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Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent. This fundamental tenet has remained experimentally challenging and is yet to be tested in the laboratory. A particularly distinct signature of the resulting optical activity of the quantum vacuum is vacuum birefringence. This offers an excellent opportunity for a precision test of nonlinear quantum electrodynamics in an uncharted parameter regime. Recently, the operation of the high-intensity Relativistic Laser at the X-ray Free Electron Laser provided by the Helmholtz International Beamline for Extreme Fields has been inaugurated at the High Energy Density scientific instrument of the European X-ray Free Electron Laser. We make the case that this worldwide unique combination of an X-ray free-electron laser and an ultra-intense near-infrared laser together with recent advances in high-precision X-ray polarimetry, refinements of prospective discovery scenarios and progress in their accurate theoretical modelling have set the stage for performing an actual discovery experiment of quantum vacuum nonlinearity.
When deciding whether to support a military operation, do citizens in democracies weigh whether soldiers themselves support the operation? Recent research has concluded that, in the United States, public support for military operations rests in part on people’s beliefs that soldiers favor their own deployment. However, it is not known whether this finding extends beyond the United States to democracies with diverse national citizenship discourses and threat profiles, and its theoretical basis is not well understood. This article addresses both these gaps. Using novel survey data and an experiment in four democracies with divergent citizenship traditions—France, Israel, the United Kingdom, and the United States—we show that, in all four nations, support for military operations depends significantly on whether people believe that soldiers themselves favor the operation. We highlight two reasons: (1) battlefield performance (respondents think that soldiers who favor their mission fight better), and (2) soldier consent (humans’ capacity for empathy makes them sensitive to whether soldiers are willingly sent into harm’s way). This article has significant implications for debates on public support for the use of military force, the nature of citizenship in modern democracies, and contemporary militarism.
Recent stressful life events (SLE) are a risk factor for psychosis, but limited research has explored how SLEs affect individuals at clinical high risk (CHR) for psychosis. The current study investigated the longitudinal effects of SLEs on functioning and symptom severity in CHR individuals, where we hypothesized CHR would report more SLEs than healthy controls (HC), and SLEs would be associated with poorer outcomes.
Methods
The study used longitudinal data from the EU-GEI High Risk study. Data from 331 CHR participants were analyzed to examine the effects of SLEs on changes in functioning, positive and negative symptoms over a 2-year follow-up. We compared the prevalence of SLEs between CHR and HCs, and between CHR who did (CHR-T) and did not (CHR-NT) transition to psychosis.
Results
CHR reported 1.44 more SLEs than HC (p < 0.001), but there was no difference in SLEs between CHR-T and CHR-NT at baseline. Recent SLEs were associated with poorer functioning and more severe positive and negative symptoms in CHR individuals (all p < 0.01) but did not reveal a significant interaction with time.
Conclusions
CHR individuals who had experienced recent SLEs exhibited poorer functioning and more severe symptoms. However, as the interaction between SLEs and time was not significant, this suggests SLEs did not contribute to a worsening of symptoms and functioning over the study period. SLEs could be a key risk factor to becoming CHR for psychosis, however further work is required to inform when early intervention strategies mitigating against the effects of stress are most effective.
The United States provides limited direct support to its citizens abroad, but provides significant indirect support, via a global order in which capitalism, and US businesses in particular, can thrive. Historically, driven by laissez-faire ideological commitments and a limited welfare state at home, the US has rarely and only reluctantly organized or offered significant assistance when its citizens abroad have been in distress. However, mobilization by hostage families and advocacy organizations has forced the US to take a more active role in recent years, especially in prominent cases. With a vast security, diplomatic, and intelligence apparatus at its disposal to conduct matters of state, the US does not rely on citizens abroad to conduct foreign policy. It has sometimes engaged in repression of dissenting citizens through travel controls, and it has subjected citizens and others to significant surveillance. Although US citizens in distress abroad often receive limited direct assistance, US businesses can, in contrast, avail themselves of robust federal and state government aid for their commercial activities overseas – in line with US interests and ideology.
Cardiometabolic diseases are highly prevalent in Aotearoa New Zealand(1). Dietary intake is a modifiable risk factor for such diseases and certain dietary patterns, specifically the Mediterranean diet (MedDiet), are associated with improved metabolic health(2). This study aims to test whether an intervention of a Mediterranean dietary pattern incorporating high quality New Zealand foods (NZMedDiet pattern) using behaviour change science can improve the metabolic health of participants and their household/whānau. This is a multi-centre, three-stage trial, with two randomised controlled trials (RCTs), both parallel groups, superiority trials, and a longitudinal cohort study. The first RCT (RCT1) is a comparison of the NZMedDiet pattern implemented using behaviour science compared to usual diet for 12 weeks, and the second (RCT2) is a behaviour-change intervention compared to no intervention for 12 weeks, administered after participants have been exposed to the intervention in RCT1. The third stage is a longitudinal cohort study where all participants are followed for up to a year. The primary outcome measure for each stage is the metabolic syndrome severity score (MetSSS). Two hundred index participants and their household/whānau have been recruited and randomised into the trial. Participants are from four centres, two of which are University research units (University of Auckland (n = 57) and University of Otago, Christchurch (n = 60)), one a community-based traditional meeting place (Tu¯ Kotahi Māori Asthma and Research Trust at Ko¯kiri Marae in Lower Hutt, Wellington (n = 19)), and the other based at a hospital-based research unit (the Centre for Endocrine Diabetes and Obesity Research (CEDOR) in Wellington (n = 64). The trial will test whether the NZMedDiet pattern and behaviour change support improves the cardiometabolic health of people in New Zealand.
Management of primary headache (PHA) varies across emergency departments (ED), yet there is widespread agreement that computed tomography (CT) scans are overused. This study assessed emergency physicians’ (EPs) PHA management and their attitudes towards head CT ordering.
Methods:
A cross-sectional study was undertaken with EPs from one Canadian center. Drivers of physicians’ perceptions regarding the appropriateness of CT ordering for patients with PHA were explored.
Results:
A total of 73 EPs (70% males; 48% with <10 years of practice) participated in the study. Most EPs (88%) did not order investigations for moderate-severe primary headaches; however, CT was the common investigation (47%) for headaches that did not improve. Computed tomography ordering was frequently motivated by the need for specialist consultation (64%) or admission (64%). A small proportion (27%) believed patients usually/frequently expected a scan. Nearly half of EPs (48%) identified patient imaging expectations/requests as a barrier to reducing CT ordering. Emergency physicians with CCFP (EM) certification were less likely to perceive CT ordering for patients with PHA as appropriate. Conversely, those who identified the possibility of missing a condition as a major barrier to limiting their CT use were more likely to perceive CT ordering for patients with PHA as appropriate.
Conclusions:
Emergency physicians reported consistency and evidence-based medical management. They highlighted the complexities of limiting CT ordering and both their level of training and their perceived barriers for limiting CT ordering seem to be influencing their attitudes. Further studies could elucidate these and other factors influencing their practice.
We recently reported on the radio-frequency attenuation length of cold polar ice at Summit Station, Greenland, based on bi-static radar measurements of radio-frequency bedrock echo strengths taken during the summer of 2021. Those data also allow studies of (a) the relative contributions of coherent (such as discrete internal conducting layers with sub-centimeter transverse scale) vs incoherent (e.g. bulk volumetric) scattering, (b) the magnitude of internal layer reflection coefficients, (c) limits on signal propagation velocity asymmetries (‘birefringence’) and (d) limits on signal dispersion in-ice over a bandwidth of ~100 MHz. We find that (1) attenuation lengths approach 1 km in our band, (2) after averaging 10 000 echo triggers, reflected signals observable over the thermal floor (to depths of ~1500 m) are consistent with being entirely coherent, (3) internal layer reflectivities are ≈–60$\to$–70 dB, (4) birefringent effects for vertically propagating signals are smaller by an order of magnitude relative to South Pole and (5) within our experimental limits, glacial ice is non-dispersive over the frequency band relevant for neutrino detection experiments.
Adverse childhood experiences (ACE) can affect educational attainments, but little is known about their impact on educational achievements in people at clinical high risk of psychosis (CHR).
Methods
In total, 344 CHR individuals and 67 healthy controls (HC) were recruited as part of the European Community’s Seventh Framework Programme-funded multicenter study the European Network of National Schizophrenia Networks Studying Gene–Environment Interactions (EU-GEI). The brief version of the Child Trauma Questionnaire was used to measure ACE, while educational attainments were assessed using a semi-structured interview.
Results
At baseline, compared with HC, the CHR group spent less time in education and had higher rates of ACE, lower rates of employment, and lower estimated intelligence quotient (IQ). Across both groups, the total number of ACE was associated with fewer days in education and lower level of education. Emotional abuse was associated with fewer days in education in HC. Emotional neglect was associated with a lower level of education in CHR, while sexual abuse was associated with a lower level of education in HC. In the CHR group, the total number of ACE, physical abuse, and neglect was significantly associated with unemployment, while emotional neglect was associated with employment.
Conclusions
ACE are strongly associated with developmental outcomes such as educational achievement. Early intervention for psychosis programs should aim at integrating specific interventions to support young CHR people in their educational and vocational recovery. More generally, public health and social interventions focused on the prevention of ACE (or reduce their impact if ACE occur) are recommended.
The impact of the coronavirus disease 2019 (COVID-19) pandemic on mental health is still being unravelled. It is important to identify which individuals are at greatest risk of worsening symptoms. This study aimed to examine changes in depression, anxiety and post-traumatic stress disorder (PTSD) symptoms using prospective and retrospective symptom change assessments, and to find and examine the effect of key risk factors.
Method
Online questionnaires were administered to 34 465 individuals (aged 16 years or above) in April/May 2020 in the UK, recruited from existing cohorts or via social media. Around one-third (n = 12 718) of included participants had prior diagnoses of depression or anxiety and had completed pre-pandemic mental health assessments (between September 2018 and February 2020), allowing prospective investigation of symptom change.
Results
Prospective symptom analyses showed small decreases in depression (PHQ-9: −0.43 points) and anxiety [generalised anxiety disorder scale – 7 items (GAD)-7: −0.33 points] and increases in PTSD (PCL-6: 0.22 points). Conversely, retrospective symptom analyses demonstrated significant large increases (PHQ-9: 2.40; GAD-7 = 1.97), with 55% reported worsening mental health since the beginning of the pandemic on a global change rating. Across both prospective and retrospective measures of symptom change, worsening depression, anxiety and PTSD symptoms were associated with prior mental health diagnoses, female gender, young age and unemployed/student status.
Conclusions
We highlight the effect of prior mental health diagnoses on worsening mental health during the pandemic and confirm previously reported sociodemographic risk factors. Discrepancies between prospective and retrospective measures of changes in mental health may be related to recall bias-related underestimation of prior symptom severity.
Over the last 25 years, radiowave detection of neutrino-generated signals, using cold polar ice as the neutrino target, has emerged as perhaps the most promising technique for detection of extragalactic ultra-high energy neutrinos (corresponding to neutrino energies in excess of 0.01 Joules, or 1017 electron volts). During the summer of 2021 and in tandem with the initial deployment of the Radio Neutrino Observatory in Greenland (RNO-G), we conducted radioglaciological measurements at Summit Station, Greenland to refine our understanding of the ice target. We report the result of one such measurement, the radio-frequency electric field attenuation length $L_\alpha$. We find an approximately linear dependence of $L_\alpha$ on frequency with the best fit of the average field attenuation for the upper 1500 m of ice: $\langle L_\alpha \rangle = ( ( 1154 \pm 121) - ( 0.81 \pm 0.14) \, ( \nu /{\rm MHz}) ) \,{\rm m}$ for frequencies ν ∈ [145 − 350] MHz.
At the end of the Cold War, the United States came to pursue a policy of “liberal primacy” that would maintain America’s hegemonic status while expanding the liberal institutions that constituted the postwar international order. At least three important, long-standing questions persist about liberal primacy. First, was liberal primacy consistent with, or a radical departure from, US strategy during the Cold War? Second, how did the United States come to embrace primacy as a central objective of its foreign policy in the post-Cold War period? Finally, why did the United States choose specific strategies of expansion, especially its decision to enlarge NATO, rather than pursue other options like Partnership for Peace? We suggest that focusing on the legitimation of US foreign policy can shed light on these questions. Over the decades, US leaders have consistently invoked familiar liberal concepts and tropes to justify US foreign policy. From a legitimation perspective, there is much more continuity than change between Cold War and post-Cold War US foreign policy. We argue liberal legitimation made the post-Cold War strategy of primacy palatable both at home and abroad. Finally, liberal legitimating language bolstered the proponents of NATO expansion, clearing the path for expansionist policies.
Anxiety and depressive disorders can be chronic and disabling. Although there are effective treatments, only a fraction of those impaired receive treatment. Predictors of treatment-seeking and treatment receipt could be informative for initiatives aiming to tackle the burden of untreated anxiety and depression.
Aims
To investigate sociodemographic characteristics associated with treatment-seeking and treatment receipt.
Method
Two binary retrospective reports of lifetime treatment-seeking (n = 44 810) and treatment receipt (n = 37 346) were regressed on sociodemographic factors (age, gender, UK ethnic minority background, educational attainment, household income, neighbourhood deprivation and social isolation) and alternative coping strategies (self-medication with alcohol/drugs and self-help) in UK Biobank participants with lifetime generalised anxiety or major depressive disorder. Analyses were also stratified by gender.
Results
Treatment access was more likely in those who reported use of self-help strategies, with university-level education and those from less economically advantaged circumstances (household income <£30 000 and greater neighbourhood deprivation). Treatment access was less likely in those who were male, from a UK ethnic minority background and with high household incomes (>£100 000). Men who self-medicated and/or had a vocational qualification were also less likely to seek treatment.
Conclusions
This work on retrospective reports of treatment-seeking and treatment receipt at any time of life replicates known associations with treatment-seeking and treatment receipt during time of treatment need. More work is required to understand whether improving rates of treatment-seeking improves prognostic outcomes for individuals with anxiety or depression.
An influential model of democratic civil-military relations insists that civilian politicians and officials, accountable to the public, have “the right to be wrong” about the use of force: they, not senior military officers, decide when force will be used and set military strategy. While polls have routinely asked about Americans’ trust in the military, they have rarely probed deeply into Americans’ views of civil-military relations. We report and analyze the results of a June 2019 survey that yields two important, and troubling, findings. First, Americans do not accept the basic premises of democratic civil-military relations. They are extraordinarily deferential to the military’s judgment regarding when to use military force, and they are comfortable with high-ranking officers intervening in public debates over policy. Second, in this polarized age, Americans’ views of civil-military relations are not immune to partisanship. Consequently, with their man in the Oval Office in June 2019, Republicans—who, as political conservatives, might be expected to be more deferential to the military—were actually less so. And Democrats, similarly putting ideology aside, wanted the military to act as a check on a president they abhorred. The stakes are high: democracy is weakened when civilians relinquish their “right to be wrong.”
Psychosis is associated with a reasoning bias, which manifests as a tendency to ‘jump to conclusions’. We examined this bias in people at clinical high-risk for psychosis (CHR) and investigated its relationship with their clinical outcomes.
Methods
In total, 303 CHR subjects and 57 healthy controls (HC) were included. Both groups were assessed at baseline, and after 1 and 2 years. A ‘beads’ task was used to assess reasoning bias. Symptoms and level of functioning were assessed using the Comprehensive Assessment of At-Risk Mental States scale (CAARMS) and the Global Assessment of Functioning (GAF), respectively. During follow up, 58 (16.1%) of the CHR group developed psychosis (CHR-T), and 245 did not (CHR-NT). Logistic regressions, multilevel mixed models, and Cox regression were used to analyse the relationship between reasoning bias and transition to psychosis and level of functioning, at each time point.
Results
There was no association between reasoning bias at baseline and the subsequent onset of psychosis. However, when assessed after the transition to psychosis, CHR-T participants showed a greater tendency to jump to conclusions than CHR-NT and HC participants (55, 17, 17%; χ2 = 8.13, p = 0.012). There was a significant association between jumping to conclusions (JTC) at baseline and a reduced level of functioning at 2-year follow-up in the CHR group after adjusting for transition, gender, ethnicity, age, and IQ.
Conclusions
In CHR participants, JTC at baseline was associated with adverse functioning at the follow-up. Interventions designed to improve JTC could be beneficial in the CHR population.
Certaines études ont retrouvé que la consommation précoce de cannabis était associée à une fréquence plus élevée de troubles cognitifs ou psychiatriques, mais l’âge exact reste indéterminé, entre 13 et 18 ans selon les études [1–4].
Objectif
Comparer certaines caractéristiques cliniques des sujets dépendants au cannabis ayant commencé leur consommation à l’âge de 13 ans ou moins et celles de ceux qui ont commencé après.
Méthodes
Cent soixante-douze patients, consultant consécutivement dans le service d’Addictologie du CH Sainte-Anne pour dépendance au cannabis (critères DSM-IV), entre juin 2007 et juin 2013, ont été inclus dans l’étude. Les patients présentant des troubles psychotiques, bipolaires type 1, des dépendances opiacées ou à la cocaïne étaient exclus de l’étude. Ils ont été évalués à l’aide du Diagnostic Interview for Genetic Studies (DIGS).
Résultats
Les sujets ayant commencé leur consommation de cannabis à l’âge de 13 ans (n = 37) ou moins présentaient plus fréquemment un diagnostic de trouble de personnalité antisociale (respectivement 58,8 % vs 22,1 % ; Chi2 = 16,6 p = 0,0001, OR : 4,9) et rapportaient plus fréquemment des troubles subjectifs de l’attention que les sujets ayant commencé leur consommation plus tard (n = 135) (respectivement 86,5 % vs 66,7 %, Chi2 = 5,53, p = 0,03, OR : 3,02). En revanche, il n’y avait pas de différences significatives entre les deux groupes concernant la fréquence des troubles dépressifs, des phobies sociales, des troubles anxieux, des conduites suicidaires, des traitements anxiolytiques ou antidépresseurs antérieurs, ni de différence au niveau des symptômes de sevrage et des effets subjectifs induits par le cannabis.
Conclusions
Les sujets dépendants au cannabis qui commencent leur consommation avant l’âge de 13 ans ont un risque de présenter un trouble de la personnalité antisociale cinq fois plus élevé et des troubles subjectifs de l’attention trois fois plus élevés, par rapport aux sujets qui commencent le cannabis après l’âge de 13 ans.
Cortical excitability is modified in schizophrenia [1] but the effect of antipsychotic drugs has been disputed. In particular, patients receiving olanzapine and risperidone showed less cortical disinhibition compared to untreated schizophrenic subjects [2]. However, despite the observed increase, the Resting Motor Threshold (RMT) remained inferior to the RMT in normal controls, and the Transcallosal Conduction Time (TCT) did not change.
There is no comparative study of the effect of clozapine, an effective antipsychotic with proconvulsant properties.
We studied cortical excitability by transmagnetic stimulation in stabilized schizophrenic patients treated by clozapine (n=10), olanzapine (n=10) compared to healthy volunteers (n=10).
The aim of this study was to extend previous research into inhibitory deficits in schizophrenia and to compare the effect of clozapine and olanzapine on neurophysiological parameters such as RMT, Intracortical Inhibition (ICI), Intracortical Facilitation (ICF), Cortical Silence Period (CSP) and Transcallosal Inhibition (TI).
In clozapine treated patients, the RMT and ICI were significantly lower (p<0.05) compared to olanzapine treated and healthy subjects. TCT was longer in schizophrenic patients without difference in treatment subgroups.
Conclusion
The trend toward normalization of RMT and ICI with antipsychotic treatment seems to be independent of the magnitude of therapeutic effect.
This case-control study found an association between Seasonal Affective Disorder (SAD) and a single nucleotide polymorphism (intronic rs2072621) of the gene encoding GPR50 (an orphan member of the G protein-coupled melatonin receptor subfamily) in females. This may represent a gender-specific risk factor and a molecular link between melatonin and SAD.
Berseem clover (Trifolium alexandrinum L.) is an important forage legume and is the primary winter forage crop in Pakistan. There are significant gaps in yield potential among varieties of berseem clover, as well as yields obtained at research stations and on-farm. To address this problem a survey of farmers was undertaken in the districts of Kasur and Okara, Punjab, Pakistan to determine the level of knowledge and understanding of berseem forage cultivation and seed production. The study comprised 44% smallholder (<3 ha), 26% medium (3–5 ha) and 30% large farmers (>5 ha) with average age of 42 years. Most farmers had little or no knowledge of the role of seed quality, inoculation with rhizobium, pollination, fertiliser use, irrigation management and the importance of forage nutritional value in improving livestock productivity. Most farmers (56%) had received no input from the government or private sector to improve forage production, relying instead on traditional knowledge. Knowledge of the importance of land preparation (95%), sowing rate (98%) and insect and pest management (75%) was higher than seed selection and fertilisation. Adoption of improved varieties (3%) and production technologies (14%) was low due to various constraints including ignorance, high cost of inputs, lack of availability of inputs in the market and a perceived high level of financial risk. Almost 100% of the respondents agreed that seed of improved varieties was a pre-requisite for higher forage and seed production as well as essential to start village-based forage seed enterprises.
Introduction: Headache is a common emergency department (ED) presentation. Benign (i.e., non-pathological) headaches are particularly common, including exacerbations of chronic migraine, tension, and cluster headache. Several studies have reported concerns over the frequent use of advanced imaging, specifically computed tomography (CT), in the ED management of benign or primary headache presentations. This systematic review examined the proportion of adult ED benign headache presentations who receive a CT(head). Methods: Eight bibliographic databases and the grey literature were searched. All studies reporting the proportion of benign headache patients receiving a CT(head) in the ED were eligible for inclusion. Studies which included a secondary headache population of 15% of their total study population or less where eligible for inclusion. Two reviewers independently assessed study inclusion and completed quality assessment and data extraction. Weighted medians were calculated for the primary and secondary outcomes, as appropriate. Results: The search returned 2,444 unique citations, of which 20 met the inclusion criteria (21 patient groups were analyzed). The majority of the studies were descriptive in nature and conducted in North America. The reported proportion of benign headache patients receiving a CT(head) varied considerably (range: 2.06-67.21%); with a weighted median of 30.0% (interquartile range: 30.0, 30.0). Studies published in 2000 or later (18/21 groups) were found to have a higher weighted median percentage compared to those published pre-2000 (p=0.016). Neither the country of origin nor the proportion of patients with secondary headache included within the study population had a significant effect on CT utilization. Of the three studies which reported the discharge diagnosis of all patients, sub-arachnoid hemorrhage was discovered in 2/241 (0.83%) of CT scans. Conclusion: Considerable variation in CT utilization for benign headache ED presentations exists and estimates indicate that more than a quarter of patients receive a CT(head). Overall, these CT scans rarely identify significant pathology, suggesting imaging may be safely reduced. Further research is required to identify interventions which can safely and effectively reduce unnecessary imaging among headache presentations.