Two-loop stability of a complex singlet extended Standard Model

Motivated by the dark matter and the baryon asymmetry problems, we analyze a complex singlet extension of the Standard Model with a Z(2) symmetry (which provides a dark matter candidate). After a detailed two-loop calculation of the renormalization group equations for the new scalar sector, we study the radiative stability of the model up to a high energy scale (with the constraint that the 126 GeV Higgs boson found at the LHC is in the spectrum) and find it requires the existence of a new scalar state mixing with the Higgs with a mass larger than 140 GeV. This bound is not very sensitive to the cutoff scale as long as the latter is larger than 10(10) GeV. We then include all experimental and observational constraints/measurements from collider data, from dark matter direct detection experiments, and from the Planck satellite and in addition force stability at least up to the grand unified theory scale, to find that the lower bound is raised to about 170 GeV, while the dark matter particle must be heavier than about 50 GeV.

Undoubtable signs of CP-violation in Higgs decays at the LHC run 2

With the discovery of the Higgs boson at the Large Hadron Collider the high energy physics community's attention has now turned to understanding the properties of the Higgs boson, together with the hope of finding more scalars during run 2. In this work we discuss scenarios where using a combination of three decays, involving the 125 GeV Higgs boson, the Z boson and at least one more scalar, an indisputable signal of CP-violation arises. We use a complex two-Higgs doublet model as a reference model and present some benchmark points that have passed all current experimental and theoretical constraints, and that have cross sections large enough to be probed during run 2.

Contributo para o estudo da infec����o cong��nita pelo v��rus citomeg��lico em Portugal

Resumo O v��rus citomeg��lico humano (CMV) �� o principal agente de infec����o cong��nita, atingindo cerca de 0.2 a 2.2% de todos os rec��m-nascidos. As crian��as que nascem infectadas por este v��rus t��m cerca de 11% a 12.7% de probabilidades de apresentarem sintomas e sinais de doen��a citomeg��lica ao nascimento, podendo cerca de 40 a 58% destas virem a apresentar sequelas neurol��gicas permanentes. Das crian��as infectadas que ter��o infec����o assintom��tica no per��odo neo-natal, 5 a 15% poder��o vir igualmente a sofrer de sequelas tardias, sobretudo a surdez ou o atraso mental. Em Portugal, desconhece-se a dimens��o deste problema. O primeiro objectivo desta disserta����o foi, desta forma, a determina����o da preval��ncia atrav��s do recurso aos cart��es do diagn��stico precoce (���Guthrie cards���), utilizando uma t��cnica de nested-PCR dirigida para o v��rus. Foram estudados 3600 cart��es, seleccionados de todo o territ��rio nacional (continente e ilhas), de uma forma proporcional ao n��mero de nascimentos em cada distrito, dos quais 38 foram positivos, o que d�� uma preval��ncia de 1.05% (intervalo de confian��a para 95%: 0.748-1.446). A revis��o sobre a experi��ncia acumulada nos ��ltimos 15 anos, na ��rea do diagn��stico pr��-natal, juntamente com um estudo adicional sobre a t��cnica da avidez, permitiu retirar algumas ila����es, nomeadamente que este diagn��stico constitui uma arma diagnostica fi��vel para a avalia����o pr��-natal desta infec����o cong��nita e que a selec����o dos casos para amniocentese dever�� obedecer a indica����es serol��gicas precisas, como a ���seroconvers��o para IgG��� ou a ���IgM confirmada��� (devendo o m��todo de confirma����o ser a avidez das IgG com um ��ndice <0,6) e as altera����es ecogr��ficas de etiologia n��o esclarecida. A possibilidade de utilizar pools de urinas para detectar a infec����o cong��nita por CMV foi abordada na terceira parte do trabalho experimental. A metodologia a�� descrita teve correla����o total com o m��todo de refer��ncia, permitindo uma redu����o bastante significativa nos tempos de execu����o e nos custos em consum��veis, pelo que abre a possibilidade da sua utiliza����o para o rastreio da infec����o cong��nita por CMV nos rec��m-nascidos.

Preserving the validity of the two-Higgs-doublet model up to the Planck scale

We examine the constraints on the two Higgs doublet model (2HDM) due to the stability of the scalar potential and absence of Landau poles at energy scales below the Planck scale. We employ the most general 2HDM that incorporates an approximately Standard Model (SM) Higgs boson with a flavor aligned Yukawa sector to eliminate potential tree-level Higgs-mediated flavor changing neutral currents. Using basis independent techniques, we exhibit robust regimes of the 2HDM parameter space with a 125 GeV SM-like Higgs boson that is stable and perturbative up to the Planck scale. Implications for the heavy scalar spectrum are exhibited.

Chlamydia trachomatis Infec����o na gr��vida e no rec��m-nascido

A infec����o urogenital causada por Chlamydia trachomatis �� a doen��a bacteriana sexualmente transmiss��vel mais comum na Europa, tanto em homens como em mulheres. Constitui um grave problema de sa��de p��blica devido �� elevada percentagem de portadores assintom��ticos, ��s complica����es cl��nicas que da�� podem resultar e �� possibilidade de transmiss��o vertical. O presente trabalho teve como principais objectivos: i) avaliar a preval��ncia da infec����o por C. trachomatis e por Neisseria gonorrhoeae num grupo de gr��vidas de 36 semanas atendidas na consulta externa de Obstetr��cia do Hospital Amadora Sintra e nos rec��m-nascidos de m��es infectadas, ii) identificar os serovares respons��veis pelas infec����es por C. trachomatis, iii) verificar a distribui����o da preval��ncia da infec����o por C. trachomatis em fun����o da idade e iv) avaliar a utilidade de uma t��cnica de PCR multiplex e de PCR multiplex em tempo real no diagn��stico desta infec����o. Foram testadas 1201 amostras de urina do primeiro jacto de gr��vidas e 18 exsudados oculares provenientes de rec��m-nascidos cujas m��es estavam infectadas com C. trachomatis. Cada amostra foi testada pelas t��cnicas de PCR multiplex e de PCR multiplex em tempo real, tendo como alvos de amplifica����o um fragmento do plasm��dio cr��ptico e outro do gene omp1. Todos os resultados positivos foram confirmados com uma t��cnica de nested PCR e posteriormente enviados para sequencia����o para identifica����o dos serovares envolvidos. Em todas as amostras foi ainda pesquisada a presen��a de ADN de N. gonorrhoeae atrav��s de t��cnicas de PCR e de PCR em tempo real sendo que, na primeira, o alvo a amplificar foi um fragmento do gene ccpB do plasm��dio pJDI e na segunda o pseudogene porA. Os resultados positivos foram confirmados por RFLP. A preval��ncia da infec����o por C. trachomatis e por N. gonorrhoeae foi de 3,7% (45/1201) e de 0,08% (1/1201), respectivamente. Nos rec��m-nascidos, a preval��ncia foi de 0% para ambas as infec����es, embora o n��mero de rec��m-nascidos estudados (18/45) dificilmente seja representativo. O serovar mais prevalente foi o E (31,1%), seguido do G (15,6%), do D/Da (13,3%), do F, I/Ia e do J (11,1%). O serovar K foi identificado em 4,4% das amostras infectadas e o H em apenas 2,2%. A t��cnica de PCR multiplex em tempo real parece ser mais adequada para o diagn��stico da infec����o por C. trachomatis do que a t��cnica de PCR multiplex, tendo a primeira detectado 100% dos casos de infec����o por este microrganismo (45/45), enquanto que a segunda detectou apenas 71% (32/45) dos mesmos.

A simple PCR-based procedure for plaque diagnosis

Supernatant of boiled spleen saline-suspensions of Yersinia pestis experimentally infected animals were used as template for PCR amplification without DNA extraction. PCR sensitivity was enhanced by a second round of amplification (Nested). No amplification was observed from non-infected animals.

Persistent infections in chronic Chagas' disease patients treated with anti-Trypanosoma cruzi nitroderivatives

We used a molecular method and demonstrated that treatment of the chronic human Trypanosoma cruzi infections with nitroderivatives did not lead to parasitological cure. Seventeen treated and 17 untreated chronic Chagas' disease patients, with at least two out of three positive serologic assays for the infection, and 17 control subjects formed the study groups. PCR assays with nested sets of T. cruzi DNA primers monitored the efficacy of treatment. The amplification products were hybridized to their complementary internal sequences. Untreated and treated Chagas' disease patients yielded PCR amplification products with T. cruzi nuclear DNA primers. Competitive PCR was conducted to determine the quantity of parasites in the blood and revealed < 1 to 75 T. cruzi/ml in untreated (means 25.83 �� 26.32) and < 1 to 36 T. cruzi/ml in treated (means 6.45 �� 9.28) Chagas' disease patients. The difference between the means was not statistically significant. These findings reveal a need for precise definition of the role of treatment of chronic Chagas' disease patients with nitrofuran and nitroimidazole compounds.

Cytomegalovirus infection in children with Down syndrome in a day-care center in Brazil

This study evaluates the transmission of CMV infection in 120 children aged 1 to 15 years with Down syndrome who attended a day-care center for handicapped children in S��o Paulo, Brazil. A blood sample was obtained from each children at the beginning of the study for detection of IgG and IgM cytomegalovirus (CMV) antibodies by an immunofluorescence assay. Samples of saliva and urine were obtained every 3 months from the children with CMV antibodies to detect shedding of the virus by culture in human foreskin fibroblasts, by detection of pp65 CMV-antigen and by a nested PCR assay. The prevalence of anti CMV-IgG antibodies was 76.6% (92/120), and IgM anti-CMV antibodies were detected in 13% (12/92) of the seropositive children. During the first viral evaluation, CMV was detected in the urine and/or saliva in 39/90 (43.3%) of the seropositive children. In the second and third evaluations, CMV was detected in 41/89 (46%) and in 35/89 (39.3%) children, respectively. Detection of CMV was shown both in urine and saliva in 28/39 (71.8%), 19/41(46.3%) and 20/35 (57.1%) of the children excreting the virus, respectively. Additionally, in 33/49 (67.4%) of the excreters CMV could be demonstrated in urine or saliva in at least two out of the three virological evaluations carried out sequentially in a six month period. Of the 28 initially seronegative children, 26 were re-examined for anti-CMV IgG antibodies about 18 months after the negative sample; seroconversion was found in 10/26 (38.5%). Taking all 536 samples of urine or saliva examined by virus culture and pp65 antigen detection during the study into account, 159 (29.6%) were positive by virus culture and 59 (11%) gave a positive result with the pp65 assay. These data demonstrate the high prevalence of CMV shedding and the high risk of CMV infection in children with Down syndrome attending a day-care center for mentally handicapped patients. The virus culture was more sensitive than the pp65 CMV antigen assay for CMV detection in both urine and saliva samples.

Outbreaks of human-herpes virus 6 (HHV-6) infection in day-care centers in Bel��m, Par��, Brazil

A total of 730 children aged less than 7 years, attending 8 day-care centers (DCCs) in Bel��m, Brazil were followed-up from January to December 1997 to investigate the occurrence of human-herpes virus 6 (HHV-6) infection in these institutional settings. Between October and December 1997 there have been outbreaks of a febrile- and -exanthematous disease, affecting at least 15-20% of children in each of the DCCs. Both serum- and- plasma samples were obtained from 401 (55%) of the 730 participating children for the detection of HHV-6 antibodies by enzyme-linked immunosorbent assay (ELISA), and viral DNA amplification through the nested-PCR. Recent HHV-6 infection was diagnosed in 63.8% (256/401) of them, as defined by the presence of both IgM and IgG-specific antibodies (IgM+/IgG+); of these, 114 (44.5%) were symptomatic and 142 (55.5%) had no symptoms (p = 0.03). A subgroup of 123 (30.7%) children were found to be IgM-/IgG+, whereas the remaining 22 (5.5%) children had neither IgM nor IgG HHV-6- antibodies (IgM-/IgG-). Of the 118 children reacting strongly IgM-positive ( > or = 30 PANBIO units), 26 (22.0%) were found to harbour the HHV-6 DNA, as demonstrated by nested-PCR. Taken the ELISA-IgM- and- nested PCR-positive results together, HHV-6 infection was shown to have occurred in 5 of the 8 DCCs under follow-up. Serological evidence of recent infections by Epstein-Barr virus (EBV) and parvovirus B19 were identified in 2.0% (8/401) and 1.5% (6/401) of the children, respectively. Our data provide strong evidence that HHV-6 is a common cause of outbreaks of febrile/exanthematous diseases among children attending DCCs in the Bel��m area.

Blood-sucking lice may disseminate Trypanosoma cruzi infection in baboons

Trypanosoma cruzi (Schyzotrypanum, Chagas, 1909), and Chagas disease are endemic in captive-reared baboons at the Southwest Foundation for Biomedical Research, San Antonio, Texas. We obtained PCR amplification products from DNA extracted from sucking lice collected from the hair and skin of T. cruzi-infected baboons, with specific nested sets of primers for the protozoan kinetoplast DNA, and nuclear DNA. These products were hybridized to their complementary internal sequences. Selected sequences were cloned and sequencing established the presence of T. cruzi nuclear DNA, and minicircle kDNA. Competitive PCR with a kDNA set of primers determined the quantity of approximately 23.9 �� 18.2 T. cruzi per louse. This finding suggests that the louse may be a vector incidentally contributing to the dissemination of T. cruzi infection in the baboon colony.

Controlo da velocidade e posi����o de um tapete rolante

A utiliza����o eficiente da energia �� essencial para a competitividade econ��mica de um pa��s. Sendo a intensidade energ��tica de Portugal elevada, onde a utiliza����o de motores el��tricos, absorve cerca de metade da energia el��trica consumida na ind��stria, a utiliza����o de conversores eletr��nicos de pot��ncia permite obter economias de energia. Nesta tese pretende-se controlar a velocidade e o posicionamento de um tapete rolante atrav��s da utiliza����o de um conversor eletr��nico de pot��ncia. Na fundamenta����o te��rica s��o referidos os conceitos de varia����o da tens��o e frequ��ncia, controle escalar e vetorial, modela����o por largura de pulso (PWM) assim como a retifica����o e ondula����o da tens��o de um variador de velocidades. Na parte pr��tica ser�� utilizado um servo motor, controlado por um variador eletr��nico de velocidades, para efetuar o referido projeto. �� ainda objeto desta tese o estudo dos par��metros fundamentais assim como a pesquisa dos par��metros a utilizar para o desempenho pretendido.

Association between human parvovirus B19 and arthropathy in Bel��m, Par��, north Brazil

A total of 220 patients with arthropathy were selected in Bel��m, Par�� between January 1994 and December 2000, and screened for the presence of human parvovirus B19 IgM and IgG antibodies by enzyme-linked immunosorbent assay (ELISA). A subgroup (n = 132) of patients with high levels of antibodies (either IgM+/IgG+ or IgM-/IgG+) were examined for the presence of DNA by polymerase chain reaction/nested PCR. Recent/active infection (detection of IgM and/or IgG-specific antibodies and presence of viral DNA) was identified in 47.7% of the 132 individuals with arthropathy. In our study, women were significantly more affected (59.7%) than men (35.4%) (P = 0.0006). The age group of 11-20 years (84.6%), among female patients, and 21-30 years (42.1%), among male, were those with the highest incidence rates. The analysis of the temporal distribution of B19-associated arthropaties showed a cyclic pattern, with peak incidence rates occuring at 3-5 year intervals. Significant diference (P = 0.01) was observed when comparing both the highest (39.0%) and the lowest (11.0%) seropositivity rates for the years of 1995 and 2000, respectively. The interfalangial joints of hands and feet were mostly affected, with 50.0% and 48.0% of cases among both women and men, respectively. In a smaller proportion, other joints such as those of knee, ankle, pulse and shoulder were affected. As for the duration, symptoms lasted 1 to 5 days in 54.0% of the individuals, whereas in 46.0% of them the disease lasted 6-10 days, if considered the subgroup (n = 63) of patients with recent/active infection by parvovirus B19. In our study, joint clinical manifestations occurred symmetrically. Our results indicate that B19 may be an important agent of arthropathies in our region, and this underscores the need for specific laboratory diagnosis when treating patients suffering from acute arthropathy, mainly pregnant women.

No evidence of vertical transmission of HTLV-I in bottle-fed children

The most frequent pathway of vertical transmission of HTLV-I is breast-feeding, however bottle fed children may also become infected in a frequency varying from 4 to 14%. In these children the most probable routes of infection are transplacental or contamination in the birth canal. Forty-one bottle-fed children of HTLV-I seropositive mothers in ages varying from three to 39 months (average age of 11 months) were submitted to nested polymerase chain reaction analysis (pol and tax genes). 81.5% of the children were born by an elective cesarean section. No case of infection was detected. The absence of HTLV-I infection in these cases indicates that transmission by transplacental route may be very infrequent.

Incremental Recomputation of Pig Latin���s Nest and Unnest Operators

This master���s thesis addresses the maintenance of pre-computed structures, which store a frequent or expensive query, for the nested bag data type in the high level work-flow language Pig Latin. This thesis defines a model suitable to accommodate incremental expressions over nested bags on Pig Latin. Afterwards, the partitioned normal form for sets is extended with further restrictions, in order to accommodate the nested bag model, allow the Pig Latin nest and unnest operators revert each other, and create a suitable environment to the incremental computations. Subsequently, the extended operators ��� extended union and extended difference ��� are defined for the nested bag data model with the partitioned normal form for bags (PNF Bag) restriction, and semantics for the extended operators are given. Finally, incremental data propagation expressions are proposed for the nest and unnest operators on the data model proposed with the PNF Bag restriction, and the proof of correctness is given.

Diagnosis of cytomegalovirus infections by qualitative and quantitative PCR in HIV infected patients

A high incidence of cytomegalovirus (CMV) infections is observed in Brazil. These viruses are causatives of significant morbidity and mortality among patients with advanced human immunodeficiency virus (HIV) infection. This work, shows the application of a PCR on determination of CMV load in the buffy coat and plasma. We analyzed the samples of 247 HIV infected patients in order to diagnose CMV infection and disease. We developed a semi-quantitative PCR that amplifies part of the glycoprotein B (gB) gene of CMV. The semi-quantitative PCR was carried out only in positive clinical samples in a qualitative PCR confirmed by a nested-PCR. CD4 lymphocyte count, HIV viral load and CMV disease symptom were correlated with CMV load. CMV genome was detected in the buffy coat of 82 of 237 (34.6%) patients, in 10 of these the CMV load was determined varying between 928 and 332 880 viral copies/mug DNA. None of these 237 patients developed any suggestive manifestation of CMV disease. For the other 10 HIV infected patients selected based on the suspicion of CMV disease, CMV genome was detected in only one case. This patient presented a high CMV load, 8 000 000 copies/mug DNA, and developed a disseminated form of CMV disease including hepatitis and retinitis. Our results were greatly influenced by the impact of the highly active antiretroviral therapy that reduced incidence of CMV viremia and occurrence of CMV disease in the HIV infected patients.