bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of electron temperature of imploded capsules at the National Ignition Facility
Authors: Izumi N. , Ma T. , Barrios M. , Benedetti L. R. , Callahan D. , Cerjan C. , Edwards J. , Glenn S. , Glenzer S. , Kilkenny J. , Kline J. , Kyrala G. , Landen O. L. , Regan S. , Springer P. , Suter L. , Tommasini R. , Town R. , Mackinnon A. J. , Bell P. , Bradley D. K.
Published: August 2012

The electron and ion temperatures of the imploded core plasma are two of the most important metrics of inertial confinement fusion experiments. We have developed a technique for inferring electron temperatures from the contrast of x-ray images observed through a group of x-ray filters. Generally, the plasma electron temperature exhibits spatial and temporal variations, so time-averaged and time-resolved measurements are expected to yield somewhat different results. By analyzing the intensity of images observed with both a time-integrated detector (imaging plates) and a time-resolved detector (gated micro-channel plate), we found the electron temperature observed from x-ray images to be systematically higher than the ion temperature inferred from fusion neutron spectroscopy.
Existence of attractors for modified Zakharov equations for plasmas with a quantum correction
Authors: Jin Lingyu , Fang Shaomei , Guo Boling
Published: August 2012

In this paper, we consider the asymptotic behavior of the solutions for the quantum Zakharov system in one dimension, with the inclusion of phenomenological damping terms in both equations for the envelope electric field and for the density fluctuation. The existence of solutions and attractors are obtained, respectively, in different Sobolev spaces via a prior estimates and the Galerkin method.
Understanding Si(111) solid phase epitaxial regrowth using Monte Carlo modeling: Bi-modal growth, defect formation, and interface topology
Authors: Martin-Bragado Ignacio , Sklenard Benoit
Published: August 2012

This work studies the intriguing experimental observations that Si(111) solid phase epitaxial regrowth velocity is not constant as recrystallization progresses, but has a sudden change after recrystallization of ≈100 nm and progresses faster afterward.[L. Csepregi, J. W. Mayer, and T. W. Sigmon, Appl. Phys. Lett. 29(2), 92 (1976)] These two modes have important implications in the quality of the recrystallized silicon. The first recrystallization produces a flat advancing front leaving a heavy dense network of small and parallel to the surface twins behind, while the second mode creates a more rough advancing front that leaves bigger, although less dense inclined twins. By using a comprehensive and efficient lattice kinetic Monte Carlo model that explicitly accounts for the formation of different crystalline twin orientations, we simulate and expose the physical explanation of such observations. We explain the origin for the formation and subsequent evolution of different type of twins (parallel to the interface and inclined) and its implication in the overall evolution of Si(111) recrystallization.
Study on lattice dynamics of filled skutterudites InxYbyCo4Sb12
Authors: Peng Jiangying , Xu Wei , Yan Yonggao , Yang Junyou , Fu Liangwei , Kang Hyejung , He Jian
Published: August 2012

As a promising class of thermoelectric materials, skutterudites are featured by the naturally formed oversize cages in its crystal lattice. Cage-filling by guest atoms has thus become an important approach to reducing the lattice thermal conductivity and optimizing the thermoelectric performance. To probe the impact of filler atoms on lattice dynamics, we herein reported specific heat measurements in two single-filled skutterudite samples In0.2Co4Sb12 and Yb0.2Co4Sb12, and a double-filled skutterudite sample In0.2Yb0.2Co4Sb12. The low temperature specific heat data was analyzed in the context of combined electronic specific heat (the Sommerfeld term), the Debye mode (long wavelength acoustic phonon modes), and the Einstein modes (localized vibration modes). We found that the specific heat difference between the single and double-filled samples can be well accounted by one extra Einstein mode, as expected from the extra filler atom and confirmed by the results of inelastic neutron scattering measurements. Interestingly, two Einstein modes, in addition to the Sommerfeld term and the Debye term, are needed to satisfactorily account for the specific heat of the single-filled sample. The Einstein mode with lower frequency has the frequency close to the low-lying mode reported in La, Ce, Tl single-filled skutterudites, this mode is largely unaffected when the second type of filler atoms is introduced. The frequency of this mode has been verified by inelastic neutron scattering measurement. The other Einstein mode with higher frequency may be originated from the motion of Sb atoms.
Analysis of surface acoustic wave propagation in a two-dimensional phononic crystal
Authors: Li Yong , Hou Zhilin , Oudich Mourad , Badreddine Assouar M.
Published: August 2012

In this paper, we present a numerical technique to calculate the surface acoustic wave (SAW) in a two-dimensional phononic crystal (PC). By the technique, the SAW in the system, which is obtained by adding an additional composite surface layer on the xy-cut surface of a two-dimensional PC, is investigated. Result shows that the behavior of SAW in the studied system is mainly determined by the residual penetration depth of the SAW into the PC structure. Based on this understanding, we show that the SAW in the band gap of the PC can be controlled efficiently by changing the structure of the surface layer.
Wave packet simulations of phonon boundary scattering at graphene edges
Authors: Wei Zhiyong , Chen Yunfei , Dames Chris
Published: August 2012

Wave packet dynamics is used to investigate the scattering of longitudinal (LA), transverse (TA), and bending-mode (ZA) phonons at the zigzag and armchair edges of suspended graphene. The interatomic forces are calculated using a linearized Tersoff potential. The strength of a boundary scattering event at impeding energy flow is described by a forward scattering coefficient, similar in spirit to a specularity parameter. For armchair boundaries, this scattering coefficient is found to depend strongly on the magnitude, direction, and polarization of the incident wavevector, while for zigzag boundaries, the forward scattering coefficient is found to always be unity regardless of wavevector and polarization. Wave packet splitting is observed for ZA phonons incident on armchair boundaries, while both splitting and mode conversion are observed for LA and TA phonons incident on both zigzag and armchair boundaries. These simulation results show that armchair boundaries impede the forward propagation of acoustic phonon energy much more strongly than zigzag boundaries do, suggesting that graphene nanoribbons will have substantially lower thermal conductivity in armchair rather than zigzag orientation.
Evolution of coefficient of friction with deposition temperature in diamond like carbon thin films
Authors: Kataria S. , Dhara Sandip , Barshilia Harish C. , Dash S. , Tyagi A. K.
Published: August 2012

Diamond like carbon (DLC) thin films, used as excellent solid lubricant, are grown on Si substrates at temperatures in the range of 100–600 °C using pulsed direct current magnetron sputtering to understand the role of substrate temperature on the tribological properties. Friction tests have been carried out using a micro-tribometer at a load of 2 N. Phase evolution in the films with temperature is studied using micro-Raman spectroscopy. Lateral force microscopy is employed to study the evolution of surface and friction topography in the films. We have observed an increase in the coefficient of friction (μ) from 0.05 to 0.30 with increase in deposition temperature. The films deposited below 400 °C exhibited excellent tribological properties with film deposited at 100 °C depicting the lowest value of μ (approx. 0.05). The films deposited above 400 °C have been found to wear out at early stages. The degradation in tribological properties of DLC films deposited at high temperatures is explained on the basis of structural transformation taking place during the film deposition.
Communication: Hydration structure and polarization of heavy alkali ions: A first principles molecular dynamics study of Rb+ and Cs+
Authors: Ikeda Takashi , Boero Mauro
Published: August 2012

Hydration structure and polarization of Rb+ and Cs+ in liquid water at ambient conditions were studied by first principles molecular dynamics. Our systematic analysis of the relevant electronic structures, based on maximally localized Wannier functions, revealed that the dipole moment of H2O molecules in the first solvation shell of the ions slightly increases with increasing the atomic number. We also found that the polarization of heavy alkali ions, particularly Cs+, tends to stabilize a peculiar asymmetric hydration structure with relevant consequences in the extraction of the harmful 137Cs resulting from nuclear wastes.
Modified nonlinear evolution of Langmuir waves
Authors: Shah Kushal
Published: August 2012

Zakharov equations describe the nonlinear coupling between the electron and ion motion in a plasma mediated by the ponderomotive effect. It has been recently shown that the conventional ponderomotive theory has several limitations and under certain conditions, the plasma density depends on the square of the electric potential and not the electric field [K. Shah, Phys. Plasmas 17, 112301 (2010)]. In this paper, the modified Zakharov equations are derived using this modified ponderomotive density. This modified equation does not admit any spatially localized solution and leads to a spatial broadening of the periodic wave solutions of the Zakharov equations. It is also shown that in this modified description of the nonlinear evolution of Langmuir waves, the high frequency electron oscillations must have a frequency slightly higher than the electron plasma frequency.
Tolerance responses of Brassica juncea to salinity, alkalinity and alkaline salinity
Authors: Javid Muhammad , Ford Rebecca , Nicolas Marc E.
Published: August 2012

Soil salinity and alkalinity are common constraints to crop productivity in low rainfall regions of the world. These two stresses have been extensively studied but not the combined stress of alkaline salinity. To examine the effects of mild salinity (50 mM NaCl) combined with alkalinity (5 mM NaHCO3) on growth of Brassica juncea (L.) Czern., 30 genotypes were grown in hydroponics. Growth of all genotypes was substantially reduced by alkaline salinity after 4 weeks of stress. Based on large genotypic differences, NDR 8501 and Vaibhav were selected as tolerant and Xinyou 5 as highly sensitive for further detailed physiological study. Shoot and root biomass and leaf area of the selected genotypes showed greater reduction under alkaline salinity than salinity or alkalinity alone. Alkalinity alone imposed larger negative effect on growth than salinity. K+ and P concentrations in both shoot and root were significantly reduced by alkaline salinity but small difference existed among the selected genotypes. Leaf Fe concentration in Xinyou 5 decreased under alkaline salinity below a critical level of 50 mg kg–1, which explained why more chlorosis and a larger growth reduction occurred than in NDR 8501 and Vaibhav. Relatively large shoot and root Na+ concentration also had additional adverse effect on growth under alkaline salinity. Low tissue K+, P and Fe concentrations by alkalinity were the major factors that reduced growth in the selected genotypes. Growth reduction by salinity was mainly caused by Na+ toxicity. Shoot Na+ concentration of NDR 8501 and Vaibhav was almost half those in Xinyou 5, suggesting NDR 8501 and Vaibhav excluded more Na+. However, Na+ exclusion was reduced by more than 50% under alkaline salinity than salinity in the selected genotypes. In conclusion, our results demonstrated that alkaline salinity reduced uptake of essential nutrients and Na+ exclusion that resulted in more negative consequences on growth than salinity alone.
The social and emotional skills of bullies, victims, and bully–victims of Egyptian primary school children
Authors: Habashy Hussein Mohamed
Published: August 2012

This study examined whether bullies, victims, bully–victims (who are both bullies and victims), and students who reported no or low levels of bullying and victimization differed in their levels of social and emotional skills. Data were collected from 623 children in fifth and sixth grades from four Egyptian elementary schools; their ages ranged from 10 to 12 years. K‐means cluster analysis revealed four groups: bullies (n = 138), victims (n = 178), bully–victims (n = 59), and children who were not involved in bullying behaviour (n = 248). Data were analyzed using multinomial logistic regression. The findings indicated that boys were more involved in bullying behaviour than girls, and both bullies and bully–victims were less likely to adhere to social rules and politeness than children who were not involved in bullying. Both bullies and victims were less aware of the physiological reactions of their emotions than uninvolved children, and were less able to apply social rules in social interaction. Both victims and bully–victims reported less likeability than children not involved in bullying. Verbal sharing, attending to others’ emotions, and analysis of emotions did not have a statistically significant relationship with the probabilities of classifying children to any bullying group versus children not involved in bullying. Social skills were more important than emotional awareness in predicting the likelihood of classifying children in one of the three bullying groups versus children who not involved in bullying. The main conclusion is that social and emotional skills together may provide an effective means of intervention for bullying problems.
Using Boat Electrofishing to Estimate the Abundance of Invasive Common Carp in Small Midwestern Lakes
Authors: Bajer Przemyslaw G. , Sorensen Peter W.
Published: August 2012

The common carp Cyprinus carpio is among the most invasive fish worldwide, but practical methods for estimating its abundance have not yet been developed. Particularly needed are methods that can accurately assess low densities of common carp to enact proactive management strategies before populations reach damaging levels. In this study we tested whether the density of adult common carp in small Minnesota lakes could be accurately predicted from their catch rates using boat electrofishing. We used mark and recapture to estimate the abundance of common carp in eight Midwestern lakes with a wide range of common carp densities (13–400 carp/ha), while also surveying each lake using boat electrofishing. In addition, we reduced common carp abundance by up to 90% in two lakes to test whether this was accompanied by a similar drop in electrofishing catch rates. A regression analysis showed that electrofishing catch rates increased linearly with increasing densities of common carp. A cross-validation procedure showed that boat electrofishing can accurately estimate common carp densities; however, we observed a tendency to overestimate low densities and underestimate high densities. Our results suggest that electrofishing surveys can be routinely employed to estimate common carp densities in small lakes.

Received December 13, 2011; accepted April 26, 2012
Experimental observation of ion heating by mode-converted ion Bernstein waves in tokamak plasmas
Authors: Zhang X.J. , Zhao Y.P. , Wan B.N. , Gong X.Z. , Lin Y. , Zhang W.Y. , Mao Y.Z. , Qin C.M. , Yuan S. , Deng X. , Wang L. , Ju S.Q. , Chen Y. , Li Y.D. , Li J.G. , Noterdaeme J.M. , Wukitch S.J.
Published: August 2012

We report the experimental observation of ion heating by the mode-converted ion Bernstein waves (MC IBWs) in tokamak plasmas. The MC IBW is created from the fast waves launched from the high-field-side antenna in the HT-7 tokamak in plasmas consisting of deuterium majority, hydrogen minority and 7Li ions. Experimental evidence and numerical simulation show that the interaction between the MC IBW and 7Li ions at the first ion-cyclotron harmonic resonance of 7Li (i.e. ω = 2ΩLi-7) is the main mechanism for radio-frequency power deposition. By comparing with previous experiments of direct-launch IBW flow drive on tokamaks and existing theories, we hypothesize that this MC IBW and 7Li interaction also leads to the observed flow drive effect.
An integrated model for materials in a fusion power plant: transmutation, gas production, and helium embrittlement under neutron irradiation
Authors: Gilbert M.R. , Dudarev S.L. , Zheng S. , Packer L.W. , Sublet J.-Ch.
Published: August 2012

The high-energy, high-intensity neutron fluxes produced by the fusion plasma will have a significant life-limiting impact on reactor components in both experimental and commercial fusion devices. As well as producing defects, the neutrons bombarding the materials initiate nuclear reactions, leading to transmutation of the elemental atoms. Products of many of these reactions are gases, particularly helium, which can cause swelling and embrittlement of materials.

This paper integrates several different computational techniques to produce a comprehensive picture of the response of materials to neutron irradiation, enabling the assessment of structural integrity of components in a fusion power plant. Neutron-transport calculations for a model of the next-step fusion device DEMO reveal the variation in exposure conditions in different components of the vessel, while inventory calculations quantify the associated implications for transmutation and gas production. The helium production rates are then used, in conjunction with a simple model for He-induced grain-boundary embrittlement based on electronic-structure density functional theory calculations, to estimate the timescales for susceptibility to grain-boundary failure in different fusion-relevant materials. There is wide variation in the predicted grain-boundary-failure lifetimes as a function of both microstructure and chemical composition, with some conservative predictions indicating much less than the required lifetime for components in a fusion power plant.
Fire creates host plant patches for monarch butterflies
Authors: Baum Kristen A. , Sharber Wyatt V.
Published: August 2012

Monarch butterflies (
Danaus plexippus
) depend on the presence of host plants (
Asclepias
spp.) within their breeding range for reproduction. In the southern Great Plains,
Asclepias viridis
is a perennial that flowers in May and June, and starts to senesce by August. It is locally abundant and readily used by monarchs as a host plant. We evaluated the effects of summer prescribed fire on
A. viridis
and the use of
A. viridis
by monarch butterflies. Summer prescribed fire generated a newly emergent population of
A. viridis
that was absent in other areas. Pre-migrant monarch butterflies laid eggs on
A. viridis
in summer burned plots in late August and September, allowing adequate time for a new generation of adult monarchs to emerge and migrate south to their overwintering grounds. Thus, summer prescribed fire may provide host plant patches and/or corridors for pre-migrant monarchs during a time when host plant availability may be limited in other areas.
Physical basis for the adaptive flexibility of
Bacillus
spore coats
Authors: Sahin Ozgur , Yong Ee Hou , Driks Adam , Mahadevan L.
Published: August 2012

Bacillus
spores are highly resistant dormant cells formed in response to starvation. The spore is surrounded by a structurally complex protein shell, the coat, which protects the genetic material. In spite of its dormancy, once nutrient is available (or an appropriate physical stimulus is provided) the spore is able to resume metabolic activity and return to vegetative growth, a process requiring the coat to be shed. Spores dynamically expand and contract in response to humidity, demanding that the coat be flexible. Despite the coat's critical biological functions, essentially nothing is known about the design principles that allow the coat to be tough but also flexible and, when metabolic activity resumes, to be efficiently shed. Here, we investigated the hypothesis that these apparently incompatible characteristics derive from an adaptive mechanical response of the coat. We generated a mechanical model predicting the emergence and dynamics of the folding patterns uniformly seen in
Bacillus
spore coats. According to this model, spores carefully harness mechanical instabilities to fold into a wrinkled pattern during sporulation. Owing to the inherent nonlinearity in their formation, these wrinkles persist during dormancy and allow the spore to accommodate changes in volume without compromising structural and biochemical integrity. This characteristic of the spore and its coat may inspire design of adaptive materials.
Thermal acclimation of interactions: differential responses to temperature change alter predator–prey relationship
Authors: Grigaltchik Veronica S. , Ward Ashley J. W. , Seebacher Frank
Published: August 2012

Different species respond differently to environmental change so that species interactions cannot be predicted from single-species performance curves. We tested the hypothesis that interspecific difference in the capacity for thermal acclimation modulates predator–prey interactions. Acclimation of locomotor performance in a predator (Australian bass,Macquaria novemaculeata) was qualitatively different to that of its prey (eastern mosquitofish,Gambusia holbrooki). Warm (25°C) acclimated bass made more attacks than cold (15°C) acclimated fish regardless of acute test temperatures (10–30°C), and greater frequency of attacks was associated with increased prey capture success. However, the number of attacks declined at the highest test temperature (30°C). Interestingly, escape speeds of mosquitofish during predation trials were greater than burst speeds measured in a swimming arena, whereas attack speeds of bass were lower than burst speeds. As a result, escape speeds of mosquitofish were greater at warm temperatures (25°C and 30°C) than attack speeds of bass. The decline in the number of attacks and the increase in escape speed of prey means that predation pressure decreases at high temperatures. We show that differential thermal responses affect species interactions even at temperatures that are within thermal tolerance ranges. This thermal sensitivity of predator–prey interactions can be a mechanism by which global warming affects ecological communities.
Mothers adjust offspring sex to match the quality of the rearing environment
Authors: Pryke Sarah R. , Rollins Lee A.
Published: August 2012

Theory predicts that mothers should adjust offspring sex ratios when the expected fitness gains or rearing costs differ between sons and daughters. Recent empirical work has linked biased offspring sex ratios to environmental quality via changes in relative maternal condition. It is unclear, however, whether females can manipulate offspring sex ratios in response to environmental quality alone (i.e. independent of maternal condition). We used a balanced within-female experimental design (i.e. females bred on both low- and high-quality diets) to show that female parrot finches (
Erythrura trichroa
) manipulate primary offspring sex ratios to the quality of the rearing environment, and not to their own body condition and health. Individual females produced an unbiased sex ratio on high-quality diets, but over-produced sons in poor dietary conditions, even though they maintained similar condition between diet treatments. Despite the lack of sexual size dimorphism, such sex ratio adjustment is in line with predictions from sex allocation theory because nutritionally stressed foster sons were healthier, grew faster and were more likely to survive than daughters. These findings suggest that mothers may adaptively adjust offspring sex ratios to optimally match their offspring to the expected quality of the rearing environment.
Family and Personal Adjustment of Economically Disadvantaged Chinese Adolescents in Hong Kong
Authors: Shek Daniel T. L. , Tsui Pik Fong
Published: August 2012

This study attempted to examine the relationship between poverty and adolescent developmental outcomes in the family and personal domains in 3,328 Chinese secondary school students in Hong Kong. Developmental outcomes included positive youth development constructs, problem behaviors, perceived family interaction, and parental parenting. Results showed that adolescents experiencing poverty did not differ from nonpoor adolescents in terms of risk behavior and in most indicators of positive youth development. On the other hand, adolescents with economic disadvantage displayed lower levels of positive identity, family interaction, and perceived paternal parenting than did those without economic disadvantage.
Collaboration between HPMC and NaCMC in order to Reach the Polymer Critical Point in Theophylline Hydrophilic Matrices
Authors: Contreras L. , Melgoza L. M. , Aguilar-de-Leyva A. , Caraballo I.
Published: August 2012

Percolation theory has been applied in order to study the existence of critical points as well as the possibility to find a “combined percolation threshold” for ternary hydrophilic matrices prepared with HPMC, NaCMC, and theophylline. For this purpose, different batches of ternary as well as binary hydrophilic matrices have been prepared. Critical points have been found for binary hydrophilic matrices between 21.5 and 31.3% (v/v) of HPMC and between 39 and 54% (v/v) of NaCMC, respectively. In a previous work carried out with the same polymers but a much more soluble drug (KCl), it was demonstrated the existence of a partial collaboration between the polymers in order to establish the gel layer. In this work, it has been observed for the first time the need of a minimum concentration of one of the matrix-forming polymer (between 10 and 20% v/v, approximately) for establishing an effective collaboration.
The Efficacy of Pramipexole, a Dopamine Receptor Agonist, as an Adjunctive Treatment in Treatment-Resistant Depression: An Open-Label Trial
Authors: Hori Hiroaki , Kunugi Hiroshi
Published: August 2012

Dopaminergic dysfunction is implicated in the pathophysiology of treatment-resistant depression. Although the efficacy of adjunctive pramipexole treatment has been demonstrated in treatment-resistant bipolar depression, such data are scarce for major depressive disorder (MDD). We recruited 17 patients with DSM-IV major depressive episode who have failed to respond to previous treatment with a selective serotonin reuptake inhibitor. Five patients were diagnosed as having bipolar II disorder and 12 as having unipolar MDD. Patients were monitored at an ambulatory care facility every two weeks until 12 weeks. Pramipexole was added to existing medication. Depression severity was assessed with the Hamilton Depression Rating Scale 21-item version (HDRS-21). The mean maximum dosage of pramipexole was 1.6 mg (SD 0.9). The HDRS-21 total score decreased from 19.4 (SD 3.8) at baseline to 7.2 (SD 5.4) at endpoint (P<0.000001). Twelve patients (71%) were responders based on the definition of 50% or more reduction in the HDRS-21 score. Ten patients (59%) remitted (HDRS-21 total score at endpoint<8). These results were almost unchanged when the sample was confined to patients with MDD. No serious adverse events were observed. Our findings indicate that pramipexole augmentation therapy may be effective and well tolerated in refractory depressed patients.
Different Modulating Effects of Adenosine on Neonatal and Adult Polymorphonuclear Leukocytes
Authors: Hou Pei-Chen , Yu Hong-Ren , Kuo Ho-Chang , Wang Lin , Lin Li-Yan , Sheen Jiunn-Ming , Hsu Te-Yao , Ou Chia-Yu , Jheng Yi-Jyun , Yang Kuender D. , Cheng Wen-Hsin
Published: August 2012

Polymorphonuclear leukocytes (PMNs) are the major leukocytes in the circulation and play an important role in host defense. Intact PMN functions include adhesion, migration, phagocytosis, and reactive oxygen species (ROS) release. It has been known for a long time that adenosine can function as a modulator of adult PMN functions. Neonatal plasma has a higher adenosine level than that of adults; however, little is known about the modulating effects of adenosine on neonatal PMNs. The aim of this study was to investigate the effects of adenosine on neonatal PMN functions. We found that neonatal PMNs had impaired adhesion, chemotaxis, and ROS production abilities, but not phagocytosis compared to adult PMNs. As with adult PMNs, adenosine could suppress the CD11b expressions of neonatal PMNs, but had no significant suppressive effect on phagocytosis. In contrast to adult PMNs, adenosine did not significantly suppress chemotaxis and ROS production of neonatal PMNs. This may be due to impaired phagocyte reactions and a poor neonatal PMN response to adenosine. Adenosine may not be a good strategy for the treatment of neonatal sepsis because of impaired phagocyte reactions and poor response.
Expanding the Use of a Fluorogenic Method to Determine Activity and Mode of Action ofBacillus thuringiensisBacteriocins Against Gram-Positive and Gram-Negative Bacteria
Authors: de la Fuente-Salcido Norma M. , Barboza-Corona J. Eleazar , Espino Monzón A. N. , Pacheco Cano R. D. , Balagurusamy N. , Bideshi Dennis K. , Salcedo-Hernández Rubén
Published: August 2012

Previously we described a rapid fluorogenic method to measure the activity of five bacteriocins produced by Mexican strains ofBacillus thuringiensisagainstB. cereus183. Here we standardize this method to efficiently determine the activity of bacteriocins against both Gram-positive and Gram-negative bacteria. It was determined that the crucial parameter required to obtain reproducible results was the number of cells used in the assay, that is,~4 × 108 cell/mL and~7 × 108 cell/mL, respectively, for target Gram-positive and Gram-negative bacteria. Comparative analyses of the fluorogenic and traditional well-diffusion assays showed correlation coefficients of 0.88 to 0.99 and 0.83 to 0.99, respectively, for Gram-positive and Gram-negative bacteria. The fluorogenic method demonstrated that the five bacteriocins ofB. thuringiensishave bacteriolytic and bacteriostatic activities against all microorganisms tested, including clinically significant bacteria such asListeria monocytogenes, Proteus vulgaris,andShigella flexnerireported previously to be resistant to the antimicrobials as determined using the well-diffusion protocol. These results demonstrate that the fluorogenic assay is a more sensitive, reliable, and rapid method when compared with the well-diffusion method and can easily be adapted in screening protocols for bacteriocin production by other microorganisms.
Study of Physico-Chemical Characteristics of Wastewater in an Urban Agglomeration in Romania
Authors: Popa Paula , Timofti Mihaela , Voiculescu Mirela , Dragan Silvia , Trif Catalin , Georgescu Lucian P.
Published: August 2012

This study investigates the level of wastewater pollution by analyzing its chemical characteristics at five wastewater collectors. Samples are collected before they discharge into the Danube during a monitoring campaign of two weeks. Organic and inorganic compounds, heavy metals, and biogenic compounds have been analyzed using potentiometric and spectrophotometric methods. Experimental results show that the quality of wastewater varies from site to site and it greatly depends on the origin of the wastewater. Correlation analysis was used in order to identify possible relationships between concentrations of various analyzed parameters, which could be used in selecting the appropriate method for wastewater treatment to be implemented at wastewater plants.
Temporal Dynamics of Reproduction of the Neotropical Fish,Crenicichla menezesi(Perciformes: Cichlidae)
Authors: Araújo Andréa Soares de , do Nascimento Wallace Silva , Yamamoto Maria Emília , Chellappa Sathyabama
Published: August 2012

The reproductive biology and the gonadal development cycle of the Neotropical cichlid fish,Crenicichla menezesi, is described. This species exhibits sexual dimorphism only during the spawning season. First sexual maturity of females is attained earlier than the males. Both macroscopic and histological investigations of ovaries and testes revealed four stages of gonadal maturation. Mean batch fecundity of females was 372 (±10,41) of mature oocytes. This species is a partial spawner, with an extended spawning period. Monthly values of GSI and the condition factor are negatively correlated during the gonadal development cycle of this species.
Effects of Repetitive Hyperbaric Oxygen Treatment in Patients with Acute Cerebral Infarction: A Pilot Study
Authors: Chen Cheng-Hsin , Chen Shao-Yuan , Wang Vinchi , Chen Chao-Ching , Wang Kaw-Chen , Chen Chih-Hao , Liu Yi-Chien , Lu Kuo-Cheng , Yip Ping-Keung , Ma Wen-Ya , Liu Chuan-Chieh
Published: August 2012

The role of hyperbaric oxygen therapy (HBOT) in the treatment of acute ischemic stroke is controversial. This prospective study assessed the efficacy and safety of HBOT as adjuvant treatment on 46 acute ischemic stroke in patients who did not receive thrombolytic therapy. The HBOT group (n=16) received conventional medical treatment with 10 sessions of adjunctive HBOT within 3–5 days after stroke onset, while the control group (n=30) received the same treatment but without HBOT. Early (around two weeks after onset) and late (one month after onset) outcomes (National Institutes of Health Stroke Scale, NIHSS scores) and efficacy (changes of NIHSS scores) of HBOT were evaluated. The baseline clinical characteristics were similar in both groups. Both early and late outcomes of the HBOT group showed significant difference (P≤0.001). In the control group, there was only significant difference in early outcome (P=0.004). For early efficacy, there was no difference when comparing changes of NIHSS scores between the two groups (P=0.140) but there was statistically significant difference when comparing changes of NIHSS scores at one month (P≤0.001). The HBOT used in this study may be effective for patients with acute ischemic stroke and is a safe and harmless adjunctive treatment.
Blunt-ended telomeres: an alternative ending to the replication and end protection stories
Authors: Nelson Andrew D.L. , Shippen Dorothy E.
Published: August 2012

Telomeres ensure the complete replication of genetic material while simultaneously distinguishing the chromosome terminus from a double-strand break. A prevailing theme in telomere biology is that the two chromosome ends are symmetrical. Both terminate in a single-strand 3′ extension, and the 3′ extension is crucial for telomere end protection. In this issue of Genes & Development, Kazda and colleagues (pp. 1703–1713) challenge this paradigm using a series of elegant biochemical and genetic assays to demonstrate that half of the chromosomes in flowering plants are blunt-ended. This discovery reveals unanticipated complexity in telomeric DNA processing and a novel mode of chromosome end protection.
Fluorescence-Activated Cell Sorting (FACS) of Fluorescently Tagged Cells from Zebrafish Larvae for RNA Isolation
Authors: Manoli Martha , Driever Wolfgang
Published: August 2012

This article describes a procedure for the dissociation of zebrafish (Danio rerio) embryos to produce a suspension of single cells that is suitable for fluorescence-activated cell sorting (FACS). The method has been applied to embryos at stages from 14 h post fertilization (hpf) to larvae at 5 d post fertilization (dpf), and it has also been successfully used for isolating fluorescently tagged neurons from whole dissociated embryos and early larvae. The cell collection procedures described in this protocol may also be adapted for older embryos and juvenile zebrafish. RNA can be extracted from the sorted cells and used for subsequent quantitative real-time PCR (qRT-PCR), microarrays, or next-generation sequencing (NGS) experiments.
Preparing, Handling, and Applying Caged Compound Solutions for Acousto-Optical Deflector-Based Patterned Uncaging with Ultraviolet Light
Authors: Civillico Eugene F. , Shoham Shy , O'Connor Daniel H. , Sarkisov Dmitry V. , Wang Samuel S.-H.
Published: August 2012

The method of patterned photoactivation is a natural fit for the study of neuronal dendritic integration. Photoactivatable molecules that influence a wide range of extracellular and intracellular neurophysiological functions are available. The choice of photosensitive molecules depends on the research question and will influence the design of the experimental apparatus. An acousto-optical deflector (AOD)-based system can be used for rapid ultraviolet (UV) photolysis in arbitrary spatial and temporal patterns. This protocol describes how to prepare caged neurotransmitter compound solutions for use in this system and discusses options for introducing caged compounds into an experimental preparation.
Risk factors of heavy episodic drinking among Korean adolescents
Authors: Chung S. S. , Joung K. H.
Published: August 2012

Accessible summary

Heavy episodic drinking among adolescents is a growing concern in Korea.

This paper presents risk factors for decision making about heavy episodic drinking among grades 7–12 students based on 2009 Korean national data.

We expect these results to be useful in detecting susceptible groups for high‐risk drinking.

The main objective of this study was to identify the risk factors and develop a decision tree model of heavy episodic drinking (HED) among adolescents. Data were obtained from a representative nationwide Korean population. Nine variables (such as last 30 days smoking, school grade, sex, depression, school achievement, level of stress, region, and economic status) were found as risk factors of HED. On the highest level of the tree root, major classification rule was played by dividing based on the last 30 days smoking and school grades. These findings should be helpful for school and mental healthcare providers to detect Korean adolescents with high possibility of HED, which will aid in planning of healthcare interventions for at‐risk adolescents.
Robot‐assisted or pure laparoscopic nerve‐sparing radical prostatectomy: What is the optimal procedure for the surgical margins? A single center experience
Authors: Koutlidis Nicolas , Mourey Eric , Champigneulle Jacqueline , Mangin Philippe , Cormier Luc
Published: August 2012

Objectives:  To compare positive surgical margin rates after robot‐assisted and pure laparoscopic radical prostatectomy when neurovascular bundles are preserved, and to identify parameters affecting surgical margin status.

Methods:  From March 2004 to January 2009, 279 consecutive prostatectomies with preservation of neurovascular bundles were carried out by the same surgeon: 175 robot‐assisted radical prostatectomies and 104 laparoscopic radical prostatectomies. An intraperitoneal Montsouris's technique was used for all cases. Patient's age, body mass index, prostate weight, prostate‐specific antigen level, clinical stage, preoperative and postoperative Gleason score, percentage of positive biopsies, pathological stage, and positive surgical margin status were prospectively recorded in an institutional database. The two groups were retrospectively analyzed and compared.

Results:  Positive surgical margin rates were 17% and 13% for the robot‐assisted radical prostatectomy and laparoscopic radical prostatectomy group (P = 0.4), respectively. At multivariable analysis, only prostate‐specific antigen level and prostate weight significantly affected the surgical margin status, where the type of procedure (robotic vs laparoscopic) did not have any effect.

Conclusion:  In our single‐surgeon experience, prostate‐specific antigen levels and prostate weight are predictive of positive surgical margin in patients undergoing nerve‐sparing radical prostatectomy, whereas there seems to be no difference between the robot‐assisted radical prostatectomy and the laparoscopic radical prostatectomy techniques.
Reactive histiocytosis of the orbit and posterior segment in a dog
Authors: Pumphrey Stephanie A. , Pizzirani Stefano , Pirie Christopher G. , Sato Amy F. , Buckley Faith I.
Published: August 2012

We present a case of reactive histiocytic disease involving the orbit, optic nerve, retina, and choroid in a Border Collie dog initially presenting for vision loss. Long‐term partial return of vision has been achieved with systemic immunosuppression. Anterior segment and ocular surface manifestations of reactive histiocytic disease in dogs are relatively common. Posterior segment and orbital involvement, however, are minimally documented in the existing literature. To the authors’ knowledge, this is the first report of disease confined to the orbit and posterior segment as well as the first report of vision loss as a presenting complaint for reactive histiocytic disease. Clinical, magnetic resonance imaging, cytologic, and histopathologic findings are reviewed.
Diabetes self‐risk assessment questionnaires coupled with a multimedia health promotion campaign are cheap and effective tools to increase public awareness of diabetes in a large Chinese population
Authors: Zhang Y. L. , Gao W. G. , Pang Z. C. , Sun J. P. , Wang S. J. , Ning F. , Song X. , Kapur A. , Qiao Q.
Published: August 2012

Aims  To evaluate costs and effectiveness of implementing a diabetes self‐risk assessment (Diabetes Risk Score) questionnaire coupled with a multimedia health promotion campaign on changes in diabetes awareness in a large diabetes prevention programme.

Methods  Between 2007 and 2010, a multimedia health promotion campaign was conducted targeting the 1.94 million population of Qingdao, China, using newspapers, radio programmes, distribution of free booklets and Diabetes Risk Score flyers. Diabetes awareness questionnaires filled out by people first interviewed in 2006 (survey A), before the initiation of the campaign, were compared with those first interviewed between 2007 and 2010 during the campaign period (survey B). The rates of diabetes awareness in both surveys were studied amongst adults aged 35–74 years without a prior history of diabetes, but with a Diabetes Risk Score of ≥ 14.

Results  In survey B, 85, 82 and 76% of the urban participants correctly recognized obesity, family history of diabetes and physical inactivity, respectively, as important risk factors for diabetes; while the awareness rates were 43, 46 and 25%, respectively, in survey A (P < 0.001). The corresponding figures among rural participants were 65, 63 and 53% in survey B and 29, 22 and 11% in survey A (P < 0.001). To cover 1000 individuals, the programme spent €5.4 on the use of the Diabetes Risk Score flyer, €31.3 on the education booklet, €7.7 on the newspaper campaign and €37.5 on radio programmes.

Conclusions  The combination of a Diabetes Risk Score questionnaire with a multimedia health promotion campaign is a cheap and effective health promotion tool to raise public awareness of diabetes.
Economic consequences of SFAS 142 goodwill write‐offs
Authors: Jarva Henry
Published: August 2012

This paper examines the economic consequences of goodwill write‐offs under Statement of Financial Accounting Standards No. 142 (SFAS 142). Although write‐off firms have performed poorly, it is evident that deteriorating economic performance explains only a small proportion of write‐offs. After controlling for endogeneity of write‐off choice, I fail to find evidence that investors and analysts fixate on SFAS 142 goodwill write‐offs. I also provide evidence that write‐off firms pay higher audit fees, suggesting that auditors charge higher fees in response to extra audit effort. These results are consistent with the principles of market efficiency, analyst‐forecast rationality and efficient audit pricing.
Cultural influences on body dissatisfaction, body change behaviours, and disordered eating of Japanese adolescents
Authors: Brokhoff Miki , Mussap Alexander J. , Mellor David , Skouteris Helen , Ricciardelli Lina A. , McCabe Marita P. , Fuller‐Tyszkiewicz Matthew
Published: August 2012

We administered a paper‐and‐pencil questionnaire to 133 female and 99 male Japanese high school students 13–18 years old (M = 15.9, SD = 1.57) from the Kansai area to examine cultural influences on their body image and body change behaviours. Our aim was to ascertain the independent and combined influences from traditional Japanese, modern Japanese, and Western values. Cluster analyses identified four ‘acculturative’ groups: ‘anti‐modern’, ‘traditional’, ‘pro‐modern/anti‐traditional’, and ‘pro‐Western/anti‐Japanese’. Pro‐modern and pro‐Western adolescents were most dissatisfied with their bodies, and pro‐Western adolescents were also most likely to attempt weight loss. The results demonstrate the value of assessing cultural interactions in Japan along three dimensions.
Electrical Delay in Apically Positioned Left Ventricular Leads and Clinical Outcome After Cardiac Resynchronization Therapy
Authors: KANDALA JAGDESH , UPADHYAY GAURAV A. , ALTMAN ROBERT K. , BOSE ABHISHEK , HEIST E. KEVIN , MELA THEOFANIE , SINGH JAGMEET P.
Published: August 2012

Electrical Delay in Apically Positioned LV Leads. Introduction: In recent studies, an anatomical apical left ventricular (LV) lead pacing location has been associated with deleterious outcome after cardiac resynchronization therapy (CRT). The differential impact of the LV lead electrical location in these patients remains unknown.

Methods and Results: Thirty‐one consecutive CRT patients (mean age 71.7 ± 12.7 years, 55% left bundle‐branch block [LBBB] morphology) with an apical LV lead and LV lead electrical delay (LVLED) were studied. Anatomical LV lead location was determined via review of coronary venography and chest radiographs. Electrical location was assessed through intraprocedural LVLED measurement. Patients were dichotomized into either “long” LVLED (LVLED ≥ 50% of QRS) or “short” LVLED groups (LVLED < 50%). Patients in the long LVLED group demonstrated significantly greater freedom from a primary composite endpoint of all‐cause death, heart failure hospitalization, and cardiac transplantation at 2 years (81% vs 30%, P = 0.007 vs short LVLED patients). Longer LVLED was also associated with more favorable LV remodeling (LV end‐systolic volume –41.9 ± 10.3 mL vs –4.3 ± 17.2 mL; P = 0.05), and greater improvement in LV ejection fraction (+9.4 ± 2.9% vs +2.3 ± 7.5%; P = 0.04). Even after multivariate adjustment, LVLED remained an independent predictor of the primary composite endpoint (HR 0.47, P = 0.031).

Conclusions: Electrical lead localization, as estimated by LVLED ≥ 50%, is associated with improved long‐term clinical outcome and measures of LV remodeling in patients with apical LV leads. Intraprocedural LVLED assessment may provide incremental utility in targeting lead placement even in conventionally unfavorable anatomical segments. (J Cardiovasc Electrophysiol, Vol. 24, pp. 182‐187, February 2013)