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OBJECTIVES: Patient education is crucial for preventing hospital falls, yet workforce constraints can hinder targeted delivery. Utilising supervised healthcare assistants can enhance standard care. This study sought to understand factors that impact the feasibility of supplementing usual care with patient falls education delivered by supervised allied health assistants. METHODS: In a qualitative study nested within a randomised controlled trial, focus groups and interviews were conducted with twelve health assistants, seven allied health professionals and two managers from the participating hospital. This elicited insights on barriers and facilitators to implementing workforce redesign to deliver tailored patient falls education. An inductive approach was used to thematically analyse the data. RESULTS: Three key themes emerged: (i) it was feasible for health assistants to deliver hospital patient education; (ii) patients engaged with hospital falls prevention education delivered by assistants; (iii) hospital workforce redesign can be successfully implemented provided there is system-wide buy-in. CONCLUSIONS: Health assistants can be trained to successfully deliver hospital falls prevention education provided they have adequate supervision, training, and resources. PRACTICE IMPLICATIONS: Sustained implementation requires dedicated staffing hours for service delivery and staff education.
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Objectives: The objective of this study is to report the pilot phase of the Targeted Prostate Health Check programme that aims to identify men in the Surrey and Sussex region who have prostate cancer and who failed to be detected during the Covid era. Subjects and methods: Men aged 50 to 70, or 45 to 70 if Black or with a family history of prostate cancer, were identified from participating general practitioner (GP) records. Short message service (SMS) texts invited men to visit www.talkprostate.co.uk for information on prostate cancer and give consent to prostate-specific antigen (PSA) checks coordinated by a third-party virtual healthcare provider. Elevated age-related PSA levels, or levels below age-related thresholds but at 3 ng/mL or more, triggered referral to a rapid access urology clinic. GPs were informed of the results. Results: From 1842 text messages inviting 1549 people, 544 men consented to a PSA check. From 500 phlebotomy appointments, 485 (30% of invited men) took the PSA test of whom 68 (14%) were referred with an elevated PSA. After clinical review with multiparametric magnetic resonance imaging (mp-MRI), 22 patients underwent transperineal biopsies, and prostate cancer was detected in 18 men of whom 17 (95%) had clinically significant cancer. Conclusion: Our Targeted Prostate Cancer Health Check system identifies men at risk without burdening primary care. Awareness on prostate cancer risk was raised in 1549 invited men, half of whom were further educated via the registration website. One third of invited men were checked in whom clinically significant prostate cancer was found in 3.5%.
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The authors conducted a review of pharmacologic therapy in older adults with hypertension. They reviewed the evidence supporting their use in older adults, understanding the physiologic changes and potential adverse drug effects associated with aging and antihypertensive medication use, exploring guideline recommendations for antihypertensive use in older adults, and evaluating the associated risks and benefits of specific classes of antihypertensive medications.
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Antihipertensivos , Hipertensión , Humanos , Hipertensión/tratamiento farmacológico , Antihipertensivos/uso terapéutico , Anciano , Envejecimiento/fisiología , Anciano de 80 o más Años , Guías de Práctica Clínica como AsuntoRESUMEN
Perception of quality of life for cats and dogs of low-income Spanish and English-speaking veterinary clients attending problem focused or routine veterinary visits is an important area of focus for community based veterinary service providers. Using a qualitative approach, 50 New York City based American Society for the Prevention of Cruelty to Animals (ASPCA) veterinary clients completed semi-structured interviews as well as a survey about their perception of life with their pets. Veterinary clients shared both human-animal bond (HAB) related and quality of life (QoL) related factors in their daily experience of life with their pets. Results indicated that this demographic perceives QoL similarly to previous QoL research that either does not report sample demographics or reports sample demographics with more affluence. Moreover, 60% of qualitative excerpts included both HAB and QoL themes and 40% were discretely HAB or QoL. An analog single item 10-point scale measuring veterinary client perception of their pets QoL did not differentiate between sample demographics at a statistically significant level. Finally, pet QoL literature has not traditionally reflected diverse demographic identities of veterinary clients or widely included reliable and valid measures of the human-animal bond (HAB). These results support the importance of measuring the HAB when researching pet QoL and provide evidence that lower-income Spanish and English-speaking veterinary clients are similarly bonded and attentive to their pets as other demographics.
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Identifying contacts in a military context can require operators to integrate multiple cues and to adjust response criteria to event base rates. The current experiment tested whether support from a decision aid would improve these processes. Participants performed a signal identification task that required them to integrate cues displayed as visual scale readings. In a static condition, participants saw a single set of readings each trial. In dynamic conditions, readings were updated over time. Base rates of signal categories were unequal, requiring participants to adopt biased response criteria to maximise response accuracy. Participants worked with or without an aid that combined cues and base rate information in an ideal manner. Support from the aid pushed participants' response criteria towards optimal and improved integration of dynamic cues. Decision aids may be especially useful when task demands require biased response criteria and when cues are sampled over time.
Applied decision making often requires operators to gather and integrate multiple probabilistic cues. An experiment examined the information processing steps in multiple-cue decision tasks that could be improved by an automated decision aid. Statistically ideal aids improved operators' response bias and information integration, although operator performance remained suboptimal.
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BACKGROUND: In Canada's largest COVID-19 serological study, SARS-CoV-2 antibodies in blood donors have been monitored since 2020. No study has analysed changes in the association between anti-N seropositivity (a marker of recent infection) and geographic and sociodemographic characteristics over the pandemic. METHODS: Using Bayesian multi-level models with spatial effects at the census division level, we analysed changes in correlates of SARS-CoV-2 anti-N seropositivity across three periods in which different variants predominated (pre-Delta, Delta and Omicron). We analysed disparities by geographic area, individual traits (age, sex, race) and neighbourhood factors (urbanicity, material deprivation and social deprivation). Data were from 420 319 blood donations across four regions (Ontario, British Columbia [BC], the Prairies and the Atlantic region) from December 2020 to November 2022. RESULTS: Seropositivity was higher for racialized minorities, males and individuals in more materially deprived neighbourhoods in the pre-Delta and Delta waves. These subgroup differences dissipated in the Omicron wave as large swaths of the population became infected. Across all waves, seropositivity was higher in younger individuals and those with lower neighbourhood social deprivation. Rural residents had high seropositivity in the Prairies, but not other regions. Compared to generalized linear models, multi-level models with spatial effects had better fit and lower error when predicting SARS-CoV-2 anti-N seropositivity by geographic region. CONCLUSIONS: Correlates of recent COVID-19 infection have evolved over the pandemic. Many disparities lessened during the Omicron wave, but public health intervention may be warranted to address persistently higher burden among young people and those with less social deprivation.
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Teorema de Bayes , Donantes de Sangre , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiología , COVID-19/sangre , Donantes de Sangre/estadística & datos numéricos , Masculino , Femenino , Adulto , SARS-CoV-2/inmunología , Persona de Mediana Edad , Canadá/epidemiología , Estudios Seroepidemiológicos , Anticuerpos Antivirales/sangre , Adulto Joven , Adolescente , Disparidades en el Estado de Salud , Factores Socioeconómicos , Características de la Residencia , AncianoRESUMEN
AIM: Access to timely treatment is key to early intervention in psychosis. Despite this, barriers to treatment exist. In this review, we aimed to understand the structural barriers that patients and caregivers face in help-seeking for first-episode psychosis, and the recommendations provided to address these. METHODS: We conducted a systematic review (PROSPERO: CRD42021274609) of qualitative studies reporting structural barriers to help-seeking from the patient or caregiver perspective. Searches were performed in September 2023, restricted to studies published from 2001. Study quality was appraised using Critical Appraisal Skills Programme. Data were analysed using thematic synthesis. RESULTS: Nineteen papers from 11 countries were included. Across all papers, participants reported experiencing structural barriers to receiving healthcare. For many patients and caregivers, the process of accessing healthcare is complex. Access requires knowledge and resources from parents, caregivers and healthcare providers, yet too often there is a misalignment between patients' needs and service resources. Expertise amongst healthcare providers vary and some patients and caregivers experience negative encounters in healthcare. Patients highlighted earlier caregiver involvement and greater peer support as potential routes for improvement. CONCLUSION: Patients and caregivers face multiple structural barriers, with legislative practices that discourage family involvement, and healthcare and transport costs found to be particularly problematic. Understanding these barriers can facilitate the co-design of both new and existing services to provide easier access for patients and caregivers. Further research is needed focusing not only on the perspectives of patients and caregivers who have accessed professional help but also crucially on those who have not.
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Accesibilidad a los Servicios de Salud , Aceptación de la Atención de Salud , Trastornos Psicóticos , Humanos , Trastornos Psicóticos/terapia , Aceptación de la Atención de Salud/psicología , Cuidadores/psicología , Conducta de Búsqueda de Ayuda , Servicios de Salud MentalRESUMEN
Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA's F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms-1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes - B1, provided by the Japanese space agency, JAXA, and B2 - that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission's science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.
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OBJECTIVE: To examine the feasibility of using allied health assistants to deliver patient falls prevention education within 48 h after hospital admission. DESIGN AND SETTING: Feasibility study with hospital patients randomly allocated to usual care or usual care plus additional patient falls prevention education delivered by supervised allied health assistants using an evidence-based scripted conversation and educational pamphlet. PARTICIPANTS: (i) allied health assistants and (ii) patients admitted to participating hospital wards over a 20-week period. OUTCOMES: (i) feasibility of allied health assistant delivery of patient education; (ii) hospital falls per 1,000 bed days; (iii) injurious falls; (iv) number of falls requiring transfer to an acute medical facility. RESULTS: 541 patients participated (median age 81 years); 270 control group and 271 experimental group. Allied health assistants (n = 12) delivered scripted education sessions to 254 patients in the experimental group, 97% within 24 h after admission. There were 32 falls in the control group and 22 in the experimental group. The falls rate was 8.07 falls per 1,000 bed days in the control group and 5.69 falls per 1,000 bed days for the experimental group (incidence rate ratio = 0.66 (95% CI 0.32, 1.36; P = 0.26)). There were 2.02 injurious falls per 1,000 bed days for the control group and 1.03 for the experimental group. Nine falls (7 control, 2 experimental) required transfer to an acute facility. No adverse events were attributable to the experimental group intervention. CONCLUSIONS: It is feasible and of benefit to supplement usual care with patient education delivered by allied health assistants.
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Hospitalización , Hospitales , Anciano de 80 o más Años , Humanos , Estudios de Factibilidad , Recursos HumanosRESUMEN
BACKGROUND: Existing literature implies there may be gaps in post-treatment support for young people with cancer. This service evaluation explored the needs and experiences of young people when ending cancer treatment in a UK children's hospital to inform service provisions. METHODS: Semi-structured interviews were conducted with nine young people, aged 13-18 years, who had finished active cancer treatment and were receiving follow-up care. The data was analysed using thematic analysis. RESULTS: Four main themes were developed: being in the dark (i.e. limited awareness of what happens when treatment ends); separation from the hospital (i.e. the loss of valued support from staff); consequences of cancer (i.e. managing ongoing psychological and physical effects); and getting back to normal life (i.e. shifting from hospital to everyday life). CONCLUSIONS: Recommendations for improving clinical practice were made. Greater preparedness for ending treatment could be achieved by clearly setting out ongoing care arrangements, providing resource packs, having opportunities to mark the end of treatment, and offering peer support. To identify specific post-treatment needs, there should be an end of treatment multidisciplinary review and space for young people to share how they are feeling in follow-up medical appointments.
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Neoplasias , Aceptación de la Atención de Salud , Niño , Humanos , Adolescente , Investigación Cualitativa , Neoplasias/terapia , Neoplasias/psicologíaRESUMEN
OBJECTIVES: This study aimed to synthesise the psychosocial stressors of siblings of people with experiences of psychosis (SOPEP). Understanding the specific needs of siblings across diverse cultures would help mental health services to provide culturally specific psychosocial family and sibling-centred support. This may result in improved relationships between families, better psychosocial well-being for siblings and better outcomes for patients. METHODS: Following PRISMA guidelines, a systematic review was conducted to explore the psychosocial stressors of SOPEP. Six databases were utilised to identify literature using qualitative methodology. RESULTS: Twenty-two studies were included that investigated the Psychosocial Stressors of SOPEP. SOPEP's experiences were influenced by various stages: individual factors, social factors, physical and macro-level environments. Six key components contributed to SOPEP's psychosocial stressors and facilitated or hindered their intentions, behaviours and experiences of caregiving. These were the SOPEP's beliefs about psychosis, caregiving beliefs, family and cultural values, personality traits, pragmatic challenges and access to resources. CONCLUSIONS: Globally, SOPEP and families may benefit from their involvement in family interventions and individual support that facilitates caregiving and acknowledges their responsibilities, resources, psychosocial needs and emotional experiences.
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The CERT-D program offers a new treatment approach addressing disturbed cognitive and psychosocial functioning in major depressive disorder (MDD). The current analysis of a randomised controlled trial (RCT) comprises two objectives: Firstly, evaluating the program's efficacy of a personalised versus standard treatment and secondly, assessing the treatment's persistence longitudinally. Participants (N = 112) were randomised into a personalised or standard treatment group. Both groups received 8 weeks of cognitive training, followed by a three-month follow-up without additional training. The type of personalised training was determined by pre-treatment impairments in the domains of cognition, emotion-processing and social-cognition. Standard training addressed all three domains equivalent. Performance in these domains was assessed repeatedly during RCT and follow-up. Treatment comparisons during the RCT-period showed benefits of personalised versus standard treatment in certain aspects of social-cognition. Conversely, no benefits in the remaining domains were found, contradicting a general advantage of personalisation. Exploratory follow-up analysis on persistence of the program's effects indicated sustained intervention outcomes across the entire sample. A subsequent comparison of clinical outcomes between personalised versus standard treatment over a three-month follow-up period showed similar results. First evidence suggests that existing therapies for MDD could benefit from an adjunct administration of the CERT-D program.
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Trastorno Depresivo Mayor , Humanos , Trastorno Depresivo Mayor/terapia , Trastorno Depresivo Mayor/tratamiento farmacológico , Resultado del Tratamiento , CogniciónRESUMEN
Introduction: In the midst of a global climate emergency and with health care systems across the world facing extreme pressure, interest in digital approaches as a potential part-solution to these challenges has increased rapidly. The evidence base to support the role that digitalization can play in moving towards more sustainable models of healthcare is growing, as is the awareness of this key area of healthcare reform amongst policy makers, clinicians and the public. Method and Results: In this policy and practice review we explore four domains of healthcare sustainability-environmental, economic, and patient and clinician, delineating the potential impact that digitally enabled healthcare can have on each area. Real-world examples are provided to illustrate the impact individual digital interventions can have on each pillar of sustainability and demonstrate the scale of the potential benefits which can be achieved. Discussion: Digitally enabled healthcare solutions present an approach which offer numerous benefits, including environmental sustainability, economic benefits, and improved patient experience. There are also potential drawbacks such as the risk of digital exclusion and the need for integration with existing technology platforms. Overall, it is essential to strike a balance between the benefits and potential drawbacks of digital healthcare solutions to ensure that they are equitable, effective, and sustainable.
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Introduction: The etiology of major depressive disorder (MDD) involves the interaction between genes and environment, including treatment. Early molecular signatures for treatment response and remission are relevant in a context of personalized medicine and stratification and reduce the time-to-decision. Therefore, we focused the analyses on patients that responded or remitted following a cognitive intervention of 8 weeks. Methods: We used data from a randomized controlled trial (RCT) with MDD patients (N = 112) receiving a cognitive intervention. At baseline and 8 weeks, blood for DNA methylation (Illumina Infinium MethylationEPIC 850k BeadChip) was collected, as well as MADRS. First, responders (N = 24; MADRS-reduction of at least 50%) were compared with non-responders (N = 60). Then, we performed longitudinal within-individual analyses, for response (N = 21) and for remission (N = 18; MADRS smaller or equal to 9 and higher than 9 at baseline), respectively, as well as patients with no change in MADRS over time. At 8 weeks the sample comprised 84 individuals; 73 patients had DNA methylation for both time-points. The RnBeads package (R) was used for data cleaning, quality control, and differential DNA-methylation (limma). The within-individual paired longitudinal analysis was performed using Welch's t-test. Subsequently gene-ontology (GO) pathway analyses were performed. Results: No CpG was genome-wide significant CpG (p < 5 × 10-8). The most significant CpG in the differential methylation analysis comparing response versus non-response was in the IQSEC1 gene (cg01601845; p = 1.53 × 10-6), linked to neurotransmission. The most significant GO-terms were linked to telomeres. The longitudinal response analysis returned 67 GO pathways with a p < 0.05. Two of the three most significant pathways were linked to sodium transport. The analysis for remission returned 46 GO terms with a p-value smaller than 0.05 with pathways linked to phosphatase regulation and synaptic functioning. The analysis with stable patients returned mainly GO-terms linked to basic cellular processes. Discussion: Our result suggest that DNA methylation can be suitable to capture early signs of treatment response and remission following a cognitive intervention in depression. Despite not being genome-wide significant, the CpG locations and GO-terms returned by our analysis comparing patients with and without cognitive impairment, are in line with prior knowledge on pathways and genes relevant for depression treatment and cognition. Our analysis provides new hypotheses for the understanding of how treatment for depression can act through DNA methylation and induce response and remission.
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Cognitive dysfunction contributes significantly to the burden caused by Major Depressive Disorder (MDD). Yet, while compelling evidence suggests that different biological processes play a part in both MDD aetiology and the development of cognitive decline more generally, we only begin to understand the molecular underpinnings of depression-related cognitive impairment. Developments in psychometric assessments, molecular high-throughput methods and systems biology derived analysis strategies advance this endeavour. Here, we aim to identify gene expression signatures associated with cognitive dysfunction and cognitive improvement following therapy using RNA sequencing to analyze the whole blood-derived transcriptome of altogether 101 MDD patients who enrolled in the CERT-D study. The mRNA(Nova)Seq based transcriptome was analyzed from whole blood taken at baseline assessment, and patients' cognitive performance was measured twice at baseline and following eight weeks of therapy by means of the THINC integrated tool. Thirty-six patients showed comparatively low cognitive performance at baseline assessment, and 32 patients showed comparatively strong cognitive improvement following therapy. Differential gene expression analysis was performed using limma to a significance threshold of 0.05 and a logFC cutoff of |1.2|. Although we observed some indications for expression differences related to low cognitive performance and cognitive therapy response, signals did not withstand adjustment for multiple testing. Applying WGCNA, we retrieved altogether 25 modules of co-expressed genes and we used a combination of correlational and linear analyses to identify modules related to baseline cognitive performance and cognitive improvement following therapy. Three immune modules reflected distinct but interrelated immune processes (the yellow module: neutrophil-mediated immunity, the darkorange module: interferon signaling, the tan module: platelet activation), and higher expression of the yellow (r = -0.21, p < .05), the dark orange (r = 0.2, p < .05), and the tan (r = -0.23, p < .05) module correlated significantly negatively with patients' cognitive baseline performance. Patients' cognitive baseline performance was a significant predictor of the darkorange module (b = -0.039, p < .05) and the tan module's expression (b = 0.02, p < .05) and was close to becoming a significant predictor of the yellow module's expression (b = -0.02, p = .05). Furthermore, patients characterized by comparatively low cognitive performance at baseline showed significantly higher expression of the tan module when compared to all other patients F(1,97) = 4.32, p < .05, η= 0.04. Following eight weeks of treatment, we observed altogether significant improvement in patients' cognitive performance (b = 0.30, p < .001), and patients with comparatively high cognitive gain showed noticeably lower, but not significantly lower F(1,98) = 3.76, p = .058, expression of a dark turquoise module, which reflects complement and B-cell-associated immune processes. Noteworthy, the relation between cognitive performance and module expression remained observable after controlling for symptom severity and BMI, which partly accounted for variance in module expression. As such, our findings provide further evidence for the involvement of immune processes in MDD related cognitive dysfunction and they suggest that different immune processes contribute to the development and long-term persistence of cognitive dysfunction in the context of depression.
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Disfunción Cognitiva , Trastorno Depresivo Mayor , Humanos , Transcriptoma , Trastorno Depresivo Mayor/psicología , Depresión , Disfunción Cognitiva/complicaciones , ARN Mensajero , Redes Reguladoras de Genes , Perfilación de la Expresión GénicaRESUMEN
BACKGROUND: DNA methylation as a biomarker is well suited to investigate dynamic processes, such as symptom improvement. For this study we focus on epigenomic state or trait markers as early signatures of cognitive improvement in individuals receiving a cognitive intervention. We performed a first epigenome-wide association study (EWAS) on patients with cognitive dysfunction in depression comparing those with vs without cognitive dysfunction and those cognitively improving vs non-improving following a cognitive intervention. METHOD: Data from a randomized controlled trial (RCT) were used for this analysis, where cognitive function of 112 patients randomly assigned to a personalized cognitive intervention was compared to standard cognitive treatment. Cognition was measured for this study using the four cognitive tasks from the THINC-it battery. We compared individuals with cognitive impairment with individuals without cognitive impairment at baseline and after a cognitive intervention of 8 weeks. Blood for DNA methylation analysis (Illumina Infinium MethylationEPIC 850 k BeadChip) was collected at baseline and 8 weeks into the treatment. For the baseline analysis, after quality control, the final sample comprised 90 individuals, and analyses at week 8 were performed on 84 individuals. Data cleaning, quality control, and differential methylation analysis of DNA methylation data was performed using the RnBeads package (R). Analyses were corrected for gender, age, depression score (MADRS), reported years of education, height and weight, as well as surrogate variables estimated by the pipeline used. The within-individual paired longitudinal analysis was performed using Welch's t-test. RESULTS: Analyses at baseline and at week 8 did not show any genome-wide significant CpGs (p < 5 × 10-8) comparing patients with and without cognitive impairment. The most significant result in the baseline analysis comparing the groups with and without cognitive impairment at baseline is located in an open Sea region with predominantly regulatory qualities (cg10962945; 6.61 × 10-7). The most significant CpG at 8 weeks was also located in open sea, though in exon 13 of the NTRK2-gene, linked to the BDNF pathway (cg13620631, 5.56 × 10-7). Finally, a within-individual paired longitudinal analysis with only patients that show improved cognitive function over time was performed, showing 65 CpGs that overlapped between the 1% most significant of this analysis and the 1% most significant CpGs from the cross-sectional analysis at 8 weeks. CONCLUSION: Our result suggest that DNA methylation can be suitable to capture early signs of treatment response of a cognitive intervention in depression. In our layered approach we could capture dynamics that can help differentiate between biological trait and state markers of cognitive function in depression. Despite not being genome-wide significant, the CpG locations returned by our analysis comparing patients with and without cognitive impairment, are in line with prior knowledge on pathways and genes relevant for depression treatment and cognition.
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Entrenamiento Cognitivo , Depresión , Humanos , Epigénesis Genética , Metilación de ADN , Cognición , Epigenómica , Estudio de Asociación del Genoma Completo , Islas de CpGRESUMEN
Gaseous fuels for heavy-duty internal combustion engines provide inherent advantages for reducing CO2, particulate matter (PM), and NOX emissions. Pilot-ignited direct-injected NG (PIDING) combustion uses a small pilot injection of diesel to ignite a late-cycle main direct injection of NG, resulting in significant reduction of unburned CH4 emissions relative to port-injected NG. Previous works have identified NG premixing as a critical parameter establishing indicated efficiency and emissions performance. To this end, a recent experimental investigation using a metal engine identified six general regimes of PIDING heat release and emissions behavior arising from variation of NG stratification through control of relative injection timing (RIT) of the NG with respect to the pilot diesel. The objective of the current work is to provide comprehensive description of in-cylinder fuel mixing of direct injected gaseous fuel and its impacts on combustion and pollutant formation processes for stratified PIDING combustion. In-cylinder imaging of OH*-chemiluminescence (OH*-CL) and PM (700 nm), and measurement of local concentration of fuel is considered for 11 different RIT , representing 5 regimes of stratified PIDING combustion (performed with P inj = 22 . 0 MPa and Ï = 0 . 63 ). The magnitude and cyclic variability of premixed fuel concentration near the bowl wall provides direct experimental validation of thermodynamic metrics ( RI T premix , SO I NG , trans , RI T * ) that describe the fuel-air mixture state of all 5 regimes of PIDING combustion. The local fuel concentration develops non-monotonically and is a function of RIT. High indicated efficiency and low CH4 emissions previously observed for stratified-premixed PIDING combustion in previous (non-optical) investigations are due to: (i) very rapid reaction zone growth ( > 45 m/s) and (ii) more distributed early reaction zones when overlapping pilot and NG injections cause partial pilot quenching. These results connect and extend the findings of previous investigations and guide the future strategic implementation of NG stratification for improved combustion and emissions performance.
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The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 min was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision1, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement (ß) was possible2,3. In the years before impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos4-6. Here we report the change in the orbital period of Dimorphos as a result of the DART kinetic impact to be -33.0 ± 1.0 (3σ) min. Using new Earth-based lightcurve and radar observations, two independent approaches determined identical values for the change in the orbital period. This large orbit period change suggests that ejecta contributed a substantial amount of momentum to the asteroid beyond what the DART spacecraft carried.
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Some active asteroids have been proposed to be formed as a result of impact events1. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) mission of NASA2, in addition to having successfully changed the orbital period of Dimorphos3, demonstrated the activation process of an asteroid resulting from an impact under precisely known conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope from impact time T + 15 min to T + 18.5 days at spatial resolutions of around 2.1 km per pixel. Our observations reveal the complex evolution of the ejecta, which are first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and subsequently by solar radiation pressure. The lowest-speed ejecta dispersed through a sustained tail that had a consistent morphology with previously observed asteroid tails thought to be produced by an impact4,5. The evolution of the ejecta after the controlled impact experiment of DART thus provides a framework for understanding the fundamental mechanisms that act on asteroids disrupted by a natural impact1,6.
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Evidence from the prehistoric archaeological record clearly shows that ancient societies had a sense of and engaged with their own histories, be it by reusing, re-appropriating or recreating past material culture. The affective qualities of materials, places and even human remains would have enabled people to remember and connect with aspects of their immediate and more distant pasts. In some cases, this may have elicited specific emotive responses, similar to how nostalgic triggers operate today. Nostalgia is not a word commonly used by archaeologists, but through exploring the materiality and sensory affect of objects and spaces in the past, we can consider that what we deal with archaeologically may have held nostalgic qualities.