Micromegas operation in high pressure xenon: charge and scintillation readout

The operational characteristics of a Micromegas operating in pure xenon at the pressure range of 1 to 10 bar are investigated. The maximum charge gain achieved in each pressure is approximately constant, around 4x10^2, for xenon pressures up to 5 bar and decreasing slowly above this pressure down to values somewhat above 10^2 at 10 bar. The MM presents the highest gains for xenon pressures above 4 bar, when compared to other micropattern gaseous multipliers. The lowest energy resolution obtained for X-rays of 22.1 keV exhibits a steady increase with pressure, from 12% at 1bar to about 32% at 10 bar. The effective scintillation yield, defined as the number of photons exiting through the MM mesh holes per primary electron produced in the conversion region was calculated. This yield is about 2x10^2 photons per primary electron at 1 bar, increasing to about 6x10^2 at 5 bar and, then, decreasing again to 2x10^2 at 10 bar. The readout of this scintillation by a suitable photosensor will result in higher gains but with increased statistical fluctuations.Comment: 22 pages, 11 figure

Advances in Cryogenic Avalanche Detectors

Cryogenic Avalanche Detectors (CRADs) are referred to as a new class of noble-gas detectors operated at cryogenic temperatures with electron avalanching performed directly in the detection medium, the latter being in gaseous, liquid or two-phase (liquid-gas) state. Electron avalanching is provided by Micro-Pattern Gas Detector (MPGD) multipliers, in particular GEMs and THGEMs, operated at cryogenic temperatures in dense noble gases. The final goal for this kind of detectors is the development of large-volume detectors of ultimate sensitivity for rare-event experiments and medical applications, such as coherent neutrino-nucleus scattering, direct dark matter search, astrophysical (solar and supernova) neutrino detection experiments and Positron Emission Tomography technique. This review is the first attempt to summarize the results on CRAD performances obtained by different groups. A brief overview of the available CRAD concepts is also given and the most remarkable CRAD physics effects are discussed.Comment: 60 pages, 58 figures. Invited talk at MPGD2011 Conference, Aug 29 - Sep 3, 2011, Kobe, Japan. Journal version + Fig. 1a adde

Natural clusters of tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND): new findings from the TOSCA TAND research project.

BACKGROUND: Tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND) have unique, individual patterns that pose significant challenges for diagnosis, psycho-education, and intervention planning. A recent study suggested that it may be feasible to use TAND Checklist data and data-driven methods to generate natural TAND clusters. However, the study had a small sample size and data from only two countries. Here, we investigated the replicability of identifying natural TAND clusters from a larger and more diverse sample from the TOSCA study. METHODS: As part of the TOSCA international TSC registry study, this embedded research project collected TAND Checklist data from individuals with TSC. Correlation coefficients were calculated for TAND variables to generate a correlation matrix. Hierarchical cluster and factor analysis methods were used for data reduction and identification of natural TAND clusters. RESULTS: A total of 85 individuals with TSC (female:male, 40:45) from 7 countries were enrolled. Cluster analysis grouped the TAND variables into 6 clusters: a scholastic cluster (reading, writing, spelling, mathematics, visuo-spatial difficulties, disorientation), a hyperactive/impulsive cluster (hyperactivity, impulsivity, self-injurious behavior), a mood/anxiety cluster (anxiety, depressed mood, sleep difficulties, shyness), a neuropsychological cluster (attention/concentration difficulties, memory, attention, dual/multi-tasking, executive skills deficits), a dysregulated behavior cluster (mood swings, aggressive outbursts, temper tantrums), and an autism spectrum disorder (ASD)-like cluster (delayed language, poor eye contact, repetitive behaviors, unusual use of language, inflexibility, difficulties associated with eating). The natural clusters mapped reasonably well onto the six-factor solution generated. Comparison between cluster and factor solutions from this study and the earlier feasibility study showed significant similarity, particularly in cluster solutions. CONCLUSIONS: Results from this TOSCA research project in an independent international data set showed that the combination of cluster analysis and factor analysis may be able to identify clinically meaningful natural TAND clusters. Findings were remarkably similar to those identified in the earlier feasibility study, supporting the potential robustness of these natural TAND clusters. Further steps should include examination of larger samples, investigation of internal consistency, and evaluation of the robustness of the proposed natural clusters

Improving university-industry partnership: the brazilian experience through the scientific and technological development support program (PADCT III)

Developing countries' scientific and technological development depends on the assistance of several government spheres, in particular from the federal one, in order to formulate policies and generate financial support mechanisms. Aiming to explore better the research results for the benefit of the productive sector, the Brazilian government has implemented programs whose main focus is the promotion of the interaction between academia (universities and public research institutions) and companies. Among these initiatives, it is worth mentioning the Scientific and Technological Development Support Program (PADCT), an initiative undertaken by the Brazilian government and the World Bank. The third version of this Program (PADCT III) was set up during the period 1998-2002 and supported 142 projects through its Technological Development Component (CDT), contemplating four lines of action: Technological Platforms (PLAT), Sectoral and Regional Development (PCRS), Specific Collaborative Projects (CE) and Technological Support to Small and Medium Finns (AMPE). This paper aims at presenting this experience through the exploration of an ex-post evaluation related to a set of results demonstrating the feasibility of this S&T policy option for developing countries27547548

Genetic Diversity In Yellow Passion Fruit (passiflora Edulis Sims) Based On Rapd [diversidade Genética De Maracujazeiro 'amarelo' (passiflora Edulis Sims) Com Base Em Marcadores Rapd]

This study aimed to evaluate the genetic diversity by RAPD markers in 20 genotypes of 'yellow' passion fruit (Passiflora edulis Sims). The 16 primers generated 92 markers, 57 (62%) of which were polymorphic. The genetic distance (gd ij) estimated by the complement of the Dice index (gd ij = 0.19) and genotype grouping based on UPGMA algorithm showed low variability among genotypes. These results show a narrower genetic basis than reported for other Passiflora populations and the need to increase this variability by germplasm introduction. Divergent genotypes were also identified for the choice of parents for crosses for genetic gains in traits previously selected within the population studied.102154159Araújo, F.P., Silva, N.S., Queiroz, M.A., Divergência genética entre acessos de Passiflora cincinnata Mast com base em descritores morfoagronômicos (2008) Revista Brasileira de Fruticultura, 30, pp. 723-730Bellon, G., Faleiro, F.G., Junqueira, K.P., Junqueira, N.T.V., Santos, E.C., Braga, M.F., Guimarães, C.T., Variabilidade genética de acessos silvestres e comerciais de Passiflora edulis Sims com base em marcadores RAPD (2007) Revista Brasileira de Fruticultura, 29, pp. 124-127Bellon, G., Faleiro, F.G., Peixoto, J.R., Junqueira, K.P., Junqueira, N.T.V., Fonseca, K.G., Braga, M.F., Variabilidade genética de acessos obtidos de populações cultivadas e silvestres de maracujazeiro-doce com base em marcadores RAPD (2009) Revista Brasileira de Fruticultura, 31, pp. 197-202Bernacci, L.C., Meletti, L.M.M., Soares-Scott, M.D., Passos, I.R.S., Espécies de maracujá: Caracterização e conservação da biodiversidade (2005) Maracujá: Germoplasma e melhoramento genético, pp. 559-586. , In Faleiro FG, Junqueira NTV and Braga MF (eds.), Embrapa Cerrados, PlanaltinaBorém, A., Caixeta, E.T., (2006) Marcadores moleculares, p. 374. , UFV, ViçosaBorges, R.S., Scaranari, C., Nicoli, A.M., Coelho, R.R., Novas variedades: Validação e transferência de tecnologia (2005) Maracujá: Germoplasma e melhoramento genético, pp. 618-640. , In Faleiro FG, Junqueira NTV and Braga MF (eds.), Embrapa Cerrados, PlanaltinaCardoso-Silva, C.B., Melo, J.R.F., Pereira, A.S., Cerqueira-Silva, C.B.M., Oliveira, A.C., Estudo da diversidade genética mediante caracterização físico-química de frutos de maracujazeiros-dosono nativos do estado da Bahia (2007) Magistra, 19, pp. 352-358Cerqueira-Silva, C.B.M., Cardoso-Silva, C.B., Notato, J.V.A., Corrêa, R.X., Oliveira, A.C., Genetic dissimilarity of 'yellow' and 'sleep' passion fruit accessions based on the fruits ́ physicalchemical characteristics (2009) Crop Breeding and Applied Biotechnology, 9, pp. 210-218Cerqueira-Silva, C.B.M., Cardoso-Silva, C.B., Conceição, L.D.H.C.S., Nonato, J.V.A., Oliveira, A.C., Corrêa, R.X., Comparison of coefficients and distance measurements in passion fruit plants with molecular markers and physical-chemical descriptors (2009) Genetics and Molecular Research, 8, pp. 870-879Cerqueira-Silva, C.B.M., Moreira, C.N., Figueira, A.R., Corrêa, R.X., Oliveira, A.C., Detection of resistance gradient to the Passion fruit woodiness virus and selection of yellow passion fruit plants in field conditions (2008) Genetics and Molecular Research, 7, pp. 1209-1216Cruz, C.D., (2001) Programa Genes: Aplicativo computacional em genética e estatística, p. 648. , Editora UFV, ViçosaDias, L.A.S., Picoli, E.A.T., Rocha, R.B.R., Alfenas, A.C., A priori choice of hybrid parents in plants (2004) Genetics and Molecular Research, 3, pp. 356-368Dice, L.R., Measures of the amount of ecologic association between species (1945) Ecology, 26, pp. 297-302Doyle, J.J., Doyle, J.L., Isolation of plant DNA from fresh tissue (1990) Focus, 12, pp. 13-15Fajardo, D., Angel, F., Grum, M., Tohme, J., Lobo, M., Roca, W.M., Sanchez, I., Genetic variation analysis of the genus Passiflora L. using RAPD markers (1998) Euphytica, 101, pp. 341-347Faleiro, F.G., Junqueira, N.T.V., Braga, M.F., Germoplasma e melhoramento genético do maracujazeiro-desafios da pesquisa (2005) Maracujá: Germoplasma e melhoramento genético, pp. 187-210. , In Faleiro FG, Junqueira NTV and Braga MF (eds.), Embrapa Cerrados, PlanaltinaFerrão, F.A.G., Fonseca, A.F.A., Ferrão, R.G., Barbosa, W.M., Souza, L.M.R., Genetic divergence in conilon coffee revealed by RAPD markers (2009) Crop Breeding and Applied Biotechnology, 9, pp. 67-74Ferreira, F.R., Recursos genéticos de Passiflora (2005) Maracujá: Germoplasma e melhoramento genético, pp. 41-50. , In Faleiro FG, Junqueira NTV and Braga MF (eds.), Embrapa Cerrados, PlanaltinaFonseca, K.G., Faleiro, F.G., Peixoto, J.R., Junqueira, N.T.V., Silva, M.S., Bellon, G., Junqueira, K.P., Vaz, C.F., Análise da recuperação do genitor recorrente em maracujazeiro-azedo por meio de marcadores RAPD (2009) Revista Brasileira de Fruticultura, 31, pp. 145-153Juchum, F.S., Leal, J.B., Santos, L.M., Almeida, M.P., Ahnert, D., Corrêa, R.X., Evaluation of genetic diversity in a natural rosewood population (Dalbergia nigra Vell. Allemão ex Benth.) using RAPD markers (2007) Genetics and Molecular Research, 6, pp. 543-553Junqueira, K.P., Faleiro, F.G., Junqueira, N.T.V., Bellon, G., Ramos, J.D., Braga, M.F., Souza, L.S., Confirmação de híbridos interespecíficos artificiais no gênero Passiflora por meio de marcadores RAPD (2008) Revista Brasileira de Fruticultura, 30, pp. 191-196Junqueira, K.P., Faleiro, F.G., Ramos, J.D., Bellon, G., Junqueira, N.T.V., Braga, M.F., Variabilidade genética de acessos de maracujásuspiro com base em marcadores moleculares (2007) Revista Brasileira de Fruticultura, 29, pp. 571-575Junqueira, N.T.V., Anjos, J.R.N., Silva, A.P.O., Chaves, R.C., Gomes, A.C., Reaction to diseases and yield of eleven cultivars of sour-passion fruit cultivated with no pesticides (2003) Pesquisa Agropecuária Brasileira, 38, pp. 1005-1010Kruskal, J.B., Multidimensional scaling by optimizing goodness of fit to a non-metric hypothesis (1964) Psychometrika, 29, pp. 1-27Leal, J.B., Santos, L.M., Santos, C.A.P., Pires, J.L., Ahnert, D., Corrêa, R.X., Diversidade genética entre acessos de cacau de fazendas e de banco de germoplasma na Bahia (2008) Pesquisa Agropecuária Brasileira, 43, pp. 851-858Leão, R.M.K., Peixoto, J.R., Junqueira, N.T.V., Resende, R.O., Mattos, J.K.A., Melo, B., Reação de progênies de maracujazeiroazedo ao vírus do endurecimento do fruto (cowpea aphid-borne mosaic virus-CABMV) em casa de vegetação (2006) Bioscience Journal, 22, pp. 87-92Meletti, L.M.M., Santos, R.R., Minami, K., Melhoramento do maracujazeiro-amarelo: Obtenção do cultivar 'composto IAC-27'1,2 (2000) Scientia Agricola, 57, pp. 491-498Nonato, J.V.A., Cerqueira-Silva, C.B.M., Oliveira, A.C., Avaliação biométrica e química de frutos de maracujazeiros amarelo (Passiflora edulis Sims f. flavicarpa O. Deg.) contrastantes quanto a prolificidade de produção de frutos (2008) Proceedings Interamerican Society for Tropical Horticulture, 52, pp. 153-155Pham, T.D., Bui, T.M., Werlemark, G., Bui, T.C., Merker, A., Carlsson, A.S., A study of genetic diversity of sesame (Sesamum indicum L.) in Vietnam and Cambodia estimated by RAPD markers (2009) Genetic Resources and Crop Evolution, 56, pp. 679-690Sánchez, I., Angel, F., Grum, M., Duque, M.C., Lobo, M., Tohme, J., Roca, W., Variability of chloroplast DNA in the genus Passiflora L (1999) Euphytica, 106, pp. 15-26Segura, S.D., Coppens, D.E.G., Ocampo, C.H., Ollitrault, P., Isozyme variation in Passiflora subgenera Tacsonia and Manicata. Relationships between cultivated and wild species (2003) Genetic Resources and Crop Evolution, 50, pp. 417-427Segura, S.D., Coppens, D.E.G., Bohorquez, A., Ollitrault, P., Tohmé, J., An AFLP diversity study of the genus Passiflora focusing on subgenus Tacsonia (2002) Genetic Resources and Crop Evolution, 0, pp. 1-13Viana, A.P., Pereira, T.N.S., Pereira, M.G., Souza, M.M., Maldonado, J.V.M., Amaral Jr., A.T., Genetic diversity among yellow passion fruit commercial genotypes and among Passiflora species using RAPD (2003) Revista Brasileira de Fruticultura, 25, pp. 489-493Williams, J.G., Kubelik, A.R., Livak, K.J., Rafalski, L.A., Tingel, S.V., DNA polymorphism amplified by arbitrary initiator are useful as genetic markers (1990) Nucleic Acids Research, 18, pp. 6531-653

Optical readout tracking detector concept using secondary scintillation from liquid argon generated by a thick gas electron multiplier

For the first time secondary scintillation, generated within the holes of a thick gas electron multiplier (THGEM) immersed in liquid argon, has been observed and measured using a silicon photomultiplier device (SiPM). 250 electron-ion pairs, generated in liquid argon via the interaction of a 5.9 keV Fe-55 gamma source, were drifted under the influence of a 2.5 kV/cm field towards a 1.5 mm thickness THGEM, the local field sufficiently high to generate secondary scintillation light within the liquid as the charge traversed the central region of the THGEM hole. The resulting VUV light was incident on an immersed SiPM device coated in the waveshifter tetraphenyl butadiene (TPB), the emission spectrum peaked at 460 nm in the high quantum efficiency region of the device. For a SiPM over-voltage of 1 V, a THGEM voltage of 9.91 kV, and a drift field of 2.5 kV/cm, a total of 62 +/- 20 photoelectrons were produced at the SiPM device per Fe-55 event, corresponding to an estimated gain of 150 +/- 66 photoelectrons per drifted electron