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  1. Article ; Online: Multispectral Filter Array Design by Optimal Sphere Packing.

    Diaz, Nelson / Alvarado, Alejandro / Meza, Pablo / Guzman, Felipe / Vera, Esteban

    IEEE transactions on image processing : a publication of the IEEE Signal Processing Society

    2023  Volume 32, Page(s) 3634–3649

    Abstract: Multispectral imaging (MSI) collects a datacube of spatio-spectral information of a scene. Many acquisition methods for spectral imaging use scanning, preventing its widespread usage for dynamic scenes. On the other hand, the conventional color filter ... ...

    Abstract Multispectral imaging (MSI) collects a datacube of spatio-spectral information of a scene. Many acquisition methods for spectral imaging use scanning, preventing its widespread usage for dynamic scenes. On the other hand, the conventional color filter array (CFA) method often used to sample color images has also been extended to snapshot MSI using a Multispectral Filter Array (MSFA), which is a mosaic of selective spectral filters placed over the Focal Plane Array (FPA). However, even state-ofthe- art MSFAs coding patterns produce artifacts and distortions in the reconstructed spectral images, which might be due to the nonoptimal distribution of the spectral filters. To reduce the appearance of artifacts and provide tools for the optimal design of MSFAs, this paper proposes a novel mathematical framework to design MSFAs using a Sphere Packing (SP) approach. By assuming that each sampled filter can be represented by a sphere within the discrete datacube, SP organizes the position of the equal-size and disjoint spheres's centers in a cubic container. Our method is denoted Multispectral Filter Array by Optimal Sphere Packing (MSFA-OSP), which seeks filter positions that maximize the minimum distance between the spheres's centers. Simulation results show an image quality improvement of up to 2 dB and a remarkable boost in spectral similarity when using our proposed MSFA design approach for a variety of reconstruction algorithms. Moreover, MSFA-OSP notably reduces the appearance of false colors and zipper effect artifacts, often seen when using state-of-the-art demosaicking algorithms. Experiments using synthetic and real data prove that the proposed MSFA-OSP outperforms state-of-the-art MSFAs in terms of spatial and spectral fidelity. The code that reproduces the figures of this article is available at https://github.com/nelson10/DemosaickingMultispectral3DSpherePacking.git.
    Language English
    Publishing date 2023-07-03
    Publishing country United States
    Document type Journal Article
    ISSN 1941-0042
    ISSN (online) 1941-0042
    DOI 10.1109/TIP.2023.3288414
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Shuffled rolling shutter for snapshot temporal imaging.

    Vera, Esteban / Guzmán, Felipe / Díaz, Nelson

    Optics express

    2022  Volume 30, Issue 2, Page(s) 887–901

    Abstract: We propose a modification to the rolling shutter mechanism found in CMOS detectors by shuffling the pixels in every scanline. This potential hardware modification improves the sampling of the space-time datacube, allowing the recovery of high-speed ... ...

    Abstract We propose a modification to the rolling shutter mechanism found in CMOS detectors by shuffling the pixels in every scanline. This potential hardware modification improves the sampling of the space-time datacube, allowing the recovery of high-speed videos from a single image using either tensor completion methods or reconstruction algorithms often used for compressive temporal video. We also present a design methodology for optimal sampling schemes and compare them to random shuffling. Simulations, and experimental results obtained by optically emulating the hardware, demonstrate the ability of the shuffled rolling shutter to capture images that allow reconstructing videos, which would otherwise be impossible when using the traditional rolling shutter mechanism.
    Language English
    Publishing date 2022-02-21
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1491859-6
    ISSN 1094-4087 ; 1094-4087
    ISSN (online) 1094-4087
    ISSN 1094-4087
    DOI 10.1364/OE.444864
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Effect of dietary inclusion of microalgae (Nannochloropsis gaditana and Schizochytrium spp) on non-specific immunity and erythrocyte maturity in Atlantic salmon fingerlings

    Sánchez, Felipe / Lozano-Muñoz, Ivonne / Muñoz, Susana / Diaz, Nelson / Neira, Roberto / Wacyk, Jurij

    Fish and Shellfish Immunology. 2023 Sept., v. 140 p.108975-

    2023  

    Abstract: The parr-smolt transformation in salmonids involves a critical period characterized by systemic changes associated with the fish's immune response. In this context, as a dietary ingredient in functional diets, microalgae offer an alternative due to their ...

    Abstract The parr-smolt transformation in salmonids involves a critical period characterized by systemic changes associated with the fish's immune response. In this context, as a dietary ingredient in functional diets, microalgae offer an alternative due to their nutritional and bioactive compounds that could strengthen the immune status. This study evaluated the effect of a diet supplemented with Schizochytrium spp and Nannochloropsis gaditana on the expression of genes associated with the antibacterial response. Additionally, the study assessed the effect on the leukocyte population and erythrocyte maturity in Salmo salar blood. Fish were fed for 30 days with a microalgal mixture (1:1) at a 10% inclusion. Each diet was randomly assigned to a tank using a completely randomized design (CRD) with four replications. Each tank was stocked with 70 Atlantic salmon fingerlings with an initial mean weight of 78.87 ± 0.84. Transcription levels were quantified and analyzed by qRT-PCR from cell isolates and mucus tissue. Furthermore, cell count and identification of leukocytes and classification of cellular maturity of erythrocytes using a neural network with a multilayer perceptron (MLP) were performed. Our results showed a significant (p < 0.05) increase in fold change expression of C3 (2.54 ± 0.65) and NK-Lysine (6.84 ± 0.94) in erythrocytes of microalgae-supplemented fish. Moreover, a significant increase of 1.59 and 2.35 times in monocytes and immature erythrocytes, respectively, was observed in the same group of fish (p < 0.05). This study's results indicate that dual microalgae (Schizochytrium spp and N. gaditana) supplementation can increase innate humoral antibacterial components, particularly in erythrocyte tissue, and increase phagocytic cells and immature erythrocytes in S. salar blood.
    Keywords Nannochloropsis ; Salmo salar ; Schizochytrium ; diet ; erythrocytes ; fish ; immune response ; ingredients ; microalgae ; monocytes ; mucus ; neural networks ; shellfish ; Fish erythrocytes ; Humoral antibacterial component ; Nannochloropsis gaditana ; Schizochytrium spp
    Language English
    Dates of publication 2023-09
    Publishing place Elsevier Ltd
    Document type Article ; Online
    ZDB-ID 1067738-0
    ISSN 1095-9947 ; 1050-4648
    ISSN (online) 1095-9947
    ISSN 1050-4648
    DOI 10.1016/j.fsi.2023.108975
    Database NAL-Catalogue (AGRICOLA)

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  4. Article: Real-time ground filtering algorithm of cloud points acquired using Terrestrial Laser Scanner (TLS)

    Diaz, Nelson / Gallo, Omar / Caceres, Jhon / Porras, Hernan

    International journal of applied earth observation and geoinformation. 2021 Dec. 25, v. 105

    2021  

    Abstract: 3D modeling based on point clouds requires ground-filtering algorithms that separate ground from non-ground objects. This study presents two ground filtering algorithms. The first one is based on normal vectors. It has two variants depending on the ... ...

    Abstract 3D modeling based on point clouds requires ground-filtering algorithms that separate ground from non-ground objects. This study presents two ground filtering algorithms. The first one is based on normal vectors. It has two variants depending on the procedure to compute the k-nearest neighbors. The second algorithm is based on transforming the cloud points into a voxel structure. To evaluate them, the two algorithms are compared according to their execution time, effectiveness and efficiency. Results show that the ground filtering algorithm based on the voxel structure is faster in terms of execution time, effectiveness, and efficiency than the normal vector ground filtering.
    Keywords algorithms ; scanners ; spatial data
    Language English
    Dates of publication 2021-1225
    Publishing place Elsevier B.V.
    Document type Article
    ISSN 1569-8432
    DOI 10.1016/j.jag.2021.102629
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Lemierre-like syndrome after soft tissue infection due to methicillin-resistant Staphylococcus aureus: A case report and literature review.

    Carreras, Xosse / Salcedo, Andrea S / Ponce-Rosas, Linda / Gonzales-Zamora, Jose A / Diaz, Nelson / Alave, Jorge

    Medicine

    2024  Volume 103, Issue 7, Page(s) e37006

    Abstract: Rationale: Lemierre-like syndrome (LLS) is characterized by bacteremia, septic thrombophlebitis of the internal jugular vein, and metastatic abscesses. In contrast to classic Lemierre syndrome, sources of infection are not related to oropharyngeal ... ...

    Abstract Rationale: Lemierre-like syndrome (LLS) is characterized by bacteremia, septic thrombophlebitis of the internal jugular vein, and metastatic abscesses. In contrast to classic Lemierre syndrome, sources of infection are not related to oropharyngeal infections, as are frequent soft tissue infections. In recent years, Staphylococcus aureus has been identified as an emergent pathogen that causes this syndrome. The mortality rate of LLS caused by this pathogen is approximately 16%. Timely diagnosis, antibiotic treatment, and infection control are the cornerstones to treat LLS. Anticoagulant therapy as adjuvant treatment remains controversial.
    Patient concerns: A 31-year-old woman from California, United States (US), was admitted to the emergency room with a history of 2 days of fever and severe throbbing pain in the left cervical region. Thorax and neck CT tomography revealed confluent cavities suggestive of septic embolism in the lungs and a filiform thrombus in the lumen of the left internal jugular vein, with moderate swelling of the soft and muscular tissues. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from the blood culture.
    Diagnosis: The thrombus in the internal jugular vein associated with cellulitis in the neck and multiple cavitary lesions in the lungs support the diagnosis of LLS caused by MRSA with septic embolization.
    Interventions: During treatment, the patient received vancomycin IV for 25 days and returned to the US with linezolid orally. In addition, assisted video-thoracoscopy and bilateral mini-thoracotomy with pleural decortication were performed for infectious source control, where 1700cc of purulent pleural fluid was drained.
    Outcomes: The patient was discharged with optimal evolution.
    Lessons: LLS should be suspected in patients with skin and soft tissue infections who develop thrombosis or metastatic infections. MRSA infections should be considered in patients from areas where this pathogen is prevalent.
    MeSH term(s) Female ; Humans ; Adult ; Lemierre Syndrome/diagnosis ; Methicillin-Resistant Staphylococcus aureus ; Soft Tissue Infections/diagnosis ; Soft Tissue Infections/therapy ; Soft Tissue Infections/complications ; Thrombophlebitis/etiology ; Thrombophlebitis/drug therapy ; Staphylococcus aureus ; Anti-Bacterial Agents/therapeutic use
    Chemical Substances Anti-Bacterial Agents
    Language English
    Publishing date 2024-02-16
    Publishing country United States
    Document type Review ; Case Reports ; Journal Article
    ZDB-ID 80184-7
    ISSN 1536-5964 ; 0025-7974
    ISSN (online) 1536-5964
    ISSN 0025-7974
    DOI 10.1097/MD.0000000000037006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Entomological parameters and population structure at a microgeographic scale of the main Colombian malaria vectors Anopheles albimanus and Anopheles nuneztovari.

    Altamiranda-Saavedra, Mariano / Naranjo-Díaz, Nelson / Conn, Jan E / Correa, Margarita M

    PloS one

    2023  Volume 18, Issue 1, Page(s) e0280066

    Abstract: Population subdivision among several neotropical malaria vectors has been widely evaluated; however, few studies have analyzed population variation at a microgeographic scale, wherein local environmental variables may lead to population differentiation. ... ...

    Abstract Population subdivision among several neotropical malaria vectors has been widely evaluated; however, few studies have analyzed population variation at a microgeographic scale, wherein local environmental variables may lead to population differentiation. The aim of the present study was to evaluate the genetic and geometric morphometric structure of Anopheles nuneztovari and Anopheles albimanus in endemic localities of northwestern Colombia. Genetic and phenetic structures were evaluated using microsatellites markers and wing geometric morphometrics, respectively. In addition, entomological indices of importance in transmission were calculated. Results showed that the main biting peaks of Anopheles nuneztovari were between 20:00 and 22:00, whereas Anopheles albimanus exhibited more variation in biting times among localities. Infection in An. nuneztovari by Plasmodium spp. (IR: 4.35%) and the annual entomological inoculation rate (30.31), indicated high vector exposure and local transmission risk. We did not detect Plasmodium-infected An. albimanus in this study. In general, low genetic and phenetic subdivision among the populations of both vectors was detected using a combination of phenotypic, genetic and environmental data. The results indicated high regional gene flow, although local environmental characteristics may be influencing the wing conformation differentiation and behavioral variation observed in An. albimanus. Furthermore, the population subdivision detected by microsatellite markers for both species by Bayesian genetic analysis provides a more accurate picture of the current genetic structure in comparison to previous studies. Finally, the biting behavior variation observed for both vectors among localities suggests the need for continuous malaria vector surveys covering the endemic region to implement the most effective integrated local control interventions.
    MeSH term(s) Animals ; Malaria/epidemiology ; Anopheles/genetics ; Colombia/epidemiology ; Bayes Theorem ; Mosquito Vectors/genetics ; Plasmodium
    Language English
    Publishing date 2023-01-06
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0280066
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Spatial and Temporal Diversity Variation in the Anopheles Communities in Malaria-Endemic Regions of Colombia.

    Naranjo-Díaz, Nelson / C Hernández-Valencia, Juan / F Gómez, Giovan / M Correa, Margarita

    The American journal of tropical medicine and hygiene

    2023  Volume 108, Issue 4, Page(s) 744–754

    Abstract: This study aimed to evaluate at a temporospatial scale, the influence of anthropogenic land cover changes in the Anopheles species community composition and diversity in two Colombian malaria-endemic regions, Bajo Cauca and Pacific. To determine ... ...

    Abstract This study aimed to evaluate at a temporospatial scale, the influence of anthropogenic land cover changes in the Anopheles species community composition and diversity in two Colombian malaria-endemic regions, Bajo Cauca and Pacific. To determine variations over time, mosquitoes were collected in two time periods; land cover types were characterized on orthorectified aerial photographs, and landscape metrics were estimated for each locality and period. A temporal dissimilarity analysis to evaluated species replacement and the nestedness species loss/gain showed the influence of the species loss or gain component on Anopheles species assemblage (23%). The relationship between land cover variation and Anopheles beta diversity, evaluated by regression analysis, showed the effect of forest variation in the Anopheles community (βsim and forest r2 = 0.9323; βsne and forest r2 = 0.9425). Furthermore, a canonical correspondence analysis showed that the land cover types associated with Anopheles species presence were bare soil, shrub, wet areas, and forest. Results demonstrated the impact of land cover changes attributed to human activities on Anopheles population dynamics, over time; this was evidenced as species loss or gain, which was specific to each locality. Notably, the main malaria vectors were dominant in most localities over time, suggesting their tolerance to anthropogenic transformations; alternatively, the environmental changes are providing adequate ecological conditions for their persistence. Finally, the data generated are relevant for understanding the impact that environmental change may have on the dynamics of the neotropical malaria vectors. Thus, this research has potential implications for vector control interventions.
    MeSH term(s) Humans ; Animals ; Anopheles ; Colombia/epidemiology ; Mosquito Vectors ; Malaria/epidemiology ; Forests
    Language English
    Publishing date 2023-02-20
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2942-7
    ISSN 1476-1645 ; 0002-9637
    ISSN (online) 1476-1645
    ISSN 0002-9637
    DOI 10.4269/ajtmh.22-0569
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Effect of dietary inclusion of microalgae (Nannochloropsis gaditana and Schizochytrium spp) on non-specific immunity and erythrocyte maturity in Atlantic salmon fingerlings.

    Sánchez, Felipe / Lozano-Muñoz, Ivonne / Muñoz, Susana / Diaz, Nelson / Neira, Roberto / Wacyk, Jurij

    Fish & shellfish immunology

    2023  Volume 140, Page(s) 108975

    Abstract: The parr-smolt transformation in salmonids involves a critical period characterized by systemic changes associated with the fish's immune response. In this context, as a dietary ingredient in functional diets, microalgae offer an alternative due to their ...

    Abstract The parr-smolt transformation in salmonids involves a critical period characterized by systemic changes associated with the fish's immune response. In this context, as a dietary ingredient in functional diets, microalgae offer an alternative due to their nutritional and bioactive compounds that could strengthen the immune status. This study evaluated the effect of a diet supplemented with Schizochytrium spp and Nannochloropsis gaditana on the expression of genes associated with the antibacterial response. Additionally, the study assessed the effect on the leukocyte population and erythrocyte maturity in Salmo salar blood. Fish were fed for 30 days with a microalgal mixture (1:1) at a 10% inclusion. Each diet was randomly assigned to a tank using a completely randomized design (CRD) with four replications. Each tank was stocked with 70 Atlantic salmon fingerlings with an initial mean weight of 78.87 ± 0.84. Transcription levels were quantified and analyzed by qRT-PCR from cell isolates and mucus tissue. Furthermore, cell count and identification of leukocytes and classification of cellular maturity of erythrocytes using a neural network with a multilayer perceptron (MLP) were performed. Our results showed a significant (p < 0.05) increase in fold change expression of C3 (2.54 ± 0.65) and NK-Lysine (6.84 ± 0.94) in erythrocytes of microalgae-supplemented fish. Moreover, a significant increase of 1.59 and 2.35 times in monocytes and immature erythrocytes, respectively, was observed in the same group of fish (p < 0.05). This study's results indicate that dual microalgae (Schizochytrium spp and N. gaditana) supplementation can increase innate humoral antibacterial components, particularly in erythrocyte tissue, and increase phagocytic cells and immature erythrocytes in S. salar blood.
    MeSH term(s) Animals ; Salmo salar ; Microalgae ; Stramenopiles ; Diet/veterinary ; Immunity, Innate ; Erythrocytes ; Anti-Bacterial Agents ; Animal Feed/analysis
    Chemical Substances Anti-Bacterial Agents
    Language English
    Publishing date 2023-07-22
    Publishing country England
    Document type Randomized Controlled Trial, Veterinary ; Journal Article
    ZDB-ID 1067738-0
    ISSN 1095-9947 ; 1050-4648
    ISSN (online) 1095-9947
    ISSN 1050-4648
    DOI 10.1016/j.fsi.2023.108975
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: New records of Sabethini (Diptera: Culicidae) from Colombia

    Naranjo-Díaz, Nelson / Suaza-Vasco, Juan / Pineda-Angel, Jacobo / Uribe, Sandra

    Biodiversity data journal. 2022 Feb. 03, v. 10

    2022  

    Abstract: In the Neotropical Region, the mosquitoes, grouped in the tribe Sabethini (Arthropoda, Insecta, Diptera: Culicidae) are considered of medical importance by the role that some species may have in arbovirus transmission; also, because they are good ... ...

    Abstract In the Neotropical Region, the mosquitoes, grouped in the tribe Sabethini (Arthropoda, Insecta, Diptera: Culicidae) are considered of medical importance by the role that some species may have in arbovirus transmission; also, because they are good bioindicators. More than 400 species are currently recognised and are mainly associated with forest areas. The tribe Sabethini is poorly studied and the information about diversity and distribution for species relating to it is scarce. In Colombia, 54 species of the tribe are known; however, several geographical areas have not been included in the studies for this group and data for recent field collections are not available; therefore, the records are outdated. This study presents the species list of the Sabethini tribe in Colombia, based on a review of previous publications and recent unpublished data. The list includes 68 species of nine genera and 16 subgenera. The genus Wyeomyia has the highest species number (39), followed by Sabethes (14). A total of 29 new records are registered and actualized information related to the local distribution in some Departments is presented, including geographic coordinates. In this paper, the distribution records of Sabethini for Colombia are updated, revealing the high diversity of this group in the country and providing some useful information for species that may need surveillance or control.
    Keywords Neotropics ; Sabethes ; Wyeomyia ; arboviruses ; biodiversity ; forests ; monitoring ; Colombia
    Language English
    Dates of publication 2022-0203
    Publishing place Pensoft Publishers
    Document type Article
    ZDB-ID 2736709-5
    ISSN 1314-2828
    ISSN 1314-2828
    DOI 10.3897/BDJ.10.e68413
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  10. Article: Minerals in edible seaweed: health benefits and food safety issues

    Lozano Muñoz, Ivonne / Díaz, Nelson F.

    Critical reviews in food science and nutrition. 2020 Nov. 24, v. 62, no. 6

    2020  

    Abstract: An adequate daily intake of minerals is essential for the prevention of chronic nutrition-related and degenerative diseases, including cancer, cardiovascular disease, and obesity. Seaweeds are marine aquatic vegetable that are rich in nutrients. They ... ...

    Abstract An adequate daily intake of minerals is essential for the prevention of chronic nutrition-related and degenerative diseases, including cancer, cardiovascular disease, and obesity. Seaweeds are marine aquatic vegetable that are rich in nutrients. They also have a natural and sustainable origin and clean and renewable sources when they come from marine aquaculture or controlled fisheries. Seaweeds have high nutritional value as a source of polyunsaturated fatty acids, proteins, carbohydrates, vitamins, and especially minerals. They are known for their high mineral content, which is gathered from seawater depending on the seasonal variation and the environment. Seaweeds are consequently rich in macro-elements and trace elements, with a mineral content at least 10 times higher than terrestrial plants and reaching 20-50% of its dry weight. Therefore, seaweeds can make an important contribution to the daily intake of minerals and are a promising source of essential minerals for functional food, food supplements, and nutraceuticals. The aim of the present review is to compare the contents of essential minerals (K, Ca, Na, P, Cu, Fe, Se, Mn, Zn, Mg, Cr, and I) as well as potential toxic minerals (Hg, Pb, Cd, As, and Al) in 14 main edible seaweeds that have availability of biomass from harvest and aquaculture. Another goal is to establish their safety in foods and contributions to the Recommended Dietary Allowance (RDA) and adequate intake (AI) values.
    Keywords Adequate Intakes ; biomass ; cardiovascular diseases ; dietary supplements ; edible seaweed ; food safety ; functional foods ; mariculture ; mineral content ; nutritive value ; obesity ; seasonal variation ; seawater ; toxicity ; vegetables
    Language English
    Dates of publication 2020-1124
    Size p. 1592-1607.
    Publishing place Taylor & Francis
    Document type Article
    ZDB-ID 1037504-1
    ISSN 1549-7852 ; 1040-8398
    ISSN (online) 1549-7852
    ISSN 1040-8398
    DOI 10.1080/10408398.2020.1844637
    Database NAL-Catalogue (AGRICOLA)

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