Inter-stage line ratio of He- and Li-like Ti emissions for the electron temperature measurement

Under coronal conditions, the steady state rate-equations are used to calculate the inter-stage line ratios between Li-like Is(2)2p(P-2(3/2))-> 1s(2)2s -> ((2) S-1/2) and He-like 1s2p (P-1(1))-> 1s(2) (S-1(0)) transitions for Ti in the electronic temperature ranges from 0.1 keV to 20 keV. The results show that the. temperature sensitivities are higher at the electronic temperature less than 5000 eV and the temperature sensitivities will decrease with the increase of electronic temperature.

Ground-state energy shifts of H-like Ti under dense and hot plasma conditions

In this study, by adopting the ion sphere model, the self-consistent. field method is used with the Poisson-Boltzmann equation and the Dirac equation to calculate the ground-state energies of H-like Ti at a plasma electron density from 10(22) cm(-3) to 10(24) cm(-3) and the electron temperature from 100 eV to 3600 eV. The ground-state energy shifts of H-like Ti show different trends with the electron density and the electron temperature. It is shown that the energy shifts increase with the increase in the electron density and decrease with the increase in the electron temperature. The energy shifts are sensitive to the electron density, but only sensitive to the low electron temperature. In addition, an accurately fitting formula is obtained to fast estimate the ground-state energies of H-like Ti. Such fitted formula can also be used to estimate the critical electron density of pressure ionization for the ground state of H-like Ti.

Engineered discoidin domain from factor VIII binds αvβ3 integrin with antibody-like affinity

Alternative scaffolds are non-antibody proteins that can be engineered to bind new targets. They have found useful niches in the therapeutic space due to their smaller size and the ease with which they can be engineered to be bispecific. We sought a new scaffold that could be used for therapeutic ends and chose the C2 discoidin domain of factor VIII, which is well studied and of human origin. Using yeast surface display, we engineered the C2 domain to bind to αvβ3 integrin with a 16 nM affinity while retaining its thermal stability and monomeric nature. We obtained a crystal structure of the engineered domain at 2.1 Å resolution. We have christened this discoidin domain alternative scaffold the “discobody.”

A Detailed Analysis of Transcriptional Regulators Affecting the Saccharomyces cerevisiae Heat-shock Gene SSA1

The yeast Saccharomyces cerevisiae contains a family of hsp70 related genes. One member of this family, SSA1, encodes a 70kD heat-shock protein which in addition to its heat inducible expression has a significant basal level of expression. The first 500 bp upstream of the SSA1 start point of transcription was examined by DNAse I protection analysis. The results reveal the presence of at least 14 factor binding sites throughout the upstream promoter region. The function of these binding sites has been examined using a series of 5' promoter deletions fused to the recorder gene lacZ in a centromere-containing yeast shuttle vector. The following sites have been identified in the promoter and their activity in yeast determined individually with a centromere-based recorder plasmid containing a truncated CYC1 /lacZ fusion: a heat-shock element or HSE which is sufficient to convey heat-shock response on the recorder plasmid; a homology to the SV40 'core' sequence which can repress the GCN4 recognition element (GCRE) and the yAP1 recognition element (ARE), and has been designated a upstream repression element or URE; a 'G'-rich region named G-box which can also convey heatshock response on the recorder plasmid; and a purine-pyrimidine alternating sequence name GT-box which is an activator of transcription. A series of fusion constructs were made to identify a putative silencer-like element upstream of SSA1. This element is position dependent and has been localized to a region containing both an ABF1 binding site and a RAP1 binding site. Five site-specific DNA-binding factors are identified and their purification is presented: the heat-shock transcription factor or HSTF, which recognizes the HSE; the G-box binding factor or GBF; the URE recognition factor or URF; the GT-box binding factor; and the GC-box binding factor or yeast Sp1.

Expanding the Toolkit for Synthetic Biology: Frameworks for Native-like Non-natural Gene Circuits

Synthetic biology combines biological parts from different sources in order to engineer non-native, functional systems. While there is a lot of potential for synthetic biology to revolutionize processes, such as the production of pharmaceuticals, engineering synthetic systems has been challenging. It is oftentimes necessary to explore a large design space to balance the levels of interacting components in the circuit. There are also times where it is desirable to incorporate enzymes that have non-biological functions into a synthetic circuit. Tuning the levels of different components, however, is often restricted to a fixed operating point, and this makes synthetic systems sensitive to changes in the environment. Natural systems are able to respond dynamically to a changing environment by obtaining information relevant to the function of the circuit. This work addresses these problems by establishing frameworks and mechanisms that allow synthetic circuits to communicate with the environment, maintain fixed ratios between components, and potentially add new parts that are outside the realm of current biological function. These frameworks provide a way for synthetic circuits to behave more like natural circuits by enabling a dynamic response, and provide a systematic and rational way to search design space to an experimentally tractable size where likely solutions exist. We hope that the contributions described below will aid in allowing synthetic biology to realize its potential.

Sensitivity of sturgeons to environmental hypoxia: a review of physiological and ecological evidence

In this essay, three lines of evidence are developed that sturgeons in the Chesapeake Bay and elsewhere are unusually sensitive to hypoxic conditions: 1. In comparison to other fishes,sturgeons have a limited behavioral and physiological capacity to respond to hypoxia. Basal metabolism, growth, feeding rate, and survival are sensitive to changes in oxygen level, which may indicate a relatively poor ability of sturgeons to oxyregulate. 2. During summertime, temperatures >20°C amplify the effect of hypoxia on sturgeons and other fishes due to a temperature oxygen "squeeze" (Coutant 1987). In bottom waters, this interaction results in substantial reduction of habitat; in dry years, sturgeon nursery habitats in the Chesapeake Bay may be particularly reduced or even eliminated. 3. While evidence for population level effects due to hypoxia is circumstantial, there are corresponding trends between the absence of Atlantic sturgeon reproduction in estuaries like the Chesapeake Bay where summertime hypoxia predominates on a system-wide scale. Also, the recent and dramatic recovery of shortnose sturgeon in the Hudson River (4-bid increase in abundance from 1980 to1995) may have been stimulated by improvement of a large portion of the nursery habitat that was restored from hypoxia to normoxia during the period 1973-1978.

On the classification of lakes and lake-like bodies of the Ukraine [Translation from: Gidrobiologicheskie Zhurnal, Kiev 19(2) 100-101, 1983]

In the Ukraine there are several thousand large, medium and small lakes and lake-like reservoirs, distinguished by origin, salinity, regional position, productivity and by construction a significant number of large and small water bodies, ponds and industrial reservoirs of variable designation. The problem of national systems necessitates the creation of specific schemes and classifications. Classifying into specific types of reservoir by means of suitable specifications is required for planning national measures with the objective of the rational utilisation of natural resources. It is now necessary to consider the present-day characteristics of Ukranian lakes. In the case of the Ukraine it is possible to use two approaches - genetical and ecological. This paper uses the genetical system to classify the lake-like water bodies of the Ukraine.

Estudo fenotípico da região Aorta-Gônada-Mesonefros, de embriões de galinhas Gallus gallus domesticus, com ênfase na aorta dorsal

Acredita-se que os primeiros progenitores da hematopoese definitiva surjam da diferenciação do endotélio da aorta dorsal, na altura da região da Aorta-Gônada-Mesonefros (AGM). Com o intuito de estudar esta região e o fenótipo das células do endotélio da aorta dorsal nesta posição topográfica, ovos galados de Gallus gallus domesticus L. foram incubados em chocadeira, classificados em estádios de E16 a E25 e processados histotecnologicamente para obtenção de secções seriadas na altura da região AGM. Estas passaram por coloração por Hematoxilina-Eosina, histoquímica para PAS, PAS-diastase e Alcian Blue pH 1.0 e pH 2.5, histoquímica por lectinas fluoresceinadas e imunofluorescência para moléculas de superfície, citoesqueleto e matriz extracelular. Foi observada hipertrofia endotelial no assoalho da aorta nos estádios observados, o qual se apresentava positivo ao PAS, com ocorrência frequente de vacuolizações basais PAS negativas, e o surgimento ocasional de grupamentos celulares intravasculares. Nestes, as células que se destacavam da membrana basal do endotélio expressavam progressivamente mais material PAS positivo, o qual, no entanto, em nenhum momento pareceu se tratar de glicogênio. Em relação às glicosaminoglicanas, notamos a presença predominante de ácido hialurônico por todo o mesênquima da região e em outras estruturas como periferia da notocorda, tubo neural e mesoderma lateral. Ocorreu co-expressão de fibronectina e α-actina de músculo liso em células circunjacentes à aorta, na face ventral do vaso. GFAP e BMP-4 são expressas entre as células do tubo neural e em sua periferia, assim como na notocorda do embrião. As lectinas Abrus precatorius, Lens culinarise Ricinus communis mostraram-se positivas principalmente na região subedotelial do assoalho da aorta nos estádios observados neste trabalho. Bandeiraea simplicifolia exibiu pouca marcação na aorta dorsal e a Arachis hypogeae foi negativa. Outras estruturas da região AGM também expressaram resíduos de açúcares revelados por estas lectinas, tais como: notocorda, tubo neural, mesênquima, intestino primitivo e saco vitelínico. Estes resultados acrescentam elementos morfológicos e bioquímicos ao conhecimento sobre a região AGM de embriões de galinha e sobre o endotélio, possivelmente hemogênico, da aorta dorsal.