Photonic crystal devices modelled as grating stacks: matrix generalizations of thin film optics

A rigorous semi-analytic approach to the modelling of coupling, guiding and propagation in complex microstructures embedded in two-dimensional photonic crystals is presented. The method, which is based on Bloch mode expansions and generalized Fresnel coefficients, is shown to be able to treat photonic crystal devices in ways which are analogous to those used in thin film optics with uniform media. Asymptotic methods are developed and exemplified through the study of a serpentine waveguide, a potential slow wave device.

Homicide and affective disorder

The background, offence characteristics and psychiatric diagnosis were reviewed of 115 referrals of offenders charged with homicide made by procurators fiscal to the State Hospital, Carstairs, Scotland's only special secure hospital. A retrospective casenote review was performed using a structured questionnaire. A higher percentage of mental illness and substance misuse (11% and 40%) was recorded than that reported by Gillies in 1976. The results are discussed in the context of comparable studies and, in particular, the National Confidential Inquiry into Suicide and Homicide by People with Mental Illness and the Discussion Paper on Insanity and Diminished Responsibility published by the Scottish Law Commission.

An improved assay for genotyping the common Alu insertion in the tissue-type plasminogen activation gene PLAT

An improved assay for genotyping the common Alu insertion in the tissue-type plasminogen activator (PLAT) locus is described in this report. The assay is a valuable asset to clinical researchers interested in exploring disease associations with this allele. The automation and improved accuracy will facilitate future population-based studies, as well as clinical screening.

Audit of the Forensic Psychiatry Liaison Service to Glasgow Sheriff Court 1994 to 1998

This study seeks to describe the demographic, offence, and diagnostic details of subjects referred by the Procurator Fiscal at Glasgow Sheriff Court to the Forensic Psychiatry Liaison between 1994 and 1997. The initial outcome of the assessment and an assessment of medical time involved is presented. This study is a retrospective review of audit forms completed between 1993 and 1994 and once more in 1997. The referral criteria, age structure and offence pattern was broadly similar to that reported in court diversion schemes in England. A primary diagnosis of alcohol and/or drug dependence was seen in one third of referrals during both years of the audit. A marked increase (250%) in referrals between 1994 and 1997 resulted in a marked reduction of those admitted to hospital, and an increase in the percentage who had 'no psychiatric diagnosis'. The need for ongoing liaison between the Procurators Fiscal and the Forensic Psychiatrists involved would appear important in modifying referral criteria.

Calculations of air-guided modes in photonic crystal fibers using the multipole method

We demonstrate that a combination of multipole and Bloch methods is well suited for calculating the modes of air core photonic crystal fibers. This includes determining the reflective properties of the cladding, which is a prerequisite for the modal calculations. We demonstrate that in the presence of absorption, the modal losses can be substantially smaller than in the corresponding bulk medium.

A comparison of individual and family psychology of adolescents with chronic fatigue syndrome, rheumatoid arthritis, and mood disorders

Chronic fatigue syndrome (CFS) is a controversial diagnosis with unknown cause. Adult studies indicate high rates of psychosocial dysfunction and psychiatric comorbidity. The authors compared three groups of pediatric patients selected by diagnosis-(1l) CFS (n = 15), (2) juvenile rheumatoid arthritis (n = 15), and (3) mood disorders (n = 15)-across many psychological measures. CFS subjects had dramatic elevation of the Somatic Complaints subscale (mean T score = 75), whereas the mood disorders group had higher externalizing scores (mean T score = 68) on the Child Behavior Checklist. The CFS subjects missed significantly more school compared with the two control groups. After the onset of CFS, 13 of 15 of the CFS patients required significant educational accommodation. Only 4 of the 15 CFS patients had an Axis I psychiatric diagnosis, as determined by the Computerized Diagnostic Interview for Children. Despite a low rate of psychiatric diagnosis in the CFS sample, these data attest to their psychosocial and school dysfunction.

Effects of olanzapine on cerebellar functional connectivity in schizophrenia measured by fMRI during a simple motor task

BACKGROUND

According to current theories, schizophrenia results from altered connectivity in brain circuits for fundamental cognitive operations. Consequently, the poorly understood mechanisms of neuroleptic treatment may be explainable by altered functional interactions within such networks. The 'cognitive dysmetria' model hypothesizes that one key structure in these circuits is the cerebellum. To investigate the effects of olanzapine on cerebellar functional connectivity (CFC), a seed-voxel correlation analysis (SVCA) was used in a functional magnetic resonance imaging (fMRI) study of a simple finger-tapping task.

METHODS

fMRI scans were obtained from six schizophrenic patients under both drug-free and olanzapine-treated conditions and from a matched control group of six healthy subjects at corresponding time points. SVCAs were performed for anatomically and functionally standardized seed voxels in the anterior cerebellum. SVCA results were then processed by three different randomization analyses.

RESULTS

The analyses revealed that olanzapine caused widespread changes of CFC, including prominent changes in prefrontal cortex and mediodorsal thalamus. Significant changes in motor structures were found after subtractions within both groups and may thus indicate repetition effects rather than drug effects. Olanzapine 'normalized' the patients' CFC patterns for the right, but not for the left cerebellum.

CONCLUSION

Even for a simple motor task, olanzapine affects functional interactions between the cerebellum and many non-motor brain regions, including elements of the 'cognitive dysmetria' circuit. Altogether, our findings suggest that olanzapine has a stronger differential effect on neural activity in prefrontal cortex and thalamus than in motor structures.

Geology and palaeontology of the Late Miocene Middle Awash valley, Afar rift, Ethiopia

The Middle Awash study area of Ethiopia's Afar rift has yielded abundant vertebrate fossils (approximately 10,000), including several hominid taxa. The study area contains a long sedimentary record spanning Late Miocene (5.3-11.2 Myr ago) to Holocene times. Exposed in a unique tectonic and volcanic transition zone between the main Ethiopian rift (MER) and the Afar rift, sediments along the western Afar rift margin in the Middle Awash provide a unique window on the Late Miocene of Ethiopia. These deposits have now yielded the earliest hominids, described in an accompanying paper and dated here to between 5.54 and 5.77 Myr. These geological and palaeobiological data from the Middle Awash provide fresh perspectives on hominid origins and early evolution. Here we show that these earliest hominids derive from relatively wet and wooded environments that were modulated by tectonic, volcanic, climatic and geomorphic processes. A similar wooded habitat also has been suggested for the 6.0 Myr hominoid fossils recently recovered from Lukeino, Kenya. These findings require fundamental reassessment of models that invoke a significant role for global climatic change and/or savannah habitat in the origin of hominids.

Molecular typing of pathogenic fungi

In this Round Table, the application of several methods of molecular typing were discussed in reference to four important pathogenic fungi: Coccidioides immitis, Histoplasma capsulatum, Candida albicans and Paracoccidioides brasiliensis. Among the different methods the following were discussed: restriction fragment length polymorphisms (RFLP), single nucleotide polymorphisms, random amplified polymorphic DNA (RAPD), polymerase chain reaction (PCR)-RFLP and microsatellites. By means of these methods, several important biological questions related to speciation, mode of reproduction and population genetics could be approached. The basic information obtained from this approach has implications in the understanding of these pathogenic fungi in relation to their behavior and the development of pathogenic features, such as resistance to antimicrobials and virulence factors used for colonization of mammalian hosts. The knowledge obtained from these studies could also be used for the development of innovative diagnostic methods, as well as for novel therapeutic approaches and production of vaccines.

Effect of immune deficiency on lipoproteins and atherosclerosis in male apolipoprotein E-deficient mice

To determine whether T cells and B cells influence lipid metabolism and atherosclerosis, we crossed apolipoprotein E-deficient (apoE degrees ) mice with recombination activating gene 2-deficient (RAG2 degrees ) mice. Total plasma cholesterol levels were approximately 20% higher in male apoE degrees mice compared with the apoE degrees RAG2 degrees mice at 8 weeks of age, and plasma triglyceride levels were 2.5-fold higher in the apoE degrees mice even when plasma cholesterol levels were similar. Male mice with plasma cholesterol levels between 400 and 600 mg/dL at 8 weeks of age were euthanized at 27 and 40 weeks of age. The aortic root lesion area in the apoE degrees RAG2 degrees mice, compared with that in the immune-competent apoE degrees mice, was 81% and 57% smaller at 27 and 40 weeks of age, respectively. In contrast, there was no difference in the size of the brachiocephalic trunk lesions. Similar results were obtained with mice euthanized at 40 weeks of age that had 8-week cholesterol levels between 300 and 399 mg/dL. In apoE degrees RAG2 degrees mice, aortic root atherosclerosis was more profoundly suppressed at lower cholesterol levels. Thus, T and B cells and their products differentially influence the development of atherosclerosis at different sites. We also demonstrate a profound effect of the immune system on plasma lipid homeostasis.

Effect of nasal dilators on nasal structures, sniffing strategies, and olfactory ability

This paper describes the effects that nasal dilators have on olfactory ability. Experimental results demonstrate that nasal dilators increase odorant identification, lower odorant threshold, and increase perceptual odorant intensity. In other experiments, magnetic resonance imaging (MRI) data demonstrates that the size of the nasal cavity especially around the region of the nasal valve is increased when nasal dilators are worn. Additionally, pneumotachograph data demonstrates that during a sniff, the peak flow, maximum flow rate, volume, and duration are all increased when nasal dilators are worn. Taken together, the increase in olfactory ability can most easily be explained by an increase in both the amount and the proportion of inspired odorant molecules that are directed to the olfactory mucosa and are, therefore, available for odorant perception.

A genetically engineered human Kunitz protease inhibitor with increased kallikrein inhibition in an ovine model of cardiopulmonary bypass

A recombinant human serine protease inhibitor known as Kunitz protease inhibitor (KPI) wild type has functional similarities to the bovine Kunitz inhibitor, aprotinin, and had shown a potential to reduce bleeding in an ovine model of cardiopulmonary bypass (CPB). The aim of this study was to assess KPI-185, a modification of KPI-wild type that differs from KPI-wild type in two amino acid residues and which enhances anti-kallikrein activity in a further double-blind, randomized study in an ovine model of CPB, and to compare with our previous study of KPI-wild type and aprotinin in the same ovine model. Post-operative drain losses and subjective assessment of wound 'dryness' showed no significant differences between KPI-185 and KPI-wild type, despite the significant enhancement of kallikrein inhibition using KPI-185 seen in serial kallikrein inhibition assays. These preliminary findings support the hypothesis that kallikrein inhibition is not the major mechanism by which Kunitz inhibitors such as aprotinin reduce perioperative bleeding.

Anatomic and functional variability: the effects of filter size in group fMRI data analysis

In the analysis of group fMRI scans, an optimal spatial filter should be large enough to accurately blend functionally homologous anatomic regions, yet small enough not to blur the functionally distinct regions. Hanning filters varying from 0.0 to 18.0 mm were evaluated in a group analysis of six healthy controls performing a simple finger-tapping paradigm. Test-retest reliability and Talairach-based measurements of the sensorimotor region were used to explore the optimal filter size. Two distinct regions of functional activation were noted in the sensorimotor cortex in group images (n = 6) at both time 1 and time 2. These regions merge once the filter size exceeds approximately 6.0 mm. The original hypothesis that these represented a motor and sensory activation was rejected on the basis of structural and functional variability. A discussion of the inherent difficulties in choosing an appropriate filter size is presented.

A review of suicide within the State Hospital, Carstairs 1972-1996

This retrospective case note review describes the demographic, forensic and psychiatric backgrounds of 14 in-patient suicides in a maximum secure hospital. The majority were schizophrenic with chronic treatment-resistant illnesses, who had committed proportionally more violent offences, had a history of serious self-injury but no recognized clear depressive episodes. This profile is markedly different from that reported in general psychiatric in-patients, out-patients and suicides in prison, but is similar to that described in a maximum secure hospital in the United States and in long-stay patients in Canada. Many of the patients had continued to experience significantly subjective distress over many years. The clinical relevance of this series is discussed in the context of the assessment of suicidal intent in psychotic patients. We speculate that the decrease in in-patient suicides in the State Hospital may be due to a less restrictive ward milieu, increased staff/patient ratios, or the introduction of Clozapine.

School absenteeism, parental work loss, and acceptance of childhood influenza vaccination

BACKGROUND

Influenza causes school absenteeism and may cause parents to miss work to care for sick children. However, it is not known whether these factors influence parental acceptance of childhood vaccination.

METHODS

A survey was mailed to parents of 1,805 children attending 3 elementary schools. It included questions about school absenteeism and employment status for adults who stayed home to care for an ill child. Parents were asked if they would consider vaccinating their child against a common wintertime respiratory virus.

RESULTS

Of the 972 surveys returned (54% return rate), 954 could be analyzed. Only 13% of respondents stated that they would not consider vaccination for their child. Sixty-nine percent of children had been absent from school because of a nonasthma respiratory illness, with an average of 2.54 days missed per child. Among respondents whose child had missed any school, 33% would definitely consider vaccination compared with 24% of respondents whose child had not missed school (P < 0.01). As children missed more school days, vaccine acceptance increased. In 53% of families, an adult had to miss work to care for the ill child. Vaccine acceptance was higher if an adult caretaker had to lose time from work because of a child's illness (35% versus 25% for non-working caretakers, P < 0.01).

CONCLUSION

Vaccine acceptance was closely linked with the amount of absenteeism caused by respiratory illness in the previous year. Parents who had to miss work to care for an ill child were more accepting of the vaccine than were other parents.

Simian varicella virus infects ganglia before rash in experimentally infected monkeys

Monkeys experimentally infected with simian varicella virus (SVV) develop rash 10-14 days later. However, the route and the time of ganglionic infection are unknown. Using PCR, we analyzed DNA extracted from tissues of 13 monkeys 5 to 60 days after either intratracheal or intravenous inoculation with SVV. SVV DNA was detected in ganglia from four of five monkeys sacrificed 6 to 7 days after intratracheal inoculation. Further, analysis of ganglia from monkeys sacrificed at 10 days revealed that intravenous inoculation produced a higher proportion of SVV DNA-positive ganglia (63%) than that after intratracheal inoculation (13%), pointing to the role of hematogenous spread in ganglionic infection. Like other organs, monkey ganglia become infected with SVV before the appearance of rash.

Common data model for neuroscience data and data model exchange

OBJECTIVE

Generalizing the data models underlying two prototype neurophysiology databases, the authors describe and propose the Common Data Model (CDM) as a framework for federating a broad spectrum of disparate neuroscience information resources.

DESIGN

Each component of the CDM derives from one of five superclasses-data, site, method, model, and reference-or from relations defined between them. A hierarchic attribute-value scheme for metadata enables interoperability with variable tree depth to serve specific intra- or broad inter-domain queries. To mediate data exchange between disparate systems, the authors propose a set of XML-derived schema for describing not only data sets but data models. These include biophysical description markup language (BDML), which mediates interoperability between data resources by providing a meta-description for the CDM.

RESULTS

The set of superclasses potentially spans data needs of contemporary neuroscience. Data elements abstracted from neurophysiology time series and histogram data represent data sets that differ in dimension and concordance. Site elements transcend neurons to describe subcellular compartments, circuits, regions, or slices; non-neuroanatomic sites include sequences to patients. Methods and models are highly domain-dependent.

CONCLUSIONS

True federation of data resources requires explicit public description, in a metalanguage, of the contents, query methods, data formats, and data models of each data resource. Any data model that can be derived from the defined superclasses is potentially conformant and interoperability can be enabled by recognition of BDML-described compatibilities. Such metadescriptions can buffer technologic changes.