bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting patterns of terrestrial lichen biomass recovery following boreal wildfires
Authors: Greuel Ruth J. , Degré‐Timmons Geneviève É. , Baltzer Jennifer L. , Johnstone Jill F. , McIntire Eliot J. B. , Day Nicola J. , Hart Sarah J. , McLoughlin Philip D. , Schmiegelow Fiona K. A. , Turetsky Merritt R. , Truchon‐Savard Alexandre , van Telgen Mario D. , Cumming Steven G. 
Published: April 2021

AbstractIncreased fire activity due to climate change may impact the successional dynamics of boreal forests, with important consequences for caribou habitat. Early successional forests have been shown to support lower quantities of caribou forage lichens, but geographic variation in, and controls on, the rates of lichen recovery has been largely unexplored. In this study, we sampled across a broad region in northwestern Canada to compare lichen biomass accumulation in ecoprovinces, including the Saskatchewan Boreal Shield, the Northwest Territories Taiga Shield, and Northwest Territories Taiga Plains, divided into North and South. We focused on the most valuableCladoniaspecies for boreal and barren‐ground caribou:Cladonia mitisandC. arbuscula,C. rangiferinaandC. stygia, andC. stellarisandC. uncialis. We developed new allometric equations to estimate lichen biomass from field measurements of lichen cover and height; allometries were consistent among ecoprovinces, suggesting generalizability. We then used estimates of lichen biomass to quantify patterns of lichen recovery in different stand types, ecoprovinces, and with time following stand‐replacing fire. We used a hurdle model to account both for the heterogeneous nature of lichen presence (zero inflation) and for the range of abundance in stands where lichen was present. The first component of the hurdle model, a generalized linear model, identified stand age, stand type, and ecoprovince as significant predictors of lichen presence. With a logistic growth model, a measure of lichen recovery (time to 50% asymptotic value) varied from 28 to 73 yr, dependent on stand type and ecoprovince. The combined predictions of the hurdle model suggest the most rapid recovery of lichen biomass across our study region occurred in jack pine in the Boreal Shield (30 yr), while stands located in the Taiga Plains (North and South) required a longer recovery period (approximately 75 yr). These results provide a basis for estimating future caribou habitat that encompasses some of the large variation in fire effects on lichen abundance and vegetation types across the range of boreal and barren‐ground caribou in North America.
Vegetation structure modulates ecosystem and community responses to spatial subsidies
Authors: McCary Matthew A. , Jackson Randall D. , Gratton Claudio 
Published: April 2021

AbstractEcosystem responses to external inputs of nutrients and organisms are highly variable. Theory predicts that ecosystem traits will determine the responses to spatial subsidies, but evidence for how vegetation structure can modulate those effects is lacking. We investigated how vegetation structure (i.e., leaf area index [LAI] and vegetation height) influenced the ecosystem and community responses to insect spatial subsidies in a subarctic grassland. Our experiment consisted of a 2 × 2 manipulation where in one treatment we either blocked flying insects over a 2‐yr period in 1‐m2plots near the shore of Lake Mývatn, Iceland, where deposition of aquatic adult midges (Diptera: Chironomidae) to land is high, or left control plots accessible to flying midges. In the second treatment, grassland vegetation was cut (tall vs. short) at the start of each season and then allowed to regrow. We then measured litter decomposition and arthropod composition and density within each plot (n = 6 replicates × 4 treatments). Midge‐exclusion cages reduced midge deposition by 81% relative to the open plots. Vegetation cutting initially reduced LAI and vegetation height by 3× and 1.5×, respectively, but these were not different by the end of the second‐growing season. We found that vegetation structure modulated the effects of midge subsides on litter decomposition, with taller canopies intercepting more insect subsidies than shorter ones, leading to 18% faster litter decomposition. In contrast, the short‐vegetation plots intercepted fewer subsidies and had higher temperatures and sunlight, resulting in no effects of midges on decomposition. However, by the end of the experiment when all vegetation structure characteristics had converged across all plots, we found no differences in decomposition between treatments. The effects of midge subsidies on arthropod composition depended on the vegetation structure, suggesting that arthropods might also be responding to the structural effects on spatial subsidies. Our findings indicate that vegetation structure can modify the abiotic environment and the quantity of subsidies entering a recipient ecosystem as aerial insects, resulting in ecosystem‐ and community‐level responses. Thus, changing vegetation structure via habitat disturbances will likely have important implications for ecosystem functions that rely on spatial subsidies.
Does the type of silvicultural practice influence spruce budworm defoliation of seedlings?
Authors: Lavoie Janie , Montoro Girona Miguel , Grosbois Guillaume , Morin Hubert 
Published: April 2021

AbstractSpruce budworm (Choristoneura fumiferana(Clem)) is the main defoliator in the boreal forest of North America, and its outbreaks have major ecological and economic consequences and represent a challenge for forest management. Numerous studies have addressed the effects of this defoliator on mature trees, whereas the effects of spruce budworm on regeneration remain elusive. Furthermore, intensive exploitation practices during the last decades have left a large area of the Canadian boreal forest in an early development stage. In this context, it becomes vital to understand those factors affecting the severity of spruce budworm‐related defoliation on regeneration. Here, we determine the defoliation severity of black spruce and balsam fir seedlings in both mature pure black spruce and black spruce–balsam fir stands subjected to two different silvicultural treatments (clear‐cutting and partial cutting). Defoliation intensity varied between stand types, silvicultural treatments, species, and height classes. Seedlings in black spruce–balsam fir stands experienced twice the defoliation of those in pure black spruce stands (black spruce seedlings 10% vs. 23%; balsam fir seedlings 29% vs. 47%, respectively). Harvesting methods also influenced seedling defoliation. Under clear‐cutting, black spruce seedlings (24%) were three times as defoliated as black spruce seedlings in partial cutting stands (8%), whereas balsam fir seedlings in clear‐cutting plots experienced twice the defoliation (42%) of balsam fir seedlings in partial cutting plots (20%). The level of defoliation also increased with seedling height. This study will help silvicultural strategies adapt to the effects of natural disturbance regimes. As the intensity and severity of defoliator outbreaks are expected to increase under climate change, these results will help guide forest management strategies to select harvesting methods that will limit the effects of defoliation on conifer regeneration.
Gold(I) Complexes with a Quinazoline Carboxamide Alkynyl Ligand: Synthesis, Cytotoxicity, and Mechanistic Studies
Authors: Tabrizi Leila , Yang Won Seok , Chintha Chetan , Morrison Liam , Samali Afshin , Ramos Joe W. , Erxleben Andrea 
Published: April 2021

AbstractA series of gold(I) complexes with the general formula [Au(L2)(L′)] (L2=4‐phenyl‐N‐(prop‐2‐yn‐1‐yl)quinazoline‐2‐carboxamide,L′=PPh3(triphenylphosphine),1; TPA (1,3,5‐triaza‐7‐phosphaadamantane),2, and Me2‐imy (1,3‐dimethylimidazol‐2‐ylidene),3) were synthesized and fully characterized by spectroscopic methods. The alkynyl ligandL2belongs to the quinazoline carboxamide class of ligands that are known to bind to the translocator protein (TSPO) at the outer mitochondrial membrane.1and2exert cytotoxic effects in bladder cancer cells with IC50values in the low micromolar range. Further mechanistic analysis indicated that the two complexes both act by inducing reactive oxygen species and caspase‐mediated apoptosis. The complexes inhibit thioredoxin reductase, an established target of anticancer gold(I) complexes. Docking studies confirmed that after ligand exchange the free ligandL2can interact with the TSPO binding site.
The Ugly Duckling Metamorphosis: The Ammonia/Formaldehyde Couple Made Possible in Ugi Reactions.
Authors: Rosalba Thaissa Pasquali F. , Kas Samia Sayegh A. , Sampaio Ana Beatriz S. , Salvador Carlos Eduardo M. , Andrade Carlos Kleber Z. 
Published: April 2021

AbstractUgi reactions are still a challenge when the concomitant use of ammonia and formaldehyde is required. Herein, we propose a strategy to overcome this challenge using hexamethylenetetramine (HMTA) as a singular key for the employment of these two simple starting materials in the Ugi reaction. Acylaminoacetamide derivatives were prepared in good to excellent yields by this new methodology. The scope and optimization of the reaction conditions were investigated. This novel methodology was successfully applied in the synthesis of two different diketopiperazines (DKPs) using the Ugi/Deprotection+Activation/Cyclization (UDAC) method. A continuous flow approach was also used in this methodology.
Transition Metal‐Free sp3−sp3 Carbon‐Carbon Coupling between Benzylboronic Esters and Alkyl Bromides
Authors: Russell Richard W. , Barker Timothy J. 
Published: April 2021

AbstractA transition metal‐free coupling reaction of benzylboronic esters and alkyl halides has been developed. Both alkyl bromides and alkyl iodides were found to be competent substrates with the nucleophilic boronate intermediate generated from the combination of benzylboronic ester and an alkyllithium. Good chemoselectivity was observed for the reaction with the alkyl bromide in substrates with a second electrophile present. Both secondary and tertiary benzylboronic esters were effective nucleophiles in the reaction with primary alkyl halides. Mechanistic observations are consistent with a radical mechanism.
Unmet health care need and income‐Related horizontal equity in use of health care during the COVID‐19 pandemic
Authors: Davillas Apostolos , Jones Andrew M. 
Published: April 2021

AbstractUsing monthly data from the Understanding Society (UKHLS) COVID‐19 Survey we analyse the evolution of unmet need and assess how the UK health care system performed against the principle of horizontal equity in health care use during the first wave of COVID‐19 wave. Unmet need was most evident for hospital care, and less pronounced for primary health services (non‐emergency medical helplines, GP consultations, community pharmacist advice, over the counter medications and prescriptions). Despite this, there is no evidence that horizontal equity, with respect to income, was violated for NHS hospital outpatient and inpatient care during the first wave of the pandemic. There is evidence of pro‐rich inequities in use of GP consultations, prescriptions and medical helplines at the peak of the first wave, but these were eliminated as the pandemic progressed. There are persistent pro‐rich inequities for services that may relate to individuals' ability to pay (over the counter medications and advice from community pharmacists).
The safety concern of plant‐based supplements: A public health topic
Authors: Allkanjari Olta 
Published: April 2021

AbstractNowadays, the use of food supplements has increased globally. Among them, there are also plant‐based supplements that contain phytochemical extracts with a pharmacological effect and consequently potential adverse reactions. We cannot estimate their safety profile as there are not required evidence‐based proofs before marketing. Though European Food Safety Authority is responsible for the risks derived from food supplements, there is not any centralized surveillance system of the commercialized supplements in Europe. Moreover, these products do not rely on a harmonised marketing legislation. The population is exposed unconsciously purchasing them in internet or other places that lack of a professional healthcare. Fragile subgroups like pregnant women, patients with concomitant therapies, are not aware of the risks of plant‐based supplements because the education strategies are not promoted enough. In the context of public health, the challenge is to implement measures in order to protect consumers against health risks. Future efforts are required to ensure standardised supplements. European regulatory programs should be harmonised. More clinical trials and toxicological studies should be conducted on commercial preparations. Accurate information sources could assure consumers about the correct use of botanicals.
Metformin in gestational diabetes mellitus: A double‐blind placebo‐controlled randomized trial
Authors: Tew Min P. , Tan Peng C. , Saaid Rahmah , Hong Jesrine G. S. , Omar Siti Z. 
Published: April 2021

AbstractObjectiveTo evaluate the impact of preemptive metformin on the level of glycosylated hemoglobin (HbA1c) at 36 weeks of pregnancy in women with gestational diabetes mellitus controlled by diet change (GDMA1).MethodsA randomized, double‐blind, placebo‐controlled trial was performed in a university hospital. Women with GDMA1 were recruited at 16–30 weeks of pregnancy and randomized to oral metformin 500 mg twice daily or identical placebo tablets to delivery. Level of HbA1c was taken at recruitment and at 36 weeks of pregnancy. The primary outcome was the change in level of HbA1c at recruitment and 36 weeks of pregnancy.ResultsData from 106 participants were analyzed. The level of HbA1c during pregnancy increased significantly with a mean increase of 0.20% ± 0.31% (P < 0.001; metformin) versus 0.27% ± 0.31% (P < 0.001; placebo). An increment of 0.07% across trial arms was not significant (P = 0.310). Mean birth weight was significantly lower in the metformin group (2.81 ± 0.41 kg vs 2.98 ± 0.37 kg; P = 0.030). Rates of macrosomia (≥3.5 kg; 0/53 [0%] vs 4/53 [8%]; P = 0.123) and low birth weight (<2.5 kg; 11/53 [21%] vs 5/53 [9%]; P = 0.102) were not significantly different.ConclusionPreemptive metformin did not prevent the level of HbA1c at 36 weeks of pregnancy from rising nor significantly reduce the increase of HbA1c. Mean birth weight was significantly lower in the metformin arm with a non‐significant trend to low birth weight, which is concerning.ISRCTN: ISRCTN10845466.
miR‐543 in human mesenchymal stem cell–derived exosomes promotes cardiac microvascular endothelial cell angiogenesis after myocardial infarction through COL4A1
Authors: Yang Mei , Liu Xueting , Jiang Manli , Li Jian , Tang Yaping , Zhou Lin 
Published: April 2021

AbstractTo explore the impact and mechanism of human mesenchymal stem cells (hMSCs) on the angiogenesis of cardiac microvascular endothelial cells (CMECs) after ischemia insult. Exosomes derived from hMSCs (hMSCs‐Exo) were identified by Western blotting and labeled by PHK‐67. CMECs were isolated from rat myocardial tissues. After hypoxic treatment, CMECs were cultured with hMSCs and exosome inhibitor (GW4869) or transfected with si‐COL4A1 + miR‐543 inhibitor. CMEC proliferation, migration, invasion, and angiogenesis were examined. Target genes of miR‐543 were predicted and then were identified by dual luciferase assay. Myocardial infarction (MI) rat model established by suture occlusion was intravenously injected with hMSCs‐Exo. Fluorescence microscope was applied to visualize exosomes in myocardial tissues. Infarction volume and pathologies of myocardial tissues were observed. Ki‐67 and miR‐543 expressions were detected. The isolated hMSC‐Exo expressed TSG101, HSP70, and CD63. Hypoxia‐treated CMECs cultured with hMSCs exhibited high proliferation, migration, invasion, and angiogenesis ability, while incubation with exosome inhibitor GW4969 offset the promoting effects of hMSCs on the proliferation, migration, invasion, and angiogenesis of CMECs. hMSCs transfected with miR‐543 inhibitor brought CMECs weak viability and angiogenesis ability. CMECs transfected with si‐COL4A1 and miR‐543 inhibitor showed low proliferation, migration, invasion, and angiogenesis compared to those transfected with si‐COL4A1 alone. hMSCs‐Exo entered the myocardial tissues of MI rats. Injection of hMSCs‐Exo in MI rats diminished infarction size, attenuated MI‐induced injuries, and increased Ki‐67 expression. hMSCs‐Exo facilitates the proliferation, migration, invasion, and angiogenesis of CMECs through transferring miR‐543 and downregulating COL4A1 expression.
Characteristics and Early Recurrence of Hepatocellular Carcinomas Categorized as LR‐M: Comparison with Those Categorized as LR‐4 or 5
Authors: Shin Jaeseung , Lee Sunyoung , Kim Seung‐seob , Chung Yong Eun , Choi Jin‐Young , Park Mi‐Suk , Kim Myeong‐Jin 
Published: April 2021

BackgroundAccording to the Liver Imaging Reporting and Data System (LI‐RADS), the LI‐RADS category M (LR‐M), which are probably or definitely malignant but are not specific for hepatocellular carcinomas (HCCs), does not exclude HCCs. A gap in knowledge remains, including their characteristics and recurrence of HCCs categorized as LR‐M.PurposeTo compare the characteristics of HCCs categorized as LR‐M with HCCs categorized as LR‐4 or LR‐5 (LR‐4/5) using the LI‐RADS version 2018 and evaluate the relationship of these categories with the risk of early recurrence after curative resections of single HCCs.Study TypeRetrospective.SubjectsTwo hundred and eighty‐one patients (mean age, 57 years; 191 men and 90 women) who underwent curative resections for single HCCs and preoperative contrast‐enhanced MRI between 2015 and 2017.Field Strength/Sequence3T Dual gradient‐echo T1WI with in‐ and opposed‐phase, turbo spin‐echo T2WI, diffusion‐weighted echo‐planar images, and three‐dimensional gradient‐echo T1WI before and after administration of contrast agent.AssessmentMRI features according to the LI‐RADS version 2018 were evaluated and LI‐RADS category were assigned for each observation. Clinical, imaging, and histopathological features were compared based on LI‐RADS categorization. Early recurrence rates (<2 years) and associated factors were also evaluated.Statistical TestsFisher's exact test, two‐sample t test after satisfying assumption of normality through Shapiro–Wilk test, Fleiss κ coefficient, Cox proportional hazards regression analysis, Kaplan–Meier method, and log‐rank test.ResultsForty‐one HCCs (14.6%) were categorized as LR‐M and 240 HCCs (85.4%) were categorized as LR‐4/5. LR‐M HCCs showed poorer differentiation than LR‐4/5 HCCs. In the multivariate analysis, the LR‐M category was an independent predictor for early recurrence (hazard ratio, 1.904; 95% confidence interval, 1.024–3.542; P < 0.05). Early recurrence rates were significantly higher in patients with LR‐M HCCs than in patients with LR‐4/5 HCCs (32.0% vs. 18.4%, respectively, P < 0 05).Data ConclusionCompared to LR‐4/5 HCCs, LR‐M HCCs were associated with poorer tumor differentiation and higher early recurrence rates after curative resections of single HCCs.Level of Evidence: 3Technical Efficacy Stage: 2
Purification of Bacillus licheniformis Lipase and its Application as an Additive in Detergent for Destaining
Authors: Bredai Rania , Belhaj Ben Romdhane Ines , Bouchaala Imen , Srih Belghith Karima , Belghith Hafedh 
Published: April 2021

AbstractIn this study, we aimed to optimize the nutritional and environmental conditions for the production of a novel lipase (LBL) from Bacillus licheniformis (GenBank accession no. MT118724). This strain was characterized by morphological and biochemical assays and Sanger sequencing of 16S rDNA. The crude lipolytic activity reached a maximum level 7.5 U mL−1 at 40 °C and pH 8.0 using olive oil as substrate. Additionally, the crude enzyme maintained 100% of its initial activity after incubation for 1 h at 50 °C and pH 9.0. It is mandatory to note that LBL lipase displayed appreciable stability over a wide pH range and extreme temperatures. After purification, the optimal lipolytic activity was observed at pH 8.0 and 40 °C. LBL was shown to be a monomeric protein with an estimated molecular weight of 40 kDa. This novel lipase exhibited high stability and excellent compatibility compared to lipase extracted from Thermomyces lanuginosa (Lipolase® from Novozymes, Denmark) toward various detergents. Washing performance analysis revealed that it efficiently removes tomato sauce stain from cotton cloth. All these interesting enzymatic properties favor this new lipase as a potent candidate for applications in detergent formulations.
Sustainable tourist behaviour: Developing a second order scale based on three destinations
Authors: Chandran Arun , Mandal Santanu , Shanmugeshwari Muthiah , Nair Gayathri , Das Payel , Ramachandran Naveen , John Elza 
Published: April 2021

AbstractThe current study develops a second order measurement instrument for sustainable tourist behaviour through confirmatory factor analysis from tourists' responses based on three prominent destinations in India namely, Goa, Munnar and Manali. Factorial validity, invariance analysis and nomological validity were also assessed. Results showed that STB is a second order reflective factor consisting of destination specific pro‐environmental, socially responsible, environmental learning, cultural and economically favourable behaviours. Furthermore, while environmental engagement is a significant enabler for STB, the latter contributes significantly in the development of memorable experiences and tourist satisfaction.
Hypoxia dynamics and spatial distribution in a low gradient river
Authors: Carter Alice M. , Blaszczak Joanna R. , Heffernan James B. , Bernhardt Emily S. 
Published: April 2021

AbstractDeoxygenation of aquatic ecosystems is a key feature of the Anthropocene. Studies are increasingly reporting low oxygen conditions in rivers and headwater streams even in the absence of high nutrient loads. We examined the frequency of river hypoxia (dissolved oxygen [DO] < 50% saturated in O2) in the North Carolina Piedmont by examining monitoring records collected since the 1960s, and by collecting high‐resolution measurements of DO saturation along a 20 km segment of New Hope Creek. State records reported nearly 11,000 incidences of hypoxia from a total of ~ 140,000 measurements (7.8% over 55 yr). In contrast, our measurements in New Hope Creek suggest that assessing river hypoxia from point measurements is highly problematic. We propose new approaches for evaluating and comparing river oxygen regimes. In a detailed longitudinal survey of DO in May 2018, 31% of measurements over 20 km were hypoxic. Over a 3‐week period, 11 of our 12 sites throughout this segment experienced hypoxia 5%–96% of the time. Interannual comparisons for several long‐term monitoring sites document significant potential for hypoxia even in well‐aerated reaches during particularly warm, low flow periods. Oxygen regimes within this river vary between near continuous hypoxia to near continuous saturation and call into question the binary distinction between lotic and lentic oxygen dynamics with which we tend to categorize and model freshwater ecosystems.