Far-infrared activity and starburst galaxies

After the IRAS discovery of galaxies with large far-infrared to blue luminosity ratio, it has been proposed that an enhanced star formation could be the origin of the far-infrared emission through dust heating. Whether a simple photometric model is able to account for the FIR and optical properties of IRAS galaxies was investigated. The L sub IR/L sub B ratio, (B-V) color and H sub alpha equivalent width of normal spirals are well reproduced with smooth star formation histories. In the case of starburst galaxies, several theoretical diagrams allow us to estimate the burst strength and extinction. L sub IR/L sub B ratio up to 100 can be rather easily reached, whereas extreme values probably require IMF truncated at the low end

Constraints on the distance to SGR 1806-20 from HI absorption

The giant flare detected from the magnetar SGR 1806-20 on 2004 December 27 had a fluence more than 100 times higher than the only two other SGR flares ever recorded. Whereas the fluence is independent of distance, an estimate for the luminosity of the burst depends on the source's distance, which has previously been argued to be ~15 kpc. The burst produced a bright radio afterglow, against which Cameron et al. (2005) have measured an HI absorption spectrum. This has been used to propose a revised distance to SGR 1806-20 of between 6.4 and 9.8 kpc. Here we analyze this absorption spectrum, and compare it both to HI emission data from the Southern Galactic Plane Survey and to archival 12-CO survey data. We confirm ~6 kpc, as a likely lower limit on the distance to SGR 1806-20, but argue that it is difficult to place an upper limit on the distance to SGR 1806-20 from the HI data currently available. The previous value of ~15 kpc thus remains the best estimate of the distance to the source.Comment: 3 pages, 1 embedded EPS figure. Added sentences to end of Abstract and Conclusion, clarifying that most likely distance is 15 kpc. ApJ Letters, in pres

Host responses influence on the induction of lambda prophage

Inactivation of bacteriophage lambda CI repressor leads almost exclusively to lytic development. Prophage induction can be initiated either by DNA damage or by heat treatment of a temperature-sensitive repressor. These two treatments also cause a concurrent activation of either the host SOS or heat-shock stress responses respectively. We studied the effects of these two methods of induction on the lytic pathway by monitoring the activation of different lambda promoters, and found that the lambda genetic network co-ordinates information from the host stress response networks. Our results show that the function of the CII transcriptional activator, which facilitates the lysogenic developmental pathway, is not observed following either method of induction. Mutations in the cro gene restore the CII function irrespective of the induction method. Deletion of the heat-shock protease gene ftsH can also restore CII function following heat induction but not following SOS induction. Our findings highlight the importance of the elimination of CII function during induction as a way to ensure an efficient lytic outcome. We also show that, despite the common inhibitory effect on CII function, there are significant differences in the heat- and SOS-induced pathways leading to the lytic cascade

The cardiovascular and intracranial effects of laryngoscopy and endotracheal intubation in hypercarbic neonatal piglets

Laryngoscopy and endotracheal intubation is a potent sympathetic stimulus in adults. Neonates are frequendy intubated, but few data exist on the cerebral effects of this intervention. The cardiovascular and intracranial effects of laryngoscopy and endotracheal intubation were studied in 17 hypercarbic neonatal piglets. The mean arterial pressure in the study group (11 piglets) increased significandy within 2 minutes of the stimulus, and remained elevated for almost 14 minutes. The intubated animals showed significantly more haemorrhage in the basal area of the brain than the 6 control animals. The distribution suggests bleeding in the choroid plexus of the 4th ventricle. The significance of such bleeds is not immediately apparent, since none of the animals was grossly neurologically affected by the intervention. However, subtle long-term neurological deficits cannot be excluded and this aspect requires further study. Laryngoscopy and endotracheal intubation may cause non-lethal haemorrhage in the choroid plexus and central canal of the hindbrain  in hypercarbic, neonatal piglets

Distance determination by GIY-YIG intron endonucleases: discrimination between repression and cleavage functions

GIY-YIG homing endonucleases are modular proteins, with conserved N-terminal catalytic domains connected by linkers to C-terminal DNA-binding domains. I-TevI, the T4 phage GIY-YIG intron endonuclease, functions both in promoting td intron homing, and in acting as a transcriptional autorepressor. Repression is achieved by binding to an operator, which is cleaved at 100-fold reduced efficiency relative to the intronless homing site. The linker includes a zinc finger, which functions in distance determination, to constrain the catalytic domain to cleave the homing site at a fixed position. Here we show that I-BmoI, a related GIY-YIG endonuclease lacking a zinc finger, also possesses some cleavage distance discrimination. Furthermore, hybrid endonucleases constructed by swapping the domains of I-BmoI and I-TevI are active, precise and demonstrate that features other than the zinc finger facilitate distance determination. Most importantly, I-TevI zinc finger mutants cleave the operator more efficiently than the homing site, the converse of wild-type protein. These results are consistent with the zinc finger acting as a measuring device, directing efficient cleavage of the homing site to promote intron mobility, while reducing cleavage at the operator to ensure transcriptional autorepression and phage viability

Método prático de secagem de sementes de urucu para produção de mudas.

bitstream/item/34097/1/CPATU-CirTec67.pd

Técnicas de produção de mudas de urucuzeiro.

bitstream/item/34091/1/CPATU-CirTec66.pd

Clinical and molecular findings in a cohort of 152 Brazilian severe early onset inherited retinal dystrophy patients

Leber congenital amaurosis (LCA) and early‐onset retinal dystrophy (EORD) are severe inherited retinal dystrophy that can cause deep blindness childhood. They represent 5% of all retinal dystrophies in the world population and about 10% in Brazil. Clinical findings and molecular basis of syndromic and nonsyndromic LCA/EORD in a Brazilian sample (152 patients/137 families) were studied. In this population, 15 genes were found to be related to the phenotype, 38 new variants were detected and four new complex alleles were discovered. Among 123 variants found, the most common were CEP290: c.2991+1655A>G, CRB1: p.Cys948Tyr, and RPGRIP1: exon10‐18 deletion

Antibiotic Prophylaxis for Presumptive Group B Streptococcal Infection in Preterm Premature Rupture of the Membranes: Effect on Neonatal and Maternal Infectious Morbidity

Objective: The purpose of this study was to determine if the prevalence of neonatal and maternal infectious morbidity in patients with preterm premature rupture of membranes (PROM) who received ampicillin prophylaxis for presemptive group B streptococcal colonization is increased compared to those who received no prophylaxis