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result(s) for
"Castro, Mario G."
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Correlated evolution between body size and echolocation in bats (order Chiroptera)
by
Olalla-Tárraga, Miguel Á.
,
Castro, Mario G.
,
Amado, Talita Ferreira
in
Allometric patterns
,
Allometry
,
Analysis
2024
Background
Body size and echolocation call frequencies are related in bats. However, it is unclear if this allometry applies to the entire clade. Differences have been suggested between nasal and oral emitting bats, as well as between some taxonomic families. Additionally, the scaling of other echolocation parameters, such as bandwidth and call duration, needs further testing. Moreover, it would be also interesting to test whether changes in body size have been coupled with changes in these echolocation parameters throughout bat evolution. Here, we test the scaling of peak frequency, bandwidth, and call duration with body mass using phylogenetically informed analyses for 314 bat species. We specifically tested whether all these scaling patterns differ between nasal and oral emitting bats. Then, we applied recently developed Bayesian statistical techniques based on large-scale simulations to test for the existence of correlated evolution between body mass and echolocation.
Results
Our results showed that echolocation peak frequencies, bandwidth, and duration follow significant allometric patterns in both nasal and oral emitting bats. Changes in these traits seem to have been coupled across the laryngeal echolocation bats diversification. Scaling and correlated evolution analyses revealed that body mass is more related to peak frequency and call duration than to bandwidth. We exposed two non-exclusive kinds of mechanisms to explain the link between size and each of the echolocation parameters.
Conclusions
The incorporation of Bayesian statistics based on large-scale simulations could be helpful for answering macroevolutionary patterns related to the coevolution of traits in bats and other taxonomic groups.
Journal Article
Physical constraints on thermoregulation and flight drive morphological evolution in bats
by
Cruz-Neto, Ariovaldo P.
,
Martinez, Pablo A.
,
Dobrovolski, Ricardo
in
Adaptation
,
Animals
,
Bats
2022
Body size and shape fundamentally determine organismal energy requirements by modulating heat and mass exchange with the environment and the costs of locomotion, thermoregulation, and maintenance. Ecologists have long used the physical linkage between morphology and energy balance to explain why the body size and shape of many organisms vary across climatic gradients, e.g., why larger endotherms are more common in colder regions. However, few modeling exercises have aimed at investigating this link from first principles. Body size evolution in bats contrasts with the patterns observed in other endotherms, probably because physical constraints on flight limit morphological adaptations. Here, we develop a biophysical model based on heat transfer and aerodynamic principles to investigate energy constraints on morphological evolution in bats. Our biophysical model predicts that the energy costs of thermoregulation and flight, respectively, impose upper and lower limits on the relationship of wing surface area to body mass (S-MR), giving rise to an optimal S-MR at which both energy costs are minimized. A comparative analysis of 278 species of bats supports the model’s prediction that S-MR evolves toward an optimal shape and that the strength of selection is higher among species experiencing greater energy demands for thermoregulation in cold climates. Our study suggests that energy costs modulate the mode of morphological evolution in bats—hence shedding light on a long-standing debate over bats’ conformity to ecogeographical patterns observed in other mammals—and offers a procedure for investigating complex macroecological patterns from first principles.
Journal Article
Tuberculosis control and elimination 2010–50: cure, care, and social development
by
Chakaya, Jeremiah Muhwa
,
Raviglione, Mario C
,
Castro, Kenneth G
in
Acquired immune deficiency syndrome
,
AIDS-Related Opportunistic Infections - diagnosis
,
AIDS-Related Opportunistic Infections - drug therapy
2010
Rapid expansion of the standardised approach to tuberculosis diagnosis and treatment that is recommended by WHO allowed more than 36 million people to be cured between 1995 and 2008, averting up to 6 million deaths. Yet tuberculosis remains a severe global public health threat. There are more than 9 million new cases every year worldwide, and the incidence rate is falling at less than 1% per year. Although the overall target related to the Millennium Development Goals of halting and beginning to reverse the epidemic might have already been reached in 2004, the more important long-term elimination target set for 2050 will not be met with present strategies and instruments. Several key challenges persist. Many vulnerable people do not have access to affordable services of sufficient quality. Technologies for diagnosis, treatment, and prevention are old and inadequate. Multidrug-resistant tuberculosis is a serious threat in many settings. HIV/AIDS continues to fuel the tuberculosis epidemic, especially in Africa. Furthermore, other risk factors and underlying social determinants help to maintain tuberculosis in the community. Acceleration of the decline towards elimination of this disease will need invigorated actions in four broad areas: continued scale-up of early diagnosis and proper treatment for all forms of tuberculosis in line with the Stop TB Strategy; development and enforcement of bold health-system policies; establishment of links with the broader development agenda; and promotion and intensification of research towards innovations.
Journal Article
Antimicrobial and antibiofilm activity of biopolymer-Ni, Zn nanoparticle biocomposites synthesized using R. mucilaginosa UANL-001L exopolysaccharide as a capping agent
by
Díaz Barriga Castro, E
,
López-Vázquez, Mario Alberto
,
Garza-Cervantes, Javier Alberto
in
Antibiofilm activity
,
Antibiotics
,
Body weight
2019
Global increase in the consumption of antibiotics has induced selective stress on wild-type microorganisms, pushing them to adapt to conditions of higher antibiotic concentrations, and thus an increased variety of resistant bacterial strains have emerged. Metal nanoparticles synthesized by green methods have been studied and proposed as potential antimicrobial agents against both wild-type and antibiotic-resistant strains; in addition, exopolysaccharides have been used as capping agent of metal nanoparticles due to their biocompatibility, reducing biological risks in a wide variety of applications.
In this work, we use an exopolysaccharide, from
UANL-001L, an autochthonous strain from the Mexican northeast, as a capping agent in the synthesis of Zn, and Ni, nanoparticle biopolymer biocomposites.
To physically and chemically characterize the synthesized biocomposites, FT-IR, UV-Vs, TEM, SAED and EDS analysis were carried out. Antimicrobial and antibiofilm biological activity were tested for the biocomposites against two resistant clinical strains, a Gram-positive
, and a Gram-negative
. Antimicrobial activity was determined using a microdilution assay whereas antibiofilm activity was analyzed through crystal violet staining.
Biocomposites composed of exopolysaccharide capped Zn and Ni metal nanoparticles were synthesized through a green synthesis methodology. The average size of the Zn and Ni nanoparticles ranged between 8 and 26 nm, respectively. The Ni-EPS biocomposites showed antimicrobial and antibiofilm activity against resistant strains of
and
at 3 and 2 mg/mL, respectively. Moreover, Zn-EPS biocomposites showed antimicrobial activity against resistant
at 1 mg/mL. Both biocomposites showed no toxicity, as renal function showed no differences between treatments and control in the in vivo assays with male rats tests in this study at a concentration of 24 mg/kg of body weight.
The exopolysaccharide produced by
UANL-001L is an excellent candidate as a capping agent in the synthesis of biopolymer-metal nanoparticle biocomposites. Both Ni and Zn-EPS biocomposites demonstrate to be potential contenders as novel antimicrobial agents against both Gram-negative and Gram-positive clinically relevant resistant bacterial strains. Moreover, Ni-EPS biocomposites also showed antibiofilm activity, which makes them an interesting material to be used in different applications to counterattack global health problems due to the emergence of resistant microorganisms.
Journal Article
Role of Biologics in Asthma
by
Castro, Mario
,
McGregor, Mary Clare
,
Nair, Parameswaran
in
Allergies
,
Anti-Asthmatic Agents - therapeutic use
,
Antibodies, Monoclonal, Humanized - therapeutic use
2019
Patients with severe uncontrolled asthma have disproportionally high morbidity and healthcare utilization as compared with their peers with well-controlled disease. Although treatment options for these patients were previously limited, with unacceptable side effects, the emergence of biologic therapies for the treatment of asthma has provided promising targeted therapy for these patients. Biologic therapies target specific inflammatory pathways involved in the pathogenesis of asthma, particularly in patients with an endotype driven by type 2 (T2) inflammation. In addition to anti-IgE therapy that has improved outcomes in allergic asthma for more than a decade, three anti-IL-5 biologics and one anti-IL-4R biologic have recently emerged as promising treatments for T2 asthma. These targeted therapies have been shown to reduce asthma exacerbations, improve lung function, reduce oral corticosteroid use, and improve quality of life in appropriately selected patients. In addition to the currently approved biologic agents, several biologics targeting upstream inflammatory mediators are in clinical trials, with possible approval on the horizon. This article reviews the mechanism of action, indications, expected benefits, and side effects of each of the currently approved biologics for severe uncontrolled asthma and discusses promising therapeutic targets for the future.
Journal Article
Dupilumab Efficacy and Safety in Moderate-to-Severe Uncontrolled Asthma
by
Corren, Jonathan
,
Stahl, Neil
,
Chao, Jingdong
in
Adolescent
,
Adult
,
Anti-Asthmatic Agents - adverse effects
2018
Treatment of uncontrolled asthma with dupilumab, an anti–interleukin-4 and anti–interleukin-13 receptor monoclonal antibody, in addition to usual therapy, led to a rate of severe exacerbations that was approximately 50% lower than the rate with placebo.
Journal Article
Venezuela's humanitarian crisis, resurgence of vector-borne diseases, and implications for spillover in the region
by
Streicker, Daniel G
,
Hernandez-Pereira, Carlos E
,
Schwabl, Philipp
in
Animals
,
Chagas disease
,
Communicable Disease Control
2019
In the past 5–10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 and 2015, Venezuela witnessed a 359% increase in malaria cases, followed by a 71% increase in 2017 (411 586 cases) compared with 2016 (240 613). Neighbouring countries, such as Brazil, have reported an escalating trend of imported malaria cases from Venezuela, from 1538 in 2014 to 3129 in 2017. In Venezuela, active Chagas disease transmission has been reported, with seroprevalence in children (<10 years), estimated to be as high as 12·5% in one community tested (n=64). Dengue incidence increased by more than four times between 1990 and 2016. The estimated incidence of chikungunya during its epidemic peak is 6975 cases per 100 000 people and that of Zika virus is 2057 cases per 100 000 people. The re-emergence of many vector-borne diseases represents a public health crisis in Venezuela and has the possibility of severely undermining regional disease elimination efforts. National, regional, and global authorities must take action to address these worsening epidemics and prevent their expansion beyond Venezuelan borders.
Journal Article
Meaningful Work, Happiness at Work, and Turnover Intentions
by
Ballesteros-Valdés, Rosalinda
,
Charles-Leija, Humberto
,
Toledo, Mario
in
Beliefs, opinions and attitudes
,
Costs
,
Economics
2023
It has been documented that there is a positive relationship between a worker’s subjective well-being and productivity, and individuals who are happy in their work have a better attitude when performing activities: happier employees are more productive. Turnover intention, on the other hand, may arise from various factors rather than merely the need to increase a salary, as the traditional economic theory states. The fact that the work performed does not contribute to the worker’s life purpose, that there might be a bad relationship with colleagues, or else might play a role in the search for a new job. This study aims to show the relevance of meaningful work in happiness at work and turnover intention. Data from 937 professionals, in 2019, in Mexico were analyzed. Regression analyses were used to assess the impact of meaningful work on happiness at work and turnover intention. Results show that meaningful work, feeling appreciated by coworkers, and enjoyment of daily tasks significantly predict happiness at work. A logit model showed that having a job that contributes to people’s life purpose, feeling appreciated, and enjoyment of daily tasks reduces turnover intention. The main contribution of the study is to identify the importance of elements of purpose and meaning in the work context, contributing to economic theory. Limitations include the use of single items from a more extensive survey, which might diminish the validity and reliability of the constructs under scrutiny. Future directions point towards the need for more robust indicators of the variables of interest, but the findings emphasize the importance of research focused on the meaning workers attribute to their own work and the effects this attribution might have on their own wellbeing, organizational results, and productivity, including a return of investment (ROI) indicators.
Journal Article
Population genomics and geographic dispersal in Chagas disease vectors: Landscape drivers and evidence of possible adaptation to the domestic setting
by
Day, Casey C.
,
Ocaña-Mayorga, Sofía
,
Matthews, Louise
in
Adaptation
,
Adaptation, Biological - genetics
,
Animals
2022
Accurate prediction of vectors dispersal, as well as identification of adaptations that allow blood-feeding vectors to thrive in built environments, are a basis for effective disease control. Here we adopted a landscape genomics approach to assay gene flow, possible local adaptation, and drivers of population structure in Rhodnius ecuadoriensis , an important vector of Chagas disease. We used a reduced-representation sequencing technique (2b-RADseq) to obtain 2,552 SNP markers across 272 R . ecuadoriensis samples from 25 collection sites in southern Ecuador. Evidence of high and directional gene flow between seven wild and domestic population pairs across our study site indicates insecticide-based control will be hindered by repeated re-infestation of houses from the forest. Preliminary genome scans across multiple population pairs revealed shared outlier loci potentially consistent with local adaptation to the domestic setting, which we mapped to genes involved with embryogenesis and saliva production. Landscape genomic models showed elevation is a key barrier to R . ecuadoriensis dispersal. Together our results shed early light on the genomic adaptation in triatomine vectors and facilitate vector control by predicting that spatially-targeted, proactive interventions would be more efficacious than current, reactive approaches.
Journal Article
Effect of poor glycemic control in cognitive performance in the elderly with type 2 diabetes mellitus: The Mexican Health and Aging Study
by
Ávila-Funes, J. Alberto
,
Pérez-Zepeda, Mario U.
,
Jiménez-Castillo, Gilberto A.
in
Aged
,
Aging
,
Analysis
2020
Background
Cognitive impairment is twice more frequent in elderly with type 2 diabetes mellitus (DM). This study was conducted to determine the association between glycemic control and cognitive performance among community-dwelling elderly persons in Mexico.
Methods
Cross-sectional study conducted in individuals aged 60 years or elderly participating in the 2012 Mexican Health and Aging Study. Type 2 DM participants were classified in 3 groups according to their glycated hemoglobin levels (Hb
A1c
): < 7% (intensive control), 7–7.9% (standard control) or ≥ 8% (poor control), and cognitive performance: low (CCCE ≤44 points), intermediate (44.1–59.52 points), or high (≥59.53 points). Multinomial logistic regression models were constructed to determine this association.
Results
Two hundred sixteen community-dwelling adults aged 60 and older with type 2 diabetes were selected. Subjects in the low cognitive performance group were older (69.7 ± 6.6 vs 65.86 ± 5.18 years,
p
< .001) and had a lower educational level (2.5 ± 2.6 vs 7.44 ± 4.15 years,
p
< .000) when compared to the high cognitive performance participants. Hb
A1c
≥ 8% was associated with having low (Odds Ratio (OR) 3.17, 95% CI 1.17–8.60,
p
= .024), and intermediate (OR 3.23, 95% CI 1.27–8.20,
p
= .014) cognitive performance; this trend was not found for Hb
A1c
7.0–7.9% group.
The multinomial regression analysis showed that the presence of Hb
A1c
≥ 8% (poor glycemic control) was associated with low (OR 3.17, 95% CI = 1.17–8.60,
p
= .024), and intermediate (OR 3.23, 95% CI = 1.27–8.20,
p
= .014) cognitive performance. After adjusting for confounding variables.
Conclusions
Glycemic control with a Hb
A1c
≥ 8% was associated with worse cognitive performance.
Journal Article