Find research datasets worth reusing

Data from: Evolution and systematics of polyploid Nigritella (Orchidaceae)

Members of the orchid genus Nigritella are widespread in European mountains, but species circumscriptions and evolutionary patterns in the genus are subjects to conflicting opinions. We analyzed a representative material of Nigritella for differentiation at nuclear and plastid marker loci. In agreement with predictions from embryological studies, diploid members of Nigritella are sexual and mostly out-crossing, whereas triploid, tetraploid and pentaploid members are apomicts. The diploid taxa were poorly differentiated in the investigated molecular markers, except for the western N. gabasiana, which was separated in plastid haplotypes. Polyploid Nigritella aggregate into three groups and within each of these groups apomictic polyploids have given rise to new species. Within the N. nigra group, the tetraploid N. nigra ssp. austriaca is somewhat differentiated from the triploid ssp. nigra at nuclear as well as plastid loci. Fusion of an unreduced egg cell from ssp. nigra with a haploid microgamete from Gymnadenia conopsea gave rise to Gymnigritella runei. Within the N. widderi group, N. archiducis-joannis is poorly separated from N. widderi in molecular markers, and the pentaploid N. buschmanniae has evolved by fusion of an unreduced egg cell from N. widderi with a haploid microgamete from a diploid Nigritella. Within the N. miniata group, N. stiriaca is somewhat differentiated from N. miniata at nuclear loci, but no other segregates of N. miniata are supported at species level. Polyploid Nigritella species accumulate genetic diversity by somatic mutations. In the widespread N. nigra ssp. austriaca and N. miniata this diversity is correlated to geography. Although some polyploids may be of recent origins, each polyploid contain genetic markers no longer encountered in diploid members of the genus. According to plastid marker data, Nigritella and Gymnadenia may constitute monophyletic sister genera.

opencc-zeroDec 2016View details →

Data from: Systematics and diversification of Anindobothrium Marques, Brooks & Lasso, 2001 (Eucestoda: Rhinebothriidea)

Tapeworms of the genus Anindobothrium Marques, Brooks & Lasso, 2001 are found in both marine and Neotropical freshwater stingrays of the family Potamotrygonidae. The patterns of host association within the genus support the most recent hypothesis about the history of diversification of potamotrygonids, which suggests that the ancestor of freshwater lineages of the Potamotrygonidae colonized South American river systems through marine incursion events. Despite the relevance of the genus Anindobothrium to understand the history of colonization and diversification of potamotrygonids, no additional efforts were done to better investigate the phylogenetic relationship of this taxon with other lineages of cestodes since its erection. This study is a result of recent collecting efforts to sample members of the genus in marine and freshwater potamotrygonids that enabled the most extensive documentation of the fauna of Anindobothrium parasitizing species of Styracura de Carvalho, Loboda & da Silva, Potamotrygon schroederi Fernández-Yépez, P. orbignyi (Castelnau) and P. yepezi Castex & Castello from six different countries, representing the eastern Pacific Ocean, Caribbean Sea, and river basins in South America (Rio Negro, Orinoco, and Maracaibo). The newly collected material provided additional specimens for morphological studies and molecular samples for subsequent phylogenetic analyses that allowed us to address the phylogenetic position of Anindobothrium and provide molecular and morphological evidence to recognize two additional species for the genus. The taxonomic actions that followed our analyses included the proposition of a new family, Anindobothriidae fam. n., to accommodate the genus Anindobothrium in the order Rhinebothriidea Healy, Caira, Jensen, Webster & Littlewood, 2009 and the description of two new species — one from the eastern Pacific Ocean, A. carrioni sp. n., and the other from the Caribbean Sea, A. inexpectatum sp. n. In addition, we also present a redescription of the type species of the genus, A. anacolum (Brooks, 1977) Marques, Brooks & Lasso, 2001, and of A. lisae Marques, Brooks & Lasso, 2001. We also discuss the paleogeographical events mostly linked with the diversification of the genus and the protocols adopted to uncover cryptic diversity in Anindobothrium.

Data from: Systematics and taxonomy of the Snubnose Darter, Etheostoma simoterum (Cope)

A taxonomic revision of Etheostoma simoterum (Cope) published in 2007 resulted in the recognition of six species, with two species distributed in the Tennessee River system. A newly defined Etheostoma simoterum was restricted to populations in the Holston River above the confluence of the North and South Forks, and the Russell Fork system of the Ohio River drainage. A newly described species, Etheostoma tennesseense Powers & Mayden, included all other populations historically considered Etheostoma simoterum in the Tennessee River system from near the mouth of the Duck River upstream to the Clinch River, including the Holston River below the forks. A subsequent study utilizing molecular phylogenetics and analysis of male nuptial coloration did not support the recognition of Etheostoma tennesseense. Molecular phylogenies resolve both Etheostoma simoterum and Etheostoma tennesseense as paraphyletic. In addition, it was determined that male coloration patterns are not diagnostic for the more restricted and new definition of Etheostoma simoterum. In this study, we examine the systematics of Etheostoma simoterum using meristic traits sampled from more than 1,000 specimens, including Cope's syntype series of Hyostoma simoterum and Powers and Mayden's paratopotype series of Etheostoma tennesseense. Our results show a pattern of clinal variation, where meristic traits are higher in the in the lower Tennessee River system. Comparisons of populations above and below the forks of the Holston River show no differences in meristic traits, but populations sampled from the Watauga River system exhibit scale counts lower than any other population of Etheostoma simoterum. We cannot reject the hypothesis that Etheostoma tennesseense is conspecific with the specimens that comprise the Hyostoma simoterum syntype series. Based on both morphological and molecular species delimitation strategies, we treat Etheostoma tennesseense as a synonym of Etheostoma simoterum.

Data from: Variation across mitochondrial gene trees provides evidence for systematic error: how much gene tree variation is biological?

The use of large genomic datasets in phylogenetics has highlighted extensive topological variation across genes. Much of this discordance is assumed to result from biological processes. However, variation among gene trees can also be a consequence of systematic error driven by poor model fit, and the relative importance of biological versus methodological factors in explaining gene tree variation is a major unresolved question. Using mitochondrial genomes to control for biological causes of gene tree variation, we estimate the extent of gene tree discordance driven by systematic error and employ posterior prediction to highlight the role of model fit in producing this discordance. We find that the amount of discordance among mitochondrial gene trees is similar to the amount of discordance found in other studies that assume only biological causes of variation. This similarity suggests that the role of systematic error in generating gene tree variation is underappreciated and critical evaluation of fit between assumed models and the data used for inference is important for the resolution of unresolved phylogenetic questions.

Data from: Phylogenetic systematics of subtribe Spiranthinae (Orchidaceae: Orchidoideae: Cranichideae) based on nuclear and plastid DNA sequences of a nearly complete generic sample

Subtribe Spiranthinae is the most species-rich lineage of terrestrial Neotropical orchids, encompassing > 500 species and 40 genera. We conducted maximum parsimony and maximum likelihood phylogenetic analyses of DNA sequence data of plastid matK-trnK and trnL-trnF and nuclear ribosomal ITS sequences for 36 genera and 182 species of Spiranthinae plus appropriate outgroups. The results strongly support monophyly of Spiranthinae (minus Discyphus, Discyphinae and Galeottiella, Galeottiellinae) and five major lineages, namely monospecific Cotylolabium (sister to the remaining Spiranthinae) and the Eurystyles, Pelexia, Spiranthes and Stenorrhynchos clades. Eighteen of the 27 genera of Spiranthinae for which more than one species was included in our analyses are monophyletic. Paraphyly of large genera, such as Cyclopogon and Sarcoglottis, resulted from segregation of particular species or groups of species exhibiting minor modifications of structures directly involved in pollination (e.g. nectary, rostellum and viscidium). Conversely, polyphyly has resulted from convergent evolution of floral attributes in distantly related species (e.g. Mesadenus). Some of the morphological characters used traditionally for generic delimitation and in non-molecular cladistic analyses of Spiranthinae are discussed against the evolutionary framework set by our molecular trees, emphasizing putative synapomorphies and problems derived from inappropriate character coding or incorrect homology assessments. Our ancestral area analysis indicates that Spiranthinae originated in eastern South America, with subsequent migrations and secondary radiations in Mesoamerica and North America, plus a derived migration from the latter region to the Old World (Spiranthes).

opencc-zeroDec 2012View details →

Data from: Systematics of spiny-backed treefrogs (Hylidae: Osteocephalus): an Amazonian puzzle

Spiny-backed tree frogs of the genus Osteocephalus are conspicuous components of the tropical wet forests of the Amazon and the Guiana Shield. Here, we revise the phylogenetic relationships of Osteocephalus and its sister group Tepuihyla, using up to 6134 bp of DNA sequences of nine mitochondrial and one nuclear gene for 338 specimens from eight countries and 218 localities, representing 89% of the 28 currently recognized nominal species. Our phylogenetic analyses reveal (i) the paraphyly of Osteocephalus with respect to Tepuihyla, (ii) the placement of 'Hyla' warreni as sister to Tepuihyla, (iii) the non-monophyly of several currently recognized species within Osteocephalus and (iv) the presence of low (<1%) and overlapping genetic distances among phenotypically well-characterized nominal species (e.g. O. taurinus and O. oophagus) for the 16S gene fragment used in amphibian DNA barcoding. We propose a new taxonomy, securing the monophyly of Osteocephalus and Tepuihyla by rearranging and redefining the content of both genera and also erect a new genus for the sister group of Osteocephalus. The colouration of newly metamorphosed individuals is proposed as a morphological synapomorphy for Osteocephalus. We recognize and define five monophyletic species groups within Osteocephalus, synonymize three species of Osteocephalus (O. germani, O. phasmatus and O. vilmae) and three species of Tepuihyla (T. celsae, T. galani and T. talbergae) and reallocate three species (Hyla helenae to Osteocephalus, O. exophthalmus to Tepuihyla and O. pearsoni to Dryaderces gen. n.). Furthermore, we flag nine putative new species (an increase to 138% of the current diversity). We conclude that species numbers are largely underestimated, with most hidden diversity centred on widespread and polymorphic nominal species. The evolutionary origin of breeding strategies within Osteocephalus is discussed in the light of this new phylogenetic hypothesis, and a novel type of amplexus (gular amplexus) is described.

opencc-zeroDec 2019View details →

Predator responses to fire: a global systematic review and meta-analysis

1. Knowledge of how disturbances such as fire shape habitat structure and composition, and affect animal interactions, is fundamental to ecology and ecosystem management. Predators also exert strong effects on ecological communities, through top-down regulation of prey and competitors, which can result in trophic cascades. Despite their ubiquity, ecological importance and potential to interact with fire, our general understanding of how predators respond to fire remains poor, hampering ecosystem management. 2. To address this important knowledge gap, we conducted a systematic review and meta-analysis of the effects of fire on terrestrial, vertebrate predators worldwide. We found 160 studies spanning 1978–2018. There were 36 studies with sufficient information for meta-analysis, from which we extracted 96 effect sizes (Hedge's g) for 67 predator species relating to changes in abundance indices, occupancy or resource selection in burned and unburned areas, or before and after fire. 3. Studies spanned geographic locations, taxonomic families, and study designs, but most were located in North America and Oceania (59% and 24%, respectively), and largely focussed on felids (24%) and canids (25%). Half (50%) of the studies reported responses to wildfire, and nearly one third concerned prescribed fires. 4. There were no clear, general responses of predators to fire, nor relationships with geographic area, biome or life history traits (e.g. body mass and diet). Responses varied considerably between species. Analysis of species for which at least three effect sizes had been reported in the literature revealed that red foxes (Vulpes vulpes) mostly responded positively to fire (e.g. higher abundance in burned compared to unburned areas) and eastern racers (Coluber constrictor) negatively, with variances overlapping zero only slightly for both species. 5. Our systematic review and meta-analysis revealed strong variation in predator responses to fire, and geographic and taxonomic knowledge gaps. Varied responses of predator species to fire likely depend on ecosystem context. Consistent reporting of ongoing monitoring and management experiments is required to improve understanding of the mechanisms driving predator responses to fire, and any broader effects (e.g. trophic interactions). The divergent responses of species in our study suggest that adaptive, context-specific management of predator-fire relationships is required. 23-Oct-2019

Data from: Anatomy, systematics, paleoenvironment, growth, and age of the sauropod dinosaur Sonorasaurus thompsoni from the Cretaceous of Arizona, USA

Sauropod dinosaurs are rare in the Cretaceous North American fossil record in general and are absent from that record for most of the Late Cretaceous. Sonorasaurus thompsoni from the Turney Ranch Formation of the Bisbee Group of Arizona, USA, potentially represents one of the youngest sauropods before their ca. 30-million-year-long hiatus from the record. The anatomy of Sonorasaurus has only been briefly described, its taxonomic validity has been questioned, several hypotheses have been proposed regarding its phylogenetic relationships, and its life history, geologic age, and reported paleoenvironment are ambiguous. Herein we assess the systematics, paleoenvironment, life history, and geologic age of Sonorasaurus based on firsthand observation, bone histology, and fieldwork in the holotypic quarry and environs. The validity of S. thompsoni is substantiated by autapomorphies. Cladistic analysis firmly places it within the Brachiosauridae, in contrast to results of some recent analyses. Bone histology suggests that the only known exemplar of Sonorasaurus grew slowly and sporadically compared to other sauropods and was approaching its adult size. In contrast with previous assessments of a coastal/estuarine paleoenvironment for the Turney Ranch Formation, our sedimentological and plant macrofossil data indicate that Sonorasaurus lived in a semiarid, low relief evergreen woodland that received highly variable (perhaps seasonal) precipitation. We obtained detrital zircons from the holotypic quarry for U-Pb dating, which only yielded Barremian-aged and older grains, whereas other radiometric and biostratigraphic data suggest that the sediments at the quarry were deposited near the Albian-Cenomanian boundary. Sonorasaurus is taxonomically valid, represents one of the geologically youngest brachiosaurid sauropods, and inhabited a harsh inland evergreen-dominated woodland environment that limited its growth. A review of other Bisbee Group dinosaurs suggests that its fauna, although poorly sampled, exhibits broad similarity to those from coeval North American horizons, reinforcing the apparent faunal homogeneity at the time.

opencc-zeroJun 2020View details →

Data from: Mysuru City Bird Atlas (2014–16): a systematic study of birds across space and time

The Mysuru City Bird Atlas is an ambitious volunteer project to map the birds of an entire city – the first systematic effort of its kind in India. Mysuru city was gridded into a set of square cells, and each cell was surveyed for birds in the winter and in the summer of 2014, 2015 and 2016. The goal of this effort was to assess the distribution and abundance of the birds of Mysuru such that the accumulated information can be used to assess seasonal changes in avifauna as well as to examine the relationship between birds and their habitat in an urban setting. In this article, we present selected outcomes, including maps as well as raw comparisons of abundance across the two seasons and the three years of the atlas surveys. Some of the results recapture broadly understood phenomena, such as long-distance migration resulting in seasonal differences in bird communities and species richness. Other results are suggestive of previously undescribed patterns, such as seasonal local movements. Further learnings from the project include areas of improvement in Atlas design and the identification of more sophisticated approaches to data analysis. Taken as a whole, the information generated through the Mysuru City Bird Atlas can be used as a baseline against which long-term change in avifauna can be assessed.

opencc-zeroDec 2014View details →

Data from: Sensitivity analysis of conservation targets in systematic conservation planning

Systematic conservation planning has rapidly advanced in the past decade and has been increasingly incorporated in multiple studies and conservation projects. One of its requirements is a quantitative definition of conservation targets. While the Convention on Biological Diversity aims to expand the world's protected area network to 17% of the land surface, in many cases such uniform policy-driven targets may not be appropriate for achieving persistence of various species. Targets are often set arbitrarily, often because information required for the persistence of each species is unavailable or unknown in the focal region. Conservation planners therefore need to establish complementary novel approaches to address the gaps in setting targets. Here, we develop and present a novel method that aims to help guide the selection of conservation targets, providing support for decision makers, planners, and managers. This is achieved by examining the overall flexibility of the conservation network resulting from conservation prioritization, and aiming for greater flexibility. To test this approach we applied the decision support tool Marxan to determine marine conservation priority areas in the eastern Mediterranean Sea as a case study. We assessed the flexibility of the conservation network by comparing 80 different scenarios in which conservation targets were gradually increased and assessed by a range of calculated metrics (e.g., the percentage of the total area selected, the overall connectivity). We discovered that when conservation targets were set too low (i.e., below 10% of the distribution range of each species), very few areas were identified as irreplaceable and the conservation network was not well defined. Interestingly, when conservation targets were set too high (over 50% of the species' range), too many conservation priority areas were selected as irreplaceable, an outcome which is realistically infeasible to implement. As a general guideline, we found that flexibility in a conservation network is adequate when ~10−20% of the study area is considered irreplaceable (selection frequency values over 90%). This approach offers a useful sensitivity analysis when applying target-based systematic conservation planning tools, ensuring that the resulting protected area conservation network offers more choices for managers and decision makers.

opencc-zeroJun 2019View details →

Data from: Butterfly abundance declines over 20 years of systematic monitoring in Ohio, USA

Severe insect declines make headlines, but they are rarely based on systematic monitoring outside of Europe. We estimate the rate of change in total butterfly abundance and the population trends for 81 species using 21 years of systematic monitoring in Ohio, USA. Total abundance is declining at 2% per year, resulting in a cumulative 33% reduction in butterfly abundance. Three times as many species have negative population trends compared to positive trends. The rate of total decline and the proportion of species in decline mirror those documented in three comparable long-term European monitoring programs. Multiple environmental changes such as climate change, habitat degradation, and agricultural practices may contribute to these declines in Ohio and shift the makeup of the butterfly community by benefiting some species over others. Our analysis of life-history traits associated with population trends shows an impact of climate change, as species with northern distributions and fewer annual generations declined more rapidly. However, even common and invasive species associated with human-dominated landscapes are declining, suggesting widespread environmental causes for these trends. Declines in common species, although they may not be close to extinction, will have an outsized impact on the ecosystem services provided by insects. These results from the most extensive, systematic insect monitoring programs in North America demonstrate an ongoing defaunation in butterflies that on an annual scale might be imperceptible, but cumulatively has reduced butterfly numbers by a third over 20 years.

opencc-zeroApr 2020View details →

Data from: Systematic review on barriers and enablers for access to diabetic retinopathy screening services in different income settings

Background: Diabetic retinopathy (DR) can lead to visual impairment and blindness if not detected and treated in time. Knowing the barriers/enablers in advance in contrasting different country income settings may accelerate development of a successful DR screening (DRS) program. This would be especially applicable in the low-income settings with the rising prevalence of DR. Objectives: The aim of this systematic review is to identify and contrast the barriers/enablers to DRS for different contexts using both consumers i.e., people with diabetes (PwDM) and provider perspectives and system level factors in different country income settings. Methods: We searched MEDLINE, Embase, CENTRAL in the Cochrane Library from the databases start date to December 2018. We included the studies reported on barriers and enablers to access DRS services based at health care facilities. We categorised and synthesized themes related to the consumers (individuals), providers and the health systems (environment) as main dimensions according to the constructs of social cognitive theory, supported by the quantitative measures i.e., odds ratios as reported by each of the study authors. Main Results: We included 77 studies primarily describing the barriers and enablers. Most of the studies were from high income settings (72.7%, 56/77) and cross sectional in design (76.6%, 59/77). From the perspectives of consumers, lack of knowledge, attitude, awareness and motivation were identified as major barriers. The enablers were fear of blindness, proximity of screening facility, experiences of vision loss and being concerned of eye complications. In providers' perspectives, lack of skilled human resources, training programs, infrastructure of retinal imaging and cost of services were the main barriers. Higher odds of uptake of DRS services was observed when PwDM were provided health education (odds ratio (OR) 4.3) and having knowledge on DR (OR range 1.3-19.7). Conclusion: Knowing the barriers to access DRS is a pre-requisite in development of a successful screening program. The awareness, knowledge and attitude of the consumers, availability of skilled human resources and infrastructure emerged as the major barriers to access to DRS in any income setting.

opencc-zeroDec 2016View details →

Data from: Ecology, biofacies, biogeography and systematics of micromorphic lingulate brachiopods from the Ordovician (Darriwilian–Sandbian) of south-central China

Ordovician (Darriwilian to Sandbian) micromorphic linguliform lingulate brachiopods are described from the Guniutan Formation at the Fenxiang section in Hubei province, and the Maocaopu and Cili sections in Hunan province of south-central China, situated on the Yangtze Platform. A total of 7560 specimens from 155 limestone samples (within the interval of Lenodus variabilis – Pygodus anserinus biozones) are assigned to 22 species, representing a low taxonomic diversity and low abundance fauna. The fauna is dominated by the Acrotretoidea, mainly species of the Torynelasmatidae, with Torynelasma the most abundant (more than 40% of total number of specimens), along with the Eoconulidae and Eoconulus (18% of total) representing the second most common forms. Species of the Ephippelasmatidae are also common (16% of total) diverse, and include representatives of Myotreta and Numericoma, as well as Ephippelasma, whereas species of the Scaphelasmatidae are somewhat less common (13% of total). All three investigated sections represent outer shelf environments, but the Maocaopu section is situated in a relatively deeper position, in proximity of the south-eastern outer margin of the Upper Yangtze Platform, close to its boundary with the Jiangnan Slope. A quantitative analysis of the relative abundance data was carried out in order to investigate the biofacies distribution of the micromorphic brachiopod communities across the Yangtze Platform, something that has not been attempted before with Palaeozoic linguliforms. Six lingulate microbrachiopod communities could be recognized in the sections. The major biofacies shift, which occurred in the Cili section in the upper part of the Microzarkodina ozarkodella Zone, at the time of the onset and initial rise of the Mid Darriwilian Carbon Isotope Excursion (MDICE) suggests that these biofacies may have been depth controlled.

opencc-zeroDec 2018View details →

Data from: The evolutionary history of the Cape hare (Lepus capensis sensu lato): insights for systematics and biogeography

Inferring the phylogeography of species with large distributions helps deciphering major diversification patterns that may occur in parallel across taxa. Here, we infer the evolutionary history of the Cape hare, Lepus capensis sensu lato, a species distributed from southern Africa to Asia, by analysing variation at 18 microsatellites and 9 DNA (1 mitochondrial and 8 nuclear) sequenced loci, from field and museum-collected samples. Using a combination of assignment and coalescent-based methods, we show that the Cape hare is composed of five evolutionary lineages, distributed in distinct biogeographic regions – north-western Africa, eastern Africa, southern Africa, the Near East and the Arabian Peninsula. A deep phylogenetic break possibly dating to the Early Pleistocene was inferred between the African and Asian L. capensis groups, and the latter appear more closely related to other Eurasian hare species than to African Cape hares. The inferred phylogeographic structure is shared by numerous taxa distributed across the studied range, suggesting that environmental changes, such as the progressive aridification of the Saharo-Arabian desert and the fluctuations of savannah habitats in Sub-Saharan Africa, had comparable impacts across species. Fine-scale analyses of the western Sahara-Sahel populations showed rich fragmentation patterns for mitochondrial DNA but not for microsatellites, compatible with the environmental heterogeneity of the region and female philopatry. The complex evolutionary history of L. capensis sensu lato, which possibly includes interspecific gene flow, is not reflected by taxonomy. Integrating evolutionary inference contributes to an improved characterization of biodiversity, which is fundamental to foster the conservation of relevant evolutionary units.

Data from: Global prevalence of chronic kidney disease: a systematic review and meta-analysis

Chronic kidney disease (CKD) is a global health burden with a high economic cost to health systems and is an independent risk factor for cardiovascular disease (CVD). All stages of CKD are associated with increased risks of cardiovascular morbidity, premature mortality, and/or decreased quality of life. CKD is usually asymptomatic until later stages and accurate prevalence data are lacking. Thus we sought to determine the prevalence of CKD globally, by stage, geographical location, gender and age. A systematic review and meta-analysis of observational studies estimating CKD prevalence in general populations was conducted through literature searches in 8 databases. We assessed pooled data using a random effects model. Of 5,842 potential articles, 100 studies of diverse quality were included, comprising 6,908,440 patients. Global mean(95%CI) CKD prevalence of 5 stages 13·4%(11·7–15·1%), and stages 3–5 was 10·6%(9·2–12·2%). Weighting by study quality did not affect prevalence estimates. CKD prevalence by stage was Stage-1 (eGFR>90+ACR>30): 3·5% (2·8–4·2%); Stage-2 (eGFR 60–89+ACR>30): 3·9% (2·7–5·3%); Stage-3 (eGFR 30–59): 7·6% (6·4–8·9%); Stage-4 = (eGFR 29–15): 0·4% (0·3–0·5%); and Stage-5 (eGFR<15): 0·1% (0·1–0·1%). CKD has a high global prevalence with a consistent estimated global CKD prevalence of between 11 to 13% with the majority stage 3. Future research should evaluate intervention strategies deliverable at scale to delay the progression of CKD and improve CVD outcomes.

Data from: Wear, tear and systematic repair: testing models of growth dynamics in conodonts with high-resolution imaging

Conodont elements are the earliest mineralised vertebrate dental tools and the only ones capable of extensive repair. Two models of conodont growth, as well as the presence of a larval stage, have been hypothesised. We analysed normally and pathologically developed elements to test these hypotheses and identified three ontogenetic stages characterised by different anisometric growth and morphology. The distinction of these stages is independently corroborated by differences in tissue strontium content. The onset of the last stage is marked by the appearance of wear resulting from mechanical food digestion. At least five episodes of damage and repair could be identified in the normally developed specimen. In the pathological element, function was compromised by development of abnormal denticles. This development can be reconstructed as addition of new growth centres out of the main growth axis during an episode of renewed growth. Our findings support the model of periodic retraction of elements and addition of new growth centres. Changes in strontium content coincident with distinct morphology and lack of wear in the early life stage indicate that conodonts might have assumed their mature feeding habit of predators or scavengers after an initial larval stage characterised by a different feeding mode.

opencc-zeroJun 2021View details →

Measuring resilience and resistance in aging and Alzheimer disease using residual methods: A systematic review and meta-analysis

Objective: There is currently a lack of consensus on how to optimally define and measure resistance and resilience in brain and cognitive aging. Residual methods use residuals from regression analysis to quantify the capacity to avoid (resistance) or cope (resilience) "better or worse than expected" given a certain level of risk or cerebral damage. We reviewed the rapidly-growing literature on residual methods in the context of aging and Alzheimer's disease (AD), and performed meta-analyses to investigate associations of residual-method based resilience and resistance measures with longitudinal cognitive and clinical outcomes. Methods: A systematic literature search of PubMed and Web-of-Science databases (consulted until March 2020) and subsequent screening led to 54 studies fulfilling eligibility criteria, including 10 studies suitable for the meta-analyses. Results: We identified articles using residual methods aimed at quantifying resistance (n=33), cognitive resilience (n=23) and brain resilience (n=2). Critical examination of the literature revealed that there is considerable methodological variability in how the residual measures were derived and validated. Despite methodological differences across studies, meta-analytic assessments showed significant associations of levels of resistance (HR[95%CI]=1.12[1.07-1.17], p<0.0001) and levels of resilience (HR[95%CI]=0.46[0.32-0.68], p<0.001) with risk of progression to dementia/AD. Resilience was also associated with rate of cognitive decline (β[95%CI]=0.05[0.01-0.08], p<0.01). Conclusion: This review and meta-analysis supports the usefulness of residual methods as appropriate measures of resilience and resistance, as they capture clinically meaningful information in aging and AD. More rigorous methodological standardization is needed, however, to increase comparability across studies and, ultimately, application in clinical practice.

Data from: Phylogeny and systematics of Kewa (Kewaceae)

The genus Kewa in the monogeneric family Kewaceae (Caryophyllales) is revised. Six species are recognized, K. acida on St. Helena, K. angrae-pequenae in Namibia and South Africa, K. arenicola (incl. K. trachysperma) in South Africa, K. bowkeriana (incl. K. suffruticosa) widespread in eastern and southern Africa and in Madagascar, K. caespitosa in Angola and Namibia, and K. salsoloides in Namibia, Botswana, and South Africa. Kewa is morphologically distinctive, notably by its simple perianth where the two outer perianth-segments are more or less sepaloid and the three inner ones more or less petaloid, and by its indumentum of short glandular hairs, often with prominent, persistent, wart-like bases. All species have an acid taste, apparently due to the presence of oxalic acid. All names are typified, including one lectotype designated here. An identification key and distribution maps for all species are provided. The phylogeny of Kewa is reconstructed based on plastid trnK-matK and rbcL and nuclear ITS sequences. Kewa is strongly supported and the included species have strong to no support, whereas the relationships between the species are mostly unsupported. The phylogeny is dated and the estimated age of the Kewa stem clade is (37.5‐)45.0(‐57.0) million years and of the crown clade (3.0‐)3.9(‐7.4) million years. The age of the crown clade would also be the estimated date when K. acida on the approximately 14 million years old St. Helena diverged from its potential sister group on the African continent, and would coincide with the earliest possible date for the introduction of the ancestor of K. acida to St. Helena.

opencc-zeroDec 2014View details →

Data from: Systematic site selection for multispecies monitoring networks

The importance of monitoring biodiversity to detect and understand changes throughout time and to inform management is increasingly recognized. Monitoring schemes should be globally unified, spatially integrated across scales, long term, and cost-efficient. We propose a framework to design optimized multispecies-targeted monitoring networks over large areas. The method builds upon previous developments on systematic conservation planning in terms of optimizing resource allocation in space, and comprises seven steps: (a) determine which questions will be addressed, (b) define species to be monitored, (c) compile occurrence data for all defined species, (d) predict the overall distribution of each species, (e) collect relevant environmental data and identify homogeneous strata, (f) set targets for the minimum number of monitoring sites per species and/or stratum and (g) identify optimal monitoring sites. We tested whether the monitoring networks designed with our framework have increased performance when compared to networks obtained with simple-random or stratified-random sampling by using a set of different indicators. To that end, we designed monitoring networks using optimized and non-optimized sampling schemes, applied to a case study in Portugal, where the goal was to design a monitoring network for amphibians and reptiles, to complement the one currently established in Spain. Results allowed us to conclude that monitoring networks designed with our method tend to outperform the non-optimized ones, in terms of higher species diversity (i.e. higher number of species and equity across monitoring sites), higher representation of environmental strata, and particularly higher coverage of rare species, with less survey effort. Synthesis and applications. We developed a framework to allocate monitoring sites for multiple species at broad scales using predictive models and optimization algorithms currently applied in systematic conservation planning. This framework presents field survey cost-efficiency advantages when compared to other standard sampling designs and can significantly contribute to improving the design of monitoring schemes. Thus, we recommend its application to design new multispecies monitoring networks or to extend existing ones.

Data from: A systematic review of cetothere baleen whales (Cetacea, Cetotheriidae) from the Late Miocene of Crimea and Caucasus, with a new genus

Nine taxa of Miocene baleen whales were described from the Black Sea region under the name Cetotherium before 1951, and a further four closely related species representing three genera have been added in recent years. This rich diversity requires taxonomic revision and ordering. Here, a new genus, Mithridatocetus, is described from the Tortonian of Crimea and Caucasus, with two species, M. eichwaldi and M. adygeicus (originally Kurdalagonus adygeicus); 'Cetotherium' mayeri (a nomen dubium) is also a member of this genus. In comparison with other Cetotheriinae, Mithridatocetus is distinguished by the autapomorphic shape of the tympanic bulla with the swollen main ridge, the lowered anterior portion of the involucrum and the oblique anterolateral margin; such synapomorphies, as a transversely narrow squamosal with the ventromedially oriented postglenoid process (shared with Eucetotherium), a squamosal cleft (shared with Kurdalagonus) and an oval surface of the compound posterior process of the tympanoperiotic on the posterolateral skull wall (shared with Brandtocetus); and a unique combination of a high neurocranium and a long and robust paroccipital process. The genus Kurdalagonus is redefined here as containing only one described species, K. mchedlidzei. Therefore, the group Cetotheriinae is now restricted to the latest Serravallian and Tortonian of the Eastern Paratethys and includes at least five genera: Cetotherium, Brandtocetus, Kurdalagonus, Mithridatocetus and Zygiocetus. In addition, ?Cetotherium priscum and C. incertum are considered to be nomina dubia; 'Cetotherium' klinderi and 'Cetotherium' pusillum require more complete specimens for reassessment; 'Cetotherium' maicopicum and Eucetotherium helmersenii require further research to identify their taxonomical affinities.