scholarly journals Variación en la abundancia de árboles maderables por efecto de borde en un bosque tropical subcaducifolio

2019 ◽  
Vol 97 (1) ◽  
pp. 35 ◽  
Author(s):  
Víctor Abraham Vargas-Vázquez ◽  
Crystian Sadiel Venegas-Barrera ◽  
Arturo Mora-Olivo ◽  
José Guadalupe Martínez-Ávalos ◽  
Eduardo Alanís-Rodríguez ◽  
...  
Keyword(s):  
Edge Effect ◽  
Environmental Conditions ◽  
Life Stage ◽  
Life Stages ◽  
Cedrela Odorata ◽  
Economic Implications ◽  
Bursera Simaruba ◽  
Environmental Requirements ◽  
Guazuma Ulmifolia ◽  
Favorable Conditions

<p><strong>Background: </strong>The edge effect differentially affects the species in their life stages. We analyzed the environmental conditions associated with the abundance by life stage of four species of timber trees on the edge of a subdeciduous tropical forest.<strong></strong></p><p><strong>Hypothesis:</strong> The edges have higher light incidence and temperature, favorable conditions for the seedlings, so it is expected that the edge will have more abundance of seedlings with respect to the forest interior.</p><p><strong>Species under study:</strong> <em>Bursera simaruba</em> (L.) Sarg.<em>, Cedrela odorata</em> L.<em>, Guazuma ulmifolia </em>Lam.<em>, Lysiloma divaricatum </em>(Jacq.) J.F. Macbr.</p><p><strong>Study site and dates:</strong> Reserva de la Biosfera "El Cielo" (Tamaulipas), Mexico. January-December 2016.</p><p><strong>Methods: </strong>The abundance by life stages and environmental conditions were quantified within the gradient. These variables were correlated, in addition the requirements between stages were contrasted and they were associated with the identified environments.</p><p><strong>Results:</strong> <em>Guazuma ulmifolia</em> showed a negative response to the edge effect, while <em>Cedrela</em> <em>odorata</em> responded positively. The environmental requirements differed between the first life stages and adults. The abundance of the seedlings was associated to conditions of higher light incidence.</p><strong>Conclusions:</strong> Environmental requirements differentially affect each life stage. The abundance of seedlings increases in conditions of higher light incidence, but not in the rest of the stages, except in <em>C. odorata</em>. The loss of cover and the consequent formation of borders can lead to a reduction in the abundance of these species, with economic implications.

scholarly journals Especies útiles de la selva baja caducifolia en las dunas costeras del centro de Veracruz

2016 ◽  
Vol 15 (3) ◽  
pp. 21-44 ◽  
Author(s):  
Patricia Moreno-Casasola ◽  
Krystina Paradowska
Keyword(s):  
Cocos Nucifera ◽  
Gliricidia Sepium ◽  
Cedrela Odorata ◽  
La Selva ◽  
Bursera Simaruba ◽  
La Mancha ◽  
Brosimum Alicastrum ◽  
Guazuma Ulmifolia ◽  
Enterolobium Cyclocarpum ◽  
Tabebuia Rosea

La selva baja caducifolia es un ecosistema bajo fuerte presión por las actividades humanas. Se distribuye tanto sobre dunas costeras como tierra adentro. El trabajo tiene como objetivo identificar las especies de árboles y palmas nativos útiles que crecen en las selvas bajas caducifolias y acahuales sobre las dunas costeras. En el trabajo se aplicaron cuestionarios y se realizaron entrevistas entre pobladores de San Isidro y Colonia La Mancha, en la costa de Veracruz. Se preguntó acerca del uso de los árboles de la selva baja caducifolia. Entre las 55 especies registradas, las más mencionadas fueron Cedrela odorata, Diphysa robinioides, Enterolobium cyclocarpum, Bursera simaruba, Gliricidia sepium, Tabebuia rosea, Chrysobalanus icaco, Guazuma ulmifolia, Acacia cochliacantha, Brosimum alicastrum, Bumelia celastrina, Cocos nucifera, Maclura tinctoria, Piscidia piscipula, Spondias mombin y Ficus spp. Se registraron 18 usos, siendo los más frecuentes la construcción de casas (119 menciones), postes y cercas vivas (99), leña (72) y comestibles (48), aunque también hay muchos usos que son poco mencionados. Cuatro de los usos se refirieron a servicios ambientales que prestan las plantas en las dunas. La especie con mayor número de usos es Gliricidia sepium y Bursera simaruba, es la especie con más partes aprovechadas, seguida por Gliricidia sepium, Guazuma ulmifolia y Brosimum alicastrum. También se preguntó acerca de las partes del árbol más usadas, la frecuencia de uso y su venta y precio local. Con base en los resultados se propone un conjunto de especies para enriquecer los acahuales y pastizales de las dunas para proveer madera, forraje, etc., a los habitantes y para mantener la cubierta arbolada de las dunas.

scholarly journals Optimal reproductive phenology under size-dependent cannibalism

2019 ◽  
Author(s):  
Nao Takashina ◽  
Øyvind Fiksen
Keyword(s):  
Environmental Conditions ◽  
Early Life ◽  
Life Stage ◽  
Larval Growth ◽  
Reproductive Phenology ◽  
Life Stages ◽  
Breeding Phenology ◽  
Early Life Stages ◽  
Size Dependent ◽  
Game Theoretic

AbstractIntra-cohort cannibalism is an example of a size-mediated priority effect. If early life stages cannibalize slightly smaller individuals, then parents face a trade-off between breeding at the best time for larval growth or development and predation risk from offspring born earlier. This game-theoretic situation among parents may drive adaptive reproductive phenology towards earlier breeding. However, it is not straightforward to quantify how cannibalism affects seasonal egg fitness or to distinguish emergent breeding phenology from alternative adaptive drivers. Here, we devise an age-structured game-theoretic mathematical model to find evolutionary stable breeding phenologies. We predict how size-dependent cannibalism acting on eggs, larvae, or both change emergent breeding phenology, and find that breeding under inter-cohort cannibalism occurs earlier than the optimal match to environmental conditions. We show that emergent breeding phenology patterns at the level of the population are sensitive to the ontogeny of cannibalism, i.e. which life stage is subject to cannibalism. This suggests that the nature of cannibalism among early life stages is a potential driver of the diversity of reproductive phenologies seen across taxa, and may be a contributing factor in situations where breeding occurs earlier than expected from environmental conditions.

Automated reverse engineering control system model

2020 ◽  
pp. 39-43
Author(s):  
A. V. Vinnichenko ◽  
S. A. Nazarevich ◽  
I. R. Karpova
Keyword(s):  
Control System ◽  
Reverse Engineering ◽  
Flaw Detection ◽  
Production Capacity ◽  
Speed Up ◽  
Environmental Requirements ◽  
Traditional Technologies ◽  
The Moment ◽  
Control System Model ◽  
Favorable Conditions

The article deals with the task of simplifying the reverse design process by implementing three-point 3D scanning, which allows you to speed up the technological stages of reverse design to the moment of product manufacture, as well as simplify the procedure for defecating finished products and create favorable conditions for the implementation of the principles of unification. The model of the control system in this article refers to the structuring of elements of the technological organization of the process of creating 3D prototyping of existing copies created by the use of reverse engineering. For this purpose, the problems of traditional technologies that do not allow timely coping with changes in the technical system under the influence of in accordance with the requirements of regulatory documents and environmental requirements were considered. We also analyzed not only the principles of operation of traditional technologies, but also the zone of reverse engineering, which allows you to achieve an increased level of production capacity by identifying a group of key defects based on the process of flaw detection and statistical analysis.

‘And all my children?’

2018 ◽  
Author(s):  
Charlotte Scott
Keyword(s):  
Early Modern ◽  
Life Stage ◽  
Early Modern Period ◽  
Life Stages ◽  
Cultural Imagination ◽  
Modern Period

Beginning with an exploration of the role of the child in the cultural imagination, Chapter 1 establishes the formative and revealing ways in which societies identify themselves in relation to how they treat their children. Focusing on Shakespeare and the early modern period, Chapter 1 sets out to determine the emotional, symbolic, and political registers through which children are depicted and discussed. Attending to the different life stages and representations of the child on stage, this chapter sets out the terms of the book’s enquiry: what role do children play in Shakespeare’s plays; how do we recognize them as such—age, status, parental dynamic—and what are the effects of their presence? This chapter focuses on how the early moderns understood the child, as a symbolic figure, a life stage, a form of obligation, a profound bond, and an image of servitude.

scholarly journals Ether Oxidation by an Evolved Fungal Heme-Peroxygenase: Insights into Substrate Recognition and Reactivity

2021 ◽  
Vol 7 (8) ◽  
pp. 608
Author(s):  
Raul Mireles ◽  
Joaquin Ramirez-Ramirez ◽  
Miguel Alcalde ◽  
Marcela Ayala
Keyword(s):  
Molecular Weight ◽  
Environmental Conditions ◽  
Substrate Recognition ◽  
Enzyme Inactivation ◽  
Biochemical Reaction ◽  
Low Molecular Weight ◽  
Factors Influencing ◽  
Secondary Reactions ◽  
Oxidation Efficiency ◽  
Favorable Conditions

Ethers can be found in the environment as structural, active or even pollutant molecules, although their degradation is not efficient under environmental conditions. Fungal unspecific heme-peroxygenases (UPO were reported to degrade low-molecular-weight ethers through an H2O2-dependent oxidative cleavage mechanism. Here, we report the oxidation of a series of structurally related aromatic ethers, catalyzed by a laboratory-evolved UPO (PaDa-I) aimed at elucidating the factors influencing this unusual biochemical reaction. Although some of the studied ethers were substrates of the enzyme, they were not efficiently transformed and, as a consequence, secondary reactions (such as the dismutation of H2O2 through catalase-like activity and suicide enzyme inactivation) became significant, affecting the oxidation efficiency. The set of reactions that compete during UPO-catalyzed ether oxidation were identified and quantified, in order to find favorable conditions that promote ether oxidation over the secondary reactions.

scholarly journals Bile acid production is life-stage and sex-dependent and affected by primer pheromones in the sea lamprey

2021 ◽  
pp. jeb.229476
Author(s):  
Yu-Wen Chung-Davidson ◽  
Ugo Bussy ◽  
Skye D. Fissette ◽  
Anne M. Scott ◽  
Weiming Li
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Life Stage ◽  
Sea Lamprey ◽  
Life Stages ◽  
Pheromone Production ◽  
Primer Pheromone ◽  
Petromyzonol Sulfate ◽  
Sea Lampreys ◽  
Primer Pheromones

Pheromonal bile salts are important for sea lampreys (Petromyzon marinus Linnaeus) to complete their life cycle. The synthesis and release of a releaser/primer pheromone 3-keto petromyzonol sulfate (3kPZS) by spermiating males have been well characterized. 3kPZS evokes sexual behaviors in ovulatory females, induces immediate 3kPZS release in spermiating males, and elicits neuroendocrine responses in prespawning adults. Another primer pheromone released by spermiating males, 3-keto allocholic acid (3kACA), antagonizes the neuroendocrine effects of 3kPZS in prespermiating males. However, the effects of 3kACA and 3kPZS on pheromone production in prespawning adults is unclear. To understand the foundation of pheromone production, we examined sea lamprey bile salt levels at different life stages. To investigate the priming effects of 3kACA and 3kPZS, we exposed prespawning adults with vehicle or synthetic 3kACA or 3kPZS. We hypothesized that endogenous bile salt levels were life-stage and sex-dependent, and differentially affected by 3kACA and 3kPZS in prespawning adults. Using ultra-performance liquid chromatography tandem mass spectrometry, we found that sea lampreys contained distinct mixtures of bile salts in the liver and plasma at different life stages. Males usually contained higher amounts of bile salts than females. Petromyzonamine disulfate was the most abundant C27 bile salt and petromyzonol sulfate was the most abundant C24 bile salt. Waterborne 3kACA and 3kPZS exerted differential effects on bile salt production in the liver and gill, their circulation and clearance in the plasma, and their release into water. We conclude that bile salt levels are life-stage and sex-dependent and differentially affected by primer pheromones.

scholarly journals Seedling Survival and Growth of Tree Species: Site Condition and Seasonality in Tropical Dry Forest Restoration

2014 ◽  
Vol 90 (3) ◽  
pp. 313
Author(s):  
CLAUDIA ALVAREZ-AQUINO ◽  
GUADALUPE WILLIAMS-LINERA
Keyword(s):  
Forest Restoration ◽  
Seedling Survival ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Cedrela Odorata ◽  
Guazuma Ulmifolia ◽  
Survival And Growth ◽  
Tabebuia Rosea ◽  
Dry Forest Restoration ◽  
Ceiba Aesculifolia

La restauración del bosque tropical seco es prioritaria por ser el bosque más amenazado. En Veracruz, el bosque seco se ha reducido al 7% de su cobertura original. Nuestro objetivo fue determinar el efecto de la condición del sitio a restaurar y la estacionalidad en la supervivencia y tasa de crecimiento relativo en altura y diámetro de especies de árboles nativos. Estudiamos el desempeño de plántulas durante dos estaciones secas y dos lluviosas, y el efecto de la vegetación leñosa existente &gt; 1 m de altura. Se trasplantaron 960 plantas: 40 individuos de seis especie (Cedrela odorata, Ceiba aesculifolia, Guazuma ulmifolia, Ipomoea wolcottiana, Luehea candida, Tabebuia rosea) en cuatro sitios abandonados. La supervivencia y la tasa de crecimiento relativo se registraron cada cuatro meses durante dos años. La mayor supervivencia se observó en sitios con mayor riqueza de especies arbóreas y la tasa de crecimiento relativo en altura estuvo positivamente correlacionada con la altura de la vegetación existente. La mayor tasa de crecimiento relativo para especies y sitios se registró durante la estación lluviosa. En el sitio con menos vegetación, el desempeño de las plántulas fue pobre y sólo Guazuma sobrevivió. Ceiba mostró la mayor supervivencia (82-90%) pero una tasa de crecimiento relativo baja; Guazuma presentó una supervivencia elevada (20-94%) y la mayor tasa de crecimiento relativo; Cedrela mostró la menor supervivencia (3-7%) y tasa de crecimiento relativo alta. Los resultados sugieren que la vegetación del sitio, la estacionalidad y las especies afectan el desempeño de las plántulas durante el establecimiento temprano. La implicación en términos de la restauración ecológica es la importancia de aprovechar la vegetación existente aunque ésta sea escasa.

scholarly journals What wild dogs want: habitat selection differs across life stages and orders of selection in a wide-ranging carnivore

BMC Zoology ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Helen M. K. O’Neill ◽  
Sarah M. Durant ◽  
Rosie Woodroffe
Keyword(s):  
Habitat Selection ◽  
Human Population ◽  
Life Stage ◽  
Selection Function ◽  
Order Selection ◽  
Life Stages ◽  
Population Densities ◽  
Selection For ◽  
Wild Dogs ◽  
Selection Of

Abstract Background Habitat loss is a key threat to the survival of many species. Habitat selection studies provide key information for conservation initiatives by identifying important habitat and anthropogenic characteristics influencing the distribution of threatened species in changing landscapes. However, assumptions about the homogeneity of individual choices on habitat, regardless of life stage, are likely to result in inaccurate assessment of conservation priorities. This study addresses a knowledge gap in how animals at different life stages diverge in how they select habitat and anthropogenic features, using a free-ranging population of African wild dogs living in a human-dominated landscape in Kenya as a case study. Using GPS collar data to develop resource selection function and step selection function models, this study investigated differences between second order (selection of home range across a landscape) and third order (selection of habitat within the home range) habitat selection across four life history stages when resource requirements may vary: resident-non-denning, resident-heavily-pregnant, resident-denning and dispersing. Results Wild dogs showed strong second order selection for areas with low human population densities and areas close to rivers and roads. More rugged areas were also generally selected, as were areas with lower percentage tree cover. The strength of selection for habitat variables varied significantly between life stages; for example, dispersal groups were more tolerant of higher human population densities, whereas denning and pregnant packs were least tolerant of such areas. Conclusions Habitat selection patterns varied between individuals at different life stages and at different orders of selection. These analyses showed that denning packs and dispersal groups, the two pivotal life stages which drive wild dog population dynamics, exhibited different habitat selection to resident-non-breeding packs. Dispersal groups were relatively tolerant of higher human population densities whereas denning packs preferred rugged, remote areas. Evaluating different orders of selection was important as the above trends may not be detectable at all levels of selection for all habitat characteristics. Our analyses demonstrate that when life stage information is included in analyses across different orders of selection, it improves our understanding of how animals use their landscapes, thus providing important insights to aid conservation planning.

scholarly journals Survey of bacteria associated with western corn rootworm life stages reveals no difference between insects reared in different soils

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dalton C. Ludwick ◽  
Aaron C. Ericsson ◽  
Lisa N. Meihls ◽  
Michelle L. J. Gregory ◽  
Deborah L. Finke ◽  
...  
Keyword(s):  
Pest Management ◽  
Life Stage ◽  
Management Strategies ◽  
Diabrotica Virgifera Virgifera ◽  
Western Corn Rootworm ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Corn Rootworm ◽  
Life Stages ◽  
Different Soils

Abstract Western corn rootworm (Diabrotica virgifera virgifera LeConte) is a serious pest of maize (Zea mays L.) in North America and parts of Europe. With most of its life cycle spent in the soil feeding on maize root tissues, this insect is likely to encounter and interact with a wide range of soil and rhizosphere microbes. Our knowledge of the role of microbes in pest management and plant health remains woefully incomplete, yet that knowledge could play an important role in effective pest management strategies. For this study, insects were reared on maize in soils from different locations. Insects from two different laboratory colonies (a diapausing and a non-diapausing colony) were sampled at each life stage to determine the possible core bacteriome. Additionally, soil was sampled at each life stage and resulting bacteria were identified to determine the possible contribution of soil to the rootworm bacteriome, if any. We analyzed the V4 hypervariable region of bacterial 16S rRNA genes with Illumina MiSeq to survey the different species of bacteria associated with the insects and the soils. The bacterial community associated with insects was significantly different from that in the soil. Some differences appear to exist between insects from non-diapausing and diapausing colonies while no significant differences in community composition existed between the insects reared on different soils. Despite differences in the bacteria present in immature stages and in male and female adults, there is a possible core bacteriome of approximately 16 operational taxonomic units (i.e., present across all life stages). This research may provide insights into Bt resistance development, improved nutrition in artificial rearing systems, and new management strategies.

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