bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-medication practice among preclinical university students in a medical school from the city of Pokhara, Nepal
Authors: Banerjee Indrajit , Sathian Brijesh , Gupta Rajesh Kumar , Amarendra Annavarapu , Roy Bedanta , Bakthavatchalam Pugazhandhi , Saha Archana , Banerjee Indraneel
Published: July 2016

Introduction: In developing countries like Nepal medicines can be acquired from the chemist's without of a prescription which sometime may have many drawbacks due to intake of excessive drugs without a proper diagnosis.  The primary objective of the study was to find out the pattern of self-medication practice among the preclinical medical students at Manipal College of Medical Sciences.Materials and Methods: This was a cross sectional study carried out using structured questionnaire at Manipal College of Medical Sciences, Pokhara, Nepal between November 2012- July 2014.Results: The overall response rate of this study was 95.31%. 81.35% of the students were practicing self-medication in this institution. Most common group of drugs that were consumed were antipyretics 31%, antibiotics 26.2%, analgesics 18.89%, antihistaminics 10.1% respectively. Paracetamol was the most common drug used for self-medication 31%, followed by Azithromycin 17.6% and combination of Paracetamol and Ibuprofen 15.6%, Cetirizine 8.6%, Amoxicillin 6.5%, Omeprazole 6.3%, Albendazole 3.3%, Mefenemic acid 2.8%, Cefpodoxime2% respectively. Conclusion: Medical student should be educated through awareness programme regarding pros and cons of self-medication practice and they should be motivated regarding the rationale use of antibiotics.
Therapeutic effect of erythropoietin in patients with traumatic brain injury: a meta-analysis of randomized controlled trials
Authors: Liu Wen-Chao , Wen Liang , Xie Tao , Wang Hao , Gong Jiang-Biao , Yang Xiao-Feng
Published: July 2016

OBJECTIVE

Erythropoietin (EPO) exerts a neuroprotective effect in animal models of traumatic brain injury (TBI). However, its effectiveness in human patients with TBI is unclear. In this study, the authors conducted the first meta-analysis to assess the effectiveness and safety of EPO in patients with TBI.

METHODS

In December 2015, a systematic search was performed of PubMed, Web of Science, MEDLINE, Embase, the Cochrane Library databases, and Google Scholar. Only English-language publications of randomized controlled trials (RCTs) using EPO in patients with TBI were selected for analysis. The assessed outcomes included mortality, favorable neurological outcome, hospital stay, and associated adverse effects. Continuous variables were presented as mean difference (MD) with a 95% confidence interval (CI). Dichotomous variables were presented as risk ratio (RR) or risk difference (RD) with a 95% CI. Statistical heterogeneity was examined using both I2 and chi-square tests.

RESULTS

Of the 346 studies identified in the search, 5 RCTs involving 915 patients met the inclusion criteria. The overall results demonstrated that EPO significantly reduced mortality (RR 0.69, 95% CI 0.49–0.96, p = 0.03) and shortened the hospitalization time (MD −7.59, 95% CI −9.71 to −5.46, p < 0.0001) for patients with TBI. Pooled results of favorable outcome (RR 1.00, 95% CI 0.88–1.15, p = 0.97) and deep vein thrombosis (DVT; RD 0.00, 95% CI −0.05 to 0.05, p = 1.00) did not show a significant difference.

CONCLUSIONS

The authors suggested that EPO is beneficial for patients with TBI in terms of reducing mortality and shortening hospitalization time without increasing the risk of DVT. However, its effect on improving favorable neurological outcomes did not reach statistical significance. Therefore, more well-designed RCTs are necessary to ascertain the optimum dosage and time window of EPO treatment for patients with TBI.
Carotid artery stenosis with a high-intensity signal plaque on time-of-flight magnetic resonance angiography and association with evidence of intraplaque hypoxia
Authors: Ogata Atsushi , Kawashima Masatou , Wakamiya Tomihiro , Nishihara Masashi , Masuoka Jun , Nakahara Yukiko , Ebashi Ryo , Inoue Kohei , Takase Yukinori , Irie Hiroyuki , Abe Tatsuya
Published: July 2016

OBJECTIVE

Hypoxia induces angiogenesis and plays a major role in the progression of carotid plaques. During carotid intervention, plaques with high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) often cause ischemic stroke and embolic complications. However, the role of intraplaque hypoxia before carotid endarterectomy (CEA) and carotid artery stenting is not presently understood. In this study the authors aimed to investigate the relationship between intraplaque hypoxia and MRA findings.

METHODS

Nineteen consecutive patients with 20 carotid artery stenoses who underwent CEA at Saga University Hospital between August 2008 and December 2014 were enrolled in the study. The expressions of hypoxia-inducible transcription factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were analyzed by immunohistochemical analysis. In addition, the relationship between the findings on TOF MRA and pathology for the carotid plaques was analyzed.

RESULTS

High-intensity plaques on TOF MRA showed higher expression levels of HIF-1α (p = 0.015) and VEGF (p = 0.007) compared with isointensity plaques. The rate of intraplaque hemorrhage (IPH) on TOF MRA was also significantly higher in the high-intensity plaques than in the isointensity plaques (p = 0.024). Finally, the mean number of neovessels was significantly higher in those without plaque hemorrhage than in those with plaque hemorrhage (p = 0.010).

CONCLUSIONS

Plaques with high-intensity signals on TOF MRA were associated with IPH and evidence of intraplaque hypoxia. This fact may represent an opportunity to establish novel therapeutic agents targeting intraplaque hypoxia.
Spontaneous cerebrospinal fluid leak from an anomalous thoracic nerve root: case report
Authors: Lopez Alejandro J. , Campbell Robert K. , Arnaout Omar , Curran Yvonne M. , Shaibani Ali , Dahdaleh Nader S.
Published: July 2016

The authors report the case of a 28-year-old woman with a spontaneous cerebrospinal fluid leak from the sleeve of a redundant thoracic nerve root. She presented with postural headaches and orthostatic symptoms indicative of intracranial hypotension. CT myelography revealed that the lesion was located at the T-11 nerve root. After failure of conservative management, including blood patches and thrombin glue injections, the patient was successfully treated with surgical decompression and ligation of the duplicate nerve, resulting in full resolution of her orthostatic symptoms.
Optimization and Characterization of Chitosan Enzymolysis by Pepsin
Authors: Gohi Bi , Zeng Hong-Yan , Pan A
Published: July 2016

Pepsin was used to effectively degrade chitosan in order to make it more useful in biotechnological applications. The optimal conditions of enzymolysis were investigated on the basis of the response surface methodology (RSM). The structure of the degraded product was characterized by degree of depolymerization (DD), viscosity, molecular weight, FTIR, UV-VIS, SEM and polydispersity index analyses. The mechanism of chitosan degradation was correlated with cleavage of the glycosidic bond, whereby the chain of chitosan macromolecules was broken into smaller units, resulting in decreasing viscosity. The enzymolysis by pepsin was therefore a potentially applicable technique for the production of low molecular chitosan. Additionally, the substrate degradation kinetics of chitosan were also studied over a range of initial chitosan concentrations (3.0~18.0 g/L) in order to study the characteristics of chitosan degradation. The dependence of the rate of chitosan degradation on the concentration of the chitosan can be described by Haldane’s model. In this model, the initial chitosan concentration above which the pepsin undergoes inhibition is inferred theoretically to be about 10.5 g/L.
Cumulative Paired φ-Entropy
Authors: Klein Ingo , Mangold Benedikt , Doll Monika
Published: July 2016

A new kind of entropy will be introduced which generalizes both the differential entropy and the cumulative (residual) entropy. The generalization is twofold. First, we simultaneously define the entropy for cumulative distribution functions (cdfs) and survivor functions (sfs), instead of defining it separately for densities, cdfs, or sfs. Secondly, we consider a general “entropy generating function” φ, the same way Burbea et al. (IEEE Trans. Inf. Theory 1982, 28, 489–495) and Liese et al. (Convex Statistical Distances; Teubner-Verlag, 1987) did in the context of φ-divergences. Combining the ideas of φ-entropy and cumulative entropy leads to the new “cumulative paired φ-entropy” ( C P E φ ). This new entropy has already been discussed in at least four scientific disciplines, be it with certain modifications or simplifications. In the fuzzy set theory, for example, cumulative paired φ-entropies were defined for membership functions, whereas in uncertainty and reliability theories some variations of C P E φ were recently considered as measures of information. With a single exception, the discussions in the scientific disciplines appear to be held independently of each other. We consider C P E φ for continuous cdfs and show that C P E φ is rather a measure of dispersion than a measure of information. In the first place, this will be demonstrated by deriving an upper bound which is determined by the standard deviation and by solving the maximum entropy problem under the restriction of a fixed variance. Next, this paper specifically shows that C P E φ satisfies the axioms of a dispersion measure. The corresponding dispersion functional can easily be estimated by an L-estimator, containing all its known asymptotic properties. C P E φ is the basis for several related concepts like mutual φ-information, φ-correlation, and φ-regression, which generalize Gini correlation and Gini regression. In addition, linear rank tests for scale that are based on the new entropy have been developed. We show that almost all known linear rank tests are special cases, and we introduce certain new tests. Moreover, formulas for different distributions and entropy calculations are presented for C P E φ if the cdf is available in a closed form.
Runoff and Soil Erosion Assessment on Forest Roads Using a Small Scale Rainfall Simulator
Authors: Zemke Julian
Published: July 2016

Forestry operations can significantly alter hydrological and erosional processes in a catchment. In the course of developing timberland, a network of persistent roads and skid trails causing soil compaction is usually established. Hereby, the infiltration rate of the soil is distinctly reduced, which leads to the generation of overland flow—this may also cause soil erosion. In this study, a small-scale rainfall simulator is used to investigate hydrological and erosional processes on forest roads and skid trails. The results show increased runoff rates on forest roads, up to 25 times higher than on undisturbed forest topsoil. On skid trails, the runoff rates were altered especially in rutted areas (16 times higher) while unrutted parts showed a lesser change (four times higher). With sufficient overland flow, soil erosion rates also rose, particularly when the vegetation cover of the surface was removed: bare road surfaces featured higher mean erosion rates (195 g·m−2) than partly or completely vegetated skid trails (13 g·m−2) and undisturbed sites (5 g·m−2). The findings presented in this study indicate the need for the use of compaction reducing technology during forestry operations and a revegetation of road surfaces in order to minimize the detrimental factor of roads and skid trails on water retention and soil conservation.
Approaches to Children’s Exposure Assessment: Case Study with Diethylhexylphthalate (DEHP)
Authors: Ginsberg Gary , Ginsberg Justine , Foos Brenda
Published: July 2016

Children’s exposure assessment is a key input into epidemiology studies, risk assessment and source apportionment. The goals of this article are to describe a methodology for children’s exposure assessment that can be used for these purposes and to apply the methodology to source apportionment for the case study chemical, diethylhexylphthalate (DEHP). A key feature is the comparison of total (aggregate) exposure calculated via a pathways approach to that derived from a biomonitoring approach. The 4-step methodology and its results for DEHP are: (1) Prioritization of life stages and exposure pathways, with pregnancy, breast-fed infants, and toddlers the focus of the case study and pathways selected that are relevant to these groups; (2) Estimation of pathway-specific exposures by life stage wherein diet was found to be the largest contributor for pregnant women, breast milk and mouthing behavior for the nursing infant and diet, house dust, and mouthing for toddlers; (3) Comparison of aggregate exposure by pathways vs biomonitoring-based approaches wherein good concordance was found for toddlers and pregnant women providing confidence in the exposure assessment; (4) Source apportionment in which DEHP presence in foods, children’s products, consumer products and the built environment are discussed with respect to early life mouthing, house dust and dietary exposure. A potential fifth step of the method involves the calculation of exposure doses for risk assessment which is described but outside the scope for the current case study. In summary, the methodology has been used to synthesize the available information to identify key sources of early life exposure to DEHP.
Transcriptome Sequencing Analyses between the Cytoplasmic Male Sterile Line and Its Maintainer Line in Welsh Onion (Allium fistulosum L.)
Authors: Liu Qianchun , Lan Yanping , Wen Changlong , Zhao Hong , Wang Jian , Wang Yongqin
Published: July 2016

Cytoplasmic male sterility (CMS) is important for exploiting heterosis in crop plants and also serves as a model for investigating nuclear–cytoplasmic interaction. The molecular mechanism of cytoplasmic male sterility and fertility restoration was investigated in several important economic crops but remains poorly understood in the Welsh onion. Therefore, we compared the differences between the CMS line 64-2 and its maintainer line 64-1 using transcriptome sequencing with the aim of determining critical genes and pathways associated with male sterility. This study combined two years of RNA-seq data; there were 1504 unigenes (in May 2013) and 2928 unigenes (in May 2014) that were differentially expressed between the CMS and cytoplasmic male maintainer Welsh onion varieties. Known CMS-related genes were found in the set of differentially expressed genes and checked by qPCR. These genes included F-type ATPase, NADH dehydrogenase, cytochrome c oxidase, etc. Overall, this study demonstrated that the CMS regulatory genes and pathways may be associated with the mitochondria and nucleus in the Welsh onion. We believe that this transcriptome dataset will accelerate the research on CMS gene clones and other functional genomics research on A. fistulosum L.
Remote Sensing of Grass Response to Drought Stress Using Spectroscopic Techniques and Canopy Reflectance Model Inversion
Authors: Bayat Bagher , Van der Tol Christiaan , Verhoef Wouter
Published: July 2016

The aim of this study was to follow the response to drought stress in a Poa pratensis canopy exposed to various levels of soil moisture deficit. We tracked the changes in the canopy reflectance (450–2450 nm) and retrieved vegetation properties (Leaf Area Index (LAI), leaf chlorophyll content (Cab), leaf water content (Cw), leaf dry matter content (Cdm) and senescent material (Cs)) during a drought episode. Spectroscopic techniques and radiative transfer model (RTM) inversion were employed to monitor the gradual manifestation of drought effects in a laboratory setting. Plots of 21 cm × 14.5 cm surface area with Poa pratensis plants that formed a closed canopy were divided into a well-watered control group and a group subjected to water stress for 36 days. In a regular weekly schedule, canopy reflectance and destructive measurements of LAI and Cab were taken. Spectral analysis indicated the first sign of stress after 4–5 days from the start of the experiment near the water absorption bands (at 1930 nm, 1440 nm) and in the red (at 675 nm). Spectroscopic techniques revealed plant stress up to 6 days earlier than visual inspection. Of the water stress-related vegetation indices, the response of Normalized Difference Water Index (NDWI_1241) and Normalized Photochemical Reflectance Index (PRI_norm) were significantly stronger in the stressed group than the control. To observe the effects of stress on grass properties during the drought episode, we used the RTMo (RTM of solar and sky radiation) model inversion by means of an iterative optimization approach. The performance of the model inversion was assessed by calculating R2 and the Normalized Root Mean Square Error (RMSE) between retrieved and measured LAI (R2 = 0.87, NRMSE = 0.18) and Cab (R2 = 0.74, NRMSE = 0.15). All parameters retrieved by model inversion co-varied with soil moisture deficit. However, the first strong sign of water stress on the retrieved grass properties was detected as a change of Cw followed by Cab and Cdm in the earlier stages. The results from this study indicate that the spectroscopic techniques and RTMo model inversion have a promising potential of detecting stress on the spectral reflectance and grass properties before they become visibly apparent.
Heterogeneous Multi-Robot System for Mapping Environmental Variables of Greenhouses
Authors: Roldán Juan , Garcia-Aunon Pablo , Garzón Mario , De León Jorge , Del Cerro Jaime , Barrientos Antonio
Published: July 2016

The productivity of greenhouses highly depends on the environmental conditions of crops, such as temperature and humidity. The control and monitoring might need large sensor networks, and as a consequence, mobile sensory systems might be a more suitable solution. This paper describes the application of a heterogeneous robot team to monitor environmental variables of greenhouses. The multi-robot system includes both ground and aerial vehicles, looking to provide flexibility and improve performance. The multi-robot sensory system measures the temperature, humidity, luminosity and carbon dioxide concentration in the ground and at different heights. Nevertheless, these measurements can be complemented with other ones (e.g., the concentration of various gases or images of crops) without a considerable effort. Additionally, this work addresses some relevant challenges of multi-robot sensory systems, such as the mission planning and task allocation, the guidance, navigation and control of robots in greenhouses and the coordination among ground and aerial vehicles. This work has an eminently practical approach, and therefore, the system has been extensively tested both in simulations and field experiments.
Sequential Total Variation Denoising for the Extraction of Fetal ECG from Single-Channel Maternal Abdominal ECG
Authors: Lee Kwang , Lee Boreom
Published: July 2016

Fetal heart rate (FHR) is an important determinant of fetal health. Cardiotocography (CTG) is widely used for measuring the FHR in the clinical field. However, fetal movement and blood flow through the maternal blood vessels can critically influence Doppler ultrasound signals. Moreover, CTG is not suitable for long-term monitoring. Therefore, researchers have been developing algorithms to estimate the FHR using electrocardiograms (ECGs) from the abdomen of pregnant women. However, separating the weak fetal ECG signal from the abdominal ECG signal is a challenging problem. In this paper, we propose a method for estimating the FHR using sequential total variation denoising and compare its performance with that of other single-channel fetal ECG extraction methods via simulation using the Fetal ECG Synthetic Database (FECGSYNDB). Moreover, we used real data from PhysioNet fetal ECG databases for the evaluation of the algorithm performance. The R-peak detection rate is calculated to evaluate the performance of our algorithm. Our approach could not only separate the fetal ECG signals from the abdominal ECG signals but also accurately estimate the FHR.
Content-Based Multi-Channel Network Coding Algorithm in the Millimeter-Wave Sensor Network
Authors: Lin Kai , Wang Di , Hu Long
Published: July 2016

With the development of wireless technology, the widespread use of 5G is already an irreversible trend, and millimeter-wave sensor networks are becoming more and more common. However, due to the high degree of complexity and bandwidth bottlenecks, the millimeter-wave sensor network still faces numerous problems. In this paper, we propose a novel content-based multi-channel network coding algorithm, which uses the functions of data fusion, multi-channel and network coding to improve the data transmission; the algorithm is referred to as content-based multi-channel network coding (CMNC). The CMNC algorithm provides a fusion-driven model based on the Dempster-Shafer (D-S) evidence theory to classify the sensor nodes into different classes according to the data content. By using the result of the classification, the CMNC algorithm also provides the channel assignment strategy and uses network coding to further improve the quality of data transmission in the millimeter-wave sensor network. Extensive simulations are carried out and compared to other methods. Our simulation results show that the proposed CMNC algorithm can effectively improve the quality of data transmission and has better performance than the compared methods.
From Waste Management to Resource Efficiency—The Need for Policy Mixes
Authors: Wilts Henning , Von Gries Nadja , Bahn-Walkowiak Bettina
Published: July 2016

Treating waste as a resource and the design of a circular economy have been identified as key approaches for resource efficiency. Despite ambitious targets, policies and instruments that would enable a transition from a conventional waste management to an integrated and comprehensive resource management are still missing. Moreover, this will require innovative policy mixes which do not only address different end-of-pipe approaches but integrate various resource efficiency aspects from product design to patterns of production and consumption. Based on the results of a project funded by the Seventh Framework Programme for Research and Technological Development named “POLFREE—Policy Options for a resource efficient economy”, this paper addresses several aspects of the conceptualization of policy mixes with regard to waste as a specific resource efficiency challenge. The guiding research interest of this paper is the combination of policies necessary to create a full circular economy. In a first step, the present waste policy frameworks, institutions and existing incentives at national level are examined in order to disclose regulatory and policy gaps. Based on this, the second part of the paper describes and analyses specific waste-related resource efficiency instruments with regard to their potential impacts under the constraints of various barriers. Based on the assessment of the country analyses and the innovative instruments, the paper draws conclusions on waste policy mixes and political needs.
MOISTURE DAMAGE EVALUATION USING ENERGY BASED RESPONSES
Authors: MEHRARA Amir , KHODAII Ali
Published: July 2016

Monotonic Indirect Tensile tests were performed on asphalt concrete mixtures made of two different types of aggregates. Since the environmental condition is a determining factor in propagation of moisture damage, the effects of temperature and aging were also observed. Three levels of temperature including 4.4 °C, 21.1 °C and 37.8 °C were used in testing. In order to consider the effect of aging, part of the samples were aged according to AASHTO R 30-02 (2010). The parameters of fracture energy, elastic energy and dissipated creep strain energy were obtained for dry and moisture conditioned samples. The sensitivity of the responses to testing parameters was investigated using analysis of variance methods and visual inspections. According to the results, common energy responses cannot be used as realistic criteria to evaluate asphalt mixtures’ moisture damage. To overcome the inadequacy of common energy based responses, modi­fied energy responses were defined using conventional energy based responses normalized by specimens’ failure strain. The analysis of variance showed that the modified energy responses can effectively evaluate the mixtures’ moisture and temperature susceptibility.
SHEAR STRENGTH OF REINFORCED RECYCLED AGGREGATE CONCRETE BEAMS WITHOUT SHEAR REINFORCEMENTS
Authors: YUN Hyun-Do , CHOI Won-Chang
Published: July 2016

As the demand for sustainable construction materials has risen over recent years, researchers have conducted several studies to expand the practical application of recycled construction materials, such as recycled aggregate. The author’s previous research shows the potential application of recycled aggregate over a broad range of structural mem­ber types. This paper continues the earlier work and investigates the shear behaviour of reinforced recycled aggregate concrete beams without shear reinforcement using findings from the author’s previous research. The variables in the test program are replacement rate (0%, 30%, 60%, and 100%) of recycled aggregate and shear span-to-depth ratio (2.0, 2.5, 3.0, 4.0, and 5.0). This work compares the experimental results with results obtained using current code equations found in American Concrete Institute (ACI) 318 (2014) and equations proposed in the literature. This research has found that the current code equations can adequately predict the shear strength of recycled coarse aggregate concrete beams and possibly can be applied for the use of recycled aggregate in structural elements.
THE IMPACT OF ECONOMIC RECESSION ON COMPANY ACTIVITIES / LĖTĖJANČIOS EKONOMIKOS POVEIKIS ĮMONIŲ VEIKLAI
Authors: Gurskij Pavel , Liučvaitienė Aušra
Published: July 2016

Negative consequences of economic fluctuations and economic downturns influence the significance of research in this area. Results of such research allow providing insights and sugges¬tions for governments to make political-economic decisions. The article investigates the impact of slowing economy on enterprises, the reasons of fluctuations of economic cycles and their characteristics, phases of economic cycle: growth, peak, downturn and crisis. The article studies definition of slowing economy, its reasons, ratios, and inter-relationship between various ratios. Methodology of evaluating economic cycles is provided in the article. Didėjantys neigiami ekonominių svyravimų ir ekonomikos nuosmukio padariniai nulemia šioje srityje atliekamų tyrimų svarbą. Remiantis tyrimų rezultatais, pateikiamos įžvalgos ir pasiūlymai vyriausybės politiniams – ekonominiams sprendimams priimti. Straipsnyje nagrinėjamas lėtėjančios ekonomikos poveikis įmonėms, išgrynintos pagrindinės ekonomikos ciklų svyravimų priežastys ir jų charakteristikos. Nagrinėjamos ekonominio ciklo fazės: pakilimas, viršūnė, nuosmukis ir krizė. Analizuojama ekonomikos lėtėjimo samprata, priežastys, rodikliai ir įvairių ekonominių rodiklių sąveika. Taip pat pateikiama ekonominių ciklų vertinimo metodika.
THE CONDITIONS OF DETERMINANTS OF THE FOREIGN DIRECT INVESTMENT DEVELOPMENT IN THE CONTEXT OF GLOBALIZATION OF ECONOMY / TIESIOGINIŲ UŽSIENIO INVESTICIJŲ PLĖTROS SĄLYGOS GLOBALIZACIJOS PROCESŲ KONTEKSTE
Authors: Naulickaitė Justina , Solnyšnikienė Jolanta
Published: July 2016

The article analyzes the complex issue of foreign direct investment and unequal distribution of its flows into different countries (the analysis of foreign direct investment determinants in the con-text of globalization). In the thesis there are the comprehensive theoretical study of foreign direct investment and the attraction of its flows consdering the nowadays context of globalization presented, the results of other empirical studies that analyzes foreign direct investment determinants were systematized. The model for the analysis of foreign direct investment determinants in the circumstances of globalization developed and presented. Based on this model studies to assess the determinants of foreign direct investment in Central and Eastern European countries carried out taking into account the differences of determinants among these countries and the countries of investment sources, also considering the possible lagging effects of these factors and the different volume of attracted foreign direct investment by different countries. Straipsnyje kompleksiškai vertinamos tiesioginės užsienio investicijos ir netolygaus tiesioginių užsienio investicijų srautų pritraukimo šalių atžvilgiu problema (tiesioginių užsienio investicijų pritraukimą globalizacijos sąlygomis lemiantys veiksniai). Atlikta teorinė studija, skirta tiesioginėms užsienio investicijoms, jų pritraukimo šiuolaikinėje globalizacijos aplinkoje reiškiniui, susisteminti empirinių tyrimų, vertinančių tiesioginių užsienio investicijų pritraukimą lemiančius veiksnius, rezultatai. Parengtas tiesioginių užsienio investicijų pritraukimą globalizacijos sąlygomis lemiančių veiksnių vertinimo modelis, kurio pagrindu atliktas tyrimas, leidžiantis įvertinti tiesioginių užsienio investicijų pritraukimą Centrinės ir Rytų Europos šalyse lemiančių veiksnių reikšmingumą ir poveikio kryptį, atsižvelgiant į šių veiksnių skirtumus tarp šių šalių ir šalių, investicijų šaltinių, taip pat atsižvelgiant į galimą laiko atžvilgiu atsiliekantį šių veiksnių poveikį ir į šalių pritraukiamų tiesioginių užsienio investicijų mastą.
E-LOYALTY / LOJALUMAS ELEKTRONINĖJE ERDVĖJE
Authors: Tūskaitė Ieva , Šlimaitė Viktorija
Published: July 2016

Business incomes depend on goods demand. Important element of demand is loyalty of consumer. Scientists actively research consumer’s loyalty from 1990. Business has new form, because technologies has improvements in a fast paced environment and that is the reason why emerges e-loyalty in virtual space. The main objective of this article is to do theoretical analysis of Scientist‘s researches of e-loyalty models. This research shows consumer‘s loyalty levels and elements in virtual space and com¬pares e-commerce and e-service models of loyalty. Methodology involves theoretical analysis of Scientist‘s researches which shows that the most important e-loyalty factors are consumer‘s satisfaction and confidence on the seller. Relevance of this article is practical research in the future using selected factors in e-loyalty. Kiekvieno verslo pajamos priklauso nuo paklausos, kurią lemia vienas iš veiksnių – vartotojų lojalumas. Mokslininkai intensyviai tiria vartotojų lojalumą jau nuo 1990 m. Atsirandant naujoms technologijoms, verslas įgyja naują formą, todėl atsiranda lojalumas virtualioje erdvėje, kurio nagrinėjimo pradžia siejama su interneto ir kompiuterinės technikos prieinamumu bei e. verslo modelių pradžia. Straipsnio tikslas yra atlikti vartotojų lojalumo virtualioje erdvėje teorinę analizę. Šis straipsnis tiria vartotojų lojalumo lygius ir veiksnius virtualioje erdvėje ir lygina e. komercijos ir e. paslaugų lojalumo modelius. Metodologija apima teorinę atliktų mokslininkų tyrimų analizę, kuri parodė, jog svarbiausi vartotojų lojalumo veiksniai elektroninėje erdvėje yra vartotojo pasitenkinimas ir pasitikėjimas pardavėju. Šio straipsnio aktualumas pasižymi tuo, jog galimas praktinis pagrindinių lojalumo veiksnių tyrimas ateityje.
THE COMPANY‘S LIQUIDITY AS INSTRUMENT FOR VALUE CREATION OF THE COMPANY / ĮMONĖS FINANSINIS LIKVIDUMAS KAIP PRIEMONĖ ĮMONĖS VERTEI DIDINTI
Authors: Bartkauskaitė Ieva , Stankevičienė Jelena
Published: July 2016

The liquidity indicators in the financial analysis are considered to be one of the most important parameters that characterise the state of the company. Since the liquidity is an integral part of the company’s value, the question is, whether it is possible to affect the company’s value by controlling the liquidity of the assets of the company, and to which variables the attention should be paid seeking to increase company‘s value. The model of the de-pendence of liquidity variables, according to the DuPont analysis and working capital, which affects the the value of the company EVA, is presented as well as the practical operation of the model and the conclusions. The results achieved by research are useful to the managers and shareholders of the company, evaluating the opportunity to increase the value of the company, searching for additional arguments for company’s liquidity management.
Likvidumo rodikliai traktuojami kaip vieni iš svarbiausių įmonės finansinę būklę rodančių rodiklių. Likvidumas neatsiejamai veikia įmonės vertę. Svarbu nustatyti, kaip, kontroliuojant įmonės likvidumo rodiklius, teigiamai paveikti įmonės vertę ir identifikuoti esminius įmonės finansinio likvidumo veiksnius, kuriems reikėtų skirti daugiausiai dėmesio, siekiant maksimizuoti įmonės vertę. Straipsnyje pateikiamas išvestinis DuPont analizės modelis, pagal kurį vertinamas įmonės grynasis apyvartinis kapitalas ir pridėtinė ekonominė vertė (angl. Economic Value Added – EVA). Ši minėto modelio kintamųjų priklausomybės schema pagrindžia likvidumo poveikį galutinei įmonės vertei. Pateikiamas praktinis modelio veikimas bei išvados. Šis išvestinis DuPont analizės modelis, paremtas apyvartinio kapitalo ir EVA kintamaisiais – tai instrumentas, naudingas įmonės vadovams bei akcininkams, siekiant padidinti įmonės vertę valdant įmonės likvidumą, ieškant papildomų galimybių didinti įmonės likvidumą.
INVESTIGATION OF ELECTRICAL POWER GRID MICROINVERTER EFFICIENCY / ELEKTROS TINKLO MIKROINVERTERIO NAUDINGUMO FAKTORIAUS TYRIMAS
Authors: Bielskis Edvardas , Šapurov Martynas , Platakis Andrius
Published: July 2016

In this paper the investigation results of a boost Flyback convert-er, which is used in a micro-inverter, are presented. The efficien-cy characteristics of the converter at various carrier frequencies and output loads were investigated. An alternative circuit diagram solution, which is less complex in structure and has fever com-ponents but has the same properties as the classic circuit scheme, for the converter is proposed. The proposed Flyback converter is less expensive. Its efficiency is 2–3 % higher than the classic Flyback converter when the converter output power is less than 95 W.
Darbe tirtas fotovoltinės energijos moduliams skirto mikroinverterio įtampą aukštinantis Flyback topologijos keitiklis. Ištirtos šio keitiklio naudingumo faktoriaus charakteristikos esant įvairioms nešlio dažnių ir keitiklio tiekiamos energijos galioms. Ištyrus klasikinį keitiklį, pasiūlytas patobulintas keitiklis, kuriame naudojama mažiau elektronikos komponentų. Pasiūlytas Flyback keitiklis yra pigesnis. Jo naudingumo faktorius yra 2–3 % aukštesnis už klasikinio, kai tiekiama keitiklio galia nesiekia 95 W.
APPLICATION OF MAJORITARIAN ELEMENT TO IMPROVE IO COMMUNICATION / DAUGUMOS ELEMENTO TAIKYMAI SKIRTI TOBULESNIAM RYŠIUI TARP INTERNETO DAIKTŲ
Authors: Dvali Tornike
Published: July 2016

The work introduces the circle of the basic ideas and methods of error-free recovery of the binary signal to the multichannel digital technology based on the model of formal (artificial) neuron and aims to contribute to the further development of this theo-ry of reliability. The work is useful for reservation or for exchange of a highly valuable information. During communication be-tween machines, connection related problems could occur and this work will be of a great help for machines to choose right channel for connection. Work also is a successful attempt of figuring out binary signal error recovery probability of minimum highest value. Moreover, binary channels optimization problems addressed by using threshold model and exploring three differ-ent approaches. In the future, this work will be used in Internet of Things (IoT) for the exact communication between machines. Work will be used with threshold model for minimizing errors in the communication between things.
Straipsnyje pristatomos idėjos ir metodai skirti daugiakanalių sistemų klaidoms skaitmeniniuose signaluose atstatyti. Nagrinėjama technologija grindžiama formaliuoju (dirbtiniu) neuronu, plėtoja patikimumo teoriją ir gali būti taikoma rezervavimo, siunčiant labai svarbią informaciją, sprendimams. Siekiant pagrįsti alternatyvaus kanalo tinkamą parinkimą, trimis skirtingais būdais nagrinėjamos dvejetainių signalų atstatymo tikimybės. Gauti rezultatai ateityje planuojami taikyti tiksliam (be klaidų) informacijos perdavimui ryšiuose tarp interneto daiktų.
ICMPV6 RA FLOODING VULNERABILITY RESEARCH / ICMPV6 PROTOKOLO RA ŽINUČIŲ ATSISAKYMO APTARNAUTI ATAKOS TYRIMAS
Authors: Jočys Linas Juozas
Published: July 2016

ICMPv6 is the newest version of internet control message protocol, whose main purpose is to send error message indicating packet processing failure. It is know that ICMPv6 is technologically vulnerable. One of those vulnerabilities is the ICMPv6 RA flooding vulnerability, which can lead to systems in Local Area Network slow down or full stop. This paper will discuss Windows (XP, 7, 8.1) and Linux Ubuntu 14 operating systems resistance to RA flooding attack research and countermeasures to minimize this vulnerability.
ICMPv6 yra naujausios versijos interneto kontrolės žinučių protokolas, kurio pagrindinis tikslas pranešti apie paketų apdorojimo klaidas IPv6 tinklo mazgams. Analizuojant ICMPv6 protokolą nustatyta, jog šis protokolas yra technologiškai pažeidžiamas. Vienas iš pažeidžiamumų yra ICMPv6 maršrutizatoriaus skelbimo žinučių (RA) atsisakymo aptarnauti pažeidžiamumas, kuris leidžia sulėtinti arba visiškai sutrikdyti operacinių sistemų darbą kompiuteriuose, esančiuose vietiniame tinkle. Straipsnyje aprašomas Windows (XP, 7, 8.1) ir Linux Ubuntu tipų operacinių sistemų atsparumo ICMPv6 protokolo RA žinučių atsisakymo aptarnauti atakai tyrimas. Tyrimo metu nustatytas pasirinktų operacinių sistemų atsparumas RA žinučių atsisakymo aptarnauti atakai, esant skirtingiems techninės įrangos resursams. Straipsnyje taip pat pateiktos prevencinės priemonės ICMPv6 RA žinučių atsisakymo aptarnauti pažeidžiamumui šalinti arba minimizuoti.
RESEARCH OF RELATION OF SAMPLERS FREQUENCY CHARACTERISTICS / STROBAVIMO ĮTAISO DAŽNINIŲ CHARAKTERISTIKŲ SĄRYŠIO TYRIMAS
Authors: Tankeliun Tomaš
Published: July 2016

This paper proposes an algorithm to reduce limitations in band-width measurements of sampling oscilloscopes then using a swept sine-wave measurement method. The traditional swept sine-wave method allow measure only magnitude response. Phase response can be computed only if a sampler is a minimal phase circuit. In this paper alternative bandwidth measurement algorithm using the nose-to-nose method with measurements corrections for the non-idle properties of oscilloscope is de-scribed. Algorithm includes for noise, time base distortions and jitter in measurement signals corrections methods. Proposed algorithm allows to measure phase and magnitude responses when only two similar oscilloscopes and the source of sync pulse are used. Algorithm performs as well as the swept sine-wave method in case when both samplers have the same frequency characteristics.
Stroboskopiniai osciloskopai skirti matuoti sparčius periodinius signalus naudojant sąlyginai nesparčius didelio skiltiškumo analoginius-skaitmeninius keitiklius. Vienas iš pagrindinių stroboskopinio osciloskopo mazgų, užtikrinančių, kad osciloskopo charakteristikos atitiktų metrologinius reikalavimus, ir kuriame vyksta matuojamo aukštadažnio signalo spektro transformacija į žemų dažnių sritį, yra strobavimo įtaisas. Šiame darbe pateikiamas strobavimo įtaiso veikimo principas, nagrinėjami įtaiso dažninių charakteristikų matavimo būdai taikant pastovios amplitudės, kintančio dažnio harmoninio virpesio ir priešpriešiais sujungtų strobavimo grandinių metodus. Gauti rezultatai rodo, kad nagrinėjamas strobavimo įtaisas nepriklauso minimalios fazės grandinių klasei ir apskaičiuoti įtaiso dažninę fazės charakteristiką (DFCh) iš dažninės amplitudės charakteristikos (DACh) neįmanoma, tačiau taikant priešpriešiais sujungtų strobavimo grandinių matavimo metodą galima gauti įtaiso DACh ir DFCh nenaudojant papildomos aukštadažnės matavimo įrangos ir mažinant matavimo proceso trukmę.
EXPERIMENTAL INVESTIGATION OF A SIX-PHASE VARIABLE FREQUENCY DRIVE / ŠEŠIŲ FAZIŲ DAŽNINĖS PAVAROS EKSPERIMENTINIS TYRIMAS
Authors: Lipinskis Tadas , Bleizgys Vytautas
Published: July 2016

Experimental results of a variable frequency drive, consisting of a six-phase voltage source inverter and six-phase asynchronous AC motor are presented in this paper. Frequency converter uses a six-phase space vector PWM scheme created by the author. The voltage forming scheme is implemented in Matlab/Simulink, and logical signals for inverter control are transferred from PC via the National instruments PCI-6024E data acquisition card. Voltages, at which the experimental motor operates at maximum efficiency, were determined experimentally. Motor transitions, when it is operating with one, two, and three failed phase windings are presented, confirming that a six-phase motor can operate with up to three failed windings. Darbe pateikiami dažninės pavaros, sudarytos iš šešių fazių dažnio keitiklio ir šešių fazių asinchroninio elektros variklio, eksperimentinių tyrimų rezultatai. Šešių fazių įtampai formuoti taikomas autoriaus sukurtas erdvinių vektorių moduliacijos algoritmas, naudojantis vidutinio ilgio vektorius. Algoritmas realizuotas asmeniniu kompiuteriu Matlab/Simulink terpėje. Signalams inverterio raktų valdymui iš kompiuterio gauti panaudotas National Instruments PCI-6024E duomenų įvesties/ išvesties įrenginys. Atlikti inverterio įtampos, kuriai esant šešių fazių variklis dirba maksimaliu naudingumo koeficientu, tyrimai. Pateikiami šešių fazių variklio greičio ir sukimo momento pereinamųjų procesų tyrimo rezultatai, esant vienos, dviejų ir trijų variklio apvijų gedimams, patvirtinantys, kad šešių fazių variklis gali ribotai veikti sugedus iki trijų apvijų.
STABILITY AND OCCURRENCE RATE CONSTRAINTS ON THE PLANETARY SCULPTING HYPOTHESIS FOR “TRANSITIONAL” DISKS
Authors: Dong (董若冰) Ruobing , Dawson (噹噹) Rebekah
Published: July 2016

Transitional disks, protoplanetary disks with deep and wide central gaps, may be the result of planetary sculpting. By comparing numerical planet-opening-gap models with observed gaps, we find systems of 3–6 giant planets are needed in order to open gaps with the observed depths and widths. We explore the dynamical stability of such multi-planet systems using N-body simulations that incorporate prescriptions for gas effects. We find they can be stable over a typical disk lifetime, with the help of eccentricity damping from the residual gap gas that facilitates planets locking into mean motion resonances. However, in order to account for the occurrence rate of transitional disks, the planet sculpting scenario demands gap-opening-friendly disk conditions, in particular, a disk viscosity α ≲ 0.001. In addition, the demography of giant planets at ∼3–30 au separations, poorly constrained by current data, has to largely follow occurrence rates extrapolated outward from radial velocity surveys, not the lower occurrence rates extrapolated inward from direct imaging surveys. Even with the most optimistic occurrence rates, transitional disks cannot be a common phase that most gas disks experience at the end of their life, as popularly assumed, simply because there are not enough planets to open these gaps. Finally, as consequences of demanding almost all giant planets at large separations participate in transitional disk sculpting, the majority of such planets must form early and end up in a chain of mean motion resonances at the end of disk lifetime.
COSMIC REIONIZATION ON COMPUTERS: THE FAINT END OF THE GALAXY LUMINOSITY FUNCTION
Authors: Gnedin Nickolay Y.
Published: July 2016

Using numerical cosmological simulations completed under the “Cosmic Reionization On Computers” project, I explore theoretical predictions for the faint end of the galaxy UV luminosity functions at

. A commonly used Schechter function approximation with the magnitude cut at

provides a reasonable fit to the actual luminosity function of simulated galaxies. When the Schechter functional form is forced on the luminosity functions from the simulations, the magnitude cut

is found to vary between −12 and −14 with a mild redshift dependence. An analytical model of reionization from Madau et al., as used by Robertson et al., provides a good description of the simulated results, which can be improved even further by adding two physically motivated modifications to the original Madau et al. equation.
Physiological and molecular characteristics of carbapenem resistance in Klebsiella pneumoniae and Enterobacter aerogenes
Authors: Pereira Rito Santo , Dias Vanessa Cordeiro , Ferreira-Machado Alessandra Barbosa , Resende Juliana Alves , Bastos André Netto , Andrade Bastos Lucas Quinet , Andrade Bastos Victor Quinet , Bastos Ricardo Villela , Da Silva Vânia Lúcia , Diniz Cláudio Galuppo
Published: July 2016

Introduction: Bacterial resistance is a growing concern in the nosocomial environment in which Klebsiella pneumoniae and Enterobacter aerogenes play an important role due to their opportunism and carbapenemase-production. This work aimed to evaluate physiological and molecular characteristics of carbapenem-resistant K. pneumoniae and E. aerogenes isolated in a Brazilian tertiary hospital. Methodology: In total, 42 carbapenem-resistant bacteria isolated from clinical specimens were included (21 K. pneumoniae and 21 E. aerogenes). Drug-sensitive K. pneumoniae (n = 27) were also included. Antimicrobial susceptibility and biocide tolerance patterns, hemolytic activity, tolerance to oxidative stress, and aggregative ability were assessed. Genetic markers related to carbapenem resistance, or ESBL-production were screened by PCR. Results: Compared to drug-sensitive strains, carbapenem-resistant K. pneumoniae were more tolerant to biocides and to oxidative stress, and they displayed an increase in biofilm formation. The genetic markers blaKPC (95.2%) and blaTEM (90.5%) were the most frequent. Among the carbapenem-resistant E. aerogenes strains, blaKPC, and blaTEM were detected in all bacteria. Drug-sensitive E. aerogenes were not isolated in the same period. blaSHV, blaVIM, and blaCTX markers were also observed among carbapenem-resistant bacteria. Conclusions: Results suggest that carbapenemase-producing enterobacteria might show peculiar characteristics regarding their physiology associated with their environmental persistency, virulence, and multidrug resistance. The observed phenomenon may have implications not only for antimicrobial chemotherapy, but also for the prognosis of infectious diseases and infection control.