bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processes that drive the population structuring of Jenynsia lineata (Cyprinidontiformes, Anablepidae) in the La Plata Basin
Authors: Briñoccoli Yanina F. , Jardim de Queiroz Luiz , Bogan Sergio , Paracampo Ariel , Posadas Paula E. , Somoza Gustavo M. , Montoya‐Burgos Juan I. , Cardoso Yamila P. 
Published: May 2021

Abstract

The distribution of genetic diversity across a species distribution range is rarely homogeneous, as the genetic structure among populations is related to the degree of isolation among them, such as isolation by distance, isolation by barrier, and isolation by environment.

Jenynsia lineata is a small viviparous fish that inhabits a wide range of habitats in South America. To decipher the isolation processes that drive population structuring in J. lineata, we analyzed 221 sequences of the mitochondrial cytochrome c oxidase I gene (COI), from 19 localities. Then, we examined the influence of the three most common types of isolation in order to explain the genetic variation found in this species.

Our results revealed a marked structuration, with three groups: (a) La Plata/Desaguadero Rivers (sampling sites across Argentina, Uruguay, and Southern Brazil), (b) Central Argentina, and (c) Northern Argentina. A distance‐based redundancy analysis, including the explanatory variables geographical distances, altitude, latitude, and basin, was able to explain up to 65% of the genetic structure. A variance partitioning analysis showed that the two most important variables underlying the structuration in J. lineata were altitude (isolation by environment) and type of basin (isolation by barrier).

Our results show that in this species, the processes of population diversification are complex and are not limited to a single mechanism. The processes that play a prominent role in this study could explain the high rate of diversity that characterizes freshwater fish species. And these processes in turn are the basis for possible speciation events.
New karyotype for Mesomys stimulax (Rodentia, Echimyidae) from the Brazilian Amazon: A case for species complex?
Authors: Malcher Stella Miranda , Pieczarka Julio Cesar , Pereira Adenilson Leão , do Amaral Paulo José Siqueira , Rossi Rogério Vieira , Saldanha Juliane , Nagamachi Cleusa Yoshiko 
Published: May 2021

AbstractMesomys Wagner, 1845 (Rodentia, Echimyidae, Eumysopinae) currently has four recognized species, three of which occur in Brazil: Mesomys hispidus (probably a species complex), M. occultus, and M. stimulax. Mesomys leniceps is found in montane forests of northern Peru. Mesomys stimulax, the focus of the present study, has a distribution that is restricted to the central and eastern Amazonia south of the Amazon River, extending from the left bank of the Tapajós River to the right bank of the Tocantins River, and south to the southeast portion of Pará State. The genus presents karyotypes with diploid number 2n = 60 and Fundamental Number (FN) = 116 for M. hispidus and M. stimulax, and 2n = 42, FN = 54 for M. occultus. We studied the karyotype of a female specimen of M. stimulax collected from the Tapirapé‐Aquiri National Forest, Marabá, Pará, Brazil, in the Xingu/Tocantins interfluvium. The obtained karyotype (2n = 60 and FN = 110) differs from that described in the literature for both M. stimulax and M. hispidus by exhibiting more biarmed chromosomes, probably due to pericentric inversions and/or centromeric repositioning, and exhibiting differences in the amount and distribution of constitutive heterochromatin (CH). These results suggest that, similar to what has already been proposed for M. hispidus, M. stimulax may represent a species complex and/or cryptic species. The mechanisms of chromosomal diversification in Mesomys and the biogeographic implications are discussed reinforcing the need for broad systematic review for Mesomys.
Directional seed and pollen dispersal and their separate effects on anisotropy of fine‐scale spatial genetic structure among seedlings in a dioecious, wind‐pollinated, and wind‐dispersed tree species, Cercidiphyllum japonicum
Authors: Nakanishi Atsushi , Goto Susumu , Sumiyoshi Chikako , Isagi Yuji 
Published: May 2021

AbstractPrevailing directions of seed and pollen dispersal may induce anisotropy of the fine‐scale spatial genetic structure (FSGS), particularly in wind‐dispersed and wind‐pollinated species. To examine the separate effects of directional seed and pollen dispersal on FSGS, we conducted a population genetics study for a dioecious, wind‐pollinated, and wind‐dispersed tree species, Cercidiphyllum japonicum Sieb. et Zucc, based on genotypes at five microsatellite loci of 281 adults of a population distributed over a ca. 80 ha along a stream and 755 current‐year seedlings. A neighborhood model approach with exponential‐power‐von Mises functions indicated shorter seed dispersal (mean = 69.1 m) and much longer pollen dispersal (mean = 870.6 m), effects of dispersal directions on the frequencies of seed and pollen dispersal, and the directions with most frequent seed and pollen dispersal (prevailing directions). Furthermore, the distance of effective seed dispersal within the population was estimated to depend on the dispersal direction and be longest at the direction near the prevailing direction. Therefore, patterns of seed and pollen dispersal may be affected by effective wind directions during the period of respective dispersals. Isotropic FSGS and spatial sibling structure analyses indicated a significant FSGS among the seedlings generated by the limited seed dispersal, but anisotropic analysis for the seedlings indicated that the strength of the FSGS varied with directions between individuals and was weakest at a direction near the directions of the most frequent and longest seed dispersal but far from the prevailing direction of pollen dispersal. These results suggest that frequent and long‐distance seed dispersal around the prevailing direction weakens the FSGS around the prevailing direction. Therefore, spatially limited but directional seed dispersal would determine the existence and direction of FSGS among the seedlings.
Relating leaf traits to seedling performance in a tropical forest: building a hierarchical functional framework
Authors: Umaña María Natalia , Swenson Nathan G. , Marchand Philippe , Cao Min , Lin Luxiang , Zhang Caicai 
Published: May 2021

AbstractTrait‐based approaches have been extensively used in community ecology to provide a mechanistic understanding of the drivers of community assembly. However, a foundational assumption of the trait framework, traits relate to performance, has been mainly examined through univariate relationships that simplify the complex phenotypic integration of organisms. We evaluate a conceptual framework in which traits are organized hierarchically combining trait information at the individual‐ and species‐level from biomass allocation and organ‐level traits. We focus on photosynthetic traits and predict that the positive effects of increasing plant leaf mass on growth depend on species‐level leaf traits. We modeled growth data on more than 1,500 seedlings from 97 seedling species from a tropical forest in China. We found that seedling growth increases with allocation to leaves (high leaf area ratio and leaf mass fraction) and this effect is accentuated for species with high specific leaf area and leaf area. Also, we found that light has a significant effect on growth, and this effect is additive with leaf allocation traits. Our work offers an approach to gain further understanding of the effects of traits on the whole plant‐level growth via a hierarchical framework including organ‐level and biomass allocation traits at species and individual levels.
Hide ‘n seq: Direct versus indirect metabarcoding of coral reef cryptic communities
Authors: Nichols Patrick K. , Timmers Molly , Marko Peter B. 
Published: May 2021

AbstractEcological patterns in biodiversity are primarily based on conspicuous organisms. Few methods are used to survey the taxonomically rich cryptobiome, which is made up of inhabitants from within microhabitats. One way that cryptic marine biodiversity can be non‐invasively surveyed is by analyzing environmental DNA (eDNA) present in seawater. Using coral reefs as a model system, here we compare estimates of cryptic diversity among community biomass and eDNA metabarcoding sampling methods with a broad eukaryotic marker (COI). First, contributions to eDNA were investigated across cryptobiomes through a comparison of community metabarcoded biomass from standardized autonomous reef monitoring structures (ARMS) to eDNA acquired from seawater in which individual ARMS were soaked. Second, we compared these results to those from eDNA samples taken from within reef crevices and the ambient water column. Metabarcoding of community biomass from ARMS and eDNA from the two types of water samples revealed significantly different communities of cryptic coral reef habitat with little overlap between methods. Taxa that were unique to metabarcoding of ARMS biomass were predominantly from chitinous and calcifying groups (polychaetes, palaemonid shrimp, mollusks, brittle stars, and red algae), which suggests that these taxa are underrepresented in eDNA surveys. Other than the corals themselves, sponges and red algae were significant drivers of reef crevice community differences, while ambient seawater samples detected mostly planktonic organisms and reef fishes. Our data indicate that both eDNA and ARMS provide incomplete accounting of cryptic diversity. Direct sampling of biomass is best suited for building taxonomies and improving databases, whereas eDNA methods offer rapid insights into the composition of cryptobiomes. Because each method likely captures different taxa, multiple targeted assays can be used to provide the greatest estimates of metazoan and macroalgal richness.
Prevalence of transthyretin amyloidosis in patients with heart failure and no left ventricular hypertrophy
Authors: Devesa Ana , Camblor Blasco Andrea , Pello Lázaro Ana María , Askari Elham , Lapeña Gregoria , Gómez Talavera Sandra , Taibo Urquía Mikel , Rodríguez Olleros Celia , Tuñón José , Ibáñez Borja , Aceña Álvaro 
Published: May 2021

AbstractAimsAs evidenced by scintigraphy imaging, the prevalence of transthyretin (TTR) cardiac amyloidosis in heart failure patients with preserved ejection fraction (HFpEF) and left ventricular hypertrophy (LVH) ranges between 13% and 19%. The natural evolution of cardiac amyloidosis begins with the deposition of amyloid material in the myocardium, with LVH ensuing at later stages. With current imaging modalities, it is possible to detect TTR cardiac amyloidosis before the hypertrophic stage. The aim of this study was to determine the prevalence of TTR cardiac amyloidosis in HFpEF patients without LVH.Methods and resultsThe study prospectively enrolled patients admitted for HF with LV ejection fraction (LVEF) ≥ 50% and LV wall thickness <12 mm. TTR cardiac amyloidosis was diagnosed according to accepted criteria, which include positive cardiac 99‐Tc‐DPD scintigraphy in the absence of monoclonal protein expansion in blood. Transthyretin gene sequencing was performed in positive patients. From July 2017 to January 2020, 329 patients with HFpEF and LV thickness <12 mm were identified. After exclusions, 58 patients completed the study with cardiac scintigraphy (79 years, 54% men; median LVEF 60% and LV wall thickness 10.5 mm). Three patients (5.2%) were positive for TTR cardiac amyloidosis; genetic analysis excluded the presence of hereditary TTR amyloidosis. Positive patients baseline characteristics (84 years, 67% men, LVEF 60%, and LV wall thickness 11 mm) were similar to patients without TTR, except for troponin levels (0.05 vs. 0.02 ng/mL, P = 0.03) and glomerular filtration rate (82 vs. 60 mL/min, P = 0.032), which were higher in TTR patients.ConclusionsIn a cohort of patients with HFpEF without LVH, the prevalence of TTR cardiac amyloidosis was 5%. Early diagnosis of cardiac involvement in TTR amyloidosis (before manifest LVH) would seem recommendable because newly approved specific treatments can prevent additional deposition of amyloid material.
Association of preoperative infections, nasal Staphylococcus aureus colonization and gut microbiota with left ventricular assist device outcomes
Authors: Yuzefpolskaya Melana , Lumish Heidi S. , Javaid Azka , Cagliostro Barbara , Mondellini Giulio M. , Bohn Bruno , Sweat Austin , Onat Duygu , Braghieri Lorenzo , Takeda Koji , Naka Yoshifumi , Sayer Gabriel T. , Uriel Nir , Aaron Justin G. , Montassier Emmanuel , Demmer Ryan T. , Colombo Paolo C. 
Published: May 2021

AbstractAimsInfections are common following left ventricular assist device (LVAD) implantation and predict adverse events. Infections are frequent prior to LVAD implantation although their impact on postoperative outcomes remains unknown. Gut and nasal microbial imbalance may predispose to mucosal colonization with pathogens. Herein, we investigated the predictive role of pre‐LVAD infections, and explored the association of nasal Staphylococcus aureus (SA) colonization and gut microbiota, on postoperative outcomes.Methods and resultsOverall, 254 LVAD patients were retrospectively categorized based on pre‐LVAD infection status: Group 1, bacterial/fungal bloodstream infection (BSI); Group 2, other bacterial/fungal; Group 3, viral; and Group 4, no infection. In a subset of patients, nasal SA colonization (n = 140) and pre‐LVAD stool (n = 25) were analysed using 16S rRNA sequencing. A total of 75 (29%) patients had a pre‐LVAD infection [Group 1: 22 (29%); Group 2: 41 (55%); Group 3: 12 (16%)]. Pre‐LVAD BSIs were independent predictors of 1‐year postoperative mortality and infections [Group 1 vs. 4: hazard ratio (HR) 2.70, P = 0.036 vs. HR 1.8, P = 0.046]. In an unadjusted analysis, pre‐LVAD infections other than BSIs, INTERMACS profile ≤2, higher serum creatinine, lower serum albumin and nasal SA colonization were also significantly associated with postoperative infections. Patients with early post‐LVAD infections exhibited decreased microbial diversity (P < 0.05).ConclusionsPre‐LVAD infections are common. BSIs independently predict postoperative mortality and infections. Additional studies are needed to confirm our findings that pre‐LVAD SA nasal colonization and gut microbial composition can help stratify patients' risk for infectious complications after LVAD implantation.
Regulatory T cells and transplantation tolerance: Emerging from the darkness?
Authors: Waldmann Herman 
Published: May 2021

AbstractThe field of tissue transplantation has revolutionized the treatment of patients with failing organs. Its success, thus far, has depended on combinations of immunosuppressive drugs that damp host immunity, while also imposing numerous unwanted side‐effects. There is a longstanding recognition that better treatment outcomes, will come from replacing these drugs, fully or in part, by taking advantage of tractable physiological mechanisms of self‐tolerance. The past 50 years have seen many advances in the field of self‐tolerance, but perhaps, the most tractable of these has been the more recent discovery of a subset T‐cells (Treg) whose role is to regulate or damp immunity.This article is intended to first provide the reader with some historical background to explain why we have been slow to identify these cells, despite numerous clues to their existence, and also to indicate how little we know about how they achieve their regulatory function in averting transplant rejection. However, as is often the case in immunology, the therapeutic needs often dictate that our advances move to translation even before detailed explanations of the science are available. The final part of the article will briefly summarize how Treg are being harnessed as agents to interface with or perhaps, replace current drug combinations.
Differential Interleukin‐8 thresholds for chemotaxis and netosis in human neutrophils
Authors: Teijeira Alvaro , Garasa Saray , Ochoa Maria del Carmen , Cirella Assunta , Olivera Irene , Glez‐Vaz Javier , Andueza Maria Pilar , Migueliz Itziar , Alvarez Maite , Rodríguez‐Ruiz Maria Esperanza , Rouzaut Ana , Berraondo Pedro , Sanmamed Miguel F. , Perez Gracia Jose L. , Melero Ignacio 
Published: May 2021

AbstractIn humans, IL‐8 (CXCL8) is a key chemokine for chemotaxis of polymorphonuclear leukocytes and monocytes/macrophages when acting on CXCR1 and CXCR2. CXCL8 activity on neutrophils includes chemotaxis and eliciting the extrusion of neutrophil extracellular traps (NETs). In this study, we show that concentrations of IL‐8 that induce NETosis surpass in at least one order of magnitude those required to elicit chemoattraction in human neutrophils. IL‐8‐induced NETosis was less dependent on G‐proteins than migration, while extracellular Ca+2 chelation similarly inhibited both processes. Reactive oxygen species (ROS) were more important for NETosis than for chemotaxis as evidenced by neutralization with N‐acetyl ‐cysteine. Interestingly, selective blockade with anti‐CXCR1 mAb inhibited NETosis much more readily than chemotaxis, while pharmacological inhibition of both CXCR1 and CXCR2, or selective inhibition for CXCR2 alone, similarly inhibited both functions. Together, these results propose a model according to which low concentrations of IL‐8 in a gradient attract neutrophils to the inflammatory foci, while high receptor‐saturating concentrations of IL‐8 give rise to NETosis once leukocytes reach the core of the inflammatory insult.
The Chemistry of β‐Hydroxy Hydroperoxides
Authors: Louvel Dan , De Dios Miguel Thomas , Duc Vu Nam , Duguet Nicolas 
Published: May 2021

Abstractβ‐Hydroxy hydroperoxides (β‐hydroperoxy alcohols) are interesting chemical platforms, notably for the preparation of 1,2,4‐trioxanes, that are key features of numerous bioactive products such as artemisinin. In this review, the main synthetic methods to prepare β‐hydroxy hydroperoxides are presented, such as the photooxidation of allylic alcohols with singlet oxygen and the ring‐opening of epoxides with H2O2. The main applications of β‐hydroxy hydroperoxides are also detailed, including their peracetalization to 1,2,4‐trioxanes, their use as epoxidating agents and their fragmentation to carbonyl compounds. A final section is dedicated to the general characteristics and practical aspects of β‐hydroxy hydroperoxides, including their stability, safety and characterization through spectroscopic means.
Is Europe also facing an opioid crisis?—A survey of European Pain Federation chapters
Authors: Häuser Winfried , Buchser Eric , Finn David P. , Dom Geerd , Fors Egil , Heiskanen Tarja , Jarlbaek Lene , Knaggs Roger D. , Kosek Eva , Krcevski‐Škvarč Nevenka , Pakkonen Kaire , Perrot Serge , Trouvin Anne‐Priscille , Morlion Bart 
Published: May 2021

AbstractBackgroundThere is considerable public interest in whether Europe is facing an opioid crisis comparable to the one in the United States and the contribution of opioid prescriptions for pain to a potential opioid crisis.MethodsA task force of the European Pain Federation (EFIC) conducted a survey with its national chapter representatives on trends of opioid prescriptions and of drug‐related emergency departments and substance use disorder treatment admissions and of deaths as proxies of opioid‐related harms over the last 20 years.ResultsData from 25 European countries were received. In most European countries opioid prescriptions increased from 2004 to 2016. The levels of opioid consumption and their increase differed between countries. Some Eastern European countries still have a low opioid consumption. Opioids are mainly prescribed for acute pain and chronic noncancer pain in some Western and Northern European countries. There was a parallel increase in opioid prescriptions and some proxies of opioid‐related harms in France, Finland and the Netherlands, but not in Germany, Spain and Norway. In United Kingdom, opioid overdose deaths, but not opioid prescriptions increased between 2016 and 2018. There are no robust data available on whether prescribed opioids for pain patients contributed to opioid‐related harms.ConclusionsThere are marked differences between European countries in trends of opioid prescribing and of proxies for opioid‐related harms. Europe as a whole is not facing an opioid crisis. Discussions on the potential harms of opioids should not obstruct their prescription for cancer pain and palliative care.SignificanceEurope as a whole is not facing an opioid crisis. Some Eastern European countries have limited access to opioid medicines. Discussions on the potential harms of opioid medicines for noncancer pain should not obstruct opioid therapy for cancer therapy and palliative care.
The effect of experimental and clinical musculoskeletal pain on spinal and supraspinal projections to motoneurons and motor unit properties in humans: A systematic review
Authors: Sanderson Andy , Wang Shuwfen F. , Elgueta‐Cancino Edith , Martinez‐Valdes Eduardo , Sanchis‐Sanchez Enrique , Liew Bernard , Falla Deborah 
Published: May 2021

AbstractBackground and ObjectiveNumerous studies have examined the influence of pain on spinal reflex excitability, motor unit behaviour and corticospinal excitability. Nevertheless, there are inconsistencies in the conclusions made. This systematic review sought to understand the effect of pain on spinal and supraspinal projections to motoneurons and motor unit properties by examining the influence of clinical or experimental pain on the following three domains: H‐reflex, corticospinal excitability and motor unit properties.Databases and Data TreatmentMeSH terms and preselected keywords relating to the H‐reflex, motor evoked potentials and motor unit decomposition in chronic and experimental pain were used to perform a systematic literature search using Cumulative Index of Nursing and Allied Health Literature (CINAHL), Excerpta Medica dataBASE (EMBASE), Web of Science, Medline, Google Scholar and Scopus databases. Two independent reviewers screened papers for inclusion and assessed the methodological quality using a modified Downs and Black risk of bias tool; a narrative synthesis and three meta‐analyses were performed.ResultsSixty‐one studies were included, and 17 different outcome variables were assessed across the three domains. Both experimental and clinical pain have no major influence on measures of the H‐reflex, whereas experimental and clinical pain appeared to have differing effects on corticospinal excitability. Experimental pain consistently reduced motor unit discharge rate, a finding which was not consistent with data obtained from patients. The results indicate that when in tonic pain, induced via experimental pain models, inhibitory effects on motoneuron behaviour were evident. However, in chronic clinical pain populations, more varied responses were evident likely reflecting individual adaptations to chronic symptoms.SignificanceThis is a comprehensive systematic review and meta‐analysis which synthesizes evidence on the influence of pain on spinal and supraspinal projections to motoneurons and motor unit properties considering measures of the H‐reflex, corticospinal excitability and motor unit behaviour. The H‐reflex is largely not influenced by the presence of either clinical or experimental pain. Whilst inhibitory effects on corticospinal excitability and motor unit behaviour were evident under experimental pain conditions, more variable responses were observed for people with painful musculoskeletal disorders.