A smart end-effector for assembly of space truss structures

A unique facility, the Automated Structures Research Laboratory, is being used to investigate robotic assembly of truss structures. A special-purpose end-effector is used to assemble structural elements into an eight meter diameter structure. To expand the capabilities of the facility to include construction of structures with curved surfaces from straight structural elements of different lengths, a new end-effector has been designed and fabricated. This end-effector contains an integrated microprocessor to monitor actuator operations through sensor feedback. This paper provides an overview of the automated assembly tasks required by this end-effector and a description of the new end-effector's hardware and control software

Composite isogrid structures for parabolic surfaces

The invention relates to high stiffness parabolic structures utilizing integral reinforced grids. The parabolic structures implement the use of isogrid structures which incorporate unique and efficient orthotropic patterns for efficient stiffness and structural stability

Dechlorinative Oligomerization of Multiply Chlorinated Methanes Catalyzed by Activated Carbon Supported Pt-Co

The hydrodechlorination of dichloromethane, trichloromethane, and their mixtures catalyzed by a Pt- Co/C catalyst has been investigated in an effort to elucidate the chemistry associated with the generation of hydrocarbon oligomerization products. In the reaction of dichloromethane with hydrogen, the catalyst did not exhibit deactivation and maintained the steady-state activity within 18 h on stream at 523 K; whereas, when trichloromethane was added or converted in the absence of dichloromethane, significant deactivation occurred within the first 5 h on stream. Hydrocarbon oligomerization products were observed with all three reaction mixtures; the selectivity followed the order dichloromethane + dihydrogen < trichloromethane + dihydrogen < dichloromethane + trichloromethane + dihydrogen. The generation of ethane and propane was virtually independent of the reaction mixture composition. However, selectivity toward ethylene and propylene was significantly greater with the trichloromethane + dihydrogen and dichloromethane + trichloromethane + dihydrogen mixtures compared to the dichloromethane + dihydrogen feed. It was concluded that the saturated hydrocarbon products are formed by means of the alkyl mechanism of hydrocarbon chain growth; whereas, the alkenyl mechanism is responsible for the formation of the unsaturated hydrocarbons.Изучено дегидрохлорирование дихлорметана, трихлорметана и их смесей в присутствии Pt-Co/C катализатора с целью выяснения механизма образования высших углеводородов. Установлено, что в реакции дихлорметана с водородом при 523 К катализатор не подвергается дезактивации и сохраняет постоянную активность в течение, по крайней мере, 18 ч, в то время как присутствие трихлорметана в реакционной смеси вызывает значительную дезактивацию катализатора в течение первых 5 ч работы. Углеводородные продукты наблюдались во всех реакционных смесях с селективностью дихлорметан + водород < трихлорметан + водород < дихлорметан + трихлорметан + водород. При этом селективность по этану и пропану не зависела от состава реакционной смеси. В то же время селективность по этилену и пропилену была существенно выше в случае дехлорирования трихлорметана и дехлорирования смеси дихлорметана и трихлорметана, чем в случае дехлорирования дихлорметана. На основании полученных результатов сделано заключение, что насыщенные углеводороды образуются в соответствии с так называемым алкильным механизмом роста цепи, в то время как непредельные углеводороды образуются по алкенильному механизму

The Multiproblem Neighborhood project

This is a brief report on a Multiproblem Neighborhood project in a moderate size metropolitan community. It presents the conceptual frame of reference of the project and some of the tangible organizational outgrowths of the research penetration into the complex community structures enclosing the neighborhood .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44314/1/10597_2005_Article_BF01434446.pd

Transfer RNA-derived small RNAs in the cancer transcriptome

The cellular lifetime includes stages such as differentiation, proliferation, division, senescence and apoptosis.These stages are driven by a strictly ordered process of transcription dynamics. Molecular disruption to RNA polymerase assembly, chromatin remodelling and transcription factor binding through to RNA editing, splicing, post-transcriptional regulation and ribosome scanning can result in significant costs arising from genome instability. Cancer development is one example of when such disruption takes place. RNA silencing is a term used to describe the effects of post-transcriptional gene silencing mediated by a diverse set of small RNA molecules. Small RNAs are crucial for regulating gene expression and microguarding genome integrity.RNA silencing studies predominantly focus on small RNAs such as microRNAs, short-interfering RNAs and piwi-interacting RNAs. We describe an emerging renewal of inter-est in a‘larger’small RNA, the transfer RNA (tRNA).Precisely generated tRNA-derived small RNAs, named tRNA halves (tiRNAs) and tRNA fragments (tRFs), have been reported to be abundant with dysregulation associated with cancer. Transfection of tiRNAs inhibits protein translation by displacing eukaryotic initiation factors from messenger RNA (mRNA) and inaugurating stress granule formation.Knockdown of an overexpressed tRF inhibits cancer cell proliferation. Recovery of lacking tRFs prevents cancer metastasis. The dual oncogenic and tumour-suppressive role is typical of functional small RNAs. We review recent reports on tiRNA and tRF discovery and biogenesis, identification and analysis from next-generation sequencing data and a mechanistic animal study to demonstrate their physiological role in cancer biology. We propose tRNA-derived small RNA-mediated RNA silencing is an innate defence mechanism to prevent oncogenic translation. We expect that cancer cells are percipient to their ablated control of transcription and attempt to prevent loss of genome control through RNA silencing

Cdkn2a (Arf) loss drives NF1-associated atypical neurofibroma and malignant transformation

Plexiform neurofibroma (PN) tumors are a hallmark manifestation of neurofibromatosis type 1 (NF1) that arise in the Schwann cell (SC) lineage. NF1 is a common heritable cancer predisposition syndrome caused by germline mutations in the NF1 tumor suppressor, which encodes a GTPase-activating protein called neurofibromin that negatively regulates Ras proteins. Whereas most PN are clinically indolent, a subset progress to atypical neurofibromatous neoplasms of uncertain biologic potential (ANNUBP) and/or to malignant peripheral nerve sheath tumors (MPNSTs). In small clinical series, loss of 9p21.3, which includes the CDKN2A locus, has been associated with the genesis of ANNUBP. Here we show that the Cdkn2a alternate reading frame (Arf) serves as a gatekeeper tumor suppressor in mice that prevents PN progression by inducing senescence-mediated growth arrest in aberrantly proliferating Nf1−/− SC. Conditional ablation of Nf1 and Arf in the neural crest-derived SC lineage allows escape from senescence, resulting in tumors that accurately phenocopy human ANNUBP and progress to MPNST with high penetrance. This animal model will serve as a platform to study the clonal development of ANNUBP and MPNST and to identify new therapies to treat existing tumors and to prevent disease progression

Restrictive ID policies: implications for health equity

We wish to thank Synod Community Services for their critical work to develop, support, and implement a local government-issued ID in Washtenaw County, MI. We also thank Yousef Rabhi of the Michigan House of Representatives and Janelle Fa'aola of the Washtenaw ID Task Force, Lawrence Kestenbaum of the Washtenaw County Clerk's Office, Sherriff Jerry Clayton of the Washtenaw County Sherriff's Office, and the Washtenaw ID Task Force for their tireless commitment to developing and supporting the successful implementation of the Washtenaw ID. Additionally, we thank Vicenta Vargas and Skye Hillier for their contributions to the Washtenaw ID evaluation. We thank the Curtis Center for Research and Evaluation at the University of Michigan School of Social Work, the National Center for Institutional Diversity at the University of Michigan, and the University of California-Irvine Department of Chicano/Latino Studies and Program in Public Health for their support of the Washtenaw ID community-academic research partnership. Finally, we thank the reviewers for their helpful comments on earlier drafts of this manuscript. (Curtis Center for Research and Evaluation at the University of Michigan School of Social Work; National Center for Institutional Diversity at the University of Michigan; University of California-Irvine Department of Chicano/Latino Studies; Program in Public Health)https://link.springer.com/content/pdf/10.1007/s10903-017-0579-3.pdfPublished versio