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1.
Philos Trans R Soc Lond B Biol Sci ; 379(1904): 20230102, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38705182

RESUMEN

Insect monitoring is pivotal for assessing biodiversity and informing conservation strategies. This study delves into the complex realm of insect monitoring in the Global South-world developing and least-developed countries as identified by the United Nations Conference on Trade and Development-highlighting challenges and proposing strategic solutions. An analysis of publications from 1990 to 2024 reveals an imbalance in research contributions between the Global North and South, highlighting disparities in entomological research and the scarcity of taxonomic expertise in the Global South. We discuss the socio-economic factors that exacerbate the issues, including funding disparities, challenges in collaboration, infrastructure deficits, information technology obstacles and the impact of local currency devaluation. In addition, we emphasize the crucial role of environmental factors in shaping insect diversity, particularly in tropical regions facing multiple challenges including climate change, urbanization, pollution and various anthropogenic activities. We also stress the need for entomologists to advocate for ecosystem services provided by insects in addressing environmental issues. To enhance monitoring capacity, we propose strategies such as community engagement, outreach programmes and cultural activities to instill biodiversity appreciation. Further, language inclusivity and social media use are emphasized for effective communication. More collaborations with Global North counterparts, particularly in areas of molecular biology and remote sensing, are suggested for technological advancements. In conclusion, advocating for these strategies-global collaborations, a diverse entomological community and the integration of transverse disciplines-aims to address challenges and foster inclusive, sustainable insect monitoring in the Global South, contributing significantly to biodiversity conservation and overall ecosystem health. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.


Asunto(s)
Biodiversidad , Insectos , Insectos/fisiología , Animales , Conservación de los Recursos Naturales/métodos , Monitoreo del Ambiente/métodos , Países en Desarrollo , Entomología/métodos , Ecosistema , Cambio Climático
2.
Accid Anal Prev ; 200: 107533, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38492347

RESUMEN

Today, cities seek to transition to more sustainable transportation modes. Cycling is critical in this shift, promoting a more beneficial lifestyle for most. However, cyclists are exposed to many hazardous circumstances or environments, resulting in accidents, injuries, and even death. Transport authorities must understand why accidents occur, to reduce the risk of those who cycle. This study applies a new modeling framework to analyze cycling accident severities. We employ a latent class discrete outcome model, where classes are derived from a Gaussian-Bernoulli mixture, applied to data from Berlin, and augmented with volunteered geographic information. We jointly estimate model components, combining machine learning and econometric approaches, allowing for more intricate and flexible representations while maintaining interpretability. Results show the potential of our approach. Risk factors are indexed depending on where accidents occurred and their contribution. We can discover complex relations between specific built environments and accident characteristics and uncover differences in the impact of certain accident factors on one environment typology but not others. Using multiple data sources also proves helpful as an additional layer of knowledge, providing unique value to understand and model cycling accidents. Another critical aspect of our approach is the potential for simulation, where locations can be examined through simulated accident features to understand the inherent risk of various locations. These findings highlight the ability to capture heterogeneity in accidents and their relation to the built environment. Capturing such relations allows for more direct countermeasures to risky situations or policies to be designed, simulated, and targeted.


Asunto(s)
Accidentes de Tránsito , Entorno Construido , Humanos , Factores de Riesgo , Ciclismo/lesiones , Ciudades
3.
PeerJ ; 11: e16640, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38107564

RESUMEN

Brazil stands out for presenting the highest amphibian anuran diversity in the world. However, taxonomic studies that address characteristic of larval stage of anurans are incipient, representing only 62% of known species. We assess the species diversity of tadpoles from eastern Maranhão state, mid-northern region of Brazil based on morphological and molecular identification (i.e., 16S rRNA gene fragment), and we also provide characteristics of the habitats occupied by each species. We carried out 30 field samplings during 13 months in 16 environments along an ecotonal area, over five cities inside the limits of state of Maranhão, between the Maranhão Babaçu Forest and Cerrado ecoregions. We searched for tadpoles in a variety of water bodies, and the tadpoles that reached the developmental stage between 34 to 40 Gosner were morphologically identified. The tadpoles collected herein represent 26 species belonging to five families. The external morphology enabled the identification of 24 species, while the molecular data recognized 22 unique evolutionary units. The most represented family was Hylidae (Hylinae 11 spp., Phyllomedusinae one spp.) followed by Leptodactylidae (Leptodactylinae seven spp., Leiuperinae three spp.), Microhylidae (Gastrophryninae two spp.), and Bufonidae (two spp.). Our results show that oral morphology was the most important character for identifying tadpoles based on morphology, and the specific 16S rRNA primer was suitable for molecular identification. This study pioneers the use of both morphological and molecular data to identify tadpoles in the state of Maranhão. It also provides, for the first-time, habitat characteristic for the species. Our study reveals a high number of anuran species sampled at the larval stage in the region, identifies species that require further taxonomic and systematic attention, and extends the geographic distribution of six species, three of which represent new occurrences for the state. Our results strengthen the hypothesis that the diversity of amphibians from Maranhão is underestimated and highlight the importance of herpetological inventories in poorly sampled areas, decentralizing the knowledge of biodiversity.


Asunto(s)
Biodiversidad , Ecosistema , Humanos , Animales , Larva/genética , Brasil , ARN Ribosómico 16S/genética
4.
Braz J Infect Dis ; 27(5): 102806, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37802128

RESUMEN

INTRODUCTION: Nocardiosis is a rare bacterial infection caused by Nocardia spp. However, an increasing incidence has been described whereby data about epidemiology and prognosis are essential. METHODS: A retrospective descriptive study was conducted among patients with positive Nocardia spp. culture, from January 2019 to January 2023, at a Terciary Hospital in Portugal. RESULTS: Nocardiosis was considered in 18 cases with a median age of 63.8-years-old. At least one immunosuppressive cause was identified in 70% of patients. Five patients had Disseminated Nocardiosis (DN). The lung was the most common site of clinical disease (77.8%) and Nocardia was most commonly identified in respiratory tract samples. The most frequently isolated species were Nocardia nova/africana (n = 7) followed by Nocardia cyriacigeorgica (n = 3) and Nocardia pseudobrasiliensis (n = 3). The majority of the patients (94.4%) received antibiotic therapy, of whom as many as 55.6% were treated with monotherapy. The most frequently prescribed antibiotic was trimethoprim-sulfamethoxazole. Selected antimicrobial agents were generally effective, with linezolid and cotrimoxazole (100% Susceptibility [S]) and amikacin (94% S) having the most activity against Nocardia species. The median (IQR) duration of treatment was 24.2 (1‒51.4) weeks for DN; The overall one-year case fatality was 33.3% (n = 6) and was higher in the DN (66.7%). No recurrence was observed. CONCLUSION: Nocardiosis is an emerging infectious disease with a poor prognosis, particularly in DN. This review offers essential epidemiological insights and underscores the importance of gaining a better understanding of the microbiology of nocardiosis. Such knowledge can lead to the optimization of antimicrobial therapy and, when necessary, guide appropriate surgical interventions to prevent unfavorable outcomes.


Asunto(s)
Antiinfecciosos , Nocardiosis , Nocardia , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Nocardiosis/diagnóstico , Nocardiosis/tratamiento farmacológico , Nocardiosis/epidemiología , Antibacterianos/uso terapéutico , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Antiinfecciosos/uso terapéutico
5.
Plants (Basel) ; 12(10)2023 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-37653940

RESUMEN

Brazil stands out as the largest producer of sour passion fruit; however, the water available for irrigation is mostly saline, which can limit its cultivation. This study was carried out with the objective of evaluating the effects of salicylic acid in the induction of tolerance in sour passion fruit to salt stress. The assay was conducted in a protected environment, using a completely randomized design in a split-plot scheme, with the levels of electrical conductivity of the irrigation water (0.8, 1.6, 2.4, 3.2, and 4.0 dS m-1) considering the plots and concentrations of salicylic acid (0, 1.2, 2.4, and 3.6 mM) the subplots, with three replications. The physiological indices, production components, and postharvest quality of sour passion fruit were negatively affected by the increase in the electrical conductivity of irrigation water, and the effects of salt stress were intensified in the second cycle. In the first cycle, the foliar application of salicylic acid at concentrations between 1.0 and 1.4 mM partially reduced the harmful effects of salt stress on the relative water content of leaves, electrolyte leakage, gas exchange, and synthesis of photosynthetic pigments, in addition to promoting an increase in the yield and quality parameters of sour passion fruit.

6.
Plants (Basel) ; 12(16)2023 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-37631104

RESUMEN

Water scarcity is one of the main abiotic factors that limit agricultural production. In this sense, the identification of genotypes tolerant to water deficit associated with irrigation management strategies is extremely important. In this context, the objective of this study was to evaluate the morphology, production, water consumption, and water use efficiency of colored fiber cotton genotypes submitted to irrigation strategies with a water deficit in the phenological phases. Two experiments were conducted in succession. In the first experiment, a randomized block design was used in a 3 × 7 factorial scheme, corresponding to three colored cotton genotypes (BRS Rubi, BRS Jade, and BRS Safira) in seven irrigation management strategies with 40% of the real evapotranspiration (ETr) varying the phenological stages. In the second experiment, the same design was used in a 3 × 10 factorial arrangement (genotypes × irrigation management strategies). The water deficit in the vegetative phase can be used in the first year of cotton cultivation. Among the genotypes, 'BRS Jade' is the most tolerant to water deficit in terms of phytomass accumulation and fiber production.

7.
Plants (Basel) ; 12(15)2023 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-37570936

RESUMEN

Salicylic acid is a phytohormone that has been used to mitigate the effects of saline stress on plants. In this context, the objective was to evaluate the effect of salicylic acid as a salt stress attenuator on the physiology and growth of precocious-dwarf cashew plants in the post-grafting phase. The study was carried out in a plant nursery using a randomized block design in a 5 × 4 factorial arrangement corresponding to five electrical conductivity levels of irrigation water (0.4, 1.2, 2.0, 2.8, and 3.6 dS m-1) and four salicylic acid concentrations (0, 1.0, 2.0, and 3.0 mM), with three replications. Irrigation water with electrical conductivity levels above 0.4 dS m-1 negatively affected the relative water content in the leaf blade, photosynthetic pigments, the fluorescence of chlorophyll a, and plant growth and increased electrolyte leakage in the leaf blade of precocious-dwarf cashew plants in the absence of salicylic acid. It was verified through the regression analysis that salicylic acid at a concentration of 1.1 mM attenuated the effects of salt stress on the relative water content and electrolyte leakage in the leaf blade, while the concentration of 1.7 mM increased the synthesis of photosynthetic pigments in precocious-dwarf cashew plants.

8.
Cureus ; 15(7): e41647, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37575717

RESUMEN

Introduction Multiple risk factors, such as human immunodeficiency virus (HIV) infection and immunosuppressive therapies, increase the odds of latent tuberculosis infection (LTBI) reactivation and progression to active tuberculosis. A six-to-nine-month preventive treatment with isoniazid (INH) decreases the risk of LTBI reactivation, but its effectiveness can be limited by its long duration and adverse events (AEs), including liver toxicity. Due to comorbidities and polypharmacy, people living with HIV (PLHIV) may be at increased risk of INH-associated AEs. Our study aimed to assess the prevalence of AEs among patients receiving INH treatment for LTBI, to identify risk factors for their occurrence, and to evaluate whether PLHIV have higher odds of developing INH-associated AEs. Methods We conducted a single-center retrospective case-control study, including 130 outpatients with LTBI treated with INH between July 2019 and March 2022. Participants who developed AE (cases) were compared to controls, and a subgroup of PLHIV was compared to HIV-negative participants. Demographics, socioeconomic variables, comorbidities, and clinical variables were compared between study groups. Patient data were obtained from institutional electronic medical records, and outcomes were measured at regularly scheduled appointments. Results We included 130 participants, of which 54 were PLHIV. The PLHIV subgroup was significantly younger (p = 0.01) and demonstrated significantly higher prevalences of chronic liver disease, previous viral hepatitis, daily alcohol consumption, and intravenous drug use (IDU). One-third of the participants had an AE (45 cases, 34.6%), with liver toxicity being the most common (22.3%). Participants who developed AEs were significantly older (p = 0.030) and had a higher prevalence of economic hardship (p = 0.037), as well as higher scores of the Charlson comorbidity index (p = 0.002) than the controls. INH withdrawal occurred in 17 participants (13.1%) and was mainly associated with liver toxicity (p < 0.01) and gastrointestinal symptoms (p = 0.022). In the adjusted effect model, an age ≥ 65 years, economic hardship, and excessive alcohol consumption were significantly associated with higher odds of AEs, while HIV infection decreased the odds by 68.4% (p = 0.033). Conclusions In our study, INH-associated AEs were common, with liver toxicity being the most frequent. Older age, economic hardship, and excessive alcohol consumption increased the odds of INH-associated AEs, while PLHIV had lower odds of developing INH-associated AEs, even when adjusting for other variables in the multivariate analysis. Further studies should be conducted to assess if these results are replicable in a larger population and in different settings.

9.
Plants (Basel) ; 12(11)2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37299070

RESUMEN

Salt stress reduces the yield and quality of colored fiber cotton production, but this problem can be mitigated by the foliar application of hydrogen peroxide in adequate concentrations. In this context, the objective of the present study was to evaluate the production and characteristics of fibers of naturally colored cotton cultivares under irrigation with low- and high-salinity water and leaf application of hydrogen peroxide. The experiment was carried out in a greenhouse under a randomized block design, arranged in 4 × 3 × 2 factorial scheme, corresponding to four concentrations of hydrogen peroxide (0, 25, 50, and 75 µM), three cultivares of colored fiber cotton ('BRS Rubi', 'BRS Topázio', and 'BRS Verde'), and two electrical conductivities of water (0.8 and 5.3 dS m-1), with three replicates and one plant per plot. Irrigation with water of 0.8 dS m-1 associated with a foliar application of 75 µM of hydrogen peroxide favored the lint and seed weight, strength, micronaire index, and maturity of 'BRS Topázio'. The 'BRS Rubi' cotton cultivar showed higher tolerance to salinity, followed by the 'BRS Topázio' and 'BRS Verde' cultivares regarding the yield of seed cotton weight, with reduction below 20% under water of 5.3 dS m-1.

10.
Plants (Basel) ; 12(7)2023 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-37050199

RESUMEN

This research aimed to evaluate the effects of salt stress, varying the phenological stages, and K fertilization on NPK concentrations, physiology, and production of Passiflora edulis Sims. The research was carried out at the University Farm of São Domingos, Paraíba, Brazil, using a randomized block design with a 6 × 2 factorial arrangement. Six irrigation strategies were evaluated (use of low electrical conductivity water (0.3 dS m-1) during all stages of development and application of high-salinity water (4.0 dS m-1) in the following stages: vegetative, flowering, fruiting, successively in the vegetative/flowering, and vegetative/fruiting stages) and two potassium levels (207 and 345 g K2O per plant), with four replications and three plants per plot. The leaf concentrations of N, P, and K in the sour passion fruit plants found in the present study were below the optimal levels reported in the literature, regardless of the development stage and the cultivation cycle. The relative water content, stomatal conductance, and photosynthesis were reduced by salt stress in the first cycle. However, in the second cycle, irrigation with 4.0 dS m-1 in the vegetative/flowering stages increased the CO2 assimilation rate. Passion fruit is sensitive to salt stress in the vegetative/flowering stages of the first cycle. In the second cycle, salt stress in the fruiting stage resulted in higher production per plant.

11.
Plants (Basel) ; 12(3)2023 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-36771685

RESUMEN

Hydrogen peroxide at low concentrations has been used as a salt stress attenuator because it induces a positive response in the antioxidant system of plants. This study aimed to assess the gas exchange, quantum yield, and development of soursop plants cv. Morada Nova grown with saline water irrigation and foliar hydrogen peroxide application. The experiment was carried out under greenhouse conditions using a randomized block design in a 4 × 4 factorial scheme corresponding to four levels of electrical conductivity of irrigation water, ECw (0.8, 1.6, 2.4, and 3.2 dS m-1), and four doses of hydrogen peroxide, H2O2 (0, 10, 20, and 30 µM), with three replicates. The use of irrigation water with electrical conductivity above 0.8 dS m-1 inhibited stomatal conductance, internal CO2 concentration, transpiration, maximum fluorescence, crown height, and vegetative vigor index of the Morada Nova cultivar of soursop. Compared to untreated plants, the hydrogen peroxide concentration of 30 µM resulted in greater stomatal conductance. Water salinity of 0.8 dS m-1 with hydrogen peroxide concentrations of 16 and 13 µM resulted in the highest variable fluorescence and quantum efficiency of photosystem II, respectively, of soursop plants cv. Morada Nova at 210 days after transplantation.

12.
Braz. j. infect. dis ; 27(5): 102806, 2023. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1520456

RESUMEN

ABSTRACT Introduction: Nocardiosis is a rare bacterial infection caused by Nocardia spp. However, an increasing incidence has been described whereby data about epidemiology and prognosis are essential. Methods: A retrospective descriptive study was conducted among patients with positive Nocardia spp. culture, from January 2019 to January 2023, at a Terciary Hospital in Portugal. Results: Nocardiosis was considered in 18 cases with a median age of 63.8-years-old. At least one immunosuppressive cause was identified in 70% of patients. Five patients had Disseminated Nocardiosis (DN). The lung was the most common site of clinical disease (77.8%) and Nocardia was most commonly identified in respiratory tract samples. The most frequently isolated species were Nocardia nova/africana (n = 7) followed by Nocardia cyriacigeorgica (n = 3) and Nocardia pseudobrasiliensis (n = 3). The majority of the patients (94.4%) received antibiotic therapy, of whom as many as 55.6% were treated with monotherapy. The most frequently prescribed antibiotic was trimethoprim-sulfamethoxazole. Selected antimicrobial agents were generally effective, with linezolid and cotrimoxazole (100% Susceptibility [S]) and amikacin (94% S) having the most activity against Nocardia species. The median (IQR) duration of treatment was 24.2 (1-51.4) weeks for DN; The overall one-year case fatality was 33.3% (n = 6) and was higher in the DN (66.7%). No recurrence was observed. Conclusion: Nocardiosis is an emerging infectious disease with a poor prognosis, particularly in DN. This review offers essential epidemiological insights and underscores the importance of gaining a better understanding of the microbiology of nocardiosis. Such knowledge can lead to the optimization of antimicrobial therapy and, when necessary, guide appropriate surgical interventions to prevent unfavorable outcomes.

13.
Plants (Basel) ; 11(19)2022 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-36235374

RESUMEN

The association between population increase and the exploitation of natural resources and climate change influences the demand for food, especially in semi-arid regions, highlighting the need for technologies that could provide cultivated species with better adaptation to agroecosystems. Additionally, developing cultivation technologies that employ waste materials is highly desirable for sustainable development. From this perspective, this study aimed to evaluate whether seed priming with glass waste microparticles used as a silicon source under red light irradiation mitigates the effects of thermal and water stress on seedlings of Moringa oleifera. The experimental design was set up in randomized blocks using a 2 × 2 × 2 factorial arrangement consisting of seed priming (NSP-no seed priming, and SPSi-seed priming with glass microparticles under red light irradiation), soil water replenishment (W50-50%, and W100-100% of crop evapotranspiration-ETc), and temperature change (TC30°-30 °C day/25 °C night and TC40°-40 °C day/35 °C night). Seed priming with glass microparticles under red light irradiation mitigated the effects of thermal and water stress on seedlings of Moringa oleifera seedlings through the homeostasis of gas exchange, leaf water status, osmotic adjustment, and the antioxidant mechanism.

14.
Environ Monit Assess ; 194(9): 614, 2022 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35895142

RESUMEN

Aquatic ecosystems are affected by different land uses that modify gradients of environmental conditions. These impacts act directly on the community structure, especially the most sensitive ones, such as aquatic insects. Thus, dragonflies have been used as good models to assess these changes, since their suborders Anisoptera and Zygoptera have different ecophysiological and behavioral requirements. This study aimed to evaluate the following hypotheses: (1) dragonfly species composition differs along the environmental gradients of streams; therefore, we expect a higher proportion of species of the suborder Anisoptera in environments with a higher degree of disturbance, since these environmental conditions select heliothermic species with exophytic oviposition; (2) the reduction of habitat integrity and canopy cover will lead to a lower richness of the Zygoptera suborder, due to the restrictions of its thermoregulation and oviposition behavior in relation to Anisoptera, since the higher light input would favor heliothermic and exophytic species; (3) alterations in habitat integrity create ecological thresholds and points of change in the abundance and frequency of Odonata species, generating gradients in the environmental integrity conditions. Specimens were collected from 24 streams (first to third order), in a gradient of land uses. Canopy cover and stream width were predictors of taxonomic richness and abundance of the suborders Anisoptera and Zygoptera, with greater coverage and smaller width, positively affecting Zygoptera and negatively Anisoptera. The turning points were determined by a habitat integrity index, where below 0.38 there is an increase in generalist taxa and a decline in sensitive taxa. On the other hand, above 0.79, there was a sensitive taxa increase in detriment of generalists. Four individual taxa indicators were selected, two of which associated with a negative response (Perithemis tenera and Acanthagrion aepiolum) and two with positive responses (Epipleoneura metallica and Zenithoptera lanei) for habitat integrity. Our results are important to guide management strategies, recovery, and protection policies for areas of permanent protection, aiming to conserving biodiversity and natural resources essential to life quality maintenance.


Asunto(s)
Odonata , Animales , Biodiversidad , Dipterocarpaceae , Ecosistema , Monitoreo del Ambiente , Odonata/fisiología , Ríos
15.
Rev Bras Parasitol Vet ; 31(1): e018121, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35043873

RESUMEN

During a survey Myxozoa, four specimens of the sheepshead (18 ± 1.5 cm and 59 ± 2.5 g) (Archosargus probatocephalus) were collected in the Ipioquinha river (Maceió/AL). Transmission electron microscopy observations revealed erythrocyte agglutinations in gill capillaries located near spherical cysts containing myxospores of the genus Henneguya. This hemagglutination partially or totally obstructed the gill capillaries. Erythrocytes occurred in close adherence to each other, with a closed intercellular space. A few lysed erythrocytes were observed among agglutinated cells. The reduced lumen of the capillaries was partially filled with amorphous dense homogenous material adhering to the erythrocytes. In addition, heterogeneous masses of irregular lower electron density were observed in the reduced channel of the capillary. The agglutinated erythrocytes appeared dense and homogenous, lacking cytoplasmic organelles. The nuclei had the appearance of normal condensed chromatin masses, generally without visible nucleoli. This occurrence of hemagglutination only in the capillaries located in close proximity to the developing myxozoan cysts suggests that parasite development may be a factor triggering erythrocyte agglutination. This is supported by previous experimental studies that showed a probable correlation between parasitic infections and hemagglutination. Nonetheless, further studies are necessary in order to better understand the physicochemical processes involved in this phenomenon.


Asunto(s)
Enfermedades de los Peces , Myxozoa , Perciformes , Animales , Capilares , Branquias , Hemaglutinación
16.
Zookeys ; 1111: 339-353, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36760851

RESUMEN

A new species of dobsonfly from Venezuela, Corydalusralphi Martins, Azevêdo, Hamada & Contreras, sp. nov., was discovered a decade after the last description of a species of this genus in the country. The new species is morphologically similar to C.wanningeri Contreras-Ramos & von der Dunk, sharing a uniform reddish coloration of body and wings and similar male genitalic structures. Likewise, it shares this particular coloration with C.neblinensis Contreras-Ramos but the genitalic structure fits within the C.crossi Contreras-Ramos species group. Two specimens, one male and one female, were collected on Tarotá River, in the Gran Sabana region, Canaima National Park, in southern Venezuela. A key to identify males of the Venezuelan species of Corydalus is provided.

17.
Rev. bras. parasitol. vet ; 31(1): e018121, 2022. graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1357151

RESUMEN

Abstract During a survey Myxozoa, four specimens of the sheepshead (18 ± 1.5 cm and 59 ± 2.5 g) (Archosargus probatocephalus) were collected in the Ipioquinha river (Maceió/AL). Transmission electron microscopy observations revealed erythrocyte agglutinations in gill capillaries located near spherical cysts containing myxospores of the genus Henneguya. This hemagglutination partially or totally obstructed the gill capillaries. Erythrocytes occurred in close adherence to each other, with a closed intercellular space. A few lysed erythrocytes were observed among agglutinated cells. The reduced lumen of the capillaries was partially filled with amorphous dense homogenous material adhering to the erythrocytes. In addition, heterogeneous masses of irregular lower electron density were observed in the reduced channel of the capillary. The agglutinated erythrocytes appeared dense and homogenous, lacking cytoplasmic organelles. The nuclei had the appearance of normal condensed chromatin masses, generally without visible nucleoli. This occurrence of hemagglutination only in the capillaries located in close proximity to the developing myxozoan cysts suggests that parasite development may be a factor triggering erythrocyte agglutination. This is supported by previous experimental studies that showed a probable correlation between parasitic infections and hemagglutination. Nonetheless, further studies are necessary in order to better understand the physicochemical processes involved in this phenomenon.


Resumo Durante pesquisa de mixozoários foram coletados quatro espécimes do peixes sargo-de-dente (18 ± 1.5 cm e 59 ± 2.5 g) (Archosargus probatocephalus), no rio Ipioquinha (Maceió/AL). Observações por microscopia eletrônica de transmissão revelaram aglutinação de eritrócitos em capilares branquiais localizados próximos a cistos esféricos, contendo mixosporos do gênero Henneguya. Essa hemaglutinação obstruiu parcial ou totalmente os capilares branquiais. Os eritrócitos apareceram em forte aderência entre si, com espaço intercelular fechado. Foram observados poucos eritrócitos lisados entre as células aglutinadas. O lúmen reduzido dos capilares foi parcialmente preenchido com material homogêneo denso amorfo aderido aos eritrócitos, além de massas livres heterogêneas de densidade eletrônica baixa e irregular observadas no canal reduzido dos capilares. Os eritrócitos aglutinados pareciam densos e homogêneos, sem organelas citoplasmáticas. Os núcleos apareceram como massas normais de cromatina condensada, geralmente sem nucléolos visíveis. A ocorrência de hemaglutinação apenas nos capilares, localizados nas proximidades dos cistos mixozoários, sugere que o desenvolvimento parasitário pode ser um fator desencadeante da aglutinação eritrocitária. Isso é corroborado por estudos experimentais anteriores que mostraram uma provável correlação entre infecções parasitárias e hemaglutinação. No entanto, novos estudos são necessários para melhor compreender os processos físico-químicos envolvidos neste fenômeno.


Asunto(s)
Animales , Perciformes , Myxozoa , Enfermedades de los Peces , Capilares , Branquias , Hemaglutinación
18.
J Synchrotron Radiat ; 28(Pt 5): 1558-1572, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34475303

RESUMEN

A feasible implementation of a novel X-ray detector for highly energetic X-ray photons with a large solid angle coverage, optimal for the detection of Compton X-ray scattered photons, is described. The device consists of a 20 cm-thick sensitive volume filled with xenon at atmospheric pressure. When the Compton-scattered photons interact with the xenon, the released photoelectrons create clouds of secondary ionization, which are imaged using the electroluminescence produced in a custom-made multi-hole acrylic structure. Photon-by-photon counting can be achieved by processing the resulting image, taken in a continuous readout mode. Based on Geant4 simulations, by considering a realistic detector design and response, it is shown that photon rates up to at least 1011 photons s-1 on-sample (5 µm water-equivalent cell) can be processed, limited by the spatial diffusion of the photoelectrons in the gas. Illustratively, if making use of the Rose criterion and assuming the dose partitioning theorem, it is shown how such a detector would allow obtaining 3D images of 5 µm-size unstained cells in their native environment in about 24 h, with a resolution of 36 nm.

19.
Eur J Protistol ; 81: 125825, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34333451

RESUMEN

The Apicomplexa Aggregata spp. are intracellular parasites of cephalopods that infect the intestinal tract of commercially important species such as Octopus bimaculatus, which sustains the octopus fishery in Baja California (B.C.), Mexico. In this study, Aggregata polibraxiona n. sp. was described from the cecum of O. bimaculatus collected from Bahia de Los Angeles, B. C. Light and electron microscopy revealed that oocysts and sporocysts were spherical to ovoid in shape. Sporulated oocysts (293-835 × 177-688 µm) contained 135-674 sporocysts (12-24 × 11-22 µm). The sporocyst wall was covered by tubular projections (0.55-2.19 µm in length) bifurcated in the top, unevenly distributed, covered by a thin membrane. Each sporocyst contains 11-13 sporozoites (16-26 × 1.20-3 µm). Three partial sequences of the 18S rDNA gene were obtained, and two phylogenetic approaches were performed according to Bayesian inference and Maximum Likelihood. In both phylogenetic reconstructions, the sequences of A. polibraxiona n. sp. were recovered as a monophyletic group within the genus Aggregata and placed as a sister group to Aggregata octopiana Lineage II. Aggregata polibraxiona n. sp. is the first Apicomplexa described from a cephalopod host from Mexico and extends the geographical range of Apicomplexa infecting cephalopods.


Asunto(s)
Apicomplexa , Octopodiformes , Animales , Apicomplexa/genética , Teorema de Bayes , México , Filogenia
20.
J Invertebr Pathol ; 183: 107553, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33596434

RESUMEN

The ostreid herpes virus (OsHV-1), associated with massive mortalities in the bivalve Crassostrea gigas, was detected for the first time in the cephalopod Octopus vulgaris. Wild adult animals from a natural breeding area in Spain showed an overall prevalence of detection of 87.5% between 2010 and 2015 suggesting an environmental source of viral material uptake. Overall positive PCR detections were significantly higher in adult animals (p = 0.031) compared to newly hatched paralarvae (62%). Prevalence in embryos reached 65%. Sequencing of positive amplicons revealed a match with the variant OsHV-1 µVar showing the genomic features that distinguish this variant in the ORF4. Gill tissues from adult animals were also processed for in situ hybridization and revealed positive labelling. Experimental exposure trials in octopus paralarvae were carried out by cohabitation with virus injected oysters and by immersion in viral suspension observing a significant decrease in paralarval survival in both experiments. An increase in the number of OsHV-1 positive animals was detected in dead paralarvae after cohabitation with virus injected oysters. No signs of viral replication were observed based on lack of viral gene expression or visualization of viral structures by transmission electron microscopy. The octopus response against OsHV-1 was evaluated by gene expression of previously reported transcripts involved in immune response in C. gigas suggesting that immune defences in octopus are also activated after exposure to OsHV-1.


Asunto(s)
Virus ADN/aislamiento & purificación , Octopodiformes/virología , Animales , Secuencia de Bases , Genoma Viral , Larva/crecimiento & desarrollo , Larva/virología , Octopodiformes/crecimiento & desarrollo , Alineación de Secuencia
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