Chromosome Complements in Desmanthus (Leguminosae)

Desmanthus, a genus of the subfamily Mimosoideae of the Leguminosae, is represented in the United States by ten species, one of which has two varieties. Nine species are found in Texas (Turner, 1950b). The genus has its greatest concentration in Mexico where sixteen species occur (Turner, 1950a). In the present paper chromosome studies on Desmanthus acuminatus, D. brevipes, D. leptolobus, D. velutinus and D. virgatus var. depressus are reported. These five species occur in Texas

Parametric Representation of Part Contours in SLS Process

Current layer-based SFF technologies process faceted geometric input data to produce polygonal contours of the part's boundary in each layer. However, for improved part quality, other more accurate representations of part contours are desirable. Likewise, implementation of Wu's minimum time optimal laser tracking control method for selective laser sintering (SLS) requires contour curves that exhibit higher order continuity. In this paper, we first analyze the requirements of optimal laser tracking to develop evaluation criteria for choosing a contour representation. Several possible representation methods are reviewed. We show that the NonUniform Rational B-Spline (NURBS) curve meets the criteria. A demonstration program illustrates the advantages of NURBS curves for representing contours with uniform point distributions. The results can be used in other control areas where uniform point distribution or constant velocity is required.Mechanical Engineerin

Functionally Gradient Material Design and Modeling Using Hypertexture for Solid Freeform Fabrication

SFF technologies have the potential to become manufacturing process that are capable of producing parts that have not been feasible by other techniques. The fabrication of Functionally Gradient Material (FGM) is one of the possible candidate. It is critical.to provide three dimensional material gradient data in the solid model to fabricate FGM. The approach is to model spatially varying material density distribution on implicit solid geometry using a hypertexturing scheme and a procedural volumetric modeling. It is essentially an extension of procedural solid texture synthesis, which has been effectively used to model cloud, gas, and flow stream. It will save the amount of information storage especially when the gradient pattern is repeating. Geometric operation becomes convenient since the material data are linked to the geometry only by the reference surfaces.Mechanical Engineerin

Advances in Functional Testing with SFF Parts

Functional testing of SFF parts represents an exciting area of research in solid freeform fabrication. One approach to functional testing is to use similitude techniques to correlate the behavior of an SFF model and a product. Previous research at UT Austin has resulted in development of an empirical similitude technique to correlate the behavior of parts of dissimilar materials and geometry. Advances in the empirical similitude technique are presented in this paper. Sources of coupling between material and geometry characteristics that produce errors in the current empirical similitude technique are outlined. A modified approach that corrects for such errors is presented. Numerical examples are used to illustrate both the current and the advanced empirical similitude methods.Mechanical Engineerin

A Study of Functional Testing with SFF Parts

A study of functional testing with SFF parts is presented. The study includes the use of traditional similitude methods as well as advanced similitude methods for predicting product performance through prototype testing. Cantilever beams created from the selective laser sintering process are used to predict the static deflection of both aluminum and polycarbonate beams. The results of 20 experiments using various geometric, loading, and material configurations are presented. Results of the study suggest that a coupling between geometry and material properties exists in SLS parts. Possible sources for the coupling are discussed. An approach for establishing the functional relationship between material and geometry is outlined.Mechanical Engineerin

Beta2-adrenoceptor agonists for dysmenorrhoea

Background:Dysmenorrhoea is a common gynaecological complaint that can affect as many as 50% of premenopausal women, 10% of whom suffer severely enough to be rendered incapacitated for one to three days during each menstrual cycle. Primary dysmenorrhoea is where women suffer from menstrual pain but lack any pathology in their pelvic anatomy. Beta2-adrenoceptor agonists have been used in the treatment of women with primary dysmenorrhoea but their effects are unclear.Objectives:To determine the effectiveness and safety of beta2-adrenoceptor agonists in the treatment of primary dysmenorrhoea. Search methods: We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, CENTRAL (The Cochrane Library 2011, Issue 8), MEDLINE, EMBASE, PsycINFO and the EBM Reviews databases. The last search was on 22 August 2011.Selection criteriaRandomised controlled trials comparing beta2-adrenoceptor agonists with placebo or no treatment, each other or any other conventional treatment in women of reproductive age with primary dysmenorrhoea. Data collection and analysisTwo review authors independently assessed trial quality and extracted the data.Main results:Five trials involving 187 women with an age range of 15 to 40 years were included. Oral isoxsuprine was compared with placebo in two trials, terbutaline oral spray, ritodrine chloride and oral hydroxyphenyl-orciprenalin were compared with placebo in a further three trials. Clinical diversity in the studies in terms of the interventions being evaluated, assessments at different time points and the use of different assessment tools mitigated against pooling of outcome data across studies in order to provide a summary estimate of effect for any of the comparisons. Only one study, with unclear risk of bias, reported pain relief with a combination of isoxsuprine, acetaminophen and caffeine. None of the other studies reported any significant clinical difference in effectiveness between the intervention and placebo. Adverse effects were reported with all of these medications in up to a quarter of the total number of participants. They included nausea, vomiting, dizziness, quivering, tremor and palpitations.Authors\u27 conclusions:The evidence presented in this review was based on a few relatively small-sized studies that were categorised to have unclear to high risk of bias, which does not allow confident decision-making at present about the use of beta2-adrenoceptor agonists for dysmenorrhoea. The benefits as reported in one study should be balanced against the wide array of unacceptable side effects documented with this class of medication. We have emphasised the lack of precision and limitations in the reported data where appropriate

Outbreak of Sporotrichosis, Western Australia

A cluster of sporotrichosis cases occurred in the Busselton-Margaret River region of Western Australia from 2000 to 2003. Epidemiologic investigation and mycologic culture for Sporothrix schenckii implicated hay initially distributed through a commercial hay supplier as the source of the outbreak. Declining infection rates have occurred after various community measures were instigated

Direct Selective Laser Sintering of High Temperature Materials

Abstract Selective Laser Sintering (SLS) involving a coexisting liquid and particulate solid during the SLS processing can be used to produce freeform parts directly with high temperature materials. Factors such as scanning laser power density, residence time, scan line spacing, the interfacial energies between the liquid and solid phases, powder bed biasing temperature, and sintering atmosphere greatly affect the microstructure evolution in the SLS process. Direct SLS of high melting temperature mixed powder materials was demonstrated using a 1.1 kW C02 laser SLS system. The relationship between the microstructures and the process parameters will be described