Purpose – This study reports on a project to monitor deliberate self-poisoning in a rural area of Northern Ireland over a 20-year period. Comparison is made with reports from large urban centres. In addition, a local prescribing database allows assessment of any association between psychotropic drug prescription and use for deliberate self-poisoning. Materials and methods – Frequency of self-poisoning, demographic details and drugs used were recorded for all episodes of deliberate self-poisoning occurring at Craigavon Area Hospital for the years 1976, 1986, 1991 and 1996. It was possible to compare prescriptions of psychotropic drugs with their use for deliberate self-poisoning between the years 1991 and 1996 in the region served by the hospital, using the Defined Daily Dose (DDD) system. Results – In this rural area the pattern of deliberate self-poisoning has changed, as in urban centres, with a rise in frequency and the male/female ratio approaching unity. The pattern of drug use has altered, with paracetamol overtaking benzodiazepines as the most commonly used agent. More recently, antidepressants have become the second most frequently used drug class for this purpose. Psychotropic medications used for self-poisoning altered in proportion to their prescription between the years 1991 and 1996. Conclusions – In the face of a continuing rise in deliberate self-poisoning, which is effecting both urban and rural areas, care should be taken to prescribe the least toxic agent available as this is associated with likely frequency of self-poisoning for most classes of psychotropic drug.

A legionellosis outbreak at an industrial site was investigated to identify and control the source. Cases were identified from disease notifications, workplace illness records, and from clinicians. Cases were interviewed for symptoms and risk factors and tested for legionellosis. Implicated environmental sources were sampled and tested for legionella. We identified six cases with Legionnaires’ disease and seven with Pontiac fever; all had been exposed to aerosols from the cooling towers on the site. Nine cases had evidence of infection with either Legionella pneumophila serogroup (sg) 1 or Legionella longbeachae sg1; these organisms were also isolated from the cooling towers. There was 100% DNA sequence homology between cooling tower and clinical isolates of L. pneumophila sg1 using sequence-based typing analysis; no clinical L. longbeachae isolates were available to compare with environmental isolates. Routine monitoring of the towers prior to the outbreak failed to detect any legionella. Data from this outbreak indicate that L. pneumophila sg1 transmission occurred from the cooling towers; in addition, L. longbeachae transmission was suggested but remains unproven. L. longbeachae detection in cooling towers has not been previously reported in association with legionellosis outbreaks. Waterborne transmission should not be discounted in investigations for the source of L. longbeachae infection.

Cerebral aneurysms are extremely rare in all animals except man. We report the occurrence of a carotid-ophthalmic aneurysm in a cynomolgous monkey two months following accidental occlusion of the ipsilateral cervical internal carotid artery. This was documented angiographically. The aneurysm was deliberately ruptured by the insertion and withdrawal of fine needles. This produced a large subarachnoid hemorrhage visualized on CT scan. There was a progressive severe fall in cerebral blood flow and moderate vasospasm. The neurological status deteriorated on the tenth day and the animal was sacrificed on day 13. On electron microscopy, the aneurysm showed a fibrous wall, and the endothelium showed balloon-like endothelial cells with gaps. Corrugations occurred in the inner aspect of the anterior circulation arteries.

The boron-doped single crystal diamond films were grown homoepitaxially on synthetic (100) oriented Type Ib diamond substrates using a Microwave Plasma Chemical Vapor Deposition (MPCVD) technique. Raman spectrum showed a few additional bands at the lower wavenumber regions along with the zone center optical phonon mode for diamond. The change in the peak profile of the zone center optical phonon mode and its downshift were observed with the increasing boron content in the film. A modification in surface morphology of the film with increasing boron content had been observed by atomic force microscopy. Four point probe electrical measurement indicated that different conduction mechanisms are operating in various temperature regions for these semiconducting films.

In this study, we report low temperature x-ray diffraction studies combined with electrical resistance measurements on single crystals of iron-based layered superconductor FeSe to a temperature of 10 K and a pressure of 44 GPa. The low temperature high pressure x-ray diffraction studies were performed using a synchrotron source and superconductivity at high pressure was studied using designer diamond anvils. At ambient temperature, the FeSe sample shows a phase transformation from a PbO-type tetragonal phase to a NiAs-type hexagonal phase at 10 ± 2 GPa. On cooling, a structural distortion from a PbO-type tetragonal phase to an orthorhombic Cmma phase is observed below 100 K. At a low temperature of 10 K, compression of the orthorhombic Cmma phase results in a gradual transformation to an amorphous phase above 15 GPa. The transformation to the amorphous phase is completed by 40 GPa at 10 K. A loss of superconductivity is observed in the amorphous phase and a dramatic change in the temperature behavior of electrical resistance indicates formation of a semiconducting state at high pressures and low temperatures. The formation of the amorphous phase is attributed to a kinetic hindrance to the growth of a hexagonal NiAs phase under high pressures and low temperatures.

A survey of ABO blood groups, secretor status and smoking habits among 389 students and staff of a school in which there was an outbreak of meningococcal disease found no difference in the distribution of the ABO blood groups but a significantly higher proportion of non-secretors (37·6%) in the population examined compared with that reported for previous surveys of the neighbouring population in Glasgow (26·2%) (P < 0·0005). There was also a significantly higher proportion of non-secretors among carriers of meningococci (47%) compared with non-carriers (32%). Increased carriage of meningococci among non-secretors might contribute to the increased susceptibility of individuals with this genetic characteristic to meningococcal disease observed in previous studies. Although passive exposure to cigarette smoke has been associated with meningococcal disease, there was no association between passive smoking and carriage. There was, however, a significant association between active smoking and carriage.

Toxigenic strains of Staphylococcus aureus have been suggested to play a role in sudden infant death syndrome (SIDS). In this study we examined two factors that might enhance binding of toxigenic staphylococci to epithelial cells of infants in the age range in which cot deaths are prevalent: expression of the Lewisa antigen and infection with respiratory syncytial virus (RSV). By flow cytometry we demonstrated that binding of three toxigenic strains of S. aureus to cells from non-secretors was significantly greater than to cells of secretors. Pre-treatment of epithelial cells with monoclonal anti-Lewisa or anti-type-1 precursor significantly reduced bacterial binding (P < 0·01); however, attachment of the bacteria correlated only with the amount of Lewisa antigen detected on the cells (P < 0·01). HEp-2 cells infected with RSV bound significantly more bacteria than uninfected cells. These findings are discussed in context of factors previously associated with SIDS (mother's smoking, bottle feeding and the prone sleeping position) and a hypothesis proposed to explain some cases of SIDS.

Extending earlier duality results for multiobjective programs, this paper defines dual problems for convex and generalised convex multiobjective programs without requiring a constraint qualification. The duals provide multiobjective extensions of the classical duals of Wolfe and Schechter and some of the more recent duals of Mond and Weir.

Microwave plasma chemical vapor deposition (CVD) was used to coat nanostructured diamond onto a copper–beryllium alloy (∼1.7 wt% Be) commonly used as a nonmagnetic gasket material in diamond anvil cell devices. The coating is expected to be useful in preventing plastic flow of Cu–Be gaskets in diamond anvil cell devices, thus allowing for increased sample volume at high pressures and leading to improved sensitivity of magnetic measurements. The coatings were characterized by Raman spectroscopy, glancing-angle x-ray diffraction, microscopy (optical, scanning electron, and atomic force), Rockwell indentation, and nanoindentation. CVD diamond deposition on pure copper substrates has historically resulted in poor coating adhesion caused by the very large thermal expansion mismatch between the substrate and coating as well as the inability of copper to form a carbide phase at the interface. While an interfacial graphite layer formed on the pure copper substrates and resulted in complete film delamination, well-adhered 12.5 μm thick nanostructured diamond coatings were produced on the copper–beryllium (Cu–Be) alloy. The nanostructured diamond coatings on Cu–Be exhibit hardness of up to 84 GPa and can withstand strains from Rockwell indentation loads up to 150 kg without delamination.

The catalytic effect of nitrogen during the homoepitaxial diamond growth on a diamond anvil was investigated using isotopically enriched carbon-13 methane in a feed-gas mixture in a microwave plasma chemical vapor deposition reactor. The use of isotopically enriched carbon-13 allows us to precisely measure the film thickness in this homoepitaxial growth process by Raman spectroscopy. It is found that the addition of 0.4 sccm of nitrogen to an H2/CH4/O2 gas-phase mixture increases the growth rate by a factor of 2.3. This enhanced growth rate with the addition of trace amounts of nitrogen allows for a quick encapsulation of embedded sensors in the designer diamond anvils and is a key control parameter in the fabrication process. Photoluminescence spectroscopy reveals nitrogen-vacancy defect centers in the high-growth-rate diamonds. Atomic force microscopy reveals dramatic changes in the surface microstructure as is indicated by a total loss of step-flow growth morphology on the addition of nitrogen in the plasma.

The greatest benefits of nitrogen incorporation into gate dielectrics may be obtained by placing nitrogen preferentially at the interfacial regions of the dielectric film. One method of distributing nitrogen in this manner is by using a three-step thermal process consisting of 1.) oxynitridation in NO, 2.) subsequent reoxidation in O2, and 3.) a final NO anneal. This study investigates the effect of NO processing on substrate/dielectric interface roughness and correlates that roughness with dielectric reliability. The initial NO-containing step can roughen the interface, as can subsequent reoxidation. Increased NO exposure yields a greater nitrogen content and a concomitant increase in interface roughness. These films show a degradation in charge to breakdown (Qbd) of at least an order of magnitude when compared with similarly prepared O2-oxide films. An O2/NO process produces films with interface roughness and Qbd comparable to that of pure SiO2, independent of nitrogen content. The oxynitride reliability depends on the exact scheme for incorporating nitrogen into SiO2.

An understanding of dielectric breakdown mechanisms is critical for continued oxide scaling. Although working transistors have been demonstrated with sub-2nm SiO2 gate dielectrics, the manufacturability of such devices hinges on the reliability of the oxide. As oxides become thinner and operating voltages become lower, a fundamentally different mode of dielectric breakdown occurs. This has been called soft breakdown and is considered to be the formation of a small, localized tunneling path through a dielectric. For transistors with 2-nm gate oxides, threshold voltage and maximum transconductance are not affected by soft breakdown, implying that circuits may continue to operate after soft breakdown. The increase in gate current or voltage noise associated with soft breakdown is not a limiting factor for many applications. However, some cases will be shown in which soft breakdown does degrade device function.

In order to make comparisons of ultra-thin oxide quality, it is important to be able to reliably detect soft breakdown. J-ramp, a commonly used ramped-current measurement to determine oxide quality, is unable to detect soft breakdown in ultra-thin oxides. We will demonstrate the incorporation of noise measurements in a commercial J-ramp algorithm.

The Galileo Near Infrared Mapping Spectrometer (NIMS) obtains spectral images in the wavelength range 0.7 to 5.2 μm with a spectral resolving power of approximately 200. This spectral range allows NIMS to sense cloud-reflected solar radiation, thermal emission produced in the deep atmosphere, and auroral emission from the thermosphere of Jupiter. Using 5 μm thermal emission spectroscopy, the amount of water vapor in the deep atmosphere, at approximately the (i to 8 bar level, is found to vary by a factor > 100. Deep atmosphere ammonia was also found to vary, with a spatial behavior different from that of water vapor. No evidence is found for a massive water cloud. Using reflected solar radiation in conjunction with thermal emission, two cloud layers are found, the upper at 0.5 bars and a lower one at 1-1.3 bars. The inferred absorption properties of these clouds are consistent with ammonia crystals (the upper cloud) and ammonium hydrosulfide particles (the lower cloud).

Defects in the AGXT gene mapped to chromosome 2q37.3 cause primary hyperoxaluria type 1 (PH1), one of the inherited disorders of endogenous oxalate overproduction. In order to identify diagnostically useful linkage markers in this region of chromosome 2 we have typed three microsatellite loci mapping to the q37 region of chromosome 2 in 192 individuals from 30 families. They were additionally studied for mutations and polymorphisms in the AGXT gene. Maximum lod scores of 29·1, 22·8 and 15·8 were obtained for D2S140, D2S125 and D2S395 respectively at recombination fractions (theta) of 0·001, 0·015 and 0·02. Confidence intervals for recombination as determined by the ‘lod-1 rule’ were 0·015, 0·05 and 0·06. Three recombinants were identified between AGXT and D2S125/D2S395, whereas no recombination between AGXT and D2S140 was observed. These data allow the calculation of the risk of incorrect prenatal diagnosis of PH1 based solely on linkage analysis with these extragenic markers.

By using a combination of smooth epi substrates (0.7 Å rms roughness), in-situ UV/Cl2 processing, and rapid thermal oxidation, highly reliable ultrathin gate oxides were produced with ≤ 1.0 Å rms interface roughness.

This study reports on the use of zirconolite-rich Synroc to demonstrate the safe immobilisation of ‘high-fired’ Pu02. The zirconolite-rich Synroc used in this study was prepared by adding 13 wt% Pu with equimolar amounts of Gd and Hf, relative to Pu, as neutron absorbers. The incorporation of the Pu and neutron absorbers has been studied microstructurally as well as by longer-term leach testing. This work has shown that the sintered ceramic can immobilise 13 wt% of Pu with almost complete incorporation of the Pu (≃ 98%) into the zirconolite phase. Durability studies have shown that under a wide range of leaching conditions there is no major separation of the Pu and neutron absorbers, with the majority of these elements either remaining in the matrix or leaching at low (< 10−4 g m−2 d−1) and comparable rates from the waste form.

A pair of symmetric dual multiobjective fractional programming problems is formulated and appropriate duality theorems are established.