976 research outputs found
Sustainable Microalgal Harvesting Process Applying Opuntia cochenillifera: Process Parameters Optimization
Microalgae harvesting by coagulation can use coagulant agents such as alum, synthetic polymers or biocoagulants. Biocoagulants have attracted the attention of researchers because they are natural, biodegradable, and promote high microalgal harvesting efficiencies. This study aims to optimize the harvesting of Chlorella vulgaris based on the dosage of the Opuntia cochenillifera extract and the choice of eluent for biopolymer extraction. The outdoor cultivation of C. vulgaris achieved a specific growth rate of 0.455 d(-1) and a maximum biomass concentration of 1.28 g(DW) L-1. In order to harvest the microalgal biomass, the polymer present in the mucilage of O. cochenillifera was extracted using NaOH and HCl. Coagulation and sedimentation assays were performed with different coagulant dosages: 3.5, 5.9, and 8.2 g L-1. The maximum harvesting efficiencies using the acid and alkaline extract coagulant solutions were 80.8% and 99.5%, respectively, with a dosage of 3.5 g L-1. According to the results, the C. vulgaris biomass can be harvested with the mucilage from O. cochenillifera in acid and alkaline eluents. The application of this biocoagulant constitutes a sustainable solution for microalgal harvesting
Checkpoints are blind to replication restart and recombination intermediates that result in gross chromosomal rearrangements
Replication fork inactivation can be overcome by homologous recombination, but this can cause gross chromosomal rearrangements that subsequently missegregate at mitosis, driving further chromosome instability. It is unclear when the chromosome rearrangements are generated and whether individual replication problems or the resulting recombination intermediates delay the cell cycle. Here we have investigated checkpoint activation during HR-dependent replication restart using a site-specific replication fork-arrest system. Analysis during a single cell cycle shows that HR-dependent replication intermediates arise in S phase, shortly after replication arrest, and are resolved into acentric and dicentric chromosomes in G2. Despite this, cells progress into mitosis without delay. Neither the DNA damage nor the intra-S phase checkpoints are activated in the first cell cycle, demonstrating that these checkpoints are blind to replication and recombination intermediates as well as to rearranged chromosomes. The dicentrics form anaphase bridges that subsequently break, inducing checkpoint activation in the second cell cycle
Tratamento do câncer de laringe: revisão da literatura publicada nos últimos dez anos
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Supply chain management of biomass for energy generation: a critical analysis of main trends
The increasing need of decarbonising energy intensive processes has risen the demand for biomass. Biomass production, distribution and use for energy generation involve several supply chain systems of which understanding requires a comprehensive analysis of the biomass supply chain management. The present article maps the volume and diversity of research carried out in the production and management of biomass supply chains for energy generation. It critically evaluates how well studies have captured multidimensional issues pertaining the supply chain management of biomass used for energy production and identifies future research trends in this field. The VOSviewer (Center for Science and Technology Studies, Leiden University, Leiden, The Netherlands) and SciMat (University of Granada, Spain) tools are employed for the construction of scientific maps that demonstrate the evolution of research in the biomass supply chain management area for energy production. The results revealed that research on the biomass supply chain for power generation is booming, especially in the United States, England and Italy. However, in developing nations such as Brazil, India and China, studies are still at an infant stage. There is a rising concern about the emerging new trends related to biomass supply chain management for energy generation, especially if clean energy aims to be a prominent place in the global energy matrix
Comprehensiveness and programmatic vulnerability to stds/hiv/aids in primary care
This study aimed to identify programmatic vulnerability to STDs/HIV/AIDS in primary health centers (PHCs). This is a descrip - tive and quantitative study carried out in the city of SĂŁo Paulo. An online survey was applied (FormSUS platform), involving administrators from 442 PHCs in the city, with responses received from 328 of them (74.2%), of which 53.6% were nurses. At - tention was raised in relation to program - matic vulnerability in the PHCs regarding certain items of infrastructure, prevention, treatment, prenatal care and integration among services on STDs/HIV/AIDS care. It was concluded that in order to reach comprehensiveness of actions for HIV/ AIDS in primary health care, it is necessary to consider programmatic vulnerability, in addition to more investment and reor - ganization of services in a dialogue with the stakeholders (users, multidisciplinary teams, and managers, among others)
Role of ultrasound, clinical and scintigraphyc parameters to predict malignancy in thyroid nodule
Background: This study aimed to evaluate clinical, laboratory, ultrasound (US) and scintigraphyc parameters in thyroid nodule and to develop an auxiliary model for clinical application in the diagnosis of malignancy. Methods: We assessed 143 patients who were surgically treated at a single center, 65% (93) benign vs. 35% (50) malignant lesions at final histology (1998-2008). The clinical, laboratory, scintigraphyc and US features were compared and a prediction model was designed after the multivariate analysis. Results: There were no differences in gender, serum TSH and FT4 levels, thyroid auto-antibodies (TAb), thyroid dysfunction and scintigraphyc results (P = 0.33) between benign and malignant nodule groups. The sonographic study showed differences when the presence of suspected characteristics was found in the nodules of the malignant lesions group, such as: microcalcifications, central flow, border irregularity and hypoechogenicity. After the multivariate analysis the model obtained showed age (>39 years), border irregularity, microcalcifications and nodule size over 2 cm as predictive factors of malignancy, featuring 81.7% of accuracy. Conclusions: This study confirmed a significant increase of risk for malignancy in patients of over 39 years and with suspicious features at US
Effect of an aqueous extract of annatto (Bixa orellana) seeds on lipid profile and biochemical markers of renal and hepatic function in hipercholesterolemic rats
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
No Intra-Locus Sexual Conflict over Reproductive Fitness or Ageing in Field Crickets
Differences in the ways in which males and females maximize evolutionary fitness can lead to intra-locus sexual conflict in which genes delivering fitness benefits to one sex are costly when expressed in the other. Trade-offs between current reproductive effort and future reproduction and survival are fundamental to the evolutionary biology of ageing. This leads to the prediction that sex differences in the optimization of age-dependent reproductive effort may generate intra-locus sexual conflict over ageing rates. Here we test for intra-locus sexual conflict over age-dependent reproductive effort and longevity in the black field cricket, Teleogryllus commodus. Using a half-sib breeding design, we show that the most important components of male and female reproductive effort (male calling effort and the number of eggs laid by females) were positively genetically correlated, especially in early adulthood. However, the genetic relationships between longevity and reproductive effort were different for males and females, leading to low genetic covariation between male and female longevity. The apparent absence of intra-locus sexual conflict over ageing suggests that male and female longevity can evolve largely independently of one another
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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