418 research outputs found

    Invasive mammals in the National Parks System of Argentina

    Get PDF
    Fil: Merino, Mariano Lisandro. DivisiĂłn ZoologĂ­a Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Carpinetti, Bruno N.. AdministraciĂłn de Parques Nacionales. Ciudad AutĂłnoma de Buenos Aires; ArgentinaFil: Abba, AgustĂ­n Manuel. DivisiĂłn ZoologĂ­a Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

    Habitat use by armadillos in agroecosystems of central Argentina: does plot identity matter?

    Get PDF
    In agroecosystems, the use of cultivated plots by mammals depends on habitat structure as well as on the degree of species specialization. In the Pampas of Argentina, during the last 2-3 decades, there has been a continuing expansion of cropland. The aim of this study was to analyze how the identity and characteristics of agricultural plots may have affected the activity of 2 species of armadillos (Chaetophractus villosus and Dasypus hybridus) in a rural landscape. We carried out 4 sampling sessions between December 2011 and June 2013, surveying 175 plots during spring-summer and 194 during fall at 25 different sites in the Pampas of Buenos Aires province, Argentina. In each plot, we surveyed for signs (burrows and holes) along a 600Ă—6 m transect in order to assess armadillo activity and measured 4 habitat structural variables. As expected, there were structural differences between types of agricultural plots. Across all plots, a total of 6,654 armadillo signs were found (C. villosus = 5,009, D. hybridus = 1,645). Generalized linear mixed models revealed that during both seasons, the type of plot explained much of the variation in armadillo activity, except during spring-summer for D. hybridus. C. villosus had higher use of plots with a longer history of non-tillage (e.g., soybean), while there was more evidence of D. hybridus activity in plots with less human intervention (e.g., grasslands), especially during fall. Overall, D. hybridus and C. villosus were more sensitive to the particular structural features of plots rather than to the kind of land use practiced (crop field or rangeland). These results have important implications for future management decisions in the Pampas region because during the last decades, farming of soybeans has expanded at the expense of grasslands, and this change appears to have differentially affected these 2 species of armadillos.Centro de Estudios ParasitolĂłgicos y de VectoresFacultad de Ciencias Naturales y Muse

    Orbital Myositis with Sudden Visual Loss: A Case Study in Niamey, Niger

    Get PDF
    This paper focuses on presenting a case study of three cases of orbital myositis in one male and two female adult patients. All patients presented sudden loss of vision and proptosis at the initial stage. Ophthalmological examination outlined optic nerve atrophie. The diagnosis of all cases was confirmed with a CT scan which showed specific muscle inflammation. The treatment was successfully carried out using bolus doses of corticosteroids relayed with oral prednisolone for over 6 weeks. Six (6) months follow-up, however, did not show any relapse in all the cases

    Understanding phishing awareness among students in tertiary institutions and setting-up defensive mechanisms against the attackers

    Get PDF
    The average loss by companies to phishing in 2021 is $14.8 million, more than triple what it was in 2015. That translates to hundreds of billions of dollars in total losses from phishing attacks on global businesses, and the vulnerability of these attacks is every day increasing, particularly among the younger generation less than 40 years of age. This paper begins with a background exposition on phishing trends and highlights previous findings concerning users' susceptibility to phishing attacks. It however explores the term Phishing itself, its kinds, types and some basic measures necessary for defense against phishing activities. The research was employed with a major focus on the email aspect of phishing. Alongside the website aspect of phishing, the certificate of a website was also considered. The purpose of this study was to identify the level of student awareness related to specific phishing tactics. Findings revealed that while students are unlikely to provide personal information in response to an email/SMS request, they can be easily tricked by numerous other tactics. This paper reports the findings of the study in addition to listing suggested points to employ for creating phishing awareness

    Atteintes Oculaires Au Cours Du Syndrome De Wolfram À Propos De Deux Cas Et Revue De La Littérature

    Get PDF
    Introduction: Wolfram syndrome is an autosomal recessive neurodegenerative disorder. Diabetes mellitus and juvenile bilateral optic atrophy are its major signs. It is recognized that this association, which started in childhood or during adolescence, is sufficient to diagnose Wolfram syndrome. Optic atrophy occurs in 98% to 100% of cases with an average age of onset of 11 years. We reported a study of two confirmed cases referred by the internal medicine department. Observations: Case 1: A 23- year-old woman, deaf and dumb by birth, went through a diabetic ketosis test. Ophthalmologic examination showed reduced visual acuity in the fingers at 5 meters P2 in both eyes. Also, the fundus of the eye showed bilateral atrophic papillary palpation with no signs of retinopathy. She had deafness of deep perception and hypogonadotropic hypogonadism. Deafness, diabetes, optic atrophy, and hypogonadism led to the diagnosis. Case 2: A 21-year-old man born from a first-degree consanguineous marriage serves as a supplement to the management of diabetes. The visual acuity was at counting fingers at 1m to the right eye and sees the hand move to 0.5 m to the left eye. On examination at the slit lamp, it had a bilateral dense cataract. After phacoexeresis, the base revealed bilateral optic atrophy. Ultrasound of the urinary tree showed hypotonia of the renal cavities and a neurogenic bladder. Also, audiometry showed mild sensory deafness. The diagnosis of Wolfram syndrome was made in front of the tetrad: diabetes, optic atrophy, deafness, and urinary signs. Discussion: Wolfram syndrome may be familial or sporadic. The gene however is located on the short arm of chromosome 4. Optic atrophy is secondary to the involvement of pre-genetic fibers, and it is characterized initially by temporal palpation of the papilla. The evolution towards diffuse whitish discoloration occurs in a few months or years with the gradual establishment of a blindness around the age of 17 to 30 years. Conclusion: Wolfram syndrome is a clinical entity characterized by clinical and genetic polymorphism. This diagnosis should be considered in the presence of any type I diabetes associated with optic atrophy in childre

    Typologie des eaux de surface du bassin du Sebou par multi-approche : corrélation entre indice biologique global des réseaux de contrôle et de surveillance (IBG-RCS) et l’approche physicochimique et microbiologique

    Get PDF
    L’étude consiste en l’utilisation de la démarche biologique, particulièrement les indices IBGN et IBG-RCS, pour montrer l’évolution de la qualité biologique des eaux de surface du bassin du Sebou dans la période 2009-2011. La caractérisation physicochimique/microbiologique de la qualité des eaux de surface et la caractérisation biologique moyennant l’indice biocénotique IBG-RCS de l’an 2011ont fait l’objet d’un traitement statistique. Les résultats obtenus montrent une certaine amélioration dans la qualité des eaux de surface du bassin d’étude. L’analyse statistique a montré la formation de deux groupes corrélés négativement, le premier composé de l’oxygène dissous et l’indice IBG-RCS alors que le deuxième est formé des paramètres révélateurs de pollution organique (DBO5, DCO, NH4+, Phosphate Total PT et coliformes fécaux : CF).Mots-clés : Bassin Hydraulique du Sebou, indice IBG-RCS, qualité - biologique, macro-invertébrés, qualité physicochimique.Sebou’s water surface multi-approaches typology: correlation between the global biological index of control and surveillance networks (IBG-RCS) and the physicochemical/microbiological approachThe study consists of using the biological approach, especially the IBGN and the IBG-RCS indexes, to show the evolution of the biological surface waters quality of the Sebou basin in the period of 2009-2011. The physicochemical/microbiological surface waters quality characterization and the biological characterization (IBG-RCS index) of the year 2011 were the subject of a statistical processing. The results showed some improvement in surface waters quality. The statistical analysis showed the formation of two negatively correlated groups, the first consisting of dissolved oxygen and the IBG-RCS index while the second consists of the parameters indicative of pollution (BOD5, COD, NH4+, PT and CF).Keywords : hydraulic basin of Sebou, IBG-RCS index, biological quality, macroinvertebrates, physicochimical quality

    Intracranial EEG fluctuates over months after implanting electrodes in human brain.

    Get PDF
    OBJECTIVE: Implanting subdural and penetrating electrodes in the brain causes acute trauma and inflammation that affect intracranial electroencephalographic (iEEG) recordings. This behavior and its potential impact on clinical decision-making and algorithms for implanted devices have not been assessed in detail. In this study we aim to characterize the temporal and spatial variability of continuous, prolonged human iEEG recordings. APPROACH: Intracranial electroencephalography from 15 patients with drug-refractory epilepsy, each implanted with 16 subdural electrodes and continuously monitored for an average of 18 months, was included in this study. Time and spectral domain features were computed each day for each channel for the duration of each patient\u27s recording. Metrics to capture post-implantation feature changes and inflexion points were computed on group and individual levels. A linear mixed model was used to characterize transient group-level changes in feature values post-implantation and independent linear models were used to describe individual variability. MAIN RESULTS: A significant decline in features important to seizure detection and prediction algorithms (mean line length, energy, and half-wave), as well as mean power in the Berger and high gamma bands, was observed in many patients over 100 d following implantation. In addition, spatial variability across electrodes declines post-implantation following a similar timeframe. All selected features decreased by 14-50% in the initial 75 d of recording on the group level, and at least one feature demonstrated this pattern in 13 of the 15 patients. Our findings indicate that iEEG signal features demonstrate increased variability following implantation, most notably in the weeks immediately post-implant. SIGNIFICANCE: These findings suggest that conclusions drawn from iEEG, both clinically and for research, should account for spatiotemporal signal variability and that properly assessing the iEEG in patients, depending upon the application, may require extended monitoring

    The artificial retina for track reconstruction at the LHC crossing rate

    Full text link
    We present the results of an R&D study for a specialized processor capable of precisely reconstructing events with hundreds of charged-particle tracks in pixel and silicon strip detectors at 40 MHz40\,\rm MHz, thus suitable for processing LHC events at the full crossing frequency. For this purpose we design and test a massively parallel pattern-recognition algorithm, inspired to the current understanding of the mechanisms adopted by the primary visual cortex of mammals in the early stages of visual-information processing. The detailed geometry and charged-particle's activity of a large tracking detector are simulated and used to assess the performance of the artificial retina algorithm. We find that high-quality tracking in large detectors is possible with sub-microsecond latencies when the algorithm is implemented in modern, high-speed, high-bandwidth FPGA devices.Comment: 3 pages, 3 figures, ICHEP14. arXiv admin note: text overlap with arXiv:1409.089

    Simulation and performance of an artificial retina for 40 MHz track reconstruction

    Get PDF
    We present the results of a detailed simulation of the artificial retina pattern-recognition algorithm, designed to reconstruct events with hundreds of charged-particle tracks in pixel and silicon detectors at LHCb with LHC crossing frequency of 40 MHz40\,\rm MHz. Performances of the artificial retina algorithm are assessed using the official Monte Carlo samples of the LHCb experiment. We found performances for the retina pattern-recognition algorithm comparable with the full LHCb reconstruction algorithm.Comment: Final draft of WIT proceedings modified according to JINST referee's comment
    • …
    corecore