Complete nucleotide sequence and structural organization of pPB1, a small Lactobacillus plantarum cryptic plasmid that originated by modular exchange

A small cryptic plasmid designated pPB1 was isolated from Lactobacillus plantarum BIFI-38 and its complete 2899 bp nucleotide sequence was determined. Sequence analysis revealed four putative open reading frames. Based on sequence analysis two modules could be identified. First, the replication module consisted of a sequence coding for a replication protein (RepB) and its corresponding target site, and two putative repressor proteins (RepA and RepC). Sequence analysis indicated the possible synthesis of an antisense RNA that might regulate RepB production. A putative laggingstrand initiation site was also found, suggesting that pPB1 replicates via a rolling circle mechanism. The second module of pPB1 consisted of a sequence coding for a putative mobilization protein and its corresponding oriT site. Since the nucleotide sequence of the replication module showed 94.5% identity to the similar region on the Leuconostoc lactis plasmid pCI411, and the nucleotide sequence of the mobilization module had 97.5% identity to L. plantarum plasmid pLB4, it is concluded that pPB1 originated by modular exchange between two such plasmids by homologous recombination. Putative recombination sites where crossover might have taken place were also identifiedThis work was supported by Grant 07G/0035/2003 from the Comunidad de Madrid and RM03-002 from the Instituto Nacional de Investigación y Tecnologı´a Agraria y Alimentaria (INIA). We thank R. Gonza´lez and A.V. Carrascosa for their advice and critical reading of the manuscript. B. de las Rivas was a recipient of a postdoctoral fellowship and A. Marcobal of a predoctoral fellowship both from the Comunidad de Madrid.Peer reviewe

Characterization of the monocyte-specific esterase (MSE) gene

Carboxylic esterases are widely distributed in hematopoietic cells. Monocytes express the esterase isoenzyme (termed 'monocyte-specific esterase', MSE) that can be inhibited by NaF in the alpha-naphthyl acetate cytochemical staining. We examined the expression of MSE in normal cells and primary and cultured leukemia-lymphoma cells. The MSE protein was demonstrated by isoelectric focusing (IEF); MSE mRNA expression was investigated by Northern blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). The following samples were positive for MSE protein and Northern mRNA expression: 20/24 monocytic, 4/32 myeloid, and 1/20 erythroid-megakaryocytic leukemia cell lines, but none of the 112 lymphoid leukemia or lymphoma cell lines; of the normal purified cell populations only the monocytes were positive whereas, T, B cells, and granulocytes were negative; of primary acute (myelo) monocytic leukemia cells (CD14-positive, FAB M4/M5 morphology) 14/20 were Northern mRNA and 11/14 IEF protein positive. RT-PCR revealed MSE expression in 29/49 Northern-negative lymphoid leukemia-lymphoma cell lines. The RT-PCR signals in monocytic cell lines were on average 50-fold stronger than the mostly weak trace expression in lymphoid specimens. On treatment with various biomodulators, only all-trans retinoic acid significantly upregulated MSE message and protein levels but could not induce new MSE expression in several leukemia cell lines; lipopolysaccharide and interferon-gamma increased MSE expression in normal monocytes. Analysis of DNA methylation with sensitive restriction enzymes showed no apparent regulation of gene expression by differential methylation; the MSE gene is evolutionarily conserved among mammalian species; the half-life of the human MSE transcripts was about 5-6 h. The extent of MSE expression varied greatly among different monocytic leukemia samples. However, the MSE overexpression in a significant number of specimens was not associated with gene amplification, gross structural rearrangements or point mutations within the cDNA region. Taken together, the results suggest that MSE expression is not absolutely specific for, but strongly associated with cells of the monocytic lineage; MSE is either not expressed at all or expressed at much lower levels in cells from other lineages. The biological significance, if any, of rare MSE messages in lymphoid cells detectable only by the hypersensitive RT-PCR remains unclear. Further studies on the regulation of this gene and on the physiological function of the enzyme will no doubt be informative with respect to its striking overexpression in some malignant cells and to a possible role in the pathobiology of monocytic leukemias

Forschungsvorhaben MAW- und HTR-BE-Versuchseinlagerung in Bohrlöchern

Der fast zweijährige Bestrahlungsversuch unter simulierten in situ-Bedingungen im Salz hat gezeigt, daß die für den Einlagerungsversuch als sicherheitsrelevant eingestuften Meßwertgeber (Drehpotentiometer, Temperaturfühler) und das zu deren Anschluß vorgesehene Meßkabel vom Typ KKWM der abgeschätzten und maximal während der fünfjährigen Einlagerdauer von den Abfallgebinden zu erwartenden Strahlendosis von ca. 1,3 x 10$^{6}$ Gy (1,3 x 10$^{8}$ rad) sicher standhalten werden. Die im Bestrahlungsversuch aufgebrachte Dosis lag mit 6 x 10$^{6}$ Gy (6 x 10$^{8}$ rad) (Meßwertgeber) bzw. 3 x 10$^{6}$ Gy (3 x 10$^{8}$ rad) (Kabel) um mehr als Faktor 2 höher, ohne daß ein Bauteilversagen hätte festgestellt werden können. Auch das zum Wärmeeintrag in die Bohrlöcher zum Einsatz kommende Metallmantel-Heizkabel und das zur Stromversorgung ausgewählte Energiekabel vom Typ ERR sind mit Sicherheit strahlenbeständig genug, um das Versuchsziel eines endlagerrelevanten Temperaturniveaus während der fünfjährigen Versuchsdauer in den Bohrlöchern aufrechtzuerhalten. Hinsichtlich der Korrosion der metallischen Hüll- und Strukturmaterialien zeigten sich zwar Unterschiede im Korrosionsverhalten der verschiedenen Materialien, aber die lange Versuchsdauer und die anhand der metallografischen Untersuchungen erkennbaren, geringen Korrosionsschäden berechtigen zu der Annahme, daß ein Versagender Bauteile durch Korrosion bei dem ca. fünfjährigen in situ-Versuch nicht zu erwarten ist

A 700 year record of Southern Hemisphere extratropical climate variability

Annually dated ice cores from West and East Antarctica provide proxies for past changes in atmospheric circulation over Antarctica and portions of the Southern Ocean, temperature in coastal West and East Antarctica, and the frequency of South Polar penetration of El Niño events. During the period AD 1700–1850, atmospheric circulation over the Antarctic and at least portions of the Southern Hemisphere underwent a mode switch departing from the out-of-phase alternation of multi-decadal long phases of EOF1 and EOF2 modes of the 850 hPa field over the Southern Hemisphere (as defined in the recent record by Thompson and Wallace, 2000; Thompson and Solomon, 2002) that characterizes the remainder of the 700 year long record. From AD 1700 to 1850, lower-tropospheric circulation was replaced by in-phase behavior of the Amundsen Sea Low component of EOF2 and the East Antarctic High component of EOF1. During the first phase of the mode switch, both West and East Antarctic temperatures declined, potentially in response to the increased extent of sea ice surrounding both regions. At the end of the mode switch, West Antarctic coastal temperatures rose and East Antarctic coastal temperatures fell, respectively, to their second highest and lowest of the record. Polar penetration of El Niño events increased during the mode switch. The onset of the AD 1700–1850 mode switch coincides with the extreme state of the Maunder Minimum in solar variability. Late 20th-century West Antarctic coastal temperatures are the highest in the record period, and East Antarctic coastal temperatures close to the lowest. Since AD 1700, extratropical regions of the Southern Hemisphere have experienced significant climate variability coincident with changes in both solar variability and greenhouse gase

Обоснование актуальности использования в трансмиссии геохода эксцентриково-циклоидального зацепления

Рассматривается состояние вопроса по темпам формирования подземного пространства в России. Проводится анализ недостатков имеющегося проходческого оборудования (щиты, комбайны). Отмечается, что перспективным способом проведения горных выработок является геовинчестерная технология, базовым функциональным элементом которой является геоход. Утверждается, что одной из ключевых систем геохода, определяющей его работоспособность, является трансмиссия. Отмечается, что реализованная в настоящее время в опытном образце геохода трансмиссия с гидроцилиндрами, имеет, как свои достоинства, так и недостатки. Это не позволяет считать трансмиссию с гидроцилиндрами оптимальным решением для её использования, при разработке геоходов нового поколения. Проводится обзор различных видов зубчатых зацеплений и делаются выводы о перспективности их применения в трансмиссии геохода

Impact of the hydraulic loading rate on the hydrodynamic characteristics of an anaerobic fixed bed reactor treating cattle slaughterhouse wastewater

The hydrodynamic behavior of an anaerobic fixed bed reactor (AFBR) was evaluated in the treatment of cattle slaughterhouse wastewater. The AFBR was operated at hydraulic retention time (HRT) of 14, 11 and 8 h. Stimulus-response assays were carried out with Eosin Y and the experimental data were adjusted to the single-parameter theoretical models of dispersion and N-continuous stirred tank reactors in series (N-CSTR). The experimental results of the residence time distribution curves showed that at lower flow rate, the reactor showed plug flow behavior with correlation coefficient (r) of 0.88 and number of dispersion of 0.2 for high dispersion (HD). However, at higher and intermediate flow rates, the AFBR behave as a complete mixture flow, (r) of 0.94 and 0.96, respectively. Residence time distribution curves in the AFBR showed a good approximation of the complete mixing model at hydraulic residence time of 11 and 8 h, with 5 and 2 N-CSTR reactors in series, respectively. The volume of dead zones corresponding to 43.0, 37.4 and 11.2% of the volume of the reactor for HRT of 14, 11 and 8 h, respectively, was noted, and hydraulic short circuiting were not confirmedinfo:eu-repo/semantics/publishedVersio

Применение треугольной схемы расположения скважин для добычи урана из малого изометрического рудного тела

The dynamical behaviour of the laser beam fusion cutting process of metals is investigated. Integral methods such as the variational formulation are applied to the partial differential equations for the free boundary problem and a finite dimensional approximation of the dynamical system is obtained. The model describes the shape of the evolving cutting kerf and the melt flow. The analysis is aimed at revealing the characteristic features of the resultant cut, for example, ripple formation and adherent dross. The formation of the ripples in the upper part of the put, where no resolidified material is detectable, is discussed in detail. A comparison with numerical simulations and experiments is made

The spectral and chemical measurement of pollutants on snow near South Pole, Antarctica

Remote sensing of light-absorbing particles (LAPs), or dark colored impurities, such as black carbon (BC) and dust on snow, is a key remaining challenge in cryospheric surface characterization and application to snow, ice, and climate models. We present a quantitative data set of in situ snow reflectance, measured and modeled albedo, and BC and trace element concentrations from clean to heavily fossil fuel emission contaminated snow near South Pole, Antarctica. Over 380 snow reflectance spectra (350–2500 nm) and 28 surface snow samples were collected at seven distinct sites in the austral summer season of 2014–2015. Snow samples were analyzed for BC concentration via a single particle soot photometer and for trace element concentration via an inductively coupled plasma mass spectrometer. Snow impurity concentrations ranged from 0.14 to 7000 part per billion (ppb) BC, 9.5 to 1200 ppb sulfur, 0.19 to 660 ppb iron, 0.013 to 1.9 ppb chromium, 0.13 to 120 ppb copper, 0.63 to 6.3 ppb zinc, 0.45 to 82 parts per trillion (ppt) arsenic, 0.0028 to 6.1 ppb cadmium, 0.062 to 22 ppb barium, and 0.0044 to 6.2 ppb lead. Broadband visible to shortwave infrared albedo ranged from 0.85 in pristine snow to 0.62 in contaminated snow. LAP radiative forcing, the enhanced surface absorption due to BC and trace elements, spanned from \u3c1 W m­–2 for clean snow to ~70 W m­–2 for snow with high BC and trace element content. Measured snow reflectance differed from modeled snow albedo due to specific impurity-dependent absorption features, which we recommend be further studied and improved in snow albedo models