A User Configurable B-tree Implementation as a Utility

B-trees are widely used in management of data to support good performance for storage, retrievals and updates. Many excellent implementations of B-tree exist in industry and academia. However, it is hard to find one that is easily configurable for clients who need to create and use B-trees. In this work, we undertake implementation of B-trees as a utility. The utility absorbs most of the logistical support needed in creation and maintenance of a B-tree leaving only tasks that can only be performed by the clients to them. For exchange of data a two ended iterator-based framework called PTC, short for produce, transform, consume, is offered that produces one record at a time, the record is optionally processed, and then consumed. The PTC-based exchange is quite versatile. For example, it can be used in generating data and storing it in a file, converting data from text (resp. binary) to binary (resp. text) formats, creating a B-tree by inserting one tuple at a time or bulk loading, and out streaming the data from a B-tree to a destination such as query processor.ÃÂ XML is used to describe essential configuration settings for B-trees, records, and keys. A Java class file is automatically generated from the record configuration to provide support to upper level modules such as page-based storage and comparisons of keys needed by B-tree algorithms

Chinese Female Graduate Students\u27 Academic Socialization Across Disciplines - Perspectives On Language, Culture, And Gender

From the mid-1950s, international education in the United States has witnessed stupendous growth. China boasts the largest number of English language learners in the world, and contributes to an increasingly large share of the global international student market. Being informed by a community of practice perspective and poststructuralist conceptualization of identity, the present study aims to explore the academic socialization experience of three female Chinese graduate students in the United States. The ethnographic case study collected data from various sources such as classroom observations, open-ended questionnaires, interviews with participants and with their course instructors, and written documents. The findings revealed different degrees of similarities and variations in relation to the construction and negotiation of their linguistic, cultural and gendered identities across disciplines. Participants\u27 immediate and imagined communities significantly influenced their learning investment. Instead of being marginalized, all three female Chinese learners were able to participate legitimately, competently, and strategically in their academic disciplines

Self-interaction corrected SCAN functional for molecules and solids in the numeric atom-center orbital framework

Das „Strongly Constrained and Appropriately Normed“ (SCAN) Austausch-Korrelations-Funktional gehört zur Familie der meta-GGA (generalized gradient approximation) Funktionale. Es gibt aber auch Nachteile Zum einen leiden SCAN Rechnungen oft unter numerischen Instabilitäten, wodurch sehr viele Iteration zum Erreichen von Selbst-Konsistenz benötigt werden. Zum anderen leidet SCAN unter dem von GGA Methoden bekannten Selbstwechselwirkung-Fehler. Im ersten Teil der Arbeit habe ich die numerischen Stabilitätsprobleme in SCAN Rechnungen im Rahmen der numerischen Realraum-Integrationsroutinen im Code FHI-aims untersucht. Diese Analyse zeigt, dass die genannte Probleme durch Anwendung von standardisierten Dichte-Mischalgorithmen für die kinetische Energiedichte abgemildert werden können. Dadurch wird auch in SCAN-Rechnungen eine schnelle und stabile Konvergenz zur selbstkonsistenten Lösung ermöglicht. Im zweiten Teil der Arbeit habe ich untersucht, in welchem Rahmen sich der Selbstwechselwirkung-Fehler in SCAN mittels des von Perdew und Zunger vorgeschlagenen Selbstinteraktionskorrekturalgorithmus (PZ-SIC) verringern lässt. Es wurden aber auch Optimierungen für die PZ-SIC Methode entwickelt. Inspiriert von den ursprünglichen Argumenten in der PZ-SIC-Methode und anderen lokalisierten Methoden, wird in dieser Arbeit eine neuartige Randbedingung (orbital density constraint) vorgeschlagen, die sicherstellt, dass die PZ-SIC Orbitale während des Selbstkonsistenzzyklus lokalisiert bleiben. Dies mildert die Anfangswertabhängigkeit deutlich ab und hilft dabei, in die korrekte selbst-konsistente Lösung mit minimaler Energie zu konvergieren, unabhängig davon ob reelle oder komplexe SIC Orbitale verwendet werden. Die in dieser Arbeit getägtigen Entwicklungen und Untersuchungen sind Wegbereiter dafür, in Zukunft mit SIC-SCAN Rechnungen deutlich genauere ab initio Rechnungen mit nur gering höherem Rechenaufwand durchführen zu können.The state-of-the-art “Strongly Constrained and Appropriately Normed” (SCAN) functional pertains to the family of meta-generalized-gradient approximation (meta-GGA) exchange-correlation functionals. Nonetheless, SCAN suffers from some well-documented deficiencies. In the first part of this thesis, I revisited the known numerical instability problems of the SCAN functional in the context of the numerical, real-space integration framework used in the FHI-aims code. This analysis revealed that applying standard density-mixing algorithms to the kinetic energy density attenuates and largely cures these numerical issues. By this means, SCAN calculations converge towards the self-consistent solution as fast and as efficiently as lower-order GGA calculations. In the second part of the thesis, I investigated strategies to alleviate the self-interaction error in SCAN calculations by using the self-interaction correction algorithm proposed by Perdew and Zunger (PZ-SIC). Inspired by the original arguments in PZ-SIC and other localized methods, I introduced a mathematical constraint, i.e., the orbital density constraint, that forces the orbitals to retain their localization throughout the self-consistency cycle. In turn, this alleviates the multiple-solutions problem and facilitates the convergence towards the correct, lowest-energy solution both for complex and real SIC orbitals. The developments and investigations performed in this thesis pave the road towards a more wide-spread use of SIC-SCAN calculations in the future, allowing more accurate predictions within only moderate increases of computational cost

Function of monocytes in chronic HCV infection: Role for IL-10 and interferon

Hepatitis C virus (HCV) establishes persistent infection in about 80% of the infected individuals. The symptoms are initially mild in those persistently infected patients, and it may take decades before the serious consequences of chronic HCV infection become apparent. Up to 20% of infected individuals may develop complications, including cirrhosis, liver failure, or hepatocellular carcinoma [3]. HCV infection is now the leading indication for liver transplantation in the United States and Europe

Obesity in the Otsuka Long Evans Tokushima Fatty Rat: Mechanisms and Discoveries

Understanding the neural systems underlying the controls of energy balance has been greatly advanced by identifying the deficits and underlying mechanisms in rodent obesity models. The current review focuses on the Otsuka Long Evans Tokushima Fatty (OLETF) rat obesity model. Since its recognition in the 1990’s significant progress has been made in identifying the causes and consequences of obesity in this model. Fundamental is a deficit in the cholecystokinin (CCK) 1 receptor gene resulting in the absence of CCK 1 receptors in both the gastrointestinal track and the brain. OLETF rats have a deficit in their ability to limit the size of meals and in contrast to CCK1 receptor knock-out mice, do not compensate for this increase in the size of their spontaneous meals, resulting in hyperphagia. Prior to becoming obese and in response to pair feeding, OLETF rats have increased expression of neuropeptide Y (NPY) in the compact region of the dorsomedial hypothalamus (DMH) and this over-expression contributes to their overall hyperphaigia. Study of the OLETF rats has revealed important differences in the organization of the DMH in rats and mice and elucidated previously unappreciated roles for DMH NPY in energy balance and glucose homeostasis

Renormalization group improved pQCD prediction for Υ(1S)\Upsilon(1S) leptonic decay

The complete next-to-next-to-next-to-leading order short-distance and bound-state QCD corrections to $\Upsilon(1S)$ leptonic decay rate $\Gamma(\Upsilon(1S)\to \ell^+\ell^-)$ has been finished by Beneke {\it et al.} \cite{Beneke:2014qea}. Based on those improvements, we present a renormalization group (RG) improved pQCD prediction for $\Gamma(\Upsilon(1S)\to \ell^+\ell^-)$ by applying the principle of maximum conformality (PMC). The PMC is based on RG-invariance and is designed to solve the pQCD renormalization scheme and scale ambiguities. After applying the PMC, all known-type of $\beta$-terms at all orders, which are controlled by the RG-equation, are resummed to determine optimal renormalization scale for its strong running coupling at each order. We then achieve a more convergent pQCD series, a scheme- independent and more accurate pQCD prediction for $\Upsilon(1S)$ leptonic decay, i.e. $\Gamma_{\Upsilon(1S) \to e^+ e^-}|_{\rm PMC} = 1.270^{+0.137}_{-0.187}$ keV, where the uncertainty is the squared average of the mentioned pQCD errors. This RG-improved pQCD prediction agrees with the experimental measurement within errors.Comment: 11 pages, 4 figures. Numerical results and discussions improved, references updated, to be published in JHE

Study on thermal conductivity of gas phase in nano-porous aerogel

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Nano-porous aerogel has an ultra low thermal conductivity and is usually used as the super insulator. To evaluate the insulation performance of the aerogel, we focus on studying the thermal conductivity of gas phase in the aerogel. We present a modified model to take into account the effect of nonuniform pore-size distribution on the gaseous thermal conductivity, and the present model predicts more agreement results with available data than the existing models. The gaseous thermal conductivity of the aerogel at high temperature gradient condition is also numerically studied. We also study the effect of the thermal transpiration flow on the gaseous thermal conductivity, and the results shows that the thermal transpiration flow effect leads to a reduction of the gaseous thermal conductivity