In this article, we develop a new model based on the Birnbaum-Saunders distribution that results to be both useful and practical for environmental sciences. The density, distribution and hazard ...functions, moments and properties of this new model are presented. A graphical analysis of the density is also provided. Furthermore, we estimate parameters, propose asymptotic inference and discuss influence diagnostics by using likelihood methods for the new distribution. An illustrative example with real data related to water quality indicates the adequacy on the new distribution.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Sarcoptic mange is a disease caused by an infectious parasite in the vicuñas (Vicugna vicugna) from South America. Although molecular studies have provided much information about the epidemiology of ...this disease, this information is still unknown in vicuñas. This study determined the prevalence and molecular characterization of Sarcoptes scabiei from vicuñas from Southern Peruvian Andes. During the 2018 shearing season, 181 vicuñas were clinically evaluated for lesions compatible with mange. Sarcoptes scabiei was detected in 35 (19.3%) vicuñas, and 50 mites from 25 vicuñas were selected for molecular analyses of the mitochondrial (cox1) and nuclear (ITS2) genetic markers. Molecular analyses of the cox1 and ITS2 sequences showed an identity of 94–99% and 99.8–100% with previous S. scabiei sequences registered in the GenBank, respectively. Sequence polymorphisms were more evident in the ITS2 than in the cox1, but only the cox1 had an association with the host. Phylogenetic analysis of S. scabiei cox1 sequences from vicuñas showed a cluster with S. scabiei cox1 sequences from canids, suggesting that the origin of S. scabiei from vicuña is associated with canid mites. This research is the first molecular analysis of S. scabiei from vicuñas. Future molecular studies will be necessary to determine the species variety, geographic segregation and host–parasite adaptation for this vicuña's mite.
The traditional model of systematic amortization over its useful life was replaced by the annual application of an impairment test, with the intention of correcting the problems of the lack of ...relevance and difficulty in estimating said useful life of the previous regulatory framework. The aim of this study is to investigate whether the application of the impairment test between 2005 and 2015 in the main European banks has overcome these problems or whether, on the contrary, its application by managers has been discretionary, opportunistic and arbitrary, presenting, as a result, artificially inflated earnings. Our results obtained show that systematic amortisation has been replaced by opportunistic impairment, which does not reflect the economic conditions underlying the financial activity of the main European banks, which gives rise to less relevant financial information and possible harmful pro-cyclical effects.
Hydatigera taeniaeformis
is a cestode that uses felines and rodents as definitive and intermediate hosts, respectively. Its larval stage, or metacestode, infects a wide variety of rodent species and ...develops in the liver parenchyma into a cyst. The aim of this study was to evaluate the occurrence of
H. taeniaeformis
metacestode in various species of wild rodents from Peru. For this, the livers of 356 rodents were macroscopically examined for any parasitic form compatible with metacestodes. Metacestodes were identified by measuring characteristic morphological parameters, and the diagnosis was confirmed by molecular analysis of a fragment of the cytochrome
c
oxidase subunit 1 gene (
cox1
). Five rodents: two small-eared pygmy rice rats (
Oligoryzomys microtis
), two white-naped squirrels (
Simosciurus nebouxii
), and one pygmy rice rat (
Oligoryzomys
sp.) were infected with
H. taeniaeformis
metacestodes. The
cox1
sequences from our metacestodes showed up to 100% identity with previous
H. taeniaeformis
sequences from the GenBank. These results demonstrated the occurrence of
H. taeniaeformis
in new intermediate hosts, as well as the first molecular contribution for
H. taeniaeformis
from Peru.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Different approaches and tools have been adopted for the analysis and characterization of regional seismicity based on spatio–temporal series of event occurrences. Two main aspects of interest in ...this context concern scaling properties and dimensional interaction. This paper is focused on the statistical use of information-theoretic concepts and measures in the analysis of structural complexity of seismic distributional patterns. First, contextual significance is motivated, and preliminary elements related to informational entropy, complexity and multifractal analysis are introduced. Next, several technical and methodological extensions are proposed. Specifically, limiting behaviour of some complexity measures in connection with generalized dimensions is established, justifying a concept of multifractal complexity. Under scaling behaviour, a mutual-information-related dependence coefficient for assessing spatio–temporal interaction is defined in terms of generalized dimensions. Also, an alternative form of generalized dimensions based on Tsallis entropy convergence rates is formulated. Further, possible incorporation of effects, such as earthquake magnitude, is achieved in terms of weighted box-counting distributions. Different aspects in relation to the above elements are analyzed and illustrated using two well-known series of seismic event data of an underlying different nature, occurred in the areas of Agrón (Granada, Spain) and El Hierro (Canary Islands, Spain). Finally, various related directions for continuing research are indicated.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Brain–computer interfaces are systems capable of mapping brain activity to specific commands, which enables to remotely automate different types of processes in hardware devices or software ...applications. However, the development of brain–computer interfaces has been limited by several factors that affect their performance, such as the characterization of events in brain signals and the excessive processing load generated by the high volume of data. In this paper, we propose a method based on computational intelligence techniques to handle these problems, turning them into a single optimization problem. An artificial neural network is used as a classifier for event detection, along with an evolutionary algorithm to find the optimal subset of electrodes and data points that better represents the target event. The obtained results indicate our approach is a competitive and viable alternative for feature extraction in electroencephalograms, leading to high accuracy values and allowing the reduction of a significant amount of data.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Vaccination against porcine circovirus type 2 (PCV2) is commonly performed in piglets worldwide, and increasingly also in sows. We conducted a literature search and review to assess the potential ...interference of maternally derived antibodies (MDA) in piglets with vaccination against PCV2. The effectiveness of vaccination was compared to no vaccination in the presence of high levels of MDA (≥8 log2 IPMA titer), as reported in field studies. In total, 13 papers fulfilled the predefined inclusion criteria, allowing up to 24 comparisons per parameter. In the presence of high levels of MDA, vaccinated pigs had, on average, a 20 g/d higher mean daily weight gain and a 34% lower mortality compared to non-vaccinates. The maximum percentage of viremic pigs was reduced by 63% and the maximum viral load in serum was 0.72 log10 PCV2 DNA copies lower. Vaccination at 3 weeks of age was associated with the highest improvements in production parameters and reductions in viremia. Our findings suggest that the vaccination of piglets is effective with respect to production parameters and viremia even in the presence of high MDA, with an age of 3 weeks at vaccination being most beneficial.
Objective To analyze the usefulness of dilatation in the treatment of ureteropelvic junction obstruction (UPJ) in children <18 months of age, including newborns and infants. Methods Patients (n = 50; ...<18 months of age) were diagnosed using abdominal ultrasound, cystogram, and diuretic renography. Treatment was with endourologic retrograde balloon dilatation under fluoroscopic guidance. The balloons were, in all cases, semicompliant with a profile of 5 mm, 6 mm, or 7 mm. Follow-up was for 42.9 ± 23.2 months (mean ± SD). Double-J stents were inserted postdilatation, the caliber and length depending on the patient's body weight. Results Intervention duration was 22 ± 19 minutes. Dilatation was not possible in 5 patients, and pyeloplasty was the alternative treatment. Hospital stay was 24 hours in 44 patients. Analgesic needs were met exclusively by nonsteroidal anti-inflammatory drugs. The double-J stent was withdrawn using cystoscopy and the UPJ was calibrated.Residual stenosis was found in 7 patients. A second dilatation was required in 3 patients 6-18 months after surgery because of the lack of improvement of hydronephrosis. During follow-up, resolution of the hydronephrosis was observed in 45 cases (anterior-posterior diameter of the renal pelvis 7 ± 5 mm). The diuretic renography improved in 45 infants; the shape of the curve being normal in 44 cases and semi-obstructive in 1. Conclusion We believe that high-pressure balloon dilatation could be a valid and safe option in the minimally invasive treatment of UPJ obstruction in infants. The outcome is acceptable with a low complication rate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Space deformation modelling and estimation techniques based on Multidimensional Scaling (MDS) methods play an important role in nonparametric approaches to the covariance structure analysis of the ...spatiotemporal processes underlying environmental studies. Since any related procedure depends on the planar MDS representation, the stability of the estimated dispersion, together with the determination of the most influential stations in the estimation of the dispersion space, are important issues that must be analysed before performing the final mapping. In this paper, stability analysis, both in terms of the MDS model and of the variogram function, as well as concerning the derivation of kriging interpolation estimates, is addressed using a special analytical jackknife procedure. Furthermore, the influence of each station in the solution given is assessed, thus providing relevant information regarding not only the MDS procedure but also the interpolation process and the variogram estimation of the spatial dispersion.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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