bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequential adaptive utility decision making for system failure correction
Authors: Houlding B , Coolen F. P. A.
Published: January 2008

The theory of adaptive utility for sequential decision making offers a generalization of the classical Bayesian approach, permitting initial utility uncertainty. This paper examines how the possibility to learn preferences can be of interest for decisions in the area of reliability. The resulting differences in determining optimal strategies are explained and two examples are explored in which utility depends on the unknown cost of system failure. The paper concludes with a commentary on further research required.
Aircraft fuel rig system fault diagnostics based on the application of digraphs
Authors: Kelly E. M. , Bartlett L. M.
Published: January 2008

The issue of fault diagnostics is a dominant factor concerning current engineering systems. Information regarding possible failures is required in order to minimize disruption caused to functionality. A method proposed in this paper utilizes digraphs to model the information flow within an application system. Digraphs are composed from a set of nodes representing system process variables or component failure modes. The nodes are connected by signed edges thus illustrating the influence, be it positive or negative, one node has on another. System fault diagnostics is conducted through a procedure of back-tracing in the digraph from a known deviating variable. A computational method has been developed to conduct this process. Comparisons are made between retrieved transmitter readings and those expected while the system is in a known operating mode. Any noted deviations are assumed to indicate the presence of a failure. The current paper looks in detail at the application of the digraph diagnostic method to an industrially based test stand of an aircraft fuel system. This research includes transient system effects; the rate of change of a parameter is taken into consideration as a means of monitoring the system dynamically. The validity of the results achieved, through performing fault diagnostics based on the use of a digraph model, is evaluated. Finally, the effectiveness and scalability issues associated with the application of the method are addressed.
Vaccinating Adolescents in High-Risk Settings: Lessons Learned From Experiences With Hepatitis B Vaccine
Authors: Sneller Vishnu-Priya , Fishbein Daniel B. , Weinbaum Cindy M. , Lombard Andrea , Murray Paula , McLaurin Jennie A. , Friedman Lawrence ,   for the Working Group on Vaccination of High-Risk Adolescents
Published: January 2008

Meeting the health needs of adolescents who live in high-risk settings such as homeless shelters, migrant camps, juvenile detention centers, prisons, and other types of residential facilities presents many challenges. Although there is no doubt that adolescents in many high-risk settings are at increased risk for hepatitis B and human papillomavirus, acute medical and psychological problems may consume all of the provider's time and resources. Potential health threats such as vaccine-preventable diseases must necessarily be given lower priority. Lack of vaccination expertise, supplies, and access to records further complicate delivery of vaccines. Since the 1990s, a number of approaches have been used to deliver hepatitis B vaccine to adolescents in many high-risk settings. Close collaboration among state and federal programs, local health departments, and community-based organizations has been necessary to introduce and sustain the delivery of vaccines to these young people. Medicaid, Statute 317 of the Public Health Service Act, the Vaccines for Children program, and State Children's Health Insurance Program have been used to finance vaccinations for adolescents 18 years or younger, and the expanded Medicaid option in the Foster Care Independence Act of 1999 has been used for adolescents older than 18 years of age. A number of states allow adolescents under age 18 to consent to their own hepatitis B vaccination under laws passed to allow treatment of sexually transmitted infections without parental consent. In this article, we present the experiences of several model programs that developed successful hepatitis B vaccination programs in venues that serve adolescents at risk, the important role of state laws and state agencies in funding immunization and other preventive health services for adolescents in high-risk situations, and discuss barriers and means to resolve them.
Movement and Habitat Selection by Invasive Asian Carps in a Large River
Authors: DeGrandchamp Kelly L. , Garvey James E. , Colombo Robert E.
Published: January 2008

We evaluated the habitat use and movements of 50 adult bighead carp Hypophthalmichthys nobilis and 50 silver carp H. molitrix by means of ultrasonic telemetry during spring‐summer 2004 and 2005 to gain insight into the conditions that facilitate their establishment, persistence, and dispersal in the lower Illinois River (river kilometer 0‐130). Movement and habitat use were monitored with stationary receivers and boat‐mounted tracking. The relative availability of four macrohabitat categories (main channel, island side channel, channel border, and connected backwater) was quantified to determine selection; discriminant function analysis was used to evaluate changes in physical characteristics within each category. A flood pulse occurred in spring through early summer of 2004 but not 2005. Movement rates (km/week) of both species were positively correlated with flow but not with temperature. Including data from stationary receivers greatly increased estimates of daily movement. During low summer flow, both species typically selected channel borders and avoided the main channel and backwaters. Both species rarely occupied depths over 4 m, regardless of abiotic conditions. Flood pulses appear to trigger dispersal, while habitat use is only specific during low summer flow. Thus, movement prevention efforts (e.g., dispersal barriers) will require particular vigilance during late‐winter or spring flooding, and controlled removal (e.g., harvest) should be directed toward selected habitats during summer.
Estado de frescor e qualidade higiênica do pescado vendido numa cidade do interior de Portugal
Authors: Fontes M.C. , Esteves A. , Caldeira F. , Saraiva C. , Vieira-Pinto M. , Martins C.
Published: January 2008

Avaliaram-se o estado de frescor e a qualidade higiênica do pescado disponível em alguns estabelecimentos comerciais de Vila Real, uma cidade do interior de Portugal. Vinte e três amostras foram submetidas a uma análise sensorial e a análises fisico-químicas - determinação do teor de azoto básico volátil total (ABVT), do índice de refração do humor aquoso e do pH. A avaliação da qualidade higiênica do pescado foi feita por meio de diferentes análises microbiológicas na superfície e na profundidade do músculo do pescado. O pescado fresco, considerado por todos os métodos de análise, próprio para consumo, apresentou estado de frescor entre bom e satisfatório. O ABVT foi considerado o método objetivo de eleição, sempre que surgiram dúvidas relativamente ao grau de frescor do pescado. O pescado próprio para consumo apresentou valores que variaram entre os 20,60 e 27,36mgN/100g e perfil microbiológico aceitável, com contagens de microrganismos psicrotróficos entre 5,41 e 6,03 UFC/cm² na superfície e entre 4,79 e 5,28 UFC/cm² no músculo.
A cidade de Santos no roteiro de expansão da homeopatia nos serviços públicos de saúde no Brasil
Authors: Justo Célia Maria Patriani , Gomes Mara H. de Andréa
Published: January 2008

Em coerência com os princípios de integralidade, eqüidade e universalidade presentes na reforma sanitária e na criação do Sistema Único de Saúde (SUS), alguns municípios passaram a oferecer a homeopatia como opção terapêutica. Este artigo aborda o contexto de implantação e consolidação da homeopatia na cidade de Santos (SP), até a sua incorporação como alternativa de atenção médica na rede pública de serviços de saúde. Naquela cidade, a implantação muito se deveu não só a médicos e farmacêuticos, mas também a médiuns receitantes que atuavam nos centros espíritas. Todos esses personagens tornaram possível a reivindicação de oferta dessa modalidade de atendimento pelos serviços de atenção primária do município. Nossa análise baseou-se em entrevistas com profissionais que participaram desse processo, em relatórios técnicos, artigos de jornais, revistas científicas e em livro escrito sobre a primeira sociedade espírita da cidade.
Ranking Community Health Status to Stimulate Discussion of Local Public Health Issues: The Wisconsin County Health Rankings
Authors: Peppard Paul E. , Kindig David A. , Dranger Elizabeth , Jovaag Amanda , Remington Patrick L.
Published: January 2008

United Health Foundation’s America’s Health Rankings, which ranks the states from “least healthy” to “healthiest,” receives wide press coverage and promotes discussion of public health issues. The University of Wisconsin Population Health Institute used the United Health Foundation’s model to develop the Wisconsin County Health Rankings (“Health Rankings”) from existing county-level data. The institute first released the rankings in 2004. A survey of the Wisconsin county health officers indicated that they intend to use the rankings for needs assessment, program planning, and discussion with county health boards. The institute implemented many of the health officers’ suggestions for improvement of the rankings in subsequent editions. The methods employed to create the rankings should be applicable in other states.
The Impact of Tobacco Control Programs on Adult Smoking
Authors: Farrelly Matthew C. , Pechacek Terry F. , Thomas Kristin Y. , Nelson David
Published: January 2008

Objectives. We examined whether state tobacco control programs are effective in reducing the prevalence of adult smoking.

Methods. We used state survey data on smoking from 1985 to 2003 in a quasi-experimental design to examine the association between cumulative state antitobacco program expenditures and changes in adult smoking prevalence, after we controlled for confounding.

Results. From 1985 to 2003, national adult smoking prevalence declined from 29.5% to 18.6% (P<.001). Increases in state per capita tobacco control program expenditures were independently associated with declines in prevalence. Program expenditures were more effective in reducing smoking prevalence among adults aged 25 or older than for adults aged 18 to 24 years, whereas cigarette prices had a stronger effect on adults aged 18 to 24 years. If, starting in 1995, all states had funded their tobacco control programs at the minimum or optimal levels recommended by the Centers for Disease Control and Prevention, there would have been 2.2 million to 7.1 million fewer smokers by 2003.

Conclusions. State tobacco control program expenditures are independently associated with overall reductions in adult smoking prevalence.
Proximal, Distal, and the Politics of Causation: What’s Level Got to Do With It?
Authors: Krieger Nancy
Published: January 2008

Causal thinking in public health, and especially in the growing literature on social determinants of health, routinely employs the terminology of proximal (or downstream) and distal (or upstream).

I argue that the use of these terms is problematic and adversely affects public health research, practice, and causal accountability. At issue are distortions created by conflating measures of space, time, level, and causal strength.

To make this case, I draw on an ecosocial perspective to show how public health got caught in the middle of the problematic proximal–distal divide—surprisingly embraced by both biomedical and social determinist frameworks—and propose replacing the terms proximal and distal with explicit language about levels, pathways, and power.
The Role of Attachment Style in Coping with Job Loss and the Empty Nest in Adulthood
Authors: Hobdy Juliann , Hayslip Bert , Kaminski Patricia L. , Crowley Barbara J. , Riggs Shelley , York Christina
Published: January 2008

The current study employed a life events perspective to examine the relationship between attachment style and both adjustment and coping processes in adults during two specific life events involving both the loss of and a renegotiation of an attachment relationship: the launching of children from the family of origin and job loss, which represent both normative and nonnormative transitions, respectively. Using median splits for each attachment dimension (closeness, dependency, and anxiety) to define secure, anxious, and avoidant styles, based on the work of Collins and Read, analyses failed to yield a significant multivariate life event by style interaction. However, a statistically significant multivariate main effect for life event and for attachment style was obtained. Additionally, findings suggested that to a certain extent, the impact of attachment style and life events is moderated by gender, wherein a supplemental analysis yielded a significant life event by gender by level of closeness interaction. The data support the notion that securely attached individuals may be more equipped to meet developmental life challenges in adulthood, and extend previous work that is limited to women and to the empty nest.
Alprazolam (Xanax®) Use among Southern Youth: Beliefs and Social Norms concerning Dangerous Rides on “Handlebars”
Authors: Peters Ronald J. , Meshack Angela F. , Kelder Steven H. , Webb Patrick , Smith Dexter , Garner Kevin
Published: January 2008

While the epidemiologic trends concerning alprazolam (Xanax®) are unknown, the use of benzodiazepines, in general, has increased in popularity among youth within recent years. To shed light on the drug problem, the current pilot study used a qualitative approach to investigate relevant beliefs, norms, and perceived addiction associated with alprazolam initiation among 46 youth who were attending an inpatient drug treatment program during the spring of 2004. Overwhelmingly, most participants stated that addiction to alprazolam occurs as early as initial consumption. Most youth in the study stated that their friends felt it was normal to use alprazolam. In addition, their control beliefs revealed that if someone wanted to stop it would be difficult because of the widespread use in their communities and family social reinforcement involved with its use. In this study, a majority of students stated that medical professionals such as doctors and pharmacists were the greatest facilitator of alprazolam acquisition. Implications for these results are discussed.
Gombrich, Galenson, and Beyond: Integrating Case Study and Typological Frameworks in the Study of Creative Individuals
Authors: Kozbelt Aaron
Published: January 2008

Art historian E. H. Gombrich raised challenging questions about creativity that remain neglected in contemporary psychological research. Emphasizing continuity with tradition, expertise, evaluation, and learning, Gombrich's foci exemplify a particular kind of creator, dubbed “seekers” by Galenson (2001, 2005). Gombrich's place in Galenson's typology and his own views on categories of creators motivate an overview of existing creative typologies. While in principle such typologies have great promise for bridging nomothetic and ideographic approaches to creativity, they have important limitations, like predominantly uni-dimensional structures and limited reliability and validity. Following Gombrich's (1960) principle of “ping and pong,” I argue that a further proliferation of such typologies would be counterproductive; a more informative strategy is to integrate them at the level of their components, rather than reconciling broad category labels.
Special Considerations in Conducting Bereavement Focus Groups
Authors: Briller Sherylyn H. , Schim Stephanie Myers , Meert Kathleen L. , Thurston Celia S.
Published: January 2008

Focus groups conducted with grieving people pose special challenges. However, this method can be successfully used in bereavement research especially when group interaction is central to the research aim. This article builds on key articles discussing ethical, methodological, logistical, and analytical issues in conducting focus groups with vulnerable populations (Owen, 2001; Seymour, Bellamy, Gott, Ahmedzai, & Clark, 2002). For bereaved people, vulnerability stems from heightened potential for harm by virtue of participation in sensitive, personal exploration of death-related experiences. We discuss reasons for selecting focus group methods and our experiences with planning and implementing focus groups with bereaved people. Issues found to be highly salient in our work include: team composition, participant recruitment, creating the environment, starting and ending the group, language and listening, managing emotional discussions and time, and analytic considerations. Recommendations are made for effectively using focus groups to generate new knowledge in bereavement research.
Modeling Effects of Transit System Transfers on Travel Behavior
Authors: Guo Zhan , Wilson Nigel H. M.
Published: January 2008

Transfers can have an important influence on customer satisfaction and on whether many customers find transit service an attractive option. An empirical investigation of transfers from commuter rail to subway in downtown Boston, Massachusetts, is performed. The research identifies a higher transfer penalty between commuter rail and subway than between subway lines. Fare payment and network familiarity also are shown to affect transfer decisions. Despite a large variation of the transfer experience between the stations analyzed, riders seem to have a similar perception of transfers. For example, in most cases, the perceived transfer penalty has a narrow distribution, with a coefficient of variation below 0.5. Potential applications of the research findings to transit planning are presented.
Microstimulation and architectonics of frontoparietal cortex in common marmosets (Callithrix jacchus)
Authors: Burish Mark J. , Stepniewska Iwona , Kaas Jon H.
Published: January 2008

We investigated the organization of frontoparietal cortex in the common marmoset (Callithrix jacchus) by using intracortical microstimulation and an architectonic analysis. Primary motor cortex (M1) was identified as an area that evoked visible movements at low levels of electric current and had a full body representation of the contralateral musculature. Primary motor cortex represented the contralateral body from hindlimb to face in a mediolateral sequence, with individual movements such as jaw and wrist represented in multiple nearby locations. Primary motor cortex was coextensive with an agranular area of cortex marked by a distinct layer V of large pyramidal cells that gradually decreased in size toward the rostral portion of the area and was more homogenous in appearance than other New World primates. In addition to M1, stimulation also evoked movements from several other areas of frontoparietal cortex. Caudal to primary motor cortex, area 3a was identified as a thin strip of cortex where movements could be evoked at thresholds similar to those in M1. Rostral to primary motor cortex, supplementary motor cortex and premotor areas responded to higher stimulation currents and had smaller layer V pyramidal cells. Other areas evoking movements included primary somatosensory cortex (area 3b), two lateral somatosensory areas (areas PV and S2), and a caudal somatosensory area. Our results suggest that frontoparietal cortex in marmosets is organized in a similar fashion to that of other New World primates. J. Comp. Neurol. 507:1151–1168, 2008. © 2008 Wiley‐Liss, Inc.
A 12‐week open‐label pilot study of donepezil for cognitive functioning and instrumental activities of daily living in late‐life bipolar disorder
Authors: Gildengers Ariel G. , Butters Meryl A. , Chisholm Denise , Reynolds Charles F. , Mulsant Benoit H.
Published: January 2008

Objective

To determine whether donepezil is effective in enhancing cognitive functioning and instrumental activities of daily living (IADLs) in older adults with bipolar disorder.

Methods

Twelve elderly patients with bipolar I or II disorder, with evidence of mild cognitive decrements, were administered donepezil 5–10 mg daily for 3 months. Participants had cognitive and functional evaluation pre‐, on‐, and 3‐months post donepezil administration.

Results

Three subjects dropped out of the study. In the remaining nine subjects, no significant effects were observed in cognitive and functional measures. Seven of the nine participants asked to resume the medication after completion of the study because of the perceived beneficial effects.

Conclusions

In this small pilot study of older adults with bipolar disorder, acute treatment with donepezil was not associated with improvements in cognitive and IADL functioning. Given limitations of the study design, placebo effects could not be ruled out in the subjects who asked to resume donepezil. Copyright © 2008 John Wiley & Sons, Ltd.
Association of body rolling, leg rolling, and rhythmic feet movements in a young adult: A video‐polysomnographic study performed before and after one night of clonazepam
Authors: Merlino Giovanni , Serafini Anna , Dolso Pierluigi , Canesin Roberto , Valente Mariarosaria , Luigi Gigli Gian
Published: January 2008

We report clinical and polysomnographic data of a young adult affected by several forms of rhythmic movement disorder (RMD), present in the same night, including a new kind of it, known as rhythmic feet movements. The patient was monitored by means of three consecutive video‐polysomnographic recordings, the first two performed to confirm the presence of the sleep disorder and the last one to observe the acute effectiveness of clonazepam on rhythmic movements. We discuss the characteristics of the RMD and the response to the first administration of pharmacological treatment, observed in our patient. © 2007 Movement Disorder Society
Brachial Plexopathy/Nerve Root Avulsion in a Football Player: The Role of Electrodiagnostics
Authors: Feinberg Joseph H. , Radecki Jeffrey , Wolfe Scott W. , Strauss Helene L. , Mintz Douglas N.
Published: January 2008

Electromyography (EMG) studies are a useful tool in anatomical localization of peripheral nerve and brachial plexus injuries. They are especially helpful in distinguishing between brachial plexopathy and nerve root injuries where surgical intervention may be indicated. EMG can also assist in providing prognostic information after nerve injury as well as after nerve repair. In this case report, a football player presented with weakness in his right upper limb after a traction/traumatic injury to the right brachial plexus. EMG studies revealed evidence of both pre- and postganglionic injury to multiple cervical roots. The injury was substantial enough to cause nerve root avulsions involving the C6 and C7 levels. Surgical referral led to nerve grafts targeted at regaining function in shoulder abduction and elbow flexion. After surgery, the patient's progress was monitored utilizing EMG to assist in identifying true axonal regeneration.
Influence of bed material size heterogeneity on bedload transport uncertainty
Authors: Chen Li , Stone Mark C.
Published: January 2008

The bed material grain size distribution of gravel bed streams is often spatially heterogeneous. The heterogeneity is actually a random parameter, even for a “well‐mixed mixture,” which potentially causes the transport rate for a given bed material to become an uncertain variable. The cause of bed material heterogeneity is the nonuniformity of the bed material, which is analyzed in this paper using examples from field observations and experimental data. The Monte Carlo simulation method is applied to study the uncertainty of the bedload transport rate using Wilcock's experimental data (P. R. Wilcock et al., 2001; P. R. Wilcock and J. C. Crowe, 2003). Each realization of the Monte Carlo simulation employed a randomly generated grain size distribution field for the entire simulation domain. With sufficient realizations the simulation results were adequate to show that the transport rates were a random variable and the mean transport rates did not fall on a single‐valued curve when the local heterogeneity was taken into account. The results indicate that the bedload transport rate of nonuniform sediment has an intrinsic uncertainty that can result solely from the bed material. The results also partially account for the scatter of the fractional transport rate within Wilcock's experimental data. This study presents an important concept in understanding the uncertainty associated with estimates of sediment transport.
Exact scaling laws for 3D electron MHD turbulence
Authors: Galtier S.
Published: January 2008

A von Kármán‐Howarth equation is derived for three‐dimensional (3D) electron magnetohydrodynamics (MHD) in the case of an homogeneous and isotropic turbulence. From this exact relation, we then derive the “one‐sixths” law for the third‐order correlation tensors; this is the analog of the Kolmogorov 4/5ths law for hydrodynamic turbulence. We show how this result is compatible with direct numerical simulations where a well‐extended k−7/3 energy spectrum is found. The observation of this exact relation in geophysical flows may be used as an evidence of the applicability of the electron MHD model.
An approximate theory of the ozone isotopic effects: Rate constant ratios and pressure dependence
Authors: Gao Yi Qin , Marcus R. A.
Published: January 2008

The isotopic effects in ozone recombination reactions at low pressures are studied using an approximate theory which yields simple analytic expressions for the individual rate constant ratios, observed under “unscrambled” conditions. It is shown that the rate constant ratio between the two competing channels XYZ→X+YZ and XYZ→XY+Z is mainly determined by the difference of the zero-point energies of diatomic molecules YZ and XY and by the efficiency of the deactivation of the newly formed excited ozone molecules, whereas the mass-independent fractionation depends on a “nonstatistical” symmetry factor η and the collisional deactivation efficiency. Formulas for the pressure effects on the enrichment and on the rate constant ratios are obtained, and the calculated results are compared with experiments and more exact calculations. In all cases, ratios of isotope rates and the pressure dependence of enrichments, the agreement is good. While the initial focus was on isotope effects in the formation of O3, predictions are made for isotope effects on ratios of rate constants in other reactions such as O+CO→CO2, O+NO→NO2, and O+SO→SO2.
Statics and dynamics of a cylindrical droplet under an external body force
Authors: Servantie J. , Müller M.
Published: January 2008

We study the rolling and sliding motion of droplets on a corrugated substrate by Molecular Dynamics simulations. Droplets are driven by an external body force (gravity) and we investigate the velocity profile and dissipation mechanisms in the steady state. The cylindrical geometry allows us to consider a large range of droplet sizes. The velocity of small droplets with a large contact angle is dominated by the friction at the substrate and the velocity of the center of mass scales like the square root of the droplet size. For large droplets or small contact angles, however, viscous dissipation of the flow inside the volume of the droplet dictates the center of mass velocity that scales linearly with the size. We derive a simple analytical description predicting the dependence of the center of mass velocity on droplet size and the slip length at the substrate. In the limit of vanishing droplet velocity we quantitatively compare our simulation results to the predictions and good agreement without adjustable parameters is found.
The role of short-ranged energetic correlations in the mobility field dependence of disordered organic materials
Authors: Tonezer Camila , Freire José A.
Published: January 2008

We studied the mobility of charge carriers in a model for disordered organic solids where the energies of the localized states are Gaussianly distributed with short-ranged correlations. We obtained an expression for the mobility as a function of electric field, temperature, energetic variance, and correlation radius. The temperature dependence obtained with short-ranged energetic correlations is different from that obtained with power-law decaying energetic correlations and suggests a possible way to distinguish the two types of correlations from the measured mobility. This work also presents a practical way of computing the mobility, applicable to any transport model based on a linear master equation, directly from the matrix of the hopping rates.
Two types of generalized integrable decompositions and new solitary-wave solutions for the modified Kadomtsev-Petviashvili equation with symbolic computation
Authors: Xu Tao , Zhang Hai-Qiang , Zhang Ya-Xing , Li Juan , Feng Qian , Tian Bo
Published: January 2008

The modified Kadomtsev-Petviashvili (mKP) equation is shown in this paper to be decomposable into the first two soliton equations of the 2N-coupled Chen-Lee-Liu and Kaup-Newell hierarchies by, respectively, nonlinearizing two sets of symmetry Lax pairs. In these two cases, the decomposed (1+1)-dimensional nonlinear systems both have a couple of different Lax representations, which means that there are two linear systems associated with the mKP equation under the same constraint between the potential and eigenfunctions. For each Lax representation of the decomposed (1+1)-dimensional nonlinear systems, the corresponding Darboux transformation is further constructed such that a series of explicit solutions of the mKP equation can be recursively generated with the assistance of symbolic computation. In illustration, four new families of solitary-wave solutions are presented and the relevant stability is analyzed.
High-performance carbon nanotube coatings for high-power laser radiometry
Authors: Ramadurai Krishna , Cromer Christopher L. , Lewis Laurence A. , Hurst Katherine E. , Dillon Anne C. , Mahajan Roop L. , Lehman John H.
Published: January 2008

Radiometry for the next generation of high-efficiency, high-power industrial lasers requires thermal management at optical power levels exceeding 10 kW. Laser damage and thermal transport present fundamental challenges for laser radiometry in support of common manufacturing processes, such as welding, cutting, ablation, or vaporization. To address this growing need for radiometry at extremely high power densities, we demonstrate multiwalled carbon nanotube (MWCNT) coatings with damage thresholds exceeding 15 000 W/cm2 and absorption efficiencies over 90% at 1.06 μm. This result demonstrates specific design advantages not possible with other contemporary high-power laser coatings. Furthermore, the results demonstrate a performance difference between MWCNTs and single-walled carbon nanotube coatings, which is attributed to the lower net thermal resistance of the MWCNT coatings. We explore the behavior of carbon nanotubes at two laser wavelengths (1.06 and 10.6 μm) and also evaluate the optical-absorption efficiency and bulk properties of the coatings.
Discharge phenomena associated with a preheated wire explosion in vacuum: Theory and comparison with experiment
Authors: Beilis I. I. , Baksht R. B. , Oreshkin V. I. , Russkikh A. G. , Chaikovskii S. A. , Labetskii A. Yu. , Ratakhin N. A. , Shishlov A. V.
Published: January 2008

This paper presents the experimental and simulation results of electrical explosions of preheated tungsten wires at a current rise time of several tens of nanoseconds and at a current density of ∼108A∕cm2. The electrical characteristics of wire explosion (WE) were measured. The image of a wire during the electrical explosion was obtained with the help of a framing camera. The proposed magnetohydrodynamic (MHD) model takes into account different stages of WE, namely, the wire heating and vaporization, the phase transition, and the shunting discharge. Two different mathematical approaches were used for WE simulation at different stages. At the first stage, the simulation included a code describing the wire state. At the second stage, the shunting discharge was simulated together with the wire state. The simulation code includes the set of MHD equations, the equilibrium equation of state (density and temperature-dependent pressure and specific internal energy), electron transport models (density and temperature-dependent electrical conductivity and thermal conductivity), and electric circuit equations. Thermionic emission and vapor ionization initiate the plasma layer, which develops around the wire core and supports the shunting discharge. The calculated waveforms of the wire voltage and current, as well as the velocity of the expanding plasma, are in a good agreement with the experimental data.
Influences of ZnO sol-gel thin film characteristics on ZnO nanowire arrays prepared at low temperature using all solution-based processing
Authors: Huang Jing-Shun , Lin Ching-Fuh
Published: January 2008

Zinc oxide (ZnO) nanowire arrays with controlled nanowire diameter, crystal orientation, and optical property were prepared on sol-gel ZnO-seed-coated substrates with different pretreatment conditions by a hydrothermal method. The vertical alignment, crystallinity, and defect density of ZnO nanowire arrays are found to be strongly dependent on the characteristics of the ZnO thin films. Field-emission scanning electron microscopy, energy dispersive spectroscopy, x-ray diffraction, and room temperature photoluminescence were applied to analyze the quality of the ZnO nanowire arrays. The annealing temperature of the ZnO thin film plays an important role on the microstructure of the ZnO grains and then the growth of the ZnO nanowire arrays. The x-ray diffraction results indicate that the thin film annealed at the low temperature of 130°C is amorphous, but the thereon nanowire arrays are high-quality single crystals growing along the c-axis direction with a high consistent orientation perpendicular to the substrates. The as-synthesized ZnO nanowire arrays via all solution-based processing enable the fabrication of next-generation nanodevices at low temperature.
Valence band offset of ZnO∕GaAs heterojunction measured by x-ray photoelectron spectroscopy
Authors: Zhang P. F. , Liu X. L. , Zhang R. Q. , Fan H. B. , Yang A. L. , Wei H. Y. , Jin P. , Yang S. Y. , Zhu Q. S. , Wang Z. G.
Published: January 2008

X-ray photoelectron spectroscopy has been used to measure the valence band offset at the ZnO∕GaAs heterojunction interface. The valence band offset is determined to be 2.39±0.23eV. As a consequence, a type-II heterojunction with a conduction band offset of −0.44±0.23eV is found. The directly obtained value is in good agreement with the result of theoretical calculations based on the interface-induced gap states and the chemical electronegativity theory.
Charge transport mechanisms in microcrystalline silicon
Authors: Konezny S. J. , Bussac M. N. , Zuppiroli Libero
Published: January 2008

A heterogeneous charge transport model for microcrystalline silicon based on fluctuation-induced tunneling is presented that fits the low-temperature saturation observed in dark conductivity measurements and accounts for the film microstructure. Excellent agreement is found when the model is applied to data reported in the literature, particularly for highly crystalline samples, which produce the highest performance transistors. Values obtained for the three fitting parameters are consistent with typical measurements of microcrystalline silicon film morphology and the conduction band offset between amorphous and crystalline silicons.
A multiaxial stretchable interconnect using liquid-alloy-filled elastomeric microchannels
Authors: Kim Hyun-Joong , Son Chulwoo , Ziaie Babak
Published: January 2008

We report on the fabrication and characterizations of a multiaxial stretchable interconnect using room-temperature liquid-alloy-filled elastomeric microchannels. Polydimethylsiloxane (PDMS) microchannels coated at the bottom with a gold wetting layer were used as the reservoirs which were subsequently filled by room-temperature liquid alloy using microfluidic injection technique. Using a diamond-shaped geometry to provide biaxial performance, a maximum stretchability of 100% was achieved (ΔR=0.24Ω). Less than 0.02Ω resistance variation was measured for 180° bending. Active electronics, light emitting diode, was also integrated onto the PDMS substrate with stretchable interconnects to demonstrate stable electrical connection during stretching, bending, and twisting.
Fullerene thermal insulation for phase change memory
Authors: Kim Cheolkyu , Suh Dong-Seok , Kim Kijoon H. P. , Kang Youn-Seon , Lee Tae-Yon , Khang Yoonho , Cahill David G.
Published: January 2008

Phase change random access memory (PRAM) is unique among semiconductor devices because heat is intrinsic to the operation of the device, not just a by-product. Here, we apply a material that is exotic in the context of typical semiconductor devices but has highly desirable properties for PRAM. Thin films of C60 are semiconducting and show very low thermal conductance. By inserting a C60 layer between the phase change material and the metal electrode, we dramatically reduced the heat dissipation and, thereby, the operating current. A PRAM device incorporating a C60 layer operated stably for more than 105cycles.
New experiments view details of nuclear two-proton emission
Authors: Blau Steven K.
Published: January 2008

A decay mode predicted almost 50 years ago has been directly observed for the first time.
Visualization of AP-1–NF-κB ternary complexes in living cells by using a BiFC-based FRET
Authors: Shyu Y. John , Suarez Christopher D. , Hu Chang-Deng
Published: January 2008

Protein–protein interactions are essential for maintaining cell structure and for executing almost all cellular processes. Determination of where and how each protein interacts with its partners provides significant insight into proteins' cellular roles. Although several assays, such as FRET and bimolecular fluorescence complementation (BiFC), have been developed and widely used for visualization and identification of protein interactions in living cells, there is no simple and convenient assay to visualize and identify multiple protein complexes in living cells. Because many signaling molecules often function as ternary complexes, availability of an assay for visualization and identification of ternary complexes will significantly expand the repertoire of protein interaction studies in living cells. By using the Fos–Jun–nuclear factor of activated T cells (NFAT) ternary complex as a model and the fluorescent proteins Cerulean and Venus, two mutant proteins of CFP and YFP with better folding and less environment sensitivity, as a donor and acceptor, respectively, we have combined a Venus-based BiFC system with Cerulean to develop a BiFC-based FRET (BiFC-FRET) assay for visualization of ternary complexes in living cells with a conventional three-filter FRET setup. We also have applied the BiFC-FRET to identify a ternary complex formed between Fos–Jun heterodimers and the NF-κB subunit, p65. This finding reveals a cross-talk between AP-1 and NF-κB. Thus, the BiFC-FRET represents a convenient assay for identification and visualization of ternary complexes in living cells.
Photolysis of a caged peptide reveals rapid action of
N
-ethylmaleimide sensitive factor before neurotransmitter release
Authors: Kuner T. , Li Y. , Gee K. R. , Bonewald L. F. , Augustine G. J.
Published: January 2008

The time at which the
N
-ethylmaleimide-sensitive factor (NSF) acts during synaptic vesicle (SV) trafficking was identified by time-controlled perturbation of NSF function with a photoactivatable inhibitory peptide. Photolysis of this caged peptide in the squid giant presynaptic terminal caused an abrupt (0.2 s) slowing of the kinetics of the postsynaptic current (PSC) and a more gradual (2–3 s) reduction in PSC amplitude. Based on the rapid rate of these inhibitory effects relative to the speed of SV recycling, we conclude that NSF functions in reactions that immediately precede neurotransmitter release. Our results indicate the locus of SNARE protein recycling in presynaptic terminals and reveal NSF as a potential target for rapid regulation of transmitter release.
A geological excursion in the Wadi Fatima area, near Jiddah, Saudi Arabia
Authors: GRAINGER DAVID J.
Published: January 2008

Wadi Fatima, east of jiddah on the Red Sea coast of Saudi Arabia, is a microcosm of the geology of the jiddah area. Rocks ranging in age from 800‐million‐year‐old metamorphic rocks to Tertiary lava flows are exposed, and illustrate the geological richness of western Saudi Arabia. The valley is a major south‐west‐trending fault zone that has been active since Precambrian times. A major Tertiary dyke swarm in the vicinity of Wadi Fatima is related to the opening of the Red Sea as the African‐Arabian landmass split apart.
The Silurian geology of Gotland, Sweden
Authors: KERSHAW STEVE
Published: January 2008

Gotland is an island in the central Baltic, long recognized as the most outstanding outcrop of Silurian shallow‐water marine sediments in the world. These represent deposition in tropical environments in an epeiric sea on the small continent of Baltica. The sediments are interbedded limestones and shales with subordinate sandstones and are developed as a carbonate platform on the underlying Precambrian, Cambrian and Ordovician. Particularly spectacular are reef deposits, rich in stromatoporoid sponges, which occur throughout the Gotland sequence. The sequence is almost undisturbed and provides an excellent field laboratoy to study a variety of Silurian facies.
Zimbabwe: a country rich in geological history
Authors: WILDING RICHARD
Published: January 2008

A holiday in Zimbabwe provided the opportunity to examine some of the rocks, many of Archaean age, in one of the geologically most interesting parts of the world. Here, a great deal of the Earth's geological history can be unravelled.
Geological excursion guide 9: Jamaica
Authors: DONOVAN STEPHEN K.
Published: January 2008

Apart from its obvious attractions for the visiting tourist, Jamaica is geologically significant, with a rock record dating from the Cretaceous and occupying a position at the north–east end of the Nicaraguan Rise, adjacent to the North Caribbean Plate Boundary Zone. During the Cretaceous, Jamaica was part of an island arc, but since the Eocene the rock record has been dominated by limestones.
Lake Bogoria, Kenya: soda, hot springs and about a million flamingoes
Authors: RENAUT ROBIN W. , TIERCELIN JEAN‐JACQUES
Published: January 2008

Lake Bogoria is a saline, alkaline, meromictic lake in a geothermally active part of the Kenya Rift Valley. Coring of the lake floor has shown two types of sedimentation – a shallow fan–deltaic clastic zone and a deeper zone with alternating organic muds and evaporites. The organic muds formed during periods of relatively high lake level and high microbial productivity, the evaporites during more arid phases. Analyses of the cores show many environmental fluctuations during the past 30000 years, related to regional climatic changes and to local tectonic and hydrological controls.
Famines and cataclysmic volcanism
Authors: WHITE ROBERT S. , HUMPHREYS COLIN J.
Published: January 2008

The gases released by some large volcanic eruptions in history (e.g. Santorini in the seventeenth century BC) have led to famine. Similar events are likely in the future but could be made worse by the huge quantities of material already in the atmosphere as a result of industrial and domestic Processes.
The beating heart of Earth's climate revealed: caves5 coral reefs and coastlines in the Balearic Islands
Authors: LYNAS BRYAN
Published: January 2008

Studies of cave formations, an exhumed Miocene reef platform and drowned Pleistocene coastlines in the Balearic Islands show how sea levels are constantly changing. Could even more exhaustive studies of this sort help us predict future climates'?
Frederick M'Coy: an eminent Victorian palaeontologist and his synopses of Irish palaeontology of 1844 and 1846
Authors: JACKSON PATRICK N. WYSE , MONAGHAN NIGEL T.
Published: January 2008

To most modern‐day students of palaeontology, the name Frederick M'Coys (c. 1823–1899) is familiar; to other Earth scientists it possibly won't be. Who was M'Coy and why is 1994 a significant year for palaeontologists and historians of the Earth sciences? This year marks the sesquicentenary of the publication of M'Coy's A Synopsis of the Characters of the Carboniferous Limestone Fossils of Ireland (1844). This monograph, together with that for Lower Palaeozoic fossils, A Synopsis of the Silurian Fossils of Ireland, published two years later, which describe the collections of Richard Griffith, remain highly important to palaeontologists working today.
The local geologist 14: Museums, geology and the National Curriculum
Authors: SLADEN SUE
Published: January 2008

Museums may not be the first place that people think of in connection with a scientific specialism such as geology. They are more frequently associated with the study of history: the Victorians, the Romans, Ancient Egypt. This popular misconception is not, however, based on fact; the Doughty Report of the early 1980s showed that there are around 300 museums in Britain with geology collections just waiting to be used.
Fountaineering
Authors: ROBINSON ERIC
Published: January 2008

Old fountains offer yet another way of approaching geology and learning about rocks.
CAROTENOID PIGMENTS AND THE IN VIVO SPECTRUM OF BACTERIOCHLOROPHYLL
Authors: Crounse J. , Sistrom W. R. , Nemser Suzanne
Published: January 2008

Abstract— The isolation of a mutant, strain PM‐9, of Rhodopseudonionus spheroides with an abnormal complement of carotenoid pigments is described.

PM‐9 accumulates phytoene, phytofluene, ζ‐carotene and neurosporene. Semi‐aerobic cultures form more ζ‐carotene and neurosporene relative to total carotenoids than do photo‐synthetic cultures.

PM‐9 is killed on exposure to light and oxygen.

By making use of the effect of oxygen on the nature of the carotenoids in PM‐9, we have shown that these pigments do not directly influence the in vivo spectrum of bacteriochlorophyll.

Diphenylamine inhibits the synthesis of coloured carotenoids in Rhodopseudonionos gelatinosa but does not change the bacteriochlorophyll spectrum.
RôLE OF DNA REPAIR MECHANISMS IN MICROBIAL INACTIVATION AND RECOVERY PHENOMENA1
Authors: Haynes Robert H.
Published: January 2008

Summary We have described what appears to be the major cause of death in bacteria treated with ultraviolet light, X‐rays or nitrogen mustard (HN2): all of these agents produce structural defects in DNA which, unless repaired, are likely to inhibit DNA synthesis or cause some error in protein synthesis, which leads to cell death. Thus, survival is determined by the net probability that these defects either persist and prove lethal, or are repaired after irradiation during the first few hours of incubation on the plating medium. The apparent correlations of u.v., X‐ray and HN2 sensitivity with DNA base composition suggest that the relevant damage caused by these agents is associated with adenine‐thymine base pairs for u.v. and guanine.
ON THE MECHANISM OF PHOTOSENSITIZING ACTION OF CHLOROPHYLL
Authors: Evstigneev V. B.
Published: January 2008

Abstract— The paper presents ideas according to which the primary photochemical reaction of chlorophyll and its analogs can be either photooxidation or photoreduction of the pigment sensitizer depending on the reaction conditions. The factors determining the course of the process of photosensitization comprise the nature and state of the pigment and participating reagents, the nature and reaction of the medium, concentration of the oxidant and reductant, their ability to form complexes with the pigment, etc.

The paper presents the results of simple kinetic investigations in which, by means of changing pH of the medium, conditions were created favouring either the primary photo‐oxidation or the primary photoreduction of the pigment‐sensitizer. These results, as well as the data of experiments on the changes in reagents' concentration show the reality of the above mentioned concepts.

Considerations are presented on the possibility of photochemical interaction of two chlorophyll molecules in vivo during the photosensitization of photosynthesis.