524 research outputs found
Relació entre la vegetació i els paràmetres ambientals als boscos pirinencs de pi roig (Pinus sylvestris L.)
S'estudia la relació de la vegetació dels boscos pirinencs de pi roig (Pinus sylvestris L.) amb els paràmetres ambientals (p.e., altitud, radiació solar, nutrients al sòl, etc.) mitjançant mètodes d'andisi multivariant (ordenació, classificació i anàlisi canònica). Els resultats suggereixen que existeix una forta relació entre la vegetació i els paràmetres ambientals. Aquests boscos on l'única espècie arbòria és el pi roig, poden ser dividits en diierentes comunitats ecològicament diferenciades. Els principals paràmetres que determinen la vegetació corresponen a la capacitat de bescanvi catiònic del sòl i a la radiació solar incident.The relation between vegetation and their environment (e.g., altitude, solar radiation, soil nutrients) is studied in Pyrenean Scots pine (Pinus sylvestris L.) forests by means of multivariate analyses (i.e., ordination, classification and canonical analysis). The results suggest a strong correlation between vegetation and the environment. Although these forests are dominated by one overstorey species they can be subdivided into several ecologically differentiated communities. Cation exchange capacity and incoming solar radiation are the main parameters determining the vegetation composition
Estructura en l'espai del sotabosc als boscos pirinencs de pi roig (Pinus sylvestris L.)
A partir d'un mostreig basat en transectes a 59 parcel·les de bosc de pi roig (Pinus sylvestris L.), s'estudia el comportament en l'espai (dins les parce1,les) que presenten les espècies. El mètode utilitzat es basa en el càlcul del coeficient d'autocorrelació de cada espècie en cada parcel·la. Els resultats suggereixen que les espècies als boscos estudiats tendeixen a distribuir-se formant claps (distribució agregada), i no pas amb una distribució uniforme o a l'atzar, i que existeix certa relació entre el patró de distribució de les diferentes espècies i la seva forma vital.Spatial pattern of understorey species in Pyrenean Scots pine forests was studied from transect data in 59 plots. Autocorrelation coefficient was computed for each species in each plot. The results suggest that most of the species tend to show a clumped pattern, rather than random or uniform pattern, and that there is some relationship between the spatial pattern of the different species and their life form
Revision of the types of species of Alloxysta described by Cameron and Fergusson (Hymenoptera: Figitidae: Charipinae) and deposited in the Natural History Museum (London), including a key to the fauna of Great Britain
Type material of the species of Alloxysta described by Cameron and Fergusson and deposited in the Natural History Museum of London has been revised. Seven species are considered valid: Alloxysta abdera Fergusson, 1986, A. basimacula (Cameron, 1886), A. crassa (Cameron, 1889), A. mullensis (Cameron, 1883), A. piceomaculata (Cameron, 1883), A. pleuralis (Cameron, 1879) and A. semiaperta Fergusson, 1986. A. basimacula, A. crassa, A. maculicollis (Cameron, 1886), A. perplexa (Cameron, 1889) and A. piceomaculata are here removed from synonymy with A. macrophadna (Hartig, 1841). A. rufi ceps (Cameron, 1883) is removed from synonymy with A. victrix (Westwood, 1833). A. caledonica (Cameron, 1886) and A. perplexa are here synonymized with A. basimacula. A. maculicollis, A. ruficeps and A. ruficollis (Cameron, 1883) are here synonymized with A. castanea (Hartig, 1841). A. ancylocera (Cameron, 1886) was correctly synonymized with A. fuscicornis (Hartig, 1841), A. curvicornis (Cameron, 1883) was correctly synonymized with A. victrix and A. filicornis (Cameron, 1889) was correctly synonymized with A. macrophadna. Complete redescriptions and illustrations are given for valid species. A key for all the Alloxysta species found so far in Great Britain is given
Disturbance ecology in human societies
1. We define societal disturbances as discrete events that abruptly disrupt the functioning
of human societies. There is a variety of such events, including hurricanes,
floods, epidemics, nuclear accidents, earthquakes and wars, among others. These
disturbances can interact, further increasing their impacts. The severity of disturbances
does not only depend on their intrinsic properties (type, intensity and
magnitude) but also greatly on human aspects (socioeconomic, historical, political
and cultural aspects that define vulnerability).
2. Very large or severe disturbances are infrequent and unpredictable. Yet societal
disturbances are intrinsic to human societies; they have occurred through the
entire human history and will continue to occur in the future. We can increase
preparedness and recovery capacity but cannot avoid disturbances. The type,
regime and scale of disturbances change with the development of societies. The
increase in population density and complexity also increases the severity of many
disturbances.
3. Societal disturbances can temporarily disrupt the functioning of societies.
However, when those disturbances are frequent, societies adapt to them and
thus disturbances contribute to shape cultural evolution. That is, societal disturbances
have a cost at short temporal scales, but they can build up resilience at
mid-to
long-term
scales.
4. Understanding this dynamic view of human systems is becoming more important
as climate is changing, humans are overexploiting natural resources and humanity
is dense and hyperconnected. We need to take advantage of frequent small
disturbances, as they can build resilience and reduce the likelihood of infrequent
large and severe disturbances. Our challenge is to encourage actions and policies
to be prepared for unknown, unpredictable and unprecedented (infrequent)
large-scale
societal disturbances that will surely arrive
Differential pollinator response underlies plant reproductive resilience after fires
Background and aims
Assessing the resilience of plant-animal interactions is critical to understanding how plant communities respond to habitat disturbances. Most ecosystems experience some level of natural disturbance (e. g., wildfires) to which many organisms are adapted to. Wildfires have structured biotic communities for millennia; however, the effects of fire on interactions such as pollination have only recently received attention. A few studies have shown that generalist plants can buffer the impact of fires by pollinator replacement, suggesting that the resilience to disturbance could depend on the level of specialization of the interactions.
Here, we hypothesize that i) fires could impose negative effects on plants with specialized pollination systems, and ii) in large wildfires, these negative effects will be stronger with increasing distance inside the burnt because pollinators will need more time to recolonize.
Methods
These questions were tested in the specialized pollination system of a widespread Mediterranean palm, Chamaerops humilis. The postfire pollination resilience was assessed in
replicated wildfires representing three postfire ages by measuring the abundance of beetle pollinators and by estimating fruit set (i.e., proportion of flowers setting fruits) in burnt and unburned areas. To test for distance effects, plants were sampled along transects inside the burnt.
Key results
This study revealed that despite a marked postfire decline in the specialist pollinator, exacerbated by the distance from the fire’s edge, the palm’s fruit set was barely affected. The temporary replacement by a sap beetle at burnt sites - an effective pollinator that had not been previously recognized - provided postfire reproductive resilience.
Conclusions
The study shows that differential pollinator responses to disturbance can ensure plant success even in plants with only two functionally similar pollinators. This highlights the importance of pollinator 1 replacement and dynamics for the resilience of interactions and ultimately of plant reproduction in disturbance-prone ecosystems
Pemanfaatan Asap Cair Tempurung Kelapa Untuk Mengendalikan Cendawan Penyebab Penyakit Antraknosa Dan Layu Fusarium Pada Ketimun
Asap cair hasil destilasi kering tempurung kelapa pada konsentrasi antara 0,25-6,0% mampu menghambat pertumbuhan koloni cendawan baik pada Colletotrichum gloeosporoides maupun Fusarium oxysporum. Penghambatan asap cair pada koloni Colletotrichum gloeosporoides dan Fusarium oxysporum masing-masing sebesar 5,59-97,85% dan 6,06-94,97%. Penghambatan sampai 100% untuk kedua cendawan, dimulai pada konsentrasi 7%. Asap cair yang dihasilkan dari pemanasan 400 oC menunjukkan hambatan koloni cendawan paling tinggi, yaitu sebesar 16.26% untuk Colletotrichum gloeosporoides dan 15,06% untuk Fusarium oxysporum. Hasil uji in vivo menunjukkan bahwa asap cair dengan konsentrasi 0,5%, 1% dan 5%, efektif menghambat perkembangan penyakit antraknosa dan layu fusarium, sampai 100%. Meskipun demikian, asap cair dengan konsentrasi 5% tidak dianjurkan, karena dapat menyebabkan nekrosis pada daun ketimun
First record of Phaenoglyphis villosa (Hartig, 1841) from Korea (Hymenoptera: Cynipoidea : Figitidae: Charipinae)
The first record of Phaenoglyphis villosa (Hartig, 1841) (Hymenoptera: Figitidae: Charipinae) from Korea is given herein, being the second record of this species from the continental Eastern Palaearctic. The examined material, distribution, host associations and some data on the morphology of the Korean specimens are detailed.Phaenoglyphis villosa (Hartig, 1841) (Hymenoptera: Figitidae: Charipinae) es cita per primer cop a Corea y per segona vegada a la zona continental del Paleàrtic Oriental. Es menciona el material examinat, alguns aspectes referents a la distribució, els hostes associats i la morfologia dels espècimens col·lectats a Corea
Comparative biochemistry of CO2 fixation and the evolution of autotrophy
Carbon dioxide fixation is a polyphyletic trait that has evolved in widely separated prokaryotic branches. The three principal CO2-assimilation pathways are (i) the reductive pentose-phosphate cycle, i. e. the Calvin-Benson cycle; (ii) the reductive citric acid (or Arnon) cycle; and (iii) the net synthesis of acetyl-CoA from CO/CO2, or Wood pathway. Sequence analysis and the comparative biochemistry of these routes suggest that all of them were shaped to a considerable extent by the evolutionary recruitment of enzymes. Molecular phylogenetic trees show that the Calvin-Benson cycle was a relatively late development in the (eu)bacterial branch, suggesting that some form(s) of carbon assimilation may have been operative before chlorophyll-based photosynthesis. On the other hand, the ample phylogenetic distribution of both the Arnon and the Wood pathways does not allow us to infer which one of them is older. However, different lines of evidence, including experimental reports on the NiS/FeS-mediated C–C bond formation from CO and CH3SH are used here to argue that the first CO2-fixation route may have been a semienzymatic Wood-like pathway
Estrategia did?ctica para el fortalecimiento del pensamiento matem?tico del grado 1? del colegio "San Sim?n" sede Montealegre jornada ma?ana Ibague - Tolima
111 p. Recurso Electr?nicoEl presente proyecto pretende fomentar participativamente el pensamiento matem?tico por medio de actividades l?dicas e innovadoras en estudiantes del grado 1? del colegio ?San Sim?n?. Por este hecho, se quiere dejar establecido un camino de apoyo a futuros docentes para transformar las competencias matem?ticas con un soporte fijado a partir del juego. Para los antecedentes, se tuvieron en cuenta algunas investigaciones y tesis realizadas en M?xico y Colombia de acuerdo a la problem?tica vista desde diferentes contextos educativos que llevan como punto central la ense?anza-aprendizaje en las matem?ticas de primaria. As? mismo, se retroaliment? significativamente con te?ricos contempor?neos para conocer, indagar y ampliar otros trabajos investigativos.
Adicionalmente, este proyecto est? basado en el modelo de investigaci?n-acci?n en el aula con enfoque cualitativo; la poblaci?n objeto de estudio son aproximadamente 42 estudiantes, cuatro docentes de la instituci?n donde se llev? a cabo e trabajo investigativo y un docente de la Universidad del Tolima a los cuales se les aplic? instrumentos de dicho enfoque como lo son: gu?a de observaci?n, pre-test, ficha de redacci?n, unidad did?ctica y pos-test. Para el an?lisis de la informaci?n se realizar? un cruce de informaci?n recolectada (contraste), espec?ficamente de los grupos focales de estudiantes y profesores con el fin de obtener informaci?n concreta del problema de investigaci?n. Los datos obtenidos ser?n analizados con la finalidad de crear categor?as y subcategor?as para, despu?s redactar el informe final detallado.
Los resultados que se esperan con este proyecto investigativo son, en primera instancia despertar el inter?s a los estudiantes por las matem?ticas usando actividades l?dicas e innovadoras dentro y fuera del aula y en segundo lugar dejar establecido un camino de apoyo a futuros docentes para transformar la visi?n de la ense?anza-aprendizaje de las matem?ticas en primaria.This project aims to encourage participatory mathematical thinking through playful and innovative activities in 1st grade students of the school "San Simon". Because of this, you want to leave in place a way to support future teachers to transform math skills with a bracket from the game. For background, some research and thesis made in Mexico and Colombia, according to the problems seen from different educational contexts that take as a central point of teaching and learning in primary mathematics were considered. He also fed back significantly to contemporary to know, explore and expand other theoretical research work.
Additionally, this project is based on the model of action research in the classroom with a qualitative approach; the study population are about 42 students, four teachers from the institution where he was held and research work and teaching at the University of Tolima to which we applied instruments of this approach as they are: observation guide, pre -test, record of writing, teaching unit and post-test.
For the analysis of the information collected a cross information (contrast) will be held, specifically in the focus groups of students and teachers in order to obtain specific information research problem. The data obtained will be analyzed in order to create categories and subcategories to then draft the detailed final report.
The results are expected with this research project are, firstly arouse interest students in mathematics using playful and innovative activities within and outside the classroom and secondly let established a way to support future teachers to transform the vision the teaching and learning of mathematics in primary school.
Keywords: encouraging, teaching and learning, class, fun, math, teaching strategy
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