Accurate prediction of gene feedback circuit behavior from component properties

A basic assumption underlying synthetic biology is that analysis of genetic circuit elements, such as regulatory proteins and promoters, can be used to understand and predict the behavior of circuits containing those elements. To test this assumption, we used time‐lapse fluorescence microscopy to quantitatively analyze two autoregulatory negative feedback circuits. By measuring the gene regulation functions of the corresponding repressor–promoter interactions, we accurately predicted the expression level of the autoregulatory feedback loops, in molecular units. This demonstration that quantitative characterization of regulatory elements can predict the behavior of genetic circuits supports a fundamental requirement of synthetic biology

Environmental and climatic proxies for the Cañadón Asfalto and Neuquén basins (Patagonia, Argentina): review of middle to upper jurassic continental and near coastal sequences

In this review, we include several proxies (sedimentology, palynology, invertebrates) from the Cañadón Asfalto and Neuquén basins, to infer the environments and regional climatic context during the Middle to Late Jurassic of Patagonia. In central Patagonia, early in the Middle Jurassic, and associated with a magmatic arc, began the sedimentary fi lling of Jurassic continental sub-basins in the Cañadón Asfalto Basin. Lacustrine and fl uvio-deltaic sediments, bearing a continental Middle Jurassic palynobiota, correspond to the Las Chacritas Member, while the sediments and palynobiota from the Late Jurassic Puesto Almada Member (both in the Cañadón Asfalto Formation) indicate a palustrine wetland subenvironment immersed within an arid macroenvironment. Paleoinvertebrates (conchostracans and sponges) of this formation suggest wet-dry cycles in the water bodies they inhabited. The sedimentological information together with the continental and coastal palynomorph assemblages of the back arc Neuquén Basin, allowed distinguishing a complete regressive-transgressive sequence for the Middle Jurassic Lajas Formation. For the Upper Jurassic in this basin, the thick gypsum and anhydrite deposits of the evaporitic coastal Auquilco Formation correlate with extended deposits of eolian sandstones corresponding to the Botucatú paleodesert, and a saltmarsh environment is inferred from the palynofl ora. The palynologic associations from both basins indicate a regional warm climate with seasonal aridity. Climatic conditions would have been drier in the continental interior (Cañadón Asfalto Basin), with strongly seasonally distributed temperatures, and moister in the western coast of the continent (Neuquén Basin), during the marine transgressions.Na presente revisão foram incluídos vários proxies (sedimentologia, palinologia, invertebrados), das bacias de Cañadón Asfalto e Neuquén, para inferir o contexto climático regional e ambiental durante o Jurássico Médio e Superior da Patagônia. Na região central da Patagônia, no início do Jurássico Médio, e associado a um arco magmático, começou o preenchimento sedimentar de sub-bacias continentais jurássicas na bacia Cañadón Asfalto. Os sedimentos flúvio-deitaico e lacustres, tendo uma palinobiota continental do Jurássico Médio correspondente ao Membro Las Chacritas, enquanto os sedimentos e a palinobiota do Jurássico Superior do Membro Puesto Almada (ambos na Formação Cañadón Asfalto) indicam um subambiente palustre úmido imerso em um macroambiente árido. Os paleoinvertebrados (conchostráceos e esponjas) desta formação sugerem ciclos úmidos-secos nos corpos de água por eles habitados. A informação sedimentológica juntamente com as assembleias de palinomorfos continentais e costeiros do “back arc” da bacia Neuquén permitiu distinguir uma sequência completa regressiva-transgressiva para o Jurássico Médio da Formação Lajas. Para o Jurássico Superior, os depósitos de anidrita e gesso espessos da Formação Auquilco costeira evaporítica correlacionam-se com depósitos extensos de arenitos eólicos correspondentes ao paleodeserto Botucatu. Um ambiente “saltmarsh” é inferido a partir da palinoflora. As associações palinológicas de ambas as bacias indicam um clima regional quente com aridez sazonal. As condições climáticas teriam sido mais secas no interior continental (bacia Cañadón Asfalto), com temperaturas fortemente distribuídas de forma sazonal, e úmidas na costa ocidental do continente (bacia de Neuquén), durante as transgressões marinhas.Fil: Volkheimer, Wolfang. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Quattrocchio, Mirta Elena. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabaleri, Nora Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Narvaez, Paula Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Rosenfeld, U.. Westfälische Wilhelms-universität Münster; AlemaniaFil: Scafati, Laura Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Melendi, Daniel Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin

Phase behaviour of additive binary mixtures in the limit of infinite asymmetry

We provide an exact mapping between the density functional of a binary mixture and that of the effective one-component fluid in the limit of infinite asymmetry. The fluid of parallel hard cubes is thus mapped onto that of parallel adhesive hard cubes. Its phase behaviour reveals that demixing of a very asymmetric mixture can only occur between a solvent-rich fluid and a permeated large particle solid or between two large particle solids with different packing fractions. Comparing with hard spheres mixtures we conclude that the phase behaviour of very asymmetric hard-particle mixtures can be determined from that of the large component interacting via an adhesive-like potential.Comment: Full rewriting of the paper (also new title). 4 pages, LaTeX, uses revtex, multicol, epsfig, and amstex style files, to appear in Phys. Rev. E (Rapid Comm.

Structure Factor and Electronic Structure of Compressed Liquid Rubidium

We have applied the quantal hypernetted-chain equations in combination with the Rosenfeld bridge-functional to calculate the atomic and the electronic structure of compressed liquid-rubidium under high pressure (0.2, 2.5, 3.9, and 6.1 GPa); the calculated structure factors are in good agreement with experimental results measured by Tsuji et al. along the melting curve. We found that the Rb-pseudoatom remains under these high pressures almost unchanged with respect to the pseudoatom at room pressure; thus, the effective ion-ion interaction is practically the same for all pressure-values. We observe that all structure factors calculated for this pressure-variation coincide almost into a single curve if wavenumbers are scaled in units of the Wigner-Seitz radius $a$ although no corresponding scaling feature is observed in the effective ion-ion interaction.This scaling property of the structure factors signifies that the compression in liquid-rubidium is uniform with increasing pressure; in absolute Q-values this means that the first peak-position ($Q_1$) of the structure factor increases proportionally to $V^{-1/3}$ ($V$ being the specific volume per ion), as was experimentally observed by Tsuji et al.Comment: 18 pages, 11 figure

Estudio palinologico de la Formacion Piedra Pintada, Jurasico inferior da la Cuenca Neuquina (Argentina)

This is a study of four microfloristic assemblages, in which the terrestrial species (43) are prevailing. The genera present are Deltoidospora, Alsophilidites, Dictyophyllidites, Lygodiumsporites, Concavisporites, Verrucosisporites, Leptolepidites, Foveosporites, Granulat isporit es, Baculatisporites, Lycopodiumsporites, Gleicheniidites, Antulsporites, Interulobites, Nevesisporites, Taurocusporites, Peromonolites, Vitreisporites, Alisporites, Podocarpidites, Phrixipollenites, Microcachryidites, Inaperturopollenites, Araucariacites, Perinopollenites, Classopollis, Cycadopites and Monosulcites, and the marine genera Pleurozonaria and Leiosphaeridia. The age indicated by the microflora (Nevesiporites vallatus-Assemblage, previous to the income of Callialasporites spp.), is the pre-upper Toarcian Lower Jurassic

CTGF (IGFBP-rP2) is specifically expressed in malignant lymphoblasts of patients with acute lymphoblastic leukaemia (ALL)

Connective tissue growth factor (CTGF) is a major chemotactic and mitogenic factor for connective tissue cells. The amino acid sequence shares an overall 28–38% identity to IGFBPs and contains critical conserved sequences in the amino terminus. It has been demonstrated that human CTGF specifically binds IGFs with low affinity and is considered to be a member of the IGFBP superfamily (IGFBP-rP2). In the present study, the expression of CTGF (IGFBP-rP2) in human leukaemic lymphoblasts from children with acute lymphoblastic leukaemia (ALL) was investigated. RNA samples from tumour clones enriched by ficoll separation of bone marrow or peripheral blood mononuclear cells (MNC) from 107 patients with childhood ALL at diagnosis and 57 adult patients with chronic myeloid leukaemia (CML) were studied by RT-PCR. In addition MNC samples from children with IDDM and cord blood samples from healthy newborns were investigated as control groups. Sixty-one percent of the patients with ALL (65 of 107) were positive for CTGF (IGFBP-rP2) expression. In the control groups, no expression of CTGF (IGFBP-rP2) in peripheral MNC was detected, and in the group of adult CML patients only 3.5% (2 of 57) were positive for this gene. The role of CTGF (IGFBP-rP2) in lymphoblastic leukaemogenesis requires further evaluation, as does its potential utility as a tumour marker. © 2000 Cancer Research Campaig

Relationship between bank vole abundance, seroprevalence and human hantavirus infections

Reil, D., Imholt, C., Schmidt, S., Rosenfeld, U.M., Ulrich, R.G., Eccard, J.A., Jacob, J

An alternative model for the electroweak symmetry breaking sector and its signature in future e-gamma colliders

We perform a preliminary study of the deviations from the Standard Model prediction for the cross section for the process $e \gamma \rightarrow \nu_e W \gamma$. We work in the context of a higgsless chiral lagrangian model that includes an extra vector resonance $V$ and an anomalous $\gamma W V$ coupling. We find that this cross section can provide interesting constraints on the free parameters of the model once it is measured in future $e \gamma$ colliders.Comment: LaTex , 14 pages, 5 figures not included but available as postscript files upon request, NUB-3086/94-T

Longitudinal development of initial, chronic and mucoid Pseudomonas aeruginosa infection in young children with cystic fibrosis

BACKGROUND: While the emergence of chronic and mucoid Pseudomonas aeruginosa (Pa) infection are both associated with poorer outcomes among CF patients, their relationship is poorly understood. We examined the longitudinal relationship of incident, chronic and mucoid Pa in a contemporary, young CF cohort in the current era of Pa eradication therapy. METHODS: This retrospective cohort was comprised of patients in the U.S. CF Foundation Patient Registry born 2006-2015, diagnosed before age 2, and with at least 3 respiratory cultures annually. Incidence and age-specific prevalence of Pa infection stages (initial and chronic [≥ 3Pa+cultures in prior year]) and of mucoid Pa were summarized. Transition times and the interaction between Pa stage and acquisition of mucoid Pa were examined via Cox models. RESULTS: Among the 5592 CF patients in the cohort followed to a mean age of 5.5years, 64% (n=3580) acquired Pa. Of those, 13% (n=455) developed chronic Pa and 17% (n=594) cultured mucoid Pa. Among those with mucoid Pa, 36% (211/594) had it on their first recorded Pa+culture, while mucoid Pa emerged at or after entering the chronic stage in 12% (73/594). Mucoidy was associated with significantly increased risk of transition to chronic Pa infection (HR=2.59, 95% CI 2.11, 3.19). CONCLUSIONS: Two-thirds of early-diagnosed young children with CF acquired Pa during a median 5.6years of follow up, among whom 13% developed chronic Pa and 17% acquired mucoid Pa. Contrary to our hypothesis, 87% of young children who developed mucoid Pa did so before becoming chronically infected