bluuebunny/crossref_metadata_2025 huggingface dataset:
Rare Earth Metals Leaching from Coal Ash and Theirs Concentration
Authors: Сеник  , Senik E. , Виноградов  , Vinogradov M. , Таранов  , Taranov R. , Козодаев  , Kozodaev A. , Ксенофонтов  , Ksyenofontov Boris , Воропаева  , Voropaeva A.
Published: May 2016

Problems related to rare earth metals leaching from coal ash and theirs ion-exchange concentration from sulfuric solutions, in particular the characteristics of scandium, yttrium and lanthanum sorption by different ion exchange resins have been considered in this work. It has been shown that the best way to leach rare earth metals from coal ash is a complex acid and biological treatment of ash waste. Kinetics related to the process of scandium, yttrium and lanthanum acid leaching from ash and slag waste of CHPP in Kumertau has been investigated. Subsequent metal solutions concentration was achieved using ion exchange resins. The results of experimental studies related to the processes of rare-earth metals (in particularly scandium) ion exchange concentration by cation exchange resin in the Naform PC-100 have been presented, as well as the results of experimental studies related to rare earth metals (scandium including) sedimentation process, using special sedimentators. Dependences of rare earth metals (in particular scandium) sedimentation efficiency against pH value have been constructed, and recommendations for pH values, that are optimal for rare earth metals sedimentation, have been given. Based on obtained experimental results it was created and tested an experimental laboratory prototype of plant for rare earth metals (scandium, yttrium and lanthanum including) extraction from located near Moscow brown coal basin’s slag heaps, and from ash dumps of Russian Federation’s energy enterprises. This plant’s process flow diagram as well as its operation description has been presented. The created plant was tested in modes previously fulfilled in laboratory conditions. At the same time, carried out integrated exploration have showed the prospects for implementation of developed technical solutions for processing of ash dumps of Russian Federation’s various energy enterprises.
THE USE OF SHUNGITE IN THE DIETS OF HIGH PRODUCTIVE CATTLE
Authors: Девяткин  , Devyatkin Vladimir , Романов  , Romanov Viktor , Боголюбова  , Bogolyubova Nadezhda , Долгошева  , Dolgosheva Elena
Published: May 2016

The research focused on the optimization and stimulation of digestion by using of biologically active substances and their complexes. The task was to study the possibility of optimizing the digestive processes and, consequently, increase the productivity of highly productive ruminants caused by the feeding of mineral shungite. Studies conducted on lactating cows and calves Black-Motley breed in the conditions of the FUSE «Kljonovo-Chegodaevo», Moscow region. 1 scientific-economic experience on the principle analogues was formed 2 groups of lactating cows of Black-Motley breed, on 15 ones in each, while the level of productivity 6500-7000 kg of milk per lactation. In the 2nd scientific and economic experience was formed 2 groups of calves of Black-Motley breed at the age of 3-4 months, staged with the live weight of 100-110 kg, 15 heads in each group. Animals of the experimental groups received the basic diet of farm mineral shungite at the rate of 0.3% of the ration dry matter. The results showed that the inclusion in the composition of the diet of dairy cattle shungite contributes to the optimization of fermentation processes in the rumen, which is manifested in the decrease of ammonia concentration by 25.4%, the increase of amylolytic activity of microorganisms by 2.6%, the concentration of LFP 3.3% and mass of microorganisms. Introduction to the basic diet of lactating cows mineral shungite helped increase milk productivity of cows to 5.4-8.9 percent. Data of individual weighing of calves showed that feeding of mineral shungite improves the intensity of animals growth. Thus, the average daily live weight gain of calves fed the diet with the mineral shungite, increased by 8.4%.
NON-CONVENTIONAL SOURCES OF PROTEIN EFFICIENCY IN COMBIFEEDS FOR LACTING COWS
Authors: Симонов  , Simonov Gennadiy , Зотеев  , Zoteev Vladimir , Писарев  , Pisarev Evgeniy
Published: May 2016

The purpose of research is improving the efficiency of use of feed concentrates for lactating cows newly calved by use in their feed the rapeseed meal and camelina meal. The feasibility of using protein components obtained from the seeds of cruciferous crops – canola and winter camelina has been determined in two trials for Hoilstein cows of Black-Motley breed. In the first trial it has been found that the inclusion of 5.0-10.0% rapeseed meal in animal feed provides the 1.4-3.4% increase in protein milk yield. Introduction into the feed 10.0-15.0% of camelina meal provides the 2.8-4.2%. Increase of milk production within the animal of experimentsl groups (in terms of milk 4% fat). The best indicators of cost per 1 kg of 4% fat milk have been found to be in the 2nd and 3d experimental groups: 8.53-8,57 MJ OE; 135-137 crude protein; 343-348 g of combifeed. Replacing of sunflower meal by 15.0% Camelina sativa in the combifeed-concentrate has raised nutrient digestibility of feed ration compounds. Profitability level of milk production has been 7.5 abs.% higher than the control.
Facilitating the Transformational: An Exploration of Control in Cyberinfrastructure Projects and the Discovery of Field Control
Authors: Moody Gregory D. , Kirsch Laurie J. , Slaughter Sandra A. , Dunn Brian Kimball , Weng Qin
Published: May 2016

Emerging from rapid advances in digitization and technological capabilities is a new form of information systems development project: cyber projects. Cyber projects are complex, massive, and ambitious, often involving hundreds of academic, government, and industry professionals, requiring years of development, and costing millions of dollars. In our study, we examine how control is exercised in cyber projects. Based on a longitudinal study over eight years, we develop a process theory of the control of cyber projects. Initially we observe that project control is driven by the field, i.e., all of the individual or collective entities that subscribe to the general purpose of the project. This form of control is later replaced by a more bureaucratic form from government-sponsored entities to ensure that traditional project objectives are met. Once construction begins and the field understands the implications and promise of the project, we observe that control is again exerted by the primary project users in the field, complemented by authority-based control exerted by the government-sponsored entisty in the field.
PM3 and DFT Computational Studies of the Reaction Mechanism of Formaldehyde and Isoleucine
Authors: Hamza Umar , Uzairu Adamu , Sallau Muhammad S. , Abechi Stephen E. , Shallangwa Gideon A.
Published: May 2016

The reaction of formaldehyde and Isoleucine was studied using semi-empirical and density functional theory methods. Possible reactive sites are proposed and reaction mechanism postulated. It was found that the Isoleucine nitrogen attacks the carbonyl carbon of formaldehyde and forms a methylol intermediate that undergoes a condensation with another Isoleucine to produce a Methylenediisoleucine through a methylene bridge (cross-linking). The enthalpies of the reaction are -78.79 kJ/mol and -39.14kJ/mol for PM3 and DFT respectively also ΔSo and ΔGo, for the PM3 and DFT studies predicted. The reaction was found to be exothermic and second order.
Correlation and Factor Analysis of Grain Yield and Some Important Component Characters in Spring Bread Wheat Genotypes
Authors: Ebrahimnejad S. , Rameeh V.
Published: May 2016

In order to evaluate several agro-morphological traits in 21 spring bread wheat genotypes, an experiment based on randomized complete block design with three replications was carried out in two locations during three years (2008-2011). The traits including grain yield (GY), biological yield (BY), spike weight (SW), grain weight per spike(GWS), harvest index (HI), spike length (SL), spikelet per spike (SPS), number of grain per spike (NGS), number of spike per square meter (SPM), 1000-grain weight (GW), plant height (PH), stem straw weight (SSW), spike straw weight (SRW) were evaluated. The result of combined analysis of variance revealed that years, genotypes and their interaction effects were significant for all the traits. Location had significant difference for all the traits except SL and SPS. GY was significant correlated with BY (0.72**), SW (0.75**), GWS (0.69**), NGS (0.59**), SSW (0.62**) and SRW (0.66**). Factor analysis was used for understanding the data structure and trait relations. The factor analysis divided the thirteen traits into three factors. The cumulative variation for these factors was 0.76 and also it’s portions for factor one to three were 0.59, 0.16 and 0.06, respectively. In the first factor, the traits including GY, BY, SW, GWS, SPS, NGS and SSW had high factor loadings. The traits compromise HI, SSW and SRW had high factor loadings in second factor and also SPM, GW and PH had high values of factor loadings in third factor. The genotypes including Morvarid, N-80-19 and N-85-14 had high mean values of grain yield. The genotypes had high genetic coefficient variation for SRW, BY, SW and GY, therefore the efficiency of selection of the genotypes for improving these traits will be high.
Effect of Different Nitrogen Sources on Vegetative Traits, Grain Yield and Essential Oil Yield of Coriander (Coriandrum sativum)
Authors: Abdollahi F. , Salehi A. , Shahabi R. , Rahimi A.
Published: May 2016

Coriander (Coriandrum sativum) is one of the medicinal plants that its essential oil yield has abundance medicinal and food value. One of the main concepts in the production of medicinal plants is to increase of yield by biofertilizers. In order to evaluate the separate and combined effect of nitrogen and biofertilizer Nitroxin (mixture of bacteria Azotobacter and Azospirillum) fertilizer on vegetative traits, grain yield and essential oil yield of coriander, an experiment was conducted as a factorial in a randomized complete block design (RCBD) with three replications in the field research of Islamic Azad University, Jiroft, Iran. The experiment factors were consisted of three levels of nitrogen (0, 75 and 150 kg·ha−1) and three levels of Nitroxin biofertilizer (0, 2 and 4 L·ha−1). The results showed that application of 150 kg·ha−1 N significantly increased height and stem diameter, number of lateral branches and shoot dry weight, compared with control and application of 75 kg·ha−1 N. Nitroxin biofertilizer significantly improved vegetative traits of coriander when compared with control, so that application of 4 L·ha−1 of Nitroxin caused increase the mean of traits compared to control. In the most evaluated growth traits, the highest means were obtained with combining of 150 kg·ha−1 N with 4 L·ha−1 of Nitroxin. Application of 150 kg·ha−1 N increased the number of umbels per plant, 1000 seeds weigh, seed yield and essential oil yield, 29.9, 33.0, 72.9, 40.7, 147.4 and 177.1 percent, compared with the control, respectively. In the presence of Nitroxin, yield and yield component and essential oil yield of coriander increased significantly. Maximum average of these traits obtained when 4 L·ha−1 of Nitroxin was applied. Integrated of nitrogen and Nitroxin increased yield and yield component and essential oil yield significantly, when compare with application separately of them. So that the maximum mean of these traits obtained with combined application of 150 kg·ha−1 nitrogen and 4 L·ha−1 of Nitroxin. The results of this research was showed that application Nitroxin biofertilizer have an important role in increase of quantity and quality yield of coriander medicinal plant and can be used as an alternative of nitrogen fertilizer in sustainable agriculture.
Effect of Gibberellic and Salicylic Acids Pre-Soaking on Seed Germination Attributes of Cucumber (Cucumis sativus L.) under Induced Salt Stress
Authors: Al Sahil A. A.
Published: May 2016

Saline stress is one of the most deleterious abiotic stress determining a considerable reduction in agricultural production. Seed germination is the primitive plant growth stage and considered as vulnerable to saline stress. However, the exogenous application of natural plant growth regulators has been reported as one of the mitigation strategies. A Petri dish experiment under controlled conditions was conducted at King Saud University. The aim was to quantify the negative impact of induced saline stress (NaCl) on seed germination attributes and role of gibberellic acid (GA3) and salicylic acid (SA) to reduce the inhibitory effect of saline stress on cucumber (Cucumis sativus L.) seeds. The treatments consist of two sets as: seed pre-soaking solution and NaCl stress. Five pre-soaking solutions were prepared as: H2O (control), GA3 (100 ppm), GA3 (200 ppm), SA (0.5 ppm) and SA (1.0 ppm). While saline stress was imposed by NaCl at three levels such as: no stress (distilled water, control), mild stress (NaCl, 50 mM) and higher stress (NaCl, 100 mM). Results depicted that NaCl induced stress has significantly affected the all studied germinations attributes. The maximum NaCl stress (100 mM) stood highest in inhibiting seed germination percentage, seedling length, and seedling fresh and dry weights, followed by mild stress and control, respectively. Seed pre-soaking treatments were recorded non-significant for seedling length, fresh and dry weights while significant for germination percentage and number of seeds germinated over period of time. The interaction between seed pre-soaking treatments and induced saline stress was recorded significant. Overall, GA3 at the rate of 100 ppm solution performed a contributory role to mitigate the negative effect of saline stress.
Sodium chloride-induced conformational change in tRNA as measured by circular dichroism
Authors: Sarbak Szymon , Kujawa Melania , Jurga-Nowak Hanna , Dobek Andrzej
Published: May 2016

The effect of 0.01-1 M sodium ions on the conformation of the folded brewer’s yeast tRNAPhe was examined by circular dichroism method in the region 200-350 nm. The minimum peak at about 210 nm for tRNA solution with 50 mM sodium chloride showed a decrease in magnitude by 26-30% in comparison to that recorded for the solution of higher NaCl content. The depths of the peaks at 225 nm and 233 nm for two solutions with the lowest sodium chloride concentrations (cNaCl = 10mM, cNaCl = 50mM) were changed by 3-10% relative to the those in the spectra of other samples, for the 260 nm maximum peak a decrease in height was 21-25%. In the region 300-350 nm no significant difference was observed. The results point to a strong relationship between concentration of sodium ions and stabilization process of secondary and tertiary tRNA structure, which indicates the influence of sodium ions on stacking and base-pairing interactions.
Foreign Direct Investment Impact on Economic Indicators of the Baltic Countries
Authors: Barkauskaite Aida , Naraskeviciute Violeta
Published: May 2016

The foreign direct investment movement is becoming increasingly important nowadays. Various studies are conducted to determine the influence of foreign direct investments on certain countries. That is why it is important and useful to evaluate and compare how foreign direct investments affect the economic indicators of the Baltic countries - countries having similar economies. Methods used in the analysis are: logical comparative and generalization methods, systematic literature analysis and methods of mathematical statistics. The results have showed that foreign direct investments have positive influence on economies through gross domestic product and labour productivity growth in all Baltic countries, though foreign direct investments do not influence the unemployment rate in all Baltic countries
Latvian Potential in the Trade with the EU Countries
Authors: Pančenko Ērika , Ivanova Tatjana
Published: May 2016

The importance of international trade for the economic development of any country, on the one hand, and the decreasing rates of goods turnover within the EU countries in recent years, on the other hand, reveal the relevance of the research on the assessment of Latvia’s trade potential with the EU countries.

The aim of this study is to measure and assess Latvia’s export potential with the European Union countries based on the gravity model.

Since the development of trade relations is influenced by various factors, the article provides an overview of empirical studies that analyse various factors determining the level of trade among the countries.

Possible volume of exports from Latvia to the EU countries was calculated on the basis of gravity model; calculations were conditioned by several factors included in the model, such as GDP, geographical distance and the degree of country’s economic freedom. The article also provides an assessment of Latvia’s export potential realisation extent.

The method described in this article allowed applying the gravity model for the assessment of cooperation between Latvia and the EU countries, and was suitable for the quantitative evaluation of the extent to which export potential was realised in other countries
The Efficiency of Regional Innovation Systems in New Member States of the European Union: A Nonparametric DEA Approach
Authors: Dzemydaitė Giedrė , Dzemyda Ignas , Galinienė Birutė
Published: May 2016

This paper evaluates the Eastern and Central EU regions according to the efficiency level of innovation systems by application of nonparametric data envelopment analysis (DEA). The most technologically inefficient NUTS2 regions of Central and Eastern EU are identified. The governmental institutions in these regions should enforce a higher level of regional innovative activity, as regional potential to create a higher value to the economy with current resources has not been reached yet.
Motivation in foreign language learning: a look at type of school environment as a contextual variable
Authors: Pavičić Takać Višnja , Berka Nives
Published: May 2016

Impelled by the observation that motivation might be one of the most important factors within the affective domain influencing foreign language learning (FLL), the field of second language acquisition (SLA) has seen an intense worldwide interest in empirical research in motivational issues. The studies have been rooted in different theories and methodologies, (most notably those advanced by Gardner and Dörnyei and their respective associates) that have given precedence to a number of variables assumed to play an important role in understanding the phenomenon of FLL motivation. The present study is set between the macroperspective of the social-psychological period–by giving a general view of second language motivation–and the situation-specific period–by taking into consideration the immediate learning context. It focuses on exploring the nature of FLL motivation in Croatia at secondary education level where FLL is part of core curriculum. In particular, it explores the role of one specific contextual variable that has been largely ignored in SLA motivational research, i.e. type of school environment, and its interaction with gender and success in FLL.
Using authentic materials for students of tourism in Slovenia: English language acquisition for students of the Faculty of Tourism of the University of Maribor
Authors: Potočnik Topler Jasna
Published: May 2016

The article examines the process of teaching English for specific purposes at the Faculty of Tourism of the University of Maribor, Slovenia using coursebooks and authentic supplementary materials. The survey has shown that the students of the Faculty of Tourism prefer supplementary authentic materials to coursebooks because they find them sufficiently interesting or challenging. Specially designed classroom materials that are put into the Moodle by the teacher also offer opportunities for various activities in lesson planning for teaching, listening, speaking, reading and writing. Another important aspect of supplementary materials is that they facilitate the teacher’s creativity. However, there are advantages and disadvantages to using only coursebooks or only specially prepared classroom materials, and both - coursebooks and supplementary materials - should be used only after careful consideration. Although authentic materials may contain complex grammatical structures and difficult vocabulary, they bring real-life situations into classrooms, and students therefore find them very motivating, the survey has shown.
Behavioural Present Value Defined as Fuzzy Number – a New Approach
Authors: Piasecki Krzysztof , Siwek Joanna
Published: May 2016

The behavioural present value is defined as a fuzzy number assessed under the impact of chosen behavioural factors. The first formal model turned out to be burdened with some formal defects which are finally corrected in the presented article. In this way a new modified formal model of a behavioural present value is obtained. New model of the behavioural present value is used to explain the phenomenon of market equilibrium on the efficient financial market remaining in the state of financial imbalance. These considerations are illustrated by means of extensive numerical case study.
Estimation of Employee Turnover with Competing Risks Models
Authors: Grzenda Wioletta , Buczyński Michał K.
Published: May 2016

Employee turnover accompanies every business organization, regardless of the industry and size. Nowadays, many companies struggle with problems related to the lack of sufficient information about the nature of employee turnover processes. Therefore, comprehensive analysis of these processes is necessary. This article aims to examine the turnover of employees from a big manufacturing company using competing risks models with covariates and without covariates. This technique allows to incorporate the information about the type of employment contract termination. Moreover, Cox proportional hazard model enables the researcher to analyse simultaneously multiple factors that affect employment duration. One of the major observations is that employee remuneration level differentiates most strongly the risk of job resignation.
Statistical Computing in Information Society
Authors: Domański Czesław , Jędrzejczak Alina
Published: May 2016

In the presence of massive data coming with high heterogeneity we need to change our statistical thinking and statistical education in order to adapt both - classical statistics and software developments that address new challenges. Significant developments include open data, big data, data visualisation, and they are changing the nature of the evidence that is available, the ways in which it is presented and the skills needed for its interpretation. The amount of information is not the most important issue – the real challenge is the combination of the amount and the complexity of data. Moreover, a need arises to know how uncertain situations should be dealt with and what decisions should be taken when information is insufficient (which can also be observed for large datasets). In the paper we discuss the idea of computational statistics as a new approach to statistical teaching and we try to answer a question: how we can best prepare the next generation of statisticians.
Procathepsin E is highly abundant but minimally active in pancreatic ductal adenocarcinoma tumors
Authors: O’Donoghue Anthony J. , Ivry Sam L. , Chaudhury Chaity , Hostetter Daniel R. , Hanahan Douglas , Craik Charles S.
Published: May 2016

The cathepsin family of lysosomal proteases is increasingly being recognized for their altered expression in cancer and role in facilitating tumor progression. The aspartyl protease cathepsin E is overexpressed in several cancers and has been investigated as a biomarker for pancreatic ductal adenocarcinoma (PDAC). Here we show that cathepsin E expression in mouse PDAC tumors is increased by more than 400-fold when compared to healthy pancreatic tissue. Cathepsin E accumulates over the course of disease progression and accounts for more than 3% of the tumor protein in mice with end-stage disease. Through immunoblot analysis we determined that only procathepsin E exists in mouse PDAC tumors and cell lines derived from these tumors. By decreasing the pH, this procathepsion E is converted to the mature form, resulting in an increase in proteolytic activity. Although active site inhibitors can bind procathepsin E, treatment of PDAC mice with the aspartyl protease inhibitor ritonavir did not decrease tumor burden. Lastly, we used multiplex substrate profiling by mass spectrometry to identify two synthetic peptides that are hydrolyzed by procathepsin E near neutral pH. This work represents a comprehensive analysis of procathepsin E in PDAC and could facilitate the development of improved biomarkers for disease detection.
HUWE1 interacts with PCNA to alleviate replication stress
Authors: Choe Katherine N , Nicolae Claudia M , Constantin Daniel , Imamura Kawasawa Yuka , Delgado‐Diaz Maria Rocio , De Subhajyoti , Freire Raimundo , Smits Veronique AJ , Moldovan George‐Lucian
Published: May 2016

Defects in DNA replication, DNA damage response, and DNA repair compromise genomic stability and promote cancer development. In particular, unrepaired DNA lesions can arrest the progression of the DNA replication machinery during S‐phase, causing replication stress, mutations, and DNA breaks. HUWE1 is a HECT‐type ubiquitin ligase that targets proteins involved in cell fate, survival, and differentiation. Here, we report that HUWE1 is essential for genomic stability, by promoting replication of damaged DNA. We show that HUWE1‐knockout cells are unable to mitigate replication stress, resulting in replication defects and DNA breakage. Importantly, we find that this novel role of HUWE1 requires its interaction with the replication factor PCNA, a master regulator of replication fork restart, at stalled replication forks. Finally, we provide evidence that HUWE1 mono‐ubiquitinates H2AX to promote signaling at stalled forks. Altogether, our work identifies HUWE1 as a novel regulator of the replication stress response.
HUWE1 comes to the rescue at stalled replication forks
Authors: Coleman Kate E , Huang Tony T
Published: May 2016

HUWE1 is a multi‐faceted E3 ubiquitin ligase of the HECT family with many confirmed substrates, but mechanistic understanding of its functional roles in signaling pathways remains limited. In this issue of EMBO Reports, Choe et al demonstrate a novel function for HUWE1 in promoting DNA damage tolerance mechanisms to bypass DNA lesions during replication stress, thereby preserving genome stability. The authors connect this role for HUWE1 with its function in maintaining H2AX monoubiquitination levels for efficient signaling at stalled replication forks . Thus, this work highlights HUWE1 as a novel player in the replication stress response and prompts further investigation of its regulation during replication and other cellular processes.
The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity
Authors: Sundaram Meera V , Buechner Matthew
Published: May 2016

The excretory system of the nematode Caenorhabditis elegans is a superb model of tubular organogenesis involving a minimum of cells. The system consists of just three unicellular tubes (canal, duct, and pore), a secretory gland, and two associated neurons. Just as in more complex organs, cells of the excretory system must first adopt specific identities and then coordinate diverse processes to form tubes of appropriate topology, shape, connectivity, and physiological function. The unicellular topology of excretory tubes, their varied and sometimes complex shapes, and the dynamic reprogramming of cell identity and remodeling of tube connectivity that occur during larval development are particularly fascinating features of this organ. The physiological roles of the excretory system in osmoregulation and other aspects of the animal’s life cycle are only beginning to be explored. The cellular mechanisms and molecular pathways used to build and shape excretory tubes appear similar to those used in both unicellular and multicellular tubes in more complex organs, such as the vertebrate vascular system and kidney, making this simple organ system a useful model for understanding disease processes.
Counseling in Eye Care
Authors:   Vision Care Eye Hospital Bhubaneswar, Patro Manisha Kumari
Published: May 2016

Health is a basic need. When patients come to the hospital they are very anxious about their condition, cause and the nature of their disease. Many questions play on their mind. Is it curable or not? How much time and money is required for cure ? Tthey are also anxious to know each and every information related to their disease. Counselling is a very powerful process to allay their fears. It plays a vital role in all segments of health care. Nowadays counseling is no more restricted to treat mentally deranged or drug addicted people. In eye care, counselling is very useful to increase compliance and allay fears.
The Potential Role of Nicotine in the Treatment of Learning and Memory Impairment after REM Sleep Deprivation
Authors:   BRAINetwork Centre for Neurocognitive Sciences, School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian Kelantan, Malaysia, LONG IDRIS , RASHID NORLINDA ABD ,   BRAINetwork Centre for Neurocognitive Sciences, School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian Kelantan, Malaysia
Published: May 2016

Sleep depri vation has become a contributing factor to the world’s health concerns such as cardiovascular disease, mental illness and inattentiveness in occupationand decision making. It can also disturb synaptic plasticity that can lead to learning and memory impairment. Therefore, boosting cholinergic activity using acetylcholine imitator that can be found in the tobacco plant, known as nicotine, is essential in reversing the negative influences of sleep loss in the brain. Thus, studies on the effects of nicotine treatment on molecular mechanisms and structural changes of hippocampal brain cells are vital in order to gain more understanding and to overcome the detrimental consequencesof learning and memory impairment related to sleep divest.
Fundamentos económicos y cuentas nacionales: una propuesta de medición de la evolución del valor
Authors: Kennedy Damián
Published: May 2016

El producto social anual de un país es concebido unilateralmente como una masa de valores de uso, cuya evolución es captada por la medición a precios constantes. En tal contexto, el presente artículo desarrolla dos objetivos consecutivos. Primero, sobre la base de una relectura crítica de los fundamentos generales de las distintas escuelas de pensamiento, presenta una conceptualización alternativa del producto social, que considera también su carácter de masa de valor. Segundo, propone un indicador de la evolución de dicho carácter, complementario al producto a precios constantes. Como cierre, aplica este indicador al caso argentino para el lapso 1935-2010.
Una aproximación a los efectos del "derrame" del salario mínimo en la estructura de remuneraciones de Argentina
Authors: Groisman Fernando
Published: May 2016

En este artículo se examina si las modificaciones practicadas al salario mínimo en la Argentina durante los últimos años generaron efectos "derrame" en la estructura salarial. Se recurre para ello al análisis de las variaciones en las remuneraciones para distintos intervalos salariales que no estarían alcanzados por esta normativa. El enfoque metodológico se basa en la estimación de diferencias en diferencias, a través de mínimos cuadrados ordinarios, aplicada a datos de panel provenientes de la Encuesta Permanente de Hogares (EPH-Indec). Los resultados hallados confirman la existencia de estos efectos en aquellos segmentos de trabajadores con remuneraciones moderadamente superiores al mínimo legal.
Mandelbrot, Fama and the emergence of econophysics
Authors: Salazar Trujillo Boris
Published: May 2016

It is argued that Mandelbrot's stable Lévy-Pareto distributions were not accepted into the emerging field of financial economics due to their incompatibility with the analytical techniques and properties of equilibrium economics, and to the absence -both in physics and in economics- of analytical solutions to the infinite variance associated with those distributions. Whilst physicists made stable Lévy distributions plausible, creating Econophysics in the meantime, economists just forgot about them, suggesting their strong bias towards desirable properties and against established facts.
Income distribution in the Colombian economy from an econophysics perspective
Authors: Quevedo Cubillos Hernando , Quevedo María N.
Published: May 2016

Recently, in econophysics, it has been shown that it is possible to analyze economic systems as equilibrium thermodynamic models. We apply statistical thermodynamics methods to analyze income distribution in the Colombian economic system. Using the data obtained in random polls, we show that income distribution in the Colombian economic system is characterized by two specific phases. The first includes about 90% of the interviewed individuals, and is characterized by an exponential Boltzmann-Gibbs distribution. The second phase, which contains the individuals with the highest incomes, can be described by means of one or two power-law density distributions that are known as Pareto distributions.
Efectos del programa Asignación Universal por Hijo en la deserción escolar adolescente
Authors: Jiménez Maribel , Jiménez Mónica
Published: May 2016

El objetivo de este artículo es examinar el impacto del programa de transferencias condicionadas denominado Asignación Universal por Hijo (AUH), implementado en la Argentina desde 2009, en la deserción escolar adolescente. Además se analiza si su efecto en esta variable responde a su impacto en la tasa de ocupación juvenil y en el ingreso familiar per cápita, utilizando una base de datos novedosa: la Encuesta Nacional de Gasto de los Hogares del 2012/2013. Para ello se aplica el método propensity score matching. Los resultados sugieren que la AUH redujo la tasa de deserción escolar entre los adolescentes beneficiarios.
Tax shields, financial expenses and losses carried forward
Authors: Vélez-Pareja Ignacio
Published: May 2016

This article deals with the proper procedure for calculating Tax Shields (TS). The calculation includes cases where Losses Carried Forward are allowed and there is financial Other Income (OI). The procedure takes into account the magnitude of Adjusted Earnings before Interest and Taxes (EBITAdj) -that is, EBIT + OI - OE excluding Financial- compared with Financial Expenses (FE). This comparison defines three intervals and results for TS. If EBITAdj. < 0, TS will be 0; if EBITAdj. > 0 and less than FE, TS is T x EBITAdj.; finally if EBITAdj. > FE, TS is T x FE. When firm possesses OI, TS are not equivalent to the difference in taxes and an adjustment is needed. Proper calculation of TS is important because their value might represent a substantial part of firm value.
Análisis de los factores de riesgo en el seguro de automóvil mediante ecuaciones estructurales
Authors: Segovia Vargas María Jesús , Camacho-Miñano María Del Mar , Pascual Ezama David , Rodríguez-Piñero Piedad Tolmos
Published: May 2016

La gestión de riesgos, asociada al seguro del automóvil, es una cuestión crucial a la que se enfrentan en la actualidad tanto actuarios como profesionales del sector. Es clave seleccionar adecuadamente los factores de riesgos para asignar las tarifas a los asegurados en función del riesgo asociado. Por tanto, el objetivo de este trabajo es comprobar empíricamente la validez de la utilización de los niveles de "bonus-malus" para clasificar adecuadamente a los asegurados a través de dos modelos de ecuaciones estructurales. Los análisis sobre una muestra de 4.365 pólizas automovilísticas españolas descritas a través de 11 factores de riesgo muestran que la variable BM contribuye a mejorar la capacidad explicativa del modelo pero no de manera significativa.
Design, measurement and analysis of a Knowledge Management model in the context of a Mexican University
Authors: Rivera González Gibrán , Rivera González Igor Antonio
Published: May 2016

The paper aims to design and apply a Knowledge Management (KM) model within the context of a Higher Education (HE) institution in Mexico. The model is composed of six enablers: leadership, culture, structure, human resources, information technologies and measurement, which facilitate the processes of knowledge creation, storage, transfer and application. A 53-question survey applied to thirty-six (36) people allowed to evaluate the degree of development and implementation of knowledge enablers and processes. Objectivity, reliability and overall model fit were assessed.
Tipología de compradores online mayores de 55 años
Authors: Villarejo-Ramos Ángel F. , Rondán-Cataluña Francisco J. , Revilla-Camacho María Ángeles
Published: May 2016

La edad se considera una de las variables determinantes del riesgo de exclusión social de la población, especialmente con relación al uso de las nuevas tecnologías en general y de Internet en particular. Esto ha incidido en una creciente preocupación por el estudio del colectivo de mayores de 55 años y sus peculiaridades en lo relativo al acceso, uso y aprovechamiento de las TIC (Tecnologías de la Información y la Comunicación). Sin embargo, los esfuerzos se han centrado, mayoritariamente, en el análisis del grupo de mayores como algo homogéneo, lo que ha llevado a establecer sus perfiles de comportamiento en comparación con el de otros grupos de edad. En esta investigación, con una muestra útil de 595 mayores, partimos de la consideración del colectivo como grupo heterogéneo, con distintas características y condiciones de uso de Internet, y proponemos un modelo de clases latentes que nos permite establecer tres perfiles de mayores internautas en función de la utilización de un servicio avanzado de Internet, la compra online.
Efecto del diseño conjunto en la capacidad cognitiva y el rendimiento. Una propuesta de diseño basado en bloques incompletos balanceados
Authors: Huertas-García Rubén , Segura Carolina Consolación , Mas-Machuca Marta , Forgas-Coll Santiago
Published: May 2016

La utilización del análisis conjunto para estudiar procesos de decisión estratégica se considera un avance respecto a los métodos habituales post-hoc. Pero, dado que los experimentos conjuntos evalúan percepciones sobre perfiles del entorno descritos por frases, en lugar de preferencias, surge el problema de que la carga informativa que generan estos escenarios puede superar la capacidad del entrevistado, dificultando su evaluación y delimitando su uso a pocos factores. Este trabajo investiga cómo el diseño (el número de atributos) afecta a la complejidad de la evaluación y el rendimiento del experimento. Además, se propone un diseño mixto basado en bloques incompletos balanceados y, mediante un experimento, se compara su rendimiento frente a un diseño de bloques estándar. Los resultados muestran que la complejidad derivada del número de atributos tiene un efecto moderado en la variación explicada pero mayor en el peso de los factores, vislumbrando el uso de heurísticas distintas de los encuestados en el proceso de evaluación.
Alternativas de reducción de las emisiones de dióxido de carbono (C02) en la producción de cemento. Propuesta de un modelo de evaluación
Authors: Gessa Perera Ana , Sancha Dionisio Mª Del Pilar
Published: May 2016

La combinación óptima de las medidas disponibles de ajuste de emisiones de dióxido de carbono (C02) para compatibilizar los objetivos de producción con las exigencias medioambientales requiere planteamientos en la planificación de la producción industrial, con incorporación de nuevos parámetros y variables que permitan evaluar el impacto de las decisiones operativas sobre dichas emisiones, sujetas a las limitaciones del Protocolo de Kyoto. Tras realizar un análisis detallado del potencial de mejora de las alternativas disponibles para reducir las emisiones de C02 derivadas de la producción de cemento, abordamos en este trabajo las decisiones de optimización con un enfoque integrado, empleando un modelo de programación lineal que contempla conjuntamente las alternativas viables para reducir las emisiones y considerando tanto las derivadas de la aplicación de los mecanismos de flexibilidad del Protocolo de Kyoto como las destinadas a mejorar los productos y los procesos productivos. Su aplicación permitirá mejorar el proceso de toma de decisiones, al permitir considerar diferentes escenarios y obtener información relevante a través del análisis postoptimal. Se incluye, entre otras alternativas, la cantidad máxima a pagar por las instalaciones en el mercado de derechos para emitir una tonelada adicional de C02 o posibles cambios en el mix de producción para aumentar la rentabilidad, tanto relativos a tipo de productos como a cantidad a fabricar de los mismos.
Cultura nacional y crecimiento internacional de la empresa: una revisión de la literatura
Authors: González-Díaz Belén , López-Duarte Cristina , Vidal-Suárez Marta María
Published: May 2016

En este trabajo se realiza una revisión de la literatura existente sobre el papel de la cultura nacional y la diversidad cultural en los procesos de crecimiento internacional de la empresa con el objeto de sistematizar los tópicos ya abordados, los paradigmas dominantes y las conclusiones alcanzadas. Ello ha permitido, asimismo, identificar lagunas, así como resultados contradictorios y evidencias no concluyentes, apuntando a la necesidad de nuevas líneas de investigación al respecto. Para ello se ha llevado a cabo una revisión sistemática de los 171 trabajos publicados en las 26 revistas científicas internacionales de mayor impacto tanto en el ámbito general del management como en el campo específico de la gestión internacional. El periodo objeto de revisión es 2006-2011.
Redes de control político en el Amazonas colombiano Movimiento reciente de su historia política
Authors: Tobón Marco Alejandro , Cubeo Ronald Gregorio
Published: May 2016

A través de métodos etnográficos aplicados a los comicios electorales de 2011 a la gobernación del Amazonas y a la alcaldía de su capital Leticia, este artículo analiza los comportamientos electorales de las poblaciones amazónicas y las fuerzas económicas y políticas que participan en su control institucional y social, hechos que ilustran una realidad política que parece repetirse en su historia y, específicamente, en los comicios electorales futuros. La discusión central está dirigida a comprender las complejas redes sociales, económicas y culturales que participan en la definición del ejercicio político en el departamento del Amazonas, un conflictivo escenario configurado por extensas fronteras internacionales con Perú y Brasil, tensos encuentros culturales entre indígenas y no indígenas y la participación de actores de la política nacional que pretenden controlar las realidades locales.
Estructura trófica del ensamblaje íctico de los lagos de Yahuarcaca, Amazonas, Colombia
Authors: Prieto Piraquive Edgar Francisco , Duque Santiago Roberto , Sabogal González Alexander
Published: May 2016

El objetivo de esta investigación es determinar la dieta y cambios tróficas durante las temporadas de aguas altas y bajas de la ictiofauna predominante en un lago de várzea en la Amazonia colombiana. Las colectas se realizaron durante aguas altas y bajas en 2010, utilizando redes agalleras, red de arrastre y jamas. Se analizaron los contenidos estomacales de 875 ejemplares de 66 especies (30 para aguas altas y 48 aguas bajas); a través del Índice de Bray-Curtis se determinó la similitud entre las dietas de las especies; se utilizó el Índice de Levin para determinar la amplitud del nicho trófico. Hubo cambios en la composición de los gremios tróficos en ambas temporadas (X2=323.95, P=<0.001). Se hallaron seis gremios tróficos para la temporada de aguas bajas y cinco durante las aguas altas. Durante las dos temporadas se registraron cambios en la composición de la dieta que parecen corresponder a la oferta de recursos. Se recomienda en futuras investigaciones incrementar el número de muestras de los contenidos estomacales y ampliar el muestreo a las otras temporadas del ciclo hidrológico para determinar la variación trófica con mayor precisión.
“Revivir a la gente”: Herlinda Agustín, onaya del pueblo Shipibo-Konibo
Authors: Belaunde Luisa Elvira
Published: May 2016

Este artículo presenta una entrevista con Herlinda Agustín, mujer onaya ‘médica’, shipibo-konibo y reconocida artista de los diseños kené, fallecida en 2010. En ella describe su trayectoria de aprendizaje, comenzando por los masajes y las dietas terapéuticas y culminando con la práctica del chamanismo ayahuasquero, después del nacimiento de su último hijo. Herlinda percibía su carrera intrínsecamente relacionada a su deseo de sanar a sus hijos y de generar ingresos económicos para sustentar su educación escolar y superior en las ciudades. También tenía una aguda percepción de su poder y de su vulnerabilidad como mujer curandera. La necesidad de protegerse espiritual, corporal y emocionalmente para conciliar la maternidad con el ejercicio del chamanismo, según ella, va más allá de una cuestión individual, ya que se trata de manejar el riesgo de enfermedad inherente a la práctica chamánica, para evitar perjudicar a los hijos y demás familiares próximos.
Simulación de plantas de procesamiento de minerales a través de MODSIM®
Authors: Bustamante Rúa Moisés Oswaldo , Daza Aragón Alan José , Bustamante Baena Pablo , Barros Daza Manuel Julián
Published: May 2016

Se presentan los resultados del estudio y análisis de dos escenarios particulares en la industria minera como lo son el caolín y el carbón, para determinar la utilidad del software MODSIM®  en la simulación de plantas de procesamiento minero-metalúrgicas. Para esto, se partió de datos obtenidos de información tanto bibliográfica como de la obtenida directamente en mediciones que se realizaron a estas minas. Se pudo analizar que el uso de este software aporta grandes ventajas a la hora de conocer la eficiencia en las plantas de beneficio de minerales. En las baterías de hidrociclones para la separación de caolín, se evidencian algunos problemas en la operación; mientras que en el proceso de lavado de carbón, se logra una buena separación. Esto es de vital importancia en las plantas, puesto que permite conocer la eficiencia de los equipos y además, facilita la toma de medidas correctivas para mejorar el proceso.
Procesos de maquilización productiva y su configuración en el norte del Estado de México
Authors: Monroy Gaytán José Francisco
Published: May 2016

La presente investigación tuvo como objetivo identificar la composición del sistema de producción textil constituido por maquiladoras en la región Atlacomulco, Estado de México, a partir del análisis de dos categorías de aglomeraciones: precisión de la complejidad interna y precisión de la conformación morfológica; lo que llevó a la indagación sobre las especificidades en la constitución y el comportamiento de las maquiladoras. A partir de esto se logró entender los procesos intraterritoriales originados por sus actividades. Como resultado principal de esta investigación se destaca la descripción de las condiciones en las que se encuentra la región norte del Estado de México, en términos de procesos productivos, localización y relocalización de la industria maquiladora, así como la configuración que ha tenido esta en la región.