Descripción: Chenopodium stuckertii is identified as Holmbergia tweedii and lectotypified.

Descripción: The existence of ammonium anomalies in mineralized deposits in Argentina is presented. These anomalies are given by the substitution of potassium ion by ammonium ion in certain feldspars, clay minerals and sulfates. This substitution doesn't produce physical changes either in the minerals or the host rocks. Ammonium-bearing minerals have been found in several hydrothermally altered metallic deposits. Ammonium ion is specially sensible to SWIR reflectance spectroscopy method, so it became an ideal, easy and valuable tool for ammonium anomalies detection. Although ammonium-bearing minerals are not always associated with metallic ore, they can be used as an exploration guide, being thus a very useful prospective method for metallic deposits in general. © 2006 Asociación Geológica Argentina.

Descripción: Leptospirosis is a worldwide zoonosis caused by a spirochete that belongs to the genus Leptospira. In the last years, new methods, such as the PCR-based multiple-locus variable-number tandem repeat analysis (MLVA), have been developed for the genotyping of leptospires. In the present work, the MLVA patterns for all reference strains used in Argentina for bovine, ovine, porcine, equine, caprine and canine leptospirosis diagnosis, as well as in human and wild animal diagnosis, were obtained. MLVA results are presented in such a way that they can be readily used for the identification of these strains by the simple and direct comparison of agarose gels. Making the use and interpretation of the MLVA for leptospires typing easier will help increase the use of this method as a routine procedure for human and animal diagnosis, for epidemiological studies, vaccine control and other applications.

Descripción: Addition of affinity tags to bacteriophage particles facilitates a variety of applications, including vaccine construction and diagnosis of bacterial infections. Addition of tags to phage capsids is desirable, as modification of the tails can lead to poor adsorption and loss of infectivity. Although tags can readily be included as fusions to head decoration proteins, many phages do not have decoration proteins as virion components. The addition of a small (10-amino-acid) Strep-tag II (STAG II) to the mycobacteriophage TM4 capsid subunit, gp9, was not tolerated as a genetically homogenous recombinant phage but could be incorporated into the head by growth of wild-type phage on a host expressing the capsid-STAG fusion. Particles with capsids composed of wild-type and STAG-tagged subunit mixtures could be grown to high titers, showed good infectivities, and could be used to isolate phage-bacterium complexes. Preparation of a STAG-labeled fluoromycobacteriophage enabled capture of bacterial complexes and identification of infected bacteria by fluorescence. © 2013, American Society for Microbiology.

Descripción: A combination of two methodologies is presented for detection and mapping of gypsum using ASTER L3A imagery. One of the methodologies uses the Quartz index defined for the ASTER TIR subsystem, which can be used for gypsum detection given its low response in Qi. The other consists in the combination of two band ratios of the ASTER SWIR subsystem, (4/5)/(7/5), which allows the identification of gypsum highlighting its high response in 4/5 and low response in 7/5. Two areas in the Cordillera Principal in the province of Mendoza were selected as case studies, and a field survey was conducted in order to evaluate the results. Both techniques are proved successful, yet classify erroneously some pixels as gypsum. Errors by excess are different for each method, which allows for these two techniques to be combined using a "decision tree" classifier to solve the misclassifications.

Descripción: Background: Detailed analysis of the dynamic interactions among biological, environmental, social, and economic factors that favour the spread of certain diseases is extremely useful for designing effective control strategies. Diseases like tuberculosis that kills somebody every 15 seconds in the world, require methods that take into account the disease dynamics to design truly efficient control and surveillance strategies. The usual and well established statistical approaches provide insights into the cause-effect relationships that favour disease transmission but they only estimate risk areas, spatial or temporal trends. Here we introduce a novel approach that allows figuring out the dynamical behaviour of the disease spreading. This information can subsequently be used to validate mathematical models of the dissemination process from which the underlying mechanisms that are responsible for this spreading could be inferred. Methodology/Principal Findings: The method presented here is based on the analysis of the spread of tuberculosis in a Brazilian endemic city during five consecutive years. The detailed analysis of the spatio-temporal correlation of the yearly geo-referenced data, using different characteristic times of the disease evolution, allowed us to trace the temporal path of the aetiological agent, to locate the sources of infection, and to characterize the dynamics of disease spreading. Consequently, the method also allowed for the identification of socio-economic factors that influence the process. Conclusions/Significance: The information obtained can contribute to more effective budget allocation, drug distribution and recruitment of human skilled resources, as well as guiding the design of vaccination programs. We propose that this novel strategy can also be applied to the evaluation of other diseases as well as other social processes. © 2010 Zorzenon dos Santos et al.

Descripción: Nitrogen compounds like urea and melamine are known to be commonly used for milk adulteration resulting in undesired intoxication; a well-known example is the Chinese episode occurred in 2008. The development of a rapid, reliable and economic test is of relevance in order to improve adulterated milk identification. Cyclic voltammetry studies using an Au working electrode were performed on adulterated and non-adulterated milk samples from different independent manufacturers. Voltammetric data and their first derivative were subjected to functional principal component analysis (f-PCA) and correctly classified by the KNN classifier. The adulterated and non-adulterated milk samples showed significant differences. Best results of prediction were obtained with first derivative data. Detection limits in milk samples adulterated with 1% of its total nitrogen derived from melamine or urea were as low as 85.0 mg·L-1 and 121.4 mg·L-1, respectively. We present this method as a fast and robust screening method for milk adulteration analysis and prevention of food intoxication. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Descripción: Ciénaga del Río Huaco Formation was deposited during the Cretaceous in the Precordillera Central (La Rioja and San Juan provinces). The unit forms part of a thick red-bed sequence including rocks of different ages (from Late Paleozoic to Tertiary) and problematic identification. In the La Troya river area, the red bed sequence is composed of the Panacán (Permian), Santo Domingo (Late Triassic- Early Jurassic), Ciénaga del Río Huaco (Cretaceous) and Puesto La Flecha Formations (Oligocene- Early Nfiocene). In the past, all these formations were included in the same stratigrapbic unit and only in recent years the different formations could be separated mainly based on their fossil contain. In the case of Ciénaga del Rio Huaco Formation, the finding of microfossils (palynomorphs and ostracods) allowed to infer a Late Cretaceous age for these rocks. However, a radiometric age of 108,1 ± 4,4 Ma presented in this paper, clearly suggest that the unit was deposited at the end of the Early Cretaceous. This age is the first Cretaceous absolute age in the Precordillera Central and enhances the time constraints of of the Cretaceous Basin.

Descripción: A new eigentechnique approach, Principal Sequence Pattern Analysis (PSPA), is introduced for the analysis of spatial pattern sequence, as an extension of the traditional Principal Component Analysis set in the T-Mode. In this setting, the variables are sequences of k spatial fields of a given meteorological variable. PSPA is described and applied to a sample of 256 consecutive daily 1000 hPa geopotential height fields. The results of the application of the technique to 5-day sequences demonstrate the advantages of this procedure in identifying field pattern sequences, thereby allowing the determination of the evolution and development of the systems, together with cyclogenesis and anticyclogenesis processes. In order to complete the study, the more traditional Extended Empirical Orthogonal Function (EEOF) analysis, which is the S-mode equivalent of the PSPA, was applied to the same dataset. For EEOF, it was not possible to identify any real sequences that could correspond to the sequences of patterns yielded by the EEOF. Furthermore, the explained variance distribution in the EEOF was significantly different from that obtained with PSPA. Conversely, the PSPA approach allowed for the identification of the sequences corresponding to those sequences observed in the data. Using diagrams of the squares of the component loadings values, as a function of time, the study of the times of occurrence of dominant field characteristics was also possible. In other words, successful determination of periods where the basic flow was dominant and times when strongly perturbed transient events with a significant meridional component occurred, was facilitated by PSPA. © 2001 Royal Meteorological Society.

Descripción: Background. Considering that sunflower production is expanding to arid regions, tolerance to abiotic stresses as drought, low temperatures and salinity arises as one of the main constrains nowadays. Differential organ-specific sunflower ESTs (expressed sequence tags) were previously generated by a subtractive hybridization method that included a considerable number of putative abiotic stress associated sequences. The objective of this work is to analyze concerted gene expression profiles of organ-specific ESTs by fluorescence microarray assay, in response to high sodium chloride concentration and chilling treatments with the aim to identify and follow up candidate genes for early responses to abiotic stress in sunflower. Results. Abiotic-related expressed genes were the target of this characterization through a gene expression analysis using an organ-specific cDNA fluorescence microarray approach in response to high salinity and low temperatures. The experiment included three independent replicates from leaf samples. We analyzed 317 unigenes previously isolated from differential organ-specific cDNA libraries from leaf, stem and flower at R1 and R4 developmental stage. A statistical analysis based on mean comparison by ANOVA and ordination by Principal Component Analysis allowed the detection of 80 candidate genes for either salinity and/or chilling stresses. Out of them, 50 genes were up or down regulated under both stresses, supporting common regulatory mechanisms and general responses to chilling and salinity. Interestingly 15 and 12 sequences were up regulated or down regulated specifically in one stress but not in the other, respectively. These genes are potentially involved in different regulatory mechanisms including transcription/translation/protein degradation/protein folding/ROS production or ROS-scavenging. Differential gene expression patterns were confirmed by qRT-PCR for 12.5% of the microarray candidate sequences. Conclusion. Eighty genes isolated from organ-specific cDNA libraries were identified as candidate genes for sunflower early response to low temperatures and salinity. Microarray profiling of chilling and NaCl-treated sunflower leaves revealed dynamic changes in transcript abundance, including transcription factors, defense/stress related proteins, and effectors of homeostasis, all of which highlight the complexity of both stress responses. This study not only allowed the identification of common transcriptional changes to both stress conditions but also lead to the detection of stress-specific genes not previously reported in sunflower. This is the first organ-specific cDNA fluorescence microarray study addressing a simultaneous evaluation of concerted transcriptional changes in response to chilling and salinity stress in cultivated sunflower.