Fingerprints of the Hierarchical Building up of the Structure on the Mass-Metallicity Relation

We study the mass-metallicity relation of galactic systems with stellar masses larger than 10^9 Mo in Lambda-CDM scenarios by using chemical hydrodynamical simulations. We find that this relation arises naturally as a consequence of the formation of the structure in a hierarchical scenario. The hierarchical building up of the structure determines a characteristic stellar mass at M_c ~10^10.2 Moh^-1 which exhibits approximately solar metallicities from z ~ 3 to z=0. This characteristic mass separates galactic systems in two groups with massive ones forming most of their stars and metals at high redshift. We find evolution in the zero point and slope of the mass-metallicity relation driven mainly by the low mass systems which exhibit the larger variations in the chemical properties. Although stellar mass and circular velocity are directly related, the correlation between circular velocity and metallicity shows a larger evolution with redshift making this relation more appropriate to confront models and observations. The dispersion found in both relations is a function of the stellar mass and reflects the different dynamical history of evolution of the systems.Comment: 4 pages, 4 figures. Accepted MNRAS Letter

Contractual Testing

Variants of must testing approach have been successfully applied in Service Oriented Computing for capturing compliance between (contracts exposed by) a client and a service and for characterising safe replacement, namely the fact that compliance is preserved when a service exposing a ’smaller’ contract is replaced by another one with a ’larger’ contract. Nevertheless, in multi-party interactions, partners often lack full coordination capabilities. Such a scenario calls for less discriminating notions of testing in which observers are, e.g., the description of uncoordinated multiparty contexts or contexts that are unable to observe the complete behaviour of the process under test. In this paper we propose an extended notion of must preorder, called contractual preorder, according to which contracts are compared according to their ability to pass only the tests belonging to a given set. We show the generality of our framework by proving that preorders induced by existing notions of compliance in a distributed setting are instances of the contractual preorder when restricting to suitable sets of observers

Development of an improved Pseudoalteromonas haloplanktis TAC125 strain for recombinant protein secretion at low temperature

Background: In a previous paper, we reported the accomplishment of a cold gene-expression system for the recombinant secretion of heterologous proteins in Pseudoalteromonas haloplanktis TAC125. This system makes use of the psychrophilic α-amylase from P. haloplanktis TAB23 as secretion carrier, and allows an effective extra-cellular addressing of recombinant proteins. However, Pseudoalteromonales are reported to secrete a wide range of extra-cellular proteases. This feature works against the efficiency of the cold-adapted secretion system, because of the proteolytic degradation of recombinant products. The aim of this study is the construction of a P. haloplanktis TAC125 mutant strain with reduced extra-cellular proteolytic activity. Results: P. haloplanktis TAC125 culture medium resulted to contain multiple and heterogeneous proteases. Since the annotation of the Antarctic bacterium genome highlighted the presence of only one canonical secretion machinery, namely the Type II secretion pathway (T2SS), we have inactivated this secretion system by a gene insertion strategy. A mutant strain of P. haloplanktis TAC125 in which the gspE gene was knocked-out, actually displayed a remarkable reduction of the extra-cellular protease secretion. Quite interestingly this strain still retained the ability to secrete the psychrophilic amylase as efficiently as the wild type. Moreover, the decrease in extra-cellular proteolytic activity resulted in a substantial improvement in the stability of the secreted amylase-β-lactamase chimera. Conclusion: Here we report a cell engineering approach to the construction of a P. haloplanktis TAC125 strain with reduced extra-cellular protease activity. The improved strain is able to secrete the psychrophilic α-amylase (the carrier of our recombinant secretion system), while it displays a significant reduction of protease content in the culture medium. These features make the gspE mutant an improved host with a remarkable biotechnological potential in recombinant protein secretion at low temperature. Moreover this work demonstrates that P. haloplanktis TAC125 is a versatile psychrophilic host for recombinant protein production since it can be easily improved by a directed engineering approach. To the best of our knowledge, this is the first described example of a strain improvement strategy applied to an Antarctic bacterium

Dark Monopoles in Grand Unified Theories

We consider a Yang-Mills-Higgs theory with gauge group $G=SU(n)$ broken to $G_{v} = [SU(p)\times SU(n-p)\times U(1)]/Z$ by a Higgs field in the adjoint representation. We obtain monopole solutions whose magnetic field is not in the Cartan Subalgebra. Since their magnetic field vanishes in the direction of the generator of the electromagnetic group $U(1)_{em}$, we call them Dark Monopoles. These Dark Monopoles must exist in some Grand Unified Theories (GUTs) without the need to introduce a dark sector. We analyze the particular case of $SU(5)$ GUT, where we obtain that their mass is $M = 4\pi v \widetilde{E}(\lambda/e^{2})/e$, where $\widetilde{E}(\lambda/e^{2})$ is a monotonically increasing function of $\lambda/e^{2}$ with $\widetilde{E}(0)=1.294$ and $\widetilde{E}(\infty)=3.262.$ We also give a geometrical interpretation to their non-abelian magnetic charge.Comment: 22 pages; added some comments on possible cosmological implications of Dark Monopoles in the last section and added some references. Published Versio

Used food oils: physical-chemical indicators of quality degradation

Comunicação apresentada em 11th Baltic Conference on Food Science and Technology “Food science and technology in achanging world” FOODBALT 2017 Conference Proceedings. Jelgava, LLUUsed food oil (UFO), designated as frying oil, is a residue. Degradation by reuse or during storage, may occur by contacting, chemical, enzymatic and microbiological pathways, but oxidation is a major concern of the industry, as it affects sensory and nutritional quality of edible oils, with potentially toxic compounds formation. In Portugal, UFO's main destination still is the sewerage system, an environmental problem and waste of raw material, which can be re-qualified for non-food uses. However, quality control applied to UFO's, often results into expensive analysis inappropriate for small laboratories and catering industry. This project, developed with the Musketeers Group Portugal co-promotion (2012-2016), aimed to identify low-cost physicochemical parameters for further implementation as UFO's Quality Degradation Indicators (QDI) indicating defects quickly and accurately. UFO's analysis was tested on the use, for industrial frying, and by degradation induced in the laboratory (frying and heat stability tests) by applying following parameters: moisture, water activity (a(w)), total acidity, peroxide index, iodine index, colour (CIE, CIE Lab), UV absorbency, total polar compounds and microbiological indicators. Internal procedures (ESAS) were validated, redefining working ranges and test conditions, as standards procedures did not provide reliable results for the entire life cycle of oils, whose profile changes with time and reuse. Results demonstrate significant differences with quick response parameters as Total Acidity, Peroxide Index and CIE Lab colour, outlined as QDI's. Moisture, aw and CIE Lab colour proved to be inadequate for this purpose. Iodine Index and UV Absorbency are more complex and time-consuming and were profiled as reference methods.info:eu-repo/semantics/publishedVersio

“Música em PAS”: music as an evaluation object of the program of serial university entrance examination of University of Brasília (PAS/UnB)

This paper discusses the musical proposal to Program of Serial University Entrance Examination of University of Brasília (PAS/UnB). The discussion is based on author’s participation on elaboration, systematization, and review groups of 2001 and 2006 programs, as well her researches and her teacher training activities with PAS. The text presents the program, its evaluation conception and the music-pedagogical principles and purposes that guide the insertion of musical knowledge as compulsory evaluation’s object in the university entrance examination. The last program’s version has adopted an Evaluation’s Matrix with some music competences, abilities and evaluation’s objects. The development of music’s competences and abilities is oriented by a music repertoire that defi- nes the content and should be a way for development of musical practices and experiences (performance, improvisation and composition), reception (musical appraising) and context. In this process, the schools and its music teachers are responsible for create learning and teaching situations where the musical experience could be celebrated in sense of to promote a musical significant learning experience and the student’s success in PAS/UnB exams

Understanding the Effects of Lactose Hydrolysis Modeling on the Main Oligosaccharides in Goat Milk Whey Permeate.

Enzymatic hydrolysis of lactose is a crucial step to improve the efficiency and selectivity of membrane-based separations toward the recovery of milk oligosaccharides free from simple sugars. Response surface methodology was used to investigate the effects temperature (25.9 to 54.1 °C) and amount of enzyme (0.17 to 0.32% w/w) at 1, 2, and 4 h of reaction on the efficiency of lactose hydrolysis by Aspergillus oryzae β-galactosidase, preservation of major goat whey oligosaccharides, and on the de-novo formation of oligosaccharides. Lactose hydrolysis above 99% was achieved at 1, 2, and 4 h, not being significantly affected by temperature and amount of enzyme within the tested conditions. Formation of 4 Hexose (Hex) and 4 Hex 1 Hex and an increased de-novo formation of 2 Hex 1 N-Acetyl-Neuraminic Acid (NeuAc) and 2 Hex 1 N-Glycolylneuraminic acid (NeuGc) was observed in all treatments. Overall, processing conditions using temperatures ≤40 °C and enzyme concentration ≤0.25% resulted in higher preservation/formation of goat whey oligosaccharides

Quenched lattice calculation of semileptonic heavy-light meson form factors

We calculate, in the continuum limit of quenched lattice QCD, the matrix elements of the heavy-heavy vector current between heavy-light pseudoscalar meson states. We present the form factors for different values of the initial and final meson masses at finite momentum transfer. In particular, we calculate the non-perturbative correction to the differential decay rate of the process B --> D l nu including the case of a non-vanishing lepton mass.Comment: 16 pages, 10 figures, version accepted for publication on JHE

Hydra tropomyosin TROP1 is expressed in head-specific epithelial cells and is a major component of the cytoskeletal structure that anchors nematocytes

A cDNA clone encoding a 253 amino acid tropomyosin was isolated from Hydra in a differential screen for headspecific genes. The Hydra tropomyosin gene, designated trop1, is a single copy gene, lacks introns and is strongly expressed in tentacle-specific epithelial cells. Analysis of protein synthesis in head and gastric tissue indicated a high rate of tropomyosin synthesis in head tissue. Immunolocalization of tropomyosin in tentacle tissue revealed a cushion-like tropomyosin-containing structure within battery cells at the base of nematocytes. The structure appears to form part of the cytoskeletal anchor for nematocytes. Tropomyosin cushions were also observed in epithelial cells along the body column, which contain mounted stenotele nematocytes