68 research outputs found
The Serendipitous Value of Soil Fauna in Ecosystem Functioning: The Unexplained Explained
Soil fauna is crucial to soil formation, litter decomposition, nutrient cycling, biotic regulation, and for promoting plant growth. Yet soil organisms remain underrepresented in soil processes and in existing modeling exercises. This is a consequence of assuming that much of the below-ground diversity is just ecologically “redundant” and that soil food webs exhibit a higher degree of omnivory. However, evidence is accumulating on the strong influence of abiotic filters (temperature, moisture, soil pH) and soil habitat characteristics in controlling their spatial and temporal patterns. From this, new emerging concepts such as “hot moments,” “biological accessibility,” and “trophic cascades” have been coined to enable plausible explanations of the observed faunal responses to environmental changes. Here, I argue that many of these findings are indeed “happy accidents” (i.e., “eureka discoveries”) that remain disjointed between disciplines, impeding us from making significant breakthroughs. Therefore, here I provide some new perspectives on soil fauna research and highlight some experimental approaches to better explore the great variety of organisms living in soils and their complex interactions. A more comprehensive and dynamic holistic approach is needed to couple soil pedological and biological processes and to combine current experimental and theoretical knowledge if we aim to improve our predictive capacities in determining the persistence of soil organic matter and soil ecosystem functioning
Contribucion al conocimiento de la flora del Sistema Iberico Septentrional
Se aporta un catálogo florístico de 313 táxones seleccionados procedentes de algunas de las sierras septentrionales del Sistema Ibérico aragonés: Sierras de Villarroya, Vicort, Cucalón y Retuerta, Monte de Herrera, la Modorra de Bádenas y Baños de Segura. La visita a algunas de las localidades clásicas de ASSO, ha permitido confirmar numerosas citas de las que aparecen en su Synopsis stirpium indigenarum Aragoniae (1779), así como establecer algunas sinonimias. En el aspecto nomenclatural se propone una nueva combinación: Androsace elongata L. subsp. breistrofferi (Charpin & Greuter) J . Molero & JM. Montserrat, comb. nova. En el aspecto corológico, una lista, que no pretende ser exahustiva, sobre novedades para la Flora aragonesa y otras especies escasamente citadas que incluye: Paronychia rouyana, Suene scabriflora, Sisymbrium macroloma, Hutera hispida, Saxifraga losae var. camarae, Rosa arvensis, Aphanes cornucopioides, Lathyrus cirrhosus, Trifolium retusum, Trifolium gemellum, Seseli cantabricum, Daucus durieua, Anthemis alpestris fma. ligulata , Hieracium castellanum, Festuca capillifolia , Avenula pubescens, Carex tomentosa, etc
The Effect of a Physical Activity Program on the Total Number of Primary Care Visits in Inactive Patients: A 15-Month Randomized Controlled Trial
Abstract
Background: Effective promotion of exercise could result in substantial savings in healthcare cost expenses in terms of
direct medical costs, such as the number of medical appointments. However, this is hampered by our limited knowledge of
how to achieve sustained increases in physical activity.
Objectives: To assess the effectiveness of a Primary Health Care (PHC) based physical activity program in reducing the total
number of visits to the healthcare center among inactive patients, over a 15-month period.
Research Design: Randomized controlled trial.
Subjects: Three hundred and sixty-two (n = 362) inactive patients suffering from at least one chronic condition were
included. One hundred and eighty-three patients (n = 183; mean (SD); 68.3 (8.8) years; 118 women) were randomly allocated
to the physical activity program (IG). One hundred and seventy-nine patients (n = 179; 67.2 (9.1) years; 106 women) were
allocated to the control group (CG). The IG went through a three-month standardized physical activity program led by
physical activity specialists and linked to community resources.
Measures: The total number of medical appointments to the PHC, during twelve months before and after the program, was
registered. Self-reported health status (SF-12 version 2) was assessed at baseline (month 0), at the end of the intervention
(month 3), and at 12 months follow-up after the end of the intervention (month 15).
Results: The IG had a significantly reduced number of visits during the 12 months after the intervention: 14.8 (8.5). The CG
remained about the same: 18.2 (11.1) (P = .002).
Conclusions: Our findings indicate that a 3-month physical activity program linked to community resources is a shortduration,
effective and sustainable intervention in inactive patients to decrease rates of PHC visits.
Trial Registration: ClinicalTrials.gov NCT0071483
KEYLINK: towards a more integrative soil representation for inclusion in ecosystem scale models. I. review and model concept
The relatively poor simulation of the below-ground processes is a severe drawback for many ecosystem models, especially when predicting responses to climate change and management. For a meaningful estimation of ecosystem production and the cycling of water, energy, nutrients and carbon, the integration of soil processes and the exchanges at the surface is crucial. It is increasingly recognized that soil biota play an important role in soil organic carbon and nutrient cycling, shaping soil structure and hydrological properties through their activity, and in water and nutrient uptake by plants through mycorrhizal processes. In this article, we review the main soil biological actors (microbiota, fauna and roots) and their effects on soil functioning. We review to what extent they have been included in soil models and propose which of them could be included in ecosystem models. We show that the model representation of the soil food web, the impact of soil ecosystem engineers on soil structure and the related effects on hydrology and soil organic matter (SOM) stabilization are key issues in improving ecosystem-scale soil representation in models. Finally, we describe a new core model concept (KEYLINK) that integrates insights from SOM models, structural models and food web models to simulate the living soil at an ecosystem scale
Towards an integrative understanding of soil biodiversity
Soil is one of the most biodiverse terrestrial habitats. Yet, we lack an integrative conceptual framework for understanding the patterns and mechanisms driving soil biodiversity. One of the underlying reasons for our poor understanding of soil biodiversity patterns relates to whether key biodiversity theories (historically developed for aboveground and aquatic organisms) are applicable to patterns of soil biodiversity. Here, we present a systematic literature review to investigate whether and how key biodiversity theories (species-energy relationship, theory of island biogeography, metacommunity theory, niche theory and neutral theory) can explain observed patterns of soil biodiversity. We then discuss two spatial compartments nested within soil at which biodiversity theories can be applied to acknowledge the scale-dependent nature of soil biodiversity.Peer reviewe
Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli
Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts. Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins. Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
Research trends in ecosystem services provided by insects
Insects play a key role in the regulation and dynamics of many ecosystem services (ES). However, this role is often assumed, with limited or no experimental quantification of its real value. We examined publication trends in the research on ES provided by insects, ascertaining which ES and taxa have been more intensively investigated, and which methodologies have been used, with particular emphasis on experimental approaches. We first performed a systematic literature search to identify which ES have been attributed to insects. Then we classified the references retrieved according to the ES, taxonomic group and ecosystem studied, as well as to the method applied to quantify each ES (in four categories: no quantification, proxies, direct quantification and experiments). Pollination, biological control, food provisioning, and recycling organic matter are the most studied ES. However, the majority of papers do not specify the ES under consideration, and from those that do, most do not quantify the ES provided. From the rest, a large number of publications use proxies as indicators for ES, assuming or inferring their provision through indirect measurements such as species abundances, species density, species richness, diversity indices, or the number of functional groups. Pollinators, predators, parasitoids, herbivores, and decomposers are the most commonly studied functional groups, while Hymenoptera, Coleoptera, and Diptera are the most studied taxa. Experimental studies are relatively scarce and they mainly focus on biological control, pollination, and decomposition performed in agroecosystems. These results suggest that our current knowledge on the ES provided by insects is relatively scarce and biased, and show gaps in the least-studied functional and taxonomic groups. An ambitious research agenda to improve the empirical and experimental evidence of the role played by insects in ES provision is essential to fully assess synergies between functional ecology, community ecology, and biodiversity conservation under current global changes
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Global data on earthworm abundance, biomass, diversity and corresponding environmental properties
Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change
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