Universidad de Magallanes
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Relación entre los niveles de estrés, la calidad del sueño y la actividad física en estudiantes universitarios de medicina
No full textAbstract Introduction: Stress is a contemporary phenomenon that affects the world population and university students, this factor could be one of those involved in the quality of sleep, which is important to take care of, especially in students because of its relevance in the learning process, and on the other hand physical activity can affect both how to manage stress levels or prevent sleep disorders, which is why this study aims to relate stress levels with sleep quality and physical activity in medical students. Methods: A descriptive, correlational, and cross-sectional study was developed based on different studies. the responses of 116 Medicine students from the University of Magallanes were analyzed using three evaluations: The perceived Stress Scale, the International Physical Activity Questionnaire (IPAQ), and the Pittsburgh Test). Results: Medicine students presented a positive correlation (p=0.64, p<0.001) between the Perceived Stress Scale (PSS) and Pittsburgh (Pitts). One of the PSS variables (unable to control things) and the student's dysfunction in performing their essential daily tasks (dysfunction during the day) have a positive correlation (p=0.54, p<0.001). Physical activity averaged 930 METs, and no significant correlation was found with the PSS and Pitts variables. Conclusion: The relationship between stress and sleep quality is inversely proportional; therefore, the higher the level of stress perceived, the lower the student's sleep quality, which is not related
Frailty, Seasonal Sensitivity and Health-related Quality of Life in Older People Living in High Southern Latitudes: a Bayesian Analysis
No full textBackground In older people, a notable research gap exists regarding the intricate dynamics between frailty, seasonal sensitivity, and health-related quality of life (HRQoL). This study aimed to determine the association between frailty, seasonal sensitivity, and HRQoL in older people from high southern latitudes. Methods A cross-sectional observational study was conducted. Frailty, seasonal sensitivity, and HRQoL measurements were selfreported by participants through questionnaires. A total of 118 older people were recruited from a local community. The participants were selected through intentional nonprobabilistic sampling. Results The adjusted models showed a trend where lower education was associated with a higher risk of frailty (BF = 0.218). For frailty and HRQoL, we observed a trend suggesting that HRQoL decreases with increasing severity of frailty (BF = 1.76). In addition, we observed a linear effect based on the severity of seasonal sensitivity, meaning that older people with higher perceived severity report a proportional decrease in HRQoL (BF = 6.66). Conclusion Sociodemographic factors, such as lower education levels, have increased the risk of frailty. At the same time, frailty and seasonal sensitivity perceived severity were associated with a lower HRQoL in older people
Ancient diversification in extreme environments: exploring the historical biogeography of the Antarctic winged midge Parochlus steinenii (Diptera: Chironomidae)
No full textThe terrestrial fauna of Antarctica consists of a limited number of species, notably insects, small crustaceans and other micro-invertebrates. Over long periods of evolutionary isolation, these organisms have developed varying degrees of tolerance to multifaceted environmental stresses. Recent molecular biogeographical research highlights the enduring persistence of much of Antarctica's current terrestrial fauna, with estimates spanning from hundreds of thousands to millions of years. Parochlus steinenii, commonly known as the Antarctic winged midge, stands out as one of the only two insect species native to Antarctica. Distributed across three biogeographic regions, southern South America and the Falkland/Malvinas Islands, sub-Antarctic South Georgia and the Maritime Antarctic South Shetland Islands, this midge raises questions about the temporal isolation of its populations and their divergence. Employing mitochondrial and nuclear genetic markers, we conducted phylogeographic and demographic analyses on 151 individuals of P. steinenii obtained across the three main biogeographic regions including the Magellanic sub-Antarctic Ecoregion (MSE) of southern South America, the sub-Antarctic Island of South Georgia (SG) and the South Shetland Islands (SSI) within the Maritime Antarctic (MA). Our data support the diversification of P. steinenii during the mid-Pleistocene around 1.46 Mya. This period included a branching event between a clade containing only specimens from the MSE and a clade containing individuals from a broader range of locations including the SSI and SG. Based on intraspecific phylogeographic and demographic inferences, we detected strong evolutionary divergence between the three main biogeographic regions. We also detected a signal of population growth during the deglaciation process in SSI and SG, contrary to the pattern seen in the MSE. The different demographic and phylogeographic histories between the sampled biogeographic regions could result from the MA and SG experiencing a strong genetic bottleneck due to a reduction in population size during the Last Glacial Maximum, while the MSE maintained a significant effective population size. The high level of divergence detected between individuals from the MSE and the remaining biogeographic regions supports the hypothesis of a speciation process taking place in P. steinenii
Azorella compacta Organic Extracts Exacerbate Metabolic Dysfunction-Associated Fatty Liver Disease in Mice Fed a High-Fat Diet
No full textAzorella compacta (A. compacta) is a shrub of the Andean Altiplano of Bolivia, Chile and Peru, consumed by local communities as a traditional medicine for several maladies such as diabetes, hepatic and inflammatory diseases. A. compacta is rich in mulinane- and azorellane-type diterpenoids. For two of these, acute hypoglycemic effects have been described, but the impact of A. compacta diterpenoids on fatty liver disease has not been investigated. Therefore, A. compacta organic fractions were prepared using petroleum ether, dichloromethane and methanol. Their content was characterized by UHPLC/MS, revealing the presence of ten diterpenoids, mainly mulinic acid, azorellanol and mulin-11,13-diene. Next, mice fed with a high-fat diet (HFD), a model of metabolic dysfunction-associated fatty liver disease (MAFLD), received one of the fractions in drinking water for two weeks. After this treatment, hepatic parameters were evaluated. The A. compacta fractions did not reduce hyperglycemia or body weight in the HFD-fed mice but increased the serum levels of hepatic transaminases (AST and ALT), reduced albumin and increased bilirubin, indicating hepatic damage, while histopathological alterations such as steatosis, inflammation and necrosis generated by the HFD were, overall, not ameliorated by the fractions. These results suggest that organic A. compacta extracts may generate hepatic complications in patients with MAFLD
Morphospace of lanternfish larvae and their interplay with oceanographic conditions from the southeastern Pacific Ocean
No full textLanternfish larval morphology is highly variable probably due to their adaptations to highly variable environmental conditions throughout ontogeny. To study the morphological variability of the larval stage of lanternfishes, samples were collected from the southeast Pacific Ocean between 2014 and 2022. Of the 24 species, nine belonged to the subfamily Lampanyctinae, two to the subfamily Diaphinae, one to the subfamily Notolychinae, one to the subfamily Gymnoscopelinae and 11 to the subfamily Myctophinae. A principal component analysis indicated the presence of body shapes varying from a slender and curved body, and upper jaw oriented downwards, with relatively rounded eyes, to taxa with robust bodies, particularly both the head and trunk, and elongated eyes in a dorsal-ventral plane (PC1 33%). Also, specimens varied from having short jaw, short snout, and slender body, to specimens with larger jaw (reaching behind the eye) and taller snout and trunk (PC2, 23%). Allometric effects were related to variations in body curvature and thickness (Diaphus theta, 12.9%), the curvature of the body and position of the eyes (Lampanyctodes hectoris, 25.1%), lengthening of the jaw and increase in eye size (Diogenichthys atlanticus, 24.6%), and a narrower body and smaller eyes (Hygophum bruuni, 20.5%). Four of the five subfamilies showed covariation between morphometrics and environmental conditions. Diaphinae, Gymnoscopelinae and Lampanyctinae body shape covaried with mean sea temperature of the water column, while Myctophinae larval shape covaried with mean salinity. In conclusion, this study quantifies shape variations during early lanternfish ontogeny from the southeastern Pacific Ocean, identifying main differences and allometric changes between the subfamilies belonging to Myctophidae, with a covariation between the shape of most lanternfish larvae and the environmental conditions experienced by myctophid early stages
Holocene interactions between marine nomads and their coastal landscape in the Strait of Magellan, southern Patagonia: Ichthyoarchaeological and isotopic evidence
No full textMarked environmental changes occurred in the southern Patagonian archipelago during the middle and late Holocene, including increased variability in glacial coverage and marine productivity. Those changes likely impacted the lives of marine hunter gatherers and their exploitation of faunal resources. Here, we examine temporal trends in fishes captured during the mid- and late Holocene, including variation in stable isotope values (delta 13C and delta 15N) of the most commonly exploited taxa to explore potential changes in fishing strategies due to environmental and cultural causes. We examined fish remains from eight archaeological sites and cultural periods in the Strait of Magellan. The ichthyoarchaeological results indicate drastic changes in the assemblages of fishes captured, with demersal species dominating catches before 2700 cal. yr BP and a subsequent switch to coastal fishes associated with subtidal kelp forests afterwards until 500 cal yr BP, both in the Strait of Magellan and adjacent seas. Although limited by sample sizes, our isotopic data show little obvious variation in Eleginops maclovinus over the different periods. However, Patagonotothen sp. and Salilota australis displayed significant isotopic shifts during the Holocene, but followed distinct, taxon-specific trajectories. This suggests that responses to the late Holocene environmental changes differed between species. This study also contributes to the baseline ecological information prior to the impact of modern industrial fishing practices with data from native fishes that are important components in kelp forests (Macrocystis pyrifera) ecosystems of the sub-Antarctic region
Development of a temperate rainforest zonation on the Pacific slopes of the North Patagonian Andes since-18 ka
No full textFew studies along the western slopes of the Andes in Northwestern Patagonia (NWP: 40 degrees-44 degrees S) allow examining vegetation development through environmental gradients in latitude and elevation along a time continuum since the Last Glacial Termination (T1, -18-11 ka). This complete biostratigraphic context is necessary for assessing the sequence, timing, rates, and direction of compositional/structural changes of the former vegetation, and for deciphering their environmental drivers. Here we report palynological results from two NWP sites spaced -22 km apart on the western Andean slopes, Caleta Puelche roadside section located near sea level and Lago Reflejos at mid elevations (-800 m a.s.l.) and assess their continuous records since local ice-free conditions against other NWP sites. We find that cold-tolerant early successional trees dominated the initial stages of vegetation development in the Seno Reloncaví lowlands (-18-17 ka), followed by thermophilous shade-tolerant North Patagonian rainforest (NPRF) trees, which achieved their maxima between -17 and 15 ka at low-elevations. A spread of cold- and shade-tolerant hygrophilous NPRF conifers ensued (-14.8-13 ka) reaching similar magnitude at lowand mid-elevations, interrupted by increases in trees favored by canopy fragmentation linked to fire and explosive volcanism (-13-11 ka). Thermophilous, shade-intolerant, summer-drought tolerant Valdivian rainforest (VRF) trees increased and achieved maxima between -10 and 8 ka, most notably in the lowlands, coeval with peak abundance of the NPRF conifers Fitzroya/Pilgerodendron and Podocarpus nubigena in mid-elevation Lago Reflejos, contemporaneous with their virtual disappearance near sea level. Widespread increases in coldtolerant hygrophilous NPRF trees occurred after -8 ka, followed by mixing of NPRF and VRF elements in the lowlands after -6.3 ka with centennial-scale alternations. Inter-site and regional coherences of our findings suggest that variations in Southern Westerly Wind influence, along with disturbance regimes of natural and human origin, have driven the composition, structure, dynamics, and zonation of temperate rainforests in NWP since T1. We observe that Lago Reflejos features the highest abundance of Fitzroya cupressoides at regional scale since -12 ka, attesting to the importance of mid-elevation Andean environments for the persistence of these highly valued trees in the context of postglacial climate evolution, shifts in fire regimes, volcanic, and human disturbance in NWP
Social-ecological resilience: Knowledge of agrobiodiversity by campesinos and migrants in the face of global changes
No full textThere is concern that agrobiodiversity is being irreversibly eroded in the face of agricultural industrialization. While academic and policy debates stress loss of landraces, little attention has been paid to evaluating how agricultural knowledge systems endure in response to broader social-ecological changes (i.e., "system's resilience"). For being resilient, agricultural knowledge systems should incorporate new information (modern seed varieties) whilst maintaining its traditional components (landraces) and functions. However, the loss or continuing utilization of landraces may be influenced by several social-ecological filters, which are processes that selectively remove varieties according to their phenotype, local uses, or value. We examined the resilience of agricultural knowledge systems in the southern Andes. These systems include the knowledge of landraces and modern varieties by campesinos and lifestyle migrants. We further assessed the association of social-ecological filters with the knowledge of agrobiodiversity. Over four years (2018-2022), we used mixed-methods including semi-structured interviews with gardener experts and conducted knowledge exercises of seed varieties and surveys of gardeners (n = 132). We assessed the association of 'knowledge score on varieties' (general, landraces, and modern) with a priori-defined social-ecological filters. Gardeners with more proficient knowledge of landraces were more knowledgeable of modern varieties too. The general knowledge of agrobiodiversity and the knowledge of landraces, but not of modern varieties, was higher for campesinos than migrants. The main seed source of gardeners, the participation in seed exchanges, gardeners' origin, and gardeners' age were the social-ecological filters that influenced gardeners ' knowledge of agrobiodiversity. We highlight that socialecological, small-scale farming systems, are being resilient when they have the capacity of incorporating new information (knowledge of modern varieties) whilst maintaining their identity (knowledge of landraces) without undergoing a major shift in their basic structures and functions in this Important Agricultural Heritage Site and Global Biodiversity Hotspot, and beyond
Máxima expansión del Glaciar Tenerife (51°S) durante el último milenio
No full textIn the Patagonian Andes it is still under debate when the glaciers reached their maximum expansion during the last millennium. In this work we analyze the fluctuations of Tenerife Glacier (51°), a small mountain glacier located immediately to the south of the Patagonian Ice Fields. A detailed analysis of the glacial landforms of the valley allowed us to identify three moraine systems, in the south-central, southwestern, and northern parts of the Monte Tenerife valley, respectively. Based on ages obtained by count tree rings (Nothofagus pumilio) and Placopsis cf. gelida (L.) Linds lichens diameter measure-ments, we estimated that the Tenerife Glacier receded from its maximum extent in the last thousand years immediately after 1742-1765 AD. The maximum expansion of the Te-nerife Glacier during the last millennium coincides with the maximum expansions of the Schiaparelli (54°S) and Stoppani (55°S) glaciers. However, other glaciers reached their glacial maximum limit earlier and show temporal asynchrony in when they reached their largest extents. This suggests a temporal variability in the glacial maximum during the last millennium in southern Patagonia (49° and 55°S)
Phenolics and enzyme inhibitors from the Patagonian Empetrum rubrum berries
No full textThe small fruits from Empetrum rubrum were consumed by Native Americans in southern Patagonia. Two samples collected close to the Magellan Street and the Beagle channel in Tierra del Fuego were investigated. Three different extracts from the berries were analyzed, namely: methanol, phenolic-enriched (PEE) and ethyl acetate (EtOAc). The total phenolic, flavonoid, procyanidin and anthocyanin content of the extracts was determined. The effect of the extracts towards the metabolic syndrome-associated enzymes alpha-glucosidase, alpha-amylase and pancreatic lipase was assessed. In addition, the antioxidant capacity was measured using DPPH, FRAP, TEAC and ORAC assays. The composition of the extracts was determined by HPLC-MS/MS. Seventy-one compounds were identified for the first time in the berries, including 10 anthocyanins, 35 flavonoids, 11 phenylpropanoids and 13 procyanidins. The main compounds were quantified by HPLC-DAD. The extracts displayed strong activity as alpha-glucosidase inhibitors, with IC50 values ranging from 0.10 to 0.19 mu g/mL for the PEE and 0.82-1.95 mu g/mL for the EtOAc extracts, respectively. The results show high chemical diversity and differences with the boreal species E. nigrum