Influence on screening performance of second reading strategies in two lowvolume programs

BACKGROUND: The European Guidelines specify a minimum of 5,000 screening cases to be read yearly by radiologists carrying out second reading in non-centralized programs. This professional requirement is difficult to reach and/or to implement in regional programs covering a sparse population with a high number of participating radiology units, so that alternative blind double reading strategies must be devised. OBJECTIVE: To evaluate the effect on breast cancer screening performances of two second reading strategies used in non-centralized, low-volume programs. METHODS: Reading performances in two Swiss regional breast cancer screening programs (cantons of Wallis and Vaud), covering female populations, aged 50-69, of about 31'000 and 72'000 inhabitants were computed and compared. Both programs had similar screening regimens and organizations, but differed with respect to second reading. One setting applied a selective strategy whereby only experienced radiologists performed second reading; the other elicited not to restrict second readers on the basis of their individual screening activity. Analysis included some 140,000 mammograms performed between 1999 and 2005. RESULTS: Overall, screening performances improved with increasing total volume of reading, albeit not in a linear fashion. Regardless of setting, radiologists attained a higher level of screening accuracy when performing second rather than first readings, and incident rather than prevalent screening cases. The effect of a selective, small group of second readers appeared to impact favorably on the false-positive rate and other indicators of screening quality. As the learning curve depends on the number of mammograms read, these distinct strategies may bear different outcome in the long run. Implications and practical issues for low-volume programs are discussed.

New clinical practice guideline on enteral feeding in very low birth wieght infants; second part

INTRODUCTION: The nutrition of very low birth weight (VLBW) infants is aimed at promoting a similar growth to that occurring in the uterus. However, in practice this is difficult to achieve and extrauterine growth restriction is frequent. The current tendency is to avoid this restriction by means of early parenteral and enteral nutrition. Nonetheless, uncertainty about many of the practices related with nutrition has resulted in a great variation in the way it is undertaken. In 2009 and 2011 in our hospital there was an unexpected increase in necrotizing enterocolitis. To check to see wether our nutrition policy was involved, we underlook a systematic review and drewup clinical practice guidelines (CPG) about enteral feeding in VLBW infants. New considerations about the duration of the fortification and the use of probiotics have led to an update of these CPG. METHODS: A total of 21 clinical questions were designed dealing with the type of milk, starting age, mode of administration, rate and volume of the increments, fortification, use of probiotics and protocol. Afete conducting a systematic search of the available evidence, the information was contrasted and summarized in order to draw up the recommendations. The quality of the evidence and the strength of the recommendations were determined from the SIGN scale. COMMENT: These CPG aim to help physicians in their decision making. The protocolized application of wellproven measurements reduces the variation in clinical practice and improves results.

Mlle [Fernande] Cormier, second grand prix de Rome [de peinture en 1919] : [photographie de presse] / [Agence Rol]

R��f��rence bibliographique : Rol, 56730

Complex genetics in idiopathic hypogonadotropic hypogonadism.

Idiopathic hypogonadotropic hypogonadism (IHH) is an important human disease model. Investigations of the genetics of IHH have facilitated insights into critical pathways regulating sexual maturation and fertility. IHH has been traditionally considered a monogenic disorder. This model holds that a single gene defect is responsible for the disease in each patient. In the case of IHH, 30% of cases are explained by mutations in one of eleven genes. In recent years, several lines of evidence have challenged the monogenic paradigm in IHH. First, disease-associated mutations display striking incomplete penetrance and variable expressivity within and across IHH families. Second, each locus is responsible for only a small percentage of cases. Third, more than one disease-associated mutation seems to be segregating in some families with IHH, and their combined or separate presence in individuals accounts for the variability in disease severity. Finally, IHH is not strictly a congenital and life-long disorder; occasionally it manifests itself during adulthood (adult-onset IHH); in other cases, the disease is not permanent, as evidenced by normal activity of the hypothalamic-pituitary-gonadal axis after discontinuation of treatment in adulthood (IHH reversal). Together, these observations suggest that IHH is not strictly a monogenic mendelian disease, as previously thought. Rather, it is emerging as a digenic, and potentially oligogenic disease, in which hormonal and/or environmental factors may critically influence genetic predisposition and clinical course. Future investigations of IHH should characterize the extent of the involvement of multiple genes in disease pathogenesis, and elucidate the contributions of epigenetic factors.

Theoretical study of the second-order vibrational Stark effect

The behaviour of the harmonic infrared frequency of diatomic molecules subjected to moderate static uniform electric fields is analysed. The potential energy expression has been developed as a function of a static uniform electric field, which brings about a formulation describing the frequency versus field strength curve. With the help of the first and second derivatives of the expressions obtained, which correspond to the first- and second-order Stark effects, it was possible to find the maxima of the frequency versus field strength curves for a series of molecules using a Newton-Raphson search. A method is proposed which requires only the calculation of a few energy derivatives at a particular value of the field strength. At the same time, the expression for the dependence of the interatomic distance on the electric field strength is derived and the minimum of this curve is found for the same species. Derived expressions and numerical results are discussed and compared with other studi

On the origin and scope of the second language speech production disadvatage

Los hablantes biling��es tienen un acceso al l��xico m��s lento y menos robusto que los monoling��es, incluso cuando hablan en su lengua materna y dominante. Este fen��meno, com��nmente llamado ���la desventaja biling��e��� tambi��n se observa en hablantes de una segunda lengua en comparaci��n con hablantes de una primera lengua. Una causa que posiblemente contribuya a estas desventajas es el uso de control inhibitorio durante la producci��n del lenguaje: la inhibici��n de palabras coactivadas de la lengua actualmente no en uso puede prevenir intrusiones de dicha lengua, pero al mismo tiempo ralentizar la producci��n del lenguaje. El primer objetivo de los estudios descritos en este informe era testear esta hip��tesis mediante diferentes predicciones generadas por teor��as de control inhibitorio del lenguaje. Un segundo objetivo era investigar la extensi��n de la desventaja biling��e dentro y fuera de la producci��n de palabras aisladas, as�� como avanzar en el conocimiento de las variables que la modulan. En lo atingente al primer objetivo, la evidencia obtenida es incompatible con un control inhibitorio global, desafiando la idea de mecanismos espec��ficos en el hablante biling��e utilizados para la selecci��n l��xica. Esto implica que una explicaci��n com��n para el control de lenguaje y la desventaja biling��e en el acceso al l��xico es poco plausible. En cuanto al segundo objetivo, los resultados muestran que (a) la desventaja biling��e no tiene un impacto al acceso a la memoria; (b) la desventaja biling��e extiende a la producci��n del habla conectada; y (c) similitudes entre lenguas a diferentes niveles de representaci��n as�� como la frecuencia de uso son factores que modulan la desventaja biling��e. ������

An LMI approach to H��� synchronization of second-order neutral master-slave systems

The H��� synchronization problem of the master and slave structure of a second-order neutral master-slave systems with time-varying delays is presented in this paper. Delay-dependent sufficient conditions for the design of a delayed output-feedback control are given by Lyapunov-Krasovskii method in terms of a linear matrix inequality (LMI). A controller, which guarantees H��� synchronization of the master and slave structure using some free weighting matrices, is then developed. A numerical example has been given to show the effectiveness of the method

War Signals: A Theory of Trade, Trust and Conflict

We construct a dynamic theory of civil conflict hinging on inter-ethnic trust and trade. The model economy is inhabitated by two ethnic groups. Inter-ethnic trade requires imperfectly observed bilateral investments and one group has to form beliefs on the average propensity to trade of the other group. Since conflict disrupts trade, the onset of a conflict signals that the aggressor has a low propensity to trade. Agents observe the history of conflicts and update their beliefs over time, transmitting them to the next generation. The theory bears a set of testable predictions. First, war is a stochastic process whose frequency depends on the state of endogenous beliefs. Second, the probability of future conflicts increases after each conflict episode. Third, "accidental" conflicts that do not reflect economic fundamentals can lead to a permanent breakdown of trust, plunging a society into a vicious cycle of recurrent conflicts (a war trap). The incidence of conflict can be reduced by policies abating cultural barriers, fostering inter-ethnic trade and human capital, and shifting beliefs. Coercive peace policies such as peacekeeping forces or externally imposed regime changes have instead no persistent effects.

La reine d'Espagne et son second fils Jaime : [photographie de presse] / [Agence Rol]

R��f��rence bibliographique : Rol, 57057

Assessing High-Speed Internet Access in the State of Iowa: Second Assessment, February 2002

Report for Iowa Utilities Board

Cultural self-identification(s) and personal social networks among first and second-generation immigrants

L���estudi examina les relacions entre (1) les xarxes socials personals de la poblaci�� immigrant resident a Barcelona i (2) les seves identitats culturals m��ltiples. L���objectiu principal de l���estudi ��s entendre com el contingut i l���estructura de les relacions socials dels immigrants facilita o dificulta (1) tenir un sentiment de pertinen��a a les noves cultures d���acollida, la catalana i la espanyola, i (2) la integraci�� d���aquestes noves identitats socioculturals amb la seva identitat d���origen en una nova identitat bicultural cohesiva. El nostre plantejament inicial era que els immigrants amb xarxes socials m��s diverses des del punt de vista de la seva composici�� cultural tindrien m��s recursos socials i experi��ncies cognitives m��s diverses , factors que afavoreixen les identificacions m��ltiples i la participaci�� c��vica. Els resultats de l���estudi mostren que el grau d���identificaci�� dels participants amb la seva cultura ��tnica o d���origen ��s for��a alt i, en certa mesura, m��s alt en comparaci�� amb les cultures d���acollida ( catalana, c��vica i espanyola). Tanmateix, el vincle dels participants amb les cultures d���acollida (p. ex., la cultura catalana) ��s prou rellevant per a indicar una orientaci�� bicultural (catalana i ��tnica). Les an��lisis de correlacions revelen que sentir-se catal�� no impedeix sentir-se part de la comunitat etnocultural d���origen. A m��s, existeix una interrelaci�� entre l'orientaci�� cultural catalana i la identificaci�� amb les comunitats c��viques locals. De la mateixa manera, tenir compet��ncies en llengua catalana no va en detriment de les compet��ncies en llengua castellana. Les an��lisis tamb�� mostren que factors com l���orientaci�� cultural catalana, l�����s del catal�� i la identificaci�� amb la cultura catalana tenen una correlaci�� positiva amb el grau de chohesio de la indentitat bicultural, afavoreixen el benestar psicol��gic i disminueixen l���estr��s aculturatiu. L���an��lisi de les xarxes socials mostra que la identificaci�� amb la cultura catalana, l���orientaci�� cultural catalana i la integraci�� de la identitat s��n factors clau per tenir xarxes socials m��s diverses des del punt de vista ��tnic i ling����stic, amb menys membres del col���lectiu d���origen, i amb subgrups o ���cliques��� culturalment m��s heterogenis. La identificaci�� espanyola tamb�� prediu, en mesura m��s redu��da, la diversitat de les xarxes. Els nostres resultats contribueixen a la recerca actual i les teories sobre interculturalitat i identitat cultural.

Anharmonicity contributions to the vibrational second hyperpolarizability of conjugated oligomers

Restricted Hartree-Fock 6-31G calculations of electrical and mechanical anharmonicity contributions to the longitudinal vibrational second hyperpolarizability have been carried out for eight homologous series of conjugated oligomers - polyacetylene, polyyne, polydiacetylene, polybutatriene, polycumulene, polysilane, polymethineimine, and polypyrrole. To draw conclusions about the limiting infinite polymer behavior, chains containing up to 12 heavy atoms along the conjugated backbone were considered. In general, the vibrational hyperpolarizabilities are substantial in comparison with their static electronic counterparts for the dc-Kerr and degenerate four-wave mixing processes (as well as for static fields) but not for electric field-induced second harmonic generation or third harmonic generation. Anharmonicity terms due to nuclear relaxation are important for the dc-Kerr effect (and for the static hyperpolarizability) in the ��-conjugated polymer, polysilane, as well as the nonplanar �� systems polymethineimine and polypyrrole. Restricting polypyrrole to be planar, as it is in the crystal phase, causes these anharmonic terms to become negligible. When the same restriction is applied to polymethineimine the effect is reduced but remains quantitatively significant due to the first-order contribution. We conclude that anharmonicity associated with nuclear relaxation can be ignored, for semiquantitative purposes, in planar ��-conjugated polymers. The role of zero-point vibrational averaging remains to be evaluated

The curvature of the conical intersection seam: an approximate second-order analysis

We present a method for analyzing the curvature (second derivatives) of the conical intersection hyperline at an optimized critical point. Our method uses the projected Hessians of the degenerate states after elimination of the two branching space coordinates, and is equivalent to a frequency calculation on a single Born-Oppenheimer potential-energy surface. Based on the projected Hessians, we develop an equation for the energy as a function of a set of curvilinear coordinates where the degeneracy is preserved to second order (i.e., the conical intersection hyperline). The curvature of the potential-energy surface in these coordinates is the curvature of the conical intersection hyperline itself, and thus determines whether one has a minimum or saddle point on the hyperline. The equation used to classify optimized conical intersection points depends in a simple way on the first- and second-order degeneracy splittings calculated at these points. As an example, for fulvene, we show that the two optimized conical intersection points of C2v symmetry are saddle points on the intersection hyperline. Accordingly, there are further intersection points of lower energy, and one of C2 symmetry - presented here for the first time - is found to be the global minimum in the intersection space

Second-order M��ller-Plesset perturbation theory without basis set superposition error : II : open-shell systems

The basis set superposition error-free second-order M��ller-Plesset perturbation theory of intermolecular interactions was studied. The difficulties of the counterpoise (CP) correction in open-shell systems were also discussed. The calculations were performed by a program which was used for testing the new variants of the theory. It was shown that the CP correction for the diabatic surfaces should be preferred to the adiabatic ones