bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relationship among host plant species, egg clutch size, and level of parasitism for the sharpshooter Tapajosa rubromarginata
Authors: Virla Eduardo G. , Aguirre María B. , Van Nieuwenhove Guido A. , Luft Albarracin Erica B. , Logarzo Guillermo A. 
Published: October 2020

AbstractThe sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae, Proconiini), a vector of the bacterium Xylella fastidiosa Wells et al. (Xanthomonadaceae) that causes citrus variegated chlorosis, has more than 30 reported host plant species. The fitness of a phytophagous insect is determined by the host plant suitability, plant resistance, and the natural enemies. The aim of this study was to: (1) identify plant species utilized as oviposition substrate by T. rubromarginata in the field; (2) establish the relationship between plants and clutch size; (3) establish the relationship among host plants, clutch size, and level of parasitism; and (4) establish variations in parasitoid composition and abundance in the various host plants. Egg masses of the sharpshooter were surveyed on plants reported as hosts, or those that were abundant in the study site. The number of eggs of the sharpshooter and emerged parasitoids were recorded for all the collected masses. We found egg masses of T. rubromarginata on 12 out of 21 plant species sampled. The size of the egg masses was greatly influenced by the type of leaf venation and to a lesser extent by the plant species. Parasitism rates were influenced by both leaf venation and host plant. Trichogrammatidae species were mostly associated with egg masses in plants with parallel‐veined leaves, whereas Mymaridae attacked masses laid in reticular‐veined leaves. The choice between a good host plant, but heavily attacked by parasitoids, and the host plants that are less suitable for nymphs but less frequently attacked by natural enemies, was a trade‐off for T. rubromarginata females to increase their fitness. We conclude that the host plant utilization by T. rubromarginata females in the field could be influenced by leaf structure and the strategy to avoid parasitism by selecting plants that were less attractive for parasitoids.
Association of amyloid angiopathy with microbleeds in logopenic progressive aphasia: an imaging‐pathology study
Authors: Buciuc M. , Duffy J. R. , Machulda M. M. , Spychalla A. J. , Gunter J. L. , Jack C. R. , Giannini C. , Raghunathan A. , Dickson D. W. , Josephs K. A. , Whitwell J. L. 
Published: October 2020

Background and purposeCerebral microbleeds (MB) and superficial siderosis (SS) are frequent neuroimaging findings in patients with logopenic progressive aphasia (LPA), often with frontal lobe predilection. Cerebral amyloid angiopathy (CAA) is hypothesized to be the major pathologic determinant of MB/SS in these patients; however, neuroimaging‐pathologic data are limited.MethodsAll patients who had been prospectively recruited by the Neurodegenerative Research Group at the Mayo Clinic (Rochester, MN) between 2010 and 2015 and met the following inclusion criteria were included: (i) received an antemortem LPA diagnosis, (ii) had a gradient‐recalled echo T2*‐weighted magnetic resonance imaging (MRI) performed, (iii) died and completed a brain autopsy. Demographic, genetic, neuroimaging, and clinical and pathologic characteristics were compared between patients with/without MB/SS. Two‐tailed Fisher exact and Wilcoxon rank sum tests were used for comparison of categorical and continuous variables, respectively.ResultsThirteen patients met inclusion criteria, six (46%) had MB/SS on MRI. Moderate/severe CAA was associated with the presence of MB/SS (p = 0.029). As expected, MB/SS most frequently involved the frontal lobes, followed by the parietal lobes. No clear associations were found between regional MB/SS distribution and regional distribution of CAA or hypometabolism on [18F]‐fluorodeoxyglucose–positron emission tomography. There was some evidence for a regional association between MB/SS and uptake on Pittsburgh compound B, although not in all patients. No formal statistical analyses to assess topographic relationships were performed due to the small sample size.ConclusionsThe presence of MB/SS is a strong indicator of underlying moderate/severe CAA in LPA, although the biological mechanisms underlying the topographic distribution of MB/SS remain unclear.
Intensive versus guideline‐recommended blood pressure reduction in acute lacunar stroke with intravenous thrombolysis therapy: The ENCHANTED trial
Authors: Zhou Zien , Xia Chao , Carcel Cheryl , Yoshimura Sohei , Wang Xia , Delcourt Candice , Malavera Alejandra , Chen Xiaoying , Mair Grant , Woodward Mark , Chalmers John , Demchuk Andrew M. , Lindley Richard I. , Robinson Thompson G. , Parsons Mark W. , Wardlaw Joanna M. , Anderson Craig S. 
Published: October 2020

AbstractBackground and purposeThis was an investigation of the differential effects of early intensive versus guideline‐recommended blood pressure (BP) lowering between lacunar and non‐lacunar acute ischaemic stroke (AIS) in the BP arm of the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED).MethodsIn 1,632 participants classified as having definite or probable lacunar (n = 454 [27.8%]) or non‐lacunar AIS according to pre‐specified definitions based upon clinical and adjudicated imaging findings, mean BP changes over days 0–7 were plotted, and systolic BP differences by treatment between subgroups were estimated in generalized linear models. Logistic regression models were used to estimate the BP treatment effects on 90‐day outcomes (primary, an ordinal shift of modified Rankin scale scores) across lacunar and non‐lacunar AIS after adjustment for baseline covariables.ResultsMost baseline characteristics, acute BP and other management differed between lacunar and non‐lacunar AIS, but mean systolic BP differences by treatment were comparable at each time point (all pinteraction > 0.12) and over 24 h post‐randomization (−5.5, 95% CI −6.5, −4.4 mmHg in lacunar AIS vs. −5.6, 95% CI −6.3, −4.8 mmHg in non‐lacunar AIS, pinteraction = 0.93). The neutral effect of intensive BP lowering on functional outcome and the beneficial effect on intracranial haemorrhage were similar for the two subgroups (all pinteraction > 0.19).ConclusionsThere were no differences in the treatment effect of early intensive versus guideline‐recommended BP lowering across lacunar and non‐lacunar AIS.
Impaired consolidation of visuomotor adaptation in patients with multiple sclerosis
Authors: Nguemeni Carine , Nakchbandi Luis , Homola György , Zeller Daniel 
Published: October 2020

AbstractBackgroundApart from inflammation and neurodegeneration, the individual clinical course of multiple sclerosis (MS) might be determined by differential adaptive capacities of the central nervous system. It has been postulated that the retention of adaptive training effects may be impaired in persons with MS (PwMS).ObjectiveTo investigate motor adaptation and consolidation capacities of people with MS in a visual motor adaptation task (VAT).MethodsA total of 23 PwMS (Expanded Disability Status Scale (EDSS) score < 6) and 20 matched healthy controls were recruited. All participants completed three sessions of a VAT where a clockwise rotation angle of 30° was introduced as perturbation during the active learning part of the paradigm. The training session (T0) was repeated after 24 h (T1) and 72 h (T2). Directional errors and parameters of adaptation and retention were evaluated.ResultsPwMS showed similar adaptation and online learning abilities as controls. However, the retention ratio was significantly lower in patients compared to controls at T1 (p = 0.036) and T2 (p = 0.039). There was no significant correlation between the overall adaptation or retention ratio and the EDSS score, respectively.ConclusionOur findings indicate intact adaptation, but limited consolidation, in patients with mild‐to‐moderate MS. Future studies are needed to define the neurobiological substrates of this plasticity and the extent to which it can influence clinical outcomes.
Angiotensin‐converting enzyme open for business: structural insights into the subdomain dynamics
Authors: Cozier Gyles E. , Lubbe Lizelle , Sturrock Edward D. , Acharya K. Ravi 
Published: October 2020

Angiotensin‐1‐converting enzyme (ACE) is a key enzyme in the renin–angiotensin–aldosterone and kinin systems where it cleaves angiotensin I and bradykinin peptides, respectively. However, ACE also participates in numerous other physiological functions, can hydrolyse many peptide substrates and has various exo‐ and endopeptidase activities. ACE achieves this complexity by containing two homologous catalytic domains (N‐ and C‐domains), which exhibit different substrate specificities. Here, we present the first open conformation structures of ACE N‐domain and a unique closed C‐domain structure (2.0 Å) where the C terminus of a symmetry‐related molecule is observed inserted into the active‐site cavity and binding to the zinc ion. The open native N‐domain structure (1.85 Å) enables comparison with ACE2, a homologue previously observed in open and closed states. An open S2_S′‐mutant N‐domain structure (2.80 Å) includes mutated residues in the S2 and S′ subsites that effect ligand binding, but are distal to the binding site. Analysis of these structures provides important insights into how structural features of the ACE domains are able to accommodate the wide variety of substrates and allow different peptidase activities.DatabaseThe atomic coordinates and structure factors for Open nACE, Open S2_S′‐nACE and Native G13‐cACE structures have been deposited with codes 6ZPQ, 6ZPT and 6ZPU, respectively, in the RCSB Protein Data Bank, www.pdb.org
The lysosomal membrane—export of metabolites and beyond
Authors: Rudnik Sönke , Damme Markus 
Published: October 2020

Lysosomes are degradative organelles in eukaryotic cells mediating the hydrolytic catabolism of various macromolecules to small basic building blocks. These low‐molecular‐weight metabolites are transported across the lysosomal membrane and reused in the cytoplasm and other organelles for biosynthetic pathways. Even though in the past 20 years our understanding of the lysosomal membrane regarding various transporters, other integral and peripheral membrane proteins, the lipid composition, but also its turnover has dramatically improved, there are still many unresolved questions concerning key aspects of the function of the lysosomal membrane. These include a possible function of lysosomes as a cellular storage compartment, yet unidentified transporters mediating the export such as various amino acids, mechanisms mediating the transport of lysosomal membrane proteins from the Golgi apparatus to lysosomes, and the turnover of lysosomal membrane proteins. Here, we review the current knowledge about the lysosomal membrane and identify some of the open questions that need to be solved in the future for a comprehensive and complete understanding of how lysosomes communicate with other organelles, cellular processes, and pathways.
Living phosphatic stromatolites in a low‐phosphorus environment: Implications for the use of phosphorus as a proxy for phosphate levels in paleo‐systems
Authors: Büttner Steffen H. , Isemonger Eric W. , Isaacs Michelle , van Niekerk Deon , Sipler Rachel E. , Dorrington Rosemary A. 
Published: October 2020

AbstractIn the geological record, fossil phosphatic stromatolites date back to the Great Oxidation Event in the Paleoproterozoic, but living phosphatic stromatolites have not been described previously. Here, we report on cyanobacterial stromatolites in a supratidal freshwater environment at Cape Recife, South African southern coast, precipitating Ca carbonate alternating with episodes of Ca phosphate deposition. In their structure and composition, the living stromatolites from Cape Recife closely resemble their fossilized analogues, showing phosphatic zonation, microbial casts, tunnel structures and phosphatic crusts of biogenic origin. The microbial communities appear to be also similar to those proposed to have formed fossil phosphatic stromatolites. Phosphatic domains in the material from Cape Recife are spatially and texturally associated with carbonate precipitates, but form distinct entities separated by sharp boundaries. Electron Probe Micro‐Analysis shows that Ca/P ratios and the overall chemical compositions of phosphatic precipitates are in the range of octacalcium phosphate, amorphous tricalcium phosphate and apatite. The coincidence in time of the emergence of phosphatic stromatolites in the fossil record with a major episode of atmospheric oxidation led to the assumption that at times of increased oxygen release the underlying increased biological production may have been linked to elevated phosphorus availability. The stromatolites at Cape Recife, however, form in an environment where ambient phosphorus concentrations do not exceed 0.28 μM, one to two orders of magnitude below the previously predicted minimum threshold of >5 μM for biogenic phosphate precipitation in paleo‐systems. Accordingly, we contest the previously proposed suitability of phosphatic stromatolites as a proxy for high ambient phosphate concentrations in supratidal to shallow ocean settings in earth history.
Climate change facilitates a parasite’s host exploitation via temperature‐mediated immunometabolic processes
Authors: Scharsack Jörn P. , Wieczorek Bartholomäus , Schmidt‐Drewello Alexander , Büscher Janine , Franke Frederik , Moore Andrew , Branca Antoine , Witten Anika , Stoll Monika , Bornberg‐Bauer Erich , Wicke Susann , Kurtz Joachim 
Published: October 2020

AbstractGlobal climate change can influence organismic interactions like those between hosts and parasites. Rising temperatures may exacerbate the exploitation of hosts by parasites, especially in ectothermic systems. The metabolic activity of ectotherms is strongly linked to temperature and generally increases when temperatures rise. We hypothesized that temperature change in combination with parasite infection interferes with the host's immunometabolism. We used a parasite, the avian cestode Schistocephalus solidus, which taps most of its resources from the metabolism of an ectothermic intermediate host, the three‐spined stickleback. We experimentally exposed sticklebacks to this parasite, and studied liver transcriptomes 50 days after infection at 13°C and 24°C, to assess their immunometabolic responses. Furthermore, we monitored fitness parameters of the parasite and examined immunity and body condition of the sticklebacks at 13°C, 18°C and 24°C after 36, 50 and 64 days of infection. At low temperatures (13°C), S. solidus growth was constrained, presumably also by the more active stickleback's immune system, thus delaying its infectivity for the final host to 64 days. Warmer temperature (18°C and 24°C) enhanced S. solidus growth, and it became infective to the final host already after 36 days. Overall, S. solidus produced many more viable offspring after development at elevated temperatures. In contrast, stickleback hosts had lower body conditions, and their immune system was less active at warm temperature. The stickleback's liver transcriptome revealed that mainly metabolic processes were differentially regulated between temperatures, whereas immune genes were not strongly affected. Temperature effects on gene expression were strongly enhanced in infected sticklebacks, and even in exposed‐but‐not‐infected hosts. These data suggest that the parasite exposure in concert with rising temperature, as to be expected with global climate change, shifted the host's immunometabolism, thus providing nutrients for the enormous growth of the parasite and, at the same time suppressing immune defence.
A role for differential Rubisco activase isoform expression in C4 bioenergy grasses at high temperature
Authors: Kim Sang Yeol , Slattery Rebecca A. , Ort Donald R. 
Published: October 2020

AbstractRubisco activase (Rca) facilitates the release of sugar‐phosphate inhibitors at Rubisco catalytic sites during CO2 fixation. Most plant species express two Rca isoforms, the larger Rca‐α and the shorter Rca‐β, either by alternative splicing from a single gene or expression from separate genes. The mechanism of Rubisco activation by Rca isoforms has been intensively studied in C3 plants. However, the functional role of Rca in C4 plants where Rubisco and Rca are located in a much higher [CO2] compartment is less clear. In this study, we selected four C4 bioenergy grasses and the model C4 grass setaria (Setaria viridis) to investigate the role of Rca in C4 photosynthesis. All five C4 grass species contained two Rca genes, one encoding Rca‐α and the other Rca‐β, which were positioned closely together in the genomes. A variety of abiotic stress‐related motifs were identified in the Rca‐α promoter of each grass, and while the Rca‐β gene was constantly highly expressed at ambient temperature, Rca‐α isoforms were expressed only at high temperature but never surpassed 30% of Rca‐β content. The pattern of Rca‐α induction on transition to high temperature and reduction on return to ambient temperature was the same in all five C4 grasses. In sorghum (Sorghum bicolor), sugarcane (Saccharum officinarum), and setaria, the induction rate of Rca‐α was similar to the recovery rate of photosynthesis and Rubisco activation at high temperature. This association between Rca‐α isoform expression and maintenance of Rubisco activation at high temperature suggests that Rca‐α has a functional thermo‐protective role in carbon fixation in C4 grasses by sustaining Rubisco activation at high temperature.
A Synthetic Haematite Reference Material for LA‐ICP‐MS U‐Pb Geochronology and Application to Iron Oxide‐Cu‐Au Systems
Authors: Courtney‐Davies Liam , Gilbert Sarah E. , Ciobanu Cristiana L. , Tapster Simon R. , Richardson Marcus W. , Cook Nigel J. , Wade Benjamin P. , Verdugo‐Ihl Max R. , Ehrig Kathy , Condon Daniel J. 
Published: October 2020

In both nature and synthetic experiments, the common iron oxide haematite (α‐Fe2O3) can incorporate significant amounts of U into its crystal structure and retain radiogenic Pb over geological time. Haematite is a ubiquitous component of many ore deposit types and, therefore, represents a valuable hydrothermal mineral geochronometer, allowing direct constraints to be placed on the timing of ore formation and upgrading. However, to date, no suitable natural haematite reference material has been identified. Here, a synthetic haematite U‐Pb reference material (MR‐HFO) is characterised using LA‐ICP‐MS and ID‐TIMS. Centimetre‐scale ‘chips’ of synthesised α‐Fe2O3 were randomly microsampled via laser ablation‐extraction and analysed using ID‐TIMS. Reproducible U/Pb and Pb/Pb measurements were obtained across four separate chips (n = 13). Subsequently, an evaluation of the suitability MR‐HFO in constraining U‐Pb data via LA‐ICP‐MS is presented using a selection of natural samples ranging from Cenozoic to Proterozoic in age. The MR‐HFO normalised U‐Pb ratios are more concordant and ages more accurate versus the same LA‐ICP‐MS spot analyses normalised to zircon reference material, when compared with independently acquired ID‐TIMS data from the same natural haematite grains. Results establish MR‐HFO as a suitable reference material for LA‐ICP‐MS haematite U‐Pb geochronology.
Universities as orchestrators of the development of regional innovation ecosystems in emerging economies
Authors: Thomas Elisa , Faccin Kadigia , Asheim Bjørn Terje 
Published: October 2020

AbstractThis paper analyses the role of universities as orchestrators of the development of a regional ecosystem that is conducive to innovation and entrepreneurship. We argue that universities in emerging economies, due to many social challenges, must go beyond their missions of teaching, research, and collaboration with industry for innovation. We present a unique case study of an alliance of three universities in Porto Alegre, Brazil that, in addition to being competitors in the above‐mentioned missions, are orchestrating a network of stakeholders in this region to develop an ecosystem for innovation and entrepreneurship. We demonstrate that universities perform several orchestration processes that are consistent with the literature, such as fostering knowledge mobility, managing innovation appropriability, and increasing network stability. Furthermore, we found differences in how innovation ecosystems are orchestrated as compared to firm networks. In the case of innovation ecosystems, appropriability reaches the broader region, and the benefits are not limited to participant stakeholders. Such orchestration processes emerge when universities take on leadership positions in the region; they can influence the beginning of collective actions and projects as well as transfer responsibility, delegating power to other actors in the network.
Bone marrow haemophagocytosis indicates severe infection with severe acute respiratory syndrome coronavirus 2
Authors: Swoboda Julia , Wittschieber Daniel , Sanft Juliane , Kleemann Sandra , Elschner Stefan , Ihle Hannah , Hubig Michael , Pletz Mathias W , Mall Gita , Gassler Nikolaus 
Published: October 2020

AimsHaemophagocytosis in the bone marrow of patients who have succumbed to coronavirus disease 19 (COVID‐19) has not been widely studied. The aims of the present study were to perform morphological analyses and morphometry of haemophagocytosis in the bone marrow of patients with severe COVID‐19, and to correlate the findings with the clinical course of the disease.Methods and resultsIn this single‐centre study performed at the University Hospital Jena, bone marrow specimens of 15 deceased patients who had experienced a severe course of COVID‐19 were sampled from the vertebral column during autopsy. Slides of the bone marrow were stained with routine stains or immunohistochemically, and further examined for haemophagocytosis by the use of light microscopy. To substantiate the morphological findings, additional slides were stained for CD163 and morphometry was performed. In all bone marrow samples, an increase in cellularity was found. Haemophagocytes with erythrophagocytosis were detected in 67% of the deceased patients. In tissues with low numbers of haemophagocytes or ill‐defined haemophagocytes, an increase in iron deposits was frequently seen. Morphological findings were then correlated with several important clinical data, and the HScore (probability of having a reactive hemophagocytic syndrome) was calculated to posthumously confirm the diagnosis of secondary haemophagocytic lymphohistiocytosis. The median duration of disease and the hospitalisation time were lower in patients with haemophagocytosis (n = 10) than in patients without haemophagocytosis (n = 5). In addition, patients with haemophagocytes showed increased inflammatory parameters 2–5 days prior to death, in contrast to patients without haemophagocytes.ConclusionsHaemophagocytosis is a common finding in the bone marrow of deceased individuals with severe COVID‐19, and may indicate fatal severe acute respiratory syndrome coronavirus 2 infections.