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Grijalva, I.

Publications and source records attributed to Grijalva, I..

3 recordsLinked to original sources

Self-supervised Component Segmentation To Improve Object Detection and Classification For Bumblebee Identification

The performance of computer vision models for object detection and classification is heavily influenced by the number of classes and quality of input images, particularly in biological applications such as species-level identification of bumblebees. Bee identification is time-consuming, costly, and requires specialized taxonomic training. Different deep learning based computer vision models have been proven to overcome this methodological bottleneck through automated identification of bee species from captured images. However, accurate identification of bee species in images containing multiple objects of various classes poses significant challenges due to ambiguity, poor image quality, and noisy backgrounds. Existing pipelines (baselines) primarily rely on object detection to crop bees from images and classify the species for each cropped instance. This approach is limited by the inclusion of noisy backgrounds, low resolution, and poor image quality. To address these limitations, we propose an enhanced pipeline that integrates object detection with segmentation to generate body masks for bees and remove background noise. This process is complemented by a classification model that identifies the top k species for each masked image. The proposed methodology significantly improves both detection and classification performance in most cases, demonstrating its potential to advance automated identification of bee species in complex image datasets. For the cases where the baselines performed much better, we investigated using a state-of-the-art explainable AI model (Grad-CAM) to explain the reason.

zoology↗

Zika and dengue but not chikungunya are associated with Guillain-Barre syndrome in Mexico: a case-control study

BackgroundZika, dengue and chikungunya viruses (ZIKV, CHIKV and DENV) are temporally associated with neurological diseases such as Guillain-Barre syndrome (GBS). Because these three arboviruses coexist in Mexico, the frequency and severity of GBS could theoretically increase. This study aimed to determine the association between these arboviruses and GBS in a Mexican population, and to establish the clinical features of the patients, including the severity of the infection. Methodology/Principal findingsA case-control study was conducted (2016/07/01-2018/06/30) in hospitals from the Instituto Mexicano del Seguro Social. Serum and urine samples were collected to determine the exposure to ZIKV, DENV and CHIKV by RT-qPCR and serology (IgM). The association between arboviral infection and GBS was analysed with {chi}2 or exact Fisher tests and Kruskall-Wallis folloed by Mann Whitney U test for comparing symptomatology. A p [≤] 0.05 was considered as significant. Ninety-seven GBS cases and 184 controls were included. Evidence of association of GBS with ZIKV acute infection (OR, 8.04; 95% CI, 0.89-73.01, p =0.047), as well as ZIKV recent infection (OR, 16.68; 95% CI, 2.05-135.31; p = 0.001) and Flavivirus (ZIKV and DENV) recent infection (OR, 5.8; 95% CI, 1.8-18.8; p = 0.002) was observed. Cases with GBS associated with ZIKV demonstrated a greater impairment of functional status, a higher percentage of mechanical ventilation and mortality. Dizziness, ataxia and low blood pressure showed statistically signifant differences in cases with GBS associated with DENV. Co-infection cases were not observed. Conclusions/SignificanceAccording to the laboratory results, an association between ZIKV or ZIKV and DENV infection in patients with GBS was found. Cases of GBS associated with ZIKV but not with DENV exhibited a more severe clinical picture. Cases with co-infection were not found. Author summaryDengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) are considered as emerging or re-emerging viruses. In recent years, these viruses have produced great epidemics in tropical climate urban centers, and have been associated with neurological manifestations, including Guillain-Barre syndrome (GBS), which causes muscle weakness, unstable gait, and decreased or absent musculoskeletal reflexes. This study aimed to investigate the association between these viral infections and GBS. A case and control study was conducted nationwide, including 97 cases of GBS and 184 controls matched by age, gender, and locality, but without the disease. This study showed the positive association between GBS cases and ZIKV or ZIKV and DENV infection. GBS cases associated with ZIKV showed a more severe clinical picture (more impairment of functional status and incapacity, a higher percentage of mechanical ventilation, and mortality). GBS associated with DENV cases seemed to show more dizziness, ataxia, and low blood pressure. Finally, the symptoms of ZIKV or DENV suspected disease before the development of GBS were similar to some previous reports. The impact of the interaction of these three arboviruses, particularly ZIKV, on the health of the Mexican population was less than expected. The Mexican experience could be useful for other populations.

microbiology↗

Oxidative stress in an aged population with diabetes mellitus and/or hypertension

BackgroundMexico City has the highest aging rate in the country, as well as a high prevalence of diabetes mellitus (DM) and arterial hypertension (HT). All three on their own, are known to increase oxidative stress (OE).\n\nMethodsFinal groups included 18 patients without DM or HT (control group), 12 with DM, 23 with HT, and 18 with DM and HT. The EO was measured by the quantification of reactive oxygen species (ROS), and by determination of lipid peroxidation.\n\nResultsHAS patients showed increased ROS levels as did men with HAS compared with the respective DM and HT groups. Also, women of the control group showed higher levels of ROS compared with men. HT in an aged population turned out to be the most influential factor for oxidative stress increase while DM had no effect whatsoever.

epidemiology↗