Cryo-Scanning Electron Microscopy of Microorganisms in a Liquid Film on Spoiled Chicken Skin

Cryo-scanning electron microscopy was used to examine bacteria which had grown in a liquid film on the skin surface of poultry carcasses. Pits or void zones surrounding bacteria on ethanol-dehydrated, critical point dried (CPD) samples were not found on washed or untreated specimens frozen prior to examination by scanning electron microscopy (SEM). However, pits equivalent to those produced during chemical fixation and dehydration were formed when skin tissue was treated with ethanol prior to freezing. We conclude that the pits are dehydration artifacts caused by the chemical preparative methods employed rather than the result of degradation of film proteins by extracellular enzymes of microbial origin

Quantitative Study of Geological Target Spotting with the use of Eye Tracking

In this paper we describe the use of eye tracking to quantitatively evaluate and analyse the variations in data interpretation performed by various geoscientists, measuring this against their ability to spot geological targets. We also describe an approach to evaluate the impact data preprocessing (i.e. enhancement) has on one's ability to perform the interpretation task. We adapted a mobile eye tracker to enable it to accurately map the point of gaze to the actual image coordinate instead of the forward facing eye tracker camera allowing the user to move their head as they view. Several visual interpretation tasks were performed by six geoscientists and the results are described in this paper

Endometrial Carcinoma: A Review of Chemotherapy, Drug Resistance, and the Search for New Agents

The article examines current treatment options in patients with endometrial carcinoma, the role of drug resistance, and the rationale for the use of epothilones in treating this disease

Search and orchestration of data and processes in a federated environment

This paper describes on-going research on streamlining the access and use of spatial data and processes in Australia. Spatial data in Australia is available on-line at many levels of government from local authorities, state and territories (jurisdictions), and nationally from the Commonwealth and other sources. Much of this data is available via Open Geospatial Consortium and World Wide Web Consortium standard web services. This abstract discusses three related research topics that have been identified by a wide range of stakeholders through a comprehensive consultation process. These are search and discovery, federation and orchestration of data and processes. The commonality across the three research topics is that they all require Semantic Web and Artificial Intelligence methods and embrace the various standards, and if needed, propose modifications to such standard

A review of size and geometrical factors influencing resonant frequencies in metamaterials

Although metamaterials and so-called left-handed media have originated from theoretical considerations, it is only by their practical fabrication and the measurement of their properties that they have gained credibility and can fulfil the potential of their predicted properties. In this review we consider some of the more generally applicable fabrication methods and changes in geometry as they have progressed, exhibiting resonant frequencies ranging from radio waves to the visible optical region

Quantitative microbiology: a basis for food safety.

Because microorganisms are easily dispersed, display physiologic diversity, and tolerate extreme conditions, they are ubiquitous and may contaminate and grow in many food products. The behavior of microbial populations in foods (growth, survival, or death) is determined by the properties of the food (e.g., water activity and pH) and the storage conditions (e.g., temperature, relative humidity, and atmosphere). The effect of these properties can be predicted by mathematical models derived from quantitative studies on microbial populations. Temperature abuse is a major factor contributing to foodborne disease; monitoring temperature history during food processing, distribution, and storage is a simple, effective means to reduce the incidence of food poisoning. Interpretation of temperature profiles by computer programs based on predictive models allows informed decisions on the shelf life and safety of foods. In- or on-package temperature indicators require further development to accurately predict microbial behavior. We suggest a basis for a "universal" temperature indicator. This article emphasizes the need to combine kinetic and probability approaches to modeling and suggests a method to define the bacterial growth/no growth interface. Advances in controlling foodborne pathogens depend on understanding the pathogens' physiologic responses to growth constraints, including constraints conferring increased survival capacity

Changes in environmental tobacco smoke (ETS) exposure over a 20-year period: cross-sectional and longitudinal analyses

AIMS:  To examine long‐term changes in environmental tobacco smoke (ETS) exposure in British men between 1978 and 2000, using serum cotinine. DESIGN:  Prospective cohort: British Regional Heart Study. SETTING:  General practices in 24 towns in England, Wales and Scotland. PARTICIPANTS:  Non‐smoking men: 2125 studied at baseline [questionnaire (Q1): 1978–80, aged 40–59 years], 3046 studied 20 years later (Q20: 1998–2000, aged 60–79 years) and 1208 studied at both times. Non‐smokers were men reporting no current smoking with cotinine < 15 ng/ml at Q1 and/or Q20. MEASUREMENTS: Serum cotinine to assess ETS exposure. FINDINGS:  In cross‐sectional analysis, geometric mean cotinine level declined from 1.36 ng/ml [95% confidence interval (CI): 1.31, 1.42] at Q1 to 0.19 ng/ml (95% CI: 0.18, 0.19) at Q20. The prevalence of cotinine levels ≤ 0.7 ng/ml [associated with low coronary heart disease (CHD) risk] rose from 27.1% at Q1 to 83.3% at Q20. Manual social class and northern region of residence were associated with higher mean cotinine levels both at Q1 and Q20; older age was associated with lower cotinine level at Q20 only. Among 1208 persistent non‐smokers, cotinine fell by 1.47 ng/ml (95% CI: 1.37, 1.57), 86% decline. Absolute falls in cotinine were greater in manual occupational groups, in the Midlands and Scotland compared to southern England, although percentage decline was very similar across groups. CONCLUSIONS:  A marked decline in ETS exposure occurred in Britain between 1978 and 2000, which is likely to have reduced ETS‐related disease risks appreciably before the introduction of legislation banning smoking in public places

Phylogenetic diversity of picocyanobacteria in Arctic and Antarctic ecosystems, p. 317–322

ABSTRACT Oxyphotobacteria ascribed to the genera Synechococcus and Synechocystis are widely distributed in Arctic and Antarctic lakes, yet they are poorly represented in the marine polar environment. Arctic lakes contain phycoerythrin-rich as well as phycocyanin-rich picoplankton, implying a level of genetic diversity within this group that is poorly resolved by classic taxonomic criteria. Our culture studies of isolates from ponds on Bylot Island in the Canadian Arctic (lat. 6 cells/ml. Analysis of the 16S rDNA of phycoerythrin-rich isolates from lakes in this region show that they form a distinct cluster, most closely related (97% similar) to P. marinus

Elucidating the long-range charge carrier mobility in metal halide perovskite thin films

Many optoelectronic properties have been reported for lead halide perovskite polycrystalline films. However, ambiguities in the evaluation of these properties remain, especially for long-range lateral charge transport, where ionic conduction can complicate interpretation of data. Here we demonstrate a new technique to measure the long-range charge carrier mobility in such materials. We combine quasi-steady-state photo-conductivity measurements (electrical probe) with photo-induced transmission and reflection measurements (optical probe) to simultaneously evaluate the conductivity and charge carrier density. With this knowledge we determine the lateral mobility to be ~ 2 cm2/Vs for CH3NH3PbI3 (MAPbI3) polycrystalline perovskite films prepared from the acetonitrile/methylamine solvent system. Furthermore, we present significant differences in long-range charge carrier mobilities, from 2.2 to 0.2 cm2/Vs, between films of contemporary perovskite compositions prepared via different fabrication processes, including solution and vapour phase deposition techniques. Arguably, our work provides the first accurate evaluation of the long-range lateral charge carrier mobility in lead halide perovskite films, with charge carrier density in the range typically achieved under photovoltaic operation