bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-English Majors’ Listening Teaching based on Lexical Chunks Theory and Schema Theory
Authors: He Xiaoyu
Published: January 2016

English listening is seen as a vital means of linguistic input for Chinese EFL (English as a Foreign Language) learners, which lays a solid foundation for English learning and communication with English speakers. Besides, with increasing of scores of the listening part in the newly-reformed CET-4 and CET-6 (CET refers to college English test in China and both tests are the evaluation criteria of non-English majors’ English proficiency), it is urgent to improve non-English majors’ listening abilities in language teaching. However, students find listening to English stressful and painful and it is hard for them to process information quickly enough when listening. Meanwhile, their listening abilities cannot be improved effectively by the traditional English listening teaching methods. Researchers at home and abroad have discussed listening strategies, but seldom study the combination of lexical chunks theory and schema theory in improving non-English majors’ listening. Therefore, this research first proposes a lexical chunks schema-oriented listening teaching method which can effectively improve non-English majors’ listening abilities and then conducts an empirical study to verify its effectiveness. As the lexical chunks schema-oriented listening teaching method suggests, activities about memorization, recognition and reconstruction of lexical chunks, activation of the existed schema and building up new schema should be carried out in pre-listening, while-listening and post-listening in the listening class.
Two atypical new species of the genus Sectonema Thorne, 1930 (Nematoda, Dorylaimida, Aporcelaimidae) from Vietnam
Authors: Nguyen Thi Anh Duong , Abolafia Joaquín , Bonkowski Michael , Peña-Santiago Reyes , Álvarez-Ortega Sergio
Published: January 2016

Two new species of the genus Sectonema from natural habitats of northern Vietnam are studied. This paper includes their descriptions, measurements, line illustrations, and light microscope (LM) and scanning electron microscope (SEM) pictures. Sectonema tropicum sp. nov. is characterized by a 2.56–3.24 mm long body, 19–21 μm broad lip region, odontostyle 20–21 μm long at its ventral side, 730–834 μm long neck, pharyngeal expansion occupying 52–59% of total neck length, uterus a simple tube-like structure 150–242 μm long or 1.2–2.5 times the body diameter, pars refringens vaginae present, V = 48–52, short (31–40 μm, c = 70–91, c’ = 0.5–0.6) and rounded tail, 91–97 μm long spicules, and only one weakly developed ventromedian supplement. Sectonema vietnamense sp. nov. is characterized by its slender (a = 33–49) and 2.71–4.25 mm long body, 14–16 μm broad lip region, odontostyle 8–9 μm long at its ventral side, 716–918 μm long neck, pharyngeal expansion occupying 63–67% of total neck length, uterus simple and 209–242 μm long or 2.5–2.9 times the corresponding body diameter, pars refringens vaginae absent, V = 54, short (34–39 μm, c = 70–115, c’ = 0.6–0.8) and rounded tail, 59–75 μm long spicules, and three or four irregularly spaced ventromedian supplements bearing hiatus. Both species are also characterized by their nearly continuous lip region, an atypical feature in this genus. Molecular analysis of S. tropicum sp. nov. confirms that Sectonema is a natural (monophyletic) taxon, very close to Metaporcelaimus.
Negritude sem etnicidade: o local e o global nas relações raciais e na produção cultural negra do Brasil
Authors: Sansone Livio
Published: January 2016

Com base em 15 anos de pesquisa na Bahia, no Rio, no Suriname e na Holanda, Livio Sansone indaga sobre as formas específicas que "raça" e etnicidade assumem no Brasil e no resto da América Latina. Ele compara as concepções latino-americanas de "raça" com as concepções dominantes nas ciências sociais, centradas em contextos determinados por identidades branco-negro claramente definidas, formuladas na base da situação dos Estados Unidos e da Europa do Noroeste. Sansone sugere que o estudo de noções de identidade e cultura mais complexas e até "ambíguas", certamente contribui para uma compreensão mais universal das tensões etno-raciais e de por que o pensamento racial continua tão forte. Ele também investiga os efeitos da globalização sobre as diferentes construções da noção de raça.
Influence of voltage on etching rate of hydrogenated amorphous carbon films with HNO3 studied using surface plasmon resonance
Authors: Tunmee Sarayut , Nakaya Yasuyuki , Zhou XiaoLong , Arakawa Satoru , Komatsu Keiji , Ito Haruhiko , Saitoh Hidetoshi
Published: January 2016

Etching of hydrogenated amorphous carbon (a-C:H) films in 0.1 M nitric acid was evaluated using surface plasmon resonance at the applied voltages of 0.0, −1.0, and 1.0 V. The etching rates of the a-C:H films as functions of the applied voltages and etching duration were obtained to be 0.0368 (at 0.0 V), 0.0117 (at −1.0 V), and 0.0074 nm/min (at 1.0 V). These results clearly indicate that the etching rates decrease significantly under the conditions of applying positive or negative voltage, demonstrating the enhanced corrosion resistance of the a-C:H films upon applying voltage.
Leadership Behaviors and Its Relation with Principals’ Management Experience
Authors: Mehdinezhad Vali , Sardarzahi Zaid
Published: January 2016

This paper aims at studying the leadership behaviors reported by principals and observed by teachers and its relationship with management experience of principals. A quantitative method was used in this study. The target population included all principals and teachers of guidance schools and high schools in the Dashtiari District, Iran. A sample consisting of 46 principals and 129 teachers was selected by stratified sampling and simple random sampling methods. A leadership Behavior Description Questionnaire (LBDQ) developed by Kozes and Posner (2001) was used for data collection. The obtained data were analyzed using one sample and independent t-test, correlation coefficient and crosstabs pearson Chi-square test. The results showed that teachers describe leadership behaviors of their principals relatively well. However, principals themselves evaluated their leadership behaviors as very well. Comparing between leadership behaviors self-reported by principals and those observed by teachers, a significant difference was found between the views and evaluations of teachers and principals on all components of leadership behaviors of principals, except that regarding empowerment. In fact, principals described their leadership behaviors better and at a more appropriate level than teachers. From the perspective of both teachers and principals, there was no significant relationship between any of the components of leadership behaviors and management experience of principals.
Ionospheric data assimilation and forecasting during storms
Authors: Chartier Alex T. , Matsuo Tomoko , Anderson Jeffrey L. , Collins Nancy , Hoar Timothy J. , Lu Gang , Mitchell Cathryn N. , Coster Anthea J. , Paxton Larry J. , Bust Gary S.
Published: January 2016

Ionospheric storms can have important effects on radio communications and navigation systems. Storm time ionospheric predictions have the potential to form part of effective mitigation strategies to these problems. Ionospheric storms are caused by strong forcing from the solar wind. Electron density enhancements are driven by penetration electric fields, as well as by thermosphere‐ionosphere behavior including Traveling Atmospheric Disturbances and Traveling Ionospheric Disturbances and changes to the neutral composition. This study assesses the effect on 1 h predictions of specifying initial ionospheric and thermospheric conditions using total electron content (TEC) observations under a fixed set of solar and high‐latitude drivers. Prediction performance is assessed against TEC observations, incoherent scatter radar, and in situ electron density observations. Corotated TEC data provide a benchmark of forecast accuracy. The primary case study is the storm of 10 September 2005, while the anomalous storm of 21 January 2005 provides a secondary comparison. The study uses an ensemble Kalman filter constructed with the Data Assimilation Research Testbed and the Thermosphere Ionosphere Electrodynamics General Circulation Model. Maps of preprocessed, verticalized GPS TEC are assimilated, while high‐latitude specifications from the Assimilative Mapping of Ionospheric Electrodynamics and solar flux observations from the Solar Extreme Ultraviolet Experiment are used to drive the model. The filter adjusts ionospheric and thermospheric parameters, making use of time‐evolving covariance estimates. The approach is effective in correcting model biases but does not capture all the behavior of the storms. In particular, a ridge‐like enhancement over the continental USA is not predicted, indicating the importance of predicting storm time electric field behavior to the problem of ionospheric forecasting.
Surface slip during large Owens Valley earthquakes
Authors: Haddon E. K. , Amos C. B. , Zielke O. , Jayko A. S. , Bürgmann R.
Published: January 2016

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross‐correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple‐event displacements. Lateral offsets for 1872 vary systematically from ∼1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east‐down between ∼0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral‐to‐vertical ratio compiled at specific sites is ∼6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7–11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw∼7.5 for the 1872 event. We attribute progressively higher‐offset lateral COPD peaks at 7.1 ± 2.0 m, 12.8 ± 1.5 m, and 16.6 ± 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between ∼0.6 and 1.6 mm/yr (1σ) over the late Quaternary.
Stable and clumped isotopes in shell carbonates of land snails Cathaica sp. and Bradybaena sp. in north China and implications for ecophysiological characteristics and paleoclimate studies
Authors: Wang Xu , Cui Linlin , Zhai Jixuan , Ding Zhongli
Published: January 2016

Knowledge of ecophysiological characteristics of different land snail species is crucial for defining climatic significance of snail faunal assemblages. However, little work has been done in this aspect, hindering our obtaining unambiguous paleoclimatic information using these proxy indicators. Here we document for the first time the different ecophysiological characteristics of Cathaica sp. and Bradybaena sp. land snails using the stable isotopes and clumped isotope (Δ47) of the shell carbonates. The Δ47‐derived temperatures for both species revealed a robust correlation with environmental temperatures. Moreover, the temperatures for Cathaica sp. are 3–5°C higher than those for Bradybaena sp. land snails, indicating different ecophysiological adaptations or growing seasons of the two species. Specifically, Cathaica sp. snails prefer living in a warm‐humid summer, whereas Bradybaena sp. snails are active in the relatively cool‐arid spring and/or autumn. The result testifies to the Δ47 in snail shell carbonates as a promising paleothermometer in monsoonal region and presents new insight into paleoclimatic explanation of these land snail species. This finding highlights the importance of climatic seasonality in the changes of the faunal assemblages of land snails.
Coherence and phase structure of compressional ULF waves at low‐Earth orbit observed by the Swarm satellites
Authors: Heilig B. , Sutcliffe P. R.
Published: January 2016

In this paper we present results of a study of Pc3 compressional waves observed at low‐Earth orbit (LEO) by the Swarm satellites. The particular emphasis has been to investigate the distribution of wave coherence and phase difference as functions of magnetic latitude and local time. This is the first time that a study of this nature has been carried out using magnetic field data from multiple LEO satellites. We have also for the first time shown how our analysis technique can be used to discriminate between static spatial and simultaneous temporal wave structures observed in the ionosphere. We believe that our study provides the first observational evidence to support the prediction by the inductive thin ionosphere model that incident Alfvén mode waves are partially converted into compressional mode waves by the ionosphere.
The Bolivian, Botswana, and Bilybara Highs and Southern Hemisphere drought/floods
Authors: Reason C. J. C.
Published: January 2016

Semipermanent anticyclones in the midlevel troposphere over the subtropical landmasses are a prominent component of Southern Hemisphere climate. Typically, they occur over Bolivia, Botswana/Namibia, and northwestern Australia from austral spring to about April and are strongest in late summer. Here a mode of variability is studied that modulates the strength of these midlevel anticyclones and which is not strongly tied to El Niño–Southern Oscillation. This mode leads to variations in January–March rainfall over large parts of South America, southern Africa, and Australia on both interannual and near‐decadal scales.
Time scales of the European surface air temperature variability: The role of the 7–8 year cycle
Authors: Jajcay Nikola , Hlinka Jaroslav , Kravtsov Sergey , Tsonis Anastasios A. , Paluš Milan
Published: January 2016

Air temperature variability on different time scales exhibits recurring patterns and quasi‐oscillatory phenomena. Climate oscillations with the period about 7–8 years have been observed in many instrumental records in Europe. Although these oscillations are weak if considering their amplitude, they might have nonnegligible influence on temperature variability on shorter time scales due to cross‐scale interactions recently observed by Paluš (2014). In order to quantify the cross‐scale influence, we propose a simple conditional mean approach which estimates the effect of the cycle with the period close to 8 years on the amplitude of the annual cycle in surface air temperature (SAT) in the range 0.7–1.4°C and the effect on the overall variability of the SAT anomalies (SATA) leads to the changes 1.5–1.7°C in the annual SATA means. The strongest effect in the winter SATA means reaches 4–5°C in central European station and reanalysis data.
On the unique divergent response of the equatorial electrojet vertical polarization electric field to different solar flare events
Authors: Manju G.
Published: January 2016

The response of ionospheric E region to different flare events is investigated using coherent HF backscatter radar to bring out divergent observations. The study reveals the following aspects: (i) increase of absolute mean Doppler frequency by ~25–52% during the initial phase of the morning time flares of 9 September 2005 with concurrent fall in backscattered power and (ii) decrease of absolute mean Doppler frequency by ~11.6–16.2% during the initial phase of the flare of 20 February 2002 with concurrent fall in backscattered power. The Doppler frequency is directly related to vertical polarization electric field. Therefore, these observations are unique and in contrast to earlier works which have, in general, reported only a decrease in equatorial electrojet (EEJ) vertical polarization electric field during the initial phase of flare events. The present study also brings out the possible important role played by the height‐integrated conductivities in producing the divergent response of the EEJ. The large reduction in backscattered power for weak M class flare events is also observed in this study. In view of the importance of the ionosphere as a major source of error in GPS‐based navigation, the present result assumes significance.
Nonlinearity in chorus waves during a geomagnetic storm on 1 November 2012
Authors: Matsui H. , Paulson K. W. , Torbert R. B. , Spence H. E. , Kletzing C. A. , Kurth W. S. , Skoug R. M. , Larsen B. A. , Breneman A. W.
Published: January 2016

In this study, we investigate the possibility of nonlinearity in chorus waves during a geomagnetic storm on 1 November 2012. The data we use were measured by the Van Allen Probe B. Wave data and plasma sheet electron data are analyzed. Chorus waves were frequently measured in the morning side during the main phase of this storm. Large‐amplitude chorus waves were seen of the order of ∼0.6 nT and >7 mV/m, which are similar to or larger than the typical ULF waves. The waves quite often consist of rising tones during the burst sampling. Since the rising tone is known as a signature of nonlinearity, a large portion of the waves are regarded as nonlinear at least during the burst sampling periods. These results underline the importance of nonlinearity in the dynamics of chorus waves. We further compare the measurement and the nonlinear theories, based on the inhomogeneity ratio, our own calculation derived from the field equation and the backward wave oscillator model. The wave quantities examined are frequency, amplitude, frequency drift rate, and duration. This type of study is useful to more deeply understand wave‐particle interactions and hence may lead to predicting the generation and loss of radiation belt electrons in the future.
A wind‐driven, hybrid latent and sensible heat coastal polynya off Barrow, Alaska
Authors: Hirano Daisuke , Fukamachi Yasushi , Watanabe Eiji , Ohshima Kay I. , Iwamoto Katsushi , Mahoney Andrew R. , Eicken Hajo , Simizu Daisuke , Tamura Takeshi
Published: January 2016

The nature of the Barrow Coastal Polynya (BCP), which forms episodically off the Alaska coast in winter, is examined using mooring data, atmospheric reanalysis data, and satellite‐derived sea‐ice concentration and production data. We focus on oceanographic conditions such as water mass distribution and ocean current structure beneath the BCP. Two moorings were deployed off Barrow, Alaska in the northeastern Chukchi Sea from August 2009 to July 2010. For sea‐ice season from December to May, a characteristic sequence of five events associated with the BCP has been identified; (1) dominant northeasterly wind parallel to the Barrow Canyon, with an offshore component off Barrow, (2) high sea‐ice production, (3) upwelling of warm and saline Atlantic Water beneath the BCP, (4) strong up‐canyon shear flow associated with displaced density surfaces due to the upwelling, and (5) sudden suppression of ice growth. A baroclinic current structure, established after the upwelling, caused enhanced vertical shear and corresponding vertical mixing. The mixing event and open water formation occurred simultaneously, once sea‐ice production had stopped. Thus, mixing events accompanied by ocean heat flux from the upwelled warm water into the surface layer played an important role in formation/maintenance of the open water area (i.e., sensible heat polynya). The transition from a latent to a sensible heat polynya is well reproduced by a high‐resolution pan‐Arctic ice‐ocean model. We propose that the BCP, previously considered to be a latent heat polynya, is a wind‐driven hybrid latent and sensible heat polynya, with both features caused by the same northeasterly wind.
Impacts of Noah model physics on catchment‐scale runoff simulations
Authors: Zheng Donghai , Van der Velde Rogier , Su Zhongbo , Wen Jun , Wang Xin , Booij Martijn J. , Hoekstra Arjen Y. , Lv Shihua , Zhang Yu , Ek Michael B.
Published: January 2016

Noah model physics options validated for the source region of the Yellow River (SRYR) are applied to investigate their ability in reproducing runoff at the catchment scale. Three sets of augmentations are implemented affecting descriptions of (i) turbulent and soil heat transport (Noah‐H), (ii) soil water flow (Noah‐W), and (iii) frozen ground processes (Noah‐F). Five numerical experiments are designed with the three augmented versions, a control run with default model physics and a run with all augmentations (Noah‐A). Each experiment is set up with vegetation and soil parameters from Weather Research and Forecasting data set, soil organic matter content from China Soil Database, 0.1° atmospheric forcing data from Institute of Tibetan Plateau Research (Chinese Academy of Sciences), and initial equilibrium model states achieved using a single‐year recurrent spin‐up. In situ heat flux, soil temperature (Ts), and soil moisture (θ) profile measurements are available for point‐scale assessment, whereas monthly streamflow is utilized for the catchment‐scale evaluation. The comparison with point measurements shows that the augmentations invoked with Noah‐H resolve issues with the heat flux and Ts simulation and Noah‐W mitigates deficiencies in the θ simulation, while Noah‐A yields improvements for both simulated surface energy and water budgets. In contrast, Noah‐F has a minor effect. Also, at catchment scale, the best model performance is found for Noah‐A leading to a base flow‐dominated runoff regime, whereby the surface runoff contribution remains significant. This study highlights the need for a complete description of vertical heat and water exchanges to correctly simulate the runoff in the seasonally frozen and high‐altitude SRYR at the catchment scale.
Meltwater influences on deep stick‐slip icequakes near the base of the Greenland Ice Sheet
Authors: Roeoesli Claudia , Helmstetter Agnes , Walter Fabian , Kissling Edi
Published: January 2016

We detected over 11,000 stick‐slip icequakes near the base of the western margin of the Greenland Ice Sheet using a 17‐seismometer array. These icequakes have negative (i.e., very small) moment magnitudes and, according to similarities in their waveforms, group into over 100 distinct clusters distributed beneath our 3 × 3 km study area. Some clusters were active for several weeks, while others have burst‐like episodes lasting 1–6 days only. Some clusters correlate with subglacial water pressure measured within a nearby moulin. For these clusters, we observe high water pressure concurrent with many small yet numerous stick‐slip icequakes and periods of lower water pressures with larger, less frequent icequakes. These patterns might change over time and are not common to all clusters. We explain these observations that the stick‐slip icequakes are located at sticky spots at the interface of the ice sheet with the glacier bed that consists of basal till characterized by different connectivity to the subglacial drainage system. Because the till's frictional strength depends on its pore pressure, variations in subglacial water pressure can either weaken or strengthen the bed; this explains the variation in seismic moments and interevent times. Our results suggest that seismogenic stick‐slip motion is an integral part of the flow mechanism in the ablation zone in western Greenland, which is highly sensitive to the configuration of the local subglacial drainage system. Stick‐slip motion may therefore play a key role in the relationship between climate‐induced changes of surface runoff and ice sheet dynamics.
Impacts of chronic N input on the carbon and nitrogen storage of a postfire Mediterranean‐type shrubland
Authors: Vourlitis George L. , Hentz Cloe S.
Published: January 2016

Mediterranean‐type shrublands are subject to periodic fire and high levels of nitrogen (N) deposition, but little is known how chronic N deposition affects carbon (C) and N storage during succession. We conducted a long‐term experiment in Californian chaparral to test the hypothesis that chronic N enrichment would increase postfire C and N accumulation. The experimental layout consisted of a randomized design where four 10 × 10 m plots received 5 g N m−2annually since 2003 and four 10 × 10 m plots served as controls. Aboveground and belowground C and N pools and fluxes were measured seasonally (every 3 months) for a period of 10 years. Added N rapidly increased soil extractable N pools and decreased soil pH; however, total soil C and N storage were not affected. Added N plots initially had significantly lower C and N storage than control plots, presumably because of nutrient losses from leaching and/or higher belowground C allocation. However, rates of aboveground N and C storage became significantly higher in added N plots after 4–5 years of exposure, thus increasing fuel buildup, which has implications for future fire intensity. This recovering chaparral stand is not yet “N saturated” after 10 years of chronic N input. However, N leaching continues to be higher in added N plots, indicating that postfire chaparral stands in high‐N deposition areas can be important sources of N to groundwater/aquatic systems even if productivity is stimulated by N input.
Estimation of evaporation over the upper Blue Nile basin by combining observations from satellites and river flow gauges
Authors: Allam Mariam M. , Jain Figueroa Anjuli , McLaughlin Dennis B. , Eltahir Elfatih A. B.
Published: January 2016

Reliable estimates of regional evapotranspiration are necessary to improve water resources management and planning. However, direct measurements of evaporation are expensive and difficult to obtain. Some of the difficulties are illustrated in a comparison of several satellite‐based estimates of evapotranspiration for the Upper Blue Nile (UBN) basin in Ethiopia. These estimates disagree both temporally and spatially. All the available data products underestimate evapotranspiration leading to basin‐scale mass balance errors on the order of 35 percent of the mean annual rainfall. This paper presents a methodology that combines satellite observations of rainfall, terrestrial water storage as well as river‐flow gauge measurements to estimate actual evapotranspiration over the UBN basin. The estimates derived from these inputs are constrained using a one‐layer soil water balance and routing model. Our results describe physically consistent long‐term spatial and temporal distributions of key hydrologic variables, including rainfall, evapotranspiration, and river‐flow. We estimate an annual evapotranspiration over the UBN basin of about 2.55 mm per day. Spatial and temporal evapotranspiration trends are revealed by dividing the basin into smaller subbasins. The methodology described here is applicable to other basins with limited observational coverage that are facing similar future challenges of water scarcity and climate change.
Enhancing multiple‐point geostatistical modeling: 1. Graph theory and pattern adjustment
Authors: Tahmasebi Pejman , Sahimi Muhammad
Published: January 2016

In recent years, higher‐order geostatistical methods have been used for modeling of a wide variety of large‐scale porous media, such as groundwater aquifers and oil reservoirs. Their popularity stems from their ability to account for qualitative data and the great flexibility that they offer for conditioning the models to hard (quantitative) data, which endow them with the capability for generating realistic realizations of porous formations with very complex channels, as well as features that are mainly a barrier to fluid flow. One group of such models consists of pattern‐based methods that use a set of data points for generating stochastic realizations by which the large‐scale structure and highly‐connected features are reproduced accurately. The cross correlation‐based simulation (CCSIM) algorithm, proposed previously by the authors, is a member of this group that has been shown to be capable of simulating multimillion cell models in a matter of a few CPU seconds. The method is, however, sensitive to pattern's specifications, such as boundaries and the number of replicates. In this paper the original CCSIM algorithm is reconsidered and two significant improvements are proposed for accurately reproducing large‐scale patterns of heterogeneities in porous media. First, an effective boundary‐correction method based on the graph theory is presented by which one identifies the optimal cutting path/surface for removing the patchiness and discontinuities in the realization of a porous medium. Next, a new pattern adjustment method is proposed that automatically transfers the features in a pattern to one that seamlessly matches the surrounding patterns. The original CCSIM algorithm is then combined with the two methods and is tested using various complex two‐ and three‐dimensional examples. It should, however, be emphasized that the methods that we propose in this paper are applicable to other pattern‐based geostatistical simulation methods.
Enhancing multiple‐point geostatistical modeling: 2. Iterative simulation and multiple distance function
Authors: Tahmasebi Pejman , Sahimi Muhammad
Published: January 2016

This series addresses a fundamental issue in multiple‐point statistical (MPS) simulation for generation of realizations of large‐scale porous media. Past methods suffer from the fact that they generate discontinuities and patchiness in the realizations that, in turn, affect their flow and transport properties. Part I of this series addressed certain aspects of this fundamental issue, and proposed two ways of improving of one such MPS method, namely, the cross correlation‐based simulation (CCSIM) method that was proposed by the authors. In the present paper, a new algorithm is proposed to further improve the quality of the realizations. The method utilizes the realizations generated by the algorithm introduced in Part I, iteratively removes any possible remaining discontinuities in them, and addresses the problem with honoring hard (quantitative) data, using an error map. The map represents the differences between the patterns in the training image (TI) and the current iteration of a realization. The resulting iterative CCSIM—the iCCSIM algorithm—utilizes a random path and the error map to identify the locations in the current realization in the iteration process that need further “repairing;” that is, those locations at which discontinuities may still exist. The computational time of the new iterative algorithm is considerably lower than one in which every cell of the simulation grid is visited in order to repair the discontinuities. Furthermore, several efficient distance functions are introduced by which one extracts effectively key information from the TIs. To increase the quality of the realizations and extracting the maximum amount of information from the TIs, the distance functions can be used simultaneously. The performance of the iCCSIM algorithm is studied using very complex 2‐D and 3‐D examples, including those that are process‐based. Comparison is made between the quality and accuracy of the results with those generated by the original CCSIM algorithm, which demonstrates the superior performance of the iCCSIM.
Trading‐off tolerable risk with climate change adaptation costs in water supply systems
Authors: Borgomeo Edoardo , Mortazavi‐Naeini Mohammad , Hall Jim W. , O'Sullivan Michael J. , Watson Tim
Published: January 2016

Choosing secure water resource management plans inevitably requires trade‐offs between risks (for a variety of stakeholders), costs, and other impacts. We have previously argued that water resources planning should focus upon metrics of risk of water restrictions, accompanied by extensive simulation and scenario‐based exploration of uncertainty. However, the results of optimization subject to risk constraints can be sensitive to the specification of tolerable risk, which may not be precisely or consistently defined by different stakeholders. In this paper, we recast the water resources planning problem as a multiobjective optimization problem to identify least cost schemes that satisfy a set of criteria for tolerable risk, where tolerable risk is defined in terms of the frequency of water use restrictions of different levels of severity. Our proposed method links a very large ensemble of climate model projections to a water resource system model and a multiobjective optimization algorithm to identify a Pareto optimal set of water resource management plans across a 25 years planning period. In a case study application to the London water supply system, we identify water resources management plans that, for a given financial cost, maximize performance with respect to one or more probabilistic criteria. This illustrates trade‐offs between financial costs of plans and risk, and between risk criteria for four different severities of water use restrictions. Graphical representation of alternative sequences of investments in the Pareto set helps to identify water management options for which there is a robust case for including them in the plan.
Fungal Pathogens of Humans
Authors: Mitchell Thomas G
Published: January 2016

Most fungi that cause human infections are free‐living saprobes and only accidental pathogens. The most prevalent mycoses are caused by fungi that are either members of the normal human microbiota, such as species ofCandidaandMalassezia, or ubiquitous, exogenous fungi that are highly adapted for survival on the human host, such as species ofAspergillusandCryptococcus. This article will summarise the aetiology, risk factors and clinical manifestations of the most common mycoses. Strategies for their diagnoses include traditional methods of microscopy and culture, as well as the detection of fungal antigens and antifungal antibodies, fungal deoxyribonucleic acid and structural components. Because both infectious fungi and their human hosts are eukaryotes, they share many cellular processes and macromolecules. Consequently, it is difficult to identify targets for antifungal drugs that do not inflict collateral damage on the patients.

Key Concepts

Superficial and cutaneous mycoses are among the most common of all communicable diseases.

Geophilic and zoophilic dermatophytes usually cause acute, inflammatory lesions that respond to topical treatment within weeks and rarely recur. Conversely, anthropophilic dermatophytes tend to cause relatively mild, chronic lesions that may require months or years of treatment and frequently relapse.

Subcutaneous mycoses may be caused by dozens of environmental moulds associated with vegetation and soil. These fungi are usually acquired by contamination of minor wounds. The infections are generally chronic and rarely spread to deeper tissues.

The endemic mycoses (coccidioidomycosis, histoplasmosis, blastomycosis and paracoccidioidomycosis) are caused by dimorphic environmental moulds and associated with distinct geographic regions.

More than 90% of endemic mycoses are caused by inhaling airborne conidia, and, in immunocompetent persons, the infections are asymptomatic or self‐limited; however, latent, viable fungal cells may persist and subsequently reactivate to cause overt disease. Risk factors for the manifestation of disease include compromised cell‐mediated immunity, genetic predisposition and male gender.

Opportunistic mycoses are caused by globally distributed fungi that are either members of the human microbiota or ubiquitous environmental fungi. These mycoses have the highest global mortality.

Innate immune responses (e.g. neutrophils, monocytes) provide crucial protection from systemic candidiasis, invasive aspergillosis and mucormycosis.

Most patients with HIV/AIDS develop mucosal candidiasis (e.g. thrush, oesophagitis). Those with CD4+counts less than 100 cells μL−1are at risk for invasive fungi, such asCryptococcus,Aspergillusand others.

Effective treatment of invasive mycoses relies on rapid identification of the fungus, administration of the appropriate antifungal drug and management of any underlying disease or condition.
Cytokine Assays
Authors: Butterfield Lisa H , Whiteside Theresa L
Published: January 2016

Cytokines are small molecular weight proteins or glycoproteins produced by various cells. They mediate cellular interactions and play a key role in health and disease. They bind to high‐affinity receptors located on various target cells and deliver signals responsible for a variety of biological effects. Once induced by external or internal stimuli, cytokines work as cascades. They regulate physiological interactions between cells, but they also have a potential for inducing tissue damage. While cytokines are local mediators meant to transiently regulate cells within microenvironments, in disease, they may trigger powerful and long‐lasting systemic toxicities. Cytokines are mediators of inflammation, and their qualitative and quantitative ‘profiles’ change as acute states become chronic. Today, cytokine expression by individual cells, their levels in body fluids and localisation in tissues can be readily measured and serially monitored to follow disease‐associated alterations. Measurements of ‘cytokine profiles’ are emerging as an important and informative parameter in diagnosis and prognosis of many human diseases.

Key Concepts

Assessments of cytokines underscore their physiological importance in health and disease.

A broad spectrum of assays for cytokine measurements is available.

Measuring several cytokines, establishing a ‘cytokine profile’, is most informative.

Cytokines are induced mediators and their biological effects are transient.

Cytokines mediate inflammation and thus impact on many clinical symptoms.

Profiling of cytokines may be diagnostically and prognostically useful.

Serial monitoring of cytokine profiles in disease emerges as a clinically helpful strategy.

The role of cytokines as biomarkers of disease progression and outcome is still to be validated.
Plant Reproduction
Authors: Brownfield Lynette , Twell David
Published: January 2016

Reproduction is required for the generation of new individuals. In land plants, reproduction can be asexual, where the offspring are genetically identical to the parent, or sexual, creating genetic variation. The life cycle of plants involves two alternating generations; a sporophyte that makes spores and a gametophyte that produces male and female gametes. During land plant evolution, this life cycle has altered from the gametophyte generation being the larger dominant generation to the sporophyte being the dominant plant we are familiar with. The structures that make spores and gametes, and the way reproductive cells are exchanged and dispersed, have also altered greatly as plants became better adapted to living in drier environments. Reproduction in the flowering plants has been extensively studied due to their economic importance, and we are beginning to uncover intriguing details of the molecular events that control critical aspects of the process in model and crop plants.

Key Concepts

Asexual reproduction produces genetically identical offspring and is beneficial under good conditions.

Plants alternate between a diploid spore‐producing generation and a haploid gamete‐producing generation.

In plants, spores are produced by meiosis and can be either released into the environment (bryophytes and nonseed plants) or develop within maternal tissues (seed plants).

Distinct male and female gametes are produced in plants by mitotic divisions of haploid cells.

Pollen is an evolutionary advance as it enables the dispersal and the delivery of the male gametes to the female gametes in the absence of free water.

Seeds aid in the dispersal of offspring by providing a protective coat and a nutrition source to support seedlings during germination.

The time of flowering is controlled through both internal signals and environmental cues, which control the production of a flower promoting protein.

The development of the male and female gametophytes in flowering plants requires precise regulation to ensure the correct cell types are generated in the correct locations.

Pollination is the process by which a pollen grain lands on a receptive female and grows a pollen tube through the female tissue towards an ovule.

Seed development in flowering plants requires two fertilisation events (double fertilisation) to produce the embryo and an endosperm needed for seed development.
Roots: Contribution to the Rhizosphere
Authors: Curlango‐Rivera Gilberto , Gunawardena Uvini , Wen Fushi , Zhao Xiaowen , Xiong Zhongguo , Hawes Martha C
Published: January 2016

Diverse compounds exuded by different parts of the root system create a unique environment known as the rhizosphere. Interactions among microorganisms found within the rhizosphere and communication between these microorganisms and plant roots play an important role in maintaining plant health. In 2004, the discovery of deoxyribonucleic acid (DNA)‐based neutrophil extracellular traps (NETs) have transformed our understanding of mammalian immune responses. Subsequent studies revealed that plant roots express a similar mechanism in the rhizosphere, where root border cells secrete extracellular DNA together with antibiotic amino acids, enzymes and other proteins, to trap pathogens and prevent their invasion of the root system. As in animals, the defense response is impaired if extracellular proteins and/or extracellular DNA are degraded by protease and/or by DNase at the time of inoculation with fungal or bacterial pathogens. Defining species‐specific mechanisms of plant extracellular trapping may yield new avenues for engineering the rhizosphere to improve crop production.

Key Concepts

Extracellular DNA (exDNA) in the rhizosphere has long been observed, and was presumed to result from cell death.

Recent studies have revealed that exDNA is a key component of an extracellular matrix involved in trapping and immobilisation of pathogens.

The specificity of exDNA‐based trapping may play a critical role in microbial population structure in the rhizosphere.

The discovery that DNA‐based extracellular trapping operates in animals and plants suggests that this previously unrecognised process is an ancient underpinning of eukaryotic defence.

Efforts to engineer the rhizosphere may be facilitated by a better understanding of how plants control the environment surrounding their roots.
Enzyme‐Linked Immunosorbent Assay
Authors: Paulie Staffan , Perlmann Hedvig
Published: January 2016

Enzyme‐linked immunosorbent assay (ELISA) is a highly sensitive immunoassay utilising enzyme‐conjugated antibodies, with antigen or antibodies bound to a solid support. The assay measures changes in enzyme activities proportional to the antigen or antibody concentrations involved in the underlying immune reactions. The assay exists in many variants and can be designed both for detection of antigen‐specific antibodies and for quantitative measurements of virtually any substance. Major applications include diagnostic assessment of disease‐related antibodies and detection and quantitation of hormones, cytokines and antigens from common pathogens. A special variant of the assay, ELISpot, can be used for studying secretion of analytes by single cells and is widely used for studying immune responses to vaccination and natural infection at the level of individual T and B cells.

Key Concepts

ELISA assays can be configured in many ways and used in many fields of science.

The combination of high sensitivity and specificity, simple procedure and the possibility to use both for analysing individual samples and for automated high‐throughput screening makes ELISA an ideal assay for many purposes.

Indirect ELISA is the basis for a large number of serological assays where detection of antibodies to infectious pathogens, allergens and autoimmune target antigens is the main diagnostic indicator of disease.

Sandwich ELISA, using an immobilised capture antibody and a labelled detection antibody, allows highly specific and sensitive detection and quantitation of virtually any antigenic substance including hormones, cytokines, toxins and microbial pathogens.

ELISpot allows detection of secreted products at the single‐cell level, making it possible to identify individual antigen‐specific T and B cells based on their secretion of cytokines and antibodies, respectively.
History of Insulin
Authors: Dagen Morag M
Published: January 2016

Type 1 diabetes mellitus is an endocrine disorder in which the pancreas fails to produce the peptide hormone insulin, which is necessary for the regulation of glucose metabolism. Before the advent of insulin treatment, the condition was invariably fatal. At the beginning of the twentieth century, aware of the accumulating evidence that the hyperglycaemia of diabetes mellitus could be controlled by an extract of the pancreas, Banting and Best produced the first clinically useful insulin preparation at the University of Toronto.

Insulin research led to a number of important breakthroughs in biochemistry: insulin was the first protein to be sequenced, it was the first peptide hormone shown to be formed by a posttranslational transformation of an inactive precursor and it was also the first genetically engineered protein to be approved for clinical use.

Key Concepts

Control of blood glucose levels is vitally important for health, and these are regulated by the hormone insulin.

Insulin is a peptide hormone produced by the pancreas.

Insufficient insulin results in the endocrine disease, diabetes mellitus.

Hyperglycaemia and glycosuria (glucose in urine) are important signs of diabetes mellitus.

Insulin and C‐peptide are produced by cleavage of proinsulin, a precursor protein.

Pharmaceutical insulin preparations do not currently contain C‐peptide.
Genetic Risk for Substance Abuse and Addiction: Family and Twin Studies
Authors: Prescott Carol A , Khoddam Rubin , Arpawong Thalida E
Published: January 2016

Evidence from family, adoption and twin studies indicates that genetic variation contributes to the risk for developing addiction to alcohol, tobacco and illicit drugs and to the comorbidity of addictions with other psychiatric disorders. For instance, it is estimated that 50–60% of the variation in risk for alcoholism is accounted for by genetic factors. Genetic influences are implicated in multiple aspects of substance involvement, including predispositions to drug‐seeking behaviour and development of physiological dependence. These influences likely occur through multiple mechanisms, ranging from cellular processes (e.g. metabolic, pharmacologic) to psychological (e.g. personality traits). Environmental factors are also key – individuals' psychosocial histories may outweigh their genetic predispositions or can combine with genetic factors to magnify or decrease risk for developing addictions.

Key Concepts

Substance abuse and addiction run in families.

Genetic epidemiology uses family, adoption and twin studies to address whether the familiality of addiction is due to environmental factors, genetic transmission or a combination of both.

For both men and women, 50–60% of the risk for developing alcoholism is familial and virtually all of this is due to genetic factors.

Experimenting with tobacco is primarily environmentally influenced, but genetic factors influence who develops addiction.

Addiction to illicit substances also appears to have a genetic component for males; fewer studies have been conducted in females.

The available research is based on samples of European ancestry; genetic and environmental estimates could differ for other populations.