Publications by authors named "HILLERS A"

Article Synopsis
  • * Analysis of data from over 1 million forest plots and thousands of tree species shows that wood density varies significantly by latitude, being up to 30% denser in tropical forests compared to boreal forests, and is influenced mainly by temperature and soil moisture.
  • * The research also finds that disturbances like human activity and fire alter wood density at local levels, affecting forest carbon stock estimates by up to 21%, emphasizing the importance of understanding environmental impacts on forest ecosystems.
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Objective: The objective of this study is to independently assess skeletal muscle index (SMI) and body mass index (BMI) as prognostic determinants for renal cell carcinoma (RCC) and investigate their correlation with surgical outcomes.

Patients And Methods: A retrospective cohort study of 524 RCC patients diagnosed between August 2010 and July 2018 was conducted using data from the Zealand University Hospital Renal Cancer Database in Denmark. Patient information was extracted from electronic patient records and the National Cancer Registry and encompassed demographics, clinical factors, tumour characteristics and surgical details.

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Malaria remains the most important arthropod-borne infectious disease globally. The causative agent, Plasmodium, is a unicellular eukaryote that develops inside red blood cells. Identifying new Plasmodium parasite species that infect mammalian hosts can shed light on the complex evolution and diversity of malaria parasites.

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Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system. Remote-sensing estimates to quantify carbon losses from global forests are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced and satellite-derived approaches to evaluate the scale of the global forest carbon potential outside agricultural and urban lands.

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Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records.

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Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies. Here, leveraging global tree databases, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity.

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The distribution of the White-Lipped Frog Amnirana albolabris was long assumed to extend from eastern-central to western African rainforests. However, recent molecular phylogenetic analyses revealed that this taxon likely represents several undescribed species. Because the name-bearing types were collected in Gabon, the distantly related West African populations clearly represent an undescribed species that partly occurs in sympatry with Amnirana fonensis.

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Article Synopsis
  • The latitudinal diversity gradient (LDG) reflects a global trend showing that species richness typically increases towards the tropics, but understanding its causes has been challenging due to insufficient data.
  • A new high-resolution map of local tree species richness was created using extensive global forest inventory data and local biophysical factors, analyzing around 1.3 million sample plots.
  • Findings indicate that annual mean temperature is a significant predictor of tree species richness, aligning with the metabolic theory of biodiversity, but additional local factors also play a crucial role, especially in tropical regions.
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Forty-nine years after the last description of a slippery frog, we describe a seventh species of the genus Conraua. The new Conraua is endemic to the Atewa Range Forest Reserve, central Ghana, and is described based on genetic, bioacoustics, and morphological evidence. Recent molecular phylogenetic and species delimitation analyses support this population as distinct from nominotypical C.

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Despite the large body of literature on ape conservation, much of the data needed for evidence-based conservation decision-making is still not readily accessible and standardized, rendering cross-site comparison difficult. To support knowledge synthesis and to complement the IUCN SSC Ape Populations, Environments and Surveys database, we created the A.P.

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Though human activities are postulated to be the main drivers of the worldwide biodiversity crisis, humans are also suggested by some to be an important part of the solution to the crisis. How can such a paradox be best solved? This paradox requires an adaptive, context-specific, dynamic solution, at a fine-grained scale that varies by location. The Wild Chimpanzee Foundation (WCF) works on the ground in three West African countries: In Côte d'Ivoire, where bushmeat consumption is a recurrent and generalized threat to wildlife, WCF used live theater performances in the villages to address this issue.

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The aim of this study was to describe the circumstances surrounding firework-related deaths in Denmark, locate similarities and compare findings to the other known literature. Autopsy files, including police reports, located through searches in the archives of the three Danish institutes of forensic medicine were accessed. Data describing the age, gender, toxicology findings, circumstances of the accident, cause of death, autopsy findings and type of fireworks were examined.

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Article Synopsis
  • Sexual dimorphism, particularly in color (sexual dichromatism), may accelerate speciation and diversification in animals, but studies yield mixed results on its impact.
  • African reed frogs exhibit unique female-biased sexual dichromatism, where females often have more vibrant colors than males, diverging from typical patterns seen in vertebrates.
  • Research shows that sexual dichromatism in these frogs evolved once and is linked to higher diversification rates compared to monochromatic species, although the specific function of this color change in reed frogs remains uncertain.
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We describe a new species of Phrynobatrachus from the eastern part of the Upper Guinea forest region, Ghana, West Africa. Morphologically, the new species can be distinguished from all of its congeners by the combination of a slender body, short and pointed snout, a relatively warty dorsum, a black-spotted throat in both sexes, a gular flap in males, a dark spotted chest, a white-greyish venter with occasional blackish spots, rudimentary pedal webbing, none to slightly dilated finger tips and strongly delated toe tips, presence of both inner and outer metatarsal tubercles and absence of a dark face mask, eyelid tubercles and longer dorsal ridges. We collected mitochondrial DNA (mtDNA) sequence data from the 16S rRNA gene to measure the genetic diversity of the new species, and to estimate phylogenetic relationships.

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A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd). While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species) for the presence of Bd.

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Specimens from across the range of the Hyperolius nasutus species group were sequenced for two mitochondrial genes and one nuclear gene. Advertisement calls were recorded from the same specimens where possible, and morphological characters were compared. Bayesian inference and maximum likelihood produced a tree indicating 16 clades.

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Puddle frogs (Anura: Phrynobatrachidae) are one of the most species-rich sub-Saharan amphibian groups, occupying an extraordinarily diverse range of habitats. We construct the first phylogeny of puddle frogs, utilizing mitochondrial (12S rRNA, valine-tRNA, and 16S rRNA) and nuclear (RAG-1) DNA. Phylogenetic analyses are conducted using separate and combined partitions under maximum parsimony, maximum likelihood, and Bayesian criterion.

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Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs.

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