766 research outputs found

    Attitudes toward the handicapped

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    Thesis (M.S.)--Boston Universit

    Cardiovascular disease in free living wild animals with particular reference to the African elephant (Loxodonta africana)

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    A field survey to investigate the ecology of cardio-vascular disease in free living wild animals is described. Its aim was i) to assess the susceptibility of such animals to arteriosclerosis. and particularly to athero-sclerosis ii) to examine in greater detail the ecology of oardiovascular disease in a single, naturally-susceptible species in relation to dietary change and stress in naturally occurring situations. A total of 201 specimens, representing species of mammals and 25 of birds, was examined: 37 species of mammals had uncomplicated lipid deposits in the arterial intima, thought to represent a normal physiological occurrence; 13 had atheroma-like lesions of the intima; 20 species of birds shoved positive lipidosis. These findings. compared with those reported in taxonomioally equivalent groups of captive animals, are discussed. The African elephant was selected for special study. The eoology of its cardiovascular disease patterns was studied in three different habitat types: one natural (the 'control'). and two degenerate ('stressed'). Athero-sclerosis and medial sclerosis were found not to occur in the 'natural' habitat type, but to be directly correlated with habitat degeneration in the other two 'stressed ranges, where 'stress' factors included excessive exposure to sunlight, dietary changes, frustration of the migrator/ habit, disrupted calving patterns9 and over-population neither disease was found to be directly related to age, and each had a distinct intra-arterial development patterns the aetiology of each is therefore thought to be basically independent, although in advanced cases interaction may occur. Incidental results of the survey includes i) observations on the importance of relating the functional anatomy of the arterial supportive thickenings at ostia, bifurcation and regions of mechanical strain to the normal intra-aortic distribution of uncomplicated intimal lipid deposits; ii) observations on a valve-like structure in the aorta of the klipspringer; and iii) the formulation of a new field technique for assessing relative age in the African elephant.<p

    Get Off My Porch: \u3ci\u3eUnited States v. Carloss\u3c/i\u3e and the Escalating Dangers of “Knock and Talks”

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    Balancing the Initiation and Molecular Recognition Capabilities of Eosin Macroinitiators of Polymerization-Based Signal Amplification Reactions

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    Coupling polymerization initiators to molecular recognition events provide the ability to amplify these events and detect them using the formation of a cross-linked polymer as an inexpensive readout that is visible to the unaided eye. The eosin-tertiary amine co-initiation system, activated by visible light, has proven utility in this context when an average of three eosin molecules are coupled to a protein detection reagent. The present work addresses the question of how detection sensitivity is impacted when the number of eosin molecules per binding event increases in the range of two to fifteen. Unlike in other initiation systems, a non-monotonic relationship is observed between the number of initiators per binding event and the observed detection sensitivity.Burroughs Wellcome Fund (Career Award at the Scientific Interface)Massachusetts Institute of Technology. James H. Ferry Fund for Innovation in Research Educatio

    Reductive C−C Coupling from α,β‐Unsaturated Nitriles by Intercepting Keteniminates

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    We present an atom‐economic strategy to catalytically generate and intercept nitrile anion equivalents using hydrogen transfer catalysis. Addition of α,β‐unsaturated nitriles to a pincer‐based Ru−H complex affords structurally characterized κ‐N‐coordinated keteniminates by selective 1,4‐hydride transfer. When generated in situ under catalytic hydrogenation conditions, electrophilic addition to the keteniminate was achieved using anhydrides to provide α‐cyanoacetates in high yields. This work represents a new application of hydrogen transfer catalysis using α,β‐unsaturated nitriles for reductive C−C coupling reactions.Eine atomökonomische Strategie zur katalytischen Erzeugung und Verwendung von Nitrilanion‐Äquivalenten basiert auf Wasserstofftransferkatalyse. Die Addition von α,β‐ungesättigten Nitrilen an einen Ru‐H‐Pinzettenkomplex generiert durch selektiven 1,4‐Hydridtransfer Keteniminate, die in einer hydrierenden Acylierung eingesetzt wurden.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149558/1/ange201904530_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149558/2/ange201904530-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149558/3/ange201904530.pd

    ヒト前立腺癌の進行モデルと新しい治療法

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    著者等はヒト前立腺癌の進展に関した2つの細胞モデルを開発した.LNCaP前立腺癌進展モデルは, 生体内での前立腺又は骨の間質細胞とLNCaP細胞との相互作用に基づいており, これによって腫瘍形成能と転移能を獲得したものである.派生株C4-2は去勢動物で容易に発育し, リンパ節, 精嚢腺, 骨に転移する.次のモデルARCaPは, 癌性腹水由来のヒト前立腺癌細胞で, アンドロゲン及びエストロゲンによって増殖を抑制され, 去勢下で腫瘍を形成した.ARCaPはアンドロゲン受容体及びPSAを低レベルで発現し, 同所移植によって肝, 腎, 骨等に高頻度で転移した.これらのモデルを用いて遺伝子治療の研究を行ったOur laboratory has developed two cellular models of human prostate cancer progression. The LNCaP prostate cancer progression model is based upon the well-known cellular interaction between human prostate or bone stromal cells and LNCaP cells in vivo. The marginally tumorigenic LNCaP cells acquired tumorigenic and metastatic potential upon cellular interaction with either prostate or bone fibroblasts. A subline termed C4-2 was observed to grow readily in castrated animals and acquired metastatic potential spreading from the primary tumor site to the lymph node, the seminal vesicles, and the axial skeleton, resulting in an intense osteoblastic reaction. The second model is ARCaP, where prostate cancer cells derived from the ascites fluid of a man with metastatic disease exhibited an Androgen- and estrogen-Repressed Prostate Cancer cell growth and tumor formation in either a hormone-deficient or a castrated environment. However, the growth of either the tumor cells in vitro or the tumors in vivo was suppressed by both estrogen and androgen. While the tumor cells expressed low levels of androgen receptor and prostate-specific antigen (PSA), they were highly metastatic when inoculated orthotopically. Distant metastases to a number of organs were detected, including the liver, lung, kidney, and bone. We have employed a human prostate cancer progression model as a system to study the efficacy of gene therapy. Results of the study show that whereas universal promoters, such as Cytomegalovirus (CMV) and Rous Sarcoma Virus (RSV) promoter-driven tumor suppressors (e.g. p53, p21, and p16), were effective in inhibiting prostate tumor growth, the advantages of driving the expression of therapeutic toxic genes using a tissue-specific promoter prostate-specific antigen (PSA) and a tumor--but not tissue-specific promoter, osteocalcin (OC), are preferred. In the case of the PSA promoter, we can achieve cell-kill in PSA-producing human prostate cancer cells. To circumvent the supporting role of bone stroma for prostate cancer epithelial growth, we have recently developed a novel concept where the expression of therapeutic toxic genes is driven by a tumor--but not a tissue-specific OC promoter. Osteocalcin-thymidine kinase (OC-TK) was found to efficiently eradicate the growth of osteosarcoma, prostate, and brain tumors both in vitro and in vivo. We observed that androgen-independent human prostate cancer cells lines expressed OC-TK at higher levels than androgen-dependent human prostate cancer cell lines. We have obtained data to suggest that Ad-OC-TK plus a pro-drug acyclovir (ACV) may be used as an effective therapy to treat prostate cancer bone metastasis in models where the growth of androgen-independent PC-3 and C4-2 tumors in the bone has occurred

    Temperature dependent transport in suspended graphene

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    The resistivity of ultra-clean suspended graphene is strongly temperature dependent for 5K<T<240K. At T~5K transport is near-ballistic in a device of ~2um dimension and a mobility ~170,000 cm^2/Vs. At large carrier density, n>0.5*10^11 cm^-2, the resistivity increases with increasing T and is linear above 50K, suggesting carrier scattering from acoustic phonons. At T=240K the mobility is ~120,000 cm^2/Vs, higher than in any known semiconductor. At the charge neutral point we observe a non-universal conductivity that decreases with decreasing T, consistent with a density inhomogeneity <10^8 cm^-2

    Comparison of Methods for Purification of DNA From Rice

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    Three techniques were employed to purify genomic DNA from deomstic rice (Oryza sativa L). Following extraction, the DNA was electrophoresed through agarose to determine its integrity. We determined that spooling yielded better quality, through lower quantity DNA than either of the other two techniques
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