bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Chloride and Potassium Nutrition on Seed Yield of Annual Canarygrass
Authors: May William E. , Malhi Sukhdev S. , Holzapfel Christopher B. , Nybo Bryan X. , Schoenau Jeff J. , Lafond Guy P.
Published: June 2012

The year‐to‐year variability of seed yield in annual canarygrass (Phalaris canariensis L.) is a major concern among growers. A field experiment was conducted at 13 site‐years across Saskatchewan to determine the response of annual canarygrass seed yield to K and Cl, and to provide better recommendations to producers on the use of KCl fertilizer in annual canarygrass based on soil test results. Potassium did not affect the yield or development of annual canarygrass over a range of 155 to 717 kg K ha−1 in the top 15 cm of soil. Chloride had a large impact on annual canarygrass seed yield; seed yield increased by approximately 24% when Cl was added in the form of KCl or CaCl2 when averaged across all sites. The seed yield increased because the application of Cl increased panicle size (seeds panicle−1). The magnitude of the response tended to increase as level of Cl in the soil decreased. Annual canarygrass growers need to measure Cl when using soil tests to determine fertilizer requirements. It is recommended that 9.1 kg Cl ha−1 in the form of 20 kg ha−1 of KCl be applied when the Cl level in the surface soil (0–15 cm) is below 70 kg Cl ha−1. The findings encourage growers to conduct individual field test strips to determine the strength of the Cl response.
Maize Evapotranspiration and Water‐Use Efficiency in Response to Row Spacing
Authors: Barbieri P. , Echarte L. , Della Maggiora A. , Sadras V. O. , Echeverria H. , Andrade F. H.
Published: June 2012

Reduced row spacing has shown to increase maize (Zea mays L.) yield; however there are conflicting results on whether narrow rows increases maize crop evapotranspiration and/or water use efficiency. This work analyzes the response of maize yield, crop evapotranspiration (ET) and water use efficiency to reduced row spacing under different water and N regimes. Maize crops were grown at Balcarce, Argentina, during two seasons. Treatments included two water regimes (rain‐fed and irrigated), two rows spacing (35 and 70 cm) and two rates of N (i.e., 180 kg N ha−1 or nonfertilized). Soil water content was measured through the growing seasons using a neutron probe, grain yield and shoot dry matter were determined at physiological maturity. Grain yield response to narrow rows ranged from 0 to 23%; it was higher for water limited (i.e., rain‐fed crops) and/or N deficient crops (i.e., nonfertilized crops) and lower for crops with high N fertilization and irrigation. Narrow rows consistently increased (8%) crop ET during the initial stages of crop growth; and N fertilization did not influence ET response to reduced row spacing during this period. Initial differences in ET between row spacing treatments were diluted as the season progressed, and seasonal crop ET was not influenced by row spacing. Reduced row spacing increased water use efficiency for grain production up to 17%; increments were larger in N deficient crops and/or with water limitations but were negligible in N fertilized and irrigated crops.
Lack of Hybrid, Seeding, and Nitrogen Rate Interactions for Corn Growth and Yield
Authors: Cox William J. , Cherney J. H.
Published: June 2012

Corn (Zea mays L.) seeding rates have increased because new hybrids purportedly optimize yield at high seeding and N rates. Two hybrids were evaluated in New York at four seeding and two sidedress N rates to determine if recommended rates (74,100 kernels ha−1 and 111 kg N ha−1) still optimize yield. Precipitation from June through August varied (389 mm in 2010 and 198 mm in 2011), so year × hybrid and year × seeding rate interactions existed for yield and yield components, but no two– or three‐way interactions existed among hybrid and N and seeding rates. Quadratic regression analysis predicted maximum yield at 88,000 kernels ha−1 in 2010, although yields varied by only 2% between 74,100 (18.5 Mg ha−1) and 98,800 kernels ha−1 (18.9 Mg ha−1). Seeding rate did not affect yield in 2011. As seeding rates increased from 61,875 to 98,800 kernels ha−1, kernel number per plant had negative linear decreases in 2010 (818 to 694) and 2011 (567 to 383). Kernel weight had a negative quadratic response to seeding rates in 2010 but a linear response in 2011 (338 to 317 and 312 to 332 mg, respectively, from 74,100 to 98,800 kernels ha−1). A year × N rate interaction existed for kernel weight (320 and 338 mg in 2010 and 318 mg in 2011 at 111 and 167 kg N ha−1, respectively) but not for yield (18.2 and 18.4 Mg ha−1 in 2010 and 11.1 and 11.3 Mg ha−1 in 2011, respectively). Overall, recommended seeding and sidedress N rates achieved close to optimum yield in this study.
Intensification of Field Pea Production: Impact on Soil Microbiology
Authors: Lupwayi Newton Z. , Lafond Guy P. , May William E. , Holzapfel Chris B. , Lemke Reynald L.
Published: June 2012

The economic and environmental benefits of including grain legumes in crop rotations may tempt farmers to grow them more frequently than recommended, resulting in potential changes to soil chemical, physical, and biological properties. We investigated the effects of increasing the frequency of field pea (Pisum sativum L.) (P) in a wheat (Triticum aestivum L.) (W)‐based cropping system on soil microbial biomass C (MBC), β‐glucosidase enzyme activity, bacterial diversity, and populations of Rhizobium leguminosarum bv. viceae in the last 3 yr of a 13‐yr field study. The treatments consisted of three rotations: P‐P, W‐P, and W‐W‐P. Fertilizer N at 5, 20, and 40 kg N ha−1 was applied to pea in P‐P and W‐P rotations to examine the role of starter N. Soil MBC and diversity were lower in P‐P than pea rotated with wheat, presumably due to reduced amounts and diversity of C inputs under P‐P. These reductions in soil MBC and diversity probably further reduced field pea growth and grain yields through reduced nutrient cycling. In field pea, β‐glucosidase activity increased with increasing N, suggesting that N was limiting the capacity of soil microorganisms to recycle nutrients from organic materials (including crop residues). Populations of soil rhizobia were not affected by treatment. Wheat grown after pea in the 3‐yr W‐W‐P rotation had greater MBC and β‐glucosidase activity than that in the W‐P rotation, indicating the importance of long rotations. Therefore, pea monoculture reduced soil microbial quality, with adverse effects on nutrient cycling.
Simulating the Production Potential of Dryland Spring Canola in the Central Great Plains
Authors: Nielsen D. C. , Saseendran S. A. , Ma L. , Ahuja L. R.
Published: June 2012

Canola (Brassica napus L.) has potential to be grown as a dryland crop to diversify the winter wheat (Triticum aestivum L.)–fallow production system of the semiarid central Great Plains. Extensive regional field studies have not been conducted under rainfed conditions to provide farmers, agricultural lenders, and crop insurance providers with information about the production potential and expected yield variability of canola in this region. The purpose of this study was to use an agricultural system model to simulate canola production under rainfed conditions in the central Great Plains and to determine the economic viability of canola production. The CROPGRO‐canola model was used within the Root Zone Water Quality Model (RZWQM2) with weather data (1993–2008) to simulate canola yield for nine central Great Plains locations under four plant‐available water (PAW) contents at planting. Average yield with 75% PAW was highest (1725 kg ha−1) at Champion, NE, in the north‐central area and lowest (975 kg ha−1) at Walsh, CO, in the south‐central area. Simulated yields increased with increasing PAW at planting at an average rate of 5.31 kg ha−1 mm−1. Yield variability was simulated to be lowest at Sidney, NE, Stratton, CO, and Walsh, CO, and highest at Akron, CO, Tribune, KS, and Garden City, KS. Yield variability did not consistently change with amount of PAW across the region. Calculated average net returns indicate that profitable canola production is possible across a large portion of the central Great Plains when PAW at planting is at least 50%.
Rainfall as a Limiting Factor for Wheat Grain Yield in Permanent Raised‐Beds
Authors: Limon-Ortega Agustin , Sayre Ken
Published: June 2012

The planting system on permanent raised‐beds for rainfed wheat (Triticum aestivum L.) production in the central highlands of Mexico is an option that needs to be documented for moderate‐yield environments. Long‐term plots were established under this technology in the 2002 crop season. The objective was to evaluate wheat grain yield performance as related to rainfall and soil characteristics until 2009. The experiment was conducted in rotation with maize (Zea mays L.) and monoculture. Four N rates were applied to wheat (0, 40, 80, and 120 kg ha−1) and three to maize (0, 60, and 120 kg ha−1). Nitrogen rates to the subsequent wheat crop were superimposed to each one of the preceding maize crop. Crop residues of both crops were left on the soil surface. Results showed that the amount of soil N measured as N–NO3 and N–NH4 was reduced during the first three seasons after the establishment of permanent beds. Although this reduction was substantial, stepwise regression procedures indicated that wheat grain yield was mostly determined by the amount of rainfall and distribution during the crop season, except for the 2009 season when the standard deviation of this measurement was larger. In addition to those N measurements, total soil N, available P, and exchangeable K had no effect on grain yield. The response of grain yield to N application rates >40 kg ha−1 was negligible for both crop rotations. In average, wheat grain yield in rotation was greater than wheat in monoculture. Grain yield reduction in monoculture resulted from fewer heads m−2.
Reliable method for assessing the COD mass balance of a submerged anaerobic membrane bioreactor (SAMBR) treating sulphate-rich municipal wastewater
Authors: Giménez J. B. , Carretero L. , Gatti M. N. , Martí N. , Borrás L. , Ribes J. , Seco A.
Published: June 2012

The anaerobic treatment of sulphate-rich wastewater causes sulphate reducing bacteria (SRB) and methanogenic archaea (MA) to compete for the available substrate. The outcome is lower methane yield coefficient and, therefore, a reduction in the energy recovery potential of the anaerobic treatment. Moreover, in order to assess the overall chemical oxygen demand (COD) balance, it is necessary to determine how much dissolved CH4 is lost in the effluent. The aim of this study is to develop a detailed and reliable method for assessing the COD mass balance and, thereby, to establish a more precise methane yield coefficient for anaerobic systems treating sulphate-rich wastewaters. A submerged anaerobic membrane bioreactor (SAMBR) treating sulphate-rich municipal wastewater was operated at 33 °C for an experimental period of 90 d, resulting in a high COD removal (approximately 84%) with a methane-enriched biogas of 54 ± 15% v/v. The novelty of the proposed methodology is to take into account the sulphide oxidation during COD determination, the COD removed only by MA and the dissolved CH4 lost with the effluent. The obtained biomethanation yield (333 L CH4 kg−1 CODREM MA) is close to the theoretical value, which confirms the reliability of the proposed method.
Effects of extracellular polymeric substances on granulation of anoxic sludge in sequencing batch reactor
Authors: Wang Binbin , Liu Shunlian , Zhao Hongmei , Zhang Xinyan , Peng Dangcong
Published: June 2012

Variations of extracellular polymeric substances (EPS) and its components with sludge granulation were examined in a lab-scale sequencing batch reactor (SBR) which was fed with sodium nitrate and sodium acetate. Ultrasonication plus cation exchange resin (CER) were used as the EPS extraction method. Results showed that after approximately 90 d cultivation, the sludge in the reactor was almost granulated. The content of extracellular polysaccharides increased from 10.36 mg/g-VSS (volatile suspended solids) at start-up with flocculent sludge to 23.18 mg/g-VSS at 91 d with matured granular sludge, while the content of extracellular proteins were almost unchanged. Polysaccharides were the major components of EPS in anoxic granular sludge, accounting for about 70.6–79.0%, while proteins and DNA accounted for about 16.5–18.9% and 4.6–9.9%, respectively. It is proposed that EPS play a positive role in anoxic sludge granulation and polysaccharides might be strongly involved in aggregation of flocs into granules.
Liquid–gas partitioning of selected volatile organic sulfur compounds in anaerobically digested sludges
Authors: Du Weiwei , Parker Wayne
Published: June 2012

The gas phase partitioning of volatile organic sulfur compounds (VOSCs) in anaerobic sludge digesters contributes to odors and can impact upon the suitability of biogases for use in alternative energy recovery technologies. In the present study, effective Henry's law coefficients (H′) were estimated for methyl mercaptan (MM), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS) in both deionized water and deactivated digested sludge. It was found that the complex matrix of digested sludge did not significantly affect the partitioning of VOSCs. Therefore, partitioning of VOSCs in digesters could be represented by their partitioning in clean water. A regression model was developed for the linear relationship between ln H′ and 1/T in the gas-water system. The H′ values of MM, DMS, and DMDS were able to be calculated over a temperature range of 12–58 °C.
Two-stage biofilm-MBR for nitrogen removal and enhanced membrane performance
Authors: Sun Cheng , Leiknes TorOve
Published: June 2012

A two-stage biofilm-membrane bioreactor (MBR) was developed in this study. High total nitrogen removal (maximum: 81.4% with recycle ratio = 3.5) was observed by recycling the suspension liquid between an anaerobic FBBR and an aerobic MBBR. Very low (less than 60 mg/L) suspended solids was kept in the membrane unit, which could improve the membrane filtration performance. Membrane fouling was further reduced by increasing the recycle ratio. When influent organic load increased, the membrane fouling rate increased, coupling with higher FCOD and suspended solids (SS) values in the feed solution around the membrane.
Evaluation of sewer infiltration/inflow using COD mass flux method: case study in Prague
Authors: Bareš V. , Stránský D. , Sýkora P.
Published: June 2012

The combined sewer system of the City of Prague, similar to other relevant locations, is strongly affected by infiltrating waters. The knowledge of their volume is one of the important parameters with respect to sewer system operation, maintenance and reconstruction. The methodology is based on the variation of diurnal chemical oxygen demand (COD) load and continuous water quality monitoring using in-line absorption spectrometry. This approach allows the identification of individual components of the diurnal wastewater hydrograph, in particular the contribution of parasitic water flow to wastewater discharge. The statistical relevance was tested using Monte Carlo simulations on a 7-year data series of flow rate. The results show that application of this methodology provides specific relevant information about individual sub-catchments within an entire sewer system, particularly in terms of absolute and relative values of I/I and structural state indicators. Processing of long-term data series gives clear information about the significance of the monitoring period length for the relevance of obtained results.
Nematode suppression and growth stimulation in corn plants (Zea mays L.) irrigated with domestic effluent
Authors: Barros Kenia Kelly , do Nascimento Clístenes Williams Araújo , Florencio Lourdinha
Published: June 2012

Treated wastewater has great potential for agricultural use due to its concentrations of nutrients and organic matter, which are capable of improving soil characteristics. Additionally, effluents can induce suppression of plant diseases caused by soil pathogens. This study evaluates the effect of irrigation with effluent in a UASB reactor on maize (Zea mays L.) development and on suppression of the diseases caused by nematodes of the genus Meloidogyne. Twelve lysimeters of 1 m3 each were arranged in a completely randomized design, with four treatments and three replicates. The following treatments were used: T1 (W+I), irrigation with water and infestation with nematodes; T2 (W+I+NPK), irrigation with water, infestation with nematodes and fertilization with nitrogen (N), phosphorus (P) and potassium (K); T3 (E+I), irrigation with effluent and infestation with nematodes; and T4 (E+I+P), irrigation with effluent, infestation with nematodes and fertilization with phosphorus. The plants irrigated with the effluent plus the phosphorus fertilizer had better growth and productivity and were more resistant to the disease symptoms caused by the nematodes. The suppression levels may have been due to the higher levels of Zn and NO3− found in the leaf tissue of the plants irrigated with the effluent and phosphorus fertilizer.
Interactions between Tacrolimus and Metronidazole in a renal transplant patient
Authors: Catic-Djordjevic Aleksandra , Velickovic-Radovanovic Radmila , Stefanovic Nikola , Cvetkovic Tatjana
Published: June 2012

We present a case which reports the occurrence of a potential elevation of Tacrolimus (Tac) plasma levels to toxic values in a renal transplant recipient after adding Metronidazole (Met) to the medication regimen. A 30-year old female, status post living-related renal transplant, who was stabilized on Tac 4.5 mg, twice daily, for 4 months, presented to the clinic with diarrhea. We used Microparticle Enzyme Immunoassay (MEIA) to determine Tac trough concentration (trough concentrations 5–10 ng/ml). After 6 days of Met therapy on 1.5 g/d, Tac trough concentration and serum creatinine (sCr) increased to 20.2 ng/ml and 7.8 mg/dl respectively. Met therapy was discontinued, also one dose of Tac was withheld, while daily dose was decreased to 2 mg/d. Four days after Met discontinuation, Tac concentration dropped to 8.7 ng/ml, sCr to 2.1 mg/dl, warranting Tac dose increase to 3 mg/d. Co-administration of Tac with Met may result in elevated Tac concentrations, possibly leading to tacrolimus nephrotoxicity. Clinicians should be aware of this potential interaction and closely monitor Tac concentration and renal function.
Ergodic theory approach to chaos: Remarks and computational aspects
Authors: Mitkowski Paweł , Mitkowski Wojciech
Published: June 2012

Ergodic theory approach to chaos: Remarks and computational aspects

We discuss basic notions of the ergodic theory approach to chaos. Based on simple examples we show some characteristic features of ergodic and mixing behaviour. Then we investigate an infinite dimensional model (delay differential equation) of erythropoiesis (red blood cell production process) formulated by Lasota. We show its computational analysis on the previously presented theory and examples. Our calculations suggest that the infinite dimensional model considered possesses an attractor of a nonsimple structure, supporting an invariant mixing measure. This observation verifies Lasota's conjecture concerning nontrivial ergodic properties of the model.
Hand gesture recognition based on free-form contours and probabilistic inference
Authors: Kasprzak Włodzimierz , Wilkowski Artur , Czapnik Karol
Published: June 2012

Hand gesture recognition based on free-form contours and probabilistic inference

A computer vision system is described that captures color image sequences, detects and recognizes static hand poses (i.e., "letters") and interprets pose sequences in terms of gestures (i.e., "words"). The hand object is detected with a double-active contour-based method. A tracking of the hand pose in a short sequence allows detecting "modified poses", like diacritic letters in national alphabets. The static hand pose set corresponds to hand signs of a thumb alphabet. Finally, by tracking hand poses in a longer image sequence, the pose sequence is interpreted in terms of gestures. Dynamic Bayesian models and their inference methods (particle filter and Viterbi search) are applied at this stage, allowing a bi-driven control of the entire system.
Backpropagation generalized delta rule for the selective attention Sigma-if artificial neural network
Authors: Huk Maciej
Published: June 2012

Backpropagation generalized delta rule for the selective attention Sigma-if artificial neural network

In this paper the Sigma-if artificial neural network model is considered, which is a generalization of an MLP network with sigmoidal neurons. It was found to be a potentially universal tool for automatic creation of distributed classification and selective attention systems. To overcome the high nonlinearity of the aggregation function of Sigma-if neurons, the training process of the Sigma-if network combines an error backpropagation algorithm with the self-consistency paradigm widely used in physics. But for the same reason, the classical backpropagation delta rule for the MLP network cannot be used. The general equation for the backpropagation generalized delta rule for the Sigma-if neural network is derived and a selection of experimental results that confirm its usefulness are presented.
Development and validation of a bioanalytical LC-UV method with solid-phase extraction for determination of valproic acid in saliva
Authors: Tonic-Ribarska Jasmina , Haxhiu Arlinda , Sterjev Zoran , Kiteva Gordana , Suturkova Ljubica , Trajkovic-Jolevska Suzana
Published: June 2012

Development and validation of a bioanalytical LC-UV method with solid-phase extraction for determination of valproic acid in saliva

A bioanalytical HPLC method with UV detection for the determination of the antiepileptic drug valproic acid in human saliva has been developed and validated. Saliva represents an alternative matrix for therapeutic monitoring of antiepileptic drugs due to the increasing interest in free drug concentration. The proposed method involved solid-phase extraction for sample preparation and yielded very good mean recoveries of 99.4 % and 97.9 % for valproic acid and IS, respectively. The calibration function for valproic acid was linear over the concentration range of 1.0-50.0 μg mL-1(R2= 0.9989). Within-run and between-run precision and accuracy were studied at four concentrations and RSDs were less than 7.3 and 2.2 %, while accuracy values were higher than 96.8 and 97.5 %, respectively. The described method provides sensitivity, linearity, precision, accuracy and is suitable for analyses of valproic acid in saliva samples.
Simplified Method of GED Distribution Parameters Estimation
Authors: Purczyński Jan
Published: June 2012

Simplified Method of GED Distribution Parameters Estimation

In this paper a simplified method of estimating GED distribution parameters has been proposed. The method uses first, second and 0.5-th order absolute moments. Unlike in maximum likelihood method, which involves solving a set of equations including special mathematical functions, the solution is given in the form of a simple relation. Application of three different approximations of Euler's gamma function value results in three different sets of results for which the χ2test is conducted. As a final solution (estimation of distribution parameters) the set is chosen which yields the smallest value of the χ2test statistic. The method proposed in this paper yields the χ2test statistic value which does not exceed the value of statistic for a distribution with parameters obtained with the maximum likelihood method.
Does the modification of ball mass influence the types of attempted and successful shots in youth basketball?
Authors: Arias José L.
Published: June 2012

Purpose

This study aimed at determining: (a) whether the effect of modifying ball mass allowed youth basketball players to attempt a greater number of lay-ups and hook shots during real games, and (b) whether the modification affected successful shots.

Methods

Fifty-four boys from six basketball teams, aged between 10–11 years, participated in the study. The independent variable was ball mass and the dependent variable was the attempted and successful type of shots (set and jump shot, lay-ups, and hook shot). We established three situations in which four games were played with each of the following balls: (a) a regulation ball, (b) a ball of smaller mass (440 g), and (c) a ball of greater mass (540 g). Four observers were trained (intra- and inter-observer reliability > 0.96). Four observers recorded the data utilizing a systematized register from observation of the game videos.

Results

A higher percentage of lay-ups were attempted with the 440-g ball in comparison with the regulation ball (U = 227906, p = 0.01, ES = 0.152) and with the 540-g ball (U = 218614, p = 0.01, ES = 0.160). A higher percentage of lay-ups were successful with the 440-g ball in comparison to the 540-g ball (U = 223080, p = 0.02, ES = 0.210).

Conclusions

Only attempted lay-ups increased with the 440-g ball in comparison to the regulation ball, but the percentage of the rest of kinds of attempted shots and successful shots were similar when comparing the modified balls to the regulation ball.
The relationships between the effectiveness of team play and the sporting level of a team
Authors: Panfil Ryszard , Superlak Edward
Published: June 2012

Purpose

This study aimed at determining what relationships exist between the determinants of team play efficiency (cooperation) for creating scoring situations in volleyball and the sporting level of a team. These relationships take into consideration the number of players who cooperate within a team and the speed at which sets are performed.

Methods

The study gathered observational data on how three leading male volleyball teams, namely Brazil, Russia and Serbia, played in the semi-finals of the 2010 World League, finishing first, second and fourth, respectively. The research tool was a self-made data registration sheet which included the description of the chosen variables, namely the type of plays used and how sets were formed, and the criteria for their quantification. The collected results were presented as tables and indexes. An interdisciplinary interpretation of the results was conducted, which included a qualitative identification of the dependencies that existed between the chosen variables.

Results

The efficiency of team cooperation when solving situational problems in the offense was not significantly different in the analysed teams. The prevailing activities during the game were those performed in the 2nd tempo, i.e. team play requiring the coordination and synchronization of three players. Players’ activity as well as the performance efficiency of the sets they performed in the 2nd tempo increased along with an increase in the sporting efficiency of the examined teams. In the case of sets performed in the 3rd tempo, activity and the efficiency of coordination declined along with the growth of sports efficiency. The suggested indexes of the employment and application of synergy enable us to determine its level within the teams which differ in regards to sports efficiency. A diagnostic value of the index of synergy usage, which is determined by the efficiency of sets in various paces, is higher than a diagnostic value of the index that is determined by the activity of team play.

Conclusions

Nowadays, sport teams, especially those which play volleyball at the highest world level, are characterized by a high level of dynamic organization of players’ activities, which is manifested in the game with the high efficiency of team play when solving situational problems in the offense, particularly with the use of two or three players conducted in the 1st and 2nd tempos.
Long-term investigation of metal concentrations in brown algae Fucus vesiculosus from the Gulf of Riga, Baltic Sea
Authors: Seisuma Zinta , Kuļikova Irīna , Botva Uldis , Boikova Elmīra
Published: June 2012

Long-term investigation of metal concentrations in brown algae Fucus vesiculosus from the Gulf of Riga, Baltic Sea

The study was conducted in the coastal area of the Gulf of Riga at three stations (Ainaži, Saulkrasti, Mērsrags) from 1997 till 2010. Brown algae samples were collected at 3.0-m depth from a boat using scuba gear in August and September. The concentrations of metals (Cd, Pb, Cu, Ni, Zn) were determined by atomic absorption spectrophotometry method (model Spektra A 880), and of Hg by FIMS (Flow Injection Mercury System, Perkin Elmer). The aim of this investigation was to determine the concentration levels of metals (Hg, Cd, Pb, Cu, Ni, Zn) in the dominant species of macroalgae (Fucus vesiculosus) in the Gulf of Riga in different stations and years. Metal concentrations in F. vesiculosus varied between sampling years and stations, and significant differences in Hg, Pb and Ni concentrations between years were detected. In some years the concentrations of metals in F. vesiculosus were similar in all three stations. Brown algae F. vesiculosus can accumulate metals to concentrations thousand times higher than in marine water.
Genetic profiles and diversity of Baltic spring barley material
Authors: Brantestam Agnese , Rashal Isaak , Tuvesson Stine , Weibull Jens , von Bothmer Roland
Published: June 2012

Genetic profiles and diversity of Baltic spring barley material

The objectives of this study were to generate molecular passport data for identification and differentiation of Baltic spring barley accessions (cultivars, landraces and breeding lines) and to estimate the genetic variation within and among these accessions. Allelic profiles of 21 microsatellite and 8 isoenzyme loci were obtained and analysed for 64 Baltic spring barley accessions. The microsatellite data was successfully used to separate all of the accessions by individual allelic pattern and frequencies, whereas only 30 of the studied accessions could be distinguished by isozyme data. Variation was detected both among and within the accessions and was significant. The variation within accessions accounted for 20.6% and 14.3% of the total variation, based on microsatellite and isozyme data, respectively. The six-rowed and two-rowed material was well differentiated by both types of marker data: according to AMOVA this differentiation accounted for 16.9% of the microsatellite variation and 26.8% of isozyme variation. Differentiation of accessions based on the country of origin could be detected only by isozyme markers and accounted for 9% of the total izozyme variation. Both isozyme and microsatellite data showed that accessions of Latvian origin had the highest total diversity values, while material from Estonia was the least diverse.
Contribution of Jānis Lielmanis in plant breeding in Latvia
Authors: Belicka Ina , Kalmanis Zigurds
Published: June 2012

Contribution of Jānis Lielmanis in plant breeding in Latvia

In autumn 1922, the Ministry of Agriculture of Latvia delegated agronomist Jānis Hilarijs Lielmanis (1895-1970) to organise and establish the State Stende Breeding Station. For many years, he was a director (1922-1940) and later a researcher (1945-1956) of the State Stende Breeding Station. Under the guidance of Lielmanis, an infrastructure for breeding work was formed and research into the morphological, biological, and economic traits of local plant varieties obtained from different Latvian regions were begun in the station. Already in 1924, breeders started breeding of cereals, peas, flax, potato, and clover, using selection from local and foreign varieties and also hybridisation. Until 1945, breeders in Stende, under the guidance of Jānis Lielmanis, developed 16 plant varieties, in the period from 1945 to 1960 — 19 varieties. Parallel to his work in Stende, Lielmanis delivered lectures on plant breeding at the University of Latvia (1933-1940) and lectures on genetics, breeding, and seed production at the Latvian University of Agriculture (1940-1944, then Jelgava Academy of Agriculture; 1945-1948). In the later part of his life, Lielmanis worked in the Latvian Scientific Research Institute of Agriculture (1957-1970), where he conducted research in crop farming and breeding of red clover using traditional breeding methods, as well as polyploidy and heterosis methods, which was modern for that time. The research results of oat growth and acclimatisation were summarised by Lielmanis in his habilitation paper (1933), and the results of breeding and growth of red clover — in his dissertation thesis. He was awarded a degree of candidate of agricultural sciences in 1957 and a doctoral degree in 1968. He was very principled in his scientific viewpoints; he supervised five doctoral theses written by candidates of agricultural sciences, published 457 scientific and popular-scientific articles, and wrote six books. Taking into consideration the contribution of Lielmanis to Latvian agricultural science, in 1995, the Jānis Lielmanis award was established, which has been received by breeders, breeding groups, and seed producers for their contribution in plant breeding and seed production in Latvia.
Temperamental traits and life and job satisfaction
Authors: Kasprzak Elżbieta , Brzuszkiewicz Katarzyna
Published: June 2012

Temperamental traits and life and job satisfaction

The aim of this research project was to evaluate the impact of the temperamental traits and structure (as defined by Strelau's Regulative Theory of Temperament) on the level of life satisfaction and job satisfaction (interpreted according to Zalewska's Transactional Model of Quality of Life). The participants of the study were employees (N=199) having different jobs and from different workplaces. The results indicate that there exists a positive relationship between both types of satisfaction and activity and endurance as well as a negative relationship between the measures of satisfaction and emotional reactivity. Multiple linear regression analysis revealed that activity and emotional reactivity are temperamental predictors of life satisfaction. The temperamental predictor of job satisfaction in the cognitive aspect is only activity, whereas in the case of job satisfaction in the emotional aspect - activity and endurance. The statistical analysis revealed that the temperament structure harmonising in the dimension of under-stimulation - over-stimulation has no correlation with any types of satisfaction.
The Influence of Remelting on the Properties of AlSi6Cu4 Alloy Modified by Antimony
Authors: Medlen D. , Bolibruchova D.
Published: June 2012

The Influence of Remelting on the Properties of AlSi6Cu4 Alloy Modified by Antimony

The paper deals with the problem of multiple remelting influence on AlSi6Cu4 alloy modified by antimony on chosen mechanical characteristics, microstructure and gas content. This foundry alloy is used mostly in automotive industry. Foundry Aluminum-Silicon alloys are also used in number of industrial weight sensitive applications because of their low weight and very good castability and good mechanical properties. Modifiers are usually added to molten aluminum-silicon alloys to refine the eutectic phase particle shape and improve the mechanical properties of the final cast products and Al-Si alloys cast properties.
Antioxidant Activity of Milling Fractions of Selected Cereals
Authors: Ivanišová Eva , Ondrejovič Miroslav , Šilhár Stanislav
Published: June 2012

Antioxidant Activity of Milling Fractions of Selected Cereals

The aim of this study was to evaluate antioxidant potential of four milling fractions of selected cereals grew in the year 2009 and 2010. Free radical scavenging activity of samples was measured using DPPH assay and reducing power was determined using FRAP assay. Secondary, total phenolic and flavonoid content of cereal extracts was evaluated. We found that flour fractions (break flour and reduction flour) showed the lower proportion of the total antioxidant potential than bran fractions (fine bran and coarse bran), which was balanced in observed years. Extract from barley had the highest values of antioxidant activity and polyphenol content.
Solid-Phase Extraction for Photometric Determination of Rosmarinic Acid in Lemon Balm (Melissa Officinalis) Extracts
Authors: Ondrejovič Miroslav , Maliar Tibor , Benkovičová Hana , Kubincová Jana
Published: June 2012

Solid-Phase Extraction for Photometric Determination of Rosmarinic Acid in Lemon Balm (Melissa Officinalis) Extracts

The aim of this study was evaluation of the solid-phase extraction for elimination of interference compounds from lemon balm extracts aimed for photometric determination of rosmarinic acid. In experiments, evaluated conditions were as follows: composition and volume of mobile phase, ratio between volume of sample and mass of stationary phase and flow rate of mobile phase during separation. The results indicated that interfered compounds were eliminated. The lemon balm extracts should be pretreated by adsorption on normal stationary phase (silica gel) in ratio sample volume to silica gel weight 1:1 (v/w) elution by mobile phase - diethyl ether: acetic acid (9:1; v/v) - volume - 40 times of crude extract volume - with flow rate 5 ml/min. After selection of SPE conditions, the method was validated with comparison to HPLC analysis. The results suggest that this method may be useable for determination of rosmarinic acid by photometric measurement based on the complexation of Fe2+ ions with rosmarinic acid.
Painful Hypertrophic Osteoarthropathy and Metastatic Bone Lesions as the Initial Presentation of Lung Cancer
Authors: Hung Man-Hsin , Hou Kuan-Ting , Liu Chun-Yu
Published: June 2012

The patient was a 67-year-old woman, who was evaluated by her primary care physician for progressively worsening right knee pain, described as constant in nature and as having been present for the past week. The patient's symptoms were insidious in onset, not associated with a traumatic event, and interfered with activities of daily living and sleeping.

J Orthop Sports Phys Ther 2012;42(7):659. doi:10.2519/jospt.2012.0413
A Warpage Optimization Method for Injection Molding Using Artificial Neural Network Combined Weighted Expected Improvement
Authors: Shi H. , Wang X. , Xie S.
Published: June 2012

A surrogate-based warpage optimization for injection molding is proposed in this study. The optimization process aims at minimizing the warpage of the injection molding parts in which process parameters, i.e., the mold temperature, melt temperature, injection time, packing time, packing pressure, and cooling time are the design variables. The warpage values are reduced by optimizing the process parameters. A new optimization iteration scheme based on artificial neural network (ANN) combined weighted expected improvement (WEI) is employed to speed up the optimization process and to ensure very rapid and steady convergence. The ANN is used to build an surrogate warpage function for the process parameters, replacing the expensive simulation analysis in the optimization iterations. The adaptive process is executed by the WEI function, which is an infilling sampling criterion. Although the design of experiment (DOE) size is small, this criterion can precisely balance the local and global search and tend to find the global optimal design. As examples, a TV cover and a scanner are investigated. The results show that the proposed approach can effectively reduce the warpage of the injection molding parts.
Rotational Molding of Polyamide-6 Nanocomposites with Improved Flame Retardancy
Authors: Calò E. , Massaro C. , Terzi R. , Cancellara A. , Pesce E. , Re M. , Greco A. , Maffezzoli A. , Gonzalez-Chi P. I. , Salomi A.
Published: June 2012

The aim of this work was to develop polyamide-6/ organic-modified montmorillonite (omMMT) nanocomposites for the production of hollow parts by rotational molding. Particular emphasis was placed on the mechanical and flame retardancy properties needed for the fabrication of vessels for flammable liquids. The morphology of the melt compounded nanocomposites, produced by melt compounding, was investigated by X-ray diffraction measurements (WAXD), and Transmission Electron Microscopy (TEM) showed an exfoliated structure. Rheological measurements were used in order to verify whether the viscosity of materials was adequate for rotational molding. While thermomechanical analysis has revealed that neat PA6 and its nanocomposites were not suitable for rotational molding, due to the very low thermal stability of the polymer, the addition of a thermal stabilizer, shifted the onset of degradation to higher temperatures, thus widening the processing window of both PA6 and PA6 nanocomposites. Large-scale vessel prototypes were obtained by rotational molding of thermo-stabilized PA6 and its nanocomposites, and samples extracted from the rotomolded parts were characterized with respect to physical and mechanical properties. It was found that the PA6 nanocomposites exhibited significant improvements at cone calorimeter tests in comparison with neat PA6.
Effect of Blending Protocol on the Rheological Properties and Morphology of HDPE/LLDPE Blend-based Nanocomposites
Authors: Passador F. R. , Ruvolo-Filho A. , Pessan L. A.
Published: June 2012

Nanocomposites based on high density polyethylene (HDPE)/linear low density polyethylene (LLDPE) blend were prepared by melt compounding in a torque rheometer using an organoclay (montmorillonite) as nano-filler and maleic anhydride-grafted linear low density polyethylene (LLDPE-g-MA) as compatibilizer. The effects of five blending protocols on microstructure, crystallinity and rheological properties of the prepared samples were examined. The steady state rheological properties showed that the addition of nanoclay to the HDPE/LLDPE blend increased its shear viscosity at low shear rates changing the behavior of the HDPE/LLDPE matrix to a more pronounced shear thinning behavior. The blending sequence (LLDPE/LLDPE-g-MA/20A)/HDPE (where LLDPE and LLDPE-g-MA were first mixed with organoclay and then this system was later blended with HDPE) showed a lower slope of the log versus log curve and these results can be an indicative that the interactions between the matrix and the organoclay are stronger. The organoclay interlayer spacing and the crystallinity of the polymer domains were also influenced by the blending sequence. The crystallinity was calculated through the mathematical deconvolution of the peaks observed in the WAXD profiles. Overall, the crystallization of HDPE in the blends was hardly influenced by the presence of LLDPE. The blending sequence (LLDPE/LLDPE-g-MA/20A)/HDPE showed lower cristallinity when compared to others blending sequences. On the other hand, it was observed an increase in the organoclay interlayer spacing of this nanocomposite because the intercalation and/or exfoliation process occurs preferentially in the amorphous phase.
Cost-effectiveness of confirmatory techniques for the placement of lumbar pedicle screws
Authors: Sanborn Matthew R. , Thawani Jayesh P. , Whitmore Robert G. , Shmulevich Michael , Hardy Benjamin , Benedetto Conrad , Malhotra Neil R. , Marcotte Paul , Welch William C. , Dante Stephen , Stein Sherman C.
Published: June 2012

Object

There is considerable variation in the use of adjunctive technologies to confirm pedicle screw placement. Although there is literature to support the use of both neurophysiological monitoring and isocentric fluoroscopy to confirm pedicle screw positioning, there are no studies examining the cost-effectiveness of these technologies. This study compares the cost-effectiveness and efficacy of isocentric O-arm fluoroscopy, neurophysiological monitoring, and postoperative CT scanning after multilevel instrumented fusion for degenerative lumbar disease.

Methods

Retrospective data were collected from 4 spine surgeons who used 3 different strategies for monitoring of pedicle screw placement in multilevel lumbar degenerative disease. A decision analysis model was developed to analyze costs and outcomes of the 3 different monitoring strategies. A total of 448 surgeries performed between 2005 and 2010 were included, with 4 cases requiring repeat operation for malpositioned screws. A sample of 64 of these patients was chosen for structured interviews in which the EuroQol-5D questionnaire was used. Expected costs and quality-adjusted life years were calculated based on the incidence of repeat operation and its negative effect on quality of life and costs.

Results

The decision analysis model demonstrated that the O-arm monitoring strategy is significantly (p < 0.001) less costly than the strategy of postoperative CT scanning following intraoperative uniplanar fluoroscopy, which in turn is significantly (p < 0.001) less costly than neurophysiological monitoring. The differences in effectiveness of the different monitoring strategies are not significant (p = 0.92).

Conclusions

Use of the O-arm for confirming pedicle screw placement is the least costly and therefore most cost-effective strategy of the 3 techniques analyzed.
Comparison of manually shaped and computer-shaped titanium mesh for repairing large frontotemporoparietal skull defects after traumatic brain injury
Authors: Luo JianMing , Liu Bin , Xie ZeYu , Ding Shan , Zhuang ZeRui , Lin Lan , Guo YanChun , Chen Hui , Yu Xiaojun
Published: June 2012

Object

The object of this study was to compare the effects and complications of manual and computer-aided shaping of titanium meshes for repairing large frontotemporoparietal skull defects following traumatic brain injury.

Methods

From March 2005 to June 2011, 161 patients with frontotemporoparietal skull defects were observed. Patients were divided into 2 groups according to the repair materials used for cranioplasty: 83 cases used computer-aided shaping for the titanium mesh, whereas the remaining 78 cases used a manually shaped titanium mesh. The advantages and disadvantages of the 2 methods were compared.

Results

No case of titanium mesh loosening occurred in either group. Subcutaneous fluid collection, titanium mesh tilt, and temporal muscle pain were the most common complications. In the manually shaped group, there were 14 cases of effusion, 10 cases of titanium mesh tilt, and 15 cases of temporal muscle pain. In the computer-aided group, there were 6 cases of effusion, 3 cases of titanium mesh tilt, and 6 cases of temporal muscle pain. The differences were significant between the 2 groups (p < 0.05). Other common complications were scalp infection, exposure of titanium mesh, epidural hematoma, and seizures. In the computer-aided group, the operative time decreased (p < 0.01), the number of screws used was reduced (p < 0.01), and the satisfaction of patients was significantly increased (p < 0.05).

Conclusions

Computer-aided shaping of titanium mesh for repairing large frontotemporoparietal skull defects decreases postoperative complications and the operative duration, reduces the number of screws used, increases the satisfaction of patients, and restores the appearance of the patient's head, making it an ideal choice for cranioplasty.