17 research outputs found

    Composition of lower urinary tract stones in canines in Mexico City

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    11th International symposium on urolithiasis, Nice, France, 2–5 September 2008 Urological Research (2008) 36:157–232. doi:10.1007/s00240-008-0145-5. http://www.springerlink.com/ content/x263655772684210/fulltext.pdf.Effective long-term management of urolithiasis depends on identification and manipulation of factors contributing to initial stone formation; identification of these factors depends on accurate identification of the mineral composition of the urolith involved. The purpose of this study was to determine the chemical composition of uroliths obtained from the low urinary tract of dogs in Mexico City. One hundred and five cases of urolithiasis were studied in which stones were surgically obtained from the low urinary tracts of dogs treated in different hospitals. The chemical composition of the uroliths was quantita- tively and qualitatively determined by stereoscopic microscopy, IR-spectroscopy, scanning electron micros- copy and X-ray microanalysis. Age of animals ranged from 4 months to 14 years, with a median of 5 years. Compo- sition and distribution of the uroliths were struvite 38.1%,calcium oxalate 26.7%, silica 13.3%, urate 7.6%, mixed 11.4%, compounds 1.9%, and cystine 1%. Most uroliths were found in pure breed dogs (75.2%); 23 different breeds were identified, and more than half of the submissions were from breeds of small size. In our study, the frequency of struvite, calcium oxalate, cystine, urates, mixed and com- pounds stones are in agreement with papers that report on dog populations in America and Europe, but a higher fre- quency of silica uroliths was observed in Mexico City dogs.This work has been partially supported by a project of Waltham Foundation in Mexico

    Level of agreement between objectively determined body composition and perceived body image in 6- To 8-year-old South African children- To Body Composition-Isotope Technique study

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    To assess the level of agreement between body size self-perception and actual body size determined by body mass index (BMI) z-score and body fatness measured by the deuterium dilution method (DDM) in South African children aged 6-8 years. A cross-sectional sample of 202 children (83 boys and 119 girls) aged 6-8 years from the Body Composition-Isotope Technique study (BC-IT) was taken. Subjective measures of body image (silhouettes) were compared with the objective measures of BMI z-score and body fatness measured by the DDM. The World Health Organization BMI z-scores were used to classify the children as underweight, normal, overweight, or obese. DDM-measured fatness was classified based on the McCarthy centile curves set at 2nd, 85th and 95th in conjunction with fatness cut-off points of 25% in boys and 30% in girls. Data were analyzed using SPSS v26. Of 202 children, 32.2%, 55.1%, 8.8%, and 2.4% perceived their body size as underweight, normal, overweight, and obese, respectively. Based on BMI z-score, 18.8%, 72.8%, 6.9%, and 1.5% were classified as underweight, normal, overweight, and obese, respectively. Body fatness measurement showed that 2.5%, 48.0%, 21.8%, and 29.7% were underweight, normal weight, overweight, and obese, respectively

    SSVEP detection assessment by combining visual stimuli paradigms and no-training detection methods

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    IntroductionBrain-Computer Interfaces (BCI) based on Steady-State Visually Evoked Potentials (SSVEP) have great potential for use in communication applications because of their relatively simple assembly and in some cases the possibility of bypassing the time-consuming training stage. However, among multiple factors, the efficient performance of this technology is highly dependent on the stimulation paradigm applied in combination with the SSVEP detection algorithm employed. This paper proposes the performance assessment of the classification of target events with respect to non-target events by applying four types of visual paradigms, rectangular modulated On-Off (OOR), sinusoidal modulated On-Off (OOS), rectangular modulated Checkerboard (CBR), and sinusoidal modulated Checkerboard (CBS), with three types of SSVEP detection methods, Canonical Correlation Analysis (CCA), Filter-Bank CCA (FBCCA), and Minimum Energy Combination (MEC).MethodsWe set up an experimental protocol in which the four types of visual stimuli were presented randomly to twenty-seven participants and after acquiring their electroencephalographic responses to five stimulation frequencies (8.57, 10.909, 15, 20, and 24 Hz), the three detection methods were applied to the collected data.ResultsThe results are conclusive, obtaining the best performance with the combination of either OOR or OOS visual stimulus and the FBCCA as a detection method, however, this finding contrasts with the opinion of almost half of the participants in terms of visual comfort, where the 51.9% of the subjects felt more comfortable and focused with CBR or CBS stimulation.DiscussionFinally, the EEG recordings correspond to the SSVEP response of 27 subjects to four visual paradigms when selecting five items on a screen, which is useful in BCI navigation applications. The dataset is available to anyone interested in studying and evaluating signal processing and machine-learning algorithms for SSVEP-BCI systems

    EEG-Based Classification of Spoken Words Using Machine Learning Approaches

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    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects the nerve cells in the brain and spinal cord. This condition leads to the loss of motor skills and, in many cases, the inability to speak. Decoding spoken words from electroencephalography (EEG) signals emerges as an essential tool to enhance the quality of life for these patients. This study compares two classification techniques: (1) the extraction of spectral power features across various frequency bands combined with support vector machines (PSD + SVM) and (2) EEGNet, a convolutional neural network specifically designed for EEG-based brain–computer interfaces. An EEG dataset was acquired from 32 electrodes in 28 healthy participants pronouncing five words in Spanish. Average accuracy rates of 91.04 ± 5.82% for Attention vs. Pronunciation, 73.91 ± 10.04% for Short words vs. Long words, 81.23 ± 10.47% for Word vs. Word, and 54.87 ± 14.51% in the multiclass scenario (All words) were achieved. EEGNet outperformed the PSD + SVM method in three of the four classification scenarios. These findings demonstrate the potential of EEGNet for decoding words from EEG signals, laying the groundwork for future research in ALS patients using non-invasive methods

    Endothelial Cell Loss in Corneal Grafts From Donors Who Sustained Gunshot Wound to the Head or Airbag Deployment in a Motor Vehicle Accident.

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    PURPOSE: To compare the endothelial cell density (ECD) and quality of corneal grafts from young donors who sustained airbag deployment in motor vehicle accidents (MVA) or gunshot wounds (GSW) to the head with grafts from donors of similar age who died of other causes. METHODS: This is a retrospective comparative series of 65 corneal grafts from 33 young donors (mean age, 29.60 ± 8.95 yrs), with the cause of death either MVA with airbag deployment (n = 7), GSW to the head (n = 14), or other nontrauma-related cause (n = 12). Donor characteristics, graft quality on slit-lamp examination, ECD, and areas of endothelial cell loss on specular microscopy were compared between the groups. RESULTS: Donor age, graft quality on slit-lamp examination, and death-to-preservation time were similar between the groups. Statistically significant differences in focal areas of endothelial cell loss were found in the MVA- and GSW-derived grafts compared with the nontrauma-related grafts (85.7% vs. 0%, P value 0.0002 and 92.5% vs. 0%, P value <0.0001, respectively). Mean ECD was significantly lower in the 14 MVA-derived grafts (ECD, 3117 ± 218 cells/mm) and in the 27 GSW-derived grafts (ECD, 3234 ± 381 cells/mm) than in the 24 nontrauma-related grafts (ECD, 3511 ± 312 cells/mm, P values 0.0002 and 0.0068, respectively). No primary graft failures were reported for any of the grafts by masked observers. CONCLUSIONS: MVA- and GSW-derived grafts have lower ECD counts and more areas of endothelial cell loss compared with nontrauma-related grafts. Further studies are needed to evaluate long-term outcomes of such donor grafts

    Respuesta del Tumor Venéreo Transmisible Canino a Presentaciones de Vincristina de Patente y Genérica

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    El objetivo del presente estudio fue comparar la respuesta de perros infectados naturalmente con el Tumor VenĂ©reo Transmisible (TVTc) al tratamiento con vincristina comercial de patente y genĂ©rica. Se trabajĂł con 12 perros infectados naturalmente y con diagnĂłstico por citologĂ­a y PCR. Los perros fueron asignados aleatoriamente a un tratamiento semanal con 0.025 mg/kg de vincristina de patente comercial o de tipo genĂ©rico, hasta que dos citologĂ­as consecutivas resultaran negativas. Se hicieron pruebas de citologĂ­a y hemograma antes de cada aplicaciĂłn para determinar reacciones adversas al tratamiento. En ambos grupos se aplicĂł un mĂĄximo de cinco dosis para dar por concluido el tratamiento. El mĂ­nimo de aplicaciones en el grupo Patente fue de cuatro, mientras que en el grupo GenĂ©rico fue de tres aplicaciones, aunque sin diferencia significativa en el nĂșmero de dosis aplicadas ni en el tiempo de remisiĂłn. Los perros de ambos grupos presentaron algĂșn tipo de reacciĂłn adversa ligera sin mostrar diferencia estadĂ­stica entre grupos. En ningĂșn caso hubo que descontinuar el tratamiento por este tipo de reacciones. Se concluye que las presentaciones de patente y genĂ©rica son igualmente eficaces para el tratamiento de TVTc
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