287 research outputs found
Weight 2 cohomology of graph complexes of cyclic operads and the handlebody group
We compute the weight 2 (resp.~top) cohomology of the Feynman transforms
of the cyclic (co)operads , , and
. Using a result of Giansiracusa we compute in particular the
weight top-cohomology of the handlebody group. We compare the result to the
weight top cohomology of the moduli space of curves ,
recently computed by Payne and the last-named author. We also provide another
proof of a recent result of Hainaut--Petersen identifying the
top-weight-cohomology of the handlebody group with the Kontsevich graph
cohomology
FTIR diferentiation based on genomic DNA for species identifcation of Shigella isolates from stool samples
Shigellosis is one of the major public health concerns in developing and low-income countries caused
by four species of Shigella. There is an apparent need to develop rapid, cost-efective, sensitive and
specifc methods for diferentiation of Shigella species to be used in outbreaks and health surveillance
systems. We developed a sensitive and specifc Fourier-transform infrared spectroscopy (FTIR) based
method followed by principal component analysis (PCA) and hierarchical clustering analysis (HCA)
assays to diferentiate four species of Shigella isolates from stool samples. The FTIR based method
was evaluated by diferentiation of 91 Shigella species from each other in clinical samples using both
gold standards (culture-based and agglutination methods) and developed FTIR assay; eventually, the
sensitivity and specifcity of the developed method were calculated. In summary, four distinct FTIR
spectra associated with four species of Shigella were obtained with wide variations in three defnite
regions, including 1800–1550 Âcm−1, 1550–1100 Âcm−1, and 1100–800 Âcm−1 distinguish these species
from each other. In this study, we found the FTIR method followed by PCA analysis with specifcity,
sensitivity, diferentiation error and correct diferentiation rate values of 100, 100, 0 and 100%,
respectively, for identifcation and diferentiation of all species of the Shigella in stool samples
Expanding the Portfolio by a Novel Monomeric Oleate Hydratase from Pediococcus parvulus
Oleate hydratases convert oleic acid into 10-hydroxy stearic acid, a valuable fine chemical, useful in lubricant and surfactant formulations. They are of large interest due to their high expression rates and solubility, however, they differ drastically by their overall stability and pH- and temperature ranges. To expand their portfolio, another oleate hydratase named OhyPp (originating from Pediococcus parvulus) was characterized. It is a close relative of the well-known oleate hydratase OhyRe from Rhodococcus erythropolis. OhyPp is only the second member of the monomeric oleate hydratase family with some surprising catalytic features. A distinct characteristic is OhyPp's higher affinity towards FAD compared to OhyRe's helping to understand and improve FAD binding in the future, which is a current drawback for the industrial application of oleate hydratases
A quantitative prevalence of Escherichia coli O157 in different food samples using real-time qPCR method
Escherichia coli serogroup O157 is the main causative agent of several intestinal and
extra-intestinal foodborne diseases in humans through consumption of low-dose contaminated foods such as milk, beef, and vegetables. To date, studies regarding the
quantitative prevalence of E. coli O157 in foods are so limited. Therefore, this study
aimed to evaluate the quantitative prevalence rate of E. coli serogroup O157 in raw
milk (n = 144), vegetable salad (n = 174), and minced beef samples (n = 108) using
the real-time qPCR SYBR green melting curve method targeting the rfbA gene. First,
we evaluated the method and found a sensitive and specific qPCR assay with 1 log
of CFU/ml detection limit to detect E. coli O157 (Tm = 80.3 ± 0.1°C). About 2.77%,
10.18%, and 9.19% of raw milk, minced beef, and vegetable salad samples, respectively, were contaminated with E. coli O157. Minced beef and vegetable salad samples
were significantly more contaminated than raw milk samples. Population average of
E. coli O157 in raw milk, minced beef, and vegetable salad samples were 2.22 ± 0.57,
3.30 ± 0.40, and 1.65 ± 0.44 log CFU/ml or gr, respectively. Significantly higher levels
of population of E. coli O157 were observed in minced beef samples. Minced beef can
be regarded as the main food in the transmission of this foodborne pathogen. Routine
quantitative rapid monitoring is strongly suggested to be carried out to prevent foodborne diseases caused by E. coli O157
Sensory quality of turnip greens and turnip tops grown in northwestern Spain
In Galicia (northwestern Spain), Brassica rapa var. rapa L. includes turnip greens and turnip tops as vegetable products. They are characterized by a particular sulfurous aroma, pungent flavor, and a bitter taste. In this work twelve local varieties grown as turnip greens and turnip tops were evaluated to define the sensory attributes, to relate them with secondary metabolites, and to select those sensorial traits that better describe these crops. Results showed differences in the sensory profiles of B. rapa varieties. Turnip greens were significantly differed for aroma intensity, leaf color, and salty taste, while turnip tops were for color and firmness of leaves, moistness and fibrosity in mouth, sharpness, and bitter taste. Secondary metabolites as glucosinolates in turnip greens and phenolic compounds in turnip tops were highly correlated with texture and flavor. Glucosinolates especially progoitrin (in turnip greens) and gluconapin (in turnip tops) showed correlation with bitter taste and aftertaste persistence. Correlation between sensory traits showed highest values between leaf firmness and stalk firmness (0.94**), leaf firmness and fibrosity (R=0.92**), aftertaste persistence and bitterness (R=0.91**) and between bitterness and moistness (R=-0.89**).Research supported by the Xunta de Galicia (PGIDIT06RAG40302PR) and Excma. Diputación Provincial de Pontevedra.Peer reviewe
Towards a comprehensive understanding of the structural dynamics of a bacterial diterpene synthase during catalysis
Terpenes constitute the largest and structurally most diverse natural product family. Most terpenoids exhibit a stereochemically complex macrocyclic core, which is generated by C–C bond forming of aliphatic oligo-prenyl precursors. This reaction is catalysed by terpene synthases (TPSs), which are capable of chaperoning highly reactive carbocation intermediates through an enzyme-specific reaction. Due to the instability of carbocation intermediates, the proteins’ structural dynamics and enzyme:substrate interactions during TPS catalysis remain elusive. Here, we present the structure of the diterpene synthase CotB2, in complex with an in crystallo cyclised abrupt reaction product and a substrate-derived diphosphate. We captured additional snapshots of the reaction to gain an overview of CotB2’s catalytic mechanism. To enhance insights into catalysis, structural information is augmented with multiscale molecular dynamic simulations. Our data represent fundamental TPS structure dynamics during catalysis, which ultimately enable rational engineering towards tailored terpene macrocycles that are inaccessible by conventional chemical synthesis
Komodifikasi Perempuan Dalam Iklan Televisi
: Women and sexual attraction is to be one weapon in the arsenal of the ads. In the version of AXE advertisement “Turun Hargaâ€, the author indicates the presence of the commodification of women. This paper discusses how the signs set in them to communicate with the target and how the structure of the message that commodificate women. The method of analysis used in this paper is semiotics Greimasian combined with Marxian feminist perspective.
Identification, characterization and molecular adaptation of class I redox systems for the production of hydroxylated diterpenoids
Background De novo production of multi-hydroxylated diterpenoids is
challenging due to the lack of efficient redox systems. Results In this study
a new reductase/ferredoxin system from Streptomyces afghaniensis (AfR·Afx) was
identified, which allowed the Escherichia coli-based production of the
trihydroxylated diterpene cyclooctatin, a potent inhibitor of human
lysophospholipase. This production system provides a 43-fold increase in
cyclooctatin yield (15 mg/L) compared to the native producer. AfR·Afx is
superior in activating the cylcooctatin-specific class I P450s CotB3/CotB4
compared to the conventional Pseudomonas putida derived PdR·Pdx model. To
enhance the activity of the PdR·Pdx system, the molecular basis for these
activity differences, was examined by molecular engineering. Conclusion We
demonstrate that redox system engineering can boost and harmonize the
catalytic efficiency of class I hydroxylase enzyme cascades. Enhancing
CotB3/CotB4 activities also provided for identification of CotB3 substrate
promiscuity and sinularcasbane D production, a functionalized diterpenoid
originally isolated from the soft coral Sinularia sp
The Neural Correlates of Face-Voice-Integration in Social Anxiety Disorder
Faces and voices are very important sources of threat in social anxiety disorder (SAD), a common psychiatric disorder where core elements are fears of social exclusion and negative evaluation. Previous research in social anxiety evidenced increased cerebral responses to negative facial or vocal expressions and also generally increased hemodynamic responses to voices and faces. But it is unclear if also the cerebral process of face-voice-integration is altered in SAD. Applying functional magnetic resonance imaging, we investigated the correlates of the audiovisual integration of dynamic faces and voices in SAD as compared to healthy individuals. In the bilateral midsections of the superior temporal sulcus (STS) increased integration effects in SAD were observed driven by greater activation increases during audiovisual stimulation as compared to auditory stimulation. This effect was accompanied by increased functional connectivity with the visual association cortex and a more anterior position of the individual integration maxima along the STS in SAD. These findings demonstrate that the audiovisual integration of facial and vocal cues in SAD is not only systematically altered with regard to intensity and connectivity but also the individual location of the integration areas within the STS. These combined findings offer a novel perspective on the neuronal representation of social signal processing in individuals suffering from SAD
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