bluuebunny/crossref_metadata_2025 huggingface dataset:
Edge disturbance drives liana abundance increase and alteration of liana–host tree interactions in tropical forest fragments
Authors: Campbell Mason J. , Edwards Will , Magrach Ainhoa , Alamgir Mohammed , Porolak Gabriel , Mohandass D. , Laurance William F.
Published: April 2018

Closed‐canopy forests are being rapidly fragmented across much of the tropical world. Determining the impacts of fragmentation on ecological processes enables better forest management and improves species‐conservation outcomes. Lianas are an integral part of tropical forests but can have detrimental and potentially complex interactions with their host trees. These effects can include reduced tree growth and fecundity, elevated tree mortality, alterations in tree‐species composition, degradation of forest succession, and a substantial decline in forest carbon storage. We examined the individual impacts of fragmentation and edge effects (0–100‐m transect from edge to forest interior) on the liana community and liana–host tree interactions in rainforests of the Atherton Tableland in north Queensland, Australia. We compared the liana and tree community, the traits of liana‐infested trees, and determinants of the rates of tree infestation within five forest fragments (23–58 ha in area) and five nearby intact‐forest sites. Fragmented forests experienced considerable disturbance‐induced degradation at their edges, resulting in a significant increase in liana abundance. This effect penetrated to significantly greater depths in forest fragments than in intact forests. The composition of the liana community in terms of climbing guilds was significantly different between fragmented and intact forests, likely because forest edges had more small‐sized trees favoring particular liana guilds which preferentially use these for climbing trellises. Sites that had higher liana abundances also exhibited higher infestation rates of trees, as did sites with the largest lianas. However, large lianas were associated with low‐disturbance forest sites. Our study shows that edge disturbance of forest fragments significantly altered the abundance and community composition of lianas and their ecological relationships with trees, with liana impacts on trees being elevated in fragments relative to intact forests. Consequently, effective control of lianas in forest fragments requires management practices which directly focus on minimizing forest edge disturbance.
Strong population structure but no equilibrium yet: Genetic connectivity and phylogeography in the kelp Saccharina latissima (Laminariales, Phaeophyta)
Authors: Luttikhuizen Pieternella C. , van den Heuvel Freek H. M. , Rebours Céline , Witte Harry J. , van Bleijswijk Judith D. L. , Timmermans Klaas
Published: April 2018

Kelp aquaculture is globally developing steadily as human food source, along with other applications. One of the newer crop species is Saccharina latissima, a northern hemisphere kelp inhabiting temperate to arctic rocky shores. To protect and document its natural genetic variation at the onset of this novel aquaculture, as well as increase knowledge on its taxonomy and phylogeography, we collected new genetic data, both nuclear and mitochondrial, and combined it with previous knowledge to estimate genetic connectivity and infer colonization history. Isolation‐with‐migration coalescent analyses demonstrate that gene flow among the sampled locations is virtually nonexistent. An updated scenario for the origin and colonization history of S. latissima is developed as follows: We propose that the species (or species complex) originated in the northwest Pacific, crossed to the northeast Pacific in the Miocene, and then crossed the Bering Strait after its opening ~5.5 Ma into the Arctic and northeast Atlantic. It subsequently crossed the Atlantic from east to west. During the Pleistocene, it was compressed in the south with evidence for northern refugia in Europe. Postglacial recolonization led to secondary contact in the Canadian Arctic. Saccharina cichorioides is shown to probably belong to the S. latissima species complex and to derive from ancestral populations in the Asian North Pacific. Our novel approach of comparing inferred gene flow based on coalescent analysis versus Wright's island model suggests that equilibrium levels of differentiation have not yet been reached in Europe and, hence, that genetic differentiation is expected to increase further if populations are left undisturbed.
Temperature effects on ballistic prey capture by a dragonfly larva
Authors: Quenta Herrera Estefania , Casas Jérôme , Dangles Olivier , Pincebourde Sylvain
Published: April 2018

Understanding the effects of temperature on prey–predator interactions is a key issue to predict the response of natural communities to climate change. Higher temperatures are expected to induce an increase in predation rates. However, little is known on how temperature influences close‐range encounter of prey–predator interactions, such as predator's attack velocities. Based on the speed–accuracy trade‐off concept, we hypothesized that the increase in predator attack velocity by increasing temperature reduces the accuracy of the attack, leading to a lower probability of capture. We tested this hypothesis on the dragonfly larvae Anax imperator and the zooplankton prey Daphnia magna. The prey–predator encounters were video‐recorded at high speed, and at three different temperatures. Overall, we found that (1) temperature had a strong effect on predator's attack velocities, (2) prey did not have the opportunity to move and/or escape due to the high velocity of the predator during the attack, and (3) neither velocity nor temperature had significant effects on the capture success. By contrast, the capture success mainly depended on the accuracy of the predator in capturing the prey. We found that (4) some 40% of mistakes were undershooting and some 60% aimed below or above the target. No lateral mistake was observed. These results did not support the speed–accuracy trade‐off hypothesis. Further studies on dragonfly larvae with different morphological labial masks and speeds of attacks, as well as on prey with different escape strategies, would provide new insights into the response to environmental changes in prey–predator interactions.
Seasonal variations in body melanism and size of the wolf spiderPardosa astrigera(Araneae: Lycosidae)
Authors: Yang Jinjian , Wu Qijia , Xiao Rong , Zhao Jupeng , Chen Jian , Jiao Xiaoguo
Published: April 2018

Variations in species morphology and life‐history traits strongly correlate with geographic and climatic characteristics. Most studies on morphological variations in animals focus on ectotherms distributed on a large geographic scale across latitudinal and/or altitudinal gradient. However, the morphological variations of spiders living in the same habitats across different seasons have not been reported. In this study, we used the wolf spider,Pardosa astrigera, as a model to determine seasonal differences in adult body size, melanism, fecundity, and egg diameter both in the overwintering and the first generation for 2010 and 2016. The results showed that in 2010, both females and males of the overwintering generation were significantly darker than the first generation. Moreover, the overwintering females were markedly larger and produced more and bigger eggs than the first generation in both 2010 and 2016. Considering the overwinteringP. astrigeraexperiencing low temperature and/or desiccation stress, these results suggest that substantially darker and larger body of the overwintering generation is adaptive to adverse conditions.
Diversity and evolution of rice progenitors in Australia
Authors: Moner Ali M. , Furtado Agnelo , Chivers Ian , Fox Glen , Crayn Darren , Henry Robert J.
Published: April 2018

In the thousands of years of rice domestication in Asia, many useful genes have been lost from the gene pool. Wild rice is a key source of diversity for domesticated rice. Genome sequencing has suggested that the wild rice populations in northern Australia may include novel taxa, within the AA genome group of close (interfertile) wild relatives of domesticated rice that have evolved independently due to geographic separation and been isolated from the loss of diversity associated with gene flow from the large populations of domesticated rice in Asia. Australian wild rice was collected from 27 sites from Townsville to the northern tip of Cape York. Whole chloroplast genome sequences and 4,555 nuclear gene sequences (more than 8 Mbp) were used to explore genetic relationships between these populations and other wild and domesticated rices. Analysis of the chloroplast and nuclear data showed very clear evidence of distinctness from other AA genome Oryza species with significant divergence between Australian populations. Phylogenetic analysis suggested the Australian populations represent the earliest‐branching AA genome lineages and may be critical resources for global rice food security. Nuclear genome analysis demonstrated that the diverse O. meridionalis populations were sister to all other AA genome taxa while the Australian O. rufipogon‐like populations were associated with the clade that included domesticated rice. Populations of apparent hybrids between the taxa were also identified suggesting ongoing dynamic evolution of wild rice in Australia. These introgressions model events similar to those likely to have been involved in the domestication of rice.
Continuous purification of Candida antarctica lipase B using 3‐membrane adsorber periodic counter‐current chromatography
Authors: Brämer Chantal , Schreiber Sarah , Scheper Thomas , Beutel Sascha
Published: April 2018

Batch chromatography has several disadvantages, such as insufficient utilization of the capacity of the resin, high buffer consumption and discontinuity. Considering the high costs for downstream processing, a continuously working chromatographic system with three membrane adsorber units was designed, tested and put into operation. The basic principle of the setup is periodic counter‐current chromatography (PCCC). The PCCC system was used for capturing and purifying Candida antarctica lipase B (CalB) directly from cell lysate in one single unit operation. The best purification result was achieved by means of anion‐exchange chromatography. The dynamic binding capacity with Sartobind® Q 75 amounted to 4.2 mg (56 g/cm2). After transferring the method to the 3MA‐PCCC, 0.22 g CalB (73 U/mg) were obtained from 0.9 L E. coli lysate within 6 h and a recovery of 80%. Compared to the batch process, the productivity could be increased by 36% and the buffer consumption could be reduced by about 20%. Although the purification of CalB from lysate by means of anion‐exchange chromatography was not selective and quantitative using the 3MA‐PCCC device, it could be shown that the concept of the system was successfully implemented and led to a significant improvement of CalB purification.
Theoretical link between rainfall and flood magnitude
Authors: Criss Robert E.
Published: April 2018

The rainfall–run‐off convolution integral is analytically solved for several models for the elementary hydrograph. These solutions can be combined with available rainfall frequency analyses to predict flood flows along streams for different recurrence intervals, using no free parameters for gauged streams and one estimable parameter for ungauged streams. Extreme discharge magnitudes at gauged sites can be typically estimated within a factor of two of actual records, using no historical data on extreme flows. The flow predictions reproduce several important characteristics of the flood phenomenon, such as the slope of the regression line between observed extreme flows and basin area on the conventional logQ versus logA plot. Importantly, for the models and data sets investigated, the storm duration of greatest significance to flooding was found to approximate the intrinsic transport timescale of the particular watershed, which increases with basin size. Thus, storms that deliver extraordinary amounts of rainfall over a particular time interval will most greatly activate basins whose time constants approximately equal that interval. This theoretical finding is supported by examination of the regional hydrological response to the massive storms of September 14, 2008, and April 28–30, 2017, which caused extraordinary record flooding of basins of about 5–100 km2 and 500–4,000 km2, respectively, but produced few records in basins that were larger or smaller than those ranges.
Three‐dimensional coculture of primary hepatocytes and stellate cells in silk scaffold improves hepatic morphology and functionality in vitro
Authors: Wei Guofeng , Wang Jiwen , Lv Qiang , Liu Ming , Xu Hong , Zhang He , Jin Lingling , Yu Jiachuan , Wang Xiuli
Published: April 2018

A vigorous in vitro model of liver that could recapitulate hepatic phenotype and functionality in vivo would exclusively improve the efficiency of bioartificial liver, drug discovery, or even transplantation therapy. Owing to the indispensable role of three‐dimensional (3D) microenvironment in supporting viability and function of hepatocytes in vitro, much effort recently has been focused on improving reproducibility and standardization of primary hepatocyte cultures with a paradigm shift to 3D culture system, In the present study, an improved 3D coculture system of hepatocytes was established in which rat primary hepatocytes were cocultured with hepatic stellate cells in silk porous scaffolds. Silk scaffolds with incorporated extracellular matrix provided a suitable microenvironment for maintaining the viability, morphology and gene expression of the primary hepatocyte in vitro. The presence of stromal cells promoted primary hepatocyte to generate cellular aggregates with well‐organized 3D architecture after 3 days of coculture in vitro. These aggregates exhibited proper morphology similar to liver tissue in vivo. Consistent with their phenotypic appearance, well‐maintained functionality of hepatocytes was also observed in the cocultures, where albumin secretion/expression, urea synthesis as well as messenger ribonucleic acid expression of multiple cytochrome Ps (CYPs) enzymes increased significantly compared to either the 3D monocultures or monolayer cultures. Additionally, this 3D multicellular coculture model displayed an improved metabolic activity of CYPs enzymes to the probe drugs treatment. Thus, this culture system would not only contribute to the construction of micro‐organoid tissue of liver but also potentially provide a robust tool for drug metabolism evaluation in vitro. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2171‐2180, 2018.
Effects of multidimensional tunneling in the kinetics of hydrogen abstraction reactions of O (3P) with CH3OCHO
Authors: de Carvalho E. F. V. , Roberto‐Neto O.
Published: April 2018

Quantum tunneling paths are important in reactions when there is a significant component of hydrogenic motion along the potential energy surface. In this study, variational transition state with multidimensional tunneling corrections are employed in the calculations of the thermal rate constants for hydrogen abstraction from the cis‐CH3OCHO by O (3P) giving CH3OCO + OH (R1) and CH2OCHO + OH (R2). The structures and electronic energies are computed with the M06‐2X method. Benchmark calculations with the CBSD–T approach give an enthalpy of reaction at 0 K for R1 (−2.8 kcal/mol) and R2 (−2.5 kcal/mol) which are in good agreement with the experiment, i.e. −2.61 and −1.81 kcal/mol. At the low and intermediate values of temperatures, small‐ and large‐curvature tunneling dominate the kinetics of R1, which is the dominant path over the range of temperature from 250 to 1200 K. This study shows the importance of multidimensional tunneling corrections for both R1 and R2, for which the total rate constant at 298 K calculated with the CVT/μOMT method is 8.2 × 10−15 cm3 molecule−1 s−1 which agrees well with experiment value of 9.3 × 10−15 cm3 molecule−1 s−1 (Mori, Bull. Inst. Chem. Res. 1981, 59, 116). © 2018 Wiley Periodicals, Inc.
Designer nuclease‐mediated gene correction via homology‐directed repair in an in vitro model of canine hemophilia B
Authors: Bergmann Thorsten , Ehrke-Schulz Eric , Gao Jian , Schiwon Maren , Schildgen Verena , David Stephan , Schildgen Oliver , Ehrhardt Anja
Published: April 2018

Background

Gene correction at specific target loci provides a powerful strategy for overcoming genetic diseases. In the present study, we aimed to use an in vitro model for canine hemophilia B containing a single point mutation in the catalytic domain of the canine coagulation factor IX (cFIX) gene. To correct the defective gene via homology‐directed repair (HDR), we designed transcription‐activator like effector nucleases and clustered regularly interspaced short palindromic repeats including Cas9 (CRISPR/Cas9) for introduction of double‐strand breaks at the mutation site.

Methods

To generate a stable cell line containing the mutated cFIX locus, a 2‐kb genomic DNA fragment derived from a hemophilia B dog was amplified and integrated utilizing the phiC31 integrase system. Designer nucleases were assembled and cloned into vectors for constitutive and inducible expression. To detect mutations, insertions and deletions, and HDR events after nuclease treatment T7E1 assays, an amplification‐refractory mutation system‐quantitative polymerase chain reaction and pyrosequencing were performed.

Results

To perform HDR correction experiments, we established a cell line carrying the mutated cFIX locus. In HDR approaches we either explored a wild‐type or an optimized cFIX sequence and we found that our modified HDR cassette showed higher gene correction efficiencies of up to 6.4%. Furthermore, we compared inducible and constitutive designer nuclease expression systems and found that the inducible system resulted in comparable HDR efficiencies.

Conclusions

In conclusion, the present study demonstrates the potential of this strategy for gene therapeutic approaches in vitro and in a canine model for hemophilia B.
Synthesis of New Benzoxazinone, Quinazolinone, and Pyrazoloquinazolinone Derivatives and Evaluation of Their Cytotoxic Activity Against Human Breast Cancer Cells
Authors: El‐Bordany Eman A. , Ali Rania S.
Published: April 2018

Synthesis of 2‐[3‐(3,4‐dichlorophenyl)‐3‐oxoprop‐1‐enyl]‐4H‐benzo[3,1]oxazin‐4‐one 2 as a precursor to synthesize quinazolinones 5, 7 pyrazolylquinazolinones, 4, 12, 13, 14, 16 benzothiazine thione 10, benzene derivative 3 pyrroloquinazolinone 6, benzoimidazoquinazolinone 8, and pyrazolotriazepinoquinazolinone 15. The structures of the newly synthesized compounds were established by their elemental analyses and spectral data. Most of the synthesized compounds exhibited high antitumor and cytotoxic activity against human breast cancer cells.
An efficient method to isolate Kupffer cells eliminating endothelial cell contamination and selective bias
Authors: Lynch Ruairi W , Hawley Catherine A , Pellicoro Antonella , Bain Calum C , Iredale John P , Jenkins Stephen J
Published: April 2018

Multicolor flow cytometry and cell sorting are powerful immunologic tools for the study of hepatic mϕ, yet there is no consensus on the optimal method to prepare liver homogenates for these analyses. Using a combination of mϕ and endothelial cell reporter mice, flow cytometry, and confocal imaging, we have shown that conventional flow-cytometric strategies for identification of Kupffer cells (KCs) leads to inclusion of a significant proportion of CD31hi endothelial cells. These cells were present regardless of the method used to prepare cells for flow cytometry and represented endothelium tightly adhered to remnants of KC membrane. Antibodies to endothelial markers, such as CD31, were vital for their exclusion. This result brings into focus recently published microarray datasets that identify high expression of endothelial cell-associated genes by KCs compared with other tissue-resident mϕ. Our studies also revealed significant and specific loss of KCs among leukocytes with commonly used isolation methods that led to enrichment of proliferating and monocyte-derived mϕ. Hence, we present an optimal method to generate high yields of liver myeloid cells without bias for cell type or contamination with endothelial cells.

Protocol to remove endothelial cell contamination and selection bias inherent in conventional methods for isolating and analyzing liver Kupffer cells.
DP1 receptor signaling prevents the onset of intrinsic apoptosis in eosinophils and functions as a transcriptional modulator
Authors: Peinhaupt Miriam , Roula David , Theiler Anna , Sedej Miriam , Schicho Rudolf , Marsche Gunther , Sturm Eva M , Sabroe Ian , Rothenberg Marc E , Heinemann Akos
Published: April 2018

Prostaglandin (PG) D2 is the ligand for the G-protein coupled receptors DP1 (D-type prostanoid receptor 1) and DP2 (also known as chemoattractant receptor homologous molecule, expressed on Th2 cells; CRTH2). Both, DP1 and DP2 are expressed on the cellular surface of eosinophils; although it has become quite clear that PGD2 induces eosinophil migration mainly via DP2 receptors, the role of DP1 in eosinophil responses has remained elusive. In this study, we addressed how DP1 receptor signaling complements the pro-inflammatory effects of DP2. We found that PGD2 prolongs the survival of eosinophils via a DP1 receptor-mediated mechanism that inhibits the onset of the intrinsic apoptotic cascade. The DP1 agonist BW245c prevented the activation of effector caspases in eosinophils and protected mitochondrial membranes from depolarization which—as a consequence—sustained viability of eosinophils. DP1 activation in eosinophils enhanced the expression of the anti-apoptotic gene BCL-XL, but also induced pro-inflammatory genes, such as VLA-4 and CCR3. In HEK293 cells that overexpress recombinant DP1 and/or DP2 receptors, activation of DP1, but not DP2, delayed cell death and stimulated proliferation, along with induction of serum response element (SRE), a regulator of anti-apoptotic, early-response genes. We conclude that DP1 receptors promote the survival via SRE induction and induction of pro-inflammatory genes. Therefore, targeting DP1 receptors, along with DP2, may contribute to anti-inflammatory therapy in eosinophilic diseases.

The PGD2-DP1 axis impedes caspase activity, protects mitochondrial function and consequently sustains eosinophil survival by controlling SRE induction and upregulation of pro-inflammatory and anti-apoptotic genes.
Shear strain rate from phase contrast velocity encoded MRI: Application to study effects of aging in the medial gastrocnemius muscle
Authors: Sinha Usha , Malis Vadim , Csapo Robert , Narici Marco , Sinha Shantanu
Published: April 2018

Background

Strain rate (SR) is a measure of the rate of regional deformation that can be computed by analyzing velocity‐encoded phase‐contrast 2D images. Recent studies have explored the changes in normal components of the strain tensor in aging muscle, while shear strain may also provide valuable information.

Purpose

To compute the shear SR from velocity‐encoded MRI of the lower leg and to study the correlation of SR parameters measured in the medial gastrocnemius (MG) to muscle force in a cohort of young and senior subjects.

Study Type

Prospective cohort study.

Subjects

Six young (26.1 ± 2.3 years) and six senior (76.7 ± 8.3 years) healthy females; two other subjects were scanned on three separate occasions for repeatability studies.

Field Strength/Sequence

1.5T using a single oblique sagittal slice with velocity‐encoding in three directions (velocity‐encoded phase contrast gradient echo sequence).

Assessment

Age‐related and regional differences in the SR eigenvalues (SRfiber, SRin‐plane), normal SRs (SRff, SRcc), and shear SRs (SRfc, SRfc_max) were statistically analyzed.

Statistical Tests

Difference between young and senior cohorts were assessed using two‐way analysis of variance (ANOVAs). The coefficient of variation and repeatability coefficient were calculated from repeat studies. Univariate and stepwise multivariable linear regression was performed to identify predictors of force.

Results

During isometric plantarflexion contraction, SRs in the principal basis (SRfiber, SRin‐plane) and maximum shear SR (SRfc_max) was significantly lower in the senior cohort (P < 0.05). On multiple variable regression, maximum shear SR (SRfc_max) and normal SR in the fiber cross‐section (SRcc) were significantly associated with force (R = 0.681, F = 14.034, P < 0.001).

Data Conclusion

This study establishes that computation of shear strain is feasible and is a significant predictor of force variability with age.

Level of Evidence: 2

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2018;47:1351–1357.
Linking atmospheric circulation patterns with hydro‐geomorphic disasters in Peru
Authors: Rodríguez‐Morata C. , Ballesteros‐Canovas J. A. , Rohrer M. , Espinoza J. C. , Beniston M. , Stoffel M.
Published: April 2018

The occurrence of El Niño has been generally considered the main driver of hydro‐geomorphic processes in Peru. However, the climatic characterization of hydro‐geomorphic events (HGE) occurring in the absence of El Niño remains scarce. Information contained in the DesInventar disaster database suggests a widespread occurrence of HGE associated to cold‐neutral sea surface temperature (SST) in the central Pacific and south tropical Atlantic. Here, we aim at characterizing synoptic patterns associated with HGE that have occurred over last 35 years related to the different El Niño types and focusing as well on the non‐Niño phases. We use the ERA‐Interim reanalysis climate data and implement self‐organizing maps to assess the link between HGE in Peru and specific synoptic patterns. Results suggest that synoptic patterns associated with La Niña and neutral conditions play an important role in the occurrence of hydro‐geomorphic disasters in Peru during the austral summer. A total of 21% of the events are associated only with the 1972–1973, 1982–1983 and 1997–1998 El Niño events and are mainly focused in the northern Pacific coast of the country (i.e., Tumbes, Piura and Lambayeque) while more than 36% of the recorded events in the database were associated with La Niña and neutral conditions between 1970 and 2013. La Niña‐related events were more relevant in the Andean–Amazonian regions, whereas neutral conditions were related to more frequent HGEs in the southern regions (south of the 13.25°S) along the Peruvian Pacific coast. These outcomes imply an enhanced understanding of the synoptic mechanisms leading to the occurrence of HGE and contribute to a better understanding of the triggers of HGE causing disaster no exclusively related to El Niño‐like years in Peru.
Cautionary note on the use of genetic programming in statistical downscaling
Authors: Sachindra D. A. , Ahmed K. , Shahid S. , Perera B. J. C.
Published: April 2018

The selection of inputs (predictors) to downscaling models is an important task in any statistical downscaling exercise. The selection of an appropriate set of predictors to a downscaling model enhances its generalization skills as such set of predictors can reliably explain the catchment‐scale hydroclimatic variable (predictand). Among the predictor selection procedures seen in the literature, the use of genetic programming (GP) can be regarded as a unique approach as it not only selects a set of predictors influential on the predictand but also simultaneously determines a linear or nonlinear regression relationship between the predictors and the predictand. In this short communication, the details of an investigation on the assessment of effectiveness of GP in identifying a unique optimum set of predictors influential on the predictand and its ability to generate a unique optimum predictor–predictand relationship are presented. In this investigation, downscaling models were evolved for relatively wet and dry precipitation stations pertaining to two study areas using two different sets of reanalysis data for each calendar month maintaining the same GP attributes. It was found that irrespective of the climate regime (i.e., wet and dry) and reanalysis data set used, the probability of identification of a unique optimum set of predictors influential on precipitation by GP is quite low. Therefore, it can be argued that the use of GP for the selection of a unique optimum set of predictors influential on a predictand is not effective. However, when run repetitively, GP algorithm selected certain predictors more frequently than others. Also, when run repetitively, the structure of the predictor–predictand relationships evolved by GP varied from one run to another, indicating that the physical interpretation of the predictor–predictand relationships evolved by GP in a downscaling exercise can be unreliable.
Statistics of multi‐year droughts from the method for object‐based diagnostic evaluation
Authors: Abatan Abayomi A. , Gutowski William J. , Ammann Caspar M. , Kaatz Laurna , Brown Barbara G. , Buja Lawrence , Bullock Randy , Fowler Tressa , Gilleland Eric , Halley Gotway John
Published: April 2018

This study uses the method for object‐based diagnostic evaluation (MODE) technique to examine and compare the statistics of drought attributes over the upper Colorado River basin (UCRB). The drought objects are based on the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) on a 36‐month timescale (SPI36 and SPEI36, respectively). The drought indicators are calculated using monthly precipitation as well as minimum and maximum temperatures from the Precipitation–Elevation Regression on Independent Slopes Model data sets from 1948 to 2012. MODE uses paired object attributes such as centroid distance, orientation angle, area ratio, and intersection area and a combination of parameter thresholds to determine the number of objects identified and retained in the merging and matching process in the two fields. Using MODE run with convolution radius of zero (no smoothing) and an area threshold of four grid points, this study computes and analyses object statistics including centroid locations, areas, and intensity percentiles. Results of the analysis show that SPI36 produces more drought objects than SPEI36. Although the spatial patterns are roughly similar leading up to almost similar statistics of object attributes, such as locations of the object centroids, the SPI36 produces higher percentile intensity of drought objects than does SPEI36, which is clearly obvious in the 90th percentile intensity of drought objects. The largest difference between SPEI36 and SPI36 occurs in the area of drought objects during the early 2000s when the region experienced multi‐year drought resulting from increased warming of the atmosphere. This study demonstrates the use of MODE as a tool to evaluate and monitor drought event over the UCRB.
Discrimination of nitrogen fertilizer levels of tea plant (Camellia sinensis) based on hyperspectral imaging
Authors: Wang Yujie , Hu Xin , Hou Zhiwei , Ning Jingming , Zhang Zhengzhu
Published: April 2018

BACKGROUND

Nitrogen (N) fertilizer plays an important role in tea plantation management, with significant impacts on the photosynthetic capacity, productivity and nutrition status of tea plants. The present study aimed to establish a method for the discrimination of N fertilizer levels using hyperspectral imaging technique.

RESULTS

Spectral data were extracted from the region of interest, followed by the first derivative to reduce background noise. Five optimal wavelengths were selected by principal component analysis. Texture features were extracted from the images at optimal wavelengths by gray‐level gradient co‐occurrence matrix. Support vector machine (SVM) and extreme learning machine were used to build classification models based on spectral data, optimal wavelengths, texture features and data fusion, respectively. The SVM model using fused data gave the best performance with highest correct classification rate of 100% for prediction set.

CONCLUSION

The overall results indicated that visible and near‐infrared hyperspectral imaging combined with SVM were effective in discriminating N fertilizer levels of tea plants. © 2018 Society of Chemical Industry
The effect of natural rainfall on salt leaching under watertable management
Authors: Li Shan , Luo Wan , Jia Zhonghua , Tang Shuangcheng , Chen Cheng
Published: April 2018

Natural rainfall may produce effective leaching in some salt‐impacted irrigation areas; but the variable nature of rainfall often makes it difficult to assess the actual leaching effect of rainfall under different irrigation and drainage management. With a proposed analytical model that considers watertable management and crop use of shallow groundwater, this paper presents a case study that examined salt leaching effect of the natural rainfall in a semiarid irrigation area; the salt balance calculation was based on the daily watertable depth predicted by the DRAINMOD model using 55‐year weather data. The results showed that salt leaching effect of the natural rainfall depended on the control depth of field watertable through drainage system, crop use of shallow groundwater, and supplemental irrigation. For the salt tolerant crop—cotton, with the field watertable depth controlled at 1.5 m and the annual supplemental irrigation as 80 mm, the predicted average root zone salinity did not exceed the cotton tolerance level (4.92 g/L) in the simulation period. When the watertable depth was controlled at 1.2 m, due to increased shallow groundwater use, the predicted average root zone salinity was below the cotton tolerance level in 80% years with annual irrigation of 100 mm; and the predicted root zone salinity was below the cotton tolerance level in 96.4% years with annual irrigation of 150 mm. To achieve higher water use efficiency in semiarid irrigation area with saline shallow groundwater, proper watertable management is necessary to make use of the natural rainfall for salt leaching and shallow groundwater for temporary drought relief.
Ideal density‐dependent incompressible viscoelastic flow in the critical Besov spaces
Authors: Hua Qiu , Fang Shaomei
Published: April 2018

In this paper, we consider the well‐posedness issue for the density‐dependent incompressible viscoelastic fluids of the Oldroyd model for the ideal case in space dimension greater than 2. We obtain the local well‐posedness of this model under the assumption that the initial density is bounded away from zero in the critical Besov spaces by means of the Littlewood‐Paley theory and Bony's paradifferential calculus. In particular, we obtain a Beale‐Kato‐Majida–type regularity criterion.
Physical therapy needs for patients with physical function injuries post‐earthquake disasters: A systematic review of Chinese and Western literature
Authors: Li Hao , Nyland John , Kuban Katrina , Givens Justin
Published: April 2018

Background and purpose

Over the last 500 years, the most earthquakes with 10,000 or more fatalities and the most overall fatalities have occurred in China. Physical therapists must develop a better understanding of the patient and injury types that they are likely to treat post‐earthquake disasters. This systematic review of Chinese and Western literature identified the primary patients treated by physical therapists post‐earthquake disasters for injuries that negatively impacted physical function, activity, and participation.

Methods

Comparisons were made between reports of earthquakes in China and reports from the rest of the world combined.

Results

Sixty‐seven studies of 71,986 patients (51.8% male) at 40.6 ± 15 years of age were included. Studies were mostly prospective (n = 48, 71.6%). Reports of earthquakes in China represented more recently occurring disasters (p = .003) and more prospective research designs (p = .003). Reports from China also had a higher median fracture number (p = .004). Studies from China used manual muscle testing (p = .02), visual analogue pain scales (p = .008), Barthel index or modified Barthel index (p < .0001), and joint motion assessment (p = .007) with greater frequencies.

Discussion

Physical therapists from China are more likely to treat patients with a fracture; however, physical therapists from both regions are likely to treat patients with general injuries representing poly‐trauma to multiple body regions, traumatic brain‐closed head injuries, spinal cord injuries, peripheral nerve injuries, and soft tissue injuries.

Implications on physiotherapy practice

These data can help improve earthquake disaster planning, infrastructure development, and resource needs assessment effectiveness. More prospective research study designs and more recent earthquake disasters in China are likely associated with greater explicit use of valid and reliable outcome measurements such as joint motion assessment, manual muscle testing, visual analogue pain scale, and the Barthel index or modified Barthel index.
Adaptive multivariate double sampling and variable sampling interval Hotelling's T2 charts
Authors: Khatun Mahfuza , Khoo Michael B.C. , Yeong W.C. , Teoh W.L. , Chong Z.L.
Published: April 2018

In this article, two adaptive multivariate charts, which combine the double sampling (DS) and variable sampling interval (VSI) features, called the adaptive multivariate double sampling variable sampling interval T2 (AMDSVSI T2) and the adaptive multivariate double sampling variable sampling interval combined T2 (AMDSVSIC T2) charts, are proposed. The real purpose of using the proposed charts is to provide flexibility by enabling the sampling interval length of the DS T2 chart to be varied so that the chart's sensitivity can be enhanced. The fundamental difference between the two proposed charts is that when a second sample is taken, the AMDSVSI T2 chart uses the information of the combined sample mean vectors while the AMDSVSIC T2 chart uses the information of the combined T2 statistics, in deciding about the process status. This research is motivated by existing combined DS
and VSI
charts in the literature, which show convincing performance improvement over the standard DS
chart. Consequently, it is believed that adopting this existing approach in the multivariate case will enable superior multivariate DS charts to be proposed. Numerical results show that the proposed charts outperform the existing standard T2 and other adaptive multivariate charts, in detecting shifts in the mean vector, for the zero‐state and steady‐state cases. The performances of both charts when the shift sizes in the mean vector are unknown are also measured. The application of the AMDSVSI T2 chart is illustrated with an example.
Relationship between Roe and Metz simulation model for multireader diagnostic data and Obuchowski‐Rockette model parameters
Authors: Hillis Stephen L.
Published: April 2018

For the typical diagnostic radiology study design, each case (ie, patient) undergoes several diagnostic tests (or modalities) and the resulting images are interpreted by several readers. Often, each reader is asked to assign a confidence‐of‐disease rating to each case for each test, and the diagnostic tests are compared with respect to reader‐performance outcomes that are functions of the reader receiver operating characteristic (ROC) curves, such as the area under the ROC curve. These reader‐performance outcomes are frequently analyzed using the Obuchowski and Rockette method, which allows conclusions to generalize to both the reader and case populations. The simulation model proposed by Roe and Metz (RM) in 1997 emulates confidence‐of‐disease data collected from such studies and has been an important tool for empirically evaluating various reader‐performance analysis methods. However, because the RM model parameters are expressed in terms of a continuous decision variable rather than in terms of reader‐performance outcomes, it has not been possible to evaluate the realism of the RM model. I derive the relationships between the RM and Obuchowski‐Rockette model parameters for the empirical area under the ROC curve reader‐performance outcome. These relationships make it possible to evaluate the realism of the RM parameter models and to assess the performance of Obuchowski‐Rockette parameter estimates. An example illustrates the application of the relationships for assessing the performance of a proposed upper one‐sided confidence bound for the Obuchowski‐Rockette test‐by‐reader variance component, which is useful for sample size estimation.
Separable covariance models for health care quality measures across years and topics
Authors: Hatfield Laura A. , Zaslavsky Alan M.
Published: April 2018

Public quality reports for Medicare Advantage health plans include 11 measures of patient experiences reported in the annual Consumer Assessment of Healthcare Providers and Systems surveys. Computing summaries at the health plan level (of multiple measures in multiple years) yields an array‐structured random variable. To summarize associations among measures and years, we model the variance‐covariance matrix governing the plan‐level vectors of yearly quality measures as a Kronecker product of an across‐measure matrix and an across‐year matrix, or a sum of such Kronecker products. This approach extends separable covariance structure to Fay‐Herriot models. In addition, we develop linear combinations of Kronecker products similar to principal components for array random variables. To each Kronecker‐product term, we apply post hoc analyses suited to the corresponding dimension of the cross‐classification: 1‐way factor analysis for the across‐measure factor and time‐series analysis to the across‐year factor. These methods draw out key patterns of variation in the quality measures over time and suggest new strategies for reporting quality information to consumers.
Neurodevelopmental outcome of fetal isolated ventricular asymmetry without dilation: a cohort study
Authors: Meyer R. , Bar‐Yosef O. , Barzilay E. , Hoffman D. , Toussia‐Cohen S. , Zvi E. , Achiron R. , Katorza E.
Published: April 2018

Objective

Fetal isolated ventricular asymmetry (IVA) is a relatively common finding in pregnancy, but data regarding its effect on neurodevelopmental outcome are scarce and founded principally on ultrasound‐based studies. The purpose of this study was to assess the neurodevelopmental outcome of IVA cases in a magnetic resonance imaging (MRI)‐based study.

Methods

Cases referred for fetal brain MRI as part of the assessment of IVA without ventriculomegaly (lateral ventricular atrial diameter ≤ 10 mm), identified during routine ultrasound examination, were assessed for possible inclusion. Asymmetry was defined as a difference in width of ≥ 2 mm between the two lateral ventricles. Forty‐three cases were included in the study group and compared with a control group of 94 normal cases without IVA. Children were assessed at ages 13–74 months using the Vineland‐II Adaptive Behavior Scales (VABS‐II).

Results

VABS‐II scores were within normal range. There was no significant difference in composite VABS‐II score between the study and control groups (106.5 vs 108.0; P = 0.454). VABS‐II scores did not differ between the groups when matched for gender and age at VABS‐II interview (109.6 in study group vs 107.8 in control group; P = 0.690).

Conclusion

In cases of IVA without ventriculomegaly on MRI, neurodevelopmental test scores were normal and did not differ from cases without IVA. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Integrated free‐form method for aerostructural optimization of wind turbine blades
Authors: Barrett R. , Ning A.
Published: April 2018

A typical approach to optimize wind turbine blades separates the airfoil shape design from the blade planform design. This approach is sequential, where the airfoils along the blade span are preselected or optimized and then held constant during the blade planform optimization. In contrast, integrated blade design optimizes the airfoils and the blade planform concurrently and thereby has the potential to reduce cost of energy (COE) more than sequential design. Nevertheless, sequential design is commonly performed because of the ease of precomputation, or the ability to compute the airfoil analyses prior to the blade optimization. This research compares 2 integrated blade design approaches. The precomputational method combines precomputation with the ability to change the airfoil shapes in limited ways during the optimization. The free‐form method allows for a complete range of airfoil shapes, but without precomputation. The airfoils are analyzed with a panel method (XFOIL) and a Reynolds‐averaged Navier‐Stokes computational fluid dynamics method (RANS CFD). Optimizing the NREL 5‐MW reference turbine showed COE reductions of 2.0%, 4.2%, and 4.7% when using XFOIL and 2.7%, 6.0%, and 6.7% when using RANS CFD for the sequential, precomputational, and free‐form methods, respectively. The precomputational method captures most of the benefits of integrated design for minimal additional computational cost and complexity, but the free‐form method provides modest additional benefits if the extra effort is made in computational cost and development time.
Argyres-Douglas matter and S-duality. Part II
Authors: Xie Dan , Ye Ke
Published: April 2018

Abstract

We study S-duality of Argyres-Douglas theories obtained by compactification of 6d (2,0) theories of ADE type on a sphere with irregular punctures. The weakly coupled descriptions are given by the degeneration limit of auxiliary Riemann sphere with marked points, among which three punctured sphere represents isolated superconformal theories. We also discuss twisted irregular punctures and their S-duality.
Coherence effects in disordered geometries with a field-theory dual
Authors: Andrade Tomás , García-García Antonio M. , Loureiro Bruno
Published: April 2018

Abstract

We investigate the holographic dual of a probe scalar in an asymptotically Anti-de-Sitter (AdS) disordered background which is an exact solution of Einstein’s equations in three bulk dimensions. Unlike other approaches to model disorder in holography, we are able to explore quantum wave-like interference effects between an oscillating or random source and the geometry. In the weak-disorder limit, we compute analytically and numerically the one-point correlation function of the dual field theory for different choices of sources and backgrounds. The most interesting feature is the suppression of the one-point function in the presence of an oscillating source and weak random background. We have also computed analytically and numerically the two-point function in the weak disorder limit. We have found that, in general, the perturbative contribution induces an additional power-law decay whose exponent depends on the distribution of disorder. For certain choices of the gravity background, this contribution becomes dominant for large separations which indicates breaking of perturbation theory and the possible existence of a phase transition induced by disorder.
Migdal effect in dark matter direct detection experiments
Authors: Ibe Masahiro , Nakano Wakutaka , Shoji Yutaro , Suzuki Kazumine
Published: April 2018

Abstract

The elastic scattering of an atomic nucleus plays a central role in dark matter direct detection experiments. In those experiments, it is usually assumed that the atomic electrons around the nucleus of the target material immediately follow the motion of the recoil nucleus. In reality, however, it takes some time for the electrons to catch up, which results in ionization and excitation of the atoms. In previous studies, those effects are taken into account by using the so-called Migdal’s approach, in which the final state ionization/excitation are treated separately from the nuclear recoil. In this paper, we reformulate the Migdal’s approach so that the “atomic recoil” cross section is obtained coherently, where we make transparent the energy-momentum conservation and the probability conservation. We show that the final state ionization/excitation can enhance the detectability of rather light dark matter in the GeV mass range via the nuclear scattering. We also discuss the coherent neutrino-nucleus scattering, where the same effects are expected.