bluuebunny/crossref_metadata_2025 huggingface dataset:
Small‐mammal herbivore control of secondary succession in New England tidal marshes
Authors: Gedan Keryn Bromberg , Crain Caitlin M. , Bertness Mark D.
Published: February 2009

Secondary succession is impacted by both biotic and abiotic forces, but their relative importance varies due to environmental drivers. Across estuarine salinity gradients, physical stress increases with salinity, and biotic stresses are greater at lower salinities. In southern New England tidal marshes spanning a landscape‐scale salinity gradient, we experimentally examined the effects of physical stress and consumer pressure by mammalian herbivores on secondary succession in artificially created bare patches. Recovery was slower in marshes exposed to full‐strength seawater, where physical stress is high. Compared to full‐strength salt marshes, recovery in low‐salinity marshes was much faster and was influenced by small‐mammal consumers. At lower salinities, small mammals selectively ate and prevented the establishment of several native and two invasive, nuisance species (Typha angustifolia and Phragmites australis) but were unable to control the expansion of established P. australis stands. By controlling the establishment of competitively dominant species and the trajectory of secondary succession in low‐salinity marshes, small mammals may play a cryptic keystone role in estuarine plant communities and are a critical, overlooked consideration in the conservation and management of estuarine marshes.
Local neighborhood and species' shade tolerance influence survival in a diverse seedling bank
Authors: Comita Liza S. , Hubbell Stephen P.
Published: February 2009

Accumulating evidence suggests that negative density dependence, particularly at early life stages, is widespread in plant communities. We hypothesized that survival in forest seedling banks declines with increasing density of conspecific neighbors and that local‐scale effects cause a negative correlation between seedling survival and tree species abundance in the community. We tested these hypotheses using data on 48 956 established seedlings of 235 species over three years in a 50‐ha plot in Panama. For all species combined, we found a significant negative effect of conspecific seedling and adult neighbors within 10 m. In species‐level analyses, neighbor density affected survival for 45 of 59 species, with effects of conspecifics different from heterospecifics for 29 species. Despite negative effects of local conspecific neighbors, seedling survival tended to be positively correlated with species abundance at the 50‐ha scale. However, when accounting for species' shade tolerance, we found a significant negative relationship between seedling survival and species' basal area, but not density, in the 50‐ha plot. Our findings indicate that attempts to quantify the contribution of density dependence to tropical tree species coexistence must integrate effects of neighbors across multiple life stages and should also take into account variation in life history strategy.
Predator‐specific landscapes of fear and resource distribution: effects on spatial range use
Authors: Willems Erik P. , Hill Russell A.
Published: February 2009

Although ecologists have long recognized that animal space use is primarily determined by the presence of predators and the distribution of resources, the effects of these two environmental conditions have never been quantified simultaneously in a single spatial model. Here, in a novel approach, predator‐specific landscapes of fear are constructed on the basis of behavioral responses of a prey species (vervet monkey; Cercopithecus aethiops), and we show how these can be combined with data on resource distribution to account for the observed variation in intensity of space use. Results from a mixed regressive–spatial regressive analysis demonstrate that ranging behavior can indeed be largely interpreted as an adaptive response to perceived risk of predation by some (but not all) predators and the spatial availability of resources. The theoretical framework behind the model is furthermore such that it can easily be extended to incorporate the effects of additional factors potentially shaping animal range use and thus may be of great value to the study of animal spatial ecology.
Sex‐ and context‐dependent migration in a pond‐breeding amphibian
Authors: Grayson Kristine L. , Wilbur Henry M.
Published: February 2009

Partial migration, variation in the percentage of a population that completes a migration, can be influenced by the local environment and condition of an individual. We examined the direct and interacting effects of habitat quality and gender on migration decision by manipulating population density and sex ratio in a factorial field experiment using aquatic enclosures. In partially migrating red‐spotted newts (Notophthalmus viridescens), we measured the percentage of newts migrating to the terrestrial habitat vs. overwintering as pond residents. Density significantly influenced migration, with 63% of newts migrating from high‐density enclosures compared to 39% from low‐density enclosures. Newts also migrated earlier from high‐density enclosures, but no significant effects of the sex ratio treatment were found. Females migrated earlier than males, and 64% more females developed the migrant phenotype, suggesting important sex‐based trade‐offs of migration. No differences were found between migrants and residents in initial body size, counter to our prediction that larger individuals would be more likely to remain pond residents. This study demonstrates experimentally that migration can be a plastic response influenced by both local density and gender.
Biogeography and the molecular dating game: a futile revival of phenetics?
Authors: Nelson Gareth , Ladiges Pauline Y.
Published: February 2009

In molecular dating, branch lengths are considered parameters that may be estimated by counting similarities and differences in DNA sequences. Long and short branches imply long and short time spans, which might appear informative additions when imposed on a tree that is otherwise cladistic. Recent attempts to apply molecular dating to southern hemisphere biogeography (Nothofagus, Adansonia) seem only another “excursion into futility,” as was the fate of phenetic systematics [H.H. Ross, 1964]. Some conceptual matters are clarified with reference to the experimental approach of Claude Bernard (1813–1878).
Heat Transfer of Polymer Particles in Gas-Phase Polymerization Reactors
Authors: Behjat Yaghoub , Dehnavi Mohammad Ali , Shahhosseini Shahrokh , Hashemabadi Seyed Hassan
Published: February 2009

In this paper the effects of particles configuration and particles distance on the heat transfer rate in a gas phase olefin polymerization reactor have been studied using the computational fluid dynamic (CFD) modeling approach. The goal was to determine the causes of particle overheating in this reactor. It has been shown that classic correlations such as Ranz-Marshall are sufficiently adequate when far away particles with no interactions are to be modeled. However, when particles are sufficiently close to having interactions, these correlations fail to satisfactorily predict the convective heat transfer coefficient. The results indicate an increase in particle distance leads to an increase in the Nusselt number on the particle surface. Therefore, for particles with a large distance and triangular or rotated square configurations, the local Nusselt number is closer to the Nusselt number for a single particle.
Hydrogen Adsorption and Equilibrium Models on Multi-Walled Carbon Nanotubes at Moderate Temperatures and Pressures
Authors: Gholamhosseiny Mehrdad , Fatemi Shohreh , Rasoolzadeh Maryam
Published: February 2009

Hydrogen adsorption was studied on treated multi-walled carbon nanotubes (MWCNTs). The amounts of hydrogen adsorbed on this adsorbent were measured at three temperatures (298, 273 and 263 K) and various pressures from 10 up to 70 bar in a volumetric adsorption apparatus. In the studied ranges of operational conditions, the maximum adsorbed hydrogen was determined as 0.28 wt%, at the lowest temperature of 263 K and the highest pressure of 70 bar, by the static measurements at the equilibrium condition. The experimental adsorption isotherms were obtained at different temperatures and they were correlated by Dubinin-Astokhov (DA), Sips, Freundlich and Dubinin-Rudushkevich (DR) equations. The isosteric heat of adsorption was determined from both experimental isosters and isotherm models as a function of the adsorbed amount. The isosteric heats of adsorption revealed that MWCNTs would be an energetically heterogeneous surface. Sips model showed a better fitting of the experimental and theoretical isosteric heats of adsorption values and indicated a weak temperature dependency of the isosteric heat.
A Note on the Valuation of Collective Goods: Overlooked Input Market Free Riding for Non-Individually Incrementable Goods
Authors: Graves Philip E
Published: February 2009

For at least fifty years economists have argued that vertically-aggregated marginal willingness to pay, when set equal to marginal provision cost, will result in optimal public good provision levels. This methodological approach would be expected to yield an exact analog, in terms of optimal levels of public good provision, to efficient provision of private goods in a perfect market setting. There is, however, a potentially serious flaw in the approach as actually practiced, since initial incomes are implicitlyand wronglytaken to be optimal. From a given income, the output demand revelation problem has long been recognizedthat there will be difficulty inferring true demands for public goods at that income (the traditional `free rider' problem). But what has failed to receive widespread recognition among theoreticians, and especially among practitioners, is that there will also be a concomitant `input demand revelation' problem. In any situation where workers cannot individually increment a class of goods by increasing their income (e.g. public goods), they will have no incentive to generate the income that would have been devoted to that class of goods. They will only generate income that is optimal to pay the higher taxes or prices associated with whatever initial public goods levels are provided. As a consequence, the benefit-cost practitioner will, even if somehow able to accurately guess marginal willingness-to-pay out of current income, observe only one apparent optima. There are an infinite number of such optima, one for each level of free riding in input markets, where aggregated marginal willingness-to-pay will appear to equal marginal provision cost. The one true Samuelson `optimum optimorum' occurs when there is free riding in neither output nor input markets (that is, when the `full' demand revelation problem is solved). As a consequence, pure public goods, as well as other `non-incrementable' goods and goods for which non-use values are of importance will be undervalued, hence under-provided. Evidence is presented that the problem raised here might be of importance, undermining the practical significance of the Coase theorem vis-à-vis Pigouvian taxation.
Two faces of global open society
Authors: Cveticanin Neven
Published: February 2009

The Essay considers 'the rule' of the so called post-civil political centre that corresponds to the familiar concept of open society, questioning the good as well as the bad sides of such 'rule'. The research is in the first place about global open society stability and attention is addressed to its present enemies - from terrorism, over organized crime, all the way to the so called local legitimates that are confronting the universal and global legitimates represented by the followers of the open society from the post civil political centre area. The Essay presents the debate with Fukuyama's thesis about the 'end of history' considering that open society, i.e. global post civil political centre has visible enemies who do not allow for dialectics of history to stand still as Fukuyama believed. Instead of Fukuyama's 'end of history' the Essay comes to the conclusion that present global situation is marked by post-modern opposition of liberal-democratic post civil centre and extreme anti civil margins, with reference to the opposition of open society and its enemies, which will put under limits further steps of history towards new socio-historical forms.
On a botanical analogy in modern theory of society
Authors: Krstic Predrag
Published: February 2009

The author, first of all, undertakes to perceive and analyze the role that the metaphor of 'root' plays, as well as the discourse connected with it - 'rooted', 'root out' and so on - in order to examine the functioning of botanical metaphors in modern political theory. Ideological duality is here shown as, in equal measure but in different ways, fixed to the idea of the root of human existence or of the well ordered society - and an image of a tree in blossom, if it has grown out of this condition - in which it is a privileged possession, giving the right to 'radical' actions. The difference is found where one group advocates unconditional nurturing of the given root and the other one urgent necessity of replacing it with new one. As a conclusion, it is suggested that the abandoning of the floral metaphor could not only open up space for reasonable dispute about the questions that it was believed to answer, but also that this kind of retreat from the fascination with root could really be - radical.
One solution of main controller in thermal power plants
Authors: Radmilovic Nebojsa , Stojakovic Slavisa , Kvascev Goran
Published: February 2009

This paper describes functionality between pressure regulation of steam boiler and electrical power regulation of turbine-generator system at thermal power plants. Importans of this control is essentially in coordinate work mode when these complex and non-linear systems have to work as one integrated entity with tendency to produce electrical power at optimal and stable way. Steam generator - boiler is system with long transport delay and here is recommendation for improving pressure regulation. This regulation realized at thermal power plant nominal power 308MW and given working results in real time. Index Terms - boiler control, combustion control, thermal power plants, PID controller.
Functional electrical stimulation with surface electrodes
Authors: Bajd Tadej , Crt Marincek , Munih Marko
Published: February 2009

The review investigates the objective evidences of benefits derived from surface functional electrical stimulation (FES) of lower and upper extremities for people after incomplete spinal cord injury (SCI) and stroke. FES can offer noticeable benefits in walking ability. It can be efficiently combined with treadmill and body weight support. Voluntary muscle strength and endurance gain can be achieved through FES assisted gait training together with increased gait velocity in absence of electrical stimulator. Cyclic FES, FES augmented by biofeedback, and FES used in various daily activities can result in substantial improvements of the voluntary control of upper extremities.
Central nervous system lesions leading to disability
Authors: Popovic Dejan , Sinkjær Thomas
Published: February 2009

The introductory tutorial to this special issue was written for readers with engineering background with the aim to provide the basis for comprehending better the natural motor control and the terminology used in description of impairments and disability caused by to CNS injuries and diseases. The tutorial aims to emphasize the differences between natural and artificial control, complexity of sensory-motor systems in humans, the high level of articulation redundancy, and the fact that all of the said systems are modified after the central nervous system lesion. We hope that the tutorial will simplify the following of the subsequent papers in this special issue dedicated to the use of electrical stimulation with surface electrodes for assisting motor functions.
Functional electrical stimulation therapy improves grasping in chronic cervical spinal cord injury: Two case studies
Authors: Miller Rosalynn , Popovic Milos , Thrasher Adam , Verrier Molly
Published: February 2009

OBJECTIVE AND IMPORTANCE: To present case studies of two individuals with chronic cervical spinal cord injury (SCI) who participated in functional electrical stimulation (FES) therapy with the objective to restore voluntary grasp function. CLINICAL PRESENTATION: Both individuals (right hand dominant males, age 24 and 31) had a sustained a cervical SCI (C6 and C4-5, respectively) at least 8 years prior to participation in this study. INTERVENTION: Both individuals participated in an individualized FES therapy program for 6 weeks. FES therapy was administered through a regimen of three, one-hour sessions, per week for three months. A single arm of each participant (n = 2) was treated. FES therapy is an integrative intervention strategy combining muscle strengthening, functional movement training and stretching. The participant's hand movement abilities were assessed pre and post FES therapy using the Manual Muscle Test (MMT), a modified Sollerman Hand Function Test (mSHFT), and the Reach, Grasp, Transport and Release Task (RGTR). DISCUSSION: As the injuries of participants in the current study were chronic and thus neurologically stable, no spontaneous improvements/recovery in hand function was expected. However, FES as part of an integrated therapeutic approach affected restoration and improvement of hand function in both participants. CONCLUSION: The concurrent improvement in strength, integrated motor function and object contact following FES therapy, demonstrated that there is potential for affecting change in hand function of individuals with chronic SCI.
Neural prosthesis for the therapy of low back pain
Authors: Miler Vera , Bijelic Goran , Schwirtlich Laszlo
Published: February 2009

We present methods to treat Low Back Pain (LBP) with electrical stimulation. The conventional method of treating LBP with electrical stimulation is based on mechanisms of reduction of pain. The method that we suggest uses electrical stimulation of trunk muscles at motor suprathreshold level synchronized with exercising of the trunk muscles. The hypothesis was that the combination of voluntary activity augmented with electrical stimulation would lead to higher levels of recovery of postural control and thereby, reduction of LBP. The electrical stimulation in this treatment was delivered with the lumbar belt with eight pairs of electrodes named Stimbelt. The outcome measures included: a Visual Analogue Scale (VAS), the Oswestry LBP disability questionnaire, the SF-12 health survey, and Manual Muscle Test (MMT). We specifically address the selection of the most appropriate statistical tests for the analysis of results. The analysis of the results of the clinical study indicates significant benefits of the addition of the Stimbelt to the conventional therapy.
Synthesis, reactions and biological activity of 3-arylidene-5-(4-methylphenyl)-2(3H)-furanones?
Authors: Husain Asif , Alam Mumtaz , Siddiqui Nadeem
Published: February 2009

3-Arylidene-5-(4-methylphenyl)-2(3H)-furanones 2a-m were prepared from 3-(4-methyl-benzoyl)propanoic acid 1 and several aromatic aldehydes. Some of the selected furanones were reacted with ammonia gas and benzylamine to give corresponding 3-arylidene-1,3-dihydro-5-(4-methylphenyl)-2H-pyrrol- 2-ones 3a-h and 3-arylidene-1-benzyl-1,3-dihydro-5-(4-methylphenyl)-2H- -pyrrol-2-ones 4a-f, respectively, which were characterized on the basis of IR, 1H-NMR, mass spectral data and elemental analysis results. These compounds were tested for their anti-inflammatory and antibacterial activities. The compounds, which showed significant anti-inflammatory activity, were further screened for their analgesic and ulcerogenic activities. Three new compounds (2e, 2h and 4d), out of twenty-seven showed very good anti-inflammatory activity in the carrageenan induced rat paw edema test, with significant analgesic activity in the acetic acid induced writhing test together with negligible ulcerogenic action. The antibacterial activity is expressed as the corresponding MIC values.
Characterization of volatile compounds of 'Drenja', an alcoholic beverage obtained from the fruits of Cornelian cherry
Authors: Tesevic Vele , Nikicevic Ninoslav , Milosavljevic Slobodan , Bajic Danica , Vajs Vlatka , Vuckovic Ivan , Vujisic Ljubodrag , Djordjevic Iris , Stankovic Miroslava , Velickovic Milovan
Published: February 2009

In this study, volatile compounds were analyzed in five samples of home-made spirit beverage made by the distillation of fermented fruits of cornelian cherry (Cornus mas L.). The major volatile compounds, besides ethanol, identified and quantified were: methanol, acetaldehyde, 1-propanol, ethyl acetate, 2-methyl-1-propanol, 1-butanol, amyl alcohols, 1-hexanol and 2-phenylethanol. The minor volatiles were submitted to liquid-liquid extraction with dichloromethane and analyzed by gas chromatography and gas chromatography/ /mass spectrometry (GC/MS). A total of 84 compounds were identified. The most abundant compounds were straight-chain free fatty acids, ethyl esters of C6-C18 acids, limonene, 2-phenylethanol and 4-ethylphenol. Most of the compounds found in the 'Drenja' spirits investigated in this study are similar to those present in other alcoholic beverages.
Secondary metabolites of Hypericum monogynum from Pakistan
Authors: Arfan Mohammad , Raziq Naila , Aljancic Ivana , Milosavljevic Slobodan
Published: February 2009

4-Chlorobenzoic acid (1), quercitrin (2), astilbin (3), along with ?-sitosterol, ?-sitosterol, friedelin and ?-amyrin were isolated from the aerial parts of Hypericum monogynum. Whereas compound 1 was isolated for the first time from natural sources, flavanonol 3 was not found before in these species.
Spectrophotometric determination of the acidity constants of calcon in water and mixed water-organic solvents
Authors: Mazloum-Ardakani Mohammad , Lotfi Shahram , Ghasemi Jahanbakhsh , Shababi Alahdad , Noroozi Mohammad
Published: February 2009

The acid-base properties of calcon (1-(2-hydroxy-1-naphthylazo)-2- -naphthol-4-sulfonic acid) in water and mixed water-organic solvents at 25 ?C at an ionic strength of 0.10 M are studied by a multiwavelength spectrophotometric method. The organic solvents used were the amphiprotic (methanol), dipolar aprotic (dimethylsulfoxide), and low basic aprotic (acetonitrile). To evaluate the pH absorbance data, a resolution method based on the combination of soft- and hard-modeling was applied. The acidity constants of all related equilibria were estimated using the whole spectral fitting of the collected data to an established factor analysis model. The data analysis program Datan was applied for determination of the acidity constants. The corresponding pKa values were determined in water and mixed water-organic solvents. Linear relationship between the acidity constants and the mole fraction of the different solvents in the mixtures exist. The effect of solvent properties on acid-base behavior is discussed.
Traumatic brain injuries: Forensic and expertise aspects
Authors: Vulekovic Petar , Simic Milan , Misic-Pavkov Gordana , Cigic Tomislav , Kojadinovic Zeljko , Djilvesi Djula
Published: February 2009

Introduction. Traumatic brain injuries have major socio-economic importance due to their frequency, high mortality and serious consequences. According to their nature the consequences of these injuries may be classified as neurological, psychiatric and esthetic. Various lesions of brain structures cause neurological consequences such as disturbance of motor functions, sensibility, coordination or involuntary movements, speech disturbances and other deviations, as well as epilepsy. Psychiatric consequences include cognitive deficit, emotional disturbances and behavior disturbances. Criminal-legal aspect of traumatic brain injuries and litigation. Criminal-legal aspect of traumatic brain injuries expertise understands the qualification of these injuries as mild, serious and qualified serious body injuries as well as the expertise about the mechanisms of their occurrence. Litigation expertise includes the estimation of pain, fear, diminished, i.e. lost vital activity and disability, esthetic marring, and psychological suffer based on the diminished general vital activity and esthetic marring. Competence and timing of expertise. Evaluation of consequences of traumatic brain injuries should be performed only when it can be positively confirmed that they are permanent, i.e. at least one year after the injury. Expertise of these injuries is interdisciplinary. Among clinical doctors the most competent medical expert is the one who is in charge for diagnostics and injury treatment, with the recommendation to avoid, if possible, the doctor who conducted treatment. For the estimation of general vital activity, the neurological consequences, pain and esthetic marring expertise, the most competent doctors are neurosurgeon and neurologist. Psychological psychiatric consequences and fear expertise have to be performed by the psychiatrist. Specialists of forensic medicine contribute with knowledge of criminal low and legal expertise.
Neurophysiological conception of pain in craniomandibular disfunction
Authors: Stankovic Sasa , Boskovic Mirjana , Ajdukovic Zorica , Kesic Ljiljana , Aleksov Ljiljana , Radosavljevic Radivoje
Published: February 2009

Introduction. Ethiopathogenesis of dysfunction and pain in temporomandibular joints has been the subject of passionate discussions between supporters of purely mechanical conception and the ones who are supporters of psyhosomatic conception. The aim of the study: Relying on neurophysiological data, the authors are trying to reveal the main role of reticular mesencephalical formation in mechanisms which provoke craniomandibular dysfunctions and confront the influence of emotional factors from neocortex and painful stimuli from oral structures. Discussion. From dynamical point of view, not only the morphological aspects of teeth and arcades, but also sensitive-sensorial mechanisms connected to masticatory muscles, periodontal structures and oral structures, should be considered. The ideal bite and perfect morphology of tooth arcades are not enough for reconstitution of correct occlusion, if there are no neuromuscular system, temporomandibular joint, and especially central nervous system. Conclusion. The presence of pain is just one of the craniomandibular dysfunction symptoms, but if it is added to the other clinical signs and emotional or affect - provoking factor, it will provoke dysfunctional syndrome.
Mortality rate of adolescents in the Republic of Serbia
Authors: Roncevic Nevenka , Stojadinovic Aleksandra
Published: February 2009

Introduction. Adolescents are the healthiest age group of the population but many studies show that period of adolescence is marked by significant morbidity and mortality. Health indicators of adolescent population have been getting worse during past decades. The aim of this study was to determine mortality rate of adolescents in the Republic of Serbia to determine most common causes of death in adolescence and to explore regional differences in adolescent mortality. Materials and methods: Documentation tables of vital statistics in the Republic of Serbia in 2004, and Documentation Tables of Census 2002 were used. The causes of mortality were classified according to ICD 10. Results and discussion. Specific morality rate in the Republic of Serbia is 32.08 on 100.000 adolescents. The leading causes of death in adolescence are injuries, malignancies and non specified causes, and there are significant regional differences, as well as gender and age differences. The mortality rate of male adolescents is about 2.4 times higher than the mortality rates in female adolescents. The mortality rate of older adolescents is significantly higher than mortality rate of younger adolescents. The mortality of adolescents is higher in Vojvodina than in Central Serbia. Precise data of external causes of death do not exist in vital statistics in our country. Conclusion. The mortality of adolescents is high, especially for older male adolescents (15 to 19 years of age) and majority of deaths among adolescents could be prevented. It is necessary to improve data of vital statistics to get better insight into causes of adolescent death.
Hemodynamic effects of intravenous administration of ACE inhibitor in prevention of heart failure following coronary artery bypass surgery
Authors: Lausevic-Vuk Ljiljana
Published: February 2009

Introduction. Our study was designed to explore the hemodynamic effects of intravenous administration of ACE-inhibitor quinaprilat in comparison with standard inotropic-vasodilator therapy. Patients with poor left ventricular function following coronary artery bypass (CABG) surgery were examined. Materials and methods. Thirty patients with poor left ventricular function (EF<30 %) following CABG surgery with use of cardiopulmonaly bypass were examined. Fourty patients were control group. All patients had complete invasive hemodynamic monitoring. The ACE-inhibitor quinaprilat 0.5mg/h was administered intravenously via infusion pump. The following parameters were analyzed: arterial blood pressure, systemic vascular resistance, pulmonary vascular resistance, heart rate, cardiac output, cardiac index, left ventricular stroke work index and the level of mixed venous oxygen saturation. Results. The results of our study were as follows: Cardiac output, cardiac index and left ventricular stroke work index were significantly increased in comparison to the control group. Systemic arterial systolic pressure and pulmonary vascular resistance were decreased and there was no significant difference in systemic vascular resistance, mixed venous oxygen saturation, heart rate and diastolic blood pressure in comparison to the control group. Discussion. Our results pointed at very satisfactory hemodynamic effects of quinaprilat on 'stunned myocardium', after CABG surgery. The ACE inhibitors greatly reduce mortality in patients in all stages of heart failure, from asymptomatic dysfunction of the left ventricle to severe symptomatic stages. Conclusion. In prevention of heart failure in patients with impaired left ventricle function (LVEF<30%), who had undergone CABG surgery with use of cardiopulmonaly bypass, we achieved the best effects on the hemodynamics with parenteral administration of quinaprilat.
The mode of operation of CANDU power reactor in thorium self-sufficient fuel cycle
Authors: Bergelson Boris , Gerasimov Alexander , Tikhomirov Georgy
Published: February 2009

This paper presents the results of calculations for CANDU reactor operation in the thorium fuel cycle. The calculations were performed to estimate feasibility of operation of a heavy-water thermal neutron power reactor in the self-sufficient thorium cycle. The parameters of the active core and the scheme of fuel reloading were considered to be the same as for the standard operation in the uranium cycle. Two modes of operation are discussed in the paper: the mode of preliminary accumulation of 233U and the mode of operation in the self-sufficient cycle. For calculations for the mode of accumulation of 233U, it was assumed that plutonium was used as the additional fissile material to provide neutrons for 233U production. Plutonium was placed in fuel channels, while 232Th was located in target channels. The maximum content of 233U in the target channels was about 13 kg/t of ThO2. This was achieved by six year irradiation. The start of reactor operation in the self-sufficient mode requires content of 233U not less than 12 kg/t. For the mode of operation in the self-sufficient cycle, it was assumed that all the channels were loaded with the identical fuel assemblies containing ThO2 and a certain amount of 233U. It was shown that the non-uniform distribution of 233U in a fuel assembly is preferable.
Valence electronic state density in thorium dioxide
Authors: Teterin Anton , Ryzhkov Mikhail , Teterin Yury , Vukcevic Labud , Terekhov Vladimir , Maslakov Konstantin , Ivanov Kirill
Published: February 2009

This work analyses the fine low energy (0-40 eV) X-ray photoelectron spectra of ThO2, taking into account relativistic X?-discrete variation electronic structure calculations for the ThO8 (D4h) cluster reflecting thorium's close environment in ThO2. As a result, it was theoretically shown and experimentally confirmed that Th5f electrons in ThO2 can participate directly (~0.6 Th5f electrons) in chemical bond formation.Th6p electrons were shown to be a significant part (~0.44 Th6p electrons) not only of inner valence molecular orbitals, but to play a significant role in outer valence molecular orbitals formation, as well. Inner valence molecular orbitals composition and sequent order were established to belong to the binding energy range of 13 eV to 40 eV. The valence electronic state density in the range of 0-40 eV in ThO2 was also calculated. For the first time, these data allowed an interpretation of the fine X-ray photoelectron spectra (0-40 eV) and high resolution O4,5(Th) X-ray emition spectral structure (~60 - ~85 eV) of ThO2.
Role of Rosemary leaves extract against radiation-induced hematological and biochemical alterations in mice
Authors: Acharya Garima , Goyal Pradeep
Published: February 2009

The present paper is a study of the modulatory effect of Rosmarinus officinalis leaves extract on radiation-induced hematological and biochemical changes in Swiss albino mice. The dose reduction factor for the Rosemary extract against gamma rays was calculated 1.53 from LD50/30 values. The Rosemary extract was administered orally for 5 consecutive days prior to radiation exposure. The hematological and biochemical parameters were assessed from day 1 to 30 post-irradiation intervals. The total erythrocyte count, total leucocytes count, hemoglobin, and hematocrit values in the experimental group were found to be elevated as compared to the control group of mice. Furthermore, the Rosemary extract treatment enhanced reduced glutathione content in the liver and blood against radiation-induced depletion. Treatment with the plant extract brought a significant fall in the lipid peroxidation level, suggesting rosemary's role in protection against radiation-induced membrane and cellular damage. The results from the present study suggest a radio-protective effect of the Rosemary extract against radiation-induced hematological and biochemical alterations in mice.
Priming of object categorization within and across levels of specificity
Authors: Martinovic Jasna , Gruber Thomas , Müller Matthias
Published: February 2009

Identification of objects can occur at different levels of specificity. Depending on task and context, an object can be classified at the superordinate level (as an animal), at the basic level (a bird) or at the subordinate level (a sparrow). What are the interactions between these representational levels and do they rely on the same sequential processes that lead to successful object identification? In this electroencephalogram study, a task-switching paradigm (covert naming or living/non-living judgment) was used. Images of objects were repeated either within the same task, or with a switch from a covert naming task to a living or non-living judgment and vice versa. While covert naming accesses entrylevel (basic or subordinate), living/non-living judgments rely on superordinate classification. Our behavioral results demonstrated clear priming effects within both tasks. However, asymmetries were found when task-switching had occurred, with facilitation for covert naming but not for categorization. We also found lower accuracy and early-starting and persistent enhancements of event-related potentials (ERPs) for covert naming, indicating that this task was more difficult and involved more intense perceptual and semantic processing. Perceptual priming was marked by consistent reductions of the ERP component L1 for repeated presentations, both with and without task switching. Additional repetition effects were found in early event-related activity between 150-190 ms (N1) when a repeated image had been named at initial presentation. We conclude that differences in N1 indicate task-related changes in the identification process itself. Such enhancements for covert naming again emerge in a later time window associated with depth of semantic processing. Meanwhile, L1 reflects modulations due to implicit memory of objects. In conclusion, evidence was found for representational overlap; changes in ERP markers started early and revealed cross-task priming at the level of object structure analysis and more intense perceptual and semantic processing for covert naming.
Can deployment of attention be strategically controlled?
Authors: Popovic Marjena , Zdravkovic Suncica
Published: February 2009

Department of Psychology, University of Novi Sad, Serbia The main goal of the experiment was to test whether deployment of attention could be strategically controlled. Subjects viewed five-letter arrays. Each array included a letter unique in shape (i.e. target). One of the letters in each array (target or non-target) also differed from other letters in color or in position in relation to the array. That letter will be referred to as a feature singleton. The probability ratio of the feature singleton being the target or a non-target letter was varied throughout three experiments. The ratios were (1) 0.5 (target) : 0.5 (non-target); (2) 0.2 (target) : 0.8 (non-target); (3) 0.8 (target) : 0.2 (non-target). Subjects in all three experimental conditions deployed serial processes, but failed to maintain complete intentional control during the course of the search.
Vector based semantic analysis reveals absence of competition among related senses
Authors: Filipovic-Djurdjevic Dusica , Djurdjevic Djordje , Kostic Aleksandar
Published: February 2009

Previous research demonstrated that processing time was facilitated by number of related word senses (polysemy) and inhibited by number of unrelated word meanings (homonymy). The starting point of this research were the findings described by Moscoso del Prado Mart?n and colleagues, who offered a unique account of processing of two forms of lexical ambiguity. By applying the techniques they proposed, for the set of strictly polysemous Serbian nouns we calculated ambiguity measures they introduced. Based on the covariance matrix of the context vectors, we derived entropy of equivalent Gaussian distribution, and based on the context vectors probability density function, we derived differential entropy. Negentropy was calculated as the difference between the two. Based on interpretation that entropy of equivalent Gaussian mirrors sense cooperation, or polysemy, while negentropy mirrors meaning competition, or homonymy, we predicted that in the set of strictly polysemous nouns, negentropy effect would disappear. In accordance with our predictions, entropy of equivalent Gaussian distribution accounted for significant proportion of processing latencies variance. Negentropy did not affect reaction time. This finding is in accordance with the hypothesis that entropy of equivalent Gaussian distribution, as a measure of general width of activation in semantic space, reflects polysemy, that is, the existence of related senses. Therefore, polysemy advantage could be the result of the wide-spread activation in semantic space and reduced competition among overlapping Gaussians.
The Key to Global Understanding: World Languages Education—Why Schools Need to Adapt
Authors: Tochon Francois Victor
Published: February 2009

This review article is a plea for the education community to reconsider the place of world languages teaching within the schools. With globalization, languages education should be one of the strategic goals of public as well as private education. The article reviews research on the best age level for learning a language, the assets of bilingualism, the problems that arise from lack of recognition for other languages and cultures, the ways to change current language education, and the integration of international language policies. The literature reviewed points at how the issues discussed can be resolved to increase global understanding.
Animal Welfare and the Human–Animal Bond: Considerations for Veterinary Faculty, Students, and Practitioners
Authors: Wensley Sean P.
Published: February 2009

Consideration of the human–animal bond typically focuses on the benefits of companion animals to human health and well-being, but it is essential that in realizing these benefits the welfare needs of the animals, both physical and mental, are also met. Positive emotional relationships with animals are likely to increase recognition of animal sentience and so help create positive attitudes toward animals at the societal level, but, at the individual level, the animals to which humans are bonded should also benefit from the human–animal relationship. A strong human–animal bond may benefit animal welfare (e.g., by motivating an owner to commit time and funds to necessary veterinary medical treatment), but may also be the source of compromised welfare. Highly bonded owners may, for example, be reluctant to permit euthanasia on humane grounds, and the anthropomorphic nature of many human–companion animal bonds can contribute to the development of problem behaviors and obesity. The challenge for the veterinary profession is to ensure that widespread positive sentiment toward animals, which the human–animal bond generates, is translated in to human behavior and actions that are conducive to good animal welfare. This, it is suggested, can be achieved through adequate veterinary education in veterinary and animal welfare science, ethics, and communication.
LIVE: The Creation of an Academy for Veterinary Education
Authors: Pirkelbauer Birgit , Pead Matthew , Probyn Paul , May Stephen A.
Published: February 2009

The purpose of this paper is to introduce a new educational development and research program; to describe the vision which created the LIVE Centre for Excellence in Teaching and Learning (CETL) at the Royal Veterinary College, University of London, UK; and to give details of the educational developments and research that have been pursued in LIVE since 2005. LIVE's purpose, to act as an “incubator” to help support all those interested in veterinary teaching and learning, and associated research, is discussed. The paper describes how the aims of the initial funding bid are being realized through the development of a multi-layered strategy. The discussion concludes by suggesting that new faculty models such as the US Academy Network for Medical Educators or veterinary hubs such as LIVE could act as catalysts for the development of a new breed of clinical teachers and educational researchers, empowered by innovative teaching and learning methods relevant to both medical and veterinary education.
Contextualized Simulation and Procedural Skills: A View from Medical Education
Authors: Kneebone Roger , Baillie Sarah
Published: February 2009

Simulation offers an attractive solution to the profound changes affecting traditional approaches to learning clinical procedural skills. Technical developments in physical models and virtual-reality computing make it possible to practice an increasing range of procedures “in vitro.” However, too narrow a focus on technical skill can overlook crucial elements of clinical care such as communication and professionalism. Patient-focused simulation (the combination of a simulated patient with an inanimate simulator or item of medical equipment) allows clinical procedures to be practiced and assessed within realistic scenarios that recreate clinical challenges by placing a real person at the center of the encounter. This paper draws on work with human clinical procedures, exploring the parallels with veterinary practice and highlighting possible developments in client-focused simulation. The paper concludes by arguing for closer collaboration and dialogue between the medical and veterinary professions, for the benefit of both.
Attitudes of Veterinary Faculty to the Assessment of Clinical Reasoning Using Extended Matching Questions
Authors: Tomlin Jane L. , Pead Matthew J. , May Stephen A.
Published: February 2009

For assessment purposes, clinical expertise is often divided into three broad components: scientific and clinical knowledge, clinical reasoning, and practical/technical skills. This structure can be used to define the tools used for assessment of clinical students. Knowledge can be assessed through a variety of written formats and skills through various practical assessments, including the objective structured clinical examination (OSCE), but the assessment of clinical reasoning has proved to be far more challenging. A companion paper (Tomlin JL, Pead MJ, May SA. Veterinary students’ attitudes toward the assessment of clinical reasoning using extended matching questions. J Vet Med Educ 35:612–621, 2008) reports on the identification and implementation of a valid and reliable method to assess clinical reasoning using clinical-scenario-based extended matching questions (EMQs) in the final examinations at the Royal Veterinary College and looks at students’ response to the new examination format. Although EMQs were generally well accepted, many students were concerned about the implied encouragement of pattern recognition, a non-analytical form of clinical reasoning that results from recognition of familiar clinical situations.

This paper addresses the attitudes of the teaching faculty to the EMQ format. The students’ concerns about promotion of pattern recognition, was also explored in more depth. Overall, faculty perceived EMQs as an appropriate way to test clinical reasoning and as relevant to the experience that students would have gained during their clinical rotations. However, faculty felt that EMQs were difficult to write and that poorly written questions tended to promote pattern recognition. Almost half reiterated the students’ concerns that pattern recognition may be an inappropriate reasoning strategy for undergraduates.
National trends in spinal arteriovenous malformations
Authors: Lad Shivanand P. , Santarelli Justin G. , Patil Chirag G. , Steinberg Gary K. , Boakye Maxwell
Published: February 2009

Object

Spinal arteriovenous malformations (AVMs) are rare and understudied vascular lesions that cause neurological insult by mass effect, venous obstruction, and vascular steal. These lesions are challenging entities to treat because of their complicated anatomy and physiology. Current management options include open microsurgery, endovascular embolization, and stereotactic radiosurgery.

Methods

Our study used the National Inpatient Sample database to analyze outcome data for spinal AVMs treated nationwide over an 11-year period from 1995 through 2006. Trends in procedural management, hospital course, and epidemiology of spinal AVMs are investigated.

Results

Annually, an average of 300 patients presented with spinal AVMs requiring hospital treatment. The average length of hospital stay for this treatment has declined from more than 9 days in 1995 to 6 days in 2006. However, the average cost of a hospital stay has increased from < $30,000 to nearly $70,000. Whereas one-half of spinal AVMs were treated operatively in 1995, one-third were managed operatively in 2006.

Conclusions

Spinal AVMs are being increasingly treated by endovascular, radiosurgical, or combined means. A discussion of modern strategies to treat these disorders is presented.