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Social behavior is a key adaptation for group-living primates. It is important to assess changes to social behavior in human-impacted landscape zones to better understand the impact of anthropogenic disturbance on primate species. We investigated social behavior rate and type in three species of platyrrhines across 100 m anthropogenic edge and interior zones of a fragmented forest in Costa Rica, La Suerte Biological Research Station (LSBRS). Following results from other sites, we predicted that spider monkeys (Ateles geoffroyi), capuchin monkeys (Cebus imitator) and howler monkeys (Alouatta palliata) would show lower rates and fewer types of social behavior in forest edge compared to interior. We collected 1341 h of instantaneous focal data from 2017 to 2023 across the three monkey species. We found mixed support for our predictions, with spider and capuchin monkeys modifying some but not all aspects of social behavior across forest zones at LSBRS. Spider monkeys had lower rates of social behavior and capuchin monkeys performed different types of social behaviors in forest edge compared to interior at LSBRS. In contrast, howler monkeys did not modify social behavior. Two out of three platyrrhine species altered their social behavior when in anthropogenic edges, indicating behavioral adjustment when in human-altered habitat areas at LSBRS.
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Forest loss and degradation due to land cover changes imperil biodiversity worldwide. Subtropical and tropical ecosystems experience high deforestation rates, negatively affecting species like primates. Madagascar's endemic lemurs face exceptionally high risks of population declines and extirpation. We examined how short-term land cover changes within a fragmented landscape in southeastern Madagascar impacted the density of lemur species. Using line transects, we assessed density changes in nine lemur species across five forest fragments. Diurnal surveys were conducted monthly from 2015 to 2019 on 35 transects (total effort = 1268 km). Additionally, 21 transects were surveyed nocturnally in 2015 and 2016 (total effort = 107.5 km). To quantify forest cover changes, we generated land use/land cover (LULC) maps from Sentinel-2 imagery using supervised classification for each year. For the LULC maps, we overlayed species-specific buffers around all transects and calculated the proportion of land cover classes within them. We observed declines in the annual densities of four diurnal and cathemeral lemur species between 2015 and 2019, with species-specific declines of up to 80% (Varecia variegata). While the density of two nocturnal species decreased, one increased fivefold (Cheirogaleus major) between 2015 and 2016. By 2019, Grassland was the dominant land type (50%), while Paddy Fields had the smallest coverage (1.03%). Mature Agricultural Land increased the most (63.37%), while New Agricultural Land decreased the most (-66.36%). Unexpectedly, we did not find evidence that higher forest cover supported a higher lemur population density within sampled areas, but we found support for the negative impact of degraded land cover types on three lemur species. Our study underscores the urgent need to address land-use changes and their repercussions for primate populations in tropical ecosystems. The diverse responses of lemur species to modified habitats highlight the complexity of these impacts and emphasize the importance of targeted conservation efforts.
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Forest fragmentation increases forest edge relative to forest interior, with lower vegetation quality common for primates in edge zones. Because most primates live in human-modified tropical forests within 1 km of their edges, it is critical to understand how primates cope with edge effects. Few studies have investigated how primates inhabiting a fragment alter their behaviour across forest edge and interior zones. Here we investigate how anthropogenic edges affect the activity and spatial cohesion of mantled howler monkeys (Alouatta palliata) at the La Suerte Biological Research Station (LSBRS), a Costa Rican forest fragment. We predicted the monkeys would spend greater proportions of their activity budget feeding and resting and a lower proportion travelling in edge compared to forest interior to compensate for lower resource availability in the edge. We also predicted that spatial cohesion would be lower in the edge to mitigate feeding competition. We collected data on activity and spatial cohesion (nearest neighbour distance; number of individuals within 5 m) in forest edge and interior zones via instantaneous sampling of focal animals. Contrary to predictions, the monkeys spent equal proportions of time feeding, resting and travelling in forest edge and interior. Similarly, there were no biologically meaningful differences in the number of individuals or the distance between nearest neighbours in the edge (1.0 individuals; 1.56 m) versus the interior (0.8 individuals; 1.73 m). Our results indicate that A. palliata at LSBRS do not adjust their activity or spatial cohesion patterns in response to anthropogenic edge effects, suggesting that the monkeys here exhibit less behavioural flexibility than A. palliata at some other sites. To develop effective primate conservation plans, it is therefore crucial to study primate species' responses to fragmentation across their geographic range.
Asunto(s)
Alouatta/fisiología , Ecosistema , Bosques , Animales , Conducta Animal/fisiología , Costa Rica , Conducta Alimentaria , Femenino , Masculino , Actividad Motora , Descanso , Conducta SocialRESUMEN
The Founders included the privilege against self-incrimination in the Constitution to protect individual privacy and ensure a fair judicial process. Courts have failed U.S. citizens by neglecting to protect them from compelled unlocking of biometrically encrypted devices. This inaction has created a loophole that contradicts the framework of the privilege against self-incrimination. To correct this mistake courts should reconsider the trend they have set for the Constitution and the Fifth Amendment and consider adopting a forward-thinking cybersecurity lens to conclude that biometric authentication is testimonial. Courts should consider that biometric encryption is akin to a compelled password entry for the purposes of the foregone conclusion doctrine. The foregone conclusion doctrine should be applied in limited circumstances with a specific and high burden of proof so that the "jealous protection of the privilege against self-incriminating testimony" can be preserved. Allowing law enforcement such easy access to smart devices narrows Fifth Amendment protections and the expansive foregone conclusion exception is contrary to both principles of cybersecurity and the spirit of the Fifth Amendment. Courts should move to remediate this at once. These liberties and values can only be guaranteed by courts that are willing to take on cases with issues revolving around biometric encryption, the Fifth Amendment, and the foregone conclusion doctrine.
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Identificación Biométrica , Privacidad , Seguridad Computacional , Aplicación de la LeyRESUMEN
BACKGROUND: Although left ventricular global longitudinal strain (GLS) is an index of systolic function recommended by the guidelines, poor image quality may hamper strain measurements. While contrast agents are commonly used to improve endocardial visualization, no commercial speckle-tracking software is able to measure strain in contrast-enhanced images. This study aimed to test the accuracy of speckle-tracking software when applied to contrast-enhanced images in patients with suboptimal image quality. METHODS: We studied patients with a wide range of GLS values who underwent transthoracic echocardiography. Protocol 1 included 44 patients whose images justified use of contrast but still allowed noncontrast speckle-tracking echocardiography (STE), which was judged as accurate and used as a reference. Protocol 2 included 20 patients with poor image quality that precluded noncontrast STE; cardiac magnetic resonance- (CMR-) derived strain was used as the reference instead. Half the manufacturer recommended dose of a commercial contrast agent (Definity/Optison/Lumason) was used to provide partial contrast enhancement. Higher than normal mechanical indices (0.6-0.7) and lowest frequency range for maximal penetration settings were used for imaging. GLS was measured (Epsilon) with and without contrast-enhanced images and by CMR-derived feature tracking (TomTec). Comparisons included linear regression and Bland-Altman analyses. RESULTS: The contrast STE analysis failed in 4/64 patients (6%). Manual corrections were needed to optimize tracking with contrast in all patients. GLS measurements were in good agreement between contrast and noncontrast images (r = 0.85; mean GLS in the contrast images, -12.9% ± 4.7%; bias, 0.34% ± 2.4%). Good agreement was also noted between contrast STE- and CMR-derived strain (r = 0.83; mean, GLS -13.5% ± 4.0%; bias, 0.72% ± 2.5%). CONCLUSIONS: We found that GLS measurements from contrast-enhanced images are feasible and accurate in most patients, even in those with poor image quality that precludes strain measurements without contrast enhancement.
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Cardiomiopatías/diagnóstico , Medios de Contraste/farmacología , Ecocardiografía Tridimensional/métodos , Ecocardiografía/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Contracción Miocárdica/fisiología , Función Ventricular Izquierda/fisiología , Anciano , Cardiomiopatías/fisiopatología , Estudios de Factibilidad , Femenino , Ventrículos Cardíacos/fisiopatología , Humanos , Imagen por Resonancia Cinemagnética , Masculino , Estudios Prospectivos , Reproducibilidad de los ResultadosRESUMEN
A connectionist model of the cerebral cortex as a Markov chain is presented. The model reconciles localization of cortical functions, apparent in neuropsychological data, with the equipotentiality and diffusion of function that was noted in classical studies of learning. In addition, the model suggests that the specificity of some cortical activity can develop quickly from initial connections that are predominantly chaotic. It is not necessary to assume a high degree of "prewired" connections in the cortex of newborns. While the model does not require initial settings to be chaotic, neither does it require initial ordering stronger than chaos. Specifically, a large and initially randomly connected network of neurons rapidly develops several ergodically distinct subnetworks that operate independently. While the ergodic units operate independently and distinctly, they exhibit the property of equipotentially in that the specific events caused by an initial event are equally likely to be at any point in the ergodic set after very few synaptic events.