Cerebroventricular Microinjection (CVMI) into Adult Zebrafish Brain Is an Efficient Misexpression Method for Forebrain Ventricular Cells

The teleost fish Danio rerio (zebrafish) has a remarkable ability to generate newborn neurons in its brain at adult stages of its lifespan-a process called adult neurogenesis. This ability relies on proliferating ventricular progenitors and is in striking contrast to mammalian brains that have rather restricted capacity for adult neurogenesis. Therefore, investigating the zebrafish brain can help not only to elucidate the molecular mechanisms of widespread adult neurogenesis in a vertebrate species, but also to design therapies in humans with what we learn from this teleost. Yet, understanding the cellular behavior and molecular programs underlying different biological processes in the adult zebrafish brain requires techniques that allow manipulation of gene function. As a complementary method to the currently used misexpression techniques in zebrafish, such as transgenic approaches or electroporation-based delivery of DNA, we devised a cerebroventricular microinjection (CVMI)-assisted knockdown protocol that relies on vivo morpholino oligonucleotides, which do not require electroporation for cellular uptake. This rapid method allows uniform and efficient knockdown of genes in the ventricular cells of the zebrafish brain, which contain the neurogenic progenitors. We also provide data on the use of CVMI for growth factor administration to the brain – in our case FGF8, which modulates the proliferation rate of the ventricular cells. In this paper, we describe the CVMI method and discuss its potential uses in zebrafish

Welcome to the new world disorder: conflict and transformation in Ian McEwan’s saturday

Ian McEwan‘s novel Saturday deals with the complex issues of conflict and transformation in the age of terrorism. The plot presents one internal dilemma and several interpersonal altercations that occur within a mere twenty-four hours: a) Perowne (the protagonist) vs. himself, in face of his ambivalent thoughts regarding British military participation in the war in the Middle East; b) The protagonist vs. Baxter, a ruffian from East End, in the context of a car accident; c) Perowne vs. a fellow anaesthetist, Jay Strauss, during a squash game; d) Perowne‘s daughter, Daisy vs. her grandfather, John Grammaticus, both poets and rivals; e) Perowne‘s family vs. Baxter, who intrudes the protagonist‘s house. In this paper, I exemplify, analyse and discuss how: a) Understanding the causes of what we call evil constitutes an important step towards mutual understanding; b) Both science and arts (which Perowne considers, at first, irrelevant) are important elements in the process of transformation; c) Both personal and interpersonal conflicts are intrinsic to human nature — but they also propitiate healthy changes in behaviour and opinion, through reflection. In order to do so, I resort to Saturday, and to the work of several specialists in the field of conflict management.O romance Saturday, de Ian McEwan, aborda as complexas questões do conflito e da transformação na era do terrorismo. O enredo apresenta um dilema interno e várias altercações interpessoais que ocorrem em apenas vinte e quatro horas: a) Perowne (o protagonista) vs. ele próprio, perante opiniões ambivalentes acerca da participação britânica na guerra do Médio Oriente; o protagonista vs. Baxter, um rufia de East End, no contexto de um acidente rodoviário; c) Perowne vs. um colega anestesista, Jay Strauss, no decorrer de uma partida de squash; d) Daisy, a filha de Perowne vs. o avô, John Grammaticus, ambos poetas e rivais; e) A família de Perowne vs. Baxter, que invade a residência do protagonista. Neste artigo, exemplifico, analiso e debato como: a) Compreender as causas daquilo a que chamamos o mal constitui um passo importante para uma compreensão mútua; b) Tanto a ciência como a arte (que Perowne considera, inicialmente, irrelevante) são elementos importantes no processo de transformação; c) Os conflitos pessoais e interpessoais são intrínsecos à natureza humana, mas também propiciam saudáveis mudanças de comportamento e ideias, através da reflexão. Para tanto, recorro ao romance Saturday e ao trabalho de vários especialistas no campo da gestão de conflitos

De novo assembly and characterization of a maternal and developmental transcriptome for the emerging model crustacean Parhyale hawaiensis

<p>Abstract</p> <p>Background</p> <p>Arthropods are the most diverse animal phylum, but their genomic resources are relatively few. While the genome of the branchiopod <it>Daphnia pulex </it>is now available, no other large-scale crustacean genomic resources are available for comparison. In particular, genomic resources are lacking for the most tractable laboratory model of crustacean development, the amphipod <it>Parhyale hawaiensis</it>. Insight into shared and divergent characters of crustacean genomes will facilitate interpretation of future developmental, biomedical, and ecological research using crustacean models.</p> <p>Results</p> <p>To generate a transcriptome enriched for maternally provided and zygotically transcribed developmental genes, we created cDNA from ovaries and embryos of <it>P. hawaiensis</it>. Using 454 pyrosequencing, we sequenced over 1.1 billion bases of this cDNA, and assembled them <it>de novo </it>to create, to our knowledge, the second largest crustacean genomic resource to date. We found an unusually high proportion of C2H2 zinc finger-containing transcripts, as has also been reported for the genome of the pea aphid <it>Acyrthosiphon pisum</it>. Consistent with previous reports, we detected trans-spliced transcripts, but found that they did not noticeably impact transcriptome assembly. Our assembly products yielded 19,067 unique BLAST hits against <b>nr </b>(E-value cutoff e-10). These included over 400 predicted transcripts with significant similarity to <it>D. pulex </it>sequences but not to sequences of any other animal. Annotation of several hundred genes revealed <it>P. hawaiensis </it>homologues of genes involved in development, gametogenesis, and a majority of the members of six major conserved metazoan signaling pathways.</p> <p>Conclusions</p> <p>The amphipod <it>P. hawaiensis </it>has higher transcript complexity than known insect transcriptomes, and trans-splicing does not appear to be a major contributor to this complexity. We discuss the importance of a reliable comparative genomic framework within which to consider findings from new crustacean models such as <it>D. pulex </it>and <it>P. hawaiensis</it>, as well as the need for development of further substantial crustacean genomic resources.</p

A virtual reality collaborative planning simulator and its method for three machines in a fully mechanized coal mining face

The existing automatic control program and its parameters for three machines in a fully mechanized Coal Mining face are static and simplex and are therefore inadequate for satisfying the complex and dynamic environment of underground coal mines. To overcome this problem, a collaborative mathematical model is established that includes the effects of a dynamic environment. A virtual reality collaborative planning simulator with methods for the three machines is also proposed based on a multi-agent system. According to the dynamic characteristics of the environment, equipment, and technologies, a fully mechanized Unity3D simulator (FMUnitySim) is designed in terms of multiple factors and multiple dimensions. The factors affecting the coordinated operation of the three machines are analyzed and modeled. The communication modes, coordination, and redundant sensing process among multiple agents, which include the shearer agent and the scraper conveyor agent, are also investigated in detail. Using this system, the key parameters of the three machines can be planned and adjusted online to design and distinctly observe the corresponding collaborative simulations of coordinated operation with multiple perspectives and in real time. Tests of different maximum shearer haulage speeds for regular or reverse transporting coal are designed; their key parameters, including the average shearer haulage speed, average follower distance, and average scraper conveyor load, are planned and simulated using FMUnitySim. The optimal parameter combination is obtained by analyzing and comparing the simulation results. The proposed FMUnitySim offers an effective means and theoretical basis for the rapid planning and safe automatic production of a fully mechanized Coal Mining face

Zebrafish regenerate full thickness optic nerve myelin after demyelination, but this fails with increasing age

INTRODUCTION: In the human demyelinating central nervous system (CNS) disease multiple sclerosis, remyelination promotes recovery and limits neurodegeneration, but this is inefficient and always ultimately fails. Furthermore, these regenerated myelin sheaths are thinner and shorter than the original, leaving the underlying axons potentially vulnerable. In rodent models, CNS remyelination is more efficient, so that in young animals (but not old) the number of myelinated axons is efficiently restored to normal, but in both young and old rodents, regenerated myelin sheaths are still short and thin. The reasons for these differences in remyelination efficiency, the thinner remyelinated myelin sheaths compared to developmental myelin and the subsequent effect on the underlying axon are unclear. We studied CNS remyelination in the highly regenerative adult zebrafish (Danio rerio), to better understand mechanisms of what we hypothesised would be highly efficient remyelination, and to identify differences to mammalian CNS remyelination, as larval zebrafish are increasingly used for high throughput screens to identify potential drug targets to improve myelination and remyelination. RESULTS: We developed a novel method to induce a focal demyelinating lesion in adult zebrafish optic nerve with no discernible axonal damage, and describe the cellular changes over time. Remyelination is indeed efficient in both young and old adult zebrafish optic nerves, and at 4 weeks after demyelination, the number of myelinated axons is restored to normal, but internode lengths are short. However, unlike in rodents or in humans, in young zebrafish these regenerated myelin sheaths were of normal thickness, whereas in aged zebrafish, they were thin, and remained so even 3 months later. This inability to restore normal myelin thickness in remyelination with age was associated with a reduced macrophage/microglial response. CONCLUSION: Zebrafish are able to efficiently restore normal thickness myelin around optic nerve axons after demyelination, unlike in mammals. However, this fails with age, when only thin myelin is achieved. This gives us a novel model to try and dissect the mechanism for restoring myelin thickness in CNS remyelination. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40478-014-0077-y) contains supplementary material, which is available to authorized users

The plasma lipid peroxidation intensity (MDA) and chain-breaking antioxidant concentrations in the cows with clinic or subclinic mastitis

The aim of this study was to determine lipid peroxidation intensity by measurement of plasma malonedialdehyde (MDA) concentrations and plasma chain-breaking antioxidant concentrations such as reduced glutathione (GSH), vitamin A, E, C and beta-carotene in the cows with and without mastitis. The study was conducted on 30 Holstein cows which were divided into 3 equal groups on the basis of clinical examination and California Mastitis Test (CMT): in the group CM, clinical mastitis was evidenced; in the group SCM, mastitis was subclinical, and the group C served as a control. The plasma lipid peroxidation index was measured according to the concentration of thiobarbituric acid reactive species (MDA), and GSH activity was measured spectrophotometrically using Ellman's reagent. Vitamin A, P-carotene and vitamin E values were spectrophotometrically determined, and vitamin C value was colorimetrically determined using a phosphotungstic acid method. The mean plasma GSH (p<0.01) and beta-carotene (p<0.001) concentrations were showed significant differences between the 3 groups, whereas mean plasma MDA and serum vitamin C concentrations significantly differed only between the C and CM groups (p<0.05). The decreased chain-breaking antioxidant concentrations and the enhanced concentrations of GSH and MDA suggest that an inflammatory-related oxidative stress occurs in the cows with clinical and subclinical mastitis

Effects of different harvest periods on essential oil components of Lippia citriodora Kunth under semi-arid climatic conditions and biological activities of its essential oil

Lemon verbena is cultivated mainly due to the lemon-like aroma emitted from its leaves that are utilized for most purposes. The chemical composition of the essential oil of lemon verbena was analyzed by GC/MS in July at pre flowering, in September at full flowering and in end of October at post flowering period. The in vitro antimicrobial activity of the essential oil, extracted from Lippia citriodora was tested against laboratory control strains belonging to the American Type Culture Collection (Maryland, USA) four Gram (+) and Gram (-) bacteria using the disc diffusion test. Antioxidant activity of the sample was determined by 1,1-diphenil-2- -picrly-hydrazil (DPPH) assay. Well-known antioxidant compounds such as ascorbic acid and α-tocopherol were used as standard. Results showed, among different harvest periods high fresh and dry herbage and dry leaf yields per plant were obtained from full flowering stage. Harvest periods were found to have a significant effect on the content of essential oil and the highest amounts of limonene, neral and geranial and measured as 31.15, 11.92 and 15.53%, respectively at full flowering stage. In all samples, the main constituents were limonene, neral and geranial constituting 46.03%–58.59% of the total essential oil yield depend on development stages. Lemon verbena essential oil was found to have antibacterial activity especially against Gram (+) microorganisms. In DPPH system, the moderate radical scavenging activity was exhibited. Therefore, L. citriodora has potential to be used as a natural antioxidant and antimicrobial agent in food processing