bluuebunny/crossref_metadata_2025 huggingface dataset:
Moving cautiously: Public involvement and the health technology assessment community
Authors: Gauvin François-Pierre , Abelson Julia , Giacomini Mita , Eyles John , Lavis John N.
Published: January 2011

Objectives: This study explores the factors that enhance or reduce the prospects for public involvement in the activities of health technology assessment (HTA) agencies.

Methods: The analytical framework for this study is based on the work of John W. Kingdon, which provides a comprehensive synthesis of the factors influencing governments and public organizations' agenda. The study draws insights from forty-two semistructured telephone interviews with informants involved in international HTA networks and/or in HTA agencies in Canada, Denmark, and the United Kingdom.

Results: This exploratory study suggests that the HTA community is moving toward greater public involvement. However, the HTA community remains cautious and ambivalent about the technical feasibility of public involvement, its acceptability to policy makers and practitioners, and its impacts on HTA agencies' resources and procedures.

Conclusions: The study stresses the importance of conducting rigorous and compelling evaluations to inform HTA agencies' decision to adopt, or reject, public involvement practices.
Reply to the letter by Mundy, Hiller, and Merlin on the true role of horizon scanning in Australia
Authors: O'Malley Susanne P. , Jordan Ernest
Published: January 2011

Thank you for the opportunity to reply to the letter by Mundy, Hiller, and Merlin “The true role of horizon scanning in Australia: Who it informs and why”. This letter states that our paper (1) “Horizon scanning of new and emerging medical technology in Australia: Its relevance to Medical Services Advisory Committee health technology assessments and public funding,” published in July 2009, contains fundamental errors and misunderstands the process it claims to describe.
ICER is good for us—Possibly not for you, he or she
Authors: Pekurinen Markku
Published: January 2011

Cleemput et al. make a point that the incremental cost-effectiveness ratio (ICER) alone is not a sufficient criterion to guide decision making in health care, and needs many other supplementary inputs. This is nothing new, it has been well known for years to researchers and decision makers alike. ICER serves as an important ingredient to guide decision making, at least in some healthcare systems.
Introducing patients' and the public's perspectives to health technology assessment: A systematic review of international experiences
Authors: Gagnon Marie-Pierre , Desmartis Marie , Lepage-Savary Dolorès , Gagnon Johanne , St-Pierre Michèle , Rhainds Marc , Lemieux Renald , Gauvin Francois-Pierre , Pollender Hugo , Légaré France
Published: January 2011

Objectives:The aim of this study was to review international experiences of patient or public involvement in the field of health technology assessment (HTA).

Methods:A systematic review of the scientific literature was conducted. A literature search was performed across nine databases. Other literature was identified through citation tracking, government websites (HTA agencies), and Internet search engines. Characteristics of the studies, description of the activities related to patient or public involvement, impact of these activities on the HTA process, and factors facilitating or limiting involvement were abstracted independently by two reviewers.

Results:A total of 1,441 potentially relevant papers were identified by the main search strategy. Among these, seventeen papers met the inclusion criteria; other search strategies identified seven additional documents. The findings reveal that patient or public involvement in HTA activities was reported in two domains, research and HTA process. In the research domain, patients are consulted to gather evidence about their perspectives, experiences, or preferences about a health technology. These perspectives could add key dimensions to the evaluation of health technologies that might otherwise be overlooked. In the domain of the HTA process, patients or public representatives participate in different stages of this process: prioritization, evidence assessment, or dissemination of findings.

Conclusions:There are few published examples of experiences involving patients and the public in HTA. These examples show that patients' or the public's perspectives could add important dimensions to the evaluation of health technologies. However, there is a need to develop more systematic approaches to considering patients' and the public's perspectives in HTA.
Catalytic properties of the retinal rod outer segment disk ADP-ribosyl cyclase
Authors: FABIANO ANDREA , PANFOLI ISABELLA , CALZIA DANIELA , BRUSCHI MAURIZIO , RAVERA SILVIA , BACHI ANGELA , CATTANEO ANGELA , MORELLI ALESSANDRO , CANDIANO GIOVANNI
Published: January 2011

Cyclic ADP-ribose (cADPR) is a second messenger modulating intracellular calcium levels. We have previously described a cADPR-dependent calcium signaling pathway in bovine rod outer segments (ROS), where calcium ions play a pivotal role. ROS ADP-ribosyl cyclase (ADPR-cyclase) was localized in the membrane fraction. In the present work, we examined the properties of the disk ADPR-cyclase through the production of cyclic GDP-ribose from the NAD+analogue NGD+. The enzyme displayed an estimatedKmfor NGD+of 12.5 ± 0.3μM, aVmaxof 26.50 ± 0.70 pmol cyclic GDP-ribose synthesized/min/mg, and optimal pH of 6.5. The effect of divalent cations (Zn2+, Cu2+, and Ca2+) was also tested. Micromolar Zn2+and Cu2+inhibited the disk ADPR-cyclase activity (half maximal inhibitory concentration, IC50= 1.1 and 3.6μM, respectively). By contrast, Ca2+ions had no effect. Interestingly, the properties of the intracellular membrane–associated ROS disk ADPR-cyclase are more similar to those of the ADPR-cyclase found in CD38-deficient mouse brain, than to those of CD38 or CD157. The novel intracellular mammalian ADPR-cyclase would elicit Ca2+release from the disks at various rates in response to change in free Ca2+concentrations, caused by lightversusdark adaptation, in fact there was no difference in disk ADPR-cyclase activity in light or dark conditions. Data suggest that disk ADPR-cyclase may be a potential target of retinal toxicity of Zn2+and may shed light to the role of Cu2+and Zn2+deficiency in retina.
Subgraphs of Dense Random Graphs with Specified Degrees
Authors: McKAY BRENDAN D.
Published: January 2011

Let d = (d1, d2, . . ., dn) be a vector of non-negative integers with even sum. We prove some basic facts about the structure of a random graph with degree sequence d, including the probability of a given subgraph or induced subgraph.

Although there are many results of this kind, they are restricted to the sparse case with only a few exceptions. Our focus is instead on the case where the average degree is approximately a constant fraction of n.

Our approach is the multidimensional saddle-point method. This extends the enumerative work of McKay and Wormald (1990) and is analogous to the theory developed for bipartite graphs by Greenhill and McKay (2009).
Factors affecting success of blood pressure measurements during ambulatory blood pressure monitoring in children with renal disease
Authors: Sinha Manish D. , Booth Caroline J. , Reid Christopher J.D.
Published: January 2011

Aim

To analyse blood pressure characteristics during 24-hour ambulatory blood pressure monitoring in children and to assess factors that influence its success over 24 hours and during patient-recorded awake (DAY) and sleep (NIGHT) periods.

Methods

A total of 169 consecutive ambulatory blood pressure monitoring studies were conducted in 154 patients over 30 months. For each ambulatory study, we measured the percentage of successful measurements both at the first attempt (S-initial%) and following any automated repeat attempt if initial attempts had failed (S-final%). These were measured over 24-hour, DAY, and NIGHT periods.

Results

We found that blood pressure measurements at NIGHT were more successful than measurements attempted during the DAY (p<0.05). There was no influence of age, gender, height, weight, body mass index and estimated glomerular filtration rate with the proportion of successful measurements during the 24-hour, DAY, and NIGHT periods. On stepwise multiple regression analysis, the indexed mean systolic blood pressure over 24 hours was the only factor having a significant influence on the proportion of successful measurements over the 24-hour and DAY periods, although it only accounted for three-tenths of the variance; it had no influence on the overall success of measurements at NIGHT.

Conclusion

Ambulatory blood pressure monitoring in children provides reliable data both during the patient's awake and sleep periods with higher success of measurements at NIGHT as opposed to DAY periods.
ATOMIC DECOMPOSITION OF WEIGHTED TRIEBEL–LIZORKIN SPACES ON SPACES OF HOMOGENEOUS TYPE
Authors: LI JI
Published: January 2011

We obtain an atomic decomposition for weighted Triebel–Lizorkin spaces on spaces of homogeneous type, using the area function, the discrete Calderón reproducing formula and discrete sequence spaces.
A general framework for equivalences in Answer-Set Programming by countermodels in the logic of Here-and-There
Authors: FINK MICHAEL
Published: January 2011

Different notions of equivalence, such as the prominent notions of strong and uniform equivalence, have been studied in Answer-Set Programming, mainly for the purpose of identifying programs that can serve as substitutes without altering the semantics, for instance in program optimization. Such semantic comparisons are usually characterized by various selections of models in the logic of Here-and-There (HT). For uniform equivalence however, correct characterizations in terms of HT-models can only be obtained for finite theories, respectively programs. In this paper, we show that a selection of countermodels in HT captures uniform equivalence also for infinite theories. This result is turned into coherent characterizations of the different notions of equivalence by countermodels, as well as by a mixture of HT-models and countermodels (so-called equivalence interpretations). Moreover, we generalize the so-called notion of relativized hyperequivalence for programs to propositional theories, and apply the same methodology in order to obtain a semantic characterization which is amenable to infinite settings. This allows for a lifting of the results to first-order theories under a very general semantics given in terms of a quantified version of HT. We thus obtain a general framework for the study of various notions of equivalence for theories under answer-set semantics. Moreover, we prove an expedient property that allows for a simplified treatment of extended signatures, and provide further results for non-ground logic programs. In particular, uniform equivalence coincides under open and ordinary answer-set semantics, and for finite non-ground programs under these semantics, also the usual characterization of uniform equivalence in terms of maximal and total HT-models of the grounding is correct, even for infinite domains, when corresponding ground programs are infinite.
Detecting inconsistencies in large biological networks with answer set programming
Authors: GEBSER MARTIN , SCHAUB TORSTEN , THIELE SVEN , VEBER PHILIPPE
Published: January 2011

We introduce an approach to detecting inconsistencies in large biological networks by using answer set programming. To this end, we build upon a recently proposed notion of consistency between biochemical/genetic reactions and high-throughput profiles of cell activity. We then present an approach based on answer set programming to check the consistency of large-scale data sets. Moreover, we extend this methodology to provide explanations for inconsistencies by determining minimal representations of conflicts. In practice, this can be used to identify unreliable data or to indicate missing reactions.
Limitations on the Substitutability of Self-Protective Processes
Authors: McCrea Sean M. , Hirt Edward R.
Published: January 2011

Goal-striving and achievement can be undermined when individuals have a competing desire to protect a cherished self-view. When individuals are more concerned with avoiding the negative implications of a likely failure than with self-improvement, they may ignore negative information or may even go so far as to purposefully undermine their own performance. For example, self-handicapping involves creating or claiming obstacles to success in order to protect self-esteem in the event of task failure. One method to reduce such destructive behavior is to address self-protection concerns through other means. Notably, affirming overall self-integrity by drawing attention to other positive aspects of the self has been previously shown to reduce subsequent self-handicapping behavior. The present studies demonstrate, however, that these effects may not be as broad as previously assumed. Specifically, only self-affirmations in domains unrelated to the current threat seem to be effective in reducing self-handicapping. Self-affirmations related to the threatened domain may only serve to create a standard of comparison for the current performance, maintaining or even intensifying the existing threat. Thus, it appears that attempts to protect a specific self-conception can severely hamper goal-striving and subsequent achievement. Implications for understanding the motivations underlying self-handicapping and for reducing this self-defeating behavior are discussed.
If-Then Planning Helps School-Aged Children to Ignore Attractive Distractions
Authors: Wieber Frank , von Suchodoletz Antje , Heikamp Tobias , Trommsdorff Gisela , Gollwitzer Peter M.
Published: January 2011

Can children improve shielding an ongoing task from distractions by if-then planning (i.e., by forming implementation intentions)? In an experimental study, the situational and personal limits of action control by distraction-inhibiting implementation intentions (“If a distraction comes up, then I will ignore it!”) were tested by comparing them to simple goal intentions (“I will ignore distractions!”). Goal intentions were sufficient to successfully ignore distractions of low attractiveness. In the presence of moderately and highly attractive distractions, as well as a distraction presented out of the children’s sight, however, only implementation intentions improved children’s task shielding, as indicated by faster response times in an ongoing categorization task and shorter periods of looking at highly attractive distractions presented out of their field of vision. These findings held true regardless of the children’s temperament and language competency. Implications for research on planning and developmental research on self-control are discussed.
Nonconceptual Representations for Action and the Limits of Intentional Control
Authors: Pacherie Elisabeth
Published: January 2011

In this paper I argue that, to make intentional actions fully intelligible, we need to posit representations of action the content of which is nonconceptual. I further argue that an analysis of the properties of these nonconceptual representations, and of their relationships to action representations at higher levels, sheds light on the limits of intentional control. On the one hand, the capacity to form nonconceptual representations of goal-directed movements underscores the capacity to acquire executable concepts of these movements, thus allowing them to come under intentional control. On the other hand, the degree of autonomy these nonconceptual representations enjoy, and the specific temporal constraints stemming from their role in motor control, set limits on intentional control over action execution.
On the local concentration probability density function of solutes reacting upon mixing
Authors: Bellin A. , Severino G. , Fiori A.
Published: January 2011

The probability density function (pdf) of solute concentration is a useful tool for modeling transport of contaminants in heterogeneous aquifers that is increasingly used in risk assessment and, more generally, as a mean to quantify uncertainty in transport modeling. In order to be effective the pdfs should be linked in a simple manner to the spatial variability model of hydraulic properties, pore‐scale (local) dispersion, and a suitable parametrization of the geochemical processes. We analyze the pdf and concentration moments of two aqueous species in equilibrium with their precipitate reacting upon mixing in two‐ and three‐dimensional geological formations. The speciation equations, resulting from application of the chromatographic theory, provide the link between concentration pdfs (and moments) of the aqueous species and that of a passive tracer. Within this framework, we investigate the role of pore‐scale dispersion and macrodispersion in enhancing mixing, and thus reaction between the aqueous species, in the case of an instantaneous injection of a water with contrasting concentrations with respect to the ambient water under the constraint that in both waters the two aqueous species are in equilibrium with their precipitate. The main conclusion of our analysis is that for the pore‐scale dispersion typically observed in natural formations, the local concentration pdfs of both species are far from being Gaussian, and therefore the first two concentration moments provide very limited information of the underlying transport dynamics. Instead, the pdfs provide crucial information for applications, such as the probability of exceeding a given concentration, for example, the regulatory limit, at a particular location within the domain of interest. Furthermore, by analyzing the second‐order moments of the concentration, we show that mixing is strongly affected by space dimensionality and that the two‐dimensional approach, often used for computational convenience, may severely underestimate reaction rates in real settings.
Weight Loss Goals Among African‐American Women With Type 2 Diabetes in a Behavioral Weight Control Program
Authors: White Della B. , Bursac Zoran , DiLillo Vicki , West Delia S.
Published: January 2011

African‐American women with type 2 diabetes experience limited weight loss in behavioral weight control programs. Some research suggests that overly ambitious weight loss expectations may negatively affect weight losses achieved but it is unknown whether they affect weight loss among African‐American women. The current study examined personal weight loss goals and expected satisfaction with a reasonable weight loss among African‐American women with type 2 diabetes starting a behavioral obesity treatment. We also explored associations among these factors and weight loss treatment outcomes. Self‐identified African‐American women (N = 84) in a 24‐session group program were assessed at baseline and 6‐month follow‐up. At baseline, women indicated weight loss goals of 14.1 ± 6.6 kg (14% of initial weight). They also reported relatively high expected satisfaction with a reasonable weight loss (7–10%). On average, participants lost 3.0 ± 3.9 kg (3% of initial weight) and attended 73 ± 21% of group sessions. Neither weight loss goals nor expected satisfaction with a reasonable weight loss was correlated with either actual weight loss outcome or attendance. Having higher personal weight loss goals was associated with lower expectations of satisfaction with a reasonable weight loss. This suggests that African‐American women with type 2 diabetes enter treatment hoping to lose far more weight than they are likely to achieve. It is important to understand the psychosocial sequelae of failing to reach these goals on subsequent weight maintenance and future weight loss attempts within this population.
Note: Electrostatic beams from a 5 T Penning–Malmberg trap
Authors: Weber T. R. , Danielson J. R. , Surko C. M.
Published: January 2011

A procedure is described to extract beams from specially tailored electron plasmas in a Penning–Malmberg trap in a 4.8 T field. Transport to 1 mT is followed by extraction from the magnetic field and electrostatic focusing. Potential applications to positron beams are discussed.
Sagnac-loop phase shifter with polarization-independent operation
Authors: Ng Tien Tjuen , Gosal Darwin , Lamas-Linares Antía , Kurtsiefer Christian
Published: January 2011

A bulk-optics, polarization-independent phase shifter for photonic quantum information applications is demonstrated. The device is based on a transverse electro-optic modulator in a Sagnac-type loop containing Faraday rotators. This direction-dependent polarization rotation in the loop is combined with a Mach–Zehnder interferometer to form an optical switch with an on/off contrast of 96% and a switching time of 1.6 ns. We demonstrate that the device's operation maintains any arbitrary polarization state.
Cold atmospheric pressure plasma jet interactions with plasmid DNA
Authors: O’Connell D. , Cox L. J. , Hyland W. B. , McMahon S. J. , Reuter S. , Graham W. G. , Gans T. , Currell F. J.
Published: January 2011

The effect of a cold (<40 °C) radio frequency-driven atmospheric pressure plasma jet on plasmid DNA has been investigated. Gel electrophoresis was used to analyze the DNA forms post-treatment. The experimental data are fitted to a rate equation model that allows for quantitative determination of the rates of single and double strand break formation. The formation of double strand breaks correlates well with the atomic oxygen density. Taken with other measurements, this indicates that neutral components in the jet are effective in inducing double strand breaks.
Automated estimation of rare event probabilities in biochemical systems
Authors: Daigle Bernie J. , Roh Min K. , Gillespie Dan T. , Petzold Linda R.
Published: January 2011

In biochemical systems, the occurrence of a rare event can be accompanied by catastrophic consequences. Precise characterization of these events using Monte Carlo simulation methods is often intractable, as the number of realizations needed to witness even a single rare event can be very large. The weighted stochastic simulation algorithm (wSSA) [J. Chem. Phys. 129, 165101 (2008)] and its subsequent extension [J. Chem. Phys. 130, 174103 (2009)] alleviate this difficulty with importance sampling, which effectively biases the system toward the desired rare event. However, extensive computation coupled with substantial insight into a given system is required, as there is currently no automatic approach for choosing wSSA parameters. We present a novel modification of the wSSA—the doubly weighted SSA (dwSSA)—that makes possible a fully automated parameter selection method. Our approach uses the information-theoretic concept of cross entropy to identify parameter values yielding minimum variance rare event probability estimates. We apply the method to four examples: a pure birth process, a birth-death process, an enzymatic futile cycle, and a yeast polarization model. Our results demonstrate that the proposed method (1) enables probability estimation for a class of rare events that cannot be interrogated with the wSSA, and (2) for all examples tested, reduces the number of runs needed to achieve comparable accuracy by multiple orders of magnitude. For a particular rare event in the yeast polarization model, our method transforms a projected simulation time of 600 years to three hours. Furthermore, by incorporating information-theoretic principles, our approach provides a framework for the development of more sophisticated influencing schemes that should further improve estimation accuracy.
The free volume of poly(vinyl methylether) as computed in a wide temperature range and at length scales up to the nanoregion
Authors: Račko Dušan , Capponi S. , Alvarez F. , Colmenero J.
Published: January 2011

In the present work, we focus on the free volume evaluations from different points of view, including the aspect of probe sizes, temperature, and cavity threshold. The free volume structure is analyzed on structures of poly(vinyl methylether) prepared by fully atomistic molecular dynamics. At first, the temperature behavior of an overall free volume and a free volume separated into individual cavities is shown. The origin of large free volume cavities is explained. A complex view on the cavity number is provided, while a complicated behavior previously observed is now explained. The number of large cavities remained almost constant with the temperature. Oppositely, the number of small cavities related to the atomic packing changes with temperature in a distinct way for glassy and supercooled regions. The cavity number maxima determine a percolation threshold according to percolation theory. The change in polymer properties with temperature can be related to a percolation of the free volume according to the free volume theory, when proper probe radii ∼0.8 Å are used for its observation. A construction of probabilistic distribution of free volume sizes is suggested. The free volume distributions reported here are bimodal. The bimodal character is explained by two different packings—atomic and segmental—forming a prepeak and a main peak on the distribution. Further attention is dedicated to comparisons of the computed free volume sizes and the ortho-positronium (o-Ps) lifetimes. The prepeak of the free volume distribution is probably unseen by o-Ps because of a cavity threshold limit. The effect of the shape factor on the computed o-Ps lifetimes is tested. The quasicavities obtained by redistributing the free volume maintain the ratio of the main dimensions with temperature. Finally, novel data on the cavity environment are provided, while it is suggested how these can be useful with the recent developments in the positron annihilation methods. The coordination number of large cavities with the polymer segments is around 1, as predicted in the free volume theory. Similarly to the percolation and the cavity number, the coordination number exhibits a change when explored by a suitable probe radius ∼0.8 Å. The insightful visualizations showed properties of interest investigated within the actual work.
Collapse of a two-state sticky hard sphere chain
Authors: Evans Glenn T.
Published: January 2011

The collapse of a homopolymer Gaussian chain into a globule is represented as a transition between two states, viz., extended and collapsed. Appropriately, this model has been labeled as the all-or-none view of chain collapse. In the collapsed state, the single polymer partition function is expressed by a single Mayer diagram with the maximum number of f-bonds arising from nonbonded square well interactions. Our target is the dependence of the transition temperature on chain length and the interaction range of the square well, as indicated through the behavior of the radius of gyration and the constant volume heat capacity. Properties of the collapse transition are calculated exactly for chains with three to six backbone atoms and heuristically for long chains using arguments derived from the small chains and from conditions of integrability. Comparison with simulation studies is made.
Association structures of ionic liquid/DMSO mixtures studied by high-pressure infrared spectroscopy
Authors: Jiang Jyh-Chiang , Lin Kuan-Hung , Li Sz-Chi , Shih Pao-Ming , Hung Kai-Chan , Lin Sheng Hsien , Chang Hai-Chou
Published: January 2011

Using high-pressure infrared methods, we have investigated close interactions of charge-enhanced C–H–O type in ionic liquid/dimethyl sulfoxide (DMSO) mixtures. The solvation and association of the 1-butyl-3-methylimidazolium tetrafluoroborate (${\rm BMI}^ + {\rm BF}_4^ - $ BMI + BF 4−) and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (${\rm BMM}^ + {\rm BF}_4^ - $ BMM + BF 4−) in DMSO-d6 were examined by analysis of C–H spectral features. Based on our concentration-dependent results, the imidazolium C–H groups are more sensitive sites for C–H–O than the alkyl C–H groups and the dominant imidazolium C–H species in dilute ionic liquid/DMSO-d6 should be assigned to the isolated (or dissociated) structures. As the dilute mixtures were compressed by high pressures, the loss in intensity of the bands attributed to the isolated structures was observed. In other words, high pressure can be used to perturb the association–dissociation equilibrium in the polar region. This result is remarkably different from what is revealed for the imidazolium C–H in the ${\rm BMM}^ + {\rm BF}_4^ - $ BMM + BF 4−/D2O mixtures. DFT-calculations are in agreement with our experimental results indicating that C4–H–O and C5–H–O interactions seem to play non-negligible roles for ${\rm BMM}^ + {\rm BF}_4^ - $ BMM + BF 4−/DMSO mixtures.
Dissimilar bouncy walkers
Authors: Lomholt Michael A. , Lizana Ludvig , Ambjörnsson Tobias
Published: January 2011

We consider the dynamics of a one-dimensional system consisting of dissimilar hardcore interacting (bouncy) random walkers. The walkers’ (diffusing particles’) friction constants \documentclass[12pt]{minimal}\begin{document}$\xi _n$\end{document}ξn, where n labels different bouncy walkers, are drawn from a distribution \documentclass[12pt]{minimal}\begin{document}$\varrho (\xi _n)$\end{document}ϱ(ξn). We provide an approximate analytic solution to this recent single-file problem by combining harmonization and effective medium techniques. Two classes of systems are identified: when \documentclass[12pt]{minimal}\begin{document}$\varrho (\xi _n)$\end{document}ϱ(ξn) is heavy-tailed, \documentclass[12pt]{minimal}\begin{document}$\varrho (\xi _n)\simeq \xi _n^{-1-\alpha } \ (0<\alpha <1)$\end{document}ϱ(ξn)≃ξn−1−α(0<α<1) for large \documentclass[12pt]{minimal}\begin{document}$\xi _n$\end{document}ξn, we identify a new universality class in which density relaxations, characterized by the dynamic structure factor S(Q, t), follows a Mittag-Leffler relaxation, and the mean square displacement (MSD) of a tracer particle grows as \documentclass[12pt]{minimal}\begin{document}$t^\delta$\end{document}tδ with time t, where δ = α/(1 + α). If instead ϱ is light-tailed such that the mean friction constant exist, S(Q, t) decays exponentially and the MSD scales as \documentclass[12pt]{minimal}\begin{document}$t^{1/2}$\end{document}t1/2. We also derive tracer particle force response relations. All results are corroborated by simulations and explained in a simplified model.
A heuristic model of damped quantum rotation effects in nuclear magnetic resonance spectra
Authors: Szymański S.
Published: January 2011

The damped quantum rotation (DQR) theory describes temperature effects in NMR spectra of hindered molecular rotators composed of identical atoms arranged in regular N-gons. In the standard approach, the relevant coherent dynamics are described quantum mechanically and the stochastic, thermally activated motions classically. The DQR theory is consistent. In place of random jumps over one, two, etc., maxima of the hindering potential, here one has damping processes of certain long-lived coherences between spin-space correlated eigenstates of the rotator. The damping-rate constants outnumber the classical jump-rate constants. The jump picture is recovered when the former cluster appropriately around only as many values as the number of the latter. The DQR theory was confirmed experimentally for hindered methyl groups in solids and even in liquids above 170 K. In this paper it is shown that for three-, four-, and sixfold rotators, the Liouville space equations of NMR line shapes, derived previously with the use of the quantum mechanical reduced density matrix approach, can be be given a heuristic justification. It is based on an equation of motion for the effective spin density matrix, where the relevant spin Hamiltonian contains randomly fluctuating terms. The occurrence of the latter can be rationalized in terms of fluctuations of the tunneling splittings between the torsional sublevels of the rotator, including momentary liftings of the Kramers degeneracies. The question whether such degeneracy liftings are physical or virtual is discussed. The random terms in the effective Hamiltonian can be Monte Carlo modeled as piecewise constant in time, which affords the stochastic equation of motion to be solved numerically in the Hilbert spin space. For sixfold rotators, this way of calculating the spectra can be useful in the instances where the Liouville space formalism of the original DQR theory is numerically unstable.
Effect of the number of layers on determination of spin asymmetries in current-perpendicular-to-plane giant magnetoresistance
Authors: Taniguchi Tomohiro , Imamura Hiroshi , Nakatani Tomoya M. , Hono Kazuhiro
Published: January 2011

Current-perpendicular-to-plane giant-magnetoresistance effect in a ferromagnetic/nonmagnetic multilayer is studied theoretically by solving the diffusion equation of the spin accumulation without assuming the periodic boundary condition. We show that the Valet and Fert theory underestimates spin asymmetries with decreasing the number of layers.
Self-force via energy–momentum and angular momentum balance equations
Authors: Yaremko Yurij
Published: January 2011

The radiation reaction for a pointlike charge coupled to a massive scalar field is considered. The retarded Green's function associated with the Klein–Gordon wave equation has support not only on the future light cone of the emission point (direct part) but extends inside the light cone as well (tail part). Dirac's scheme of decomposition of the retarded electromagnetic field into the “mean of the advanced and retarded field” and the “radiation” field is adapted to theories where Green's function consists of the direct and the tail parts. The Harish-Chandra equation of motion of radiating scalar charge under the influence of an external force is obtained. This equation includes effect of particle's own field. The self-force produces a time-changing inertial mass.
Design of subwavelength superscattering nanospheres
Authors: Ruan Zhichao , Fan Shanhui
Published: January 2011

We design a subwavelength superscattering nanosphere with plasmonic-dielectric-plasmonic layer structure. We show that the scattering cross section of such a particle can be significantly enhanced by employing multiple resonances with different total angular momenta, and by ensuring that all these resonances have almost the same frequency and operate in the overcoupling region.
A full analytical solution for the force-driven compressible Poiseuille gas flow based on a nonlinear coupled constitutive relation
Authors: Myong R. S.
Published: January 2011

The compressible Poiseuille gas flow driven by a uniform force is analytically investigated using a phenomenological nonlinear coupled constitutive relation model. A new fully analytical solution in compact tangent (or hyperbolic tangent in the case of diatomic gases) functional form explains the origin behind the central temperature minimum and a heat transfer from the cold region to the hot region. The solution is not only proven to satisfy the conservation laws exactly but also well-defined for all physical conditions (the Knudsen number and a force-related dimensionless parameter). It is also shown that the non-Fourier law associated with the coupling of force and viscous shear stress in the constitutive relation is responsible for the existence of the central temperature minimum, while a kinematic constraint on viscous shear and normal stresses identified in the velocity shear flow is the main source of the nonuniform pressure distribution. In addition, the convex pressure profile with a maximum at the center is theoretically predicted for diatomic gases. Finally, the existence of the Knudsen minimum in the mass flow rate is demonstrated by developing an exact analytical formula for the average temperature of the bulk flow.
Exciton–polariton transmission in quantum dot waveguides and a new transmission path due to thermal relaxation
Authors: Kubota Yoji , Nobusada Katsuyuki
Published: January 2011

Exciton–polariton transmission in quantum dot waveguides is investigated with quantum time-evolution equations in Liouville space for exciton wave packet dynamics. The transmission efficiency of the exciton–polariton wave with the longitudinal and transverse mode transformations strongly depends on the geometric parameters (bending angle and interdot distance) of the waveguides and on configuration of an additional branch attached to the waveguide. We have numerically demonstrated that the transmission efficiency significantly improves by controlling these geometric parameters and the configuration of the branched waveguide. The optimal bending angle for efficient transmission with the longitudinal and transverse mode transformations deviates from the right angle owing to more than nearest-neighbor-site interactions through a shortcut. We have also found that existence of thermal relaxation enables to open a new transmission channel along which the exciton–polariton transmission through the Coulomb interaction is suppressed.
First drop dissimilarity in drop-on-demand inkjet devices
Authors: Famili Amin , Palkar Saurabh A. , Baldy William J.
Published: January 2011

As inkjet printing technology is increasingly applied in a broader array of applications, careful characterization of its method of use is critical due to its inherent sensitivity. A common operational mode in inkjet technology known as drop-on-demand ejection is used as a way to deliver a controlled quantity of material to a precise location on a target. This method of operation allows ejection of individual or a sequence (burst) of drops based on a timed trigger event. This work presents an examination of sequences of drops as they are ejected, indicating a number of phenomena that must be considered when designing a drop-on-demand inkjet system. These phenomena appear to be driven by differences between the first ejected drop in a burst and those that follow it and result in a break-down of the linear relationship expected between driving amplitude and drop mass. This first drop, as quantified by high-speed videography and subsequent image analysis, can be different in morphology, trajectory, velocity, and volume from subsequent drops within a burst. These findings were confirmed orthogonally by both volume and mass measurement techniques which allowed quantitation down to single drops.
Analytic integrability of Hamiltonian systems with a homogeneous polynomial potential of degree 4
Authors: Llibre Jaume , Mahdi Adam , Valls Claudia
Published: January 2011

In the analytic case we prove the conjecture of Maciejewski and Przybylska [J. Math. Phys. 46(6), 062901 (2005)] regarding Hamiltonian systems with a homogeneous polynomial potential of degree 4. The proof of the conjecture completes the characterization of all the analytic integrable Hamiltonian system with a homogeneous polynomial potential of degree 4.
Bulk heterojunction solar cells with thick active layers and high fill factors enabled by a bithiophene-co-thiazolothiazole push-pull copolymer
Authors: Peet J. , Wen L. , Byrne P. , Rodman S. , Forberich K. , Shao Y. , Drolet N. , Gaudiana R. , Dennler G. , Waller D.
Published: January 2011

A push-pull copolymer is presented which can be used in bulk heterojunction (BHJ) solar cells with active layers greater than 200 nm and fill factors above 60%. The efficiencies of most BHJ solar cells are limited by the fact that they have active layers which are between 60 and 110 nm. While this thickness regime enables peak quantum efficiencies (EQE) of 60%–70%, the ability to fabricate thicker devices would increase average EQE values and thus device efficiencies. Discovery of materials which can maintain high performance at large thicknesses will enable higher performance in BHJ hero cells and increase the commercial viability of this technology.
Communication: An exact short-time solver for the time-dependent Schrödinger equation
Authors: Sun Zhigang , Yang Weitao
Published: January 2011

The short-time integrator for propagating the time-dependent Schrödinger equation, which is exact to machine's round off accuracy when the Hamiltonian of the system is time-independent, was applied to solve dynamics processes. This integrator has the old Cayley's form [i.e., the Padé (1,1) approximation], but is implemented in a spectrally transformed Hamiltonian which was first introduced by Chen and Guo. Two examples are presented for illustration, including calculations of the collision energy-dependent probability passing over a barrier, and interaction process between pulse laser and the \documentclass[12pt]{minimal}\begin{document}${\rm I}_2$\end{document}I2 diatomic molecule.
Use of the internet and self-collected samples as a sexually transmissible infection intervention in rural Illinois communities
Authors: Jenkins Wiley D. , Rabins Charlie , Barnes Mathilda , Agreda Patricia , Gaydos Charlotte
Published: January 2011

Background: In the USA, reported cases of chlamydia (Chlamydia trachomatis) continue to rise despite substantial funding for screening. National gonorrhoea (Neisseria gonorrhoeae) rates have remained relatively stable, with clusters associated with metropolitan areas. Rural areas are no exception, as every county in Illinois reported cases of chlamydia in 2007. Morbidity associated with infection remains a public health concern, with costs of $US2.5+ billion annually. Novel screening interventions must be examined for their ability to reach those at risk who are missed by traditional methods. Methods: The website Iwantthekit.org was modified to allow residents from 25 contiguous counties in Central Illinois to request a self-collected sample kit. Returned kits were tested for chlamydia and gonorrhoea. The initial study period was 12 months. Results: During the study period, 343 kits were requested from 20 counties and 39.9% were satisfactorily returned for analysis. Positivity rates for chlamydia and gonorrhoea were 5.8% and 1.2%, respectively, for females and 1.9% and 0% for males. Males comprised 37.7% of all internet samples (compared with 23.4% for traditional screening venues) and 40.4% of all internet samples submitted by whites (compared with only 17.2% of traditional screening). Conclusions: The female positivity rate was comparable to those seen in other screening venues and the method successfully engaged at-risk males. Overall, participation was low and the costs associated with the program outweighed the averted costs associated with the few cases identified. While this methodology resulted in sample requests from a wide area, it must be utilised by more individuals to become cost-effective.
Significant increase in testing rates for sexually transmissible infections following the introduction of an anal cytological screening program, targeting HIV-positive men who have sex with men
Authors: Botes Leon P. , McAllister John , Ribbons Edward , Jin Fengyi , Hillman Richard J.
Published: January 2011

ObjectivesTo evaluate whether the introduction of an anal cytology screening program (ACSP) targeting HIV-positive men who have sex with men (MSM) affected rates of sexually transmissible infection (STI) testing and detection in an urban HIV outpatient clinic. Methods: STI testing was offered as part of an ACSP. Uptake of STI testing and diagnoses were compared before and after the introduction of an ACSP. Results: The number of men undergoing STI testing increased significantly from 67 (20.4%) to 123 (34.8%) (relative risk 1.7, 95% confidence interval (CI) 1.40–2.07), but the increase in the total number of patients with any STI did not achieve significance (from 7 to 11, prevalence ratio 0.86, 95% CI 0.33–2.21). Rates of STI diagnosed in men participating in the ACSP were no different (11.3% v. 7.7%, P = 0.557) from those men declining screening. Conclusions: STI testing, when combined with an ACSP in HIV-positive MSM, may lead to an increase in STI testing and increased opportunities for risk reduction interventions. Men participating in an ACSP appear to have similar risk of STIs to those who decline participation in an ACSP. The inclusion of STI testing could potentially enhance the public health benefit of ACSPs.
Prevalence of Chlamydia trachomatis among young German adolescents, 2005 - 06
Authors: Desai Sarika , Meyer Thomas , Thamm Michael , Hamouda Osamah , Bremer Viviane
Published: January 2011

Background:
Chlamydia trachomatis prevalence among 12–17-year-old adolescents in Germany was determined in the present study.
Methods: A random age-stratified sample of 1815 urine specimens of boys and girls was selected from a population-based nationwide health survey conducted in 2003–06. Urine samples were pooled and tested for chlamydia using strand displacement amplification. Positive pools were individually retested. Prevalence, prevalence ratios (PR) and corresponding 95% confidence intervals (CI) were calculated. Associations between infection and socio-demographic factors (age, sex, place of residence), sexual activity (defined by oral contraceptive use or gynaecologist visits) and abdominal pain among females were examined in univariate analysis.
Results: Sixteen samples (0.9% 95% CI: 0.5–1.3%), all from 15–17-yearolds, were positive for chlamydia. Prevalence increased with age to 2% (95% CI: 0.8–3.2%) among 17 year olds and was higher among girls than boys (1.8% v. 0.1%; P < 0.001). A total of 4.6% (95% CI: 1.4–7.7%) of sexually active girls aged 17 were infected and 5/7 of them had no regular abdominal pain. Of all girls with abdominal pains, 52% had visited gynaecologists. Prevalence of infection was higher among those with pains than those without (PR = 3.8, 95% CI: 1.3–11.0).
Conclusions: This is the first nationwide study based on a representative sample of boys and girls to measure chlamydia prevalence among adolescents in Germany. Prevalence in Germany is consistent with other countries. Among sexually active females, prevalence was comparable to screening thresholds. As gynaecological visits were common among females, we recommend that gynaecologists should actively offer screening to sexually active females, which would strengthen the newly implemented screening for females under 25 years.
Survey investigating homosexual behaviour among adult males used to estimate the prevalence of HIV and AIDS among men who have sex with men in Japan
Authors: Ichikawa Seiichi , Kaneko Noriyo , Koerner Jane , Shiono Satoshi , Shingae Akitomo , Ito Toshihiro
Published: January 2011

Background: This study investigated the prevalence of male homosexual behaviour among adult men and of HIV and AIDS among men who have sex with men (MSM) and non-MSM in Japan. Methods: An anonymous self-administered postal questionnaire, and national HIV and AIDS notifications. Results: Same-sex sexual experience was reported by 2.0% of respondents. The prevalence of HIV and AIDS was 0.8818% among MSM and 0.0130% among non-MSM, indicating that HIV and AIDS are 68 times more prevalent among MSM. Conclusion: Our findings underestimate homosexual and HIV prevalence due to several methodological limitations. The high prevalence of HIV and AIDS among MSM in comparison with non-MSM indicates the urgent need to prioritise funding and programs targeting MSM in Japan.
Is it time to move to nucleic acid amplification tests screening for pharyngeal and rectal gonorrhoea in men who have sex with men to improve gonorrhoea control?
Authors: Fairley Christopher K. , Chen Marcus Y. , Bradshaw Catriona S. , Tabrizi Sepehr N.
Published: January 2011

The use of nucleic acid amplification tests (NAAT), as well as or in preference to culture for non-genital sites is now recommended both in Australia and overseas because of their greater sensitivity and improved specificity. A survey of 22 Australian sexual health clinics who each year test over 14 500 men who have sex with men (MSM) show that culture remains the predominate method for detecting gonorrhoea at pharyngeal (64%) and rectal (73%) sites. This editorial discusses the potential disadvantages of using culture over NAAT in relation to optimal gonorrhoea control among MSM and advocates that significantly improved control would be achieved by moving to NAAT with the proviso that culture samples are taken wherever possible on NAAT-positive samples and from clients with urethritis to ensure continued surveillance for antimicrobial resistance.