bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biology, natural enemies and damage of the sugarcane whitefly (Neomaskellia andropogonis) (Homoptera: Aleyrodidae) in Iran
Authors: Askarianzadeh Alireza , Minaeimoghadam Mehrnoosh 
Published: September 2018

AbstractAn outbreak of the sugarcane whitefly (Neomaskellia andropogonis Corbett) recently occurred in sugarcane fields in Khuzestan Province of Iran. This pest sucks plant sap producing large amounts of honeydew. In Khuzestan Province, populations of all developmental stages increase from early August until late November. At this time, when sugarcane is at the ripening stage, nymphs suck the sap, and in cases of severe infestation, retard the growth of sugarcane plants. In this study, we investigated the biology of the pest on different cultivars of sugarcane and under different temperatures. Also, we conducted experiments to determine the damage caused by the pest in the field. Mean pre-adult developmental times were 24.09, 28.06, 27.27 and 26.64 days on CP69-1062, CP57-1062, CP48-103 and NCO-310 cultivars, respectively, and only female progeny were produced. Mean longevity of females on the four cultivars was 6, 8.49, 4.15 and 4.60 days, respectively. Adult females laid an average of 61.80, 58.80, 41.10 and 39.38 eggs on the four cultivars, respectively. Results show that the optimum temperature for development of different stages of N. andropogonis is 30±1°C during the day and 25±1°C at night, and at this temperature, egg and nymphal duration (including first, second, third instars and pupae) and adult longevity were 6.2, 17.0 and 7.6 days, respectively. Females of cultivar CP69-1062 laid an average of 50.09 eggs. Analysis of data on the quality of damage (including Brix, pol and refined sugar factors) shows that damage was inversely and significantly correlated with the number of infested leaves. Whitefly damage differed among cultivars; and, based on the quality of damage, early maturing cultivars were more susceptible to whitefly damage. We collected two parasitoid wasps from nymphs—Encarsia inaron (Walker) (Hym.: Aphelinidae) and Eretmocerus delhiensis Mani (Hym.: Aphelinidae). To the best of our knowledge, this is the first study to assess the biology, damage and natural enemies of N. andropogonis on sugarcane in Iran.
Field sampling strategies for coffee berry borer (Coleoptera: Curculionidae: Scolytinae) infesting berries in coffee farms in Hawaii
Authors: Aristizábal Luis F. , Shriner Suzanne , Hollingsworth Robert , Mascarin Gabriel Moura , Chaves Bernardo , Matsumoto Traice , Arthurs Steven P. 
Published: September 2018

AbstractThe coffee berry borer (CBB),Hypothenemus hampeiFerrari, a recent invader to Hawaii, is impacting coffee growers by reducing yields and quality and increasing production costs. Monitoring strategies are needed to assess infestations and where control operations are warranted, and evaluate their effectiveness. To develop and validate a fixed-precision sequential sampling plan, an intensive CBB sampling programme was conducted in 17 small farms in Kona and Kau districts in the Big Island in 2016/17. At each location, 30 trees/ha were monitored at 2–4 week intervals. Results show that the CBB has an aggregated spatial distribution based on Taylor's power law parameters. According to Green's stop line formula, between 6 and 50 coffee branches per ha (sample unit) are required to estimate infestation rates of 1.5–2.5% infested green berries (suggested economic threshold) with a precision fixed at 10 to 25%. Concurrently, a modified strategy was tested on 14 farms, in which only infested green berries (not total) was counted. The standard and modified sampling methods were highly correlated (R2≥ 0.98), while the modified approach required on average only 35 min (27% less time) to complete, with an additional 24 min taken to observe the position of the CBB inside the berry. Our data also show that berry infestation rates of CBB prior to harvest were a good predictor of the total defects resulting in processed green coffee from these farms (Pearson'srcoefficient of 0.82). Our findings support improved sampling for the CBB under Hawaiian conditions using a simpler and faster monitoring strategy based on counting green infested berries.
Diversity and seasonal variation of insect pests of Jatropha in Gaborone, Botswana
Authors: Masukujane Masego , Coetzee Tidimalo , Ngwanathebe Robert Bob , Ishimoto Yudai , Akashi Kinya 
Published: September 2018

AbstractJatropha curcas L. is a stem-succulent shrub that produces high concentrations of seed oils that are convertible into biodiesel. In this study, the incidence of four insect pests on Jatropha, Strabala rufa, Gnathamitermes tubiformans, Pempelia morosalis, and Acanthoplus discoidalis was recorded over three years in a semi-arid climate in Gaborone, Botswana. The occurrence of these insects was concentrated in the summer season from October to April, while lower numbers of all species were found in May as the temperature began to reduce towards the winter season, suggesting that insect pests of Jatropha exhibit a unique temporal pattern in this region. A considerable variation was observed among Jatropha accessions regarding the insect pest occurrence, indicating a vast difference in the susceptibility to insect pests among Jatropha accessions.
Fluid Controls on the Heterogeneous Seismic Characteristics of the Cascadia Margin
Authors: Delph Jonathan R. , Levander Alan , Niu Fenglin 
Published: September 2018

AbstractThe dehydration of oceanic slabs during subduction is mainly thermally controlled and is often expressed as intermediate‐depth seismicity. In warm subduction zones, shallow dehydration can also lead to the buildup of pore‐fluid pressure near the plate interface, resulting in nonvolcanic tremor. Along the Cascadia margin, tremor density and intermediate‐depth seismicity correlate but vary significantly from south to north despite little variation in the thermal structure of the Juan de Fuca Plate. Along the northern and southern Cascadia margin, intermediate‐depth seismicity likely corresponds to increased fluid flux, while increased tremor density may result from fluid infiltration into thick underthrust metasediments characterized by very slow shear wave velocities (<3.2 km/s). In central Cascadia, low intermediate‐depth seismicity and tremor density may indicate a lower fluid flux, and shear wave velocities indicate that the Siletzia terrane extends to the plate interface. These results indicate that the presence of thick underthrust sediments is associated with increased tremor occurrence.
Surface Meltwater Impounded by Seasonal Englacial Storage in West Greenland
Authors: Kendrick A. K. , Schroeder D. M. , Chu W. , Young T. J. , Christoffersen P. , Todd J. , Doyle S. H. , Box J. E. , Hubbard A. , Hubbard B. , Brennan P. V. , Nicholls K. W. , Lok L. B. 
Published: September 2018

AbstractThe delivery of surface meltwater through englacial drainage systems to the bed of the Greenland Ice Sheet modulates ice flow through basal lubrication. Recent studies in Southeast Greenland have identified a perennial firn aquifer; however, there are few observations quantifying the input or residence time of water within the englacial system and it remains unknown whether water can be stored within solid ice. Using hourly stationary radar measurements, we present observations of englacial and episodic subglacial water in the ablation zone of Store Glacier in West Greenland. We find significant storage of meltwater in solid ice damaged by crevasses extending down to 48 m below the ice surface during the summer, which is released or refrozen during winter. This is a significant hydrological component newly observed in the ablation zone of Greenland that could delay the delivery of meltwater to the bed, changing the ice dynamic response to surface meltwater.
Solar Eruptions, Forbush Decreases, and Geomagnetic Disturbances From Outstanding Active Region 12673
Authors: Chertok I. M. , Belov A. V. , Abunin A. A. 
Published: September 2018

AbstractBased on our tool for the early diagnostics of solar eruption geoeffectiveness (EDSEG tool; Chertok et al., 2013, https://doi.org/10.1007/s11207‐012‐0127‐1; 2015, https://doi.org/10.1007/s11207‐014‐0618‐3; 2017, https://doi.org/10.1007/s11207‐017‐1081‐8), we have analyzed space weather disturbances that occurred in early September 2017. Two flares, SOL2017‐09‐04T20:33 (M5.5) and SOL2017‐09‐06T12:02 (X9.3), accompanied by Earth‐directed halo coronal mass ejections (CMEs) were found to be geoeffective. We extracted the associated extreme ultaviolet dimmings and arcades and calculated their total unsigned magnetic flux. This calculation allowed us to estimate the possible scales of the Forbush decreases (FDs) and geomagnetic storms (GMSs) in the range from moderate to strong, and they are close to the observed scales. More precisely, after the first eruption, an FD approximately equal to 2% and almost no GMS occurred because the Bz magnetic field component in front of the corresponding interplanetary CME (ICME) was northern. The stronger second eruption produced somewhat larger composite disturbances (FD ≈ 9.3% and GMS with indexes Dst ≈ −144 nT, Ap ≈ 235) than expected (FD ≈ 4.4%, Dst ≈ −135 nT, Ap ≈ 125) because the second ICME overtook the trailing part of the first ICME near Earth, and the resulting Bz component was more intense and southern. Both ICMEs arrived at Earth earlier than expected because they propagated in the high‐speed solar wind emanated from an extended coronal hole adjacent to the active region AR12673 along their entire path. Overall, the presented results provide further evidence that the EDSEG tool can be used for the earliest diagnostics of actual solar eruptions to forecast the scale of the corresponding geospace disturbances.
When Should Irrigators Invest in More Water‐Efficient Technologies as an Adaptation to Climate Change?
Authors: Malek Keyvan , Adam Jennifer , Stockle Claudio , Brady Michael , Rajagopalan Kirti 
Published: September 2018

AbstractThe western U.S. is expected to experience more frequent and severe droughts as a result of climate change, with potentially large impacts on agricultural production and the economy. Irrigated farmers have multiple options for minimizing the impact of drought including switching to more efficient irrigation technologies. More efficient technologies that increase the fraction of the water available to the crop root zone would allow farmers to maintain current production levels with less water. However, these systems are capital intensive. The objective of this study is to explore when (and under what climatic conditions) it makes economic sense for farmers to invest in new irrigation systems. We examine this in the Yakima River Basin in Washington State of the U.S. We use VIC‐CropSyst, a large‐scale grid‐based modeling framework that mechanistically simulates hydrologic and agricultural processes. Water supply simulated by VIC‐CropSyst drives a river system and water management model (YAK‐RW). A computational platform was developed to perform the economic analysis for each grid cell, crop type, and future climate scenario separately, which allowed us to explore whether the implementation of more efficient irrigation systems would be economically viable. Our results indicate that investing in a more efficient irrigation system improves agricultural economy of the Yakima River Basin (9% −25%). We also show that at the farm level, more significant droughts can provide economic incentives for investment up to a point. For severe climate change projections, droughts become frequent and severe enough that economic benefits of improving water use efficiency do not exceed investment costs.
Microscale Analysis of Fractured Rock Sealed With Microbially Induced CaCO3 Precipitation: Influence on Hydraulic and Mechanical Performance
Authors: Tobler Dominique J. , Minto James M. , El Mountassir Gráinne , Lunn Rebecca J. , Phoenix Vernon R. 
Published: September 2018

AbstractMicrobially induced CaCO3 precipitation (MICP) has shown great potential to reduce permeability in intact rocks as a means to seal fluid pathways in subsurface ground, for example, to secure waste storage repositories. However, much less is known about how to apply MICP to seal fractured rock. Furthermore, there is limited information on the hydraulic and mechanical properties of MICP filled fractures, which are essential criteria to assess seal performance. Here MICP injection strategies were tested on sandstone cores, aimed at obtaining a homogeneous porosity fill that reduced permeability by 3 orders of magnitude. The injection strategy resulting in the most homogenous calcite distribution was then applied to fractured granite cores, to yield transmissivity reduction of up to 4 orders of magnitude. Microscale analysis of these sealed granite cores using X‐ray‐computed tomography and electron microscopy showed that >67% of the fracture aperture was filled with calcite, with crystals growing from both fracture planes, and bridging the fracture aperture in several places. Shear strength tests performed on these cores showed that the peak shear strength correlated well with the percentage of the fracture area where calcite bridged the aperture. Notably, brittle failure occurred within the MICP grout, showing that the calcite crystals were strongly attached to the granite surface. If MICP fracture‐sealing strategies can be designed such that the majority of CaCO3 crystals bridge across the fracture aperture, then MICP has the potential to provide significant mechanical stability to the rock mass as well as forming a hydraulic barrier.
Balancing Flood Risk and Water Supply in California: Policy Search Integrating Short‐Term Forecast Ensembles With Conjunctive Use
Authors: Nayak Munir Ahmad , Herman Jonathan D. , Steinschneider Scott 
Published: September 2018

AbstractShort‐term weather forecasts have the potential to improve reservoir operations for both flood control and water supply objectives, especially in regions currently relying on fixed seasonal flood pools to mitigate risk. The successful development of forecast‐based policies should integrate uncertainty from modern forecast products to create unambiguous rules that can be tested on out‐of‐sample periods. This study investigates the potential for such operating policies to improve water supply efficiency while maintaining flood protection, combining state‐of‐the‐art weather hindcasts with downstream conjunctive use to transfer surplus flood releases to groundwater storage. Because available weather hindcasts are relatively short (10–20 years), we propose a novel statistical framework to develop synthetic forecasts over longer periods of the historical record. Operating rules are trained with a recently developed policy search framework in which decision rules are structured as binary trees. Policies are developed for a range of scenarios with varying forecast skill and conjunctive use capacity, using Folsom Reservoir, California, as a case study. Results suggest that the combination of conjunctive use and short‐term weather forecasts can substantially improve both water supply and flood control objectives by allowing storage to remain high until forecasts trigger a release. Further, increased conjunctive use capacity reduces the importance of forecast skill, since surface storage can be moved to groundwater during the flood season without losing water supply. This analysis serves the development of forecast‐based operating policies for large, multipurpose reservoirs in California and other regions with similar flood hydroclimatology.
Implications of Simulating Global Digital Elevation Models for Flood Inundation Studies
Authors: Hawker Laurence , Rougier Jonathan , Neal Jeffrey , Bates Paul , Archer Leanne , Yamazaki Dai 
Published: September 2018

AbstractThe Shuttle Radar Topography Mission has long been used as a source topographic information for flood hazard models, especially in data‐sparse areas. Error corrected versions have been produced, culminating in the latest global error reduced digital elevation model (DEM)—the Multi‐Error‐Removed‐Improved‐Terrain (MERIT) DEM. This study investigates the spatial error structure of MERIT and Shuttle Radar Topography Mission, before simulating plausible versions of the DEMs using fitted semivariograms. By simulating multiple DEMs, we allow modelers to explore the impact of topographic uncertainty on hazard assessment even in data‐sparse locations where typically only one DEM is currently used. We demonstrate this for a flood model in the Mekong Delta and a catchment in Fiji using deterministic DEMs and DEM ensembles simulated using our approach. By running an ensemble of simulated DEMs we avoid the spurious precision of using a single DEM in a deterministic simulation. We conclude that using an ensemble of the MERIT DEM simulated using semivariograms by land cover class gives inundation estimates closer to a light detection and ranging‐based benchmark. This study is the first to analyze the spatial error structure of the MERIT DEM and the first to simulate DEMs and apply these to flood models at this scale. The research workflow is available via an R package called DEMsimulation.
Spatially Distributed Conceptual Hydrological Model Building: A Generic Top‐Down Approach Starting From Lumped Models
Authors: Tran Quoc Quan , De Niel J. , Willems P. 
Published: September 2018

AbstractChanging environmental conditions might have severe impacts on future flood frequencies and water availability. In order to develop mitigation strategies by carrying out impact studies, lumped hydrological models might not suffice anymore and the need for flexibility in spatial resolution arises. Recent developments already allow to change the grid size of hydrological models depending on the needs and to use different spatial resolutions in parallel for different applications. These developments, however, still face some challenges such as the following: how to avoid strong or sudden changes in simulation results when level of spatial details is changed and how to limit the problem of overparameterization/equifinality while increasing the spatial resolution. We developed a methodology to partially meet these challenges by building parsimonious distributed conceptual hydrological models with a flexible spatial resolution. The methodology starts with calibrated lumped conceptual models. Parameters are then spatially disaggregated based on spatially variable catchment properties, introducing only few additional calibration parameters. The approach is demonstrated for three different conceptual rainfall‐runoff models for two medium‐sized Belgian catchments. The resulting spatial models are found to be accurate with respect to the observations and consistent with the lumped conceptual model results, when evaluated for peak, low, and cumulative total runoff and subflows at downstream and internal gauging stations. A climate change impact analysis further shows consistency of lumped and spatial model results for changing conditions.
Phosphoglycerate dehydrogenase inhibition induces p-mTOR-independent autophagy and promotes multilineage differentiation in embryonal carcinoma stem-like cells
Authors: Sharif Tanveer , Martell Emma , Dai Cathleen , Ghassemi-Rad Mohammad Saleh , Lee Kristen , Singh Sheila K. , Weaver Ian C. G. , Gujar Shashi 
Published: September 2018

AbstractCancer cells with a less differentiated stem-like phenotype are more resistant to therapeutic manipulations than their differentiated counterparts, and are considered as one of the main causes of cancer persistence and relapse. As such, induction of differentiation in cancer stem-like cells (CSLCs) has emerged as an alternative strategy to enhance the efficacy of anticancer therapies. CSLCs are metabolically distinct from differentiated cells, and any aberration from the intrinsic metabolic state can induce differentiation of CSLCs. Therefore, metabolism-related molecular targets, with a capacity to promote differentiation within CSLCs, are of therapeutic importance. Here, we demonstrate that phosphoglycerate dehydrogenase (PHGDH), an essential enzyme catalyzing the synthesis of amino acid serine, is important for maintaining the poorly differentiated, stem-like state of CSLCs. Our data shows that PHGDH deficiency impairs the tumorsphere formation capacity in embryonal carcinoma stem-like cells (ECSLCs), breast cancer stem-like cells (BCSLCs) and patient-derived brain tumor-initiating cells (BTICs), which is accompanied by the reduced expression of characteristic stemness-promoting factors, such as Oct4, Nanog, Sox-2, and Bmi-1. Mechanistically, PHGDH deficiency in ECSLCs promotes differentiation to various lineages via degradation of Oct4 and by increasing the stability of differentiation marker β3-tubulin. Furthermore, PHGDH inhibition promotes p-mTOR independent but Beclin-1-dependent autophagy, independent of apoptosis. When studied in combination, the inhibition of both PHGDH and p-mTOR in ECSLCs causes further augmentation of autophagy, and additionally promotes apoptosis, demonstrating the clinical applicability of PHGDH-based manipulations in cancer therapies. Recapitulating these in vitro findings in CSLC models, the intratumoral PHGDH expression in patient-derived tumors is positively correlated with the mRNA levels of stemness factors, especially Oct4, and cancer patients co-expressing high levels of PHGDH and Oct4 display significantly lower survival than those with low PHGDH/Oct4 co-expression. Altogether, this study identifies a clinically-relevant role for PHGDH in the regulation of stemness-differentiation axis within CSLCs.
VDAC2 interacts with PFKP to regulate glucose metabolism and phenotypic reprogramming of glioma stem cells
Authors: Zhou Kai , Yao Yue-Liang , He Zhi-Cheng , Chen Cong , Zhang Xiao-Ning , Yang Kai-Di , Liu Yu-Qi , Liu Qing , Fu Wen-Juan , Chen Ya-Ping , Niu Qin , Ma Qing-Hua , Zhou Rong , Yao Xiao-Hong , Zhang Xia , Cui You-Hong , Bian Xiu-Wu , Shi Yu , Ping Yi-Fang 
Published: September 2018

AbstractPlastic phenotype convention between glioma stem cells (GSCs) and non-stem tumor cells (NSTCs) significantly fuels glioblastoma heterogeneity that causes therapeutic failure. Recent progressions indicate that glucose metabolic reprogramming could drive cell fates. However, the metabolic pattern of GSCs and NSTCs and its association with tumor cell phenotypes remain largely unknown. Here we found that GSCs were more glycolytic than NSTCs, and voltage-dependent anion channel 2 (VDAC2), a mitochondrial membrane protein, was critical for metabolic switching between GSCs and NSTCs to affect their phenotypes. VDAC2 was highly expressed in NSTCs relative to GSCs and coupled a glycolytic rate-limiting enzyme platelet-type of phosphofructokinase (PFKP) on mitochondrion to inhibit PFKP-mediated glycolysis required for GSC maintenance. Disruption of VDAC2 induced dedifferentiation of NSTCs to acquire GSC features, including the enhanced self-renewal, preferential expression of GSC markers, and increased tumorigenicity. Inversely, enforced expression ofVDAC2 impaired the self-renewal and highly tumorigenic properties of GSCs. PFK inhibitor clotrimazole compromised the effect of VDAC2 disruption on glycolytic reprogramming and GSC phenotypic transition. Clinically, VDAC2 expression inversely correlated with glioma grades (Immunohistochemical staining scores of VDAC2 were 4.7 ± 2.8, 3.2 ± 1.9, and 1.9 ± 1.9 for grade II, grade III, and IV, respectively, p < 0.05 for all) and the patients with high expression of VDAC2 had longer overall survival than those with low expression of VDAC2 (p = 0.0008). In conclusion, we demonstrate that VDAC2 is a new glycolytic regulator controlling the phenotype transition between glioma stem cells and non-stem cells and may serves as a new prognostic indicator and a potential therapeutic target for glioma patients.