bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constraint programming for air traffic management: a survey
Authors: Allignol Cyril , Barnier Nicolas , Flener Pierre , Pearson Justin 
Published: July 2012

AbstractAir traffic management (ATM) under its current paradigm is reaching its structural limits considering the continuously growing demand. The need for a decrease in traffic workload opens numerous problems for optimization, from capacity balancing to conflict solving, using many different degrees of freedom, such as re-routing, flight-level changes, or ground-holding schemes. These problems are usually of a large dimension (there are 30 000 daily flights in Europe in the year 2012) and highly combinatorial, hence challenging for current problem solving technologies. We give brief tutorials on ATM and constraint programming (CP), and survey the literature on deploying CP technology for modelling and solving combinatorial problems that occur in an ATM context.
Scheduling safe movement of air traffic in crowded air spaces
Authors: Hildum David W. , Smith Stephen F. 
Published: July 2012

AbstractThis paper considers the problem of generating conflict-free movement schedules for a set of vehicles that are operating simultaneously in a common airspace. In both civilian air traffic management and military air campaign planning contexts, it is crucial that the movements of different vehicles be coordinated so as to avoid collisions and near misses. Our approach starts from a view of airspace management as a 4D resource allocation problem, where the space in which vehicles must maneuver is itself managed as a capacitated resource. We introduce a linear octree representation of airspace capacity to index vector-based vehicle routes and efficiently detect regions of potential conflict. Generalizing the notion of contention-based search heuristics, we next define a scheduling algorithm that proceeds by first solving a relaxed version of the problem to construct a spatial capacity profile (represented as an octree), and then using spatio-temporal regions where demand exceeds capacity to make conflict-avoiding vehicle routing and scheduling decisions. We illustrate the utility of this basic representation and search algorithm in two ways. First, to demonstrate the overall viability of the approach, we present experimental results using data representing a realistically sized air campaign planning domain. Second, we define a more abstract notion of ‘encounter set’, which tolerates some amount of conflict on the assumption that on-board deconfliction processes can take appropriate avoidance maneuvers at execution time, and show that generation of this more abstract form of predictive guidance can be obtained without loss in computational efficiency.
Habitat selection and conservation status of the endemic Ninox hawk-owl on Cebu, Philippines
Authors: JAKOSALEM P. GODFREY C. , COLLAR NIGEL J. , GILL JENNIFER A. 
Published: July 2012

SummaryThe largely deforested island of Cebu, Philippines, hosts a forest-dwelling hawk-owl identified in the literature as Ninox philippensis spilonota but which is in fact a Cebu island endemic species, soon to be named. To determine the current distribution and habitat requirements of this hawk-owl, the five largest of 11 remaining forest patches on Cebu were surveyed between March and June 2011, involving 64 post-sunset 500-m walked transects with playback and habitat assessments. Radio-telemetry studies were also conducted on 10 owls but only for 3–5 days per owl as they removed the transmitters. A total of 52 owls were located across all five forests (at 16 sites two owls responded together to playback) but only the largest forest, Alcoy, contained enough transects for analyses of habitat in relation to owl distribution. Alcoy stands on steep-sided hills and some planting of exotic species occurs within it. Owls were detected in forest interior, forest edge and forest-plantation mix in Alcoy, and on ridges and in gullies despite lower tree densities and greater proximity to clearings in the gullies. However, parts of Alcoy experience strong winds, and owl occupancy decreased significantly with increasing wind speed. Home ranges for the 10 radio-tagged owls were estimated to cover ∼10 ha, although given the short tracking periods this may be an underestimate. Suitable forest studied covers roughly 1,670 ha, with six unstudied forests totalling 250 ha, so assuming a pair every 10 ha would give a tentative global population estimate of ∼ 200 pairs of Cebu Hawk-owls, and even fewer if home ranges are larger than estimated. This, coupled with continuing habitat degradation, triggers the IUCN Red List category ‘Endangered’. Tree cavities suitable for nests may be limiting, and nest-box provision could be explored, provided this does not increase predator pressure on other rare species.
Neuron–Glial Interactions in the Developing Cerebellum
Authors: Dunaevsky Anna 
Published: July 2012

AbstractAdvances in microscopy allow one to probe the structure of neurons and their interactions with astrocytes in brain slices and in vivo at ever increasing resolution. Moreover, the dynamic interactions between the cells can be examined in live preparation. In this paper we discuss how a variety of imaging approaches: confocal microscopy, electron microscopy, and multiphoton time-lapse microscopy are employed to probe neuron glia interactions in the developing cerebellum.
On-Column 2pBound State with Topological Charge ±1 Excited by an Atomic-Size Vortex Beam in an Aberration-Corrected Scanning Transmission Electron Microscope
Authors: Xin Huolin L. , Zheng Haimei 
Published: July 2012

AbstractAtomic-size vortex beams have great potential in probing the magnetic moment of materials at atomic scales. However, the limited depth of field of vortex beams constrains the probing depth in which the helical phase front is preserved. On the other hand, electron channeling in crystals can counteract beam divergence and extend the vortex beam without disrupting its topological charge. Specifically, in this article, we report that atomic vortex beams with topological charge ±1 can be coupled to the 2pcolumnar bound states and propagate for more than 50 nm without being dispersed and losing its helical phase front. We give numerical solutions to the 2pcolumnar orbitals and tabulate the characteristic size of the 2pstates of two typical elements, Co and Dy, for various incident beam energies and various atomic densities. The tabulated numbers allow estimates of the optimal convergence angle for maximal coupling to 2pcolumnar orbital. We have also developed analytic formulae for beam energy, convergence angle, and hologram-dependent scaling for various characteristic sizes. These length scales are useful for the design of pitch-fork apertures and operations of microscopes in the vortex-beam imaging mode.
α,ω-Dihexylsexithiophene Self-Assembled Nanostructures on Mica: Atomic Force Microscopy Study
Authors: Wang Li , Ye Shuhong , Yuan Huizhen , Song Yonghai , Zhu Haozhi , Hou Haoqing , Li Pengcheng 
Published: July 2012

AbstractSelf-assembled nanostructures of α,ω-dihexylsexithiophene (DH6T) formed by spreading DH6T solutions onto freshly cleaved mica surface were studied by atomic force microscopy. The effects of solvent and concentration on the nanostructures of DH6T molecules were studied. Flat, well-ordered, and platelet-like domains were observed on mica surfaces after treatment with various polar solvent solutions of DH6T. These domains form a uniform film with height of 2.4 ± 0.2 nm, which is consistent with a 45° tilt in the molecular conformation of DH6T on mica surfaces. The formation mechanism of these multilayers is discussed in detail.
The Single Molecule Imaging Approach to Membrane Protein Stoichiometry
Authors: Hallworth Richard , Nichols Michael G. 
Published: July 2012

AbstractRecent technical advances have enabled the imaging of single fluorescent molecules. The application of single molecule visualization techniques has opened up new avenues of experimentation in biology at the molecular level. In this article, we review the application of single fluorescent molecule visualization and analysis to an important problem, that of subunit stoichiometry in membrane proteins, with particular emphasis on our approach. Single fluorescent molecules, coupled to fluorescent proteins, are localized in the membranes of cells. The molecules are then exposed to continuous low-level excitation until their fluorescent emissions reach background levels. The high sensitivity of modern instrumentation has enabled direct observations of discrete step decreases in the fluorescence of single molecules, which represent the bleaching of single fluorophores. By counting the number of steps over a large number of single molecules, an average step count is determined from which the stoichiometry is deduced using a binomial model. We examined the stoichiometry of a protein, prestin, that is central to mammalian hearing. We discuss how we prepared, identified, and imaged single molecules of prestin. The methodological considerations behind our approach are described and compared to similar procedures in other laboratories.
From cosmos to intelligent life: the four ages of astrobiology
Authors: Gleiser Marcelo 
Published: July 2012

AbstractThe history of life on Earth and in other potential life-bearing planetary platforms is deeply linked to the history of the Universe. Since life, as we know, relies on chemical elements forged in dying heavy stars, the Universe needs to be old enough for stars to form and evolve. The current cosmological theory indicates that the Universe is 13.7 ± 0.13 billion years old and that the first stars formed hundreds of millions of years after the Big Bang. At least some stars formed with stable planetary systems wherein a set of biochemical reactions leading to life could have taken place. In this paper, I argue that we can divide cosmological history into four ages, from the Big Bang to intelligent life. The physical age describes the origin of the Universe, of matter, of cosmic nucleosynthesis, as well as the formation of the first stars and Galaxies. The chemical age began when heavy stars provided the raw ingredients for life through stellar nucleosynthesis and describes how heavier chemical elements collected in nascent planets and Moons gave rise to prebiotic biomolecules. The biological age describes the origin of early life, its evolution through Darwinian natural selection and the emergence of complex multicellular life forms. Finally, the cognitive age describes how complex life evolved into intelligent life capable of self-awareness and of developing technology through the directed manipulation of energy and materials. I conclude discussing whether we are the rule or the exception.
EISCAT observations of pump‐enhanced plasma temperature and optical emission excitation rate as a function of power flux
Authors: Bryers C. J. , Kosch M. J. , Senior A. , Rietveld M. T. , Yeoman T. K. 
Published: July 2012

We analyze optical emissions and enhanced electron temperatures induced by high power HF radio waves as a function of power flux using the EISCAT heater with a range of effective radiated powers. The UHF radar was used to measure the electron temperatures and densities. The Digital All Sky Imager was used to record the 630.0 nm optical emission intensities. We quantify the HF flux loss due to self‐absorption in the D‐region (typically 3–11 dB) and refraction in the F‐region to determine the flux which reaches the upper‐hybrid resonance height. We find a quasi‐linear relationship between the HF flux and both the temperature enhancement and the optical emission excitation rate with a threshold at ∼37.5 μWm−2. On average ∼70% of the HF flux at the upper‐hybrid resonance height goes in to heating the electrons for fluxes above the threshold compared to ∼40% for fluxes below the threshold.
Dispersal of thermophilic Desulfotomaculum endospores into Baltic Sea sediments over thousands of years
Authors: de Rezende Júlia Rosa , Kjeldsen Kasper Urup , Hubert Casey R J , Finster Kai , Loy Alexander , Jørgensen Bo Barker 
Published: July 2012

Abstract
Patterns of microbial biogeography result from a combination of dispersal, speciation and extinction, yet individual contributions exerted by each of these mechanisms are difficult to isolate and distinguish. The influx of endospores of thermophilic microorganisms to cold marine sediments offers a natural model for investigating passive dispersal in the ocean. We investigated the activity, diversity and abundance of thermophilic endospore-forming sulfate-reducing bacteria (SRB) in Aarhus Bay by incubating pasteurized sediment between 28 and 85 °C, and by subsequent molecular diversity analyses of 16S rRNA and of the dissimilatory (bi)sulfite reductase (dsrAB) genes within the endospore-forming SRB genus Desulfotomaculum. The thermophilic Desulfotomaculum community in Aarhus Bay sediments consisted of at least 23 species-level 16S rRNA sequence phylotypes. In two cases, pairs of identical 16S rRNA and dsrAB sequences in Arctic surface sediment 3000 km away showed that the same phylotypes are present in both locations. Radiotracer-enhanced most probable number analysis revealed that the abundance of endospores of thermophilic SRB in Aarhus Bay sediment was ca. 104 per cm3 at the surface and decreased exponentially to 100 per cm3 at 6.5 m depth, corresponding to 4500 years of sediment age. Thus, a half-life of ca. 300 years was estimated for the thermophilic SRB endospores deposited in Aarhus Bay sediments. These endospores were similarly detected in the overlying water column, indicative of passive dispersal in water masses preceding sedimentation. The sources of these thermophiles remain enigmatic, but at least one source may be common to both Aarhus Bay and Arctic sediments.
A prospective study of learning, memory, and executive function in new MDMA users
Authors: Wagner Daniel , Becker Benjamin , Koester Philip , Gouzoulis‐Mayfrank Euphrosyne , Daumann Joerg 
Published: July 2012

AbstractAimsIt is still unclear if cognitive abnormalities in human 3,4‐methylenedioxymeth‐amphetamine (MDMA) users existed before the beginning of use or if other confounders could explain the deficits. The present study was conducted in order to assess the relationship between beginning MDMA use and subsequent cognitive performance and to overcome previous methodological shortcomings.DesignA prospective cohort study in new MDMA users between 2006 and 2009 with a follow‐up duration of 12 months.Setting and ParticipantsOf the 149 almost MDMA‐naive subjects examined at the initial assessment, 109 subjects participated again after 1 year. During this period, 43 subjects did not use any other illicit substance apart from cannabis; 23 subjects used more than 10 pills MDMA (mean = 33.6). These groups then were compared by means of multivariate analyses of variance.MeasurementsChange scores between the initial examination and follow‐up on a neuropsychological test battery including measures of learning, memory, and frontal executive functions [Auditiv‐Verbaler Lerntest (AVLT), Lern‐ und Gedächtnistest (LGT) 3, digit span test, digit symbol test, Stroop task, Trail‐making test]. In addition, a comprehensive number of possibly relevant confounders including age, general intelligence, cannabis use, alcohol use, cigarette use, medical treatment, participation in sports, nutrition, sleep patterns and subjective wellbeing was assessed.FindingsGroups did not differ in any of the potential confounders. However, significant effects of immediate and delayed recall of a visual paired associates learning task between MDMA users and controls were found (respectively, F
(1,64) = 11.43, P = 0.001, η2 = 0.136 and F
(1,64) = 11.08, P = 0.002, η2 = 0.144). No significant differences on the other neuropsychological tests were found.ConclusionsMDMA appears to impair visual paired associates learning in new users, suggesting serotonergic dysfunction in hippocampal regions as a consequence of MDMA use.
DOSE‐RESPONSE RELATIONSHIPS IN TROPICAMIDE‐INDUCED MYDRIASIS AND CYCLOPLEGIA
Authors: SMITH S.E. 
Published: July 2012

Mydriatic and cycloplegic effects of tropicamide in the normal and in the guanethidine‐treated human eye have been recorded following prolonged exposure of the eye to drug solutions.
Marked effects and satisfactory dose‐response relationships were observed at drug concentrations within the range 1.25–40 μg/ml, by comparison with concentrations of 5–10 mg/ml usually applied as eye‐drops.
The findings are discussed in relation to drug concentrations which produce cholinergic antagonism in vitro.
INTERACTION BETWEEN DEBRISOQUINE AND PHENYLEPHRINE IN MAN
Authors: ALLUM WENDY , AMINU J. , BLOOMFIELD T.H. , DAVIES CAROL , SCALES A.H. , VERE D.W. 
Published: July 2012

The interaction between phenylephrine and debrisoquine was studied using normal and hypertensive human volunteers, measuring blood pressure, pulse rate and pupil diameter. Single doses of phenylephrine were given before, during and after a short course of debrisoquine treatment.
The circulatory effects of phenylephrine are potentiated by debrisoquine; in a few subjects this potentiation was marked and a potential hazard.
Limited deductions could be made about the effects of debrisoquine on baroceptor responses and adrenergic mechanisms.
INHIBITION OF PHENYTOIN METABOLISM BY SULTHIAME IN EPILEPTIC PATIENTS
Authors: HOUGHTON G.W. , RICHENS A. 
Published: July 2012

Measurements have been made of steady state serum phenytoin concentration, serum half‐life of 14C‐labelled phenytoin, and the urinary ratio of the major metabolite of phenytoin to the unchanged drug (p‐HPPH: DPH ratio) in epileptic patients on and off sulthiame therapy.
Starting sulthiame treatment produced an increase in serum phenytoin concentration, a prolongation of the half‐life and an increase in the p‐HPPH: DPH ratio. The total urinary output of phenytoin plus p‐HPPH was unaltered by sulthiame.
The results indicate that sulthiame or one of its metabolites inhibits the parahydroxylation of phenytoin by hepatic enzymes.
EFFECTS OF FOOD AND EXERCISE ON THE ABSORPTION OF EFFERVESCENT ASPIRIN
Authors: VOLANS G.N. 
Published: July 2012

The absorption of effervescent aspirin was studied in normal volunteers of both sexes under varied conditions of activity in both fasting and non‐fasting states.
Moderate activity resulted in no significant changes in absorption compared with that at rest.
In non‐fasting subjects the absorption was reduced but this reduction was attenuated with time until after 60 min the plasma levels were similar.
There was no interaction between the resting/non‐resting and fasting/non‐fasting absorption.
Ro 3–4787, A NEW β‐ADRENOCEPTOR BLOCKING AGENT: STUDIES IN NORMAL VOLUNTEERS
Authors: KILBORN J.R. , TURNER P. 
Published: July 2012

A new β‐adrenoceptor blocking agent, Ro 3–4787, was administered orally to resting subjects. Peak levels of 106.2 ±15.5 ng/ml were reached after 20 mg given in the fasting state. After intravenous administration, an inverse rectilinear relationship was shown between the log dose (2 mg‐20 mg) and the heart rate during vigorous exercise on a bicycle ergometer.
A double‐blind study in five normal subjects using 0.03 mg/kg and 0.15 mg/kg showed that propranolol and Ro 3–4787 were equally effective in reducing the exercise heart rate. There was an inverse correlation between the log plasma level before exercise and the heart rate during exercise for both drugs over the range studied.
PHENYTOIN DOSE ADJUSTMENT IN EPILEPTIC PATIENTS
Authors: MAWER G.E. , MULLEN P.W. , RODGERS MARGARET , ROBINS A.J. , LUCAS S.B. 
Published: July 2012

A preliminary survey showed that many outpatients with partially controlled epilepsy had serum concentrations of phenytoin below the recommended therapeutic range (10–20 μg/ml). A phenytoin tolerance test was devised with the intention of predicting a more adequate daily dose for such a patient.
Fifteen patients were each given an oral test dose of 600 mg phenytoin sodium and the serum concentration of phenytoin was measured at intervals over 48 h; the concentration rose during the first 4 h and decayed between 12–48 h as an almost linear function of time.
The serum concentration/time curves were fitted by an iterative computer program based on the Michaelis‐Menten equatioa The mean saturated rate of elimination of phenytoin was 435 mg/day and the serum concentration (Km) corresponding with 50% saturation was 3.8 μg/ml. The mean calculated dose of phenytoin sodium required for a steady state serum concentration of 10–20 μg/ml was 345–400 mg/day.
The Michaelis‐Menten principle was used to predict steady state serum phenytoin concentrations in individual patients receiving daily doses of phenytoin sodium adjusted by steps of 100 mg. The serum concentrations tended to be either too low or too high. The steep relationship between phenytoin concentration and dose indicates that when the concentration reaches 5–10 μg/ml it is then appropriate to adjust dose by small steps of about 25 mg.
EFFECT OF CAFFEINE ON SLEEP: EEG STUDY IN LATE MIDDLE AGE PEOPLE
Authors: BŘEZINOVÁ VLASTA 
Published: July 2012

The effect of caffeine alkaloid base (300 mg) on whole night sleep was investigated by electrophysiological techniques in six late middle age subjects (mean age 56 years), comparison being made with decaffeinated coffee and with no drink prior to sleep, using each condition five times in a balanced order on non‐consecutive nights.
After caffeine the mean total sleep time decreased on average by 2 h, the mean sleep latency increased to 66 minutes. The number of awakenings increased and the mean total intervening wakefulness was more than doubled after caffeine.
In the first 3 h of sleep a decreased amount of stage 3 + 4 was observed, accompanied by an increased amount of stage 2 and of intervening wakefulness, without a significant change in the amount of rapid eye movement sleep.
The change in sleep pattern observed suggests an increased capability for arousal and decreased ability to develop or sustain deeper stages of non‐rapid eye movement sleep after caffeine.
CORRELATION BETWEEN PLASMA QUINIDINE AND CARDIAC EFFECT
Authors: EDWARDS I.R. , HANCOCK B.W. , SAYNOR R. 
Published: July 2012

The relationship between serum quinidine levels and rate‐corrected QT (QTc) interval after administration of single identical doses of quinidine was assessed. Quinidine concentrations were determined by a modification of Hamfelt & Malers' (1963) method. The significance and clinical application of our findings is discussed.
Individual responses (both in quinidine concentration and QTc prolongation) were variable, though the variation was no greater with QTc prolongation response than with serum quinidine levels. A significant peak in QTc prolongation occurred after quinidine administration and this was not accompanied by a similar peak in quinidine levels. There was some correlation (r = 0.53) between serum quinidine levels and QTc interval but a better correlation was found between rate of rise of quinidine concentration and QTc prolongation (r = 0.87).
One individual showed marked QTc prolongation with slow rate of rise of quinidine levels. Red cell quinidine levels were lower in this individual and he may be showing increased myocardial sensitivity to quinidine.