2,479 research outputs found

    The Law of White Spaces: Race, Culture, and Legal Education

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    The scene, drawn from memory, is a first-year law school classroom. It is the early 1980s and the class is on civil procedure. The teacher is a white woman. She is nervous, and the class is dominated by students who provide standard right answers to formulaic law school questions. Other points of view, particularly those of a critical or feminist nature, are either passed over quickly or ignored. Questions of color are never mentioned. More than that, the teacher never calls on any African-American students. Students of color are either ignored completely or told, when they have questions, “We are moving on.” What initially seemed to be nervousness or inexperience becomes accentuated over time as discrimination. As the semester progresses, the African-American students start to test in subtle and quiet ways the teacher\u27s practice of excluding them. Things come to a head when they organize a systematic protest. After every statement or question made by the teacher, at least two of the students raise their hands. After several unsuccessful attempts at asking or answering questions, one African-American student confronts the teacher. When she tells him that she is moving on, the student insists: “I have a question.” The teacher reiterates: “We are moving on.” The student persists, the teacher repeats. All the African-American students then stand up and walk out of the class. One white student stands up and leaves as well. The rest of the class stays. The course continues without any real interruption. Sometime later a curt apology—“I didn\u27t mean to offend anyone”—suffices to paper over the color lines that the incident revealed

    Testing the selectivity of pesticide effects on natural enemies in laboratory bioassays

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    The toxic effects of older classes of pesticides on natural enemies are typically acute and exposure usually occurs through direct contact with foliar residues. However, older chemistries are being replaced by newer classes of pesticides that can cause sublethal effects in addition to direct mortality. We developed a set of life table response protocols to quantify the effects of multiple routes of exposure to pesticides on individual-level life history parameters of predators and parasitoids. We then integrated the data into population-level endpoint estimates of population growth rates using stage-structured population models. For this study, we evaluated the impacts of five insecticides (cyantraniliprole, chlorantraniliprole, spinetoram, novaluron and lambda-cyhalothrin) and two fungicides (sulfur and a mixture of copper hydroxide and mancozeb) on a generalist insect predator Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and an aphid parasitoid Trioxys pallidus (Haliday) (Hymenoptera: Braconidae). Green lacewings and T. pallidus are key members of the natural enemy community in western USA orchards. The results of these laboratory studies demonstrate that both C. carnea and T. pallidus were negatively affected by cyantraniliprole, spinetoram and lambda-cyhalothrin while only one species was affected by chlorantraniliprole and novaluron (C. carnea) or sulfur (T. pallidus). The benefits of integrating acute, chronic, and sublethal effects from laboratory bioassays to assess the selectivity of pesticides with respect to natural enemies are discussed

    Non cell autonomous upregulation of CDKN2 transcription linked to progression of chronic hepatitis C disease

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    Chronic hepatitis C virus infection (C-HC) is associated with higher mortality arising from hepatic and extrahepatic disease. This may be due to accelerated biological aging; however, studies in C-HC have thus far been based solely on telomere length as a biomarker of aging (BoA). In this study, we have evaluated CDKN2 locus transcripts as alternative BoAs in C-HC. Our results suggest that C-HC induces non-cell-autonomous senescence and accelerates biological aging. The CDKN2 locus may provide a link between C-HC and increased susceptibility to age-associated diseases and provides novel biomarkers for assessing its impact on aging processes in man

    Thermal poling of glass modified by femtosecond irradiation

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    Thermal poling of silica glass modified by femtosecond laser irradiation is demonstrated. Increase of second-harmonic generation in the irradiated regions is observed. This enhancement is interpreted in terms of structural modifications in silica glass that make the poling process more efficient. Evidence of a change in the distribution of the electrostatic field frozen in glass during poling is obtained. This technique is used for (2) grating fabrication

    Settlement Chronologies and Shifting Resource Exploitation in Ka‘ū District, Hawaiian Islands

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    Museum collections contribute valuable information for cultural heritage, biological conservation, and the application of innovative and new methodological approaches. Collections deriving from archaeological projects in Hawai‘i serve as a case in point. Here, we report on re-analysis of two Ka‘ū District collections from Hawai‘i Island (HA-B22-64 and -248) to demonstrate what can be learned when applying new research questions to old collections. Our research goals center on two main themes: re-dating the HA-B22-64 and -248 sites to place them within the newly refined Hawaiian archipelago settlement chronology; and using diverse data sources to look at changing resource use in pre-Contact Hawai‘i through time. Our new AMS dating results indicate that the lower levels of rockshelter HA-B22-64 date to the mid- to Late Prehistoric period during the fifteenth and seventeenth centuries, while upper levels calibrate to the ninteenth century. Both levels of HA-B22-248 calibrate to the late eighteenth to nineteenth centuries. In terms of resource use, Pu‘u Wa‘awa‘a volcanic glass is present at both sites in small amounts, which is consistent with other sites in the South Point area. However, the high percentage of Group 3 volcanic glass is unusual for the area, and represents the highest percentage for the Kona side of Hawai‘i Island. HA-B22-64 has a small number of basalt artifacts consistent with the Keahua I source on Kaua‘i, while both sites have evidence for artifacts produced from the Mauna Kea quarry. Technological data from our basalt assemblages do not support direct access to the Mauna Kea quarry nor the presence of adze specialists in Ka‘ū households; rather, we find rejuvenation and use of already finished adzes. Measurements on Scarine oral and pharyngeal jawbones illustrate a consistent and stable size structure of fish populations at both sites. This, along with the large overall fish size, is indicative of sustainable fishing practices

    Comparative analysis of pesticide effects on natural enemies in western orchards: A synthesis of laboratory bioassay data

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    Pesticides are commonly used for pest management in apple, pear and walnut orchards in the western U.S. and may disrupt biological control of secondary pests in these crops. A comparative analysis was made of results obtained from a series of laboratory bioassays of acute mortality and life table response experiments to estimate lethal and sublethal effects of eight pesticides on seven natural enemy species through use of stage-structured population models. Even though a number of the pesticides tested were reduced-risk products, all of them with the exception of copper plus mancozeb and chlorantraniliprole, caused more than 80% acute mortality of at least one life stage of at least one of the natural enemy species at a full field-rate concentration and could thus be considered moderately harmful according to the International Organization for Biological Control classification for laboratory bioassays. Important sublethal effects included reductions in daily fecundity and egg fertility. From integration of the lethal and sublethal effects in matrix models, the mean of the estimated intrinsic rates of increase for natural enemy species was negative for exposure to cyantraniliprole, lambda-cyhalothrin and spinetoram, but positive and not significantly different from the control for exposure to chlorantraniliprole, copper plus mancozeb, novaluron, and sulfur. For comparisons among pesticides, there appears to be considerable variation in response among natural enemy species that can only be represented effectively from a full life table response experiment and a population-level endpoint, whereas among natural enemy species, their population-level response to the range of pesticides tested could frequently be represented by acute adult mortality alone

    Genotypic and phenotypic spectrum of pyridoxine-dependent epilepsy (ALDH7A1 deficiency)

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    Pyridoxine-dependent epilepsy was recently shown to be due to mutations in the ALDH7A1 gene, which encodes antiquitin, an enzyme that catalyses the nicotinamide adenine dinucleotide-dependent dehydrogenation of L-{alpha}-aminoadipic semialdehyde/L-{Delta}1-piperideine 6-carboxylate. However, whilst this is a highly treatable disorder, there is general uncertainty about when to consider this diagnosis and how to test for it. This study aimed to evaluate the use of measurement of urine L-{alpha}-aminoadipic semialdehyde/creatinine ratio and mutation analysis of ALDH7A1 (antiquitin) in investigation of patients with suspected or clinically proven pyridoxine-dependent epilepsy and to characterize further the phenotypic spectrum of antiquitin deficiency. Urinary L-{alpha}-aminoadipic semialdehyde concentration was determined by liquid chromatography tandem mass spectrometry. When this was above the normal range, DNA sequencing of the ALDH7A1 gene was performed. Clinicians were asked to complete questionnaires on clinical, biochemical, magnetic resonance imaging and electroencephalography features of patients. The clinical spectrum of antiquitin deficiency extended from ventriculomegaly detected on foetal ultrasound, through abnormal foetal movements and a multisystem neonatal disorder, to the onset of seizures and autistic features after the first year of life. Our relatively large series suggested that clinical diagnosis of pyridoxine dependent epilepsy can be challenging because: (i) there may be some response to antiepileptic drugs; (ii) in infants with multisystem pathology, the response to pyridoxine may not be instant and obvious; and (iii) structural brain abnormalities may co-exist and be considered sufficient cause of epilepsy, whereas the fits may be a consequence of antiquitin deficiency and are then responsive to pyridoxine. These findings support the use of biochemical and DNA tests for antiquitin deficiency and a clinical trial of pyridoxine in infants and children with epilepsy across a broad range of clinical scenarios

    Large-plot field studies to assess impacts of newer insecticides on non-target arthropods in Western U.S. orchards

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    The non-target impacts of two reduced risk insecticides, chlorantraniliprole and spinetoram, were evaluated for two years in Oregon pear and California walnut orchards. Experiments were conducted in large replicated plots (approximately 0.25–0.4ha) to assess the impact of these two insecticides on natural enemies of secondary pests when applied against codling moth, Cydia pomonella. Cumulative insect days (CID) of secondary pests and natural enemies were calculated from leaf samples, plant volatile traps, beat trays or cardboard trunk bands. Ratios of natural enemies and prey were also calculated. Results from these field studies demonstrate that applications of chlorantraniliprole can reduce abundance of predatory Neuroptera and that spinetoram negatively impacts parasitic Hymenoptera. However, these trends did not always occur each year. As a percentage among all trials within a crop, there were more treatment differences for natural enemy/prey ratios (50 and 33% for pears and walnut plots, respectively) than for natural enemy CIDs (25 and 13% for pears and walnut plots, respectively). It is likely that unseasonably cool weather during the two years of this study impacted both pest and natural enemy abundance. The intrinsic value of large-plot field studies is discussed

    Femtosecond direct writing of embedded photonic structures

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    In the last few years, femtosecond lasers have proven to be of great utility for micromachining within the bulk of transparent materials and this processing technique has attracted much attention due to its simplicity compared to lithographic methods and its ability to write in three-dimensions. When an intense femtosecond laser pulse is tightly focused into transparent material, high-order non-linear absorption allows the energy to be deposited predominantly within the focal volume producing a local permanent refractive index modification
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