Magnetic anisotropy of asbestos fibres

Original article can be found at : http://jap.aip.org/jap/ Copyright American Institute of PhysicsThe anisotropy of magnetic susceptibility of single asbestos fibers is measured. The alignment of both chrysotile and crocidolite fibers in magnetic fields is found to be due to the anisotropy. The average measured anisotropy of volume susceptibility is 0.40×10−6 for chrysotile and 83×10−6 for crocidolite. Fiber shape effects are estimated to contribute, on average, about 10% and 6%, respectively, to the total anisotropy of the two types of fiber. There is no evidence of significant permanent magnetic moments. The magnitude of the observed alignment makes the effect potentially useful in real-time detection of airborne asbestos fibers. The experimental technique developed in the study can be used for measuring the anisotropy of small particles of well-defined shape. High sensitivity of the technique permits the measurement of torques lower than 10−21 Nm on particles down to picogram mass.Peer reviewe

Diagnosis and Prognosis of Seizures and Epilepsy in Childhood: Dutch study of epilepsy in childhood

Many people suffer from one or more epileptic seizures during life, but not all these people have epilepsy. Moreover, epilepsy is not one disease or syndrome, but a collection of different disorders, which have in common the repeated occurrence of unprovoked epileptic seizures during some time in life.There are many genetically determined and acquired causes of epilepsy. The symptomatology of the seizures can be very different. Also the course in time of epilepsies is very diverging. The cause, symptoms, signs and course are influenced to a great deal by age. Therefore, the epilepsies in childhood and in adulthood differ in many aspects. For this reason, children and adults should not be mixed in studies on epilepsy

Phakomatosis Pigmentovascularis

We report a patient with phakomatosis pigmentovascularis IIb and numerous iris hamartomas. Phakomatosis pigmentovascularis IIb is characterized by the simultaneous occurrence of a nevus flammeus, a mongolian spot, and sometimes a nevus anemicus in the same individual, with systemic involvement. To our knowledge, the association with multiple iris hamartomas has been reported only once. This second patient suggests that the association might be more common. Additional reports will indicate if such an association is more frequent than is now assumed

Parent-completed scales for measuring seizure severity and severity of side-effects of antiepileptic drugs in childhood epilepsy: development and psychometric analysis.

We have developed two outcome measures for childhood epilepsy: a seizure severity (SS) scale and a side-effects (SE) scale. Both scales have been designed for completion by parents. The scales were tested in two pilot phases and the results of this stepwise analysis are described here. The final scales' psychometric properties were assessed in a group of 80 children with active epilepsy, representative of the population at whom the scales were aimed: children with chronic epilepsy, aged 4-16 years, including all seizure types and epilepsies, as well as children with neurological comorbidity. The SS scale and SE scale showed good internal consistency and test-retest stability. Although there was a significant positive correlation between the SS scale and the SE scale, this was low, indicating that the scales measure a different clinical trait. The SE scale consisted of two subscales: a Toxic subscale, measuring the severity of dose-related side-effects, and a Chronic subscale, measuring the severity of long-term behavioural and cognitive side-effects. These subscales for side-effects showed a high correlation and can be used as a joint scale. These scales have the potential to improve outcome assessment in childhood epilepsy and they can be used to assess important aspects of quality of life in this population

The Role of ICTs in Supporting Collaborative Networks in the Agro-Food Sector: Two Case Studies from South West England

Over recent years, in a wide range of countries, grassroots initiatives have emerged aimed at overcoming the limits of the mainstream agro-business system. These initiatives aim at improving farmers’ access to local and regional markets and consumers’ access to fresh local produce. Among these initiatives, Food Hubs have emerged as a promising way to improve local food supply systems. They represent collaborative networks of producers and consumers that aggregate, distribute, and market local food products. ICTs enable these collaborative networks by allowing information exchange among their actors and by providing collaborative tools that allow quick co-ordination between members of the network. The paper aims to analyse how the adoption of ICTs have fostered the development of new, initiatives oriented at establishing local food networks and to reconnect producers and consumers. The study will present results from the analysis of two food-hub initiatives based in South West England, which are adopting informative systems to support their activities and to implement novel business models: Stroudco Food Hub and Dean Forest Food Hub

Endocrinologic disorders and optic pathway gliomas in children with neurofibromatosis type 1

Objective. To establish the prevalence of endocrinologic disorders in children with neurofibromatosis type 1 (NF1) and the relationship between these disorders and cerebral abnormalities on magnetic resonance imaging. Design. A prospective follow-up study. Setting. A multidisciplinary neurofibromatosis clinic. Patients. A total of 122 children diagnosed with NF1 according to diagnostic criteria set by the National Institutes of Health. Results. Central precocious puberty (CPP) was diagnosed in 3 children and growth hormone deficiency (GHD) in 3 children. Optic pathway gliomas were observed in 15 children; in 9 of the 15 cases, the optic chiasm was involved. Of the 3 children with CPP, only 1 showed a chiasma glioma on magnetic resonance imaging. In 1 case with GHD, an optic chiasm glioma was detected on neuroimaging. Two of the 9 children with an optic chiasm glioma presented with CPP or GHD. Conclusions. It has been suggested that CPP in children with NF1 is found exclusively in the presence of a chiasma glioma. We conclude that chiasma glioma may not be obligatory in children with NF1 and CPP or GHD. Moreover, we report a prevalence of GHD in children with NF1 of 2.5%, which has not been established earlier

Effects of dipole position, orientation and noise on the accuracy of EEG source localization

BACKGROUND: The electroencephalogram (EEG) reflects the electrical activity in the brain on the surface of scalp. A major challenge in this field is the localization of sources in the brain responsible for eliciting the EEG signal measured at the scalp. In order to estimate the location of these sources, one must correctly model the sources, i.e., dipoles, as well as the volume conductor in which the resulting currents flow. In this study, we investigate the effects of dipole depth and orientation on source localization with varying sets of simulated random noise in 4 realistic head models. METHODS: Dipole simulations were performed using realistic head models and using the boundary element method (BEM). In all, 92 dipole locations placed in temporal and parietal regions of the head with varying depth and orientation were investigated along with 6 different levels of simulated random noise. Localization errors due to dipole depth, orientation and noise were investigated. RESULTS: The results indicate that there are no significant differences in localization error due tangential and radial dipoles. With high levels of simulated Gaussian noise, localization errors are depth-dependant. For low levels of added noise, errors are similar for both deep and superficial sources. CONCLUSION: It was found that if the signal-to-noise ratio is above a certain threshold, localization errors in realistic head models are, on average the same for deep and superficial sources. As the noise increases, localization errors increase, particularly for deep sources

A public health approach to understanding and preventing violent radicalization

<p>Abstract</p> <p>Background</p> <p>Very recent acts of terrorism in the UK were perpetrated by 'homegrown', well educated young people, rather than by foreign Islamist groups; consequently, a process of violent radicalization was proposed to explain how ordinary people were recruited and persuaded to sacrifice their lives.</p> <p>Discussion</p> <p>Counterterrorism approaches grounded in the criminal justice system have not prevented violent radicalization. Indeed there is some evidence that these approaches may have encouraged membership of radical groups by not recognizing Muslim communities as allies, citizens, victims of terrorism, and victims of discrimination, but only as suspect communities who were then further alienated. Informed by public health research and practice, a new approach is proposed to target populations vulnerable to recruitment, rather than rely only on research of well known terrorist groups and individual perpetrators of terrorist acts.</p> <p>Conclusions</p> <p>This paper proposes public health research and practice to guard against violent radicalization.</p