1,221 research outputs found

    The Inheritance of Some Human Traits

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    Although the proper collection and observation of necessary data with reference to the application of Mendel\u27s laws of heredity to man has been brief, it has disclosed evidence significant enough to make it appear highly probable that many of the characters in man follow these laws as well as do the traits of lower animals. The object of this thesis was to determine whether or not certain human traits were inherited, the mode of their transmission from parent to offspring, and, if possible, the establishment of any proof of linkage in the human line

    Optimising the life cycle energy performance of residential buildings

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    A holistic approach to low-energy building design is essential to ensure that any efficiency improvement strategies provide a net energy benefit over the life of the building. Previous work by the authors has established a model for informing low-energy building design based on a comparison of the life cycle energy demand associated with a broad range of building assemblies. This model ranks assemblies based on their combined initial and recurrent embodied energy and operational energy demand. The current study applies this model to an actual residential building in order to demonstrate the application of the model for optimising a building’s life cycle energy performance. The aim of this study was to demonstrate how the availability of comparable energy performance information at the building design stage can be used to better optimise a building’s energy performance. The life cycle energy demand of the case study building, located in the temperate climate of Melbourne, Australia, was quantified using a comprehensive embodied energy assessment technique and TRNSYS thermal energy simulation software. The building was then modelled with variations to its external assemblies in an attempt to optimise its life cycle energy performance. The alternative assemblies chosen were those shown through the author’s previous modelling to result in the lowest life cycle energy demand for each building element. The best performing assemblies for each of the main external building elements were then combined into a best-case scenario to quantify the potential life cycle energy savings possible compared to the original building. The study showed that significant life cycle energy savings are possible through the modelling of individual building elements for the case study building. While these findings relate to a very specific case, this study demonstrates the application of a model for optimising building life cycle energy performance that may be applied more broadly during early-stage building design to optimise life cycle energy performance

    Validation of the use of Australian input-output data for building embodied energy simulation

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    Traditional!y, the simulation of buildings has focused 011 operational energy consumption in an attempt to determine the potential for energy savings. Whilst operational energy of Australian buildings accounts for around 20% of total energy consumption nationally, embodied energy represents 20 to 50 times the annual operational energy of 1110st Australian buildings. Lower values have been shown through a number of studies that have analysed the embodied energy of buildings and their products, however these have now shown to be incomplete in system boundary. Many of these studies have used traditional embodied energy analysis methods, such as process analysis and input-output analysis, Hybrid embodied energy analysis methods have been developed, but these need to be compared and validated. This paper reports on preliminary work on this topic. The findings so far suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependant upon data quality and availability.<br /

    Demographic structure of a transplanted Tlaxcalan population in the Valley of Mexico

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    This is the published version, also available here: http://www.jstor.org/stable/41462806.This research explores the evolutionary consequences of the transplantation and subsequent demographic adaptation of Cuanalan, a migrant population in the Valley of Mexico. Through comparisons with historical and contemporary populations from the area of origination—the state of Tlaxcala—an attempt is made to reconstruct the demographic and evolutionary changes which have occurred in the splinter population over the past four centuries. Both demographic and preliminary genetic data indicate that Cuanalan is a hybridized population. About two-thirds of marriages of Cuanalan-born individuals are endogamous. Average number of liveborn children for prolific women over 40 is 6.5. Since 1866, mean age at death in the community is 20.8 years, and the infant death rate is 30%. Major causes of death are respiratory diseases, gastrointestinal disorders, and childhood infections. The high variance in completed fertility and high pre-reproductive mortality indicate a continuation of conditions making for the rapid action of natural selection which have historically characterized Tlaxcalan populations. Genetic drift was probably an important factor in the early differentiation of the migrant population. The data suggest that the evolutionary divergence of Cuanalan from the Tlaxcalan gene pool has been rapid and extensive

    A comprehensive framework for assessing the life-cycle energy of building construction assemblies

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    Building environmental design typically focuses on improvements to operational efficiencies such as building thermal performance and system efficiency. Often the impacts occurring across the other stages of a building\u27s life are not considered or are seen as insignificant in comparison. However, previous research shows that embodied impacts can be just as important. There is limited consistent and comprehensive information available for building designers to make informed decisions in this area. Often the information that is available is from disparate sources, which makes comparison of alternative solutions unreliable. It is also important to ensure that strategies to reduce environmental impacts from one life cycle stage do not come at the expense of an increase in overall life-cycle impacts. A consistent and comprehensive framework for assessing and specifying building assemblies for enhanced environmental outcomes does not currently exist. This article presents the initial findings of a project that aims to establish a database of life cycle energy requirements for a broad range of construction assemblies, based on a comprehensive assessment framework. Life cycle energy requirements have been calculated for eight residential construction assemblies integrating an innovative embodied energy assessment technique with thermal performance modelling and ranked according to their performance. &copy; #2010 Earthscan ISSN: 0003-8628

    Heterogeneous Chemistry Involving Methanol in Tropospheric Clouds

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    In this report we analyze airborne measurements to suggest that methanol in biomass burning smoke is lost heterogeneously in clouds. When a smoke plume intersected a cumulus cloud during the SAFARI 2000 field project, the observed methanol gas phase concentration rapidly declined. Current understanding of gas and aqueous phase chemistry cannot explain the loss of methanol documented by these measurements. Two plausible heterogeneous reactions are proposed to explain the observed simultaneous loss and production of methanol and formaldehyde, respectively. If the rapid heterogeneous processing of methanol, seen in a cloud impacted by smoke, occurs in more pristine clouds, it could affect the oxidizing capacity of the troposphere on a global scale

    A Transgenic Rat for Investigating the Anatomy and Function of Corticotrophin Releasing Factor Circuits.

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    Corticotrophin-releasing factor (CRF) is a 41 amino acid neuropeptide that coordinates adaptive responses to stress. CRF projections from neurons in the central nucleus of the amygdala (CeA) to the brainstem are of particular interest for their role in motivated behavior. To directly examine the anatomy and function of CRF neurons, we generated a BAC transgenic Crh-Cre rat in which bacterial Cre recombinase is expressed from the Crh promoter. Using Cre-dependent reporters, we found that Cre expressing neurons in these rats are immunoreactive for CRF and are clustered in the lateral CeA (CeL) and the oval nucleus of the BNST. We detected major projections from CeA CRF neurons to parabrachial nuclei and the locus coeruleus, dorsal and ventral BNST, and more minor projections to lateral portions of the substantia nigra, ventral tegmental area, and lateral hypothalamus. Optogenetic stimulation of CeA CRF neurons evoked GABA-ergic responses in 11% of non-CRF neurons in the medial CeA (CeM) and 44% of non-CRF neurons in the CeL. Chemogenetic stimulation of CeA CRF neurons induced Fos in a similar proportion of non-CRF CeM neurons but a smaller proportion of non-CRF CeL neurons. The CRF1 receptor antagonist R121919 reduced this Fos induction by two-thirds in these regions. These results indicate that CeL CRF neurons provide both local inhibitory GABA and excitatory CRF signals to other CeA neurons, and demonstrate the value of the Crh-Cre rat as a tool for studying circuit function and physiology of CRF neurons

    Reducing in-stent restenosis therapeutic manipulation of miRNA in vascular remodeling and inflammation

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    Background: Drug-eluting stents reduce the incidence of in-stent restenosis, but they result in delayed arterial healing and are associated with a chronic inflammatory response and hypersensitivity reactions. Identifying novel interventions to enhance wound healing and reduce the inflammatory response may improve long-term clinical outcomes. Micro–ribonucleic acids (miRNAs) are noncoding small ribonucleic acids that play a prominent role in the initiation and resolution of inflammation after vascular injury.&lt;p&gt;&lt;/p&gt; Objectives: This study sought to identify miRNA regulation and function after implantation of bare-metal and drug-eluting stents.&lt;p&gt;&lt;/p&gt; Methods: Pig, mouse, and in vitro models were used to investigate the role of miRNA in in-stent restenosis.&lt;p&gt;&lt;/p&gt; Results: We documented a subset of inflammatory miRNAs activated after stenting in pigs, including the miR-21 stem loop miRNAs. Genetic ablation of the miR-21 stem loop attenuated neointimal formation in mice post-stenting. This occurred via enhanced levels of anti-inflammatory M2 macrophages coupled with an impaired sensitivity of smooth muscle cells to respond to vascular activation.&lt;p&gt;&lt;/p&gt; Conclusions: MiR-21 plays a prominent role in promoting vascular inflammation and remodeling after stent injury. MiRNA-mediated modulation of the inflammatory response post-stenting may have therapeutic potential to accelerate wound healing and enhance the clinical efficacy of stenting
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