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Deforestation and fragmentation trends of seasonal dry tropical forest in Ecuador: impact on conservation

Forest Ecosystems 2021年第3期8卷 615-627页

作者： carlos a.rivas JoséGuerrero-Casado Rafael M.Navarro-Cerillo Instituto de Ciencias Básicas Universidad Técnica de ManabíPortoviejoManabíEcuador Department of Forest Engineering Laboratory of DendrochronologySilviculture and Global Change–DendrodatLab–ERSAFUniversity of CordobaCampus de RabanalesCrta.IVkm.396E-14071 CordobaSpain Departamento de Medicina Veterinaria Facultad de Ciencias VeterinariasUniversidad Técnica de ManabíPortoviejoManabíEcuador Department of Zoology University of CordobaCampus de Rabanales14071 CordobaSpain

Background:Fragmentation and deforestation are one of the greatest threats to forests,and these processes are of even more concern in the tropics,where the seasonal dry forest is possibly one of the most threatened ecosystems with the least remaining surface ***:The deforestation and fragmentation patterns that had occurred in Ecuadorian seasonal dry forests between 1990 and 2018 were verified,while geographic information systems and land cover shapes provided by the Ecuadorian Ministry of the Environment were employed to classify and evaluate three types of seasonal dry forests:deciduous,semi-deciduous,and *** study area was tessellated into 10 km2 hexagons,in which six fragmentation parameters were measured:number of patches,mean patch size,median patch size,total edge,edge density and reticular fragmentation index(RFI).The RFI was also measured both outside and inside protected natural areas(unprotected,national protected areas and protected forest).Moreover,the areas with the best and worst conservation status,connectivity and risk of disappearance values were identified by means of a Getis-Ord Gi*statistical ***:The deforestation of seasonal dry forests affected 27.04%of the original surface area still remaining in 1990,with an annual deforestation rate of−1.12%between 1990 and *** RFI has increased by 11.61%as a result of the fact that small fragments of forest have tended to disappear,while the large fragments have been fragmented into smaller *** semi-deciduous forest had the highest levels of fragmentation in *** three categories of protection had significantly different levels of fragmentation,with lower RFI values in national protected areas and greater values in protected ***:The seasonal dry forest is fragmenting,deforesting and disappearing in some *** increased protection and conservation of the Ecuadorian seasonal dry forest is,therefore,necessary owing to the fact that not all prot

关键词： Deciduous forest Semi-deciduous forest Remnant forest Patch isolation Habitat loss Protected areas

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Olfactory receptors in neural regeneration in the central nervous system

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Neural Regeneration Research 2025年第9期20卷 2480-2494页

作者： Rafael Franco Claudia Garrigós Toni Capó Joan Serrano-Marín Rafael rivas-Santisteban Jaume Lillo Molecular Neurobiology Laboratory Department of Biochemistry and Molecular BiomedicineFacultat de BiologiaUniversitat de BarcelonaBarcelonaSpain CiberNed Network Center for Biomedical Research in Neurodegenerative Diseases Spanish National Health Institute Carlos ⅢMadridSpain School of Chemistry Universitat de BarcelonaBarcelonaSpain Department of Biochemistry and Physiology School of Pharmacy and Food SciencesUniversitat de BarcelonaBarcelonaSpain Laboratory of Computational Medicine Biostatistics UnitFaculty of MedicineAutonomous University of BarcelonaCampus BellaterraBarcelonaSpain

Olfactory receptors are crucial for detecting odors and play a vital role in our sense of smell,influencing behaviors from food choices to emotional *** receptors also contribute to our perception of flavor and have potential applications in medical diagnostics and environmental *** ability of the olfactory system to regenerate its sensory neurons provides a unique model to study neural regeneration,a phenomenon largely absent in the central nervous *** gained from how olfactory neurons continuously replace themselves and reestablish functional connections can provide strategies to promote similar regenerative processes in the central nervous system,where damage often results in permanent *** the molecular and cellular mechanisms underpinning olfactory neuron regeneration could pave the way for developing therapeutic approaches to treat spinal co rd injuries and neurodegenerative diseases like Alzheimer's *** ctory receptors are found in almost any cell of eve ry orga n/tissue of the mammalian *** ectopic expression provides insights into the chemical structures that can activate olfactory *** addition to odors,olfactory receptors in ectopic expression may respond to endogenous compounds and molecules produced by mucosal colonizing *** analysis of the function of olfactory receptors in ectopic expression provides valuable information on the signaling pathway engaged upon receptor activation and the receptor's role in proliferation and cell differentiation *** review explo res the ectopic expression of olfa ctory receptors and the role they may play in neural regeneration within the central nervous system,with particular attention to compounds that can activate these receptors to initiate regenerative *** suggests that olfactory receptors could serve as potential therapeutic targets for enhancing neural repair and recovery following central nervous syste

关键词： adenosine receptors adrenergic receptors ectopic expression G proteincoupled receptors glia neurons

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Variable-top stem biomass equations at tree-level generated by a simultaneous density-integral system for second growth forests of roble, raulí,and coigüe in Chile

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Journal of Forestry Research 2019年第3期30卷 993-1010页

作者： carlos Valenzuela Eduardo Acuna Alicia Ortega Geronimo Quinonez-Barraza Jose Corral-rivas Jorge Cancino Departamento Manejo de Bosques y Medio Ambiente Facultad de Ciencias ForestalesUniversidad de Concepcion Victoria 631Barrio Universitario4070386 ConcepcionChile Instituto de Bosques y Sociedad Facultad de Ciencias Forestales y Recursos NaturalesUniversidad Austral de ChileCampus Isla Teja5110566 ValdiviaChile Campo Experimental Valle del Guadiana Instituto Nacional de Investigaciones Forestales Agricolas y Pecuarias (INIFAP)km 4.5 Carretera Durango-Mezquital34170 DurangoDGOMexico Instituto de Silvicultura e Industria de la Madera Universidad de Juarez del Estado de Durango34120 DurangoMexico

Variable-top stem biomass models at the tree level for second growth forests of roble (Nothofagus obliqua), rauli(Nothofagus alpina), and coigüe (Nothofagus dombeyi) were fitted by a simultaneous density-integral system, which combines a stem taper model and a wood basic density model. For each model, an autoregressive structure of order 2 and a power equation of residual variance were incorporated to reduce residual autocorrelation and heteroscedasticity, respectively. By using dummy variables in the regression analysis, zonal effects on the parameters in the variable-top stem biomass equations were detected in roble. Consequently, equations for clusters of zones were obtained. These equations presented significant parameters and a high precision in both fitting and validation processes (i.e., CV<11.5% and CVp<11.9%, respectively), demonstrating that they are unbiased. The advantage of these types of functions is that they provide estimates of volume and biomass of sections of the stem, defined between any two points of the stem in the three species. Thus, depending on the final use of the wood and the dimensions of the tree, a stem fraction can be quantified in units of volume and the remaining fraction in units of weight.

关键词： Autocorrelation Density-integral Dummy variables Autoregressive error structure Heteroscedasticity

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Oxidative stress modulation in hepatitis C virus infected cells

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World Journal of Hepatology 2015年第29期7卷 2880-2889页

作者： Sonia A Lozano-Sepulveda Owen L Bryan-Marrugo carlos Cordova-Fletes Maria C Gutierrez-Ruiz Ana M rivas-Estilla Department of Biochemistry and Molecular Medicine School of MedicineUniversidad Autonoma de Nuevo LeonMonterreyNuevo Leon 64460Mexico Department of Health Sciences Biological Sciences and Health DivisionSchool of Biological SciencesUniversidad Autonoma Metropolitana

Hepatitis C virus(HCV) replication is associated with the endoplasmic reticulum, where the virus can induce cellular stress. Oxidative cell damage plays an important role in HCV physiopathology. Oxidative stress is triggered when the concentration of oxygen species in the extracellular or intracellular environment exceeds antioxidant defenses. Cells are protected and modulate oxidative stress through the interplay of intracellular antioxidant agents, mainly glutathione system(GSH) and thioredoxin; and antioxidant enzyme systems such as superoxide dismutase, catalase, GSH peroxidase, and heme oxygenase-1. Also, the use of natural and synthetic antioxidants(vitamin C and E, N-acetylcysteine, glycyrrhizin, polyenylphosphatidyl choline, mitoquinone, quercetin, S-adenosylmethionine and silymarin) has already shown promising results as co-adjuvants in HCV therapy. Despite all the available information, it is not known how different agents with antiviral activity can interfere with the modulation of the cell redox state induced by HCV and decrease viral replication. This review describes an evidence-based consensus on molecular mechanisms involved in HCV replication and their relationship with cell damage induced by oxidative stress generated by the virus itself and cell antiviral machinery. It also describes some molecules that modify the levels of oxidative stress in HCV-infected cells.

关键词： Hepatitis C virus Oxidative stress Reactiveoxygen species Vitamin E Antioxidants Glycyrrhizin S-adenosylmethionine N-acetylcysteine Silymarin

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Primary Leiomyosarcoma of the Ovary: A Case Report

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Case Reports in Clinical Medicine 2014年第4期3卷 192-196页

作者： Giovanna.rivas carlos Bonilla Juan Rubiano Natalia Arango Division of Medical Oncology Cancerology National Institute Bogotá Colombia Universidad el Bosque Bogotá Colombia Division of Medical Oncology Cancerology National Institute Bogotá Colombia Universidad el Bosque Bogotá Colombia Integral Cancer Center Clínica de Occidente Cali Colombia

Leiomyosarcoma of the ovary is a rare disease, with aggressive behavior and poor prognosis, which mainly occurs in postmenopausal women. Surgery is the cornerstone of treatment, while the role of chemotherapy and radiotherapy is still not clear because substantial data is lacking. This paper presents the case of an adult woman who is diagnosed with primary leiomyosarcoma of the left ovary, and who receives a surgical approach and adjuvant treatment with chemotherapy currently achieving 20 months free from disease.

关键词： Leiomyosarcoma Ovarian Neoplasms Treatment

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A Summary, Insight and Autocriticism of Information Systems That We Have Developed for Medical Education

A Summary, Insight and Autocriticism of Information Systems ...

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2011 The Second International Conference on Information, Communication and Education Application（ICEA 2011）

作者： rivas-ECHEVERRíA carlos rivas-ECHEVERRíA Francklin MOLINA Lizmar GONZáLEZ Solange rivas Verónica Calle Manuel Fraga Iribarne 6 portal 14 ASoria42005Spain Urb. Sta. María sur calle Pico EspejoQTA MónicaMérida5101Venezuela

Along 24 years, our team in the University of Los Andes, Mérida-Venezuela, has developed several softwares intended to have educational applications in medicine. All of them were just prototypes and were never completed. We have always thought that information systems have a very important place in education and that in the future they would have a leading role. We have been thinking that the future paradigm of education is based on informatics, communications and their applications. Nevertheless, our insight and autocriticism has open new windows, points of view and approaches of this "new paradigm" and some questions have invaded our minds. Metaphorically speaking, are information systems applications a teacher, a model, a way, a mean, a goal? Or;might it be just a sort of a tool, comparable with a book;or even more dispensable ones like a pencil, a piece of paper, an eraser or a pencil-sharpener? In this paper we will briefly present some of our products(information systems), their features, applications, rationale, some difficulties that we have encountered while introducing them. We will describe the evolution of the new ideas and developments that we incorporated and finally we will discuss some of the thoughts that have emerged. Answers to these questions might be given by the readers.

关键词： Information Systems,Medical Diagnosis,Medical Education,Artificial Intelligence

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Study of the Reactivity of (100) Felodipine Surface Model Based on DFT Concepts

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Open Journal of Physical Chemistry 2019年第1期9卷 1-12页

作者： carlos Tepech-Carrillo Roxana Licona-Ibarra J. Francisco rivas-Silva Antonio Flores-Riveros Instituto de Física “Luis Rivera Terrazas” Benemérita Universidad Autónoma de Puebla Puebla México Facultad de Ciencias Químicas Benemérita Universidad Autónoma de Puebla Puebla Mexico

In this study, Density Functional Theory including a dispersion correction is employed to model and analyze the structural, electronic and local reactivity of the (100) surface of felodipine. The surface energy calculated at the Generalized Gradient Approximation (GGA) level, along with plane waves as basis set and ultrasoft pseudopotentials, shows that the (100) surface is the most stable as compared to the (010) and (110) ones. In particular, we have focused on performing a quantitative study of the reactivity of the surface by means of the Fukui function and through the HOMO and LUMO populations. Our results can be related to some applications in the pharmaceutical chemistry of this compound.

关键词： 1 4-Dihydropyridine Felodipine Density Functional Theory Fukui Functions

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Risk Assessment of an Environmental Liability in the Commercialization of Hydrocarbons-A Secondary Publication

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Journal of World Architecture 2024年第2期8卷 108-117页

作者： Yamila Navarro Sosa Josécarlos Rojas Acosta Lester rivas Trasancos carlos C.Cañete Pérez Yuletsis Díaz Rodríguez Center for Petroleum Research(CEINPET) HavanaCuba Technological University of Havana JoséAntonio Echeverría HavanaCuba

The risk analysis evaluates the probability of occurrence with the impact of said *** the hydrocarbon sector,an environmental liability is an improperly abandoned facility,soil contaminated by spills or *** objective of this work is to define a risk management *** characterization of the residue and the area was carried *** events were identified:overflow spill,soil contamination by infiltration,as well as radiant heat and suffocating and toxic fumes from a *** matrix method was applied considering the probability of occurrence against *** danger of infiltration implied a high level of *** risk management plan was drawn up,its main action being the liquidation of the pool and the sanitation of the area.

关键词： Hazardous events Environmental liability Waste Risk Vulnerability

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Alcohol use disorder and its impact on chronic hepatitis C virus and human immunodeficiency virus infections

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World Journal of Hepatology 2016年第31期8卷 1295-1308页

作者： Daniel Fuster Arantza Sanvisens Ferran Bolao Inmaculada.rivas Jordi Tor Robert Muga Department of Internal Medicine Addiction Unit Hospital Univer-sitari Germans Trias i Pujol Department of Internal Medicine Hospital Univer-sitari de Bellvitge IDIBELL Municipal Center for Substance Abuse Treatment (Centro Delta) IMSP

Alcohol use disorder(AUD) and hepatitis C virus(HCV) infection frequently co-occur. AUD is associated with greater exposure to HCV infection, increased HCV infection persistence, and more extensive liver damage due to interactions between AUD and HCV on immune responses, cytotoxicity, and oxidative stress. Although AUD and HCV infection are associated with increased morbidity and mortality, HCV antiviral therapy is less commonly prescribed in individuals with both conditions. AUD is also common in human immunodeficiency virus(HIV) infection, which negatively impacts proper HIV care and adherence to antiretroviral therapy, and liver disease. In addition, AUD and HCV infection are also frequent within a proportion of patients with HIV infection, which negatively impacts liver disease. This review summarizes the current knowledge regarding pathological interactions of AUD with hepatitis C infection, HIV infection, and HCV/HIV co-infection, as well as relating to AUD treatment interventions in these individuals.

关键词： Hepatitis C virus Human immunodeficiency virus Hepatitis C virus/human immunodeficiency virus co-infection Liver Alcohol

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Pontocerebellar Progressive Multifocal Leukoencephalopathy. Radiological, Clinical, Histological and Immunohistochemical Findings in a Hematological Patient

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Open Journal of Pathology 2023年第4期13卷 177-183页

作者： Javier Ortiz Juan carlos Paniagua Isidro Cavaco Raquel rivas Andrea Jimenez Luis Chinchilla Elisa Muñoz María Dolores Ludeña Departamento de Biología Celular y Patología Universidad de Salamanca (USAL) Salamanca Spain Servicio de Anatomía Patológica Hospital Universitario de Salamanca Salamanca Spain Servicio de Radiodiagnóstico Hospital Universitario de Salamanca Salamanca Spain

Objective: To describe the radiological, histological and immunohistochemical findings in a case of Progressive Multifocal Leukoencephalopathy (PML) affecting the cerebellar peduncles in a patient with chronic lymphocytic leukemia. Patient and Methods: Magnetic Resonance Imaging (MRI), histological picture (H.E., Kluver-Barrera) and immunohistochemical picture (GFAP, neurofilaments, CD68, JC virus) were obtained. Results: 1) Magnetic resonance imaging: Asymmetric and progressive lesions on middle cerebellar peduncles, that were hyperintense in T2/FLAIR, extended towards the pons, had no mass effect and were unmodified after intravenous contrast. 2) Histology: Marked reactive gliosis with cytopathic changes suggesting viral infection, plus demyelination areas with axonal preservation. 3) Immunohistochemistry: Marked positivity for viral (polyoma and JC virus) markers in glial cells showing cytopathic changes. Conclusions: The importance of histological and immunohistochemical diagnosis in everyday assistance;of the collaboration between clinicians, radiologists and pathologists;and the validity of postmortem studies as a key element for research and clinical quality assessment must be stressed.

关键词： Progressive Multifocal Leukoencephalopathy JC Virus Immunohistochemistry

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