Comparison of epifluorescent viable bacterial count methods

Two methods, the 2-(4-Iodophenyl) 3-(4-nitrophenyl) 5-phenyltetrazolium chloride (INT) method and the direct viable count (DVC), were tested and compared for their efficiency for the determination of the viability of bacterial populations. Use of the INT method results in the formation of a dark spot within each respiring cell. The DVC method results in elongation or swelling of growing cells that are rendered incapable of cell division. Although both methods are subjective and can result in false positive results, the DVC method is best suited to analysis of waters in which the number of different types of organisms present in the same sample is assumed to be small, such as processed waters. The advantages and disadvantages of each method are discussed

Microbial biofilm studies of the environmental control and life support system water recovery test for Space Station Freedom

NASA is developing a water recovery system (WRS) for Space Station Freedom to reclaim human waste water for reuse by astronauts as hygiene or potable water. A water recovery test (WRT) currently in progress investigates the performance of a prototype of the WRS. Analysis of biofilm accumulation, the potential for microbially influenced corrosion (MIC) in the WRT, and studies of iodine disinfection of biofilm are reported. Analysis of WRT components indicated the presence of organic deposits and biofilms in selected tubing. Water samples for the WRT contained acid-producing and sulfate-reducing organisms implicated in corrosion processes. Corrosion of an aluminum alloy was accelerated in the presence of these water samples; however, stainless steel corrosion rates were not accelerated. Biofilm iodine sensitivity tests using an experimental laboratory scale recycled water system containing a microbial check valve (MCV) demonstrated that an iodine concentration of 1 to 2 mg/L was ineffective in eliminating microbial biofilm. For complete disinfection, an initial concentration of 16 mg/L was required, which was gradually reduced by the MCV over 4 to 8 hours to 1 to 2 mg/L. This treatment may be useful in controlling biofilm formation

Analysis of debris from Spacelab Space Life Sciences-1

Airborne microbiological and particulate contamination generated aboard Spacelab modules is a potential safety hazard. In order to shed light on the characteristics of these contaminants, microbial and chemical/particulate analyses were performed on debris vacuumed from cabin and avionics air filters in the Space Life Sciences-1 (SLS-1) module of the Space Transportation System 40 (STS-40) mission 1 month after landing. The debris was sorted into categories (e.g., metal, nonmetal, hair/fur, synthetic fibers, food particles, insect fragments, etc.). Elemental analysis of particles was done by energy dispersive analysis of x rays (metals) and Fourier transform infrared spectroscopy (nonmetals). Scanning electron micrographs were done of most particles. Microbiological samples were grown on R2A culture medium and identified. Clothing fibers dominated the debris by volume. Other particles, all attributed to the crew, resulted from abrasions and impacts during missions operations (e.g., paint chips, plastic, electronic scraps and clothing fibers). All bacterial species identified are commonly found in the atmosphere or on the human body. Bacillus sp. was the most frequently seen bacterium. One of the bacterial species, Enterobacter agglomerans, could cause illness in crew members with depressed immune systems

Poultry house remodeling

May, 1938

Adolescent Pregnancy

More than 14 million adolescents in the world annually give birth, and nearly 800,000 adolescents in the United States become pregnant each year. This chapter considers concepts of teen pregnancy including risks to the mother as well as offspring, the adolescent father, issues related to abortion, and concepts of prevention of unwanted pregnancy in youth. Adolescent pregnancy is global phenomenon affecting all societies and cultures

Pregnancy in Adolescence

Over 14 million adolescents in the world annually give birth and nearly 800.000 adolescents in the United States become pregnant each year. This paper considers concepts of teen pregnancy including risks to the mother as well as offspring, the adolescent father, issues related to abortion, and concepts of prevention of unwanted pregnancy in youth. Adolescent pregnancy is a global phenomenon affecting all societies and cultures

Modeling Requirements for Value Configuration Design

Breadth and depth complexity are key challenges in achieving business process fusion as the enabler for value configuration design. The PARM framework is proposed as the requirement to address breadth and depth complexity through the independent but integrated operation of the process, activity, resource and management viewpoints. The operational scenarios for each viewpoint result in varying process modeling extension requirements. Existing process modeling constructs have varying support for these requirements. The PARM framework solution is an extension and integration of existing modeling constructs rather than a solution in its own right. Using the MDA approach of abstracting a platform independent model from a platform specific implementation, it is the goal in future papers to define process modeling extensions to support the PARM framework and map these into existing implementation architectures

Introduction to the Anti-Racism Virtual Issue of the Journal of Occupational Science

The anti-racism virtual issue of the Journal of Occupational Science (JOS) came about after the Editorial Board expressed its commitment to anti-racist work, publishing the position statement ‘A Pledge to Mobilize Against Racism’ (Stanley et al., 2020). In this statement, the Board promised to republish a collection of articles to call attention to racism and its impact on individuals’ doing and society. The intent is to stimulate critical reflection on the contribution occupational scientists can make to exposing and countering racism in everyday doing. As such, the anti-racism virtual issue helps meet a pressing need to recognize the power of occupation in shaping and reproducing social ideologies, attitudes, and behaviors. We, the authors, urge all occupational scientists to build on this knowledge and continue learning about racism to better understand and address how its different dimensions manifest through occupation and everyday life