Universidad de Magallanes
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How Are Synapses Born? A Functional and Molecular View of the Role of the Wnt Signaling Pathway
No full textSynaptic transmission is a dynamic process that requires precise regulation. Early in life, we must be able to forge appropriate connections (add and remove) to control our behavior. Neurons must recognize appropriate targets, and external soluble factors that activate specific signaling cascades provide the regulation needed to achieve this goal. Wnt signaling has been implicated in several forms of synaptic plasticity, including functional and structural changes associated with brain development. The analysis of synapses from an electrophysiological perspective allows us to characterize the functional role of cellular signaling pathways involved in brain development. The application of quantal theory to principles of developmental plasticity offers the possibility of dissecting the function of structural changes associated with the birth of new synapses as well as the maturation of immature silent synapses. Here, we focus on electrophysiological and molecular evidence that the Wnt signaling pathway regulates glutamatergic synaptic transmission, specifically N-methyl-d-aspartate receptors (NMDARs), to control the birth of new synapses. We also focus on the role of Wnts in the conversion of silent synapses into functional synapses
Funcionalidad en personas mayores con EPOC, rehabilitación presencial y telerrehabilitación: una revisión sistemática
No full textResumen Objetivo: Sintetizar la evidencia existente sobre los principales resultados de programas de rehabilitación presenciales y/o mediante telerrehabilitación, sobre la funcionalidad en personas mayores con Enfermedad Pulmonar Obstructiva Crónica (EPOC). Materiales y método: Se realizó la búsqueda de artículos científicos en las bases de datos: Medline vía PubMed y BVS Lilacs que cumplan con los criterios de elegibilidad, entre la fecha del 1 de enero del 2019 hasta el 1 de enero de 2021, seleccionando 4 documentos. Para la identificaciónde artículos se utilizó las palabras clave "Aged", "Pulmonary Disease, Chronic Obstructive", "Rehabilitation - Telerehabilitation". Resultados: La edad promedio de las personas participantes, fue de 65.4, predominaron los estudios en género masculino y de las personas mayores incluidas con EPOC, el 50% lo padecía de forma severa. Sobre la descripción de los programas de rehabilitación, el 75% tuvo seguimiento de los resultados, desde los 3 a los 12 meses, el 50% de los programas tuvo una duración de 10 semanas, en el 50% de los casos se les proporcionó a los pacientes tecnología para el uso en domicilio y solo un 15% utilizó una aplicación móvil. Conclusión: Los resultados respaldan la opinión de que los proveedores de atención médica pueden usar la telerrehabilitación, para el tratamiento de las personas mayores con EPOC junto con la rehabilitación habitual
Late Quaternary climatic inferences from southern Patagonia (-53°S): A holistic palaeoecological approach to tracking the behaviour of the southern westerly winds
No full textThe glacial and vegetation patterns of Patagonia are strongly correlated to the behaviour of the Southern westerly winds (SWWs) with palaeoenvironmental evidence for the behaviour of the SWWs interpreted as past changes in southern hemisphere climate and ocean currents. To fully define shifts in the position and intensity of the SWWs palaeoenvironmental data sets must be generated from climate sensitive proxies with sites located in regions that are responsive to changes in effective moisture. Here we present a c. 15,700 yr-old record from a peat bog at Punta Arenas (53 degrees 09 ' S) which was analysed for pollen, pollen preservation, charcoal and organic content to reconstruct changes in the surrounding vegetation, fire history and mire surface wetness. The peat bog lies in a closed basin and so environmental changes likely reflect changes in effective moisture primarily driven by fluctuations in precipitation. During the Late glacial the landscape was virtually treeless and dominated by cold-tolerant steppe/tundra vegetation. This was followed by substantial vegetation changes as Nothofagus woodland expanded and the local site transitioned from a small lake to a fen and later a raised mire. The Early and Mid-Holocene (11,600-6000 cal a BP) was marked by a period of sustained drier conditions evidenced by reduced pollen preservation and increased fire activity. After c. 4600 cal a BP there was a shift to increased effective moisture superimposed with higher magnitude and higher frequency changes in precipitation. The palaeoenvironmental record presented here is used to better define the nature and timing of latitudinal shifts in the position of the SWWs. Careful interpretation of the Nothofagus pollen signal is required as during drier periods small increases in humidity can drive large woodland responses in the pollen record while during periods of higher humidity the woodland may appear to be unresponsive to climatic changes
Under the floor of the Church. An archaeological study in a context of heritage restoration in San Juan, Chiloé (Chile) Bajo el piso de la Iglesia. Estudio arqueológico en un contexto de restauración patrimonial en San Juan, Chiloé (Chile)
No full textHeritage restoration of historic monuments involves specific challenges for its implementation. In this scenario, archaeological work is a fundamental part of that legal, conservation, and community process. We present the results of the documentation and archaeological excavations carried out beneath the floor of the centenarian Church of San Juan (Dalcahue, Chiloé) and the San Juan 1 archaeological site in the western Patagonian archipelago. Historical burials (ca. 280 to 140 cal years BP) and diverse archaeological materials recovered from sedimentary matrices that resulted from a succession of occupations by marine hunter-gatherers (from ca. 6.000 BP) constitute a set of information that supports the cultural sequence of the area. Thus, the bioanthropological, ceramic, lithic, archaeofaunistic, and historical analyses inform us about the subsistence of human groups and part of the technological assemblages used and discarded both in pre-Hispanic and historical times at Chiloé island. We expect that the example set in this work contributes to future restoration and enhancement strategies that respect historical and contemporary uses of various heritage sites
Actual and perceived motor competence in children from Chilean Patagonia: perception of the students and their physical education teachers Competencia motriz real y percibida en niños y niñas de la Patagonia Chilena: La percepción del estudiantado y del profesorado de Educación Física
No full textThe promotion of motor competence during childhood is one of the main objectives of physical education (PE) class according to UNESCO. For its development, it is important for students to perceive themselves as competent, and for teachers to perceive how competent their students are in the motor tasks they offer in their classes. This study aims at analyzing the relationship between students' and PE teachers' perception of actual motor competence. A total of 248 students (46% girls; age M=11.2; SD=0.94) of 5th and 6th year of primary school from schools in Chilean Patagonia participated in the study. We assessed actual and perceived motor competence with the MOBAK 5-6 test and the SEMOK questionnaire, respectively. We used Pearson's coefficient to determine the relationships; Student's t-test to determine differences according to sex; and calculated a difference component (delta) to determine the difference between actual and perceived motor competence of both students and teachers. We found moderate and weak-moderate relationships between the actual motor competence and the students' perception (Object Control r=0.401; Self-movement r=0.402), and their physical education teachers' perception (Object Control r=0.352; Self-movement r=0.264). The teachers (Δ=1.94) present a more accurate perception than the students (Δ=2.46) only in motor competence related to object control. The perception of competence allows a closer look at the actual motor competence. Physical education teachers can predict the motor performance of their students and could use this information as a resource for the preparation of activities that aim at the development of the students' motor competence
ARQUEOLOGÍA HISTÓRICA EN REY DON FELIPE (PUERTO DEL HAMBRE): 50 AÑOS DESPUÉS DE ORTIZ-TRONCOSO
No full textRESUMEN: Este artículo retoma el trabajo en Rey Don Felipe (Puerto del Hambre), dando continuidad a las investigaciones iniciadas hace medio siglo por el arqueólogo Omar Ortiz-Troncoso. Se resume el conocimiento histórico-arqueológico previo y se dan a conocer nuevos análisis estratigráficos, artefactuales y ecofactuales obtenidos a partir de prospecciones y excavaciones en el sitio entre los años 2019 y 2022. De este modo, se evalúan las conclusiones planteadas por distintos investigadores en torno a la relevancia del asentamiento, materialidades y ocupaciones identificadas. Se proponen cuatro ocupaciones principales en el asentamiento y se releva el potencial interpretativo de nuevas líneas de evidencia respecto de los procesos coloniales estudiados por la arqueología
Relationship between body composition and somatotype with dynamic postural balance in young basketball players Relación entre composición corporal y somatotipo con equilibrio postural dinámico en jóvenes basquetbolistas Relación entre composición corporal y somatotipo con equilibrio postural dinámico en jóvenes basquetbolistas
No full textObjective: The aim of this study was to determine the relationship between body composition and somatotype with dynamic postural balance in young basketball players. Methods: The sample included 33 young male athletes aged (17.03 ± 0.94 years old). Body composition and somatotype were obtained from anthropometric measurements of diameters, perimeters, and skinfolds. Dynamic postural balance was measured with the modified star excursion balance test (mSEBT) in anterior, posteromedial, and posterolateral directions. The Pearson correlation test was used to identify the relationship between body composition and somatotype variables with the dynamic postural balance of the athletes. Results: In the dominant lower limb, body composition showed significant correlations for the anterior direction of the mSEBT with adipose mass (r=-0.741; p=0.001), muscle mass (r=0.662; p=0.009), endomorph (r=-0.822; p=0.009) and ectomorph (r=0.790; p=0.002). Adipose mass also showed significant relationships with the posteromedial (r=-0.413; p=0.037) and posterolateral direction of mSEBT (r=-0.291; p=0.041). In the non-dominant lower limb, in the anterior direction of the mSEBT, there was a significant correlation with the adipose mass (r=-0.691; p=0.009), muscle mass (r=0.472; p=0.025), endomorph (r=-0.778; p=0.001) and ectomorph (r=0.843; p=0.001) somatotypes. Adipose mass was also correlated with the posteromedial (r=-0.451; p=0.012) and posterolateral (r=-0.390; p=0.022) directions of the mSEBT. Conclusions: In the present study, it was possible to find a relationship between the percentage of fat mass, muscle mass, endomorph, and ectomorph somatotypes with the performance of dynamic postural balance in young basketball players
The extreme southern origins of globality: Circumnavigation, habitability, and geopolitics
No full textThis article analyses how the first circumnavigation of the world, from 1519 to 1522, introduced South America as a key space in the formation of the 'global', thus producing a historical point of inflection. We examine the commercial and political plans and networks that began to function as a result of this new connectivity, which turned the American continent into a major global axis. The analysis focuses on the way in which this voyage gave new prominence to an unexplored region of the world, namely the southernmost tip of America, thus changing the notion of habitability that had prevailed for centuries in Europe. These changes questioned the authority of 'ancient' Greek thinkers and strengthened a European historical narrative that appropriated the discovered territories and distinguished the extreme southern part of America from other southern regions, as symbolized through figures such as the Patagonian giants. I consider these changes based on evidence from Spanish sources
Sleep impairment and altered pattern of circadian biomarkers during a long-term Antarctic summer camp
No full textAntarctic expeditions include isolation and exposure to cold and extreme photoperiods (with continuous natural light during summer) that may influence psychophysiological responses modulated by luminosity and sleep. We assessed changes in night sleep patterns by actigraphy, salivary biomarkers, and perceptual variables in seven participants in the following time points along a 50-day camping expedition in Antarctica (Nelson Island): Pre-Field (i.e., on the ship before camp), Field-1, Field-2, Field-3, Field-4 (from 1st to 10th, 11th to 20th, 21st to 35th and 36th to 50th days in camp, respectively), and Post-Field (on the ship after camp). We also characterized mood states, daytime sleepiness, and sleep quality by questionnaires. Staying in an Antarctic camp reduced sleep efficiency (5.2%) and increased the number of awakenings and wakefulness after sleep onset (51.8% and 67.1%, respectively). Furthermore, transient increases in time in bed (16.5%) and sleep onset latency (4.8 +/- 4.0 min, from Pre- to Field-3) was observed. These changes were accompanied by an altered pattern of the emerging circadian marker beta-Arrestin-1 and a trend to reduce nocturnal melatonin [57.1%; P=0.066, with large effect size (ES) from Pre-Field to Field-2 (ES=1.2) and Field-3 (ES=1.2)]. All changes returned to Pre-Field values during the Post-Field. The volunteers reported sleep-related physical complaints (feeling of cold and pain, discomfort to breathe, and cough or loud snoring), excessive daytime sleepiness, and reduced vigor during the camp. Thus, a 50-day camp alters neuroendocrine regulation and induces physical discomfort, which may explain the impaired sleep pattern and the consequent daytime sleepiness and mood changes
Extraction of fatty acids and cellulose from the biomass of algae Durvillaea antarctica and Ulva lactuca: An alternative for biorefineries
No full textAlgae have cellular structures, rich in polysaccharides, proteins, lipids, vitamins and minerals. In addition, fatty acids are known for their benefits to human health, such as in treating blood pressure, diabetes, and obesity. These properties determine the algal biomass value as a raw material for different applications. One of the polysaccharides present in algae and is still little explored is cellulose, an important material for numerous technological applications. In this study, Durvillaea antarctica and Ulva lactuca algae were used as raw materials for the production of a cellulosic-based materials combining alkaline treatment, bleaching and freeze-drying. The samples were analyzed by XRD,13C-CP-MAS-NMR, FT-IR, SEM, TEM and TGA techniques. XRD analysis showed that the material obtained presented crystallinity of above 60 %. FT-IR revealed that the methodology was effective in obtaining cellulose. SEM and TEM images exhibited a morphology consisted of cellulose fibers