In silicio expression analysis of PKS genes isolated from Cannabis sativa L.

Cannabinoids, flavonoids, and stilbenoids have been identified in the annual dioecious plant Cannabis sativa L. Of these, the cannabinoids are the best known group of this plant's natural products. Polyketide synthases (PKSs) are responsible for the biosynthesis of diverse secondary metabolites, including flavonoids and stilbenoids. Biosynthetically, the cannabinoids are polyketide substituted with terpenoid moiety. Using an RT-PCR homology search, PKS cDNAs were isolated from cannabis plants. The deduced amino acid sequences showed 51%-73% identity to other CHS/STS type sequences of the PKS family. Further, phylogenetic analysis revealed that these PKS cDNAs grouped with other non-chalcone-producing PKSs. Homology modeling analysis of these cannabis PKSs predicts a 3D overall fold, similar to alfalfa CHS2, with small steric differences on the residues that shape the active site of the cannabis PKSs

Localization Properties of the Periodic Random Anderson Model

We consider diagonal disordered one-dimensional Anderson models with an underlying periodicity. We assume the simplest periodicity, i.e., we have essentially two lattices, one that is composed of the random potentials and the other of non-random potentials. Due to the periodicity special resonance energies appear, which are related to the lattice constant of the non-random lattice. Further on two different types of behaviors are observed at the resonance energies. When a random site is surrounded by non-random sites, this model exhibits extended states at the resonance energies, whereas otherwise all states are localized with, however, an increase of the localization length at these resonance energies. We study these resonance energies and evaluate the localization length and the density of states around these energies.Comment: 4 page

Los insectos plaga del camu camu (Myrciaria dubia H.B.K.) y del araza (Eugenia stipitata Mc Vaugh) identificacion y control

Le camu camu (#Myrciaria dubio H.B.K.) et l'araza (#Eugenia stipitata Mc Vaugh) sont des cultures nouvelles en Amazonie péruvienne. Dans ce travail sont citées 21 espèces d'insectes nuisibles au camu camu, parmi lesquelles 6 espèces doivent être considérées comme des ravageurs économiquement importants, ce sont : #Austrotachardiella sp, #Ceroplastes sp., #Conotrachelus sp.1., #Dysmicoccus brevipes Cock, #Tuthillia cognata Hodk. y #Xylosandrus compactus Heichh. Sur araza 9 espèces ont été répertoriées, dont 4 sont des ravageurs importants : #Anastrepha obliqua Macq., #Atractomerus immigrans Clark, #Conotrachelus sp. 2 y #Plectrophoroides impressicollis Chevr. Quelques espèces nouvelles pour la science ont été décrites récemment ou sont en cours d'étude. On donne les premières informations sur les espèces dont la biologie et l'écologie n'étaient pas connues, ainsi que des méthodes de contrôle adaptées au système de gestion des plantations. (Résumé d'auteur

Obstacles to Preventing Obesity in Children Aged 2 to 5 Years: Latino Mothers’ and Fathers’ Experiences and Perceptions of Their Urban Environments

Background The prevalence of obesity among Latino children is alarmingly high, when compared to non-Latino White children. Low-income Latino parents living in urban areas, even if they are well-educated, face obstacles that shape familial health behaviors. This study used qualitative methods to explore parents’ experiences in providing meals and opportunities to play to their children aged 2 to 5 years. In contrast to most prior studies, this study examined perceptions of familial behaviors among both mothers and fathers. Methods An ecological framework for exploring the associations of parental feeding behaviors and children’s weight informed this study. An interview guide was developed to explore parents’ experiences and perceptions about children’s eating and physical activity and administered to six focus groups in a community-based organization in the Mission District of San Francisco. Transcripts were coded and analyzed. Twenty seven mothers and 22 fathers of Latino children ages 2 to 5 participated. Results Mothers, fathers, and couples reported that employment, day care, neighborhood environments and community relationships were experienced, and perceived as obstacles to promoting health behavior among their children, including drinking water instead of soda and participating in organized playtime with other preschool-age children. Conclusions Results from this study suggest that the parents’ demographic, social and community characteristics influence what and how they feed their children, as well as how often and the types of opportunities they provide for physical activity, providing further evidence that an ecological framework is useful for guiding research with both mothers and fathers. Mothers and fathers identified numerous community and society-level constraints in their urban environments. The results point to the importance of standardized work hours, resources for day care providers, clean and safe streets and parks, strong community relationships, and reduced access to sugar-sweetened beverages in preventing the development of obesity in preschool-age Latino children

A Verilog-A Based Fractional Frequency Synthesizer Model for Fast and Accurate Noise Assessment

This paper presents a new strategy to simulate fractional frequency synthesizer behavioral models with better performance and reduced simulation time. The models are described in Verilog-A with accurate phase noise predictions and they are based on a time jitter to power spectral density transformation of the principal noise sources in a synthesizer. The results of a fractional frequency synthesizer simulation is compared with state of the art Verilog-A descriptions showing a reduction of nearly 20 times. In addition, experimental results of a fractional frequency synthesizer are compared to the simulation results to validate the proposed model

The Indoor Radon Concentration within the Tunnels of the Cholula Pyramid Through a Nuclear Tracks Methodology

Global organizations, including the World Health Organization (WHO), the Environmental Protection Agency of the United States (US-EPA) and the European Atomic Energy Community (EURATOM) recognize that radon gas as one of the main contributors to environmental radiation exposure for humans. Accordingly, a study and analysis of the indoors radon concentrate in the Cholula Pyramid contributes to understand the Radon dynamic inside of the Pyramid tunnels and to evaluate the radiological health risk to visitors, archaeologists, anthropologists and persons who spend extended periods inside the Pyramid. In this paper, the radon measurements along the Pyramid tunnels are presented. The Nuclear Track Methodology (NTM) was chosen for the measurements, using a close end-cup device developed at the Dosimetry Application Project (DAP) of the Physics Institute UNAM, following very well established protocols for the chemical etching and reading with the Counting Analysis Digital Imaging System (CADIS). The Cholula Pyramid consists of eight stages of constructions, each built in different periods of time. Cholula Pyramid is recognized as the pyramid with the largest base in the World, with 400 meters per side and 65 meters high. The tunnels of the pyramid were built in 1931 by architect Ignacio Marquina, with the aim of exploring and studying the structure. The results show an important indoor radon concentration in the measured tunnels, several times higher than levels recommended by United States Environmental Protection Agency (US-EPA). The recommendation will be to mitigate the radon concentration levels, in order to avoid unnecessary exposition to the people