Mixtures of Spatial Spline Regressions

We present an extension of the functional data analysis framework for univariate functions to the analysis of surfaces: functions of two variables. The spatial spline regression (SSR) approach developed can be used to model surfaces that are sampled over a rectangular domain. Furthermore, combining SSR with linear mixed effects models (LMM) allows for the analysis of populations of surfaces, and combining the joint SSR-LMM method with finite mixture models allows for the analysis of populations of surfaces with sub-family structures. Through the mixtures of spatial splines regressions (MSSR) approach developed, we present methodologies for clustering surfaces into sub-families, and for performing surface-based discriminant analysis. The effectiveness of our methodologies, as well as the modeling capabilities of the SSR model are assessed through an application to handwritten character recognition

Resistance to Fracture of Two All-Ceramic Crown Materials Following Endodontic Access

Statement of problem There is currently no protocol for managing endodontic access openings for all-ceramic crowns. A direct restorative material is generally used to repair the access opening, rendering a repaired crown as the definitive restoration. This endodontic procedure, however, may weaken the restoration or initiate microcracks that may propagate, resulting in premature failure of the restoration. Purpose The purpose of this in vitro study was to evaluate how an endodontic access opening prepared through an all-ceramic crown altered the structural integrity of the ceramic, and the effect of a repair of this access on the load to failure of an all-ceramic crown. Material and methods Twenty-four alumina (Procera) and 24 zirconia (Procera) crowns were fabricated and cemented (Rely X Luting Plus Cement) onto duplicate epoxy resin dies. Twelve crowns of each were accessed to simulate root canal treatment therapy. Surface defects of all accessed specimens were evaluated with an environmental scanning electron microscope. The specimens were repaired with a porcelain repair system (standard adhesive resin/composite resin protocol) and were loaded to failure in a universal testing machine. Observations made visually and microscopically noted veneer delamination from the core, core fracture, shear within the veneer porcelain, or a combination thereof. A Kruskal-Wallis test was used to determine if a significant difference (α=.05) in load to failure existed between the 4 groups, and a Mann-Whitney test with a Bonferroni correction (P Results All specimens exhibited edge chipping around the access openings. Some displayed larger chips within the veneering porcelain, and 4 zirconia crowns showed radial crack formation. There was a significant difference in load to failure among all groups with the exception of the alumina intact and repaired specimens (P=.695). The alumina crowns generally showed fracture of the coping with the veneering porcelain still bonded to the core, whereas the zirconia copings tended not to fracture but experienced veneering porcelain delamination. Conclusion Endodontic access through all-ceramic crowns resulted in a significant loss of strength in the zirconia specimens but not in the alumina specimens

Cyclin D(1) expression during rat mammary tumor development and its potential role in the resistance of the Copenhagen rat

BACKGROUND: Resistance to mammary tumorigenesis in Copenhagen rats is associated with loss of early preneoplastic lesions known as intraductal proliferations. The cause of this disappearance, however, is unknown. RESULTS: There were no differences in the numbers of lesions in mammary whole-mounts prepared from Copenhagen or Wistar-Furth rats at 20 or 30 days after N-methyl-N-nitrosourea treatment, but at 37 days there were significantly fewer lesions in Copenhagen glands. Furthermore, lesions in Copenhagen glands were exclusively intraductal proliferations, whereas in Wistar-Furth glands more advanced lesions were also present. Immunohistochemical staining showed frequent cyclin D(1) overexpression in Wistar-Furth lesions at 37 days, but not in Copenhagen lesions. There were, however, no differences in p16(INK4a) protein expression, bromodeoxyuridine labeling and apoptotic indices, or mast cell infiltration between Copenhagen and Wistar-Furth lesions at any time. CONCLUSIONS: Overexpression of cyclin D(1) in preneoplastic lesions may be important in the development of mammary tumors in susceptible rats, although this overexpression does not appear to cause significant changes in cell kinetics. Furthermore, the low levels of cyclin D(1) expression in Copenhagen intraductal proliferations may play a role in the resistance of these rats to mammary tumorigenesis

A Spectral Classification System for Hydrogen-deficient Carbon Stars

Stellar spectral classification, and especially the Yerkes system, has been highly useful in the study of stars. While there is a currently accepted classification system for carbon stars, the subset of Hydrogen-deficient Carbon (HdC) stars has not been well described by such a system, due in part to their rarity and their variability. Here we present a new system for the classification of HdCs based on their spectra, which is made wholly on their observable appearance. We use a combination of dimensionality reduction and clustering algorithms with human classification to create such a system. We classify over half of the known sample of HdC stars using this, and roughly calibrate the temperatures of each class using their colors. Additionally, we express trends in the occurrence of certain spectral peculiarities such as the presence of Hydrogen and Lithium lines. We also present three previously unpublished spectra, and report the discovery of three new Galactic dustless HdC (dLHdC) stars and additionally discuss one especially unique star that appears to border between the hottest HdCs and the coolest Extreme Helium (EHe) stars.Comment: 30 pages, 18 figures, submitted to MNRA

International Journal of Human Resource Management (IJHRM) Special Issue on:International human resource management in contexts of high uncertainties

The aim of this special issue is to examine more closely of the implementations of international human resource management (IHRM) practices in the contexts of high uncertainties. It seeks contexts of relevance, encompassing those experiencing financial crisis, economic sanctions, political and civil uncertainty, environmental collapse and/or deep recession. It aims to supplement the Danger and Risk as Challenges for HRM in the IJHRM special issue which encompasses terrorism, violent disorder, crime and other physical risks, by focusing on initially seemingly peaceful forms of uncertainty, even if their consequences might lead to societal collapse. While appreciating that these contexts are very different, the key theme that cuts across all of these contexts are the unexpected changes that they brought, creating considerable ambiguity for businesses, and how they manage their people. Businesses will face the challenges of coping in such contexts, with unpredictability in demand, and in supplier relations, in adding greater time pressure to the decision-making process, and in terms of work and employment relations (Pearson & Clair, 1998). Through operating in different settings, multinational enterprises (MNEs) may be able to hedge risk, but at the same time protecting their own interest from a distance can be extremely difficult (Cantwell, Dunning, & Lundan, 2010). They will also impact on MNE decisions to invest and reinvest in particular settings (Oh & Oetzel, 2011). However, reducing or eliminating their presence in the host location is not always possible. MNEs may have substantial resources and infrastructural interests in the host location that need to be protected. Again, there is often a pressing need of MNEs to use expatriates on international assignments to complete strategically critical tasks, but the same time managing expatriate staff becomes much more difficult when countries of domicile become less certain. However, these situations often present golden opportunity for businesses. Studies have found that the option value of MNEs in entering a country under the uncertain conditions can be high (Miller, 1998). This is because government and international bodies often inject considerable amount of investments into the affected countries in aiding the recovery and rebuilding process and, in turn, pumped up the local aggregate demands, opening new opportunities for MNEs in relevant industries (Vigdor, 2008). At the same time, consumers’ demand for products and services may change; demand may not necessarily decline, but what consumers may want may be different, and this will impact on the demands placed on a firm’s human resources. These MNEs may therefore experience expansion of workforce under these situations.Full Tex

Resource Cursed Economies and HR Practices

This chapter explores HR practices in resource-cursed economies, with a particular focus on the context of Brunei. The literature available on the resource curse implies that organisations in non-oil and -gas sectors across petro-states experience a number of key obstacles to achieving competitiveness and becoming self-sustaining. This chapter investigates the link between particular HR policies and practices and business performance; emphasis is placed on examining and drawing contrasts between oil and gas and non-oil and -gas sectors, whilst further seeking to highlight the comparative lessons aimed at garnering insight into the possible and performance-related results associated with HR interventions in resource-focused national economies

Suppressive impact of metronomic chemotherapy using UFT and/or cyclophosphamide on mediators of breast cancer dissemination and invasion

Producción CientíficaMetronomic chemotherapy using the 5-FU prodrug uracil-tegafur (UFT) and cyclophosphamide (CTX) was previously shown to only modestly delay primary tumor growth, but nevertheless markedly suppressed the development of micro-metastasis in an orthotopic breast cancer xenograft model, using the metastatic variant of the MDA-MB-231 cell line, 231/LM2-4. Furthermore, a remarkable prolongation of survival, with no toxicity, was observed in a model of postsurgical advanced metastatic disease. A question that has remained unanswered is the seemingly selective anti-metastatic mechanisms of action responsible for this treatment. We assessed the in vivo effect of metronomic UFT, CTX or their combination, on vascular density, collagen deposition and c-Met (cell mediators or modulators of tumor cell invasion or dissemination) via histochemistry/immunohistochemistry of primary tumor sections. We also assessed the effect of continuous exposure to low and non-toxic doses of active drug metabolites 5-fluorouracil (5-FU), 4-hydroperoxycyclophosphamide (4-HC) or their combination, on 231/LM2-4 cell invasiveness in vitro. In the in vivo studies, a significant reduction in vascular density and p-Met[Y1003] levels was associated with UFT+CTX treatment. All treatments reduced intratumoral collagen deposition. In the in vitro studies, a significant reduction of collagen IV invasion by all treatments was observed. The 3D structures formed by 231/LM2-4 on Matrigel showed a predominantly Mass phenotype under treated conditions and Stellate phenotype in untreated cultures. Taken together, the results suggest the low-dose metronomic chemotherapy regimens tested can suppress several mediators of tumor invasiveness highlighting a new perspective for the anti-metastatic efficacy of metronomic chemotherapy.Canadian Institutes of Health Research (grant 364411

Human resource management in multinational and domestic enterprises: A comparative institutional analysis in Southeast Asia

This paper looks at the relative impact of context on the role of senior managers. It compares HR Directors of Domestic Enterprises (DEs) against those of multinational enterprises (MNEs), within an emerging market setting, based on a survey of HR Directors in Brunei. We found that that, with the exception of some aspects of selection and recruitment, HR Directors of MNEs accorded a higher priority to strategic tasks, yet were more reluctant to delegate. This study confirms the importance of MNEs in pioneering more modern and integrated approaches to people management, but also limitations to the extent to which they might act as evangelists of new practices that are adopted by their local peers. In contrast, local firms were more likely to concentrate their attention on administrative, rather than strategic, issues. We draw out the implications of our findings for theory and practice