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We describe the investigation of two temporally coincident illness clusters involving salmonella and Staphylococcus aureus in two states. Cases were defined as gastrointestinal illness following two meal events. Investigators interviewed ill persons. Stool, food and environmental samples underwent pathogen testing. Alabama: Eighty cases were identified. Median time from meal to illness was 5·8 h. Salmonella Heidelberg was identified from 27 of 28 stool specimens tested, and coagulase-positive S. aureus was isolated from three of 16 ill persons. Environmental investigation indicated that food handling deficiencies occurred. Colorado: Seven cases were identified. Median time from meal to illness was 4·5 h. Five persons were hospitalised, four of whom were admitted to the intensive care unit. Salmonella Heidelberg was identified in six of seven stool specimens and coagulase-positive S. aureus in three of six tested. No single food item was implicated in either outbreak. These two outbreaks were linked to infection with Salmonella Heidelberg, but additional factors, such as dual aetiology that included S. aureus or the dose of salmonella ingested may have contributed to the short incubation periods and high illness severity. The outbreaks underscore the importance of measures to prevent foodborne illness through appropriate washing, handling, preparation and storage of food.
Kummerite, ideally Mn2+Fe3+A1(PO4)2(OH)2.8H2O, is a new secondary phosphate mineral belonging to the laueite group, from the Hagendorf-Süd pegmatite, Hagendorf, Oberpfalz, Bavaria, Germany. Kummerite occurs as sprays or rounded aggregates of very thin, typically deformed, amber yellow laths. Cleavage is good parallel to ﹛010﹜. The mineral is associated closely with green Zn- and Al-bearing beraunite needles. Other associated minerals are jahnsite-(CaMnMn) and Al-bearing frondelite. The calculated density of kummerite is 2.34 g cm 3. It is optically biaxial (-), α= 1.565(5), β = 1.600(5) and y = 1.630(5), with weak dispersion. Pleochroism is weak, with amber yellow tones. Electron microprobe analyses (average of 13 grains) with H2O and FeO/Fe2O3 calculated on structural grounds and normalized to 100%, gave Fe2O3 17.2, FeO 4.8, MnO 5.4, MgO 2.2, ZnO 0.5, Al2O3 9.8, P2O5 27.6, H2O 32.5, total 100 wt.%. The empirical formula, based on 3 metal apfu is (Mn2+0.37Mg0.27Zn0.03Fe2+0.33)Σ1.00(Fe3+1.06Al0. 94)Σ2.00PO4)1.91(OH)2.27(H2O)7.73. Kummerite is triclinic, P1̄, with the unit-cell parameters of a = 5.316(1) Å, b =10.620(3) Å , c = 7.118(1) Å, α = 107.33(3)°, β= 111.22(3)°, γ = 72.22(2)° and V= 348.4(2) Å3. The strongest lines in the powder X-ray diffraction pattern are [dobs in Å(I) (hkl)] 9.885 (100) (010); 6.476 (20) (001); 4.942 (30) (020); 3.988 (9) (̄110); 3.116 (18) (1̄20); 2.873 (11) (1̄21). Kummerite is isostructural with laueite, but differs in having Al and Fe3+ ordered into alternate octahedral sites in the 7.1 Å trans-connected octahedral chains.
We describe the design and current status of the Degree Angular Scale Interferometer (DASI), a compact cm-wave interferometer operating at the Amundsen-Scott South Pole research station. With 20-cm diameter primary antenna elements operating over the frequency range 26 − 36 GHz, DASI is optimized to measure the power spectrum of the cosmic microwave background radiation (CMBR) over the multipole range 140 − 920, (corresponding to scales of 25′ − 2°.6), as well as make high-sensitivity maps of the microwave sky. The telescope was built at the University of Chicago and deployed at the South Pole during the 1999-2000 austral summer.
Introduction: Some low acuity Emergency Department (ED) presentations are considered non-urgent or convenience visits and potentially avoidable with improved access to primary care. This study explored self-reported reasons why non-urgent patients presented to the ED. Methods: Patients, 17 years and older, were randomly selected from electronic registration records at three urban EDs in Edmonton, Alberta (AB), Canada during weekdays (0700 to 1900). A 47-item questionnaire was completed by each consenting patient, which included items on whether the patient believed the ED was their best care option and the rationale supporting their response. A thematic content analysis was performed on the responses, using previous experience and review of the literature to identify themes. Results: Of the 2144 eligible patients, 1408 (65.7%) questionnaires were returned, and 1402 (65.4%) were analyzed. For patients who felt the ED was their best option (n = 1234, 89.3%), rationales included: safety concerns (n = 309), effectiveness of ED care (n = 284), patient-centeredness of ED (n = 277), and access to health care professionals in the ED (n = 204). For patients who felt the ED was not their best care option (n = 148, 10.7%), rationales included a perception that: access to health professionals outside the ED was preferable (n = 39), patient-centeredness (particularly timeliness) was lacking in the ED (n = 26), and their health concern was not important enough to require ED care (n = 18). Conclusion: Even during times when alternative care options are available, the majority of non-urgent patients perceived the ED to be the most appropriate location for care. These results highlight that simple triage scores do not accurately reflect the appropriateness of care and that understanding the diverse and multi-faceted reasons for ED presentation are necessary to implement strategies to support non-urgent, low acuity care needs.
Introduction: Some non-urgent/low-acuity Emergency Department (ED) presentations are considered convenience visits and potentially avoidable with improved access to primary care services. This study surveyed patients who presented to the ED and explored their self-reported reasons and barriers for not being connected to a primary care provider (PCP). Methods: Patients aged 17 years and older were randomly selected from electronic registration records at three urban EDs in Edmonton, Alberta (AB), Canada. Following initial triage, stabilization, and verbal informed consent, patients completed a 47-item questionnaire. Data from the survey were cross-referenced to a minimal patient dataset consisting of ED and demographic information. The questionnaire collected information on patient characteristics, their connection to a PCP, and patients' reasons for not having a PCP. Results: Of the 2144 eligible patients, 1408 (65.7%) surveys were returned and 1402 (65.4%) were completed. The majority of patients (74.4%) presenting to the ED reported having a family physician; however, the ‘closeness’ of the connection to their family physician varied greatly among ED patients with the most recent family physician visit ranging from 1 hour before ED presentation to 45 years prior. Approximately 25% of low acuity ED patients reported no connection with a family physician. Reasons for a lack of PCP connection included: prior physician retired, left, or died (19.8%), they had never tried to find one (19.2%), they had recently moved to Alberta (18.0%), and they were unable to find one (16.5%). Conclusion: A surprisingly high proportion of ED patients (25.6%) have no identified PCP. Patients had a variety of reasons for not having a family physician. These need to be understood and addressed in order for primary care access to successfully contribute to diverting non-urgent, low acuity presentations from the ED.
Increasing evidence shows attachment security influences symptom expression and adaptation in people diagnosed with schizophrenia and other psychoses.
To describe the distribution of secure and insecure attachment in a cohort of individuals with first-episode psychosis, and to explore the relationship between attachment security and recovery from positive and negative symptoms in the first 12 months.
The study was a prospective 12-month cohort study. The role of attachment, duration of untreated psychosis (DUP), baseline symptoms and insight in predicting and mediating recovery from symptoms was investigated using multiple regression analysis and path analysis.
Of the 79 participants, 54 completed the Adult Attachment Interview (AAI): 37 (68.5%) were classified as insecure, of which 26 (48.1%) were insecure/dismissing and 11 (20.4%) insecure preoccupied. Both DUP and insight predicted recovery from positive symptoms at 12 months. Attachment security, DUP and insight predicted recovery from negative symptoms at 12 months.
Attachment is an important construct contributing to understanding and development of interventions promoting recovery following first-episode psychosis.
Increasing human occupation of the Brazilian Amazon has led to the intensification of deforestation over the last 50 years. The present study is aimed at analysing the impacts of the first year of slash-and-burn cultivation on soil physicochemical properties. Sampling was done in 26 small-scale farms of the Tapajós River basin. In August 2004, soil samples were collected from primary forest plots planned for slash-and-burn cultivation. In September 2005, 1 year after the initial burning and the beginning of cultivation, the same sites were re-sampled. The results indicated that soil fertility after burning was relatively moderate, as the increase of base cations was not particularly marked. Moreover, although an increase of some nutrients (such as exchangeable phosphorus) was observed at soil surface, total carbon and nitrogen (N) pools did not change significantly. Nutrient leaching was also detected through the accumulation of both forms of available nitrogen (NO3 and NH4) as well as potassium in subsoil horizons. In addition, signs of erosion were seen, as a significant increase surface density occurred, coupled with up to 25% fine particle loss at the surface. The present study draws attention to the early impacts of slash-and-burn agriculture on soil properties within a year of cultivation. Furthermore, its regional dimension highlights undisturbed soils natural variability as well as differentiated responses to deforestation according to soil texture.
The phase behaviour of aqueous suspensions of NAu1 nontronite was studied on size-selected particles by combining osmotic pressure measurements, visual observations under polarized light, rheological experiments and Small Angle X-ray Scattering (SAXS). NAu1 suspensions display a liquid crystalline behaviour as they exhibit a Isotropic/Nematic (I/N) transition that occurs before the sol/gel transition for ionic strengths below 10–3 M/L. This I/N transition shifts towards lower volume fractions for increasing particle anisotropy and its position in the phase diagram agrees well with the theoretical predictions for platelets. SAXS measurements reveal the presence of characteristic interparticular distances in the isotropic, nematic and gel phases. In the gel phase a local lamellar order is observed which shows that the “house of cards” model is not appropriate for describing the gel structure in swelling clay materials at low ionic strength. Furthermore, by combining results from osmotic pressure measurements and X-ray scattering, it appears that the pressure of the system can be well described using a simple Poisson-Boltzmann treatment based on the repulsion between charged infinite parallel planes. In terms of rheological properties, even if the thermodynamical status of the sol/gel transition remains partially unclear, the yield stress and elasticity of the gels can be easily renormalized for all particle sizes on the basis of the volume of the particles. Furthermore, rheological modelling of the flow curves shows that for all the particles an approach based on excluded volume effects captures most features of nontronite suspensions.
Few studies have prospectively investigated psychological morbidity in UK head and neck cancer patients. This study aimed to explore changes in psychological symptoms over time, and associations with patients' tumour and treatment characteristics, including toxicity.
Two hundred and twenty patients were recruited to complete the Hospital Anxiety and Depression Scale and the Late Effects on Normal Tissue (Subjective, Objective, Management and Analytic) (‘LENT-SOMA’) questionnaires, both pre- and post-treatment.
Anxiety was highest pre-treatment (38 per cent) and depressive symptoms peaked at the end of treatment (44 per cent). Anxiety significantly decreased and depression significantly increased, comparing pre- versus post-treatment responses (p < 0.001). Hospital Anxiety and Depression Scale scores were significantly correlated with toxicity, age and chemotherapy (p < 0.01 for all).
This is the first study to analyse the relationship between Hospital Anxiety and Depression Scale scores and toxicity scores in head and neck cancer patients. It lends support for the use of the Hospital Anxiety and Depression Scale and the Late Effects on Normal Tissue (Subjective, Objective, Management and Analytic) questionnaire in routine clinical practice; furthermore, continued surveillance is required at multiple measurement points.
The objective of this study was to quantify the effectiveness of selected surgical masks in arresting vegetative cells and endospores in an experimental model that simulated contagious patients.
Five commercially available surgical masks were tested for their ability to arrest infectious agents. Surgical masks were placed over the nose and mouth of mannequin head forms (Simulaids adult model Brad CPR torso). The mannequins were retrofitted with a nebulizer attached to an automated breathing simulator calibrated to a tidal volume of 500 mL/breath and a breathing rate of 20 breaths/min, for a minute respiratory volume of 10 L/min. Aerosols of endospores or vegetative cells were generated with a modified microbiological research establishment-type 6-jet collision nebulizer, while air samples were taken with all-glass impinger (AGI-30) samplers downstream of the point source. All experiments were conducted in a horizontal bioaerosol chamber.
Mean arrestance of bioaerosols by the surgical masks ranged from 48% to 68% when the masks were challenged with endospores and from 66% to 76% when they were challenged with vegetative cells. When the arrestance of endospores was evaluated, statistical differences were observed between some pairs, though not all, of the models evaluated. There were no statistically significant differences in arrestance observed between models of surgical masks challenged with vegetative cells.
The arrestance of airborne vegetative cells and endospores by surgical masks worn by simulated contagious patients supports surgical mask use as one of the recommended cough etiquette interventions to limit the transmission of airborne infectious agents.
The use of CVD W as a diffusion barrier between Al and Si is becoming widespread. The initial stage of the deposition involves the Si reduction of WF6 according to the following reaction:
The reaction is thought to be self-limiting, since once a sufficiently thick W film forms, WF6 and Si are no longer able to be in contact. We have studied the effects of implanted dopant and damage on the rate of this reaction and the thickness of the self-limiting W film. To study the mechanism of W film growth, Si wafers were implanted with As, P or Sb. These wafers were either left in the as-implanted state (amorphized surface layer) or were annealed to drive-in the implant and recrystallize the Si. The reactivity with WF6 of these wafers, as well as unimplanted Si wafers, was then studied as a function of temperature between 210° C and 700° C. Si-WF6 reactivity is shown to have a strong temperature dependence, with maximum reactivity occuring at 340 °C, at which temperature a 960A thick film of W can form. Enhanced diffusion of Si through the growing W film is thought to be the mechanism responsible for thick film growth. At higher temperatures, thinner films form, due to the cessation of enhanced diffusion. Lower temperature films are also thinner, probably due to a nucleation barrier, not a kinetic barrier, to growth. Implantation lowers the temperature of the onset of enhanced reactivity between Si and WF6, when the wafers are reacted in the as-implanted state.
While its high-temperature strength, resistance to oxidation, and other properties make silicon nitride an attractive candidate for many advanced structural applications, its propensity for brittle failure has hindered its widespread adoption. One approach to avoiding brittle failure is through incorporation of continuous fiber-reinforcement; however, conventional (powderbased) methods of silicon nitride fabrication can degrade fibers and are not amenable to the production of complex shapes. The Southwest Research Institute has developed a number of polymeric precursors to silicon nitride which are available as thermosetting liquids, and we have shown that these materials can be used in combination with near net-shape manufacturing techniques to produce fiber-reinforced silicon nitride composites. Mechanical property tests conducted at room temperature suggest that these polymer-derived composites exhibit fracture behavior comparable to those produced through conventional techniques; micromechanical investigations conducted at 800°C indicate that non-brittle failure is maintained at elevated temperature.
Over the past few years, there has been an increased awareness of the potential hazard of energetic chemical reactions in high-level radioactive waste tanks at the Hanford tank farm. In particular, a mixture of Na2NiFe(CN)6 with NaNO3 and NaNO2 in several high-level waste tanks has caused concern. The problem of the FeCN tanks is fundamentally one of a potentially unstable mixture of fuel (the CN- moiety) and oxidizer (NO3- or NO2-).
At Los Alamos National Laboratory, we have performed an extensive reanalysis of the safety problems associated with the presence of Na2NiFe(CN)6 mixed with NaNO3/NO2 for a particular tank (104-BY) that contains by far the largest amount of the nickel ferrocyanide salt (∼2E5 mol). Our approach is to use conservative assumptions to bound both the energy density for a potential runaway reaction and the mass that could participate if we assume ignition as the result of bounding radionuclide concentrations. The subsequent progress of the accident is analyzed using an advanced hydrodynamics computer code called MESA to evaluate the loads on the structure and the generation of aerosols. The subsequent doses are shown to be low both on and off the site. The conservatism in the analysis is quite large, and the expected results using more realistic assumptions are discussed.
The effects of friction and wear were examined on plasma enhanced chemical vapor deposition (PECVD) diamond films deposited on tungsten substrates. The tribology of diamond on diamond was studied and the changes in surface roughness and the bearing ratio were determined before and after wear. The (111) textured heteroepitaxial films were studied morphologically by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The changes in morphology involved a transition from the large as grown diamond crystallites with a mean diameter of 10 μm to a surface with grains as small as 100 nm. The nature of the wear-modified films will be discussed regarding the possible mechanisms for the surface changes.
Work partially supported by NASA Lewis Research Center grant NAG3–1430.
Hemoglobin (Hb) and myoglobin (Mb) were encapsulated in transparent silica glasses prepared by the sol-gel method. The preparation of the silica glasses was tailored so that when proteins were entrapped in the pores of the inorganic matrix, they retained their biochemical activity, i.e. they could bind ligands reversibly. Using optical spectroscopy to monitor ligand binding, we studied the binding of O2, CO, and NO with these two heme proteins encapsulated in silica glasses and compared them to heme proteins in aqueous buffer. Both Hb and Mb in the sol-gel glass bound O2, CO, and NO, producing the same spectroscopic properties as those in aqueous buffer. In addition, silica encapsulated Mb was used to evaluate the rate of ligand (O2) transport through the pores of the glass. When varying oxygen concentration and measuring the time required for full conversion of deoxyMb to MbO2 in the silica gel, the time vs. concentration data followed an exponential trend, as expected for diffusion controlled processes.
This paper presents a study of creep in polycrystalline aluminum. The sample was deformed in a scanning electron microscope and local strain was measured by analyzing micrographs taken during the test. EBSP was used to examine grain curvature and recrystallization The results showed that tensile strain developed during the test. The strain was not constant but varied both spatially and with time. Significant grain boundary migration occurred during the test, and near a triple point a grain with a completely new orientation was formed.
Diamond based power device structures such as resistor, capacitor, Schottky diode, p-n diode, thyristor, and field emitters are being investigated. Diamond resistors similar to standard thick film components in form and dimension were fabricated of polycrystalline diamond film. Using PECVD (plasma-enhanced chemical vapor deposition) processing to achieve diamond dielectric layers, high power, high energy density capacitors have been built. Despite grain boundaries and defects of polycrystalline diamond film, electronic devices such as field-effecttransistors and Schottky diodes have been developed. We have fabricated micro-patterned microtip arrays with this versatile new diamond technology as electron emitters. This paper will review diamond technology and results of this work.
Diffuse elastic scattering of electrons by single nanometer-sized defects in ion irradiated Au has been measured quantitatively. Results are given for two dislocation loops and compared with published calculations to establish the loop geometry and interstitial or vacancy nature. Defect images using only diffuse scatttering are achieved with high sensitivity and good resolution by a hollow-cone dark-field method.