bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence that Indirect Inhibition of Saccade Initiation Improves Saccade Accuracy
Authors: McSorley Eugene , Cruickshank Alice G
Published: December 2010

Saccadic eye-movements to a visual target are less accurate if there are distracters close to its location (local distracters). The addition of more distracters, remote from the target location (remote distracters), invokes an involuntary increase in the response latency of the saccade and attenuates the effect of local distracters on accuracy. This may be due to the target and distracters directly competing (direct route) or to the remote distracters acting to impair the ability to disengage from fixation (indirect route). To distinguish between these, we examined the development of saccade competition by recording saccade latency and accuracy responses made to a target and local distracter compared with those made with an addition of a remote distracter. The direct route would predict that the remote distracter impacts on the developing competition between target and local distracter, while the indirect route would predict no change as the accuracy benefit here derives from accessing the same competitive process but at a later stage. We found that the presence of the remote distracter did not change the pattern of accuracy improvement. This suggests that the remote distracter was acting along an indirect route that inhibits disengagement from fixation, slows saccade initiation, and enables more accurate saccades to be made.
Pioneers of Eye Movement Research
Authors: Wade Nicholas J
Published: December 2010

Recent advances in the technology affording eye movement recordings carry the risk of neglecting past achievements. Without the assistance of this modern armoury, great strides were made in describing the ways the eyes move. For Aristotle the fundamental features of eye movements were binocular, and he described the combined functions of the eyes. This was later given support using simple procedures like placing a finger over the eyelid of the closed eye and culminated in Hering's law of equal innervation. However, the overriding concern in the 19th century was with eye position rather than eye movements. Appreciating discontinuities of eye movements arose from studies of vertigo. The characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare in 1879; both used similar techniques of listening to sounds made during contractions of the extraocular muscles. Photographic records of eye movements during reading were made by Dodge early in the 20th century, and this stimulated research using a wider array of patterns. In the mid-20th century attention shifted to the stability of the eyes during fixation, with the emphasis on involuntary movements. The contributions of pioneers from Aristotle to Yarbus are outlined.
The Influence of Onsets and Offsets on Saccade Programming
Authors: Hermens Frouke , Walker Robin
Published: December 2010

When making a saccadic eye movement to a peripheral target, a simultaneous stimulus onset at central fixation generally increases saccadic latency, while offsets reduce latency (‘gap effect’). Visual onsets remote from fixation also increase latency (‘remote distractor effect’); however, the influence of remote visual offsets is less clear. Previous studies, which used a search task, found that remote offsets either facilitated, inhibited, or did nothing to saccade latencies towards a peripheral target. It cannot be excluded, however, that the target selection process in such search tasks influenced the results. We therefore simplified the task and asked participants to make eye movements to a predictable target. Simultaneously with target onset, either one or multiple remote stimulus onsets and offsets were presented. It was found that peripheral onsets increased saccade latencies, but offsets did not influence the initiation of a saccade to the target. Moreover, the number of onsets and offsets did not affect the results. These results suggest that earlier effects of remote stimulus offsets and of the number of remote distractor onsets reside in the target identification process of the visual search task rather than the competition between possible saccade goals. The results are discussed in the context of models of saccade target selection.
Differential Effect of Luminance Contrast Reduction and Noise on Motion Induction
Authors: Hanada Mitsuhiko
Published: December 2010

Motion perception in a region is affected by motion in the surround regions. When a physically static or flickering stimulus surrounded by moving stimuli appears to move in the direction opposite to that of the surround motion, it is referred to as motion contrast. When the centre appears to move in the same direction, it is referred to as motion assimilation. We investigated how noise and luminance contrast affect motion induction by employing static and dynamic counterphase flickering targets. The tendency of motion assimilation was found to be stronger at a high noise level than at a low noise level for both static and dynamic targets. On the other hand, a decrease of luminance contrast tended to strengthen the tendency of motion contrast. However, the addition of noise and the decrease of luminance contrast decreased the visibility of motion comparably. These results suggest that the visual system changes the mode of motion induction according to the noise level, but not the visibility.
Motion Impressions Enhanced by Converging Motion Lines
Authors: Ito Hiroyuki , Seno Takeharu , Yamanaka Miyuki
Published: December 2010

We investigated how motion lines drawn in the background of a running human silhouette affect motion impressions of a runner in a static image. Observers evaluated the strength and direction of motion impression. The results show that parallel lines do not enhance frontoparallel motion impressions, while converging lines do so in an in-depth direction. This is a counter-example to the hypothesis that motion lines in the background represent motion streaks of the background when one visually tracks a moving object.
The Importance of Social Factors is a Matter of Perception
Authors: Short Lindsey A , Mondloch Catherine J
Published: December 2010

Caucasian female faces were randomly assigned to participants' in- or out-group following false feedback on a personality inventory. Participants recognised in-group faces better than out-group faces, but they showed no evidence of category-contingent opposing aftereffects. We conclude that the explanatory power of social-cognitive models will be enhanced when they are integrated with models of perceptual expertise.
Improving the accuracy of digestibility estimates for cattle grazing tropical pastures when sampling with oesophageal fistulated cattle
Authors: Coates D. B.
Published: December 2010

The in vitro digestibility analysis of extrusa samples collected from oesophageal fistulated cattle is widely used to estimate the digestibility of diets selected by resident grazing cattle. In the present study, oesophageal fistulated steers were used to sample a range of grass–legume pastures continuously stocked with small herds of resident cattle at two sites in northern Queensland at different times of the year. Pepsin–cellulase in vitro analysis was used to measure in vitro dry matter loss (IVDML) during incubation. Additional laboratory analyses were used to demonstrate that unless appropriate corrections are applied, serious inaccuracies can occur in the estimates of in vivo digestibility as a result of (1) differences between IVDML of extrusa (feed plus saliva) and the IVDML of the feed consumed (feed without saliva), (2) differences in the botanical and chemical composition between the extrusa samples and the diets of the resident cattle, and (3) differences between grasses and legumes in the linear-regression relationships used to estimate in vivo digestibility from IVDML. Methodologies to minimise such errors are described and results illustrating the magnitude of potential errors are presented. In the dataset from the present study, it was clear that differences between extrusa and resident diets in grass–legume proportions consumed were the major cause of error but other causes of error were also important. Appropriate methodologies to improve accuracy are recommended.
Sleep deprivation impairs precision of waggle dance signaling in honey bees
Authors: Klein Barrett A. , Klein Arno , Wray Margaret K. , Mueller Ulrich G. , Seeley Thomas D.
Published: December 2010

Sleep is essential for basic survival, and insufficient sleep leads to a variety of dysfunctions. In humans, one of the most profound consequences of sleep deprivation is imprecise or irrational communication, demonstrated by degradation in signaling as well as in receiving information. Communication in nonhuman animals may suffer analogous degradation of precision, perhaps with especially damaging consequences for social animals. However, society-specific consequences of sleep loss have rarely been explored, and no function of sleep has been ascribed to a truly social (eusocial) organism in the context of its society. Here we show that sleep-deprived honey bees (
Apis mellifera
) exhibit reduced precision when signaling direction information to food sources in their waggle dances. The deterioration of the honey bee's ability to communicate is expected to reduce the foraging efficiency of nestmates. This study demonstrates the impact of sleep deprivation on signaling in a eusocial animal. If the deterioration of signals made by sleep-deprived honey bees and humans is generalizable, then imprecise communication may be one detrimental effect of sleep loss shared by social organisms.
Redoublement Clitique, Relatives et Interrogatives en Roumain et Espagnol
Authors: Dobrovie-Sorin Carmen
Published: December 2010

This article shows that important differences between Romanian and Spanish with respect to the clitic doubling phenomenon are not due to a parametric variation in the clitic systems of the two languages, but to a specific mechanism of relative clause formation that we propose for Romanian. Our ana-lysis is further supported by data concerning the clitic doubling of quantified NPs. Another interesting confirmation comes from the Italian Clitic Left Dislocation.
The Vocative Adjectives Biaus, Dous and chiers in Old French
Authors: Love Nathan
Published: December 2010

The Vocative Adjectives biaus, dous and chiers in Old French:
These three epithets are used with far more frequency than any other adjectives accompanying titles of address in direct discourse. Nevertheless, they are not used in great abundance until the romances of Chrétien de Troyes, who employs them with ever increasing frequency throughout his romance production. The article briefly retraces the attestations of their semantic values and literary applications in rhymed verse narratives of the twelfth and early thirteenth centuries.
Remarques sur une sous-classe d'adverbes en -ment orientés vers le sujet et leurs adjectifs Sources
Authors: Molinier Christian
Published: December 2010

Remarks on a subclass of subject-oriented adverbs and their adjectival sources.
The author first intends to describe the syntactic properties of subject-oriented sentence adverbs in -ment, as opposed to subject-oriented manner adverbs in -ment. He then discusses the status of two adjectival paraphrases — related to each other — for the sentences comprising a subject-oriented sentence adverb. He finally identifies on a syntactic basis the class of the adjectival sources of this class of adverbs.
Réflexions Sur Les Restrictions Phonotactiques
Authors: Spa J.J.
Published: December 2010

Grosso modo les phonologues ont proposé trois manières pour traiter des données phonotactiques:
1. L'approche des conventions marquantes,
2. L'approche qui affirme positivement l'occurrence de tel ou tel groupe consonantique dans telle ou telle position,
3. L'approche qui exclut l'occurrence de tel ou tel groupe consonantique dans telle ou telle position.
Dans le présent texte je ferai un examen critique des deux premières approches.
Je tâcherai de démontrer que les inventeurs de conventions marquantes n'ont pas été suffisammant clairs et cohérents quant à la façon dont il faut les utiliser pour comptabiliter les m, ce qui pourtant était leur objectif.
Les restrictions phonotactiques positives expliquent moins bien certains faits que les négatives:
a. Elle n'expliquent pas pourquoi les séquences consonantiques plus longues ont été construites à partir de séquences plus courtes,
b. Elles ne prédisent pas qu'il y a des séquences consonantiques maximales,
c. Elles n'expliquent pas pourquoi les séquences consonantiques plus complexes font leur apparition après les séquences plus simples.
The tropics, its soils and horticulture.
Authors: Paull R. E. , Duarte O.
Published: December 2010

This chapter describes the tropics, its soil and horticulture in its regions. Specifically, the chapter discusses the characteristics of the tropics, major tropical climate types, altitudinal climates, subtropics, climacteric factors, and climate change. The climacteric factors focused on the chapter are: daylength; radiation; temperature; rainfall; strong winds, frost and hail; and soils.
Cultivation.
Authors: Paull R. E. , Duarte O.
Published: December 2010

This chapter focuses on the market analysis, land selection, land preparation, drainage, plantation layout, planting distances, planting and planting materials, associated crops or intercrops and orhard floor management of tropical fruit trees. The different weed control strategies and use of wind and pest barriers are also highlighted.
Avocado.
Authors: Paull R. E. , Duarte O.
Published: December 2010

This chapter focuses on the taxonomy, origin and distribution and effects of soil types and pH and climatic factors on the ecology of avocados. The general characteristics of the trees, fruits, flowers and inflorescences, pollination and fruit set are discussed and the cultivar development, cultural practices for propagation and nursery management, field preparation, transplanting and spacing, irrigation, pruning, fertilizer application and pest, disease and weed management are highlighted. The harvesting and postharvest handling and treatment of fruits and their utilization are also pointed out.
Banana and plantain.
Authors: Paull R. E. , Duarte O.
Published: December 2010

This chapter focuses on the taxonomy, ecology, morphology and physiology of bananas and plantains. The cultivar development and cultural practices for propagation, cultivation, fertilizer application, pest, weed and disease management and harvesting and postharvest handling are discussed and the utilization of different plant parts and the nutritive value of the fruits are also highlighted.
Mango.
Authors: Paull R. E. , Duarte O.
Published: December 2010

This chapter focuses on the taxonomy, origin and distribution and effects of soil and climatic factors on the ecology of mango. The morphology, physiology, cultivar development, propagation, cultivation, irrigation, pruning, fertilizer application, flower induction and weed, pest and disease management are discussed. The harvesting and postharvest handling of fruits and their marketing and utilization are also highlighted.
Persian Progressive Tense: Serial Verb Construction or Aspectual Complex Predicate?
Authors: Taleghani Azita H.
Published: December 2010

The present and past progressive tenses in Persian are the only tenses in which both the main verb and the minor verb dâštan “to have” receive agreement marking. Morpho-syntactically, Persian progressives show the similar properties of both Aspectual Complex Predicates and Serial Verb Constructions. The question that this paper addresses is: are Persian progressive tenses Aspectual Complex Predicates or Serial Verb Constructions? By presenting the morpho-syntactic and semantic analysis of Persian progressives, and highlighting the main properties of Aspectual Complex Predicates and Serial Verb Constructions, the paper shows that, despite the similarities between these verbal constructions and Aspectual Complex Predicates, Persian progressives are instances of Serial Verb Constructions where neither a complementizer nor a conjunction separates the two verbs and the complex describes a single conceptual event.
A Survey of Two Types of Alternating Agentive Nominals in Persian
Authors: Vahedi Mohammad M.
Published: December 2010

Two alternating agentive nominals in Persian are distinguished by two different agentive, derivational suffixes/forms, i.e. the simple derived de-verbal nouns and synthetic compounds formed with the suffix -ande, as in gu-y-ande “reporter/speaker,” xân-ande “singer,” pâk-kon-ande “cleaner” versus the zero-derived synthetic compounds as in soxan-gu-Ø “speaker,” “âvâz-xân-Ø “song-singer,” barf-pâk-kon-Ø “windshield wiper.” It is discussed that the alternation, and lack of alternation, between the two is totally predictable and productive. While the simple derived and synthetic nominals with -ande are eventive, denoting an underlying action performed by an agent external argument, their equivalent alternating synthetic compounds with the zero-suffix are non-eventive, denoting a result nominal with an instrumental or agentive denotation. The analysis is cast in the framework of Distributed Morphology.
The Modernization of Iran and the Development of the Persian Carpet Industry: The Neo-Classical Era in the Persian Carpet Industry, 1925–45
Authors: Rudner Martin
Published: December 2010

The two decades, 1925–45, witnessed a dramatic transformation and revitalization of the Persian carpet industry in response to developments in Iranian governance, society and economy. Two historical watersheds were covered by that period, notably the replacement of the Qajar dynasty by a modernizing administration under Reza Shah Pahlavi, and the subsequent wartime occupation of Iran jointly by the Soviet Union and Great Britain. It was during those two decades that Iran acquired a centralized system of government and the beginnings of a modern industrial base. The accompanying social transformation brought about the emergence of new classes of administrators and managers who constituted the dominant elite of the Reza Shah era. This twin process of centralization and modernization had a telling impact on Iranian culture and the arts, including the carpet arts.
Mitochondria help dynamins get a grip
Authors: Leslie Mitch
Published: December 2010

Pair of studies clarifies how organelles attract enzymes that promote their fission.
Liz Rhoades: Single molecules tell many stories
Authors: Sedwick Caitlin
Published: December 2010

Rhoades studies protein folding and binding using single-molecule fluorescence techniques.
Phosphorylation of Lte1 by Cdk prevents polarized growth during mitotic arrest in S. cerevisiae
Authors: Geymonat Marco , Spanos Adonis , Jensen Sanne , Sedgwick Steven G.
Published: December 2010

Lte1 is known as a regulator of mitotic progression in budding yeast. Here we demonstrate phosphorylation-dependent inhibition of polarized bud growth during G2/M by Lte1. Cla4 activity first localizes Lte1 to the polarity cap and thus specifically to the bud. This localization is a prerequisite for subsequent Clb–Cdk-dependent phosphorylation of Lte1 and its relocalization to the entire bud cortex. There, Lte1 interferes with activation of the small GTPases, Ras and Bud1. The inhibition of Bud1 prevents untimely polarization until mitosis is completed and Cdc14 phosphatase is released. Inhibition of Bud1 and Ras depends on Lte1’s GEF-like domain, which unexpectedly inhibits these small G proteins. Thus, Lte1 has dual functions for regulation of mitotic progression: it both induces mitotic exit and prevents polarized growth during mitotic arrest, thereby coupling cell cycle progression and morphological development.
RNAi screen identifies a role for adaptor protein AP-3 in sorting to the regulated secretory pathway
Authors: Asensio Cédric S. , Sirkis Daniel W. , Edwards Robert H.
Published: December 2010

The regulated release of proteins depends on their inclusion within large dense-core vesicles (LDCVs) capable of regulated exocytosis. LDCVs form at the trans-Golgi network (TGN), but the mechanism for protein sorting to this regulated secretory pathway (RSP) and the cytosolic machinery involved in this process have remained poorly understood. Using an RNA interference screen in Drosophila melanogaster S2 cells, we now identify a small number of genes, including several subunits of the heterotetrameric adaptor protein AP-3, which are required for sorting to the RSP. In mammalian neuroendocrine cells, loss of AP-3 dysregulates exocytosis due to a primary defect in LDCV formation. Previous work implicated AP-3 in the endocytic pathway, but we find that AP-3 promotes sorting to the RSP within the biosynthetic pathway at the level of the TGN. Although vesicles with a dense core still form in the absence of AP-3, they contain substantially less synaptotagmin 1, indicating that AP-3 concentrates the proteins required for regulated exocytosis.
FSHD: copy number variations on the theme of muscular dystrophy
Authors: Cabianca Daphne Selvaggia , Gabellini Davide
Published: December 2010

In humans, copy number variations (CNVs) are a common source of phenotypic diversity and disease susceptibility. Facioscapulohumeral muscular dystrophy (FSHD) is an important genetic disease caused by CNVs. It is an autosomal-dominant myopathy caused by a reduction in the copy number of the D4Z4 macrosatellite repeat located at chromosome 4q35. Interestingly, the reduction of D4Z4 copy number is not sufficient by itself to cause FSHD. A number of epigenetic events appear to affect the severity of the disease, its rate of progression, and the distribution of muscle weakness. Indeed, recent findings suggest that virtually all levels of epigenetic regulation, from DNA methylation to higher order chromosomal architecture, are altered at the disease locus, causing the de-regulation of 4q35 gene expression and ultimately FSHD.
Mff is an essential factor for mitochondrial recruitment of Drp1 during mitochondrial fission in mammalian cells
Authors: Otera Hidenori , Wang Chunxin , Cleland Megan M. , Setoguchi Kiyoko , Yokota Sadaki , Youle Richard J. , Mihara Katsuyoshi
Published: December 2010

The cytoplasmic dynamin-related guanosine triphosphatase Drp1 is recruited to mitochondria and mediates mitochondrial fission. Although the mitochondrial outer membrane (MOM) protein Fis1 is thought to be a Drp1 receptor, this has not been confirmed. To analyze the mechanism of Drp1 recruitment, we manipulated the expression of mitochondrial fission and fusion proteins and demonstrated that (a) mitochondrial fission factor (Mff) knockdown released the Drp1 foci from the MOM accompanied by network extension, whereas Mff overexpression stimulated mitochondrial recruitment of Drp1 accompanied by mitochondrial fission; (b) Mff-dependent mitochondrial fission proceeded independent of Fis1; (c) a Mff mutant with the plasma membrane–targeted CAAX motif directed Drp1 to the target membrane; (d) Mff and Drp1 physically interacted in vitro and in vivo; (e) exogenous stimuli–induced mitochondrial fission and apoptosis were compromised by knockdown of Drp1 and Mff but not Fis1; and (f) conditional knockout of Fis1 in colon carcinoma cells revealed that it is dispensable for mitochondrial fission. Thus, Mff functions as an essential factor in mitochondrial recruitment of Drp1.
Statistical mechanics of collisionless relaxation in a non-interacting system
Authors: de Buyl Pierre , Mukamel David , Ruffo Stefano
Published: December 2010

We introduce a model of uncoupled pendula, which mimics the dynamical behaviour of the Hamiltonian mean-field (HMF) model. This model has become a paradigm for long-range interactions, such as Coulomb or dipolar forces. As in the HMF model, this simplified integrable model is found to obey the Vlasov equation and to exhibit quasi-stationary states (QSSs), which arise after a ‘collisionless’ relaxation process. Both the magnetization and the single-particle distribution function in these QSSs can be predicted using Lynden-Bell’s theory. The existence of an extra conserved quantity for this model, the energy distribution function, allows us to understand the origin of some discrepancies of the theory with numerical experiments. It also suggests an improvement of Lynden-Bell’s theory, which we fully implement for the zero-field case.
Quantum Bochkov–Kuzovlev work fluctuation theorems
Authors: Campisi Michele , Talkner Peter , Hänggi Peter
Published: December 2010

The quantum version of the Bochkov–Kuzovlev identity is derived on the basis of the appropriate definition of work as the difference of the measured internal energies of a quantum system at the beginning and the end of an external action on the system given by a prescribed protocol. According to the spirit of the original Bochkov–Kuzovlev approach, we adopt the ‘exclusive’ viewpoint, meaning that the coupling to the external work source is
not
counted as part of the internal energy. The corresponding canonical and microcanonical quantum fluctuation theorems are derived as well, and are compared with the respective theorems obtained within the ‘inclusive’ approach. The relations between the quantum inclusive work
w
, the exclusive work
w
0
and the dissipated work
w
dis
, are discussed and clarified. We show by an explicit example that
w
0
and
w
dis
are distinct stochastic quantities obeying different statistics.
Irreversibility in quantum maps with decoherence
Authors: García-Mata Ignacio , Casabone Bernardo , Wisniacki Diego A.
Published: December 2010

The Boltzmann echo (BE) is a measure of irreversibility and sensitivity to perturbations for non-isolated systems. Recently, different regimes of this quantity were described for chaotic systems. There is a perturbative regime where the BE decays with a rate given by the sum of a term depending on the accuracy with which the system is time reversed and a term depending on the coupling between the system and the environment. In addition, a parameter-independent regime, characterized by the classical Lyapunov exponent, is expected. In this paper, we study the behaviour of the BE in hyperbolic maps that are in contact with different environments. We analyse the emergence of the different regimes and show that the behaviour of the decay rate of the BE is strongly dependent on the type of environment.
Continuous description of lattice discreteness effects in front propagation
Authors: Clerc Marcel G. , Elías Ricardo G. , Rojas René G.
Published: December 2010

Models describing microscopic or mesoscopic phenomena in physics are inherently discrete, where the lattice spacing between fundamental components, such as in the case of atomic sites, is a fundamental physical parameter. The effect of spatial discreteness over front propagation phenomenon in an overdamped one-dimensional periodic lattice is studied. We show here that the study of front propagation leads in a discrete description to different conclusions that in the case of its, respectively, continuous description, and also that the results of the discrete model, can be inferred by effective continuous equations with a supplementary spatially periodic term that we have denominated
Peierls–Nabarro drift
, which describes the bifurcation diagram of the front speed, the appearance of particle-type solutions and their snaking bifurcation diagram. Numerical simulations of the discrete equation show quite good agreement with the phenomenological description.
Hydrodynamics at the smallest scales: a solvability criterion for Navier–Stokes equations in high dimensions
Authors: Viswanathan T. M. , Viswanathan G. M.
Published: December 2010

Strong global solvability is difficult to prove for high-dimensional hydrodynamic systems because of the complex interplay between nonlinearity and scale invariance. We define the Ladyzhenskaya–Lions exponent
α

l

(
n
)=(2+
n
)/4 for Navier–Stokes equations with dissipation −(−
Δ
)

α

in

, for all
n
≥2. We review the proof of strong global solvability when
α
≥
α

l

(
n
), given smooth initial data. If the corresponding Euler equations for
n
>2 were to allow uncontrolled growth of the enstrophy

, then no globally controlled coercive quantity is currently known to exist that can regularize solutions of the Navier–Stokes equations for
α
<
α

l

(
n
). The energy is critical under scale transformations only for
α
=
α

l

(
n
).
Collective Poisson process with periodic rates: applications in physics from micro-to nanodevices
Authors: Da Silva Roberto , Lamb Luis C. , Wirth Gilson Inacio
Published: December 2010

Continuous reductions in the dimensions of semiconductor devices have led to an increasing number of noise sources, including random telegraph signals (RTS) due to the capture and emission of electrons by traps at random positions between oxide and semiconductor. The models traditionally used for microscopic devices become of limited validity in nano- and mesoscale systems since, in such systems, distributed quantities such as electron and trap densities, and concepts like electron mobility, become inadequate to model electrical behaviour. In addition, current experimental works have shown that RTS in semiconductor devices based on carbon nanotubes lead to giant current fluctuations. Therefore, the physics of this phenomenon and techniques to decrease the amplitudes of RTS need to be better understood. This problem can be described as a collective Poisson process under different, but time-independent, rates,
τ
c
and
τ
e
, that control the capture and emission of electrons by traps distributed over the oxide. Thus, models that consider calculations performed under time-dependent periodic capture and emission rates should be of interest in order to model more efficient devices. We show a complete theoretical description of a model that is capable of showing a noise reduction of current fluctuations in the time domain, and a reduction of the power spectral density in the frequency domain, in semiconductor devices as predicted by previous experimental work. We do so through numerical integrations and a novel Monte Carlo Markov chain (MCMC) algorithm based on microscopic discrete values. The proposed model also handles the ballistic regime, relevant in nano- and mesoscale devices. Finally, we show that the ballistic regime leads to nonlinearity in the electrical behaviour.
Singularities of the susceptibility of a Sinai–Ruelle–Bowen measure in the presence of stable–unstable tangencies
Authors: Ruelle David
Published: December 2010

Let
ρ
be a Sinai–Ruelle–Bowen (SRB or ‘physical’) measure for the discrete time evolution given by a map
f
, and let
ρ
(
A
) denote the expectation value of a smooth function
A
. If
f
depends on a parameter, the derivative
δρ
(
A
) of
ρ
(
A
) with respect to the parameter is formally given by the value of the so-called susceptibility function
Ψ
(
z
) at
z
=1. When
f
is a uniformly hyperbolic diffeomorphism, it has been proved that the power series
Ψ
(
z
) has a radius of convergence
r
(
Ψ
)>1, and that
δρ
(
A
)=
Ψ
(1), but it is known that
r
(
Ψ
)<1 in some other cases. One reason why
f
may fail to be uniformly hyperbolic is if there are tangencies between the stable and unstable manifolds for (
f
,
ρ
). The present paper gives a crude, non-rigorous, analysis of this situation in terms of the Hausdorff dimension
d
of
ρ
in the stable direction. We find that the tangencies produce singularities of
Ψ
(
z
) for |
z
|<1 if
d
<1/2, but only for |
z
|>1 if
d
>1/2. In particular, if
d
>1/2, we may hope that
Ψ
(1) makes sense, and the derivative
δρ
(
A
)=
Ψ
(1) thus has a chance to be defined.
Dynamics of dislocations in a two-dimensional block copolymer system with hexagonal symmetry
Authors: Pezzutti Aldo D. , Vega Daniel A. , Villar Marcelo A.
Published: December 2010

Block copolymer thin films have attracted considerable attention for their ability to self-assemble into nanometre-scale architectures. Recent advances in the use of block copolymer thin films as nano-lithographic masks have driven research efforts in order to have better control of long-range ordering in the plane of the film. Irrespective of the method of sample preparation, different quasi-two-dimensional systems with hexagonal symmetry unavoidably contain translational defects, called dislocations. Dislocations control the process of coarsening in the nano/meso-scales and provide one of the most important mechanisms of length-scale selection in hexagonal patterns. Although in the last decade the nonlinear dynamics of topological defects in quasi-two-dimensional systems has witnessed significant progress, still little is known about the role of external fields on the creation and annihilation mechanisms involved in the relaxation process towards equilibrium states. In this paper, the dynamics of dislocations in non-optimal hexagonal patterns is studied in the framework of the Ohta–Kawasaki model for a diblock copolymer. Measurements of the climb and glide velocities as a function of the wave vector deformation reveal the main mechanisms of relaxation associated with the motion of dislocations.
Kinetics of string-gel formation in a system of dipolar colloidal particles
Authors: Marconi Verónica I. , Serra Pablo , Carignano Marcelo A.
Published: December 2010

The formation of string-gels of dipolar colloidal particles is investigated using molecular dynamics simulations. The characteristic gelation time consistently increases as the temperature of the system increases; it also increases as the density of the system increases. This latter result suggests that the gel formation is not a simple nucleation process. In particular, the energy barriers separating the embryonic nuclei from the final phase appear to be lower for the low-density system, suggesting an important entropic contribution.
Quantifying the complexity of the delayed logistic map
Authors: Masoller Cristina , Rosso Osvaldo A.
Published: December 2010

Statistical complexity measures are used to quantify the degree of complexity of the delayed logistic map, with linear and nonlinear feedback. We employ two methods for calculating the complexity measures, one with the ‘histogram-based’ probability distribution function and the other one with ordinal patterns. We show that these methods provide complementary information about the complexity of the delay-induced dynamics: there are parameter regions where the histogram-based complexity is zero while the ordinal pattern complexity is not, and vice versa. We also show that the time series generated from the nonlinear delayed logistic map can present zero missing or forbidden patterns, i.e. all possible ordinal patterns are realized into orbits.
The (human) science of medical virtual learning environments
Authors: Stone Robert J.
Published: December 2010

The uptake of virtual simulation technologies in both military and civilian surgical contexts has been both slow and patchy. The failure of the virtual reality community in the 1990s and early 2000s to deliver affordable and accessible training systems stems not only from an obsessive quest to develop the ‘ultimate’ in so-called ‘immersive’ hardware solutions, from head-mounted displays to large-scale projection theatres, but also from a comprehensive lack of attention to the needs of the end users. While many still perceive the science of simulation to be defined by technological advances, such as computing power, specialized graphics hardware, advanced interactive controllers, displays and so on, the true science underpinning simulation—the science that helps to guarantee the transfer of skills from the simulated to the real—is that of human factors, a well-established discipline that focuses on the abilities and limitations of the end user when designing interactive systems, as opposed to the more commercially explicit components of technology. Based on three surgical simulation case studies, the importance of a human factors approach to the design of appropriate simulation content and interactive hardware for medical simulation is illustrated. The studies demonstrate that it is unnecessary to pursue real-world fidelity in all instances in order to achieve psychological fidelity—the degree to which the simulated tasks reproduce and foster knowledge, skills and behaviours that can be reliably transferred to real-world training applications.
The injured mind in the UK Armed Forces
Authors: Greenberg N. , Jones E. , Jones N. , Fear N. T. , Wessely S.
Published: December 2010

The mental health of the UK Armed Forces is a topic much debated by healthcare professionals, politicians and the media. While the current operations in Afghanistan, and the recent conflict in Iraq, are relevant to this debate, much of what is known about the effects of war upon the psyche still derives from the two World Wars. This paper will examine the historical and contemporary evidence about why it is that some Service personnel suffer psychological injuries during their military service and others do not. The paper will also consider some of the strategies that today's Armed Forces have put in place to mitigate the effects of sending military personnel into danger.
Military nutrition: maintaining health and rebuilding injured tissue
Authors: Hill Neil , Fallowfield Joanne , Price Susan , Wilson Duncan
Published: December 2010

Food and nutrition are fundamental to military capability. Historical examples demonstrate that a failure to supply adequate nutrition to armies inevitably leads to disaster; however, innovative measures to overcome difficulties in feeding reap benefits, and save lives. In barracks, UK Armed Forces are currently fed according to the relatively new Pay As You Dine policy, which has attracted criticism from some quarters. The recently introduced Multi-Climate Ration has been developed specifically to deal with issues arising from Iraq and the current conflict in Afghanistan. Severely wounded military personnel are likely to lose a significant amount of their muscle mass, in spite of the best medical care. Nutritional support is unable to prevent this, but can ameliorate the effects of the catabolic process. Measuring and quantifying nutritional status during critical illness is difficult. A consensus is beginning to emerge from studies investigating the effects of nutritional interventions on how, what and when to feed patients with critical illness. The Ministry of Defence is currently undertaking research to address specific concerns related to nutrition as well as seeking to promote healthy eating in military personnel.
End-to-end military pain management
Authors: Aldington D. J. , McQuay H. J. , Moore R. A.
Published: December 2010

The last three years have seen significant changes in the Defence Medical Services approach to trauma pain management. This article seeks to outline these changes that have occurred at every level of the casualty's journey along the chain of evacuation, from the point of injury to rehabilitation and either continued employment in the Services or to medical discharge. Particular attention is paid to the evidence for the interventions used for both acute pain and chronic pain management. Also highlighted are possible differences in pain management techniques between civilian and military casualties.
In-vehicle extremity injuries from improvised explosive devices: current and future foci
Authors: Ramasamy Arul , Masouros Spyros D. , Newell Nicolas , Hill Adam M. , Proud William G. , Brown Katherine A. , Bull Anthony M. J. , Clasper Jon C.
Published: December 2010

The conflicts in Iraq and Afghanistan have been epitomized by the insurgents' use of the improvised explosive device against vehicle-borne security forces. These weapons, capable of causing multiple severely injured casualties in a single incident, pose the most prevalent single threat to Coalition troops operating in the region. Improvements in personal protection and medical care have resulted in increasing numbers of casualties surviving with complex lower limb injuries, often leading to long-term disability. Thus, there exists an urgent requirement to investigate and mitigate against the mechanism of extremity injury caused by these devices. This will necessitate an ontological approach, linking molecular, cellular and tissue interaction to physiological dysfunction. This can only be achieved via a collaborative approach between clinicians, natural scientists and engineers, combining physical and numerical modelling tools with clinical data from the battlefield. In this article, we compile existing knowledge on the effects of explosions on skeletal injury, review and critique relevant experimental and computational research related to lower limb injury and damage and propose research foci required to drive the development of future mitigation technologies.
Resuscitation and coagulation in the severely injured trauma patient
Authors: Midwinter Mark J. , Woolley Tom
Published: December 2010

Developments in the resuscitation of the severely injured trauma patient in the last decade have been through the increased understanding of the early pathophysiological consequences of injury together with some observations and experiences of recent casualties of conflict. In particular, the recognition of early derangements of haemostasis with hypocoagulopathy being associated with increased mortality and morbidity and the prime importance of tissue hypoperfusion as a central driver to this process in this population of patients has led to new resuscitation strategies. These strategies have focused on haemostatic resuscitation and the development of the ideas of damage control resuscitation and damage control surgery continuum. This in turn has led to a requirement to be able to more closely monitor the physiological status, of major trauma patients, including their coagulation status, and react in an anticipatory fashion.
Traumatic brain injury
Authors: Risdall Jane E. , Menon David K.
Published: December 2010

There is an increasing incidence of military traumatic brain injury (TBI), and similar injuries are seen in civilians in war zones or terrorist incidents. Indeed, blast-induced mild TBI has been referred to as the signature injury of the conflicts in Iraq and Afghanistan. Assessment involves schemes that are common in civilcian practice but, in common with civilian TBI, takes little account of information available from modern imaging (particularly diffusion tensor magnetic resonance imaging) and emerging biomarkers. The efficient logistics of clinical care delivery in the field may have a role in optimizing outcome. Clinical care has much in common with civilian TBI, but intracranial pressure monitoring is not always available, and protocols need to be modified to take account of this. In addition, severe early oedema has led to increasing use of decompressive craniectomy, and blast TBI may be associated with a higher incidence of vasospasm and pseudoaneurysm formation. Visual and/or auditory deficits are common, and there is a significant risk of post-traumatic epilepsy. TBI is rarely an isolated finding in this setting, and persistent post-concussive symptoms are commonly associated with post-traumatic stress disorder and chronic pain, a constellation of findings that has been called the polytrauma clinical triad.
Blast injury research models
Authors: Kirkman E. , Watts S. , Cooper G.
Published: December 2010

Blast injuries are an increasing problem in both military and civilian practice. Primary blast injury to the lungs (blast lung) is found in a clinically significant proportion of casualties from explosions even in an open environment, and in a high proportion of severely injured casualties following explosions in confined spaces. Blast casualties also commonly suffer secondary and tertiary blast injuries resulting in significant blood loss. The presence of hypoxaemia owing to blast lung complicates the process of fluid resuscitation. Consequently, prolonged hypotensive resuscitation was found to be incompatible with survival after combined blast lung and haemorrhage. This article describes studies addressing new forward resuscitation strategies involving a hybrid blood pressure profile (initially hypotensive followed later by normotensive resuscitation) and the use of supplemental oxygen to increase survival and reduce physiological deterioration during prolonged resuscitation. Surprisingly, hypertonic saline dextran was found to be inferior to normal saline after combined blast injury and haemorrhage. New strategies have therefore been developed to address the needs of blast-injured casualties and are likely to be particularly useful under circumstances of enforced delayed evacuation to surgical care.
Characterization of the response to primary blast injury
Authors: Kirkman E. , Watts S.
Published: December 2010

Lung injuries, predominantly arising from blast exposure, are a clinical problem in a significant minority of current military casualties. This special feature consists of a series of articles on lung injury. This first article examines the mechanism of the response to blast lung (primary blast injury to the lung). Subsequent articles examine the incidence of blast lung, clinical consequences and current concepts of treatment, computer (
in silico
) modelling of lung injury and finally chemical injuries to the lungs. Blast lung is caused by a shock wave generated by an explosion causing widespread damage in the lungs, leading to intrapulmonary haemorrhage. This, and the ensuing inflammatory response in the lung, leads to a compromise in pulmonary gas exchange and hypoxia that can worsen over several hours. There is also a characteristic cardio-respiratory effect mediated via an autonomic reflex causing apnoea (or rapid shallow breathing), bradycardia and hypotension (the latter possibly also due to the release of nitric oxide). An understanding of this response, and the way it modifies other reflexes, can help the development of new treatment strategies for this condition and for the way it influences the patient's response to concomitant injuries.
Theoretical and experimental developments for accurate determination of crystallinity of cellulose I materials
Authors: Driemeier Carlos , Calligaris Guilherme A.
Published: December 2010

This work defines the crystallinity of cellulose I materials on a dry-weight basis. Theoretical and experimental developments in X-ray diffraction lead to a crystallinity determination method that is estimated to reach 1σ accuracies of better than 0.05 (crystallinity defined between 0 and 1). The method is based on Rietveld modelling, to resolve cellulose I Bragg peaks, and a standard truncated invariant integral. Corrections are derived to account for incoherent scattering, moisture content and other compositional deviations from pure cellulose. The experimental development uses X-ray diffraction in transmission fibre geometry with two-dimensional pattern Rietveld modelling, including a crystal-orientation distribution function. The crystallinities of a few commercial cellulose I materials were determined with the aim of illustrating the applicability of the method.