD NANOPARTICLES ON SURFACE-MODIFIED COTTON TEXTILES
Authors: LIU HONGJUN , GOH WEI-PENG , NORSTEN TYLER B.
Published: April 2012

A facile and environmental friendly route has been developed to synthesize gold nanoparticles (AuNPs) by using amine stabilizers and N-vinyl pyrrolidone (NVP) as the reductant in an aqueous medium. This synthetic concept can be applied to the formation of Au NPs on normal cotton fibers via in situ surface modification of the cotton fibers by (3-aminopropyl)triethoxysilane (ATS) followed by nanoparticle formation. This scheme produces red Au NP-dyed cotton textiles. Surface treatment of the cotton textiles by ATS was found to be crucial for the formation of nano- Au . X-ray photoelectron spectroscopy (XPS), diffused reflectance UV-visible spectroscopy (UV-vis) and energy dispersive X-ray (EDX) were used to investigate the fiber surfaces. The distribution of Au NPs as well as surface treatment agent on the fiber surface was located by time of flight secondary ion mass spectroscopy (TOF-SIMS).
CONTROL OF WETTING BEHAVIOR USING POST-POLYMERIZATION MODIFICATIONS OF SURFACE CHEMICAL FUNCTIONALITY
Authors: GRIFFITHS JON-PAUL , LEONARD DAVID M. L. , MOLONEY MARK G. , STRATTON NICHOLAS J.
Published: April 2012

Modification of surface chemical functionality of a variety of materials using the reactions of readily accessible diarylcarbenes permits the control of wetting behavior. When coupled with an additional chemical derivatization step, a wider range of surface polarity becomes available.
(Invited) Photoluminescence Excitation Spectroscopy of Si Nanocrystals in SiO2
Authors: De Boer Wieteke D. , Timmerman D , Roldán Gutiérrez Manuel A. , Molina Sergio I. , Gregokiewicz T.
Published: April 2012

We present results on time-resolved spectroscopy and quantum yield of photolu-minescence from Si nanocrystals (NCs) embedded in a SiO2-matrix. The materials are prepared by co-sputtering. Transmission electron microscopy reveals formation of Si NC with diameters in the 3-5 nm range. We identify 3 different emission bands, corresponding to radiative recombination of excitons, hot carriers and electron-hole pairs trapped at oxygen-related defects, and give their spectral and temporal characteristics. We evaluate external quantum yield (EQY) of these recombination channels and conclude that the overall emission is determined by the excitonic channel, with the other contribution not exceeding 1‰. Subsequently, we investigate EQY of the excitonic emission as a function of excitation photon energy and find a significant increase for shorter wavelengths. This is explained in terms in exciton multiplication taking place for sufficiently large energies of the incoming photons.
(Invited) Growing Si Nanocrystals within a-Si Nanoclusters Embedded in a-SiO2: Evolution of Photoluminescence
Authors: Borrero-González L.J. , Nunes L.A.O. , Guimarães F.E.G. , Wojcik J. , Mascher P. , Gennaro A.M. , Tirado M. , Comedi D.
Published: April 2012

We combine X-ray absorption, electron spin resonance and Raman spectroscopies, X-ray diffraction and photoluminescence (PL) techniques to determine the structure and luminescence mechanisms in Si nanoclusters (Si-ncls) embedded within Si oxides at various intermediate formation stages. The Si-ncls/oxide systems are fabricated by thermally annealing plasma-enhanced chemical vapor deposited Si-rich Si-oxide films. The structural and chemical orders in the amorphous oxide matrix, the Si-ncls amorphous and crystalline volume fractions and sizes, the dangling bond density and PL spectra and decay rates are followed closely as a function of the annealing temperature. The results can be interpreted by a crystalline core/amorphous shell model for the Si-ncls. The important role of the shell, often ignored in the literature, is discussed. As the Si-ncls crystalline cores grow at the expense of thinning amorphous shells, the PL undergoes a transition from a regime dominated by disorder-induced effects to a situation where quantum confinement prevails.
(Invited) Ultrafast Carrier Dynamics in Silicon Nanocrystal Films
Authors: Titova Lyubov V. , Cocker Tyler L. , Wang Xiongyao , Meldrum Al , Hegmann Frank A.
Published: April 2012

We have applied time-resolved THz spectroscopy to probe the transient photoexcited carrier dynamics and THz conductivity in Si nanocrystal films with varying silicon volume filling fractions and nanocrystal sizes on picosecond time scales. The THz conductivity reveals microscopic carrier motion with significant interface scattering within nanocrystals as well as percolative transport between nanocrystals. The time variation of the THz conductivity is analyzed within the framework of the Drude-Smith model, an extension of the Drude model that characterizes carrier localization in nanostructured materials. Below the percolation threshold, transport between nanocrystals is inhibited and photoexcited carriers are localized within individual nanocrystals. These films also exhibit efficient optical emission. In films with Si filling fractions above the percolation threshold, photoluminescence is suppressed and a transition from long-range inter-nanocrystal transport immediately after photoexcitation to increased carrier localization over a 50 ps time scale due to accumulation of charges at interface defect sites is observed.
XANES and XEOL Investigation of Cerium and Terbium Co-Doped Silicon Oxide Films
Authors: Wilson Patrick R. , Khatami Zahra , Dabkowski Ryszard , Dunn Kayne , Chelomentsev Evgueni , Wojcik J. , Mascher P.
Published: April 2012

The luminescent and structural properties of cerium and terbium co-doped silicon oxide thin films were investigated through transmission electron microscopy, photoluminescence spectroscopy, and synchrotron-based X-ray absorption spectroscopy. While combined blue and green luminescence characteristic of Ce3+ and Tb3+ ions, respectively, was observed from different compositions of films, the emission intensity from samples in which Ce2Si2O7 nanocrystallites were formed after high temperature annealing was much stronger than in films where the Ce and Tb co-dopants were incorporated in an amorphous SiO2 host matrix. Films containing the cerium silicate phase also exhibited a very strong enhancement of Tb emission. X-ray absorption near edge structure and X-ray excited optical luminescence analysis at the Si L3,2-, Si K-, O K-, Ce N4-, and Ce M5,4-edges indicated this enhancement was likely the result of a direct energy transfer process between the cerium silicate and Tb levels.
Surface Energy Modification as a Means of Promoting Nanoparitcle-Substrate Electronic Couping
Authors: Giles Alexander J. , Stokes E. B.
Published: April 2012

The focus of this paper is to describe studies on the wet chemical treatment of indium tin oxide (ITO) films to promote improved nanoparticle adhesion. Water contact angle measurements, Langmuir Blodgett (LB) film depositions, scanning electron microscopy (SEM) and photoluminescence spectra were used to characterize the treated substrates and the resulting films deposited on them. The authors found a highly diluted aqua regia treatment produced the lowest energy ITO surfaces which in turn saw the highest quality nanocrystal films deposited on them.
Optical Down-Conversion in Tb3+-Doped Zn-Chalcogenide Quantum Dots
Authors: Das Sandip , Mandal Krishna C.
Published: April 2012

Large quantities of ZnSe host nanocrystals have been synthesized by a low-cost synthetic chemical route and doped with rare earth (RE) terbium (Tb3+) ions. The resulting RE3+-doped nanocrystals show a complete broadband absorption below their band edge (400-440 nm) to the deep UV region and Tb3+ emission lines in the visible region under room temperature photoluminescence (PL) measurements were observed. Tb3+ energy transition peaks were visible under optical excitation below the band edge of the host ZnSe nanocryatals indicating energy transfer from host ZnSe nanocrystals to the rare earth Tb3+. Our results show for the first time that this novel earth-abundant, environment friendly, cadmium free RE3+-doped nanocrystals can be used as wavelength shifter and as an optical down-converter for enhanced solar spectral matching in solar cells and for various nanoscale optoelectronic device applications.
Optical and Luminescence Properties of Electrosynthesized ZnSe Thin Films
Authors: Mahalingam Thaiyan , Dhanasekaran Vickraman , Ravi Ganesan
Published: April 2012

Optical constants of ZnSe thin films for various deposition potentials were determined in the spectral range 400 nm to 1200 nm using the optical absorption and transmittance measurements. The Tauc's plot were drawn to determine the energy band gap values of the deposited films and are estimated to be in the range between 2.52 eV and 2.61 eV respectively. Their optical constants like refractive index (n), dielectric constants (ε), optical conductivity (σ), average excitation energy (E0), oscillator strength (Ed), effective mass (m*), plasma frequency (ωp), static dielectric constant (ε∞) and carrier concentration (N) were estimated and reported. The room temperature photo luminescence studies were also performed. The near band edge luminescence emission has been observed and reported.