bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping CRMP3 domains involved in dendrite morphogenesis and voltage-gated calcium channel regulation
Authors: Quach Tam T , Wilson Sarah M , Rogemond Veronique , Chounlamountri Naura , Kolattukudy Pappachan E , Martinez Stephanie , Khanna May , Belin Marie-Francoise , Khanna Rajesh , Honnorat Jerome , Duchemin Anne-Marie
Published: July 2013

Although hippocampal neurons are well-distinguished by the morphological characteristics of their dendrites and their structural plasticity, the mechanisms involved in regulating their neurite initiation, dendrite growth, network formation and remodeling are still largely unknown, in part because the key molecules involved remain elusive. Identifying new dendrite-active cues could uncover unknown molecular mechanisms that would add significant understanding to the field and possibly lead to the development of novel neuroprotective therapy since these neurons are impaired in many neuropsychiatric disorders. In our previous studies, we deleted the gene coding CRMP3 in mice and identified the protein as a new endogenous signaling molecule that shapes diverse features of the hippocampal pyramidal dendrites without affecting axon morphology. We also found that CRMP3 protects dendrites against dystrophy induced by prion peptide PrP106–126. Here, we report that CRMP3 has a profound influence on neurite initiation and dendrite growth of hippocampal neurons in vitro. Our deletional mapping revealed that the carboxyl terminus of CRMP3 likely harbors its dendritogenic capacity and supports an active transport mechanism. In contrast, overexpression of the C-terminal truncated CRMP3 phenocopied the effect of CRMP3 gene deletion with inhibition of neurite initiation or decrease in dendrite complexity, depending on the stage of cell development. In addition, this mutant inhibited the activity of CRMP3, similarly to siRNA. Voltage-gated calcium channel inhibitors prevented CRMP3-induced dendritic growth and somatic Ca2+influx in CRMP3-overexpressing neurons was augmented largely via L-type channels. These results support a link between CRMP3-mediated Ca2+ influx and CRMP3-mediated dendritic growth in hippocampal neurons.
PDZ-RhoGEF is essential for CXCR4-driven breast tumor cell motility through spatial regulation of RhoA
Authors: Struckhoff Amanda P. , Rana Manish K. , Kher Swapnil S. , Burow Matt E. , Hagan Joseph L. , Del Valle Luis , Worthylake Rebecca A.
Published: July 2013

The CXCL12–CXCR4 chemokine signaling pathway is a well-established driver of cancer progression. One key process promoted by CXCR4 stimulation is tumor cell motility; however, the specific signaling pathways leading to migration remain poorly understood. Previously, we have shown that CXCL12 stimulation of migration depends on temporal regulation of RhoA. However, the specific RhoGEF that translates CXCR4 signaling into RhoA activity and cell motility is unknown. We screened the three regulator of G-protein signaling RhoGEFs (LSC, LARG and PRG) and found that PRG selectively regulated the migration and invasion of CXCR4-overexpressing breast tumor cells. Interestingly, we found that PDZ-RhoGEF (PRG) was required for spatial organization of F-actin structures in the center, but not periphery of the cells. The effects on the cytoskeleton were mirrored by the spatial effects on RhoA activity that were dependent upon PRG. Loss of PRG also enhanced adherens junctions in the epithelial-like MCF7-CXCR4 cell line, and inhibited directional persistence and polarity in the more mesenchymal MDA-MB-231 cell line. Thus, PRG is essential for CXCR4-driven tumor cell migration through spatial regulation of RhoA and the subsequent organization of the cytoskeletal structures that support motility. Furthermore, immunohistochemical analysis of human breast tumor tissues shows a significant increase of PRG expression in the invasive areas of the tumors, suggesting that this RhoGEF is associated with breast tumor invasion in vivo.
Uptake, handling, and excretion of Na+ and Cl- from the diet in vivo in freshwater and seawater-acclimated killifish, Fundulus heteroclitus, an agastric teleost
Authors: Bucking Carol , Wood Christopher M. , Grosell Martin
Published: July 2013

A radiotracer approach using diets labeled with 22Na+, 36Cl-, and [14C]polyethylene-4000 (PEG-4000) was employed to investigate the role of intestinal uptake from the food in ion homeostasis in the killifish (Fundulus heteroclitus). This euryhaline teleost lacks both a stomach and a capacity for Cl- uptake at the gills in freshwater. PEG-4000 appearance in the water was minimal up to 10-11 h post-feeding, indicating the virtual absence of Na+ and Cl- loss in the faeces up until this time. Rapid uptake of dietary Na+ and Cl- occurred and more than 88% of 22Na+ and 36Cl- were absorbed in the intestine by 3 h post-feeding, and excretion rates of Na+ and Cl- originating from the food were greatest during this period. Uptake and excretion of Cl- from the diet was 5-6-fold greater than that of Na+ in freshwater, and about 3-fold greater in seawater. Excretions of dietary Na+ and Cl- by seawater-acclimated killifish were far greater than by freshwater-acclimated killifish in this time frame, reflecting the much greater branchial efflux rates and turnover rates of the internal exchangeable pools. At both 3 h and 9 h post-feeding, the largest fraction of dietary Na+ was found in the carcass of freshwater-acclimated fish, followed by the external water, and finally the digestive tract. However in seawater-acclimated fish, more was excreted to the water, and less was retained in the carcass. For Cl-, which was taken up and excreted more rapidly than Na+, the majority of the dietary load had moved to the external water by 9 h in both freshwater and seawater animals. After 7 days training on a low salt natural diet (live Lumbriculus variegatus worms; 31.5 μmol Na+ g-1 wet weight) versus a high salt synthetic pellet diet (911 μmol Na+ g-1 dry food weight), freshwater killifish exhibited a lower absolute excretion rate of Na+ from the low salt diet, but relative uptake from the intestine and retention in the carcass were virtually identical from the two diets. Seawater killifish excreted relatively more Na+ from the low salt diet. Overall, our results emphasize the importance of dietary Na+ and Cl- in the electrolyte economy of the killifish, particularly in freshwater, and especially for Cl-.
Adjustments of global and hindlimb local properties during the terrestrial locomotion of the common quail (Coturnix coturnix)
Authors: Andrada Emanuel , Nyakatura John A. , Bergmann Florian , Blickhan Reinhard
Published: July 2013

Increasing insight into neuro-mechanical control strategies during perturbed locomotion is gained. In contrast, more general analyses on simple model (template) related parameters during avian terrestrial locomotion are still rare. Quails kinematic data obtained using X-ray videography combined with ground reaction force measurements were used as a basis to investigate how "global" template and "local" leg joint parameters in this small predominantly terrestrial bird change with speed and gait. Globally, quail locomotion approximates a spring-like behavior in all investigated gaits. However, ground reaction forces are more vertically oriented which may help to balance the trunk. At the joint level, practically all the spring like work was found to occur in the ITJ (intertarsal joint). From walking to grounded running the local stiffness of the ITJ decreases similarly to the reduction observed in global leg stiffness. Thus, in gaits without aerial phases the quails may modulate ITJ stiffness to regulate global leg stiffness, and therefore gait changes, to a significant degree. At higher speeds leg compression and leg stiffness are increased (the latter to values not significantly different to those obtained during walking). This enables the animals to shorten contact time and to generate aerial phases (running). However, we did not observe a change in the stiffness in the ITJ with a change of gait from grounded running to running. We hypothesize that a more extended leg at touch-down, controlled by the joint angles in knee and ITJ, has an important influence in the leg stiffness adjustment process during running.
Differential expression and novel permeability properties of three aquaporin 8 paralogs from seawater-challenged Atlantic salmon smolts
Authors: Engelund Morten B. , Chauvigné François , Christensen Birgitte M. , Finn Roderick N. , Cerdà Joan , Madsen Steffen S.
Published: July 2013

Aquaporins may facilitate transepithelial water absorption in the intestine of seawater (SW) acclimated fish. Here we have characterized three full-length aqp8 paralogs from Atlantic salmon (Salmo salar). Bayesian inference revealed that each paralog is a representative of the three major classes of aqp8aa, aqp8ab and aqp8b genes found in other teleosts. The permeability properties were studied by heterologous expression in Xenopus laevis oocytes, and the expression levels examined by qPCR, immunofluorescence and immunoelectron microscopy, and immunoblotting of membrane fractions from intestines of SW challenged smolts. All three Aqp8 paralogs were permeable to water and urea, whereas Aqp8ab and -8b were, surprisingly, also permeable to glycerol. The mRNA tissue distribution of each paralog was distinct although some tissues, such as the intestine showed redundant expression of more than one paralog. Immunofluorescence microscopy localized Aqp8aa(1+2) to intracellular compartments of the liver and intestine, and Aqp8ab and Aqp8b to apical plasma membrane domains of the intestinal epithelium, with Aqp8b also in goblet cells. In a control experiment with rainbow trout, immunoelectron microscopy confirmed abundant labeling of Aqp8ab and -8b at apical plasma membranes of enterocytes in the middle intestine and also in subapical vesicular structures. During SW-challenge, Aqp8ab showed significantly increased levels of protein expression in plasma membrane enriched fractions of the intestine. These data indicate that the Atlantic salmon Aqp8 paralogs have neofunctionalized on a transcriptional as well as on a functional level, and that Aqp8ab may play a central role in the intestinal transcellular uptake of water during SW acclimation.
The protective effect of rapid cold-hardening develops more quickly in frozen versus supercooled larvae of the Antarctic midge, Belgica antarctica
Authors: Kawarasaki Yuta , Teets Nicholas M. , Denlinger David L. , Lee Richard E.
Published: July 2013

During the austral summer, larvae of the terrestrial midge, Belgica antarctica (Diptera: Chironomidae), experience highly variable and often unpredictable thermal conditions. In addition to remaining freeze tolerant year-round, larvae are capable of swiftly increasing their cold tolerance through the rapid cold-hardening (RCH) response. The present study compared the induction of RCH in frozen versus supercooled larvae. At the same induction temperature, RCH occurred more rapidly and conferred a greater level of cryoprotection in frozen versus supercooled larvae. Furthermore, RCH in frozen larvae could be induced at temperatures as low as -12°C, which is the lowest temperature reported to induce RCH. Remarkably, as little as 15 min at -5°C significantly enhanced larval cold tolerance. Not only is protection from RCH acquired swiftly, but it is also quickly lost after thawing for 2 h at 2°C. Because the primary difference between frozen and supercooled larvae is cellular dehydration caused by freeze concentration of body fluids, we also compared the effects of acclimation in dehydrated versus frozen larvae. Since slow dehydration without chilling significantly increased larval survival to a subsequent cold exposure, we hypothesize that cellular dehydration caused by freeze concentration promotes the rapid acquisition of cold tolerance in frozen larvae.
A new approach to evaluate multimodal orientation behaviour of migratory passerine birds recorded in circular orientation cages
Authors: Ożarowska Agnieszka , Ilieva Mihaela , Zehtindijev Pavel , Åkesson Susanne , Muś Krzysztof
Published: July 2013

Circular orientation cages have been used for several decades to record the migratory orientation of passerine migrants, and have been central when investigating of the functional characteristics of the biological compasses used for orientation. The technique offers unique possibilities to study the migratory behaviour of songbirds, but suffers from statistical limitations to evaluate the directions of the activity recorded in the cages. The migratory activity has been reported to vary, including complex multimodal orientation of migratory passerines tested in orientation cages irrespective of species studied. The currently applied circular statistical methods fail to describe orientation responses differing from unimodal and axial distributions. We propose for the first time a modelling procedure enabling the analyses of multimodal distributions either at an individual or group level. In this paper we compare the results of conventional methods and the recommended modelling approach. Migratory routes may be more complex than a simple migratory direction and multimodal behaviour in migratory species at the individual and population levels can be advantageous. Individuals may select the expected migratory direction, but may also return to more safe sites en route, i.e. sites already known, which provide food and/or shelter in reverse directions. In individual birds several directions may be expressed in the same test hour. At the species level multimodal orientation may give an opportunity to expand the range or may refer to differential migration route preferences in different populations of birds. A conflicting experimental situation may also result in different preferential orientation. In this paper we suggest a statistical solution to deal with these types of variations in orientation preferences.
Lizard tricks: Overcoming conflicting requirements of speed vs climbing ability by altering biomechanics of the lizard stride
Authors: Clemente Christofer J. , Withers Philip C. , Thompson Graham , Lloyd David
Published: July 2013

Adaptations promoting greater performance in one habitat are thought to reduce performance in others. However, there are many examples of where, despite habitat differences, such predicted differences in performance do not occur. One such example is the relationship between locomotory performance to habitat for varanid lizards. To explain the lack of difference in locomotor performance we examined detailed observation of the kinematics of each lizard's stride. Differences in kinematics were greatest between climbing and non-climbing species. For terrestrial lizards, the kinematics indicated that increased femur adduction, femur rotation and ankle angle all contributed positively to changes in stride length, but they were constrained for climbing species, probably due to biomechanical restrictions on the centre of mass height (to increase stability on vertical surfaces). Despite climbing species having restricted stride length, no differences have been previously reported in sprint speed between climbing and non-climbing varanids. This is best explained by climbing varanids using an alternative speed modulation strategy of varying stride frequency to avoid the potential trade-off of speed vs stability on vertical surfaces. Thus, by measuring the relevant biomechanics for lizard strides, we have shown how kinematic differences among species can mask performance differences typically associated with habitat variation.
Ceramic Coating of Liposomal Gene Carrier for Minimizing Toxicity to Primary Hippocampal Neurons
Authors: Tahara Keishiro , Moriuchi Takanobu , Tsukui Miku , Hirota Akira , Maeno Takanori , Toriyama Michinori , Inagaki Naoyuki , Kikuchi Jun-ichi
Published: July 2013

Ceramic-coated liposomes, cerasomes, were used as a new gene carrier for transfecting primary hippocampal neurons, to overcome the fusibility of conventional liposomal carriers. Cerasomes successfully mediated the transfection of primary neurons and minimized toxicity without adverse effects on axonal growth to acquire their unique neuronal morphology.
Synthesis of Monofluoromethylcyclopropanes from Alkenes without Using Freons: Novel Synthesis of Chlorofluoromethyl Phenyl Sulfide and Its Application in Cyclopropanation
Authors: Kirihara Masayuki , Ogata Tomomi , Itou Atsushi , Naito Sayuri , Kishida Mari , Yamazaki Kento , Tabata Hidetsugu , Takahashi Hideyo
Published: July 2013

Chlorofluoromethyl phenyl sulfide was prepared from the reaction of chloromethyl phenyl sulfide with Selectfluor™. Monofluorocyclopropanation of an alkene was achieved via cyclopropanation using a fluorocarbene derived from the product chlorofluoromethyl phenyl sulfide, followed by oxidation and desulfurization.
Investigation of Delamination on I-65 in Indiana
Authors: Lee Jusang , Ahn Hyungjun , Shah Ayesha , Sommer Kurt
Published: July 2013

This paper presents an investigation of delamination on the northbound driving lane of I-65 near Brookston, IN, utilizing field pull-off tests to evaluate interface bonding strength. In addition, ultrasonic test, asphalt binder test, and mix property (mechanical and volumetric) tests [i.e., dynamic shear rheometer (DSR) test, asphalt binder extraction, binder content, sieve analysis, and mix specific gravities] were conducted to explore the cause(s) of delamination. The pull-off test results showed that the delaminated pavement had a weaker interface bond, which generated more top-down fatigue cracking. In addition, the delaminated pavement contained more aged asphalt binder and a higher percentage of air voids, which could have accelerated top-down fatigue cracking as well. In conclusion, the causes of delamination were a combination of weak interface bonding and asphalt mix durability of the surface course.
Rheological Behavior of Asphalt–Rubber Binders Modified With Shale-Oil Residue and Polyphosphoric Acid
Authors: Faxina Adalberto Leandro , Furlan Ana Paula , Fabbri Glauco Tulio Pessa
Published: July 2013

The objective of this paper is to assess the effects of adding two modifiers of different chemical nature on the rheological behavior of asphalt–rubber binders: the shale-oil residue and the polyphosphoric acid. Four modified asphalt–rubbers were prepared: asphalt–rubber–PPA (18 % crumb rubber + 1 % PPA), asphalt–rubber–oil (18 % rubber + 10 % shale-oil residue), asphalt–rubber–oil–PPA–1 (18 % rubber + 10 % oil + 1 % PPA) and asphalt–rubber–oil–PPA–2 (9 % rubber + 5 % oil + 0.5 % PPA). A reference asphalt–rubber was prepared using 18 % crumb rubber. The samples were submitted to oscillatory-shear tests to obtain data (complex modulus, G*, and phase angle, δ) to construct master curves. Compared to the base asphalt binder, the pure asphalt–rubber improves the rutting and strain-controlled fatigue resistances. The addition of 1 % PPA enhances even more the rutting resistance and improves slightly the fatigue resistance below 20°C. The most substantial increase in fatigue resistance is obtained when 10 % oil is added to the pure asphalt–rubber, but its rutting resistance is drastically reduced. Mixtures 1 (18 % rubber + 10 % oil + 1 % PPA) and 2 (18 % rubber + 5 % oil + 0.5 % PPA) have lower rutting resistance compared to the base asphalt–rubber, but only mixture 1 has higher fatigue resistance. Compared to the base asphalt binder, all modified asphalt–rubber binders present higher G*/sinδ values (at all rutting temperatures) and lower G*·sinδ values (only below 20°C) when traffic speed reduces. Taking this evidence into account, the asphalt–rubber and the asphalt–rubber–PPA are the most appropriate. Although shale-oil residue has shown opposite results at intermediate and high pavement temperatures (enhancing the fatigue resistance and reducing the rutting resistance), it is able to reduce the viscosity of the asphalt–rubber, enhancing the workability of the HMA mixes during construction.
Evaluation of Effect of Superplasticizer on Performance of Self-Compacting Concrete
Authors: Ahmad Shamsad
Published: July 2013

This research was conducted in order to evaluate the effect of three typical brands of polycarboxylate-based superplasticizers on the performance of mixtures of self-compacting concrete, with the goal of selecting a suitable type and dosage of superplasticizer. Using different dosages of the three selected superplasticizers, several mixtures of self-compacting concrete were prepared and evaluated to study the effect of the type and dosage of superplasticizer on the properties of fresh and hardened concrete. Slump flow and V-funnel time tests were conducted on fresh concrete for self-compactability, and compressive strength, water penetration depth, and water absorption tests were conducted on hardened concrete for strength and durability. The test results indicate that the type and dosage of superplasticizer have significant effects on the properties of both fresh and hardened self-compacting concrete. The experimental study presented in this paper depicts a typical methodology for selecting a suitable type and dosage of superplasticizer for producing efficient and economical mixtures of self-compacting concrete.
Comparison between Contact and Immersion Method in Ultrasonic Stress Measurement of Welded Stainless Steel Plates
Authors: Javadi Yashar , Najafabadi Mehdi Ahmadi , Akhlaghi Mehdi
Published: July 2013

This study presents a comparison between contact and immersion ultrasonic method to measure welding residual stress of austenitic stainless steel plates (AISI 304L). Longitudinal critically refracted (LCR) waves are employed to measure the residual stresses. By using contact and immersion transducers, a 3D distribution of longitudinal residual stress for the entire of the welded plate is presented. A finite-element model of welding process, which is validated by the hole-drilling method, is used to verify the ultrasonic results. The results show no considerable differences between using contact or immersion transducers in ultrasonic stress measurement of stainless steel plates; however, some practical considerations are mentioned.
Particle Breakage of Cement Ellipsoid Aggregate—Part II: Investigation of Particle Crushing
Authors: Zhang Bing-yin , Jie Yu-xin , Kong De-zhi
Published: July 2013

The breakage of particles during triaxial compression tests on cement ellipsoids is systematically analyzed in this paper. The particles after testing are categorized into three types: apparently intact particles, partly damaged particles, and completely broken particles. The fractions of each type of particle were measured. The mass percentages of partly damaged particles and completely broken particles were correlated. Therefore, when considering the crushing characteristics of particles in real coarse aggregates, the mass percentage of completely broken particles can also be used to evaluate the amount of partly damaged particles, which cannot be determined by means of simple sieving analysis. We also found that indices that express the amount of particle breakage for a single grain size are not suitable for characterizing the overall change in particle sizes, but indices that include multiple grain sizes have good coincidence with the observed particle breakage.
Engineering Properties of Prime Coats Applied to a Granular Base
Authors: Mohan Gouri , Yildirim Yetkin , StokoeII Kenneth H. , Erten Mustafa B.
Published: July 2013

Prime coats have been widely used to protect sub-base layers during pavement construction. The engineering properties of a prime-coated base course play an important role in the overall stability of a pavement system. In this study, prime coats MC-30, AEP, EC-30, CSS-1H, SS-1H, and terra prime (TP) were used for testing. Strength and permeability of the specimens were measured. Crushed limestone was used as the base course. The prime coats were either sprayed on or mixed with the base course to evaluate the effect of the application method. In addition, penetration of the prime coats into reference sand was evaluated. For the conditions of this study, according to a developed ranking system, the best performing prime coats were TP and MC-30, with slightly better performance from TP. The results provided here can be used as a guideline for selecting the proper prime coat for field applications.
Evaluating Convention Destination Images in Australia and Asia
Authors: Lin Chin-Tsai , Lin Chiu-Wen
Published: July 2013

Meetings and conventions are important sub-sectors of tourism. Convention tourism organizations select destinations that are complex. Destination image is the key to attracting most meeting planners. Conventions create significant economic benefits and job opportunities for their destinations. This study explores the image-building of convention destinations in nine countries. This study used the grey-situation decision-making method and the technique for ordering preferences by similarity to the ideal solution to compare rankings and select ten criteria for image measurement. The evaluation was based on secondary data from the World Economic Forum of 2011 and the International Congress and Convention Association Report in 2011. The results show the strengths and weaknesses of the nine studied countries in terms of the convention image development conditions. Singapore has the best image in Asia, and marketers and meeting planners can use the study data to produce more attractive advertising.
Abrasion Testing on Multi-Component Geosynthetic Clay Liners
Authors: Herlin B. , Kennedy B.
Published: July 2013

Geosynthetic clay liners (GCLs) are used in numerous applications from earth-work-related projects such as ponds and landfills to concrete-related work such as waterproofing applications. Multi-component GCLs have been used extensively in the past two decades; however, some multi-component GCLs should be used only in specific applications and should not be used in earth-work-related projects where abrasion-type damages might occur. Two types of multi-component GCLs were used in various shear box tests to help simulate potential abrasion-type damages that might occur in field projects. A polypropylene-coated GCL and a polyethylene-laminated geofilm GCL were subjected to various subgrade conditions to determine whether damage occurred. However, it should be said that multi-component GCLs are made and offered to eliminate some unknown factors on projects such as a lack of subgrade information provided prior to deployment start up, and thus there is a need for them.
Multi-Component Geosynthetic Clay Liners: A Product With New Possibilities
Authors: Egloffstein T. A. , Kalsow J. , von Maubeuge K. P. , Ehrenberg H.
Published: July 2013

In the following publication results from overlap testing of polyethylene(PE) coated geosynthetic clay liners (GCL) are presented and discussed. A permeation can only occur through the overlaps. Overlaps were tested with a width of 300 mm and 150 mm. The wider overlaps did not show any permeation at all, however minor permeation was detected with the 150 mm wide overlaps. Additionally a series of overlaps were performed by taping the overlaps with a 50 mm wide tape. The overlapped GCL was 150 mm and 75 mm. Under these test conditions no permeation was detected. Further the research was carried out with perforated holes in the PE coating. In this case the water distribution in the area of the hole(s) was investigate. Aim of this study was to better understand the permeation in the overlap area as well through perforated holes.
Transmission Frequencies of Introgressed Festuca pratensis Chromosomes and Chromosome Segments in Lolium perenne
Authors: King Julie , Armstead Ian , Harper John , King Ian
Published: July 2013

The introgression of genetic variation from related species into crops provides an important route by which superior plant varieties can be produced. The primary aim of introgression involves the transfer of a small chromosome segment from a related species into a chromosome of a crop species (via recombination at meiosis) to generate an interspecific recombinant chromosome. Very little is known about the selective pressures that act on the products of interspecific recombination. Seven monosomic substitution lines were developed between Lolium perenne and Festuca pratensis. When each line was backcrossed to L. perenne recombination occurred between the F. pratensis chromosome and its L. perenne homoeologue, resulting in backcross populations carrying L. perenne/F. pratensis recombinant chromosomes. This paper describes the relationship between the frequency of generation of interspecific recombinant chromosomes with the frequency of their transmission to the next generation. The results reveal the presence of neutral, negative, and positive selection pressures for the transmission of F. pratensis chromosomes and L. perenne/F. pratensis recombinant chromosomes through the gametes to the next generation. The type of selection pressure observed depended on which linkage group the F. pratensis chromosome under study was derived from. The implications of these results are discussed.
Estimation of Radiative Transfer Parameters from L‐Band Passive Microwave Brightness Temperatures Using Advanced Data Assimilation
Authors: Montzka Carsten , Grant Jennifer P. , Moradkhani Hamid , Franssen Harrie-Jan Hendricks , Weihermüller Lutz , Drusch Matthias , Vereecken Harry
Published: July 2013

ESA's Soil Moisture and Ocean Salinity (SMOS) mission has been designed to extend our knowledge of the Earth's water cycle. Soil Moisture and Ocean Salinity records brightness temperatures at the L‐band, which over land are sensitive to soil and vegetation parameters. On the basis of these measurements, soil moisture and vegetation opacity data sets have been derived operationally since 2009 for applications comprising hydrology, numerical weather prediction (NWP), and drought monitoring. We present a method to enhance the knowledge about the temporal evolution of radiative transfer parameters. The radiative transfer model L‐Band Microwave Emission of the Biosphere (L‐MEB) is used within a data assimilation framework to retrieve vegetation opacity and soil surface roughness. To analyze the ability of the data assimilation approach to track the temporal evolution of these parameters, scenario analyses were performed with increasing complexity. First, the HYDRUS‐1D code was used to generate soil moisture and soil temperature time series. On the basis of these data, the L‐MEB forward model was run to simulate brightness temperature observations. Finally, the coupled model system HYDRUS‐1D and L‐MEB were integrated into a data assimilation framework using a particle filter, which is able to update L‐MEB states as well as L‐MEB parameters. Time invariant and time variable radiative transfer parameters were estimated. Moreover, it was possible to estimate a “bias” term when model simulations show a systematic difference as compared to observations. An application to a USDA‐NRCS Soil Climate Analysis Network (SCAN) site showed the good performance of the proposed approach under real conditions.
Management of Postharvest Deficit Irrigation of Peach Trees Using Infrared Canopy Temperature
Authors: Zhang Huihui , Wang Dong
Published: July 2013

Remotely sensed canopy temperature from infrared thermometer (IRT) sensors is an effective tool for detecting plant water stress. Deficit irrigation, where the plants receive less than full irrigations and come under water stress at certain growth stages, can be used to help alleviate water shortage in the San Joaquin Valley of California. Thus, new irrigation scheduling procedures need to be developed. A field study was conducted from 2009 to 2011 to evaluate the performance of using midday infrared canopy to air temperature difference (ΔT) to manage postharvest deficit irrigation of early season peach trees. Threshold values of ΔT were selected, based on previous years' stem water potential and ΔT measurements, for four irrigation treatments: Furrow and surface drip irrigation with or without postharvest water stress. A wired network of 12 IRT sensors was installed above the orchard for canopy temperature measurement. Soil water content and stem water potential were also monitored weekly for each treatment. In both growing seasons (2009–2010 and 2010–2011), the measured ΔT values showed consistent differences among treatments, which correlated to both soil water content (R2 ≈ 0.47–0.53) and stem water potential readings (R2 ≈ 0.46–0.65). The relationship between fruit mass and postharvest irrigation amount indicated that up to 53% water savings could be achieved without impacting fruit size. The study demonstrated that infrared canopy temperature measured from above the tree top can potentially be used for managing deficit irrigation in peach and possibly other tree crops. Additional research is needed to further validate this approach.
Deriving Hourly Evapotranspiration Rates with SEBS: A Lysimetric Evaluation
Authors: Gowda Prasanna H. , Howell Terry A. , Paul George , Colaizzi Paul D. , Marek Thomas H. , Su Bob , Copeland Karen S.
Published: July 2013

Numerous energy balance (EB) algorithms have been developed to use remote sensing data for mapping evapotranspiration (ET) on a regional basis. Adopting any single or combination of these models for an operational ET remote sensing program requires a thorough evaluation. The Surface Energy Balance System (SEBS) was evaluated for its ability to estimate hourly ET rates of summer tall and short crops grown in the Texas High Plains by using 15 Landsat 5 Thematic Mapper scenes acquired during 2006 to 2009. Performance of SEBS was evaluated by comparing estimated hourly ET values with measured ET data from four large weighing lysimeters, each located at the center of a 4.3 ha field in the USDA‐ARS Conservation and Production Research Laboratory in Bushland, TX. The performance of SEBS in estimating hourly ET was good for crops under both irrigated and dryland conditions. A locally derived, surface albedo‐based soil heat flux (G) model further improved the G estimates. Root mean square error and mean bias error were 0.11 and −0.005 mm h−1, respectively, and the Nash–Sutcliff model efficiency was 0.85 between the measured and calculated hourly ET. Considering the equal or better performance with a minimal amount of ancillary data as compared to with other EB algorithms, SEBS is a promising tool for use in an operational ET remote sensing program in the semiarid Texas High Plains. However, thorough sensitivity and error propagation analyses of input variables to quantify their impact on ET estimations for the major crops in the Texas High Plains under different agroclimatological conditions are needed before adopting the SEBS into operational ET remote sensing programs for irrigation scheduling or other purposes.
Lacunarity of the Spatial Distributions of Soil Types in Europe
Authors: Monreal J. Caniego , Martínez F. San José , Martí J.J. Ibáñez , Pérez-Gómez R.
Published: July 2013

Fractal techniques have been increasingly and successfully applied to identify and describe spatial patterns in natural sciences. However, objects with the same fractal dimension can show very different optical properties because of their spatial arrangement. This work focuses primary attention on the geometrical structure of the geographical patterns of soils in Europe. We made use of the European Soil Database to estimate lacunarity indexes of the most abundant soils that cover 92% of the surface of Europe and investigated textural properties of their spatial distribution. We observed three main classes corresponding to three different patterns that displayed the graphs of lacunarity functions, that is, linear, convex, and mixed. They correspond respectively to homogeneous or self‐similar, heterogeneous or clustered and those in which behavior can change at different ranges of scales. Finally, we discuss the pedological implications of that classification.
Stability of nano-sized titanium dioxide in an aqueous environment: effects of pH, dissolved organic matter and divalent cations
Authors: Yang X. N. , Cui F. Y.
Published: July 2013

Nano-sized titanium dioxide in the aquatic environment has a potential impact on the environment and human health. In this study, the impact of pH value, dissolved organic matter (DOM) and divalent cations (Ca2+) on the stability of titanium dioxide nanoparticles (nano-TiO2) in an aqueous environment was investigated in batch tests. The results showed that the particle size of nano-TiO2 was not sensitive to pH value but was inversely proportional to zeta potential. The nano-TiO2 becomes more stable with surface zeta potential, accompanied by small particle size and high dispersion. In the presence of DOM, the particle size was smaller and the stability of nano-TiO2 could be enhanced. This might be a synergistic effect of the ligand exchange and electrostatic force. Particle size increased with the addition of Ca2+ and the stability decreased.
Comparison of nutrient-removing microbial communities in activated sludge from full-scale MBRs and conventional plants
Authors: Saunders A. M. , Larsen P. , Nielsen P. H.
Published: July 2013

The composition of nutrient-removing microbial communities in five full-scale membrane bioreactors (MBRs) was investigated using fluorescence in situ hybridization and 16S rRNA pyrosequencing and compared to similar analyses of conventional activated sludge (CAS) communities. The communities were highly similar but some genera that are always present in enhanced biological phosphorus removal (EBPR) (core groups) were absent in the MBRs. The overall phylogenetic similarity of the communities indicated that these differences were primarily closely related groups. More research is needed to establish the operational significance of the observed differences between MBR and CAS sludge.
Two-stage anaerobic fluidized-bed membrane bioreactor treatment of settled domestic wastewater
Authors: Bae J. , Yoo R. , Lee E. , McCarty P. L.
Published: July 2013

A two-stage anaerobic fluidized-bed membrane bioreactor (SAF-MBR) system was applied for the treatment of primary-settled domestic wastewater that was further pre-treated by either 10 μm filtration or 1 mm screening. While the different pre-treatment options resulted in different influent qualities, the effluent qualities were quite similar. In both cases at a total hydraulic retention time of 2.3 h and 25 °C, chemical oxygen demand and biochemical oxygen demand (BOD5) removals were 84–91% and 92–94%, with effluent concentrations lower than 25 and 7 mg/L, respectively. With a membrane flux of 6–12 L/m2/h, trans-membrane pressure remained below 0.2 bar during 310 d of continuous operation without need for membrane chemical cleaning or backwashing. Biosolids production was estimated to be 0.028–0.049 g volatile suspended solids/g BOD5, which is far less than that with comparable aerobic processes. Electrical energy production from combined heat and power utilization of the total methane produced (gaseous and dissolved) was estimated to be more than sufficient for total system operation.
Ammonium nitrogen removal in batch cultures treating digested piggery wastewater with microalgae Oedogonium sp.
Authors: Wang Haiping , Hu Zhiquan , Xiao Bo , Cheng Qunpeng , Li Fanghua
Published: July 2013

Due to the nutrient characteristics of the high concentration of available ammonium in digested piggery wastewater (DPW), microalgae can be used to treat DPW before its final discharge. Four green microalgae (Hydrodictyaceae reticulatum Lag, Scenedesmus obliquus, Oedogonium sp. and Chlorella pyrenoidosa) and three blue-green algae (Anabaena flos-aquae, Oscillatoria amoena Gom and Spirulina platensis) were used to remove the nutrients (N, P, C), especially ammonium nitrogen (NH4+-N), from diluted DPW with 300 mg/L algae density in batch tests. The microalgae with the best NH4+-N nutrient removal was then selected for further optimization of the variables to improve NH4+-N removal efficiency using a central composite design (CCD) experiment. Taking into account the nutrient removal efficiency, Oedogonium sp. showed the best performance (reduction of 95.9% NH4+-N, 92.9% total phosphorus (TP) and 62.5% chemical oxygen demand (COD)) based on the results of the batch tests. The CCD results suggested that the optimal values of variables were initial Oedogonium sp. density of 399.2 mg/L and DPW diluted by 16.3, while the predicted value of NH4+-N removal efficiency obtained was 97.0%.
Parameter estimation for eutrophication models in reservoirs
Authors: Vieira J. M. P. , Pinho J. L. S. , Dias N. , Schwanenberg D. , van den Boogaard H. F. P.
Published: July 2013

Excessive eutrophication is a major water quality issue in lakes and reservoirs worldwide. This complex biological process can lead to serious water quality problems. Although it can be adequately addressed by applying sophisticated mathematical models, the application of these tools in a reservoir management context requires significant amounts of data and large computation times. This work presents a simple primary production model and a calibration procedure that can efficiently be used in operational reservoir management frameworks. It considers four state variables: herbivorous zooplankton, algae (measured as chlorophyll-a pigment), phosphorous and nitrogen. The model was applied to a set of Portuguese reservoirs. We apply the model to 23 Portuguese reservoirs in two different calibration settings. This research work presents the results of the estimation of model parameters.
Comparison between InfoWorks hydraulic results and a physical model of an urban drainage system
Authors: Rubinato Matteo , Shucksmith James , Saul Adrian J. , Shepherd Will
Published: July 2013

Urban drainage systems are frequently analysed using hydraulic modelling software packages such as InfoWorks CS or MIKE-Urban. The use of such modelling tools allows the evaluation of sewer capacity and the likelihood and impact of pluvial flood events. Models can also be used to plan major investments such as increasing storage capacity or the implementation of sustainable urban drainage systems. In spite of their widespread use, when applied to flooding the results of hydraulic models are rarely compared with field or laboratory (i.e. physical modelling) data. This is largely due to the time and expense required to collect reliable empirical data sets. This paper describes a laboratory facility which will enable an urban flood model to be verified and generic approaches to be built. Results are presented from the first phase of testing, which compares the sub-surface hydraulic performance of a physical scale model of a sewer network in Yorkshire, UK, with downscaled results from a calibrated 1D InfoWorks hydraulic model of the site. A variety of real rainfall events measured in the catchment over a period of 15 months (April 2008–June 2009) have been both hydraulically modelled and reproduced in the physical model. In most cases a comparison of flow hydrographs generated in both hydraulic and physical models shows good agreement in terms of velocities which pass through the system.
Verification of flood damage modelling using insurance data
Authors: Zhou Q. , Panduro T. E. , Thorsen B. J. , Arnbjerg-Nielsen K.
Published: July 2013

This paper presents the results of an analysis using insurance data for damage description and risk model verification, based on data from a Danish case. The results show that simple, local statistics of rainfall are not able to describe the variation in individual cost per claim, but are, however, feasible for modelling the overall cost per day. The study also shows that in combining the insurance and regional data it is possible to establish clear relationships between occurrences of claims and hazard maps. In particular, the results indicate that with improvements to data collection and analysis, improved prediction of damage costs will be possible, for example based also on socioeconomic variables. Furthermore, the paper concludes that more collaboration between scientific research and insurance agencies is needed to improve inundation modelling and economic assessments for urban drainage designs.
Perspectives on modelling micropollutants in wastewater treatment plants
Authors: Clouzot Ludiwine , Choubert Jean-Marc , Cloutier Frédéric , Goel Rajeev , Love Nancy G. , Melcer Henryk , Ort Christoph , Patureau Dominique , Plósz Benedek G. , Pomiès Maxime , Vanrolleghem Peter A.
Published: July 2013

Models for predicting the fate of micropollutants (MPs) in wastewater treatment plants (WWTPs) have been developed to provide engineers and decision-makers with tools that they can use to improve their understanding of, and evaluate how to optimize, the removal of MPs and determine their impact on the receiving waters. This paper provides an overview of such models, and discusses the impact of regulation, engineering practice and research on model development. A review of the current status of MP models reveals that a single model cannot represent the wide range of MPs that are present in wastewaters today, and that it is important to start considering classes of MPs based on their chemical structure or ecotoxicological effect, rather than the individual molecules. This paper identifies potential future research areas that comprise (i) considering transformation products in MP removal analysis, (ii) addressing advancements in WWTP treatment technologies, (iii) making use of common approaches to data acquisition for model calibration and (iv) integrating ecotoxicological effects of MPs in receiving waters.
Accuracy of different sensors for the estimation of pollutant concentrations (total suspended solids, total and dissolved chemical oxygen demand) in wastewater and stormwater
Authors: Lepot Mathieu , Aubin Jean-Baptiste , Bertrand-Krajewski Jean-Luc
Published: July 2013

Many field investigations have used continuous sensors (turbidimeters and/or ultraviolet (UV)-visible spectrophotometers) to estimate with a short time step pollutant concentrations in sewer systems. Few, if any, publications compare the performance of various sensors for the same set of samples. Different surrogate sensors (turbidity sensors, UV-visible spectrophotometer, pH meter, conductivity meter and microwave sensor) were tested to link concentrations of total suspended solids (TSS), total and dissolved chemical oxygen demand (COD), and sensors' outputs. In the combined sewer at the inlet of a wastewater treatment plant, 94 samples were collected during dry weather, 44 samples were collected during wet weather, and 165 samples were collected under both dry and wet weather conditions. From these samples, triplicate standard laboratory analyses were performed and corresponding sensors outputs were recorded. Two outlier detection methods were developed, based, respectively, on the Mahalanobis and Euclidean distances. Several hundred regression models were tested, and the best ones (according to the root mean square error criterion) are presented in order of decreasing performance. No sensor appears as the best one for all three investigated pollutants.