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FPn-Injective, FPn-Flat Covers and Preenvelopes, and Gorenstein AC-Flat Covers

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Algebra Colloquium 2018年第2期25卷 319-334页

作者： Daniel bravo sergio Estrada Alina Iacob Instituto de Ciencias Fisicas y Matematicas Facultad de Ciencias Universidad Austral de Chile Valdivia Chile Departamento de Matematicas Universidad de Murcia Campus de Espinardo 30100 Murcia Spain Department of Mathematical Sciences Georgia Southern University Statesboro GA 30460 U.S.A

We prove that, for any n 〉 2, the classes of FPn-injective modules and of FPn-flat modules are both covering and preenveloping over any ring R. This includes the case of FP∞-injective and FP∞-flat modules （i.e., absolutely clean and, respectively, level modules）. Then we consider a generalization of the class of （strongly） Gorenstein flat modules, i.e., the （strongly） Gorenstein AC-flat modules （cycles of exact complexes of flat modules that remain exact when tensored with any absolutely clean module）. We prove that some of the properties of Gorenstein fiat modules extend to the class of Gorenstein AC-flat modules; for example, we show that this class is precovering over any ring R. We also show that （as in the case of Gorenstein flat modules） every Gorenstein AC-flat module is a direct summand of a strongly Gorenstein AC-flat module. When R is such that the class of Gorenstein AC-flat modules is closed under extensions, the converse is also true. Moreover, we prove that if the class of Gorenstein AC-flat modules is closed under extensions, then it is covering.

关键词： FPn-injective module FPn-flat module Ding injective module GorensteinAC-flat module

Physiological dormancy broken by endozoochory:Austral parakeets(Enicognathus ferrugineus)as legitimate dispersers of calafate(Berberis microphylla)in the Patagonian Andes

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Journal of Plant Ecology 2020年第5期13卷 538-544页

作者： Carolina bravo Daniel Chamorro Fernando Hiraldo Karina Speziale sergio A.Lambertucci JoséL.Tella Guillermo Blanco Department of Evolutionary Ecology Museo Nacional de Ciencias NaturalesCSICJoséGutiérrez Abascal 228006 MadridSpain Centre d’Etudes Biologiques de Chizé UMR 7372CNRS and La Rochelle UniversitéF-79360 Beauvoir-sur-NiortFrance Departamento de Ciencias Ambientales Universidad de Castilla-La ManchaAv.Carlos III s/n45071 ToledoSpain Department of Conservation Biology Estación Biológica de DoñanaCSICAmérico Vespucio 2641092 SevillaSpain Grupo de Investigaciones en Biología de la Conservación Departamento de EcologíaINIBIOMA(CONICET-National University of Comahue)Pasaje Gutiérrez 11258400 BarilocheArgentina

Aims Seed dispersal by endozoochory is an important process in plant regeneration and the establishment of new *** with dormancy may especially benefit after disperser gut ***,the ways in which gut passage affect the germination of plant species with physiological dormancy remain ***,we experimentally assessed the mutualistic interaction between the Austral parakeet(Enicognathus ferrugineus)as a disperser of calafate(Berberis microphylla),a thorny bush inhabiting the understory of the Austral temperate forests of South America with seeds that are characterized by deep physiological *** Germination success and viability of calafate seeds obtained from faeces and from intact fruits were tested under four treatments:(i)digested seeds,(ii)digested seeds with faecal extract,(iii)intact seeds from fruit and(iv)intact seeds from fruit with *** Findings About 65%of the Austral parakeet droppings contained calafate *** of seeds did not differ between ***,germination was significantly higher in digested seeds than in intact seeds from fruits,while no difference was found between faecal and pulp *** faecal matter nor fruit pulp provided seeds with any ecological advantages derived from enhancing germinability,but did confer some disadvantage in germination *** matter is expected to be completely lacking around seeds after several months under snow before germinating in the following spring,given intense washing due to persistent rain and the spring thaw in the Patagonian *** higher germinability along with faster germination of digested seeds supports the hypothesis of a legitimate mutualistic interaction between Austral parakeets and *** hypothesized that the passage through the disperser digestive tract might break physiological dormancy as differences in germinability between ingested and non-ingested *** results highlight the relevant role of endoz

关键词： seed dispersal Austral forest mutualism gut passage viability germination success germinability

Radical Vaginal Hysterectomy and Trachelectomy in Early-Stage Cervical Cancer

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Open Journal of Obstetrics and Gynecology 2014年第8期4卷 491-496页

作者： Erasmo bravo Catalina Alonso Montemurro sergio Rojas Sepulveda Jaime Cartagena Bustamante Hector Pinto Oncologic Gynecology Unit Gustavo Fricke HospitalViña del MarChile Oncologic Gynecology Unit Van Buren HospitalValparaísoChile Department of Gynecology and Obstetrics University of ValparaísoValparaísoChile

Objective: To communicate a minimally invasive technique for surgical handling of early-stage cervical cancer and its results. Methods: 110 patients with cervical cancer in stages IA2 and IB1, all of them operated in a period of 5 years in both hospitals, are presented. Laparoscopic systemic pelvic lymphadenectomy with radical vaginal hysterectomy or radical vaginal trachelectomy was performed to patients, with the exception of those patients who had compromised nodes detected in contemporary biopsy. Results: Between April 2008 and May 2013, 110 patients were submitted to this technique. 15 patients had their surgery aborted: 13 presented positive nodes for carcinoma in contemporary biopsy and 2 had extensive cervical compromise when performing radical vaginal hysterectomy or trachelectomy. Analysis of the remaining 95 cases shows an average age of 43.9 years (26 - 61), all of them had given birth before, 23 (21%) of them through C-section. BMI averaged 30.5 and 31 (28.2%) had cone surgery performed previously. Average duration of surgery was of 220 minutes. Postoperative hospitalization averaged 3.1 days. Bleeding volume was estimated at 125 cc and one patient required blood transfusion. En 25 patients’ uterine annexes were kept and all of them were suspended by means of laparoscopy. On average, 25.4 pelvic nodes were obtained. Complications 13.6% with eight patients suffered bladder injury, two had rectovaginal fistula, 3 patients requires surgical repair of ureteral obstruction, two patients present thromboembolic disease. The disease-free and overall survivals are consistent with reports in the literature. Conclusion: We believe that handling patients with this technique is possible and has the advantages of vaginal and laparoscopic surgery with minimal complications.

关键词： Radical Vaginal Hysterectomy Radical Vaginal Trachelectomy Early-Stage Cervical Cancer

Shade coffee plantations maintain woody plant diversity and structure in a cloud forest landscape of southern Mexico

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Journal of Forestry Research 2021年第2期32卷 637-648页

作者： Edson AAlvarez-Alvarez R.Carlos Almazán-Nunez Fernando González-García Marlene Brito-Millán Alfredo Méndez-Bahena sergio García-Ibáñez Maestría en Recursos Naturales y Ecología Facultad de Ecología MarinaUniversidad Autónoma de Guerrero39390 AcapulcoGuerreroMexico Laboratorio Integral de Fauna Silvestre Facultad de Ciencias Químico-BiológicasUniversidad Autónoma de Guerrero39090 Chilpancingo de los BravoGuerreroMexico Red Biología y Conservación de Vertebrados Instituto de EcologíaA.C.CP 91073 XalapaVeracruzMexico University of California Institute for Mexico and the United States(UC MEXUS) Cuerpo Académico Biodiversidad y Gestión Ambiental SustentableFacultad de Ciencias Químico-BiológicasUniversidad Autónoma de Guerrero39090 Chilpancingo de los BravoGuerreroMexico Laboratorio de Biología de la Conservación Facultad de Ciencias Químico-BiológicasUniversidad Autónoma de Guerrero39090 Chilpancingo de los BravoGuerreroMexico Laboratorio de Ecología Cuantitativa Facultad de Ecología MarinaUniversidad Autónoma de Guerrero39390 AcapulcoGuerreroMexico

Cloud forest ecosystems of the Latin American tropics are highly threatened by changes in land-use such as expanding croplands and livestock pastures that promote shifts in the structure and composition of plant communities in these ***,shade coffee plantations represent a forest management alternative that has been shown to maintain biodiversity in these *** this study,we evaluated changes in the composition,diversity,and structure of Mexican cloud-forest woody species for three land use categories:cattle pastures,shade coffee plantations and advanced succession *** each category,fifteen 0.28-ha plots were established and the composition and diversity of vegetation was *** of species was analyzed using ordination methods,and alpha diversity was compared using Hill ***-seven woody species belonging to 40 families were *** richness and diversity was high in both the advanced successional forest and coffee plantations compared to cattle *** composition and structure was similar between late succession forests and coffee plantations with both land uses also being more structurally complex than cattle *** results show how shade coffee cultivation is a land-use activity that maintains woody plant communities in a manner that aligns with biodiversity conservation.

关键词： Land uses Late succession Plant diversity Shade coffee Vegetation structure