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1.
Psychiatry Res ; 329: 115534, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37844353

RESUMO

High dropout rates and poor adherence associated with digital interventions have prompted research into modifications of these treatments to improve engagement and completion rates. This trial aimed to investigate the added benefit of clinician support when paired alongside a ten-session, online cognitive behaviour therapy (CBT) self-help intervention for bulimia nervosa (BN). As part of a three-arm, phase II randomised controlled trial, 114 participants (16 years or over) with full or subthreshold BN were randomly assigned to complete the intervention in a self-help mode (with administrative researcher contact; n = 38), with adjunct clinician support (weekly 30-minute videoconferencing sessions; n = 37), or a no-treatment waitlist control (WLC; n = 39). Baseline to post-treatment (12-weeks) decreases in objective binge episode frequency were significantly greater for clinician-supported participants as compared to WLC, but not for self-help when compared to WLC. However, due to continued improvements for self-help across follow-up (24-weeks), both arms outperformed WLC when analysed as an overall rate of change across three timepoints. Clinician-supported participants outperformed self-help in regards to laxative use and dietary restraint. Our results demonstrate that good clinical outcomes can be achieved with a relatively brief online CBT-based program even in the absence of structured clinical support, indicating a possible overreliance upon clinician support as a primary adherence-facilitating mechanism.


Assuntos
Bulimia Nervosa , Terapia Cognitivo-Comportamental , Humanos , Bulimia Nervosa/terapia , Bulimia Nervosa/psicologia , Terapia Cognitivo-Comportamental/métodos , Comportamentos Relacionados com a Saúde , Resultado do Tratamento
2.
Sci Rep ; 13(1): 15964, 2023 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-37749294

RESUMO

Anti-vaccine content and other kinds of misinformation are hypothesized to be more heavily monetized than other kinds of online content. We test this hypothesis by applying several novel and scalable measures of website monetization strategies to more than 400,000 links shared by 261 anti-vaccine Facebook pages and 190 pro-vaccine ones. Contrary to expectations, websites promoted in pro-vaccine venues do more to monetize attention than those promoted in anti-vaccine venues. This is a consequence of how intensely monetized news websites are-pro-vaccine venues share more links to news. The specific news sites shared by anti-vaccine venues are rated less credible by fact-checking organizations, but we find little substantive difference in their monetization strategies. These results emphasize the need to interpret measures of monetization within the context of the broader "attention economy".


Assuntos
Internet , Vacinação , Vacinas , Humanos , Internet/economia , Recusa de Vacinação , Mídias Sociais/economia
3.
Vision Res ; 212: 108297, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37527594

RESUMO

A key challenge in human and computer face recognition is to differentiate information that is diagnostic for identity from other sources of image variation. Here, we used a combined computational and behavioural approach to reveal critical image dimensions for face recognition. Behavioural data were collected using a sorting and matching task with unfamiliar faces and a recognition task with familiar faces. Principal components analysis was used to reveal the dimensions across which the shape and texture of faces in these tasks varied. We then asked which image dimensions were able to predict behavioural performance across these tasks. We found that the ability to predict behavioural responses in the unfamiliar face tasks increased when the early PCA dimensions (i.e. those accounting for most variance) of shape and texture were removed from the analysis. Image similarity also predicted the output of a computer model of face recognition, but again only when the early image dimensions were removed from the analysis. Finally, we found that recognition of familiar faces increased when the early image dimensions were removed, decreased when intermediate dimensions were removed, but then returned to baseline recognition when only later dimensions were removed. Together, these findings suggest that early image dimensions reflect ambient changes, such as changes in viewpoint or lighting, that do not contribute to face recognition. However, there is a narrow band of image dimensions for shape and texture that are critical for the recognition of identity in humans and computer models of face recognition.


Assuntos
Reconhecimento Facial , Humanos , Reconhecimento Facial/fisiologia , Face , Reconhecimento Psicológico/fisiologia , Simulação por Computador , Reconhecimento Visual de Modelos/fisiologia
4.
BMC Prim Care ; 24(1): 134, 2023 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-37386370

RESUMO

BACKGROUND: Chronic pain is among the most common conditions presenting to primary care and guideline-based care faces several challenges. A novel pain management program, Video-Telecare Collaborative Pain Management (VCPM), was established to support primary care providers and meet new challenges to care presented by the COVID-19 pandemic. METHODS: The present single-arm feasibility study aimed to evaluate the feasibility and acceptability of VCPM and its components among U.S. veterans on long-term opioid therapy for chronic pain at ≥ 50 mg morphine equivalent daily dose (MEDD). VCPM consists of evidence-based interventions, including opioid reassessment and tapering, rotation to buprenorphine and monitoring, and encouraging behavioral pain and opioid-use disorder self-management. RESULTS: Of the 133 patients outreached for VPCM, 44 completed an initial intake (33%) and 19 attended multiple VCPM appointments (14%). Patients were generally satisfied with VCPM, virtual modalities, and provider interactions. Nearly all patients who attended multiple appointments maintained a buprenorphine switch or tapered opioids (16/19; 84%), and buprenorphine switches were generally reported as acceptable by patients. Patients completing an initial intake with VCPM had reduced morphine equivalent daily dose after three months (means = 109 mg MEDD vs 78 mg), with greater reductions among those who attended multiple appointments compared to intake only (ΔMEDD = -58.1 vs. -8.40). Finally, 29 referrals were placed for evidence-based non-pharmacologic interventions. CONCLUSION: Pre-defined feasibility and acceptability targets for VCPM and its components were broadly met, and preliminary data are encouraging. Novel strategies to improve enrollment and engagement and future directions are discussed.


Assuntos
Buprenorfina , COVID-19 , Dor Crônica , Humanos , Manejo da Dor , Analgésicos Opioides/uso terapêutico , Dor Crônica/tratamento farmacológico , Estudos de Viabilidade , Pandemias , Morfina , Buprenorfina/uso terapêutico
5.
Conf Proc (IEEE Appl Power Electron Conf Expo) ; 2023: 1875-1880, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37342241

RESUMO

A cascaded H-bridge based pulse generator for transcranial magnetic stimulation is introduced. The system demonstrates complete flexibility for producing different shape, duration, direction, and rate of repetition of stimulus pulses within its electrical limits, and can emulate all commercial and research systems available to-date in this application space. An offline model predictive control algorithm, used to generate pulses and sequences, shows superior performance compared to conventional carrier-based pulse width modulation. A fully functioning laboratory prototype delivers up to 1.5 kV, 6 kA pulses, and is ready to be used as a research tool for the exploration of transcranial magnetic stimulation therapies by leveraging the many degrees-of-freedom offered by the design.

6.
Ecol Evol ; 13(4): e9905, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37038530

RESUMO

Quantifying habitat quality is dependent on measuring a site's relative contribution to population growth rate. This is challenging for studies of waterbirds, whose high mobility can decouple demographic rates from local habitat conditions and make sustained monitoring of individuals near-impossible. To overcome these challenges, biologists have used many direct and indirect proxies of waterbird habitat quality. However, consensus on what methods are most appropriate for a given scenario is lacking. We undertook a structured literature review of the methods used to quantify waterbird habitat quality, and provide a synthesis of the context-dependent strengths and limitations of those methods. Our search of the Web of Science and Scopus databases returned a sample of 666 studies, upon which our review was based. The reviewed studies assessed habitat quality by either measuring habitat attributes (e.g., food abundance, water quality, vegetation structure), or measuring attributes of the waterbirds themselves (e.g., demographic parameters, body condition, behavior, distribution). Measuring habitat attributes, although they are only indirectly related to demographic rates, has the advantage of being unaffected by waterbird behavioral stochasticity. Conversely, waterbird-derived measures (e.g., body condition, peck rates) may be more directly related to demographic rates than habitat variables, but may be subject to greater stochastic variation (e.g., behavioral change due to presence of conspecifics). Therefore, caution is needed to ensure that the measured variable does influence waterbird demographic rates. This assumption was usually based on ecological theory rather than empirical evidence. Our review highlighted that there is no single best, universally applicable method to quantify waterbird habitat quality. Individual project specifics (e.g., time frame, spatial scale, funding) will influence the choice of variables measured. Where possible, practitioners should measure variables most directly related to demographic rates. Generally, measuring multiple variables yields a better chance of accurately capturing the relationship between habitat characteristics and demographic rates.

7.
Nutrients ; 15(3)2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36771328

RESUMO

Home parenteral support (HPS) is an essential but potentially burdensome treatment that can affect quality of life (QoL). The aims of this longitudinal study were to understand whether any changes in HPS over time were associated with QoL. The Parenteral Nutrition Impact Questionnaire (PNIQ) was used, and data were collected on HPS prescribed at three time points. Data were analysed using multi-level mixed regression models presented as effect size and were adjusted for confounders. Study recruited 572 participants from 15 sites. Of these, 201 and 145 completed surveys at second and third time-points, respectively. PNIQ score was out of 20 with a higher score indicating poorer QoL. Any reduction in HPS infusions per week was associated with an improved PNIQ score of -1.10 (95% CI -2.17, -0.02) unadjusted and -1.34 (95% CI -2.45, -0.24) adjusted. Per day change to the number of infusions per week was associated with a change in the PNIQ score of 0.32 (95% CI -0.15, 0.80) unadjusted and 0.34 (95% CI -0.17, 0.85) adjusted. This is the largest national study to demonstrate improvements in QoL associated with HPS reduction over time using an HPS-specific and patient-centric tool, adding unique data for use of therapies in intestinal failure.


Assuntos
Enteropatias , Insuficiência Intestinal , Nutrição Parenteral no Domicílio , Humanos , Qualidade de Vida , Estudos Longitudinais , Enteropatias/terapia , Doença Crônica
8.
Ecol Appl ; 33(2): e2762, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36218186

RESUMO

Monitoring trends in animal populations in arid regions is challenging due to remoteness and low population densities. However, detecting species' tracks or signs is an effective survey technique for monitoring population trends across large spatial and temporal scales. In this study, we developed a simulation framework to evaluate the performance of alternative track-based monitoring designs at detecting change in species distributions in arid Australia. We collated presence-absence records from 550 2-ha track-based plots for 11 vertebrates over 13 years and fitted ensemble species distribution models to predict occupancy in 2018. We simulated plausible changes in species' distributions over the next 15 years and, with estimates of detectability, simulated monitoring to evaluate the statistical power of three alternative monitoring scenarios: (1) where surveys were restricted to existing 2-ha plots, (2) where surveys were optimized to target all species equally, and (3) where surveys were optimized to target two species of conservation concern. Across all monitoring designs and scenarios, we found that power was higher when detecting increasing occupancy trends compared to decreasing trends owing to the relatively low levels of initial occupancy. Our results suggest that surveying 200 of the existing plots annually (with a small subset resurveyed twice within a year) will have at least an 80% chance of detecting 30% declines in occupancy for four of the five invasive species modeled and one of the six native species. This increased to 10 of the 11 species assuming larger (50%) declines. When plots were positioned to target all species equally, power improved slightly for most compared to the existing survey network. When plots were positioned to target two species of conservation concern (crest-tailed mulgara and dusky hopping mouse), power to detect 30% declines increased by 29% and 31% for these species, respectively, at the cost of reduced power for the remaining species. The effect of varying survey frequency depended on its trade-off with the number of sites sampled and requires further consideration. Nonetheless, our research suggests that track-based surveying is an effective and logistically feasible approach to monitoring broad-scale occupancy trends in desert species with both widespread and restricted distributions.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Camundongos , Conservação dos Recursos Naturais/métodos , Dinâmica Populacional , Vertebrados , Austrália
9.
Curr Pain Headache Rep ; 26(12): 919-926, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36418847

RESUMO

PURPOSE OF REVIEW: The purpose of this review is to summarize advances in behavioral treatments for pain and headache disorders, as well as recent innovations in telemedicine for behavioral treatments. RECENT FINDINGS: Research for behavioral treatments continues to support their use as part of a multidisciplinary approach to comprehensive management for pain and headache conditions. Behavioral treatments incorporate both behavioral change and cognitive interventions and have been shown to improve outcomes beyond that of medical management alone. The onset of the COVID-19 public health emergency necessitated the rapid uptake of nontraditional modalities for behavioral treatments, particularly telemedicine. Telemedicine has long been considered the answer to several barriers to accessing behavioral treatments, and as a result of COVID-19 significant progress has been made evaluating a variety of telemedicine modalities including synchronous, asynchronous, and mobile health applications. Researchers are encouraged to continue investigating how best to leverage these modalities to improve access to behavioral treatments and to continue evaluating the efficacy of telemedicine compared to traditional in-person care. Comprehensive pain and headache management should include behavioral treatments to address a variety of behavior change and cognitive targets. Policy changes and advances in telemedicine for behavioral treatments provide the opportunity to address historical barriers limiting access.


Assuntos
COVID-19 , Transtornos da Cefaleia , Telemedicina , Humanos , COVID-19/terapia , Terapia Comportamental , Cefaleia/diagnóstico , Cefaleia/terapia
10.
Biophys J ; 121(15): 2981-2993, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35754183

RESUMO

When lipid membranes curve or are subjected to strong shear forces, the two apposed leaflets of the bilayer slide past each other. The drag that one leaflet creates on the other is quantified by the coefficient of interleaflet friction, b. Existing measurements of this coefficient range over several orders of magnitude, so we used a recently developed microfluidic technique to measure it systematically in supported lipid membranes. Fluid shear stress was used to force the top leaflet of a supported membrane to slide over the stationary lower leaflet. Here, we show that this technique yields a reproducible measurement of the friction coefficient and is sensitive enough to detect differences in friction between membranes made from saturated and unsaturated lipids. Adding cholesterol to saturated and unsaturated membranes increased interleaflet friction significantly. We also discovered that fluid shear stress can reversibly induce gel phase in supported lipid bilayers that are close to the gel-transition temperature.


Assuntos
Colesterol , Bicamadas Lipídicas , Fricção , Estresse Mecânico
11.
Neuropsychologia ; 172: 108275, 2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35660513

RESUMO

Successful recognition of familiar faces is thought to depend on the ability to integrate view-dependent representations of a face into a view-invariant representation. It has been proposed that a key intermediate step in achieving view invariance is the representation of symmetrical views. However, key unresolved questions remain, such as whether these representations are specific for naturally occurring changes in viewpoint and whether view-symmetric representations exist for familiar faces. To address these issues, we compared behavioural and neural responses to natural (canonical) and unnatural (noncanonical) rotations of the face. Similarity judgements revealed that symmetrical viewpoints were perceived to be more similar than non-symmetrical viewpoints for both canonical and non-canonical rotations. Next, we measured patterns of neural response from early to higher level regions of visual cortex. Early visual areas showed a view-dependent representation for natural or canonical rotations of the face, such that the similarity between patterns of response were related to the difference in rotation. View symmetric patterns of neural response to canonically rotated faces emerged in higher visual areas, particularly in face-selective regions. The emergence of a view-symmetric representation from a view-dependent representation for canonical rotations of the face was also evident for familiar faces, suggesting that view-symmetry is an important intermediate step in generating view-invariant representations. Finally, we measured neural responses to unnatural or non-canonical rotations of the face. View-symmetric patterns of response were also found in face-selective regions. However, in contrast to natural or canonical rotations of the face, these view-symmetric responses did not arise from an initial view-dependent representation in early visual areas. This suggests differences in the way that view-symmetrical representations emerge with canonical or non-canonical rotations. The similarity in the neural response to canonical views of familiar and unfamiliar faces in the core face network suggests that the neural correlates of familiarity emerge at later stages of processing.


Assuntos
Reconhecimento Psicológico , Córtex Visual , Face , Humanos , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia , Córtex Visual/fisiologia
12.
Vision Res ; 194: 108013, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35124521

RESUMO

The surface texture of the face is proposed to be the dominant cue in face recognition. In this study, we investigated the role of shape information in face recognition. We compared the roles of shape and surface texture in the recognition of face identity using familiar and unfamiliar hybrid faces in which the average shape from one facial identity was combined with the average texture of a different identity. In the first experiment (n = 53), participants had to match the name of a familiar person to one of eight hybrid face images. In texture trials, all images had the correct shape, but only one image had the correct texture. In shape trials, all images had the correct texture, but only one image had the correct shape. Importantly, neither task could be performed by perceptual matching. Although performance was lower for the shape trials (81%) compared to texture trials (99%), both were significantly above chance (12.5%). In the second experiment (n = 110), participants had to name hybrid faces. There were two potentially correct answers for each face image: one based on the texture and one based on the shape. Participants reported the correct name based on the texture on 61% of trials and the correct name based on the shape on 12% of trials. In the third experiment (n = 19), fMR-adaptation was used to measure the neural sensitivity to changes in the shape or texture. The core face-selective regions showed a similar sensitivity to shape and texture. These findings confirm that texture is the dominant cue for face recognition, but also show that shape plays an important role in the recognition and neural response to familiar faces.


Assuntos
Reconhecimento Facial , Reconhecimento Psicológico , Adaptação Fisiológica , Face , Reconhecimento Facial/fisiologia , Humanos , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 6384-6389, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34892573

RESUMO

Transcranial magnetic stimulation (TMS) is a form of non-invasive brain stimulation commonly used to modulate neural activity. Despite three decades of examination, the generation of flexible magnetic pulses is still a challenging technical question. It has been revealed that the characteristics of pulses influence the bio-physiology of neuromodulation. In this study, a second-generation programmable TMS (xTMS) equipment with advanced stimulus shaping is introduced that uses cascaded H-bridge inverters and a phase-shifted pulse-width modulation (PWM). A low-pass RC filter model is used to estimate stimulated neural behavior, which helps to design the magnetic pulse generator, according to neural dynamics. The proposed device can generate highly adjustable magnetic pulses, in terms of waveform, polarity and pattern. We present experimental measurements of different stimuli waveforms, such as monophasic, biphasic and polyphasic shapes with peak coil current and the delivered energy of up to 6 kA and 250 J, respectively. The modular and scalable design idea presented here is a potential solution for generating arbitrary and highly customizable magnetic pulses and transferring repetitive paradigms.


Assuntos
Potencial Evocado Motor , Córtex Motor , Fenômenos Magnéticos , Magnetismo , Estimulação Magnética Transcraniana
14.
Cureus ; 13(7): e16093, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34367749

RESUMO

Background The Leicestershire intestinal failure team (LIFT) service provides specialist intestinal failure care to patients in Leicestershire and surrounding counties. Aims To study the epidemiology of intestinal failure (IF) cases referred to the service and review outcomes particularly the indications and delivery of parenteral nutrition (PN). To review catheter-related sepsis (CRS) rates and identify areas for improvement. Methods Service data from January 2016 to November 2017 was analysed retrospectively. Descriptive and inferential statistical analysis was carried out. Chi-square/Fisher Exact tests were used to identify significance on categorical data and non-parametric settling was used for qualitative data analysis. Results A total of 365 patients were referred to the service from January 2016 to November 2017. 58% patients had grade I intestinal failure. 34% and 24% referrals were made by the colorectal and hepato-pancreato-biliary (HPB) units, respectively. Gut rest (27%) and small bowel obstruction (25%) were the most common indications for nutritional support. Duration of PN requirements varied greatly, but most patients (39%) required it for up to seven days. Single lumen PICC line (64%) and cephalic vein (54%) were the most commonly used catheter and site of vascular access, respectively. Chronicity of IF and number of vascular catheters required to provide PN were significantly associated with rates of CRS. Conclusion CRS was found to be statistically significantly associated with chronic IF and number of vascular access catheters required to provide PN. Cost implication and morbidity of CRS could be analysed further to identify other ways to provide safer and cost-efficient parental nutrition for patients with intestinal failure.

15.
Bioessays ; 43(9): e2100107, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34259346

RESUMO

Carrying out research means being innovative, which requires novelty. Novelty is an important source of scientific breakthroughs and has great technological impact. Research institutions stand to benefit from fostering innovation. Here, we outline what academic institutions can do to help their scientists become more innovative.


Assuntos
Criatividade
16.
SN Appl Sci ; 3(4): 406, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33748674

RESUMO

In this study we present the new power electronic circuit implementation to create the arbitrary near-rectangular electromagnetic pulse. To this end, we develop a parallel- Insulated-gate bipolar transistors (IGBT)-based magnetic pulse generator utilizing the H-bridge architecture. This approach effectively reduces the current stress on the power switches while maintaining a simple structure using a single DC source and energy storage capacitor. Experimental results from the circuit characterization show that the proposed circuit is capable of repeatedly generating near-rectangular magnetic pulses and enables the generation of configurable and stable magnetic pulses without causing excessive device stresses. The introduced device enables the production of near-rectangular pulse trains for modulated magnetic stimuli. The maximum positive pulse width in the proposed neurostimulator is up to 600 µs, which is adjustable by the operator at the step resolution of 10 µs. The maximum transferred energy to the treatment coil was measured to be 100.4 J. The proposed transcranial magnetic stimulator (TMS) device enables more flexible magnetic stimulus shaping by H-bridge architecture and parallel IGBTs, which can effectively mitigate the current stress on power switches for repetitive treatment protocols. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42452-021-04420-y.

17.
Int J Sports Physiol Perform ; 16(1): 28-36, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32357312

RESUMO

PURPOSE: To determine the effect of biological maturation on athletic movement competency as measured using the Athletic Ability Assessment-6. METHODS: Fifty-two junior Australian Rules football players were split into 3 groups based on proximity to peak height velocity, while 46 senior players were split into 2 groups based on playing status. The subjects completed the Athletic Ability Assessment-6 (inclusive of the overhead squat, double lunge, single-leg Romanian dead lift, push-up, and chin-up). All subjects were filmed and retrospectively assessed by a single rater. A 1-way analysis of variance and effect-size statistics (Cohen d) with corresponding 90% confidence intervals were used to describe between-groups differences in the component movement scores. The statistical significance was set a priori at P < .05. RESULTS: There were significant between-groups differences for all component movements (P < .05). Post hoc testing revealed that older, more mature subjects possessed greater competency in all movements except the overhead squat. The effect sizes revealed predominantly moderate to very large differences in competency between the senior and junior groups (range of d [90% confidence interval]: 0.70 [0.06 to 1.30] to 3.01 [2.18 to 3.72]), with unclear to moderate differences found when comparing the 3 junior groups (0.08 [-0.50 to 0.65] to 0.97 [0.22-1.61]). CONCLUSIONS: The findings suggest that biological maturation may be associated with changes in athletic movement competency in youth Australian Rules football players. Therefore, it is recommended that strength and conditioning coaches monitor maturity status when working with 12- to 15-y-old players. This can allow for a comparison of an individual's athletic movement competency to maturity-based standards and help guide developmentally appropriate training programs.


Assuntos
Fatores Etários , Desempenho Atlético , Futebol Americano , Adolescente , Austrália , Humanos , Movimento , Estudos Retrospectivos
18.
IEEE Trans Biomed Eng ; 68(6): 1847-1858, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32946379

RESUMO

OBJECTIVE: A transcranial magnetic stimulation system with programmable stimulus pulses and patterns is presented. The stimulus pulses of the implemented system expand beyond conventional damped cosine or near-rectangular pulses and approach an arbitrary waveform. METHODS: The desired stimulus waveform shape is defined as a reference signal. This signal controls the semiconductor switches of an H-bridge inverter to generate a high-power imitation of the reference. The design uses a new paradigm for TMS, applying pulse-width modulation with a non-resonant, high-frequency switching architecture to synthesize waveforms that leverages the low-pass filtering properties of neuronal cells. The modulation technique enables control of the waveform, frequency, pattern, and intensity of the stimulus. RESULTS: A system prototype was developed to demonstrate the technique. The experimental measurements demonstrate that the system is capable of generating stimuli up to 4 kHz with peak voltage and current values of ±1000 V and ±3600 A, respectively. The maximum transferred energy measured in the experimental validation was 100.4 Joules. To characterize repetitive TMS modalities, the efficiency of generating consecutive pulse triplets and quadruplets with interstimulus intervals of 1 ms was tested and verified. CONCLUSION: The implemented TMS device can generate consecutive rectangular pulses with a predetermined time interval, widths and polarities, enables the synthesis of a wide range of magnetic stimuli. SIGNIFICANCE: New waveforms promise functional advantages over the waveforms generated by current-generation TMS systems for clinical neuroscience research.


Assuntos
Córtex Motor , Estimulação Magnética Transcraniana , Potencial Evocado Motor , Fenômenos Magnéticos , Magnetismo
19.
Headache ; 60(9): 1930-1938, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32740940

RESUMO

OBJECTIVE: This study sought to compare ambulatory physical activity (PA) between young adults with migraine, tension-type headache (TTH), and non-headache controls and determine if differences in PA were attributable to headache activity or other relevant covariates. BACKGROUND: PA has been implicated in the development, manifestation, and treatment of various headache disorders. However, objective quantification of PA across headache types is lacking, and no study has quantified both prospective PA and the influence of headache occurrence on PA. METHODS: A prospective cohort study followed university participants with migraine, with TTH, or without headache for 7 days using an Omron HJ-112 pedometer and daily headache diaries. Daily free-living PA was compared between groups, and differences in PA as a function of headache day vs non-headache day were compared among those with migraine and TTH. RESULTS: The final sample consisted of 516 observations from 100 young adults (81/100 female, mean age = 19.0 ± 1.7) comprised of 28 individuals with migraine, 37 individuals with TTH, and 35 non-headache controls. On average, individuals with migraine engaged in less total PA than non-headache controls (6847 vs 8573 steps/day; mean difference = -1726 [95% CI: -3135 to -318], P = .017) across the 7-day monitoring period. After adjusting for relevant covariates (psychological symptoms, body mass index, weekend vs weekday), this difference was evident on both non-headache days (adjusted mean = 5987 vs 8610, P = .002) and headache days (adjusted mean = 6986 vs 9958, P = .017). In contrast, PA of individuals with TTH (mean = 7691 steps/day) did not significantly differ from those with migraine. PA within groups as a function of headache day (vs non-headache day) did not significantly differ for individuals with migraine (mean = 7357 vs 6191, P = .061) or individuals with TTH (mean = 7814 vs 7641, P = .736). CONCLUSIONS: Consistent with other studies, individuals with migraine reported lower levels of PA compared to non-headache controls. Notably, relative reductions in PA occurred even on days in which headache was not experienced and were not attributable to the examined covariates, instead supporting a more global pattern of reduced PA. Further research is needed to isolate the mechanisms underlying interictal reductions in PA among those with migraine.


Assuntos
Exercício Físico/fisiologia , Transtornos de Enxaqueca/fisiopatologia , Cefaleia do Tipo Tensional/fisiopatologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Estudos Prospectivos , Adulto Jovem
20.
Curr Pain Headache Rep ; 24(7): 33, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32472171

RESUMO

PURPOSE OF REVIEW: The purpose of this review is to summarize the role of avoidance behavior in headache-related disability and overview relevant clinical implications. RECENT FINDINGS: Avoidance occupies a central role in contemporary psychological perspectives on headache disorders and other chronic pain conditions. Several cognitive constructs of relevance to headache are influenced and maintained by avoidance behavior. A growing body of literature attests to the notion that avoidance of headache triggers, of stimuli that exacerbate headache, and of broader life domains can negatively affect headache progression, disability/quality of life, and comorbid psychiatric symptoms. Interventions targeting avoidance behavior, such as therapeutic exposure to headache triggers, mindfulness, and acceptance and commitment therapy (ACT), hold promise for headache disorders but need to be tested in larger trials. Researchers and clinicians are encouraged to attend to functional impairment as a critically important treatment outcome. Comprehensive understanding of headache disorders necessitates attention not merely to diagnostic symptoms and their reduction, but to patterns of avoidance behavior that inadvertently exacerbate headache and contribute to functional impairment.


Assuntos
Aprendizagem da Esquiva , Medo/psicologia , Transtornos da Cefaleia/psicologia , Terapia de Aceitação e Compromisso , Catastrofização/psicologia , Ansiedade ao Tratamento Odontológico/psicologia , Transtornos da Cefaleia/fisiopatologia , Transtornos da Cefaleia/terapia , Humanos , Terapia Implosiva , Atenção Plena , Modelos Psicológicos , Qualidade de Vida
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