85 research outputs found
The Interplay Between GUT and Flavour Symmetries in a Pati-Salam x S4 Model
Both Grand Unified symmetries and discrete flavour symmetries are appealing
ways to describe apparent structures in the gauge and flavour sectors of the
Standard Model. Both symmetries put constraints on the high energy behaviour of
the theory. This can give rise to unexpected interplay when building models
that possess both symmetries. We investigate on the possibility to combine a
Pati-Salam model with the discrete flavour symmetry that gives rise to
quark-lepton complementarity. Under appropriate assumptions at the GUT scale,
the model reproduces fermion masses and mixings both in the quark and in the
lepton sectors. We show that in particular the Higgs sector and the running
Yukawa couplings are strongly affected by the combined constraints of the Grand
Unified and family symmetries. This in turn reduces the phenomenologically
viable parameter space, with high energy mass scales confined to a small region
and some parameters in the neutrino sector slightly unnatural. In the allowed
regions, we can reproduce the quark masses and the CKM matrix. In the lepton
sector, we reproduce the charged lepton masses, including bottom-tau
unification and the Georgi-Jarlskog relation as well as the two known angles of
the PMNS matrix. The neutrino mass spectrum can present a normal or an inverse
hierarchy, and only allowing the neutrino parameters to spread into a range of
values between and , with .
Finally, our model suggests that the reactor mixing angle is close to its
current experimental bound.Comment: 62 pages, 4 figures; references added, version accepted for
publication in JHE
Investigação de um sistema de alimentação em recém-nascidos prematuros a partir de estimulação gustativa
Objetivo: investigar a existência do sistema de alimentação em recém-nascidos prematuros a partir da estimulação gustativa. Métodos:
estudo experimental, analítico, duplo-cego. Participaram 90 recém-nascidos prematuros, de uma maternidade pública de Sergipe. O teste foi filmado, constituindo-se por três momentos de cinco minutos. O primeiro e último momento sem realizar estímulo, o segundo momento com estimulação gustativa, sendo que os recém-nascidos foram divididos em dois grupos (água ou sacarose). Foram estudados os comportamentos específicos sucção de mão direita e esquerda, protrusão de língua e movimentos de sucção nos estados comportamentais sono profundo, sono leve, sonolento, agitado/irritado e choro. Para caracterizar a população foram utilizadas média, desvio-padrão e prevalências. Foi utilizado o teste não paramétrico Mann-Whitney para comparação de médias. O teste de Spearman verificou correlação entre estados comportamentais e comportamentos específicos em cada momento do teste. O valor de p foi significante quando menor que 0,05. Resultados: independente do estímulo administrado, a correlação aumentou em todos os comportamentos específicos. Comparando os grupos separadamente, após a estimulação, observou-se aumento de correlação em sucção de mão direita e protrusão de língua para ambos os grupos. O mesmo aconteceu em sucção, com exceção do estado agitado/irritado. Após a estimulação, houve maior correlação para o comportamento de sucção de mão esquerda no grupo sacarose quando comparado ao grupo água. Os resultados evidenciam que estímulos gustativos podem contribuir na prontidão para alimentação nesta população. Conclusões:
evidenciou-se nos recém-nascidos prematuros aumento de correlação para os comportamentos específicos relacionados ao sistema de alimentação, após estimulação oral, o que vislumbra a possibilidade da estimulação gustativa ser utilizada para ativação de um sistema de alimentação em recém-nascidos prematuros. _________________________________________________________________________________________ ABSTRACT: Purpose: to investigate the existence of the alimentation system in premature newborns in response to gustatory stimulation. Methods: experimental, analytical, double-blind study. 90 premature newborns of a public maternity in Sergipe took part in the test which was filmed and divided into three parts of five minutes. In the first and last, there was no stimulus; in the second, the gustatory stimulation was
applied and the newborn children were divided into two groups (water or sucrose). We studied the specific behaviors suction right and left hands, tongue protrusion and suction movements in behavioral states deep sleep, light sleep, drowsy, restless / irritable and crying. In the statistical analysis of the
population, average, standard deviation and prevalence studies were performed. We used the non-parametric Mann-Whitney test to compare averages. The Spearman test observed correlation between behavioral states at each time of the test. The p value was significant when less than 0.05. Results: independent of the given stimulus, the correlation increased in all specific behaviors. Comparing the
groups separately, after stimulation, we observed an increase in correlation in right hand suction and tongue protrusion for both. The same happened in suction, except for the agitated/irritated state. After stimulation, there was a higher correlation to the behavior of left hand suction in the sucrose group when compared to water. The results show that gustatory stimuli may contribute to the readiness to feed this population. Conclusions: it was found in premature newborns an increased in correlation
for the specific behaviors related to the alimentation system after oral stimulation, which envisions the possibility of gustatory stimulation be used for activating a alimentation system in premature newborns
An inverse association between West Nile virus serostatus and avian malaria infection status
BACKGROUND: Various ecological and physiological mechanisms might influence the probability that two or more pathogens may simultaneously or sequentially infect a host individual. Concurrent infections can have important consequences for host condition and fitness, including elevated mortality risks. In addition, interactions between coinfecting pathogens may have important implications for transmission dynamics. METHODS: Here, we explore patterns of association between two common avian pathogens (West Nile virus and avian malaria parasites) among a suburban bird community in Chicago, IL, USA that share mosquito vectors. We surveyed 1714 individual birds across 13 species for both pathogens through established molecular protocols. RESULTS: Field investigations of haemosporidian and West Nile virus (WNV) infections among sampled birds yielded an inverse association between WNV serostatus and Plasmodium infection status. This relationship occurred in adult birds but not in juveniles. There was no evidence for a relationship between Haemoproteus infection and WNV serostatus. We detected similar prevalence of Plasmodium among birds captured with active WNV infections and spatiotemporally paired WNV-naïve individuals of the same species, demonstrating that the two pathogens can co-infect hosts. CONCLUSIONS: Mechanisms explaining the negative association between WNV serostatus and Plasmodium infection status remain unclear and must be resolved through experimental infection procedures. However, our results highlight potential interactions between two common avian pathogens that may influence their transmission among hosts. This is especially relevant considering that West Nile virus is a common zoonotic pathogen with public health implications. Moreover, both pathogens are instructive models in infectious disease ecology, and infection with either has fitness consequences for their avian hosts. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1756-3305-7-415) contains supplementary material, which is available to authorized users
Speech therapy in food transition from probe to breast in newborn in kangaroo method
Objetivo: Verificar a relação entre idade gestacional e tempo de intervenção fonoaudiológica para início da alimentação via oral, quando utilizada a técnica de transição alimentar da sonda direta para o peito. Métodos: Trata-se de um estudo do prontuário médico/fonoaudiológico de 38 recém-nascidos de risco em Unidade Canguru. Foram coletados os seguintes dados: idade gestacional ao nascimento e corrigida, dias de vida, peso ao nascimento e atual, tipo e duração da intervenção fonoaudiológica, volume de dieta por sonda. Utilizou-se o tempo de uso de antibióticos e o suporte ventilatório como critérios de divisão dos recém-nascidos em dois grupos (G1 e G2). Na análise estatística, aplicou-se o teste não paramétrico de Mann-Whitney e o coeficiente de correlação de Pearson. Resultados: O tempo de intervenção para os recém-nascidos que receberem alta fonoaudiológica não apresentou resultados significativos entre os grupos (G1= 9,35 dias e G2= 10,12 dias), embora a hipótese inicial deste estudo fosse a de que os recém-nascidos do G1 necessitariam de menor período de atendimento fonoaudiológico que os do G2. Houve diferença estatisticamente significativa para o peso ao nascimento, entre G1 (1563,53 g) e G2 (1409,62 g). Conclusão: Quando utilizada a técnica de transição alimentar da sonda direta para o peito, em recém-nascidos de risco com média de idade gestacional semelhante e mesmo tempo de intervenção fonoaudiológica, os bebês demonstraram aptidão para coordenar os movimentos de sucção/respiração/deglutição, e consequentemente, a amamentação efetiva em seio materno exclusivo. _________________________________________________________________________________________ ABSTRACT: Purpose: Verify the relationship between gestational age and duration
of speech therapy to start oral feeding, when used the technique of feeding transition of the probe directly to the chest. Methods: This is a study of newborn medical/speech records of 38 risk in Kangaroo unit. Were collected: gestational age at birth and corrected days of life, birth weight and current, type and duration of speech therapy, enteral feeding volume. We used time use of antibiotics and ventilatory support as criteria for division of newborns into two groups (G1 and G2). At the statistical analysis was applied the nonparametric test of Mann-Whitney and the Pearson’s correlation coefficient. Results: Intervention time for
newborns were discharged speech showed no significant results between groups (G1 = 9.35 days and G2 = 10.12 days), although the initial hypothesis of this study was that the newborn G1 would require fewer days of speech therapy than the G2. There was statistically significant difference in birth weight between G1 (1563.53 g) and G2 (1409.62 g).
Conclusion: It was observed that both groups started speech therapy and oral feeding practically medium of similar gestational ages and both speech intervention, demonstrating ability to coordinate sucking
movements/breathing/swallowing, and consequently the effective and exclusive breastfeeding
Full-Exon Pyrosequencing Screening of BRCA Germline Mutations in Mexican Women with Inherited Breast and Ovarian Cancer
Hereditary breast cancer comprises 10% of all breast cancers. The most prevalent genes causing this pathology are BRCA1 and BRCA2 (breast cancer early onset 1 and 2), which also predispose to other cancers. Despite the outstanding relevance of genetic screening of BRCA deleterious variants in patients with a history of familial cancer, this practice is not common in Latin American public institutions. In this work we assessed mutations in the entire exonic and splice-site regions of BRCA in 39 patients with breast and ovarian cancer and with familial history of breast cancer or with clinical features suggestive for BRCA mutations by massive parallel pyrosequencing. First we evaluated the method with controls and found 41–485 reads per sequence in BRCA pathogenic mutations. Negative controls did not show deleterious variants, confirming the suitability of the approach. In patients diagnosed with cancer we found 4 novel deleterious mutations (c.2805_2808delAGAT and c.3124_3133delAGCAATATTA in BRCA1; c.2639_2640delTG and c.5114_5117delTAAA in BRCA2). The prevalence of BRCA mutations in these patients was 10.2%. Moreover, we discovered 16 variants with unknown clinical significance (11 in exons and 5 in introns); 4 were predicted as possibly pathogenic by in silico analyses, and 3 have not been described previously. This study illustrates how massive pyrosequencing technology can be applied to screen for BRCA mutations in the whole exonic and splice regions in patients with suspected BRCA-related cancers. This is the first effort to analyse the mutational status of BRCA genes on a Mexican-mestizo population by means of pyrosequencing
Low Pathogenic Avian Influenza Isolates from Wild Birds Replicate and Transmit via Contact in Ferrets without Prior Adaptation
Direct transmission of avian influenza viruses to mammals has become an increasingly investigated topic during the past decade; however, isolates that have been primarily investigated are typically ones originating from human or poultry outbreaks. Currently there is minimal comparative information on the behavior of the innumerable viruses that exist in the natural wild bird host. We have previously demonstrated the capacity of numerous North American avian influenza viruses isolated from wild birds to infect and induce lesions in the respiratory tract of mice. In this study, two isolates from shorebirds that were previously examined in mice (H1N9 and H6N1 subtypes) are further examined through experimental inoculations in the ferret with analysis of viral shedding, histopathology, and antigen localization via immunohistochemistry to elucidate pathogenicity and transmission of these viruses. Using sequence analysis and glycan binding analysis, we show that these avian viruses have the typical avian influenza binding pattern, with affinity for cell glycoproteins/glycolipids having terminal sialic acid (SA) residues with α 2,3 linkage [Neu5Ac(α2,3)Gal]. Despite the lack of α2,6 linked SA binding, these AIVs productively infected both the upper and lower respiratory tract of ferrets, resulting in nasal viral shedding and pulmonary lesions with minimal morbidity. Moreover, we show that one of the viruses is able to transmit to ferrets via direct contact, despite its binding affinity for α 2,3 linked SA residues. These results demonstrate that avian influenza viruses, which are endemic in aquatic birds, can potentially infect humans and other mammals without adaptation. Finally this work highlights the need for additional study of the wild bird subset of influenza viruses in regard to surveillance, transmission, and potential for reassortment, as they have zoonotic potential
Theoretical Model for Cellular Shapes Driven by Protrusive and Adhesive Forces
The forces that arise from the actin cytoskeleton play a crucial role in determining the cell shape. These include protrusive forces due to actin polymerization and adhesion to the external matrix. We present here a theoretical model for the cellular shapes resulting from the feedback between the membrane shape and the forces acting on the membrane, mediated by curvature-sensitive membrane complexes of a convex shape. In previous theoretical studies we have investigated the regimes of linear instability where spontaneous formation of cellular protrusions is initiated. Here we calculate the evolution of a two dimensional cell contour beyond the linear regime and determine the final steady-state shapes arising within the model. We find that shapes driven by adhesion or by actin polymerization (lamellipodia) have very different morphologies, as observed in cells. Furthermore, we find that as the strength of the protrusive forces diminish, the system approaches a stabilization of a periodic pattern of protrusions. This result can provide an explanation for a number of puzzling experimental observations regarding cellular shape dependence on the properties of the extra-cellular matrix
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