Differences between radiographic and non-radiographic axial spondyloarthritis patients in a Mexican cohort.

To compare the demographic, clinical, and laboratory characteristics, disease onset, and clinical features of radiographic axial Spondyloarthritis (r-axSpA) and non-radiographic axial Spondyloarthritis (nr-axSpA) patients. All patients who attended outpatient spondylarthritis (SpA) clinics at Hospital General de Mexico and the Instituto Nacional de la Nutrición from 1998 to 2005 and met the rheumatologist diagnostic criteria for SpA were selected. Then the SpA patients were classified by European Spondyloarthropathy Study Group criteria (ESSG). We selected SpA patients with axial presentation as axial SpA (axSpA), and they were classified as r-axSpA if they met modified New York (mNY) criteria for sacroiliitis and as nr-axSpA if they did not meet mNY criteria; to compared clinical, demographic, and laboratory test between the subgroups. It included 148 SpA patients; 55 (37.2%) patients had r-axSpA, and 70 (47.3%) had nr-axSpA. The nr-axSpA patients had a lower proportion of males (58.6% vs 78.2%, P < 0.05), lower HLA-B27 frequency (54.3%. vs. 92.7%, P < 0.05), were older at disease onset (21 vs 16 years; P < 0.01) and had a higher frequency of infections at disease onset (9.1% vs 32.9, P < 0.05) than r-axSpA. BASFI (2.9 vs 4.8; P < 0.0001), Dougados functional index (7 vs. 14; P < 0.05), and BASDAI (4.1 vs. 5.2; P < 0.001) were lower in patients with nr-axSpA than r-axSpA, respectively. The factors that most influenced the presentation of r-axSpA were history of uveitis (OR 14, 95% CI 2.3-85), HLA-B27 (OR 7.97, 95% CI, 2.96-122), male sex (OR 6.16, 95% CI, 1.47-25.7), axial enthesopathy count (OR 1.17 95% CI, 1.03-1.33). This study provides insight into the differences between nr-axSpA and r-axSpA in Mexico. Patients with r-axSpA were mainly male, with a younger presentation age, a higher prevalence of HLA-B27, more history of uveitis, fewer episodes of dactylitis, more axial enthesopathy, and higher disease activity than nr-axSpA.

Interactions of Opuntia ficus-indica with Dactylopius coccus and D. opuntiae (Hemiptera: Dactylopiidae) through the Study of Their Volatile Compounds.

Opuntia ficus-indica has always interacted with many phytophagous insects; two of them are Dactylopius coccus and D. opuntiae. Fine cochineal (D. coccus) is produced to extract carminic acid, and D. opuntiae, or wild cochineal, is an invasive pest of O. ficus-indica in more than 20 countries around the world. Despite the economic and environmental relevance of this cactus, D. opuntiae, and D. coccus, there are few studies that have explored volatile organic compounds (VOCs) derived from the plant-insect interaction. The aim of this work was to determine the VOCs produced by D. coccus and D. opuntiae and to identify different VOCs in cladodes infested by each Dactylopius species. The VOCs (essential oils) were obtained by hydrodistillation and identified by GC-MS. A total of 66 VOCs from both Dactylopius species were identified, and 125 from the Esmeralda and Rojo Pelón cultivars infested by D. coccus and D. opuntiae, respectively, were determined. Differential VOC production due to infestation by each Dactylopius species was also found. Some changes in methyl salicylate, terpenes such as linalool, or the alcohol p-vinylguaiacol were related to Dactylopius feeding on the cladodes of their respective cultivars. Changes in these VOCs and their probable role in plant defense mechanisms should receive more attention because this knowledge could improve D. coccus rearing or its inclusion in breeding programs for D. opuntiae control in regions where it is a key pest of O. ficus-indica.

Assessment of enthesopathy in conventional pelvis radiography: Another tool for spondyloarthritis diagnosis beyond sacroiliitis.

INTRODUCTION/OBJECTIVES: Enthesitis is a cardinal feature of spondylarthritis (SpA), and the pelvis is a common site of enthesitis. This study aimed to establish the association between pelvic enthesis involvement on pelvic X-ray and SpA diagnosis through a radiographic enthesis index (REI) and to assess the reliability and accuracy of this REI. MATERIALS AND METHODS: The participants were SpA patients and a control group composed of patients with chronic lumbar pain without SpA. Three blinded observers assessed each pelvic radiography three times. Three zones were used: Zone I (ZI), the iliopubic ramus; Zone II (ZII), the pubic symphysis, and Zone III (ZIII), the ischiopubic ramus. A grading system was created from 0 to 3 [Grade 0, normal; Grade 1, minimal changes (subcortical bone demineralization and/or periosteal wishkering, seen as radiolucency and trabeculation of the cortical bone upon tendon insertion); Grade 2, destructive changes (Grade 1 findings and erosions at the enthesis site); and Grade 3, findings of Grade 2 plus >2 mm whiskering out of the cortical bone) for the REI. The sum of the results of the three zones was called the total REI. For statistical analysis, we used the weighted kappa statistic adjusted for prevalence and bias using Gwet's agreement coefficient. RESULTS: We enrolled 161 patients, 111 of them with SpA (39.6 % with axial SpA and 47.7 % with peripheral SpA) and 50 without SpA. In the SpA group, 36.7 % and 25.7 % had REI Grades 2 and 3 in ZIII, respectively, while only 6 % of the controls had these grades. For ZI, the frequency of Grades 1 to 3 was 42.3 % in the SpA group (8.1 %, 14.4 %, and 19.8 %, respectively), compared to only 2 % in the controls. ZII was unaffected in most of the patients with SpA (82.9 %) and in the controls (98 %). In the control group, Grade 0 was the most common REI grade in all three zones. The agreement was almost perfect for each zone and between the independent readers. The ROC-curve analysis showed that the highest performance areas were the total REI, ZIII, and ZI. Most (75 %) of the SpA patients without sacroiliitis on X-ray were REI-positive. The sensitivity of the REI for SpA diagnosis was 82 %, while the sensitivity of sacroiliitis on X-ray was 38.7 %. CONCLUSIONS: The assessment of pelvic enthesis using the REI on pelvic radiography may be useful for SpA diagnosis. Total REI, ZIII, and ZI had the highest accuracy and almost perfect reliability. The REI is especially helpful in patients without sacroiliitis on imaging.

Spatial versus spatio-temporal approaches for studying metacommunities: a multi-taxon analysis in Mediterranean and tropical temporary ponds.

Prior research on metacommunities has largely focused on snapshot surveys, often overlooking temporal dynamics. In this study, our aim was to compare the insights obtained from metacommunity analyses based on a spatial approach repeated over time, with a spatio-temporal approach that consolidates all data into a single model. We empirically assessed the influence of temporal variation in the environment and spatial connectivity on the structure of metacommunities in tropical and Mediterranean temporary ponds. Employing a standardized methodology across both regions, we surveyed multiple freshwater taxa in three time periods within the same hydrological year from multiple temporary ponds in each region. To evaluate how environmental, spatial and temporal influences vary between the two approaches, we used nonlinear variation partitioning analyses based on generalized additive models. Overall, this study underscores the importance of adopting spatio-temporal analytics to better understand the processes shaping metacommunities. While the spatial approach suggested that environmental factors had a greater influence, our spatio-temporal analysis revealed that spatial connectivity was the primary driver influencing metacommunity structure in both regions. Temporal effects were equally important as environmental effects, suggesting a significant role of ecological succession in metacommunity structure.

Rapid generation of an RBL cellular model to study proteins that cause allergenic reactions in vitro.

Allergic diseases affect nearly 30% of people worldwide. There is a wide range of allergen sources, such as animal dander, food, venom, dust mites, and pollen. The skin prick test is the predominant technique used to identify allergenic sensitivity in vivo; the main problem is that it can be imprecise as many of the allergen extracts are made of mixtures of allergic and nonallergic components, making it difficult to identify the disease-eliciting allergen. An alternative to solve this problem is employing cellular models in vitro that may allow allergen identification, allergy diagnosis, and testing of novel potential compounds that can be used in immunotherapeutics. For example, rat basophilic leukemia (RBL) cells are a well-suited model for studying allergies. Unfortunately, cells generated from RBL cells are not commercially available. Therefore, we developed an RBL model with a degranulation gene reporter capable of recognizing human IgE involved in allergenic sensitivity using commercial plasmids. Employing this model, we successfully evaluated the capacity of union between IgE from allergic patients to allergenic proteins from Oleaceae tree pollen. This RBL cell model can be used as a diagnostic method for sensitivity to any allergens from different sources in vitro.

The Contribution of Mediastinal Transbronchial Nodal Cryobiopsy to Morpho-Histological and Molecular Diagnosis.

(1) Background: endobronchial ultrasound-guided mediastinal transbronchial cryo-node biopsy, previously assisted by fine-needle aspiration, is a novel technique of particular interest in the field of lung cancer diagnosis and is of great utility for extrathoracic tumor metastases, lymphomas, and granulomatous diseases. An integrated histological and molecular diagnosis of small samples implies additional difficulty for the pathologist. Additionally, emerging tumor biomarkers create the need to search for new approaches to better manage the tissue sample; (2) Methods: An analytical observational study of 32 mediastinal node cryobiopsies is carried out in 27 patients (n = 27). Statistical analysis using the t-student and Wilcoxon signed-rank tests for paired data is performed with SPSS 26 and R Statistical software. The significance level is established at p < 0.05; (3) Results: cryobiopsies were valid for diagnosis in 25 of 27 patients, with a maximum average size of 3.5 ± 0.7 mm. A total of 18 samples (66.67%) were positive for malignancy and 9 (33.33%) were benign. The tumor percentage measured in all neoplastic samples was greater than 30%. The average DNA and RNA extracted in nine non-small cell lung cancer cases was 97.2 ± 22.4 ng/µL and 26.6 ± 4.9 ng/µL, respectively; (4) Conclusions: the sample size obtained from an endobronchial ultrasound-guided mediastinal transbronchial cryo-node biopsy facilitates the morphological and histo-architectural assessment of inflammatory and neoplastic pathology. It optimizes molecular tests in the latter due to more tumor cells, DNA, and RNA.

The effect of combining different sampling tools on the performance of electromagnetic navigational bronchoscopy for the evaluation of peripheral lung lesions and factors associated with its diagnostic yield.

BACKGROUND: We assessed the performance of Electromagnetic navigational bronchoscopy (ENB) as a standalone diagnostic technique and the performance of different sampling tools used during the procedure. METHODS: We recruited 160 consecutive patients who underwent ENB for peripheral lung lesions (PLL) at a tertiary care centre. The diagnostic performance of ENB and sampling tools was assessed using a logistic regression model and a ROC-curve in which the dependent variable was diagnostic success. A multivariate model was built to predict diagnostic success before performing ENB to select the best candidates for the procedure. RESULTS: Most patients with PLLs in the study were male (65%), with a mean age of 67.9 years. The yield was 66% when the most common techniques were used together as suction catheter + transbronchial biopsy forceps (TBBx) + bronchoalveolar lavage + bronchial washing (p < 0.001) and increased to 69% when transbronchial needle aspiration (TBNA) and cytology brush were added (p < 0.001). Adding diagnostic techniques such as TBBx and TBNA resulted in an increase in diagnostic performance, with a statistically significant trend (p = 0.002). The logistic model area-under the ROC-curve for diagnostic success during ENB was 0.83 (95% CI:0.75-0.90; p < 0.001), and a logit value ≥ 0.12 was associated with ≥ 50% probability of diagnostic success. CONCLUSIONS: ENB, as a stand-alone diagnostic tool for the evaluation of PLLs when performed by experienced operators using a multi-modality technique, has a good diagnostic yield. The probability of having a diagnostic ENB could be assessed using the proposed model.

Integrative Taxonomy of Cyclocyprididae Kaufmann, 1900 (Ostracoda: Podocopa) with Description of a New Genus and Species.

The two widespread ostracod genera Cypria Zenker, 1854 and Physocypria Vávra, 1897 are traditionally distinguished based on the presence or absence of tubercles on the right valve margin. However, recent research based on soft body parts has uncovered new cryptic genera within Cypria and Physocypria. Following this line of research, a new Cyclocyprididae genus and species, Vizcainocypria viator gen. nov. sp. nov., is here described from individuals collected in rice fields and wetlands of the Iberian Peninsula. Vizcainocypria is compared with Cypria, Physocypria, Dentocypria Savatenalinton, 2017, Keysercypria Karanovic, 2011, Brasilocypria Almeida et al., 2023, and Claudecypria Almeida et al., 2023 based on morphological evidence. Besides the presence or absence of tubercles on the right valve, these genera can be distinguished according to their mandibular palp, second thoracopod, caudal ramus, and male hemipenis. Molecular analyses using mitochondrial (COX1), and nuclear (28S rDNA) genes provide further support for the differentiation of Cypria, Dentocypria, Physocypria and Vizcainocypria gen. nov. The present study highlights the importance of using an integrative taxonomy approach, combining shell and soft-body parts morphology and molecular data, to characterize the rich diversity of freshwater ostracods.

Landscape heterogeneity increases the stability of wild ungulate populations facing climatic variability in Mediterranean ecosystems.

Mediterranean environments are characterized by strong intra- and inter-annual fluctuations in plant primary production, which are likely to regulate the carrying capacity and density-dependent responses of ungulate populations. These effects may, however, vary across spatial and temporal scales. Habitat heterogeneity, particularly when associated to differentiated phenological responses, may allow wild ungulates to mitigate temporal fluctuations in plant production by using different resources along the year. In this work, we use a 15-years dataset (including remote-sensing data on vegetation distribution, phenology and production, as well as ungulate population counts) to assess how temporal variability in plant primary production and livestock abundance influence the population dynamics of two wild ungulates: native red deer, Cervus elaphus, and introduced fallow deer, Dama dama. Results show that temporal alternation in the phenological cycles of the four different vegetation types increased plant production, thus food availability for ungulates, within each year. Furthermore, complementarity in the responses of different vegetation types to variations in the amount and timing of rainfall increased the predictability of food availability across different years. This complementarity effect was further increased by the contrasting responses of ungulate populations to variation in the production of different vegetation types. Furthermore, domestic ungulates had positive effects on wild ungulate density at low to intermediate abundances, but high livestock densities decreased ungulate density and constrained the stability of the plant-ungulate system in response to the impact of climatic variation, particularly under climate change. Our findings deepen the knowledge on vegetation-ungulate interactions in Mediterranean areas, potentially contributing to develop better management strategies of ungulate populations and adapt them to ongoing climate change.

Into the void: ECM fungal communities involved in the succession from rockroses to oak stands.

Oak forests accompanied by Cistus species are a common landscape in the Mediterranean basin. It is argued that Cistus dominated fields serve as recruitment areas for Quercus seedlings, as they help in the transmission of the fungal community through vegetative succession in these ecosystems. To test these assumptions, we analyzed the fungal community in terms of its richness and composition, taking into account the effects of host (Oaks vs. Cistus) and forest structure, mainly based on age. Edaphic variables related to the different structures were also analyzed to examine how they evolve through succession and relate to shifts in the fungal community. No differences in fungal richness were observed between old Cistus stands and younger Quercus, while a brief increase in ECM richness was observed. Community composition also showed a greater overlap between old Cistus and young Quercus stands. We suggest that the most important step in fungal transfer from one host to another is the shift from the oldest Cistus fields to the youngest Quercus stands, with the genera Amanita, Cortinarius, Lactarius, Inocybe, Russula, and Tomentella probably playing a major role. In summary, our work has also revealed the network of fungal community structure in the succession of Cistus to Oak stands, it would suggest that the fungi share niches and significantly enhance the ecological setting of the transition from Cistus to Oak stands.

Clinical Diagnosis of Chikungunya Infection: An Essential Aid in a Primary Care Setting Where Serological Confirmation Is Not Available.

BACKGROUND: Chikungunya virus (CHIKV) diagnosis has become a challenge for primary care physicians in areas where the Zika virus and/or Dengue virus are present. Case definitions for the three arboviral infections overlap. METHODS: A cross-sectional analysis was carried out. A bivariate analysis was made using confirmed CHIKV infection as the outcome. Variables with significant statistical association were included in an agreement consensus. Agreed variables were analyzed in a multiple regression model. The area under the receiver operating characteristic (ROC) curve was calculated to determine a cut-off value and performance. RESULTS: 295 patients with confirmed CHIKV infection were included. A screening tool was created using symmetric arthritis (4 points), fatigue (3 points), rash (2 points), and ankle joint pain (1 point). The ROC curve identified a cut-off value, and a score ≥ 5.5 was considered positive for identifying CHIKV patients with a sensibility of 64.4% and a specificity of 87.4%, positive predictive value of 85.5%, negative predictive value of 67.7%, area under the curve of 0.72, and an accuracy of 75%. CONCLUSION: We developed a screening tool for CHIKV diagnosis using only clinical symptoms as well as proposed an algorithm to aid the primary care physician.

Effects of Chia Seeds on Growth Performance, Carcass Traits and Fatty Acid Profile of Lamb Meat.

The aim of this work was to supplement a diet with chia seeds (Salvia hispanica L.) based on the requirements of finishing lambs for meat, and to analyze biometric parameters and fatty acid profiles in meat. Eighteen male Rambouillet lambs with a bodyweight of 25 kg were used. Animals were kept in individual pens with water and feed provided ad libitum. Three finishing diets were designed with the inclusion of 0, 50 and 100 g dry matter chia seeds and divided among the animals (n = 6). The experimental period lasted 60 days. The weights of the individual lambs were recorded every 14 days. At the end of the experiment, the animals were slaughtered and the weights of the hot carcasses and non-meat components were registered. In addition, an analysis of the fatty acid composition was carried out in the muscles (Longissimus thoracis). The total weight gain and average daily gain displayed significant differences (p < 0.05). Initial and final bodyweights, such as the dry matter intake, did not display differences. The fatty acid profile of the meat tended to decrease the SFA (stearic acid) and increase MUFA (oleic acid) (p < 0.0001) when chia seeds were added to the lamb diets. In conclusion, chia seed supplementation did not increase meat production or other biometric parameters; however, it modified the fatty acid profile in L. thoracis.

Inequity and vulnerability in Latin American Indigenous and non-Indigenous populations with rheumatic diseases: a syndemic approach.

Syndemics are a framework that documents health inequities and vulnerabilities in populations with rheumatic diseases. Compared with other approaches, syndemics are able to conjunctly consider epidemiological, biological, sociodemographic and economic factors, and their interactions. OBJECTIVE: To estimate health inequity and vulnerability among Indigenous and non-Indigenous populations with rheumatic and musculoskeletal diseases (RMD) in Latin America using the syndemic approach. DESIGN: This is a secondary analysis of a previously published large-scale study on the prevalence of RMD. SETTING: Studies carried out in five Latin American countries (Argentina, Colombia, Ecuador, Mexico and Venezuela). Health inequity and vulnerability in RMD were identified through a syndemic approach using network and cluster analysis. PARTICIPANTS: A total of 44 560 individuals were studied: 29.78% self-identified as Indigenous, 60.92% were female, the mean age was 43.25 years. Twenty clusters were identified in the Indigenous population and 17 in the non-Indigenous population. RESULTS: The variables associated with RMD among Indigenous populations were rurality, public health system, high joint biomechanical stress, greater pain, disability and alcoholism; and among non-Indigenous people they were being a woman, urban origin, older age, private health system, joint biomechanical stress, greater pain and disability. We identified different health inequities among patients with RMD (ie, lower educational attainment, more comorbidities), associated with factors such as Indigenous self-identification and rural residence. CONCLUSIONS: A syndemic approach enables us to identify health inequities in RMD, as shown by higher prevalence of comorbidities, disability and socioeconomic factors like lower educational attainment. These inequities exist for the overall population of patients with RMD, although it is more evident in Indigenous groups with added layers of vulnerability.

Accuracy of computer-aided static and dynamic navigation systems in the placement of zygomatic dental implants.

BACKGROUND: Zygomatic implants are widely used in the rehabilitation of severely atrophic maxillae, but implant placement is not without risks, and it can potentially cause damage to related anatomical structures. The aim of this study was to perform a comparative analysis of the accuracy of static navigation systems in placing zygomatic dental implants in comparison to dynamic navigation systems. METHODS: Sixty zygomatic dental implants were randomly allocated to one of three study groups, categorized by which implant placement strategy was used: A: computer-aided static navigation system (n = 20) (GI); B: computer-aided dynamic navigation system (n = 20) (NI); or C: free-hand technique (n = 20) (FHI). For the computer-aided study groups, a preoperative cone-beam computed tomography (CBCT) scan of the existing situation was performed in order to plan the approach to be used during surgery. Four zygomatic dental implants were inserted in each of fifteen polyurethane stereolithographic models (n = 15), with a postoperative CBCT scan taken after the intervention. The pre- and postoperative CBCT scans were then uploaded to a software program used in dental implantology to analyze the angular deviations, apical end point, and coronal entry point. Student's t-test was used to analyze the results. RESULTS: The results found statistically significant differences in apical end-point deviations between the FHI and NI (p = 0.0053) and FHI and GI (p = 0.0004) groups. There were also statistically significant differences between the angular deviations of the FHI and GI groups (p = 0.0043). CONCLUSIONS: The manual free-hand technique may enable more accurate placement of zygomatic dental implants than computer-assisted surgical techniques due to the different learning curves required for each zygomatic dental implant placement techniques.

Co-responses of bacterial and fungal communities to fire management treatments in Mediterranean pyrophytic ecosystems.

Cistus scrublands are pyrophytic ecosystems and occur widely across Mediterranean regions. Management of these scrublands is critical to prevent major disturbances, such as recurring wildfires. This is because management appears to compromise the synergies necessary for forest health and the provision of ecosystem services. Furthermore, it supports high microbial diversity, opening questions of how forest management practices impact belowground associated diversity as research related to this issue is scarce. This study aims to investigate the effects of different fire prevention treatments and site history on bacterial and fungi co-response and co-occurrence patterns over a fire-risky scrubland ecosystem. Two different site histories were studied by applying three different fire prevention treatments and samples were analyzed by amplification and sequencing of ITS2 and 16S rDNA for fungi and bacteria, respectively. The data revealed that site history, especially regarding fire occurrence, strongly influenced the microbial community. Young burnt areas tended to have a more homogeneous and lower microbial diversity, suggesting environmental filtering to a heat-resistant community. In comparison, young clearing history also showed a significant impact on the fungal community but not on the bacteria. Some bacteria genera were efficient predictors of fungal diversity and richness. For instance, Ktedonobacter and Desertibacter were a predictor of the presence of the edible mycorrhizal bolete Boletus edulis. These results demonstrate fungal and bacterial community co-response to fire prevention treatments and provide new tools for forecasting forest management impacts on microbial communities.

CRISPRa-mediated transcriptional activation of the SlPR-1 gene in edited tomato plants.

With the continuous deterioration of arable land due to an ever-growing population, improvement of crops and crop protection have a fundamental role in maintaining and increasing crop productivity. Alternatives to the use of pesticides encompass the use of biological control agents, generation of new resistant crop cultivars, the application of plant activator agrochemicals to enhance plant defenses, and the use of gene editing techniques, like the CRISPR-Cas system. Here, we test the hypothesis that epigenome editing, via CRISPR activation (CRISPRa), activate tomato plant defense genes to confer resistance against pathogen attack. We provide evidence that edited tomato plants for the PATHOGENESIS-RELATED GENE 1 gene (SlPR-1) show enhanced disease resistance to Clavibacter michiganensis subsp. michiganensis infection. Resistance was assessed by evaluating disease progression and symptom appearance, pathogen accumulation, and changes in SlPR-1 gene expression at different time points. We determined that CRISPRa-edited plants develop enhanced disease-resistant to the pathogen without altering their agronomic characteristics and, above all, preventing the advancement of disease symptoms, stem canker, and plant death.

Oxidative Stress and Air Pollution: Its Impact on Chronic Respiratory Diseases.

Redox regulation participates in the control of various aspects of metabolism. Reactive oxygen and nitrogen species participate in many reactions under physiological conditions. When these species overcome the antioxidant defense system, a distressed status emerges, increasing biomolecular damage and leading to functional alterations. Air pollution is one of the exogenous sources of reactive oxygen and nitrogen species. Ambient airborne particulate matter (PM) is important because of its complex composition, which includes transition metals and organic compounds. Once in contact with the lungs' epithelium, PM components initiate the synthesis of inflammatory mediators, macrophage activation, modulation of gene expression, and the activation of transcription factors, which are all related to the physiopathology of chronic respiratory diseases, including cancer. Even though the pathophysiological pathways that give rise to the development of distress and biological damage are not fully understood, scientific evidence indicates that redox-dependent signaling pathways are involved. This article presents an overview of the redox interaction of air pollution inside the human body and the courses related to chronic respiratory diseases.

Unaltered fungal community after fire prevention treatments over widespread Mediterranean rockroses (Halimium lasianthum).

Mediterranean ecosystems are frequently invaded by pyrophytic scrubs such as Halimium lasianthum that colonize areas traditionally used by livestock. A diverse fungal community is associated with this kind of vegetation, playing an important ecological role in these ecosystems. However, uncontrolled expansion of these shrubs considerably increases the risk of wildfires in these stands and, hence, fire-prevention treatments are needed. To investigate the long-term effects of two different forest-fire-prevention treatments on the soil fungal community, we analyzed these communities 9 years after prescribed burning or mechanical shredding were carried out in scrubland dominated by H. lasianthum. Neither of the fire-prevention treatments had a negative long-term effect on the abundance or richness of ectomycorrhizal fungi. However, saprotrophs and lichenized fungi experienced negative effects. Soil fertility significantly affected the distribution of fungi according to their functional groups, and pH was the most influential variable in terms of the distribution of edible species. Our findings indicate that forest management practices to prevent forest fires does not negatively affect the fungal community in the long-term, but for lichens and decomposers. Moreover, prescribed burning is suggested as a more economical way of reducing the risk of wildfires without affecting the ecology of the fungal community.

Inconsistent response of taxonomic groups to space and environment in mediterranean and tropical pond metacommunities.

The metacommunity concept provides a theoretical framework that aims at explaining organism distributions by a combination of environmental filtering, dispersal, and drift. However, few works have attempted a multitaxon approach and even fewer have compared two distant biogeographical regions using the same methodology. We tested the expectation that temperate (mediterranean-climate) pond metacommunities would be more influenced by environmental and spatial processes than tropical ones, because of stronger environmental gradients and a greater isolation of waterbodies. However, the pattern should be different among groups of organisms depending on their dispersal abilities. We surveyed 30 tropical and 32 mediterranean temporary ponds from Costa Rica and Spain, respectively, and obtained data on 49 environmental variables. We characterized the biological communities of bacteria and archaea (from the water column and the sediments), phytoplankton, zooplankton, benthic invertebrates, amphibians and birds, and estimated the relative role of space and environment on metacommunity organization for each group and region, by means of variation partitioning using generalized additive models. Purely environmental effects were important in both tropical and mediterranean ponds, but stronger in the latter, probably due to their larger limnological heterogeneity. Spatially correlated environment and pure spatial effects were greater in the tropics, related to higher climatic heterogeneity and dispersal processes (e.g., restriction, surplus) acting at different scales. The variability between taxonomic groups in the contribution of spatial and environmental factors to metacommunity variation was very wide, but higher in active, compared with passive, dispersers. Higher environmental effects were observed in mediterranean passive dispersers, and higher spatial effects in tropical passive dispersers. The unexplained variation was larger in the tropical setting, suggesting a higher role for stochastic processes, unmeasured environmental factors, or biotic interactions in the tropics, although this difference affected some actively dispersing groups (insects and birds) more than passive dispersers. These results, despite our limitations in comparing only two regions, provide support, for a wide variety of aquatic organisms, for the classic view of stronger abiotic niche constraints in temperate areas compared with the tropics. The heterogeneous response of taxonomic groups between regions also points to a stronger influence of regional context than organism adaptations on metacommunity organization.