Peculiar Glitch of PSR J1119-6127 and Extension of the Vortex Creep Model

Glitches are sudden changes in rotation frequency and spin-down rate, observed from pulsars of all ages. Standard glitches are characterized by a positive step in angular velocity ($\Delta\Omega$ $>$ $0$) and a negative step in the spin-down rate ($\Delta \dot \Omega$ $<$ $0$) of the pulsar. There are no glitch-associated changes in the electromagnetic signature of rotation-powered pulsars in all cases so far. For the first time, in the last glitch of PSR J1119-6127, there is clear evidence for changing emission properties coincident with the glitch. This glitch is also unusual in its signature. Further, the absolute value of the spin-down rate actually decreases in the long term. This is in contrast to usual glitch behaviour. In this paper we extend the vortex creep model in order to take into account these peculiarities. We propose that a starquake with crustal plate movement towards the rotational poles of the star induces inward vortex motion which causes the unusual glitch signature. The component of the magnetic field perpendicular to the rotation axis will decrease, giving rise to a permanent change in the pulsar external torque.Comment: accepted by MNRAS, 10 pages, 2 figure

Determination of depression risk factors in children and adolescents by regression tree methodology.

We used a regression tree method (RTM) to determine risks of depression in children/adolescents. The survey records of 4,143 children/adolescents in a study based in Mersin, Turkey served as data in this study, and multi-step, stratified, and cluster sampling were used. Effects of 24 variables (sex, smoking, parental problems, etc.) were evaluated on depression scores. The Child Beck Depression Inventory (CBDI) was used to determine the level of depression. Subjects were into 12 different groups based on magnitudes of mean depression scores. The interactions among 7 variables determined to be risk factors are shown on a schema. The STATISTICA (ver.6.0) package program was used for all computations. Although traditional statistical methods have often been used for analysis in this field, such approaches are associated with certain disadvantages such as missing values, ignorance of interaction effects, or restriction of the shape of the distribution. To avoid such disadvantages, we therefore suggest the use of the RTM in studies involving numerical-based outcome variables and for the investigation of a large number of variables and it may be more effective than traditional statistical methods in epidemiological studies which determine risk factors.</p

The prevalence of primary headache disorders in children and adolescents in Zambia: a schools-based study

Background The Global Campaign against Headache collects data from children (6–11 years) and adolescents (12–17) to inform health and education policies and contribute to the Global Burden of Disease (GBD) study. This survey in Zambia, part of this global enquiry, was the second from sub-Saharan Africa (SSA). Methods Following the generic protocol, this was a schools-based cross-sectional survey. We used the child and adolescent versions of the structured Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire, self-completed by pupils within classes, in a total of nine schools in Lusaka (urban) and Copperbelt (semi-rural). These two of Zambia’s ten provinces were selected to represent the country’s urban/rural divide. Headache diagnostic questions were based on ICHD-3 except for undifferentiated headache (UdH). Results Of 2,759 potential participants, 2,089 (615 children [29.4%], 1,474 adolescents [70.6%]) completed questionnaires (participating proportion 75.7%). Children were therefore under-represented (mean age 13.1 ± 2.8 years), while gender distribution (1,128 [54.0%] male, 961 [46.0%] female) was close to expectation. Observed lifetime prevalence of headache was 97.5%. Gender- and age-adjusted 1-year prevalence estimates were 85.8% for all headache, 53.2% for migraine (definite 17.5%, probable 35.7%), 12.1% for tension-type headache (TTH), 14.8% for UdH, 3.3% for all headache on ≥ 15 days/month and 0.9% for probable medication-overuse headache. Headache durations were short: only 28.6% of participants with any headache, and only 10.5% of those diagnosed as probable migraine, reported usual durations of > 2 h (the threshold for definite migraine). Of the latter, 36.6% reported < 1 h, the duration criterion for UdH. There were weak associations of migraine (definite + probable) with female gender, and of TTH and headache on ≥ 15 days/month with adolescence. Headache yesterday was reported by 22.2% of the sample, 25.5% of those with headache. Conclusions Headache disorders among young people are prevalent in Zambia. Among them, migraine is the most common, with UdH also highly prevalent. In this study there were diagnostic uncertainties, which rested to a large extent on the distinction between migraine and UdH among the many participants reporting headache of < 2 h’ duration. Similar uncertainties occurred in the first study in SSA, in Ethiopia. Because of these, we conclude only that migraine affects at least 17.5% of these age groups in Zambia, which is still a large proportion, adult prevalence in an earlier study being 22.9%. Supplementary estimates of attributed burden are needed to inform public-health and educational policies in Zambia

The prevalence of headache disorders in children and adolescents in Mongolia: a nationwide schools-based study

Background The Global Campaign against Headache collects data from children (7–11 years) and adolescents (12–17 years) both to inform health and education policies and to contribute to the Global Burden of Disease (GBD) study. This survey in Mongolia was part of this global enquiry. Methods Following the generic protocol for the global enquiry, this was a schools-based cross-sectional survey. Self-completed structured questionnaires were administered, within classes, in seven schools in four districts of the Capital city and three rural areas of Mongolia, selected to represent the country’s diversities. Headache diagnostic questions were based on ICHD-3 criteria but for the inclusion of undifferentiated headache (UdH). Results Of 4515 potential participants, 4266 completed the questionnaire (children 2241 [52.5%], adolescents 2025 [47.5%]; males 2107 [49.4%], females 2159 [50.6%]). Children were therefore slightly over-represented, although overall mean age was 11.3 ± 3.3 years (range: 6–17; median 11). The non-participation proportion was 4.5%. Observed lifetime prevalence of headache was 81.0%. Gender- and age-adjusted 1-year prevalence was 59.4% (migraine: 27.3%; tension-type headache [TTH]: 16.1%; UdH: 6.6%; all headache on ≥15 days/month: 4.2%; probable medication-overuse headache: 0.7%). All headache types except UdH were more prevalent among females than males, and all were more prevalent among adolescents than children, although UdH represented a higher proportion of all headache in children (13.0%) than in adolescents (10.0%). Headache yesterday was reported by 15.9% of the sample, 26.0% of those with headache. Conclusions At least in adolescents, headache in Mongolia is no less common than in adults. The clear difference from similar studies in other countries was a lower prevalence of UdH, perhaps a consequence of reporting bias in a non-troublesome headache (mild and short-lasting by definition). This study informs policy in Mongolia and, with no similar study yet from elsewhere in Western Pacific Region, makes an important contribution to the global enquiry

Experimental study of mercury removal from exhaust gases

An initial study has been made of the use of synthetic zeolites for mercury capture from exhaust gases. Synthetic zeolites (Na-X and Na-P1), and for comparison a natural zeolite (clinoptilolite) and activated carbon with bromine (AC/Br) were tested for mercury uptake from a gaseous stream. The materials were subjected to mercury adsorption tests and their thermal stability was evaluated. The untreated synthetic zeolites had negligible mercury uptake, but after impregnation with silver, the adsorption of mercury was markedly improved. The synthetic zeolite Na-X impregnated with silver adsorbed significantly more mercury before breakthrough than the activated carbon impregnated with bromine, indicating the potential of zeolite derived from coal fly ash as a new sorbent for capture of mercury from flue gases

Wind braking of magnetars

(adapted)Considering recent observations challenging the traditional magnetar model, we explore the wind braking of magnetars. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin down measurements may be strongly biased by a particle wind. Recent challenging observations of magnetars may be explained naturally in the wind braking scenario: (1) The supernova energies of magnetars are of normal value; (2) The non-detection in Fermi observations of magnetars; (3) The problem posed by the low-magnetic field soft gamma-ray repeaters; (4) The relation between magnetars and high magnetic field pulsars; (5) A decreasing period derivative during magnetar outbursts. Transient magnetars may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. In the wind braking scenario, magnetars are neutron stars with strong multipole field. For some sources, a strong dipole field may be no longer needed. A magnetism-powered pulsar wind nebula and a braking index smaller than three are the two predictions of the wind braking model.Comment: 34 pages, 1 table, 6 figures, accepted by Ap

Validation and psychometric analysis of the Internet Addiction Test in Spanish among college students

BACKGROUND: The wide use of the Internet in the workplace, academic or social field, can have an impact on daily life. One of the most used questionnaires worldwide to analyse these problems is the Internet Addiction Test (IAT). Our aim was to validate a Spanish version of the IAT and analyse its psychometric properties. METHODS: Population of study were college students participating in the uniHcos project (Universities of Granada, Huelva, Jaén, León, Salamanca, and Vigo). The questionnaire was translated and back-translated by two native English speakers. Reliability of scores was analysed using Pearson's correlation coefficient and agreement was analysed using the Bland-Altman and Kappa techniques. Test dimensions were analysed by exploratory and confirmatory factor analysis. RESULTS: The reliability of scores was good (r = 0.899, Kappa = 0.650 and mean difference using Bland-Altman = -3.5). The psychometric assessment identified two factors (Emotional Investment; Performance and Time Management) which explained 55 % of the variance (total internal consistency of 0.91) and only 19 items. The confirmatory analysis showed an acceptable goodness of fit, especially when items 6 and 8 were related (RMSEA = 0.07 90%IC = 0.06 - 0.08; WRMR = 1.01, CFI = 0.96; TLI = 0.95). The two dimensions were negatively correlated with age and positively correlated with time spent online, especially for the purposes of leisure and entertainment. DISCUSSION: The results show good reliability and psychometric properties of the Spanish version of IAT with a two-dimensional solution. This result is partially in concordance with previous validations of the IAT in other languages that have found uni- and multi-dimensional solutions using different methodologies. Moreover, we want to highlight the possibility that some item of this questionnaire is outdated due to the technological and lifestyles changes and should be not taken into account. CONCLUSION: The reliability and psychometric properties obtained in this study support the conclusion that this Spanish short version of the IAT represents a useful tool for the analysis of problems arising from misuse of the Internet

Overview of diagnosis and management of paediatric headache. Part I: diagnosis

Headache is the most common somatic complaint in children and adolescents. The evaluation should include detailed history of children and adolescents completed by detailed general and neurological examinations. Moreover, the possible role of psychological factors, life events and excessively stressful lifestyle in influencing recurrent headache need to be checked. The choice of laboratory tests rests on the differential diagnosis suggested by the history, the character and temporal pattern of the headache, and the physical and neurological examinations. Subjects who have any signs or symptoms of focal/progressive neurological disturbances should be investigated by neuroimaging techniques. The electroencephalogram and other neurophysiological examinations are of limited value in the routine evaluation of headaches. In a primary headache disorder, headache itself is the illness and headache is not attributed to any other disorder (e.g. migraine, tension-type headache, cluster headache and other trigeminal autonomic cephalgias). In secondary headache disorders, headache is the symptom of identifiable structural, metabolic or other abnormality. Red flags include the first or worst headache ever in the life, recent headache onset, increasing severity or frequency, occipital location, awakening from sleep because of headache, headache occurring exclusively in the morning associated with severe vomiting and headache associated with straining. Thus, the differential diagnosis between primary and secondary headaches rests mainly on clinical criteria. A thorough evaluation of headache in children and adolescents is necessary to make the correct diagnosis and initiate treatment, bearing in mind that children with headache are more likely to experience psychosocial adversity and to grow up with an excess of both headache and other physical and psychiatric symptoms and this creates an important healthcare problem for their future life