Molecular dynamics simulation of the order-disorder phase transition in solid NaNO2_2

We present molecular dynamics simulations of solid NaNO$_2$ using pair potentials with the rigid-ion model. The crystal potential surface is calculated by using an \emph{a priori} method which integrates the \emph{ab initio} calculations with the Gordon-Kim electron gas theory. This approach is carefully examined by using different population analysis methods and comparing the intermolecular interactions resulting from this approach with those from the \emph{ab initio} Hartree-Fock calculations. Our numerics shows that the ferroelectric-paraelectric phase transition in solid NaNO$_2$ is triggered by rotation of the nitrite ions around the crystallographical c axis, in agreement with recent X-ray experiments [Gohda \textit{et al.}, Phys. Rev. B \textbf{63}, 14101 (2000)]. The crystal-field effects on the nitrite ion are also addressed. Remarkable internal charge-transfer effect is found.Comment: RevTeX 4.0, 11 figure

Coefficient estimates for a certain subclass of analytic and bi-univalent functions

AbstractIn this paper, we introduce and investigate an interesting subclass HΣh,p of analytic and bi-univalent functions in the open unit disk U. For functions belonging to the class HΣh,p, we obtain estimates on the first two Taylor–Maclaurin coefficients |a2| and |a3|. The results presented in this paper would generalize and improve some recent work of Srivastava et al. [H.M. Srivastava, A.K. Mishra, P. Gochhayat, Certain subclasses of analytic and bi-univalent functions, Appl. Math. Lett. 23 (2010) 1188–1192]

Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

School-based prevention for adolescent Internet addiction: prevention is the key. A systematic literature review

Adolescents’ media use represents a normative need for information, communication, recreation and functionality, yet problematic Internet use has increased. Given the arguably alarming prevalence rates worldwide and the increasingly problematic use of gaming and social media, the need for an integration of prevention efforts appears to be timely. The aim of this systematic literature review is (i) to identify school-based prevention programmes or protocols for Internet Addiction targeting adolescents within the school context and to examine the programmes’ effectiveness, and (ii) to highlight strengths, limitations, and best practices to inform the design of new initiatives, by capitalizing on these studies’ recommendations. The findings of the reviewed studies to date presented mixed outcomes and are in need of further empirical evidence. The current review identified the following needs to be addressed in future designs to: (i) define the clinical status of Internet Addiction more precisely, (ii) use more current psychometrically robust assessment tools for the measurement of effectiveness (based on the most recent empirical developments), (iii) reconsider the main outcome of Internet time reduction as it appears to be problematic, (iv) build methodologically sound evidence-based prevention programmes, (v) focus on skill enhancement and the use of protective and harm-reducing factors, and (vi) include IA as one of the risk behaviours in multi-risk behaviour interventions. These appear to be crucial factors in addressing future research designs and the formulation of new prevention initiatives. Validated findings could then inform promising strategies for IA and gaming prevention in public policy and education

Measurement of the CP-Violating Asymmetry Amplitude sin2β\beta

We present results on time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 88 million Y(4S) --> B Bbar decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B0 or B0bar from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2beta, is derived from the decay-time distributions in such events. We measure sin2beta = 0.741 +/- 0.067 (stat) +/- 0.033 (syst) and |lambda| = 0.948 +/- 0.051 (stat) +/- 0.017 (syst). The magnitude of lambda is consistent with unity, in agreement with the Standard Model expectation of no direct CP violation in these modes

A Sex-Specific Association between a 15q25 Variant and Upper Aerodigestive Tract Cancers

Sequence variants located at 15q25 have been associated with lung cancer and propensity to smoke. We recently reported an association between rs16969968 and risk of upper aerodigestive tract (UADT) cancers (oral cavity, oropharynx, hypopharynx, larynx and esophagus) in women (odds ratio (OR) =1.24, P=0.003) with little effect in men (OR=1.04, P=0.35)

Pattern-based translation of BPMN process models to BPEL web services

The Business Process Modelling Notation (BPMN) is a graph-oriented language in which control and action nodes can be connected almost arbitrarily. It is primarily targeted at domain analysts and is supported by many modelling tools, but in its current form, it lacks the semantic precision required to capture fully executable business processes. The Business Process Execution Language for Web Services (BPEL) on the other hand is a mainly block-structured language, targeted at software developers and supported by several execution platforms. In the current setting, translating BPMN models into BPEL code is a necessary step towards standards-based business process development environments. This translation is challenging since BPMN and BPEL represent two fundamentally different classes of languages. Existing BPMN-to-BPEL translations rely on the identification of block-structured patterns in BPMN models that are mapped into block-structured BPEL constructs. This paper advances the state of the art in BPMN-to-BPEL translation by defining methods for identifying not only perfectly block-structured fragments in BPMN models, but also quasi-structured fragments that can be turned into perfectly structured ones and flow-based acyclic fragments that can be mapped into a combination of block-structured constructs and control links. Beyond its direct relevance in the context of BPMN and BPEL, this paper addresses issues that arise generally when translating between graph-oriented and block-structured flow definition languages

Formal Semantics and Analysis of Control Flow in WS-BPEL

Web service composition refers to the creation of new (Web) services by combining functionalities provided by existing ones. A number of domain-specific languages for service composition have been proposed, with consensus being formed around a process-oriented language known as WS-BPEL (or BPEL). The kernel of BPEL consists of simple communication primitives that may be combined using control-flow constructs expressing sequence, branching, parallelism, synchronization, etc. We present a comprehensive and rigorously defined mapping of BPEL constructs onto Petri net structures, and use this for the analysis of various dynamic properties related to unreachable activities, conflicting messages, garbage collection, conformance checking, and deadlocks and lifelocks in interaction processes. We use a mapping onto Petri nets because this allows us to use existing theoretical results and analysis tools. Unlike approaches based on finite state machines, we do not need to construct the state space, and can use structural analysis (e.g., transition invariants) instead. We have implemented a tool that translates BPEL processes into Petri nets and then applies Petri-net-based analysis techniques. This tool has been tested on different examples, and has been used to answer a variety of questions

Method for transforming a feature vector

The present invention relates to a method for transforming a feature vector comprising a first and a second feature represented by a first and a second feature value, respectively, into a feature code using an encoder, said feature code usable in an algorithm and having a predetermined number of bits, said method comprising the steps of determining for each of the first and the second features the performance as a function of the length of the feature code, and using the dependency between the performance and the feature code length for each of the individual features derived in the step of determining to find feature code lengths for the first and the second features in such a way that the sum of the bit length of the first and the second feature codes has a length equaling said predetermined bit length. An advantage with the present invention is that it solves the problem in the case of template protection systems which only accept binary templates and where the resulting classification quality of the biometric system to a very large extend depends on the quality of the binary strings. Another advantage with the present invention is that it also solves the problem of matching time in an identification setting because binary strings can easily be compared. The present invention also relates to a similar arrangement for transforming a feature vector into a feature code