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1.
Public Health ; 231: 133-141, 2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38688166

ABSTRACT

OBJECTIVES: This study aimed to estimate the prevalence of children aged 0-19 years who have a parent with a history of heart disease and investigate their sociodemographic characteristics. STUDY DESIGN: A national register-based study. METHODS: From the Danish Fertility Register and the Danish National Patient Register information on children of parents with ischemic heart disease, arrhythmia, heart failure and heart valve disease in the period 1981-2018 were obtained. Statistical analyses including descriptive statistics, logistic and linear regression were used to illuminate associations between parental heart disease and sociodemographic characteristics. RESULTS: The study population consisted of 142,480 children aged 0-19 years with at least one parent diagnosed with heart disease, corresponding to every 9th child in Denmark in 2018. The number increased from 4.5% in 2002 to 11.1% in 2018. In the study population most had a father with heart disease (57.8%) and 4.6% had two parents with heart disease. Parents with heart disease had significantly higher odds of being out of work (OR 1.68, 95% CI 1.64; 1.72), in a single-parent household (OR 1.09, 95% CI 1.07; 1.11), divorced or widowed (OR: 1.10, 95% CI 1.08; 1.12), having a lower educational level (OR 1.35, 95% CI 1.33; 1.37), and a lower family income (-42,410 DKR, 95% CI -50,306; -34,514, P < 0.0001) compared to those without heart disease. CONCLUSION: Children affected by parental heart disease comprise a substantial part of the Danish population. These have significantly different sociodemographic characteristics than children in families without parental heart disease, which might affect social heritage and parental capacity.

2.
Sci Rep ; 14(1): 7192, 2024 03 26.
Article in English | MEDLINE | ID: mdl-38531999

ABSTRACT

Among disabling post-traumatic stress symptoms (PTSS) are irritability, aggressive behavior, distressing memories and general impaired cognition and negative mood. Art therapy interventions, including mask-making, can potentially alleviate these symptoms. We tested the hypothesis that art conveys emotions and predicted that blinded viewers would be able to perceive changes in theoretically derived emotional profiles expressed in art made by military personnel with PTSS from the onset to the end of therapy. Five service members and veterans exhibiting PTSS were enrolled in an 8-session art therapy protocol, during which they artistically transformed papier-mâché masks at the beginning and end of the protocol. We found that blinded viewers without knowledge of the masks' creation stage (onset or end of therapy) read initial masks as conveying more negative emotions (e.g., angry, upset, and challenged) and later masks as conveying more positive emotions (calm and pleasure). Based on the assessments from the blinded evaluators, we infer the emotional transition experienced by the participants was expressed in the masks. In an exploratory arm of the study, we also found that viewers were better able to empathize with the negative emotions experienced by participants with PTSS when asked to explicitly take their perspective.


Subject(s)
Art Therapy , Military Personnel , Stress Disorders, Post-Traumatic , Veterans , Humans , Stress Disorders, Post-Traumatic/psychology , Irritable Mood
3.
Article in English | MEDLINE | ID: mdl-38339776

ABSTRACT

OBJECTIVES: Although there have been remarkable strides in fetal medicine and prenatal diagnosis of congenital heart disease, a significant percentage of newborns with isolated coarctation of the aorta (CoA) - around 60 percent - are still not identified prior to birth. The prenatal detection of CoA has been shown to have a notable impact on the survival rates of affected infants. To this end, the implementation of artificial intelligence (AI) in fetal ultrasound may represent a groundbreaking advancement. Our hypothesis is that leveraging automated cardiac biometric measurements with AI during the 18-22-week anomaly scan will enhance the identification of fetuses that are at risk of developing CoA. METHODS: We have developed an AI model capable of identifying standard cardiac planes and conducting automated cardiac biometric measurements. Our data consisted of pregnancy ultrasound image and outcome data spanning from 2008 to 2018 and collected from four distinct regions in Denmark. The CoA cases from the period were paired with healthy controls in a ratio of 1:100 and matched on gestational ages of ±2 days. The cardiac biometrics on the four-chamber view and three vessel view were included in a logistic regression-based prediction model. To assess the predictive capabilities, we visualized sensitivity and specificity on Receiver Operating Characteristic (ROC) curves. RESULTS: At the 18-22 week scan, the right ventricle (RV)area and length, left ventricle (LV) width, and the ratios of RV/LV areas and main pulmonary artery/ascending aorta diameters showed significant differences with z-scores above 0.7 when comparing subjects with a postnatal diagnosis of CoA (n=73) and healthy controls (n=7300). Using logistic regression and backward feature selection, our prediction model produced a ROC curve with an AUC (Area Under the Curve) of 0.96 and a specificity of 88.9% at a sensitivity level of 90.4%. CONCLUSION: The integration of AI technology with automated cardiac biometric measurements conducted during the 18-22-week anomaly scan in fetal medicine has the potential to substantially enhance the screening for fetal CoA and subsequently the rate of CoA detection. Future research should clarify how AI technology can be used to aid in screening and detection of congenital heart anomalies to improve neonatal outcomes. This article is protected by copyright. All rights reserved.

4.
Public Health ; 225: 87-95, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37922591

ABSTRACT

OBJECTIVE: To identify risk factors for precancerous cervical lesions and factors associated with treatment delay among women in the rural Busoga Region, Uganda. STUDY DESIGN: A retrospective cross-sectional study from a regional cervical cancer screening program and from cervical cancer patients enrolled in a region-wide palliative care program. METHODS: Logistic regression analysis was conducted to assess risk factors for screening positive for precancerous lesions. In a separate analysis, factors associated with treatment delay were assessed among women enrolled in the palliative care program. RESULTS: Three thousand nine hundred forty-six women were included from the screening program and 334 from the palliative care program. In total, 7.6% of screening participants had precancerous lesions. Within Busoga Region, the highest positivity rate was found in Bugweri and Namayingo Districts. Abnormal vaginal bleeding (adjusted odds ratio [aOR] 1.60; 95% confidence interval [CI] 1.15-2.21; p = 0.005) and older age at first menstrual period (aOR 1.08; 95% CI 1.01-1.16; p = 0.03) were associated with having a precancerous lesion. Among palliative care patients, a history of previous contact with the health care system was associated with a delay in enrolment (≥12 months from first symptom presentation until commencement in palliative care; aOR 5.23; 95% CI 1.16-36.54; p = 0.047). CONCLUSIONS: The results underline an unmet need for broad-scale cervical cancer screening focusing on all women in the reproductive age. Abnormal bleeding was the only substantial risk factor for precancerous lesions, indicating that specific algorithms to identify high-risk populations may not be applicable in this population. Increased awareness, resources, and funding are still necessary to achieve global cervical cancer elimination.


Subject(s)
Precancerous Conditions , Uterine Cervical Neoplasms , Female , Humans , Uterine Cervical Neoplasms/epidemiology , Cross-Sectional Studies , Uganda/epidemiology , Prevalence , Retrospective Studies , Early Detection of Cancer , Risk Factors , Precancerous Conditions/epidemiology , Precancerous Conditions/diagnosis , Precancerous Conditions/pathology
5.
Nature ; 621(7980): 716-722, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37758891

ABSTRACT

Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.

6.
Obstet Med ; 16(2): 120-122, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37441659

ABSTRACT

Although rare, increasing numbers of women with pacemakers are becoming pregnant. We describe the complications of a woman with arrhythmia and a pacemaker for complete heart block experienced before, during, between and after her pregnancies. We illustrate the benefits of multidisciplinary care, good communication and regular assessment in a stable, but complex woman.

7.
IDCases ; 32: e01737, 2023.
Article in English | MEDLINE | ID: mdl-36938336

ABSTRACT

Background: Norovirus gastroenteritis is commonly an acute infection that lasts 2-3 days, but in immunocompromised patients norovirus can cause a chronic gastroenteritis lasting for years. Norovirus replicates in the gastrointestinal tract, but the pathway of viral clearance is not yet known. Promising results of enterally administered immunoglobulin in the treatment of chronic norovirus gastroenteritis in immunocompromised patients have previously been published. Case presentation: We report two individuals with common variable immunodeficiency and chronic debilitating norovirus gastroenteritis. Both patients were treated with enterally administered immunoglobulin via a duodenal feeding tube as other treatment modalities have been unsuccessful. The patients did not experience any immediate or long-term benefit of enterally administered immunoglobulin. Conclusion: Despite previous case reports of successful treatment of chronic norovirus infection among immunocompromised patients with enterally administered immunoglobulin, these two patients experienced no benefit of the treatment. This demonstrates the need for further research in treatment of chronic norovirus infection in immunocompromised patients.

8.
Phys Rev Lett ; 130(5): 051802, 2023 Feb 03.
Article in English | MEDLINE | ID: mdl-36800478

ABSTRACT

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×10^{20} protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃7.4% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on Q^{2} (squared four-momentum transfer) and energy, in the range 1 GeV≤E_{ν}<6 GeV. Detailed comparisons are made to the predictions of the GENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the others consistently across all three cross sections measured, though some models have especially good or poor agreement in the single differential cross section vs Q^{2}.

9.
J Eur Acad Dermatol Venereol ; 37(5): 976-983, 2023 May.
Article in English | MEDLINE | ID: mdl-36652273

ABSTRACT

Despite the emergence of novel targeted treatments for atopic dermatitis (AD), there is a lack of guidelines on standardizing analysis of clinical trial data. To define and estimate meaningful treatment comparisons, several factors, including intercurrent events, must be taken into account. Intercurrent events are defined as events occurring after treatment initiation that affect either the interpretation or existence of the measurements associated with clinical questions of interest. Due to the relapsing, unpredictable nature of AD, intercurrent events frequently occur in AD trials, such as use of rescue therapy for intense itch and sleep deprivation. Despite the impact of intercurrent events in AD, they are often handled in an inconsistent manner across trials, which limits results interpretation. The estimand framework is increasingly used to estimate treatment effects while accounting for intercurrent events. This review explores how guidance from the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) on the use of estimands can be applied to support AD clinical trial design and analysis. We propose that estimands are used in AD trials and defined early during trial design. The use of estimands can provide clinicians with interventional trial results that are more reflective of clinical practice, help facilitate comparisons across clinical trials, and are more informative to enable improved treatment selection for patients.


Subject(s)
Dermatitis, Atopic , Models, Statistical , Humans , Dermatitis, Atopic/drug therapy , Expert Testimony , Data Interpretation, Statistical , Research Design
10.
Spat Spatiotemporal Epidemiol ; 43: 100538, 2022 11.
Article in English | MEDLINE | ID: mdl-36460456

ABSTRACT

BACKGROUND: Modifying the environment is considered an effective population-level approach for increasing healthy behaviours, but associations remain ambiguous. This exploratory study aims to compare researcher-defined buffers and self-drawn neighbourhoods (SDN) to objectively measured availability of physical activity (PA) facilities and greenspaces in adolescents. METHODS: Seven consecutive days of GPS data were collected in an adolescent sample of 14-18 year olds (n = 69). Using Points of Interest and greenspace data, availability of PA opportunities within activity spaces were determined. We compared 30 different definitions of researcher-defined neighbourhoods and SDNs to objectively measured availability. RESULTS: Findings showed low agreement for all researcher-defined buffers in measuring the availability of PA facilities in activity spaces. However, results were less clear for greenspace. SDNs also demonstrate low agreement for capturing availability to the PA environment. CONCLUSION: This exploratory study highlights the inadequacy of researcher-defined buffers and SDNs to define availability to environmental features.


Subject(s)
Exercise , Parks, Recreational , Humans , Adolescent , Environment , Health Status
11.
Trials ; 23(1): 773, 2022 Sep 13.
Article in English | MEDLINE | ID: mdl-36100943

ABSTRACT

BACKGROUND: Many patients suffering from schizophrenia spectrum disorders continue having distressing auditory hallucinations in spite of treatment with antipsychotic medication. The aim of this trial is to examine the effect of a targeted virtual reality therapy for persistent auditory hallucinations in individuals with psychosis. The trial explores whether this type of therapy can decrease the severity, frequency and distress of auditory hallucinations and, additionally, whether it can reduce clinical symptoms and enhance daily functioning in individuals with psychosis. METHODS: The study is a randomised, assessor-blinded parallel-group superiority clinical trial, allocating a total of 266 patients to either the experimental intervention or supportive counselling. The participants will be randomised to either (1) seven sessions of virtual reality therapy or (2) seven sessions of supportive counselling to be delivered within the first 12 weeks after inclusion in the study. All participants will be assessed at baseline and 12 and 24 weeks post-baseline. Independent assessors blinded to the treatment allocation will evaluate the outcome. The primary outcome is the level of auditory hallucinations measured with the Psychotic Symptoms Rating Scales (PSYRATS-AH) total score at the cessation of treatment at 12 weeks. Secondary outcomes are frequency of auditory hallucinations, the distress caused by auditory hallucinations, perceived voice power, patient acceptance of voices, patients' ability to respond to voices in an assertive way and social and daily function. DISCUSSION: Promising evidence of the efficacy of this immersive virtual reality-based therapy for auditory hallucinations exist, but evidence needs to be established in a large, methodological rigorous trial. If the therapy proves to be beneficial in reducing the severity of refractory auditory hallucinations, a large group of patients with schizophrenia and related disorders could be the target group of this short-term psychotherapeutic intervention.


Subject(s)
Implosive Therapy , Psychotic Disorders , Virtual Reality Exposure Therapy , Virtual Reality , Counseling , Hallucinations/diagnosis , Hallucinations/therapy , Humans , Psychotic Disorders/complications , Psychotic Disorders/diagnosis , Psychotic Disorders/therapy , Randomized Controlled Trials as Topic
14.
J Hosp Infect ; 122: 64-71, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35077808

ABSTRACT

BACKGROUND: National and international guidelines recommend reprocessing of medical instruments to commence as soon as possible post-surgery; furthermore, they recommend that transport and storage of surgical instruments postoperatively occurs in a moist, humid atmosphere. The concern is that a dry storage environment results in deterioration of instruments. AIM: To evaluate whether residual protein or corrosion is associated with storage environment (dry or humid), holding time or number of treatment cycles. METHODS: The range of protein residue and corrosion were tested on surgical instruments contaminated with human blood amended Enterococcus faecalis ATCC 29212. Subsequently instruments were stored for 6, 12 and 24 h in dry or humid conditions. After one, 25 and 50 reprocessing cycles, instruments were examined for protein residues using the o-phthaldialdehyde (OPA) method or corrosion using stereomicroscopy, scanning electron microscopy and energy dispersive spectroscopy. FINDINGS: Protein residue found on instruments was 21.5-54.0 µg and corrosion corresponded to 0-5% of the inspected area. No associations between storage environment and protein residue (adjusted mean difference = 0.48, 95% confidence interval: -0.42, 1.37, P=0.30) or corrosion (P=0.20) were identified. Higher numbers of treatment cycles showed higher amounts of corrosion (mean: 1cycle = 0.06%, 25cycles = 0.52% and 50cycles = 1.45%). In contrast, higher numbers of treatment cycles showed lower amounts of protein residue (P<0.001). We found both lower protein residue concentration and lower corrosion rating at 12 h compared with 6 and 24 h holding time. CONCLUSION: Cleanliness and durability of instruments before reprocessing seems not to be affected by storage environment or holding time but instead by number of treatment cycles.


Subject(s)
Patient Safety , Surgical Instruments , Corrosion , Humans , Microscopy, Electron, Scanning , o-Phthalaldehyde
15.
Scand J Rheumatol ; 51(6): 441-451, 2022 Nov.
Article in English | MEDLINE | ID: mdl-34514946

ABSTRACT

OBJECTIVES: Despite distinct aetiologies, the end-stages of primary osteoarthritis (OA) and secondary OA are described by common radiological features. However, the morphology of the bone-cartilage unit may differ depending on the pathogenesis. In this cross-sectional study, we aimed to investigate the histological differences in the bone-cartilage unit of the femoral head between patients with primary OA and secondary OA due to rheumatoid arthritis (RA). METHOD: Femoral heads were obtained from 12 patients with primary OA, six patients with secondary OA due to RA, and 12 control subjects. The femoral heads were investigated using stereological methods to ensure unbiased quantification. RESULTS: The volume (mean difference [95% confidence interval]) (2.1 [0.5;3.8] cm3, p = 0.016) and thickness (413 [78.9;747] µm, p = 0.029) of the articular cartilage and the thickness of the calcified cartilage (56.4 [0.4;113] µm, p = 0.017) were larger in patients with primary OA than in patients with secondary OA due to RA. Femoral head volume (1.2 [-3.6;6.1] cm3, p = 0.598), bone volume fraction (-1.1 [-2.8;5.1] cm3, p = 0.553), subchondral bone thickness (-2.5 [-212;207] µm, p = 0.980), and osteophyte area (25.3 [-53.6;104] cm2, p = 0.506) did not differ between patients. CONCLUSION: The thicker calcified cartilage in primary OA preceding the loss of articular cartilage can be attributed to endochondral ossification. Patients with secondary OA due to RA had severely thinner calcified cartilage as the pathogenesis is driven by inflammation and is characterized by a generalized and more severe loss of articular cartilage.


Subject(s)
Arthritis, Rheumatoid , Cartilage, Articular , Osteoarthritis , Humans , Cross-Sectional Studies , Osteoarthritis/diagnostic imaging , Osteoarthritis/etiology , Osteoarthritis/pathology , Hip Joint/diagnostic imaging , Cartilage, Articular/diagnostic imaging , Cartilage, Articular/pathology , Femur Head/diagnostic imaging , Femur Head/pathology , Arthritis, Rheumatoid/complications , Arthritis, Rheumatoid/pathology
16.
Perspect Public Health ; 142(5): 278-286, 2022 Sep.
Article in English | MEDLINE | ID: mdl-33779407

ABSTRACT

AIMS: The current study aimed to evaluate implementation fidelity of an Integrated Healthy Lifestyle Service (IHLS). METHODS: A pragmatic sample of 28 individual interviews and 11 focus groups were conducted. This resulted in a total of 81 (22 male) individuals comprising key stakeholders (n = 18), as well as intervention staff across senior management (n = 4), team lead (n = 14) and practitioner (n = 11) roles, and intervention clients (n = 34). RESULTS: A mixed degree of implementation fidelity was demonstrated throughout the five a priori fidelity domains of study design, provider training, intervention delivery, intervention receipt, and enactment. Stakeholders, staff and clients alike noted a high degree of intervention receipt across all services offered. Contrastingly, practitioners noted that they received minimal formal operational, data systems, clinical, and curriculum training as well as a lack of personal development opportunities. Consequently, practitioners reported low confidence in delivering sessions and collecting and analysing any data. A top-down approach to information dissemination within the service was also noted among practitioners which affected motivation and overall team morale. CONCLUSION: Results can be used to conceptualise best practices as a process to further strengthen the design, delivery and recruitment strategies of the IHLS.


Subject(s)
Healthy Lifestyle , Research Design , Focus Groups , Humans , Male
17.
Phys Rev Lett ; 127(20): 201801, 2021 Nov 12.
Article in English | MEDLINE | ID: mdl-34860065

ABSTRACT

This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51×10^{20} protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122±11(stat.)±15(syst.) assuming mixing only between three active flavors. No evidence for ν[over ¯]_{µ}→ν[over ¯]_{s} oscillation is observed. Interpreting this result within a 3+1 model, constraints are placed on the mixing angles θ_{24}<25° and θ_{34}<32° at the 90% C.L. for 0.05 eV^{2}≤Δm_{41}^{2}≤0.5 eV^{2}, the range of mass splittings that produces no significant oscillations at the near detector. These are the first 3+1 confidence limits set using long-baseline accelerator antineutrinos.

18.
Radiography (Lond) ; 27(4): 1099-1104, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34006443

ABSTRACT

INTRODUCTION: There is an increasing trend towards deploying reporting radiographers in Danish hospitals who, among various professional groups, interpret and report skeletal radiographs from the emergency department (ED). This study aimed to compare the quality of the reports issued by reporting radiographers to three different groups of medical doctors (MDs) who interpret or report skeletal radiographs at the ED. METHODS: Four professional groups (i.e. four reporting radiographers, two radiology trainees, two orthopaedic senior trainees, and two orthopaedic trainees) reported 100 radiographs of the appendicular skeleton. The Consequence of clinical Outcome score (CO-score), accuracy, sensitivity, and specificity of each group were compared. The relative risk of a false-negative, false-positive or wrong result, the risk of a serious error, as well as the odds ratio of a more severe CO-score for each of the three MD groups, were compared to the reporting radiographers. RESULTS: There was a significant difference between the groups in reference to the CO-score (P ≤ 0.001), accuracy (P = .003), specificity (P = .022), and in the proportion of serious errors (P ≤ 0.001). Compared to the reporting radiographers, all three groups of MDs showed a significantly higher CO-score and a significantly increased risk of a wrong result. Moreover, two of the MD groups showed a significantly increased risk of a false-positive result and for severe errors. CONCLUSION: Based on the CO-score, the relative risk of errors, which could potentially cause malpractice in treatment and patient recall, significantly decreased when the reports were completed by reporting radiographers. IMPLICATIONS FOR PRACTICE: To explore the need for a 24-h radiographer reporting service to the EDs, an upscaled study, like the current, with more participants representing the professional groups is highly recommended.


Subject(s)
Clinical Competence , Radiology , Emergency Service, Hospital , Humans , Radiography , Radiology/education , Skeleton
19.
Health Place ; 69: 102569, 2021 05.
Article in English | MEDLINE | ID: mdl-33882372

ABSTRACT

BACKGROUND: There continues to be a lack of understanding as to the geographical area at which the environment exerts influence on behaviour and health. This exploratory study compares different potential methods of both researcher- and participant-defined definitions of neighbourhood reflect an adolescent's activity space. METHODS: Seven consecutive days of global positioning system (GPS) tracking data were collected at 15 s intervals using a small exploratory adolescent sample of 14-18 year olds (n = 69) in West Yorkshire, England. A total of 304,581 GPS tracking points were collected and compared 30 different definitions of researcher-defined neighbourhoods including radial, network and ellipse buffers at 400 m, 800 m, 1000 m, 1600 m and 3000 m, as well as participant-defined self-drawn neighbourhoods. RESULTS: This exploratory study supports emerging evidence cautioning against the use of static neighbourhood definitions for defining exposure. Traditional buffers (network and radial) capture at most 67% of activity space (home radial), and at worst they captured only 3.5% (school network) and range from capturing between 3 and 88% of total time. Similarly, self-drawn neighbourhoods captured only 10% of actual daily movement. Interestingly, 40% of an adolescent's self-drawn neighbourhood was not used. We also demonstrate that buffers capture a range of space (22-95%) where adolescents do not go, thus misclassifying the exposure. CONCLUSION: Our exploratory findings demonstrate that neither researcher- nor participant-defined definition of neighbourhood adequately captures adolescent activity space. Further research with larger samples are needed to confirm the findings of this exploratory study.


Subject(s)
Geographic Information Systems , Residence Characteristics , Adolescent , England , Environment , Humans , Schools
20.
Nature ; 592(7852): 35-42, 2021 04.
Article in English | MEDLINE | ID: mdl-33790445

ABSTRACT

The photon-the quantum excitation of the electromagnetic field-is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6-8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S-2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude-with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S-2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11-13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.

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