bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forb ecology research in dry African savannas: Knowledge, gaps, and future perspectives
Authors: Siebert Frances , Dreber Niels 
Published: June 2019

AbstractSavannas are commonly described as a vegetation type with a grass layer interspersed with a discontinuous tree or shrub layer. On the contrary, forbs, a plant life form that can include any nongraminoid herbaceous vascular plant, are poorly represented in definitions of savannas worldwide. While forbs have been acknowledged as a diverse component of the herbaceous layer in savanna ecosystems and valued for the ecosystem services and functions they provide, they have not been the primary focus in most savanna vegetation studies. We performed a systematic review of scientific literature to establish the extent to which forbs are implicitly or explicitly considered as a discrete vegetation component in savanna research. The overall aims were to summarize knowledge on forb ecology, identify knowledge gaps, and derive new perspectives for savanna research and management with a special focus on arid and semiarid ecosystems in Africa. We synthesize and discuss our findings in the context of different overarching research themes: (a) functional organization and spatial patterning, (b) land degradation and range management, (c) conservation and reserve management, (d) resource use and forage patterning, and (e) germination and recruitment. Our results revealed biases in published research with respect to study origin (country coverage in Africa), climate (more semiarid than arid systems), spatial scale (more local than landscape scale), the level at which responses or resource potential was analyzed (primarily plant functional groups rather than species), and the focus on interactions between life forms (rather seldom between forbs and grasses and/or trees). We conclude that the understanding of African savanna community responses to drivers of global environmental change requires knowledge beyond interactions between trees and grasses only and beyond the plant functional group level. Despite multifaceted evidence of our current understanding of forbs in dry savannas, there appear to be knowledge gaps, specifically in linking drivers of environmental change to forb community responses. We therefore propose that more attention be given to forbs as an additional ecologically important plant life form in the conventional tree–grass paradigm of savannas.
Response of riparian ecosystem to dike construction on the Middle Reaches of the Tarim River, Northwest China
Authors: Chen Yongjin , Shi Xun , Liu Jiazhen , Zhang Tianju , Guo Wenwen 
Published: June 2019

AbstractStudies have demonstrated that water management engineering may bring ecological degradation to the riparian ecosystems. However, most such works focus on dams, and the impact of dikes has been less studied. We investigated how dikes interfere with the desert riparian ecosystem on the middle reaches of the Tarim River, Xinjiang, China. We collected data of vegetation species and coverage, groundwater depth, total dissolved solids (TDS), and soil salinity, along eight transects crossing the river channel, from 2001 to 2010. We conducted spatio‐temporal analyses of the data from the transects and calculated correlations between the ecological indices and the groundwater measurements and between the ecological indices and the soil properties. We found that since the construction of dikes in 2001, both the depth of and TDS in groundwater had been increasing so did soil salinity; their spatial distributions changed from irregular to increasing along with the distance from the dikes, and the width of solute‐dilution belt became narrower. The overall species richness had been declining, and spatially, it had decreased as the distance to the dikes increases; meanwhile, the species evenness had been increasing. The correlation between the species diversity and the groundwater measurements was not significant before 2003 but became highly significant for 2006–2010, after the dikes were fully established. A shrinkage of arboreal cover is accompanied by expansions of shrubby and herbaceous covers. Particularly for the Populus euphratica community, the main arboreal community in the region, the ratio between seedlings and young trees had been declining; the structure of the community became simpler as the diversity decreased; and the lateral width of the community changed from 1,500 m to 800–1,000 m. This community degradation appears to be a consequence of the dike constructions, which prevented overbank floods, resulting in a shortage of water for groundwater recharging, an increase of soil salinity leaching, and a loss of proper habitats for seeds germination.
Direct and indirect effects of nesting density on survival and breeding propensity of an endangered shorebird
Authors: Catlin Daniel H. , Gibson Daniel , Hunt Kelsi L. , Friedrich Meryl J. , Weithman Chelsea E. , Karpanty Sarah M. , Fraser James D. 
Published: June 2019

AbstractDensity‐dependent regulation is a fundamental part of ecological theory and a significant driver of animal demography often through complex feedback loops. We investigated the relationship between flood‐ and demographically induced fluctuations in density and the breeding propensity and survival of a pioneer species, the piping plover (plover,Charadrius melodus). We captured and marked adult and hatchling plovers on the Gavins Point Reach of the Missouri River in South Dakota and Nebraska,USA, from 2005 to 2014. In 2010 and 2011, historically high water levels and flooding inundated much of the plover's sandbar nesting habitat on the Missouri River. We developed a Bayesian formulation of a multievent model, or a multistate survival model with state uncertainty to estimate breeding propensity simultaneously with survival. Although plovers are conspicuous, their breeding status can be difficult to establish with certainty, which necessitated the use of uncertain states. With this model, we investigated the effect of sex, habitat availability, river flow, and density (birds/ha nesting habitat) on survival of hatch year and breeding and non‐breeding adult plovers. In addition, we estimated the transition rates for these age classes between breeding and non‐breeding states. Non‐breeding adults ( = 0.58 ± 0.06) had lower survival rates than breeding adults ( = 0.80 ± 0.04), and both breeding survival and breeding propensity decreased with increasing nesting density. Not only did survival and breeding propensity decrease directly at higher nest densities, but survival also was indirectly impacted by increasing the proportion of non‐breeding birds with relatively low survival. Thus, plovers were regulated through a complex set of feedback loops, acting as densities increased. Our findings underscore the intricacy of density‐dependent regulation and suggest that detailed demographic studies are needed to fully understand these effects.
A physical model of the high‐frequency seismic signal generated by debris flows
Authors: Farin Maxime , Tsai Victor C. , Lamb Michael P. , Allstadt Kate E. 
Published: June 2019

AbstractWe propose a physical model for the high‐frequency (>1 Hz) spectral distribution of seismic power generated by debris flows. The modeled debris flow is assumed to have four regions where the impact rate and impulses are controlled by different mechanisms: the flow body, a coarser‐grained snout, a snout lip where particles fall from the snout on the bed, and a dilute front composed of saltating particles. We calculate the seismic power produced by this impact model in two end‐member scenarios, a thin‐flow and thick‐flow limit, which assume that the ratio of grain sizes to flow thicknesses are either near unity or much less than unity. The thin‐flow limit is more appropriate for boulder‐rich flows that are most likely to generate large seismic signals. As a flow passes a seismic station, the rise phase of the seismic amplitude is generated primarily by the snout while the decay phase is generated first by the snout and then the main flow body. The lip and saltating front generate a negligible seismic signal. When ground properties are known, seismic power depends most strongly on both particle diameter and average flow speed cubed, and also depends on length and width of the flow. The effective particle diameter for producing seismic power is substantially higher than the median grain size and close to the 73rd percentile for a realistic grain size distribution. We discuss how the model can be used to estimate effective particle diameter and average flow speed from an integrated measure of seismic power. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd.
The role of the cerebellum in adaptation: ALE meta‐analyses on sensory feedback error
Authors: Johnson Joseph F. , Belyk Michel , Schwartze Michael , Pinheiro Ana P. , Kotz Sonja A. 
Published: June 2019

AbstractIt is widely accepted that unexpected sensory consequences of self‐action engage the cerebellum. However, we currently lack consensus on where in the cerebellum, we find fine‐grained differentiation to unexpected sensory feedback. This may result from methodological diversity in task‐based human neuroimaging studies that experimentally alter the quality of self‐generated sensory feedback. We gathered existing studies that manipulated sensory feedback using a variety of methodological approaches and performed activation likelihood estimation (ALE) meta‐analyses. Only half of these studies reported cerebellar activation with considerable variation in spatial location. Consequently, ALE analyses did not reveal significantly increased likelihood of activation in the cerebellum despite the broad scientific consensus of the cerebellum's involvement. In light of the high degree of methodological variability in published studies, we tested for statistical dependence between methodological factors that varied across the published studies. Experiments that elicited an adaptive response to continuously altered sensory feedback more frequently reported activation in the cerebellum than those experiments that did not induce adaptation. These findings may explain the surprisingly low rate of significant cerebellar activation across brain imaging studies investigating unexpected sensory feedback. Furthermore, limitations of functional magnetic resonance imaging to probe the cerebellum could play a role as climbing fiber activity associated with feedback error processing may not be captured by it. We provide methodological recommendations that may guide future studies.
The hippocampus is necessary for the consolidation of a task that does not require the hippocampus for initial learning
Authors: Schapiro Anna C. , Reid Allison G. , Morgan Alexandra , Manoach Dara S. , Verfaellie Mieke , Stickgold Robert 
Published: June 2019

AbstractDuring sleep, the hippocampus plays an active role in consolidating memories that depend on it for initial encoding. There are hints in the literature that the hippocampus may have a broader influence, contributing to the consolidation of memories that may not initially require the area. We tested this possibility by evaluating learning and consolidation of the motor sequence task (MST) in hippocampal amnesics and demographically matched control participants. While the groups showed similar initial learning, only controls exhibited evidence of overnight consolidation. These results demonstrate that the hippocampus can be required for normal consolidation of a task without being required for its acquisition, suggesting that the area plays a broader role in coordinating memory consolidation than has previously been assumed.
Neuro‐wavelet based intelligent medical image fusion
Authors: Hassan Mehdi , Murtza Iqbal , Zafar Khan Muhammad Aqdus , Tahir Syed Fahad , Fahad Labiba Gillani 
Published: June 2019

AbstractImaging based sensitive clinical diagnosis is critically depending on image quality. In this article, the problem of enhancing fundus images is addressed by a novel fusion technique. The proposed approach utilizes the representation capability of wavelet transform and the learning ability of artificial neural networks. In this approach, input images are decomposed into wavelet transform followed by appropriate feature extraction for training of neural networks to obtain fused image. To ensure homogeneity, it employs consistency verification for minimizing the fusion artifacts. The visual and quantitative performance of the proposed approach is assessed using a number of experiments performed on the standard datasets of DRIVE and DRION‐DB. The experimental results demonstrate that the proposed fusion technique offers high average structural similarity of “0.99.” The proposed approach outperforms state‐of‐the‐art techniques which validates its effectiveness. The developed approach might be applied by the clinical diagnosis system for fundus related diseases.
Opportunities, barriers, and adoption factors of mobile commerce for the informal sector in developing countries in Africa: A systematic review
Authors: Pankomera Richard , van Greunen Darelle 
Published: June 2019

AbstractMobile commerce (m‐commerce) is extensively being deployed in both formal and informal sectors in Africa. There is evidence that mobile services such as m‐commerce can improve the overall revenue and productivity in various sectors globally. M‐commerce interventions have gained popularity for the last decades owing to their nature of being ubiquitous, convenient, localised, and personalised. However, there is little comprehensive and integrated literature on m‐commerce services on the informal sector in the developing countries in Africa. This article therefore provides results of systematic review from literature on the opportunities, barriers, and adoption factors of m‐commerce services for the informal sector in Africa. This systematic review followed the Preferred Reporting Items for System Reviews and Meta‐Analysis (PRISMA) guidelines. Out of 459 records that were screened, 20 was the final number of eligible studies after applying the exclusion criteria. This systematic review found that there are technical, social, cultural, and financial factors that hamper the uptake of m‐commerce for the informal sector in Africa. Furthermore, benefits and m‐commerce adoption factors have also been discussed. The study finally provides recommendations for the effective and sustainable utilisation of m‐commerce services for the informal sector in Africa.
Preoperative course of patients undergoing endoscopic nasobiliary drainage during the management of resectable perihilar cholangiocarcinoma
Authors: Maeda Takashi , Ebata Tomoki , Yokoyama Yukihiro , Mizuno Takashi , Yamaguchi Junpei , Onoe Shunsuke , Watanabe Nobuyuki , Kawashima Hiroki , Nagino Masato 
Published: June 2019

AbstractBackgroundAlthough there are many studies on technical outcomes of endoscopic nasobiliary drainage (ENBD), no authors reported on preoperative course of patients undergoing ENBD. The aim of this study was to investigate the course of patients with ENBD during the waiting period.MethodsPatients who underwent resection of perihilar cholangiocarcinoma (PHCC) between January 2013 and September 2017 were retrospectively reviewed.ResultsDuring the study period, 191 consecutive patients underwent surgical resection of PHCC after ENBD. Of the study patients, 154 (80.6%) patients were discharged, returned to their home, then re‐admitted for surgery. The remaining 37 patients were continuously hospitalized. The number of cholangitis events during the waiting period was 0 in 120 patients, 1 in 59 patients, 2 ≤ in 12 patients. Endoscopic re‐intervention was needed in 52 patients. The median length between the first admission and surgery was 37 days (range 12–197 days) in the entire cohort; it was longer in patients with portal vein embolization than in those without (43 vs. 27 days, P < 0.001).ConclusionsIn patients undergoing resection of PHCC, ENBD is widely tolerable with relatively low incidence of cholangitis and thus recommended for preoperative biliary drainage.
A kinetic assay of total lipase activity for detecting lysosomal acid lipase deficiency (LAL‐D) and the molecular characterization of 18 LAL‐D patients from Russia
Authors: Mayanskiy Nikolay , Brzhozovskaya Ekaterina , Pushkov Alexander , Strokova Tatiana , Vlasov Nikolay , Surkov Andrej , Gundobina Olga , Savostianov Kirill 
Published: June 2019

AbstractLaboratory diagnostics of lysosomal acid lipase deficiency (LAL‐D), a rare disorder associated with LIPA alterations, are based on the evaluation of LAL activity. In dry blood spots (DBS) submitted for LAL‐D diagnostics (the screening cohort) over a two‐year period or obtained from a cohort of retrospective LAL‐D patients, we measured: (1) LAL activity using a two‐reaction assay with 4‐methylumbelliferone palmitate (4‐MU‐Palm) and Lalistat‐2, a specific LAL inactivator; (2) total lipase (TL) activity by a 1‐hour kinetic 4‐MU‐Palm cleavage reaction (no Lalistat‐2). The TL activity was expressed as the area under the kinetic curve after 1 hour (TL‐AUC1h) of the reaction and presented as the median (min‐max). LAL activity was reduced in 30/537 individuals from the screening cohort, among which LIPA sequencing revealed six patients and one carrier. Overall, 16 (89%) individuals among six novel and 12 retrospective LAL‐D patients carried at least one c.894G>A mutation (six were homozygous). The TL‐AUC1h in nonLAL‐D specimens with normal LAL activity (n = 90) was unambiguously higher (9471 [4015‐23 585] RFU*h/punch) compared to LAL‐D patients, including six new and nine retrospective patients (1810 [357‐2608] RFU*h/punch). Importantly, in 13/15 examined nonLAL‐D specimens with reduced LAL activity the TL‐AUC1h was above a threshold of 2652 RFU*h/punch. Applying this threshold, the TL‐AUC1h index discriminated all LAL‐D patients (100% sensitivity) and 103/105 nonLAL‐D specimens (98% specificity). Given that there is no need for Lalistat‐2 and two parallel enzymatic reactions in conjunction with high sensitivity and specificity, the kinetic assay seems to be practical for LAL‐D screening.SynopsisLysosomal acid lipase deficiency responsible for Wolman disease and cholesterol ester storage disease could be reliably detected using a kinetic assay of total lipase activity with a fluorogenic substrate.
A Japanese case of mitochondrial 3‐hydroxy‐3‐methylglutaryl‐CoA synthase deficiency who presented with severe metabolic acidosis and fatty liver without hypoglycemia
Authors: Lee Tomoko , Takami Yuichi , Yamada Kenji , Kobayashi Hironori , Hasegawa Yuki , Sasai Hideo , Otsuka Hiroki , Takeshima Yasuhiro , Fukao Toshiyuki 
Published: June 2019

AbstractMitochondrial 3‐hydroxy‐3‐methylglutaryl‐CoA synthase deficiency (mHS deficiency) is a rare autosomal recessive inborn error of ketogenesis caused by a mutation in the HMGCS2 gene, which is characterized by non‐(hypo)‐ketotic hypoglycemia, lethargy, and hepatomegaly during acute infection and/or prolonged fasting. Clinical presentations are similar to fatty acid oxidation defects; however, diagnosis of mHS deficiency is difficult because of poor biochemical markers. We report the case of a 12‐month‐old Japanese boy with mHS deficiency who presented with a coma, and hepatomegaly, but no hypoglycemia after a febrile episode and poor oral intake. Metabolic acidosis and severe fatty liver were observed. Serum acylcarnitine analysis revealed a slightly decreased free carnitine (C0) level and an increased acetylcarnitine (C2) level. Urinary organic acid analysis revealed hypoketotic dicarboxylic aciduria, and increased excretions of glutarate, and, retrospectively, 4‐hydroxy‐6‐methyl‐2‐pyrone. Although the patient did not present with hypoglycemia, the severe fatty liver and elevated free fatty acids to total ketone bodies ratio strongly suggested an inborn error of ketogenesis. In the analysis of the HMGCS2 gene, compound heterozygous mutations of c.130_131ins C (L44PfsX29) and c.1156_1157insC (L386PfsX73) were identified, which led to the diagnosis of mHS deficiency. He had recovered without any complication by the therapy, including intravenous glucose infusion. Unlike the previously reported cases of mHS deficiency, our case did not present with hypoglycemia and the fatty liver lasted over several months. mHS deficiency should be taken into consideration when a patient has severe metabolic acidosis and fatty liver with no or subtle ketosis, even without hypoglycemia.
A quarter century of wine pigment discovery
Authors: Waterhouse Andrew L , Zhu Jian 
Published: June 2019

AbstractThe red grape berry pigments, anthocyanins, were characterized in the early 20th century, but investigations of wine pigments were stymied during that era. The question of their identity was a major challenge for wine chemists. A number of techniques showed that the pigments were polymeric in nature. Some structures were postulated by mid‐century based on reactions between anthocyanins and condensed tannin, and later postulated wine pigments were observed in model reactions. Some related compounds were then observed in wine. By the end of the 20th century, the ionization of non‐volatiles for mass spectrometry opened the door to these compounds. In addition, a new class of compounds was observed, the pyranoanthocyanins, a product of fermentation and aging metabolites with anthocyanins. These compounds possess the pigment stability to SO2 and pH change that is characteristic of aged red wine. Aging experiments show a dynamic situation with shifts in the population of pigment classes over time. The very large number of diverse pigments explains why it has been so difficult to answer the century‐old question of the structure of wine pigments. Our current understanding is founded on the use of mass spectral analysis using electrospray and related ionization techniques over the last 25 years. Future progress will rely on more sophisticated analysis of this very complex mixture of substances. © 2019 Society of Chemical Industry
Thermal decomposition of model compound of algal biomass
Authors: Jabeen Sidra , Zeng Zhe , Altarawneh Mohammednoor , Gao Xiangpeng , Saeed Anam , Dlugogorski Bogdan Z. 
Published: June 2019

AbstractThis contribution investigates thermal decomposition of leucine, as a representative model compound for amino acids in algal biomass. We map out potential energy surface for a wide array of unimolecular and self‐condensation reactions operating in the decomposition of leucine. Decarboxylation and dehydration of leucine ensues by eliminating CO2 and –OH, respectively, from the –COOH group attached to the α‐carbon. The molecular channel for deamination involves cleavage of NH2 from α‐carbon of leucine. The activation energies for direct elimination of CO2, NH3, and H2O from a leucine molecule lie within 20.7 kJ/mol of each other. Activation energies for these decomposition pathways reside below the bond dissociation enthalpy of H–C(α) of 323.1 kJ/mol. The decarboxylation, deamination, and dehydration pathways, via radical‐prompted pathways, systematically require lower energy barriers, in reference to closed‐shell reaction corridors. Detailed computations at the CBS‐QB3 level provide the Arrhenius rate parameters for the unimolecular and bimolecular reactions, and standard enthalpies of formation, standard entropies, and heat capacities for all the products and intermediates. A kinetic analysis of gas‐phase reactions, within the context of a plug‐flow reactor model, accounts qualitatively for the formation of major products observed experimentally in the thermal degradation of the condensed‐phase leucine. Among notable N‐containing species, the model predicts the prevailing of NH3 over HCN and HNCO, in addition to corresponding appreciable concentrations of amines, imines, and nitriles. Our detailed kinetic investigation illustrates a negligible contribution of the self‐condensation reactions of leucine in the gas phase.