The Timing Properties of Sco X-1 along its Z track as seen with EXOSAT

We present a systematic, homogeneous analysis of all the EXOSAT ME, high time resolution data on Sco X-1. We investigate all power spectral properties of the $<$100 Hz quasi-periodic oscillations (QPO) and noise of Sco X-1 as a function of position on the Z-shaped track traced out in the X-ray colour-colour diagram. Generally, the properties of Sco X-1 vary smoothly as a function of position along the Z track. However, some variability parameters change abruptly at either of the vertices of the Z track indicating that the branches of the Z track represent distinct source states not only in spectral state but also in rapid variability characteristics. We show that the very low frequency noise (VLFN) is consistent with being solely due to motion along the Z track. The QPO show a remarkably rapid change in frequency at or just before the normal-branch/flaring-branch (NB/FB) vertex. This transition happens within 1.5% of the entire extent of the Z track. The QPO themselves are visible for 17% of the Z. We find a new sort of behaviour near the NB/FB vertex, i.e., rapid excursions from the NB into the FB and back again taking only a few minutes.Comment: 30 pages, 15 figures, MNRAS in pres

Occurrence of LINE, gypsy-like, and copia-like retrotransposons in the clonally propagated sweet potato (Ipomoea batatas L.)

Retrotransposons are a class of transposable elements that represent a major fraction of the repetitive DNA of most eukaryotes. Their abundance stems from their expansive replication strategies. We screened and isolated sequence fragments of long terminal repeat (LTR), gypsy-like reverse transcriptase (rt) and gypsy-like envelope (env) domains, and two partial sequences of non-LTR retrotransposons, long interspersed element (LINE), in the clonally propagated allohexaploid sweet potato (Ipomoea batatas (L.) Lam.) genome. Using dot-blot hybridization, these elements were found to be present in the ~1597 Mb haploid sweet potato genome with copy numbers ranging from ~50 to ~4100 as observed in the partial LTR (IbLtr-1) and LINE (IbLi-1) sequences, respectively. The continuous clonal propagation of sweet potato may have contributed to such a multitude of copies of some of these genomic elements. Interestingly, the isolated gypsy-like env and gypsy-like rt sequence fragments, IbGy-1 (~2100 copies) and IbGy-2 (~540 copies), respectively, were found to be homologous to the Bagy-2 cDNA sequences of barley (Hordeum vulgare L.). Although the isolated partial sequences were found to be homologous to other transcriptionally active elements, future studies are required to determine whether they represent elements that are transcriptionally active under normal and (or) stressful conditions

Proteomic Characterization of Ovarian and Breast Cancer Microenvironments for Improved Diagnostics and Therapeutic Targeting

Cancers exist within complex microenvironments formed by heterogeneous cell types. This diversity creates significant challenges for detection, diagnosis and treatment. Mass spectrometry-based proteomics is a powerful approach capable of characterizing complex biological systems which are characteristic of cancer biology. In this thesis, proteomics was utilized to answer several questions related to ovarian cancer diagnosis and detection, and the effects of NODAL, an embryonic morphogen, on the breast cancer secretome and stromal cell recruitment. First, I compared multiple sample preparation techniques and found high-pH/low-pH fractionation to yield the greatest proteome coverage over commonly used approaches. Second, I compared the proteomes from two ovarian cancer subtypes (high-grade serous and endometrioid) for which histological discrimination remains difficult in a proportion of cases. I documented several unknown proteins, including KIAA1324, which were validated and confirmed to improve the differential diagnosis of endometrial ovarian cancer. Third, I extensively characterized extracellular vesicle proteomes from biological fluids (conditioned media, plasma and ascites) to catalogue potential biomarkers associated with malignant ovarian cancer. I detected many factors associated with advanced stage, high-grade serous ovarian cancer including CFHR4, MUC1, APCS and PZP that may be useful for early detection. Last, I characterized the global effects of the Transforming Growth Factor-β superfamily member NODAL on the breast cancer secretome and stromal cell recruitment in vitro. I found a previously unknown role for NODAL in modulating pro-inflammatory factors, including CXCL1 and IL6 that were correlated with multipotent stromal cell recruitment. In summary, this work represents a significant contribution to the histological assessment and detection of ovarian cancer and our understanding of the malignant properties of NODAL within the breast cancer microenvironment

A Multicoloured View of 2S 0114+650

We report the results of radio and X-ray observations of the high mass X-ray binary 2S 0114+650, made with the Giant Meterwave Radio Telescope and the Rossi X-ray Timing Explorer respectively. No emission was detected at radio wavelengths. The neutral hydrogen column density was found to vary over the orbital period, while no variability over the the super-orbital period was observed. We discuss the causes of the observed relationships and the implications for the underlying mechanisms.Comment: 4 pages, 2 figures; to appear in proceedings for "The multicoloured landscape of compact objects and their explosive progenitors", Cefalu, Sicily, 2006 June 11-24, AIP, submitte

Global Mind Monitor — determining intercultural competencies of Stenden Hotel Management School students: setting the research agenda

Ongoing Internationalization of Higher Hotel Management Education encourages professional universities to monitor and assess intercultural competence development of students. Moreover, strategic ambitions aimed at educating alumni capable of ‘global thinking’ and ‘hostmanship’ inevitably connect intercultural competence with hostmanship, a currently marginally explored academic concept. Hence, Stenden Hotel Management School needs to address both the measurement and assessment of intercultural competence development as well as the conceptualization of ‘hostmanship’. This article discusses the need to set the research agenda for determining intercultural competence development within the context of educating globally oriented, hospitable hosts.Keywords: intercultural competence development, assessment of intercultural competence development, hostmanshi

Storage; analysis and communication of information from diverse wheat field trials

Tese de doutoramento em Gestão de Empresas apresentada à Faculdade de Economia da Universidade de CoimbraNas últimas décadas, grandes transformações ocorreram no ambiente competitivo internacional, provocando mudanças significativas no mercado externo e acelerando o processo de internacionalização das empresas, para que possam se manter competitivas. Portanto, esta tese investiga como se articulam os vários antecedentes da internacionalização de empresas brasileiras e avalia a intensidade das relações existentes entre a orientação para o mercado externo, a orientação empreendedora internacional, os recursos e a inovação e o seu impacto na performance exportadora. Este estudo visa a aprofundar o conhecimento sobre a capacidade destes construtos influenciarem o resultado das empresas brasileiras que operam no mercado internacional e avaliarem as relações agregadas entre eles. Para isso, alguns passos foram fundamentais no desenvolvimento da pesquisa: a proposição de um modelo teórico hipotetizando as relações entre os temas; a validação de escalas confiáveis; o teste empírico das hipóteses. As empresas brasileiras exportadoras foram definidas como população-alvo, conforme cadastro oficial da Secretaria de Comércio Exterior (Secex) do Ministério do Desenvolvimento, Indústria e Comércio Exterior (MDIC). A amostra foi composta de 406 empresas pesquisadas. Na análise dos dados aplicou-se a técnica multivariada dos dados, por meio da modelagem de equações estruturais (MEE) e a técnica de redes neurais artificiais (RNA). Testou-se o modelo hipotético através da análise fatorial confirmatória (AFC) e os resultados confirmaram 8 entre as 10 hipóteses estabelecidas a partir do modelo adotado nesta tese. Os resultados apontaram um efeito positivo e integrado entre os construtos antecedentes e a performance exportadora, conforme proposto no modelo estrutural. Os impactos mais fortes do modelo estabeleceram-se nas relações entre a orientação para o mercado externo e os recursos, e na relação entre a orientação empreendedora internacional e a orientação para o mercado externo. Os resultados obtidos através da técnica de redes neurais apresentaram 10 construtos de 1ª ordem com pesos positivos na relação com a performance exportadora e somente 4 com pesos negativos (inibidores). No comparativo entre as duas técnicas de análise, os resultados foram semelhantes, o que pode mostrar que a linearidade das relações é a realidade dominante. No cômputo geral os resultados confirmaram que os construtos de orientação para o mercado externo, a orientação empreendedora internacional, os recursos e a inovação influenciam positivamente na performance exportadora das empresas

Six Years of ScoX-1 Monitoring with BeppoSAX Wide Field Cameras

We performed a systematic analysis of 54 Wide Field Camera (WFC) observations of ScoX-1 available in the BeppoSAX public archive. Observations span over the six years of BeppoSAX mission lifetime and include 690 hr of data. We searched for shifts and shape changes of the Z pattern in the color-color diagrams. We find that the Z pattern occupies most of the time the same locus in the color-color diagram. There are however a few exceptions, which are discussed in detail.Comment: 4 Pages, 4 figures. To appear in Proc. of the BeppoSAX Symposium: "The Restless High-Energy Universe", E.P.J. van den Heuvel, J.J.M. in 't Zand, and R.A.M.J. Wijers (Eds

Long-term Periodicities in the Flux from Low Mass X-ray Binaries

Using data from the All Sky Monitor (ASM) on the Rossi X-ray Timing Explorer (RXTE) we have searched for long term periodicities in the X-ray flux of GX 1+4, Sco X-2 (GX 349+2), and GX 339-4. For GX 1+4 we also used data from BATSE and Galactic Centre scans performed by RXTE. We find no evidence for X-ray modulations at the suggested ~304 d orbital period of GX 1+4. However, we find tentative evidence for a periodicity at 420 d to 460 d. An upper limit of 15% peak-to-peak is set on any sinusoidal modulation in the 1.5 - 3.0 keV flux of Sco X-2 for periods in the 30 to 100 d range. For GX 339-4 we confirm the Low State modulation and report the detection of significant low-frequency modulations in both the High State and Very High State. We fail to detect this modulation in the Off State. We show that if the reported orbital period of GX 339-4 lies in the range 0.5 - 1.7 d, then it is not present in the RXTE ASM light curve.Comment: 7 pages, 8 figures. Accepted for publication in Advanced in Space Research, 16th of March 200