3,715 research outputs found
Chopped random-basis quantum optimization
In this work we describe in detail the "Chopped RAndom Basis" (CRAB) optimal
control technique recently introduced to optimize t-DMRG simulations
[arXiv:1003.3750]. Here we study the efficiency of this control technique in
optimizing different quantum processes and we show that in the considered cases
we obtain results equivalent to those obtained via different optimal control
methods while using less resources. We propose the CRAB optimization as a
general and versatile optimal control technique.Comment: 9 pages, 10 figure
Adiabatic quantum dynamics of a random Ising chain across its quantum critical point
We present here our study of the adiabatic quantum dynamics of a random Ising
chain across its quantum critical point. The model investigated is an Ising
chain in a transverse field with disorder present both in the exchange coupling
and in the transverse field. The transverse field term is proportional to a
function which, as in the Kibble-Zurek mechanism, is linearly
reduced to zero in time with a rate , , starting
at from the quantum disordered phase () and ending
at in the classical ferromagnetic phase (). We first analyze
the distribution of the gaps -- occurring at the critical point --
which are relevant for breaking the adiabaticity of the dynamics. We then
present extensive numerical simulations for the residual energy
and density of defects at the end of the annealing, as a function of
the annealing inverse rate . %for different lenghts of the chain. Both
the average and are found to behave
logarithmically for large , but with different exponents, with , and
. We propose a mechanism for
-behavior of based on the Landau-Zener
tunneling theory and on a Fisher's type real-space renormalization group
analysis of the relevant gaps. The model proposed shows therefore a
paradigmatic example of how an adiabatic quantum computation can become very
slow when disorder is at play, even in absence of any source of frustration.Comment: 10 pages, 11 figures; v2: added references, published versio
Antibody Titers And Response To Vaccination Against Hepatitis A And B In Pediatric Patients With Portal Hypertension
In Brazil, approximately 130 new cases of hepatitis A per 100,000 inhabitants occur annually and 15% of the population has been in contact with hepatitis B virus. Portal hypertension causes hypersplenism and reduces T cell production, which may lead to less effective response to hepatitis vaccination. The objective of the study was to evaluate the response to hepatitis A and B vaccination in patients with portal hypertension secondary to chronic liver disease or portal vein thrombosis. Twenty-three patients (2 to 18 years) with portal hypertension seen at the Pediatric Hepatology Service of Hospital das Clínicas, Universidade Estadual de Campinas, between 1994 and 2006 were studied. Hepatitis A and B serology was tested in all patients. Patients who had not been vaccinated before their visits received the vaccines during the study period. Patients who had been vaccinated before but had negative anti-HB antibodies received a booster dose, and their serology was repeated. Blood counts were performed in each patient to assess for immunosuppression. Eighteen patients received hepatitis A vaccine and all became positive for anti-HAV antibodies. All patients had received hepatitis B vaccine and 17 (73.9%) were anti-HBs positive at the time of the study. The other 6 received a booster dose and became anti-HBs positive afterward. The anti-HBs-positive and -negative patients did not differ significantly in age, leukocytes, lymphocytes, or duration between the vaccination and positive serology. In this study, hepatitis A vaccines elicited a 100% response and hepatitis B vaccine conferred protection and induced an anamnestic response in pediatric patients with portal hypertension.383187193Brasil. Ministério da Saúde. Tópicos de saúde - Hepatites, , http://portal.saude.gov.br/portal/saude/visualizar-texto.cfm?idtext=22248, on line] 2006 [Accessed January 10, 2006] Available atPrevention of hepatitis A through active or passive immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP) (1999) MMWR, 48, pp. 26-27. , Centers for Disease Control and PreventionAkriviadis, E.A., Redeker, A.G., Fulminant hepatitis A in intravenous drug users with chronic liver disease (1989) Ann Int Med, 110, pp. 838-839Keeffe, E.B., Is hepatitis A more severe in patients with chronic hepatitis B and other liver diseases? (1995) Am J Gastroenterol, 90, pp. 201-205Vento, S., Garofano, T., Renzini, C., Cainelli, F., Casali, F., Ghironzi, G., Ferraro, T., Concia, E., Fulminant hepatitis associated with hepatitis A virus superinfection in patients with chronic hepatitis C (1998) N Engl J Med, 338, pp. 286-290Clemens, R., Safary, A., Hepburn, A., Roche, C., Stanbury, W.J., André, F.E., A clinical experience with an inactivated hepatitis A vaccine (1995) J Infect Dis, 171, pp. S44-S49Ferreira, C.T., Targa, C., Silveira, T.R., Hepatites virais: Aspectos da epidemiologia e da prevenção. (2004) Revista Brasileira de Epidemiologia, 7, pp. 473-487Foccacia, R., Conceição, O.J.G., Sette Junior, H., Sabino, E., Bassit, L., Nitrini, D.R., Lomar, A.V., Fisher, D., Estimated prevalence of viral hepatitis in the general population of the municipality of São Paulo, measures by a serological survey of a stratified, randomized and residence based population (1998) Braz J Infect Dis, 2, pp. 269-284Lee, W.M., Hepatitis B virus infection (1997) N Engl J Med, 337, pp. 1733-1745Kline, M.W., Shearer, W.T., Active and passive immunization in the prevention of infectious diseases (1996) Immunologic disorders in infants and children, pp. 916-938. , Stiehm ER, ed, 4a ed. Philadelphia: Saunders Company;Alper, C.A., Kruskall, M.S., Marcus-Bagley, D., Craven, D.E., Katz, A.J., Brink, S.J., Dienstag, J.L., Yunis, E.J., Genetic prediction of nonresponse to hepatitis B vaccine (1989) N Engl J Med, 321, pp. 708-712Craven, D.E., Awdeh, Z.L., Kunches, L.M., Yunes, E.J., Dienstag, J.L., Werner, B.G., Polk, F., Alper, C.A., Nonresponsiveness to hepatitis B vaccine in health care workers. Results of revaccination and genetic typings (1986) Ann Intern Med, 105, pp. 356-360Idilman, R., Colantoni, A., De Maria, N., Ustun, C., Sam, R., Ingin, T.S., Akan, H., Thiel, D.H.V., Impaired antibody response rates after high dose short interval hepatitis B vaccination of immunosuppressed individuals (2003) Hepato Gastroenterol, 50, pp. 217-221Karasu, Z., Ozacar, T., Akarca, U., Ersoz, G., Erensoy, S., Gunsar, F., Kobat, A., Batur, Y., HBV vaccination in liver transplant patients: Not an effective strategy in the prophylaxis of HBV recurrence (2005) J Viral Hepat, 12, pp. 212-215Lo, C.M., Liu, C.L., Chan, S.C., Lau, G.K., Fan, S.T., Failure of hepatitis B vaccination in patients receiving lamivudine prophylaxis after liver transplantation for chronic hepatitis B (2005) J Hepatol, 43, pp. 283-287Henderson, JM. Portal Hypertension. In: Corson J, Williamson R, eds. Surgery [on line] London: Mosby2000 October [Accessed September 12, 2006]. Available at: http:///www.elsevier-international.com/e-books/pdf/8.pdfPinto RB, Silveira TR. Trombose de veia porta em crianças e adolescentes: série de 14 casos. AMRIGS, Porto Alegre 2002;46:45-72Martinelli, A.L.C., Hipertensão portal. (2004) Medicina (Ribeirão Preto), 37, pp. 253-261Schettino, G.C.M., Fagundes, E.D.T., Roquete, M.L.V., Ferreira, A.R., Penna, F.J., Portal vein thrombosis in children and adolescents (2006) J Pediatr (Rio J), 82, pp. 171-178Jacob, H.S., Erythrocyte disorders - anemias related to hyperactivity of the reticuloendothelial system (1972) Hematology, pp. 511-520. , Williams WJ, Beutler E, Erslev AJ, Rundles RW, eds, New York: McGraw-Hill;MacGahan, J.P., Phillips, H.E., Cox, K.L., Sonography of the normal pediatrics gallbladdes an biliary tract (1982) Radiology, 144, pp. 873-875Patriquin, H., Tessier, G., Grignon, A., Boivert, J., Lesser omental thickness in normal children: Baseline for detection of portal hypertension (1985) AJR, 145, pp. 693-696Irigoyen, N., A importância da medida ecográfica do pequeno epíplon no diagnóstico da hipertensão portal em pediatria. (1991) Rev Imagem, 13, pp. 145-148West, M.S., Garra, B.S., Horii, S.C., Hayes, W.S., Cooper, C., Silverman, P.M., Zeman, R.K., Gallbladder varices: Imaging findings in patients with portal hypertension (1991) Radiology, 179, pp. 179-182Hoffbrand, A.V., Pettit, J.E., Moss, P.A.H., (2003) Essential Haematology, p. 331. , 4a ed. Massachusetts: Blackwell Science;Conover WJ. The use of ranks. Two independent samples. In: Conover WJ. Practical Nonparametric Statistics, 1a ed. New York: John Wiley & Sons Inc1971.p.223-236Ferreira, C.T., Taniguchi, A.N., Vieira, S.M., Pereira-Lima, J., da Silveira, T.R., Prevalência do anticorpo da hepatite A em hepatopatia crônica. (2002) J Pediatr (Rio J), 78, pp. 503-508Ferreira, C.T., Silveira, T.R., Vieira, S.M., Taniguchi, A., Pereira-Lima, J., Immunogenicity and safety of hepatitis A vaccine in children with chronic liver disease (2003) J Ped Gastroenterol Nutr, 37, pp. 258-261Arslan, M., Wiesner, R.H., Poterucha, J.J., Zein, N.N., Safety and efficacy of hepatitis A vaccination in liver transplantation recipients (2001) Transplantation, 72, pp. 272-276Dumot, J.A., Barnes, D.S., Younossi, Z., Gordon, S.M., Avery, R.K., Domen, R.E., Henderson, J.M., Carey, W.D., Immunogenicity of hepatitis A vaccine in decompensated liver disease (1999) Am J Gastroenterol, 94, pp. 1601-1604Stark, K., Günther, M., Neuhaus, R., Reinke, P., Schröder, K., Linnig, S., Bienzle, U., Immunogenicity and safety of hepatitis A vaccine in liver and renal transplant patients (1999) J Infect Dis, 180, pp. 2014-2017Keeffe, E.B., Iwarson, S., McMahon, B.J., Lindsay, K.L., Koff, R.S., Manns, M., Baumgarten, R., Krause, D.S., Safety and immunogenicity of hepatitis A vaccine in patients with chronic liver disease (1998) Hepatology, 27, pp. 881-886Aziz, A., Aziz, S., Li, D.S., Murphy, L., Leone, N., Kennedy, M., Dhillon, S., Van Thiel, D.H., Efficacy of repeated high-dose hepatitis B vaccine in patients with chronic liver disease (2006) J Viral Hepat, 13, pp. 217-221De Maria, N., Idilman, R., Colantoni, A., Van Thiel, D.H., Increased effective immunogenicity to high-dose and short-interval hepatitis B virus vaccination in individuals with chronic hepatitis without cirrhosis (2001) J Viral Hepat, 8, pp. 372-376Wiedmann, M., Liebert, U.G., Oesen, U., Porst, H., Wiese, M., Schroeder, S., Halm, U., Berr, F., Decreased immunogenicity of recombinant hepatitis B vaccine in chronic hepatitis C (2000) Hepatology, 31, pp. 230-234Ferrante, A., Davidson, G.P., Beard, L.J., Goh, D.H.B., Alterations in function and subpopulations of peripheral blood mononuclear leukocytes in children with portal hypertension (1989) Int Arch Allergy Appl Immunol, 88, pp. 348-352McGovern, B., Golan, Y., Lopez, M., Pratt, D., Lawton, A., Moore, G., Epstein, M., Knox, T.A., The impact of cirrhosis on CD4+ cell counts in HIV-seronegative patients (2007) Clin Infect Dis, 44, pp. 431-437Tokushige, K., Yamauchi, K., Komatsu, T., Takasaki, K., Hayashi, N., Predominant T helper 1 cells in patients with idiopathic portal hypertension (2000) J Gastroenterol Hepatol, 15, pp. 1312-1317Williams, I.T., Goldstein, S.T., Tufa, J., Tauillii, S., Margolis, H.S., Mahoney, F.J., Long term antibody response to hepatitis B vaccination beginning at birth and to subsequent booster vaccination (2003) Pediatr Infect Dis J, 22, pp. 157-163Boxall, E.H., Sira, J.A., El-Shunkri, N., Kelly, D.A., Long-term persistence of immunity to Hepatitis B after vaccination during infancy in a country where endemicity is low (2004) J Infect Dis, 90, pp. 1264-126
The internal structure and formation of early-type galaxies: the gravitational--lens system MG2016+112 at z=1.004
[Abridged] We combine our measurements of the velocity dispersion and the
surface brightness profile of the lens galaxy D in the system MG2016+112
(z=1.004) with constraints from gravitational lensing to study its internal
mass distribution. We find that: (i) dark matter accounts for >50% of the total
mass within the Einstein radius (99% CL), excluding at the 8-sigma level that
mass follows light inside the Einstein radius with a constant mass-to-light
ratio (M/L). (ii) the total mass distribution inside the Einstein radius is
well-described by a density profile ~r^-gamma' with an effective slope
gamma'=2.0+-0.1+-0.1, including random and systematic uncertainties. (iii) The
offset of galaxy D from the local Fundamental Plane independently constrains
the stellar M/L, and matches the range derived from our models, leading to a
more stringent lower limit of >60% on the fraction of dark matter within the
Einstein radius (99%CL).
Under the assumption of adiabatic contraction, the inner slope of the dark
matter halo before the baryons collapsed is gamma_i<1.4 (68 CL), marginally
consistent with the highest-resolution cold dark matter simulations that
indicate gamma_i~1.5. This might indicate that either adiabatic contraction is
a poor description of E/S0 formation or that additional processes play a role
as well. Indeed, the apparently isothermal density distribution inside the
Einstein radius, is not a natural outcome of adiabatic contraction models,
where it appears to be a mere coincidence. By contrast, we argue that
isothermality might be the result of a stronger coupling between luminous and
dark-matter, possibly the result of (incomplete) violent relaxation processes.
Hence, we conclude that galaxy D appears already relaxed 8 Gyr ago.Comment: 8 pages, 4 figures, ApJ, in press, minor change
Diagnosis Of Alpha-1-antitrypsin Deficiency By Dna Analysis Of Children With Liver Disease
Background - Alpha-1-antitrypsin deficiency is a genetic disorder which is transmitted in a co-dominant, autosomal form. Alpha-1-antitrypsin deficiency affects mainly the lungs and the liver leading, in the latter case, to neonatal cholestasis, chronic hepatitis or cirrhosis. A precise diagnosis of Alpha-1-antitrypsin deficiency may be obtained by biochemical or molecular analysis. Objective - The purpose of this study was to use DNA analysis to examine the presence of an alpha-1-antitrypsin deficiency in 12 children suspected of having this deficiency and who showed laboratory and clinical characteristics of the disease. Patients and Methods - Twelve patients, aged 3 months to 19 years, who had serum alpha-1-antitrypsin levels lower than normal and/or had hepatic disease of undefined etiology were studied. The mutant alleles S and Z of the alpha-1-antitrypsin gene were investigated in the 12 children. Alpha-1-antitrypsin gene organization was analyzed by amplification of genoma through the polymerase chain reaction and digestion with the restriction enzymes Xmnl (S allele) and Taq 1 (Z allele). Results - Seven of the 12 patients had chronic liver disease of undefined etiology and the other five patients had low serum levels of alpha-1-antitrypsin as well as a diagnosis of neonatal cholestasis and/or chronic liver disease of undefined etiology. Five of the 12 patients were homozygous for the Z allele (ZZ) and two had the S allele with another allele (*S) different from Z. Conclusion - These results show that alpha-1-antitrypsin deficiency is relatively frequent in children with chronic hepatic disease of undefined etiology and/or low alpha-1-antitrypsin levels (41.6%). A correct diagnosis is important for effective clinical follow-up and for genetic counseling.3816368Alagille, D., Cholestasis in the first three months of life (1979) Prog Liver Dis, 6, pp. 471-485Andresen, B.S., Knudsen, I., Jensen, P.K.A., Gregersen, N., Two novel nonradioactive polymerase chain reaction-based assays of dried blood spots, genomic DNA, or whole cells for fast, reliable detection of Z and S mutations in the alpha-1-antitrypsin gene (1992) Clin Chem, 38, pp. 2100-2107Balistreri, W.F., Schubert, W.K., Liver disease in infancy and childhood (1993) Diseases of the Liver. 7.ed., pp. 1099-1203. , Schiff L, Schiff ER, editors. Philadelphia: LippincottBillingsley, G.D., Cox, D.W., Functional assessment of genetic variants of alpha 1-antitrypsin (1982) Hum Genet, 61, pp. 118-122Brantly, M., Nukiwa, T., Crystal, R.G., Molecular basis of alpha-1-antitrypsin deficiency (1988) Am J Med, 84, pp. 13-31Carlson, J.A., Rogers, R.B., Sifers, R., Acumulation of PiZ alpha 1-antitrypsin causes liver damage in transgenic mice (1989) J Clin Invest, 83, pp. 1183-1190Carrel, R.W., Alpha 1-antitrypsin: Molecular pathology, leukocytes and tissue damage (1986) J Clin Invest, 78, pp. 1427-1431Cox, D.W., Woo, S.L., Mansfield, T., DNA restriction fragments associated with alpha 1-antitrypsin indicate a single origin for deficiency allele PI Z (1985) Nature, 316, pp. 79-81Crystal, R.G., Brantly, M.L., Hubbard, R.C., Curiel, D.T., States, D.J., Holmes, M.D., The alpha 1-antitrypsin gene and its mutations. Clinical consequences and strategies for therapy (1989) Chest, 95, pp. 196-208Crystal, R.G., Ferrans, V.J., Basset, F., Biologic basis of pulmonary fibrosis (1991) The Lung: Scientific Foundations, pp. 2031-2046. , Crystal RG, West JB, Barnes PJ, Cherniack S, editors. New YorkRaven PressCuriel, D., Brantly, M., Curiel, E., Crystal, R.G., Alpha-1-antitrypsin deficiency caused by the alpha-1-antitrypsin Nullmattawa gene. An insertion mutation rendering the alpha-1-antitrypsin gene incapable of producing alpha-1-antitrypsin (1989) J Clin Invest, 83, pp. 1144-1152Dermer, S.J., Johnson, E.M., Rapid DNA analysis of alpha 1-antitrypsin deficiency: Application of an improved method for amplifying mutated gene sequence (1988) Lab Invest, 59, pp. 403-408Deutsch, J., Becker, H., Auböck, L., Histopathological features of liver disease in alpha 1-antitrypsin deficiency (1994) Acta Paediatr, 393 (SUPPL.), pp. 8-12Dubel, J.R., Finwick, R., Hejtmancik, J.F., Denaturing gradient gel electrophoresis of the alpha 1-antitrypsin gene: Application to prenatal diagnosis (1991) Am J Med Genet, 41, pp. 39-43Evans, H.E., Levi, M., Mandl, I., Serum enzyme inhibitor concentrations in the respiratory distress syndrome (1970) Am Rev Resp Dis, 101, pp. 359-363Fagerhol, M.K., Cox, D.W., The PI polimorphism: Genetic, biochemical and clinical aspects of human alpha-1-antitrypsin (1981) Human Genetic, pp. 1-62. , Harris H, Hirchorn, K, editors. New York: PlenumGartner, J.C., Zitelli, B.J., Malatak, J.J., Shaw, B.W., Iwatsuki, S., Starzl, T.E., Orthotopic liver transplantation in children: Two-year experience with 47 patients (1984) Pediatrics, 74, pp. 140-145Ishak, K.G., Hepatic morphology in inherited metabolic diseases (1986) Sem Liver Dis, 6, pp. 246-258Jeppsson, J.O., Laurell, C.B., Fagerhol, M.K., Properties of isolated alpha-1-antitrypsin of Pi types M, S and Z (1978) Eur J Biochem, 83, pp. 143-153Lai, E.C., Kao, F.T., Law, M.L., Woo, S.L., Assignment of the alpha 1-antitrypsin gene and a sequence-related gene to human chromossome 14 by molecular hybridization (1983) Am J Hum Genet, 35, pp. 385-392Laurell, C.B., Eriksson, S., The electrophoretic alpha-1-globulin pattern of serum in alpha-1-antitrypsin deficiency (1963) Scand J Clin Lab Invest, 15, pp. 132-140Laurell, C.B., Kullander, S., Thorell, J., Effect of administration of a combined strogen-progestin contraceptive on the level of individual plasma proteins (1968) Scand J Clin Lab Invest, 21, pp. 337-343Massi, G., Chiarelli, C., Alpha 1-antitrypsin: Molecular and the Pi system (1994) Acta Paediatr, 393 (SUPPL.), pp. 1-4Mowat, A.P., Avaliação laboratorial das afecções hepatobiliares (1991) Doenças Hepáticas Em Pediatria. 2.ed., pp. 410-430. , Mowat AP. Rio de Janeiro: RevinterNukiwa, T., Brantly, M., Ogushi, F., Crystal, R.G., Characterization of the M1(ala 213) type of alpha-1-antitrypsin, a newly recognized common "normal" alpha-1-antitrypsin haplotype (1987) Biochemistry, 26, pp. 5259-5267Okayama, H., Curiel, D.T., Brantly, M.L., Holmes, M.D., Crystal, R.G., Rapid nonradioactive detection of mutations in the human genome by allele-specific amplification (1989) J Lab Clin Med, 114, pp. 105-113Perlmutter, D.H., The cellular basis for liver injury in alpha-1-antitrypsin deficiency (1991) Hepatology, 13, pp. 172-185Perlmutter, D.H., Clinical manifestations of alpha 1-antitrypsin deficiency (1995) Gastroenterol Clin North Am, 24, pp. 27-43Schroeder, W.T., Miller, M.F., Woo, S.L., Saunders, G.F., Chromosomal localization of the human alpha 1-antitrypsin gene (PI) to 14q31-32 (1985) Am J Hum Genet, 37, pp. 868-872Serra, H.G., (1998) Identificação Molecular Dos Alelos S e Z Do Gene Da Alfa-1-antitripsina Em Um Grupo de Pacientes Portadores de Doença Pulmonar Crônica [tese de Doutorado], , Campinas, SP: Instituto de Biologia da Universidade Estadual de CampinasSilverman, E.K., Miletich, J.P., Pierce, J.A., Sherman, L.A., Endicott, S.K., Broze, G.J., Campbell, E.J., Alpha-1-antitrypsin deficiency. High prevalence in the St. Louis area determined by direct population screening (1989) Am Rev Respir Dis, 140, pp. 961-966Sveger, T., Liver disease in alpha 1-antitrypsin deficiency detected by screening of 200,000 infants (1976) N Engl J Med, 294, pp. 1316-1321Sveger, T., The natural history of liver disease in alpha 1-antitrypsin deficient children (1988) Acta Paediatr Scand, 77, pp. 847-851Sveger, T., Ericksson, S., The liver in adolescents with alpha 1-antitrypsin deficiency (1995) Hepatology, 22, pp. 514-517Talbot, I.C., Mowat, A.P., Liver disease in infancy. Histological features and relationship to alpha 1-antitrypsin phenotype (1975) J Clin Pathol, 28, pp. 559-563Travis, J., Salvesen, G.S., Human plasma proteinase inhibitors (1983) Annu Rev Biochem, 52, pp. 655-709Van Steenbergen, W., Alpha 1-antitrypsin deficiency: An overview (1993) Acta Clin Belg, 48 (3), pp. 171-189Wewers, M.D., Casolaro, M.A., Sellers, S.E., Swayze, S.C., McPhaul, K.M., Wittes, J.T., Crystal, R.G., Replacement therapy deficiency associated with emphysema (1987) N Engl J Med, 316, pp. 1055-1062Woodhead, J.L., Fallon, R., Figuered, H., Longdale, J., Malcom, A.D.B., Alternative methodology of gene diagnosis (1986) Human Genetic Diseases - a Pratical Approach, pp. 51-64. , Davies KE, editor. Oxford: IRL Pres
Steady-state visual evoked potentials and phase synchronization in migraine
We investigate phase synchronization in EEG recordings from migraine
patients. We use the analytic signal technique, based on the Hilbert transform,
and find that migraine brains are characterized by enhanced alpha band phase
synchronization in presence of visual stimuli. Our findings show that migraine
patients have an overactive regulatory mechanism that renders them more
sensitive to external stimuli.Comment: 4 page
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