bluuebunny/crossref_metadata_2025_split huggingface dataset:
On convergence of regularized modified Newton's method for nonlinear ill-posed problems
Authors: George Santhosh 
Published: May 2010

Abstract
In this paper we consider regularized modified Newton's method for approximately solving the nonlinear ill-posed problem F(x) = y, where the right hand side is replaced by noisy data yδ
∈ Y with ‖y – yδ
‖ ≤ δ and F : D(F) ⊂ X → Y is a nonlinear operator between Hilbert spaces X and Y. Under the assumption that Fréchet derivative F′ of F is Lipschitz continuous, a choice of the regularization parameter and a stopping rule based on a majorizing sequence are presented. We prove that under a general source condition on , the error between the regularized approximation and the solution of optimal order.
An inverse problem for a linearized model in the theory of combustion
Authors: Colombo Fabrizio 
Published: May 2010

Abstract
In the recent paper [Colombo, Physica D 236: 81–89, 2007] the author investigates an inverse problem arising in the theory of combustion. The problem studied is: determine the temperature u and the convolution memory kernel k in the evolution equation
given suitable initial-boundary conditions and the following additional restriction on u:

∫
Ω
φ(x)u(t, x) dx = g(t),
where φ and g are given functions. The main results are a local in time existence theorem and a global in time uniqueness result. In this paper we complete the study considering the linearized version of the model. We prove that, if F(u(t, x), ∇u(t, x)) is sublinear, then the inverse problem has a unique global in time solution.
Listeners use vowel harmony and word-final stress to spot nonsense words: A study of Turkish and French
Authors: Kabak Barış , Maniwa Kazumi , Kazanina Nina 
Published: May 2010

AbstractThe study explores the role of stress and vowel harmony as cues for speech segmentation. Both in French and in Turkish stress is demarcative, typically falling on word-final syllables. Additionally, Turkish (but not French) has a regular front-back vowel harmony which dictates that all vowels within a word must be either front or back. French and Turkish participants performed a target detection task in which they had to spot nonsense words embedded in a longer auditory string. The results show that word-final stress can successfully signal an upcoming word boundary and is used for speech segmentation by speakers of both languages. In the Turkish group but not in the French group we also found a facilitatory effect of vowel disharmony. We conclude that both vowel harmony and stress can independently signal word boundaries and suggest that listeners can exploit these phonological regularities during speech segmentation.
Influence of an infaunal bivalve on the erosion of an intertidal cohesive sediment: A flume and modeling study
Authors: Willows Robert I. , Widdows J. , Wood R. G. 
Published: May 2010

A model was developed to describe the erosion of a cohesive sediment within an annular flume. The model relates the rate of resuspension of sediment per unit area to the difference between the amount of sediment available for resuspension from the bed and the amount already resuspended into the water column. The rate of erosion also depends on the excess free‐stream near‐bed current velocity above a critical threshold velocity. The basic five parameter model describes 96% of the variation in suspended sediment concentration within the flume, where natural sediment is exposed to increments in current velocity (up to 43 cm s−1, equivalent to a shear stress of 1.5 Pa) in the absence of macrofauna. The addition of a small clam, Macoma balthica, to the experimental system led to increased levels of resuspension at all velocities. This effect increased asymptotically with Macoma population density and could be modeled using two additional parameters. Complete analysis of the resulting seven‐parameter model showed that the effect of the fauna was confined solely to the amount of sediment available for resuspension.Field data supported the laboratory‐determined functional relationship between Macoma density and the quantity of sediment resuspended at environmentally realistic maximum current velocities and provided field‐based parameter estimates for modeling the erosion of in situ sediment. Using predicted flood and ebb tidal current velocities along a 3.5‐km transect normal to the shore, we determined the potential impact of Macoma on the amount of sediment resuspended over a single tidal inundation. We estimate that natural densities of Macoma increase the amount of sediment resuspended, at our sites above midtidal shore level, by 0.42 kg m−2 per tide.We suggest that experimental flume studies, which can include field deployments, combined with this parametersparse model of fauna1 impact on sediment resuspension provide a straightforward means of quantifying the complex effects of biotic components on rates of sediment erosion.
Prediction of annual and seasonal phosphorus concentrations in stratified and polymictic lakes
Authors: Nürnberg >Gertrud K. 
Published: May 2010

Phosphorus (P) concentrations in lakes arc summarized and reported in different ways. Annual whole lake P (Pann), epilimnetic summer P (Pepi), and mixed water column P during fall turnover after summer stratification (Pfall) were investigated with data from up to 150 lakes. Differences between P averages are caused by temporal variation in thermal stratification and the size of internal P sources. To predict various P averages in specific lake types, I combined a P retention model that predicts annual retention due to sedimentation (Rpred) with external and internal load estimates (Lext, Lint) in a steady‐state, P mass balance approach.Retention of internal and external loads in stratified and polymictic lakes can be predicted by the same model, Rpred = 15/(18 + qs), where qs is annual water load (m yr−1). However, lakes with chemically enhanced P coprecipitation (e.g., with calcium) are an exception. P averages can be predicted in stratified lakes, as
urn:x-wiley:19395590:media:lno19984371544:lno19984371544-math-0001although Pepi is overestimated in lakes with oxic hypolimnia. P concentrations can be approximately predicted in polymictic lakes as
urn:x-wiley:19395590:media:lno19984371544:lno19984371544-math-0002
Field study on currents in a shallow, ice‐covered lake
Authors: Malm Joakim , Bengtsson Lars , Terzhevik Arkady , Boyarinov Pjotr , Glinsky Alexander , Palshin Nikolaj , Petrov Michail 
Published: May 2010

A field study on current structure and circulation characteristics in Lake Vendyurskoe, a small, shallow, icecovered lake in Karelia, Russia, is presented. The current velocity magnitudes were generally found to be small. The most pronounced currents had an oscillating character, with velocity amplitudes on the order of millimeters per second. The oscillation period, obtained from spectral density calculations, corresponded to that of a barotropic uninodal seiche. The seichelike nature of the current oscillations was supported by the results from analysis of icelevel fluctuations, giving identical periods and a phase shift of one‐fourth the period between the two types of oscillations.Mean currents measured during the winter were on the order of millimeters per second. Because Lake Vendyurskoe does not have any significant river inflow or outflow during winter, the most probable cause of these currents is horizontal temperature (pressure) gradients. Scaling analysis indicated that these currents are geostrophic. This was supported by theoretical estimates, based on observed horizontal temperature gradients, being of the same order as the observed currents. The mean current velocities increased considerably after spring convection from <1 to several millimeters per second.
Stable isotope response to lake eutrophication: Calibration of a high‐resolution lacustrine sequence from Baldeggersee, Switzerland
Authors: Teranes Jane L. , McKenzie Judith A. , Lotter Andre F. , Sturm Michael 
Published: May 2010

Stable isotope analyses of discrete seasonal layers from a 108‐yr annually laminated freeze‐core from Baldeg‐gersee, a small, eutrophic lake in central Switzerland, provide information on the climatological and environmental factors, including lake eutrophication, that control oxygen and carbon isotopic composition of epilimnic biologically induced calcite precipitate.During the last 100 yr, Baldeggersee has undergone major increases in productivity and eutrophication in response to nutrient loading from agriculture and industrialization in the lake's watershed. Calibration of the isotopic signal in Baldeggersee to historical limnological data quantitatively links evidence of isotopic depletion in the sedimented calcite to trophic state of the lake. δ18O values from the spring/summer “light” sediment layers steadily diverged to more depleted values in response to historical eutrophication: measured δ18O values were up to 21.5‰ more negative than calculated equilibrium δ18O values. Evidence for 13C depletion in the calcite, relative to equilibrium values, is more difficult to ascertain because of an overall dominance of isotopic enrichment in the dissolved inorganic pool as productivity in Baldeggersee increases. A positive association exists between the degree of oxygen‐18 depletion and the calcite crystal size. Thus, large amorphous calcite grains can be used as a proxy for recognizing apparent isotopic nonequilibrium in sediment sequences from highly productive lacustrine environments from all geologic time scales.In contrast to the light layers, the oxygen isotopic composition of the calcite in the late summer/fall “dark” sediment layers is unaffected by the apparent isotope nonequilibrium. Oxygen and carbon isotope values from the dark laminae in the Baldeggersee sediment therefore provide environmental and climatological proxies that can be calibrated with known environmental and regional climate data for the last century.
Ferredoxin and flavodoxin as biochemical indicators of iron limitation during open‐ocean iron enrichment
Authors: Erdner Deana L. , Anderson Donald M. 
Published: May 2010

Substitution of the noniron protein flavodoxin for the iron‐sulfur protein ferredoxin is an iron‐stress response employed by a variety of unicellular organisms, including many phytoplankton. The relative abundance of these two proteins has been shown to vary with the severity of growth limitation by iron in marine diatoms. During the IronEx II mesoscale iron‐enrichment experiment, large volume (100–600 liters) phytoplankton samples were collected for analysis of community ferredoxin and flavodoxin abundance using a high‐pressure liquid chromatography (HPLC) technique. In addition, three pennate diatom species isolated from the fertilization‐induced phytoplankton bloom were used for follow‐up laboratory experiments, which examined their iron physiology.Prior to iron enrichment, biomass levels were insufficient to obtain any ferredoxin or flavodoxin signals. Measurements were successful after iron enrichment, with unexpected results. The strength of the HPLC signal tracked the biomass levels of the IronEx II phytoplankton bloom. Chromatographic peaks were evident on the fifth day following enrichment and persisted throughout the experiment before they declined and eventually disappeared following the last iron infusion. The main chromatographic peak was identified as flavodoxin; there was no evidence of ferredoxin in any of the samples. Pennate diatom clones isolated from the fertilization‐induced bloom and grown in the laboratory retain the ability to make ferredoxin when iron‐replete and induce flavodoxin when iron‐stressed. When iron‐limited, they are able to completely repress flavodoxin expression in about 1 d in response to iron resupply. Thus, the unexpected absence of ferredoxin and the persistence of flavodoxin during IronEx II, despite the observed increases in biomass and photosynthetic efficiency, suggest that the iron additions were insufficient to completely relieve physiological iron limitation.
Effects of nutrients (phosphorous, nitrogen, and carbon) and zooplankton on bacterioplankton and phytoplankton—a seasonal study
Authors: Vrede Katarina , Vrede Tobias , Isaksson Anneli , Karlsson Anna 
Published: May 2010

The effects of inorganic nutrients (P and N), organic C, and metazoan zooplankton on bacterioplankton production and abundance and on phytoplankton biomass were studied in five experiments (from May to September) in Lake Erken. In addition, the seasonal dynamics of bacterioplankton and phytoplankton were followed in the lake from April to November.Bacterioplankton production was P limited from May to August. N alone never stimulated bacterioplankton production, but bacterioplankton growth was close to colimited by P and N in July and August. Organic C stimulated bacterial production in June and September. Zooplankton enhanced bacterioplankton production in June, when bacterioplankton production was limited by P and C and the phytoplankton biomass in the lake was low. N alone stimulated phytoplankton growth in all experiments. In addition, P alone stimulated phytoplankton growth in May and July, and the combination of P and N stimulated phytoplankton growth in July and August. Zooplankton additions resulted in a decrease in phytoplankton biomass in May and September, mainly owing to grazing on Cryptophyceae.The experimental results indicate that bacterioplankton and phytoplankton growth were uncoupled during most of the open‐water period because P primarily limited bacterioplankton growth and N limited phytoplankton growth. The response of the bacterioplankton community was most likely a direct effect of nutrient additions. Primary production and bacterioplankton production were correlated during the season, but partial correlations analysis indicates that this relationship can be attributed to the fact that both primary production and bacterioplankton production showed strong positive correlations with temperature. We suggest that uncoupling of bacterioplankton production and phytoplankton production may be a common phenomenon in lakes.
Contrasting effects of solar radiation on dissolved organic matter and its bioavailability to marine bacterioplankton
Authors: Obernosterer Ingrid , Reitner Bettina , Herndl Gerhard J. 
Published: May 2010

The effect of ultraviolet radiation on the bioavailability of dissolved organic matter (DOM) to marine bacterioplankton was investigated in the Mediterranean Sea (Strait of Gibraltar, South and North Aegean Sea) and in the Caribbean Sea off Curacao. Surface‐water samples (collected between 1 and 85 m in depth) exposed to solar radiation did not show a distinct pattern in subsequent bacterial growth. However, samples collected from a pronounced chlorophyll maximum (two stations in the Strait of Gibraltar and four stations in the Aegean Sea) displayed in a 50% lower bacterial activity in the radiation‐exposed treatments compared with the dark controls. In contrast, mesopelagic water samples (200–350 m in depth) exposed to surface solar radiation exhibited a two‐ to fourfold increase in bacterial activity compared with the corresponding dark controls. Addition of the model protein bovine serum albumin (BSA) to mesopelagic‐water samples and subsequent exposure to solar radiation resulted in a 50% lower rate of bacterial activity compared with the dark treatments, thus indicating the occurrence of photochemically induced changes to this labile compound. This decrease in bacterial activity in BSA‐amended, irradiated water was also detectable in surface waters sampled off Curaçao, whereas BSA amendment to surface water from the Mediterranean Sea did not result in a distinct pattern of bacterial activity.Our data indicate that exposure of DOM to solar radiation causes a reduced bioavailability of the exposed DOM to bacterioplankton, if the bacterial activity : dissolved organic carbon (DOC) concentration ratio is high (indicative of labile DOM). If the bacterial activity:DOC ratio is low (indicative of more refractory DOM), the bioavailability of the DOM is increased upon exposure to solar radiation.
An experimental study on effects of submersed macrophytes on nitrification and denitrification in ammonium‐rich aquatic systems
Authors: Eriksson Peder G. , Weisner Stefan E. B. 
Published: May 2010

We have examined the role of microbial communities on the surface of submersed macrophytes and in the underlying sediment for nitrification and denitrification in light and dark in NH4+‐enriched microcosm systems using isotope pairing and dilution techniques. Potamogeton pectinatus L. and intact sediment cores were collected in a shallow reservoir receiving treated municipal wastewater and containing dense submersed vegetation. Chambers containing P. pectinatus shoots, sediment, or both P. pectinatus shoots and sediment were exposed to 6 h of darkness, 6 h of light, and 6 h of darkness. 14NH4+ and 15NO3− were added at ambient concentrations of 15 and 5 mg N liter−1, respectively. NH4+ was primarily nitrified in the epiphytic microbial communities, and NO3− was denitrified in the underlying sediment. In chambers containing macrophytes, there was a net production of O2 and NO3− in light and a net consumption in dark, and nitrification was higher in light than in dark. In chambers with only sediment, there was always a net consumption of NO3−, and nitrification was similar in light and dark. The results show that submersed macrophytes can be important for the N metabolism in NH4+‐	rich freshwaters (e.g., wastewater treatment systems) by stimulating nitrification through providing surfaces for attached nitrifying bacteria and possibly also through diurnal changes in the water chemistry.
Presence of enterococci in cow milk and their antibiotic resistance
Authors: Fabianová Jana , Ducková Viera , Čanigová Margita , Kročko Miroslav 
Published: May 2010

Enterococci represent an important part of contaminate microflora in raw milk and dairy products. They constitute significant part of nosocomial pathogens with a remarkable capacity of expressing resistance to several antimicrobial agents. We aimed to assess occurrence and antibiotic resistance of enterococci in the raw milk samples and pasteurized milk samples. In this study total bacterial count, psychrotrophic count and count of enterococci were determine in raw milk cistern samples, storage tank milk samples and milk samples after pasteurization. A collection of 46 enterococcal isolates were identified and screened for their antibiotic resistance. Isolates of E. faecalis were dominant in raw milk samples (56.5 %). Sensitive to teicoplanine (30 mcg/disk) were 97.9 % of enterococcal isolates and 15.2 % isolates were resistant to vankomycin (30 mcg/disk).
Migration of phthalates from plastic tank to vegetable oil as a part of feeding mixtures used for chicken broilers fattening
Authors: Jarošová Alžbeta , Stancová Vlasta , Harazim Jiří­ , Suchý Pavel 
Published: May 2010

The concentrations of phthalic acid esters (PAEs) as di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) were measured in samples of rapeseed oil, which was used as a feed. First samples were collected during the production process and second after the storage in plastic tank (21 days). The results of measurements are that there is 2.93-10.10 mg PAEs.kg-1 in the oil before storage and 22.73-61.55 mg PAEs.kg-1 after storage.
For the monitoring of distribution and accumulation of PAEs in animal tissues and organs (muscles, adipose tissue, skin and liver) broiler chicks ROSS 308 were used. The chicks were divided into 4 groups (50 chicks each). All the chicks were fed by commercial diets (complete feed, KKS) for broiler chicks (starter – BR1; grower – BR2 and finisher – BR3). The experimental diets were supplemented with vegetable oil (RO) with low (group N) or high (group V) phthalate content, or animal fat with high phthalate content (group Z). Neither the control diets (K) nor the grower (BR1) diets contained vegetable oil or animal fat. DBP and DEHP were found in all tissues of all chicks. The highest concentration of DBP of 1.28 1.00 mg.kg-1 of fresh sample (an average value from 8 chicks) was determined in the adipose tissue of V chicks. The highest concentration of DEHP of 3.27 2.87 mg.kg-1 of fresh sample (average of 8 chicks) was also determined in the V group.
Spring barley breeding for malting quality
Authors: Križanová Klára , Psota Vratislav , Sleziak Ľudoví­t , Žofajová Alžbeta , Gubiš Jozef 
Published: May 2010

The aim of this contribution is to illustrate the results of spring barley breeding for malting quality and point out an important position of variety in production of qualitative raw material for maltinq and beer industry as well as the system of evaluation the qualitative parameters of breeding materials and adaptation of barley breeding programms to the new requirements of malting and beer industry. As an example of the results obtained most recently description is made of the Ezer, Levan, Donaris, Sladar spring barley varieties with very good malting quality and effective resistance to powdery mildew. Cultivation of these varieties and malting barley production with reduced use of pesticidies is environmentally friedly alternative.
The microbiological load of sheep milk from primary production to its processing
Authors: Vasiľ Milan , Elečko Juraj , Farkašová Zuzana 
Published: May 2010

In the breeding with the average number of 220 sheep (zošľachtená valaška) with traditional hand milking in the Eastern Slovakia the microbiological load of milk during the process of primary production, transport, before and after pasteurisation as well as during dairy processing to cheese curd was observed. The results in three seasons were compared to those obtained at finishing of milking in the season before.
The microbiological load of milk was observed using the bacteriological methods for determination of the presence of Staphylococcus sp. and other bacteria, and determination of the total number of staphylococci: a) in milliliter of pool milk sample; b) the transport control – smears from transport tank and determination of the total number of staphylococci in the tank milk sample; c) bacteriological examination of bulk tank milk in the dairy plant before and after pasteurisation, including examination of cheese curd.
After pasteurisation no staphylococci were recorded as in milk as in cheese.
Out of 112 strains of Staphylococcus aureus only four strain produced staphylococcal enterotoxins (SE), but in another 7 strains a gene for production of SE, type C was found.
The measures introduced during the following season led to the fact that total numbers of coagulase-positive staphylococci in milk within the process of primary production and transport did not exceed the limit permitted by legislation, and after pasteurisation of milk and cheese curd they were not found at all.
Direct liquefaction of Mukah Balingian low‐rank Malaysian coal: optimization using response surface methodology
Authors: Ghani Zaidi Ab. , Ishak Mohd Azlan Mohd , Ismail Khudzir 
Published: May 2010

AbstractCoal liquefaction of low‐rank coals is of interest because of the formation of a liquid fuel with lower molecular weight and a higher H/C ratio than those of the parent coal, which itself is difficult to use. This study determined the optimum conditions for liquefaction of Mukah Balingian (MB) low‐rank Malaysian coal using a supercritical water–tetralin mixture. Response surface methodology (RSM) based on central composite rotatable design (CCRD) was applied to optimize the combination effect of two important reaction variables, i.e. reaction temperature (° C) and solvent mixture ratios. The reaction was performed via a high‐temperature, high‐pressure batch‐wise reactor system. A total of 13 individual experiments were conducted and the results showed that the RSM based on CCRD is very applicable to the coal liquefaction process studied in this system. The predicted optimum conditions for liquefaction of MB coal was 450° C reaction temperature and 30:70 water–tetralin ratio, resulting in coal conversion and an oil yield of 70.6 and 66.1%, respectively. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.