Search

Maternal immune activity has been linked to children with autism spectrum disorder (ASD). We examined maternal occupational exposure to asthma-causing agents during pregnancy in relation to ASD risk. Our sample included 463 ASD cases and 710 general population controls from the Study to Explore Early Development whose mothers reported at least one job during pregnancy. Asthmagen exposure was estimated from a published job-exposure matrix. The adjusted odds ratio for ASD comparing asthmagen-exposed to unexposed was 1.39 (95 % CI 0.96-2.02). Maternal workplace asthmagen exposure was not associated with ASD risk in this study, but this result does not exclude some involvement of maternal exposure to asthma-causing agents in ASD.

Improving teacher retention and resiliency are key educational problems. In this article, we share findings from case studies of six educators who, for over 200 combined years, worked in urban, high-poverty schools and highlight what teachers need to remain in such contexts. We argue that developing "professional resilience" is a process built on the interplay between individuals and their supportive contexts. In-depth interviews with these six educators reveal how connections with educator networks such as the National Writing Project (NWP) helped teachers develop into durable and reflective practitioners by providing them technical expertise, cultural support, and opportunities to develop as leaders. (Contains 1 table and 2 notes.)

This retrospective interview study investigated the role of parental support in the writing growth of eight first-generation Latino college students in the years prior to admission to a 4-year university. All of the students came from low-income households in urban settings and spoke zero English at the time they entered kindergarten. Participants provided a nuanced view of the ways parents simultaneously provided support and barriers to their writing growth prior to college. This article suggests the need for teachers and researchers to reexamine assumptions about the literacy experiences first-generation Latinos bring to the undergraduate writing curriculum from their home communities. (Contains 1 table.)

Parental dissatisfaction with special education services is a national problem. This article presents two districts that have undergone systemwide changes to decrease the dissatisfaction of families who have children with disabilities. Using qualitative inquiry, the authors analyzed documents and observed and interviewed 24 informants about the system problems and changes. Data analysis revealed three themes within the systems problems category: (a) lack of leadership, (b) not keeping up with the law, and (c) parents excluded. Systemwide changes were organized into seven themes: (a) new leadership, (b) partnerships, (c) creative use of resources, (d) updated educational practices, (e) relationship building, (f) teacher and parent support, and (g) alternative dispute resolution. Findings revealed effective leaders who focused on all levels of the system. (Contains 2 figures and 2 tables.)

The study uses an alternating treatment design to evaluate the functional effect of teacher's affect on students' task performance. Tradition in special education holds that teachers should engage students using positive and enthusiastic affect for task presentations and praise. To test this assumption, we compared two affective conditions. Three teachers working with a total of 4 elementary-age students with severe disabilities presented discrete trial tasks in neighborhood public school settings. The teachers alternated their affect between a positive affective condition characterized by smiling, enthusiasm, and rising and falling voice inflection and a neutral affect condition characterized by a flat voice tone and inexpressive facial features. Three of the four students responded more accurately to instructional tasks when teachers presented task demands and praise using positive affect. A fourth student, however, performed worse under the positive affect condition. This student had a long history of problem behavior in instructional settings. Implications for assessment practices are discussed. (Contains 2 figures.)

California's Proposition 227 (1998) has affected the education of many English language learners (ELLs). However, the extent of Proposition 227's influence on special education planning and practice is unclear. ELLs who have moderate to severe disabilities face major communication obstacles. The present qualitative study looked specifically at the impact of California's Proposition 227 and the Individuals with Disabilities Education Act (1990) on special education teachers' educational planning, assessments, and classroom practices for students identified as ELLs who have moderate to severe disabilities. Findings indicated teacher misinterpretation of Proposition 227, resource scarcity, a lack of administrative support, and the exclusion of parents from decisions regarding which language should be used to instruct ELLs with moderate to severe disabilities.

Reports on a study to determine whether placement in a remedial English class is more effective than placement in a regular English class for enabling students who are beyond the acquisition phase of reading development to pass district minimal competency tests. Data support placement in the regular English class. (NH)

Combustion pollutant concentrations were measured during the scripted operation of natural gas cooking burners in nine homes. Boiling and simmering activities were conducted on the stovetop and in the oven with and without range hood exhaust ventilation or air mixing via a forced air system. Time-resolved concentrations of carbon dioxide (CO 2 ), nitric oxide (NO), nitrogen oxides (NO x ), nitrogen dioxide (NO 2 ), particles with diameters of 6 nm or larger (PN), carbon monoxide (CO), and fine particulate matter (PM 2.5 ) were measured in the kitchen and bedroom area of each home. Four of the nine homes had kitchen 1 h NO 2 exceed the national ambient air quality standard (100 ppb). In all homes, the highest 1 h integrated PN exceeded 2 × 10 5 cm −3 -h, and the highest 4 h PN exceeded 3 × 10 5 cm −3 -hr in the kitchen. Range hood performance varied widely, but one with a large capture volume and a measured flow of 108 L/s reduced concentrations 80–95%. Increased awareness of the need to ventilate when cooking, along with building standards for minimum range hood flow rates and volume, could substantially reduce exposures to NO 2 and ultrafine particles in homes. [ABSTRACT FROM AUTHOR]

The effects of liquefied natural gas (LNG) on pollutant emission inventories and air quality in the South Coast Air Basin (SoCAB) of California are evaluated using recent appliance emissions measurements by Lawrence Berkeley National Laboratory and the Southern California Gas Company (SoCalGas), and use of a state-of-the-art air quality model. Pollutant emissions can be impacted by LNG operation because of differences in composition and physical properties including the Wobbe index, a measure of energy delivery rate. Various LNG distribution scenarios are evaluated to determine the potential impacts of LNG. Projected penetration of LNG in the SoCalGas pipeline network in SoCAB is expected to be limited, which could cause increases in overall (area-wide) emissions of nitrogen oxides that are smaller than 0.05%. Based on the photochemical state of the South Coast Air Basin of California, any increase in NO x is expected to cause an increase in the highest local ozone concentrations, which is observed in model results. However, the magnitude of NO x emissions increases due to LNG use is determined to be within the uncertainty range of natural gas combustion sources and would not be discernible with the existing monitoring network. [ABSTRACT FROM AUTHOR]

Abstract: Lacustrine sediments of the Wilson Creek Formation in the Mono Basin, California, record a paleomagnetic field excursion constrained by 14C and 40Ar/39Ar geochronology to have occurred within the last 50ka. However, 14C and 40Ar/39Ar ages are discordant, making it difficult to distinguish which of two possible excursions during this period, the Mono Lake or Laschamp, is recorded in the Mono Basin. New 40Ar/39Ar age determinations from sanidine, as well as the first biotite and obsidian ages, for three of the nineteen rhyolitic ashes intercalated with these sediments are presented and compared to previous 14C and 40Ar/39Ar data sets. Although the sanidine ages of the three ashes are stratigraphically consistent with each other and previously determined 40Ar/39Ar ages for other ashes in the Wilson Creek Formation, each is significantly older than 14C ages obtained from stratigraphically equivalent beds, relative paleointensity field correlations, oxygen isotope records, and glacial histories. These data indicate an absence of juvenile, eruptive crystals and most likely reflect the incorporation of crystals from older volcanic centers or underlying sediment. We examine the strengths and weaknesses of all available geochronologic data for the section exposed at Wilson Creek to arrive at an internally consistent set of age constraints. Using these constraints we propose two new relative paleointensity correlations for the section, both of which indicate that the excursion recorded in the Mono Basin occurred at ∼30–34ka on the Greenland Ice Sheet Project 2 (GISP2) ice core time scale. [Copyright &y& Elsevier]

The article offers information about a study presents a 20-year record of nitrate-nitrogen and suspended sediment export from a typical, grazed oak woodland watershed in the northern Sierra Nevada foothills of California. This explores the quality of environmental protection services that the California oak woodland rangelands including the long-term water quality records for assessing natural variability, impact of management, and guide regulatory processes. Results of the study highlighted the necessity of using long-term records to establish quantitative water quality targets for rangelands and demonstrated the difficulty of designing a water quality monitoring program for these ecosystems.

Previous research has shown that under-ventilation of classrooms is common and negatively impacts student health and learning. To advance understanding of contributing factors, this study visited 104 classrooms from 11 schools that had recently been retrofitted with new heating, ventilation, and air-conditioning (HVAC) units. CO 2 concentration, room and supply air temperature and relative humidity, and door opening were measured for four weeks in each classroom. Field inspections identified HVAC equipment, fan control, and/or filter maintenance problems in 51% of the studied classrooms. Across 94 classrooms with valid data, average CO 2 concentrations measured during school hours had a mean of 895 ppm and a standard deviation (SD) of 263 ppm. Ventilation rates (VRs), estimated using the daily maximum 15-min CO 2 in each classroom, had a mean of 5.2 L/s-person and a SD of 2.0 L/s-person across 94 classrooms. Classrooms with economizers, with or without demand control ventilation (DCV), tended to have lower mean CO 2. Improperly selected equipment, lack of commissioning, incorrect fan control settings and maintenance issues (heavily loaded filters) were all associated with under-ventilation in classrooms. Many classrooms in this sample were frequently too warm to support learning. There were 23 out of 103 classrooms that had indoor air temperature above 25.6 °C for more than 20% of the school hours. Better oversight on HVAC system installation and commissioning are needed to ensure adequate classroom ventilation. Periodic testing of ventilation systems and/or continuous real-time CO 2 monitoring (either as stand-alone monitors or incorporated into thermostats) is recommended to detect and correct ventilation problems. • Study of 104 recently retrofitted classrooms with new HVAC equipment. • Problems with hardware, fan control, and/or filter maintenance were commonly found. • Classrooms with identified problem(s) had higher CO 2 and lower ventilation rates. • Better oversight on HVAC system installation and filter maintenance are needed. • Periodic ventilation system testing and/or continuous CO2 monitoring is recommended. [ABSTRACT FROM AUTHOR]

Inhalation of respirable dust (RD), defined as particles <4 pm in aerodynamic diameter, is a health concern. Soil disturbance by farming produces a range of airborne soil minerals of various sizes, but little is known about RD mineralogy compared with source soil or about mineralogy of RD as a function of particle size. General assumptions are that dust mineralogy reflects the source soil and that there is no sorting of RD mineralogy by particle size. We tested these assumptions by determining the size and mineralogy of RD particles from specific farming activities and comparing them to the source soil mineralogy. Samples were taken from plots growing furrow-irrigated crops near Davis, CA. Source-soil was analyzed by x-ray diffraction (XRD). Respirable dust was analyzed by scanning electron microscopy and transmission electron microscopy (TEM) with selected area electron diffraction.Mineralogy and size data of mineral groups from the two techniques were different. The TEM method was more reliable because it included crystallographic data as well as elemental composition and particle morphology. The same major mineral groups (quartz, mica, feldspar, and clays) were found in the RD and the source soil, but minor constituents of the RD such as serpentine minerals and zeolites were not detected in the source soil because they were not sufficiently abundant to be detected by standard XRD techniques. No significant sorting of source soil mineralogy occurred over the short distance between soil andRD sampler. [ABSTRACT FROM AUTHOR]