Association of gastrointestinal illness and recreational water exposure at an inland U.S. beach

Recent epidemiology studies examining U.S. recreational water exposure and illness relationships have focused primarily on coastal and Great Lakes beaches. Human-made lakes in the U.S. have received little attention in epidemiology studies despite contributing to more waterborne disease epidemics annually than coastal U.S. waters. In a comprehensive beach cohort study, we examined relationships between water quality indicators and reported adverse health outcomes among users of a beach at an inland U.S. lake. Human health data was collected over 26 swimming days during the 2009 swimming season in conjunction with water quality measurements. Adverse health outcomes were reported 8-9 days post-exposure via a phone survey. Wading, playing or swimming in the water was observed to be a significant risk factor for GI illness (adjusted odds ratio (AOR) of 3.2; CI 1.1, 9.0). Among water users, Escherichia coli density was significantly associated with elevated GI illness risk where the highest E. coli quartile was associated with an AOR of 7.0 (CI 1.5, 32). GI illness associations are consistent with previous freshwater epidemiology studies. Our findings are unique in that our observations of positive associations with GI illness risk are based upon a single daily E. coli measurement. Lastly, this study focused on an understudied issue, illness risk at inland reservoirs. Our results support the usefulness of E. coli as a health-relevant indicator of water quality for this inland U.S. beach.     

"Shape from shadows": Correction to Cavanagh and Leclerc (1989).

Reports an error in the original article by P. Cavanagh and Y. G. Leclerc (Journal of Experimental Psychology: Human Perception and Performance, 1989, Vol 15[1], 3–27). Corrections are made to the brightness levels of panels g, h, and i of Figure 4. (The following abstract of this article originally appeared in record 1989-17755-001.) The colors, textures, and shapes of shadows are physically constrained in several ways in natural scenes. The visual system appears to ignore these constraints, however, and to accept many patterns as shadows even though they could not occur naturally. In the stimuli that we have studied, the only requirements for the perception of depth due to shadows were that shadow regions be darker than the surrounding, nonshadow regions and that there be consistent contrast polarity along the shadow border. Three-dimensional shape due to shadows was perceived when shadow areas were filled with colors or textures that could not occur in natural scenes, when shadow and nonshadow regions had textures that moved in different directions, or when they were presented on different depth planes. The results suggest that the interpretation of shadows begins with the identification… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental determination of carrier-induced differential loss in 2-section GaInAsP/InP laser-waveguide

Measurements of threshold current density and external efficiency on broad-area laser-waveguide structure have led to the determination of the optical loss and differential loss d alpha /dN approximately=1.1-2.3 *10/sup -17/ cm/sup 2/ at lambda =1.53 mu m in a lambda /sub g/=1.30 mu m GaInAsP layer. This measurement will be useful for the design of tunable lasers.<>     

2,7‐Carbazolenevinylene‐Based Oligomer Thin‐Film Transistors: High Mobility Through Structural Ordering

We have fabricated organic field‐effect transistors based on thin films of 2,7‐carbazole oligomeric semiconductors 1,4‐bis(vinylene‐(N‐hexyl‐2‐carbazole))phenylene (CPC), 1,4‐bis(vinylene‐(N′‐methyl‐7′‐hexyl‐2′‐carbazole))benzene (RCPCR), N‐hexyl‐2,7‐bis(vinylene‐(N‐hexyl‐2‐carbazole))carbazole (CCC), and N‐methyl‐2,7‐bis(vinylene‐(7‐hexyl‐N‐methyl‐2‐carbazole))carbazole (RCCCR). The organic semiconductors are deposited by thermal evaporation on bare and chemically modified silicon dioxide surfaces (SiO₂/Si) held at different temperatures varying from 25 to 200 °C during deposition. The resulting thin films have been characterized using UV‐vis and Fourier‐transform infrared spectroscopies, scanning electron microscopy, and X‐ray diffraction, and the observed top‐contact transistor performances have been correlated with thin‐film properties. We found that these new π‐conjugated oligomers can form highly ordered structures and reach high hole mobilities. Devices using CPC as the active semiconductor have exhibited mobilities as high as 0.3 cm² V^–1 s^–1 with on/off current ratios of up to 10⁷. These features make CPC and 2,7‐carbazolenevinylene‐based oligomers attractive candidates for device applications.     

The spatio-temporal variations and fluxes of polycyclic aromatic hydrocarbons in the sediments of the Saguenay Fjord, Québec, Canada

The temporal variations of polycyclic aromatic hydrocarbon (PAH) concentrations demonstrate that the inputs to the sediments have increased considerably in the Saguenay Fjord, Québec, especially since 1930. However, a decrease in the concentrations in the Fjord sediments was noted for the last decade, but it was not observed in the sediments of Baie des Ha! Ha! The data indicate that the Saguenay River is a main route of entry of PAH to the Fjord system. The calculated PAH fluxes reveal that a great portion of the PAH, released in the Saguenay hydrographic basin, is not incorporated in the Fjord sediments. The spatio-temporal behavior of PAH in the sediments suggests that the major source of PAH in the Saguenay area originates from two aluminum reduction plants located upstream of the Saguenay Fjord.     

Synthesis and X-ray crystal structure of a bis-cyclometalated phosphorescent red-emitting iridium(III) complex

The synthesis of the bis-cyclometalated complex [{Ir(μ-Cl)(ccpz)₂}₂] (1, cppz = 1-chloro-4-(4-chlorophenyl)-phthalazine) from hydrated iridium(III) chloride and the ligand ccpz in refluxing ethoxyethanol is described. Compound 1 was characterized by spectroscopic means and the crystal structure was determined by X-ray crystallography. The absorption and emission spectra exhibit the new compound as a red-emitting phosphorescent complex.     

Modelling the spread of hepatitis C via commercial tattoo parlours: implications for public health interventions

Hepatitis C (HCV) is a serious infection caused by a blood-borne virus. It is a contagious disease spreading via a variety of transmission mechanisms including contaminated tattoo equipment. Effectively regulating commercial tattoo parlours can greatly reduce this risk. This paper models the cost-effectiveness and optimal timing of such interventions, and parameterises the model with data for Vienna, Austria. This dynamic model of the contagious spread of HCV via tattooing and other mechanisms accounts for secondary infections and shows that regulating tattoo parlours as done in Vienna, Austria in 2003, is a cost-saving intervention.