John Carroll University

About: John Carroll University is a education organization based out in University Heights, Ohio, United States. It is known for research contribution in the topics: Population & Literacy. The organization has 977 authors who have published 1870 publications receiving 40072 citations. The organization is also known as: JCU & John Caroll University.

Green algae (Chlorophyta) of desert microbiotic crusts: diversity of North American taxa

Abstract: Green algae are present in desert soils as components of microbiotic communities that also include cyanobacteria and other prokaryotes, lichens, non-lichenized fungi, invertebrates, and other photosynthetic eukaryotes such as diatoms, eustigmatophytes, and xanthophytes. The green algae that occur in crusts are morphologically simple unicells, packets of cells, or weak filaments, yet represent a diverse assemblage of taxa spanning the classes Chlorophyceae, Trebouxiophyceae, and Charophyceae. As part of an ongoing study of the biodiversity of microbiotic crust communities in the western United States and Northern Mexico, a large number of green algae were isolated and characterized morphologically and genetically. Phylogenetic analyses using ribosomal RNA gene sequence data have greatly aided our understanding of the diversity and evolution of desert green algae. Our results indicate that desert green algae evolved from aquatic green algae at least five independent times. In addition, the desert green algae are derived from freshwater, not marine, green ancestors. Some lineages of green algae have a high proportion of desert taxa, while other lineages thus far have no known desert representatives. Many of the isolates are likely to be new taxa. These taxa represent independent lineages of green plants that have evolved to inhabit desert environments. Because they are distinct from but phylogenetically related to embryophyte taxa, these other "land plants" can offer important biochemical and physiological comparisons to desert-dwelling embryophytes.

The relationship of family structure to adolescent drug use, peer affiliation, and perception of peer acceptance of drug use.

Abstract: Alcohol and other drug use among adolescents has been the focus of numerous empirical investigations. To unravel the complex etiology of this phenomenon, several factors have been studied. Among these, family and peers have been identified as prominent proximal influences. Associations have been found between familial variables and children's drug involvement. Among others, parents' drug use (Ellis & Stone, 1979; Kandel, 1973; Newcomb, Huba, & Bentler, 1983), parental drug-use attitudes (Jessor & Jessor, 1977; Korsnick & Judd, 1982), child-rearing practices (Brook, Whiteman, & Gordon, 1983; Brook, Whiteman, Gordon, & Brook, 1985), and family disruption or lack of cohesion (Babst, Miran, & Koval, 1976; Jenkins & Guidubaldi, 1992) have all been found to relate to children's use of illegal substances. Family structure appears to be an important variable. Several studies have shown that youth from disrupted families evidence more frequent substance abuse (Needle, Su, & Doherty, 1990; Doherty & Needle, 1991). In a study of psychoactive substance use disorder in youth suicide, findings revealed that parental divorce was more frequent among adolescents and young adults with the disorder (Runeson, 1990). Stein, Newcomb, and Bentler (1987) found that their family-disruption factor was significantly correlated with adolescent drug use, albeit largely mediated through lack of social conformity. In their review of the literature, Ganong and Coleman (1993) noted that children in stepfamilies evidenced more internalizing behavior problems (e.g., depression, anxiety) and more antisocial behavior than did children residing in nuclear families. Interestingly, stepchildren were found not to differ from children in single-parent families on either internalizing or externalizing behaviors. Other studies have found that socioemotional and behavioral problems among children and adolescents frequently reemerge with the introduction of a stepparent (Bray, 1988; Hetherington, Cox, & Cox, 1985). Unfortunately, small and socioeconomically constricted samples and utilization of combined drug-use variables have limited the generalizability of some of the findings. In addition, some studies have failed to identify children's living arrangements or used confounded family-status variables (i.e., neglected to distinguish between different types of single-parent and intact households). For example, it is not uncommon to find intact-family categories inclusive of stepfamilies in studies on the effects of alcohol and other drug use. Similarly, in those studies that consider family structure, typically only the predominant mother-headed (single-parent) household is included. Hirschi's (1969) social control theory and Jessor and Jessor's (1977) problem-behavior theory offer an explanation for the relationship between drug use and family structure. These theories propose that family problems may create an environment that is not positively grounded in traditional social institutions, which can lead to deviant behaviors, such as drug involvement. Inasmuch as divorce and family reconstitution have been found to be related to some negative outcomes for children, these theories, in part, explain the hypothesized association. In addition to family influences, affiliation with drug-using peers has been found to represent a strong correlate of drug experimentation, and thus is a critical risk factor for adolescents (Hawkins, Lishner, & Catalana, 1985; Needle et al., 1986). Peer environments accepting of drug use may be more inviting to adolescents from nontraditional family structures, particularly younger adolescents, who are not only struggling with developmental challenges, but also coping with the stresses associated with single-parent and stepparent families. The present study sought to contribute to our understanding of adolescent drug involvement and improve upon previous designs by using several drug indicators and a large sample representative of different family types. …

The Evolution of Standard Costing in the U.K. and U.S.: From Decision Making to Control

Abstract: Decision making and control are two fundamental components of industrial management that are aided by accounting information. This article traces the evolution of standard costing in the U.K. and U.S. and describes how it has served these two purposes over time. At the start of the industrial revolution, standard costing, in the form of past actual costs, aided managers in make-or-buy, pricing, outsourcing and other routine and special decisions. In the late nineteenth century, as the mass production of homogeneous products became more common, predetermined, norm-based standard costs were promoted as the means to control operations and reduce waste. The use of predetermined costs was recommended by both academic and professional branches well into the twentieth century. Since the mid-1980s, norm-based standards have come under fire for not providing appropriate strategic signals in an era of global competition, continuous improvement and perpetual cost reduction. This article compares the nature of standard costing practices in the British Industrial Revolution with those that evolved in the U.S. under scientific management. The enquiry is not limited to double-entry systems and, like Miller and Napier (1993), the domain is broadened to include other forms of cost-keeping practices. We utilize primary and secondary sources to argue that the environment and rationales for standard costs have changed fundamentally over time. It is speculated that in the future standard costing will be used far less for individual accountability or operational control, but will return to its decision-making roots in the form of long-run cost targets that benchmark the success of continuous cost-reduction efforts.

Aulosira Bohemensis sp. nov.: Further Phylogenetic Uncertainty at The Base of The Nostocales (Cyanobacteria)

Abstract: A. Lukesova, J.R. Johansen, M.P. Martin and D.A. Casamatta. 2009. Aulosira bohemensis sp. nov.: further phylogenetic uncertainty at the base of the Nostocales (Cyanobacteria). Phycologia 48: 118–129. DOI: 10.2216/08-56.1 Aulosira bohemensis sp. nov. was isolated from a wet meadow soil in South Bohemia, Czech Republic. It shares all the features of the majority of other Aulosira species, including isopolar development with intercalary heterocytes and apoheterocytic akinete development. It differs from all other species through the production of hormogonia perpendicular to the trichome axis following akinete germination. Morphologically the genus Aulosira appears closest to Nodularia, however, phylogenetic placement of A. bohemensis based on 16S rRNA was distant from that taxon. Aulosira falls within the Nostocaceae, with possible sister taxa in Trichormus, Mojavia and Nostoc. Despite the variety of phylogenetic analyses performed, we were unable to obtain bootstrap support for its position in any ...

Nanostructured Bi2Se3 Films and Their Thermoelectric Transport Properties

Abstract: Since the discovery of the thermoelectric effect by Thomas Johann Seebeck in 1821, solid-state thermoelectric materials have long held the promise of becoming the next generation of energy converters thanks to their small size, light weight, reliability, and potential for higher conversion efficiencies. [1] However, bulk thermoelectric materials seem to have reached their performance limit; most materials exhibit an optimum thermoelectric figure of merit (ZT) of about 1 at room temperature, which equates to only around 10 % of the Carnot efficiency.Since the 1960s, the efficiencies of bulk thermoelectric materials have been improved only marginally.To promote the economic potential of these materials and to support the full development of the associated technological applications, improvements in thermoelectric efficiencies leading to ZT 3 at room temperature are required.It was not until the early 1990s that Dresselhaus and co-workers demonstrated theoretically that it is possible to increase the ZT values drastically by decreasing the size of thermoelectric materials. [2–5] However, the practical difficulties in synthesizing, testing, and utilizing structures smaller than 100 nm make the production of nanoscale thermoelectric materials a real challenge.Therefore, methods that provide reproducible and stable nanostructured thermoelectric films and reliable thermoelectric measurements are of great importance.We have developed chemically grown nanostructured thermoelectric films, the building and testing of which is a significant step towards better thermoelectric