Obfuscation-based malware update: A comparison of manual and automated methods

Indexación: Scopus; Web of Science.This research presents a proposal of malware classification and its update based on capacity and obfuscation. This article is an extension of [4]a, and describes the procedure for malware updating, that is, to take obsolete malware that is already detectable by antiviruses, update it through obfuscation techniques and thus making it undetectable again. As the updating of malware is generally performed manually, an automatic solution is presented together with a comparison from the standpoint of cost and processing time. The automated method proved to be more reliable, fast and less intensive in the use of resources, specially in terms of antivirus analysis and malware functionality checking times.http://univagora.ro/jour/index.php/ijccc/article/view/2961/112

Formación inicial de profesores de educación media de ciencia mediante la teoría de enseñanza y aprendizaje basada en modelos mentales

Este estudio describe cómo se aplica la Teoría de los Modelos Mentales en la formación inicial del profesor de Ciencias de enseñanza media en la Facultad de Educación de la Universidad de Concepción. Esta nueva modalidad de formación, se introdujo a partir del año 2004, en las asignaturas de Didáctica III y IV y en el desarrollo de la tesis de pregrado. Los sesenta estudiantes participantes de la experiencia generaron más de treinta planificaciones de unidades sobre diferentes temas científicos, en las que se utiliza la Teoría de los Modelos Mentales, y que han aplicado a alumnos de enseñanza media. Los dos estudios pilotos que midieron la efectividad de estas planificaciones, indican que el uso de esta perspectiva genera auspiciosos resultados en el aprendizaje de los estudiantes de enseñanza media y en la organización del quehacer en el aula del futuro docente

Fundamental stellar and accretion disc parameters of the eclipsing binary DQ Velorum

To add to the growing collection of well-studied double periodic variables (DPVs) we have carried out the first spectroscopic and photometric analysis of the eclipsing binary DQ Velorum to obtain its main physical stellar and orbital parameters. Combining spectroscopic and photometric observations that cover several orbital cycles allows us to estimate the stellar properties of the binary components and the orbital parameters. We also searched for circumstellar material around the more massive star. We separated DQ Velorum composite spectra and measured radial velocities with an iterative method for double spectroscopic binaries. We obtained the radial velocity curves and calculated the spectroscopic mass ratio. We compared our single-lined spectra with a grid of synthetic spectra and estimated the temperature of the stars. We modeled the V-band light curve with a fitting method based on the simplex algorithm, which includes an accretion disc. To constrain the main stellar parameters we fixed the mass ratio and donor temperature to the values obtained by our spectroscopic analysis. We obtain donor and gainer masses, the radii, and temperatures for the stellar components. We find that DQ Vel is a semi-detached system consisting of a B3V gainer and an A1III donor star plus an extended accretion disc around the gainer. The disc is filling 89% of the gainer Roche lobe and it has a concave shape that is thicker at its edge than at its centre. We find a significant sub-orbital frequency of 0.19 d^{-1} in the residuals of the V-band light curve, which we interpret as a pulsation of an slowly pulsating B-type (SPB) of a gainer star. We also estimate the distance to the binary (3.1 kpc) using the absolute radii, apparent magnitudes, and effective temperatures of the components found in our study.Comment: 12 pages, 13 Postscript figure

Manejo quirúrgico de la poliposis nasosinusal

Indexación: ScieloIntroducción: La poliposis nasosinusal es un proceso inflamatorio crónico de la mucosa rinosinusal, de etiología desconocida, y que requiere de tratamiento quirúrgico en más de 50% de los pacientes. Objetivo: Evaluar los resultados de la cirugía endoscópica en pacientes con poliposis nasosinusal en el Hospital Barros Luco-Trudeau. Material y método: Estudio retrospectivo de 180 fichas clínicas de pacientes operados en este hospital en el período 1999-2008. Resultados: La distribución según sexo fue de 63% varones y 37% mujeres (p <0,001) y el promedio etario, de 44,9 años. El motivo principal de consulta fue la obstrucción nasal. Un tercio de los pacientes tenía poliposis masiva. El 17% se asoció con asma. Más del 50% de los pacientes usó corticoides inhalados en el preoperatorio. En el 58% se realizó cirugía endoscópica hasta etmoides anterior. No hubo complicaciones mayores en esta serle estudiada. La recidiva global fue de 24%. El promedio de meses libres de recidiva fue 46,7 meses (IC 95%: 37,5-55,5), con una recidiva de 25% al año de seguimiento. No se encontró asociación entre recidiva y los factores de riesgo estudiados. Discusión: En comparación con la literatura, se observa similares características demográficas. Sin embargo, los factores de riesgo de recidiva no fueron significativos, aparentemente debido a una baja prevalenciay a pérdida del seguimiento. La tasa de recidiva aumenta con el tiempo, motivo por el cual se requiere un seguimiento a largo plazo. Conclusiones: No se detectó asociación entre recidiva y los factores de riesgo clásicamente descritos en la literatura. Las recidivas fueron tardías y se obtuvieron tasas de recidiva similares a lo publicado en la literatura.Introduction: Sinonasal polyposis is a chronic inflammatory process rhinosinusal mucosa of unknown etiology which in over 50% of patients requires surgical treatment. Aim: To evaluate the results of endoscopic surgery in patients with sinonasal polyposis in the Barros Luco-Trudeau Hospital. Material and method: Retrospective study of 180 medical records of patients operated at this hospital from 1999 to 2008. Results: The sexual distribution was 63% male and 37% women (p <0.001). The average age was 44.9years. The chief complaint was nasal obstruction. A third of the patients had massive polyposis. The 17% was associated with asthma. Over 50% of patients used inhaled corticosteroids preoperatively in 58% performed endoscopic surgery to anterior ethmoid. There were no major complications in these series studied. The overall recurrence was 24%. The average number of months free of recurrence was 46.7 months (95% Cl 37.5 to 55.5) with a recurrence of 25% per year of follow up. We found no association between recurrence and the risk factors studied. Discussion: Comparing with the lierature, we see the same demographic characteristics but risk factors for recurrence are not significant, apparently due to the low prevalence and loss of follow-up. The recurrence rate is increased over time and therefore requires a long-term monitoring. Conclusions: We found no association between recurrence and the risk factors classically described in literature. Recurrences were late and we had similar recurrence rates to publish in the lierature.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-48162010000100002&nrm=is

Inhalación de esporas de Aspergillus fumigatus induce en ratones una inflamación de las vías aéreas similar a la observada en equinos con Obstrucción Recurrente de las Vías Aéreas

The aim of this study was to determine if mice exposed to Aspergillus (A.) fumigatus spores develop airway inflammation in a similar manner to Recurrent Airway Obstruction (RAO) in horses. Different groups of 2-, 5-, 6- and 8-month-old Rockefeller (RK) mice were used throughout the experiment. The mice were maintained in the animal house for 16 days and kept in cages containing hay contaminated with A. fumigatus. After 16 days of mold exposure, the mice were bled and sacrificed to obtain bronchoalveolar lavage fluid (BALF) or lung tissues for histological analysis. In addition, we measured the levels of A. fumigatus-specific antibodies by ELISA. The results demonstrated that inhalation of A. fumigatus spores in mice induced an inflammatory response in the lungs that was characterized by peribronchiolar and perivascular mononuclear infiltration and bronchiolar luminal exudates. Moreover, there was extensive folding of the airway epithelia, which is a sign of airway smooth muscle contraction and smooth muscle hypertrophy. In addition, we observed a high number of neutrophils and an increase in IgE, IgG1 and IgG2a antibodies in the BALF from mice that were older than 5 months and were exposed to A. fumigatus. These animals recovered from their respiratory distress when they were placed in a remission environment. We conclude that simple exposure of mice to moldy hay induces a condition that is similar to RAO in horses. Therefore, using this mouse model for the study of equine RAO offers the opportunity to approximate the immunologic response to airborne irritants and allergens as well as to evaluate pharmacological therapies.El objetivo de este estudio fue determinar si ratones expuestos a esporas de Aspergillus fumigatus desarrollan una inflamación alérgica de las vías respiratorias similar a la observada en equinos con Obstrucción Recurrente de las Vías Aéreas (ORVA). Para esto se utilizaron ratones Rockefeller (RK) de 2, 5, 6 y 8 meses respectivamente, los cuales se mantuvieron por 16 días en jaulas que contenían heno contaminado con A. fumigatus. Posterior a la exposición, los animales fueron sangrados y sacrificados para la obtención de suero sanguíneo, lavado broncoalveolar (LBA) y muestras de tejido pulmonar. Además, se midieron los niveles de anticuerpos específicos para A. fumigatus a través de un ELISA indirecto. Los resultados mostraron que la inhalación de esporas de A. fumigatus en ratones induce una respuesta alérgica inflamatoria en pulmones similar a lo observado en ORVA equino, con un aumento del porcentaje de neutrófilos en el LBA y cambios histológicos pulmonares característicos de una hipersensibilidad bronquial. Asimismo, se observó un aumento de los niveles de inmunoglubulinas IgE, IgG1 e IgG2a específicas para este hongo en fluidos bronquiales. Además, los animales remitieron el estrés respiratorio cuando fueron expuestos en un ambiente de remisión. Se puede concluir que la simple exposición de esporas de A. fumugatus produce una condición alérgica similar al ORVA en equinos. Por lo tanto, este modelo experimental puede ser de utilidad para el estudio de los mecanismos inmunológicos, y probar nuevas opciones terapéuticas para esta enfermedad respiratoria de los caballos

Gene Expression Response to Sea Lice in Atlantic Salmon Skin: RNA Sequencing Comparison Between Resistant and Susceptible Animals

Sea lice are parasitic copepods that cause large economic losses to salmon aquaculture worldwide. Frequent chemotherapeutic treatments are typically required to control this parasite, and alternative measures such as breeding for improved host resistance are desirable. Insight into the host–parasite interaction and mechanisms of host resistance can lead to improvements in selective breeding, and potentially novel treatment targets. In this study, RNA sequencing was used to study the skin transcriptome of Atlantic salmon (Salmo salar) parasitized with sea lice (Caligus rogercresseyi). The overall aims were to compare the transcriptomic profile of skin at louse attachment sites and “healthy” skin, and to assess differences in gene expression response between animals with varying levels of resistance to the parasite. Atlantic salmon pre-smolts were challenged with C. rogercresseyi, growth and lice count measurements were taken for each fish. 21 animals were selected and RNA-Seq was performed on skin from a louse attachment site, and skin distal to attachment sites for each animal. These animals were classified into family-balanced groups according to the traits of resistance (high vs. low lice count), and growth during infestation. Overall comparison of skin from louse attachment sites vs. healthy skin showed that 4,355 genes were differentially expressed, indicating local up-regulation of several immune pathways and activation of tissue repair mechanisms. Comparison between resistant and susceptible animals highlighted expression differences in several immune response and pattern recognition genes, and also myogenic and iron availability factors. Components of the pathways involved in differential response to sea lice may be targets for studies aimed at improved or novel treatment strategies, or to prioritize candidate functional polymorphisms to enhance genomic selection for host resistance in commercial salmon breeding programs

Filamentous fungi isolated and identified from Antarctic soil (Fildes Bay, Antarctica)

Purpose: Antarctica is a unique place with extreme environmental conditions, including low temperature, high solar radiation, low nutrient availability and strong winds. This different environment represents a gateway to studies on the taxonomy, ecology, and biotechnology of organisms under extreme conditions. Fungi are ubiquitous and diverse organisms in Antarctica and have been described as growing in different substrates such as plants, soil, rocks, ice, snow, and animals. To survive in such extreme conditions fungi might display unusual biochemical pathways able to generate specific or novel compounds with biotechnological relevance. Before accessing the fungal biotechnological potential, knowing the fungal species is mandatory. The main aim of this study was to isolate and identify fungal strains from Antarctic soil (Fildes Bay, Antarctica). Material and methods: Soil samples were collected using a 4x25 m transect at a depth of 0- 20 cm in different geographic areas of Fildes Bay (Antarctica). A total of 13 composed soil samples were collected. Composed soil aqueous suspensions were incubated on Potato Dextrose Agar (PDA), Dichloran Glycerol Agar 18% (DG18) and Dichloran Rose Bengal Chloramphenicol Agar (DRBC) media at 10 ºC for 21 days in the dark. Subsequently, filamentous fungi were isolated and cultured on PDA. The morphological identification of the isolated strains was carried out according to the classic macro- and micromorphological taxonomy. Results: A set of c.a. 1600 fungal strains belonging to the genera Acremonium, Aspergillus, Cladosporium, Mortierella, Mucor, Penicillium, Psudogymnoascus and other four nonidentified fungal genera were isolated. In addition, a relationship between the geographical area of the soil sample and the fungal genera was observed. Conclusions: Despite both the adverse environmental conditions and Antarctic soils that are not completely devoid of life, it was possible to observe a great diversity of filamentous fungi in some assessed soil samples. This indicates the ability of filamentous fungi in adapting to and survive in extreme conditions such as some of those found in Antarctica. This work represents the first report of large-scale fungal isolation in Fildes Bay, Antarctica. Molecular biology identification is being developed for isolated fungal strains.info:eu-repo/semantics/publishedVersio

Genome-Wide Association Analysis for Resistance to Infectious Pancreatic Necrosis Virus Identifies Candidate Genes Involved in Viral Replication and Immune Response in Rainbow Trout (Oncorhynchus mykiss)

Infectious pancreatic necrosis (IPN) is a viral disease with considerable negative impact on the rainbow trout (Oncorhynchus mykiss) aquaculture industry. The aim of the present work was to detect genomic regions that explain resistance to infectious pancreatic necrosis virus (IPNV) in rainbow trout. A total of 2,278 fish from 58 full-sib families were challenged with IPNV and 768 individuals were genotyped (488 resistant and 280 susceptible), using a 57K SNP panel Axiom, Affymetrix. A genome-wide association study (GWAS) was performed using the phenotypes time to death (TD) and binary survival (BS), along with the genotypes of the challenged fish using a Bayesian model (Bayes C). Heritabilities for resistance to IPNV estimated using genomic information, were 0.53 and 0.82 for TD and BS, respectively. The Bayesian GWAS detected a SNP located on chromosome 5 explaining 19% of the genetic variance for TD. The proximity of Sentrin-specific protease 5 (SENP5) to this SNP makes it a candidate gene for resistance against IPNV. In case of BS, a SNP located on chromosome 23 was detected explaining 9% of the genetic variance. However, the moderate-low proportion of variance explained by the detected marker leads to the conclusion that the incorporation of all genomic information, through genomic selection, would be the most appropriate approach to accelerate genetic progress for the improvement of resistance against IPNV in rainbow trout

Evaluation of lipid extraction methods from Antarctic filamentous fungi

Purpose: The benefits of natural compounds have been studied for decades for the development of new technologies to answer the global change challenges. In order to develop these new technologies, lipids represent a great class of bioactive molecules. However, the research on lipids and their applications still present gaps about new sources as well as on the extraction methods. Filamentous fungi found in Antarctic territory could represent a new source of novel bioactive lipids. Currently Folch, Bligh & Dyer and Lewis methods are the most widely employed for extraction of lipid from different sample types. Nonetheless, choosing a single extraction method as the gold standard could represent a limitation, especially when the microorganism has not been studied yet. Taking the above into consideration, the main objective of the present study was to evaluate the best extraction method to obtain lipids from different Antarctic filamentous fungal genera. Material and methods: Three isolates of Antarctic fungi belonging to each genus: Mucor, Mortierella, Cladosporium, Penicillium and Pseudogymnoascus isolates from Fildes Bay, Antarctica, were evaluated. A total of 15 isolates were assessed. Folch, Bligh & Dyer and Lewis extraction method were performed. Extraction was monitored by recording spectra of FT-IR spectroscopy of the biomass before and after lipid extraction. Results: Folch was the best method to obtain lipids from filamentous Antarctic fungi, followed by Lewis extraction. Among the three extraction methods evaluated, Bligh & Dyer was the method that presented the lowest yield, compared to Folch and Lewis for each genus and strain. Strains of the genera Mortierella and Mucor were the ones that showed the best performance for the Folch and Lewis methods. The three Penicillium isolates were the third group with the best lipids yield for the Folch method. The strains of genera Cladosporium and Pseudogymnoascus showed better yields for the Lewis method. Conclusions: In this study it was observed that the lipids yield varies according to the extraction methods, as well as both the fungal isolate and fungal genus. Depending on the purpose and fungi taxa, to obtain lipids from Antarctic fungi Folch or Lewis extraction methods are recommended.info:eu-repo/semantics/publishedVersio