Hasil untuk "math.DG"

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CrossRef Open Access 2025
Leaf Litter Mixtures in Guam: Decomposition Synergism and Antagonism of Two Endangered Tree Species

Thomas E. Marler

Leaf litter traits among tree species exert a direct influence on spatiotemporal nutrient turnover and an indirect influence by shifting the decomposition dynamics of leaf litter mixtures including other sympatric species. Cycas micronesica and Serianthes nelsonii are two Mariana Island tree species that are endangered, and developing a greater understanding of the influence of these trees on biogeochemistry may improve information-based conservation decisions. The objectives of this study were to quantify the influence of mixing the leaf litter of these species with 12 sympatric forest plants to determine the additive and nonadditive influences on decomposition. The C. micronesica litter was collectively antagonistic when litter mixtures were incubated in a mesocosm study and a field litterbag study, and the response was similar among the included species. The S. nelsonii litter was collectively synergistic among the same mixed species, and the response was dissimilar among the included species. The contributions of these two threatened tree species to spatiotemporal diversity in biogeochemistry are dissimilar and considerable. These findings indicate that species recovery efforts for these two species are of paramount importance for maintaining Mariana Island ecological integrity and native biodiversity by sustaining their contributions to ecosystem services.

CrossRef Open Access 2024
Gender, Immunological Response, and COVID-19: An Assessment of Vaccine Strategies in a Pandemic Region of Oaxaca, México

Luis M. Rodríguez-Martínez, José L. Chavelas-Reyes, Carlo F. Medina-Ramírez et al.

COVID-19 is no longer a public health emergency of international concern, but long COVID’s effects are yet to be fully understood. Hence, globally, SARS-CoV-2 is still a profound threat to public health and of perilous nature as a zoonotic disease. Timely vaccination provided to individuals worldwide during the pandemic phase was under a certain degree of control; however, few studies have reported the effectiveness of vaccines administered in Mexico, and its surveillance is paramount. Furthermore, an unknown proportion of Mexican individuals have not yet received any vaccine, and the circulation of the Omicron, Pirola, and FLiRT variants is ongoing. A cross-sectional serology survey study design was employed, involving 150 individuals from Southern Mexico (Oaxaca) whose humoral immune responses after vaccination were tested by an ELISA; the receptor-binding domain of the SARS-CoV-2 spike protein served as a recombinant antigen in the ELISA. One hundred thirty-nine out of 150 individuals (92.6%; 95%-CI = 87–95%) examined were positive for the ELISA, but in 11 individuals, the vaccines did not induce any immune response. Interestingly, the immune responses (antibody prevalence and levels) of females (58%) were higher (T= −2.21; p-value = 0.02) than those of males (41%). However, in this sample population of Southern Mexico, age, vaccine type, comorbidity, and body mass index did not have any effect (p > 0.05) after COVID-19 vaccination. Taking all results together, here, we present factors that affected immune responses of individuals during the first vaccination campaign in Oaxaca, Mexico; however, vaccine surveillance during the post-pandemic phase needs further investigation.

CrossRef Open Access 2023
Adapting to sea level rise: participatory, solution-oriented policy tools in vulnerable Mediterranean areas

Xenia I. Loizidou, Demetra L. Orthodoxou, Michael I. Loizides et al.

AbstractThe coasts of the Mediterranean basin are exposed to the ongoing effects of climate change and anthropogenic pressure. Low elevated coastal plains, river deltas, lagoons and reclamation areas are experiencing beach retreat, coastal erosion and marine flooding. This makes them particularly vulnerable to sea level rise (SLR), which is expected to increase up to 1 m by 2100 AD, according to the projections of the Intergovernmental Panel on Climate Change. In this study, selected stakeholders from four Mediterranean coastal areas that are highly vulnerable to the impacts of SLR have been engaged through a structured participatory process for the development of solution-oriented, case-specific and site-specific Policy Tools to address SLR. The developed Policy Tools for the Venice Lagoon, the Metaponto reclamation area and the Basento river mouth, in Italy, the Ebro River Delta in Spain, and the coastal plain of Chalastra, near the Axios River Delta, in Greece, contain relevant, effective and implementable actions stemming from stakeholder interaction and consensus building. The interconnected stakeholder engagement steps employed in this study identified relevant issues that should be considered when defining SLR adaptation policies to bridge knowledge and perception gaps, facilitate knowledge exchange and foster social learning through structured science communication on SLR. This participatory stakeholder process can lay the foundations for more extensive participation in public processes through which the resulting Policy Tools can materialise into collectively accepted, concrete actions to help vulnerable areas adapt to the expected SLR and consequent coastal hazards by the end of this century.

16 sitasi en
CrossRef Open Access 2016
Kinetic energy preserving DG schemes based on summation‐by‐parts operators on interior node distributions

Sigrun Ortleb

AbstractIn this work, a kinetic energy preserving DG scheme in one space dimension using Gauss‐Legendre nodes is presented. Stability problems will be demonstrated when using interface terms that are derived from the Lobatto nodes within the Gauss‐Legendre skew‐symmetric DG formulation. However, combined with correct interface terms, the skew‐symmetric DG scheme constructed on Gauss‐Legendre nodes is expected to yield higher accuracy compared to its Gauss‐Lobatto counterpart. This advantage is demonstrated in the case of viscous compressible flow computation. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

7 sitasi en
CrossRef 2018
Uniqueness of dg enhancements for the derived category of a Grothendieck category

Alberto Canonaco, Paolo Stellari

We prove that the derived category of a Grothendieck abelian category has a unique dg enhancement. Under some additional assumptions, we show that the same result holds true for its subcategory of compact objects. As a consequence, we deduce that the unbounded derived category of quasi-coherent sheaves on an algebraic stack and the category of perfect complexes on a noetherian concentrated algebraic stack with quasi-finite affine diagonal and enough perfect coherent sheaves have a unique dg enhancement. In particular, the category of perfect complexes on a noetherian scheme with enough locally free sheaves has a unique dg enhancement.

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