1,573 research outputs found

    Assessing the effectiveness of a national protected area network for carnivore conservation

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    Protected areas (PAs) are essential to prevent further biodiversity loss yet their effectiveness varies largely with governance and external threats. Although methodological advances have permitted assessments of PA effectiveness in mitigating deforestation, we still lack similar studies for the impact of PAs on wildlife populations. Here we use an innovative combination of matching methods and hurdle-mixed models with a large-scale and long-term dataset for Finland's large carnivore species. We show that the national PA network does not support higher densities than non-protected habitat for 3 of the 4 species investigated. For some species, PA effects interact with region or time, i.e., wolverine densities decreased inside PAs over the study period and lynx densities increased inside eastern PAs. We support the application of matching methods in combination of additional analytical frameworks for deeper understanding of conservation impacts on wildlife populations. These methodological advances are crucial for preparing ambitious PA targets post-2020. Assessing the effectiveness of protected areas for wildlife conservation is challenging. Here, Terraube et al. combine statistical matching and hurdle mixed-effects models to show that PAs have limited impact on population densities of large carnivores across Finland.Peer reviewe

    Sustained and transient neural modulations in prefrontal cortex related to declarative long-term memory, working memory, and attention

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    Common activations in prefrontal cortex (PFC) during episodic and semantic long-term memory (LTM) tasks have been hypothesized to reflect functional overlap in terms of working memory (WM) and cognitive control. To evaluate a WM account of LTM-general activations, the present study took into consideration that cognitive task performance depends on the dynamic operation of multiple component processes, some of which are stimulus-synchronous and transient in nature; and some that are engaged throughout a task in a sustained fashion. PFC and WM may be implicated in both of these temporally independent components. To elucidate these possibilities we employed mixed blocked/event-related functional magnetic resonance imaging (fMRI) procedures to assess the extent to which sustained or transient activation patterns overlapped across tasks indexing episodic and semantic LTM, attention (ATT), and WM. Within PFC, ventrolateral and medial areas exhibited sustained activity across all tasks, whereas more anterior regions including right frontopolar cortex were commonly engaged in sustained processing during the three memory tasks. These findings do not support a WM account of sustained frontal responses during LTM tasks, but instead suggest that the pattern that was common to all tasks reflects general attentional set/vigilance, and that the shared WM-LTM pattern mediates control processes related to upholding task set. Transient responses during the three memory tasks were assessed relative to ATT to isolate item-specific mnemonic processes and were found to be largely distinct from sustained effects. Task-specific effects were observed for each memory task. In addition, a common item response for all memory tasks involved left dorsolateral PFC (DLPFC). The latter response might be seen as reflecting WM processes during LTM retrieval. Thus, our findings suggest that a WM account of shared PFC recruitment in LTM tasks holds for common transient item-related responses rather than sustained state-related responses that are better seen as reflecting more general attentional/control processes

    Watching My Mind Unfold versus Yours: An fMRI Study Using a Novel Camera Technology to Examine Neural Differences in Self-projection of Self versus Other Perspectives

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    Self-projection, the capacity to re-experience the personal past and to mentally infer another person's perspective, has been linked to medial prefrontal cortex (mPFC). In particular, ventral mPFC is associated with inferences about one's own self, whereas dorsal mPFC is associated with inferences about another individual. In the present fMRI study, we examined self-projection using a novel camera technology, which employs a sensor and timer to automatically take hundreds of photographs when worn, in order to create dynamic visuospatial cues taken from a first-person perspective. This allowed us to ask participants to self-project into the personal past or into the life of another person. We predicted that self-projection to the personal past would elicit greater activity in ventral mPFC, whereas self-projection of another perspective would rely on dorsal mPFC. There were three main findings supporting this prediction. First, we found that self-projection to the personal past recruited greater ventral mPFC, whereas observing another person's perspective recruited dorsal mPFC. Second, activity in ventral versus dorsal mPFC was sensitive to parametric modulation on each trial by the ability to relive the personal past or to understand another's perspective, respectively. Third, task-related functional connectivity analysis revealed that ventral mPFC contributed to the medial temporal lobe network linked to memory processes, whereas dorsal mPFC contributed to the fronto-parietal network linked to controlled processes. In sum, these results suggest that ventral–dorsal subregions of the anterior midline are functionally dissociable and may differentially contribute to self-projection of self versus other

    Academic Stress Level Determination among College Students in Times of Covid-19 Pandemic: Basis for an Intervention Scheme

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    This study measured the level of academic stress among students regarding personal inadequacy, fear of failure, interpersonal difficulties with teachers, and inadequate learning resources in times of Covid-19 pandemic Using a descriptive-comparative approach. Slovin's formula was used to identify the respondents with a stratified random sampling technique to generate the required sample size of the study. The results revealed that the level of academic stress in times of the Covid-19 pandemic is high. It is also revealed that there is no significant difference in the level of academic stress when respondents are grouped according to sex, year level, and the number of hours spent for modular learning per day and provided significant difference when grouped according to course. Demographic profiles show that most of the students belong to the poor classification of monthly family income and with a low allowance for internet subscriptions. It also shows that with the intensity of requirements in the course pack, most students allocated many hours to answer the lessons per day. Present findings suggest that the institution must address intervention schemes through academic and non-academic services

    Properties and Applications of Metal Phosphates and Pyrophosphates as Proton Conductors

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    We review the progress in metal phosphate structural chemistry focused on proton conductivity properties and applications. Attention is paid to structure–property relationships, which ultimately determine the potential use of metal phosphates and derivatives in devices relying on proton conduction. The origin of their conducting properties, including both intrinsic and extrinsic conductivity, is rationalized in terms of distinctive structural features and the presence of specific proton carriers or the factors involved in the formation of extended hydrogen-bond networks. To make the exposition of this large class of proton conductor materials more comprehensive, we group/combine metal phosphates by their metal oxidation state, starting with metal (IV) phosphates and pyrophosphates, considering historical rationales and taking into account the accumulated body of knowledge of these compounds. We highlight the main characteristics of super protonic CsH2PO4, its applicability, as well as the affordance of its composite derivatives. We finish by discussing relevant structure–conducting property correlations for divalent and trivalent metal phosphates. Overall, emphasis is placed on materials exhibiting outstanding properties for applications as electrolyte components or single electrolytes in Polymer Electrolyte Membrane Fuel Cells and Intermediate Temperature Fuel Cells.This research was funded by PID2019110249RB-I00 (MICIU/AEI, Spain) and PY20-00416 (Junta de Andalucia, Spain/FEDER) research projects. M.B.-G. thanks PAIDI2020 research grant (DOC_00272 Junta de Andalucia, Spain) and R.M.P.C. thanks University of Malaga under Plan Propio de Investigación for financial support

    Common prefrontal activations during working memory, episodic memory, and semantic memory

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    Regions of the prefrontal cortex (PFC) are typically activated in many different cognitive functions. In most studies, the focus has been on the role of specific PFC regions in specific cognitive domains, but more recently similarities in PFC activations across cognitive domains have been stressed. Such similarities may suggest that a region mediates a common function across a variety of cognitive tasks. In this study, we compared the activation patterns associated with tests of working memory, semantic memory and episodic memory. The results converged on a general involvement of four regions across memory tests. These were located in left frontopolar cortex, left mid-ventrolateral PFC, left mid-dorsolateral PFC and dorsal anterior cingulate cortex. These findings provide evidence that some PFC regions are engaged during many different memory tests. The findings are discussed in relation to theories about the functional contribition of the PFC regions and the architecture of memory

    Fundamentos teĂłricos de la creaciĂłn de un modelo de adquisiciĂłn corporativa internacional: Caso de las principales empresas de Nuevo LeĂłn

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    The importance to propose a success Model in the international corporate acquisitions consists of offering to the important Mexican firms the factors that will allow having greater success with the international investments. In this research we selected four of the most important firms of Nuevo Leon that have important experience with international acquisitions and present them thequestionnaire that was designed to validate the variables of the Model. In this paper we present the theories that give the theoretical foundations to the variables of the proposed Model that consist of 6 variables or key success factors that need to be considered for an international acquisitions, which are: Country Knowledge, Industry Knowledge, Customer relationship, Supplier relationship, Technology and Market.La importancia de proponer un Modelo de éxito en las adquisiciones corporativas internacionales consiste en ofrecerles a las grandes empresas mexicanas los factores que les permitirán tener un mayor éxito con sus inversiones en el extranjero. Para esta investigación se seleccionaron a cuatro de las empresas más importantes de Nuevo León y que tienen unaexperiencia importante con sus adquisiciones internacionales por lo que se les entregó el cuestionario que fue diseñado para validar las variables del Modelo. En este artículo se presentan las teorías que le dan el fundamento teórico a las variables del Modelo propuesto que se integra de 6 variables o factores de éxito que deben de ser considerados para una adquisición internacional, los cuales son: Conocimiento del País, Conocimiento de la Industria, Relación conClientes, Relación con Proveedores, Tecnología y Cuota de Mercado.

    Estudio cinético de la desdiazoación en medio acuoso del tetrafluorborato de bencenodiazonio

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    The kinetic analyses carried out at different temperatures (20ºC - 40ºC) indicate that the dediazoniation process of thebenzenediazonium ion (BZ) is of the order of one, with BZ at A = 2,3.1015 s-1 and Ea = 112,5 kJ.mol-1 for the Arrheniusequation, and ΔH‡ = 110,0 kJ.mol-1 and ΔS‡ = 40,7 J.K-1.mol-1 for the Eyring equation. The chromatographic resultsreveal that BZ decomposes through a heterolytic process mediated by the aryl ion. The presence of Cu(I) or Cu(II) saltsand ascorbic acid produce a change in the reaction mechanism. The intermediate compounds produced in these conditionsare stable species that may be transported in the bloodstream. The model studied suggests a possible explanation for thelocalisation of tumours produced by the administration of BZ in rats.Los análisis cinéticos realizados a diferentes temperaturas (20º C - 40º C) indican que el proceso de desdiazoacióndel ion bencenodiazonio (BZ) es de orden uno respecto a BZ siendo A = 2,3.1015 s-1 y Ea = 112,5 kJ.mol-1 en laecuación de Arrhenius así como ΔH‡ = 110,0 kJ.mol-1 y ΔS‡ = 40,7 J.K-1.mol-1 para la ecuación de Eyring. Losresultados cromatográficos revelan que BZ se descompone por un proceso heterolítico mediado por el catión arilo.La presencia de sales Cu(I) o de Cu(II) y ácido ascórbico produce un cambio del mecanismo de reacción. Loscompuestos intermedios originados en estas condiciones son especies estables que pueden ser transportadas en lasangre. El modelo estudiado sugiere una posible explicación para la localización descrita en la literatura para lostumores producidos por la administración de BZ a ratas
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