Genes involved in carotene synthesis and mating in Blakeslea trispora

Mating of Blakeslea trispora and other molds of the order Mucorales requires the interaction of mycelia of opposite sex, (+) and (-), leading to the development of specialized structures and to an enhanced accumulation of beta-carotene. Industry obtains beta-carotene by co-cultivating appropriate strains of Blakeslea (mated cultures). Gene transcription in single and mated cultures was assayed by cDNA-AFLP, a technique to observe the differential expression of subsets of mRNA fragments. Overexpression in mated cultures is about ten times more frequent than underexpression. We obtained and sequenced fragments of 97 candidate genes that appeared to be overexpressed during mating and confirmed four of them by reverse transcription and real-time PCR. Comparisons with gene sequences from other organisms suggest functions in carotene biosynthesis (4 genes), energy metabolism (8), cell wall synthesis (1), transfer of acetyl groups (1), and regulatory processes (10). Sodium acetate inhibited sexual overexpression in about two-thirds of the candidate genes and acted as a signal with broad effects on the metabolism and the morphology of mated cultures. Our work offers new materials for the study of carotene biosynthesis and its regulation and for the improvement of carotene production with Mucorales

Lights, Camera, Action! Exploring Effects of Visual Distractions on Completion of Security Tasks

Human errors in performing security-critical tasks are typically blamed on the complexity of those tasks. However, such errors can also occur because of (possibly unexpected) sensory distractions. A sensory distraction that produces negative effects can be abused by the adversary that controls the environment. Meanwhile, a distraction with positive effects can be artificially introduced to improve user performance. The goal of this work is to explore the effects of visual stimuli on the performance of security-critical tasks. To this end, we experimented with a large number of subjects who were exposed to a range of unexpected visual stimuli while attempting to perform Bluetooth Pairing. Our results clearly demonstrate substantially increased task completion times and markedly lower task success rates. These negative effects are noteworthy, especially, when contrasted with prior results on audio distractions which had positive effects on performance of similar tasks. Experiments were conducted in a novel (fully automated and completely unattended) experimental environment. This yielded more uniform experiments, better scalability and significantly lower financial and logistical burdens. We discuss this experience, including benefits and limitations of the unattended automated experiment paradigm

Modified bases enable high-efficiency oligonucleotide-mediated allelic replacement via mismatch repair evasion

Genome engineering using single-stranded oligonucleotides is an efficient method for generating small chromosomal and episomal modifications in a variety of host organisms. The efficiency of this allelic replacement strategy is highly dependent on avoidance of the endogenous mismatch repair (MMR) machinery. However, global MMR inactivation generally results in significant accumulation of undesired background mutations. Here, we present a novel strategy using oligos containing chemically modified bases (2′-Fluoro-Uridine, 5-Methyl-deoxyCytidine, 2,6-Diaminopurine or Iso-deoxyGuanosine) in place of the standard T, C, A or G to avoid mismatch detection and repair, which we tested in Escherichia coli. This strategy increases transient allelic-replacement efficiencies by up to 20-fold, while maintaining a 100-fold lower background mutation level. We further show that the mismatched bases between the full length oligo and the chromosome are often not incorporated at the target site, probably due to nuclease activity at the 5′ and 3′ termini of the oligo. These results further elucidate the mechanism of oligo-mediated allelic replacement (OMAR) and enable improved methodologies for efficient, large-scale engineering of genomes.Synthetic Biology Engineering Research CenterNational Science Foundation (U.S.) (Grant #SA5283-11210)United States. Dept. of Energy (Genomes to Life Center) (Grant #DE-FG02-03ER6344)Wyss Institute for Biologically Inspired Engineerin

Indicators of nutritional status of turbot Scophthalmus maximus (L., 1758) larvae

Publicado

Maní frito salado con agregado de aceite esencial de cedrón y aguaribay como antioxidantes naturales

Ponencia presentada en XXVIII Jornada Nacional del Maní. General Cabrera, Córdoba, Argentina, 19 de septiembre de 2013.El objetivo de este trabajo fue evaluar la actividad antioxidante de los aceites esenciales de aguaribay y cedrón cuando son aplicados sobre maní frito salado.Fil: Olmedo, Rubén H. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Química Biológica; Argentina.Fil: Olmedo, Rubén H. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal (IMBIV); Argentina.Fil: Olmedo, Rubén H. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto Multidisciplinario de Biología Vegetal (IMBIV); Argentina.Fil: Nepote, Valeria. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos (ICTA); Argentina.Fil: Nepote, Valeria. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal (IMBIV); Argentina.Fil: Nepote, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto Multidisciplinario de Biología Vegetal (IMBIV); Argentina.Fil: Grosso, Nelson Rubén. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Cátedra de Química Biológica; Argentina.Fil: Grosso, Nelson Rubén. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal (IMBIV); Argentina.Fil: Grosso, Nelson Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto Multidisciplinario de Biología Vegetal (IMBIV); Argentina

Augmented Reality for Real-time Navigation Assistance to Wheelchair Users with Obstacles' Management

International audienceDespite a rapid technological evolution in the field of technical assistance for people with motor disabilities, their ability to move independently in a wheelchair is still limited. New information and communication technologies (NICT) such as augmented reality (AR) are a real opportunity to integrate people with disabilities into their everyday life and work. AR can afford real-time information about buildings and locations' accessibility through mobile applications that allow the user to have a clear view of the building details. By interacting with augmented environments that appear in the real world using a smart device, users with disabilities have more control of their environment. In this paper, we propose a decision support system using AR for motor disabled people navigation assistance. We describe a real-time wheelchair navigation system equipped with geological mapping that indicates access path to a desired location, the shortest route towards it and identifies obstacles to avoid. The prototyped wheelchair navigation system was developed for use within the University of Lille campus

Processing of Thionin Precursors in Barley Leaves by a Vacuolar Proteinase

Thionins are synthesized as precursors with a signal peptide and a long C-terminal acidic peptide that is post-translationally processed. A fusion protein including the maltose-binding protein from Eschrrichia coli (MalE), thionin DG3 froin barley leaves, and its acidic C-terminal peptide has been used to obtain antibodies that recognize both domains of the precursor. In barley leaf sections. mature thionins accuinulated in the vacuolar content, while the acidic peptide was not detected in any cell fraction. Brefeldin A and inonensin inhibited processing of the precursor but its export from the microsomal fraction was not inhibited. Both purified vacuoles aiid an acid (pH 5.5) extract from leaves processed the fusion protein into a MalE-thionin and an acidic peptide fragment. A 70-kDa proteinase that effected this cleavage was purified froin the acid extract. Processing of the fusion protein by both lysed vacuoles and the purified proteinase was inhibited by Zn2+ and by Cu2+, but not by inhibitors of the previously described vacuolar processing thiol or aspartic proteinases. In vivo processing of the thionin precursor in leaf sections was also inhibited by Zn+, and Cu2+, Variants of the fusion protein with altered processing sites that represented thme of thionin precursors from different taxa were readily processed by the proteinase, whereas changing the polarity of either the C-terminal or N-terminal residues of the processing site prevented cleavage by the proteinase

Indicators of nutritional status of turbot Scophthalmus maximus (L., 1758) larvae

Se han analizado diferentes indicadores del estado nutricional de larvas de rodaballo Scophthalmus maximus (L., 1758) alimentadas de hasta 53 días de edad y se han comparado con los de otras larvas sometidas a condiciones de inanición. Los indicadores estudiados fueron longitud, peso seco, condición relativa larvaria, diámetro del otolito, histología digestiva de las larvas, contenido en ácidos grasos, ácido ascórbico, RNA, DNA Y proteínas. Los procesos de inanición se llevaron a cabo a los 3, 9, 16, 23 Y 27 días de edad y los análisis de estas larvas fueron comparados con los de larvas alimentadas de las mismas edades. Durante las primeras 24 horas de inanición, las goticulas lipídicas en las células epiteliales desaparecen por completo del intestino. Después, la condición relativa disminuye aproximadamente el 5% por día y el diámetro relativo del otolito se incrementa en el 5% por día. Se producen también disminuciones en el peso seco, el contenido proteico, los niveles de ácidos grasos 18:1Ω-9, 20:5Ω-3 (EPA) y los de otros ácidos grasos altamente insaturados (Ω-3 HUFA), y en la relación RNA/DNA. Sin embargo, la mayoría de los indicadores investigados muestran una alta variación, incluso entre las distintas experiencias de cultivo realizadas, por lo que se concluye que las gotículas de lípidos en las células epiteliales del intestino, la condición relativa y el diámetro relativo del otolito son las únicas variables que pueden ser útiles para detectar un proceso de inanición en larvas de rodaballo.Nutritional status indicators of larvae of turbot Scophthalmus maximus (L., 1758) were investigated in feeding and starving turbot larvae from hatching up to an age of 53 days. The study included the whole-larvae parameters of length, dry weight and relative condition; the organ-related characteristics otolith diameter and intestinal histology; and the biochemical indicators fatty acids, ascorbic acid, RNA, DNA and total protein. Starvation was started at day 3, 9, 16, 23 and 27, and starved larvae were compared with feeding larvae from the same rearing group. After onset of starvation, lipid droplets in the intestinal epithelial cells disappeared within 24 h. Later; the influence of starvation also became apparent in most of the other indicators studied. Relative condition decreased by about 5%/day and relative otolith diameter increased by about 5%/day. A histologically observed total disappearance of chylomicrons and lipid droplets in the intestinal epithelial cells was in accordance with a drop in dry weight, protein content, and the fatty acids 18:1Ω-9, 20:5Ω-3 (EPA) and Ω-3 HUFA (Highly Unsaturated Fatty Acids), as well as the RNA/DNA ratio in starved larvae. However, most of the indicators studied showed such a high variation between individual rearing groups that only the parameters lipid droplets in intestinal epithelial cells, relative condition and relative otolith diameter seem useful for detecting starvation in turbot larvae.Instituto Español de Oceanografí

Weighing Counts: Sequential Crowd Counting by Reinforcement Learning

We formulate counting as a sequential decision problem and present a novel crowd counting model solvable by deep reinforcement learning. In contrast to existing counting models that directly output count values, we divide one-step estimation into a sequence of much easier and more tractable sub-decision problems. Such sequential decision nature corresponds exactly to a physical process in reality scale weighing. Inspired by scale weighing, we propose a novel 'counting scale' termed LibraNet where the count value is analogized by weight. By virtually placing a crowd image on one side of a scale, LibraNet (agent) sequentially learns to place appropriate weights on the other side to match the crowd count. At each step, LibraNet chooses one weight (action) from the weight box (the pre-defined action pool) according to the current crowd image features and weights placed on the scale pan (state). LibraNet is required to learn to balance the scale according to the feedback of the needle (Q values). We show that LibraNet exactly implements scale weighing by visualizing the decision process how LibraNet chooses actions. Extensive experiments demonstrate the effectiveness of our design choices and report state-of-the-art results on a few crowd counting benchmarks. We also demonstrate good cross-dataset generalization of LibraNet. Code and models are made available at: https://git.io/libranetComment: Accepted to Proc. Eur. Conf. Computer Vision (ECCV) 202

The trans-activation domain of the sporulation response regulator Spo0A revealed by X-ray crystallography

Sporulation in Bacillus involves the induction of scores of genes in a temporally and spatially co-ordinated programme of cell development. Its initiation is under the control of an expanded two-component signal transduction system termed a phosphorelay. The master control element in the decision to sporulate is the response regulator, Spo0A, which comprises a receiver or phosphoacceptor domain and an effector or transcription activation domain. The receiver domain of Spo0A shares sequence similarity with numerous response regulators, and its structure has been determined in phosphorylated and unphosphorylated forms. However, the effector domain (C-Spo0A) has no detectable sequence similarity to any other protein, and this lack of structural information is an obstacle to understanding how DNA binding and transcription activation are controlled by phosphorylation in Spo0A. Here, we report the crystal structure of C-Spo0A from Bacillus stearothermophilus revealing a single alpha -helical domain comprising six alpha -helices in an unprecedented fold. The structure contains a helix-turn-helix as part of a three alpha -helical bundle reminiscent of the catabolite gene activator protein (CAP), suggesting a mechanism for DNA binding. The residues implicated in forming the sigma (A)-activating region clearly cluster in a flexible segment of the polypeptide on the opposite side of the structure from that predicted to interact with DNA. The structural results are discussed in the context of the rich array of existing mutational data