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Real-time obstacle detection using range images: processing dynamically-sized sliding windows on a GPU
No full textAn efficient obstacle detection technique is required so that navigating robots can avoid obstacles and potential hazards. This task is usually simplified by relying on structural patterns. However, obstacle detection constitutes a challenging problem in unstructured unknown environments, where such patterns may not exist. Talukder et al. (2002, IEEE Intelligent Vehicles Symposium, pp. 610–618.) successfully derived a method to deal with such environments. Nevertheless, the method has a high computational cost and researchers that employ it usually rely on approximations to achieve real-time. We hypothesize that by using a graphics processing unit (GPU), the computing time of the method can be significantly reduced. Throughout the implementation process, we developed a general framework for processing dynamically-sized sliding windows on a GPU. The framework can be applied to other problems that require similar computation. Experiments were performed with a\ud
stereo camera and an RGB-D sensor, where the GPU implementations were compared to multi-core and single-core CPU implementations. The results show a significant gain in the computational performance, i.e. in a particular instance, a GPU implementation is almost 90 times faster than a single-core one
Narrow band imaging versus lugol chromoendoscopy to diagnose squamous cell carcinoma of the esophagus: a systematic review and meta-analysis
No full textAbstract
Background
In the early stage esophageal cancer, changes in the mucosa are subtle and pass unnoticed in endoscopic examinations using white light. To increase sensitivity, chromoscopy with Lugol’s solution has been used. Technological advancements have led to the emergence of virtual methods of endoscopic chromoscopy, including narrow band imaging (NBI). NBI enhances the relief of the mucosa and the underlying vascular pattern, providing greater convenience without the risks inherent to the use of vital dye. The purpose of this systematic review and meta-analysis was to evaluate the ability of NBI to diagnose squamous cell carcinoma of the esophagus and to compare it to chromoscopy with Lugol’s solution.
Methods
This systematic review included all studies comparing the diagnostic accuracy of NBI and Lugol chromoendoscopy performed to identify high-grade dysplasia and/or squamous cell carcinoma in the esophagus. In the meta-analysis, we calculated and demonstrated sensitivity, specificity, and positive and negative likelihood values in forest plots. We also determined summary receiver operating characteristic (sROC) curves and estimates of the areas under the curves for both per-patient and per-lesion analysis.
Results
The initial search identified 7079 articles. Of these, 18 studies were included in the systematic review and 12 were used in the meta-analysis, for a total of 1911 patients. In per-patient and per-lesion analysis, the sensitivity, specificity, and positive and negative likelihood values for Lugol chromoendoscopy were 92% and 98, 82 and 37%, 5.42 and 1.4, and 0.13 and 0.39, respectively, and for NBI were 88 and 94%, 88 and 65%, 8.32 and 2.62, and 0.16 and 0.12, respectively. There was a statistically significant difference in only specificity values, in which case NBI was superior to Lugol chromoendoscopy in both analyses. In the per-patient analysis, the area under the sROC curve for Lugol chromoendoscopy was 0.9559. In the case of NBI, this value was 0.9611; in the per-lesion analysis, this number was 0.9685 and 0.9587, respectively.
Conclusions
NBI was adequate in evaluating the esophagus in order to diagnose high-grade dysplasia and squamous cell carcinoma. In the differentiation of those disorders from other esophageal mucosa alterations, the NBI was shown to be superior than Lugol
Mycobacterium bovis in a European bison (Bison bonasus) raises concerns about tuberculosis in Brazilian captive wildlife populations: a case report
No full textAbstract\ud
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Background\ud
Tuberculosis caused by Mycobacterium bovis is an important worldwide zoonosis and has been reported to cause clinical disease in several animal species, including captive wildlife. This report describes a case of M. bovis infection in a European bison from a Brazilian zoo and compiles a number of literature reports that raise concern regarding tuberculosis among captive wildlife in Brazil.\ud
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Case presentation\ud
A 13 year-old captive-born male bison (Bison bonasus) from a Brazilian zoo began presenting weight loss, diarrhea and respiratory symptoms, which inevitably led to his death. At the animal’s necropsy, inspection of the thoracic and abdominal cavities revealed multiple enlarged lymph nodes, ranging from 4 to 10 cm, and pulmonary nodules containing caseous masses with firm white materials consistent with mineralization. Histopathology findings showed a significant amount of acid-alcohol resistant bacilli compatible with Mycobacterium spp. Specimens from lymph nodes and lungs were cultured on Petragnani and Stonebrink media, and specific PCR assays of the bacterial isolate identified it as M. bovis.\ud
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Conclusion\ud
The European bison reported herein died from a severe form of disseminated tuberculosis caused by M. bovis. A review of the available literature indicates possible widespread occurrence of clinical disease caused by M. bovis or M. tuberculosis affecting multiple animal species in Brazilian wildlife-related institutions. These likely underestimated numbers raise concern regarding the control of the disease in captive animal populations from Brazil.CKZ received a fellowship from the National Council for Scientific and\ud
Technological Development (CNPq), Brazilian Ministry of Science, Technology\ud
and Innovation. AMSG received a Young Talent fellowship from the Science\ud
without Borders Program, Brazilian Ministry of Education (A008_2013)
Report of the first clinical case of intestinal trichomoniasis caused by Tritrichomonas foetus in a cat with chronic diarrhoea in Brazil
No full textAbstract\ud
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Background\ud
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Tritrichomonas foetus is an emergent and important enteric pathogen of cats, which causes prolonged diarrhoea in cats.\ud
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Case presentation\ud
This study describes a T. foetus infection in a seven-month-old, entire male domestic shorthair kitten with a six-month history of persistent large intestinal diarrhoea, faecal incontinence, prostration, apathy and weight loss. Parasites were microscopically observed and confirmed by PCR and DNA sequencing. Molecular analyses were carried out comparing the sequence obtained in this study with T. foetus and T. suis. Retrieved from GenBank. After treatment with ronidazole, the cat showed resolution of clinical signs.\ud
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Conclusions\ud
This is the first clinical case of T. foetus infection in a chronic diarrheic cat in Brazil and South America, confirming the presence of this pathogen in this part of the world and highlighting the importance of this protozoa being considered in the differential diagnosis of cats presenting diarrhoea of the large intestine. Our case report enriches our knowledge on the geographical distribution of T. foetus in cats in Brazil and provides further understanding of the clinical significance of feline intestinal trichomoniasis in this country.We are very grateful to the Fundação de Amparo à Pesquisa do Estado de\ud
São Paulo, Brazil (Grants no. FAPESP 2014/01919–0) and the Coordenação de\ud
Aperfeiçoamento de Pessoal de Nível Superior (Grant no. CAPES/PROEX\ud
1841/2016) for funding this research
Cat-rodent Toxoplasma gondii Type II-variant circulation and limited genetic diversity on the Island of Fernando de Noronha, Brazil
No full textAbstract\ud
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Background\ud
In Brazil, studies on animals and humans in mainland areas have shown that most strains of Toxoplasma gondii are pathogenic to mice and exhibit great genetic variability.\ud
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Results\ud
In this study, using a set of 11 PCR-RFLP and 15 microsatellite markers, we isolated and genetically characterised T. gondii strains from one cat and three rats on Fernando de Noronha Island. The cat had antibodies to T. gondii, which were revealed using a modified agglutination test (MAT, cut-off 1:25) and the seroprevalence among the 46 rodents was 15.2%. Viable T. gondii was isolated from one cat (TgCatBrFN1), two brown rats (TgRatnoBrFN1 and TgRatnoBrFN2) and one black rat (TgRatraBrFN1). Unlike the strains from mainland Brazil, these isolates were not pathogenic to outbred mice. The genotypes of these strains were compared with strains previously isolated on the island and in mainland Brazil. The analysis based on microsatellite data showed a limited genetic diversity of T. gondii on Fernando de Noronha Island with the majority of strains clustered into the following three groups: type II, III, and Caribbean 1.\ud
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Conclusions\ud
There was little variation among strains within the same group, suggesting that the majority of strains circulating on Fernando de Noronha are derived from only a few strains that were recently introduced to the island, likely from imported cats. Except for the strain belonging to the Caribbean 1 group that originates from northeast Brazil, there was little evidence that strains from the other groups were introduced to Fernando de Noronha via mainland Brazil.This work was supported in part by scholarships from Conselho Nacional\ud
de Desenvolvimento Científico e Tecnológico (CNPq), Brazil (JCRS, RAD, LCA,\ud
RAM, SMG, DA and FF), and by a departmental grant from Coordenação\ud
de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil (grant\ud
number 2327/2015)
Improving practice guidelines for the treatment of denture-related erythematous stomatitis: a study protocol for a randomized controlled trial
No full textAbstract\ud
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Background\ud
Denture-related erythematous stomatitis (DES) is a chronic biofilm-mediated disease, affecting one in every three complete denture wearers. Antifungals are the treatment most commonly prescribed by oral health professionals, based on the belief that colonization by Candida spp. is the main cause of DES. However, high recurrence rates and adverse effects are commonly observed, prompting the need for practice guidelines regarding treatment. Results from our pilot study demonstrate that palatal brushing can reduce the palatal inflammation and potentially associated Candida carriage without any need for antifungal therapy. The objective of this study is to validate these pilot results by means of a randomized controlled trial (RCT) and provide a practice guideline for clinicians.\ud
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Methods/design\ud
A pragmatic, two-parallel-arm, multicenter RCT will be conducted in Canada, Brazil, and Chile. Fifty-two adult complete denture wearers presenting with moderate to severe DES will be allocated randomly to two groups: the Intervention arm will consist of palatal brushing and standard oral and denture hygiene measures, while the Control arm will include only standard oral and denture hygiene measures. The study outcome will be the oral Candida carriage. Participants will be assessed at baseline, and at 3 and 6 months post intervention. Descriptive, bivariate, and mixed models with repeated measures will be performed following the intention-to-treat principle.\ud
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Discussion\ud
This pragmatic RCT will serve to provide a clinical practice guideline regarding the use of preventive measures in the treatment of biofilm-mediated oral diseases. Moreover, it will have a great impact on reducing the harm of antifungal overtreatment on patients suffering from DES.\ud
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Trial registration\ud
ClinicalTrials.gov, \ud
NCT02686632\ud
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. Registered on 15 February 2016.The funds from the CIHR Phase II clinician-scientist award (Award #201110 to\ud
EE) and from FRQ-S RSBO Recruitment Aid (BRDV-FRQS-201-2016-046 to\ud
RFdS) will be utilized to fund this project (Additional file 3)
Ecological parameters of the (S)-9-methylgermacrene-B population of the Lutzomyia longipalpis complex in a visceral leishmaniasis area in São Paulo state, Brazil
No full textAbstract\ud
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Background\ud
Visceral leishmaniasis (VL) is an important public health challenge in Brazil because of the high number of human and canine cases reported annually. Leishmania infantum is the etiological agent of VL and Lutzomyia longipalpis is its main vector. However, evidence suggests that this taxon constitutes a species complex. In Sao Paulo state, there are two populations of Lu. longipalpis, each secreting distinct pheromones, (S)-9-methylgermacrene-B and Cembrene 1; both have been associated with different patterns of VL transmission. The aim of the present study was to investigate the temporal distribution and natural infection of the (S)-9-methylgermacrene-B population of the Lu. longipalpis complex in a highly VL endemic area of Sao Paulo state to obtain information that may contribute to the surveillance of this zoonosis and to the planning of preventive and control measures.\ud
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Methods\ud
The study was carried out in Panorama municipality, Sao Paulo State. Captures were made during 24 months in seven domiciles. The relation between sand fly abundance and climatic variables, temperature and humidity, was analyzed and natural infection by Leishmania spp. in sand fly females was investigated by nested PCR.\ud
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Results\ud
A total of 4120 sand flies, with predominance of Lu. longipalpis (97.2%) were captured. The highest averages of sand flies/night/trap occurred in the rainy season (November-March) and a positive, significant correlation between sand fly abundance and the temperature and humidity 20 days before the capture days was found. Leishmania infantum DNA was detected in three out of 250 pools of females analyzed, giving an estimated minimum infection rate of 1.2%.\ud
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Conclusion\ud
The identification of the climatic association between the high abundance of the vector in this highly endemic VL focus constitutes a fundamental point for evaluating future vector and dog control measures and this information increases the data of VL foci in Sao Paulo state that could contribute to the public health authorities in planning prevention and control measures. The identification of natural infection by Le. infantum in Lu. longipalpis specimens reinforces the importance of entomological surveillance activities in this municipality.This study was supported by the São Paulo Research Foundation FAPESP\ud
process 12/03571-4 and 11/23541-1