149 research outputs found
Primordial Gravitational Waves Enhancement
We reconsider the enhancement of primordial gravitational waves that arises
from a quantum gravitational model of inflation. A distinctive feature of this
model is that the end of inflation witnesses a brief phase during which the
Hubble parameter oscillates in sign, changing the usual Hubble friction to
anti-friction. An earlier analysis of this model was based on numerically
evolving the graviton mode functions after guessing their initial conditions
near the end of inflation. The current study is based on an equation which
directly evolves the normalized square of the magnitude. We are also able to
make a very reliable estimate for the initial condition using a rapidly
converging expansion for the sub-horizon regime. Results are obtained for the
energy density per logarithmic wave number as a fraction of the critical
density. These results exhibit how the enhanced signal depends upon the number
of oscillatory periods; they also show the resonant effects associated with
particular wave numbers.Comment: 25 pages, 14 figure
Microbiological surveillance of hospital ventilation systems in departments at high risk of nosocomial infections
The air in hospital wards with patients at high risk (Surgeries, Intensive Care Units and Bone Marrow Transplant Centers) has been surveyed less than the one in Operating Rooms. Therefore in this study we considered useful to verify the microbic contamination of the air of those wards evaluating the consistency of ventilation systems in relation also to the presence and location of HEPA absolute filters. Seven departments of Genoese San Martino Hospital at high risk of infection were taken into account. In there, environmental investigations have been performed by air samplings and by analyzing bacterial and fungal growth on plates after an incubation period. Almost 60% of all samples taken in wards yielded a positive result and the average values of bacterial and aspergillar charges measured at air flow emission openings decisively exceed the ones considered standard in operating rooms. Still, the average values of airborne bacterial charges were significantly higher in those wards equipped with central filters (p inf. 0.001), while as far as the aspergillar charge is concerned, no statistically relevant differences were noticed. In wards with ventilation system, the bacterial charge value raises from the emission grids to the middle of the room and to the aspiration grids, while the ward not equipped with a ventilation system presents in the middle of the room an average bacterial charge 2 to 10 times higher than the one in other wards. The average values regarding bacterial and aspergillar charges resulted quite high in all the departments surveyed. Nevertheless, if we take into account ventilation systems equipped with absolute filters HEPA located centrally or peripherally, it can be outlined that the air quality from the point of view of both microbic and aspergillar contamination turns out to be decisively better in systems with peripheral filters.
Moreover, a compared analysis of the three Hematology wards allows us to infer that the presence of artificial ventilation systems can lower the bacterial and fungal compared with a ward with natural ventilation
Epigenetic deregulation of micrornas in rhabdomyosarcoma and neuroblastoma and translational perspectives
Gene expression control mediated by microRNAs and epigenetic remodeling of
chromatin are interconnected processes often involved in feedback regulatory loops, which
strictly guide proper tissue differentiation during embryonal development. Altered
expression of microRNAs is one of the mechanisms leading to pathologic conditions, such
as cancer. Several lines of evidence pointed to epigenetic alterations as responsible for
aberrant microRNA expression in human cancers. Rhabdomyosarcoma and neuroblastoma
are pediatric cancers derived from cells presenting features of skeletal muscle and neuronal
precursors, respectively, blocked at different stages of differentiation. Consistently, tumor
cells express tissue markers of origin but are unable to terminally differentiate. Several
microRNAs playing a key role during tissue differentiation are often epigenetically
downregulated in rhabdomyosarcoma and neuroblastoma and behave as tumor suppressors
when re-expressed. Recently, inhibition of epigenetic modulators in adult tumors has
provided encouraging results causing re-expression of anti-tumor master gene pathways.
Thus, a similar approach could be used to correct the aberrant epigenetic regulation of
microRNAs in rhabdomyosarcoma and neuroblastoma. The present review highlights the
current insights on epigenetically deregulated microRNAs in rhabdomyosarcoma and
neuroblastoma and their role in tumorigenesis and developmental pathways. The
translational clinical implications and challenges regarding modulation of epigenetic
chromatin remodeling/microRNAs interconnections are also discusse
Possible Enhancement of High Frequency Gravitational Waves
We study the tensor perturbations in a class of non-local, purely
gravitational models which naturally end inflation in a distinctive phase of
oscillations with slight and short violations of the weak energy condition. We
find the usual generic form for the tensor power spectrum. The presence of the
oscillatory phase leads to an enhancement of gravitational waves with
frequencies somewhat less than 10^{10} Hz.Comment: 27 pages, 11 figures, LaTeX.2
Expanding The Knowledge On Lignocellulolytic And Redox Enzymes Of Worker And Soldier Castes From The Lower Termite Coptotermes Gestroi
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Termites are considered one of the most efficient decomposers of lignocelluloses on Earth due to their ability to produce, along with its microbial symbionts, a repertoire of carbohydrate-active enzymes (CAZymes). Recently, a set of Pro-oxidant, Antioxidant, and Detoxification enzymes (PAD) were also correlated with the metabolism of carbohydrates and lignin in termites. The lower termite Coptotermes gestroi is considered the main urban pest in Brazil, causing damage to wood constructions. Recently, analysis of the enzymatic repertoire of C. gestroi unveiled the presence of different CAZymes. Because the gene profile of CAZy/PAD enzymes endogenously synthesized by C. gestroi and also by their symbiotic protists remains unclear, the aim of this study was to explore the eukaryotic repertoire of these enzymes in worker and soldier castes of C. gestroi. Our findings showed that worker and soldier castes present similar repertoires of CAZy/PAD enzymes, and also confirmed that endo-glucanases (GH9) and beta-glucosidases (GH1) were the most important glycoside hydrolase families related to lignocellulose degradation in both castes. Classical cellulases such as exo-glucanases (GH7) and endo-glucanases (GH5 and GH45), as well as classical xylanases (GH10 and GH11), were found in both castes only taxonomically related to protists, highlighting the importance of symbiosis in C. gestroi. Moreover, our analysis revealed the presence of Auxiliary Activity enzyme families (AAs), which could be related to lignin modifications in termite digestomes. In conclusion, this report expanded the knowledge on genes and proteins related to CAZy/PAD enzymes from worker and soldier castes of lower termites, revealing new potential enzyme candidates for second-generation biofuel processes.7FAPESP (The State of Sao Paulo Research Foundation) [11/20977-3, 15/06971-3, 12/19040-0, 14/10351-8, 06/59086-8, 14/20576-7, 13/03061-0, 10/11469-1]National Council for Scientific and Technological Development (CNPq) [140796/2013-4][08/58037-9][14/50371-8][08/50114-4][310186/2014-5][442333/2014-5]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Bem-estar e qualidade de ovos de codornas alimentadas com extratos de camomila e passiflora
O objetivo deste estudo foi avaliar o efeito de diferentes combinações de passiflora (Passiflora alata) e de camomila (Matricaria chamomila) sobre o desempenho, qualidade de ovos, comportamento e estresse de codornas durante as fases de recria e de postura. Foram utilizadas 196 aves, distribuídas em blocos ao acaso, com quatro tratamentos (ração convencional; 125 mg de Matricaria chamomila + 375 mg de Passiflora alata/kg de ração; 250 mg de M. chamomila + 250 mg de P. alata/kg de ração; 375 mg de M. chamomila + 125 mg P. alata/kg de ração), com sete repetições e sete aves por parcela. A fase de recria iniciou-se aos 28 dias de idade das aves, durando 14 dias. Nesta fase foram avaliados consumo diário de ração, ganho diário de peso, conversão alimentar, viabilidade de criação, o tempo em imobilidade tônica (TIT), a intensidade de ferimentos e a relação entre heterófilos e linfócitos (H:L). A fase de postura teve início quando as aves atingiram 42 dias de idade, em que foram avaliados consumo de ração, conversão alimentar, produção e qualidade de ovos, viabilidade, TIT, intensidade de ferimentos e relação H:L. Na fase de recria a inclusão dos fitoterápicos às rações não alterou o desempenho, a relação H:L e as intensidades de lesões (P≥0,05), mas diminuiu o TIT quando da adição de 250 mg de cada fitoterápico (P<0,05). Na fase de postura as diferentes combinações de camomila e passiflora não afetaram o desempenho e a qualidade externa de ovos frescos (P≥0,05). No entanto, quando se adicionou 250 mg de cada extrato nas rações houve redução no TIT, na relação H:L e na intensidade de lesões na cabeça e corpo das aves (P<0,05), indicando que as aves estavam menos estressadas. Quanto à qualidade interna de ovos frescos, verificou-se melhora na unidade Haugh e nas porcentagens de gema e de albúmen quando da inclusão de 250 mg de cada fitoterápico (P<0,05). Conclui-se que a adição de camomila e de passiflora nas rações não altera o desempenho produtivo das aves nas fases de recria e de postura, não influencia a qualidade externa e interna dos ovos e, as aves tornam-se mais calmas quando da inclusão de 250 mg de cada fitoterápico em ambas fases de criação
The brain monitoring with information technology (BrainIT) collaborative network: EC feasibility study results
The BrainIT group works collaboratively on developing standards for collection and analyses of data from brain injured patients towards providing a more efficient infrastructure for assessing new health technology. Materials and methods Over a 2 year period, core dataset data (grouped by nine categories) were collected from 200 head-injured patients by local nursing staff. Data were uploaded by the BrainIT web and random samples of received data were selected automatically by computer for validation by data validation (DV) research nurse staff against gold standard sources held in the local centre. Validated data was compared with original data sent and percentage error rates calculated by data category. Findings Comparisons, 19,461, were made in proportion to the size of the data received with the largest number checked in laboratory data (5,667) and the least in the surgery data (567). Error rates were generally less than or equal to 6%, the exception being the surgery data class where an unacceptably high error rate of 34% was found.
Conclusions The BrainIT core dataset (with the exception of the surgery classification) is feasible and accurate to collect. The surgery classification needs to be revised
Integrated analysis of microRNA and mRNA expression profiles in physiological myelopoiesis: role of hsa-mir-299-5p in CD34+ progenitor cells commitment
Hematopoiesis entails a series of hierarchically organized events that proceed throughout cell specification and terminates with cell differentiation. Commitment needs the transcription factors' effort, which, in concert with microRNAs, drives cell fate and responds to promiscuous patterns of gene expression by turning on lineage-specific genes and repressing alternate lineage transcripts. We obtained microRNA profiles from human CD34+ hematopoietic progenitor cells and in vitro differentiated erythroblasts, megakaryoblasts, monoblasts and myeloblast precursors that we analyzed together with their gene expression profiles. The integrated analysis of microRNA–mRNA expression levels highlighted an inverse correlation between microRNAs specifically upregulated in one single-cell progeny and their putative target genes, which resulted in downregulation. Among the upregulated lineage-enriched microRNAs, hsa-miR-299-5p emerged as having a role in controlling CD34+ progenitor fate, grown in multilineage culture conditions. Gain- and loss-of-function experiments revealed that hsa-miR-299-5p participates in the regulation of hematopoietic progenitor fate, modulating megakaryocytic-granulocytic versus erythroid-monocytic differentiation
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