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1.
Proc Natl Acad Sci U S A ; 121(28): e2302924121, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38950368

RESUMEN

The human colonization of the Canary Islands represents the sole known expansion of Berber communities into the Atlantic Ocean and is an example of marine dispersal carried out by an African population. While this island colonization shows similarities to the populating of other islands across the world, several questions still need to be answered before this case can be included in wider debates regarding patterns of initial colonization and human settlement, human-environment interactions, and the emergence of island identities. Specifically, the chronology of the first human settlement of the Canary Islands remains disputed due to differing estimates of the timing of its first colonization. This absence of a consensus has resulted in divergent hypotheses regarding the motivations that led early settlers to migrate to the islands, e.g., ecological or demographic. Distinct motivations would imply differences in the strategies and dynamics of colonization; thus, identifying them is crucial to understanding how these populations developed in such environments. In response, the current study assembles a comprehensive dataset of the most reliable radiocarbon dates, which were used for building Bayesian models of colonization. The findings suggest that i) the Romans most likely discovered the islands around the 1st century BCE; ii) Berber groups from western North Africa first set foot on one of the islands closest to the African mainland sometime between the 1st and 3rd centuries CE; iii) Roman and Berber societies did not live simultaneously in the Canary Islands; and iv) the Berber people rapidly spread throughout the archipelago.


Asunto(s)
Migración Humana , Humanos , España , Migración Humana/historia , Teorema de Bayes , Historia Antigua , Datación Radiométrica
2.
J Intellect Disabil Res ; 68(2): 128-139, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37779228

RESUMEN

BACKGROUND: The life expectancy of people with Down syndrome (DS) is limited by Alzheimer's disease (AD)-related deaths, mainly due to respiratory infections. The emergence of the COVID-19 pandemic could have changed known, past trends in mortality in this population. We analysed the differences in causes of mortality between individuals with DS deceased before and after the onset of the pandemic. METHOD: This is a cross-sectional study of adults with DS recruited at a tertiary, university outpatient clinic in Madrid, Spain. Demographic and clinical data were retrospectively collected from their medical records, including information on their deaths, if any. RESULTS: Five hundred seventy-two adults were included in the study, and 67 (11.7%) died. The main cause of death was respiratory infections, which occurred in 36 participants [9 (45.0%) before, and 27 (58.7%) after the appearance of COVID-19]. No significant differences were found in the determinants of pre-pandemic and post-pandemic death after adjusting for age and AD, except for an association between the use of psychotropic medication and death in the post-pandemic period (odds ratio: 2.24; 95% confidence interval: 1.04-4.82). Vaccination against COVID-19 showed a marked protective effect against mortality (odds ratio: 0.0002; 95% confidence interval: 6.7e10-6 to 0.004). CONCLUSIONS: The appearance of COVID-19 has not impacted the overall trend of increase in mean age of death of adults with DS in our milieu, probably thanks to the very important protective effect of vaccination, which supports prioritising people with DS in future immunisation campaigns. The association between psychotropic medication use and mortality requires further exploration.


Asunto(s)
Enfermedad de Alzheimer , COVID-19 , Síndrome de Down , Infecciones del Sistema Respiratorio , Adulto , Humanos , Síndrome de Down/epidemiología , Pandemias , Estudios Retrospectivos , España/epidemiología , Estudios Transversales , Enfermedad de Alzheimer/epidemiología
3.
BMC Oral Health ; 24(1): 49, 2024 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-38191353

RESUMEN

BACKGROUND: There is a lack of studies comparing the status of dental specialties worldwide. Therefore, this study aimed to analyze the differences and similarities between the number and types of dental specialties in 31 countries, including every continent, in the world. MATERIALS AND METHODS: Available official documents and webpages from regulatory bodies, official colleges and councils, and dental institutions were collected from 31 countries and analyzed to obtain reliable data on dental specialties. Differences were analyzed using the Lorentz curve and Gini test. Additionally, a cluster analysis was performed to obtain groups of countries with similar patterns in the number and types of dental specialties. RESULTS: A total of 32 different specialties were officially recognized among all the analyzed countries. Orthodontics and oral surgery (100% and 93.1%, respectively) were the two most frequently officially recognized dental specialties worldwide. The total global degree of inequality in the 31 analyzed countries was 42.4%. The Anglo-Saxon countries showed the greatest similarity, approximately 15-fold higher than the European countries. Cluster analysis differentiated six main groups of countries according to the number and types of dental specialties. European countries formed one of the two largest clusters, and the other cluster was of Anglo-Saxon, Asian, African, and several Eastern European countries with a high number of specialties. CONCLUSIONS: Officially recognized dental specialties in the different continents and countries show an asymmetric organization. The number, names, and skills of officially recognized dental specialties exhibited significant differences, showing inequalities in their organization. The Anglo-Saxon pattern of dental specialties showed greater equality than the European pattern. Orthodontics was the only constant element among the different patterns.


Asunto(s)
Atención Odontológica , Especialización , Cirugía Bucal , Análisis por Conglomerados
4.
Hum Mol Genet ; 30(R1): R64-R71, 2021 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-33295602

RESUMEN

The establishment of European colonies across the world had important demographic consequences because it brought together diverse and distant civilizations for the first time. One clear example of this phenomenon is observed in the Canary Islands. The modern Canarian population is mainly the result of the admixture of natives of North African origin and European colonizers. However, additional migratory flows reached the islands due to the importation of enslaved Africans to cultivate sugarcane and the intense commercial contact with the American continent. In this review, we evaluate how the genetic analysis of indigenous, historical and current populations has provided a glimpse into the Canary Islands' complex genetic composition. We show that each island subpopulation's characterization is needed to fully disentangle the demographic history of the Canarian archipelago. Finally, we discuss what research avenues remain to be explored to improve our knowledge of the impact that the European colonization had on its native population.


Asunto(s)
Población Negra/genética , Flujo Génico , Población Blanca/genética , África del Norte , Población Negra/etnología , Personas Esclavizadas , Europa (Continente) , Migración Humana , Humanos , España/etnología , Población Blanca/etnología
5.
Scand J Med Sci Sports ; 33(11): 2110-2124, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37497601

RESUMEN

OBJECTIVE: To analyze the contribution of active commuting to and from school (ACS) to device-measured light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) levels in young people aged 6 to 18 years old, as well as, in both trip directions (i.e., home-school, school-home). METHODS: This systematic review was conducted according to the PRISMA statement, and five different databases were used for the systematic search (PubMed, Web of Science, SPORTdiscuss, Cochrane Library, and National Transportation Library) using PECO strategy. RESULTS: A total of 14 studies met all the eligibility criteria, which compile 7127 participants. The overall ACS weighted LPA was 19.55 min (95% CI: 3.84-35.26; I2 = 99.9%, p < 0.001) and 68.74 min (95% CI: 6.09-131.39; z = 2.15, p = 0.030) during the home-school and school-home trips, respectively. For MVPA, the overall ACS weighted MVPA was 8.98 min (95% CI: 5.33-12.62; I2 = 99.95%, p < 0.001) during the home-school trip and 20.07 min (95% CI: 13.62-26.53; I2 = 99.62%, p < 0.001) during the school-home trip. CONCLUSION: ACS may contribute about 48% of the PA recommendations in young people on school days if both trip directions are actively performed. Therefore, future studies aimed at increasing daily PA levels in young population should focus on promoting students' ACS. PROSPERO registration number: CRD42020162004A.

6.
Scand J Med Sci Sports ; 33(8): 1373-1383, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36951638

RESUMEN

BACKGROUND: Physical inactivity, excessive sedentary time, and lack of sleep time have been independently associated with lower health-related physical fitness. However, little is known about the combined association between 24-h movement guidelines (i.e., physical activity, recreational screen time, and sleep duration) and components of physical fitness. OBJECTIVE: The main aim was to examine the likelihood of having high/very high levels on different components of physical fitness based on meeting with 24-h movement guidelines. METHODS: In this cross-sectional study, 1276 Spanish youths (13.07 ± 0.86; 55.88% boys), aged 11-16 years, completed self-reported questionnaires on physical activity, recreational screen time, and sleep duration. Physical fitness components were assessed by 20-m shuttle-run test, standing long jump test, handgrip strength test, and 4 × 10-m shuttle-run test. Meeting 24-h movement guidelines was defined as: 9-11 h/day (children aged 5-13) or 8-10 h/day (adolescents aged 14-17) of sleep, ≤2 h/day of recreational screen time and at least 60 min/day of moderate-to-vigorous physical activity. The probability of having a high/very high score for each physical fitness components (i.e., ≥60th centile according to the normative cut-off points for European adolescents) in relation to adherence to 24-h movement guidelines was analyzed using a series of binary logistic regressions. RESULTS: Participants who met the three 24-h movement guidelines were more likely to have high/very high for cardiorespiratory fitness (OR = 3.31; 95% CI: 1.79, 6.14; p < 0.001), standing long jump (OR = 1.91; 95% CI: 1.06, 3.45; p = 0.031), muscular fitness (OR = 2.05; 95% CI: 1.09, 3.86; p = 0.048) and physical fitness (OR = 1.99; 95% CI: 1.08, 3.66; p = 0.012), but not for handgrip strength (OR = 1.15; 95% CI: 0.64, 2.01; p = 0.636) and speed/agility (OR = 1.65; 95% CI: 0.92, 2.96; p = 0.093), compared to those who did not meet all three recommendations. CONCLUSION: Since meeting the three 24-h movement guidelines increased the likelihood of having higher levels in most physical fitness components, it seems necessary to promote these movement behaviors early in life, as they could serve as a gateway for improving health-related fitness in future generations.


Asunto(s)
Capacidad Cardiovascular , Fuerza de la Mano , Masculino , Niño , Humanos , Adolescente , Femenino , Estudios Transversales , Aptitud Física , Ejercicio Físico , Sueño
7.
BMC Oral Health ; 23(1): 280, 2023 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-37170254

RESUMEN

BACKGROUND: Although the European Economic Space usually acts in a united and organized way, several main differences are found regarding the type and number of dental specialties all around this group of member states. The aim of the study is to analyse the inequalities and similarities existing between 21 European countries, highlighting the number and types of recognized dental specialties. METHODS: Available official documents and webpages from 20 out of the 30 countries of which the European Economic Space is comprised plus the United Kingdom (UK), were analysed to obtain reliable data referred to dental specialties. Differences were tested with the Lorentz curve and Gini test. Additionally, a Cluster analysis was performed to obtain groups of countries with a similar pattern in the number and type of dental specialties. RESULTS: Up to a total of 15 different specialties are officially recognized in all the analysed countries. Orthodontics (90%) and Oral Surgery (81%) are the two most frequently recognized specialties. The total global degree of inequality of the analysed countries was 40.2%. Cluster analysis differentiated three different main groups of countries according to the number and type of dental specialties. CONCLUSIONS: The situation of dental specialties in the area of the EES plus the UK exhibits an unequal organization. Cluster analysis showed 3 main clusters of countries with a similar pattern of dental specialties.


Asunto(s)
Ortodoncia , Cirugía Bucal , Humanos , Europa (Continente) , Reino Unido , Atención Odontológica , Especialidades Odontológicas
8.
Eur J Clin Microbiol Infect Dis ; 41(6): 981-987, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35568743

RESUMEN

Among 1655 consecutive patients with infective endocarditis treated from 1998 to 2020 in three tertiary care centres, 16 were caused by Candida albicans (CAIE, n = 8) and Candida parapsilosis (CPIE, n = 8). Compared to CAIE, CPIE were more frequently community-acquired. Prosthetic valve involvement was remarkably more common among patients with CPIE. CPIE cases presented a higher rate of positive blood cultures at admission, persistently positive blood cultures after antifungals initiation and positive valve cultures. All patients but four underwent cardiac surgery. Urgent surgery was more frequently performed in CPIE. No differences regarding in-hospital mortality were documented, even after adjusting for therapeutic management.


Asunto(s)
Endocarditis Bacteriana , Endocarditis , Candida albicans , Candida parapsilosis , Estudios de Cohortes , Endocarditis/diagnóstico , Endocarditis/tratamiento farmacológico , Endocarditis/microbiología , Humanos
9.
Philos Trans A Math Phys Eng Sci ; 380(2226): 20210045, 2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35527634

RESUMEN

In this paper, we construct new, uniformly rotating solutions of the vortex sheet equation bifurcating from circles with constant vorticity amplitude. The proof is accomplished via a Lyapunov-Schmidt reduction and a second-order expansion of the reduced system. This article is part of the theme issue 'Mathematical problems in physical fluid dynamics (part 2)'.


Asunto(s)
Hidrodinámica , Matemática
10.
J Chem Phys ; 156(20): 205101, 2022 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-35649882

RESUMEN

CP29, a chlorophyll a/b-xanthophyll binding protein, bridges energy transfer between the major LHCII antenna complexes and photosystem II reaction centers. It hosts one of the two identified quenching sites, making it crucial for regulated photoprotection mechanisms. Until now, the photophysics of CP29 has been studied on the purified protein in detergent solutions since spectrally overlapping signals affect in vivo measurements. However, the protein in detergent assumes non-native conformations compared to its physiological state in the thylakoid membrane. Here, we report a detailed photophysical study on CP29 inserted in discoidal lipid bilayers, known as nanodiscs, which mimic the native membrane environment. Using picosecond time-resolved fluorescence and femtosecond transient absorption (TA), we observed shortening of the Chl fluorescence lifetime with a decrease of the carotenoid triplet formation yield for CP29 in nanodiscs as compared to the protein in detergent. Global analysis of TA data suggests a 1Chl* quenching mechanism dependent on excitation energy transfer to a carotenoid dark state, likely the proposed S*, which is believed to be formed due to a carotenoid conformational change affecting the S1 state. We suggest that the accessibility of the S* state in different local environments plays a key role in determining the quenching of Chl excited states. In vivo, non-photochemical quenching is activated by de-epoxidation of violaxanthin into zeaxanthin. CP29-zeaxanthin in nanodiscs further shortens the Chl lifetime, which underlines the critical role of zeaxanthin in modulating photoprotection activity.


Asunto(s)
Complejos de Proteína Captadores de Luz , Lípidos de la Membrana , Carotenoides/metabolismo , Clorofila A , Detergentes , Complejos de Proteína Captadores de Luz/química , Zeaxantinas
11.
Scand J Med Sci Sports ; 32(11): 1668-1681, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35856173

RESUMEN

Sedentary behavior and screen-based devices in particular have been negatively associated with a wide range of health and educational indicators. However, few have examined these relationships separately for school days and non-school days, and none have used a person-centered approach. This study aimed to identify school and non-school day screen time profiles, as well as examine possible differences in health indicators (physical fitness, fatness, physical activity, sleep duration, and Mediterranean diet) and academic performance. This study involved the participation of 1573 Spanish adolescents aged 12-16 years (54.73% girls). Academic performance was measured through grades in Mathematics, Language, English, and Physical Education. Physical fitness was measured through a battery of tests (cardiorespiratory fitness was measured using the 20 m shuttle run test, and muscular strength with both handgrip and standing long jump tests), while fatness (skinfold thicknesses) was assessed with calipers. Finally, physical activity, screen time, sleep duration, and adherence to the Mediterranean diet were measured using self-reported questionnaires. Hierarchical cluster analyses based on square Euclidian distances and Ward's method were performed based on daily minutes of screen time recorded on school and non-school days. We identified four clusters labeled and described as: (1) "High-high": highest screen time on school and non-school days; (2) "High-low": high screen time on school days and low screen time on non-school days; (3) "Low-high": low screen time on school days and high screen time on non-school days; (4) "Low-low": lowest screen time on school and non-school days. Adolescents who belonged to the "High-high" profile had worse health-related behaviors (i.e., physical activity, sleep duration, and adherence to Mediterranean diet) and academic performance than most other profiles, while adolescents who belonged to "Low-low" profile showed the opposite pattern. Adolescents in the "Low-high" profile had a higher sleep duration on school days and better academic performance than those in the "High-low" profile. No differences in body fat, cardiorespiratory fitness, and muscular strength were found between the four different profiles. The results suggest that adolescents who accumulated a large amount of screen time on school and non-school days reported worse health-related behaviors and academic performance. Moreover, adolescents who had high screen time on school days reported only a short sleep duration on school days and worse academic performance than on non-school days. Conducting interventions to reduce screen time in these four profiles, particularly in the groups of students with more screen time on school days, becomes essential to improving adolescents' healthy lifestyles and academic performance.


Asunto(s)
Capacidad Cardiovascular , Tiempo de Pantalla , Adolescente , Estudios Transversales , Femenino , Fuerza de la Mano , Humanos , Masculino , Aptitud Física , Conducta Sedentaria
12.
Sensors (Basel) ; 23(1)2022 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-36616716

RESUMEN

Nowadays the rationalization of electrical energy consumption is a serious concern worldwide. Energy consumption reduction and energy efficiency appear to be the two paths to addressing this target. To achieve this goal, many different techniques are promoted, among them, the integration of (artificial) intelligence in the energy workflow is gaining importance. All these approaches have a common need: data. Data that should be collected and provided in a reliable, accurate, secure, and efficient way. For this purpose, sensing technologies that enable ubiquitous data acquisition and the new communication infrastructure that ensure low latency and high density are the key. This article presents a sensing solution devoted to the precise gathering of energy parameters such as voltage, current, active power, and power factor for server farms and datacenters, computing infrastructures that are growing meaningfully to meet the demand for network applications. The designed system enables disaggregated acquisition of energy data from a large number of devices and characterization of their consumption behavior, both in real time. In this work, the creation of a complete multiport power meter system is detailed. The study reports all the steps needed to create the prototype, from the analysis of electronic components, the selection of sensors, the design of the Printed Circuit Board (PCB), the configuration and calibration of the hardware and embedded system, and the implementation of the software layer. The power meter application is geared toward data centers and server farms and has been tested by connecting it to a laboratory server rack, although its designs can be easily adapted to other scenarios where gathering the energy consumption information was needed. The novelty of the system is based on high scalability built upon two factors. Firstly, the one-on-one approach followed to acquire the data from each power source, even if they belong to the same physical equipment, so the system can correlate extremely well the execution of processes with the energy data. Thus, the potential of data to develop tailored solutions rises. Second, the use of temporal multiplexing to keep the real-time data delivery even for a very high number of sources. All these ensure compatibility with standard IoT networks and applications, as the data markup language is used (enabling database storage and computing system processing) and the interconnection is done by well-known protocols.

13.
Ann Hum Biol ; 48(3): 179-190, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34459342

RESUMEN

A substantial portion of ancient DNA research has been centred on understanding European populations' origin and evolution. A rchaeological evidence has already shown that the peopling of Europe involved an intricate pattern of demic and/or cultural diffusion since the Upper Palaeolithic, which became more evident during the Neolithic and Bronze Age periods. However, ancient DNA data has been crucial in determining if cultural changes occurred due to the movement of ideas or people. With the advent of next-generation sequencing and population-based paleogenomic research, ancient DNA studies have been directed not only at the study of continental human migrations, but also to the detailed analysis of particular archaeological sites, the processes of domestication, or the spread of disease during prehistoric times. With this vast paleogenomic effort added to a proper archaeological contextualisation of results, a deeper understanding of Europe's peopling is starting to emanate.


Asunto(s)
Enfermedades Transmisibles/epidemiología , ADN Antiguo/análisis , Domesticación , Genoma Humano , Migración Humana , Arqueología , Enfermedades Transmisibles/microbiología , Enfermedades Transmisibles/parasitología , Enfermedades Transmisibles/virología , Europa (Continente) , Genómica , Humanos
14.
Qual Health Res ; 31(8): 1392-1403, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33666108

RESUMEN

Grounded in self-determination theory, this study aimed to qualitatively examine women's perception of a set of motivational and affective consequences during and immediately after a physical activity intervention. In total, 11 disadvantaged adult women participated in this 20-month intervention. A total of 102 physical activity sessions based on need-supportive strategies were performed. Six discussion groups, 14 semi-structured interviews, and field notes were used to collect data. A thematic analysis was conducted based on self-determination theory. Findings highlighted that it might be advisable among these disadvantaged women to begin with relatedness-support strategies to increase group cohesion, followed by competence support strategies to increase self-confidence, and, finally, autonomy support strategies to empower women to be physically active. The development of a need-supportive environment in a physical activity intervention may have the potential to achieve motivational and affective consequences, which might promote the empowerment of these disadvantaged women to be physically active.


Asunto(s)
Motivación , Poblaciones Vulnerables , Adulto , Ejercicio Físico , Femenino , Humanos , Autonomía Personal
15.
Ann Vasc Surg ; 67: 482-489, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32173474

RESUMEN

BACKGROUND: The presence of intraluminal thrombus and mitochondrial dysfunction in human abdominal aortic aneurysms (AAAs) have been associated with aneurysmal growth and rupture. The objective of the study was to study if endogenous factor Xa (FXa) may modulate mitochondrial functionality and expression of proteins associated with mitophagy in human AAAs. METHODS: AAA sites with intraluminal thrombus were obtained from 6 patients undergoing elective AAA surgery repair. Control samples were collected from 6 organ donors. The effect of FXa was analyzed by in vitro incubation of AAA with 50 nmol/L rivaroxaban, an oral FXa inhibitor. RESULTS: The enzymatic activities of citrate synthase, a biomarker of mitochondrial density, and cytochrome C oxidase, a biomarker of mitochondrial respiratory chain functionality, were significantly reduced in the AAA sites with respect to the healthy aorta (citrate synthase activity in µU/min/µg protein: control: 3.51 ± 0.22 vs. AAA: 0.37 ± 0.15.; P < 0.01; cytochrome C oxidase activity in µOD/min/µg protein: control: 8.05 ± 1.57 vs. AAA: 3.29 ± 1.05; P < 0.05). The addition of rivaroxaban to AAA reverted the activity of both citrate synthase and cytochrome C oxidase to similar values to control. Mitochondrial Drp-1 expression was higher in AAA sites than in either control aortas or rivaroxaban-incubated AAA sites. Cytosolic content of Drp-1 phosphorylated at Ser637, mitochondrial Parkin, and mitochondrial PINK1-Parkin interaction were significantly reduced in the AAA sites with respect to control aortas. For all these parameters, rivaroxaban-incubated AAA showed similar values compared with control aortas. CONCLUSIONS: In human AAA, rivaroxaban improved mitochondrial functionality that was associated with changes in proteins related to mitophagy. Its opens possible new effects of endogenous FXa on the mitochondria in the human AAA site.


Asunto(s)
Aorta Abdominal/efectos de los fármacos , Aneurisma de la Aorta Abdominal/tratamiento farmacológico , Inhibidores del Factor Xa/farmacología , Mitocondrias/efectos de los fármacos , Proteínas Mitocondriales/metabolismo , Rivaroxabán/farmacología , Trombosis/tratamiento farmacológico , Adulto , Anciano , Aorta Abdominal/metabolismo , Aorta Abdominal/patología , Aneurisma de la Aorta Abdominal/metabolismo , Aneurisma de la Aorta Abdominal/patología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mitocondrias/metabolismo , Mitocondrias/patología , Mitofagia/efectos de los fármacos , Trombosis/metabolismo , Trombosis/patología
16.
Proc Natl Acad Sci U S A ; 114(43): 11524-11529, 2017 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-29073081

RESUMEN

Variants in the gene encoding the triggering receptor expressed on myeloid cells 2 (TREM2) were recently found to increase the risk for developing Alzheimer's disease (AD). In the brain, TREM2 is predominately expressed on microglia, and its association with AD adds to increasing evidence implicating a role for the innate immune system in AD initiation and progression. Thus far, studies have found TREM2 is protective in the response to amyloid pathology while variants leading to a loss of TREM2 function impair microglial signaling and are deleterious. However, the potential role of TREM2 in the context of tau pathology has not yet been characterized. In this study, we crossed Trem2+/+ (T2+/+) and Trem2-/- (T2-/-) mice to the PS19 human tau transgenic line (PS) to investigate whether loss of TREM2 function affected tau pathology, the microglial response to tau pathology, or neurodegeneration. Strikingly, by 9 mo of age, T2-/-PS mice exhibited significantly less brain atrophy as quantified by ventricular enlargement and preserved cortical volume in the entorhinal and piriform regions compared with T2+/+PS mice. However, no TREM2-dependent differences were observed for phosphorylated tau staining or insoluble tau levels. Rather, T2-/-PS mice exhibited significantly reduced microgliosis in the hippocampus and piriform cortex compared with T2+/+PS mice. Gene expression analyses and immunostaining revealed microglial activation was significantly attenuated in T2-/-PS mice, and there were lower levels of inflammatory cytokines and astrogliosis. These unexpected findings suggest that impairing microglial TREM2 signaling reduces neuroinflammation and is protective against neurodegeneration in the setting of pure tauopathy.


Asunto(s)
Inflamación/genética , Glicoproteínas de Membrana/metabolismo , Enfermedades Neurodegenerativas/genética , Receptores Inmunológicos/metabolismo , Tauopatías , Animales , Regulación de la Expresión Génica/fisiología , Glicoproteínas de Membrana/genética , Ratones , Ratones Noqueados , Ratones Transgénicos , Receptores Inmunológicos/genética
17.
J Strength Cond Res ; 32(4): 1063-1071, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29570597

RESUMEN

Walker, S, Serrano, J, and Van Roie, E. Maximum dynamic lower-limb strength was maintained during 24-week reduced training frequency in previously sedentary older women. J Strength Cond Res 32(4): 1063-1071, 2018-There is little study into the effects of reducing strength training below the recommended twice weekly frequency, particularly in older women, despite the possibility that individuals will encounter periods of reduced training frequency. The purpose of the present study was to determine the effects of a period of reduced training frequency on maximum strength and muscle mass of the lower limbs in comparison with the recommended training frequency of twice per week. After an initial 12-week period, where all subjects trained twice per week, a reduced strength training group (RST) trained once per week, whereas another strength training group (ST) continued to train twice per week for 24 weeks. A nontraining age-matched control group (CON) was used for comparison. All subjects were tested for leg press 1-repetition maximum (1RM), electromyogram (EMG) amplitude of vastus lateralis and medialis, and quadriceps cross-sectional area (CSA) measured by panoramic ultrasound at weeks 0, 12, and 36. Both ST and RST continued to increase 1RM during the reduced training frequency period compared with control (∼8% and ∼5% vs. ∼-3%, respectively; p ≤ 0.05). Accompanying these changes were significant increases in EMG amplitude in both ST and RST (p ≤ 0.05). However, the initial gains in quadriceps CSA made from week 0 to week 12 in RST were lost when training once per week (RST ∼-5%). Therefore, reduced training frequency in this population does not adversely affect maximum strength or muscle activity but can negatively affect muscle mass, even reversing training-induced gains. Older individuals not training at least twice per week may compromise potential increases in muscle mass, important in counteracting effects of aging.


Asunto(s)
Extremidad Inferior/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Anciano , Electromiografía , Femenino , Humanos , Persona de Mediana Edad , Conducta Sedentaria , Factores de Tiempo
19.
Philos Trans A Math Phys Eng Sci ; 373(2050)2015 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-26261369

RESUMEN

In this note, we show that there exist solutions of the Muskat problem that shift stability regimes: they start unstable, then become stable and finally return to the unstable regime. We also exhibit numerical evidence of solutions with medium-sized L(∞) norm of the derivative of the initial condition that develop a turning singularity.

20.
Proc Natl Acad Sci U S A ; 109(3): 733-8, 2012 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-22219372

RESUMEN

We exhibit smooth initial data for the two-dimensional (2D) water-wave equation for which we prove that smoothness of the interface breaks down in finite time. Moreover, we show a stability result together with numerical evidence that there exist solutions of the 2D water-wave equation that start from a graph, turn over, and collapse in a splash singularity (self-intersecting curve in one point) in finite time.

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