scholarly journals Influence of Invasive Species on Ecological Succession Routes in Disturbed Seasonal Dry Tropical Forests in Southeastern Mexico

2018 ◽  
Author(s):  
Alberto Jean-Baptiste ◽  
Pedro A. Macario ◽  
Gerald Alexander Islebe ◽  
Benedicto Vargas-Larreta ◽  
Luciano Pool ◽  
...  
Keyword(s):  
Invasive Species ◽  
Tropical Forests ◽  
Secondary Succession ◽  
Pteridium Aquilinum ◽  
Negative Effects ◽  
Importance Value ◽  
Alternative State ◽  
Recovery Strategies ◽  
And Control

Understanding the role of invasive species in ecosystem functioning represents one of the main challenges in ecology. Pteridium aquilinum is a successful cosmopolitan invasive species with negative effects on the ecological mechanisms that allow secondary succession. In this study we evaluated whether P. aquilinum favours the establishment of alternative states, as well as the effect of recovery strategies on the secondary succession. A random stratified sampling was established with three treatments, each one with at least 50 year of fern invasion and with variations on the periodicity of fires and cuttings (chapeos) vs one control without fern bracken We determined the species richness and composition, as well as the relative importance value (IVI) in each treatment. We found that P. aquilinum decreases the action of the mechanisms that allow secondary succession, particularly facilitation. The recovery strategies consist in monthly cuttings and control fires allow to recover the secondary succession and eventually, the regeneration of areas invaded by P. aquilinum. Our study has relevant implications on the ecology of alternative state, and in practical strategies to maintain tropical forests, as well as for the maintenance of environmental services and sustainability.

scholarly journals Secondary Succession under invasive species (Pteridium aquilinum) conditions in a seasonal dry tropical forest in southeastern Mexico

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6974
Author(s):  
Alberto Jean Baptiste ◽  
Pedro A. Macario ◽  
Gerald A. Islebe ◽  
Benedicto Vargas-Larreta ◽  
Luciano Pool ◽  
...  
Keyword(s):  
Invasive Species ◽  
Species Richness ◽  
Linear Model ◽  
Generalized Linear Model ◽  
Secondary Succession ◽  
Dry Forest ◽  
Pteridium Aquilinum ◽  
Soil Conditions ◽  
Site Conditions ◽  
Importance Value

The role of invasive species in ecosystem functioning represents one of the main challenges in ecology. Pteridium aquilinum is a successful cosmopolitan invasive species with negative effects on the ecological mechanisms that allow secondary succession. In this study, we evaluated the influence of P. aquilinumon secondary succession under different disturbances in a seasonal dry forest of the Yucatán Peninsula. We determined species richness, composition and the relative importance value in four sampling units. Fabaceae followed by Asteraceae, Meliaceae, Rubiaceae, Sapindaceae and Verbenaceae were the most species rich families. A dissimilarity analysis determined significant differences in beta diversity between sampling units. With a generalized linear model we found that species richness was best explained by site conditions, followed by calcium and soil organic matter. Also, the generalized linear model showed that abundance resulted in a strong correlation with site conditions and soil characteristics. Specific soil conditions related to phosphoro and calcium were also detected as beneficiary to the successional processes. Our results suggest that applying fire restriction and periodic cutting of the bracken fern, this can increase a higher diversity of species.

Managing Corporate E-Mail Systems

2011 ◽  
pp. 254-281
Author(s):  
Aidan Duane ◽  
Patrick Finnegan
Keyword(s):  
Major Elements ◽  
Electronic Business ◽  
Monitoring And Control ◽  
Negative Effects ◽  
Multiple Case ◽  
And Control ◽  
Mail System ◽  
E Mail

As the criticality of e-mail for electronic business activity increases, adhoc e-mail implementation, prolonged management neglect and user abuse of e-mail systems have generated negative effects. However, management’s ability to rectify problems with e-mail systems is hindered by our understanding of its organisational use. Research on e-mail systems is often dated and based on quantitative methodologies that cannot explain the interaction between various controls in organisational settings. Updating our understanding of the organisational aspects of e-mail systems utilizing qualitative methods is necessary. This chapter presents a multiple case study investigation of e-mail system monitoring and control. The study examines the interaction between key elements of e-mail control identified by previous researchers and considers the role of such controls at various implementation phases. The findings reveal eight major elements to be particularly important in monitoring and controlling e-mail systems within the organisations studied. These are: (1) form a cross-functional e-mail system management team; (2) implement and regularly update e-mail management software; (3) formulate a detailed and legally sound e-mail policy; (4) engage in structured e-mail system training; (5) create and maintain ongoing awareness of e-mail policy; (6) engage in a process of hybrid feedback and control-based e-mail monitoring; (7) firmly enforce discipline in accordance with the e-mail policy; and (8) conduct regular reviews and updates of the e-mail management programme.

scholarly journals Role of ghrelin in fertilization, early embryo development, and implantation periods

Reproduction ◽  
2014 ◽  
Vol 148 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Eugenia Mercedes Luque ◽  
Pedro Javier Torres ◽  
Nicolás de Loredo ◽  
Laura María Vincenti ◽  
Graciela Stutz ◽  
...  
Keyword(s):  
Embryo Development ◽  
Ovulation Induction ◽  
Physiological Role ◽  
Fertilization Rate ◽  
Early Embryo ◽  
Corpora Lutea ◽  
Negative Effects ◽  
Early Embryo Development ◽  
And Control

In order to clarify the physiological role of ghrelin in gestation, we evaluated the effects of administration of exogenous ghrelin (2 or 4 nmol/animal per day) or its antagonist (6 nmol/animal per day of (d-Lys3)GHRP6) on fertilization, early embryo development, and implantation periods in mice. Three experiments were performed, treating female mice with ghrelin or its antagonist: i) starting from 1 week before copulation to 12 h after copulation, mice were killed at day 18 of gestation; ii) since ovulation induction until 80 h later, when we retrieved the embryos from oviducts/uterus, and iii) starting from days 3 to 7 of gestation (peri-implantation), mice were killed at day 18. In experiments 1 and 3, the antagonist and/or the highest dose of ghrelin significantly increased the percentage of atrophied fetuses and that of females exhibiting this finding or a higher amount of corpora lutea compared with fetuses (nCL/nF) (experiment 3: higher nCL/nF-atrophied fetuses: ghrelin 4, 71.4–71.4% and antagonist, 75.0–62.5% vs ghrelin 2, 46.2−15.4% and control, 10–0.0%;n=7–13 females/group;P<0.01). In experiment 2, the antagonist diminished the fertilization rate, and both, ghrelin and the antagonist, delayed embryo development (blastocysts: ghrelin 2, 62.5%; ghrelin 4, 50.6%; and antagonist, 61.0% vs control 78.4%;n=82–102 embryos/treatment;P<0.0001). In experiment 3, additionally, ghrelin (4 nmol/day) and the antagonist significantly diminished the weight gain of fetuses and dams during pregnancy. Our results indicate that not only hyperghrelinemia but also the inhibition of the endogenous ghrelin effects exerts negative effects on the fertilization, implantation, and embryo/fetal development periods, supporting the hypothesis that ghrelin (in ‘adequate’ concentrations) has a physiological role in early gestational events.

Surface Electrolyte Interphase Control on Magnetite, Fe3O4, Electrodes: Impact on Electrochemistry

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 581-586
Author(s):  
Lisa M. Housel ◽  
Alyson Abraham ◽  
Genesis D. Renderos ◽  
Kenneth J. Takeuchi ◽  
Esther S. Takeuchi ◽  
...  
Keyword(s):  
Solid Electrolyte Interphase ◽  
Cycle Life ◽  
Cell Resistance ◽  
Negative Effects ◽  
Initial Formation ◽  
Magnetite Fe3o4 ◽  
Battery Systems ◽  
Recent Developments ◽  
And Control

ABSTRACTIn battery systems, a solid electrolyte interphase (SEI) is formed through electrolyte reaction on an electrode surface. The formation of SEI can have both positive and negative effects on electrochemistry. The initial formation of the layer protects the electrode from further reactivity, which can improve both shelf and cycle life. However, if the layer continues to form, it can impede charge transfer, which increases cell resistance and limits cycle life. The role of SEI is particularly important when studying conversion electrodes, since phase transformations which unveil new electroactive surfaces during reduction/oxidation can facilitate electrolyte decomposition. This manuscript highlights recent developments in the understanding and control of SEI formation for magnetite (Fe3O4) conversion electrodes through electrolyte and electrode modification.

scholarly journals Effects of lianas and Hurricane Wilma on tree damage in the Yucatan Peninsula, Mexico

2008 ◽  
Vol 24 (05) ◽  
pp. 559-562 ◽  
Author(s):  
Edgardo I. Garrido-Pérez ◽  
Juan Manuel Dupuy ◽  
Rafael Durán-García ◽  
Mario Ucan-May ◽  
Stefan A. Schnitzer ◽  
...  
Keyword(s):  
Climate Change ◽  
Tropical Forests ◽  
Secondary Succession ◽  
Forest Age ◽  
Hurricane Wilma ◽  
Tree Damage ◽  
Treefall Gaps ◽  
Feedback Cycle ◽  
Multiple Trees

Climate change may increase the intensity of hurricanes (Emanuel 1987, 2003), and thus the size of disturbance in tropical forests. As a consequence, disturbance-specialist plants, such as lianas, may increase in abundance there (Phillips &amp; Gentry 1994). Putz (1984) hypothesized that lianas create larger treefall gaps by connecting trees together and pulling down multiple trees during storms. This positive-feedback cycle may increase the prevalence of lianas in disturbed tropical forests (Schnitzer &amp; Bongers 2002, Schnitzer &amp; Carson 2001). Alternatively, Putz (1984) proposed that lianas tie and stabilize canopies together, resulting in less disturbance. Forest age may determine the role of lianas during disturbance because liana abundance and composition vary through secondary succession (De Waltet al. 2000, Schnitzeret al. 2000). To test the two hypotheses of Putz (1984), we evaluated the effect of liana cutting between forests of different successional ages on tree damage by hurricane Wilma.

scholarly journals Invasive Species in Nepal: Appraisal of Legal Provisions and Institutional Setup

2014 ◽  
Vol 5 ◽  
pp. 121-127
Author(s):  
Ajay Karki ◽  
Rajan P Paudel
Keyword(s):  
Invasive Species ◽  
Local Level ◽  
Economic Activities ◽  
Negative Effects ◽  
Legal Documents ◽  
Legal Provisions ◽  
Wide Range ◽  
Chitwan National Park ◽  
Convention On Biodiversity ◽  
And Control

Invasive species are top threat to biodiversity because of their negative effects on floral and faunal species, food web, on ecosystems and their habitat. Their inherent capability to adjust in wide range of environmental conditions and spread at higher pace with economic activities like travel, trade and tourism have necessitated a concern for their prevention and protection. This has been recognized by Convention on Biodiversity that calls the contracting parties to prevent introduction and control or eradication of invasive species. Nepal as a signatory to this convention has to take essential legal and managerial actions to abide by the convention. This paper reviews some literatures and existing legal documents dealing with the invasive species management. The paper finds out that there is impact of Mikenia micrantha in Chitwan National Park and it may affect the productivity the area. There are legal provisions and institutional setup at National and local level under different acts, regulations and guidelines that influence the introduction, control and eradication of this species. This paper recommends that the full functioning of these provisions and institutional setup is required to manage the invasive species. DOI: http://dx.doi.org/10.3126/init.v5i0.10261 The Initiation 2013 Vol.5; 121-127

Allelopathic plants 29: Eupatorium adenophorum Sprengel

2021 ◽  
Vol 53 (1) ◽  
pp. 15-22
Author(s):  
Xunzhi Zhu ◽  
Kaimei Zhang ◽  
Shijie Tang. T
Keyword(s):  
Invasive Species ◽  
Biological Invasion ◽  
Secondary Metabolite ◽  
Invasive Plant ◽  
Previous Literature ◽  
Eupatorium Adenophorum ◽  
Close Relationship ◽  
And Control

Eupatorium adenophorum is worldwide-spread invasive plant. This review focussed on unique metabolite, Euptox A, released by this plant and its importance in invasion, use and control. Based on previous literature, it is concluded that the mechanism of the invader’s success has a close relationship with a special compound, Euptox A. Its release and degradation mostly determines the spread of E. adenophorum. Besides, the control and use of this invasive species should consider the toxicity of Euptox A. This review suggests that the secondary metabolite, Euptox A, might be a key in controlling and using this invasive plant. This review will increase our knowledge of the role of a natural chemical in biological invasion.

scholarly journals The Promise of Genetics and Genomics for Improving Invasive Mammal Management on Islands

2021 ◽  
Vol 9 ◽  
Author(s):  
Brock T. Burgess ◽  
Robyn L. Irvine ◽  
Gregg R. Howald ◽  
Michael A. Russello
Keyword(s):  
Invasive Species ◽  
Mammalian Species ◽  
Negative Effects ◽  
Invasion Pathways ◽  
Migration Patterns ◽  
Control Programs ◽  
Species Invasions ◽  
Current State ◽  
Genetics And Genomics ◽  
And Control

Invasive species are major contributors to global biodiversity decline. Invasive mammalian species (IMS), in particular, have profound negative effects in island systems that contain disproportionally high levels of species richness and endemism. The eradication and control of IMS have become important conservation tools for managing species invasions on islands, yet these management operations are often subject to failure due to knowledge gaps surrounding species- and system-specific characteristics, including invasion pathways and contemporary migration patterns. Here, we synthesize the literature on ways in which genetic and genomic tools have effectively informed IMS management on islands, specifically associated with the development and modification of biosecurity protocols, and the design and implementation of eradication and control programs. In spite of their demonstrated utility, we then explore the challenges that are preventing genetics and genomics from being implemented more frequently in IMS management operations from both academic and non-academic perspectives, and suggest possible solutions for breaking down these barriers. Finally, we discuss the potential application of genome editing to the future management of invasive species on islands, including the current state of the field and why islands may be effective targets for this emerging technology.

scholarly journals THE ROLE OF INTRAGESTATIONAL GHRELIN ON POSTNATAL DEVELOPMENT AND REPRODUCTIVE PROGRAMMING IN MICE

Reproduction ◽  
2018 ◽  
Author(s):  
Pedro Javier Torres ◽  
Eugenia Mercedes Luque ◽  
Marina Flavia Ponzio ◽  
Verónica Cantarelli ◽  
Marcela Diez ◽  
...  
Keyword(s):  
Body Weight ◽  
Reproductive Function ◽  
Weight Increase ◽  
Plasma Testosterone ◽  
Negative Effects ◽  
Testicular Weight ◽  
Body Weight Increase ◽  
Puberty Onset ◽  
And Control

The purpose of this study was to evaluate the intragestational role of ghrelin in offspring development and reproductive programming in a mouse model of ghrelin imbalance during pregnancy. Female mice were injected with ghrelin (supraphysiological levels: 4 nmol/animal/day), antagonist (endogenous ghrelin inhibition with (D-Lys3)GHRP-6, 6 nmol/animal/day) or vehicle (control=normal ghrelin levels) throughout the pregnancy. Parameters evaluated in litters were growth, physical, neurobiological, and sexual development and, at adulthood, reproductive function. Litter size and initial weight did not vary between treatments. Male pups from dams treated with ghrelin showed higher body weight increase until adulthood (31.7±0.8 vs control=29.7±0.7, n=11-14 litters/treatment; p<0.05). Postnatal physical and neurobiological development were not modified by treatments. The antagonist accelerated male puberty onset, evidenced as earlier testis descent and increased relative testicular weight (antagonist=0.5±0.0% vs ghrelin=0.4±0.0% and control=0.4±0.0%, n=5-10 litters/treatment; p<0.05). At adulthood, these males exhibited lower relative testicular weight and reduced sperm motility (63.9±3.6% vs control=70.9±3.3 and ghrelin=75.6±3.0, n=13-15 animals; p<0.05), without changes in plasma testosterone or fertility. Female pups intragestationally exposed to the antagonist showed earlier vaginal opening (statistically significant only at day 25) and higher ovarian volume (antagonist=1085.7±64.0mm3 vs ghrelin=663.3±102.8mm3 and control=512.3±116.4mm3; n=4-6 animals/treatment; p<0.05), indicating earlier sexual maturation. At adulthood, these females and those exposed to ghrelin showed a tendency to higher percentages of embryo loss and/or foetal atrophy. In conclusion, ghrelin participates in reproductive foetal programming: alterations in ghrelin activity during pregnancy modified body weight increase and anticipated puberty onset, exerting (or tending to) negative effects on adult reproductive function.

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