195 research outputs found

    The Effects of Health and Environmental Regulation on Technological Change in the Chemical Industry: Theory and Evidence

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    This paper presents the final results of a research effort which investigated the effects of environmental/safety regulation on technological change in the U.S. chemical industry. (1) The term environmental/safety regulation is used to include the legislation, regulations, and other related actions which attempt to control environmental pollution, protect worker health and safety, or ensure the safety of consumer products. Technological changes arising from regulation encompass both the immediate modifications in manufactured products or industrial processes which may be necessary in order to comply with regulation and the more indirect, or ancillary, effects regulation can have on technological change for non-regulatory, "main business" purposes. The major emphasis in this work is on technological change for compliance purposes. We distinguish technological change from innovation. Innovation means new product or process technology actually brought by a firm into first commercial use. The term technological change has a broader scope and includes "non-innovative" changes

    Attention Performance in an Epidemiological Sample of Urban Children: The Role of Gender and Verbal Intelligence

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    We administered a comprehensive attentional battery to an epidemiologically defined sample of 435 first and second-grade children to assess the influence of gender and verbal intelligence on attention. The battery included three versions of the continuous performance test (CPT), two digit cancellation tasks, three subtests from the WISC-R, and the Wisconsin Card Sorting Test. The results indicated that both gender and intelligence had an impact on attentional performance. Girls performed better than boys; they made fewer errors on the CPT and obtained higher scores on the digit cancellation task and the Coding subtest of the WISC-R. Children with higher verbal intelligence also performed better on the attentional tests, but this advantage was not observed across measures or levels of performance. For example, children with limited verbal skills performed significantly worse than their peers only in measures with high processing demands(the degraded CPT and the distraction version of the digit cancellation task)

    Circulating senescent myeloid cells drive blood brain barrier breakdown and neurodegeneration

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    Neurodegenerative diseases (ND) are characterized by progressive loss of neuronal function. Mechanisms of ND pathogenesis are incompletely understood, hampering the development of effective therapies. Langerhans cell histiocytosis (LCH) is an inflammatory neoplastic disorder caused by hematopoietic progenitors expressing MAPK activating mutations that differentiate into senescent myeloid cells that drive lesion formation. Some patients with LCH subsequently develop progressive and incurable neurodegeneration (LCH-ND). Here, we show that LCH-ND is caused by myeloid cells that are clonal with peripheral LCH cells. We discovered that circulating BRAF V600E +^{+} myeloid cells cause the breakdown of the blood-brain barrier (BBB), enhancing migration into the brain parenchyma where they differentiate into senescent, inflammatory CD11a +^{+} macrophages that accumulate in the brainstem and cerebellum. Blocking MAPK activity and senescence programs reduced parenchymal infiltration, neuroinflammation, neuronal damage and improved neurological outcome in preclinical LCH-ND. MAPK activation and senescence programs in circulating myeloid cells represent novel and targetable mechanisms of ND
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