Evaluacion economica centro acuiturismo en la comuna de Longavi, VII Region

132 p.En este estudio se realizo una evaluación económica de la instalación de un centro de acuiturismo en el sector precordillerano Los Canelos de la comuna de Longavi, ubicada en la Región del Maule. Este proyecto contempla la producción de 41 ton anuales de trucha arcoiris (oncorynchus mykiss), de las cuales 33 ton netas aprox., serán comercializadas congeladas con un tamaño porción de 200-250 grs. de peso unitario, y la prestación de servicios turísticos como son acceso a cabañas, camping, visitas a la piscicultura, caminatas por los alrededores, pesca deportiva, entre otros. Se realizo una caracterización del entorno en que se desarrolla el proyecto a nivel regional y comunal, que mostró que existen buenas posibilidades para invertir, en especial por la riqueza de los recursos naturales disponibles para el turismo y aprovechables para el desarrollo de una actividad productiva como es la salmonicultura. Una vez determinados ingresos y costos para cada periodo de tiempo, el flujo de caja proyectado para 10 anos se descontó a una tasa del 10,77% determinada en base al modelo de valoración de activos de capital, CAPM, utilizando retornos accionarios de la empresa de la industria salmonera Mainstream Salmones y Alimentos S.A. Con estos datos fue posible aplicar los criterios de VAN y TIR para obtener la verdadera rentabilidad del proyecto. Los resultados demostraron que el proyecto es rentable para un precio de venta del producto trucha de US $5,6/kilo con una TIR de 21,9%; no así para niveles inferiores de precio en los que no es aconsejable invertir puesto que no se recupera la inversión

Microevolution of Pandemic Vibrio parahaemolyticus Assessed by the Number of Repeat Units in Short Sequence Tandem Repeat Regions

The emergence of the pandemic strain Vibrio parahaemolyticus O3:K6 in 1996 caused a large increase of diarrhea outbreaks related to seafood consumption in Southeast Asia, and later worldwide. Isolates of this strain constitutes a clonal complex, and their effectual differentiation is possible by comparison of their variable number tandem repeats (VNTRs). The differentiation of the isolates by the differences in VNTRs will allow inferring the population dynamics and microevolution of this strain but this requires knowing the rate and mechanism of VNTRs' variation. Our study of mutants obtained after serial cultivation of clones showed that mutation rates of the six VNTRs examined are on the order of 10−4 mutant per generation and that difference increases by stepwise addition of single mutations. The single stepwise mutation (SSM) was deduced because mutants with 1, 2, 3, or more repeat unit deletions or insertions follow a geometric distribution. Plausible phylogenetic trees are obtained when, according to SSM, the genetic distance between clusters with different number of repeats is assessed by the absolute differences in repeats. Using this approach, mutants originated from different isolates of pandemic V. parahaemolyticus after serial cultivation are clustered with their parental isolates. Additionally, isolates of pandemic V. parahaemolyticus from Southeast Asia, Tokyo, and northern and southern Chile are clustered according their geographical origin. The deepest split in these four populations is observed between the Tokyo and southern Chile populations. We conclude that proper phylogenetic relations and successful tracing of pandemic V. parahaemolyticus requires measuring the differences between isolates by the absolute number of repeats in the VNTRs considered

Variable Copy Number, Intra-Genomic Heterogeneities and Lateral Transfers of the 16S rRNA Gene in Pseudomonas

Even though the 16S rRNA gene is the most commonly used taxonomic marker in microbial ecology, its poor resolution is still not fully understood at the intra-genus level. In this work, the number of rRNA gene operons, intra-genomic heterogeneities and lateral transfers were investigated at a fine-scale resolution, throughout the Pseudomonas genus. In addition to nineteen sequenced Pseudomonas strains, we determined the 16S rRNA copy number in four other Pseudomonas strains by Southern hybridization and Pulsed-Field Gel Electrophoresis, and studied the intra-genomic heterogeneities by Denaturing Gradient Gel Electrophoresis and sequencing. Although the variable copy number (from four to seven) seems to be correlated with the evolutionary distance, some close strains in the P. fluorescens lineage showed a different number of 16S rRNA genes, whereas all the strains in the P. aeruginosa lineage displayed the same number of genes (four copies). Further study of the intra-genomic heterogeneities revealed that most of the Pseudomonas strains (15 out of 19 strains) had at least two different 16S rRNA alleles. A great difference (5 or 19 nucleotides, essentially grouped near the V1 hypervariable region) was observed only in two sequenced strains. In one of our strains studied (MFY30 strain), we found a difference of 12 nucleotides (grouped in the V3 hypervariable region) between copies of the 16S rRNA gene. Finally, occurrence of partial lateral transfers of the 16S rRNA gene was further investigated in 1803 full-length sequences of Pseudomonas available in the databases. Remarkably, we found that the two most variable regions (the V1 and V3 hypervariable regions) had probably been laterally transferred from another evolutionary distant Pseudomonas strain for at least 48.3 and 41.6% of the 16S rRNA sequences, respectively. In conclusion, we strongly recommend removing these regions of the 16S rRNA gene during the intra-genus diversity studies

Behavioural and Developmental Interventions for Autism Spectrum Disorder: A Clinical Systematic Review

Background: Much controversy exists regarding the clinical efficacy of behavioural and developmental interventions for improving the core symptoms of autism spectrum disorders (ASD). We conducted a systematic review to summarize the evidence on the effectiveness of behavioural and developmental interventions for ASD. Methods and Findings: Comprehensive searches were conducted in 22 electronic databases through May 2007. Further information was obtained through hand searching journals, searching reference lists, databases of theses and dissertations, and contacting experts in the field. Experimental and observational analytic studies were included if they were written in English and reported the efficacy of any behavioural or developmental intervention for individuals with ASD. Two independent reviewers made the final study selection, extracted data, and reached consensus on study quality. Results were summarized descriptively and, where possible, meta-analyses of the study results were conducted. One-hundred-and-one studies at predominantly high risk of bias that reported inconsistent results across various interventions were included in the review. Meta-analyses of three controlled clinical trials showed that Lovaas treatment was superior to special education on measures of adaptive behaviour, communication and interaction, comprehensive language, daily living skills, expressive language, overall intellectual functioning and socialization. High-intensity Lovaas was superior to low-intensity Lovaas on measures of intellectual functioning in two retrospective cohort studies. Pooling the results of two randomized controlle

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Outbreak of Vibrio parahaemolyticus Sequence Type 120, Peru, 2009

In 2009, an outbreak of Vibrio parahaemolyticus occurred in Piura, Cajamarca, Lambayeque, and Lima, Peru. Whole-genome sequencing of clinical and environmental samples from the outbreak revealed a new V. parahaemolyticus clone. All the isolates identified belonged to a single clonal complex described exclusively in Asia before its emergence in Peru

Effect of Static Magnetic Fields on the Composition of Marine Biofouling in Seawater Transportation Pipelines

The use of seawater for mining purposes in Chile has progressively increased in recent years as fast as the interest on the negative effects of biofouling on the inner part of pipelines used to transport seawater. To prevent biofouling, chemical antifouling compounds are traditionally used, thus, causing negative environmental impacts. The aim of this research has, therefore, been to evaluate the efficiency of static magnetic fields (SMF) generators to mitigate the biofouling. Hence, experimental activities have been conducted on high density polyethylene (HDPE) pipes equipped with neodymium magnets during two experimental periods in the year of 2019, i.e., autumn–winter (A–W) and spring–summer (S–S), and under two types of SMF, i.e., continuous-type (PCS) and pulse-type (PPS). Physicochemical parameters and cell viability of microorganisms composing the biofilm were investigated. Metagenomic analyses on biofilm were conducted as well. The results showed that the cell viability was the highest, i.e., 757,780 cells/cm2, during S–S and the lowest, i.e., 349,151 cells/cm2, in A–W, both under PCS. In S–S, as well as A–W, biofilm was characterized for the most abundant eukaryotic operational taxonomic units (OTUs) under PPS conditions. The presence of OTUs, such as Articiflavibacter spp., Chaetonotida spp. and Desmodorida spp., was observed only from SMF tests