Three-nucleon force at large distances: Insights from chiral effective field theory and the large-N_c expansion

We confirm the claim of Ref. [D.R. Phillips, C. Schat, Phys. Rev. C88 (2013) 3, 034002] that 20 operators are sufficient to represent the most general local isospin-invariant three-nucleon force and derive explicit relations between the two sets of operators suggested in Refs. [D.R. Phillips, C. Schat, Phys. Rev. C88 (2013) 3, 034002] and [H. Krebs, A.M. Gasparyan, E. Epelbaum, Phys.Rev. C87 (2013) 5, 054007]. We use the set of 20 operators to discuss the chiral expansion of the long- and intermediate-range parts of the three-nucleon force up to next-to-next-to-next-to-next-to-leading order in the standard formulation without explicit Delta(1232) degrees of freedom. We also address implications of the large-N_c expansion in QCD for the size of the various three-nucleon force contributions.Comment: 15 pages, 6 figure

Assessing the feasibility of a life history calendar to measure HIV risk and health in older South Africans

Life history calendars capture patterns of behavior over time, uncovering transitions and trajectories. Despite the growing numbers of older persons living with HIV in southern Africa, little is known about how HIV testing and risk unfold in this population. Operationalizing a life course approach with the use of an innovative Testing and Risk History Calendar [TRHC], we collected pilot data on older South Africans’ risk and HIV testing. We found older persons were able to provide (1) reference points to facilitate recall over a 10-year period, (2) specifics about HIV tests during that decade, and (3) details that contextualize the testing data, such as living arrangements, relationships, and health status. Interviewer debriefing sessions after each interview captured information on context and links across domains. On a larger scale, the TRHC has potential to reveal pathways between sexual behavior, HIV testing and risk perception, and health at older ages

Clinical epidemiology of commonly occurring anxiety disorders : insights into the phenomenology and course of anxiety disorders from the Leiden Routine Outcome Monitoring Study

Anxiety disorders as a group are the most prevalent psychiatric disorders. Although they have been studied extensively, previous research has focussed primarily on members of the general population, or on participants in clinical trials. As both groups may differ substantially from patients who are seen in clinical practice, it is unclear to what extent previous findings can be generalised to a clinical setting. In order to gain insight in the clinical epidemiology of anxiety, it is necessary to study outpatients. This thesis describes several studies in which naturalistic data, collected through Routine Outcome Monitoring, were used. Chapter two describes the age of onset of panic disorder, agoraphobia, social phobia and generalised anxiety disorder. Chapter three explores age related differences. In chapter four predictors of treatment response are identified and the fifth chapter describes patient characteristics that are associated with the course of suicidal ideation in anxiety and depression. In chapter seven a self-report measure of anxiety severity is compared with an observer rated measure and patient characteristics associated with discrepancies between both measures are identified. In the final chapter findings are discussed and recommendations for future research are made.LUMC / Geneeskund

Assessing the feasibility of a life history calendar to measure HIV risk and health in older South Africans

Life history calendars capture patterns of behavior over time, uncovering transitions and trajectories. Despite the growing numbers of older persons living with HIV in southern Africa, little is known about how HIV testing and risk unfold in this population. Operationalizing a life course approach with the use of an innovative Testing and Risk History Calendar [TRHC], we collected pilot data on older South Africans’ risk and HIV testing. We found older persons were able to provide (1) reference points to facilitate recall over a 10-year period, (2) specifics about HIV tests during that decade, and (3) details that contextualize the testing data, such as living arrangements, relationships, and health status. Interviewer debriefing sessions after each interview captured information on context and links across domains. On a larger scale, the TRHC has potential to reveal pathways between sexual behavior, HIV testing and risk perception, and health at older ages

Are Consensus Ratings of Functional Job Analysis Scales More Reliable than Ratings Made by Independent Raters?

This study addresses an open research question in regard to a well-established and widely-used job analysis system, Functional Job Analysis (FJA): Are consensus ratings of the FJA scales more reliable than the independent scale ratings that are the norm in job analysis application and the related research literature? In our experimental study, we found that this is not the case: no significant difference is found between consensus and independent ratings of the FJA scales. The reasons for this finding are explored as well as its relevance to the validity of the FJA system. Implications for other work and job analysis systems are discussed

Positive parity pentaquark towers in large Nc QCD

We construct the complete set of positive parity pentaquarks, which correspond in the quark model to {\bar s} q^{Nc+1} states with one unit of orbital angular momentum L=1. In the large Nc limit they fall into the K=1/2 and K=3/2 irreps (towers) of the contracted SU(4)c symmetry. We derive predictions for the mass spectrum and the axial couplings of these states at leading order in 1/Nc. The strong decay width of the lowest-lying positive parity exotic state is of order O(1/Nc), such that this state is narrow in the large Nc limit. Replacing the antiquark with a heavy antiquark {\bar Q} q^{Nc+1}, the two towers become degenerate, split only by O(1/mQ) hyperfine interactions. We obtain predictions for the strong decay widths of heavy pentaquarks to ordinary baryons and heavy H(*)_{\bar Q} mesons at leading order in 1/Nc and 1/mQ.Comment: 21 pages, 2 figures, 5 table

Classification of Marek's disease viruses according to pathotype: Philosophy and methodology

El concepto de patotipo en la enfermedad de Marek (MD) data probablemente de finales de los 1950s cuando se reconoció una forma más virulenta de enfermedad Benton y Cover, 1957). Las distinciones entre las diferentes cepas de virus de MD (MDV) fueron aún mayores al describirse el patotipo vv a principios de los ochenta y el vv+ en los noventa. La designación de patotipo refleja propiedades biológicas importantes que se correlacionan con la capacidad de romper la inmunidad maternal en el campo. A pesar de ello, los métodos de clasificación de los diferentes patotipos en varios laboratorios no han sido uniformes, lo cual ha impedido una comparación crítica de los resultados. El método utilizado en el Avian Disease and Oncology Laboratory (ADOL) se basa en la inducción de lesiones linfoproliferativas en pollos vacunados. Este método ha sido utilizado para clasificar más de 45 aislados y es la base para la clasificación actual de los patotipos de cepas de MDV. Las limitaciones de este método son varias: necesidad de un tipo específico de pollos (15x7 ab+), uso de un gran número de animales y de un método estadístico para comparar las respuestas lesionales con las de las cepas control JM/102W y Md5. Debido a estas limitaciones no ha sido y no es probablemente usado en otros laboratorios. La comparación en el patotipado puede ser mejorada mediante la comparación de aislados de campo con cepas prototipo como las JM/102W, Md5 y 648A (American Type Culture Collection) o sus equivalentes. Los datos pueden ser generados mediante diferentes procedimientos in vivo que miden la inducción de tumores, enfermedad neurològica (por lesiones neoplásicas o no neoplásicas), o únicamente por criterios no neoplásicos (como el peso de los órganos linfoides o la replicación vírica). Los métodos basados en criterios neoplásicos, especialmente cuando son generados en pollos inmunizados de MD, probablemente se correlacionarán mejor con el método del ADOL y serán más relevantes en cuanto a la evolución de los virus de MD en el campo. En base a los datos de diferentes experimentos, se propone una modificación del método ADOL que utiliza menos animales y puede ser llevado a cabo en pollos SPF comerciales. El método modificado se basa en una comparación con el que mejor clasifica las cepas prototipo, y se espera que de resultados en general comparables con el método original. Otros criterios alternativos (ver abajo) también se evalúan como métodos primarios de patotipificación o como adjuntos a otros métodos de patotipificación. Se presentan las ventajas y desventajas de estos métodos alternativos.The concept of pathotype in Marek's disease (MD) probably dates from the recognition of a more virulent form of the disease in the late 1950s (Benton & Cover, 1957). Distinctions between MD virus strains were further expanded with the description of the vv pathotype in the early 1980s and of the vv + pathotype in the 1990s. Pathotype designations reflect important biological properties that correlate with the break-through of vaccinal immunity in the field. However, pathotyping methods applied by various laboratories have not been uniform, preventing critical comparison of results. Better uniformity of pathotyping procedures is desirable. The Avian Disease and Oncology Laboratory (ADOL) method is based on induction of lymphoproliferative lesions in vaccinated chickens. This method has been used to pathotype more than 45 isolates and is the basis for the current pathotype classification of MD virus strains. Its limitations include requirements for a specific type of chickens (15 x 7 ab+), large numbers of animals, and a statistical method to compare lesion responses to those of JM/102W and Md5 control strains. Because of these limitations, it has not been and is not likely to be used in other laboratories. Comparability in pathotyping can be improved by the comparison of field isolates with standard prototype strains such as JM/102W, Md5 and 648A (American Type Culture Collection) or their equivalents. Data may be generated by different in vivo procedures that measure tumour induction, neurological disease (both neoplastic and non-neoplastic lesions), or solely non-neoplastic criteria (such as lymphoid organ weights or virus replication). Methods based on neoplastic criteria, especially when generated in MD-immunized chickens, will probably correlate most closely with that of the ADOL method and be most relevant to evolution of MD virus in the field. Based on data from several trials, a modification of the ADOL method that utilizes fewer chickens and can be conducted with commercial specific pathogen free strains is proposed. The modified method is based on "best fit" comparisons with prototype strains, and is expected to provide results generally comparable with the original method. A variety of other alternative criteria (see earlier) are also evaluated both for primary pathotyping and as adjuncts to other pathotyping methods. Advantages and disadvantages of alternative methods are presented.Facultad de Ciencias Veterinaria