bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat Balance Analysis of EPS Products Shaping Process
Authors: Władysiak R. , Bogus W. , Pacyniak T.
Published: September 2013

The work is a part of research into the reduction of energy consumption in the production of EPSthrough the modernization of technological equipment used. This paper presents the results of research and analysis of heat transfer process between the water vapor that was provided to machine, the mold, the product and the environment. The paper shows the calculation of the heat balance of the production cycle for two types of mold: standard and modernized. The performance tests used an infrared imaging camera. The results were used to develop a computer image analysis and statistical analysis. This paper presents the main stages of the production process and the construction of technological equipment used, changing the mold surface temperature field during the production cycle and the structure of the heat balance for the mold and its instrumentation. It has been shown that the modernization of construction of technological equipment has reduced the temperature field and as a consequence of decreased of demand for process steam production cycle.
The Stand of Horizontal Continuous Casting of Al and its Alloys
Authors: Wróbel T. , Szajnar J. , Bartocha D. , Stawarz M.
Published: September 2013

In paper is presented idea of construction and influence of selected parts of stand of horizontal continuous casting on quality of pure Al and AlSi2 alloy ingots. The main parts of the made stand belong to induction furnace, which is also tundish, water cooled continuous casting mould, system of recooling, system of continuous ingot drawing and cutting. Mainly was considered influence of electromagnetic stirrer, which was placed in continuous casting mould on refinement of ingots structure. Effect of structure refinement obtained by influence of electromagnetic stirring was compared with refinement obtained by use of traditional inoculation, which consists in introducing of additives i.e. Ti and B to metal bath. The results of studies show possibility of effective refinement of Al and AlSi2 alloy primary structure, only with use of horizontal electromagnetic field and without necessity of application of inoculants. This method of inoculation is important, because inoculants decrease the degree of purity and electrical conductivity of pure aluminum and moreover are reason of point cracks formation during rolling of ingots.
Comparative Analysis of Power Measurement Results in the Testing of Sand Mixers
Authors: Smyksy K. , Wrona R. , Ziółkowski E.
Published: September 2013

Investigations of operating parameters of widely used sand mixers reveal a wide variability range in the values of parameters associated with their power demand. Power efficiency of manufacturing processes has received a great deal of attention lately, which encourages the research efforts to optimise this aspects of operation of machines and installations as well. In the first place these machines and installations have to work properly as a part of the process line- which applies also to moulding sand mixers. Experiments conducted by the authors suggest that the same goal can be achieved at variable energy input levels. To obtain information about the power demands of sand mixers requires the use of highly specialised equipment, methodology and result processing procedures. This study provides a brief characteristic of measurement equipment and results of measurements taken on a unit AG-015 (based on a roller mixer) and a laboratory rotor mixer.
A Concept of the Differentially Driven Three Wheeled Robot
Authors: Kelemen M. , Colville D.J. , Kelemenová T. , Virgala I. , Miková L.
Published: September 2013

The paper deals with the concept of a differentially driven three wheeled robot. The main task for the robot is to follow the navigation black line on white ground. The robot also contains anti-collision sensors for avoiding obstacles on track. Students learn how to deal with signals from sensors and how to control DC motors. Students work with the controller and develop the locomotion algorithm and can attend a competition
Flow and Heat Transfer at a Nonlinearly Shrinking Porous Sheet:The Case of Asymptotically Large Powerlaw Shrinking Rates
Authors: Prasad K.V. , Vajravelu K. , Pop I.
Published: September 2013

The boundary layer flow and heat transfer of a viscous fluid over a nonlinear permeable shrinking sheet in a thermally stratified environment is considered. The sheet is assumed to shrink in its own plane with an arbitrary power-law velocity proportional to the distance from the stagnation point. The governing differential equations are first transformed into ordinary differential equations by introducing a new similarity transformation. This is different from the transform commonly used in the literature in that it permits numerical solutions even for asymptotically large values of the power-law index, m. The coupled non-linear boundary value problem is solved numerically by an implicit finite difference scheme known as the Keller- Box method. Numerical computations are performed for a wide variety of power-law parameters (1 < m < 100,000) so as to capture the effects of the thermally stratified environment on the velocity and temperature fields. The numerical solutions are presented through a number of graphs and tables. Numerical results for the skin-friction coefficient and the Nusselt number are tabulated for various values of the pertinent parameters.
Interactions due to Moving Heat Sources in Generalized Thermoelastic Half-Space using L-S Model
Authors: Sarkar N. , Lahiri A.
Published: September 2013

A one-dimensional problem for a homogeneous, isotropic and thermoelastic half-space subjected to a moving plane of heat source on the boundary of the space, which is traction free, is considered in the context of Lord- Shulaman model (L-S model) of thermoelasticity. The Laplace transform and eigenvalue approach techniques are used to solve the resulting non-dimensional coupled equations. Numerical results for the temperature, thermal stress, and displacement distributions are represented graphically and discussed
Probabilistic Study of Bone Remodeling Using Finite Element Analysis
Authors: Werner C. , Gorla R.S.R.
Published: September 2013

The dynamic bone remodeling process is a computationally challenging research area that struggles to understand the actual mechanisms. It has been observed that a mechanical stimulus in the bone greatly affects the remodeling process. A 3D finite element model of a femur is created and a probabilistic analysis is performed on the model. The probabilistic analysis measures the sensitivities of various parameters related to the material properties, geometric properties, and the three load cases defined as Single Leg Stance, Abduction, and Adduction. The sensitivity of each parameter is based on the calculated maximum mechanical stimulus and analyzed at various values of probabilities ranging from 0.001 to 0.999. The analysis showed that the parameters associated with the Single Leg Stance load case had the highest sensitivity with a probability of 0.99 and the angle of the force applied to the joint of the proximal femur had the overall highest sensitivity
Projective Synchronization of Chaotic Systems Via Backstepping Design
Authors: Tarai A. , Khan M.A.
Published: September 2013

Chaos synchronization of discrete dynamical systems is investigated. An algorithm is proposed for projective synchronization of chaotic 2D Duffing map and chaotic Tinkerbell map. The control law was derived from the Lyapunov stability theory. Numerical simulation results are presented to verify the effectiveness of the proposed algorithm
A Surveillance Of Dynamic Processes on Selected Mechatronic Systems
Authors: Kalinski Krzysztof , Galewski Marek , Mazur Michał
Published: September 2013

The paper concerns development of original method of optimal control at energy performance index and its application to dynamic processes surveillance of some mechatronic systems. The latter concerns chatter vibration surveillance during highspeed slender milling of rigid details, as well as motion control of two-wheeled mobile platform. Results of on-line computer simulations and real performance on the target objects reflect a great efficiency of the processes surveillance
Modification of the Rigid Finite Element Method in Modeling Dynamics of Lines and Risers
Authors: Adamiec-Wójcik Iwona , Brzozowska Lucyna , Wojciech Stanisław
Published: September 2013

The paper presents an application of the modified rigid finite element method to analysis of the dynamics of slender structures. The equations of motion are formulated for a system discretized by means of the method, and discussion is limited to planar systems and large deformations. Slender elements can be found in offshore engineering as lines, cables and risers. In these cases the hydrostatic influence of water and sea currents has to be taken into account. While analyzing dynamics of risers it may also be necessary to consider the flow of fluid inside the riser. The influence of hydrodynamic coefficients and the velocity of the internal flow of fluid on displacements and forces is presented
Application of the Rigid Finite Element Method for Modelling an Offshore Pedestal Crane
Authors: Krukowski Jerzy , Maczynski Andrzej
Published: September 2013

In offshore pedestal cranes one may distinguish three components of considerable length: a pedestal, a boom and a frame present in some designs. It is often necessary in dynamical analyses to take into account their flexibility. A convenient and efficient method for modelling them is the rigid finite element method in a modified form. The rigid finite element method allows us to take into account the flexibility of the beam system in selected directions while introducing a relatively small number of additional degrees of freedom to the system. This paper presents a method for modelling the pedestal, the frame and the boom of an offshore column crane, treating each of these components in a slightly different way. A custom approach is applied to the pedestal, using rigid finite elements of variable length. Results of sample numeric computations are included.
Some Practical Problems of Communications Reliability in Enviromental Monitoring Systems
Authors: Dziadak Bogdan , Makowski Lukasz , Michalski Andrzej
Published: September 2013

In this paper, some issues of building a reliable, distributed measurement system for monitoring of water quality in reservoir Lake Dobczyckie are presented. The system is based on a measurement station that has the shape of a floating buoy which is supposed to be at anchor on the reservoir. Wireless data transmission problems that were encountered during the development of the buoy, modeling a radio link, and measurements of actual signal strength on the reservoir are discussed. A mathematical approach to procedures of early situation assessment was conducted, and specialized procedures were designed for measurement stations of the system. It is also discussed how such computations can improve a qualitative assessment of system performance in terms of real-time messaging
An Efficient Method of Group Delay Equalization for Digital IIR Filters
Authors: Okoniewski Piotr , Piskorowski Jacek
Published: September 2013

The paper presents the equalization problem of non-linear phase response of digital IIR type filters. An improved analytical method of designing a low-order equalizer is presented. The proposed approach is compared with the original method. The genetic algorithm is presented as an iterative method of optimization. The vector and matrix representation of the all-pass equalizer are shown and introduced to the algorithm. The results are compared with the analytical method. In this paper we have also proposed the use of an aging factor and setting the initial population of the genetic algorithm around the solution provided by the analytical methodology
Methods for Measurement of Energy Consumption in Mobile Devices
Authors: Damaševičius Robertas , Štuikys Vytautas , Toldinas Jevgenijus
Published: September 2013

Mobile devices have become an integral part of our life and provide dozens of useful services to their users. However, usability of mobile devices is hindered by battery lifetime. Energy conservation can extend battery lifetime, however, any energy management policy requires accurate prediction of energy consumption, which is impossible without reliable energy measurement and estimation methods and tools. We present an analysis of the energy measurement methodologies and describe the implementations of the internal (profiling) software (proprietary, custom) and external software-based (Java API, Sensor API, GSM AT) energy measurement methodologies. The methods are applied to measure energy consumption on a variety of mobile devices (laptop PC, PDA, smart phone). A case study of measuring energy consumption on a mobile computer using 3DMark06 benchmarking software is presented
Sorption of Synthetic Dyes Onto River Sediments: A Laboratory Study
Authors: Bachratá Miroslava , Šuňovská Anna , Horník Miroslav , Pipíška Martin , Augustín Jozef
Published: September 2013

This work deals with sorption of cationic synthetic dye thioflavine T (ThT) onto the river sediment obtained from the Váh River under conditions of batch and column system using spectrophotometric methods. We found that sorption of ThT onto river sediment was a rapid process with reaching of concentration equilibrium within 2 h of interaction. The values of distribution coefficient (DC) defined as concentration ratio [ThT]sediment : [ThT]solution were linearly increased with increasing concentration of river sediment in solution within the range Csediment 1.25 - 10.0 g/dm3 and minimally changed in the range of initial pH values 2 - 6. The increasing concentration of ThT in model solution caused exponentially decrease in the value of DC. The sorption processes characterized by dependence between equilibrium specific sorption Qeq and ThT concentration Ceq in solution were better described by adsorption isotherm according to Freundlich (R2 = 0.979) than according to Langmuir adsorption isotherm (R2 = 0.914). From evaluation of ThT sorption onto river sediment in column system containing of 5 cm sediment layer with 30 cm of water column on the basis of ThT concentration changes in infiltrated water we found that these processes were significantly dependent on the rate of infiltrated water flow through the sediment layer Riw as well as on qualitative and quantitative composition of water. The highest ThT desorption from the sediment layer was found in seepage of 50 % (v/v) ethanol (EtOH) solution through the sediment and efficiency of ThT desorption decreased in the order: 50 % (v/v) EtOH > 0.1 mol/dm3 HCl > deionized water. Obtained data from the point of view of physico-chemical characteristics of the river sediment, such as pH, pHzpc (potentiometric titration), cation-exchange capacity (CEC) and elemental composition (X-ray fluorescence spectrometry), was also discussed
Kinetic investigation of oxidation of aromatic anils by magnesium monoperoxyphthalate in aqueous acidic medium
Authors: Ramakrishnan Venkatesh , Kulandaivelu Karunakaran
Published: September 2013

The kinetics of oxidation of aromatic anils to benzaldehyde and azobenzene by magnesium monoperoxyphthalate (MMPP) has been studied in aqueous acetic acid medium. The low dielectric constant of the medium facilitates the reactivity. It has been found that ionic strength of the reaction has no significant effect on rate. The added acrylonitrile has no effect on the reaction rate indicating the absence of free radical mechanism. The added Mn(II) decreases the rate of the reaction, which indicates the involvement of two-electron transfer. Highly negative ΔS# values indicate a structured transition state. The deviation of Hammett plot is noted and a non-linear concave downward curve is obtained for the anils with substituents in the aniline moiety. The observed break in the log kobs versus σ is attributed to the transition state whereas the non-linear concave upward curve is observed for the substituents in the benzaldehyde moiety and a non-linear concacve upward curve is observed for the substituents in the combination of aniline and benzaldehyde moiety and a suitable mechanism is proposed
Strategies to Discredit Opponents: Russian Presentations of Events in Countries of the Former Soviet Union
Authors: A’Beckett Ludmilla
Published: September 2013

Discourse in this paper is represented by the totality of texts (Koller, 2004, p. 18) covering events in former Soviet republics such as Ukraine, Georgia and the Baltic countries. Over 100 texts have been collected from the most popular Russian newspapers, Argumenty i Fakty and Komsomol’skaia Pravda, between 2004 and 2010 in order to compile a “discourse of Russian satellites.” Even though the contemporary Russian press avoids the totalitarian habits of Soviet times such as monoglossia, dysphemisms (language of insults), sanctions and social commands, it still attempts to exercise control over the formation of readers’ opinions. The Russian press tries to channel the reaction of their audience toward disapproval of independent nations. The objective of this article is to summarize those narrative techniques which generate negative responses toward sovereign countries of the former Soviet Union. These techniques, which are called “strategies for discrediting opponents,” include sourcing favorable and unfavorable opinions, humorous framing, ironic statements and constructing a negative background. The means of control are subtle, but they are no less effective than through direct coercion.
Inflectional Change Patterns in Arabic
Authors: Abu Joudeh Maisoun , Al-Shboul Sabri
Published: September 2013

Most approaches to inflectional morphology propose a single-default representation. This research on Jordanian Arabic offers an analysis having more than one default inflection. This is accomplished by showing that unlike previous morphological accounts like the single-mechanism model, dual-mechanism model, and the schema model (cf. Pinker, 1990; Rumelhart & McClelland, 1986; and Bybee, 1985), the current research relies upon the ‘openness’ mechanism to define defaultness. Openness is thus defined as the ability of the inflectional process to accept new forms into a language. The corpus used in this research contains diminutives, verbal nouns, derivatives, and loan words used in JA. Other defining factors are modified in this research, such as regularity (rule-based mechanism) and productivity (type frequency). The findings of this research indicate that there are two possible defaults in Jordanian Arabic ordered in terms of openness: the sound feminine plural and the iambic broken plural. The findings have the implication that a language’s grammar can have a multi-default system.
Environmental Awareness and the Best Environmental Practices in SME of the Food Industry in the Częstochowa Region
Authors: Seroka-Stolka Oksana , Jelonek Dorota
Published: September 2013

Caring for environmental protection through minimization of the food processing threats might turn out to be not only a complex process but it also demands a lot of expenditures. A survey carried out among small and medium-sized enterprises of the food industry in the Częstochowa region demonstrated that application of the best practices, which are environmentally friendly, is not common. It also showed that three fourth of the respondents do not implement formal environmental policies. The entrepreneurs participating in the survey exhibited a low level of environmental awareness, particularly in the area of involvement in ecological problems at the individual level.
Seroepidemiology for MERS coronavirus using microneutralisation and pseudoparticle virus neutralisation assays reveal a high prevalence of antibody in dromedary camels in Egypt, June 2013
Authors: Perera R A , Wang P , Gomaa M R , El-Shesheny R , Kandeil A , Bagato O , Siu L Y , Shehata M M , Kayed A S , Moatasim Y , Li M , Poon L L , Guan Y , Webby R J , Ali M A , Peiris J S , Kayali G
Published: September 2013

We describe a novel spike pseudoparticle neutralisation assay (ppNT) for seroepidemiological studies on Middle East respiratory syndrome coronavirus (MERS-CoV) and apply this assay together with conventional microneutralisation (MN) tests to investigate 1,343 human and 625 animal sera. The sera were collected in Egypt as a region adjacent to areas where MERS has been described, and in Hong Kong, China as a control region. Sera from dromedary camels had a high prevalence of antibody reactive to MERS-CoV by MERS NT (93.6%) and MERS ppNT (98.2%) assay. The antibody titres ranged up to 1,280 and higher in MN assays and 10,240 and higher in ppNT assays. No other investigated species had any antibody reactivity to MERS-CoV. While seropositivity does not exclude the possibility of infection with a closely related virus, our data highlight the need to attempt detection of MERS-CoV or related coronaviruses in dromedary camels. The data show excellent correlation between the conventional MN assay and the novel ppNT assay. The newly developed ppNT assay does not require Biosafety Level 3 containment and is thus a relatively high-throughput assay, well suited for large-scale seroepidemiology studies which are needed to better understand the ecology and epidemiology of MERS-CoV.
Population susceptibility to North American and Eurasian swine influenza viruses in England, at three time points between 2004 and 2011
Authors: Hoschler K , Thompson C , Casas I , Ellis J , Galiano M , Andrews N , Zambon M
Published: September 2013

Binary file ES_Abstracts_Final_ECDC.txt matches
Physical Comorbidity and Psychiatric Diagnosis in a Neuropsychiatric Clinic in Sindhuli District, Rural Nepal
Authors: Belbase M , Joshi D , Koki A , Gautam R , Sharma R , Adhikari J
Published: September 2013

Background: Presence of physical illness with mental health problems is very common occurrence. Contraindication of certain psychotropics with certain physical problem and some beneficial effects of other drugs in comorbid conditions is one of important aspect of studying comorbidity. Comorbidity identification and intervention helps to cure and contain mental problems in most effective way. Materials and methods: Descriptive study with convenient sampling in all the patients who consented and attended monthly neuropsychiatric satellite health camp in Sindhuli district of Nepal from the month of Shrawan to Poush 2069 (6 months) organized by Tranquility Hospital and Research Centre, Khumaltar, Kathamndu. Results: Out of the 172 subjects studied, the most common age group was 20-39 years (47.7 %) followed by 40-59 years (27.9 %). The most common neuropsychiatric diagnosis was mood spectrum disorder followed by neurotic (neurotic, stress-related and somatoform) disorders. Psychosis spectrum (schizophrenia, schizotypal and delusional disorders) was the least common. The most common physical comorbid diagnosis was migraine followed by hypertension and diabetes mellitus. Conclusions: Migraine, hypertension and diabetes mellitus are the most common comorbid physical problems in psychiatric population found in our study. DOI: http://dx.doi.org/10.3126/jpan.v2i1.8571 J Psychiatrists’ Association of Nepal Vol .2, No.1, 2013 26-29
Knowledge and attitude about mental illness among nursing students
Authors: Shrestha MR
Published: September 2013

Introduction: Although recent advances in psychiatry have increased our understanding of psychiatric disorders, many people may be unaware about mental illness and its treatment. The negative attitude is known hindrance to providing quality service to mental ill people. The aim of this study is to assess the knowledge and attitude about mental illness among nursing students. Method: The study was carried out in mental hospital, Lagankhel, Nepal. All one hundred eight nursing students posted for psychiatric posting for two weeks formed the study population. A structured standard questionnaire was supplied to the students at the first day of posting for their responses. Results: It was a purposive, descriptive study with 108 respondents of age group 15-20 (85.1%). The study revealed that 97.2% of the respondents thought that all mentally ill patients are not mad. The majority had showed their knowledge about cause of mental illness as genetic (78.6%) and biochemical disturbances (97.2%). Respondents expressed their faith in psychiatrist (96.3%) but less in faith healers (19.4%). Conclusion: This study revealed that there was overall adequate knowledge and by large a positive attitude towards mentally ill people among the nursing students. DOI: http://dx.doi.org/10.3126/jpan.v2i1.8573 J Psychiatrists’ Association of Nepal Vol .2, No.1, 2013 35-38
Editorial
Authors: Dudley Sandra H. , Message Kylie
Published: September 2013

Museum Worlds: Advances in Research represents trends in museum-related research and practice. It builds a profile of various approaches to the expanding discipline of museum studies and to work in the growing number of museums throughout the world. It traces major regional, theoretical, methodological, and topical themes and debates, and encourages comparison of museum theories, practices, and developments in different global settings.
Critical Museology
Authors: Shelton Anthony
Published: September 2013

Synthesizing work carried out by the author over the past twenty-five years, this article proposes a tentative disciplinary definition of critical museology, distinguishing its related methodological interdictions and describing its distinctiveness from what is here defined as operational museology. The article acknowledges the diverse intellectual sources that have informed the subject and calls for a reorientation and separation of critical museology from the operational museologies that form part of its area of study. Critical museology, it is argued, is not only an essential intellectual tool for better understanding museums, related exhibitionary institutions, fields of patrimony and counter patrimonies, and the global and local flows and conditions in which they are embedded, but is also crucial for developing new exhibitionary genres, telling untold stories, rearticulating knowledge systems for public dissemination, reimagining organizational and management structures, and repurposing museums and galleries in line with multicultural and intercultural states and communities.
Exhibition Reviews
Authors: Atkinson Jeanette , Buck Tracy , Jean Simon , Wallach Alan , Davis Peter , Klekot Ewa , Schorch Philipp , Ting Wing Yan Vivian , Turner Caroline , St John Barclay Glen , Wagelie Jennifer , Were Graeme
Published: September 2013

Steampunk (Bradford Industrial Museum, UK)

Framing India: Paris-Delhi-Bombay . . . (Centre Pompidou, Paris)

E Tū Ake: Māori Standing Strong/Māori: leurs trésors ont une âme (Te Papa, Wellington, and Musée du quai Branly, Paris)

The New American Art Galleries, Virginia Museum of Fine Arts, Richmond

Scott's Last Expedition (Natural History Museum, London)

Left-Wing Art, Right-Wing Art, Pure Art: New National Art (Museum of Modern Art, Warsaw)

Focus on Strangers: Photo Albums of World War II (Stadtmuseum, Jena)

A Museum That Is Not: A Fanatical Narrative of What a Museum Can Be (Guandong Times Museum, Guandong)

21st Century: Art in the First Decade (QAGOMA, Brisbane)

James Cook and the Exploration of the Pacific (Art and Exhibition Hall of the Federal Republic of Germany, Bonn)

Land, Sea and Sky: Contemporary Art of the Torres Strait Islands (QAGOMA, Brisbane) and Awakening: Stories from the Torres Strait (Queensland Museum, Brisbane)
Endoscopic treatment of quadrigeminal arachnoid cysts in children
Authors: El-Ghandour Nasser M. F.
Published: September 2013

Object

Quadrigeminal arachnoid cysts (QACs) are rare, comprising approximately 5%–10% of all intracranial arachnoid cysts. The management of these cysts is challenging, and their optimal surgical treatment is controversial. This study evaluates the role of endoscopy in the treatment of QACs in children, focusing on some factors or technical aspects that might influence the outcome.

Methods

Eighteen children with symptomatic QACs were the subject of this study. The group included 10 boys and 8 girls, with a mean age of 2.5 years. All patients had hydrocephalus. Surgical treatment included ventriculocystostomy (14 cases), endoscopic third ventriculostomy (14 cases), ventriculocystocisternostomy (2 cases), cystocisternostomy (2 cases), and removal of preexisting malfunctioning cystoperitoneal shunt (4 cases).

Results

Significant clinical improvement occurred in 15 cases (83.3%). Postoperative MRI showed a reduction in the cyst size in 14 cases (77.8%), whereas in the remaining 4 cases (22.2%) the cyst size was unchanged. A postoperative decrease in ventricular size was encountered in 16 cases (88.9%). Minor intraoperative bleeding occurred in 1 case (5.6%), which stopped spontaneously without any postoperative sequelae. Postoperative subdural hygroma occurred in 3 cases (16.7%) and required a subduroperitoneal shunt in 2 cases. During follow-up (mean 45.8 months), a repeat endoscopic procedure was performed in 7 patients (all 4 patients with a prior shunt and 3 patients without a prior shunt), and new shunt placement was required in 5 patients (all 4 patients with a prior shunt and 1 patient without a prior shunt). Thus, none of the patients with a prior shunt was able to become shunt independent, whereas 92.9% of patients without a prior shunt were able to avoid shunt placement.

Conclusions

Arachnoid cysts of the quadrigeminal cistern and the associated hydrocephalus can be effectively treated by endoscopy. The procedure is simple, minimally invasive, and associated with low morbidity and mortality rates. The fact that all patients who previously received shunts required a repeat endoscopic procedure and that none of these patients was able to become shunt independent makes it clear that endoscopic treatment should be considered the first choice in the management of patients with arachnoid cysts in the quadrigeminal cistern.
The impact of radiosurgery fractionation and tumor radiobiology on the local control of brain metastases
Authors: Oermann Eric K. , Kress Marie-Adele S. , Todd Jonathan V. , Collins Brian T. , Hoffman Riane , Chaudhry Huma , Collins Sean P. , Morris David , Ewend Matthew G.
Published: September 2013

Object

Experience with whole-brain radiation therapy for metastatic tumors in the brain has identified a subset of tumors that exhibit decreased local control with fractionated regimens and are thus termed radioresistant. With the advent of frameless radiosurgery, fractionated radiosurgery (2–5 fractions) is being used increasingly for metastatic tumors deemed too large or too close to crucial structures to be treated in a single session. The authors retrospectively reviewed metastatic brain tumors treated at 2 centers to analyze the dependency of local control rates on tumor radiobiology and dose fractionation.

Methods

The medical records of 214 patients from 2 institutions with radiation-naive metastatic tumors in the brain treated with radiosurgery given either as a single dose or in 2–5 fractions were analyzed retrospectively. The authors compared the local control rates of the radiosensitive with the radioresistant tumors after either single-fraction or fractionated radiosurgery.

Results

There was no difference in local tumor control rates in patients receiving single-fraction radiosurgery between radioresistant and radiosensitive tumors (p = 0.69). However, after fractionated radiosurgery, treatment for radioresistant tumors failed at a higher rate than for radiosensitive tumors with an OR of 5.37 (95% CI 3.83–6.91, p = 0.032).

Conclusions

Single-fraction radiosurgery is equally effective in the treatment of radioresistant and radiosensitive metastatic tumors in the brain. However, fractionated stereotactic radiosurgery is less effective in radioresistant tumor subtypes. The authors recommend that radioresistant tumors be treated in a single fraction when possible and techniques for facilitating single-fraction treatment or dose escalation be considered for larger radioresistant lesions.
Middle cerebral artery pulsatility index and cognitive improvement after carotid endarterectomy for symptomatic stenosis
Authors: Heyer Eric J. , Mergeche Joanna L. , Connolly E. Sander
Published: September 2013

Object

Transcranial Doppler (TCD) is frequently used to evaluate peripheral cerebral resistance and cerebral blood flow (CBF) in the middle cerebral artery prior to and during carotid endarterectomy (CEA). Patients with symptomatic carotid artery stenosis may have reduced peripheral cerebral resistance to compensate for inadequate CBF. The authors aim to determine whether symptomatic patients with reduced peripheral cerebral resistance prior to CEA demonstrate increased CBF and cognitive improvement as early as 1 day after CEA.

Methods

Fifty-three patients with symptomatic CEA were included in this observational study. All patients underwent neuropsychometric evaluation 24 hours or less preoperatively and 1 day postoperatively. The MCA was evaluated using TCD for CBF mean velocity (MV) and pulsatility index (PI). Pulsatility index ≤ 0.80 was used as a cutoff for reduced peripheral cerebral resistance.

Results

Significantly more patients with baseline PI ≤ 0.80 exhibited cognitive improvement 1 day after CEA than those with PI > 0.80 (35.0% vs 6.1%, p = 0.007). Patients with cognitive improvement had a significantly greater increase in CBF MV than patients without cognitive improvement (13.4 ± 17.1 cm/sec vs 4.3 ± 9.9 cm/sec, p = 0.03). In multivariate regression model, a baseline PI ≤ 0.80 was significantly associated with increased odds of cognitive improvement (OR 7.32 [1.40–59.49], p = 0.02).

Conclusions

Symptomatic CEA patients with reduced peripheral cerebral resistance, measured as PI ≤ 0.80, are likely to have increased CBF and improved cognitive performance as early as 1 day after CEA for symptomatic carotid artery stenosis. Revascularization in this cohort may afford benefits beyond prevention of future stroke. Clinical trial registration no: NCT00597883 (ClinicalTrials.gov).
Clinically important deterioration in patients undergoing lumbar spine surgery: a choice of evaluation methods using the Oswestry Disability Index, 36-Item Short Form Health Survey, and pain scales
Authors: Gum Jeffrey L. , Glassman Steven D. , Carreon Leah Y.
Published: September 2013

Object

Health-related quality of life (HRQOL) measures have become the mainstay for outcome appraisal in spine surgery. Clinically meaningful interpretation of HRQOL improvement has centered on the minimum clinically important difference (MCID). The purpose of this study was to calculate clinically important deterioration (CIDET) thresholds and determine a CIDET value for each HRQOL measure for patients undergoing lumbar fusion.

Methods

Seven hundred twenty-two patients (248 males, 127 smokers, mean age 60.8 years) were identified with complete preoperative and 1-year postoperative HRQOLs including the Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36), and numeric rating scales (0–10) for back and leg pain following primary, instrumented, posterior lumbar fusion. Anchor-based and distribution-based methods were used to calculate CIDET for each HRQOL. Anchor-based methods included change score, change difference, and receiver operating characteristic curve analysis. The Health Transition Item, an independent item of the SF-36, was used as the external anchor. Patients who responded “somewhat worse” and “much worse” were combined and compared with patients responding “about the same.” Distribution-based methods were minimum detectable change and effect size.

Results

Diagnoses included spondylolisthesis (n = 332), scoliosis (n = 54), instability (n = 37), disc pathology (n = 146), and stenosis (n = 153). There was a statistically significant change (p < 0.0001) for each HRQOL measure from preoperatively to 1-year postoperatively. Only 107 patients (15%) reported being “somewhat worse” (n = 81) or “much worse” (n = 26). Calculation methods yielded a range of CIDET values for ODI (0.17–9.06), SF-36 physical component summary (−0.32 to 4.43), back pain (0.02–1.50), and leg pain (0.02–1.50).

Conclusions

A threshold for clinical deterioration was difficult to identify. This may be due to the small number of patients reporting being worse after surgery and the variability across methods to determine CIDET thresholds. Overall, it appears that patients may interpret the absence of change as deterioration.
A Theoretical Study of the Mechanism and Kinetics of the Thermal Decomposition of Carbamoyl Azide
Authors: Reisi-Vanani Adel , Izadyar Mohammad
Published: September 2013

The mechanism and kinetics of the thermal decomposition of carbamoyl azide N3CONH2 were studied using the B3LYP/6-311++G(d,p) level of theory. All species involved in the pyrolysis reaction were fully optimised and corrected for zero-point energies. The results showed that the initial step mainly involved the non-homolytic fission of the N–N bond. Either the imine NHCONH or the nitrene NCONH2 could be formed by the release of molecular N2. Calculation confirmed that the formation of the nitrene is the dominant process. Then, extrusion of CO from the nitrene will produce NNH2 which decomposes to N2 and H2 as the most stable products. Transition states (TSs) are obtained and characterised on the potential energy surfaces throughout the reaction. The existence of TSs on the corresponding potential energy surfaces is ascertained by performing intrinsic reaction coordinate calculations. In all steps, comparing the bond dissociation energies suggests which one is stronger during the initiation of thermolysis. The calculated rate constant using transition state theory is 1.15 × 10−28 s−1 at 298.15 K and 1.00 atm.
Kinetic and Mechanistic Investigations of the Catalysed Hydrolysis of Bis(p-Nitrophenyl) Phosphate by a Macrocyclic Neodymium(III) Complex
Authors: Cai Shulan , Hu Wei , Li Jianzhang , Xie Bin , He Leijin , Zhang Xiaolan
Published: September 2013

The macrocyclic ligand 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclo-tetradecane (L) was synthesised and characterised. The kinetics of hydrolysis of bis( p-nitrophenyl) phosphate (BNPP) in a catalytic system comprising the macrocyclic ligand and neodymium(III) was investigated. The analysis of specific absorption spectra of the hydrolytic reaction system indicated that key intermediates containing BNPP and the Nd(III) complex are formed in the reaction. The mechanism proposed for the catalytic hydrolysis proposed is based on the analytical results of the specific absorption spectrum, and the corresponding kinetic constants are calculated. The results showed that the Nd(III) complex as a mimic hydrolase exhibits good catalytic activity, i.e. similar to that of the natural enzyme.
Mechanism and Thermodynamics of Multichannel 1:1 Ammonia and Ozone Tropospheric Oxidation Reaction
Authors: Asgharzade Somaie , Vahedpour Morteza
Published: September 2013

The reaction of NH3 + O3 on the singlet potential energy surface has been investigated theoretically using CCSD(T) and G3B3 methods with the 6-311++G(3df,3pd) basis set based on the geometric parameters optimised at the B3LYP/6-311++G(3df,3pd) level of theory. The calculated results revealed that the reactants are firstly associated with the adduct NH3–O3, through a barrier-less process and two stable collision complexes, C1 and C2 have been considered. Six kinds of products P1 (HOO + H2NO), P2 (OH + H2NO2), P3 (O2 + H3NO), P4 (HNO + H2O2), P5 (HNO2 + H2O) and P6 (NO + HO2 + H2) are obtained through a variety of transformations of C1 and C2. Thermodynamic parameters of all possible products show five production channels which are spontaneous. After taking into account the reaction barrier and enthalpy, the most probable reaction pathways are P1(2) and P4. Also, P4 is the most stable product in comparison with the others and P1 yields the other important products from the kinetic viewpoint; this is relatively stable, with a negative Gibbs free energy. Branching ratio results show P1 is the major product at low temperature. Finally, the rates constant have been computed only for the P1(2) and P4 pathways by related theories in the temperature range of 200–2500 K.
Epidemiology and Clinical Features of Typhoid Fever: Burden in Bangladesh
Authors: Sattar AFM Arshedi , Jhora Sanya Tahmina , Yusuf M Abdullah , Islam M Bodrul , Islam M Saiful , Roy Sushmita
Published: September 2013

Typhoid fever is a systemic infection caused by Salmonella typhi or by the related but less virulent Salmonella paratyphi. The provision of clean water and good sewage systems led to a dramatic decrease in the incidence of typhoid in these regions. Early antibiotic therapy has transformed a previously life-threatening illness of several weeks' duration with an overall mortality rate approaching 20.0% into a short-term febrile illness with negligible mortality. Case fatality rates of 10.0-50.0% have been reported from endemic countries when diagnosis is delayed. Attack rates are highest in persons younger than 20 years or older than 70 years; however, the highest rate is found in infants. Neonates are at a greater risk to fecal-oral transmission secondary to relative decreased stomach acidity and buffering of ingested breast milk and formula. Elderly persons are at a relative greater risk to infection secondary to chronic underlying illness and weakened immunity. In endemic areas, children aged 1-5 years are at the highest risk of infection, morbidity, and mortality because of waning of passively acquired maternal antibody and a lack of acquired immunity. In young children, the clinical syndrome is often a nonspecific febrile illness that is not recognized as typhoid fever. Typhoid is usually contracted by ingestion of food or water contaminated by fecal or urinary carriers excreting S. enterica serotype typhi. It is a sporadic disease in developed countries that occurs mainly in returning traveler, with occasional point-source epidemics. In endemic areas, identified risk factors for disease include eating food prepared outside the home, such as ice cream or flavored iced drinks from street vendors, drinking contaminated water, having a close contact or relative with recent typhoid fever, poor housing with inadequate facilities for personal hygiene, and recent use of antimicrobial drugs. The infectious dose of S. enterica serotype typhi in volunteers varies between 1000 and 1 million organisms. Vi-negative strains of S. enterica serotype typhi are less infectious and less virulent than Vi-positive strains. S. enterica serotype typhi must survive the gastric acid barrier to reach the small intestine, and a low gastric pH is an important defense mechanism.DOI: http://dx.doi.org/10.3329/jsf.v10i1.16310 J Sci Foundation, January-June 2012;10(1):38-49
Assessment of Environmental Aspects and Impacts of Scientific Laboratories of a University: Focus on Gap Analysis and Environmental Management System (EMS) Implementation
Authors: Adyel Tanveer Mehedi , Begum Fayezum Nahar , Islam SM Nazrul , Rahman Muhammad Hazifur
Published: September 2013

Environmental Management System (EMS) has become an important tool for organizations looking towards managing their environmental issues such as pollution, legal compliance and minimizing their environmental impacts. The present study was conducted to assess the environmental aspects and impact of selected scientific laboratories of Jahangirnagar University in Bangladesh with focus on the gap analysis for implementing EMS. Data and information were collected through frequent laboratory visits, focus group discussion, questionnaire survey and key informant interview. It was found that EMS was not implemented in the laboratories and the staffs and researchers of the university had very limited idea about EMS. Surface water, air and soil pollution; unsafe mixing and handling of hazardous materials and chemicals; unsustainable storage of chemicals and reagents; improper use of personal protective equipment found as the main environmental challenges in these laboratories. The maximum negative environmental impact occurred in the chemistry and botany laboratories, as large number of researchers here used high amount of chemicals and cultured media, while the minimum pollution was found in microbiology and environmental sciences laboratories. Although, the overall pollution levels were low, there were lots of gaps in introducing EMS. Therefore, initiatives should be taken. Jahangirnagar University Environmental Bulletin, Vol.2, 9-17, 2013 DOI: http://dx.doi.org/10.3329/jueb.v2i0.16325
An Evaluation of Microbial and Chemical Contamination Sources Related to the Deterioration of Tap Water Quality in the Household Water Supply System
Authors: Lee Yoonjin
Published: September 2013

The predominant microorganisms in samples taken from shower heads in residences in the Korean city “N” were Stenotrophomonas maltophilia, Sphingomonas paucimobilis, Acidovorax temperans, and Microbacterium lacticum. Legionella was not detected in this case. The volatile organic compounds (VOCs) vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were measured in five types of plastic pipes: PVC, PB, PP, PE, and cPVC. The rate of multiplication of the heterotrophic plate count (HPC) attached on the copper pipe in contact with hot tap water was higher than the rate for the copper pipe in contact with cold tap water. Biofilm accumulation on stainless steel pipes with added acetate (3 mg/L) was 2.56 times higher than the non-supplemented condition. Therefore, the growth of HPC in the pipe system was affected by the type and availability of nutrients and depended on variables such as heating during the hot water supply.
What Goes around Comes around-A Comparative Study of the Influence of Chemical Modifications on the Antimicrobial Properties of Small Cyclic Peptides
Authors: Scheinpflug Kathi , Nikolenko Heike , Komarov Igor , Rautenbach Marina , Dathe Margitta
Published: September 2013

Tryptophan and arginine-rich cyclic hexapeptides of the type cyclo-RRRWFW combine high antibacterial activity with rapid cell killing kinetics, but show low toxicity in human cell lines. The peptides fulfil the structural requirements for membrane interaction such as high amphipathicity and cationic charge, but membrane permeabilisation, which is the most common mode of action of antimicrobial peptides (AMPs), could not be observed. Our current studies focus on elucidating a putative membrane translocation mechanism whereupon the peptides might interfere with intracellular processes. These investigations require particular analytical tools: fluorescent analogues and peptides bearing appropriate reactive groups were synthesized and characterized in order to be used in confocal laser scanning microscopy and HPLC analysis. We found that minimal changes in both the cationic and hydrophobic domain of the peptides in most cases led to significant reduction of antimicrobial activity and/or changes in the mode of action. However, we were able to identify two modified peptides which exhibited properties similar to those of the cyclic parent hexapeptide and are suitable for subsequent studies on membrane translocation and uptake into bacterial cells.