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1.
Sci Adv ; 10(19): eadl6601, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38728405

RESUMO

One of the stranger planetary rings is Saturn's narrow, clumpy F ring, lying just outside the main rings, in a region disturbed by chaotic orbital dynamics. We show that the F ring has a stable "true core" that dominates its mass and is confined into discontinuous short arcs of particles larger than a few millimeters in radius. The more obvious micron-size particles seen in images, outlining and obscuring the true core, contribute only a small fraction of its mass. We found that these arcs of large particles orbit Saturn in a specific corotational resonance with the nearby 100-kilometer diameter ringmoon Prometheus, which stabilizes the F ring material and allows it to persist within the disturbed region for decades or longer. Toward the end of the observing period, a small chaotic glitch in the orbit of Prometheus temporarily disrupted the confinement, but the arcs seem to be able to adapt.

2.
Allergy Asthma Clin Immunol ; 20(1): 24, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528606

RESUMO

Asthma exacerbations are a leading cause of pediatric hospitalizations despite multiple efforts to educate patients and families on disease course and medication management. Asthma education in the pediatric emergency department (ED) is challenging, and although the use of written action plans has been associated with reduction in hospitalizations and ED visits, written tools may not be useful for individuals with low health literacy. Moreover, asthmatic children should participate in their asthma education. In this prospective randomized study of 53 families presenting to a pediatric ED with a child experiencing an asthma exacerbation, education on asthma was presented via an interactive mobile-based video-game versus a standard-of-care asthma education video (SAV). Median age was 10 years; 64% were males. Many patients had moderate-to-severe asthma, with 57% experiencing ≥ 2 asthma-related ED visits in the last year, 58% requiring hospitalization and 32% reporting a critical care admission. In this cohort, the mobile-based video-game was found to be a feasible, acceptable educational tool; 86% of parents and 96% of children liked the game, while 96% of parents and 76% of children preferred playing the game over watching a SAV. Despite a history of persistent asthma, only 34% of children used an inhaled corticosteroid while 70% required rescue inhaler use in the prior week. Basic asthma knowledge was sub-optimal with only 60% of parents and 43% of children correctly recognizing symptoms that should prompt immediate medical care. This reflects a major gap in asthma knowledge that coexists with parental misconceptions regarding optimal asthma management.

3.
Atten Percept Psychophys ; 86(1): 354-365, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36720780

RESUMO

The current experiments address the enduring debate regarding the role of attention in feature binding in visuospatial working memory by considering the nature of the to-be-bound features, i.e., whether they are intrinsic (integrated within the object, such as its color and shape) or extrinsic (not part of the object, such as its spatial location). Specifically, arrays of different-colored shapes in different locations were followed by probed recall: One feature of the probed object prompted recall of one of its remaining two features (e.g., a shape probe prompts recall of color, with the probe displayed at the center of the screen (i.e., without spatial information)) to test the retention of intrinsic (shape, color) and extrinsic (location) features. During the retention interval, we manipulated attention via disruption (Experiment 1) and retro-cues (Experiment 2) to determine their impacts on binding errors, as estimated from a three-parameter mixture model fit to recall error (i.e., the distance between the target and response). Disrupting central versus peripheral attention in Experiment 1 did not respectively increase extrinsic and intrinsic binding errors as predicted, but disrupting central attention reduced target memory of the extrinsic feature relative to a no-disruption baseline. Guiding attention via extrinsic and intrinsic retro-cues in Experiment 2 did not respectively reduce extrinsic and intrinsic binding errors as predicted, but we observed retro-cue benefits to target memory that did not distinguish between extrinsic and intrinsic features. Thus, this work highlights that attentional resources aid target memory, with no consistent distinction between intrinsic and extrinsic features.


Assuntos
Atenção , Memória de Curto Prazo , Humanos , Memória de Curto Prazo/fisiologia , Atenção/fisiologia , Sinais (Psicologia) , Rememoração Mental/fisiologia , Percepção Visual/fisiologia
4.
PLoS One ; 18(12): e0295943, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38109368

RESUMO

The Social Readjustment Rating Scale, originally devised in 1967 by Holmes and Rahe, measures the impact of life events stress. At the time, the SRRS advanced its field of research by standardising the impact of stress with a set of independently derived weights called 'life change units' (LCUs) for 43 life events found to predict illness onset. The scale has been criticised for being outdated, e.g. "Mortgage over $10,000" and biased, e.g. "Wife begin or stop work". The aim of this cross-sectional survey study is to update and improve the SRRS whilst allowing backwards compatibility. We successfully updated the SRRS norms/LCUs using the ratings of 540 predominantly UK adults aged 18 to 84. Moreover, we also updated wording of 12 SRRS items and evaluated the impact of demographics, personal experience and loneliness. Using non-parametric frequentist and Bayesian statistics we found that the updated weights were higher but broadly consistent with those of the original study. Furthermore, changes to item wording did not affect raters' evaluations relative to the original thereby ensuring cross-comparability with the original SRRS. The raters were not unduly influenced by their personal experiences of events nor loneliness. The target sample was UK rather than US-based and was proportionately representative regarding age, sex and ethnicity. Moreover, the age range was broader than the original SRRS. In addition, we modernised item wording, added one optional extra item to the end of the scale to evaluate the readjustment to living alone and identified 3 potential new items proposed by raters. Backwards-compatibility is maintained.


Assuntos
Acontecimentos que Mudam a Vida , Estresse Psicológico , Adulto , Humanos , Estudos Transversais , Teorema de Bayes , Etnicidade
5.
PLoS One ; 18(11): e0290635, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38019767

RESUMO

Stress and normal ageing produce allostatic load, which may lead to difficulties with cognition thereby degrading quality of life. The current study's objective was to assess whether ageing and cumulative stress interact to accelerate cognitive decline. With 60 participants, Marshall et al. found that ageing and cumulative stress interact significantly to impair working memory performance in older adults, suggesting vulnerability to the cumulative effects of life events beyond 60 years old. To replicate and extend this finding, we increased the sample size by conducting 3 independent studies with 156 participants and improved the statistical methods by conducting an iterative Bayesian meta-analysis with Bayes factors. Bayes factors deliver a more comprehensive result because they provide evidence for either the null hypothesis (H0), the alternative hypothesis (H1) or for neither hypothesis due to evidence not being sufficiently sensitive. Young (18-35 yrs) and older (60-85 yrs) healthy adults were categorised as high or low stress based on their life events score derived from the Life Events Scale for Students or Social Readjustment Rating Scale, respectively. We measured accuracy and reaction time on a 2-back working memory task to provide: a) Bayes factors and b) Bayesian meta-analysis, which iteratively added each study's effect sizes to evaluate the overall strength of evidence that ageing, cumulative stress and/or the combination of the two detrimentally affect working memory performance. Using a larger sample (N = 156 vs. N = 60) and a more powerful statistical approach, we did not replicate the robust age by cumulative stress interaction effect found by Marshall et al.. The effects of ageing and cumulative stress also fell within the anecdotal range (⅓

Assuntos
Memória de Curto Prazo , Qualidade de Vida , Humanos , Idoso , Pessoa de Meia-Idade , Teorema de Bayes , Cognição , Envelhecimento
6.
Trauma Surg Acute Care Open ; 8(1): e001014, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37266305

RESUMO

Objectives: In 2020, firearm injuries surpassed automobile collisions as the leading cause of death in US children. Annual automobile fatalities have decreased during 40 years through a multipronged approach. To develop similarly targeted public health interventions to reduce firearm fatalities, there is a critical need to first characterize firearm injuries and their outcomes at a granular level. We sought to compare firearm injuries, outcomes, and types of shooters at trauma centers in four pediatric health systems across the USA. Methods: We retrospectively extracted data from each institution's trauma registry, paper and electronic health records. Study included all patients less than 19 years of age with a firearm injury between 2003 and 2018. Variables collected included demographics, intent, resources used, and emergency department and hospital disposition. Descriptive statistics were reported using medians and IQRs for continuous data and counts with percentages for categorical data. χ2 test or Fisher's exact test was conducted for categorical comparisons. Results: Our cohort (n=1008, median age 14 years) was predominantly black and male. During the study period, there was an overall increase in firearm injuries, driven primarily by increases in the South (S) site (ß=0.11 (SE 0.02), p=<0.001) in the setting of stable rates in the West and decreasing rates in the Northeast and Mid-Atlantic sites (ß=-0.15 (SE 0.04), p=0.002; ß=-0.19 (SE0.04), p=0.001). Child age, race, insurance type, resource use, injury type, and shooter type all varied by regional site. Conclusion: The incidence of firearm-related injuries seen at four sites during 15 years varied by site and region. The overall increase in firearm injuries was predominantly driven by the S site, where injuries were more often unintentional. This highlights the need for region-specific data to allow for the development of targeted interventions to impact the burden of injury.Level of Evidence: II, retrospective study.

7.
Appl Opt ; 62(9): 2195-2199, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-37132856

RESUMO

We investigate the use of passive intracavity optical filters for controlling the laser output spectrum of a polarization-mode-locked, ultrafast ytterbium fiber laser. The overall lasing bandwidth is increased or extended by strategic choice of the filter cutoff frequency. Overall laser performance, including pulse compression and intensity noise, is investigated for both shortpass and longpass filters with a range of cutoff frequencies. The intracavity filter not only shapes the output spectra, but also provides a route for overall broader bandwidths and shorter pulses in ytterbium fiber lasers. These results demonstrate that spectral shaping with a passive filter is a useful tool to routinely achieve sub-45 fs pulse durations in ytterbium fiber lasers.

8.
Alcohol ; 91: 41-51, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33321179

RESUMO

Early life stress is known to impact vulnerability to psychopathological disorders in adulthood, including anxiety and alcohol use disorder (AUD), but the mechanisms underlying susceptibility to these outcomes are not fully understood. In the current study, we used adolescent social isolation (ASI) to determine whether Heterogeneous Stock (HS) rats, an outbred model used for genetic fine-mapping, could be used to study the genetics contributing to ASI-induced anxiety- and AUD-like behavior. We isolated (ASI) or group-housed (adolescent group-housed; AGH) 64 male HS rats at 4 weeks of age. After 5 weeks in these housing conditions, multiple anxiety and coping/despair-like behaviors were measured. All rats were then individually housed and assessed for voluntary ethanol self-administration. At euthanasia, synaptoneurosomes were isolated from a subset of brains to examine the expression of two proteins associated with alcohol drinking-related behaviors, GluA1 and SK2, in the dorsal (dHC) and ventral hippocampus (vHC). We found that ASI increased hyperactivity in the open field test relative to AGH, with no changes in other anxiety-like behaviors. Surprisingly, ASI rats demonstrated decreased immobility and increased climbing in the forced swim test relative to AGH. In contrast to prior studies by us and others, we found no difference in self-administration of 20% ethanol, with decreased ethanol self-administration in ASI relative to AGH rats at higher ethanol concentrations. Furthermore, while ASI in Long-Evans rats resulted in decreased SK2 expression in vHC synaptosomes, no differences were seen in vHC synaptosomes for SK2 or GluA1 in HS rats. These results demonstrate that HS rats are protected against many of the negative effects previously seen in response to ASI, namely anxiety-like behavior and increased ethanol self-administration. The current work suggests that a lack of change in SK2 and GluA1 expression levels in the vHC may play a role in conferring this protection.


Assuntos
Consumo de Bebidas Alcoólicas , Ansiedade , Hipercinese/psicologia , Estresse Psicológico/complicações , Animais , Etanol , Masculino , Ratos , Ratos Long-Evans
9.
PLoS One ; 15(11): e0241763, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33237906

RESUMO

TRIAL REGISTRATION: The authors confirm that all ongoing and related trials for this intervention are registered. The studies reported in this manuscript are registered as clinical trials at ISRCTN: Pilot ID- ISRCTN15325073 RCT ID- ISRCTN59395217.


Assuntos
Adaptação Fisiológica , Terapia Recreacional , Transtornos de Estresse Pós-Traumáticos/psicologia , Veteranos/psicologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Transtornos de Estresse Pós-Traumáticos/patologia
10.
Physiol Genomics ; 52(9): 379-390, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32687430

RESUMO

Obesity is influenced by genetics and diet and has wide ranging comorbidities, including anxiety and depressive disorders. Outbred heterogeneous stock (HS) rats are used for fine-genetic mapping of complex traits and may be useful for understanding gene by diet interactions. In this study, HS rats were fed diets containing 60% kcal from fat (high-fat diet, HFD) or 10% kcal from fat (low-fat diet, LFD) and tested for metabolic (study 1) and behavioral (study 2) outcomes. In study 1, we measured glucose tolerance, fasting glucose and insulin, fat pad weights and despair-like behavior in the forced swim test (FST). In study 2, we assessed anxiety-like (elevated plus maze, EPM; open field test, OFT) and despair-like/coping (splash test, SpT; and FST) behaviors. Body weight and food intake were measured weekly in both studies. We found negative effects of HFD on metabolic outcomes, including increased body weight and fat pad weights, decreased glucose tolerance, and increased fasting insulin. We also found negative effects of HFD on despair-like/coping and anxiety-like behaviors. These include increased immobility in the FST, decreased open arm time in the EPM, and increased movement and rest episodes and decreased rearing in the OFT. The diet-induced changes in EPM and OFT were independent of overall locomotion. Additionally, diet-induced changes in OFT behaviors were independent of adiposity, while adiposity was a confounding factor for EPM and FST behavior. This work establishes the HS as a model to study gene by diet interactions affecting metabolic and behavioral health.


Assuntos
Comportamento Animal/fisiologia , Dieta Hiperlipídica/efeitos adversos , Doenças Metabólicas/patologia , Obesidade/patologia , Adiposidade , Animais , Animais não Endogâmicos , Ansiedade/etiologia , Ansiedade/psicologia , Peso Corporal , Modelos Animais de Doenças , Teste de Tolerância a Glucose/métodos , Masculino , Doenças Metabólicas/etiologia , Doenças Metabólicas/psicologia , Obesidade/etiologia , Ratos
11.
Conscious Cogn ; 84: 102979, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32702601

RESUMO

To interact functionally with our environment, our perception must locate events in time, including discerning whether sensory events are simultaneous. The Temporal Binding Window (TBW; the time window within which two stimuli tend to be integrated into one event) has been shown to relate to individual differences in perception, including schizotypy, but the relationship with subjective estimates of duration is unclear. We compare individual TBWs with individual differences in the filled duration illusion, exploiting differences in perception between empty and filled durations (the latter typically being perceived as longer). Schizotypy has been related to both these measures and is included to explore a potential link between these tasks and enduring perceptual differences. Results suggest that individuals with a narrower TBW make longer estimates for empty durations and demonstrate less variability in both conditions. Exploratory analysis of schizotypy data suggests a relationship with the TBW but is inconclusive regarding time perception.


Assuntos
Percepção Auditiva/fisiologia , Ilusões/fisiologia , Individualidade , Percepção do Tempo/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Transtorno da Personalidade Esquizotípica/fisiopatologia , Adulto Jovem
12.
J Adolesc ; 83: 31-41, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32693219

RESUMO

INTRODUCTION: Symptoms of attention-deficit hyperactivity disorder (ADHD) and conduct problems have been associated with heightened temporal discounting of reward value resulting in a preference for immediate over delayed outcomes. We examined the cross-sectional relationship between future preference (including intertemporal choice) and prospection (the ability to bring to mind and imagine the experience of future personally-relevant events and outcomes) in adolescents with a range of ADHD symptoms and aggressive behaviour. METHODS: A combination of behavioural tasks and self-reports measured intertemporal decision making, individual differences in preference for future outcomes and experience of prospection in a convenience sample of English adolescents aged 11-17 (n = 64, 43.8% males). Parents rated symptoms of ADHD and aggression. RESULTS: & Conclusions: Factor analysis identified two factors: "Future Preference" and "Prospection". Significant negative bivariate correlations were found between ADHD and the scores of both factors and between aggression and Future Preference. A path model confirmed the independent significant association of ADHD with both factors but not with aggression. There was no evidence that Prospection was associated with Future Preference or that it reduced the associations between ADHD symptoms and Future Preference. These results provide further evidence that ADHD is associated with a tendency to prefer immediate over future outcomes. The same association with aggression seemed to be driven by the overlap with ADHD symptoms. We provide some of the first evidence that individuals with high ADHD symptoms have difficulty in prospecting about future episodes. However, this is unrelated to their preference for future outcomes.


Assuntos
Agressão/psicologia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Desvalorização pelo Atraso , Adolescente , Criança , Estudos Transversais , Inglaterra , Feminino , Humanos , Masculino , Pais , Fatores de Tempo
13.
Acta Paediatr ; 109(12): 2648-2655, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32271945

RESUMO

AIM: This study examined the direct and indirect associations between childhood psychopathology symptoms, screen use, media multitasking and participation in non-digital recreation. METHODS: Psychopathology symptoms, media use, media multitasking, participation in sports, social clubs and reading/games were reported by 520 parents about their 3- to 11-year-old children. The data were analysed using structural equation modelling. RESULTS: There were bidirectional negative associations between sports participation and emotional problems (ß = -0.16, P < .001 and ß = -0.15, P < .001); attention deficit hyperactivity disorder (ADHD) symptoms were associated with reduced reading/games (ß = -0.14, P = .004). A bidirectional positive association was found between media use and conduct problems (ß = 0.10, P = .015 and ß = 0.14, P = .015). Increased media multitasking was indirectly associated with elevated symptoms of ADHD via a reduction in reading/games (ß = 0.10, P = .026). However, there was no evidence that screen use mediated the associations between psychopathology symptoms and non-digital recreation. CONCLUSION: Depending on the specific psychological difficulties, children are either less likely to participate in non-digital recreation or are more likely to use screen media or multitask with media. Interventions for children, who experience emotional or behavioural difficulties, are needed to improve participation in non-digital recreation.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Comportamento Problema , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Criança , Comportamento Infantil , Pré-Escolar , Humanos , Saúde Mental , Pais
14.
ACS Appl Mater Interfaces ; 12(7): 8634-8641, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31990517

RESUMO

Organophosphorus chemical warfare agents function as potent neurotoxins. Whilst the destruction of nerve agents is most readily achieved by hydrolysis, their storage and transport are hazardous and lethal in milligram doses, with any spillage resulting in fatalities. Furthermore, current decontamination and remediation measures are limited by a need for stoichiometric reagents, solvents, and buffered solutions, complicating the process for the treatment of bulk contaminants. Herein, we report a composite polymer material capable of rendering bulk VX unusable by immobilization within a porous polymer until a metal-organic framework (MOF) catalyst fully hydrolyzes the neurotoxin. This is an all-in-one capability that minimizes the use of multiple reagents, facilitated by a porous high internal phase emulsion-based polystyrene monolith housing an active zirconia MOF catalyst (MOF-808); the porous polymer absorbs and immobilizes the liquid agents, while the MOF enables hydrolysis. The dichotomous hierarchy of porous materials facilitates the containment and rapid hydrolysis of VX (>80% degradation in 8 h) in the presence of excess H2O. This composite can further enable the hydrolysis of neat VX with reliance on ambient humidity (>95% in 11 days). Potentially, 4.5 kg of the composite can absorb, immobilize, and degrade the contents of a standard chemical drum/barrel (208 L, 55 gal) of the chemical warfare agent (CWA). We believe that this composite is the first example of what will be the go-to approach for CWA immobilization and degradation in the future. Furthermore, we believe that this demonstration of a catalytically reusable absorbent sponge provides a signpost for the development of similar materials where immobilization of a substrate in a catalytically active environment is desirable.


Assuntos
Substâncias para a Guerra Química/química , Descontaminação/métodos , Estruturas Metalorgânicas/química , Nanocompostos/química , Agentes Neurotóxicos/química , Polímeros/química , Zircônio/química , Catálise , Descontaminação/instrumentação , Emulsões/química , Hidrólise , Estruturas Metalorgânicas/ultraestrutura , Microscopia Eletrônica , Nanocompostos/ultraestrutura , Porosidade
15.
Trends Neurosci Educ ; 17: 100114, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31685123

RESUMO

AIMS: What helps children learn: is it a presence of a live teacher or an interaction with the learning materials? Addressing this question, we manipulated a teacher's presence (on-screen vs. present) and activity (observing vs. doing) while teaching children about the properties of geometric shapes. METHOD: Five-year-olds (n = 215) completed two shape-sorting tasks in which they distinguished between typical, atypical and non-valid shapes. In between these tasks, they took part in one of four training sessions: doing teacher-present, observing teacher-present, doing teacher-on-screen and observing teacher-on-screen. RESULTS: Although children's shape knowledge improved across all training conditions, learning showed an interaction between teacher presence and task difficulty. In a teacher's presence, children learned more about the most difficult (atypical) shapes, irrespective of activity. It may be the social interaction, associated with a teacher's presence, that enhances learning. Conversely, physically taking part in interactive touchscreen training did not result in more learning than passive screen viewing.


Assuntos
Educação/métodos , Criança , Pré-Escolar , Pessoal de Educação , Feminino , Humanos , Relações Interpessoais , Aprendizagem , Masculino , Professores Escolares , Tempo de Tela , Ensino/tendências
16.
ACS Med Chem Lett ; 10(11): 1568-1572, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31749912

RESUMO

Carfentanil is a synthetic opioid significantly more potent than clinically prescribed fentanyl. The primary metabolites of carfentanil, generated from human liver microsomes, were structurally confirmed through chemical synthesis. The synthesized compounds were evaluated for µ-opioid receptor (MOR) functional activity. Of the six metabolites assayed, a major metabolite showed comparable activity to the parent opioid. Three other metabolites showed significant MOR functional activity. The availability of the metabolites could aid improvements in the analysis of biomedical samples obtained from suspected human exposures to carfentanil and development of treatment protocols.

17.
Dev Neuropsychol ; 44(4): 385-396, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31203657

RESUMO

We investigated the immediate consequences of differently paced videos on behaviour and neural activity during response inhibition. Forty 7-year-olds watched a fast- or slow-paced video and completed a go/no-go task. Compared to the slow-paced-video group, children in the fast-paced-video group made more no-go errors. There was also an interaction between pace and no-go response type (correct, wrong) for the N2 and P3 peak latencies. In the slow-paced group, both components peaked earlier for correct response withholds. This usual pattern of activation was absent in the fast-paced group. Video pace appears to affect behaviour and the neural responses involved in inhibition.


Assuntos
Tomada de Decisões/fisiologia , Potenciais Evocados Visuais/fisiologia , Potenciais Evocados/fisiologia , Inibição Psicológica , Desempenho Psicomotor/fisiologia , Criança , Eletroencefalografia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Tempo de Reação/fisiologia , Jogos de Vídeo
18.
Science ; 364(6445)2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31196983

RESUMO

Saturn's rings are an accessible exemplar of an astrophysical disk, tracing the Saturn system's dynamical processes and history. We present close-range remote-sensing observations of the main rings from the Cassini spacecraft. We find detailed sculpting of the rings by embedded masses, and banded texture belts throughout the rings. Saturn-orbiting streams of material impact the F ring. There are fine-scaled correlations among optical depth, spectral properties, and temperature in the B ring, but anticorrelations within strong density waves in the A ring. There is no spectral distinction between plateaux and the rest of the C ring, whereas the region outward of the Keeler gap is spectrally distinct from nearby regions. These results likely indicate that radial stratification of particle physical properties, rather than compositional differences, is responsible for producing these ring structures.

19.
J Forensic Sci ; 64(5): 1530-1539, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30802952

RESUMO

Police witness intelligence stated a murdered adult male "Fred" had been vertically buried in wooded hilly terrain 30 years ago in the Midlands, U.K. Conventional search methods were unsuccessful; therefore, the police requested a geophysical investigation to be undertaken to determine whether "Fred" could be detected. A multiphased geophysical approach was conducted, using bulk ground conductivity and metal detectors, then follow-up magnetics and ground penetrating radar (GPR) survey profiles on electromagnetic (EM) anomalous areas. A tight grid pattern was used to account for the reduced target size. Relatively high-resolution EM and GPR techniques were determined optimal for this terrain and sandy soil. Geophysical anomalies were identified and the most promising intrusively investigated, and this was found to be a large boulder and tree roots. Study implications suggest careful multiphase geophysical surveys are best practice and give confidence in cold case searches. This study yielded a no-body result, effectively saving police time and costs from further investigations.


Assuntos
Sepultamento , Ciências Forenses/métodos , Condutividade Elétrica , Fenômenos Eletromagnéticos , Monitoramento Ambiental/métodos , Humanos , Masculino , Polícia , Radar
20.
Behav Brain Res ; 361: 39-49, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30578806

RESUMO

Cortical activity in frontal, parietal, and motor regions during sequence observation correlates with performance on sequence reproduction. Increased cortical activity observed during observation has therefore been suggested to represent increased learning. Causal relationships have been demonstrated between M1 and motor sequence reproduction and between parietal cortex and bimanual learning. However, similar effects have not been reported for frontal regions despite a number of reports implicating its involvement in encoding of motor sequences. Investigating causal relations between cortical activity and reproduction of motor sequences in parietal, frontal and primary motor regions can disentangle whether specific regions during simple observation can be selectively ascribed to encoding or reproduction or both. We designed a sensorimotor paradigm that included a strong motor sequence component, and tested the impact of individually adjusted transcranial alternating current stimulation (IAF-tACS) to prefrontal, parietal, and primary motor regions on electroencephalographic motor rhythms (alpha and beta bandwidths) during motor sequence observation and the ability to reproduce the observed sequences. Independently of the stimulated region, IAF-tACS led to a reduction in suppression in the lower beta-range relative to sham. Prefrontal IAF-tACS however, led to significant improvement in motor sequence reproduction, pinpointing the crucial role of prefrontal regions in motor sequence reproduction.


Assuntos
Aprendizagem/fisiologia , Córtex Motor/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adolescente , Adulto , Eletroencefalografia , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Lobo Parietal/fisiologia , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiologia
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