bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in the trophic status of lakes in the Suwałki Landscape Park (NE Poland)
Authors: Górniak Andrzej , Więcko Adam , Karpowicz Maciej
Published: February 2017

Summer field research and chemical analyses in 2015 provided the basis for the presentation of the trophic status of waters of 28 lakes of the Suwałki Landscape Park in NE Poland, located in the catchment of the River Neman, in the Natura 2000 area – Ostoja Jeleniewska. Lakes Hańcza and Szurpiły are currently mesotrophic ecosystems. The remaining lakes are moderately eutrophic, while four lakes in the group, in addition to anaerobic hypolimnion, have infertile epilimnion similar to that of mesotrophic lakes. Lake Hańcza shows considerable multiannual dynamics of water fertility, periodically reaching a status approximate to eutrophy. In Lake Szurpiły and the majority of smaller lakes of the Suwałki Landscape Park, reduced precipitation in 2015 resulted in an inconsiderable decrease in trophic status. The lakes are under the strong influence of their catchment area, as confirmed by statistically significant correlations between TSI and the Ohle and Schindler ratios. Lakes Kluczysko and Kopane currently remain the most fertile lakes in the Park. Unless rapidly developing cattle breeding leads to excessive fertilisation of waters in the catchment, the forecasted variability of weather conditions during global climate transformations will lead to fluctuations in the fertility of the majority of the analysed lakes at the threshold of meso- and eutrophy. A hypothesis is also stated regarding the considerable role of groundwater alimentation and short retention time in the maintenance of higher than average resources of silica in limnic waters.
Contribution of non-pollen palynomorphs to reconstructions of land-use changes and lake eutrophication: case study from Lake Jaczno, northeastern Poland
Authors: Weisbrodt Dawid , Enters Dirk , Żarczyński Maurycy Jacek , Poraj-Górska Anna Izabela , Tylmann Wojciech
Published: February 2017

Analysis of non-pollen palynomorphs supplemented by pollen analysis, microcharcoal analysis and geochemical data from laminated sediments from Lake Jaczno were used to establish different phases of land-use in the catchment between c.a. AD 1840 and AD 2013. The results show that during the first eighty years the vicinity of the lake was heavily deforested. During this period erosional inputs caused accumulation of abundant fungal spores, indicators of pastures and natural fertilizers (manure) as well as of corroded pollen grains and charcoal. Gradual regeneration of forest cover took place after World War II, when expansion of pioneer trees occurred (Betula, Salix, Carpinus, Populus). At the same time, a considerable increase in the lake trophy was observed, leading to the changes in phytoplankton and macrophyte communities: a decrease in the proportion of Botryococcus and an increase in the Nymphaea alba population. The non-pollen palynomorphs analyses indicate the substantial human impact that caused changing local environmental conditions, compatible with the results based on pollen analysis and geochemical data.
Convergence in total variation distance of a third order scheme for one-dimensional diffusion processes
Authors: Rey Clément
Published: February 2017

In this paper, we study a third weak order scheme for diffusion processes which has been introduced by Alfonsi [1]. This scheme is built using cubature methods and is well defined under an abstract commutativity condition on the coefficients of the underlying diffusion process. Moreover, it has been proved in [1] that the third weak order convergence takes place for smooth test functions. First, we provide a necessary and sufficient explicit condition for the scheme to be well defined when we consider the one-dimensional case. In a second step, we use a result from [3] and prove that, under an ellipticity condition, this convergence also takes place for the total variation distance with order 3. We also give an estimate of the density function of the diffusion process and its derivatives.
Ba- and Ti-enriched dark mica from the UHP metasediments of the Seve Nappe Complex, Swedish Caledonides
Authors: Majka Jarosław , Kruszewski Łukasz , Rosén Åke , Klonowska Iwona
Published: February 2017

We report on the occurrence of peculiar Ba- and Ti-enriched dark mica in metasedimentary rocks that underwent high-pressure metamorphism in the diamond stability field followed by decompression to granulite facies conditions. The mica occurs as well-developed preserved laths in a quartzofeldspathic matrix. The mean concentrations of BaO and TiO2 in the mica are 11.54 and 7.80wt%, respectively. The maximum amounts of these components are 13.38wt% BaO and 8.45wt% TiO2. The mean crystallochemical formula can be expressed as (K0.54Ba0.39Na0.02Ca0.01)Σ0.96(Fe1.37Mg0.85Ti0.50Al0.29Mn0.01Cr0.01)Σ3.03(Si2.59Al1.41)Σ4.00O10(OH1.30O0.66F0.02S0.01)Σ1.99, with oxyannite, oxy-ferrokinoshitalite and siderophyllite as dominating end-members. Based on the petrographical observations, it is proposed that the dark mica was formed at a rather late stage in the evolution of the parental rock, i.e. under granulite facies conditions.
Arrangement of material depots for line segment–modeled structures using continuous conditions
Authors: Pém Attila , Mályusz Levente
Published: February 2017

In this study, we introduce a model for optimizing the arrangement of final material depots at a construction site. The target is to minimize the construction time, cost and resources by minimizing the total delivery distance. The model simplifies the structures that shall be constructed as line segments or curves. The model uses continuous conditions: the feasible positions of the final material depots are searched on the entire XY plane and the structures are used in a continuous way also. A simple example demonstrates the algorithm, and the calculated result is compared with an expert's solution. The practicability of the model is discussed by comparing the result of the model with the output of the mentality of the laborers. The further generalization of the model is declared. It needs less input data than the discrete model does so that it can be an alternative model to the discrete model if the number of units that build up the structure is large or unknown. This article is an extended version of a conference paper (Pém and Mályusz 2016).
The role of physical exercise in the development of breast cancer
Authors: Adasik Agata
Published: February 2017

Breast cancer is one of the most common types of cancer among women worldwide. Epidemiological and experimental studies confirm the beneficial effects of physical exercise both in patients who have suffered a relapse and in those who are in the course of a treatment. Researchers suggest that regular physical effort performed 3-5 times a week at 20-40 MET reduces the risk of development of breast cancer. Scientific evidence suggests that aerobic training can be safe and effective even during the oncological treatment, which, depending on the stage of the disease, may consist of surgical treatment combined with chemotherapy, radiotherapy or hormone therapy. In addition, it significantly improves the function of the circulatory and respiratory systems, reduces fatigue and improves the quality of life of patients struggling with the disease. There are many theories on the mechanisms that are triggered by aerobic workout. Despite the numerous studies on this subject, which have been conducted over the years, we still cannot say how physical activity reduces the risk of development of breast cancer. The most frequently mentioned biological mechanisms include the influence of oestrogen, metabolic hormones, growth factor, inflammatory markers, response from the immune system, insulin resistance and oxidative stress. Many studies into the process of carcinogenesis are carried out in laboratory conditions on animals. Due to application of different experimental models, the results of such studies are often ambiguous. Nevertheless, scientists see a huge potential in this kind of experiments, because some of them have already attested to the protective effects of physical exercise against the appearance of breast cancer, but also they have increased our understanding of the processes through which this risk is reduced. Perhaps, in the future physical activity will become a part of a cancer treatment thanks to the results of such studies.
Training load in direct start preparation (DSP) in sitting volleyball players
Authors: Bolach Bartosz , Stańdo Michał , Bolach Eugeniusz
Published: February 2017

: The objective of the elaboration was to assess the degree of physical load in direct start preparation (DSP) during preparations of disabled sitting volleyball players for the Polish championships.

: Players of the “Start” Sports Club of the Disabled in Wroclaw who play sitting volleyball professionally participated in the study. The subjects of the study were men aged 17 to 53 (average age: 31.9); they have been playing sitting volleyball for 2.5 to 33 years. Twelve sitting volleyball players with various disabilities concerning uni- and bilateral amputation within the lower leg and thigh, with malformation and short lower limbs participated in the study.

: The study involved assessment of the exercise capacity of sitting volleyball players during 7 training units in introductory and intensifying micro-cycles within DSP. Heart rate results at six moments (at the beginning, in the 10

: Years of training significantly correlated with age of the participants. The participants were characterized by significantly lower resting heart rate in the intensifying micro-cycle than in the introductory microcycle which may result from adaptation of the body to physical effort. The largest differences in average heart rate values at the considered moments of training units in training micro-cycles within DSP were observed in the measurement of resting heat rate and final heart rate. Standard deviation in the introductory micro-cycle and the intensifying micro-cycle within DSP was growing in a linear manner, except for the peak heart rate index. Resting heart rate significantly impacted the value of heart rate during training units within DSP.

Volleyball players participating in the study were characterized by significantly lower resting hear rate in the intensifying micro-cycle than in the introductory micro-cycle within DSP which may result from adaptation of the body to physical effort. The lowest percentage difference of the average heart rate value occurred in the assessment of final heart rate, while at the remaining moments of training units heart rate values reached the same percentage value. The course of regeneration in both compared micro-cycles (DSP) was similar and it did not vary significantly. Restoring the value of resting heart rate occurred after more than 15 minutes after training.
Analysis of selected determinants of health-related quality of life in persons with spinal cord injury
Authors: Pokaczajło Jarosław , Tasiemski Tomasz
Published: February 2017

The aim of the study was the analysis of factors determining health-related quality of life (HRQoL) in persons with spinal cord injury (SCI).

The study involved 100 persons with SCI dependent on using a wheelchair in everyday life, including 22 females and 78 males. Study conducted using the SF-36 questionnaire used to assess HRQoL.

Based on the statistical analysis of the collected research material it has been shown highly significant correlations between the physical and mental dimensions of HRQoL and age at the day of injury and age at the day of the survey. There were also highly significant differences in the physical dimension of HRQoL due to the following variables: clinical pattern of injury, marital status, level of education and participation/non-participation in the active rehabilitation camp. In the case of the mental dimension of the HRQoL there was a significant variation due to the same variables with the exception of clinical pattern of SCI.

Based on the undertaken research it was shown that people with higher levels of HRQoL are characterized by: lower age at the time of the study, lower age at the time of injury, long time since injury, paraplegia, marital status – single, secondary/higher level of education and participation in the active rehabilitation camps in the past.
Biomechanical Assessment of Motor Abilities in Male Handball Players During the Annual Training Macrocycle
Authors: Sacewicz Tomasz , Bodasiński Sławomir , Śliwa Marcin , Szyszka Paulina , Mazur Zenon , Czaplicki Adam
Published: February 2017

Introduction. The aim of the study was to determine the torque of the knee extensors and flexors of the lead lower limb, the torque of the shoulder extensors and flexors of the dominant upper limb, and the torque generated by the muscles of the kinematic chain going from the trail lower limb to the hand of the dominant limb in male handball players during the annual training macrocycle. Changes in jump height and throwing velocity were also investigated. Material and methods. The study involved 13 handball players from a Polish second-league team. The measurements were performed four times: at the beginning of the preparation period, at the beginning of the season, at the end of the first part of the season, and at the end of the second part of the season. Torque was measured in isokinetic and isometric conditions. Jumping ability was tested using a piezoelectric platform, and throwing velocity was measured with a speed radar gun. Results. The study found statistically significant differences between the relative torque values of the knee extensors (p < 0.002) and flexors (p < 0.003) of the lead leg measured in isokinetic conditions between the first three measurements and the final one. Isokinetic measurement of the torque of the muscles of the kinematic chain going from the trail leg to the hand of the dominant arm decreased in a statistically significant way at the end of the season. As for the results of the measurement of the torque of the shoulder extensors and flexors in static conditions, no statistically significant differences were observed between the four measurements. However, statistically significant differences were noted in jumping ability and throwing velocity in the annual training macrocycle. Conclusions. The results of the study indicate that there is a need to perform regular assessments of players’ strength and jumping ability during the competition period. There is a need to modify the training methods used during the preparation period and in the second part of the season as well as to individualise training at the end of the competition period.
Causal Attributions of Success and Failure and Mood States in Football Players
Authors: Szczepaniak Joanna , Guszkowska Monika
Published: February 2017

Introduction. The aim of the study was to determine the causal attributions of success and failure in a football match in a group of football players, as well as to investigate the association of the players’ attributions with their level of achievement and the relationships between their causal attributions and affective states. Material and methods. The study involved 75 football players, including 44 players from the first league and 31 players from the third league. The research was carried out using the Profile of Mood States (POMS) by D.M. McNair, M. Lorr, and L.F. Droppleman and a specially designed questionnaire concerning the causal attributions of success and failure. Results. It was found that the football players who participated in the study tended to attribute success to internal causes and failure to external causes. More frequent use of external attributions most likely had an adverse impact on the mood state of the players. Conclusion. Information concerning the attributions that a given player makes can be useful for coaches, as it can help them develop the athlete’s mental abilities more effectively. Beliefs related to attributions can be modified. It is worth considering the benefits of encouraging internal attributions in the case of success and external attributions in situations of failure.
Differences in Body Build and Physical Fitness of PE Students from the Faculty of Physical Education and Sport in Biała Podlaska in the Years 1989, 2004, and 2014
Authors: Saczuk Jerzy , Wasiluk Agnieszka , Wilczewski Robert , Wilczewski Adam
Published: February 2017

Introduction. In the current situation of the demographic decline and simultaneous tough competition on the educational market, the issues of not only teaching levels but also the competences and aptitudes of students themselves are raised more and more often. Therefore, this study sought to analyse differences in the body build and physical fitness of physical education (PE) students from the Faculty of Physical Education and Sport in Biała Podlaska in the years 1989, 2004, and 2014. Material and methods. The material included the results of the anthropometric measurements and physical fitness tests of second-year students examined in 1989 (n = 111), 2004 (n = 181), and 2014 (n = 127). Martin and Saller’s technique was employed to measure anthropometric features necessary to establish body build types using the Heath-Carter method. Physical fitness was evaluated with the International Physical Fitness Test. Sample size (n), arithmetic mean (x̅), standard deviation (SD), and the T point scale were applied to assess the collected variables. Differences in the sizes of the analysed features between the groups were estimated with the use of ANOVA and the Newman-Keuls test. Results. The analysis revealed a constant increase in basic somatic features and endomorphy and a decrease in mesomorphy and physical fitness in male subjects. The ectomorphy of students examined in 2014 was at a level similar to that recorded in 1989. The pace of the described changes was different depending on the study period. Conclusions. Secular trends in body build and physical fitness observed in the study may stem from deterioration in the biological potential of youths or may result from lowering physical education entrance exam criteria at the university.
Building multi-country collaboration on watershed management: lessons on linking environment and public health from the Western Balkans
Authors: Cairns Maryann R. , Cox Clayton E. , Zambrana Jose , Flotemersch Joseph , Lan Alexis , Phillips Anna , Kozhuharova Gordana , Qirjo Mihallaq , Szigeti Bonifert Marta , Kadeli Lek
Published: February 2017

Community-based watershed resilience programs that bridge public health and environmental outcomes often require cross-boundary, multi-country collaboration. The CRESSIDA project, led by the Regional Environmental Center for Central and Eastern Europe (REC) and supported by the US Environmental Protection Agency (EPA), forwards a resilience-focused approach for Western Balkan communities in the Drini and Drina river watersheds with the goal of safeguarding public health and the environment. The initial phases of this project give a contextualized example of how to advance resilience-driven environmental health goals in Western Balkan communities, and experience within the region has garnered several theme areas that require focus in order to promote a holistic watershed management program. In this paper, using CRESSIDA as a case study, we show (1) how watershed projects designed with resilience-driven environmental health goals can work in context, (2) provide data surrounding contextualized problems with resilience and suggest tools and strategies for the implementation of projects to address these problems, and (3) explore how cross-boundary foci are central to the success of these approaches in watersheds that comprise several countries.
Ornithological Fauna of the Waste Water Treatment Plants in the Northern Left Bank Ukraine (Chernihiv and Kyiv Regions): Winter Populations and Ecological Structure
Authors: Fedun О. М. , Davydenko І. V.
Published: February 2017

The article discusses winter bird populations of the waste water treatment plants (WWTP) located in the North of Left -bank Ukraine. The said population comprises 12 orders and 29 families. The most numerous are Passeriformes (37 species), Аnsеriformes (16 species) and Falconiformes (6 species). Parus major was registered at all types of facilities while most of the others house Passer montanus, Carduelis carduelis, Turdus pilaris, and Parus caeruleus. The largest number of wintering birds was registered at Bortnychi aeration station, Chernihiv municipal WWTP and Chernihiv wool processing factory - 79. 51 and 15 species respectively. The nuclear part of the bird numbers are the species residing at the facilities all year around (65.8 %); species occurring there in winter only account for 34.2 %. Dendrophilous (38 species) and hydrophilous (35 species) dominate among them. The primary role in forming the winter fauna of the waste water treatment plants belongs to the zones of water bodies and dams.
Optogenetic Low-Frequency Stimulation of Specific Neuronal Populations Abates Ictogenesis
Authors: Shiri Zahra , Lévesque Maxime , Etter Guillaume , Manseau Frédéric , Williams Sylvain , Avoli Massimo
Published: February 2017

Despite many advances made in understanding the pathophysiology of epileptic disorders, seizures remain poorly controlled in approximately one-third of patients with mesial temporal lobe epilepsy. Here, we established the efficacy of cell type-specific low-frequency stimulation (LFS) in controlling ictogenesis in the mouse entorhinal cortex (EC) in anin vitrobrain slice preparation. Specifically, we used 1 Hz optogenetic stimulation of calcium/calmodulin-dependent protein kinase II-positive principal cells as well as of parvalbumin- or somatostatin-positive interneurons to study the effects of such repetitive activation on epileptiform discharges induced by 4-aminopyridine. We found that 1 Hz stimulation of any of these cell types reduced the frequency and duration of ictal discharges in some trials, while completely blocking them in others. The field responses evoked by the stimulation of each cell type revealed that their duration and amplitude were higher when principal cells were targeted. Furthermore, following a short period of silence ranging from 67 to 135 s, ictal discharges were re-established with similar duration and frequency as before stimulation; however, this period of silence was longer following principal cell stimulation compared with parvalbumin- or somatostatin-positive interneuron stimulation. Our results show that LFS of either excitatory or inhibitory cell networks in EC are effective in controlling ictogenesis. Although optogenetic stimulation of either cell type significantly reduced the occurrence of ictal discharges, principal cell stimulation resulted in a more prolonged suppression of ictogenesis, and, thus, it may constitute a better approach for controlling seizures.

SIGNIFICANCE STATEMENTEpilepsy is a neurological disorder characterized by an imbalance between excitation and inhibition leading to seizures. Many epileptic patients do not achieve adequate seizure control using antiepileptic drugs. Low-frequency stimulation (LFS) is an alternative tool for controlling epileptiform activity in these patients. However, despite the temporal and spatial control offered by LFS, such a procedure lacks cell specificity, which may limit its efficacy. Using an optogenetic approach, we report here that LFS of two interneuron subtypes and, even more so, of principal cells can reliably shorten or abolish seizuresin vitro. Our work suggests that targeted LFS may constitute a reliable means for controlling seizures in patients presenting with focal seizures.
The Epac-Phospholipase Cε Pathway Regulates Endocannabinoid Signaling and Cocaine-Induced Disinhibition of Ventral Tegmental Area Dopamine Neurons
Authors: Tong Jiaqing , Liu Xiaojie , Vickstrom Casey , Li Yan , Yu Laikang , Lu Youming , Smrcka Alan V. , Liu Qing-Song
Published: February 2017

Exchange protein directly activated by cAMP (Epac) is a direct effector for the ubiquitous second messenger cAMP. Epac activates the phospholipase Cε (PLCε) pathway. PLCβ has been linked to the synthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG). Here, we report that Epac facilitates endocannabinoid-mediated retrograde synaptic depression through activation of PLCε. Intracellular loading of a selective Epac agonist 8-CPT-2Me-cAMP into ventral tegmental area (VTA) dopamine neurons enabled previously ineffective stimuli to induce depolarization-induced suppression of inhibition (DSI) and long-term depression of IPSCs (I-LTD) in the VTA. DSI and I-LTD are mediated by 2-AG since they were blocked by a diacylglycerol lipase inhibitor. The effects of 8-CPT-2Me-cAMP on DSI and I-LTD were absent in Epac2 and PLCε knock-out mice, but remained intact in Epac1 knock-out mice. These results identify a novel mechanism for on-demand synthesis of retrograde signaling 2-AG by the Epac2-PLCε pathway. We investigated the functional significance of Epac2-PLCε-2-AG signaling in regulating inhibitory synaptic plasticity in VTA dopamine neurons induced byin vivococaine exposure. We showed that cocaine place conditioning led to a decrease in the frequency and amplitude of spontaneous IPSCs and an increase in action potential firing in wild-type mice, but not in Epac2 or PLCε knock-out mice. Together, these results indicate that the Epac2-PLCε-2-AG signaling cascade contributes to cocaine-induced disinhibition of VTA dopamine neurons.

SIGNIFICANCE STATEMENT2-arachidonoylglycerol (2-AG) is an endogenous cannabinoid that depresses synaptic transmission through stimulation of CB1receptors. Among the six isoforms of phospholipase C (PLC; PLCβ, PLCγ, PLCδ, PLCε, PLCζ, PLCη), only PLCβ has been linked to 2-AG synthesis. Here we demonstrate that 8-CPT-2Me-cAMP, a selective agonist of the cAMP sensor protein Epac, enhances 2-AG-mediated synaptic depression in ventral tegmental area (VTA) dopamine neurons via activation of PLCε. These results identify a novel mechanism for 2-AG synthesis via activation of the Epac-PLCε pathway. Furthermore, we show that cocaine-induced conditioned place preference and disinhibition of VTA dopamine neurons were impaired in mice lacking Epac or PLCε. Thus, the Epac-PLCε signaling pathway contributes to cocaine-induced disinhibition of VTA dopamine neurons and formation of drug-associated memories.
Trends in Anthropometric Measures Among US Children 6 to 23 Months, 1976–2014
Authors: Akinbami Lara J. , Kit Brian K. , Carroll Margaret D. , Fakhouri Tala H.I. , Ogden Cynthia L.
Published: February 2017

BACKGROUND AND OBJECTIVES:

The surveillance of children’s growth reflects a population’s nutritional status and risk for adverse outcomes. This study aimed to describe trends in length-for-age, weight-for-age, weight-for-length, and early childhood weight gain among US children aged 6 to 23 months.

METHODS:

We analyzed NHANES data from 1976–1980, 1988–1994, 1999–2002, 2003–2006, 2007–2010, and 2011–2014. We estimated z scores < –2 (low) and ≥+2 (high) in comparison with World Health Organization growth standards for each indicator. Weight gain (relative to sex-age–specific medians) from birth until survey participation was estimated. Trends were assessed by low birth weight status and race/Hispanic origin. Race/Hispanic origin trends were assessed from 1988–1994 to 2011–2014.

RESULTS:

In 2011–2014, the prevalence of low and high length-for-age was 3.3% (SE, 0.8) and 3.7% (SE, 0.8); weight-for-age was 0.6% (SE, 0.3) and 7.0% (SE, 1.1); and weight-for-length was 1.0% (SE, 0.4) and 7.7% (SE, 1.2). The only significant trend was a decrease in high length-for-age (5.5% in 1976–1980 vs 3.7% in 2011–2014; P = .04). Relative weight gain between birth and survey participation did not differ over time, although trends differed by race/Hispanic origin. Non-Hispanic black children gained more weight between birth and survey participation in 2011–2014 versus 1988–1994, versus no change among other groups.

CONCLUSIONS:

Between 1976–1980 and 2011–2014, there were no significant trends in low or high weight-for-age and weight-for-length among 6- to 23-month-old children whereas the percent with high length-for-age decreased. A significant trend in relative weight gain between birth and survey participation was observed among non-Hispanic black children.
Determinantes de las relaciones reales de intercambio de España con Alemania (1970-2010). Un análisis econométrico de la ventaja absoluta de costo intrasectorial
Authors: Boundi Chraki Fahd
Published: February 2017

El presente trabajo tiene como objeto analizar los determinantes de las relaciones reales de intercambio de España con Alemania, tomando como período 1970-2010. Para tal propósito, se lleva a cabo un análisis de series temporales aplicando pruebas de raíces unitarias y un test de cointegración, siendo el marco teórico de referencia el enfoque de Anwar Shaikh de la ventaja absoluta de costo intrasectorial. Finalmente, el análisis econométrico constata que el tipo de cambio real efectivo entre España y Alemania se encuentra sujeto en el largo plazo a los costos laborales unitarios reales relativos de la industria manufacturera de ambos países.
Descentralização e desigualdade na distribuição dos fundos constitucionais brasileiros. Uma análise de cointegração de séries entre 1997 e 2011
Authors: Mourao Paulo
Published: February 2017

O objetivo deste trabalho passa por discutir o modo como a distribuição de transferências pelos Estados brasileiros afecta a evolução do montante global transferido a título constitucional pelo Governo Federal. Após uma revisão da literatura, foi estudado um modelo baseado numa função de Bergson-Samuelson. Foram usados os dados oficiais (cuja fonte é o “Tesouro Nacional”) desde janeiro de 1997 até março de 2011 para estudar as transferências descentralizadas. Regredimos também os montantes transferidos noutras séries para controlar o efeito da série relativa ao padrão de desigualdade da distribuição. Em termos metodológicos, aplicaram-se técnicas de cointegração com teste da direcção de causalidade. Concluímos que existe uma validação estatística que mostra que quando a distribuição se torna mais desigual, o conjunto de transferências constitucionais brasileiras tende a aumentar.
Concentración Económica y Comercio Internacional. La Condición Marshall-Lerner en la Argentina (1993-2013)
Authors: Chena Pablo Ignacio , Bosnic Carolina
Published: February 2017

El presente artículo estudia los efectos de la concentración económica en la pérdida de sensibilidad de la balanza comercial a las variaciones del tipo de cambio real (TCR). Para esto se analizan los flujos comerciales de la Argentina (1993-2013), con el doble objetivo de, por un lado, identificar el cumplimiento de la condición Marshall-Lerner (CML) y, por otro, determinar la influencia de la concentración económica sobre la misma. Los resultados alcanzados muestran que los movimientos del TCR no generan cambios significativos en la balanza comercial. Sin embargo, cuando se aíslan los efectos directos e indirectos de la concentración económica, la balanza comercial aumenta su sensibilidad al TCR y se cumple la CML.
Proprioceptive assessment battery for patients with below-knee amputation (BEPAT in Spanish)
Authors: Benrey-Reyes Catalina , Eraso-Angulo Rosa , Porras-Estrada Diana , Landínez-Parra Nancy Stella
Published: February 2017

Introducción. La amputación trae diversos cambios biomecánicos y estructurales que generan deficiencias en el balance, el equilibrio y la propiocepción. Asimismo, la alteración de la propiocepción afecta el componente corpóreo–espacial, el control postural y demás cualidades físicas, lo cual requiere un manejo específico desde la Fisioterapia. Esta investigación se realizó teniendo en cuenta su función como herramienta adecuada y eficaz dentro de la Fisioterapia, debido a la poca documentación en la literatura de la evaluación propioceptiva en la población escogida. Objetivo. Proponer y validar una batería de evaluación propioceptiva para personas con amputación transtibial, ya protetizadas. Materiales y métodos. Estudio de tipo descriptivo-propositivo que requirió un proceso de recolección de información para proponer una batería de evaluación, basada en la evidencia científica disponible. Resultados. La batería de evaluación de la propiocepción para personas con amputación transtibial ya protetizada (BEPAT), cuenta con alta validez de contenido y constructo según los criterios de Palisano, considerando que los resultados para todos los ítems en la batería se encontraron por encima del 70%. Conclusiones. La creación de la BEPAT permitirá la obtención de información objetiva y cuantitativa sobre las alteraciones funcionales, lo que mejorará la prescripción de prótesis y el tratamiento rehabilitador y fortalecerá los procesos investigativos en el tema.
Eficacia de las modalidades deportivas del programa 40X40 en escolares con sobrepeso y obesidad
Authors: Preciado-Martínez Diana Carolina , Mancera-Soto Erica Mabel , Hernández-Álvarez Edgar Debray , Zapata Diana Marcela , Mena-Bejarano Beatriz
Published: February 2017

Introducción. En Bogotá, hay una prevalencia de sobrepeso y obesidad del 16% y del 6%, respectivamente, tanto en niños como adolescentes escolares (1). En 2013, se implementó el Programa 40X40 (P40X40) en instituciones educativas distritales (IED) con el objetivo de incrementar los niveles de actividad física de los escolares. Objetivo. El presente estudio busca determinar el efecto del P40x40 en la composición corporal de escolares con sobrepeso y obesidad de las IED de Bogotá. Materiales y métodos. Estudio controlado no aleatorizado en el que participaron 1003 escolares (6 a 17 años) asignados a un grupo de intervención (GI) (P40X40) (n=497) y a un grupo control (GC) (n=506). Se evaluó el efecto de dos meses de intervención del P40X40 sobre las variables porcentaje de grasa corporal (PGC), índice de masa corporal (IMC) e índice de masa corporal Zscore (IMCZscore). Resultados. Se presentaron cambios significativos en el GI para todas las variables (p=0.00), con mayor reducción en el PGC para los deportes de tiempo y marca por diferencia de medias (DaMs) (DaMs=1.36). Conclusiones. Al observarse cambios significativos en el GI para todas las variables (p=0.00) sin relevancia clínica, se determinó que el P40X40 requiere modificaciones en cuanto a intensidad, frecuencia y duración si su objetivo es disminuir los niveles de sobrepeso y obesidad en escolares.
Efectividad de un protocolo de entrenamiento nórdico sobre la fuerza explosiva en futbolistas del Club Deportivo La Equidad Seguros
Authors: Mancera-Soto Érica Mabel , Páez Ana Maryeli , Meneses Fuquene Mayra Yizet , Avellaneda Paola , Cortés Sergio Leonardo , Quiceno-Noguera Cristian , Ramos-Caballero Diana Marcela
Published: February 2017

Introducción. El entrenamiento nórdico ha sido estudiado para optimizar el gesto deportivo y prevenir lesiones en fútbol. Sin embargo, no se han reportado estudios que evidencien su efectividad sobre la fuerza explosiva del deporte. Objetivo. Determinar la efectividad de un protocolo de entrenamiento nórdico sobre la fuerza explosiva de miembros inferiores en futbolistas. Materiales y métodos. Se realizó un ensayo controlado y aleatorizado en el que 26 futbolistas masculinos fueron elegidos para hacer parte de un grupo intervención (n=12) y un grupo control (n=14). Al grupo intervención se le aplicó un protocolo de entrenamiento nórdico, mientras que el control realizó un programa de fortalecimiento convencional. Se evaluaron la fuerza explosiva de miembros inferiores, a través del Test de Bosco y Abalakov en una plataforma de salto, y el ángulo de mayor reclutamiento muscular del bíceps femoral durante la ejecución del ejercicio nórdico mediante de electromiografía de superficie. Resultados. Los dos grupos fueron homogéneos. Se evidenció una mejora en los componentes de la fuerza explosiva (p<0.05) para las variables de velocidad de despegue, de reclutamiento motor y de ángulo de registro del pico de reclutamiento motor en el grupo de intervención. Conclusión. La aplicación de un programa de entrenamiento en futbolistas demostró ser efectiva al influir de manera positiva en las variables involucradas en la fuerza explosiva.
Intervención fisioterapéutica en el niño quemado: construcción desde la práctica basada en la experiencia
Authors: Robayo-Torres Aydeé Luisa , Chacón-Acevedo Kelly Rocio , Pinillos-Malagón Vanesa Stefany , Rico-Barrera Angélica Viviana
Published: February 2017

Introducción. La quemadura pediátrica es una problemática de salud pública en Latinoamérica, no ajena al quehacer del fisioterapeuta. Sin embargo, la revisión del estado del arte de la intervención fisioterapéutica en niños quemados evidencia escasa producción investigativa. Por eso, existe la necesidad de plantear lineamientos que orienten la intervención en el niño quemado y que rescaten la experiencia de fisioterapeutas dedicados a la atención de estos pacientes. Objetivo. Formular una propuesta de intervención fisioterapéutica en niños quemados a partir de la práctica basada en la experiencia. Materiales y métodos. Investigación de tipo cualitativo, fenomenológico y exploratorio, realizada en tres momentos: primero, identificación del estado del arte; segundo, sistematización de la experiencia de un colectivo profesional, y tercero, trabajo observacional de campo en la unidad de quemados de una institución de salud de tercer nivel de atención del país. Además, se emplearon entrevistas semi-estructuradas, etnografías y el software SPSS para la recolección y análisis de resultados. Resultados. Se presenta el estado del arte, las entrevistas realizadas a un colectivo experto y las etnografías, producto de la observación participativa. A partir de ellos, se realiza una propuesta de lineamientos de intervención fisioterapéutica para el niño quemado. Conclusión. Los lineamientos de intervención fisioterapéutica para el niño quemado, desde la memoria viva de los profesionales, aportan al fisioterapeuta herramientas para cuestionar los criterios sobre los cuales se soporta la atención. Así mismo, estimulan a la comunidad científica y académica a producir nuevas investigaciones.
Análisis cualitativo del concepto y praxis de rehabilitación integral percibido por distintos actores involucrados
Authors: Moreno-Angarita Marisol , Balanta-Cobo Paola , Mogollón-Pérez Amparo Susana , Molina-Achury Nancy Jeanet , Hernández-Jaramillo Janeth , Rojas-Castillo Claudia
Published: February 2017

Introducción. La rehabilitación integral es un concepto de difícil consenso, dado que es resultado de una evolución histórica. Objetivo. Presentar los hallazgos del estudio “Acceso a los servicios de rehabilitación integral en Colombia: una aproximación desde los conceptos y las prácticas de distintos actores sociales” y describir las comprensiones de la rehabilitación integral de parte de diversos actores desde una perspectiva comprensiva de la discapacidad. Materiales y métodos. Se realizó un estudio descriptivo-exploratorio, cualitativo y de múltiples fuentes de evidencia para identificar las percepciones de actores responsables de formular e implementar políticas públicas (FP), académicos (A), profesionales (P), representantes de organizaciones sociales (OS), gestores de servicios (GS), gestores y profesionales de servicios de educación inclusiva (EI), personas con discapacidad (PCD) y cuidadores (C), involucrados en la rehabilitación integral en una ciudad colombiana. Se realizaron entrevistas a 18 actores y se desarrollaron seis grupos focales. Para el análisis de datos, se usó el Atlas ti®, el acuerdo entre jueces y el análisis de las narrativas. Resultados. La rehabilitación integral es percibida de distintas maneras por los actores, entre las que priman tres concepciones de ella: como resultado de un proceso de rehabilitación funcional, como derecho y como garante de inclusión social. Conclusiones. Mientras exista diversidad y dispersión acerca de la rehabilitación integral, será difícil concebir, implementar, evaluar y participar activamente en dicho proceso. En consecuencia, las barreras de acceso a ella se incrementarán y estará lejos de entenderse como un derecho que se ejerce desde una visión integral de ser humano. Dicho esto, se enuncian implicaciones para la academia, los prestadores de servicios y las políticas públicas.
Fisioterapia en la Universidad Nacional de Colombia: medio siglo liderando la formación de profesionales y el crecimiento profesional en torno al movimiento corporal humano
Authors: Landínez-Parra Nancy Stella
Published: February 2017

Cumplir 50 años representa, en cualquier contexto, una ocasión muy especial en la que se combina el reconocimiento a logros alcanzados y metas cumplidas, pero también el inicio de nuevos caminos por recorrer; de este modo, conmemorar medio siglo del programa de Fisioterapia en la Universidad Nacional de Colombia se convierte en la oportunidad de reconocer con satisfacción el camino recorrido asumiendo nuevos retos y responsabilidades.Son muchos los acumulados registrados en 50 años de historia y diversos los aportes al crecimiento de la fisioterapia a nivel nacional. El liderazgo constante en procesos investigativos en relación al objeto de estudio ha permitido avances y proyecciones en aspectos disciplinares y formativos que caracterizan al fisioterapeuta egresado de la Universidad Nacional de Colombia y responden a las problemáticas de la sociedad colombiana.
Surface Engineering of Polycrystalline Silicon Microelectromechanical Systems for Fatigue Resistance
Authors: Muhlstein C.L. , Ashurst W.R. , Stach E.A. , aboudian R. , Ritchie R.O.
Published: February 2017

Recent research has established that for silicon structural films used in microelectromechanical systems (MEMS), the susceptibility to premature failure under cyclic fatigue loading originates from a degradation process that is confined to the surface oxide. In ambient air environments, a sequential, stress-assisted oxidation and stress-corrosion cracking process can occur within the native oxide on polycrystalline silicon (referred to as reaction-layer fatigue); for the structural films of micron-scale dimensions, such incipient cracking in the oxide can lead to catastrophic failure of the entire silicon component. Since the degradation process is intimately linked to the thin reaction layer on the silicon, modification of this surface and the access of the environment to it can dramatically alter the fatigue resistance of the material. The purpose of this paper is to evaluate the efficacy of modifying the fatigue behavior of polycrystalline silicon with alkene-based monolayers. Specifically, 2-μm thick polysilicon fatigue structures were coated with a monolayer film based on 1-octadecene and cyclically tested to failure in laboratory air. By applying the coating, the formation of the native oxide was prevented. Compared to the fatigue behavior of untreated polysilicon, the lives of the coated samples ranged from 105 to >1010 cycles at stress amplitudes greater than ∼90% of the ultimate strength of the film. The dramatic improvement in fatigue resistance was attributed to the monolayer inhibiting the formation of the native oxide and stress corrosion of the surface. It is concluded that the surprising susceptibility of thin structural silicon films to premature fatigue failure can be inhibited by such monolayer coatings.
Optimization of PZT-based MEMS
Authors: Akasheh Firas , Myers Todd , Bose Susmita , Bandyopadhyay Amit
Published: February 2017

Due to their excellent piezoelectric properties, PZT ceramics are attractive materials for many MEMS applications. By depositing a PZT film on a micro-machined platinized silicon substrate, membranes can be actuated in the flexural mode. In this work, 2D arrays of PZT actuated membranes, which can be used as ultrasonic transducers, have been designed, fabricated, and tested for their ferroelectric response. The device behavior was also modeled using FEA. Data from FEA runs were used to evaluate the device performance based on its effective coupling coefficient (efficiency), acoustic impedance, and resonance frequency. Results show that the device-coupling factor is significantly affected by the PZT and silicon layers' thickness and the top electrode configuration. Results also indicate a considerable flexibility in optimizing the device performance under a wide range of operational requirements, which makes such devices attractive for different applications.
Dry Etching Techniques of Amorphous Silicon for Suspended Metal Membrane RF MEMS Capacitors
Authors: Fritschi Raphaël , Hibert Cyrille , Flückiger Philippe , Ionescu Adrian M.
Published: February 2017

A novel dry etching technique of amorphous silicon is proposed to suspend the metal membrane of RF MEMS tunable capacitors. The proposed fabrication process is simple and excludes all the drawbacks related to a wet process. Moreover, it has the advantage of being fully compatible with CMOS post-processing. Experimental results demonstrate that the capacitor suspension beams design with meanders can reduce the tuning voltage to less than 5 to 10 V.
Deep Anisotropic Etching of Gaas with Chlorine-Based Chemistries and SU-8 Mask Using Rie and High Density ICP Etching Methods
Authors: Chiang Yuh-Min (Johnson) , Lau Joy , Bachman Mark , Li G.P. , Kim H.K. , Ra Yunju , Ketola Kurt
Published: February 2017

GaAs-based micro-electro-mechanical systems (MEMS) are emerging technologies, which will lead to integration of new sensing and actuating devices with microwave and millimeter-wave electronics. However, developing the capability of selective deep etching of GaAs is a critical issue to be solved. This paper presents a study of a highly anisotropic deep GaAs etching. Two different plasma etching methods were studied for GaAs etching with chlorine-based chemistries: reactive ion etching (RIE) with Cl2/BCl3/SiCl4mixtures and high-density inductive coupled plasma (HDICP) etching with Cl2/BCl3 mixtures. A negative acting photoresist, SU-8, which allows high resolution, high aspect ratio patterning with strong resistance to etchants, was selected as the etching mask for this work. Process parameters were varied for best results, and the effects of the process parameters are presented. Issues such as etch selectivity of SU-8 and GaAs, reflow of SU-8, and loading effects were also investigated. An optimized etching process was developed to achieve a deep etch in excess of 300μm of GaAs with a single layer of SU-8 photoresist.
A Microsensor Based on a Microcantilever Patterned with an Environmentally Sensitive Hydrogel
Authors: Hilt J. Zachary , Gupta Amit K. , Bashir Rashid , Peppas Nicholas A.
Published: February 2017

A process was developed for patterning thin films of environmentally sensitive hydrogels onto silicon microcantilevers. Microcantilevers have been shown to be ultra-sensitive transducers for chemical, physical, and biological microsensors. By patterning environmentally sensitive hydrogels onto silicon microcantilevers, novel microsensors were prepared for MEMS and BioMEMS applications. Specifically, a cross-linked poly(methacrylic acid) (PMAA) network containing significant amounts of poly(ethylene glycol) dimethacrylate (PEGDMA) was studied. This hydrogel exhibits a swelling dependence on pH. By increasing the environmental pH above the pKa of PMAA to cause ionization of the carboxylic acid groups, electrostatic repulsion is produced along the main polymer chain causing the polymer network to expand and swell. Therefore, a pH change induces swelling or shrinking of the polymer network and creates stress on the microcantilever surface causing it to bend. In this study, silicon microcantilevers were fabricated on p-type (100) SOI wafers. Covalent adhesion was gained between the polymer and the silicon surface through the modification of the silicon surface with γ-methacryloxypropyl trimethoxysilane. Hydrogels were patterned onto the silicon microcantilevers utilizing a mask aligner to allow for precise positioning. The micropatterned hydrogels were analyzed using optical microscopy and profilometry. The bending response of patterned cantilevers with a change in environmental pH was observed, providing proof-of-concept for a MEMS/BioMEMS sensor based on microcantilevers patterned with environmentally sensitive hydrogels.