gebhart/patrepeval huggingface dataset:
Aqueous Phase Separation as a Possible Route to Compartmentalization of Biological Molecules (2012)

How could the incredible complexity of modern cells evolve from something simple enough to have appeared in a primordial soup? This enduring question has sparked the interest of researchers since Darwin first considered his theory of natural selection. Organic molecules, even potentially functional molecules including peptides and nucleotides, can be produced abiotically. Amphiphiles such as surfactants and lipids display remarkable self-assembly processes including the spontaneous formation of vesicles resembling the membranes of living cells. Nonetheless, numerous questions remain. Given the presumably dilute concentrations of macromolecules in the prebiotic pools where the earliest cells are thought to have appeared, how could the necessary components become concentrated and encapsulated within a semipermeable membrane? What would drive the further structural complexity that is a hallmark of modern living systems? The interior of modern cells is subdivided into microcompartments such as the nucleoid of bacteria or the organelles of eukaryotic cells. Even within what at first appears to be a single compartment, for example, the cytoplasm or nucleus, chemical composition is often nonuniform, containing gradients, macromolecular assemblies, and/or liquid droplets. What might the internal structure of intermediate evolutionary forms have looked like? The nonideal aqueous solution chemistry of macromolecules offers an attractive possible answer to these questions. Aqueous polymer solutions will form multiple coexisting thermodynamic phases under a variety of readily accessible conditions. In this Account, we describe aqueous phase separation as a model system for biological compartmentalization in both early and modern cells, with an emphasis on systems that have been encapsulated within a lipid bilayer. We begin with an introduction to aqueous phase separation and discuss how this phenomenon can lead to microcompartmentalization and could facilitate biopolymer encapsulation by partitioning of solutes between the phases. We then describe primitive model cells based on phase separation inside lipid vesicles, which mimic several basic properties of biological cells: microcompartmentation, protein relocalization in response to stimulus, loss of symmetry, and asymmetric vesicle division. We observe these seemingly complex phenomena in the absence of genetic molecules, enzymes, or cellular machinery, and as a result these processes could provide clues to possible intermediates in the early evolution of cell-like assemblies.
The Oxidative Cracking of Hydrocarbon Fuels (2010)

We describe recent results on the oxidation of n-butyl radical generated from n-butyl iodide in single pulse shock tube experiments. The procedure builds on earlier work on pyrolytic decomposition and involves adding sufficient oxygen molecules into the system so that pyrolytic decomposition is suppressed. Instead, an oxidative cracking pattern is obtained. The results show that the main products from oxidative decomposition are ethylene and 1butene with minor contributions from propene and tetrahydrofuran. These results demonstrate via mass balance considerations that under present conditions HO2 is the main product and the OH yields are over an order of magnitude smaller. These results are directly applicable for the simulation of high temperature combustion systems under the present reactive environment. Some of the problems involved in using these results to extrapolate to situations at different temperatures and pressures and molecular structures will be discussed.
Towards Definition, Clinical and Laboratory Criteria, and a Scoring System for Disseminated Intravascular Coagulation* On behalf of the Scientific Subcommittee on Disseminated Intravascular Coagulation (DIC) of the ISTH (2001)

Already in the 19th century some of the first clinical and pathological observations related to DIC were made. A more precise description of DIC and its underlying pathogenesis had to wait until the 20th century, when more insight in the mechanism of blood coagulation was attained and better laboratory tests had become available. Although the general picture of DIC is known to most clinicians, a precise description of the syndrome, a good working definition and a useful scoring system are not available. The SSC subcommittee on DIC has worked over the last years to come closer to achieve these goals. Traditionally DIC is diagnosed in association with the following
Early iron-deficiency-induced transcriptional changes in Arabidopsis roots as revealed by microarray analyses (2009)

The genomic information obtained from this study gives insights into the rapid transcriptional responses to Fe shortage in plants, and is important for understanding how changes in nutrient availability are translated into responses that help to avoid imbalances in ion distribution. We further identified rapidly induced or repressed genes with potential roles in perception and signaling during Fe deficiency which may aid in the elucidation of these processes.
Improved self-inactivating retroviral vectors derived from spleen necrosis virus (1994)

Self-inactivating (SIN) retroviral vectors contain a deletion spanning most of the right long terminal repeat's (LTR's) U3 region. Reverse transcription copies this deletion to both LTRs. As a result, there is no transcription from the 5' LTR, preventing further replication. Many previously developed SIN vectors, however, had reduced titers or were genetically unstable. Earlier, we reported that certain SIN vectors derived from spleen necrosis virus (SNV) experienced reconstitution of the U3-deleted LTR at high frequencies. This reconstitution occurred on the DNA level and appeared to be dependent on defined vector sequences. To study this phenomenon in more detail, we developed an almost completely U3-free retroviral vector. The promoter and enhancer of the left LTR were replaced with those of the cytomegalovirus immediate-early genes. This promoter swap did not impair the level of transcription or alter its start site. Our data indicate that SNV contains a strong initiator which resembles that of human immunodeficiency virus. We show that the vectors replicate with efficiencies similar to those of vectors possessing two wild-type LTRs. U3-deleted vectors carrying the hygromycin B phosphotransferase gene did not observably undergo LTR reconstitution, even when replicated in helper cells containing SNV-LTR sequences. However, vectors carrying the neomycin resistance gene did undergo LTR reconstitution with the use of homologous helper cell LTR sequences as template. This supports our earlier finding that sequences within the neomycin resistance gene can trigger recombination.
An expanded two-state allosteric model for interactions of human hemoglobin A with nonsaturating concentrations of 2,3-diphosphoglycerate. (1987)

Oxygen binding curves (OEC) for red cell suspensions have a biphasic shape and reduced n50 values when the concentration of 2,3-diphosphoglycerate (DPG) is lowered by aging or experimental procedures. The mechanism for the abnormal shape of the OEC has been related to variations in the activity of free DPG. DPG binds to tetrameric Hb at a single site, and in red cells its normal concentration is equivalent to that of tetrameric Hb. This equivalence renders the oxygen affinity of Hb and the shape of the OEC very sensitive to small changes in the activity of DPG. The OEC for stripped Hb solutions in the presence of nonsaturating concentrations of DPG also exhibit a biphasic shape but with much larger changes in the n values than observed for red cells. Upon addition of chloride, a known competitor of DPG binding to Hb, the shape of the OEC becomes similar to that of red cell suspensions with the same DPG/Hb ratio. Studies on Hb solutions in the presence of varying concentrations of DPG, but without chloride, have revealed that the cofactor shifts the entire OEC to the right, including both its upper and lower asymptotes. This finding indicates that DPG lowers the intrinsic oxygen affinity for both the T and R states. Theoretical considerations leading to a successful modeling of OEC obtained under varying conditions of DPG and chloride require an expanded two-state allosteric model in which allowance is made for DPG-dependent variations in the dissociation constants of oxygen for both the T and R conformations.
On the formation of a barrier discharge in excilamps (2007)

The dynamics of discharge formation in a two-barrier XeBr excilamp is studied. It is found that the maximal voltage drop across the lamp and the breakdown voltage of the discharge gap vary with time nonmonotonically upon switching on. This indicates that the discharge goes through several stages before it reaches the steady state. An increase in the lamp capacitance prior to secondary breakdown at the contracted stage of the discharge suggests the formation of a region with a high residual conductivity in the gas-discharge space after primary discharge. It is shown that the use of a keep-alive discharge prevents the arc stage when the excilamp is switched on.
Experimental Testing of Materials Used in Fused Deposition Modeling Rapid Prototyping Technology (2013)

In this paper are presented information about common and advanced materials used for manufacturing of products by Fused Deposition Modelling (FDM) rapid prototyping technology. In different rapid prototyping technologies the initial state of material can come in either solid, liquid or powder state. The current range materials include paper, nylon, wax, resins, metals and ceramics. In FDM are mainly used as basic materials ABS - Acrylonitrile Butadiene Styrene, polyamide, polycarbonate, polyethylene and polypropylene. Main part of the paper is focused on experimental testing of rapid prototyping materials realized by different research teams and presents outputs of testing of ABS material in FDM technology realized by authors.
The Profession of IT, Infoglut (2006)

The article of record as published may be found at http://dx.doi.org/10.1145/1139922.1139936
Eigen-based clutter filter design for ultrasound color flow imaging: a review (2010)

Proper suppression of tissue clutter is a prerequisite for visualizing flow accurately in ultrasound color flow imaging. Among various clutter suppression methods, the eigen-based filter has shown potential because it can theoretically adapt its stopband to the actual clutter characteristics even when tissue motion is present. This paper presents a formative review on how eigen-based filters should be designed to improve their practical efficacy in adaptively suppressing clutter without affecting the blood flow echoes. Our review is centered around a comparative assessment of two eigen-filter design considerations: 1) eigen-component estimation approach (single-ensemble vs. multi-ensemble formulations), and 2) filter order selection mechanism (eigenvalue-based vs. frequencybased algorithms). To evaluate the practical efficacy of existing eigen-filter designs, we analyzed their clutter suppression level in two in vivo scenarios with substantial tissue motion (intra-operative coronary imaging and thyroid imaging). Our analysis shows that, as compared with polynomial regression filters (with or without instantaneous clutter downmixing), eigen-filters that use a frequency-based algorithm for filter order selection generally give Doppler power images with better contrast between blood and tissue regions. Results also suggest that both multi-ensemble and single-ensemble eigen-estimation approaches have their own advantages and weaknesses in different imaging scenarios. It may be beneficial to develop an algorithmic way of defining the eigen-filter formulation so that its performance advantages can be better realized.
Practical recommendations for gradient-based training of deep architectures (2012)

Learning algorithms related to artificial neural networks and in particular for Deep Learning may seem to involve many bells and whistles, called hyper-parameters. This chapter is meant as a practical guide with recommendations for some of the most commonly used hyper-parameters, in particular in the context of learning algorithms based on back-propagated gradient and gradient-based optimization. It also discusses how to deal with the fact that more interesting results can be obtained when allowing one to adjust many hyper-parameters. Overall, it describes elements of the practice used to successfully and efficiently train and debug large-scale and often deep multi-layer neural networks. It closes with open questions about the training difficulties observed with deeper architectures.
Motion segmentation: a synergistic approach (2003)

Since estimation of camera motion requires knowledge of independent motion, and moving object detection and localization requires knowledge about the camera motion, the two problems of motion estimation and segmentation need to be solved together in a synergistic manner. This paper provides an approach to treating both these problems simultaneously. The technique introduced here is based on a novel concept, "scene ruggedness" which parameterizes the variation in estimated scene depth with the error in the underlying three-dimensional (3D) motion. The idea is that incorrect 3D motion estimates cause distortions in the estimated depth map, and as a result smooth scene patches are computed as rugged surfaces. The correct 3D motion can be distinguished, as it does not cause any distortion and thus gives rise to the background patches with the least depth variation between depth discontinuities, with the locations corresponding to independent motion being rugged. The algorithm presented employs a binocular observer whose nature is exploited in the extraction of depth discontinuities, a step that facilitates the overall procedure, but the technique can be extended to a monocular observer in a variety of ways.
The Chemistry of Persulfate. I. The Kinetics and Mechanism of the Decomposition of the Persulfate Ion in Aqueous Medium<sup>1</sup> (1951)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Chemistry of Persulfate. I. The Kinetics and Mechanism of the Decomposition of the Persulfate Ion in Aqueous Medium1I. M. Kolthoff and I. K. MillerCite this: J. Am. Chem. Soc. 1951, 73, 7, 3055–3059Publication Date (Print):July 1, 1951Publication History Published online1 May 2002Published inissue 1 July 1951https://pubs.acs.org/doi/10.1021/ja01151a024https://doi.org/10.1021/ja01151a024research-articleACS PublicationsRequest reuse permissionsArticle Views8240Altmetric-Citations939LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Quasi-optics of a planar dielectric waveguide with a dispersive substrate (1998)

A quasi-optic model for the treatment of a planar dielectric waveguide having a substrate with material dispersion is presented. An application of the lowest-order waveguide mode to the development of an optical sensor for monitoring the thermal degradation of a film thickness is indicated.
Molecular cloning, characterization, and expression in Escherichia coli of a cDNA encoding mammalian choline kinase. (1992)

A rat liver lambda gt11 cDNA library was screened with antibody against rat liver choline kinase. One of the putative phage clones obtained was found to express choline kinase activity in infected Escherichia coli cells and used for the isolation of fully extended cDNA clones by hybridization. The obtained clones had identical overlapping nucleotide sequences and gave a composite cDNA sequence of 2540 bases. Poly(A)+ tails were found at three different sites of the cDNA sequence. Within the sequence there was a large open reading frame encoding 435 amino acids with a molecular mass of 49,743 Da. When this open reading frame was placed after the trc promoter and introduced into E. coli cells, fully active choline kinase was produced. This enzyme was partially purified using a published choline kinase purification method and was found to mediate the phosphorylation of choline, N,N-dimethylethanolamine,N-monomethylethanolamine, and ethanolamine. Similar to the case with choline kinases from various sources, Km decreased as the number of N-methyl groups increased. The deduced amino acid sequence significantly resembled the yeast choline kinase sequence. It also showed local sequence similarity to protein kinases and some bacterial phosphotransferases. Northern blot analysis revealed that the cDNA probe hybridized to 2.8- and 1.8-kilobase RNA in various rat tissues. The sizes of the transcripts were fairly consistent with that of cDNA. The order of mRNA abundance was testis, brain, lung, kidney, and liver, but did not coincide with the order of the activity levels in these tissues. These results show that the cloned cDNA encodes one of the choline kinase isoforms present in mammalian tissues.
Effect of Specific Elicitors of <i>Cladosporium fulvum</i> on Tomato Suspension Cells (1992)

Intercellular fluid (IF) obtained from tomato (Lycopersicon esculentum L.) leaflets colonized by Cladosporium fulvum Cooke contains specific elicitors that induce necrosis in tomato cultivars resistant to the race of C. fulvum used to produce the IF. The responses of cell-suspension cultures produced from tomato lines near-isogenic for resistance genes Cf 4 and Cf 5 to IF produced from leaves infected by races 4 (virulent on Cf 4 but not Cf 5 plants), 2.4.5, and 2.4.5.9 (both virulent on Cf 4 and Cf 5 plants) were used to investigate the possibility that active oxygen (AO) species were involved in the initial host reaction to these elicitors. Concurrently, the same assays were used to determine if the cell lines retained the elicitor specificity of the original plants. An IF/cell combination that gives an incompatible reaction in leaves (race 4 IF and Cf 5 cells) showed reduced oxygen uptake and increases in malonaldehyde (a product of lipid peroxidation); cytochrome c reducing activity, which was inhibited by superoxide dismutase (SOD) (an assay for superoxide); luminol-dependent chemiluminescence (an assay for several AO species); activity of extracellular peroxidases; and extracellular phenolic compounds. In contrast, compatible combinations (IF from races 2.4.5 or 2.4.5.9 and Cf 4 or Cf 5 cells; race 4 IF and Cf 4 cells) did not exhibit any of these changes. The addition of catalase, SOD, ascorbate (a scavenger of superoxide), mannitol (a scavenger of the hydroxyl radical), KCN, or salicyl hydroxamic acid (both inhibitors of peroxidases) prior to IF treatment reduced the IF-induced increases in malonaldehyde and extracellular phenolics. Catalase was an effective inhibitor of the IF-induced changes in oxygen uptake and cytochrome c reducing activity. These results demonstrate the specificity of the IF-induced cell responses and confirm that AO species are involved in the initial cell response.
ChemInform Abstract: Photoinduced Reaction of (60)Fullerene with Tertiary Amines: Synthesis of (60)Fulleropyrrolidines. (1997)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Technological Solutions for WiMAX Network Planning (2013)

The planning of broadband access network topologies poses several challenges, as different access technologies may have different bandwidth, robustness, and installation cost requirements, which should be jointly considered in the conception of the overall network topology, to properly match the end users requirements. This paper addresses the planning of wireless networks using IEEE 802.16, for a set of different user profiles, different services and requirements, and different scenarios (residential, business, mixed) with different terrains. An application has been developed to design and plan IEEE 802.16 wireless networks. The results show that there are several possibilities of solutions to satisfy the needs of specific scenarios, whether the desired solution should have better coverage area or better capacity. The planning tool enables the user to change the solution to better fit for the deployment needs.
Statistical characterization of wide-area IP traffic (2002)

A background traffic model is fundamental to packet-level network simulation since the background traffic impacts packet drop rates, queueing delays, end-to-end delay variation, and also determines available network bandwidth. In this paper, we present a statistical characterization of wide-area IP traffic based on 90-minute traces taken from a week-long trace of packets exchanged between a large campus network a state wide educational network, and a large Internet service provider. The results of this analysis can be used to provide a basis for modelling background load in simulations of wide-area packet-switched networks such as the Internet, contribute to understanding the fractal behavior of wide-area network utilization, and provide a benchmark to evaluate the accuracy of existing traffic models. The key findings of our study include the following: (1) both the aggregate packet stream and its component substreams exhibit significant long-range dependencies in agreement with other traffic studies. (2) the empirical probability distributions of packet arrivals are log-normally distributed. (3) packet sizes exhibit only short-term correlations and (4) the packet size distribution and correlation structure are independent from both network utilization and time of day.
Drainage of the Abdomen (1972)

IN all walks of life drains are used to lead away unwanted material. Drainage of the abdomen is no exception. The material may have collected before operation, as in an intra-abdominal abscess. In these circumstances a drain is used therapeutically to ensure that the pus is all evacuated and to prevent closure of the drainage hole while the cavity is still large enough to produce more pus, which might reaccumulate. There is fairly general agreement on the use of drains in this therapeutic sense.When the drain is used prophylactically no such agreement exists. After certain procedures fluid may gather . . .