Browsing by Autor "Carlos F. Pinto"

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ACTIVIDAD REPELENTE DE LOS ACEITES ESENCIALES AMOMYRTUS MELI, PEUMUS BOLDUS Y SENECIO NUTANS, EN TRIATOMA INFESTANS (HEMIPTERA REDUVIIDAE)
(2022) Marycruz Mojica; María Noel Reynoso; Sofía L. Mengoni; Raúl A. Alzogaray; Carlos F. Pinto
Triatoma infestans, es el principal vector de la enfermedad de Chagas en Bolivia y países vecinos. Su control se basa principalmente en tratamientos con insecticidas sintéticos, pero existen pocos estudios sobre los efectos de los repelentes naturales en esta especie. El objetivo de este estudio fue evaluar la actividad repelente de los aceites esenciales (AEs) de especies nativas de Chile, Argentina y Bolivia: Amomyrtus meli (Phil.) D. Legrand & Kausel [Myrtaceae], Peumus boldus Molina [Monimiaceae] y Senecio nutans Sch. Bip. [Asteraceae] obtenidos por hidrodestilación. La arena experimental estuvo constituida por un papel filtro que tenía una mitad tratada con acetona y la otra mitad con una solución de AE en acetona. Como control positivo se utilizó N, N-dietil-3-metilbenzamida (DEET). Se colocó una ninfa de quinto estadío de T. Infestans sobre el papel y, durante 10 minutos se registró el tiempo que el insecto estuvo en la zona tratada con AE o en la zona alternativa. Se evaluaron cinco concentraciones de cada AE entre 4.12, 8.25, 16.5, 33.0 y 66.0 µg/cm2. Los tres AEs produjeron un efecto repelente sobre T. infestans, y su perfil de repelencia fue similar al de la DEET. Futuras investigaciones deberían centrarse en el estudio de la repelencia individualizada de compuestos específicos de los AE además de las interacciones toxicológicas entre ellos cuando se aplican como mezclas simples. En particular, las interacciones sinérgicas serían un fenómeno atractivo para el desarrollo de productos repelentes de triatominos.
Age-related anomalies of electrocardiograms in patients from areas with differential Seroprevalence of Chagas disease in Southern Bolivia
(Elsevier BV, 2021) Jhean-Carla Echalar; David Véliz; Omar N. Urquizo; Hermann M. Niemeyer; Carlos F. Pinto
Higher seroprevalence in rural population was attributable to a higher probability to encounter the vector in rural areas. Increased exposure to infection and to development of the disease symptoms together with increased lethality of the disease as patients age explains the age-related Chagasic electrocardiographic anomalies. Since rural and urban populations showed different reactions under Chagas disease and the rural population was mainly of guaraní stock, the genetic and environmental determinants of the results should be further explored.
Análisis multi-temporal de mosaico de etapas sucesionales del bosque chaqueño de Arenales, Parque Nacional Kaa-Iya del Gran Chaco
(2017) Carlos F. Pinto; Erika Cuéllar Soto
Assessment of Shape Variation Patterns in Triatoma infestans (Klug 1834) (Hemiptera: Reduviidae: Triatominae): A First Report in Populations from Bolivia
(Multidisciplinary Digital Publishing Institute, 2020) Carolina Vilaseca; Marco A. Méndez; Carlos F. Pinto; Hugo A. Benítez
The morphological variations of four populations of geographically isolated Triatoma infestans located in the area of inter-Andean valleys and Chaco of Chuquisaca, Bolivia, were evaluated. Fifty-three females and sixty-one males were collected in the peri-domicile and analyzed with geometric morphometrics tools to study the patterns of the head and wing shape variation. The principal component analysis and canonical variate analysis revealed morphological variations between the populations studied, which were then confirmed by the permutation test of the differences between populations using Mahalanobis and Procustes distances. The multivariate regression analysis shows that the centroid size influences the shape of the heads and wings. T. infestans of the inter-Andean valleys are longer in the head and wings compared to the population of the Chaco. We propose that the geometric shape variation may be explained by geographical changes in climatic conditions, peri-domiciliar habitats, food source quality, and the use of insecticides.
Biology and Ecology of Alchisme grossa in a Cloud Forest of the Bolivian Yungas
(Oxford University Press, 2014) Daniel Torrico-Bazoberry; Liliana Alejandra Cáceres Sanchez; Daniela Saavedra-Ulloa; Luis Flores‐Prado; Hermann M. Niemeyer; Carlos F. Pinto
Treehoppers (Membracidae) exhibit different levels of sociality, from solitary to presocial. Although they are one of the best biological systems to study the evolution of maternal care in insects, information on the biology of species in this group is scarce. This work describes the biology and ecology of Alchisme grossa (Fairmaire) (Hemiptera: Membracidae) in a rain cloud forest of Bolivia. This subsocial membracid utilizes two host-plant species, Brugmansia suaveolens (Humb. & Bonpl. ex Wild) Bercht. & J.Presl and Solanum ursinum (Rusby) (both Solanaceae), the first one being used during the whole year and the second one almost exclusively during the wet season. The development of A. grossa from egg to adult occurred on the plant where eggs were laid. Maternal care was observed during the complete nymphal development, and involved behavioral traits such as food facilitation and antidepredatory defense. Life cycle was longer on B. suaveolens during the dry season and shorter on S. ursinum during the wet season. Mortality was similar on both host plants during the wet season but was lower on B. suaveolens during the dry season. The presence of a secondary female companion to the egg-guarding female individual and occasional iteropary is also reported.
Biology, ecology and demography of the tropical treehopper <scp>E</scp> nnya maculicornis ( <scp>H</scp> emiptera: <scp>M</scp> embracidae): relationships between female fitness, maternal care and oviposition sites
(Wiley, 2017) Liliana Alejandra Cáceres Sanchez; Daniel Torrico-Bazoberry; ROMINA COSSIO; KENIA REQUE; Sandra Aguilar; Hermann M. Niemeyer; Carlos F. Pinto
1. Treehoppers ( H emiptera: M embracidae) exhibit a wide range of social behaviours related to maternal care and nymphal aggregation. Maternal care represents an investment in terms of time and energy leading to trade‐offs which bear a strong relationship with parity and can thus affect population dynamics. These trade‐offs can be modulated by biotic and abiotic features of the oviposition site. 2. Preliminary observations on E nnya maculicornis ( M embracidae: S imilinae: P olyglyptini) show that females generally lay a single egg mass, and occasionally two or three egg masses, and that maternal care is a plastic trait because some females abandoned their egg mass before it hatched while other females remained with their offspring after egg hatching. These features make this species an interesting model to study the relationship between female fitness, maternal care and ecological factors such as oviposition site. 3. The biology and natural history of E . maculicornis are described and the relationships in question analysed using demographic parameters estimated by matrix models. E nnya maculicornis showed sexual dimorphism and a longer developmental period than other species of the same tribe. Females exhibited maternal care that increased offspring survival, and preferred mature over young host leaves for oviposition. Finite rate of increase ( λ ) values were lower than 1, suggesting a tendency towards population decrease. 4. The results represent the first detailed description of the life history and ecology for a species of this genus. Additionally, new hypotheses for treehopper sexual dimorphism, oviposition site choice and the ecological effects on population dynamics are proposed.
CAPITAL SOCIAL VINCULANTE Y ESTRÉS ACADÉMICO EN ESTUDIANTES UNIVERSITARIOS
(2022) Mario Eduardo Castro Torres; Pablo Marcelo Vargas-Piérola; Carlos F. Pinto; Rubén Alvarado
Aunque el estrés académico (EA) es un problema con alta incidencia en universitarios, hay pocos estudios sobre el tema. Este trabajo busca determinar si existe correlación entre el capital social vinculante (CSV) y sus dimensiones (tamaño de red, confianza, reciprocidad y propiedad de los recursos) con los síntomas psicológicos (SPsi) del EA, determinando su fuerza y significancia. Método: Se evaluó la correlación entre las dimensiones del CSV con los SPsi del EA en una muestra de 150 estudiantes universitarios voluntarios. Se usó el coeficiente de Spearman (rs) para establecer la correlación, la prueba de independencia de Chi-cuadrado de Pearson (X2) para establecer la diferencia entre grupos y el análisis de residuos (Rü) para determinar dirección y significancia. Resultados: Un tercio de los estudiantes presenta alta frecuencia de SPsi mientras que la cuarta parte una regular. El CSV tiene una correlación negativa, débil y significativa con los SPsi (rs(123)= -.18, p= .040), al igual que la confianza (rs(123)= .-19, p= .031). Adicionalmente, se identificó una correlación negativa, significativa y fuerte entre la dimensión confianza del CSV y el SPsi 20 [ansiedad, angustia o desesperación] del EA (X2= 4.83; gl= 1; p= .028; V de Cramer= 0.21). Discusión: El tamaño del efecto de las correlaciones da cuenta de que existen otras variables involucradas en la relación entre capital social y EA, lo que implica mediación. Es necesario mejorar a futuro la explicación de la relación entre CSV y EA incluyendo más variables en un modelo más complejo de análisis. Palabras clave: capital social, estrés académico, síntomas psicológicos, estudiantes universitarios.
Demographic and performance effects of alternative host use in a Neotropical treehopper (Hemiptera: Membracidae)
(Elsevier BV, 2019) Carlos F. Pinto; Daniel Torrico-Bazoberry; Luis Flores‐Prado; Ramiro O. Bustamante; Hermann M. Niemeyer
Dominance of Capsicum minutiflorum (Solanaceae) pollen in stingless bee hives: An insight into protein composition and foraging behavior by four Meliponini species of the Bolivian-Tucumano forest
(Pensoft Publishers, 2025) M. Adler; Mariela Ajhuacho-Villalobos; Luis Flores‐Prado; Santiago Benitez‐Vieyra; Kathy Collao-Alvarado; Carlos F. Pinto
Stingless bees (Apidae: Meliponini) primarily feed on nectar and pollen from a wide diversity of flowering plants. By doing so they pollinate these flowers thus contributing to biodiversity and ecosystem stability. The pollen they collect provides essential nutrients for brood rearing and colony growth. This study aimed to characterize the floral resources available to stingless bees in a Tucumano-Boliviano Forest, including their pollen protein content and, through construction of an interaction network and preference analysis, understand their foraging behavior. Only 8 out of 25 pollen types sampled within the study site around the meliponaries were collected by the bees. Pollen pots also contained many types of pollen not from to plant species in the study area. Pollen from Capsicum minutiflorum (Solanaceae) was dominant in almost every hive (up to 98.7% of pollen composition). Additionally, protein content of Capsicum minutiflorum pollen (67% w/w) was the highest of all species present at the study site and explained almost 100% of the protein content in the hives of Tetragonisca angustula , and Scaptotrigona depilis , and almost 80% and 75% of the protein content in those of Scaptotrigona polysticta and Melipona rufiventris , respectively. These results suggest that stingless bees preferentially collect pollen with higher protein content.
Effects of Social Capital on Depression in University Students
(Multidisciplinary Digital Publishing Institute, 2025) Mario Eduardo Castro Torres; Pablo Marcelo Vargas-Piérola; Aarón Marco Layme Mamani; Ana Maria Ossa Toro; A.L Lara Domínguez; Carlos F. Pinto
This study examines how bonding social capital (BSC) is related to depression symptoms (Dsym) in university students, focusing on the mediating roles of socio-emotional support, instrumental support, self-efficacy, self-esteem, and academic stress. A cross-sectional design was employed, with data collected from 217 undergraduate students (from an initial sample of 250) using validated questionnaires. Data were analyzed using partial least squares structural equation modeling (PLS-SEM) to evaluate direct and indirect relationships. The key findings indicate that BSC has an indirect, relevant, and significant negative effect on Dsym (H5) (β = -0.201, 95% CI [-0.266, -0.216]) through six routes, involving enhanced self-esteem and reduced academic stress. The model highlights self-esteem as a critical mediator between social capital and mental health outcomes. With strong predictive validity (R2 ≥ 0.1, Q2 > 0, PLS-SEM RMSE < LM), the study provides a framework for potential interventions. The theoretical contributions include distinguishing social capital from support and prioritizing self-esteem over self-efficacy in depressive pathways. Although the cross-sectional design limits causal inferences, the model advances systemic approaches to student mental health, highlighting the need for longitudinal validation in diverse contexts.
Inexpensive Methods for Detecting and Reproducing Substrate-Borne Vibrations: Advantages and Limitations
(Springer Nature, 2022) Rachele Nieri; Sabrina Michael; Carlos F. Pinto; Omar N. Urquizo; Heidi M. Appel; Reginald B. Cocroft
Insect Fluctuating Asymmetry: An Example in Bolivian Peridomestic Populations of Triatoma infestans (Klug, 1834) (Hemiptera: Reduviidae)
(Multidisciplinary Digital Publishing Institute, 2022) Carolina Vilaseca; Carlos F. Pinto; Rodrigo Órdenes-Clavería; D. Laroze; Marco A. Méndez; Hugo A. Benítez
Fluctuating asymmetry (FA) is a morphometric tool used to measure developmental instability in organisms which have been exposed to stress or other adverse conditions. Phenotypic variability in response to stressors are the result of interactions between genomes and the environment, acting in a noisy developmental system. Most of the organisms have bilateral symmetry with a repetition of structures in different positions or orientations; asymmetrical variation has been a morphological response associated with insecticide application inducing disturbances in endocrinal system product of the chemicals. Triatoma infestans (is the main vector of Chagas disease in South America. The availability of food sources varies for populations of T. infestans living in different habitats; insects that inhabit the intradomicile feed preferentially on human blood, whereas insects that develop in the peridomicile feed on the blood of the other mammals and birds. The following research evaluate the FA to the different ecotopes in two geographical areas of Chuquisaca Bolivia; Yamparáez/Sotomayor of the high inter-Andean valleys and Huacaya/Imbochi of the boreal Chaco and a CIPEIN laboratory strain population. A combination of advanced morphometrics tools and multivariate analysis were used to quantify the levels of asymmetry produced by pyretroid near to the peridomiciles in Bolivia. Populations from Yamparáez/Sotomayor were found to have higher levels of FA which the combination of environmental conditions such as low temperatures avoid greater permanence in the habitat and more exposition to insecticide. A better understanding of the combination of these tools will allow researchers to implement better public policies to regulate insecticide applications and to understand how certain organisms adapt to multiple stressors.
Kin recognition in a subsocial treehopper ( <scp>H</scp> emiptera: <scp>M</scp> embracidae)
(Wiley, 2018) Daniel Torrico-Bazoberry; Liliana Alejandra Cáceres Sanchez; Luis Flores‐Prado; Daniel Aguilera‐Olivares; Francisco E. Fontúrbel; Hermann M. Niemeyer; Carlos F. Pinto
1. Insects exhibiting parental care usually can discriminate between kin and non‐kin individuals, allowing parents to avoid investment in foreign offspring. 2. This study investigated the occurrence of kin recognition in the sap‐feeding insect Alchisme grossa Fairmaire (Membracidae) through bioassays assessing median female distance to nymphs and degree of nymphal aggregation. Each bioassay involved groups consisting of a female and a cohort of kin or non‐kin nymphs (mother and non‐mother treatments, respectively). Furthermore, cuticular non‐volatile compounds were extracted from nymphal cohorts, analysed by gas chromatography‐mass spectrometry and compared between cohorts. 3. In both treatments, nymphs performed a ‘rocking behaviour’ which appears to be correlated with aggregation. Temporal patterns of degree of nymphal aggregation and median female–nymph distance differed between treatments, the former parameter being higher in the mother treatment and the latter being higher in the non‐mother treatment. 4. A total of 40 compounds were found in the extracts. The composition of cuticular non‐volatile compounds differed between nymphal cohorts. 5. These results support the notion that kin recognition in A. grossa is possibly mediated by nymphal rocking behaviour and/or cuticular non‐volatile compounds (i.e. visual and/or chemical cues).
Knowledge, attitudes, and practices towards the risk of zoonotic diseases, wildlife trade and wildlife consumption in Latin America
(National Institute of Environmental Health Sciences, 2024) María Teresa Solis Soto; Caroline Kühn; Denise Siqueira de Carvalho; María Soledad Burrone; Pilar Masilla; Carlos Vásquez Almazán; Carlos F. Pinto; M. Adler; Dennis Méndez; F. Fiengo Pérez
Leaf vibrations produced by chewing provide a consistent acoustic target for plant recognition of herbivores
(Springer Science+Business Media, 2020) Alexis M. Kollasch; Abdul-Rahman Abdul-Kafi; Mélanie Body; Carlos F. Pinto; Heidi M. Appel; Reginald B. Cocroft
Mate searching in Ennya maculicornis (Membracidae: Polyglyptini) initiated by females: behavioural and acoustic descriptions
(Wiley, 2019) Romina Cossio‐Rodríguez; Reginald B. Cocroft; Hermann M. Niemeyer; Carlos F. Pinto
1. In treehoppers in which courtship has been studied, males initiate the search for females by periodically emitting a vibrational signal. The responses by the female are used by males as a beacon and give rise to a duet. 2. Courtship and mating of the treehopper Ennya maculicornis were characterised through the simultaneous recording of vibrational signals and the behaviour of males and females in an arena. 3. In E. maculicornis , female initiated mate searching. Females produced two types of signals during the this process: (i) a signal that preceded the approach by the male and (ii) a signal that preceded mating. Males emitted two signals associated with two stereotyped body movements: (i) a signal produced as a response to the first signal emitted by the female, involving a change in the male's locomotory mode and the approach to the female, and (ii) a signal produced after finding and holding on to the female, involving simultaneous abdomen raising and wing fluttering. These signals were repeated several times before the female emitted the second signal. The four signalling patterns were observed in all recordings in which mating was observed. When any of the signals was missing, mating did not occur. 4. Female‐biased sex ratios in E. maculicornis , along with iteroparity, are suggested to explain the initiation of mate searching behaviour by females. A comparison of data with that from other treehoppers indicates that vibrational signals and their associated behaviour are more diverse among treehoppers than has been appreciated previously.
Multiple sequential mediation model of the effect of Social Capital Investment on Academic Stress
(Elsevier BV, 2023) Mario Eduardo Castro Torres; Pablo Marcelo Vargas-Piérola; Carlos F. Pinto; Rubén Alvarado
This study proposed a new model for understanding the relationship between social capital investment (SCI) and academic stress (AS). The effect of SCI over the psychological symptoms of AS (PsyS) through multiple and sequential mediation of bonding social capital (BSC), socio-emotional support (SES) and self-efficacy was analyzed through partial least squares structural equations modeling (PLS-SEM). Based on data from 150 university students, findings suggest that as students increase their level of SCI, their perception of greater SES and BSC grows; in turn, this raises the probability to perceive higher levels of self-efficacy; and higher levels of SES and self-efficacy decrease PsyS levels. New identified effects in the analyzed relationship provide the basis for future intervention and research.
Natural selection in the tropical treehopper Alchisme grossa (Hemiptera: Membracidae) on two sympatric host-plants
(Springer Science+Business Media, 2016) Daniel Torrico-Bazoberry; Carlos F. Pinto; Luis Flores‐Prado; Francisco E. Fontúrbel; Hermann M. Niemeyer
Pollen composition and physicochemical properties of honey produced by three stingless bees species from a mesotropical subhumid region in Bolivia
(Springer Science+Business Media, 2024) M. Adler; Gina Zambrana-Camacho; Luis Flores‐Prado; Omar N. Urquizo; Kathy Collao-Alvarado; Carlos F. Pinto
Pollen morphology of four species of salvia genus (lamiaceae) in periurban areas of Sucre, Bolivia
(2018) Alexandria Saravia; Carlos F. Pinto