Quotient Complexity of Regular Languages

The past research on the state complexity of operations on regular languages is examined, and a new approach based on an old method (derivatives of regular expressions) is presented. Since state complexity is a property of a language, it is appropriate to define it in formal-language terms as the number of distinct quotients of the language, and to call it "quotient complexity". The problem of finding the quotient complexity of a language f(K,L) is considered, where K and L are regular languages and f is a regular operation, for example, union or concatenation. Since quotients can be represented by derivatives, one can find a formula for the typical quotient of f(K,L) in terms of the quotients of K and L. To obtain an upper bound on the number of quotients of f(K,L) all one has to do is count how many such quotients are possible, and this makes automaton constructions unnecessary. The advantages of this point of view are illustrated by many examples. Moreover, new general observations are presented to help in the estimation of the upper bounds on quotient complexity of regular operations

Sí Se Puede: Using Participatory Research to Promote Environmental Justice in a Latino Community in San Diego, California

Community-based participatory research (CBPR) increasingly is seen as a potent tool for studying and addressing urban environmental health problems by linking place-based work with efforts to help effect policy-level change. This paper explores a successful CBPR and organizing effort, the Toxic Free Neighborhoods Campaign, in Old Town National City (OTNC), CA, United States, and its contributions to both local policy outcomes and changes in the broader policy environment, laying the groundwork for a Specific Plan to address a host of interlocking community concerns. After briefly describing the broader research of which the OTNC case study was a part, we provide background on the Environmental Health Coalition (EHC) partnership and the setting in which it took place, including the problems posed for residents in this light industrial/residential neighborhood. EHC’s strong in-house research, and its training and active engagement of promotoras de salud (lay health promoters) as co-researchers and policy change advocates, are described. We explore in particular the translation of research findings as part of a policy advocacy campaign, interweaving challenges faced and success factors and multi-level outcomes to which these efforts contributed. The EHC partnership's experience then is compared with that of other policy-focused CBPR efforts in urban environmental health, emphasizing common success factors and challenges faced, as these may assist other partnerships wishing to pursue CBPR in urban communities

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan

Global goods movement and the local burden of childhood asthma in southern California

OBJECTIVES: As part of a community-based participatory research effort, we estimated the preventable burden of childhood asthma associated with air pollution in the southern California communities of Long Beach and Riverside. METHODS: We calculated attributable fractions for 2 air pollution reduction scenarios to include assessment of the newly recognized health effects associated with residential proximity to major roads and impact from ship emissions. RESULTS: Approximately 1600 (9%) of all childhood asthma cases in Long Beach and 690 (6%) in Riverside were attributed to traffic proximity. Ship emissions accounted for 1400 (21%) bronchitis episodes and, in more modest proportions, health care visits for asthma. Considerably greater reductions in asthma morbidity could be obtained by reducing nitrogen dioxide and ozone concentrations to levels found in clean coastal communities. CONCLUSIONS: Both Long Beach and Riverside have heavy automobile traffic corridors as well as truck traffic and regional pollution originating in the Los Angeles-Long Beach port complex, the largest in the United States. Community-based quantitative risk analyses can improve our understanding of health problems and help promote public health in transportation plannin

Leaf photosynthesis, respiration and stomatal conductance in six Eucalyptus species native to mesic and xeric environments growing in a common garden

Trees adapted to mesic and xeric habits may differ in a suite of physiological responses that affect leaf-level carbon balance, including the relationship between photosynthesis (A) and respiration at night (Rn). Understanding the factors that regulate physiological function in mesic and xeric species is critical for predicting changes in growth and distribution under changing climates. In this study, we examined the relationship between A and Rn, and leaf traits that may regulate A and Rn, in six Eucalyptus species native to mesic or xeric ecosystems, during two 24-h cycles in a common garden under high soil moisture. Peak A and Rn generally were higher in xeric compared with mesic species. Across species, A and Rn covaried, correlated with leaf mass per area, leaf N per unit area and daytime soluble sugar accumulation. A also covaried with g s, which accounted for 93 of the variation in A within species. These results suggest that A and Rn in these six Eucalyptus species were linked through leaf N and carbohydrates. Further, the relationship between A and Rn across species suggests that differences in this relationship between mesic and xeric Eucalyptus species in their native habitats may be largely driven by environmental factors rather than inter-specific genetic variation