372 research outputs found
TRADABLE PERMITS FOR CONTROLLING NITRATES IN GROUNDWATER AT THE FARM LEVEL: A CONCEPTUAL MODEL
Nitrate contamination of municipal and domestic well water supplies is becoming an increasing problem in many rural and urban areas, raising the cost of providing safe drinking water. The objective of this paper is to describe a marketable permit scheme that can effectively manage nitrate pollution of groundwater supplies for communities in rural areas without hindering agricultural production in watersheds. They key to implementing this scheme is being able to link nitrate leaching from nitrogen fertilizer applied to crops at a farm to nitrate levels measured at a drinking water well.agriculture, groundwater pollution, leaching, nitrates, pollution trading, Environmental Economics and Policy,
Which Children are Frequently Victimized in U.S. Elementary Schools? Population-based Estimates
We analyzed a population-based cohort of 11,780 U.S. kindergarten children to identify risk and protective factors predictive of frequent verbal, social, reputational, and/or physical bullying victimization during the upper elementary grades. We also stratified the analyses by biological sex. Both girls and boys displaying kindergarten externalizing problem behaviors were at consistently higher risk of frequent victimization during 3rd-5th grade (for the combined sample of boys and girls, verbal odds ratio [OR] = 1.82, social OR = 1.60, reputational OR = 1.85, physical OR = 1.67, total OR = 1.93). Hispanic children relative to non-Hispanic White children and those from higher income families were the most strongly and consistently protected from victimization. Boys were more likely to be physically bullied but less likely to be verbally, socially or reputationally bullied than girls. Other variables including disability, cognitively stimulating parenting, academic achievement, and internalizing behavior problems had statistically significant but less consistent and generally weaker relations with frequent victimization
Tissue Engineering of Lips and Muco-Cutaneous Junctions: In Vitro Development of Tissue Engineered Constructs of Oral Mucosa and Skin for Lip Reconstruction
We report for the first time the fabrication of a three-dimensional tissue structure containing, in a continuous layer, the morphological features of a lip: epidermal skin, vermillion, and oral mucosa. This tissue engineered muco-cutaneous (M/C) equivalent was manufactured using human oral and skin keratinocytes grown on an acellular, nonimmunogenic dermal equivalent (AlloDerm-) to produce a tissue equivalent with similar anatomic and handling properties as native human lips. Confirmation of the structural composition of the construct was performed using routine histology and immunohistochemistry by identification of epithelial markers that are differentially expressed in separate anatomic areas of the lips. These full-thickness human lip skin equivalents can be used in surgical lip reconstruction in individuals suffering from lip loss from cancer, congenital deformations, and injuries after accidents. We propose this technique can be used as a general basis for tissue engineering of M/C junctions in other parts of the body, such as anus and vagina.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90465/1/ten-2Etec-2E2011-2E0406.pd
Special Project -- Legal Issues Arising from the Mexican Economic Crisis
The economic crisis in Mexico, which profoundly altered the financial and political course of that nation, has also had a significant impact on persons and corporations having business ties to Mexico. Foreign investors and businesses now are required to follow new Mexican rules that often differ dramatically from those previously in effect. The impact of the crisis has not been confined to changes in Mexican law. A substantial number of issues have arisen that will have significant bearing on United States and international law.
The Special Project discusses the changes in the legal environment following the crisis, with its focus upon issues confronting private persons, principally foreign businesses and investors. The Introduction and Overview summarizes the history and structure of Mexico\u27s regulation of foreign investment and recounts the events of the crisis. The first section of the Special Project examines the problems faced by foreign lenders and creditors. Specifically, it addresses the following: (1) the Mexican regulations that set forth the schedules for repayment of amounts owed to foreign creditors; (2) the possibilities for relief should the obligations be dishonored; (3) the efficacy of leading proposals for the restructuring of Mexican and international debt; and (4) the recently promulgated laws and regulations that will govern future international lending activity by United States banks. The second section explores the problems of investors in devalued peso-denominated accounts and the applicability of United States securities laws to those obligations. Section three addresses the immigration problem now exacerbated by the economic crisis and discusses the scope, effect, and wisdom of the proposed Simpson-Mazzoli Bill. The fourth section studies transborder environmental issues that recently have arisen as a result of Mexico\u27s desire for rapid industrial development
Smooth muscle archvillin: a novel regulator of signaling and contractility in vascular smooth muscle
The mechanisms by which protein kinase C (PKC) and extracellular-signal-regulated kinases (ERK1/2) govern smooth-muscle contractility remain unclear. Calponin (CaP), an actin-binding protein and PKC substrate, mediates signaling through ERK1/2. We report here that CaP sequences containing the CaP homology (CH) domain bind to the C-terminal 251 amino acids of smooth-muscle archvillin (SmAV), a new splice variant of supervillin, which is a known actin- and myosin-II-binding protein. The CaP-SmAV interaction is demonstrated by reciprocal yeast two-hybrid and blot-overlay assays and by colocalization in COS-7 cells. In differentiated smooth muscle, endogenous SmAV and CaP co-fractionate and co-translocate to the cell cortex after stimulation by agonist. Antisense knockdown of SmAV in tissue inhibits both the activation of ERK1/2 and contractions stimulated by either agonist or PKC activation. This ERK1/2 signaling and contractile defect is similar to that observed in CaP knockdown experiments. In A7r5 smooth-muscle cells, PKC activation by phorbol esters induces the reorganization of endogenous, membrane-localized SmAV and microfilament-associated CaP into podosome-like structures that also contain F-actin, nonmuscle myosin IIB and ERK1/2. These results indicate that SmAV contributes to the regulation of contractility through a CaP-mediated signaling pathway, involving PKC activation and phosphorylation of ERK1/2
Genomic alterations indicate tumor origin and varied metastatic potential of disseminated cells from prostate-cancer patients
Disseminated epithelial cells can be isolated from the bone marrow of a far greater fraction
of prostate-cancer patients than the fraction of patients who progress to metastatic disease.
To provide a better understanding of these cells, we have characterized their genomic alterations.
We first present an array comparative genomic hybridization method capable of detecting
genomic changes in the small number of disseminated cells (10-20) that can typically be obtained
from bone-marrow aspirates of prostate-cancer patients. We show multiple regions of
copy-number change, including alterations common in prostate cancer, such as 8p loss, 8q gain,
and gain encompassing the androgen-receptor gene on Xq, in the disseminated cell pools from
11 metastatic patients. We found fewer and less striking genomic alterations in the 48 pools of
disseminated cells from patients with organ-confined disease. However, we identify changes
shared by these samples with their corresponding primary tumors and prostate-cancer alterations
reported in the literature, evidence that these cells, like those in advanced disease, are
disseminated tumor cells (DTCs). We also demonstrate that DTCs from patients with advanced
and localized disease share several abnormalities, including losses containing cell-adhesion
genes and alterations reported to associate with progressive disease. These shared alterations
might confer the capability to disseminate or establish secondary disease. Overall, the spectrum
of genomic deviations is evidence for metastatic capacity in advanced-disease DTCs and variation
in that capacity in DTCs from localized disease. Our analysis lays the foundation for elucidation
of the relationship between DTC genomic alterations and progressive prostate cancer
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The Care Work of Access
Current approaches to AI and Assistive Technology (AT) often foreground task completion over other encounters such as expressions of care. Our paper challenges and complements such task-completion approaches by attending to the care work of access—the continual affective and emotional adjustments that people make by noticing and attending to one another. We explore how this work impacts encounters among people with and without vision impairments who complete tasks together. We find that bound up in attempts to get things done are concerns for one another and how well people are doing together. Reading this work through emerging disability studies and feminist STS scholarship, we account for two important forms of work that give rise to access: (1) mundane attunements and (2) noninnocent authorizations. Together these processes work as sensitizing concepts to help HCI scholars account for the ways that intelligent ATs both produce access while sometimes subverting people with disabilities
Re-visioning ultrasound through women's accounts of pre-abortion care in England
Feminist scholarship has demonstrated the importance of sustained critical engagement with ultrasound visualizations of pregnant women’s bodies. In response to portrayals of these images as “objective” forms of knowledge about the fetus, it has drawn attention to the social practices through which the meanings of ultrasound are produced. This article makes a novel contribution to this project by addressing an empirical context that has been neglected in the existing feminist literature concerning ultrasound, namely, its use during pregnancies that women decide to terminate. Drawing on semi-structured interviews with women concerning their experiences of abortion in England, I explore how the meanings of having an ultrasound prior to terminating a pregnancy are discursively constructed. I argue that women’s accounts complicate dominant representations of ultrasound and that in so doing, they multiply the subject positions available to pregnant women
Large-scale associations between the leukocyte transcriptome and BOLD responses to speech differ in autism early language outcome subtypes.
Heterogeneity in early language development in autism spectrum disorder (ASD) is clinically important and may reflect neurobiologically distinct subtypes. Here, we identified a large-scale association between multiple coordinated blood leukocyte gene coexpression modules and the multivariate functional neuroimaging (fMRI) response to speech. Gene coexpression modules associated with the multivariate fMRI response to speech were different for all pairwise comparisons between typically developing toddlers and toddlers with ASD and poor versus good early language outcome. Associated coexpression modules were enriched in genes that are broadly expressed in the brain and many other tissues. These coexpression modules were also enriched in ASD-associated, prenatal, human-specific, and language-relevant genes. This work highlights distinctive neurobiology in ASD subtypes with different early language outcomes that is present well before such outcomes are known. Associations between neuroimaging measures and gene expression levels in blood leukocytes may offer a unique in vivo window into identifying brain-relevant molecular mechanisms in ASD
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