Microstructural characterization of alumina-zirconia layered ceramics using positron annihilation spectroscopy

Positron annihilation spectroscopy (PAS), indentation, nanoindentation experiments and scanning electron microscopy (SEM) observations were performed on Al₂O₃-ZrO₂ laminates samples to assess the effect of residual stresses on their mechanical and microstructural properties. Layered samples were implemented by slip-casting, constituted by two thin Al₂O₃ external layers and an intermediate thick one, consisting of a mixture of Al₂O₃ and monoclinic ZrO₂ in the range 0-30 vol.%. In these systems residual tensile stresses fields were generated inside the external layers during cooling from the sintering temperature, by the expansion of the adjacent ZrO₂-containing layer. SEM observations showed the microstructural effects due to the level of tension related to the zirconia content. A correlation between the PAS parameters and the microstructural changes caused by the presence of residual stresses was found. Nanoindentation measurements were used to trace the sign and magnitude of the residual stress gradient across the interface between the layers.This work was supported by Spanish Government under Contract MAT2006-01038. The authors gratefully acknowledge the financial support from the Comunidad de Madrid and the Ministry of Education and Science of Spain, through the ESTRUMAT-CM (MAT/77) programs.Publicad

IDÉLU

ITESO, A.C

Populations and assemblages living on the edge: dung beetles responses to forests-pasture ecotones

Edge effects alter insect biodiversity in several ways. However, we still have a limited understanding on simultaneous responses of ecological populations and assemblages to ecotones, especially in human modified landscapes. We analyze edge effects on dung beetle populations and assemblages between livestock pastures and native temperate forests (Juniperus and pine-oak forests (POFs)) to describe how species abundances and assemblage parameters respond to edge effects through gradients in forest-pasture ecotones. In Juniperus forest 13 species avoided the ecotones: six species showed greater abundance in forest interior and seven in pasturelands, while the other two species had a neutral response to the edge. In a different way, in POF we found five species avoiding the edge (four with greater abundance in pastures and only one in forest), two species had a neutral response, and two showed a unimodal pattern of abundance near to the edge. At the assemblage level edge effects are masked, as species richness, diversity, functional richness, functional evenness, and compositional incidence dissimilarity did not vary along forest-pasture ecotones. However, total abundance and functional divergence showed higher values in pastures in one of the two sampling localities. Also, assemblage similarity based on species’ abundance showed a peak near to the edge in POF. We propose that conservation efforts in human-managed landscapes should focus on mitigating current and delayed edge effects. Ecotone management will be crucial in livestock dominated landscapes to conserve regional biodiversity and the environmental services carried out by dung beetles

Bayesian Classifiers in Intrusion Detection Systems

To be able to identify computer attacks, detection systems that are based on faults are not dependent on data base upgrades unlike the ones based on misuse. The first type of systems mentioned generate a knowledge pattern from which the usual and unusual traffic is distinguished. Within computer networks, different classification traffic techniques have been implemented in intruder detection systems based on abnormalities. These try to improve the measurement that assess the performance quality of classifiers and reduce computational cost. In this research work, a comparative analysis of the obtained results is carried out after implementing different selection techniques such as Info.Gain, Gain ratio and Relief as well as Bayesian (Naïve Bayes and Bayesians Networks). Hence, 97.6% of right answers were got with 13 features. Likewise, through the implementation of both load balanced methods and attributes normalization and choice, it was also possible to diminish the number of features used in the ID classification process. Also, a reduced computational expense was achieved

Sitotroga cerealella-resistant mexican maize races (Zea mays L.), new sources of resistance for commercial maize breeding

Sitotroga cerealella (Oliv.) (Lepidoptera: Gelechiidae) is one of the most important post-harvest pests of maize Zea mays L. Some Mexican maize races (Z. mays) could be a novel source of resistance against S. cerealella to improve commercial maize varieties, lines and hybrids. We studied the resistance of Mexican maize races, recollected at Chihuahua State to S. cerealella. We focused on antibiosis and tolerance of maize to S. cerealella. Cristalino-079 maize race shows low level of consumption in grams and percentage, increased larvae mortality before to entering the seed. In addition, Cristalino-079 reduced first adult’s generation and show the largest biological cycle. Due to the small number of emerged adults, there was very little grain weight loss in resistant maize race. The compound that causes high mortality of larvae before to entering the grain is in the pericarp of resistant maize races. The compound that causes longest development time is in the endosperm and embryo. Cristalino-079 show the better level of resistance to S. cerealella infestation in almost all traits studied and this can be used as source of resistance for maize breeding

Global Precipitation Measurement: Methods, Datasets and Applications

This paper reviews the many aspects of precipitation measurement that are relevant to providing an accurate global assessment of this important environmental parameter. Methods discussed include ground data, satellite estimates and numerical models. First, the methods for measuring, estimating, and modeling precipitation are discussed. Then, the most relevant datasets gathering precipitation information from those three sources are presented. The third part of the paper illustrates a number of the many applications of those measurements and databases. The aim of the paper is to organize the many links and feedbacks between precipitation measurement, estimation and modeling, indicating the uncertainties and limitations of each technique in order to identify areas requiring further attention, and to show the limits within which datasets can be used

Postoperative analgesia in total knee arthroplasty

Total knee arthroplasty is commonly performed in patients with end-stage osteoarthritis or rheumatic knee arthritis to relieve joint pain, increase mobility, and improve quality of life. Despite advances in surgical techniques, postoperative pain management in these types of patients is still deficient. An exhaustive review was performed with the available literature, using the PubMed, ScienceDirect, Scopus and Cochrane databases from 2004 to 2021. The search criteria were formulated to identify reports related to total knee replacement and pain management. Pain after total knee arthroplasty has been shown to involve both peripheral and central pain pathways, which is why various postoperative pain management strategies are currently applied, including patient-controlled analgesia, continuous peripheral nerve blocks, or single injection or local infiltration analgesia. Today local techniques such as periarticular injections are becoming more common in total knee replacement due to their effectiveness in controlling pain without causing muscle weakness. The development of minimally invasive techniques associated with multimodal and preventive analgesia improves recovery rates and early rehabilitation in patients undergoing total knee arthroplasty, reducing in-hospital costs, risk of complications, and improving patient satisfaction with chronic osteoarthropathy.

Factors impacting time to total shoulder arthroplasty among patients with primary glenohumeral osteoarthritis and rotator cuff arthropathy managed conservatively with corticosteroid injections

Background The purpose of this study was to identify predictors of the time from initial presentation to total shoulder arthroplasty (TSA) in patients with primary glenohumeral osteoarthritis (OA) and rotator cuff (RTC) arthropathy who were conservatively managed with corticosteroid injections. Methods We conducted a retrospective cohort study of patients who underwent TSA from 2010 to 2021. Kaplan-Meier survival analysis was used to estimate median time to TSA for primary OA and RTC arthropathy patients. The Cox proportional hazards model was used to identify significant predictors of time to TSA and to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Statistical significance was set at P<0.05. Results The cohort included 160 patients with primary OA and 92 with RTC arthropathy. In the primary OA group, median time to TSA was 15 months. Significant predictors of shorter time to TSA were older age at presentation (HR, 1.02; 95% CI, 1.00–1.04; P=0.03) and presence of moderate or severe acromioclavicular joint arthritis (HR, 1.45; 95% CI, 1.05–2.01; P=0.03). In the RTC arthropathy group, median time to TSA was 14 months, and increased number of corticosteroid injections was associated with longer time to TSA (HR, 0.87; 95% CI, 0.80–0.95; P=0.003). Conclusions There are distinct prognostic factors for progression to TSA between primary OA patients and RTC arthropathy patients managed with corticosteroid injections. Multiple corticosteroid injections are associated with delayed time to TSA in RTC arthropathy patients. Level of evidence III

Dog filariosis in the Lazio region (Central Italy): first report on the presence of Dirofilaria repens

BACKGROUND: Epidemiological investigations were carried out in the Lazio Region to assess the status of canine filariosis and to evaluate the actual risk for veterinary and medical public health. METHODS: Since August 2001 to June 2003, a total of 972 canine blood samples, collected in public kennels and from private owners animals of the 5 Provinces of the Region, were tested. The presence of filarial parasites was evaluated by microscopy and bio-molecular techniques; the species identification was performed by means of the same diagnostic tools. RESULTS: A total of 17/972 (1.75%; 95%CI 1.06%–2.85%) blood samples were parasitized by D. repens,13 out them drawn by dogs resident in the Province of Roma, and 4 in the other provinces. Multivariate analysis was performed in order to evaluate the association between filariosis and risk factors. The origin from coastal territories seems to be a significant risk factor to acquire the infection. CONCLUSION: This is the first report of canine filariosis in the Lazio Region, where D. repens was before reported only in foxes. The risk of human zoonotic infection is stressed, and the absence of other filarial species is discusse