3,219 research outputs found

    Report of the panel on volcanology, section 4

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    Two primary goals are identified as focal to NASA's research efforts in volcanology during the 1990s: to understand the eruption of lavas, gases, and aerosols from volcanoes, the dispersal of these materials on the Earth's surface and through the atmosphere, and the effects of these eruptions on the climate and environment; and to understand the physical processes that lead to the initiation of volcanic activity, that influence the styles of volcanic eruptions, and that dictate the morphology and evolution of volcanic landforms. Strategy and data requirements as well as research efforts are discussed

    The emergence of <i>Pax7</i>-expressing muscle stem cells during vertebrate head muscle development

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    Pax7 expressing muscle stem cells accompany all skeletal muscles in the body and in healthy individuals, efficiently repair muscle after injury. Currently, the in vitro manipulation and culture of these cells is still in its infancy, yet muscle stem cells may be the most promising route towards the therapy of muscle diseases such as muscular dystrophies.It is often overlooked that muscular dystrophies affect head and body skeletal muscle differently. Moreover, these muscles develop differently. Specifically, head muscle and its stem cells develop from the non-somitic head mesoderm which also has cardiac competence. To which extent head muscle stem cells retain properties of the early head mesoderm and might even be able to switch between a skeletal muscle and cardiac fate is not known. This is due to the fact that the timing and mechanisms underlying head muscle stem cell development are still obscure. Consequently, it is not clear at which time point one should compare the properties of head mesodermal cells and head muscle stem cells.To shed light on this, we traced the emergence of head muscle stem cells in the key vertebrate models for myogenesis, chicken, mouse, frog and zebrafish, using Pax7 as key marker. Our study reveals a common theme of head muscle stem cell development that is quite different from the trunk. Unlike trunk muscle stem cells, head muscle stem cells do not have a previous history of Pax7 expression, instead Pax7 expression emerges de-novo. The cells develop late, and well after the head mesoderm has committed to myogenesis. We propose that this unique mechanism of muscle stem cell development is a legacy of the evolutionary history of the chordate head mesoderm

    Classroom Societies and Common Markets: The Gem Fair

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    In-class societies such as the Mini-Society an

    Activation of a Translocated Human c-\u3ci\u3emyc\u3c/i\u3e Gene by an Enhancer in the Immunoglobulin Heavy-Chain Locus

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    A tissue-specific transcriptional enhancer element that is associated with the human immunoglobulin heavy-chain locus is defined. In a non-Hodgkin’s lymphoma that contains a translocated c-myc gene this enhancer is retained on the 14q+ chromosome and occurs within sequences shown to activate previously cryptic promoters of the c-myc gene

    Effects of consumer demand, product lifetime, and substitution ratio on perishable inventory management

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    With the intensification of global population, food security is a big concern. Food waste stems from inappropriate inventory management. Companies offer a wide range of products to capture more sales, yet this increases inventories and complicates inventory management. Management challenges are worsened by three factors: uncertain consumer demand, product lifetimes, and consumer substitution among the product range. This research aims to understand the effects of these factors on inventory performance. The analytic hierarchy process (AHP) method was used to weight the importance of each of the non-financial performance measures from the simulation results and data envelopment analysis (DEA) was used to rank and evaluate the scenarios. Then, the most favorable scenario or replenishment policy, which had the lowest DEA efficiency score, was chosen. The results show that when the substitution ratio is greater, its interaction with consumer demand and product lifetime has mostly a small- or medium-sized effect on retailers’ performance, in contrast to relatively larger effects on the supplier. These findings show that suppliers’ performance is affected largely by the existence of the bullwhip effect in the model. Recommendations are provided for managers who are facing uncertainties of consumer demand, substitution, and product lifetime

    Morally Respectful Listening and its Epistemic Consequences

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    What does it mean to listen to someone respectfully, that is, insofar as they are due recognition respect? This paper addresses that question and gives the following answer: it is to listen in such a way that you are open to being surprised. A specific interpretation of this openness to surprise is then defended

    Bisantrene (NSC 337766) (CL 216,942) in advanced breast cancer

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    Bisantrene (NSC 337766) is an anthracenedicarboxaldehyde hydrazone demonstrating a wide spectrum of activity in animal tumor model systems with no evidence of cardiotoxicity or alopecia, in contrast to doxorubicin. Thirty-three women with advanced adenocarcinoma of the breast were treated with 260 mg/m 2 IV every 3 weeks. All patients had received at least one prior combination chemotherapy regimen for metastatic disease and 32/33 were refractory to doxorubicin. Of 28 patients evaluable for response one had a partial response lasting 10 weeks and three patients had stable disease for 22, 22, and 9 weeks. The most significant toxicities were nonhematologic: nausea and vomiting (41%), phlebitic reactions (38%), hypotension, one fatal anaphylactic reaction, and the development of a 7th cranial nerve palsy during drug infusion. Hematologic toxicity, leukopenia, was dose-limiting but manageable without associated infections or bleeding. These results indicate that bisantrene in this dose and schedule is not a useful drug in heavily pretreated breast cancer patients. The incidence and severity of phlebitic reactions limited venous access and adversely affected patient compliance. Preliminary results of other phase II breast cancer trials indicate a similar spectrum of toxicity but suggest more significant antitumor activity even in patients previously treated with doxorubicin. Trials conducted in patients with minimal prior treatment and with bisantrene administered via central line appear warranted for definitive assessment of the activity of this agent in breast cancer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46914/1/280_2004_Article_BF00269035.pd
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