Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
528 result(s) for "Trujillo, Fernando"
Sort by:
On the brink of isolation: Population estimates of the Araguaian river dolphin in a human-impacted region in Brazil
Populations of freshwater dolphins are declining in response to increased human pressure, including habitat degradation, overfishing, bycatch, poaching and obstruction of free-flowing river corridors by dams. At least three river dolphin species occur in South America: the Amazonian river dolphin, or boto (Inia geoffrensis), the Bolivian river dolphin (Inia boliviensis) and the tucuxi (Sotalia fluviatilis). A fourth species, the Araguaian boto (Inia araguaiaensis), been proposed for the Tocantins-Araguaia, a large river basin in northern Brazil. Here we show that the Araguaian boto population in the Tocantins River is relatively small (N = 1083, CV = 0.52). During a survey to estimate density and abundance, 138 groups (198 individuals) of botos were observed along a ~600 km stretch of the Tocantins River in five different habitats (river margin, river channel, channel, island margin, and a dam reservoir). Overall, lower densities of the Araguaian boto were registered downstream of the Tucuruí dam, the world's fifth largest hydropower dam. Density was 68% lower in the river margin habitat downstream (0.23 ind./km2, CV = 0.92) than upstream (0.72 ind./km2, CV = 0.53). In addition, density within the Tucuruí reservoir decreases from upstream areas towards the dam. Geographic post-stratification of data into sub-regions (downstream, reservoir, upstream) in relation to the Tucuruí dam helped to reduce CV by ~70%, which illustrates the high variability in the encounter rate in these areas. Our findings suggest that the Araguaian boto population has been impacted by the construction of the Tucuruí dam. The construction of other dams proposed for the Tocantins-Araguaia basin should be planned strategically to minimize overlapping with the Araguaian boto distribution. Coordinated conservation actions are imperative to prevent the Araguaian boto from reaching extinction or near-extinction as some of their Asian counterparts such as the Yangtze, Ganges, and Indus river dolphins.
Identifying the current and future status of freshwater connectivity corridors in the Amazon Basin
The Amazon Basin features a vast network of healthy, free‐flowing rivers, which provides habitat for the most biodiverse freshwater fauna of any basin globally. However, existing and future infrastructure developments, including dams, threaten its integrity by diminishing river connectivity, altering flows, or changing sediment regimes, which can impact freshwater species. In this study, we assess critical rivers that need to be maintained as freshwater connectivity corridors (FCCs) for selective freshwater species—long‐distance migratory fishes and turtles (both with migrations >500 km) and river dolphins. We define FCCs as river stretches of uninterrupted river connectivity that provide important riverine and floodplain habitat for long‐distance migratory and other species and that maintain associated ecosystem functions. We assessed more than 340,000 km of river, beginning with an assessment of the connectivity status of all rivers and then combining river status with models of occurrence of key species to map where FCCs occur and how they could be affected under a scenario of proposed dams. We identified that in 2019, 16 of 26 very long (>1000 km) rivers are free‐flowing but only 9 would remain free‐flowing if all proposed dams are built. Among long and very long rivers (>500 km), 93 are considered FCCs. Under the future scenario, one‐fifth (18) of these long and very long FCCs—those that are of critical importance for long‐distance migrants and dolphins—would lose their FCC status, including the Amazon, the Negro, Marañón, Napo, Ucayali, Preto do Igapó Açu, Beni, and Uraricoera rivers. To avoid impacts of poorly sited infrastructure, we advocate for energy and water resources planning at the basin scale that evaluates alternative development options and limits development that will impact on FCCs. The results also highlight where corridors could be designated as protected from future fragmentation. Freshwater connectivity corridors of the Amazon Basin are critical to maintain river services and biodiversity. Among rivers >500 km in length, there are currently 93 freshwater connectivity corridors (FCCs) that are either free‐flowing or of good connectivity status; one‐fifth of these FCCs would lose their free‐flowing status with buildout of proposed hydropower dams. Early basin‐wide planning, which includes information on freshwater species and ecosystems and avoids FCCs, examines alternative options for meeting energy or water resources needs, and sites needed infrastructure in the least harmful locations, is necessary.
Aquatic Wildmeat Consumption of Guiana Dolphins (Sotalia guianensis) in Lake Maracaibo System, Venezuela
In many regions of the world, the use of cetaceans as bait or protein source has been reported. In most cases the individuals are from bycatch but also from intentionally killed animals. Cetaceans with coastal habits are more susceptible to negative interactions with small-scale fisheries, as in the case of the Guiana dolphin ( Sotalia guianensis ) in the Lake Maracaibo system. For decades, the use of Guiana dolphins by local communities has been reported in this region and is culturally supported by recipes for its preparation. Most of these data was outdated and some were anecdotal, so the objective of this work was to collect systematically data through surveys using the snowball method in seven artisanal fishing communities and to try to quantify the capture rate and to inquire about the potential impact of this practice on the population of Guiana dolphin. From 2017 to 2019, 95 semi-structured interviews were applied. An average bycatch of 180 individuals/year was obtained, the highest catch rate in the entire geographic distribution, an alarming situation considering that the surveys were not carried out in all the fishing ports, generating an underestimation. A total of 78% of interviewed recognized at least one bycatch event during their fishing effort. Surveys revealed a higher incidence of entanglement of offspring and juveniles (78%). 77% of the respondents deny the sale and commercialization of the species, while 5% mention some type of trade. The most frequent part exploited was the dorsal muscle, confirmed by fishermen (97%, n = 72) and the rest of the animal is discarded. During this investigation three episodes of directed capture were recorded, affecting a total of 23 individuals, two of them were pregnant females. The interviews also revealed that the majority of fishermen (93%) recognize the capture of this species as illegal. Considering the vulnerability of the Guiana dolphin in the country, the high incidence of capture and consumption and the lack of surveillance and sanctions by government entities, it is imperative to immediate actions to mitigate the negative impact on the population.
Human T-cell Lymphotropic Virus Type I Associated with Amyotrophic Lateral Sclerosis Syndrome: Immunopathological Aspects and Treatment Options
Human T-cell lymphotropic virus type I (HTLV-I) is a retrovirus related to infectious myelopathies, neoplasms, lymphomas, leukemias, and amyotrophic lateral sclerosis (ALS). It is acquired through sexual transmission, transfusion of blood products, and breastfeeding. The increased expression of human endogenous retrovirus K (HERV-K) in the brain tissue of patients with ALS has been demonstrated, a finding that supports the relationship between the virus and this disease. Therapeutic options include supportive measures and symptomatic treatment with anti-inflammatory medications including steroids, cyclosporines, pentoxifylline, danazol, interferons, and vitamin C. New management proposals are being implemented with valproic acid that acts to facilitate the recognition of the virus by the immune system and with zidovudine antivirals focused on reducing viral load. The purpose of this paper is to describe a clinical case that exhibits clinical signs and evidence of motor neuron compromise as described in electrophysiology studies along with positive laboratory tests for the HTLV-I virus.
Breaking down silos: Conservation areas for Amazonian flagship terrestrial and freshwater species
Research into the threats affecting flagship terrestrial and freshwater species in the Amazon has operated within disciplinary and ecological silos, neglecting the interconnectedness between these species and ecosystems. In this study, we aimed to bridge these divides by identifying Amazon areas harboring high jaguar densities and high richness of migratory freshwater species, highlighting the potential co‐benefits of integrated terrestrial and freshwater conservation approaches. We also assessed the risks posed to these areas by habitat and connectivity loss due to impending dam construction, deforestation, and the lack of coverage by area‐based conservation schemes. We found that 17% of the Amazon River Basin is covered by areas of high jaguar density and freshwater migratory species richness, 83% of which are found in Brazil and Peru. A third of these areas are located outside of formal protected areas or Indigenous territories, with Bolivia representing the largest gap in formal protection. The proposed construction of 54 hydroelectric dams and the expansion of deforestation poses an immediate threat to the habitats and connectivity of these areas. Given the risk of an Amazon ecological tipping point, our study underscores the need for integrated terrestrial and freshwater conservation approaches that set in motion international collaboration to secure transboundary flagship and umbrella species. This study shows that 17% of the Amazon River Basin is covered by areas of high jaguar density and freshwater migratory species richness, 83% of which are found in Brazil and Peru. A third of these areas are located outside of formal protected areas or Indigenous territories. The construction of 54 proposed hydroelectric dams and the expansion of deforestation poses an immediate threat to the habitats and connectivity of these areas. The research underscores the need for integrated conservation approaches and international collaboration to safeguard these vulnerable ecosystems.
Range extension for the common dolphin (Delphinus sp.) to the Colombian Caribbean, with taxonomic implications from genetic barcoding and phylogenetic analyses
The nearest known population of common dolphins (Delphinus sp.) to the Colombian Caribbean occurs in a fairly restricted range in eastern Venezuela. These dolphins have not been previously reported in the Colombian Caribbean, likely because of a lack of study of the local cetacean fauna. We collected cetacean observations in waters of the Guajira Department, northern Colombia (~11°N, 73°W) during two separate efforts: (a) a seismic vessel survey (December 2009-March 2010), and (b) three coastal surveys from small boats (May-July 2012, May 2013, and May 2014). Here we document ten sightings of common dolphins collected during these surveys, which extend the known range of the species by ~1000 km into the southwestern Caribbean. We also collected nine skin biopsies in 2013 and 2014. In order to determine the taxonomic identity of the specimens, we conducted genetic barcoding and phylogenetic analyses using two mitochondrial markers, the Control Region (mtDNA) and Cytochrome b (Cytb). Results indicate that these specimens are genetically closer to the short-beaked common dolphin (Delphinus delphis) even though morphologically they resemble a long-beaked form (Delphinus sp.). However, the specific taxonomic status of common dolphins in the Caribbean and in the Western Atlantic remains unresolved. It is also unclear whether the distribution of the species between northern Colombia and eastern Venezuela is continuous or disjoined, or whether they can be considered part of the same stock.
Generación de lineamientos para una propuesta de política pública que oriente la publicidad dirigida a niños de entre los 2 y 10 años, como mercado objetivo para la prevención de los efectos nocivos en ellos
El presente documento hace un rastreo de la normatividad vigente en Colombia encargada de regular la publicidad dirigida a niñas, niños y adolescentes, y de la forma en que opera la publicidad como medio de manipulación. Se expondrá un análisis de la inadecuada regulación y ejecución normativa en este campo, así como de la forma de operar de los medios de comunicación que prestan servicios a empresas productoras de bienes y servicios. Sobre estas últimas se mencionarán los métodos de captación de clientes que han utilizado para generar mayores ingresos y que han ocasionado, indirecta o directamente, efectos nocivos en el desarrollo psicológico, físico y social de muchas niñas, niños y adolescentes. Se considera que, debido a las facilidades comunicacionales y tecnológicas, los niños, niñas y adolescentes se han visto permeados por una gran cantidad de publicidad agresiva y sistemática que les ofrece servicios que van en detrimento de su desarrollo integral. Todo ello, con el ánimo de generar conciencia sobre la necesidad de una propuesta de política pública que, con apoyo interdisciplinario, redunde en la prevención y atención de los efectos nocivos que este tipo de publicidad causa en este grupo poblacional.
Altered levels of IFN-γ, IL-4, and IL-5 depend on the TLR4 rs4986790 genotype in COPD smokers but not those exposed to biomass-burning smoke
Chronic obstructive pulmonary disease (COPD) is associated with tobacco smoking and biomass-burning smoke exposure. Toll-like receptor 4 ( ) single-nucleotide polymorphisms (SNPs) may contribute to its pathogenesis. The study aimed to assess the association of rs4986790 and rs4986791 in the gene in a Mexican mestizo population with COPD secondary to tobacco smoking (COPD-TS) and biomass-burning smoke (COPD-BBS) and to evaluate whether the genotypes of risk affect cytokine serum levels. We enrolled 2,092 participants and divided them into two comparisons according to their environmental exposure. SNPs were genotyped using TaqMan probes. Serum cytokine levels (IL-4, IL-5, IL-6, IL-10, and INF-γ) were quantified by ELISA. The rs4986790 AA genotype in COPD-TS was associated with a higher COPD risk (OR = 3.53). Haplotype analysis confirmed this association, identifying a block containing the rs4986790 allele (A-C, OR = 3.11). COPD-TS exhibited elevated IL-6, IL-4, and IL-5 levels compared with smokers without COPD (SWOC), whereas COPD-BBS displayed higher IFN-γ, IL-6, and IL-10 levels. The AA carriers in the COPD-TS group had elevated IL-4, IL-5, and IFN-γ compared with carriers of AG or GG. The rs4986790 common allele and the A-C haplotype (rs4986790-rs4986791) were associated with a higher COPD risk in smokers; COPD patients carrying the AA genotype showed increased pro-inflammatory cytokines.
Prospective patterns of modifiable health risk behaviors and the utilization of healthcare services in the “Health Workers Cohort Study” in Mexico
We still lack information about how changes in modifiable health risk behaviors influence the utilization of healthcare services. This study assesses the relationships between prospective patterns of modifiable health risk behaviors and the utilization of healthcare services. This was a prospective study among men and women participants in the Health Workers Cohort Study, aged 18 years and older. The following data about modifiable health risk behaviors was collected in two waves of the study (2004-2006 and 2010-2012): 1) physical activity, b) consumption of fruit and vegetables, 3) alcohol, and 4) tobacco consumption, to determine the association between the utilization of healthcare services after 6 years of follow-up (period 2010-2012). Information was collected through self-administered questionnaires; clinical and anthropometric variables were measured following standard procedures. Analyses were conducted using zero-inflated negative binomial regression models. Participants with a pattern of consumption of < 3 portions of fruits and vegetables per day (p = 0.035) and did not meet recommended levels of PA (p = 0.013) during the two waves of the study had fewer preventative consultations; those who quit smoking reported a higher frequency of preventative consultations (p = 0.021) and more visits with a medical specialist (p = 0.048). Participants who reduced alcohol consumption to low or completely stopped its consumption reported fewer visits to the general physician (p = 0.031), p < 0.05. Changes in prospective patterns of modifiable health risk behaviors influenced the use of healthcare services after 6 years of follow-up. Findings in this study could be useful to determine possible demands of healthcare services among populations with specific modifiable health risk behaviors.