Investigation into the role of ions and excited molecules in the corona process in air

Corona is the partial breakdown of a gas in an electric field and involves many complex phenomena including the production of space charge and excited molecular states of its constituents. Air is predominantly made up of nitrogen and oxygen, both of which have a wide range of excited states. Oxygen itself is additionally an electronegative gas and has the ability to attach electrons. Together these phenomena combine to influence the electric field and the production of secondary electrons to give corona its distinctive modes. A particular state of excited molecular oxygen, known as singlet oxygen, has the characteristic that it remains excited for a relatively long period of time. It is known that singlet oxygen plays a role in the detachment of electrons from the negative oxygen ions and its role in corona discharges has been accounted for through theory and models, but due to the difficulties of measurement of the singlet oxygen, the influence it does have on corona discharges is not entirely clear. On this basis the gas processes associated with the corona discharge in air have been explored, where a Boltzmann equation solver, the electron energy distribution function, transport coefficient and Townsend coefficients are used to understand the phenomena and provide input to a flux correct transport algorithm model. The model clearly indicates the presence of singlet oxygen, however its the space charge that plays the critical role in the repetitive nature of corona due to the collapse and recovery of the electric field. Experimentally it was convenient to define and compare the modes of corona under di↵erent conditions by its peak amplitude and repetition rate. The experiments included manipulated the environment with air-flow and exciting oxygen through a 1064 nm Nd:YAG laser as well as detecting 1270 nm emission from singlet oxygen. There was no evidence to suggest that the repetition rate of the corona discharge could be related to singlet oxygen. There were no emissions detected from various configurations, whilst visible corona was clearly seen. Together with the evidence from the model, the results showed that the presence of both negative ions and singlet oxygen is relatively low in the region that should provide seed electrons. It could be inferred that a relationship between repetition rate and the presence of singlet oxygen is not a dominant process in the corona discharge

High frequency current distribution in a structure with application to lightning protection systems

In concrete reinforced buildings, the steel framework is required to be bonded and is often used as a cost effective method of lightning protection. In defining lightning protection zones, it is essential to understand where the lightning current due to a direct strike will flow. A number of models exist to evaluate the current distribution, but are often applied to relatively simple structures. Using Maxwell’s equations, an approximate skin effect model is proposed and used to eval- uate the lightning current distribution in a complex structure. A reduced scale model of a structure, consisting of conductors arranged in rings, is developed to verify the model. Particular attention is given to the return path of the current, ensuring an even distrib- ution of the current in the structure. The equivalent circuit showed an even distribution of current across each conductor at dc and low frequencies and a distribution that concentrated in the outer conductors for higher frequencies. The measurements from the structure confirmed that the current con- centrates in the outer conductors at high frequencies. Applying a reduced scale lightning impulse, it is shown that the majority of the current flows on the outermost conductors. Any current on the inner conductors is not only greatly decreased in magnitude, but significantly slower in time than the applied impulse

Treatment outcomes for children with multidrug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND: Paediatric multidrug-resistant (MDR) tuberculosis is a public health challenge of growing concern, accounting for an estimated 15% of all global cases of MDR tuberculosis. Clinical management is especially challenging, and recommendations are based on restricted evidence. We aimed to assess existing evidence for the treatment of MDR tuberculosis in children. METHODS: We did a systematic review and meta-analysis of published and unpublished studies reporting treatment outcomes for children with MDR tuberculosis. We searched PubMed, Ovid, Embase, Cochrane Library, PsychINFO, and BioMedCentral databases up to Oct 31, 2011. Eligible studies included five or more children (aged ≤16 years) with MDR tuberculosis within a defined treatment cohort. The primary outcome was treatment success, defined as a composite of cure and treatment completion. RESULTS: We identified eight studies, which reported treatment outcomes for a total of 315 patients. We recorded much variation in the characteristics of patients and programmes. Time to appropriate treatment varied from 2 days to 46 months. Average duration of treatment ranged from 6 months to 34 months, and duration of follow-up ranged from 12 months to 37 months. The pooled estimate for treatment success was 81·67% (95% CI 72·54-90·80). Across all studies, 5·9% (95% CI 1·3-10·5) died, 6·2% (2·3-10·2) defaulted, and 39·1% (28·7-49·4) had an adverse event. The most common drug-related adverse events were nausea and vomiting. Other serious adverse events were hearing loss, psychiatric effects, and hypothyroidism. INTERPRETATION: The treatment of paediatric MDR tuberculosis has been neglected, but when children are treated outcomes can be achieved that are at least as good as those reported for adults. Programmes should be encouraged to report outcomes in children to improve the knowledge base for care, especially as new drugs become available. FUNDING: None

An experimental study of the ventral striatum of the golden hamster. I. Neuronal connections of the nucleus accumbens

As part of an experimental study of the ventral striatum, the horseradish peroxidase (HRP) method was used to examine the afferent and efferent neuronal connections of the nucleus accumbens. Following iontophoretic applications or hydraulic injections of HRP in nucleus accumbens, cells labeled by retrograde transport of HRP were observed in the ipsilateral telencephalon in the posterior agranular insular, perirhinal, entorhinal, and primary olfactory cortices, in the subiculum and hippocampal field CA1, and in the anterior and posterior divisions of the basolateral amygdaloid nucleus. In the diencephalon, labeled neurons were present ipsilaterally in the central medial, paracentral and parafascicular intralaminar nuclei, and in the midline nuclei parataenialis, paraventricularis, and reuniens. Retrograde labeling was observed in the ipsilateral brainstem in cells of the ventral tegmental area and dorsal raphe. Many of these projections to nucleus accumbens were found to be topographically organized. Anterograde transport of HRP from nucleus accumbens demonstrated ipsilateral terminal fields in the ventral pallidum and substantia nigra, pars reticulata. The afferent projections to nucleus accumbens from the posterior insular and perirhinal neocortices, intralaminar thalamus, and the dopamine-containing ventral tegmental area are analogous to the connections of the caudatoputamen, as are the efferents from nucleus accumbens to the substantia nigra and ventral globus pallidus. These connections substantiate the classification of nucleus accumbens as a striatal structure and provide support for the recently proposed concept of the ventral striatum. Furthermore, the demonstration that a number of limbic system structures, including the amygdala, hippocampal formation, entorhinal cortex, and olfactory cortex are important sources of afferents to the nucleus accumbens, suggests that the ventral striatum may serve to integrate limbic information into the striatal system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50009/1/901910203_ftp.pd

The NeuARt II system: a viewing tool for neuroanatomical data based on published neuroanatomical atlases

BACKGROUND: Anatomical studies of neural circuitry describing the basic wiring diagram of the brain produce intrinsically spatial, highly complex data of great value to the neuroscience community. Published neuroanatomical atlases provide a spatial framework for these studies. We have built an informatics framework based on these atlases for the representation of neuroanatomical knowledge. This framework not only captures current methods of anatomical data acquisition and analysis, it allows these studies to be collated, compared and synthesized within a single system. RESULTS: We have developed an atlas-viewing application ('NeuARt II') in the Java language with unique functional properties. These include the ability to use copyrighted atlases as templates within which users may view, save and retrieve data-maps and annotate them with volumetric delineations. NeuARt II also permits users to view multiple levels on multiple atlases at once. Each data-map in this system is simply a stack of vector images with one image per atlas level, so any set of accurate drawings made onto a supported atlas (in vector graphics format) could be uploaded into NeuARt II. Presently the database is populated with a corpus of high-quality neuroanatomical data from the laboratory of Dr Larry Swanson (consisting 64 highly-detailed maps of PHAL tract-tracing experiments, made up of 1039 separate drawings that were published in 27 primary research publications over 17 years). Herein we take selective examples from these data to demonstrate the features of NeuArt II. Our informatics tool permits users to browse, query and compare these maps. The NeuARt II tool operates within a bioinformatics knowledge management platform (called 'NeuroScholar') either as a standalone or a plug-in application. CONCLUSION: Anatomical localization is fundamental to neuroscientific work and atlases provide an easily-understood framework that is widely used by neuroanatomists and non-neuroanatomists alike. NeuARt II, the neuroinformatics tool presented here, provides an accurate and powerful way of representing neuroanatomical data in the context of commonly-used brain atlases for visualization, comparison and analysis. Furthermore, it provides a framework that supports the delivery and manipulation of mapped data either as a standalone system or as a component in a larger knowledge management system

Tandem quadruplication of HMA4 in the zinc (Zn) and cadmium (Cd) hyperaccumulator noccaea caerulescens

Zinc (Zn) and cadmium (Cd) hyperaccumulation may have evolved twice in the Brassicaceae, in Arabidopsis halleri and in the Noccaea genus. Tandem gene duplication and deregulated expression of the Zn transporter, HMA4, has previously been linked to Zn/Cd hyperaccumulation in A. halleri. Here, we tested the hypothesis that tandem duplication and deregulation of HMA4 expression also occurs in Noccaea. A Noccaea caerulescens genomic library was generated, containing 36,864 fosmid pCC1FOSTM clones with insert sizes ~20–40 kbp, and screened with a PCR-generated HMA4 genomic probe. Gene copy number within the genome was estimated through DNA fingerprinting and pooled fosmid pyrosequencing. Gene copy numbers within individual clones was determined by PCR analyses with novel locus specific primers. Entire fosmids were then sequenced individually and reads equivalent to 20-fold coverage were assembled to generate complete whole contigs. Four tandem HMA4 repeats were identified in a contiguous sequence of 101,480 bp based on sequence overlap identities. These were flanked by regions syntenous with up and downstream regions of AtHMA4 in Arabidopsis thaliana. Promoter-reporter b-glucuronidase (GUS) fusion analysis of a NcHMA4 in A. thaliana revealed deregulated expression in roots and shoots, analogous to AhHMA4 promoters, but distinct from AtHMA4 expression which localised to the root vascular tissue. This remarkable consistency in tandem duplication and deregulated expression of metal transport genes between N. caerulescens and A. halleri, which last shared a common ancestor >40 mya, provides intriguing evidence that parallel evolutionary pathways may underlie Zn/Cd hyperaccumulation in Brassicaceae

CRIMSON [CRisis plan IMpact: Subjective and Objective coercion and eNgagement] Protocol: A randomised controlled trial of joint crisis plans to reduce compulsory treatment of people with psychosis

Background: The use of compulsory treatment under the Mental Health Act (MHA) has continued to rise in the UK and in other countries. The Joint Crisis Plan (JCP) is a statement of service users' wishes for treatment in the event of a future mental health crisis. It is developed with the clinical team and an independent facilitator. A recent pilot RCT showed a reduction in the use of the MHA amongst service users with a JCP. The JCP is the only intervention that has been shown to reduce compulsory treatment in this way. The CRIMSON trial aims to determine if JCPs, compared with treatment as usual, are effective in reducing the use of the MHA in a range of treatment settings across the UK. Methods/Design: This is a 3 centre, individual-level, single-blind, randomised controlled trial of the JCP compared with treatment as usual for people with a history of relapsing psychotic illness in Birmingham, London and Lancashire/Manchester. 540 service users will be recruited across the three sites. Eligible service users will be adults with a diagnosis of a psychotic disorder (including bipolar disorder), treated in the community under the Care Programme Approach with at least one admission to a psychiatric inpatient ward in the previous two years. Current inpatients and those subject to a community treatment order will be excluded to avoid any potential perceived pressure to participate. Research assessments will be conducted at baseline and 18 months. Following the baseline assessment, eligible service users will be randomly allocated to either develop a Joint Crisis Plan or continue with treatment as usual. Outcome will be assessed at 18 months with assessors blind to treatment allocation. The primary outcome is the proportion of service users treated or otherwise detained under an order of the Mental Health Act (MHA) during the follow-up period, compared across randomisation groups. Secondary outcomes include overall costs, service user engagement, perceived coercion and therapeutic relationships. Sub-analyses will explore the effectiveness of the JCP in reducing use of the MHA specifically for Black Caribbean and Black African service users (combined). Qualitative investigations with staff and service users will explore the acceptability of the JCPs. Discussion: JCPs offer a potential solution to the rise of compulsory treatment for individuals with psychotic disorders and, if shown to be effective in this trial, they are likely to be of interest to mental health service providers worldwide