Modeling and kinetic determination in affinity precipitation of trypsin

A mathematical model was proposed to allow the analysis of kinetic enzyme in experimental of affinity precipitation system. The methodology was tested using a system composed of enzyme, ethylene glycol and conjugated PABA-poly (NIPAM). N-isopropylacrylamide (NIPAM) is one of the monomers that have appealed to a great deal of investigation in the recent years. Its homopolymer NIPAM possesses temperature sensitivity and can act as a functional polymer with great potential. A water soluble ligand bound polymer has been synthesized by Electron Beam Irradiation for the purpose of affinity precipitation of trypsin. The affinity polymer was formed by ligand-PABA. The binding efficiency of trypsin to this polymer was dependent upon the ratio of (NIPAM), mercaptopropionic acid (MPA) as a chain transfer reagent and p-aminobenzamidine (PABA) as ligand that used in the polymer synthesis. The amount of precipitated of poly (NIPAM) present in the polymer solution also greatly affected the trypsin binding efficiency. The total binding capacity of trypsin molecules to ligand molecules approached the theoretical value which was considerably higher than that of insoluble gel matrices. Bound trypsin could be easily eluted by the ethylene glycol solution. At low molecular weight of poly (NIPAM), the conjugate polymer solution was very stable and retained its high capacity for trypsin recovery over a long period of time. The proposed analysis and simulation of kinetic parameters may be helpful in affinity precipitation technique for advanced application

Biossegurança no laboratório

The occurrence of laboratory-acquired infections have elicited in the last ten years an intense interest in methods and procedures for the safe handling of microbiological material. The major laboratory safety problem is aerial transmission, however, protection against airborne hazards is efficiently achieved by the use of microbiological safety cabinets. Biosafety rules should be strictly followed by all members of a laboratory. Evaluation of these procedures should be effectively performed by an independent biosafety committee. The/ upsurge of AIDS should stimulate the adoption of safe working procedures in the laboratory.Nos últimos dez anos tem sido travada uma luta com a finalidade de prevenir a transmissão de agentes infecciosos dentro de laboratórios. A grande fonte de dispersão de patógenos por meio de aerossóis, pode ser eliminada satisfatoriamente com o uso de câmaras de segurança biológica. Regras gerais e específicas de biossegurança devem ser cumpridas por todos os usuários de laboratórios que manuseiam patógenos ou materiais potencialmente contaminantes e, eventualmente, avaliados por um comitê de biossegurança independente. O surgimento da síndrome de imunodeficiência adquirida deve servir.como fator de estímulo à adoção de normas eficazes de segurança laboratorial

Modified Gravity and Dark Energy models Beyond w(z)w(z)CDM Testable by LSST

One of the main science goals of the Large Synoptic Survey Telescope (LSST) is to uncover the nature of cosmic acceleration. In the base analysis, possible deviations from the Lambda-Cold-Dark-Matter ($\Lambda$CDM) background evolution will be probed by fitting a $w(z)$CDM model, which allows for a redshift-dependent dark energy equation of state with $w(z)$, within general relativity (GR). A rich array of other phenomena can arise due to deviations from the standard $\Lambda$CDM+GR model though, including modifications to the growth rate of structure and lensing, and novel screening effects on non-linear scales. Concrete physical models are needed to provide consistent predictions for these (potentially small) effects, to give us the best chance of detecting them and separating them from astrophysical systematics. A complex plethora of possible models has been constructed over the past few decades, with none emerging as a particular favorite. This document prioritizes a subset of these models along with rationales for further study and inclusion into the LSST Dark Energy Science Collaboration (DESC) data analysis pipelines, based on their observational viability, theoretical plausibility, and level of theoretical development. We provide references and theoretical expressions to aid the integration of these models into DESC software and simulations, and give justifications for why other models were not prioritized. While DESC efforts are free to pursue other models, we provide here guidelines on which theories appear to have higher priority for collaboration efforts due to their perceived promise and greater instructional value.Comment: 61 pages. Some acknowledgments and references added. This is version-1.1 of an internal collaboration document of LSST-DESC that is being made public and is not planned for submission to a journa

The growth of structure in the Szekeres inhomogeneous cosmological models and the matter-dominated era

This study belongs to a series devoted to using Szekeres inhomogeneous models to develop a theoretical framework where observations can be investigated with a wider range of possible interpretations. We look here into the growth of large-scale structure in the models. The Szekeres models are exact solutions to Einstein's equations that were originally derived with no symmetries. We use a formulation of the models that is due to Goode and Wainwright, who considered the models as exact perturbations of an FLRW background. Using the Raychaudhuri equation, we write for the two classes of the models, exact growth equations in terms of the under/overdensity and measurable cosmological parameters. The new equations in the overdensity split into two informative parts. The first part, while exact, is identical to the growth equation in the usual linearly perturbed FLRW models, while the second part constitutes exact non-linear perturbations. We integrate numerically the full exact growth rate equations for the flat and curved cases. We find that for the matter-dominated era, the Szekeres growth rate is up to a factor of three to five stronger than the usual linearly perturbed FLRW cases, reflecting the effect of exact Szekeres non-linear perturbations. The growth is also stronger than that of the non-linear spherical collapse model, and the difference between the two increases with time. This highlights the distinction when we use general inhomogeneous models where shear and a tidal gravitational field are present and contribute to the gravitational clustering. Additionally, it is worth observing that the enhancement of the growth found in the Szekeres models during the matter-dominated era could suggest a substitute to the argument that dark matter is needed when using FLRW models to explain the enhanced growth and resulting large-scale structures that we observe today (abridged)Comment: 18 pages, 4 figures, matches PRD accepted versio

An inverse approach to Einstein's equations for non-conducting fluids

We show that a flow (timelike congruence) in any type $B_{1}$ warped product spacetime is uniquely and algorithmically determined by the condition of zero flux. (Though restricted, these spaces include many cases of interest.) The flow is written out explicitly for canonical representations of the spacetimes. With the flow determined, we explore an inverse approach to Einstein's equations where a phenomenological fluid interpretation of a spacetime follows directly from the metric irrespective of the choice of coordinates. This approach is pursued for fluids with anisotropic pressure and shear viscosity. In certain degenerate cases this interpretation is shown to be generically not unique. The framework developed allows the study of exact solutions in any frame without transformations. We provide a number of examples, in various coordinates, including spacetimes with and without unique interpretations. The results and algorithmic procedure developed are implemented as a computer algebra program called GRSource.Comment: 9 pages revtex4. Final form to appear in Phys Rev

All static spherically symmetric perfect fluid solutions of Einstein's Equations

An algorithm based on the choice of a single monotone function (subject to boundary conditions) is presented which generates all regular static spherically symmetric perfect fluid solutions of Einstein's equations. For physically relevant solutions the generating functions must be restricted by non-trivial integral-differential inequalities. Nonetheless, the algorithm is demonstrated here by the construction of an infinite number of previously unknown physically interesting exact solutions.Comment: Final form to appear in Phys Rev D. Includes a number of clarification

Linearized stability analysis of thin-shell wormholes with a cosmological constant

Spherically symmetric thin-shell wormholes in the presence of a cosmological constant are constructed applying the cut-and-paste technique implemented by Visser. Using the Darmois-Israel formalism the surface stresses, which are concentrated at the wormhole throat, are determined. This construction allows one to apply a dynamical analysis to the throat, considering linearized radial perturbations around static solutions. For a large positive cosmological constant, i.e., for the Schwarzschild-de Sitter solution, the region of stability is significantly increased, relatively to the null cosmological constant case, analyzed by Poisson and Visser. With a negative cosmological constant, i.e., the Schwarzschild-anti de Sitter solution, the region of stability is decreased. In particular, considering static solutions with a generic cosmological constant, the weak and dominant energy conditions are violated, while for $a_0 \leq 3M$ the null and strong energy conditions are satisfied. The surface pressure of the static solution is strictly positive for the Schwarzschild and Schwarzschild-anti de Sitter spacetimes, but takes negative values, assuming a surface tension in the Schwarzschild-de Sitter solution, for high values of the cosmological constant and the wormhole throat radius.Comment: 16 pages, 10 figures, LaTeX2e, IOP style files. Accepted for publication in Classical and Quantum Gravit

Penerapan Solar Home System Bagi Keluarga Petani di Dusun Niskolen

Abstract - This activity tries to reveal the impact of installing a solar home system with energy-saving lamps on the social and economic benefits for farming families in Niskolen hamlet. The social and economic benefits are intended for continuity in efforts to expand access to electricity services in areas not yet covered by electricity, and to encourage economic development and growth as well as improve the welfare of farmers. These social and economic benefits have long-term effects, such as increasing reading and learning opportunities, improving people's health standards, and with electricity at night farmers can carry out social and economic activities, as well as facilitate and speed up information from electronic media. The existence of electric lighting will pave the way for the development of the various talents that exist for innovation and entrepreneurship. Abstrak – Kegiatan ini mencoba untuk mengungkapkan dampak pemasangan solar home system dengan lampu hemat energi terhadap manfaat social dan ekonomi bagi keluarga petani di dusun Niskolen. Manfaat sosial dan ekonomi dimaksudkan untuk kelangsungan dalam upaya perluasan akses pelayanan listrik pada wilayah yang belum terjangkau listrik, dan mendorong pembangunan dan pertumbuhan ekonomi serta meningkatkan kesejateraan petani. Manfaat sosial dan ekonomi ini berpengaruh secara jangka panjang, antara lain seperti, peningkatan kesempatan membaca dan belajar, peningkatan taraf kesehatan rakyat, dan dengan adanya listrik pada waktu malam hari petani dapat melakukan kegiatan sosial dan ekonomi, serta memudahkan dan mempercepat informasi dari media elektronik. Dengan adanya penerangan listrik akan membuka jalan kepada pengembangan berbagai bakat yang ada untuk inovasi dan kewirausahaan

Generalized Swiss-cheese cosmologies: Mass scales

We generalize the Swiss-cheese cosmologies so as to include nonzero linear momenta of the associated boundary surfaces. The evolution of mass scales in these generalized cosmologies is studied for a variety of models for the background without having to specify any details within the local inhomogeneities. We find that the final effective gravitational mass and size of the evolving inhomogeneities depends on their linear momenta but these properties are essentially unaffected by the details of the background model.Comment: 10 pages, 14 figures, 1 table, revtex4, Published form (with minor corrections