bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trophic interactions and feedbacks maintain intact and degraded states of Hawaiian tropical forests
Authors: Yelenik Stephanie , Rose Eli , Paxton Eben H. 
Published: May 2022

AbstractFeedbacks within ecosystems can lead to internal reinforcement of the current state providing ecosystem resilience. Often, multiple biotic interactions across trophic levels play a role in such feedbacks, yet these are generally studied independently, obscuring the relative importance of interactions among different factors. We look at various potential feedbacks in intact and degraded mesic forests on Hawaiʻi Island where managers have planted nativeAcacia koa(koa) trees in an attempt to jumpstart succession in former cattle pastures. These restoration forests, however, have not undergone secondary succession, instead maintaining a koa overstory with an exotic pasture grass understory. We contrasted different trophic level processes that influence the capacity for natural understory regeneration: feedbacks between bird‐mediated seed rain and fruiting understory (“top‐down”), as well as links between understory composition and microhabitats for native seed germination (“bottom‐up”). We quantified bird‐mediated seed rain under canopy trees along transects spanning intact, fragmented, and restoration forests. Along these transects, we established plots around focal overstory trees to measure abundance of fruiting understory species, ground cover (e.g., exotic grass, bryophyte), and obtained estimates of bird density to evaluate the contribution of each of these factors to seedling abundance. We also used a factorial seed addition/grass removal experiment to directly compare the influence of seed rain and germination substrate. We found evidence of both top‐down and bottom‐up feedbacks that reinforced the current state of each forest type. In the intact and fragmented forests, the combination of comparatively high seed rain and ample germination substrate is likely critical for maintaining a diverse forest system. In contrast, exotic grasses exhibit priority effects in restoration forests, inhibiting seed germination and effectively negating any benefits that could be derived from bird‐mediated seed rain. Such internal reinforcement suggests that active, rather than passive, restoration would be beneficial to increase forest diversity in restoration areas.
Fish and invertebrate use of restored vs. natural oyster reefs in a shallow temperate latitude estuary
Authors: Grabowski Jonathan H. , Baillie Christopher J. , Baukus Adam , Carlyle Rachael , Fodrie F. Joel , Gittman Rachel K. , Hughes A. Randall , Kimbro David L. , Lee Juhyung , Lenihan Hunter S. , Powers Sean P. , Sullivan Kevin 
Published: May 2022

AbstractCoastal marine habitats continue to be degraded, thereby compelling large‐scale restoration in many parts of the world. Whether restored habitats function similarly to natural habitats and fully recover lost ecosystem services is unclear. In estuaries, oyster reefs have been degraded by multiple anthropogenic activities including destructive fishing practices and reduced water quality, motivating restoration to maintain oyster fisheries and other ecosystem services, often at relatively high cost. We compared fish and invertebrate communities on recently restored (0–1 year post‐restoration), older restored (3–4 years post‐restoration), and natural oyster reefs to determine if and when restored reefs support functionally similar faunal communities. To test the influence of landscape setting on the faunal communities, the restored and natural reefs, as well as a control without reef present, were distributed among three landscapes (on the edge of salt marsh away from seagrass [salt marsh landscape], on mudflats [mudflat landscape], and near to seagrass and salt marsh [seagrass landscape]). Oyster density and biomass were greatest on restored reef habitat, as were those of non‐oyster bivalve species. Total abundance of invertebrates was much greater on oyster reefs than in control plots, regardless of reef or landscape type, yet were frequently highest on older restored reefs. Meanwhile, juvenile fish densities were greatest on natural reefs, at intermediate densities on older restored reefs, and least abundant on controls. When comparing the effects of reef age and landscape setting, juvenile fish densities were greatest on younger reefs within the mudflat landscape. Collectively, these results indicate that oyster reefs harbor higher densities of resident invertebrate prey, which may explain why reef habitat is also important for juvenile fish. Laboratory and field experiments supported the notion that gag grouper (a predatory demersal fish) forage more effectively on oyster reefs than on unstructured mud bottom, whereas our experiments suggest that flounders that utilize oyster reefs likely forage on adjacent mud bottom. Because landscape setting influenced fish and invertebrate communities on restored reefs, the ecological consequences of landscape setting should be incorporated into restoration decision making and site selection to enhance the recovery of ecosystem goods and services.
The researcher's lament: Why do they ignore my science?
Authors: Bisbal Gustavo A. 
Published: May 2022

AbstractThe researcher's lament is shared by many environmental and conservation scientists who complain about the little support they receive for their research proposals during the review and selection process. Understandably, any hopes of having their anticipated scientific findings applied toward the formulation of environmental management decisions or natural resource policy action are shattered. They attribute this lack of endorsement to shortcomings and limitations among decision makers and proposal selection officials when, in many cases, the rejection of project proposals is often a function of a handful of self‐inflicted failures by applied scientists who anchor themselves stubbornly to doomed approaches. Familiar deficiencies in their research proposals perpetuate the disconnect between the enterprise of science and real‐world resource management challenges. Researchers themselves can affect conditions that turn up the appetite for their scientific endeavors as a more meaningful component of the decision‐making process, namely, to stage and deliver science that is more readily “actionable.” Perhaps it is time for them to consider a course correction to improve the viability of their actionable science proposals. A few basic steps may help rejigger the science planning process in this direction and, consequently, help avoid the researcher's lament. The likelihood of gaining support during the proposal review and award adjudication process, and securing practical application of scientific products, increases when the products are (1) the result of active engagement of researchers with decision makers; (2) better connected to social and political priorities; (3) clearly designed to inform specific management decisions; and (4) tailored to fit the needs of targeted end users. These considerations and activities exist beyond the comfort zone of many environmental or conservation scientists. Yet, those who adopt them will spend less time lamenting rejection and become more influential in the production of actionable knowledge.
Prognostic significance of serum potassium in patients hospitalized for acute heart failure
Authors: Lombardi Carlo Mario , Carubelli Valentina , Peveri Giulia , Inciardi Riccardo Maria , Pagnesi Matteo , Ravera Alice , Tomasoni Daniela , Garafa Emirena , Oriecuia Chiara , Specchia Claudia , Metra Marco 
Published: May 2022

AbstractAimWe investigated the prognostic significance of serum potassium abnormalities at discharge in patients hospitalized for acute heart failure (AHF).Methods and resultsIn a retrospective analysis, we included 926 patients hospitalized for AHF, stratified by serum potassium levels at discharge as hypokalaemia (<3.5 mEq/L), normokalaemia (3.5–5.0 mEq/L), and hyperkalaemia (>5.0 mEq/L). The primary endpoint was all‐cause death at 1 year since hospital discharge. At discharge, 40 patients had hypokalaemia (4.3%), 840 normokalaemia (90.7%), and 46 hyperkalaemia (5.0%). Patients with hyperkalaemia at discharge were more frequently men, had more signs of congestion, and lower LVEF while patients with hypokalaemia were more likely to be women with HFpEF. Treatment with ACEi/ARBs and MRAs ≥50% of target dose at discharge was similar across groups. One year all‐cause death occurred in 10% of the patients with hypokalaemia, 13.9% of those with normokalaemia, and 30.4% of those with hyperkalaemia (P = 0.006). After adjustment for covariates, including renal function, background treatment, and baseline potassium level, hyperkalaemia resulted an independent predictor of the primary endpoint (HR 1.96, 95% IC [1.01–3.82]; P = 0.048).ConclusionsIn patients with AHF, the presence of hyperkalaemia at discharge is an independent predictor of 1 year all‐cause death.
Prognostic relevance of B‐type natriuretic peptide in patients with moderate mixed aortic valve disease
Authors: Onishi Hirokazu , Naganuma Toru , Izumo Masaki , Ouchi Toru , Yuki Haruhito , Mitomo Satoru , Nakamura Sunao 
Published: May 2022

AbstractAimsData on B‐type natriuretic peptide (BNP) levels and adverse outcomes in patients with moderate mixed aortic valve disease (MAVD), defined as moderate aortic stenosis (AS) and regurgitation (AR), are scarce. Therefore, this study investigated the impact of BNP on the clinical outcomes in such patients.Methods and resultsClinical data from 81 patients (mean age, 74.1 ± 6.8 years; 50.6%, men) treated for moderate MAVD and left ventricular ejection fraction (LVEF) ≥ 50% during 2010–2018 were retrospectively analysed. Specific echocardiographic data of the study patients were LVEF of 57.8 ± 5.0%, aortic valve index of 0.64 ± 0.04 cm2/m2, peak aortic valve velocity of 3.38 ± 0.29 m/s, and AR vena contracta width of 4.2 ± 0.7 mm. The median BNP level was 61.4 pg/mL (interquartile range, 29.7–109.9). The primary endpoint was a composite of all‐cause death, heart failure hospitalization, and aortic valve replacement, and its cumulative incidence at 5 years was 57.7%. Multivariable analysis revealed that age (hazard ratio, 1.079; 95% confidence interval, 1.028–1.133; P = 0.002) and BNP levels (hazard ratio, 1.028; 95% confidence interval, 1.003–1.053; P = 0.027) were significantly related to the endpoint; specifically, BNP > 61.4 pg/mL had significantly higher incidence rates of the endpoint than those with a BNP ≤ 61.4 pg/mL (70.3% vs. 45.5% at 5 years; P = 0.018). Compared with patients with BNP ≤ 61.4 pg/mL, those with BNP > 61.4 pg/mL had significantly worse left ventricular global longitudinal strain (−17.1 ± 3.6% vs. −18.7 ± 2.6%; P = 0.029), along with higher left ventricular mass index (116.9 ± 27.8 g/m2 vs. 103.5 ± 19.7 g/m2; P = 0.014), relative wall thickness (0.45 ± 0.07 vs. 0.42 ± 0.05; P = 0.022), left atrial volume index (46.0 ± 28.4 mL/m2 vs. 31.4 ± 10.3 mL/m2; P = 0.003), pulmonary artery systolic pressure (32.6 ± 9.7 mmHg vs. 28.2 ± 4.7 mmHg; P = 0.011), and prevalence of moderate or greater tricuspid regurgitation (15.0% vs. 0.0%; P = 0.012).ConclusionsPatients with moderate MAVD are at higher risk of unfavourable clinical outcomes, and age and BNP are independently related to the occurrence of adverse events. High BNP levels may reflect extravalvular cardiac damage in patients with moderate MAVD.
Stabilization of Ethynyl‐Substituted Aryl‐λ3‐Iodanes by Tethered N‐Heterocylces**
Authors: Kuczmera Thomas J. , Boelke Andreas , Nachtsheim Boris J. 
Published: May 2022

AbstractA systematic investigation of ethynyl N‐heterocycle‐substituted‐λ3‐iodanes (ENHIs) is presented. In a straightforward one‐pot synthesis these novel reagents can be obtained in high yields bearing a variety of N‐heterocycles. Their reactivity as electrophilic alkyne group transfer reagents was benchmarked in well‐established and novel inter‐ and intramolecular group transfer reactions.
Flow Conditions‐Controlled Divergent Oxidative Cyclization of Reticuline‐Type Alkaloids to Aporphine and Morphinandienone Natural Products
Authors: Bali Judicaël Tra Bi , Abollé Abollé , Coeffard Vincent , Felpin François‐Xavier 
Published: May 2022

AbstractDescribed herein is a divergent continuous‐flow approach for the biomimetic oxidative cyclization of reticuline‐type alkaloids to aporphine and morphinandienone natural products using hypervalent iodine(III) reagents. The method was based on the detailed knowledge of the reaction mechanisms in order to develop robust reaction conditions toward the selective synthesis of either aporphine or morphinandienone natural products. In this frame, we exploited the ability of HFIP to stabilize radical cation intermediates and to activate hypervalent iodine(III) oxidants for the flow synthesis of aporphine natural products such as glaucine, rogersine and nantenine. On the other hand, we established that PhI(OAc)(OTf), prepared by action of TMSOTf on PhI(OAc)2, was a powerful oxidant for the synthesis of morphinandienone natural products such as sebiferine and amurine.
Palladium‐Catalyzed Synthesis of Alkylcarbazoles and Their Identification in Petroleum and Source Rocks**
Authors: Theumer Gabriele , Bauer Ingmar , Jäger Anne , Schwark Lorenz , Knölker Hans‐Joachim 
Published: May 2022

AbstractWe describe the synthesis of seven C2‐alkylcarbazoles via a sequence of Buchwald–Hartwig coupling of arylamines with aryl halides followed by oxidative cyclization of the resulting diarylamines. Methyl groups at the positions 4 and 5 were introduced by taking advantage of the ortho‐directed palladation of meta‐pivaloyloxy‐substituted diarylamines and subsequent conversion of the pivaloyloxy to methyl groups through Stille coupling of intermediate triflates. The obtained ethyl‐ and dimethylcarbazoles served as analytical standards for their identification in petroleum samples and source rocks.
Independent development and validation of a novel six‐color fluorescence multiplex panel including 61 diallelic DIPs and 2 miniSTRs for forensic degradation sample
Authors: Liu Yanfang , Mei Shuyan , Jin Xiaoye , Zhao Ming , Zhu Bofeng 
Published: May 2022

AbstractCurrent forensic DNA profiles are obtained based on analyses of PCR product sizes or DNA sequence polymorphisms. Sometimes routine forensic analysis using short tandem repeat (STR) generates unsuccessful DNA testing result if the biological sample encountered is excessively degraded and low‐template DNA. Herein, a new six‐color fluorescence labeling system, including 59 autosomal diallelic deletion or insertion polymorphisms (DIPs), 2 miniSTRs, 2 Y‐chromosome DIPs, and 1 Amelogenin gene with the amplicon sizes of less than 200 bp, was self‐developed. According to the validation guidelines for DNA analysis methods formulated by the Scientific Working Group on DNA Analysis Methods, the validation studies have also been carried out for the multiplex system. This novel panel possessed the features of strong stability, high sensitivity, and good specificity, which was especially suitable for the forensic degraded and mixed sample detections. The cumulative power of exclusion and cumulative matching probability of the system were 0.9999978 and 9.833E‐28, respectively, in Han Chinese in Hunan, China. Moreover, this system will be an effective new tool that can be independently applied to forensic personal identification and paternity testing in the populations from the East Asia region, even from the South Asia, America, and Europe regions. The system can also contribute to population phylogenetic affinity and genetic structure analyses among different populations.
Normalization methods for spatio‐temporal analysis of environmental performance: Revisiting the Min–Max method
Authors: Mazziotta Matteo , Pareto Adriano 
Published: May 2022

AbstractOver the last few years, composite indices for ranking or assessing country performance in a wide variety of complex phenomena, such as environmental sustainability, have gained a lot of popularity. However, not all indices allow for detailed spatio‐temporal analyses. For instance, if individual indicators to be aggregated are normalized by the Min–Max method, they are converted to a common scale with a range of [0, 1] and it can be difficult to appreciate any absolute change in country performance at the extremes of the range (i.e., when a country scores 0 to 1). In this article, an alternative method for normalizing data in a three‐way array of the type units × variables × times, is considered. It normalizes the range of individual indicators, similarly to the Min–Max method, but uses a common reference that allows to “center” them, without forcing them into a closed range. An application to renewable energy consumption data is also shown.
Co‐production of bioethanol and commercially important exopolysaccharides from the marine cyanobacterium Synechococcus elongatusBDU 10144 in a novel low‐cost seawater‐fertilizer‐based medium
Authors: Chandra Neha , Mallick Nirupama 
Published: May 2022

SummaryThe production of bioethanol by cyanobacteria can become economically sustainable if other valuable commercial products, such as exopolysaccharides (EPS), are produced simultaneously. This study investigates the feasibility of producing bioethanol and the commercially important EPS from a non‐nitrogen fixing marine cyanobacterium, Synechococcus elongatus BDU 10144 in a novel low‐cost seawater‐fertilizer medium for the development of a biorefinery strategy. Herein, agricultural fertilizer diammonium phosphate (DAP) (nitrogen source), magnesium sulfate (MgSO4) and potassium were optimized by the central composite design to produce maximum biomass and carbohydrate accretion. The optimal physical conditions for attaining maximum growth and carbohydrate accumulation were determined to be pH 10, 50 μmol m−2 s−1 (light intensity) and 25°C. Further, different concentrations of seawater were mixed with the optimized fertilizer‐salts, and it was observed that 70% of seawater mixed with the optimized fertilizer‐salts (hereafter FSW medium) was an optimum condition for growing the test cyanobacterium, which ultimately reduced the cost of the medium by >40 times compared to the standard artificial seawater nutrient (ASN‐III) medium. Under the optimal conditions, the maximum biomass (1.79 g/L) and carbohydrate (702.4 mg/L) yield obtained were ~1.7 and 2.2 times higher than the ASN‐III. The yield of bioethanol was noted to be 318.1 mg/L, which was ~2.3 times greater than ASN‐III. The commercially important EPS was obtained from the discarded supernatant (0.28 g/L), which was ~1.6 times higher in the FSW medium. Thus, the present investigation paves a way forward for mass cultivation of the S. elongatus BDU 1044 in the novel FSW medium for the cost‐efficient and sustainable development of a biorefinery concept.
Optimization of flame stabilization methods in the premixed microcombustion of hydrogen–air mixture
Authors: Jha Vikalp , Velidi Gurunadh , Emani Sampath 
Published: May 2022

AbstractThe premixed combustion of a lean hydrogen–air mixture is analyzed in this study to examine various properties and flame stabilization. A two‐dimensional (2D) analysis of a microscale combustor is performed with various shapes of bluff bodies (e.g., circular and triangular). Nine bluff bodies are placed at the entrance of the microscale combustor and solved with 2D governing equations. The analysis is performed with the three velocities of 10, 20, and 30 m/s, but the equivalence ratio is fixed in all cases. The various characteristics of the microscale combustor are studied such as the temperature of the wall, difference in peak temperature, the mean velocity at the outlet, and temperature of the exhaust gases. Flame stabilization depends on various factors such as bluff body shape and size, and the velocity of the fuel–air mixture at the inlet and recirculation zone. In comparison to all bluff body cases, we observe that the wall blade bluff body is the most efficient (low exhaust gas temperature, large recirculation zone, low mean velocity at the outlet of the microcombustor, and high wall temperature) compared with all eight other bluff body cases. Combustion efficiency is directly proportional to the wall temperature, meaning that the microcombustor with wall blade bluff bodies is more efficient with a stabilized flame. The simulation results are compared with published data on an L/D ratio of 15.
Study on the agricultural crop drought index based on weights of growth stages
Authors: Pei Wei , Fu Qiang , Ren Yongtai , Li Tianxiao 
Published: May 2022

AbstractDrought is one of the main natural disasters affecting economic development and food security. Drought monitoring and identification are the premise of disaster risk management, and the drought index is the main means of monitoring and identifying drought. The paper proposes a new drought index, the agricultural crop drought index (ACDI), which is suitable for rainfed agriculture in arid areas. ACDI calculates water deficit from precipitation and evapotranspiration and considers the weight of crop growth stage. The weight of growth stage and water deficit constitute the weighted data series. The fitting distribution is optimized by Kolmogorov–Smirnov test, and the data are standardized to obtain ACDI. The weight of growth stage is determined by the multiple correlation coefficient between meteorological factors and grain yield. A large weight is equivalent to a large coefficient, large coefficient means that meteorological factors in this growth stage will have a greater impact on grain yield, so the water deficit in this growth stage should play a more important role in defining drought index to better identify agricultural drought from the perspective of crops. Finally, Qiqihar, a semiarid area in Northeast China, is selected as the research area for the case study. Comparing ACDI with standard precipitation index (SPI), standardized precipitation evapotranspiration index (SPEI) and crop water deficit index (CWDI), the standard deviation of ACDI is larger, which indicates that the difference between index values is larger and it is relatively good in distinguishing the degree of drought. In addition, the correlation coefficient between ACDI and climate grain yield passed the test with a significance level of 0.05, while the other three indexes did not pass the test, which shows that the relationship between ACDI and grain yield is higher than the other three drought indexes. For arid areas, grain yield can reflect the impact of drought. Therefore, ACDI looks more promising to identify agricultural drought from the perspective of crops. ACDI provides a reference for monitoring agricultural drought from the perspective of crop growth stage, and enriches the drought index theory.