KINEMATIC ANALYSIS OF THE TRADITIONAL BACK SQUAT AND SMITH MACHINE SQUAT EXERCISES

The purpose of this study was to compare the kinematics of the traditional back squat (TBS) and the Smith Machine Squat (SMS). The squat exercise is a common exercise in strength and conditioning programs as well as in rehabilitation settings. Eight experienced college age weight lifters performed both TBS and SMS. Three dimensional video analyses were used to analyze the motions. Lower extremity joints and trunk angular motions were computed and compared using Paired T-test. The TBS generated larger ROM than the SMS in all the joints measured. Due to the linear restriction of the bar motion along the vertical axis in the SMS the subjects positioned their feet forward to enable bar lowering. This feet placement positioned the bar farther away from the knee at the instance of maximal knee flexion

The Best Nondeterministic Representations of Finite Orderings

AbstractThis paper formally presents an algorithm to compute the nondeterministic realization with the least number of states that represents an order relation. For this purpose, each input order relation is considered as a finite automaton in a straightforward way. Then the automaton is subject to an iterative reduction process where the main tool for removing states is scoop minimization. So states whose role can be accomplished by a set of other states can be skipped. Moreover, we can create new states to allow further scoop reductions. The algorithm can be configured by the user to bound its performance to polynomial time

Nanopartículas Poliméricas en Dermocosmética

Indexación: Web of Science; Scielo.Recent advances in the fields of biomaterials and nanotechnology have allowed the development of advanced nanoparticles for biomedical applications. Despite a vast number of nanostructures such as liposomes, solid­lipid nanocapsules, polymeric and hybrid lipid­polymer nanoparticles have been studied as carriers for drug delivery for different pathologies with remarkable promising results; the use of polymeric nanoparticles in dermocosmetic still has not been widely explored. The evolution of cosmetic into the care skin and dermatology represents novel technological challenges. Also, the increasing knowledge about normal skin physiology and advances in nanotechnology provide an attractive environment for the creation of innovative dermocosmetic formulations. In this work, we discuss the state of the art of polymeric nanoparticles formulated for dermocosmetics, its mechanisms of action, and diffusion into the skin.Los recientes avances en el campo de los biomateriales y la nanotecnología han permitido el desarrollo de nanopartículas avanzadas para aplicaciones biomédicas. A pesar de que un gran número de nanoestructuras tales como liposomas, nanocápsulas lípido-sólidas, nanopartículas poliméricas y lípido-polímero híbridas han sido estudiadas como vehículos para la administración de fármacos en diferentes patologías con notables resultados prometedores, el uso de nanopartículas poliméricas en dermocosmética todavía no ha sido ampliamente explorado. La evolución de la cosmética en el cuidado de la piel y la dermatología nos enfrentan a nuevos retos tecnológicos. Además, el aumento de los conocimientos sobre la fisiología de la piel normal y los avances en la nanotecnología proporcionan un entorno atractivo para la creación de formulaciones dermocosméticas innovadoras. En este trabajo se discute el estado del arte de las nanopartículas poliméricas desarrolladas para dermocosmética, sus mecanismos de acción y la difusión en la piel.http://ref.scielo.org/b68hz

Pequeñas historias de humor y de horror : usando narrativas y casos en la formación del profesorado de ciencias

En este trabajo se discute el uso de “pequeñas historias” en la formación inicial y continuada del profesorado de ciencias para todos los niveles educativos. Se presenta un proyecto de investigación e innovación didácticas dirigido a fomentar, en profesores y profesoras de ciencias, algunos procesos cognitivolingüísticos epitómicos (paradigmáticos) de las ciencias. Para tal proyecto se diseñaron dos relatos cortos basados en materiales de historia de la ciencia. Los relatos asumen un formato narrativo y se utilizan como casos de estudio; en ellos se recurre al humor y al horror como herramientas de estructuración del hilo argumental. El contenido y el formato de los relatos tiene su base en investigaciones previas acerca de la naturaleza de la ciencia; estas “pequeñas historias” pretendían construir una imagen más robusta de la ciencia como actividad profundamente humana

Learning data structure from classes: A case study applied to population genetics

In most cases, the main goal of machine learning and data mining applications is to obtain good classifiers. However, final users, for instance researchers in other fields, sometimes prefer to infer new knowledge about their domain that may be useful to confirm or reject their hypotheses. This paper presents a learning method that works along these lines, in addition to reporting three interesting applications in the field of population genetics in which the aim is to discover relationships between species or breeds according to their genotypes. The proposed method has two steps: first it builds a hierarchical clustering of the set of classes and then a hierarchical classifier is learned. Both models can be analyzed by experts to extract useful information about their domain. In addition, we propose a new method for learning the hierarchical classifier. By means of a voting scheme employing pairwise binary models constrained by the hierarchical structure, the proposed classifier is computationally more efficient than previous approaches while improving on their performance

Seed regeneration in native forests of Nothofagus antarctica under silvopastoral use in Southern Patagonia, Argentina

The aim of the present study was to evaluate the effect of silvopastoral use in two pure stands of Nothofagus antarctica (ñire, ñirre) growing at two site qualities on the regeneration cycle from production and quality of seeds, and the establishment and mortality of seedling in Southern Patagonia (Argentina). To evaluate seed production four traps were distributed to capture the spatial variation of each stand during seven years (2004-2010). Also, seed viability and germination were evaluated. In each site, permanent sampling plots were used to measure seedling establishment and mortality. Seed production in stands under silvopastoral use varied from 1 to 40 million seeds ha-1, with no differences compared to seed production in surrounding primary forests of the same site quality. Stands under silvopastoral use showed that seed quality varied among sites being higher in the lower site quality. However, there was no difference in seed quality between silvopastoral use and primary forests stands. Seedling establishment was improved in the stands under silvopastoral use compared to primary forests, but mortality rate was high (or total) in all situations. We concluded that silvopastoral use of the studied stands did not modify substantially seed regeneration compared to primary forests.Los objetivos de este estudio fueron: i) evaluar la regeneración, desde el punto de vista de su producción y calidad de semillas, así como también de la instalación y supervivencia de plántulas, de dos rodales puros de Nothofagus antarctica (ñire, ñirre) bajo uso silvopastoril en distintas calidades de sitio en Patagonia Sur (51º S, Argentina); ii) comparar estos aspectos de la regeneración de ñire entre rodales bajo uso silvopastoril y bosque primario en similares condiciones geográficas y temporales. Para evaluar la producción de semillas, se usaron cuatro trampas de captura distribuidas espacialmente en cada sitio durante siete años (2004- 2010), determinándose además tamaño, viabilidad y germinación. En cada sitio, se instalaron parcelas permanentes de muestreo para cuantificar la incorporación y supervivencia de plántulas. La producción de semillas en los rodales bajo uso silvopastoril varió desde 1 a 40 millones por hectárea, sin diferenciarse de la producción en bosques primarios aledaños de igual calidad de sitio. En los rodales bajo uso silvopastoril la calidad de las semillas varió entre clases de sitio algunos años, siendo mayor en el sitio de calidad inferior. Sin embargo, en general, no se encontraron diferencias entre bosques primarios y con uso silvopastoril. La instalación de plántulas se vio favorecida en los rodales con uso silvopastoril respecto a bosques primarios, no obstante, la supervivencia fue muy baja o nula en todas las situaciones. Se concluyó que en las situaciones estudiadas el uso silvopastoril de los bosques de ñire no modificó sustancialmente su regeneración por semillas respecto a bosques primarios.Fil: Bahamonde, Héctor A.. Instituto Nacional de Tecnologia Agropecuaria; Argentina; Universidad Nacional de la Patagonia Austral; Argentina;Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina; Instituto Nacional de Tecnologia Agropecuaria; Argentina; Universidad Nacional de la Patagonia Austral; Argentina;Fil: Monelos, Lucas H.. Universidad Nacional de la Patagonia Austral; Argentina;Fil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Associative nitrogen fixation in nodules of the conifer Lepidothamnus fonkii (Podocarpaceae) inhabiting ombrotrophic bogs in southern Patagonia

Biological N2 fixation (BNF) in the rhizosphere of Podocarpaceae is currently attributed to unspecific diazotrophs with negligible impact on N acquisition. Here, we report specific and high associative BNF in dead cells of root nodules of Lepidothamnus fonkii distributed in ombrotrophic peatlands of Patagonia. BNF of nodulated roots, intact plants of L. fonkii and rhizospheric peat was assessed by 15N2 and acetylene reduction. Diazotrophs were identified by electron microscopy, analysis of nitrogenase encoding genes (nifH) and transcripts, and 16S rRNA. Nitrogenase encoding nifH transcripts from root nodules point to Beijerinckiaceae (Rhizobiales), known as free-living diazotrophs. Electron microscopy and 16S rRNA analysis likewise identified active Beijerinckiaceae in outer dead cells of root nodules. NifH transcripts from the rhizopshere peat revealed diverse active diazotrophs including Beijerinckiaceae. Both methods revealed high activity of nitrogenase rates in cut roots of L. fonkii (2.5 μmol N g−1 d.w. d−1 based on 15N2 assay; 2.4 μmol C2H4 g−1 d.w. d−1 based on acetylene reduction assay). The data suggest that (i) nodules recruit diazotrophic Beijerinckiaceae from peat, (ii) dead nodule cells provide an exclusive habitat for Beijerinckiaceae, and (iii) BNF in L. fonkii is one potent pathway to overcome N deficiency in ombrotrophic peatlands of Patagonia.Bavarian Research Alliance (BayFOR

Discovering sounds in Patagonia: characterizing sei whale (<i>Balaenoptera borealis</i>) downsweeps in the south-eastern Pacific Ocean

The sei whale (Balaenoptera borealis) is one of the least known whale species. Information on sei whale distributions and its regional variability in the south-eastern Pacific Ocean are even more scarce than that from other areas. Vocalizations of sei whales from this region are not described yet. This research presents the first characterization of sei whale sounds recorded in Chile during the austral autumn of 2016 and 2017. Recordings were done opportunistically. A total of 41 calls were identified to be sei whale downsweeps. In 2016, calls ranged from an average maximum frequency of 105.3&thinsp;Hz down to an average minimum of 35.6&thinsp;Hz over 1.6&thinsp;s with a peak frequency of 65.4&thinsp;Hz. During 2017, calls ranged from an average maximum frequency of 93.3 down to 42.2&thinsp;Hz (over 1.6&thinsp;s) with a peak frequency of 68.3&thinsp;Hz. The absolute minimum frequency recorded was 30&thinsp;Hz and the absolute maximum frequency was 129.4&thinsp;Hz. Calls generally occurred in pairs, but triplets or singles were also registered. These low-frequency sounds share characteristics with recordings of sei whales near the Hawai'ian Islands but with differences in the maximum frequencies and duration. These calls distinctly differ from sounds previously described for sei whales in the Southern Ocean and are the first documented sei whale calls in the south-eastern Pacific.</p