Direction of Translation and Size of Bacteriophage [var phi]X174 Cistrons

Translation of the bacteriophage [var phi]X174 genome follows cistron order D-E-F-G-H-A-B-C. To establish this, the position of a nonsense mutation on the genetic map was compared with the physical size (molecular weight) of the appropriate protein fragment generated in nonpermissive cells. Distances on the [var phi]X174 genetic map and distances on a physical map constructed from the molecular weights of [var phi]X174 proteins and protein fragments are proportional over most of the genome with the exception of the high recombination region within cistron A

Finite size effects in adsorption of helium mixtures by alkali substrates

We investigate the behavior of mixed 3He-4He droplets on alkali surfaces at zero temperature, within the frame of Finite Range Density Functional theory. The properties of one single 3He atom on 4He_N4 droplets on different alkali surfaces are addressed, and the energetics and structure of 4He_N4+3He_N3 systems on Cs surfaces, for nanoscopic 4He drops, are analyzed through the solutions of the mean field equations for varying number N3 of 3He atoms. We discuss the size effects on the single particle spectrum of 3He atoms and on the shapes of both helium distributions.Comment: 12 pages, and 12 figures (PNG format

Differences into HT and HTO concentrations in air into the Western Mediterranean Basin and Continental Europe and Safety Related Issues.

Real time Tritium concentrations in air in two chemical forms, HT and HTO, coming from an ITER-like fusion reactor as source were coupled the European Centre Medium Range Weather Forecast (ECMWF) numerical model with the Lagrangian Atmospheric-particle dispersion model FLEXPART. This tool was analyzed in nominal tritium discharge operational reference and selected incidental conditions affecting the Western Mediterranean Basin during 45 days during summer 2010 together with surface “wind observations” or weather data based in real hourly observations of wind direction and velocity providing a real approximation of the tritium behavior after the release to the atmosphere from a fusion reactor. From comparison with NORMTRI - a code using climatologically sequences as input - over the same area, the real time results have demonstrated an apparent overestimation of the corresponding climatologically sequence of Tritium concentrations in air outputs, at several distances from the reactor. For this purpose two development patterns were established. The first one was following a cyclonic circulation over the Mediterranean Sea and the second one was based on the plume delivered over the Interior of the Iberian Peninsula and Continental Europe by another stabilized circulation corresponding to a High Pressure System. One of the important remaining activities defined then, was the qualification tool. In order to validate the model of ECMWF/FLEXPART we have developed of a new complete data base of tritium concentrations for the months from November 2010 to March 2011 and defined a new set of four patterns of HT transport in air, in each case using real boundary conditions: stationary to the North, stationary to the South, fast and very fast displacement. Finally the differences corresponding to those four early patterns (each one in assessments 1 and 2) has been analyzed in terms of the tuning of safety related issues and taking into account the primary phase o- - f tritium modeling, from its discharge to the atmosphere to the deposition on the ground, will affect to the complete tritium environmental pathway altering the chronic dose by absorption, reemission and ingestion both from elemental tritium, HT and from the oxide of tritium, HT

Autotrophic and Heterotrophic Growth Conditions Modify Biomolecole Production in the Microalga Galdieria sulphuraria (Cyanidiophyceae, Rhodophyta)

Algae have multiple similarities with fungi, with both belonging to the Thallophyte, a polyphyletic group of non-mobile organisms grouped together on the basis of similar characteristics, but not sharing a common ancestor. The main difference between algae and fungi is noted in their metabolism. In fact, although algae have chlorophyll-bearing thalloids and are autotrophic organisms, fungi lack chlorophyll and are heterotrophic, not able to synthesize their own nutrients. However, our studies have shown that the extremophilic microalga Galderia sulphuraria (GS) can also grow very well in heterotrophic conditions like fungi. This study was carried out using several approaches such as scanning electron microscope (SEM), gas chromatography/mass spectrometry (GC/MS), and infrared spectrophotometry (ATR-FTIR). Results showed that the GS, strain ACUF 064, cultured in autotrophic (AGS) and heterotrophic (HGS) conditions, produced different biomolecules. In particular, when grown in HGS, the algae (i) was 30% larger, with an increase in carbon mass that was 20% greater than AGS; (ii) produced higher quantities of stearic acid, oleic acid, monounsaturated fatty acids (MUFAs), and ergosterol; (iii) produced lower quantities of fatty acid methyl esters (FAMEs) such as methyl palmytate, and methyl linoleate, saturated fatty acids (SFAs), and poyliunsaturated fatty acids (PUFAs). ATR-FTIR and principal component analysis (PCA) statistical analysis confirmed that the macromolecular content of HGS was significantly different from AGS. The ability to produce different macromolecules by changing the trophic conditions may represent an interesting strategy to induce microalgae to produce different biomolecules that can find applications in several fields such as food, feed, nutraceutical, or energy production

Critical frequency for vortex nucleation in Bose-Fermi mixtures in optical lattices

We investigate within mean-field theory the influence of a one-dimensional optical lattice and of trapped degenerate fermions on the critical rotational frequency for vortex line creation in a Bose-Einstein condensate. We consider laser intensities of the lattice such that quantum coherence across the condensate is ensured. We find a sizable decrease of the thermodynamic critical frequency for vortex nucleation with increasing applied laser strength and suggest suitable parameters for experimental observation. Since 87Rb-40K mixtures may undergo collapse, we analyze the related question of how the optical lattice affects the mechanical stability of the system.Comment: 5 pages, 4 figures, revtex

From nonwetting to prewetting: the asymptotic behavior of 4He drops on alkali substrates

We investigate the spreading of 4He droplets on alkali surfaces at zero temperature, within the frame of Finite Range Density Functional theory. The equilibrium configurations of several 4He_N clusters and their asymptotic trend with increasing particle number N, which can be traced to the wetting behavior of the quantum fluid, are examined for nanoscopic droplets. We discuss the size effects, inferring that the asymptotic properties of large droplets correspond to those of the prewetting film

Tweeting the meeting. Quantitative and qualitative twitter activity during the 38th ESSO conference

Introduction: Social media is increasingly used to share information with the potential for fast and wide reach. Data on use during surgical oncology conferences is limited. We aimed to monitor twitter usage during a surgical oncology conference to audit impact of activity. Methods: A prospective, time-restricted, observational study of twitter activity using the #ESSO38 hashtag in the week before and during the 38th ESSO conference (10–12 October 2018; Budapest, Hungary). Data on individual tweets and retweets, including date and tweeter or retweeter were collected using NodeXL, FollowTheHashtag, Twitonomy and TAGS. Results: The study period (10–13 October) documented 328 tweets by 58 tweeters with 1167 retweets, with a soaring activity and mentions during the conference days, with a potential reach at over 7.5 million. The nodal network of tweets, the most active tweeters and retweeters are presented as well as the most frequently used hashtags. The top 3 hashtags used were #ESSO38, #SoMe4Surgery# and #EYSAC. A positive influence on the @ESSOweb twitter handle was noted, with the numbers of followers growing from 1.5 K to over 1.8 K representing a 20% growth in just over a week. Conclusions: Activity on tweeter during the conference was considerable, with a potential for a wide reach beyond those attending the conference. A more structured approach to the use of twitter for future conferences may enhance experience, activity and reach

Twin hydroxymethyluracil-A base pair steps define the binding site for the DNA-bending protein TF1

The DNA-bending protein TF1 is the Bacillus subtilis bacteriophage SPO1- encoded homolog of the bacterial HU proteins and the Escherichia coli integration host factor. We recently proposed that TF1, which binds with high affinity (K(d) was ~3 nM) to preferred sites within the hydroxymethyluracil (hmU)-containing phage genome, identifies its binding sites based on sequence-dependent DNA flexibility. Here, we show that two hmU-A base pair steps coinciding with two previously proposed sites of DNA distortion are critical for complex formation. The affinity of TF1 is reduced 10-fold when both of these hmU-A base pair steps are replaced with A-hmU, G-C, or C-G steps; only modest changes in affinity result when substitutions are made at other base pairs of the TF1 binding site. Replacement of all hmU residues with thymine decreases the affinity of TF1 greatly; remarkably, the high affinity is restored when the two hmU-A base pair steps corresponding to previously suggested sites of distortion are reintroduced into otherwise T- containing DNA. T-DNA constructs with 3-base bulges spaced apart by 9 base pairs of duplex also generate nM affinity of TF1. We suggest that twin hmU-A base pair steps located at the proposed sites of distortion are key to target site selection by TF1 and that recognition is based largely, if not entirely, on sequence-dependent DNA flexibility

A Density Functional for Liquid 3He Based on the Aziz Potential

We propose a new class of density functionals for liquid 3He based on the Aziz helium-helium interaction screened at short distances by the microscopically calculated two-body distribution function g(r). Our aim is to reduce to a minumum the unavoidable phenomenological ingredients inherent to any density functional approach. Results for the homogeneous liquid and droplets are presented and discussed. © 2006 American Institute of Physics.Fil:Hernández, E.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Szybisz, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Measurement report: An exploratory study of fluorescence and cloud condensation nuclei activity of urban aerosols in San Juan, Puerto Rico

Many atmospheric aerosols are cloud condensation nuclei (CCN), capable of activating as cloud droplets when the relative humidity exceeds 100 %. Some primary biological aerosol particles (PBAPs), such as plant spores, pollen, or bacteria, have been identified as such CCN. Urban environments are a source of these bioaerosols, some of which are naturally produced by the local flora or are transported from surrounding regions and others of which are a result of human activities. In the latter case, open sewage, uncovered garbage, mold or other products of such activities can be a source of PBAPs. There have been relatively few studies, especially in the tropics, where PBAPs and CCN have been simultaneously studied to establish a causal link between the two. The metropolis of San Juan, Puerto Rico, is one such urban area with a population of 2 448 000 people (as of 2020). To better understand the fluorescent characteristics and cloud-forming efficiency of aerosols in this region, measurements with a wideband integrated bioaerosol spectrometer (WIBS), a condensation nuclei (CN) counter and a CCN spectrometer were made at the University of Puerto Rico – Río Piedras Campus. Results show that the CCN / CN activation ratio and the fraction of fluorescing aerosol particles (FAPs) have repetitive daily trends when the FAP fraction is positively correlated with relative humidity and negatively correlated with wind speed, consistent with previous studies of fungi spores collected on substrates. The results from this pilot study highlight the capabilities of ultraviolet-induced fluorescence (UV-IF) measurements for characterizing the properties of FAPs as they relate to the daily evolution of PBAPs. The use of multiple excitation and emission wavelengths, along with shape detection, allows the differentiation of different PBAP types. These measurements, evaluated with respect to previous, substrate-based analysis of the local fungal and pollen spores, have established a preliminary database of measurements that future, longer-term studies will build upon.</p