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1.
Community Dent Health ; 41(2): 95-105, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38682565

RESUMEN

OBJECTIVES: To critically appraise the methodological conduct and reporting quality of economic evaluations (EE) of community water fluoridation (CWF). METHODS: A systematic literature search was conducted in general databases and specialist directories of the economic literature. The Consensus on Health Economic Criteria list (CHEC) appraised the methodological quality while the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) assessed the reporting quality of included studies. RESULTS: A total of 1,138 records were identified, of which 18 met the inclusion criteria. Cost analysis emerged as the most prevalent type of EE, though a growing trend towards conducting full EEs is observed. CHEC revealed the items most frequently unfulfilled were the study design, measurement and valuation of costs and outcomes, while CHEERS also identified reporting deficiencies in these aspects. Furthermore, the review highlights subtleties in methodological aspects that may not be discerned by CHEC, such as the estimation of the impact of fluoridation and the inclusion of treatment savings within cost estimates. CONCLUSIONS: While numerous studies were conducted before publication of these assessment instruments, this review reveals that a noteworthy subset of studies exhibited good methodological conduct and reporting quality. There has been a steady improvement in the methodological and reporting quality over time, with recently published EEs largely adhering to best practice guidelines. The evidence presented will assist policymakers in leveraging the available evidence effectively to inform resource allocation decisions. It may also serve as a resource for researchers to enhance the methodological and reporting standards of future EEs of CWF.


Asunto(s)
Fluoruración , Humanos , Análisis Costo-Beneficio , Fluoruración/economía
2.
Anaesthesia ; 78(1): 23-35, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36070622

RESUMEN

The perceived risk of transmission of aerosolised viral particles from patients to airway practitioners during the COVID-19 pandemic led to the widespread use of aerosol precautions, including personal protective equipment and modifications to anaesthetic technique. The risk of these aerosol precautions on peri-operative airway complications has not been assessed outside of simulation studies. This prospective, national, multicentre cohort study aimed to quantify this risk. Adult patients undergoing general anaesthesia for elective or emergency procedures over a 96-hour period were included. Data collected included use of aerosol precautions by the airway practitioner, airway complications and potential confounding variables. Mixed-effects logistic regression was used to assess the risk of individual aerosol precautions on overall and specific airway complications. Data from 5905 patients from 70 hospital sites were included. The rate of airway complications was 10.0% (95%CI 9.2-10.8%). Use of filtering facepiece class 2 or class 3 respirators was associated with an increased risk of airway complications (odds ratio 1.38, 95%CI 1.04-1.83), predominantly due to an association with difficult facemask ventilation (odds ratio 1.68, 95%CI 1.09-2.61) and desaturation on pulse oximetry (odds ratio 2.39, 95%CI 1.26-4.54). Use of goggles, powered air-purifying respirators, long-sleeved gowns, double gloves and videolaryngoscopy were not associated with any alteration in the risk of airway complications. Overall, the use of filtering facepiece class 2 or class 3 respirators was associated with an increased risk of airway complications, but most aerosol precautions used during the COVID-19 pandemic were not.


Asunto(s)
COVID-19 , Pandemias , Humanos , Estudios de Cohortes , Estudios Prospectivos
3.
Ir Med J ; 114(7): 412, 2021 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-34520647

RESUMEN

Introduction The Sars-CoV-2 pandemic led to a national lockdown in Ireland from March 12th to June 7th, 2020. The present study aimed to assess the change in the pattern of cycling attendances to an Irish ED during a pandemic. Methods This is a retrospective before-and-after study carried out at a university hospital ED. We compared cycling attendances during Lockdown (LD) (13th March-7th June 2020) with Pre-Lockdown (PLD) (January 1st-March 12th, 2020). Furthermore, we also compared lockdown to an historical control period during the equivalent dates in 2019 (i.e. March 13th-June 7th, 2019) Results There were 151 cycling attendances during LD, 122 in PLD and 164 during the control period. The number of cyclists presenting during "rush hour traffic" in the LD period was 30 (19.9%) versus 42 (34.4%) during PLD (p<0.05) and 51 (31.1%) during the control period (p<0.05). During LD, 8 (5.3%) collisions involved a motor vehicle compared to 26 (21.3%) in PLD (p<0.05) and 43 (26.2%) during the control period (p<0.05). Conclusion Lockdown did not result in increased cycling attendances to this ED. The patients who did sustain a cycling-related injury during lockdown were less likely to have collided with a motor vehicle compared to the control period. The reduction in motor vehicle collisions could be attributed to less traffic congestion and highlights the potential benefits of road-user segregation.


Asunto(s)
Accidentes de Tránsito/estadística & datos numéricos , Ciclismo/lesiones , COVID-19/epidemiología , Control de Enfermedades Transmisibles/estadística & datos numéricos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Adulto , Femenino , Humanos , Irlanda , Masculino , Estudios Retrospectivos , Factores de Riesgo , Seguridad
4.
Br J Anaesth ; 122(2): 277-285, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30686314

RESUMEN

BACKGROUND: Tidal recruitment/derecruitment (R/D) of collapsed regions in lung injury has been presumed to cause respiratory oscillations in the partial pressure of arterial oxygen (PaO2). These phenomena have not yet been studied simultaneously. We examined the relationship between R/D and PaO2 oscillations by contemporaneous measurement of lung-density changes and PaO2. METHODS: Five anaesthetised pigs were studied after surfactant depletion via a saline-lavage model of R/D. The animals were ventilated with a mean fraction of inspired O2 (FiO2) of 0.7 and a tidal volume of 10 ml kg-1. Protocolised changes in pressure- and volume-controlled modes, inspiratory:expiratory ratio (I:E), and three types of breath-hold manoeuvres were undertaken. Lung collapse and PaO2 were recorded using dynamic computed tomography (dCT) and a rapid PaO2 sensor. RESULTS: During tidal ventilation, the expiratory lung collapse increased when I:E <1 [mean (standard deviation) lung collapse=15.7 (8.7)%; P<0.05], but the amplitude of respiratory PaO2 oscillations [2.2 (0.8) kPa] did not change during the respiratory cycle. The expected relationship between respiratory PaO2 oscillation amplitude and R/D was therefore not clear. Lung collapse increased during breath-hold manoeuvres at end-expiration and end-inspiration (14% vs 0.9-2.1%; P<0.0001). The mean change in PaO2 from beginning to end of breath-hold manoeuvres was significantly different with each type of breath-hold manoeuvre (P<0.0001). CONCLUSIONS: This study in a porcine model of collapse-prone lungs did not demonstrate the expected association between PaO2 oscillation amplitude and the degree of recruitment/derecruitment. The results suggest that changes in pulmonary ventilation are not the sole determinant of changes in PaO2 during mechanical ventilation in lung injury.


Asunto(s)
Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/fisiopatología , Consumo de Oxígeno , Reclutamiento Neurofisiológico , Lesión Pulmonar Aguda/diagnóstico por imagen , Animales , Análisis de los Gases de la Sangre , Femenino , Masculino , Atelectasia Pulmonar/metabolismo , Atelectasia Pulmonar/fisiopatología , Respiración Artificial , Mecánica Respiratoria , Porcinos , Irrigación Terapéutica , Volumen de Ventilación Pulmonar , Tomografía Computarizada por Rayos X
7.
Ir Med J ; 111(1): 669, 2018 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-29869850

RESUMEN

In recent years there has been increased utilisation of computed tomography (CT) imaging in developed countries, however there is a paucity of data regarding the utilisation of CT in the emergency overnight setting. We retrospectively analysed trends in 'overnight' (midnight to 8am) CT utilisation over a ten-year period at a single Irish tertiary referral hospital. Over the study period, we observed a significant increase in the proportion of CT imaging that was carried out overnight. There was no significant variation in the yield of pathological findings over the study period, which remained low (64% of CT studies were normal or had non-critical findings). The multiple factors which have contributed to the increased utilization of overnight emergency CT in recent years, the potential for reporting errors overnight and the implications therein for patient safety warrant consideration.


Asunto(s)
Atención Posterior/estadística & datos numéricos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Atención Posterior/tendencias , Urgencias Médicas/epidemiología , Servicio de Urgencia en Hospital/tendencias , Humanos , Irlanda , Estudios Retrospectivos , Centros de Atención Terciaria/estadística & datos numéricos , Centros de Atención Terciaria/tendencias , Tomografía Computarizada por Rayos X/tendencias
9.
Ir Med J ; 109(6): 418, 2016 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-27814435

RESUMEN

There is little published data on cycling injuries in Ireland and the present study aims to describe the cycling related injuries presenting to the emergency department (ED), of a tertiary urban university hospital. This is a retrospective review of cycling-related injuries presenting to the ED of St. Vincent's University Hospital (SVUH) from 1st of January to 31st of December 2014. There were 534 cycling related injuries presenting to the ED during the study period. Just over 71% of the patients were male, and 14.8% of patients presented following a collision with a motor vehicle. Forty patients required admission to hospital following their injury with 6 of these patients spending time in the intensive care unit. Cycling is now a very popular means of transport and exercise activity in Ireland and using hospital based data, it is possible that EDs may provide a vector for guiding injury prevention strategies in the future.


Asunto(s)
Ciclismo/lesiones , Servicio de Urgencia en Hospital/estadística & datos numéricos , Ciclismo/estadística & datos numéricos , Femenino , Hospitalización , Hospitales Urbanos , Humanos , Irlanda/epidemiología , Masculino , Estudios Retrospectivos , Distribución por Sexo , Heridas y Lesiones/epidemiología
11.
Clin Exp Allergy ; 45(7): 1201-13, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25823600

RESUMEN

BACKGROUND: Only limited evidence is available regarding the cytokine repertoire of effector T cells associated with peanut allergy, and how these responses relate to IgE antibodies to peanut components. OBJECTIVE: To interrogate T cell effector cytokine populations induced by Ara h 1 and Ara h 2 among peanut allergic (PA) children in the context of IgE and to evaluate their modulation during oral immunotherapy (OIT). METHODS: Peanut-reactive effector T cells were analysed in conjunction with specific IgE profiles in PA children using intracellular staining and multiplex assay. Cytokine-expressing T cell subpopulations were visualized using SPICE. RESULTS: Ara h 2 dominated the antibody response to peanut as judged by prevalence and quantity among a cohort of children with IgE to peanut. High IgE (> 15 kU(A)/L) was almost exclusively associated with dual sensitization to Ara h 1 and Ara h 2 and was age independent. Among PA children, IL-4-biased responses to both major allergens were induced, regardless of whether IgE antibodies to Ara h 1 were present. Among subjects receiving OIT in whom high IgE was maintained, Th2 reactivity to peanut components persisted despite clinical desensitization and modulation of allergen-specific immune parameters including augmented specific IgG4 antibodies, Th1 skewing and enhanced IL-10. The complexity of cytokine-positive subpopulations within peanut-reactive IL-4(+) and IFN-γ(+) T cells was similar to that observed in those who received no OIT, but was modified with extended therapy. Nonetheless, high Foxp3 expression was a distinguishing feature of peanut-reactive IL-4(+) T cells irrespective of OIT, and a correlate of their ability to secrete type 2 cytokines. CONCLUSION: Although total numbers of peanut-reactive IL-4(+) and IFN-γ(+) T cells are modulated by OIT in highly allergic children, complex T cell populations with pathogenic potential persist in the presence of recognized immune markers of successful immunotherapy.


Asunto(s)
Citocinas/biosíntesis , Hipersensibilidad al Cacahuete/inmunología , Hipersensibilidad al Cacahuete/metabolismo , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Células Th2/inmunología , Células Th2/metabolismo , Albuminas 2S de Plantas/inmunología , Administración Oral , Adolescente , Alérgenos/administración & dosificación , Alérgenos/inmunología , Antígenos de Plantas/administración & dosificación , Antígenos de Plantas/inmunología , Niño , Preescolar , Desensibilización Inmunológica , Femenino , Glicoproteínas/inmunología , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunofenotipificación , Lactante , Interleucina-4/biosíntesis , Masculino , Hipersensibilidad al Cacahuete/terapia
12.
J Sports Med Phys Fitness ; 55(3): 164-78, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24998610

RESUMEN

The anabolic effect of resistance training can mitigate muscle loss during contest preparation. In reviewing relevant literature, we recommend a periodized approach be utilized. Block and undulating models show promise. Muscle groups should be trained 2 times weekly or more, although high volume training may benefit from higher frequencies to keep volume at any one session from becoming excessive. Low to high (~3-15) repetitions can be utilized but most repetitions should occur in the 6-12 range using 70-80% of 1 repetition maximum. Roughly 40-70 reps per muscle group per session should be performed, however higher volume may be appropriate for advanced bodybuilders. Traditional rest intervals of 1-3 minutes are adequate, but longer intervals can be used. Tempo should allow muscular control of the load; 1-2 s concentric and 2-3 s eccentric tempos. Training to failure should be limited when performing heavy loads on taxing exercises, and primarily relegated to single-joint exercises and higher repetitions. A core of multi-joint exercises with some single-joint exercises to address specific muscle groups as needed should be used, emphasizing full range of motion and proper form. Cardiovascular training can be used to enhance fat loss. Interference with strength training adaptations increases concomitantly with frequency and duration of cardiovascular training. Thus, the lowest frequency and duration possible while achieving sufficient fat loss should be used. Full-body modalities or cycling may reduce interference. High intensities may as well; however, require more recovery. Fasted cardiovascular training may not have benefits over fed-state and could be detrimental.


Asunto(s)
Atletas , Metabolismo Energético , Entrenamiento de Fuerza/métodos , Levantamiento de Peso , Restricción Calórica , Humanos
13.
Scand J Med Sci Sports ; 24(3): e156-64, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24118076

RESUMEN

To investigate how maturity status modifies the effects of strength training and detraining on performance, we subjected 33 young men to 8 weeks of strength training twice per week followed by 8 weeks without training. Changes in performance tests were analyzed in three maturity groups based on years from/to age of predicted peak height velocity (PHV): pre-PHV (-1.7 ± 0.4 years; n = 10), mid-PHV (-0.2 ± 0.4 years; n = 11), and post-PHV (1.0 ± 0.4 years; n = 12). Mean training effects on one repetition maximum strength (3.6-10.0%), maximum explosive power (11-20%), jump length (6.5-7.4%), and sprint times (-2.1% to -4.7%) ranged from small to large, with generally greater changes in mid- and post-PHV groups. Changes in force-velocity relationships reflected generally greater increases in strength at faster velocities. In the detraining period, the pre-PHV group showed greatest loss of strength and power, the post-PHV group showed some loss of sprint performance, but all groups maintained or improved jump length. Strength training was thus generally less effective before the growth spurt. Maintenance programs are needed for most aspects of explosive performance following strength training before the growth spurt and for sprint speed after the growth spurt.


Asunto(s)
Adaptación Fisiológica/fisiología , Desarrollo del Adolescente/fisiología , Fuerza Muscular/fisiología , Entrenamiento de Fuerza , Adolescente , Estatura , Niño , Prueba de Esfuerzo , Humanos , Masculino , Movimiento/fisiología , Músculo Esquelético/fisiología , Carrera/fisiología
14.
Int J Sports Med ; 35(9): 749-54, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24841839

RESUMEN

The purpose of this study was to assess the possible contribution of 1RM leg-press strength and jump peak power to 20-m sprint time in young athletes in three maturity groups based on age relative to predicted age of peak height velocity (PHV): Pre (- 2.5 to -1.0 years; n=25), Mid (- 1.0 to 0.5 years; n=26) and Post (0.5 to 2.0 years; n=15). Allometric scaling factors, representing percent difference in 20-m time per percent difference in strength and peak power, were derived by linear regression and were similar in the three maturity groups (-0.16%/% and -0.20%/% for strength and peak power, respectively). The moderate increase in sprint performance Pre to Mid PHV (5.7%) reduced to small (1.9%) and trivial but unclear (0.9%) magnitudes after adjustment for 1RM and peak power, while the moderate increase Mid to Post PHV (4.6%) were still moderate (3.4 and 3.0%) after adjustment. Thus percent differences in strength or power explained most of the maturity-related improvements in sprint performance before PHV age but only some improvements after PHV age. Factors in addition to strength and power should be identified and monitored for development of speed in athletes during puberty.


Asunto(s)
Rendimiento Atlético/fisiología , Pierna/fisiología , Fuerza Muscular/fisiología , Carrera/fisiología , Tejido Adiposo , Adolescente , Estatura , Índice de Masa Corporal , Niño , Humanos , Pierna/anatomía & histología , Masculino , Educación y Entrenamiento Físico , Maduración Sexual
15.
J Sports Med Phys Fitness ; 54(2): 129-38, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24509983

RESUMEN

AIM: Different jumping strategies can be used during plyometric training. Understanding how manipulating variables such as the counter-movement, flexion amplitude, the drop and the load could influence neuromuscular adaptation would be beneficial for coaches and athletes. The purpose of this study was to analyze how these variations in the vertical jump influenced kinematic and kinetic parameters as measured by a force platform. METHODS: Ten male subjects performed, eight kinds of vertical jumps on a force platform: (1) squat jump (SJ); (2) shallow counter-movement jump (S-CMJ); (3) natural counter-movement jump (N-CMJ); (4) deep counter-movement jump (D-CMJ); (5) loaded (20kg) counter-movement jump (20-CMJ); (6) shallow drop jump (S-DJ); (7) deep drop jump (D-DJ); (8) six consecutive jump test (6CJ). Customised Labview software was used to calculate time, displacement, velocity, acceleration, force, power, impulse and stiffness. After statistical analysis, jumping variables were grouped to achieve specific training objectives. RESULTS: The mechanical parameters were largely influenced by the jump strategy, all the deep jumps produced superior jump heights and concentric velocities as compared to the shallow jumps. The exercises associated with greater power outputs were the S-DJ (5386±1095 W) and 6CJ (5795±1365 W) that involved short impulse durations and very high accelerations. The greatest values of muscle stiffness were not recorded during the highest vertical jumps, meaning that stiffness is not critical for jumping high. CONCLUSION: This study gives an overview of what is changing when we manipulate jumping variables and instructions given to the athletes. Plyometric exercises should be carefully selected according to the sport and specific individual needs.


Asunto(s)
Rendimiento Atlético/fisiología , Movimiento/fisiología , Ejercicio Pliométrico , Adulto , Fenómenos Biomecánicos , Humanos , Masculino , Músculo Esquelético/fisiología , Programas Informáticos , Análisis y Desempeño de Tareas
16.
Dis Esophagus ; 24(5): 360-70, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21143697

RESUMEN

The development of Barrett's esophagus and its progression to adenocarcinoma are clearly linked to reflux of acid and bile. Our objective in this study was to develop an optimized ex vivo biopsy culture technique to study the molecular signaling events induced after insult with individual refluxate constituents. We illustrate the utility of this method by showing results for NF-kB centered cell signaling, and compare the results with those obtained from esophageal cell lines. We show that upregulation of the two NF-kB target genes show differences in pH preference, with IL-8 being preferentially upregulated by DCA at neutral pH, and IkB being upregulated by neutral DCA, acidic DCA, and acid alone. This was found to be true in both cell lines and biopsy cultures. The maximum responses were noted in both models when mixed reflux (DCA at pH 6) was utilized, perhaps reflecting the pH preference of DCA (pKa 6.2). Both the optimized ex vivo models, and the in vitro cell lines show that bile and acid are capable of inducing NF-kB dependent gene expression, with some interesting differences in preferred transcriptional target. In conclusion, in both cells and cultured biopsies, similar reflux driven gene expression changes were noted, with maximum effects noted with DCA exposures at pH 6.


Asunto(s)
Adenocarcinoma/genética , Esófago de Barrett/genética , Neoplasias Esofágicas/genética , Expresión Génica , Subunidad p50 de NF-kappa B/genética , Transducción de Señal/efectos de los fármacos , Línea Celular Tumoral , Colagogos y Coleréticos/farmacología , Ácido Desoxicólico/farmacología , Humanos , Concentración de Iones de Hidrógeno , Proteínas I-kappa B/efectos de los fármacos , Proteínas I-kappa B/genética , Técnicas In Vitro , Interleucina-8/efectos de los fármacos , Interleucina-8/genética , Interleucina-8/metabolismo , Subunidad p50 de NF-kappa B/metabolismo , Regulación hacia Arriba
17.
Int J Sports Med ; 32(3): 185-9, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21305444

RESUMEN

The purpose of this study was to examine whether time of day variations in power output can be accounted for by the diurnal fluctuations existent in body temperature. 8 recreationally trained males (29.8±5.2 yrs; 178.3±5.2 cm; 80.3±6.5 kg) were assessed on 4 occasions following a: (a) control warm-up at 8.00 am; (b) control warm-up at 4.00 pm; (c) extended warm-up at 8.00 am; and, (d) extended warm-up at 4.00 pm. The control warm-up consisted of dynamic exercises and practice jumps. The extended warm-up incorporated a 20 min general warm-up on a stationary bike prior to completion of the control warm-up, resulting in a whole body temperature increase of 0.3±0.2°C. Kinetic and kinematic variables were measured using a linear optical encoder attached to a barbell during 6 loaded counter-movement jumps. Results were 2-6% higher in the afternoon control condition than morning control condition. No substantial performance differences were observed between the extended morning condition and afternoon control condition where body temperatures were similar. Results indicate that diurnal variation in whole body temperature may explain diurnal performance differences in explosive power output and associated variables. It is suggested that warm-up protocols designed to increase body temperature are beneficial in reducing diurnal differences in jump performance.


Asunto(s)
Temperatura Corporal/fisiología , Ritmo Circadiano/fisiología , Tolerancia al Ejercicio/fisiología , Contracción Isométrica/fisiología , Músculo Esquelético/fisiología , Adaptación Fisiológica , Adulto , Fenómenos Biomecánicos , Estudios Cruzados , Humanos , Pierna/fisiología , Masculino , Monitoreo Fisiológico , Análisis y Desempeño de Tareas , Factores de Tiempo
18.
J Sports Med Phys Fitness ; 50(1): 37-42, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20308970

RESUMEN

AIM: Strength and conditioning practitioners appear focussed on developing maximal strength based on the premise that it underpins explosive muscular performance. Investigation into the relationship between strength and a multitude of explosive power measures is limited though. Furthermore, the relationship of explosive force and power with functional performance is unclear. METHODS: We examined the inter-relationships between maximal strength and explosive measures of force and power at different loads. Also investigated were the relationships between explosive measures and 10-m sprinting ability. Forty elite-level well-trained rugby union and league athletes performed 10-m sprints followed by bilateral concentric-only machine squat-jumps at 20 and 80%1RM. The magnitudes of the inter-relationships between groups of force measures, power measures and sprint times were interpreted using Pearson correlation coefficients, which had uncertainty (90% confidence limits) of approximately +/-0.25. Measures investigated included peak force, peak power, rate of force development, and some of Zatsiorsky's explosive measures, all expressed relative to body mass. RESULTS: The relationship between maximal strength and peak power was moderate at 20 %1RM (r=0.32) but trivial at 80 %1RM (r=-0.03). Practically no relationship between any of the explosive measures and 10-m sprint ability was observed (r=-0.01 to 0.06). CONCLUSION: Although correlations do not imply cause and effect, we speculate that the common practice of focussing on high levels of maximal strength in a machine squat to improve power output may be misguided. Our results also cast doubt on the efficacy of increasing explosive force and power in a machine squat-jump with the intention of improving sprint ability in well-trained athletes.


Asunto(s)
Fútbol Americano/fisiología , Pierna/fisiología , Contracción Muscular/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Carrera/fisiología , Levantamiento de Peso/fisiología , Adulto , Fenómenos Biomecánicos , Intervalos de Confianza , Humanos , Masculino , Proyectos Piloto , Estadística como Asunto , Factores de Tiempo
19.
J Neural Eng ; 17(2): 026023, 2020 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-32103828

RESUMEN

OBJECTIVE: Electrical stimulation of the human brain is commonly used for eliciting and inhibiting neural activity for clinical diagnostics, modifying abnormal neural circuit function for therapeutics, and interrogating cortical connectivity. However, recording electrical signals with concurrent stimulation results in dominant electrical artifacts that mask the neural signals of interest. Here we develop a method to reproducibly and robustly recover neural activity during concurrent stimulation. We concentrate on signal recovery across an array of electrodes without channel-wise fine-tuning of the algorithm. Our goal includes signal recovery with trains of stimulation pulses, since repeated, high-frequency pulses are often required to induce desired effects in both therapeutic and research domains. We have made all of our code and data publicly available. APPROACH: We developed an algorithm that automatically detects templates of artifacts across many channels of recording, creating a dictionary of learned templates using unsupervised clustering. The artifact template that best matches each individual artifact pulse is subtracted to recover the underlying activity. To assess the success of our method, we focus on whether it extracts physiologically interpretable signals from real recordings. MAIN RESULTS: We demonstrate our signal recovery approach on invasive electrophysiologic recordings from human subjects during stimulation. We show the recovery of meaningful neural signatures in both electrocorticographic (ECoG) arrays and deep brain stimulation (DBS) recordings. In addition, we compared cortical responses induced by the stimulation of primary somatosensory (S1) by natural peripheral touch, as well as motor cortex activity with and without concurrent S1 stimulation. SIGNIFICANCE: Our work will enable future advances in neural engineering with simultaneous stimulation and recording.


Asunto(s)
Estimulación Encefálica Profunda , Corteza Motora , Artefactos , Encéfalo , Estimulación Eléctrica , Electrocorticografía , Humanos
20.
Science ; 172(3985): 847-9, 1971 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-17792942

RESUMEN

In the quiet years after the 1956 eruption of the Bezymianny volcano in central Kamchatka, it is doubtful that any volcano vented into the stratosphere until the 1963 eruptions of Agung (Bali), Trident (Alaska), and Surtsey (Iceland). From 1963 to the Hekla (Iceland) event in May 1970, two latitudinal belts of volcanoes have ejected ash and gases into the stratosphere. One belt is equatorial and the other is just below the Arctic Circle. The latter, where the tropopause is considerably lower, may have been the principal source of replenishment of volcanic dust and gases to the stratosphere. Submarine and phreatic volcanic eruptions may have been the sources of reported increase of water vapor in the stratosphere.

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