How Overly Cautious Risk Assessment Methods Overstate Risk from PCBs in Indoor Air

The past use of building materials that contained polychlorinated biphenyls (PCBs) is prompting public concern and expensive PCB removal projects. Building materials that may contain PCBs include paint, caulk, floor finishes and many other interior and exterior construction components manufactured before 1972. While initial concern about PCBs in buildings has focused on schools, it is likely that PCB-containing materials will also be found in many residential, commercial, and industrial structures. In buildings, the primary route of human exposure is the inhalation of PCBs that volatilize out of building materials. The USEPA has indicated that inhalation of airborne PCBs may pose a significant human exposure pathway in schools. EPA’s approach to PCBs in schools is evolving quickly. Initial estimates of health risk from indoor PCBs were calculated using risk assessment methods and EPA published toxicity factors. Recently, EPA established guidance titled “Public Health Levels for PCBs in Indoor School Air” to assist school systems in remediation efforts. These criteria are intended to be “prudent public health levels that maintain PCB exposures below the \u27reference dose\u27 – the amount of PCB exposure that EPA does not believe will cause harm. This article considers two factors central to the accurate assessment of PCB indoor air risk: 1) the difference in the chemical make up of PCBs in air compared to the chemical make up of the PCBs in the building materials they originated from; and 2) how the variability in certain commercial lots of PCBs (Aroclors) can result in different degrees of toxicity. Each of these factors may act to significantly modify the level of risk associated with the inhalation of PCBs in buildings. At the present time, EPA has not incorporated these factors into its calculation of its Public Health Levels

Stressed and Happy? Investigating the Research between Happiness and Perceived Stress

Developing interventions to increase happiness is a major focus of the emerging field of positive psychology. Common beliefs about the need to reduce stress to obtain happiness suggest that stress management activities should be included in these interventions. However, the research on the relationship between positive and negative affect is equivocal. Theoretically, they are conceptualized as independent dimensions, but research has often found an inverse relationship between happiness and stress. In addition,the research generally attempts to assess stress objectively rather than in terms of the cognitive appraisal process. The current study examines the relationship between perceived stress and happiness among 100 college students to determine if the same inverse relationship exists. Linear correlations between happiness and perceived stress were significant indicating that there was an inverse relationship between these variables. The discussion focuses on several factors that might help to explain the observed relationship

Massachusetts Bar Discipline: History, Practice, and Procedure

While there have been several publications describing the bar discipline process for violations of the Massachusetts Rules of Professional Conduct, no work has described that process in great detail while also analyzing the related sanctions. The treatise seeks to fill this gap and make the practice more accessible to participants and observers by referencing, in a single volume, materials that had not previously been collected and analyzed. We begin with an overview of the history of bar discipline in the Commonwealth, followed by a discussion of the participants in, and structure of, the disciplinary process. Part II takes the reader through the steps of a typical bar discipline case from the initial complaint through the hearing. Part III discusses in detail some typical misconduct, including that related to competence, confidentiality, safekeeping of trust property, and advertising—and the sanctions typically imposed for it. This is followed by a discussion in Part IV of conduct that may aggravate or mitigate the presumptive sanction. Lastly, Part V discusses the post-hearing process as well as reciprocal discipline, resignations, duties after suspension or disbarment, reinstatement, and registration. While this volume is not a dissertation on legal ethics per se, it addresses the Rules of Professional Conduct as they arise in bar discipline

SNAPSHOT USA 2020: A second coordinated national camera trap survey of the United States during the COVID-19 pandemic

Managing wildlife populations in the face of global change requires regular data on the abundance and distribution of wild animals, but acquiring these over appropriate spatial scales in a sustainable way has proven challenging. Here we present the data from Snapshot USA 2020, a second annual national mammal survey of the USA. This project involved 152 scientists setting camera traps in a standardized protocol at 1485 locations across 103 arrays in 43 states for a total of 52,710 trap-nights of survey effort. Most (58) of these arrays were also sampled during the same months (September and October) in 2019, providing a direct comparison of animal populations in 2 years that includes data from both during and before the COVID-19 pandemic. All data were managed by the eMammal system, with all species identifications checked by at least two reviewers. In total, we recorded 117,415 detections of 78 species of wild mammals, 9236 detections of at least 43 species of birds, 15,851 detections of six domestic animals and 23,825 detections of humans or their vehicles. Spatial differences across arrays explained more variation in the relative abundance than temporal variation across years for all 38 species modeled, although there are examples of significant site-level differences among years for many species. Temporal results show how species allocate their time and can be used to study species interactions, including between humans and wildlife. These data provide a snapshot of the mammal community of the USA for 2020 and will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, and the impacts of species interactions on daily activity patterns. There are no copyright restrictions, and please cite this paper when using these data, or a subset of these data, for publication

Using Computational Physics Techniques to Predict the Populations of Select Counties in the South Georgia Region

Correctly measuring the population of each county is essential in the South Georgia Region since rising populations can mean increased business activity in the region, more state money to support county initiatives, and more federal money to support large scale regional programs. With the 2020 census being conducted this year, we look at how various computational physics techniques could be used to study the population of each county based on census data between 1930 and 2000. The calculated values provide an estimate of the population for each selected county in 2010. These results are compared with the actual populations measurements from the 2010 census. In this presentation, we will describe the various techniques used to do our predictions and describe any discrepancies between our values and the actual populations for each county

Allelopathy of weeds on the growth of vegetables.

The use of allelopathy emerges as an alternative method for weed management in crops, especially in small vegetable producing properties. Thus, the objective of this work was to identify possible allelopathic effects of aqueous extracts of the weeds Cyperus difformis L. (small-flowered nutsedge), Commelina benghalensis L. (benghal dayflower) and Galinsoga parviflora Cav. (gallant soldier) on seed germination and seedling growth of Lactuca sativa L. (lettuce) and Lycopersicum esculentum L. (tomato). Two experiments were carried out in a completely randomized design with five replications, the first with lettuce seeds and the second with tomato seeds submitted to germination in five concentrations of weeds aqueous extracts (0, 25, 50, 75 and 100%). All treatments with aqueous extracts of the three species, at different concentrations, caused a reduction in lettuce and tomato root length. There was a reduction in most of the evaluated variables, and seed germination of the crops had the lowest influence of the extracts. The weeds benghal dayflower, small-flowered nutsedge and gallant soldier showed allelopathic potential on lettuce and tomato crops. This potential allelopathic effect is directly related to the concentration and type of extract from the plant species. In general, it can be noted that the greatest allelopathic effect occurred with the use of small-flowered nutsedge extract, followed by gallant soldier and benghal dayflower