Showing papers by "University of Nebraska–Lincoln published in 2011"

TRY - a global database of plant traits

Abstract: Plant traits – the morphological, anatomical, physiological, biochemical and phenological characteristics of plants and their organs – determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services and provide a link from species richness to ecosystem functional diversity. Trait data thus represent the raw material for a wide range of research from evolutionary biology, community and functional ecology to biogeography. Here we present the global database initiative named TRY, which has united a wide range of the plant trait research community worldwide and gained an unprecedented buy-in of trait data: so far 93 trait databases have been contributed. The data repository currently contains almost three million trait entries for 69 000 out of the world's 300 000 plant species, with a focus on 52 groups of traits characterizing the vegetative and regeneration stages of the plant life cycle, including growth, dispersal, establishment and persistence. A first data analysis shows that most plant traits are approximately log-normally distributed, with widely differing ranges of variation across traits. Most trait variation is between species (interspecific), but significant intraspecific variation is also documented, up to 40% of the overall variation. Plant functional types (PFTs), as commonly used in vegetation models, capture a substantial fraction of the observed variation – but for several traits most variation occurs within PFTs, up to 75% of the overall variation. In the context of vegetation models these traits would better be represented by state variables rather than fixed parameter values. The improved availability of plant trait data in the unified global database is expected to support a paradigm shift from species to trait-based ecology, offer new opportunities for synthetic plant trait research and enable a more realistic and empirically grounded representation of terrestrial vegetation in Earth system models.

Meta-Analysis of the Impact of Positive Psychological Capital on Employee Attitudes, Behaviors, and Performance.

Abstract: The positive core construct of psychological capital (or simply PsyCap), consisting of the psychological resources of hope, efficacy, resilience, and optimism, has recently been demonstrated to be open to human resource development (HRD) and performance management. The research stream on PsyCap has now grown to the point that a quantitative summary analysis of its impact on employee attitudes, behaviors, and especially performance is needed. The present meta-analysis included 51 independent samples (representing a total of N � 12,567 employees) that met the inclusion criteria. The results indicated the expected significant positive relationships between PsyCap and desirable employee attitudes (job satisfaction, organizational commitment, psychological well-being), desirable employee behaviors (citizenship), and multiple measures of performance (self, supervisor evaluations, and objective). There was also a significant negative relationship between PsyCap and undesirable employee attitudes (cynicism, turnover intentions, job stress, and anxiety) and undesirable employee behaviors (deviance). A sub-analysis found no major differences between the types of performance measures used (i.e., between self, subjective, and objective). Finally, the analysis of moderators revealed the relationship between PsyCap and employee outcomes were strongest in studies conducted in the United States and in the service sector. These results provide a strong evidence-based recommendation for the use of PsyCap in HRD and performance programs. Theoretical contributions, future research directions, and practical guidelines for HRD conclude the article.

Peripheral education of the immune system by colonic commensal microbiota

Abstract: Understanding how the immune system becomes tolerant to foreign antigens from commensal bacteria is a fundamental question, as breakdown of tolerance can result in unwanted responses such as inflammatory bowel disease. It has been suggested that tolerogenic regulatory T (Treg) cells are generated in response to commensal bacteria, but there is little direct evidence to support this hypothesis. A study of the colonic T-cell antigen receptor repertoire of mice now shows that microbial antigens direct the generation of antigen-specific inducible Treg cells in the colon. Commensal-induced Treg cells seem to maintain mucosal tolerance and protect mice from colitis. The instruction of the immune system to be tolerant of self, thereby preventing autoimmunity, is facilitated by the education of T cells in a specialized organ, the thymus, in which self-reactive cells are either eliminated or differentiated into tolerogenic Foxp3+ regulatory T (Treg) cells1. However, it is unknown whether T cells are also educated to be tolerant of foreign antigens, such as those from commensal bacteria, to prevent immunopathology such as inflammatory bowel disease2,3,4. Here we show that encounter with commensal microbiota results in the peripheral generation of Treg cells rather than pathogenic effectors. We observed that colonic Treg cells used T-cell antigen receptors (TCRs) different from those used by Treg cells in other locations, implying an important role for local antigens in shaping the colonic Treg-cell population. Many of the local antigens seemed to be derived from commensal bacteria, on the basis of the in vitro reactivity of common colon Treg TCRs. These TCRs did not facilitate thymic Treg-cell development, implying that many colonic Treg cells arise instead by means of antigen-driven peripheral Treg-cell development. Further analysis of two of these TCRs by the creation of retroviral bone marrow chimaeras and a TCR transgenic line revealed that microbiota indigenous to our mouse colony was required for the generation of colonic Treg cells from otherwise naive T cells. If T cells expressing these TCRs fail to undergo Treg-cell development and instead become effector cells, they have the potential to induce colitis, as evidenced by adoptive transfer studies. These results suggest that the efficient peripheral generation of antigen-specific populations of Treg cells in response to an individual’s microbiota provides important post-thymic education of the immune system to foreign antigens, thereby providing tolerance to commensal microbiota.

Determination of jet energy calibration and transverse momentum resolution in CMS

Abstract: Measurements of the jet energy calibration and transverse momentum resolution in CMS are presented, performed with a data sample collected in proton-proton collisions at a centre-of-mass energy of 7TeV, corresponding to an integrated luminosity of 36pb−1. The transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results are presented for three different methods to reconstruct jets: a calorimeter-based approach, the ``Jet-Plus-Track'' approach, which improves the measurement of calorimeter jets by exploiting the associated tracks, and the ``Particle Flow'' approach, which attempts to reconstruct individually each particle in the event, prior to the jet clustering, based on information from all relevant subdetectors

The lincoln declaration on drought indices: Universal meteorological drought index recommended

Abstract: What: Fifty-four participants from 22 countries, including drought experts from each of the six WMO regions, met to discuss the development of standards for drought indices and guidelines for drought early warning systems WheN: 8–11 December 2009 Where: Lincoln, Nebraska spoNsors: WMO; National Drought Mitigation Center (NDMC) and the School of Natural Resources (SNR), both at the University of Nebraska– Lincoln; NOAA/National Integrated Drought Information System; U.S. Department of Agriculture; and the United Nations Convention to Combat Desertification Secretariat I mproved drought monitoring and early warning systems are urgently needed to cope with current and potentially changing drought patterns as we move into the future. Drought is a slow-moving natural hazard that can affect virtually all climatic regimes. Generally defined, drought is a deficiency of precipitation relative to what is expected (i.e., “normal”) that, when extended over a season or a longer period of time, results in the inability to meet the demands of human activities and the environment. As countries around the world begin to establish national drought strategies, one critical component should be the development of a comprehensive drought monitoring system that has the ability to provide an early warning of the drought’s onset, determine drought severity and spatial extent, and convey that information to decision-making groups in a timely manner. This information can then be used to either reduce or avoid the impacts of drought. With this in mind, drought experts from nearly two dozen nations,1 including from all six regions of the World Meteorological Organization (WMO), were brought together for the Inter-Regional Workshop on Indices and Early Warning Systems for Drought, which was a four-day workshop focused on developing standards for drought indices and guidelines for drought early warning systems (DEWS). The motivation behind this workshop came out of the primary recommendations from the February 2009 International Workshop on Drought and Extreme Temperatures in Beijing, China, where one of the main recommendations was for the WMO to identify AFFILIATIONS: hayes, svoboda, Wall, aNd WidhalM—National Drought Mitigation Center, University of Nebraska–Lincoln, Lincoln, Nebraska CORRESPONDING AUTHOR: Nicole Wall, 819 Hardin Hall, National Drought Mitigation Center, University of Nebraska– Lincoln, Lincoln, NE 68583 E-mail: nwall2@unl.edu

The Human Gut Microbiome: Ecology and Recent Evolutionary Changes

Abstract: The human gastrointestinal tract is divided into sections, allowing digestion and nutrient absorption in the proximal region to be separate from the vast microbial populations in the large intestine, thereby reducing conflict between host and microbes. In the distinct habitats of the gut, environmental filtering and competitive exclusion between microbes are the driving factors shaping microbial diversity, and stochastic factors during colonization history and in situ evolution are likely to introduce intersubject variability. Adaptive strategies of microbes with different niches are genomically encoded: Specialists have smaller genomes than generalists, and microbes with environmental reservoirs have large accessory genomes. A shift toward a Neolithic diet increased loads of simple carbohydrates and selected for their increased breakdown and absorption in the small intestine. Humans who outcompeted microbes for the new substrates obtained more energy from their diets and prospered, an evolutionary process reflected in modern population genetics. The three-way interactions between human genetics, diet, and the microbiota fundamentally shaped modern populations and continue to affect health globally.

Observation and studies of jet quenching in PbPb collisions at √sNN=2.76 TeV

Abstract: Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 inverse microbarns. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet transverse momentum = 120 GeV/c) up to the statistical limit of the available data sample (jet transverse momentum approximately 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet.

TAL nucleases (TALNs): hybrid proteins composed of TAL effectors and FokI DNA-cleavage domain

Abstract: DNA double-strand breaks enhance homologous recombination in cells and have been exploited for targeted genome editing through use of engineered endonucleases Here we report the creation and initial characterization of a group of rare-cutting, site-specific DNA nucleases produced by fusion of the restriction enzyme FokI endonuclease domain (FN) with the high-specificity DNA-binding domains of AvrXa7 and PthXo1 AvrXa7 and PthXo1 are members of the transcription activator-like (TAL) effector family whose central repeat units dictate target DNA recognition and can be modularly constructed to create novel DNA specificity The hybrid FN-AvrXa7, AvrXa7-FN and PthXo1-FN proteins retain both recognition specificity for their target DNA (a 26 bp sequence for AvrXa7 and 24 bp for PthXo1) and the double-stranded DNA cleaving activity of FokI and, thus, are called TAL nucleases (TALNs) With all three TALNs, DNA is cleaved adjacent to the TAL-binding site under optimal conditions in vitro When expressed in yeast, the TALNs promote DNA homologous recombination of a LacZ gene containing paired AvrXa7 or asymmetric AvrXa7/PthXo1 target sequences Our results demonstrate the feasibility of creating a tool box of novel TALNs with potential for targeted genome modification in organisms lacking facile mechanisms for targeted gene knockout and homologous recombination

The state of the art in end-user software engineering

Abstract: Most programs today are written not by professional software developers, but by people with expertise in other domains working towards goals for which they need computational support. For example, a teacher might write a grading spreadsheet to save time grading, or an interaction designer might use an interface builder to test some user interface design ideas. Although these end-user programmers may not have the same goals as professional developers, they do face many of the same software engineering challenges, including understanding their requirements, as well as making decisions about design, reuse, integration, testing, and debugging. This article summarizes and classifies research on these activities, defining the area of End-User Software Engineering (EUSE) and related terminology. The article then discusses empirical research about end-user software engineering activities and the technologies designed to support them. The article also addresses several crosscutting issues in the design of EUSE tools, including the roles of risk, reward, and domain complexity, and self-efficacy in the design of EUSE tools and the potential of educating users about software engineering principles.

The Impact of Religion on Financial Reporting Irregularities

Abstract: This paper examines the impact of religion on financial reporting. We predict that firms in religious areas are less likely to engage in financial reporting irregularities because prior research links religiosity to reduced acceptance of unethical business practices and because managers in religious areas are likely to be more averse to litigation risk. Our results suggest that firms headquartered in areas with strong religious social norms generally experience lower incidences of financial reporting irregularities. We also examine whether religiosity influences managers’ methods of managing earnings. Although we find a negative association between religiosity and abnormal accruals, we find a positive association between religiosity and two measures of real earnings management, suggesting managers in religious areas may prefer real earnings management over accruals manipulation. We provide evidence that our results are not driven by firms headquartered in rural areas and conclude that religious social norms represent a mechanism for reducing costly agency conflicts, particularly when other external monitoring is low.

Modularly assembled designer TAL effector nucleases for targeted gene knockout and gene replacement in eukaryotes

Abstract: Recent studies indicate that the DNA recognition domain of transcription activator-like (TAL) effectors can be combined with the nuclease domain of FokI restriction enzyme to produce TAL effector nucleases (TALENs) that, in pairs, bind adjacent DNA target sites and produce double-strand breaks between the target sequences, stimulating non-homologous end-joining and homologous recombination. Here, we exploit the four prevalent TAL repeats and their DNA recognition cipher to develop a 'modular assembly' method for rapid production of designer TALENs (dTALENs) that recognize unique DNA sequence up to 23 bases in any gene. We have used this approach to engineer 10 dTALENs to target specific loci in native yeast chromosomal genes. All dTALENs produced high rates of site-specific gene disruptions and created strains with expected mutant phenotypes. Moreover, dTALENs stimulated high rates (up to 34%) of gene replacement by homologous recombination. Finally, dTALENs caused no detectable cytotoxicity and minimal levels of undesired genetic mutations in the treated yeast strains. These studies expand the realm of verified TALEN activity from cultured human cells to an intact eukaryotic organism and suggest that low-cost, highly dependable dTALENs can assume a significant role for gene modifications of value in human and animal health, agriculture and industry.

Productivity Is a Poor Predictor of Plant Species Richness

Abstract: For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters−2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.

Efficiency enhancement in organic solar cells with ferroelectric polymers

Abstract: The recombination of electrons and holes in semiconducting polymer–fullerene blends has been identified as a main cause of energy loss in organic photovoltaic devices. Generally, an external bias voltage is required to efficiently separate the electrons and holes and thus prevent their recombination. Here we show that a large, permanent, internal electric field can be ensured by incorporating a ferroelectric polymer layer into the device, which eliminates the need for an external bias. The electric field, of the order of 50 V μm−1, potentially induced by the ferroelectric layer is tens of times larger than that achievable by the use of electrodes with different work functions. We show that ferroelectric polymer layers enhanced the efficiency of several types of organic photovoltaic device from 1–2% without layers to 4–5% with layers. These enhanced efficiencies are 10–20% higher than those achieved by other methods, such as morphology and electrode work-function optimization. The devices show the unique characteristics of ferroelectric photovoltaic devices with switchable diode polarity and tunable efficiency. One of the key loss mechanisms in the operation of organic solar cells is the separation and extraction of the generated charge carriers from the active region. The use of a ferroelectric layer is now shown to create large internal electric fields, resulting in an enhanced carrier extraction and increased device efficiency.

Reactive oxygen species (ROS)--induced genetic and epigenetic alterations in human carcinogenesis.

Abstract: Cancer is a multistage and complex process characterized by molecular alterations that underlie all three phases of its development: (i) initiation, (ii) promotion and (iii) progression. Some of these molecular events include alterations in gene expression that are regulated by both genetic and epigenetic mechanisms. On the other hand, "oxidative stress" implies a cellular state where ROS production exceeds the cell's ability to metabolize them resulting in excessive accumulation of ROS that overwhelms cellular defenses. Such state has been shown to regulate both genetic and epigenetic cascades underlying altered gene expression in human disease including cancer. Throughout this manuscript, we review the current state of knowledge on the role of ROS-induced oxidative stress in altering the genetic and epigenetic involvement during human carcinogenesis.

Psychological capital and employee performance: a latent growth modeling approach

Abstract: The positive core construct of psychological capital (consisting of efficacy, hope, optimism, and resilience) has been conceptually and empirically demonstrated to be related to employee performance. However, much of this work has relied on cross-sectional designs to examine these relationships. This study utilizes longitudinal data from a large financial service organization (N= 179 financial advisory-type employees) to examine within-individual change in psychological capital over time and if this change relates to their change in performance. Latent growth modeling analyses revealed statistically significant within-individual change in psychological capital over time, and that this change in psychological capital was related to change in 2 types of performance outcomes (supervisor-rated performance and financial performance, i.e., individual sales revenue). Moreover, results of an exploratory cross-lagged panel analysis suggested a causal relationship such that prior psychological capital leads to subsequent performance rather than vice versa. Taken together, these results highlight the impact employees’ psychological capital may have on their subjectively and objectively measured performance over time and offer evidence-based practical guidelines for human resource selection, development, and performance management.

Magnetic nanoparticles: recent advances in synthesis, self-assembly and applications

Abstract: Nanostructured magnetic materials have a variety of promising applications spreading from nano-scale electronic devices, sensors and high-density data storage media to controlled drug delivery and cancer diagnostics/treatment systems. Magnetic nanoparticles offer the most natural and elegant way for fabrication of such (multi-) functional materials. In this review, we briefly summarize the recent progress in the synthesis of magnetic nanoparticles (which now can be done with precise control over the size and surface chemistry), and nanoscale interactions leading to their self-assembly into 1D, 2D or 3D aggregates. Various approaches to self-organization, directed-, or template-assisted assembly of these nanostructures are discussed with the special emphasis on magnetic-field enabled interactions. We also discuss new physical phenomena associated with magnetic coupling between nanoparticles and their interaction with a substrate and the characterization of the physical properties at the nanoscale using various experimental techniques (including scanning quantum interferometry (SQUID) and magnetic force microscopy). Applications of magnetic nanoparticle assemblies in data storage, spintronics, drug delivery, cancer therapy, and prospective applications such as adaptive materials and multifunctional reconfigurable materials are also highlighted.

: Authentically leading groups: The mediating role of collective psychological capital and trust

Abstract: Summary Although there have been recent theoretical advances in what is increasingly being recognized as authentic leadership, research testing possible mediating processes and the impact on grouplevel outcomes has not received attention. To help address this need, this study examined at the group level of analysis the role that collective psychological capital and trust may play in the relationship between authentic leadership and work groups’ desired outcomes. Utilizing 146 intact groups from a large financial institution, the results indicated a significant relationship between both their collective psychological capital and trust with their grouplevel performance and citizenship behavior. These two variables were also found to mediate the relationship between authentic leadership and the desired group outcomes, even when controlling for transformational leadership. Implications for future research and practice conclude the paper. Copyright # 2009 John Wiley & Sons, Ltd.

Bacterial Killing by Dry Metallic Copper Surfaces

Abstract: Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important first steps for revealing the molecular sensitive targets in cells lethally challenged by exposure to copper surfaces and provide a scientific explanation for the use of copper surfaces as antimicrobial agents for supporting public hygiene.

Evaluation of Drought Indices Based on Thermal Remote Sensing of Evapotranspiration over the Continental United States

Abstract: The reliability of standard meteorological drought indices based on measurements of precipitation is limited by the spatial distribution and quality of currently available rainfall data. Furthermore, they reflect only one component of the surface hydrologic cycle, and they cannot readily capture nonprecipitation-based moisture inputs to the land surface system (e.g., irrigation) that may temper drought impacts or variable rates of water consumption across a landscape. This study assesses the value of a new drought index based on remote sensing of evapotranspiration (ET). The evaporative stress index (ESI) quantifies anomalies in the ratio of actual to potential ET (PET), mapped using thermal band imagery from geostationary satellites. The study investigates the behavior and response time scales of the ESI through a retrospective comparison with the standardized precipitation indices and Palmer drought index suite, and with drought classifications recorded in the U.S. Drought Monitor for the 2000–0...

Synthetic ozonide drug candidate OZ439 offers new hope for a single-dose cure of uncomplicated malaria

Abstract: Ozonide OZ439 is a synthetic peroxide antimalarial drug candidate designed to provide a single-dose oral cure in humans. OZ439 has successfully completed Phase I clinical trials, where it was shown to be safe at doses up to 1,600 mg and is currently undergoing Phase IIa trials in malaria patients. Herein, we describe the discovery of OZ439 and the exceptional antimalarial and pharmacokinetic properties that led to its selection as a clinical drug development candidate. In vitro, OZ439 is fast-acting against all asexual erythrocytic Plasmodium falciparum stages with IC50 values comparable to those for the clinically used artemisinin derivatives. Unlike all other synthetic peroxides and semisynthetic artemisinin derivatives, OZ439 completely cures Plasmodium berghei-infected mice with a single oral dose of 20 mg/kg and exhibits prophylactic activity superior to that of the benchmark chemoprophylactic agent, mefloquine. Compared with other peroxide-containing antimalarial agents, such as the artemisinin derivatives and the first-generation ozonide OZ277, OZ439 exhibits a substantial increase in the pharmacokinetic half-life and blood concentration versus time profile in three preclinical species. The outstanding efficacy and prolonged blood concentrations of OZ439 are the result of a design strategy that stabilizes the intrinsically unstable pharmacophoric peroxide bond, thereby reducing clearance yet maintaining the necessary Fe(II)-reactivity to elicit parasite death.

Cytokinin‐mediated source/sink modifications improve drought tolerance and increase grain yield in rice under water‐stress

Abstract: Drought is the major environmental factor limiting crop productivity worldwide. We hypothesized that it is possible to enhance drought tolerance by delaying stress-induced senescence through the stress-induced synthesis of cytokinins in crop-plants. We generated transgenic rice (Oryza sativa) plants expressing an isopentenyltransferase (IPT) gene driven by P(SARK) , a stress- and maturation-induced promoter. Plants were tested for drought tolerance at two yield-sensitive developmental stages: pre- and post-anthesis. Under both treatments, the transgenic rice plants exhibited delayed response to stress with significantly higher grain yield (GY) when compared to wild-type plants. Gene expression analysis revealed a significant shift in expression of hormone-associated genes in the transgenic plants. During water-stress (WS), P(SARK)::IPT plants displayed increased expression of brassinosteroid-related genes and repression of jasmonate-related genes. Changes in hormone homeostasis were associated with resource(s) mobilization during stress. The transgenic plants displayed differential expression of genes encoding enzymes associated with hormone synthesis and hormone-regulated pathways. These changes and associated hormonal crosstalk resulted in the modification of source/sink relationships and a stronger sink capacity of the P(SARK)::IPT plants during WS. As a result, the transgenic plants had higher GY with improved quality (nutrients and starch content).

Satellite-based ET estimation in agriculture using SEBAL and METRIC

Abstract: Surface Energy Balance Algorithms for Land (SEBAL) and Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) are satellite-based image-processing models that calculate evapotranspiration (ET) as a residual of a surface energy balance. Both models are calibrated using inverse modelling at extreme conditions approach to develop image-specific estimations of the sensible heat flux (H) component of the surface energy balance and to effectively remove systematic biases in net radiation, soil heat flux, radiometric temperature and aerodynamic estimates. SEBAL and METRIC express the near-surface temperature gradient as an indexed function of radiometric surface temperature, eliminating the need for absolutely accurate surface temperature and the need for air temperature measurements. Slope and aspect functions and temperature lapsing are used in METRIC applications in mountainous terrains. SEBAL and METRIC algorithms are designed for relatively routine application by trained professionals familiar with energy balance, aerodynamics and basic radiation physics. The primary inputs for the models are short-wave and long-wave (thermal) images from satellite (e.g. Landsat and MODIS), a digital elevation model and ground-based weather data measured within or near the area of interest. ET ‘maps’ (i.e. images) developed using Landsat images provide means to quantify ET on a field basis in terms of both rate and spatial distribution. METRIC takes advantage of calibration using weather-based reference ET so that both calibration and extrapolation of instantaneous ET to 24-h and longer periods compensate for regional advection effects where ET can exceed daily net radiation. SEBAL and METRIC have advantages over conventional methods of estimating ET using crop coefficient curves or vegetation indices in that specific crop or vegetation type does not need to be known and the energy balance can detect reduced ET caused by water shortage, salinity or frost as well as evaporation from bare soil. Copyright © 2011 John Wiley & Sons, Ltd.

Defect Engineering in Cubic Cerium Oxide Nanostructures for Catalytic Oxidation

Abstract: Traditional nanostructured design of cerium oxide catalysts typically focuses on their shape, size, and elemental composition We report a different approach to enhance the catalytic activity of cerium oxide nanostructures through engineering high density of oxygen vacancy defects in these catalysts without dopants The defect engineering was accomplished by a low pressure thermal activation process that exploits the nanosize effect of decreased oxygen storage capacity in nanostructured cerium oxides