bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurements of air pollution emission factors for marine transportation in SECA
Authors: Alföldy B. , Lööv J. B. , Lagler F. , Mellqvist J. , Berg N. , Beecken J. , Weststrate H. , Duyzer J. , Bencs L. , Horemans B. , Cavalli F. , Putaud J.-P. , Janssens-Maenhout G. , Csordás A. P. , Van Grieken R. , Borowiak A. , Hjorth J.
Published: July 2013

Abstract. The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg−1 fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg−1 fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 × 1015 (kg fuel)−1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.
Si cycling in a forest biogeosystem – the importance of transient state biogenic Si pools
Authors: Sommer M. , Jochheim H. , Höhn A. , Breuer J. , Zagorski Z. , Busse J. , Barkusky D. , Meier K. , Puppe D. , Wanner M. , Kaczorek D.
Published: July 2013

Abstract. The relevance of biological Si cycling for dissolved silica (DSi) export from terrestrial biogeosystems is still in debate. Even in systems showing a high content of weatherable minerals, like Cambisols on volcanic tuff, biogenic Si (BSi) might contribute > 50% to DSi (Gerard et al., 2008). However, the number of biogeosystem studies is rather limited for generalized conclusions. To cover one end of controlling factors on DSi, i.e., weatherable minerals content, we studied a forested site with absolute quartz dominance (> 95%). Here we hypothesise minimal effects of chemical weathering of silicates on DSi. During a four year observation period (05/2007–04/2011), we quantified (i) internal and external Si fluxes of a temperate-humid biogeosystem (beech, 120 yr) by BIOME-BGC (version ZALF), (ii) related Si budgets, and (iii) Si pools in soil and beech, chemically as well as by SEM-EDX. For the first time two compartments of biogenic Si in soils were analysed, i.e., phytogenic and zoogenic Si pool (testate amoebae). We quantified an average Si plant uptake of 35 kg Si ha−1 yr−1 – most of which is recycled to the soil by litterfall – and calculated an annual biosilicification from idiosomic testate amoebae of 17 kg Si ha−1. The comparatively high DSi concentrations (6 mg L−1) and DSi exports (12 kg Si ha−1 yr−1) could not be explained by chemical weathering of feldspars or quartz dissolution. Instead, dissolution of a relictic, phytogenic Si pool seems to be the main process for the DSi observed. We identified canopy closure accompanied by a disappearance of grasses as well as the selective extraction of pine trees 30 yr ago as the most probable control for the phenomena observed. From our results we concluded the biogeosystem to be in a transient state in terms of Si cycling.
Using hydrologic measurements to investigate free phase gas ebullition in a Maine Peatland, USA
Authors: Bon C. E. , Reeve A. S. , Slater L. , Comas X.
Published: July 2013

Abstract. Northern Peatlands cover more than 350 million ha and are an important source of methane (CH4) and other biogenic gases contributing to climate change. Free phase gas (FPG) accumulation and episodic release has recently been recognized as an important mechanism for biogenic gas flux from peatlands. It is likely that gas production and groundwater flow are interconnected in peatlands: groundwater flow influences gas production by regulating geochemical conditions and nutrient supply available for methanogenesis while FPG influences groundwater flow through a reduction in peat permeability and by creating excess pore water pressures. Water samples collected from three well sites at Caribou Bog, Maine, show substantial dissolved CH4 (5–16 mg L−1) in peat waters below 2 m depth and an increase in concentrations with depth. This suggests substantial production and storage of CH4 in deep peat that may be episodically released as FPG. Two minute increment pressure transducer data reveal approximately 5 cm fluctuations in hydraulic head from both deep and shallow peat that are believed to be indicative of FPG release. FPG release persists up to 24 h during decreasing atmospheric pressure and a rising water table. Preferential flow is seen towards an area of relatively lower hydraulic head associated with the esker and pool system. Increased CH4 concentrations are also found at the depth of the esker crest suggesting that the high permeability esker is acting as a conduit for groundwater flow, driving a downward transport of labile carbon, resulting in higher rates of CH4 production.
EFFECT OF POLYSULFANE SILANIZED SILICA ON THE MORPHOLOGY AND MECHANICAL PROPERTIES OF BROMBUTYL RUBBER VULCANIZATES
Authors: Liang Jiyu , Feng Na , Chang Suqin , Wang C. Xinhong , Zhang Guixia
Published: July 2013

Polysulfane silanized white silica particles were prepared by treating with various loadings of bis(3-trie-thoxysilylpropyl)tetrasulfide (TESPT) in a high-speed mixer. Brombutyl rubber (BIIR) vulcanizates filled with the silanized silica were prepared by compression molding. Compared with BIIR/untreated silica vulcanizate, the mechanical properties of BIIR/silanized silica vulcanizates improved prominently with the increase of TESPT loading and reached peak value with the TESPT loading increasing up to 2 phr but declined slightly with the continuous increment of the TESPT. Effects of various loadings of TESPT on the mechanical properties of BIIR vulcanizates were investigated by testing mechanical properties, vulcanizing properties, bound rubber, scanning electron microscopy, and dynamic mechanical analysis (DMA) to determine the extent of rubber-filler interaction. As shown in vulcanizing properties, bound rubber, and DMA measurements, the bound rubber content, cross-link density, and storage and loss modulus of BIIR vulcanizates clearly increased with the TESPT loading increasing from 0 to 2 phr and then reduced somewhat with a continuous increase of TESPT; the tanδmax value decreased significantly with the increment of TESPT loading from 0 to 2 phr and increased sharply with the TESPT content increasing to 4 phr. These experimental results indicate that the improvement in the mechanical properties of BIIR vulcanizates was mostly attributed to a strong BIIR–silica interaction and an effective dispersion of the silica. On the other hand, the decline of mechanical properties can be explained by the excess TESPT, as a kind of physical diluent, having an adverse effect on the silica dispersion and cross-link reaction. By forming the silica aggregates on the mixing, the poor dispersion of silica could cause the decline of relative volume content of silica in the matrix.
COMPARISON OF STRESS–SOFTENINGS IN CARBON-BLACK FILLED NATURAL RUBBER AND STYRENE–BUTADIENE RUBBER
Authors: Diani Julie , Merckel Yannick , Brieu Mathias , Caillard Julien
Published: July 2013

The authors compared the mechanical behavior and, more precisely, the Mullins and the cyclic (post-Mullins) softenings of two filled rubbers. A crystallizing natural rubber and a noncrystallizing styrene–butadiene rubber of similar compositions resulting in similar cross-link densities and filled with 40 phr of N347 carbon-black fillers were tested in cyclic uniaxial tension at room temperature and at 85 °C. Crystallization in filled rubbers is known to increase stress at high stretch, stretch at break, cycle hysteresis, and fatigue lifetime and to reduce crack propagation. In this study, it is shown that crystallization also seems to enhance the Mullins softening (softening at the first cycle) and to favor the apparent cyclic softening. Results reveal that natural rubber shows an amplitude dependence on the cyclic softening, whereas the styrene–butadiene rubber does not. Finally, results demonstrate that studying filled rubber softening cannot help predict lifetime.
CHANGES OF CHEMICAL STRUCTURE AND MECHANICAL PROPERTY LEVELS DURING THERMO-OXIDATIVE AGING OF NBR
Authors: Zhao Jiaohong , Yang Rui , Iervolino Rossana , Barbera Stellario
Published: July 2013

The accelerated thermo-oxidative aging of acrylonitrile–butadiene rubber (NBR) was studied at elevated temperatures. The chemical structure characterized by attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR) and pyrolysis gas chromatography–mass spectroscopy (PGC-MS) showed the loss of low-molecular-weight additives, such as antioxidants and paraffin, and the formation of carbonyl groups and unsaturated double bonds. The cross-linking degree characterized by NMR and a swelling test showed that aging is a competitive process of cross-linking and chain scission. Cross-linking dominated the thermal aging of NBR most of the time, whereas chain scission began to increase after a long time at high temperatures. The changes of mechanical property magnitudes during thermal aging of NBR were studied by using the recovery from bending test (RFB) and tensile test. By comparing the physical property results and the structural changes, their relationship is discussed.
STUDYING NR/ORGANO-MONTMORILLONITE NANOCOMPOSITES WITH SILANE COUPLING AGENTS VIA NETWORK VISUALIZATION TEM
Authors: Lowe David J. , Chapman Andrew V. , Cook Stuart , Busfield James J. C.
Published: July 2013

Organo-montmorillonite (OMMT) increases the elastic modulus of elastomers such as natural rubber (NR) by a very large amount at low strains, but this decreases as the rubber is extended. Silane coupling agents, widely used with silica-filled rubbers, were added to NR/OMMT nanocomposites to increase the effects of OMMT on modulus at high strains. Both bis(triethoxysilylpropyl)tetrasulfide (TESPT) and 3-mercaptopropyl di(tridecan-1-oxy-13-penta(ethylene oxide))ethoxysilane (MPDES) increase tensile modulus significantly at strains greater than 30%. The coupling agents strengthen the rubber–filler interface, reducing cavitation around OMMT particles and preventing NR molecules from sliding at the interface. Evidence for a stronger rubber–filler interaction is provided by measurements of bound rubber content and use of network visualization transmission electron microscopy (NVTEM). OMMT also affects the dynamic properties of NR differently from other fillers. One aspect of this is the appearance of a peak in tan δ between 20 °C and 60 °C, attributed to the glass transition of intercalated and adsorbed NR molecules. The intensity of this peak is diminished by the addition of TESPT or MPDES, implying that they are restricting the intercalation of the rubber between the clay sheets. The coupling agents also have a small effect on vulcanization behavior compared with that of OMMT.
INFLUENCE OF FIBER TYPE AND COATING ON THE COMPOSITE PROPERTIES OF EPDM COMPOUNDS REINFORCED WITH SHORT ARAMID FIBERS
Authors: Hintze C. , Shirazi M. , Wiessner S. , Talma A. G. , Heinrich G. , Noordermeer J. W. M.
Published: July 2013

There is a renewed interest in the application of short aramid fibers in elastomers because of the considerable improvement in mechanical and dynamic properties of the corresponding rubber composites. Possible applications of short aramid fiber–reinforced elastomers are tires, dynamically loaded rubber seals, diaphragms, engine mounts, transmission belts, conveyer belts, and hoses. Our studies are related to the investigation of dispersion, length distribution, and the fiber–matrix interaction of two types of short aramid fibers, standard coated and resorcinol formaldehyde latex (RFL) coated, in ethylene–propylene–diene rubber (EPDM). Because the detection of the polymer fiber morphology in rubber compounds is hampered in the presence of carbon black, which is typically used in industrial elastomer compounds, fiber length, fiber length distribution, and dispersion are investigated in corresponding carbon black–free model compounds. Optical methods, scanning electron microscopy, and tensile testing are employed to explore the short aramid fiber–reinforced elastomer composites. The effects of morphology and fiber–matrix interaction on the mechanical properties of composites are discussed. Regarding fiber type, it is shown that co-poly-(paraphenylene/3,4′-oxydiphenylene terephthalamide) (PP/ODPTA) fibers end up with a higher final length than does poly(para-phenylene terephtalamide) (PPTA), which results in considerably higher mechanical properties of corresponding rubber compounds. For each fiber type, the higher final length as a result of RFL coating and the interaction with the rubber matrix are the key factors that overcome even the negative effect of poorer dispersion of RFL-coated fibers. The differences between the short aramid fibers and aramid cords regarding the RFL coating are also discussed.
ROLE OF COAGENTS IN PEROXIDE VULCANIZATION OF NATURAL RUBBER
Authors: Rajan Rejitha , Varghese Siby , George K. E.
Published: July 2013

The drawbacks of peroxide vulcanization can largely be overcome by introducing suitable co-curing agents (coagents) in the formulation. The role of various coagents, such as zinc diacrylate (ZDA), trimethylolpropane trimethacrylate (TMPTMA), and triallyl cyanurate (TAC) in the peroxide vulcanization of natural rubber (NR) was studied by Fourier transform infrared spectroscopy. Cross-link density was measured by the equilibrium–swelling technique. Cross-linking mechanism of peroxide in NR was interpreted by comparing the spectra of cured and uncured vulcanizates. The predominance of hydrogen abstraction over the radical addition was established (at 160 °C). Coagent ZDA produces ionic as well as covalent cross-links in the vulcanizate. Ionic cross-links have the ability to slip along the hydrocarbon chains and thus resemble polysulfidic cross-links. Hence, ZDA can be chosen for applications where good mechanical properties are required. Coagent TMPTMA produces covalent cross-links between polymer chains and is suitable for high-modulus applications. TAC, although it bridges through covalent cross-links, is not a suitable coagent for highly unsaturated rubbers like NR.
"Argumentos" para la elección del centro educativo un estudio de caso con padres portugueses
Authors: Sá Virgínio , Antunes Fátima
Published: July 2013

Tomando como base empírica algunos de los datos del cuestionarioaplicado a una muestra de cerca de ochocientos padres seleccionados entres centros públicos de enseñanza secundaria, en este artículo analizamosel modo cómo diferentes categorías de padres organizan «jerarquías deexcelencia», a través de los «argumentos de elección» a los que danprioridad cuando escogen el centro educativo, al pasar a la enseñanzasecundaria en 10º curso (4º de la ESO). Del análisis de los datos destacaque, en todos los segmentos de padres, encontramos una fracción queconcede gran importancia a los indicadores de naturaleza académica;verificamos, además, una concentración desigual de estas fracciones enlos tres establecimientos estudiados, lo que refleja un predominio dediferentes tipos de público en cada escuela. De este modo, aunque varíe laimportancia atribuida a los «argumentos de elección», según el nivel deestudios de los padres, en los casos estudiados las «jerarquías deexcelencia» se distinguen, sobre todo, de acuerdo con la variable centro.
Parcel‐level model of water and energy end use: Effects of indoor water conservation
Authors: Morales Miguel A. , Heaney James P. , Friedman Kenneth R. , Martin Jacqueline M.
Published: July 2013

This article presents a parcel‐level methodology to estimate the water and energy savings associated with indoor water conservation best management practices (BMPs). By estimating fixture water savings at the parcel level for 64 public‐supply land use sectors, this approach facilitates targeting customers for water conservation by calculating their net benefits for each end use (savings in charges for water, wastewater, and energy, minus cost of water conservation BMPs). The inclusion of energy savings, primarily through reduced hot water use, is shown to be a significant benefit. The modeled end uses are male‐only toilets, mixed‐use toilets, urinals, faucets, showerheads, clothes washers, and prerinse spray valves. This article concludes with a simplified optimization formulation that determines the best fixture choice for every end‐use device so that net benefits at the parcel level are maximized. These individual fixture results are then aggregated to the parcel or any desired aggregate scale (e.g., utility).
Source water and microfiltration plant manganese control study
Authors: Lewis Daniel Olin , Ladner David A. , Karanfil Tanju
Published: July 2013

A combined field and laboratory manganese study was conducted for the Startex‐Jackson‐Wellford‐Duncan Water District in Wellford, S.C. Through source water characterization, it was found that biochemical processes in the river affected manganese concentrations more than any processes in the lake feeding the river. Because measures taken in the lake would not control manganese at the plant intake, in‐plant treatment was required. Bench‐top experiments evaluated three treatment trains: potassium permanganate (KMnO4) direct oxidation followed by microfiltration (MF), manganese‐coated media bed before MF, and manganese‐coated media bed after MF. All processes removed manganese, with the media bed processes consistently achieving < 0.004 mg/L and KMnO4 oxidation reaching as low as 0.008 mg/L Mn. Turbidity, organic carbon, and trihalomethane formation potential removals were comparable, but the process of media bed following the filter exhibited the highest rate of membrane fouling. This study provides a holistic understanding of manganese source and treatability that should prove useful to utilities with similar manganese issues.
Aquifer plume delineation of mixed population nitrate data using ArcGIS
Authors: Tyagi Avdhesh K. , Johnson Nicholas M.
Published: July 2013

The city of Enid collects most of its water for public distribution from groundwater. This groundwater is supplied from five wellfields—Enid, Drummond, Cleo Springs, Ringwood, and Ames—covering the Enid Terrace Aquifer, the Drummond Confined Aquifer, and the Cimarron Terrace Aquifer. This research explores nitrate distribution in the aquifer by analyzing trend graphs for the wells and estimating nitrate plumes for the wellfields. The US Environmental Protection Agency (USEPA) requires that public water systems not exceed a nitrate concentration that is ≤ 10 mg/L because nitrate above this level causes Blue Baby Syndrome in infants. Information for this study was provided in the form of sampling data compiled by the city of Enid. This raw data was then analyzed and distilled to determine nitrate existence and extent using USEPA standards. This article presents a methodology to delineate the high nitrate plumes in five wellfields.
Does It Make Sense to Outsource Utility Operations?
Authors: Olson Ray
Published: July 2013

Outsourcing some or part of water utility functions makes sense for some, but not all, utilities. Each water utility or district should closely review its operations and decide what's best. A few considerations can make the decision a little easier.
How Can a Professional Operator Designation Benefit Operators and the Industry?
Authors: Moore Gavin , Copeland Ari
Published: July 2013

Water and wastewater treatment plant operators often don't receive the compensation and prestige other careers offer and have difficulty with reciprocity across state lines. A Professional Operator (PO) designation, set to be released this fall, seeks to remedy these problems.
Grandmother elephants
Authors: Marder Eve
Published: July 2013

As new technology makes it possible to perform experiments that were unimaginable a decade ago, Eve Marder argues that we can still learn from the past.
The effects of pre-slaughter selection of reindeer bulls (Rangifer tarandus tarandus L.) on technological and sensory meat quality, blood metabolites and abomasal lesions
Authors: Wiklund E. , Malmfors G. , Lundström K.
Published: July 2013

Thirty reindeer bulls (age 1 1/2 years) were subjected to different pre-slaughter treatments to study the effects on ultimate pH values, muscle glycogen content, blood metabolites and abomasal lesions. Gathering and herding into a grazing corral were followed by various selection procedures. Before starting these, a control group of 10 reindeer were captured by lasso and slaughtered outside the grazing corral. Ten reindeer were then selected by hand from a small group of animals (100-150 head) in a small selection corral. Another 10 reindeer were selected from a large herd of about 1000-2000 animals, by the traditional technique of using a lasso. During a 6-hour selection, animals were captured and slaughtered after 1.5 hours (n = 2), 3-5 hours (n = 2), 5 hours (n = 3) and 6 hours (n=3) respectively. The results showed the technique of using a lasso to be stressful and glycogen-depleting, as the two lasso captured groups (the control group and the reindeer exposed to the protracted lasso selection) had the highest ultimate pH values and lowest muscle glycogen values measured. By contrast, the selection procedure where reindeer were captured by hand, was not found to be detrimental to glycogen content and ultimate pH values. Nevertheless, both selection techniques expose the reindeer to acute stress during the capture and manual restraint, which in the present study was reflected in high plasma Cortisol values in all treatment groups. The frequency of abomasal lesions was highest in the group of reindeer subjected to the prolonged selection procedure. No connection between technological and sensory meat quality was found in this study. The technique of selecting animals by hand ought to be further developed so that existing practical problems can be solved. The technique could then be recommended for wider use.
Different Cell Types In the Lower Respiratory Tract of the Reindeer (Rangifer tarandus tarandus L.) - A Transmission Electron Microscopical Study
Authors: Saari Seppo A.m.
Published: July 2013

The epithelium of the trachea and distal airways of 12 healthy adult reindeer were studied with transmission electron microscopy. The ultrastructure of the reindeer respiratory tract corresponded to the findings of previous investigators studying other mammalian species. The epithelium of the trachea and bronchi, down to the level of the distal bronchioli, was composed of three main types of cell: ciliated, goblet, and basal. In the distal brochioli, non-ciliated cells similar to those known as Clara cells were predominant. Numerous electron-dense granules and the cell organelle pattern resembled the Clara cell type observed in laboratory rodents, rabbit, sheep, pig, horse, and llama. Pneumocyte 1 and pneumocyte 2 cells were readily identified in the alveoli. The pneumocyte 2 cells possessed short microvilli and granules with lamellar content. Micropinocytotic vesicles were very numerous in the alveolar wall, and a small number of alveolar macrophages occasionally seen in the alveolar lumen.
Comparative aspects of volatile fatty acid production in the rumen and distal fermentation chamber in Svalbard reindeer
Authors: Sørmo W. , Haga Ø.E. , White R.G. , Mathiesen S.D.
Published: July 2013

Microbial fermentation end products were investigated in Svalbard reindeer at two different locations, on Nordenskioldland (NL) (n=7) and in a marginal area on Nordaustlandet (NA) (n=11), at different seasons. The pH ranged from 6.51-6.70 in rumen contents and from 6.78-7.17 in the distal fermentation chamber (DFC=caecum and proximal part of the colon) on NL compared to 6.10-6.71 in rumen contents and 6.50-7.35 in DFC contents on NA. The ruminal volatile fatty acid concentration ([VFAJ) was 84.5 ± 9.5 mmol/l compared to 63-9 ± 17.6 mmol/kg in the DFC on NL in winter. In autumn, ruminal and DFC [VFA] was high at 113.5 ± 13.0 mmol/l and 90.4 ± 10.9 mmol/kg, respectively. On NA ruminal [VFA] was 85.7 ± 12.4 mmol/l and 59-6 ± 1.3 mmol/kg in the DFC in winter, compared to 107.3 ± 18.4 mmol/l and 102.0 ± 12.7 mmol/kg in rumen and DFC, respectively, in summer. Mean acetate/propionate (A/P) ratios in the rumen indicate fermentation in favour of plant fibre digestion in winter (4.8) but not in autumn (3.0) on NL. On NA, the mean A/P ratio was 5.1 in winter, compared to 4.6 in summer. In all DFC investigated the A/P ratio was higher than 8.9. The initial ruminal [VFA] did not reflect the VFA production measured. On NL, the production rate of VFA was low or not detectable in rumen and DFC in winter, while in autumn the total production rate of VFA was 59.3 kJ/kgW0 75/d, of which 6.5% originated from the DFC. On NA in winter, a total of 121.3 kJ/kgW0 7S/d was estimated of which 17% originated from the DFC, compared to a total of 380.4 kj/kgW0.75/d in summer where the DFC only contributed 2.7%. Plants (grasses and mosses) with low quality in winter do not seem to contribute significantly to the VFA production in rumen and DFC. VFA production in the DFC seems to be of significant importance in reindeer when pastures have low availability but high quality. The concenttation and the rate of VFA production in the DFC contents were not related to the size of the chamber, but to the diet eaten.
Loss of deuterium in faecal solids and by sequestration in reindeer: effect on doubly labelled water studies
Authors: Gotaas Geir , Milne Eric , Haggarty Paul , Tyler Nicholas J.C.
Published: July 2013

An underlying assumption when estimating total energy expenditure (TEE) using doubly labelled water (DLW) is that the injected isotopes (lsO and 2H) leave the body only in the form of CO, and H20. However, both isotopes have additional routes of loss. We quantified the loss of 2H (i) attached to faecal solids and (ii) by sequestration into newly synthesised fat in reindeer (Rangifer tarandus tarandus). Estimates of the errors caused by these processes were applied to data from DLW studies with reindeer in summer and in winter. Given the net rate of faecal dry matter output and lipid synthesis in the present study, ignoring both sources of error caused the TEE of reindeer to be underestimated by approximately 5% in winter and approximately 9% in summer. The separate effect of each source of error was evaluated in summer. If ignored, loss of 2H through sequestration alone caused TEE to be underestimated by approximately 3.7%. Similarly, if ignored, loss of 2H attached to faecal solids alone caused TEE to be underestimated by approximately 5.9%.
Robust Portfolio Selection
Authors: Pachamanova Dessislava A.
Published: July 2013

Robust portfolio selection is the process of allocating assets in such a way that the resulting portfolio is less sensitive to errors in the predicted behavior of the assets in the portfolio. Tools from robust and Bayesian statistics, simulation, and stochastic and robust optimization are often used to improve the stability, theoretical properties, and computational tractability of models for portfolio selection.
Introduction to Lévy Processes
Authors: Liu Yunan , Huang Chien‐Chia L.
Published: July 2013

As continuous‐time analogs of random walks, Lévy processes form a rich class of stochastic processes, such as Brownian motions, Poisson processes, and Gamma processes. In this introductory note, we provide fundamental results and properties of Lévy processes. We present the two most important theorems: Lévy–Ito decomposition and Lévy–Khintchine formula.
Quality Design, Control, and Improvement
Authors: Mitra Amitava
Published: July 2013

A fundamental requirement for the successful operation of a manufacturing or service organization is the embracing of a culture of quality that is pervasive at all levels of the organization. In manufacturing, the phases associated with the making of a quality product start at the design phase. Incorporation of customer needs in product design is fundamental, as are issues associated with a feasible manufacturing process to make the designed product. Monitoring of the production process is dealt with in quality control while improvement of the product and process to meet customer needs is considered in the quality improvement phase, respectively.
Advanced Branching Processes
Authors: Simatos Florian
Published: July 2013

In this article, we discuss three important classes of advanced models of branching processes, namely branching processes in random environment, branching random walks, and continuous state branching processes. These models have recently been the object of intense research activity, and we highlight some of their most basic properties, linked for instance to extinction problems or long‐time behavior.
Reversibility in Queueing Models
Authors: Miyazawa Masakiyo
Published: July 2013

In stochastic models for queues and their networks, random events evolve in time. A process for their backward evolution is referred to as atime‐reversed process. If some property is unchanged under time reversal, we may better understand the model. A concept of reversibility is invented for this invariance. Local balance for a stationary Markov chain has been used, but it is still too strong for queueing applications.

We are concerned with a continuous‐time Markov chain, but do not assume it has a stationary distribution. We define reversibility in structure as an invariant property of a family of the set of models under a certain operation. Any member of this set is a pair of transition rate functions and its supporting measure, and each set represents dynamics of queueing systems such as arrivals and departures. We use a permutation Γ of the family members to describe the change of the dynamics under time reversal. This reversibility is called Γ‐reversibility in structure.

To apply these definitions, we introduce new classes of models, calledreacting systemsandself‐reacting systems. Using them, we give a unified view for queues and their networks. They include symmetric service, batch movements, and state‐dependent routing.
Reactive/proactive aggression and the development of internalizing problems in males: The moderating effect of parent and peer relationships
Authors: Fite Paula J. , Rubens Sonia L. , Preddy Teresa M. , Raine Adrian , Pardini Dustin A.
Published: July 2013

The current study examined whether reactive and/or proactive aggression in adolescent males prospectively predicted increased levels of internalizing symptoms (depression and anxiety) in late adolescence. It was postulated that reactive aggression would be robustly related to later internalizing problems, but only among adolescent males who had problematic family or peer social relationships. Participants were a racially diverse group of 289 adolescent males (Mean age = 16). Measures of reactive and proactive aggression, peer rejection, and poor parent–adolescent communication were examined as predictors of both depression and anxiety symptoms assessed approximately 3 years later. The interactive effects between the two facets of aggression and measures of peer rejection and poor parent–adolescent communication in predicting internalizing problems was also examined. Adolescents with high levels of reactive aggression were more likely to exhibit elevated internalizing problems during late adolescence, even when controlling for pre‐existing levels of anxiety/depression. However, this association only emerged for adolescents who had high levels of peer rejection and/or poor communication with their parent. Consistent with expectations, proactive aggression was unrelated to internalizing symptoms regardless of social relationship quality. Adolescent reactive, but not proactive, aggression is a risk factor for the development of internalizing problems. However, the findings suggest that interventions designed to foster positive social relationships among reactively aggressive youth may help protect them from developing significant internalizing problems over time. Aggr. Behav. 40:69–78, 2014. © 2013 Wiley Periodicals, Inc.
Dual Acid‐Responsive Micelle‐Forming Anticancer Polymers as New Anticancer Therapeutics
Authors: Kim Byungkuk , Lee Eunsun , Kim Yerang , Park Sanga , Khang Gilson , Lee Dongwon
Published: July 2013

Cinnamaldehyde, a major active compound of cinnamon, is known to induce apoptotic cell death in numerous human cancer cells. Here, dual acid‐responsive polymeric micelle‐forming cinnamaldehyde prodrugs, poly[(3‐phenylprop‐2‐ene‐1,1‐diyl)bis(oxy)bis(ethane‐2,1‐diyl)diacrylate]‐co‐4,4’(trimethylene dipiperidine)‐co‐poly(ethylene glycol), termed PCAE copolymers, are reported. PCAE is designed to incorporate cinnamaldehyde via acid‐cleavable acetal linkages in its pH‐sensitive hydrophobic backbone and self assemble to form stable micelles which can encapsulate camptothecin (CPT). PCAE self assembles to form micelles which release CPT and cinnamaldehyde in pH‐dependent manners. PCAE micelles induce apoptotic cell death through the generation of intracellular reactive oxygen species (ROS) and exert synergistic anticancer effects with a payload of CPT in vitro and in vivo model of SW620 human colon tumor‐bearing mice. It is anticipated that dual acid‐sensitive micelle‐forming PCAE with intrinsic anticancer activities has enormous potential as novel anticancer therapeutics.
Surfactant‐Free, Lipo‐Polymersomes Stabilized by Iron Oxide Nanoparticles/Polymer Interlayer for Synergistically Targeted and Magnetically Guided Gene Delivery
Authors: Hu Shang‐Hsiu , Hsieh Tsung‐Ying , Chiang Chin‐Sheng , Chen Po‐Jung , Chen You‐Yin , Chiu Tsung‐Lang , Chen San‐Yuan
Published: July 2013

Gene therapy holds promise to suppress carcinomas but still remains far removed from clinic because of the lack of a safe and effective delivery system. Besides enhancing transfection efficiency, the difficulty in gene therapy is how to deliver sufficient gene molecules to the site of interest. Herein, the rational design of surfactant‐free lipo‐polymersomes (LPPs) to overcome these problems is reported, simultaneously using a lipid‐stabilized double emulsion approach. The LPPs are designed to conceal the cationic lipids and plasmid DNA inside the core along with iron oxide nanoparticles/polymer interlayer and a relatively neutral lipid shell to avoid the undesired interaction during circulation, leading to high accumulation in the tumors of mice. Furthermore, guided by an external magnetic field and the folic acid (FA) that target tumors via folate receptor‐mediated endocytosis on the cell surface, the vectors demonstrate a 30–40‐fold increase in cell uptake. Moreover, this synergistic tumor‐targeted approach can enhance a 10‐fold increase in in vivo transfection efficacy by promoting the delivery of LPPs to cancer cells and facilitating the endosomal escape of gene molecules. The new insights and capabilities represent a major step in nanovector engineering for safe and efficient gene delivery.
Stretchable, Multiplexed pH Sensors With Demonstrations on Rabbit and Human Hearts Undergoing Ischemia
Authors: Chung Hyun‐Joong , Sulkin Matthew S. , Kim Jong‐Seon , Goudeseune Camille , Chao Hsin‐Yun , Song Joseph W. , Yang Sang Yoon , Hsu Yung‐Yu , Ghaffari Roozbeh , Efimov Igor R. , Rogers John A.
Published: July 2013

Stable pH is an established biomarker of health, relevant to all tissues of the body, including the heart. Clinical monitoring of pH in a practical manner, with high spatiotemporal resolution, is particularly difficult in organs such as the heart due to its soft mechanics, curvilinear geometry, heterogeneous surfaces, and continuous, complex rhythmic motion. The results presented here illustrate that advanced strategies in materials assembly and electrochemical growth can yield interconnected arrays of miniaturized IrOx pH sensors encapsulated in thin, low‐modulus elastomers to yield conformal monitoring systems capable of noninvasive measurements on the surface of the beating heart. A thirty channel custom data acquisition system enables spatiotemporal pH mapping with a single potentiostat. In vitro testing reveals super‐Nernstian sensitivity with excellent uniformity (69.9 ± 2.2 mV/pH), linear response to temperature (−1.6 mV °C−1), and minimal influence of extracellular ions (<3.5 mV). Device examples include sensor arrays on balloon catheters and on skin‐like stretchable membranes. Real‐time measurement of pH on the surfaces of explanted rabbit hearts and a donated human heart during protocols of ischemia–reperfusion illustrate some of the capabilities. Envisioned applications range from devices for biological research, to surgical tools and long‐term implants.
High‐Performance Lithium‐Iodine Flow Battery
Authors: Zhao Yu , Byon Hye Ryung
Published: July 2013

A cathode‐flow lithium‐iodine (Li–I) battery is proposed operating by the triiodide/iodide (I3−/I−) redox couple in aqueous solution. The aqueous Li–I battery has noticeably high energy density (≈0.28 kWh kg−1cell) because of the considerable solubility of LiI in aqueous solution (≈8.2 m) and reasonably high power density (≈130 mW cm−2 at a current rate of 60 mA cm−2, 328 K). In the operation of cathode‐flow mode, the Li–I battery attains high storage capacity (≈90% of the theoretical capacity), Coulombic efficiency (100% ± 1% in 2–20 cycles) and cyclic performance (>99% capacity retention for 20 cycles) up to total capacity of 100 mAh.
A case of Toriello–Carey syndrome with severe congenital tracheal stenosis
Authors: Yokoo Noritaka , Marumo Chieko , Nishida Yoshinobu , Iio Jun , Maeda Shinji , Nonaka Michiko , Maihara Toshiro , Chujoh Satoru , Katayama Tetsuo , Sakazaki Hisanori , Matsumoto Naomichi , Okamoto Nobuhiko
Published: July 2013

Toriello–Carey syndrome is rare condition characterized by agenesis of the corpus callosum, the Pierre Robin sequence, and facial anomalies such as telecanthus, short palpebral fissures, and a small nose with anteverted nares [Toriello and Carey, 1988]. In addition, tracheal and laryngeal anomalies are common complications in patients with Toriello–Carey syndrome, and these anomalies can lead to death [Kataoka et al., 2003]. Congenital tracheal stenosis is a life‐threatening condition with high mortality. Even if surgery is successful, several serious complications can result in a high risk of mortality. We describe a case of a Japanese boy with Toriello–Carey syndrome who had severe congenital tracheal stenosis, in whom surgical tracheal plasty was avoided because of adequate respiratory care, allowing the patient to be alive at 18 months of age. © 2013 Wiley Periodicals, Inc.
Homozygosity for the V37I GJB2 mutation in fifteen probands with mild to moderate sensorineural hearing impairment: Further confirmation of pathogenicity and haplotype analysis in Asian populations
Authors: Gallant Emily , Francey Lauren , Tsai Ellen A. , Berman Micah , Zhao Yaru , Fetting Heather , Kaur Maninder , Deardorff Matthew A. , Wilkens Alisha , Clark Dinah , Hakonarson Hakon , Rehm Heidi L. , Krantz Ian D.
Published: July 2013

Hearing impairment affects 1 in 650 newborns, making it the most common congenital sensory impairment. Autosomal recessive nonsyndromic sensorineural hearing impairment (ARNSHI) comprises 80% of familial hearing impairment cases. Mutations in GJB2 account for a significant number of ARNSHI (and up to 50% of documented recessive (e.g., more than 1 affected sibling) hearing impairment in some populations). Mutations in the GJB2 gene are amongst the most common causes of hearing impairment in populations of various ethnic backgrounds. Two mutations of this gene, 35delG and 167delT, account for the majority of reported mutations in Caucasian populations, especially those of Mediterranean and Ashkenazi Jewish background. The 235delC mutation is most prevalent in East Asian populations. Some mutations are of less well‐characterized significance. The V37I missense mutation, common in Asian populations, was initially described as a polymorphism and later as a potentially pathogenic mutation. We report here on 15 unrelated individuals with ARNSHI and homozygosity for the V37I GJB2 missense mutation. Nine individuals are of Chinese ancestry, two are of unspecified Asian descent, one is of Japanese descent, one individual is of Vietnamese ancestry, one of Philippine background and one of Italian and Cuban/Caucasian background. Homozygosity for the V37I GJB2 mutation may be a more common pathogenic missense mutation in Asian populations, resulting in mild to moderate sensorineural hearing impairment. We report a presumed haplotype block specific to East Asian individuals with the V37I mutation encompassing the GJB2 gene that may account for the high prevalence in East Asian populations. © 2013 Wiley Periodicals, Inc.
A novel device for delivery of intranasal particulate medication: a pilot study
Authors: Khalili Sammy , Tkachenko Natalia , Rotenberg Brian
Published: July 2013

Background

Intranasal medication delivery for allergic rhinitis (AR) is considered a mainstay of therapy but is hampered by poor compliance. Among reasons given are unpleasant sensations associated with spray penetration into the pharynx. Our objective was to study a novel method of particle delivery to the nose that would abrogate these issues.

Methods

This was a double‐blind, randomized study. Subjects who met study criteria underwent intranasal particle delivery using a novel device (Trivair Nasal Deposition System; Trimel Pharmaceuticals, Toronto, Canada) that delivered anhydrous lactose particles into the nose via a transoral air puff (thus elevating soft palate and blocking the nasopharynx). Subjects had nostrils randomized into 4 groups (particle sizes 5 μm and 50 μm × doses 12.5 mg and 25 mg). Particle deposition was assessed at 1 minute, 10 minutes, and 30 minutes on the inferior turbinate, middle turbinate, and nasopharynx, respectively, using high‐definition endoscopic photography. Each image was compared using an expert blinded 2‐person panel for percentage particles remaining. Nonparametric data was assessed using the Wilcoxon signed‐rank test via Strata software.

Results

Twelve nostrils in total met study criteria. The results showed no difference in effectiveness of nasal particle retention between the groups based on particle size or dose. No particles entered the nasopharynx or oropharynx.

Conclusion

This study provides proof‐of‐principle data that the Trivair Nasal Deposition System is effective at retaining medication in the nose without pharyngeal penetration. Larger studies on this device are warranted.
Introduction of Fluorine and Fluorine‐Containing Functional Groups
Authors: Liang Theresa , Neumann Constanze N. , Ritter Tobias
Published: July 2013

Over the past decade, the most significant, conceptual advances in the field of fluorination were enabled most prominently by organo‐ and transition‐metal catalysis. The most challenging transformation remains the formation of the parent CF bond, primarily as a consequence of the high hydration energy of fluoride, strong metal—fluorine bonds, and highly polarized bonds to fluorine. Most fluorination reactions still lack generality, predictability, and cost‐efficiency. Despite all current limitations, modern fluorination methods have made fluorinated molecules more readily available than ever before and have begun to have an impact on research areas that do not require large amounts of material, such as drug discovery and positron emission tomography. This Review gives a brief summary of conventional fluorination reactions, including those reactions that introduce fluorinated functional groups, and focuses on modern developments in the field.
Metallomicelles of palladium(II) complexes as efficient catalysts for the Suzuki–Miyaura reaction in neat water
Authors: Liu Yan , Ma Xiaowei , Xie Jianwei , Liu Ping , Dai Bin , He Ren
Published: July 2013

Metallomicelles of palladium(II) complex 4 are found to be an efficient catalyst for Suzuki–Miyaura reactions of aryl bromides substituted with a long alkyl chain and arylboronic acids at 80 °C in neat water. The reactions proceed smoothly to generate the corresponding biaryl compounds in moderate to excellent yields. Various biphenyl derivatives were successfully obtained by complex 4 catalysis of the Suzuki–Miyaura reactions in the absence of any surfactants in neat water. Copyright © 2013 John Wiley & Sons, Ltd.
Time‐series analysis of native and non‐native crayfish dynamics in the Thames River Basin (south‐eastern England)
Authors: Almeida David , Ellis Adam , England Judy , Copp Gordon H.
Published: July 2013

Monitoring is crucial for the conservation of endangered crayfish species as well as for managing and controlling invasive species. Yet, relatively few studies have assessed relationships between native white‐clawed crayfish Austropotamobius pallipes and non‐native signal Pacifastacus leniusculus, narrow‐clawed Astacus leptodactylus, virile Orconectes virilis and red‐swamp Procambarus clarkii crayfishes in freshwater environments at ecologically relevant spatial and temporal scales.

Thus, the present study examines the distribution dynamics of native and non‐native crayfishes in the River Thames Basin District (16 133 km2, south‐eastern England) over four decades (1971–2010).

To reveal geographical bioinvasion and decline patterns, data on occurrences (sampling site, date) of native white‐clawed and four non‐native crayfishes were used to create sequences of decade maps for each species. Cumulative numbers of occupied grid squares were used to construct ‘invasion/decline’ curves and rates. To quantify dynamic features, the frequencies of survey occurrence for each species were subjected to time‐series analysis, followed by cross‐correlation to determine relationships between crayfishes.

White‐clawed crayfish was initially widespread, but gradually disappeared after the mid‐1970s, coinciding with the introduction and initial dispersal of signal crayfish. During 2001–2010 white‐clawed crayfish numbers declined steeply. Introduced in the mid‐1980s, narrow‐clawed crayfish spread within a few years, but is now restricted to the east of the basin, where virile and red‐swamp crayfishes were reported with low presence since their introductions in 2006. Dynamics of white‐clawed and signal crayfishes showed the opposing trends with a highly significant negative association.

Geographical patterns indicate that non‐native crayfishes were introduced in multiple locations in the study area. Recovery of native crayfish seems unlikely, given the impacts of signal crayfish and the continuing arrival of new crayfish species. This paper demonstrates the utility of using broad temporal and spatial scales for revealing accurate insights on invasion and decline dynamics.

Copyright © 2013 Crown copyright.