The triatomine bug Triatoma infestans was probably originated in Bolivia and dispersed passively over large areas of South America, where it is the major vector of Trypanosoma cruzi. In its probable origin area this species shows two different patterns of behaviour, being found both in sylvatic and human related habitats. Such behaviour is not observed in other areas of its distribution, where it is exclusive to human related habitats. The main objective of the present study was to evaluate head morphometry characters and isoenzymes patterns of two T. infestans populations, one collected in Minas Gerais (Brazil) and other in the Cochabamba Valley (Bolivia), in order to elucidate the factors that could have an implication with the different colonization behaviour. The two populations presented differences in both morphometric (head size) and isoenzymes (specially PGM enzyme profile). The insects from the colonies reared for several years in laboratory conditions, showed reduction in head size starting from the third generation, maintaining this same size in all generations after, until 10 years after generation. The laboratory rearing conditions could be similar to human associated habitats, inducing certain level of genetic homogeneity. Our results showed increase of genetic homogeneity in Brazilian and laboratory-reared colonies from Bolivia, that may be due to a selection process due to passive dispersion, followed by several founder effects episodes and genetic drift.
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http://dx.doi.org/10.1016/j.actatropica.2009.07.023 | DOI Listing |
medRxiv
January 2025
Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, 90095.
Background: Electroconvulsive therapy (ECT) is a well-established and effective treatment for severe depression and other conditions. Though ECT induces a generalized seizure, it is unclear why seizures are therapeutic. This study analyzed relationships between pre-treatment brain morphology, stimulation dose, and seizure duration to better understand ECT-induced seizures.
View Article and Find Full Text PDFBMC Ophthalmol
January 2025
Department of Ophthalmology, Medical Faculty, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany.
Background/ Aims: To analyze the longitudinal change in Bruch's membrane opening minimal rim width (BMO-MRW) and peripapillary retinal nerve fiber layer (pRNFL) thickness using optical coherence tomography (OCT) after implantation of a PRESERFLO® microshunt for surgical glaucoma management in adult glaucoma patients.
Methods: Retrospective data analysis of 59 eyes of 59 participants undergoing implantation of a PRESERFLO microshunt between 2019 and 2022 at a tertiary center for glaucoma management. Surgical management included primary temporary occlusion of the glaucoma shunt to prevent early hypotony.
J Neuroimaging
January 2025
Department of Otorhinolaryngology, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea.
Background And Purpose: Tinnitus is a condition in which individuals perceive sounds, such as ringing or buzzing, without any external source. Although the exact cause is not fully understood, recent studies have indicated the involvement of nonauditory brain structures, including the limbic system. We aimed to compare the volumes of specific brain structures between patients with tinnitus and controls.
View Article and Find Full Text PDFAnimals (Basel)
December 2024
Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Rua D. Manuel II, Apartado 55142, 4051-401 Porto, Portugal.
The aim of this preliminary study was to morphologically and dimensionally characterize the cat's olfactory bulb in the sagittal plane and to establish potential relationships with the cranial conformation, based on the study of in vivo MRI images. Midsagittal and transverse T2-weighted images of the head of 40 cats subjected to MRI were selected. For each animal, the skull index was calculated to classify the cranial conformation.
View Article and Find Full Text PDFGeroscience
January 2025
Cerebral Imaging Center, Douglas Mental Health University Institute, 6875 Boulevard LaSalle, Montréal, QC, H4H 1R3, Canada.
Neuroanatomical sex differences estimated in neuroimaging studies are confounded by total intracranial volume (TIV) as a major biological factor. Employing a matching approach widely used for causal modeling, we disentangled the effect of TIV from sex to study sex-differentiated brain aging trajectories, their relation to functional networks and cytoarchitectonic classes, brain allometry, and cognition. Using data from the UK Biobank, we created subsamples that removed, maintained, or exaggerated the TIV differences in the original sample.
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