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We present a Monte Carlo collisional scheme that models single Compton scattering between leptons and photons in particle-in-cell codes. The numerical implementation of Compton scattering can deal with macro-particles of different weights and conserves momentum and energy in each collision. Our scheme is validated through two benchmarks for which exact analytical solutions exist: the inverse Compton spectra produced by an electron scattering with an isotropic photon gas and the photon–electron gas equilibrium described by the Kompaneets equation. It provides new opportunities for numerical investigation of plasma phenomena where a significant population of high-energy photons is present in the system.
This is a cross-sectional analysis of data obtained in the baseline of the Longitudinal Study on the Lifestyle and Health of University Students (n 685) carried out in a public Brazilian university. Food intake was assessed using a 24-h dietary recall. Dietary patterns (DP) for breakfast, lunch and dinner were identified using principal component analysis. Generalised linear models were used to analyse the variables associated with each DP. Three DP were extracted for each meal: breakfast: ‘White bread and butter/margarine’, ‘Coffee and tea’ and ‘Sausages, whole wheat bread and cheese’; lunch: ‘Traditional’, ‘Western’ and ‘Vegetarian’ and dinner: ‘Beans, rice and processed juice’, ‘White bread and butter/margarine’ and ‘White meat, eggs and natural juice’. Students who had meals at the campus showed greater adherence to the ‘White bread and butter/margarine’ (exp (βadj) = 1·15, 95 % CI 1·11, 1·19) and ‘Coffee and tea’ (exp (βadj) = 1·06, 95 % CI 1·02, 1·10) breakfast patterns; ‘Western’ lunch pattern (exp (βadj) = 1·04, 95 % CI 1·01, 1·08) and to the ‘Beans, rice and processed juice’ dinner pattern (exp (βadj) = 1·10, 95 % CI 1·06, 1·14). Having meals at the campus was associated with lower adherence to the ‘Sausages, whole wheat bread and cheese’ breakfast pattern (exp (βadj) = 0·93, 95 % CI 0·89, 0·97), ‘Traditional’ lunch pattern (exp (βadj) = 0·96, 95 % CI 0·93, 0·99) and to the ‘White bread and butter/margarine’ (exp (βadj) = 0·96, 95 % CI 0·93, 0·99) and ‘White meat, eggs and natural juice’ (exp (βadj) = 0·96, 95 % CI 0·93, 0·99) dinner pattern. The food environment at campus may influence students’ DP. Recognising meal eating patterns is important to support healthy eating promotion strategies on campus. Adjustments in the University Canteen menu could contribute to healthier eating choices among students.
A clear distinction between schizophrenia and some clusters of dementia is sometimes difficult to do in clinical practice.
A 38-years-old-male patient, with history of alcohol dependence, was admitted in our unit for generalized tremor, sweating, agitation, auditive, visual and cenestesic hallucinations, thought broadcasting and persecutory delusion. Agitation and the vegetative symptoms gradually subsided within 48 hours. Lab work showed no clinically significant changes. EEG and EKG were normal. MRI showed augmented cortical encephalic sulci. 5 days after the admission 10 mg of olanzapine was prescribed due to psychotic symptoms persistence. Haloperidol was stopped. A gradually improvement occurred and 26 days after the admission the patient was discharged home asymptomatic. Neuropsychological testing revealed severe fronto-temporal cognitive defect suggestive of alcoholic dementia.
The difficulty to clearly distinct schizophrenia from some dementias may be because, as Kraepelin stated in the 19th century, schizophrenia is itself a form of early dementia. His concept of dementia praecox is supported nowadays by the knowledge acquired from several neuropsychological and neuroimaging tests that a progressive cognitive deterioration appears to occur in schizophrenic patients.
Behavioral and personality changes are the core symptoms of frontotemporal dementia. Suicide and suicide attempts have been reported in demented patients.
We present a case of an 80 years-old-male patient, with a suicide attempt at the age of 76 as the presentation symptom of FTD.
There are few studies of suicide or selfharm in frontotemporal dementia where such behavior might be expected to be more common. We are conducting a clinical study in FTD patients about the relation between FTD and suicide. The results of such study will be presented and discussed.
To our knowledge, there are no reliable data or reports about suicide in FTD patients. Also, we didn’t find any case report of a suicide attempt as the first presentation symptom of FTD. We discuss the known data about this issue considering our clinical study and report.
Personal and familiar spiritual and religious beliefs are important factors to be considered when prescribing an antipsychotic drug to a schizophrenic patient.
A case report of a 29 years old male patient with a schizoaffective disorder is presented. in this case the border between what was delusion and what was the result of the patient personal and familiar spiritual beliefs was impossible to made. Only after the medication precribed has produced its effect this distinction has become clearer.
A literature revision about this issue was made.
Spiritual beliefs are important factors that influence therapeuticall adhesion. A clear distinction between them and delusion symptomatology is very difficult to made, mainly in an acute psychotic state. after medication, the delusion symptomatology disappears and personal spiritual beliefs persist.
The objective of the authors is to make a reflection about the causes of tianeptine abuse and dependence. In the scientific literature we can find case studies of anti-depressive dependence, which show amphetaminergic effects. In what concerns other anti-depressives, the information is rare, specifically about tianeptine. The few case studies reported until now, focus the psychostimulant effect as being the cause of the abuse and dependence. Though, a study case is described of a female patient, with 40 years old, previous history of alcohol abuse, who takes approximately 40 cigarettes per day and 10 cofee per day. She presents an history of tianeptine abuse for several years, which has become more severe in the last six months (1286 mg/day) and resulted in the third psychiatric hospitalization. The patient experiences and seeks for a psychostimulant effect and physically energizing through the excessive consumption of the drug. This tianeptine abuse is also accompanied by an excessive consumption of benzodiazepines (30 mg/day of bromazepam). Over the course of the hospitalization, we did not find physical symptoms and signs of withdrawal. Hepatic parameters were not affected. The authors conclued that the abuse and dependence of tianeptine seems to be an important problem in patients with history of abuse and/or dependence of other substances. Thus, this treatment and the implications that it may have in this population need more investigation.
The term depressive pseudodementia has proved to be a popular clinical concept. Little is known about the long-term outcome of this syndrome.
To compare depressed elderly patients with reversible cognitive impairment and cognitively intact depressed elderly patients.
All patients suffering from moderate or severe depression admitted to St Margaret's Hospital, UK as inpatients or day hospital outpatients between January 1, 1997 and December 31, 1999 (n=182) were screened for entry into the study. Eligible patients were divided into those presenting with pseudodementia and those who were cognitively intact and followed up for 5 to 7 years.
Seventy one percent point four percent of those suffering from pseudodementia had converted into dementia at follow up compared to only 18.2% in the cognitively intact group. The relative risk was 3.929 (95% CI: 1.985 to 7.775) and the ‘number needed to harm’ 1.88.
Reversible cognitive impairment in late-life moderate to severe depression appears to be a strong predictor of dementia. Patients with pseudodementia should probably have a full dementia screening, comprehensive cognitive testing and ongoing monitoring of their cognitive function.
Perfectionism and perseverative negative thinking/PNT are both associatedwith eating disorders symptoms. PNT is a prime candidate when investigating the pathway that links perfectionism to psychopathology.
To investigate if PNT mediates the relationshipbetween perfectionismcognitions and ED symptoms.
114 young women(mean age=23.78±6.340; mean BMI=21.59±3.127; 49.4% students) fill in the Portuguese validated versions of Eating Attitudes Test/EAT-25 (to evaluateBulimic behaviors, Diet and Social pressure to eat), MultidimensionalPerfectionism Cognitions Inventory (Concern over mistakes/CM, Personal standards/PS,Pursuit of Perfection) and Perseverative Thinking Questionnaire/PTQ-15(Repetitive Thought/RT, Cognitive interference and unproductiveness). Onlyvariables significantly correlated with the outcomes (EAT-25_Total and itsdimensions) were entered in the multiple regression models. Mediation analysesusing Preacher and Hayes bootstrapping methodology were performed.
Significantpredictors of EAT_Total were CM (b=.180)and RT (b=.169)(both p<.05). RT partially mediatedthe relationship between EAT_Total and CM. (95%CI=.0671-.0290).
Bulimicbehaviors were predicted by the same variables (b=.359;b=.154;p<.05) and RT also partially mediated the relationship between Bulimic behaviorsand CM (95%CI=.0071-.0190). Diet and Social Pressure to Eat were only predictedby PS (b=.154;b=.257,respectively; p<.05).
Although PNT mediates the relationship between perfectionist cognitions andbulimic behavior, the effect of the perfectionism on other disordered eatingdimensions, such as diet and SPE, seems to be independent of the PNT levels. Aspreviously reported in other studies with community samples, disordered eatingbehaviors are associated to negative perfectionism dimensions, but also todimensions that have been considered not entirely maladaptive.
Different psychoeducational and family-based interventions have been shown to improve chronic physical diseases, such as asthma. There is an increasing consistency of therapeutic effects in these programmes, across the literature. However, scientific validation of the benefits of each programme and what is the best model/method are required.
To evaluate the effects of Multifamily/MG and Psychoeducational/PG interventions for asthma on psychological, biological and morbidity outcomes.
A sample with 299 outpatients with asthma diagnosis from a University Hospital was recruited consecutively. Patients with moderate/severe asthma were included in a five-month randomized controlled study with simple occultation. There was a balanced inclusion of 141 patients allocated to three groups: MG, PG and control group/CG. All patients continued usual pharmacological treatment. Anxiety (SAS/STAIY), depression (BDI), coping mechanisms (WCAEL), quality of life (MiniAQLQ), asthma control (ACQ), lung function (FEV1/PEF), airway inflammation (FeNO), asthma severity and morbidity were assessed at the beginning and the end of the study.
Both MG and PG improved asthma control. The overall quality of life score increased in MG (0.5 U) and PG (0.8 U), but not in the CG. A significant decrease was also found in the use of oral steroids in MG and in the hospitalization in PG. The behavioural changes improved psychological parameters (anxiety, depression, coping), and lung function.
Multidisciplinary group interventions seem to improve physical/psychological parameters in asthma, and assessment of efficacy is necessary after a longer follow-up period, as is identification of patients’ clusters which benefit the most from each intervention.
New psychoactive substances (NPS) are substances that have recently appeared on the market and are not under international control. NPS use is experiencing an unprecedented increase. DiPT, 4-HO-DiPT and 4-AcO-DiPT are new psychoactive tryptamines and their effects may differ from those of other psychoactive tryptamines.
To explore the presence of DiPT, 4-HO-DiPT and 4-AcO-DiPT from samples delivered to and analyzed by Spanish harm reduction service Energy Control.
Materials and methods
All samples analyzed from 2009 to 2014 delivered as DiPT, 4-HO-DiPT and 4-AcO-DPT or containing these substances. Analysis was performed by gas chromatography–mass spectrometry.
From 17,432 samples, 4-HO-DiPT was found in 16, delivered as 4-HO-DiPT (6); 4-AcO-DiPT (7); DiPT (1); 4-AcO-DMT (1) and cocaine (1). 4-AcO-DiPT was found in 16, delivered as 4-AcO-DiPT (12); 5-MeO-DMT (1); 5-MeO-DiPT (1); 4-AcO-DMT (1) and cocaine (1). Only 4 samples contained DiPT, all presented as DiPT. Nine samples contained both 4-AcO-DiPT and 4-HO-DiPT. During the years of study, 4-HO-DiPT deliverance was increasing (4 samples in 2014) while deliverance of 4-AcO-DiPT and DiPT was decreasing (1 sample in 2014).
Increasing 4-HO-DiPT presence could translate a progressive replacement of 4-AcO-DiPT and DiPT recreational use. Clinical relevance comes from its growing use and the absence of scientific evidence on humans, therefore relying on users subjective experience to predict the effects.
Disclosure of interest
The authors declare that they have no competing interest.
In a recent study developed with a community sample, we have found that although PNT mediated the relationship between perfectionist cognitions and bulimic behavior, the effect of perfectionism on other disordered eating dimensions, such as diet, was independent of the PNT levels (Monteiro et al., 2015).
To investigate if PNT mediates the relationship between perfectionism and disordered eating behaviors in a clinical sample.
Fifty-two patients with eating disorders/ED (mean age = 22.54 ± 7.637; mean BMI = 20.07 ± 4.192; 14.5% Anorexia Nervosa cases; 7.8% Bulimia Nervosa and 9.0% EDNOS) were assessed with the ED section of the Diagnostic Interview for Genetic Studies and fill in the Portuguese validated versions of Eating Attitudes Test/EAT-25 (to evaluate Bulimic behaviors/BB, Diet and Social pressure to eat), Multidimensional Perfectionism Scales (to evaluate perfectionism composite dimensions Evaluative Concerns/EC and Perfectionistic Strivings/PS) and Perseverative Thinking Questionnaire/PTQ-15 (to evaluate Repetitive Thought/RT, Cognitive interference and unproductiveness/CIU). Only variables significantly correlated with the outcomes (EAT-25_Total and its dimensions) were entered in the regression models. Mediation analyses using Preacher and Hayes bootstrapping methodology were performed.
EC, PS, CIU and RT were significant predictors of EAT_Total. PA, CIU and PR were significant predictors of BB. EC and PS were significant predictors of Diet. CIU partially mediated the relationship between EC and EAT_Total (95% CI = 0.0025–0.3296) and between EC and BB (95% CI = 0.0037–0.1877).
Also in a clinical sample, CII, the most pernicious dimension of PNT, mediates the relationship between perfectionism and disordered eating behavior, particularly bulimic behavior; diet is predicted by perfectionism independently of PNT.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Shabu is a crystal methamphetamine whose consumption is common among the community of Philippine immigrants in Spain.
To describe the sociodemographic, healthcare and clinical characteristics of patients using shabu who have been treated by the psychiatry and addiction department of a tertiary hospital.
We describe the cases of patients treated in the psychiatry and addiction department of the hospital del Mar in Barcelona, Spain with methamphetamine use disorder. We collected sociodemographic variables, monitoring features and psychiatric comorbidity from the review of medical records.
Ten cases of patients with severe use disorder of shabu were identified. Eight patients are from the Philippines. Nine are men (90%). At the beginning of the medical follow-up the average age was 30 years (21–41 years). All of them reported being unemployed. Four patients were referred urgently to the hospital from an ambulatory care center, two belonged to a specific program for children and adolescents, two were treated at the emergency department and two were assessed during their admissions in other departments. Regarding clinical characteristics, six had associated psychiatric disorders: two have paranoid schizophrenia, two had induced psychotic episode, one had unspecified psychosis and other had conduct disorder.
Shabu is a drug that the Philippine community in Spain consumes in their daily life in a social context. However, consumption of this drug could be linked to the onset of psychotic symptoms. Registration is necessary to standardize the consumption pattern in order to establish a relationship between consumption and the appearance of psychotic and organic symptoms.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Infertility is not only a medical condition and its impact in mental health is well established. Although most couples facing fertility problems and the demands of medical treatment are able to adjust, some of them may show psychological difficulties with clinical relevance, such as depression and anxiety. The Mindfulness Based Program for Infertility (MBPI) is a group intervention designed for infertile women and data from its efficacy study revealed impact in depressive symptoms reduction as well as in internal and external shame, entrapment and defeat. Based on the MBPI, a mindfulness app targeting infertile patients was developed – the MindfulSpot.
This study addresses the MindfulSpot development.
The MindfulSpot is a prototype mobile app, which seeks to offer the chance of practicing mindfulness in a comfortable and accessible way. This app covers informative audio and written texts. The audio contents correspond to mindfulness formal practices and suggestions for informal practice, making possible its use throughout different moments of the day. Beyond the practices mentioned above, users are invited to explore the informative menu, including information on the impact that infertility may have in several aspects of the patients’ lives.
The efficacy of the MindfulSpot is still under analysis and results are expected to be available soon.
The MindfulSpot was designed as a medium for training mindfulness skills and it includes useful information regarding specific aspects of the emotional impact of infertility. Additionally to its independent use, it may also be used as a support tool of the MBPI.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
We present a detailed overview of the cosmological surveys that we aim to carry out with Phase 1 of the Square Kilometre Array (SKA1) and the science that they will enable. We highlight three main surveys: a medium-deep continuum weak lensing and low-redshift spectroscopic HI galaxy survey over 5 000 deg2; a wide and deep continuum galaxy and HI intensity mapping (IM) survey over 20 000 deg2 from
$z = 0.35$
to 3; and a deep, high-redshift HI IM survey over 100 deg2 from
$z = 3$
to 6. Taken together, these surveys will achieve an array of important scientific goals: measuring the equation of state of dark energy out to
$z \sim 3$
with percent-level precision measurements of the cosmic expansion rate; constraining possible deviations from General Relativity on cosmological scales by measuring the growth rate of structure through multiple independent methods; mapping the structure of the Universe on the largest accessible scales, thus constraining fundamental properties such as isotropy, homogeneity, and non-Gaussianity; and measuring the HI density and bias out to
$z = 6$
. These surveys will also provide highly complementary clustering and weak lensing measurements that have independent systematic uncertainties to those of optical and near-infrared (NIR) surveys like Euclid, LSST, and WFIRST leading to a multitude of synergies that can improve constraints significantly beyond what optical or radio surveys can achieve on their own. This document, the 2018 Red Book, provides reference technical specifications, cosmological parameter forecasts, and an overview of relevant systematic effects for the three key surveys and will be regularly updated by the Cosmology Science Working Group in the run up to start of operations and the Key Science Programme of SKA1.
The Square Kilometre Array (SKA) is a planned large radio interferometer designed to operate over a wide range of frequencies, and with an order of magnitude greater sensitivity and survey speed than any current radio telescope. The SKA will address many important topics in astronomy, ranging from planet formation to distant galaxies. However, in this work, we consider the perspective of the SKA as a facility for studying physics. We review four areas in which the SKA is expected to make major contributions to our understanding of fundamental physics: cosmic dawn and reionisation; gravity and gravitational radiation; cosmology and dark energy; and dark matter and astroparticle physics. These discussions demonstrate that the SKA will be a spectacular physics machine, which will provide many new breakthroughs and novel insights on matter, energy, and spacetime.
Recent trends in multimedia technologies indicate the need for richer imaging modalities to increase user engagement with the content. Among other alternatives, point clouds denote a viable solution that offers an immersive content representation, as witnessed by current activities in JPEG and MPEG standardization committees. As a result of such efforts, MPEG is at the final stages of drafting an emerging standard for point cloud compression, which we consider as the state-of-the-art. In this study, the entire set of encoders that have been developed in the MPEG committee are assessed through an extensive and rigorous analysis of quality. We initially focus on the assessment of encoding configurations that have been defined by experts in MPEG for their core experiments. Then, two additional experiments are designed and carried to address some of the identified limitations of current approach. As part of the study, state-of-the-art objective quality metrics are benchmarked to assess their capability to predict visual quality of point clouds under a wide range of radically different compression artifacts. To carry the subjective evaluation experiments, a web-based renderer is developed and described. The subjective and objective quality scores along with the rendering software are made publicly available, to facilitate and promote research on the field.
In this paper, we determine the growth rate of the exponential radiation amplification in the ion-channel laser, where a relativistic electron beam wiggles in a focusing ion channel that can be created in a wakefield accelerator. For the first time the radiation diffraction, which can limit the amplification, is taken into account. The electron beam quality requirements to obtain this amplification are also presented. It is shown that both the beam energy and wiggler parameter spreads should be limited. Two-dimensional and three-dimensional particle-in-cell simulations of the self-consistent ion-channel laser confirm our theoretical predictions.
The current filamentation instability (CFI) is capable of generating strong magnetic fields relevant to the explanation of radiation processes in astrophysical objects and leads to the onset of particle acceleration in collisionless shocks. Probing such extreme scenarios in the laboratory is still an open challenge. In this work, we investigate the possibility of using neutral
beams to explore the CFI with realistic parameters, by performing two-dimensional particle-in-cell simulations. We show that CFI can occur unless the rate at which the beam expands due to finite beam emittance is larger than the CFI growth rate and as long as the role of the competing electrostatic two-stream instability (TSI) is negligible. We also show that the longitudinal energy spread, typical of plasma-based accelerated electron–positron fireball beams, plays a minor role in the growth of CFI in these scenarios.
Recently, a new 2D carbon allotrope structure, named phagraphene (PG), was proposed. PG has a densely array of penta-hexa-hepta-graphene carbon rings. PG was shown to present low and anisotropic thermal conductivity and it is believed that this anisotropy should be also reflected in its mechanical properties. Although PG mechanical properties have been investigated, a detailed and comprehensive study is still lacking. In the present work we have carried out fully atomistic reactive molecular dynamics simulations using the ReaxFF force field, to investigate the mechanical properties and fracture patterns of PG membranes. The Young’s modulus values of the PG membranes were estimated from the stress-strain curves. Our results show that these curves present three distinct regimes: one regime where ripples dominate the structure and mechanical properties of the PG membranes; an elastic regime where the membranes exhibit fully planar configurations; and finally am inelastic regime where permanent deformations happened to the PG membrane up to the mechanical failure or fracture.
The study of the mechanical properties of nanostructured systems has gained importance in theoretical and experimental research in recent years. Carbon nanotubes (CNTs) are one of the strongest nanomaterials found in nature, with Young’s Modulus (EY) in the order 1.25 TPa. One interesting question is about the possibility of generating new nanostructures with 1D symmetry and with similar and/or superior CNT properties. In this work, we present a study on the dynamical, structural, mechanical properties, fracture patterns and EY values for one class of these structures, the so-called pentagraphene nanotubes (PGNTs). These tubes are formed rolling up pentagraphene membranes (which are quasi-bidimensional structures formed by densely compacted pentagons of carbon atoms in sp3 and sp2 hybridized states) in the same form that CNTs are formed from rolling up graphene membranes. We carried out fully atomistic molecular dynamics simulations using the ReaxFF force field. We have considered zigzag-like and armchair-like PGNTs of different diameters. Our results show that PGNTs present EY ∼ 800 GPa with distinct elastic behavior in relation to CNTs, mainly associated with mechanical failure, chirality dependent fracture patterns and extensive structural reconstructions.