On the Levi-Civita solutions with cosmological constant

The main properties of the Levi-Civita solutions with the cosmological constant are studied. In particular, it is found that some of the solutions need to be extended beyond certain hypersurfaces in order to have geodesically complete spacetimes. Some extensions are considered and found to give rise to black hole structure but with plane symmetry. All the spacetimes that are not geodesically complete are Petrov type D, while in general the spacetimes are Petrov type I.Comment: Typed in Revtex, including two figures. To appear in Phys. Rev.

The role of automatic shape and position recognitionin streamlining manufacturing

The main features of most components consist of simple basic functional geometries: planes, cylinders, spheres and cones. Shape and position recognition of these geometries is essential for dimensional characterization of components, and represent an important contribution in the life cycle of the product, concerning in particular the manufacturing and inspection processes of the final product. This work aims to establish an algorithm to automatically recognize such geometries, without operator intervention. Using differential geometry large volumes of data can be treated and the basic functional geometries to be dealt recognized. The original data can be obtained by rapid acquisition methods, such as 3D survey or photography, and then converted into Cartesian coordinates. The satisfaction of intrinsic decision conditions allows different geometries to be fast identified, without operator intervention. Since inspection is generally a time consuming task, this method reduces operator intervention in the process. The algorithm was first tested using geometric data generated in MATLAB and then through a set of data points acquired by measuring with a coordinate measuring machine and a 3D scan on real physical surfaces. Comparison time spent in measuring is presented to show the advantage of the method. The results validated the suitability and potential of the algorithm hereby proposedCMAT, the Research Centre of Mathematics of the University of Minho with the Portuguese Funds from the “Fundação para a Ciência e a Tecnologia”, through the Project PEstOE/MAT/UI0013/2014; MEtRICs – (Mechanical Engineering and Resource Sustainability Center); CGIT - Centro de Gestão Industrial e da Tecnologi

Modulating Effect of Cardiac Rehabilitation on Autonomic Nervous System Function in Patients with Coronary Artery Disease

info:eu-repo/semantics/publishedVersio

Identification and functional analysis of novel genes expressed in the Anterior Visceral Endoderm

During early vertebrate development, the correct establishment of the body axes is critical. The anterior pole of the mouse embryo is established when Distal Visceral Endoderm (DVE) cells migrate to form the Anterior Visceral Endoderm (AVE). Symmetrical expression of Lefty1, Cer1 and Dkk1 determines the direction of DVE migration and the future anterior side. In addition to the establishment of the Anterior-Posterior axis, the AVE has also been implicated in anterior neural specification. To better understand the role of the AVE in these processes, we have performed a differential screening using Affymetrix GeneChip technology with AVE cells isolated from cer1P-EGFP transgenic mouse embryos. We found 175 genes which were upregulated in the AVE and 36 genes in the Proximal-posterior sample. Using DAVID software, we characterized the AVE cell population regarding cellular component, molecular function and biological processes. Among the genes that were found to be upregulated in the AVE, several novel genes were identified. Four of these transcripts displaying high-fold change in the AVE were further characterized by in situ hybridization in early stages of development in order to validate the screening. From those four selected genes, one, denominated Adtk1, was chosen to be functionally characterized by targeted inactivation in ES cells. Adtk1 encodes for a serine/threonine kinase. Adtk1 null mutants are smaller and present short limbs due to decreased mineralization, suggesting a potential role in chondrogenesis during limb development. Taken together, these data point to the importance of reporting novel genes present in the AVE.F.C.T.; IGC/FCG; IBB/CBME, L

Hybrid gels: influence of water and oil phase on textural and rheological properties

The 19th Gums & Stabilisers for the Food Industry Conference: Hydrocolloid MultifunctionalityHybrid gels are biphasic systems formed by conjugating hydrogels and oleogels. The mixture of water-based and oil-based gels provides distinct and unique characteristics to hybrid gels, and based on the structurant molecules and mixture ratio used during their production, different textural and rheological properties can be obtained. Hybrid gels remain a very recent topic concerning pharmaceutical and food applications and despite recent studies on the use of hybrid gels for controlled delivery of compounds (pharmaceutical applications) these structures are still under-studied in regard to their food application possibilities [1, 2]. To improve knowledge and expanding ways to use these systems, it is important to understand how these gels behave regarding textural and rheological properties. Also, the knowledge on their micro and nanostructure allows tailoring their properties and thus maximizing their applicability in foodstuffs. We report on how the combination of a beeswaxbased oleogel and a sodium alginate-based hydrogel influences the gel structural properties at macroscopic (rheological and textural), microscopic (optical microscopy) and molecular (Xray diffraction) levels. Different ratios of both hydrogel and oleogel were used in order to evaluate the hybrid gels’ behaviour in terms of morphological, textural, rheological and polymorphic properties. Differences regarding oleogel particles distribution in the hydrogel matrix were noticed with the increase of oleogel fraction. A more disarranged distribution of oleogel particles was observable for the 50:50 ratios of hydrogel and oleogel. X-ray diffraction data unveiled that once polycrystallinity is reached (in hybrid gels) these patterns remain persistent for all tested ratios. Oleogel showed d-spacings in the range of 3.74 to 8.04 Å. Hybrid gel samples (and hydrogel control) are semi-crystalline, displaying spacings ranging in intervals of d (001) 6.99 – 7.18 Å; d (002) 3.09 – 3.23 Å and d (003) 2.45 – 2.46 Å, respectively. The samples with increasing oleogel ratio revealed a firmness decrease and a consequent reduction of spreadability values. Consequently, is observed less adhesivity for these samples, due to a more pronounced disaggregated structure. For all hybrid gels a gellike behaviour (G´ > G´´) was observed. Results showed that it is possible to modify the hybrid gels’ rheological and textural behaviour by a controlled mixture ratio of oleogels and hydrogels. This opens the possibilities of food applications for this kind of systems.info:eu-repo/semantics/publishedVersio

Empirical modeling as an experimental approach to evaluate simultaneous saccharification and wheat straw fermentation for bioethanol production

In simultaneous saccharification and fermentation (SSF) of lignocellulosic materials, a rapid conversion to ethanol of the produced glucose is expected. The principal benefits are to minimize enzyme sugar inhibition, to improve cellulose conversion rates and to reduce cost compared with separated hydrolysis and fermentation, due to the occurring synergy between enzyme-yeast-substrate in one bioreactor. Wheat straw (WS) is an abundant by-product from worldwide wheat production making it an important substrate for bioethanol production. The aim of this work was to evaluate the effect of temperature, substrate concentration and loading enzyme on bioethanol production by SSF having as substrate WS pretreated by autohydrolysis (AH) and using flocculating Saccharomyces cerevisiae CA11. A 23 central composite design was applied and the limits of the different parameters were: 30-45ºC; 2-3 % of substrate; 5-30 FPU of cellulose enzyme (Celluclast 1.5) per g dry substrate and 30-60 of β-glucosidase (Novozym 188) IU per g substrate. Ethanol production, residual glucose, and cellobiose were analyzed by HPLC. CO2 was kinetically monitored by weight loss in Erlenmeyer flasks. Results showed that after 60 h of fermentation the highest ethanol concentration – 14.84 g/l (with a corresponding CO2 value of 14.27 g/l) was obtained at 45ºC, 3% of substrate, 30 FPU and 60 IU. This value, corresponding to an ethanol yield of 84.2%, shows a low enzyme inhibition during SSF process as the glucose produced by enzymatic hydrolysis is rapidly assimilated for yeast cells. Overall, it may be concluded that WS pretreated by AH is a good substrate for SSF process as high substrate conversion into ethanol can be achieved as a result of the synergy between enzyme-yeast-substrate

An approach to dynamic line rating state estimation at thermal steady state using direct and indirect measurements

Dynamic line rating has emerged as a solution for reducing congestion in overhead lines, allowing the optimization of power systems assets. This technique is based on direct and/or indirect monitoring of conductor temperature. Different devices and methods have been developed to sense conductor temperature in critical spans. In this work, an algorithm based on WLS is proposed to estimate temperature in all ruling spans of an overhead line. This algorithm uses indirect measurements - i.e. weather reports and/or downscaling nowcasting models as inputs as well as direct measurements of mechanical tension, sag and/or conductor temperature. The algorithm has been tested using typical atmospheric conditions in Iceland along with an overhead line´s real design, showing robustness, efficiency and the ability to minimize error in measurements.Fil: Alvarez, David L.. Universidad Nacional de Colombia; ColombiaFil: Faria da Silva, F.. Aalborg Universitet; DinamarcaFil: Mombello, Enrique Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Bak, Claus Leth. Aalborg Universitet; DinamarcaFil: Rosero, Javier A.. Universidad Nacional de Colombia; ColombiaFil: Ólason, Daníel Leó. Landsnet; Islandi

Altered bone microarchitecture in a type 1 diabetes mouse model Ins2 (Akita)

Type 1 diabetes mellitus (T1DM) has been associated to several cartilage and bone alterations including growth retardation, increased fracture risk, and bone loss. To determine the effect of long term diabetes on bone we used adult and aging Ins2 Akita mice that developed T1DM around 3-4 weeks after birth. Both Ins2 Akita and wild-type (WT) mice were analyzed at 4, 6, and 12 months to assess bone parameters such as femur length, growth plate thickness and number of mature and preapoptotic chondrocytes. In addition, bone microarchitecture of the cortical and trabecular regions was measured by microcomputed tomography and gene expression of Adamst-5, Col2, Igf1, Runx2, Acp5, and Oc was quantified by quantitative real-time polymerase chain reaction. Ins2 Akita mice showed a decreased longitudinal growth of the femur that was related to decreased growth plate thickness, lower number of chondrocytes and to a higher number of preapoptotic cells. These changes were associated with higher expression of Adamst-5, suggesting higher cartilage degradation, and with low expression levels of Igf1 and Col2 that reflect the decreased growth ability of diabetic mice. Ins2 Akita bone morphology was characterized by low cortical bone area (Ct.Ar) but higher trabecular bone volume (BV/TV) and expression analysis showed a downregulation of bone markers Acp5, Oc, and Runx2. Serum levels of insulin and leptin were found to be reduced at all-time points Ins2 Akita . We suggest that Ins2 Akita mice bone phenotype is caused by lower bone formation and even lower bone resorption due to insulin deficiency and to a possible relation with low leptin signaling.SFRH/BD/76873/2011/ SFRH/BD/76429/2011/ PEst-C/MAR/LA0015/2011info:eu-repo/semantics/publishedVersio

A polymorphic residue that attenuates the antiviral potential of interferon lambda 4 in hominid lineages

As antimicrobial signalling molecules, type III or lambda interferons (IFNλs) are critical for defence against infection by diverse pathogens, including bacteria, fungi and viruses. Counter-intuitively, expression of one member of the family, IFNλ4, is associated with decreased clearance of hepatitis C virus (HCV) in the human population; by contrast, a natural frameshift mutation that abrogates IFNλ4 production improves HCV clearance. To further understand how genetic variation between and within species affects IFNλ4 function, we screened a panel of all known extant coding variants of human IFNλ4 for their antiviral potential and identify three that substantially affect activity: P70S, L79F and K154E. The most notable variant was K154E, which was found in African Congo rainforest ‘Pygmy’ hunter-gatherers. K154E greatly enhanced in vitro activity in a range of antiviral (HCV, Zika virus, influenza virus and encephalomyocarditis virus) and gene expression assays. Remarkably, E154 is the ancestral residue in mammalian IFNλ4s and is extremely well conserved, yet K154 has been fixed throughout evolution of the hominid genus Homo, including Neanderthals. Compared to chimpanzee IFNλ4, the human orthologue had reduced activity due to amino acid K154. Comparison of published gene expression data from humans and chimpanzees showed that this difference in activity between K154 and E154 in IFNλ4 correlates with differences in antiviral gene expression in vivo during HCV infection. Mechanistically, our data show that the human-specific K154 negatively affects IFNλ4 activity through a novel means by reducing its secretion and potency. We thus demonstrate that attenuated activity of IFNλ4 is conserved among humans and postulate that differences in IFNλ4 activity between species contribute to distinct host-specific responses to—and outcomes of—infection, such as HCV infection. The driver of reduced IFNλ4 antiviral activity in humans remains unknown but likely arose between 6 million and 360,000 years ago in Africa

A polymorphic residue that attenuates the antiviral potential of interferon lambda 4 in hominid lineages

As antimicrobial signalling molecules, type III or lambda interferons (IFNλs) are critical for defence against infection by diverse pathogens, including bacteria, fungi and viruses. Counter-intuitively, expression of one member of the family, IFNλ4, is associated with decreased clearance of hepatitis C virus (HCV) in the human population; by contrast, a natural frameshift mutation that abrogates IFNλ4 production improves HCV clearance. To further understand how genetic variation between and within species affects IFNλ4 function, we screened a panel of all known extant coding variants of human IFNλ4 for their antiviral potential and identify three that substantially affect activity: P70S, L79F and K154E. The most notable variant was K154E, which was found in African Congo rainforest ‘Pygmy’ hunter-gatherers. K154E greatly enhanced in vitro activity in a range of antiviral (HCV, Zika virus, influenza virus and encephalomyocarditis virus) and gene expression assays. Remarkably, E154 is the ancestral residue in mammalian IFNλ4s and is extremely well conserved, yet K154 has been fixed throughout evolution of the hominid genus Homo, including Neanderthals. Compared to chimpanzee IFNλ4, the human orthologue had reduced activity due to amino acid K154. Comparison of published gene expression data from humans and chimpanzees showed that this difference in activity between K154 and E154 in IFNλ4 correlates with differences in antiviral gene expression in vivo during HCV infection. Mechanistically, our data show that the human-specific K154 negatively affects IFNλ4 activity through a novel means by reducing its secretion and potency. We thus demonstrate that attenuated activity of IFNλ4 is conserved among humans and postulate that differences in IFNλ4 activity between species contribute to distinct host-specific responses to—and outcomes of—infection, such as HCV infection. The driver of reduced IFNλ4 antiviral activity in humans remains unknown but likely arose between 6 million and 360,000 years ago in Africa