A mathematically assisted reconstruction of the initial focus of the yellow fever outbreak in Buenos Aires (1871)

We discuss the historic mortality record corresponding to the initial focus of the yellow fever epidemic outbreak registered in Buenos Aires during the year 1871 as compared to simulations of a stochastic population dynamics model. This model incorporates the biology of the urban vector of yellow fever, the mosquito Aedes aegypti, the stages of the disease in the human being as well as the spatial extension of the epidemic outbreak. After introducing the historical context and the restrictions it puts on initial conditions and ecological parameters, we discuss the general features of the simulation and the dependence on initial conditions and available sites for breeding the vector. We discuss the sensitivity, to the free parameters, of statistical estimators such as: final death toll, day of the year when the outbreak reached half the total mortality and the normalized daily mortality, showing some striking regularities. The model is precise and accurate enough to discuss the truthfulness of the presently accepted historic discussions of the epidemic causes, showing that there are more likely scenarios for the historic facts.Comment: 25 pages, 12 figure

A GIS-based procedure for landslide intensity evaluation and specific risk analysis supported by persistent scatterers interferometry (PSI)

The evaluation of landslide specific risk, defined as the expected degree of loss due to landslides, requires the parameterization and the combination of a number of socio-economic and geological factors, which often needs the interaction of different skills and expertise (geologists, engineers, planners, administrators, etc.). The specific risk sub-components, i.e., hazard and vulnerability of elements at risk, can be determined with different levels of detail depending on the available auxiliary data and knowledge of the territory. These risk factors are subject to short-term variations and nowadays turn out to be easily mappable and evaluable through remotely sensed data and GIS (Geographic Information System) tools. In this work, we propose a qualitative approach at municipal scale for producing a “specific risk” map, supported by recent satellite PSI (Persistent Scatterer Interferometry) data derived from SENTINEL-1 C-band images in the spanning time 2014–2017, implemented in a GIS environment. In particular, PSI measurements are useful for the updating of a landslide inventory map of the area of interest and are exploited for the zonation map of the intensity of ground movements, needed for evaluating the vulnerability over the study area. Our procedure is presented throughout the application to the Volterra basin and the output map could be useful to support the local authorities with updated basic information required for environmental knowledge and planning at municipal level. Moreover, the proposed procedure is easily managed and repeatable in other case studies, as well as exploiting different SAR sensors in L- or X-band

Avaliação de genótipos de Avena sativa L. quanto a produção de forragem na região da Campanha/RS.

CONGREGA 2012

VIV regimes and simplified solutions by the spectral model description

The present paper discusses technical aspects of the vortex-induced vibrations (VIVs) of structures excited by the wind in the framework of the spectral model, which is applied by many codes and guidelines for civil engineering verifications. Quantitative thresholds related to Scruton number domains, where the structural response can be considered in \u201cforced vibration\u201d or \u201clock-in\u201d regime, are proposed. In this way, the type of VIV response and its evaluation can be assessed with simple calculations that use the parameters already present in codes and guidelines. An analytical solution of the original model allows straightforward evaluations inclusive of operative criteria to properly consider structural and flow conditions concerning the coefficients governing the VIV response in the spectral description, leaving out some assumptions that are commonly adopted. Extensive numerical applications, limited here to circular cylinders and including a real full-scale chimney, allow to identify the most significant parameters of the model and the criticalities connected with their choice

Maximum dynamic response of linear elastic SDOF systems based on an evolutionary spectral model for thunderstorm outflows

The study aims to estimate the maximum dynamic response of linear elastic SDOF systems subjected to thunderstorm outflows. Starting from a recently developed Evolutionary Power Spectral Density (EPSD) model for the wind velocity, the dynamic response is decomposed into a time-varying mean and a non-stationary random fluctuation. The EPSD and the Non-Geometrical Spectral Moments (NGSMs) of the random fluctuation are derived both accounting and neglecting the transient dynamics due to the modulating function of the load. The mean value of the maximum nonstationary fluctuating component of the response is estimated based on the definition of an equivalent stationary process following an approach proposed in the literature. In order to mitigate the overestimations of the maximum dynamic response due to the Poisson approximation, analogously to the formulation developed by Der Kiureghian for withe noise excitation, an equivalent expected frequency is introduced for thunderstorm excitation. Finally, the maximum dynamic response to thunderstorms is estimated as the sum of the maximum mean and fluctuating parts and a numerical validation of the results against real recorded thunderstorms is provided, highlighting the reliability of adding up the mean and fluctuating contributions and the advantages and limits of neglecting the transient dynamics

Mutations in Mycobacterium tuberculosis Isolates with Discordant Results for Drug-Susceptibility Testing in Peru

Evaluation of resistance to antituberculosis drugs is routinely performed with genotypic or phenotypic methods; however, discordance can be seen between these different methodologies. Our objective was to identify mutations that could explain discordant results in the evaluation of susceptibility to rifampicin and isoniazid between molecular and phenotypic methods, using whole genome sequencing (WGS). Peruvian strains showing sensitive results in the GenoType MTBDRplus v2.0 test and resistant results in the proportions in the agar-plaque test for isoniazid or rifampin were selected. Discordance was confirmed by repeating both tests, and WGS was performed, using the Next Generation Sequencing methodology. Obtained sequences were aligned "through reference" (genomic mapping) using the program BWA with the algorithm "mem", using as a reference the genome of the M. tuberculosis H37Rv strain. Discordance was confirmed in 14 strains for rifampicin and 21 for isoniazid, with 1 strain in common for both antibiotics, for a total of 34 unique strains. The most frequent mutation in the rpoB gene in the discordant strains for rifampicin was V170F. The most frequent mutations in the discordant strains for isoniazid were katG R463L, kasA G269S, and Rv1592c I322V. Several other mutations are reported. This is the first study in Latin America addressing mutations present in strains with discordant results between genotypic and phenotypic methods to rifampicin and isoniazid. These mutations could be considered as future potential targets for genotypic tests for evaluation of susceptibility to these drugs.Revisión por pare

Honey, I shrunk the organization: in search of organizational genetics

\u201cWhat makes an organization unique?\u201d has been a central question for research and practice on competitive advantage. Being unique is associated to the ability to attract and convince customers, investors, and employees, thereby easing the process of collection of resources needed to operate, and augmenting the value of products, services, and opportunities provided. At the same time, being unique makes it harder for competitors to imitate the organization, and extends the advantage in time. Uniqueness does not come without a less positive side, because it can constrain the organization, which has to maintain continuity with the perceptions of all the different audiences, thereby making radical change harder. The origins of uniqueness are a central theme for other fields of research, unrelated to management. In psychology, uniqueness lays in the underlying, and unobservable structure of personality. In chemistry and physics, uniqueness of elements is attributed to the very specific structure of their inner components. In evolutionary biology, the common thread is to attribute uniqueness to some characteristic that endows an organism, i.e. genes. All these metaphors have been explored in management research. However, one of the most fruitful appears to be the analogy with evolutionary biology, which constitutes the leading theme of the overall Genor research project. This paper provides a literature review of organizational theory from this point of observation. Research in organization theory is characterized by the problem of defining the adequate level of analysis. Different perspectives and theories adopt different levels of analysis, and multi-level theory and research is rather uncommon. Differently from other areas of scientific inquiry (like for example physics, chemistry, and biology) organization theory has not addressed explicitly the problem of searching for the smallest common unit of analysis. The widespread use of metaphors developed in other scientific domains enriched organization theory with perspectives that explicitly or implicitly affirm the existence of units of analysis beyond the individual. Among them, perspectives related to the biological metaphor play a powerful role. These perspectives adopt evolutionary mechanisms, consider the interplay between time, inertia, and change, and provide analogies to the concepts of genes (or as more broadly defined by Richard Dawkins, memes). The goal of this paper is to look at existing theories that adopt an analogy to genetics as part of a new field of inquiry that we propose to denominate Organizational genetics. After reviewing how existing theories could be related to this field, we develop an initial theoretical framework that will need to be further developed

Fish fauna from the Ajó river in Campos del Tuyú National Park, province of Buenos Aires, Argentina

We provide the first list of the ichthyofauna from the Ajó river, a water course situated at the southward border of the Samborombón bay (36°20'12 ’ S, 56°54'17 W), a RAMSAR site in Argentina. These results were obtained bi-monthly along two years. Forty-five species belonging to 26 families and 11 orders were identified. This fish fauna is composed by freshwater, euryhaline and marine species. Richest groups were Perciformes and Characiformes, with 10 species each. A single species, Micropogonias furnieri (whitemouth croaker), represented more than 70 % of the captured specimens, being juvenile individuals only. Remaining species were also represented by juvenile specimens, confirming the importance of this environment as nursery area, particularly for the whitemouth croaker

Effectiveness of the spot-on combination of moxidectin and imidacloprid (Advocate®) in the treatment of ocular thelaziosis by Thelazia callipaeda in naturally infected cats

Background: The present study evaluated the therapeutic effectiveness of moxidectin 1.0% (w/v) and imidacloprid 10% (w/v) (Advocate® spot-on solution for cats, Bayer Animal Health) against natural infections with the eyeworm Thelazia callipaeda in cats. This study was conducted as a GCP, negative-controlled, blinded and randomised field study in privately owned cats living in an area in southern Italy where T. callipaeda is enzootic. Methods: The study was carried out in 30 cats (19 females and 11 males, aged from 8 months to 5 years, weighing 1.2-5.2 kg) of different breeds, naturally infected by T. callipaeda. At study inclusion (Day 0), animals were physically examined and the infection level was assessed by examination of both eyes for clinical score and live adult T. callipaeda count. Each cat was weighed and randomly assigned to one of the treatment groups (G1: Advocate, G2: untreated control). Clinical assessments and T. callipaeda adult counts were performed on Day 14. At the study completion visit on Day 28, clinical assessments and counts of T. callipaeda adults and larvae were performed. All cats were daily observed by their owners and general health conditions were recorded during the entire period of the study. Results: The primary effectiveness variable was the percentage of animals in G1 group (Advocate) showing a complete elimination (parasitological cure) of adult eye worms at Day 14 and Day 28. The effectiveness of the treatment in the G1 group was 93.3 and 100% at Day 14 and Day 28, respectively, when compared to group G2. Total worm count reduction from both eyes for Advocate was 96.3% on Day 14 and 100% on Day 28. Clinical data were confirmed by the examination of conjunctival pouch flushing. An overall reduction in the number of cats with lacrimation and conjunctivitis was observed following treatment despite the fact that in a few cats treated with Advocate clinical signs persisted due to the chronic nature of the disease. Conclusions: Based on the results of the present trial, a single dose of Advocate was found to be safe and highly effective in the treatment of natural T. callipaeda infection in cats