bluuebunny/crossref_metadata_2025 huggingface dataset:
3026 – The Use of Internet in Prevention
Authors: Sarchiapone M.
Published: July 2013

Introduction

Internet currently has 513 million users worldwide and the young continue to be one of the highest users of the Internet. Often the young choose to use the media for get answers to their questions and also for search for mental healthrelated information. The researches show a rapid growth of mental disorders among young that often co-occurs with risk behaviours, such as suicide, which is one of the leading cause of death among young ages 15–34. Therefore it's necessary to use some tools that can promote mental health getting to young lives such as Internet and media.

Objectives

increasing the knowledge on the use of internet and media in order to promote the mental health and to prevent at-risk behaviors among young.

Aims

The main expected outcome is to improve mental health among young.

Methods

SUPREME - Suicide Prevention by Internet and Media Based Mental Health Promotion, European Project for the prevention of risk behaviours and mental health promotion through the use of mass media and Internet. The Project, financed by EACH and DG SANCO EU Public Health is developed by a consortium of 7 European countries. The intervention comprise of a highly interactive website targeted at young. In each participating country, a sample of 300 pupils have been selected and randomized in one of three different intervention arms.

Conclusions

Internet and media can be used how efficient instruments to spread information among adolescents and to promote programs aimed to improve their mental health and well-being.
3029 – Bridging the Gap Between Physio- and Psychopathology: The Example of Deep Brain Stimulation in Human-repetitive Behaviours
Authors: Mallet L.
Published: July 2013

Deep brain stimulation (DBS) is able to target with precision specific cerebral networks, thus offering hope for severe and treatment refractory illnesses, as well as to investigate in the detail the subcortical bases. In obsessive-compulsive disorder (OCD), DBS is being tested at several nodes of a prefrontal-subcortical circuit, including the subthalamic nucleus (STN). Functional imaging studies of OCD patients have shown abnormal metabolic activity of the orbito-frontal and cingulate cortices, as well as of the anterior part of the striatum. In animal and human studies, these structures have been associated with performance-monitoring and more generally metacognitive processes, thus suggesting that metacognitive dysfunctions might be central to OCD leading to pathological doubt. In this conceptual framework of hyperactive distrust metacognitive mechanism in OCD, checking behaviour can be regarded as an ill-founded metacognitive strategy designed to restore confidence in the outcome of one's actions. Within the basal ganglia network, the STN could act a crucial part in this process regarding its role in the inhibitory control of behaviour. Moreover, anatomy and neuro-computational models of the basal ganglia show that this nucleus is in the position to implement cortical metacognitive control by increasing the threshold for decision. This framework has the advantage of providing a theoretical basis to the promising clinical results obtained for STN-DBS in severe resistant OCD. Bearing in mind this model, it can be postulated that DBS, by its action on STN, positively interferes with the neural mechanism underlying compulsive behaviour.
3035 – The Magnitude of the Problem - What Price is Society Paying for under Diagnosis and Sub Optimal Treatment of Depression
Authors: Schlaepfer T.
Published: July 2013

Epidemiological surveys and treatment studies have clearly established that both detection and treatment rates in depression and in anxiety disorders revolve only around 50%. This figure appears to be stable, over a number of decades, despite significant educational and policy efforts to change this pattern. Since depression is a leading cause of disability, lost productivity and health care expenditure, the societal and individual cost of this impasse is tremendous. This talk will review this data and discuss how even small changes in our therapeutic abilities may translate into major advances for patients and their environment. Meeting mental health care needs of individuals, who currently have a low rate of depression treatment, will pose an important challenge to general medical and mental health educators and practitioners. Epidemiological surveys and treatment studies have clearly established that both detection and treatment rates in depression and in anxiety disorders revolve only around 50%. This figure appears to be stable, over a number of decades, despite significant educational and policy efforts to change this pattern. Since depression is a leading cause of disability, lost productivity and health care expenditure, the societal and individual cost of this impasse is tremendous. This talk will review this data and discuss how even small changes in our therapeutic abilities may translate into major advances for patients and their environment. Meeting mental health care needs of individuals, who currently have a low rate of depression treatment, will pose an important challenge to general medical and mental health educators and practitioners.
3036 – Patients Versus Physician’s Perspective On The Diagnosis And Treatment Of Depression
Authors: Demyttenaere K.
Published: July 2013

Outcome measures are (too) often driven by what regulatory bodies request and stick to observer rated depression scales. It is already known that self rating and observer rating scales are not always concordant but recent research even indicates that what physicians and patients expect from outcome is not the same. Physicians put a lot of emphasis on (mainly) depressive symptoms not taking into account the often comorbid anxiety and somatic symptoms while patients put more emphasis on positive mood (vigor, energy, optimism) and on feeling the usual self. Moreover, research indicates that the divergence between physicians’ and patients’ expectations also influence outcome. These differences, how they manifest and what can be done to overcome them so as to provide satisfactory outcomes of treatment, will be further discussed.
DietaryN-acetylcysteine supplementation alleviates liver injury in lipopolysaccharide-challenged piglets
Authors: Yi Dan , Hou Yongqing , Wang Lei , Ding Binying , Yang Zhengguo , Li Jiao , Long Minhui , Liu Yulan , Wu Guoyao
Published: July 2013

The present study was carried out to determine whetherN-acetylcysteine (NAC) could modulate liver injury in a lipopolysaccharide (LPS)-challenged piglet model. For this purpose, eighteen piglets were randomly assigned to the control, LPS or NAC group. Piglets in the control and LPS groups were fed a basal diet, whereas those in the NAC group were fed the basal diet supplemented with 500 mg/kg NAC. On days 10, 13 and 20 of the trial, the LPS- and NAC-treated piglets were intraperitoneally administered LPS (100 μg/kg body weight), while the control group was administered the same volume of saline. On day 20 of the trial, blood samples were obtained 3 h after LPS or saline injection. On day 21, the piglets were killed to collect liver samples. Dietary NAC supplementation attenuated LPS-induced liver histomorphological abnormalities. Compared with the control group, in the LPS-challenged piglets, the activities of alanine aminotransferase and aspartate aminotransferase and the concentrations of H2O2, TNF-α, IL-6 and PGE2were dramatically increased in the plasma and the activity of superoxide dismutase in the plasma and that of glutathione peroxidase in the liver were significantly decreased. The LPS challenge also increased the concentration of AMP and the ratio of AMP:ATP, but decreased adenylate energy charges and the levels of ATP and ADP. These adverse effects of the LPS challenge were ameliorated by NAC supplementation. Moreover, NAC inhibited the LPS-induced increases in the abundance of liver heat shock protein 70 and NF-κB proteins. In conclusion, these results suggest that dietary NAC supplementation alleviates LPS-induced liver injury by reducing the secretion of pro-inflammatory cytokines, increasing the antioxidative capacity and improving energy metabolism.
The effect of ultraviolet lasers on conversion of methane into higher hydrocarbons
Authors: Navid H.A. , Irani E. , Sadighi-Bonabi R.
Published: July 2013

Conversion of CH4molecule into higher hydrocarbons using two different wavelengths of 248 nm KrF laser and 355 nm of third harmonic of Nd:YAG laser is studied experimentally and theoretically. The stable products are analyzed and the effect of pressure on conversion of methane is measured. The detected reaction products are C2H2, C2H4, and C2H6. The conversion efficiency of 33.5% for 355 nm in comparison to 2.2% conversion for 248 nm for C2H2is achieved. The potential of laser parameters as an important variable in controlling of final products is investigated.
Fast electron transport patterns in intense laser-irradiated solids diagnosed by modeling measured multi-MeV proton beams
Authors: MacLellan David A. , Carroll David C. , Gray Ross J. , Booth Nicola , Gonzalez-Izquierdo Bruno , Powell Haydn W. , Scott Graeme G. , Neely David , McKenna Paul
Published: July 2013

The measured spatial-intensity distribution of the beam of protons accelerated from the rear side of a solid target irradiated by an intense (>1019 Wcm−2) laser pulse provides a diagnostic of the two-dimensional fast electron density profile at the target rear surface and thus the fast electron beam transport pattern within the target. An analytical model is developed, accounting for rear-surface fast electron sheath dynamics, ionization and projection of the resulting beam of protons. The sensitivity of the spatial-intensity distribution of the proton beam to the fast electron density distribution is investigated. An annular fast electron beam transport pattern with filamentary structure is inferred for the case of a thick diamond target irradiated at a peak laser intensity of 6 × 1019 Wcm−2.
A Millian Objection to Reasons as Evidence
Authors: FLETCHER GUY
Published: July 2013

Stephen Kearns and Daniel Star have recently proposed the following theory of reasons:

Reasons as Evidence: Necessarily, a fact F is a reason for an agent A to Φ iff F is evidence that A ought to Φ (where Φ is either a belief or an action).

In this article I present an objection, inspired by Mill's proof of the principle of utility, to the right-to-left reading of the biconditional. My claim is that the fact that you can perform some action can be evidence that you ought to do it without, itself, being a reason to do it. If this is true then Reasons as Evidence is false.
On singularly perturbed Filippov systems
Authors: CARDIN PEDRO T. , DA SILVA PAULO R. , TEIXEIRA MARCO A.
Published: July 2013

In this paper, we study singularly perturbed Filippov systems. More specifically, our main question is to know how the dynamics of Filippov systems is affected by singular perturbations. We extend the Fenichel theory developed in Fenichel (J. Differ. Equ., 1979, Vol. 31, pp. 53–98) to these systems. In addition, the study of non-smooth constrained systems is considered.
Long-term psychosocial outcome of adults with tetralogy of Fallot and transposition of the great arteries: a historical comparison
Authors: Opić Petra , Utens Elisabeth M.W.J. , Ruys Titia P.E. , van Domburg Ron T. , Witsenburg Maarten , Bogers Ad J.J.C. , Roos-Hesselink Jolien W.
Published: July 2013

Objective:To make a historical comparison on the long-term psychosocial outcome of cardiothoracic surgery during childhood.Methods:Adult patients operated for tetralogy of Fallot or transposition of the great arteries between 1980 and 1990 (recent sample) were compared with patients who underwent surgery and were investigated 10 years earlier (historical sample). In addition, atrial switch and arterial switch patients within the recent sample were compared. Psychosocial functioning was measured using standardised, validated psychological questionnaires.Results:Although the recent sample of patients overall shows a favourable quality of life, impairments were found in income, living conditions, relationships, offspring, and occupational level. Compared with the historical sample, the recent sample showed no significant improvements on psychosocial functioning, except for a better educational level. The amount of educational problems, such as learning difficulties, was still high compared with normative data. Recently operated patients with transposition of the great arteries (arterial switch) scored significantly better on the Short Form-36 vitality scale (p = 0.02) compared with historical patients with transposition of the great arteries (atrial switch).Conclusions:Despite improvements in medical treatment over the past few decades, hardly any change was found in the psychosocial outcome of the recent patient sample compared with the historical patient sample. In particular, the percentage of patients needing special education and showing learning problems remained high, whereas income was low compared with normative data.
Impact on energy, sodium and dietary fibre intakes of vegetables prepared at home and away from home in the USA
Authors: Lin Biing-Hwan , Wendt Minh , Guthrie Joanne F
Published: July 2013

Objective

To examine how increasing vegetable consumption from foods prepared at home (FAH) and foods prepared away from home (FAFH) would impact energy, dietary fibre and Na (sodium) intakes in the USA.

Design

Using data from the 2003–2004 US National Health and Nutrition Examination Survey, dietary intake data from two separate days were fitted with a first-difference (fixed-effects) model. Vegetables consumed from all sources, including mixed foods and juices, were disaggregated and expressed as amounts equivalent to one cup of whole vegetables.

Setting

Nationally representative sample of the US population.

Subjects

Individuals aged 2 years and above reporting 2 d of dietary intake data in 2003–2004 (n 7647).

Results

Holding constant the total amount of food consumed, consuming an additional cup of tomatoes and potatoes from FAFH increases energy intake by respectively 1522 and 665 kJ, as compared with 246 and 367 kJ for FAH. Each additional cup of tomatoes from FAH is associated with an additional 179 mg of Na, compared with 113 mg for FAFH. All vegetable consumption increases fibre intake, except for potatoes and tomatoes from FAFH. Dark green and orange vegetables from FAH add the largest amount of fibre (1·38 g/cup).

Conclusions

Because US consumers frequently consume vegetables as part of mixed foods that add energy and Na, heavier consumption of vegetables as currently prepared raises the energy content and Na density of the overall diet. This is particularly true for vegetables prepared away from home.
Comparative analysis of receiver bandwidth effects on Y-factor and cold-source noise figure measurements
Authors: Otegi Nerea , Collantes Juan-Mari , Sayed Mohamed
Published: July 2013

A known source of error in noise figure characterization is the variation of the device characteristics within the bandwidth of the instrument receiver. In this paper, an in-depth analysis of the effect of the receiver bandwidth on noise figure characterization accuracy is developed. For the first time, comparative results for Y-factor and cold-source techniques are given. The analysis clarifies some contradictions about the origin and the final impact of bandwidth effects in Y-factor. In addition, effects derived from an excessively wide bandwidth of the noise receiver are shown to be completely different in both techniques, being more critical in cold-source. As a result of the analysis, correction terms are provided for those cases in which receivers with narrow enough bandwidths are not available. The conclusions extracted from the theoretical formulation are confirmed by the measurements carried out on several narrow-band devices under tests with different characteristics.
Marketing the Market: The Ideology of Market Mechanisms for Biodiversity Conservation
Authors: Penca Jerneja
Published: July 2013

The emergence of market mechanisms for the protection of biodiversity and ecosystem services in recent years has been portrayed by most conservation institutions and epistemological frameworks as an unprecedented opportunity for the conservation of nature. This article shifts the focus from the improved effectiveness arguments concerning such mechanisms to examine their institutional and political context and origins. It outlines the field of transnational biodiversity markets and uncovers the normative biases it displays. The regulatory vocabulary of ‘market mechanisms’ is juxtaposed to the more explicit ideological approach professed by the critics of neoliberalism. The argument is that, rather than an inevitable component in contemporary conservation governance, market mechanisms imply a set of contested choices for certain values, a particular economic development trajectory, a particular understanding of the biodiversity problem, and a weak role for legal obligations. Transnational environmental law needs to establish its interest beyond that of the regulation literature if it is to account for the proliferating movements around the world in favour of a reasserted normative guidance for the markets and against the process of marketing the market.
Unified Psychology Based on Three Laws of Information Integration
Authors: Anderson Norman Henry
Published: July 2013

How are multiple variables integrated into a unitary response? This fundamental problem— integration of multiple variables—faces every field of psychology. Solid support for three exact mathematical integration laws— averaging, adding, multiplying—has been given by extensive empirical work by investigators in many countries. These three integration laws operate in almost every area of human psychology: person science, social attitudes, child development, learning/memory, language, psychophysics, and judgment—decision. These laws have nomothetic generality across persons and cultures together with idiographic capability for true measurement of personal, individual value. These integration laws are thus a foundation, both conceptual and empirical, for unifying psychological science.
Pragmatic Case Studies as a Source of Unity in Applied Psychology
Authors: Fishman Daniel B. , Messer Stanley B.
Published: July 2013

To unify or not to unify applied psychology: That is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 1960s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, using a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled pragmatic psychology and, its specific use of case studies, the Pragmatic Case Study Method (PCS Method). We call for the creation of peer-reviewed journal databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.
Psychology Unified: From Folk Psychology to Radical Enactivism
Authors: Hutto Daniel D.
Published: July 2013

A properly radical enactivism—one that eschews the idea that all mentality is necessarily contentful and representational—has better prospects of unifying psychology than does traditional cognitivism. This paper offers a five-step argument in support of this claim. The first section advances the view that a principled way of characterizing psychology's subject matter is what is required if it is to be regarded as a special science. In this light, section two examines why and how cognitivism continues to be regarded as the best potential unifier for the discipline. But the third section exposes a serious problem about the scope of cognitivism that occurs because it ascribes properties to basic minds that only belong to more sophisticated minds built atop them. In a nutshell, the root problem is that cognitivism relies on folk psychological models of mental states when it assumes that all mentality is contentful. Although this gives cognitivism its intuitive appeal, it also makes it too limited to provide a general model of the mind. Radical enactivism's way of understanding mentality as embodied activity, it is argued, avoids this and provides a more appropriate means of understanding basic forms of mentality. Against the charge that radical enactivism is also limited in scope, the final section argues that it is inclusive enough to allow for and recognize the emergence of language-based folk psychological modes of mentality, thus making it the superior potential unifier for psychology.
Describing, Explaining, and Optimizing Within-Individual Change across the Life Span: A Relational Developmental Systems Perspective
Authors: Lerner Richard M. , Agans Jennifer P. , DeSouza Lisette M. , Gasca Santiago
Published: July 2013

The goal of developmental science is to describe, explain, and optimize changes within individuals and differences between individuals across the life span. Contemporary developmental science is framed in the main by relational developmental systems models, conceptions that emphasize that change across life occurs through mutually regulative relations between individuals and their contexts. These models have important implications for research questions, methodology, and applications aimed at promoting positive human development and social justice across the life span.
A Developmental Evolutionary Framework for Psychology
Authors: Lickliter Robert , Honeycutt Hunter
Published: July 2013

Evolutionary psychology (EP) was founded on the metatheoretical assumptions of the modern (or neo-Darwinian) synthesis of evolutionary biology, which dichotomize internal from external sources of causation. By prioritizing the former, EP has promoted a preformationist view of individual development, which effectively divorces developmental from evolutionary analysis. The authors argue that these assumptions about development are in need of revision in light of recent advances in genomics, epigenetics, and developmental science. The authors outline a developmental evolutionary framework for psychology, a relational metatheory that integrates the study of developmental and evolutionary mechanisms within one explanatory framework. They argue that knowledge of the dynamics of developmental processes are necessary to illuminate mechanisms of evolutionary change and that the psychological sciences, particularly comparative and developmental psychology, are ideally positioned to contribute to this endeavor.
Healthy Skepticism: Do Adults Trust Health Information From Children in Rural Kenya?
Authors: Jukes Matthew C. H. , Zuilkowski Stephanie S. , Okello George , Harris Paul L.
Published: July 2013

Despite the frequent use of schools and schoolchildren to disseminate information to wider communities in sub-Saharan Africa, little research has been done examining whether children are seen as trustworthy sources of information. Participants (67 women and 66 men aged 19–77 years living in coastal Kenya) listened to different claims made by an adult informant and a child informant in a video scenario. The competing claims pertained to both health and nonhealth dilemmas. One claim was consistent with traditional practices, whereas the other was consistent with modern, school-based knowledge. We asked respondents the extent to which they would endorse the adult’s claim rather than the child’s and the traditional claim rather than the modern claim. Surprisingly, no preference was seen for adult advice over children’s advice. Modern claims were endorsed over traditional claims in the domain of health and particularly among more educated adults. Children’s advice was trusted less by participants who favored a high level of adult authority over children rather than a more egalitarian relationship. This study shows that children can convey credible messages to adults in Kenya and that adults who are educated and value more equal relationships with children are more receptive to the messages.
New intrinsic mechanism on gum-like superelasticity of multifunctional alloys
Authors: Liu Jia-Peng , Wang Yan-Dong , Hao Yu-Lin , Wang Yunzhi , Nie Zhi-Hua , Wang Dong , Ren Yang , Lu Zhao-Ping , Wang Jinguo , Wang Haoliang , Hui Xidong , Lu Ning , Kim Moon J. , Yang Rui
Published: July 2013

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by a pronounced tension-to-compression asymmetry and large ductility with a low Poisson's ratio. Two main contradictory arguments exist concerning the deformation mechanisms of those alloys, i.e., formation of reversible nanodisturbance and reversible martensitic transformation. Herein we used the in-situ synchrotron high-energy X-ray scattering technique to reveal the novel intrinsic physical origin of all anomalous mechanical properties of the Ti-24Nb-4Zr-8Sn-0.10O alloy, a typical gum-like metal. Our experiments provide direct evidence on two different kinds of interesting, stress-induced, reversible nanoscale martensitic transitions, i.e., the austenitic regions with B2 structure transform to α″ martensite and those with BCC structure transform to δ martensite.
Subcellular potassium and sodium distribution in Saccharomyces cerevisiae wild-type and vacuolar mutants
Authors: Herrera Rito , Álvarez María C. , Gelis Samuel , Ramos José
Published: July 2013

Living cells accumulate potassium (K+) to fulfil multiple functions. It is well documented that the model yeast Saccharomyces cerevisiae grows at very different concentrations of external alkali cations and keeps high and low intracellular concentrations of K+ and sodium (Na+) respectively. However less attention has been paid to the study of the intracellular distribution of these cations. The most widely used experimental approach, plasma membrane permeabilization, produces incomplete results, since it usually considers only cytoplasm and vacuoles as compartments where the cations are present in significant amounts. By isolating and analysing the main yeast organelles, we have determined the subcellular location of K+ and Na+ in S. cerevisiae. We show that while vacuoles accumulate most of the intracellular K+ and Na+, the cytosol contains relatively low amounts, which is especially relevant in the case of Na+. However K+ concentrations in the cytosol are kept rather constant during the K+-starvation process and we conclude that, for that purpose, vacuolar K+ has to be rapidly mobilized. We also show that this intracellular distribution is altered in four different mutants with impaired vacuolar physiology. Finally, we show that both in wild-type and vacuolar mutants, nuclei contain and keep a relatively constant and important percentage of total intracellular K+ and Na+, which most probably is involved in the neutralization of negative charges.
Proof-of-concept evaluation of trough airway hyper-responsiveness following regular racemic or levosalbutamol in genotype-stratified steroid-treated persistent asthmatic patients
Authors: Anderson William J. , Short Philip M. , Williamson Peter A. , Morrison Ashley E. , Palmer Colin , Tavendale Roger , Lipworth Brian J.
Published: July 2013

Asthmatic patients receiving ICSs (inhaled corticosteroids) may take frequent add-on therapy with salbutamol despite on-demand prescription. Frequent salbutamol use can be detrimental in asthma. The isomeric formulation of salbutamol and the B2ADR (β2 adrenoceptor) 16 genotype may also influence this phenomenon. We performed a randomized, double-blind, placebo-controlled, triple crossover, proof of concept trial comparing 2 weeks of regular therapy with inhaled racemic salbutamol [200 μg q.i.d. (four times daily)], levosalbutamol (100 μg q.i.d.) or placebo on trough methacholine PC20 [provocative concentration causing 20% fall in FEV1 (forced expiratory volume in 1 s)] 6 h post-dose (the primary outcome) in 30 persistent asthmatic patients (15 who were Arg16 homozygous and 15 who were Gly16 homozygous) all receiving ICSs. There was no worsening of AHR (airway hyper-responsiveness) at trough to methacholine after 2 weeks regular exposure to either racemic (P=0.53) or levosalbutamol (P=0.84) compared with placebo, nor between genotypes–as dd (doubling dilution) difference in methacholine PC20 from placebo [salbutamol/Arg16=0.36 dd [95% CI (confidence interval), −0.43, 1.15]; salbutamol/Gly16=0.01 dd (95% CI, −0.47, 0.49); levosalbutamol/Arg16=−0.01 dd (95% CI, −0.89, 0.87); and levosalbutamol/Gly16=0.28 dd (95% CI, −0.22, 0.77)]. Both active treatments improved morning PEF (peak expiratory flow) in Gly16 (P=0.04 overall) but not Arg16 (P=0.50 overall) patients, whereas evening PEF improved in both Gly16 (P<0.001 overall) and Arg16 (P=0.006 overall) patients. In conclusion, the regular exposure to either racemic or levosalbutamol for 2 weeks added to ICSs did not cause worsening of AHR at trough compared with placebo; with no difference seen between B2ADR 16 genotypes.
Origin of the diffuse vibrational signature of a cyclic intramolecular proton bond: Anharmonic analysis of protonated 1,8-disubstituted naphthalene ions
Authors: DeBlase Andrew F. , Bloom Steven , Lectka Thomas , Jordan Kenneth D. , McCoy Anne B. , Johnson Mark A.
Published: July 2013

We analyze the structures and spectral signatures of the cyclic intramolecular proton bond, N–H+–A, A = O and F, formed when an excess proton is added to derivatives of the 1,8-disubstituted naphthalene scaffold. These compounds provide a quasi-rigid framework with which to study the spectral complexity often associated with the N–H+–A entity. Vibrational spectra were obtained by monitoring photodissociation of weakly bound H2 adducts of the mass-selected ions cooled close to 10 K. Several bands across the 900–3500 cm−1 spectral range were traced to involvement of the bridging proton by their telltale shifts upon selective H/D isotopic substitution at that position. We account for the complex patterns that occur near the expected locations of the NH stretching fundamentals in the context of background levels mixing with a “bright” zero-order state through cubic terms in the potential energy expansion. Thus, this system provides a detailed picture of one of the mechanisms behind the line broadening often displayed by embedded excess protons. It does so in a sufficiently sparse density of states regime that many discrete transitions are observed in the vicinity of the harmonic stretching transition involving displacement of the trapped proton.
Reynolds number influence on statistical behaviors of turbulence in a circular free jet
Authors: Mi J. , Xu M. , Zhou T.
Published: July 2013

The present paper examines the effect of Reynolds number on turbulence properties in the transition region of a circular jet issuing from a smoothly contracting nozzle. Hot-wire measurements were performed for this investigation through varying the jet-exit Reynolds number Red (≡ Ujd/ν, where Uj, d, and ν are the jet-exit mean velocity, nozzle diameter, and kinematic viscosity) approximately from Red ≈ 4 × 103 to Red ≈ 2 × 104. Results reveal that the rates of the mean flow decay and spread vary with Reynolds number for Red < 104 and tend to become Reynolds-number independent at Red ≥ 104. Even more importantly, the small-scale turbulence properties, e.g., the mean rate of dissipation of kinetic energy (ɛ), the Kolmogorov and Taylor microscales, are found to vary in different forms over the Red ranges of Red > 104 and Red < 104. Namely, the critical Reynolds number appears to occur at Red,cr ≈ 104 across which the jet turbulence behaves distinctly. Two turbulence regimes are therefore identified: (i) developing or partially developed turbulence at Red < Red,cr and (ii) fully developed turbulence at Red ≥ Red,cr. It is suggested that the energy dissipation rate (DR) can be expressed as $\varepsilon \sim \nu U_c^2 /R^2$ɛ∼νUc2/R2 in regime (i) and $\varepsilon \sim U_c^3 /R$ɛ∼Uc3/R in regime (ii), where Uc and R are the centerline (or maximum) mean velocity and half-radius at which the mean velocity is 0.5Uc. In addition, the critical Reynolds number appears to vary from flow to flow.
The effect of a thermal gradient on the electromigration-driven surface morphological stabilization of an epitaxial thin film on a compliant substrate
Authors: Sfyris Georgios I. , Dasgupta Dwaipayan , Maroudas Dimitrios
Published: July 2013

We report a theoretical analysis on the surface morphological stability of a coherently strained thin film that has been grown epitaxially on a deformable substrate and is simultaneously subjected to an external electric field and a temperature gradient. Using well justified approximations, we develop a three-dimensional model for the surface morphological evolution of the thin film and conduct a linear stability analysis of the heteroepitaxial film's planar surface state. The effect of the simultaneous action of multiple external fields on the surface diffusional anisotropy tensor is accounted for. Various substrate types are considered, but emphasis is placed on a compliant substrate that has the ability to accommodate elastically some of the misfit strain in the film due to its lattice mismatch with the substrate. We derive the condition for the synergy or competition of the two externally applied fields and determine the optimal alignment of the external fields that minimizes the critical electric field-strength requirement for the stabilization of the planar film surface. We also examine the role of the temperature dependence of the thermophysical properties and show that the criticality condition for planar surface stabilization does not change when the Arrhenius temperature dependence of the surface diffusivity is considered. Our analysis shows that surface electromigration and thermomigration due to the simultaneous action of properly applied and sufficiently strong electric fields and thermal gradients, respectively, can inhibit Stranski-Krastanow-type instabilities and control the onset of island formation on epitaxial film surfaces.
Spin-up of ferrofluids: The impact of the spin viscosity and the Langevin function
Authors: Finlayson Bruce A.
Published: July 2013

The spin-up of ferrofluids (rotational motion of a magnetic fluid induced by a rotating magnetic field) is examined computationally. Key questions are the impact of the spin viscosity, a mildly non-uniform magnetic field, and the importance of the Langevin magnetization equation. Comsol Multiphysics is used with boundary layer meshes to capture the effect when the spin viscosity is small. The effect of the spin viscosity is examined as it affects the critical magnetic field for non-rotational flow to occur and the magnitude of the rotational velocity and torque. Comparisons are made for the effect of magnetic field when using the Langevin magnetization equation and a linear equation. The equations for flow, magnetic field, and spin velocity are solved in two dimensions as a representation of a long cylinder with the magnetic field oriented perpendicular to the axis of the cylinder and rotated about that axis. Solutions are obtained for spin viscosities as low as 5.8 × 10−14 kg m s−1.
Hard ellipses: Equation of state, structure, and self-diffusion
Authors: Xu Wen-Sheng , Li Yan-Wei , Sun Zhao-Yan , An Li-Jia
Published: July 2013

Despite their fundamental and practical interest, the physical properties of hard ellipses remain largely unknown. In this paper, we present an event-driven molecular dynamics study for hard ellipses and assess the effects of aspect ratio and area fraction on their physical properties. For state points in the plane of aspect ratio (1 ⩽ k ⩽ 9) and area fraction (0.01 ⩽ ϕ ⩽ 0.8), we identify three different phases, including isotropic, plastic, and nematic states. We analyze in detail the thermodynamic, structural, and self-diffusive properties in the formed various phases of hard ellipses. The equation of state (EOS) is shown for a wide range of aspect ratios and is compared with the scaled particle theory (SPT) for the isotropic states. We find that SPT provides a good description of the EOS for the isotropic phase of hard ellipses. At large fixed ϕ, the reduced pressure p increases with k in both the isotropic and the plastic phases and, interestingly, its dependence on k is rather weak in the nematic phase. We rationalize the thermodynamics of hard ellipses in terms of particle motions. The static structures of hard ellipses are then investigated both positionally and orientationally in the different phases. The plastic crystal is shown to form for aspect ratios up to k = 1.4, while appearance of the stable nematic phase starts approximately at k = 3. We quantitatively determine the locations of the isotropic-plastic (I-P) transition and the isotropic-nematic (I-N) transition by analyzing the bond-orientation correlations and the angular correlations, respectively. As expected, the I-P transition point is found to increase with k, while a larger k leads to a smaller area fraction where the I-N transition takes place. Moreover, our simulations strongly support that the two-dimensional nematic phase in hard ellipses has only quasi-long-range orientational order. The self-diffusion of hard ellipses is further explored and connections are revealed between the structure and the self-diffusion. We discuss the relevance of our results to the glass transition in hard ellipses. Finally, the results of the isodiffusivity lines are evaluated for hard ellipses and we discuss the effect of spatial dimension on the diffusive dynamics of hard ellipsoidal particles.
Algebro-geometric solutions for the Gerdjikov-Ivanov hierarchy
Authors: Hou Yu , Fan Engui , Zhao Peng
Published: July 2013

This paper is dedicated to provide theta function representations of algebro-geometric solutions and related crucial quantities for the Gerdjikov-Ivanov (GI) hierarchy. Our main tools include the polynomial recursive formalism, the hyperelliptic curve with finite number of genus, the Baker-Akhiezer functions, the meromorphic function, the Dubrovin-type equations for auxiliary divisors, and the associated trace formulas. With the help of these tools, the explicit representations of the Baker-Akhiezer functions, the meromorphic function, and the algebro-geometric solutions are obtained for the entire GI hierarchy.
Laser shaping of a relativistic circularly polarized pulse by laser foil interaction
Authors: Zou D. B. , Zhuo H. B. , Yu T. P. , Yang X. H. , Shao F. Q. , Ma Y. Y. , Yin Y. , Ouyang J. M. , Ge Z. Y. , Zhang G. B. , Wang P.
Published: July 2013

Laser shaping of a relativistic circularly polarized laser pulse in ultra-intense laser thin-foil interaction is investigated by theoretical analysis and particle-in-cell simulations. It is found that the plasma foil as a nonlinear optical shutter has an obvious cut-out effect on the laser temporal and spatial profiles. Two-dimensional particle-in-cell simulations show that the high intensity part of a Gaussian laser pulse can be well extracted from the whole pulse. The transmitted pulse with longitudinal steep rise front and transverse super-Gaussian profile is thus obtained which would be beneficial for the radiation pressure acceleration regime. The Rayleigh-Taylor-like instability is observed in the simulations, which destroys the foil and results in the cut-out effect of the pulse in the rise front of a circularly polarized laser.
Tunable multifunctional magneto-optical devices based on magnetophotonic crystals comprising liquid crystal defect layers
Authors: Keramati Sam , Zamani Mehdi , Ghanaatshoar Majid
Published: July 2013

In this paper, we are going to demonstrate how realization of tunable magnetophotonic crystals (MPCs) is possible through introduction and investigation of a couple of structures containing a single liquid crystal (LC) defect layer. Our starting point is the recently discussed issue according to which in such structures any alteration in optical characteristics of the LC component will cause changes to happen regarding the overall magneto-optical (MO) response of the LC-based MPC. It will be shown that our optimized MPC structures are not only powerful in most respects but also multifunctional. For instance, while a structure is capable of being operated as a sensing tool with regard to the very factor that tends to control its MO response, other modes of operation offer a function of a switchable optical filter and also a perfect MO isolator.
Suppression of superconductivity in epitaxial MgB2 ultrathin films
Authors: Zhang Chen , Wang Yue , Wang Da , Zhang Yan , Liu Zheng-Hao , Feng Qing-Rong , Gan Zi-Zhao
Published: July 2013

MgB2 ultrathin films have potential to make sensitive superconducting devices such as superconducting single-photon detectors working at relatively high temperatures. We have grown epitaxial MgB2 films in thicknesses ranging from about 40 nm to 6 nm by using the hybrid physical-chemical vapor deposition method and performed electrical transport measurements to study the thickness dependence of the superconducting critical temperature Tc. With reducing film thickness d, although a weak depression of the Tc has been observed, which could be attributed to an increase of disorder (interband impurity scattering) in the film, the Tc retains close to the bulk value of MgB2 (39 K), being about 35 K in the film of 6 nm thick. We show that this result, beneficial to the application of MgB2 ultrathin films and in accordance with recent theoretical calculations, is in contrast to previous findings in MgB2 films prepared by other methods such as co-evaporation and molecular-beam epitaxy, where a severe Tc suppression has been observed with Tc about one third of the bulk value in films of ∼5 nm thick. We discuss this apparent discrepancy in experiments and suggest that, towards the ultrathin limit, the different degrees of Tc suppression displayed in currently obtained MgB2 films by various techniques may arise from the different levels of disorder present in the film or different extents of proximity effect at the film surface or film-substrate interface.
Quantitative comparison of alternative methods for coarse-graining biological networks
Authors: Bowman Gregory R. , Meng Luming , Huang Xuhui
Published: July 2013

Markov models and master equations are a powerful means of modeling dynamic processes like protein conformational changes. However, these models are often difficult to understand because of the enormous number of components and connections between them. Therefore, a variety of methods have been developed to facilitate understanding by coarse-graining these complex models. Here, we employ Bayesian model comparison to determine which of these coarse-graining methods provides the models that are most faithful to the original set of states. We find that the Bayesian agglomerative clustering engine and the hierarchical Nyström expansion graph (HNEG) typically provide the best performance. Surprisingly, the original Perron cluster cluster analysis (PCCA) method often provides the next best results, outperforming the newer PCCA+ method and the most probable paths algorithm. We also show that the differences between the models are qualitatively significant, rather than being minor shifts in the boundaries between states. The performance of the methods correlates well with the entropy of the resulting coarse-grainings, suggesting that finding states with more similar populations (i.e., avoiding low population states that may just be noise) gives better results.
Infrared absorption imaging of 2D supersonic jet expansions: Free expansion, cluster formation, and shock wave patterns
Authors: Zischang Julia , Suhm Martin A.
Published: July 2013

N2O/He gas mixtures are expanded through a 10 × 0.5 mm2 slit nozzle and imaged by direct absorption vibrational spectroscopy, employing a HgCdTe focal plane array detector after interferometric modulation. N2O cluster formation in the free supersonic expansion is visualized. The expansion structure behind the frontal shock is investigated as a function of background pressure. At high pressures, a sequence of stationary density peaks along a narrow directed flow channel is characterized. The potential of the technique for the elucidation of aggregation mechanisms is emphasized.
Condensation and jumping relay of droplets on lotus leaf
Authors: Lv Cunjing , Hao Pengfei , Yao Zhaohui , Song Yu , Zhang Xiwen , He Feng
Published: July 2013

Dynamic behavior of micro water droplet condensed on a lotus leaf with two-tier roughness is studied. Under laboratory environment, the contact angle of the micro droplet on single micro papilla increases smoothly from 80° to 160° during the growth of condensed water. The best-known “self-cleaning” phenomenon will be lost. A striking observation is the out-of-plane jumping relay of condensed droplets triggered by falling droplets, as well as its sustained speed obtained in continuous jumping relays. The underlying mechanism can be used to enhance the automatic removal of dropwise condensation without the help from any external force. The surface tension energy dissipation is the main reason controlling the critical size of jumping droplet and its onset velocity of rebounding.
Unified electronic charge transport model for organic solar cells
Authors: Mottaghian Seyyed Sadegh , Biesecker Matt , Bayat Khadijeh , Farrokh Baroughi Mahdi
Published: July 2013

This paper provides a comprehensive modeling approach for simulation of electronic charge transport in excitonic solar cells with organic and organic/inorganic structures. Interaction of energy carrying particles (electrons, holes, singlet excitons, and triplet excitons) with each other and their transformation in the bulk of the donor and acceptor media as well as the donor/acceptor interfaces are incorporated in form of coupling matrices into the continuity equations and interface boundary conditions. As a case study, the model is applied to simulate an organic bilayer photovoltaic (PV) device to quantify the effects of photo generation, recombination coefficient, carrier mobility, and electrode work function on its PV characteristics. The study proves that electron-hole recombination at the donor/acceptor interface is the dominant mechanism that limits open circuit voltage of the device.