bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Agricultural Management Influence on Long‐Term Soil Organic Carbon Dynamics: Implications for Biofuel Production
Authors: Gollany H. T. , Rickman R. W. , Liang Y. , Albrecht S. L. , Machado S. , Kang S.
Published: January 2011

Long‐term field experiments (LTE) are ideal for predicting the influence of agricultural management on soil organic carbon (SOC) dynamics and examining biofuel crop residue removal policy questions. Our objectives were (i) to simulate SOC dynamics in LTE soils under various climates, crop rotations, fertilizer or organic amendments, and crop residue managements using the CQESTR model and (ii) to predict the potential of no‐tillage (NT) management to maintain SOC stocks while removing crop residue. Classical LTEs at Champaign, IL (1876), Columbia, MO (1888), Lethbridge, AB (1911), Breton, AB (1930), and Pendleton, OR (1931) were selected for their documented history of management practice and periodic soil organic matter (SOM) measurements. Management practices ranged from monoculture to 2‐ or 3‐yr crop rotations, manure, no fertilizer or fertilizer additions, and crop residue returned, burned, or harvested. Measured and CQESTR predicted SOC stocks under diverse agronomic practices, mean annual temperature (2.1–19°C), precipitation (402–973 mm), and SOC (5.89−33.58 g SOC kg−1) at the LTE sites were significantly related (r2 = 0.94, n = 186, P < 0.0001) with a slope not significantly different than 1. The simulation results indicated that the quantities of crop residue that can be sustainably harvested without jeopardizing SOC stocks were influenced by initial SOC stocks, crop rotation intensity, tillage practices, crop yield, and climate. Manure or a cover crop/intensified crop rotation under NT are options to mitigate loss of crop residue C, as using fertilizer alone is insufficient to overcome residue removal impact on SOC stocks.
Soil Organic Carbon Dynamics in the Pendleton Long‐Term Experiments: Implications for Biofuel Production in Pacific Northwest
Authors: Machado Stephen
Published: January 2011

Use of crop residues for biofuel production raises concerns on how removal will impact soil organic carbon (SOC). Information on the effects on SOC is limited and requires long‐term experimentation. Fortunately, Pendleton long‐term experiments (LTEs), dating to the 1930s, provide some answers. This study compared crop residue inputs and SOC balance in conventional tillage (CT) winter wheat (Triticum aestivum L.)–summer fallow (WW‐SF) systems with annual rotation of WW and spring pea (Pisum sativum L.). The WW‐SF consisted of crop residue (CR‐LTE) (0–90 N ha−1 yr−1, 11.2 Mg ha−1 yr−1 of steer (Bos taurus) manure and 1.1 Mg ha−1 yr−1of pea vines additions, residue burning, and tillage fertility (TF‐LTE) (tillage‐ plow, disc, sweep, and N (0–180 kg ha−1)). Winter wheat–pea (WP‐LTE) rotation treatments included maxi‐till (MT‐disc/chisel), fall plow (FP), spring plow (SP), and no‐till (NT). Soils were sampled (0–60‐cm depth) at 10‐yr intervals, and grain yield and residue data collected every year. In WW‐SF systems, SOC was maintained only by manure addition and depleted at a rate of 0.22 to 0.42 Mg ha−1 yr−1 in other treatments. In WP‐LTE, MT, FP, SP, and NT treatments increased SOC at the rate of 0.10, 0.11, 0.02, and 0.89 Mg ha−1 yr−1, respectively. Minimum straw biomass to maintain soil organic carbon (MSB) in the CR‐LTE, TF‐LTE, and WP‐LTE was 7.8, 5.8, and 5.2 Mg ha−1 yr−1, respectively. Winter wheat‐SF straw production was lower than MSB, therefore residue removal exacerbated SOC decline. Harvesting straw residues under NT continuous cropping systems is possible when MSB and conservation requirements are exceeded.
Agronomic Performance of Cropping Systems with Contrasting Crop Rotations and External Inputs
Authors: Coulter Jeffrey A. , Sheaffer Craig C. , Wyse Donald L. , Haar Milton J. , Porter Paul M. , Quiring Steven R. , Klossner Lee D.
Published: January 2011

Cropping systems with less reliance on external inputs could improve agricultural sustainability if they can produce high and stable crop yields over time. A 16‐yr experiment was conducted in southwestern Minnesota to evaluate the effects of zero external input (ZEI), low external input (LEI), high external input (HEI), and organic input (OI) systems on crop yield and yield stability in a 2‐yr soybean [Glycine max (L.) Merr.]–corn (Zea mays L.) rotation and a 4‐yr oat (Avena sativa L.)/alfalfa (Medicago sativa L.)–alfalfa–corn–soybean rotation. Oat yield was stable and highest with the LEI, HEI, and OI systems. Alfalfa yield was highest with the LEI, HEI, and OI systems in the first 8 yr and the OI system in the last 8 yr. Corn grain yield was 0, 13, 26, and 40% greater with the 4‐yr rotation than the 2‐yr rotation in the HEI, LEI, OI, and ZEI systems, respectively, and was greatest with the HEI system in the 2‐yr rotation and the LEI, HEI, and OI systems in the 4‐yr rotation. Soybean yield was 7% greater with the 4‐yr rotation than the 2‐yr rotation and was among the highest with the LEI and HEI systems. Stable corn and soybean yields occurred with the LEI and OI systems, while above‐average yield increases under favorable growing conditions occurred with the LEI and HEI systems in alfalfa and the HEI system in corn. These results demonstrate the value of extended crop rotations for corn and soybean, and that high crop yields can be obtained with reduced‐input systems.
Corn and Barnyardgrass Competition as Influenced by Relative Time of Weed Emergence and Corn Hybrid
Authors: Travlos Ilias S. , Economou Garifalia , Kanatas Panagiotis J.
Published: January 2011

Barnyardgrass [Echinochloa crus‐galli (L.) Beauv.] is a weed with global impacts on corn (Zea mays L.) production. Field experiments were conducted in western Greece in 2008 and 2009 to determine the influence of barnyardgrass emergence time and corn hybrid on corn yield and barnyardgrass growth and fecundity. Barnyardgrass was uniformly seeded at dates such that it emerged concurrently with corn and at the two, four, and six‐leaf stage of corn (VE, V2, V4, and V6 growth stages, respectively). Barnyardgrass biomass, tillers, canopy area and seed production were significantly affected by the date of barnyardgrass emergence. Barnyardgrass plants emerging with corn produced 1010 to 1305 seeds per plant compared to only 112 to 240 seeds from plants emerging after the V4 growth stage. Maximum corn grain yield loss ranged from 24 to 34% for early emerging barnyardgrass, and <9% yield loss occurred from barnyardgrass seedlings emerging later than the V4 growth stage. Corn hybrids with rapid initial growth rate (such as ‘Factor’ and ‘Dracma’) were more competitive than the other hybrids. The results of this study are essential in the development of an integrated weed management strategy for corn. Findings suggest that despite the high competitiveness of barnyardgrass, careful selection of a competitive corn hybrid and control of barnyardgrass through at least the V2 to V4 growth stage could dramatically reduce grain yield loss and weed seed production.
Growth Stage Influenced Sorghum Response to Broadcast Flaming: Effects on Yield and Its Components
Authors: Ulloa Santiago M. , Datta Avishek , Knezevic Stevan Z.
Published: January 2011

There is an increasing interest among organic producers to grow grain sorghum [Sorghum bicolor (L.) Moench] under organic crop production systems and propane flaming could be part of an integrated weed management program. Therefore, the objective of this study was to investigate the response of sorghum to broadcast flaming as influenced by propane dose and crop growth stage. Field experiments were conducted at the Haskell Agricultural Laboratory of the University of Nebraska, Concord, NE in 2008 and 2009 using five propane doses applied at three growth stages that included 3‐leaf (V3), 5‐leaf (V5), and 7‐leaf (V7). The propane doses evaluated were 0, 13, 24, 44, and 85 kg ha−1 and were applied using a custom‐built (ATV mounted) research flamer driven at a constant speed of 6.4 km h−1 Crop response to propane doses was described by using log‐logistic models on the basis of visual estimates of crop injury, various yield components (plants m−2, heads plant−1, kernels head−1, and 1000‐kernel weight), and grain yield. Sorghum response to flaming varied among crop growth stages and propane doses. Based on the evaluated parameters, sorghum flamed at V5 and V7stages showed higher tolerance compared to V3 stage. The maximum yield reductions with the highest propane dose of 85 kg ha−1 were 11, 6, and 9% for V3, V5, and V7 stages, respectively. In addition, propane doses that resulted in a 5% yield loss were 13, 72, and 46 kg ha−1 for V3, V5, and V7 stages, respectively, indicating that plants flamed at V5 or V7 stage can tolerate higher dose of propane for the same yield reduction compared to V3 stage. Flaming has a potential to be used effectively in organic sorghum production if properly used.
Cotton Lint Yield Improvement Attributed to Residual Effect of Repeated Poultry Litter Application
Authors: Tewolde Haile , Adeli Ardeshir , Rowe Dennis E. , Sistani Karamat R.
Published: January 2011

The magnitude of soil nutrients derived from poultry litter that carryover to succeeding seasons and the possibility to decrease litter rates applied to soils with only a few years of application history is not well understood. The objective of this research was to determine and quantify the potential carryover effect of moderate broiler litter fertilization rates on cotton (Gossypium hirsutum L.) lint yield in subsequent years. Cotton was fertilized with 0, 2.2, 4.5, 6.7 Mg ha−1 yr−1 broiler litter, 4.5 Mg ha−1 yr−1 litter plus 67 kg N ha−1 yr−1 as urea ammonium nitrate (UAN), or with 135 kg N ha−1 yr−1 as UAN (farm standard, Std) on a private farm under conventional till in Mississippi in 2002–2007. In 2005, each plot was divided into two equal subunits and one‐half continued to receive the same fertilization treatment and the other half was not fertilized in 2005 and the subsequent 2 yr. The results showed the 6.7 Mg ha−1 litter fertilization did not supply sufficient fertilization for optimum lint yield during the first 3 yr (2002–2004). But, lint yield of this treatment equaled that of the Std in the last 3 yr (2005–2007), suggesting a cumulative litter carryover in 2002–2004 was sufficient to meet the fertilization deficit. The results overall show that repeated litter application for a few years under conventional till management builds the nutrient pool gradually and that the rate of litter application might be reduced in subsequent years while maintaining optimum lint yield.
Effects of Natural Hail Damage on Ear Rots, Mycotoxins, and Grain Quality Characteristics of Corn
Authors: Robertson Alison E. , Munkvold Gary P. , Hurburgh Charles R. , Ensley Steve
Published: January 2011

In 2009, two severe hail storms affected more than 400,000 ha of corn (Zea mays L.) during early reproductive stages (R1 to R3) in Iowa. Concerns were raised regarding marketability, increased ear rot disease, and associated mycotoxin contamination. To address these concerns, ear samples were collected within 48 h of combine harvest from 56 fields damaged by hail and 27 undamaged fields. Ears were visually assessed for kernel damage and ear rot severity. After shelling, test weight, moisture, protein, oil, starch, and density were determined before grain was ground and tested for deoxynivalenol (DON), zearalenone, and fumonisins using commercially available antibody‐based lateral flow strip tests. Confirmation analyses on elevated samples was performed by gas chromatography for DON and high pressure liquid chromatography for zearalenone and fumonisin. Fusarium, Gibberella, and Cladosporium ear rots were the most prevalent diseases. Hail damage to kernels increased the risk of ear rot and mycotoxin contamination. The most prevalent mycotoxin detected was DON (mean 2.63 mg kg−1), followed by zearalenone (mean 0.53 mg kg−1) and fumonisin (mean 0.49 mg kg−1). Levels of DON were more than fourfold higher and ZEA levels were 10‐fold higher in grain from hail‐damaged fields compared to undamaged fields. In approximately 50% of the grain samples from hail damaged fields, DON and zearalenone levels in ethanol co‐products would likely have been above FDA advisory levels and levels recommended by veterinarians, respectively. Preharvest scouting and screening of fields with suspected mycotoxins may be necessary, particularly with increased concerns about mycotoxin in grain end products.
Performance of a Mobile Salinity Monitoring Device Developed for Turfgrass Situations
Authors: Krum J. M. , Flitcroft I. , Gerber P. , Carrow R. N.
Published: January 2011

Spatial salinity mapping with a mobile sensor platform allowing GPS‐labeled data on turfgrass areas would facilitate site‐specific leaching programs for salinity management. A salinity monitoring device (SMD) based on 4‐Wenner array electrical resistivity (ER) electrode configuration was developed for turfgrass sites and tested on three soils at Griffin, GA and a golf course fairway in Naples, FL on two dates where the fairway received saline irrigation water. Using directed soil sampling, the SMD resulted in soil apparent soil electrical conductivity (ECa) vs. laboratory saturated paste extract electrical conductivity (ECe) linear relationships with r2 of 0.59 to 0.87 (p < 0.0002) for 0 to 10 cm and 0 to 20 cm zones at Griffin, GA. For two mapping events varying two‐ to threefold in salinity levels at the golf course fairway, the ECa vs. ECe linear regressions exhibited similar slopes, different intercepts (due to two to threefold difference in background salinity), and r2 of 0.53 to 0.58 (p < 0.002). On another fairway, a detailed spatial salinity map using geographic information systems (GIS) methods was developed using a sampling grid of 2 by 3 m, which was well within the 19 m range determined for spatial autocorrelation of the data. Our data suggest the empirical methods developed for agricultural soils for relating ECa to ECe and for determining average ECa of discrete subsurface zones may differ under turfgrass conditions due to stratification of the surface organic matter layer influencing water holding capacity, soluble salt retention, and averaging ECa within a subsurface zone.
Canola Response to ESN and Urea in a Four‐Year No‐Till Cropping System
Authors: Blackshaw R. E. , Hao X. , Brandt R. N. , Clayton G. W. , Harker K. N. , O'Donovan J. T. , Johnson E. N. , Vera C. L.
Published: January 2011

Nitrogen fertilizer is a major input cost in canola (Brassica napus L.) production and farmers are interested in improving N use efficiencies. A multi‐site study in western Canada was conducted to determine the merits of polymer‐coated urea (Environmentally Smart Nitrogen, ESN) compared with urea on weed management and yield of hybrid and open‐pollinated (OP) canola. Treatments included a hybrid and OP canola cultivar, ESN and urea, 100 and 150% of soil test N fertilizer rates, and 50 and 100% of registered in‐crop herbicide rates. Canola was grown in rotation with barley (Hordeum vulgare L.) in a no‐till system and both crops of the rotation were present each year. Fertilizer and herbicide rate treatments were applied to the same plots in four consecutive years to determine annual and cumulative effects. Hybrid compared with OP canola reduced weed tissue N concentration in 40% of the cases and reduced weed biomass in 80% of the cases. Additionally, weed tissue N concentration was lower with ESN than with urea in 70% of the cases, indicating that crop–weed competition for soil N might be reduced if ESN were used. Canola yield was greater for the hybrid cultivar in 15 of 20 site‐years. Both cultivars expressed a positive yield response to the 150% N fertilizer rate in 10 of 20 site‐years. This yield response occurred in three additional site‐years with hybrid canola, indicating that hybrid cultivars have a higher N demand under favorable growing conditions. Canola yield was similar with ESN and urea in 14 of 20 site‐years. The ESN compared with urea increased canola yield in 4 site‐years and in one additional site‐year for hybrid canola, indicating that ESN may be advantageous in some situations. Canola seed oil concentration was similar with ESN and urea in 19 of 20 site‐years. Information gained in this study will be used to develop improved fertilization strategies for canola production on the semiarid Canadian prairies.
Grazing Intensity and Nitrogen Fertilization Affect Litter Responses in ‘Tifton 85’ Bermudagrass Pastures: II. Decomposition and Nitrogen Mineralization
Authors: Liu Kesi , Sollenberger Lynn E. , Silveira Maria L. , Vendramini João M.B. , Newman Yoana C.
Published: January 2011

In many grassland ecosystems, nutrient cycling via plant litter is important for plant growth and persistence. Understanding dynamics of litter decomposition and nutrient release under different management practices is critical to understanding nutrient cycling in grasslands, but this topic has received relatively little attention in C4 grass pastures. The objective of this study was to determine the effects of grazing intensity (defined as postgraze stubble height, SH) and N fertilization on litter decomposition and N release in ‘Tifton 85’ bermudagrass (Cynodon spp.) pastures. Three levels of SH (8, 16, 24 cm) were compared at the same interval between grazing events (28 d) and amount of N fertilization (250 kg N ha−1 yr−1). Three levels of N fertilization (50, 150, and 250 kg N ha−1 yr−1) were compared when SH (24 cm) and regrowth interval were constant (28 d). Loss of litter mass was most rapid early in the decomposition period. Pasture SH had no effect on decomposition of litter mass, but increasing N fertilization increased decomposition rate. Immobilization of litter N began almost immediately after placement in the field regardless of treatment, did not reach its maximum for up to 60 d, and lasted more than 128 d for most treatments. Increasing SH and N fertilization increased N immobilization in plant litter. Nitrogen immobilization in bermudagrass litter occurs across a wide range of pasture management practices, impacting N availability for plant growth.
Late Leaf Spot Effects on Growth, Photosynthesis, and Yield in Peanut Cultivars of Differing Resistance
Authors: Singh Maninder P. , Erickson John E. , Boote Kenneth J. , Tillman Barry L. , Jones James W. , van Bruggen Ariena H.C.
Published: January 2011

Cercosporidium personatum (Berk. & Curt.) Deighton causes late leaf spot (LLS) in peanut (Arachis hypogaea L.), which leads to necrotic lesions, early leaf senescence and yield losses. Detailed physiological analyses can contribute to an improved understanding of peanut‐disease interactions and cultivar improvement. A study was conducted evaluating two peanut cultivars with more (York) and less (Carver) quantitative resistance to C. personatum grown under fungicide‐sprayed and nonsprayed conditions in the field at Citra, FL over 2 yr. Data were collected on disease severity using the Florida 1 to 10 visual rating scale and by direct measurement of percent canopy lesion area. Leaf lifespan, total canopy photosynthesis (TCP), plant growth, and pod yield were also measured. Disease severity based on canopy lesion area was reduced by 30% in York compared to Carver. No additive effects of combining the resistant cultivar with fungicide were seen, as fungicide use increased yield by 364 kg ha−1 for both cultivars. Yield was more strongly related to disease severity based on canopy lesion area than to the Florida scale. Yield improvement with York was not as closely related to disease severity with only a 6% gain in pod yield in York compared to Carver. In addition, reduction in TCP was greater in York compared to Carver given their respective disease severity. These results indicated that combining resistance with the maintenance of physiological function during LLS infection could result in improved peanut yields under diseased conditions.
Predicting Flowering Dates in Wheat with a New Statistical Phenology Model
Authors: Sharma Darshan L. , D'Antuono Mario F.
Published: January 2011

Wheat growers in Western Australia (WA) value flowering date predictions for risk aversion from frost and terminal stresses. Currently used statistical models such as the “flowering calculator” (referred to as photothermal model as programmed by Tennant and Tennant [2000] [TT]) are less robust in colder regions and/or higher latitudes of WA. We developed a new statistical model (named DM) that includes a vernalization component in addition to photoperiod and temperature components, the three biological drivers of reproductive growth and development in wheat (Triticum spp.). The model assumes that heatsums required for flowering comprise a variety specific minimum, plus some more that are linearly contingent on sowing day, daylength, and the statistical summaries of daily temperature profiles. The vernalization opportunity was quantified using a term named “coldsum” calculated as equal to the sum of daily periods under 5°C in hourly temperature profile, while “heatsum” referred to the periods above 0°C. Environments were characterized using a log‐log transformation on heatsums and a segmented‐lines approach on coldsums. The model coefficients were estimated using data from four sowing dates spanning prevalent sowing times in WA over 4 yr at three diverse locations. The DM predictions were statistically far superior to TT (F probability < 0.001; RMSD 6.1 and 17.4, respectively) in all respect of location, season, sowing date, and cultivar factors when compared in independent datasets from six cultivar × sowing date trials across WA wheatbelt. Since DM relies on a structured application of seasonal profiles, it should be applicable to other geographic areas, cultivars, and crops.
Introduction: Evaluating Long‐Term Impacts of Harvesting Crop Residues on Soil Quality
Authors: Huggins David R. , Karow Russell S. , Collins Harold P. , Ransom Joel K.
Published: January 2011

Utilizing crop residues as biofuel feedstocks will involve trade‐offs between bioenergy production and agroecosystem services. Consequently, agricultural production managers and policymakers need to critically evaluate current functions of crop residues in light of increasing demands for agricultural intensification including bioenergy. At issue are the short‐ and long‐term impacts of residue harvest on the sustainability of soil resources and related food and energy production and the often disparate economic, environmental, edaphic, climatic, technological, and logistical factors involved. Although field studies cannot address all scenarios, long‐term studies can provide insights on how crop residue harvest will impact key factors of agricultural sustainability such as soil organic matter (SOM). This topic was the major theme of the 2009 International American Society of Agronomy symposium entitled “Residue Removal and Soil Quality—Findings from Long‐Term Research Plots.” The seven papers in this special Agronomy Journal section were developed from this symposium and draw on long‐term studies from Europe, Canada, Australia, and the United States to examine residue harvest impacts on SOM and factors related to long‐term sustainably. In combination, these papers conclude that residue harvest will impact SOM, although the nature of the effects is situation‐dependent. Also clear is that the assessment of harvesting residues must be placed in a farming systems context that includes an evaluation of economic and environmental trade‐offs specific for a given farm and location. Therefore, future challenges include the development of science‐based, site‐specific decision aids that enable growers to make economically sound and environmentally sustainable choices regarding residue harvest.
Perceptions of parental behavior with regard to parents’ gender and respondents’ age and gender
Authors: Opsenica-Kostic Jelena , Stefanovic-Stanojevic Tatjana
Published: January 2011

The findings of the research into the perceived parental behavior provide
contrasting data as to the existence and the nature of differences in the
perception of parental behavior based on parents? gender and respondents?
gender. The purpose of the present study is to examine the differences in the
perceived parental behavior in adolescents with regard to parents? gender and
respondents? age and gender. The study included 466 respondents (262 girls
and 204 boys), in middle to late adolescence, divided into four sub-groups
according to their age. The respondents were asked to fill in the Parental
Bonding Instrument (PBI) questionnaire which measures the care and
overprotection in mothers and fathers respectively. The obtained findings
show the existence of significant difference based on the parents? gender for
both subscales: both maternal care and maternal overprotection were estimated
as higher. Observing the differences by respondents? gender on the whole
sample, only one significant difference is found: paternal overprotection was
estimated as higher by girls. The differences by age as observed within
gender groups are completely disparate for girl and boy groups. The best
insight into the differences is obtained through analysis by gender, for
groups relatively homogenous in terms of their age (for the first three
groups the only significant difference appears in the paternal overprotection
subscale; the difference disappears in the subgroup of the oldest
respondents?, while the differences between the perception of maternal and
paternal care are of significance here). One particularly important finding
for future research into rearing behavior is the fact that the perception of
parental behavior changes over the period of adolescence differently for
boys and girls; therefore, the analysis including perceived parental
behavior should be performed for subgroups by gender, which are as
homogenous as possible in terms of their age.
Thermal diffusion in a binary fluid mixture flows due to a rotating disc of uniform high suction in presence of a weak axial magnetic field
Authors: Sharma B.R. , Singh R.N.
Published: January 2011

The effect of a weak uniform axial magnetic field on separation of a binary
mixture of incompressible viscous thermally and electrically conducting
fluids flowing due to a rotating disc of uniform high suction is examined.
Neglecting the induced electric field the equations governing the motion,
temperature and concentration are solved in cylindrical polar coordinate by
expanding the flow parameters as well as the temperature and the
concentration in powers of suction parameter. The solution obtained for
concentration distribution is plotted against the different axial distances
from the disc for various values of non-dimensional parameters. It is found
that the temperature gradient, axial magnetic field, Reynolds number,
Schmidt number, Prandtl number and suction parameter effect the species
separation significantly.
On the state of pure shear
Authors: Jaric Jovo , Kuzmanovic Dragoslav , Golubovic Zoran
Published: January 2011

The algebraic proof of the fundamental theorem concerning pure shear, by
making use only of the notion of orthogonal projector, is presented. It has
been shown that the state of pure shear is the same for all singular
symmetric traceless tensors in E3, up to the rotation.
Web 2.0: Challenges and Opportunities for Media Education and beyond
Authors: Cheung Chi-Kim
Published: January 2011

The nature of knowledge is being redefined by a new media landscape that allows all participants to be media producers and owners. Without a comprehensive strategy to include Web 2.0 tools and social media practices within schools, powerful new skills will be neither harnessed, nor developed. Despite the challenge to the relationship between students (digital natives) and teachers (digital immigrants) that Web 2.0 tools present, teachers are still the vital link to supporting students and giving meaning to the practices they engage in, including developing critical thinking in an information age. This article discusses the challenges and opportunities presented to media education by Web 2.0 tools and social media practices and vice versa. Consistently, it can be demonstrated that these symbiotic potentials are reflected beyond the microcosm of media education in schools. Future performance at work and functioning within a global economy and the effect of collaborative networking skills on local, national and global societies go further than the challenge to school curricula. Local specific effects of ‘co-learning’ and the new status of ‘learner voice’ on learning experiences show the beginnings of a gradual influence that has far-reaching potentials.
‘I Link, Therefore I Am’: Network Literacy as a Core Digital Literacy
Authors: Pegrum Mark
Published: January 2011

Networks have emerged as the dominant organizational structures of our time. In the networked era, social networks underpinned by the internet are crucial to obtaining and filtering information as well as reaching audiences and collaborators. To remain relevant in this era, educational institutions must foster network literacy, teaching students about and through networks, and helping them to establish and manage personal learning networks. This will ensure that all students, and not just the elite, are able to capitalize on the benefits and avoid the pitfalls of the networks which will be an integral part of their social and professional futures.
Evidence of changes in hydrophilic/hydrophobic balance and in chemical activity of HSA induced by thermal treatments
Authors: Sahini Victor , Ionita Gabriela
Published: January 2011

Samples of human serum albumin (HSA) obtained as a result of heat denaturation followed by refolding controlled by a cooling of the protein solution were studied by several methods: chromatographic measurements, kinetic of the reaction with a water soluble free radical and by electron paramagnetic resonance (EPR) spectroscopy. In this context the interaction of this protein with β-cyclodextrin (β-CD) and sodium dodecyl sulfate (SDS) was also investigated. Reversed phase thin layer chromatography (RP-TLC) showed changes in lipophylicity of HSA, which are related with the existence of different ensembles of conformers. The UV-Vis absorption spectra had shown the broadening of absorption band of the protein and a hyperchrom effect in the presence of SDS; β-CD reduces the effect of SDS on protein UV-Vis spectra.

Kinetic measurements related to the reaction of HSA with a water soluble DPPH type free radical provided evidence that reactivity of the HSA denaturated conformers is higher compared with the natural conformer. The affinity of SDS to the albumins surface and the effect of β-CD on the SDS/protein aggregates were also evident by changes in the EPR spectra of the spin probe CAT16.
Modifying of etching anisotropy of silicon substrates by surface active agents
Authors: Rola Krzysztof , Zubel Irena
Published: January 2011

The influence of alcohol additives on etch rate anisotropy of Si(hkl) planes has been studied. The etching processes were carried out in 3 and 5 M KOH aqueous solutions saturated and non-saturated with alcohols. Isopropanol, 1-propanol and tert-butanol were examined. It has been showed that the etching process cannot be controlled only by the surface tension of the solution. Saturation of the etching solution with alcohols modifies etch rate anisotropy, lowering the ratio of the etch rate of (110) and vicinal planes to the etch rate of (100) plane. The morphology of Si(hkl) planes etched in 3 M KOH solution saturated with tert-butyl alcohol has been studied in detail. Smooth (331) and (221) planes have been achieved in this solution. The (100) plane turned out to be densely covered by hillocks, opposite to the (100) plane etched in weak-alkaline solution saturated with isopropanol. To explain this phenomenon, the mechanism of hillocks formation on Si(100) surface has been proposed.
Relationships between Balance and Functional Performance in Football Players
Authors: Erkmen Nurtekin , Taşkin Halil , Sanioğlu Ahmet , Kaplan Turgut , Baştürk Dede
Published: January 2011

Relationships between Balance and Functional Performance in Football Players

The aim of the present study was to examine the relationships between balance performance as measured by the Balance Error Scoring System and functional performance in football players. Twenty-two football players from University League Final Group in Turkey (age 23.05 ± 1.65 years, height 176.58 ± 6.99 cm, weight 68.80 ± 7.00 kg) volunteered to participate in the study. Postural performance was measured by the Balance Error Scoring System (BESS). For functional performance, standing broad jump, triple-hop, vertical jump, four-line sprint and three-corner run test were used. There was not a statistically significant relationship among the all BESS scores and triplehop in non-dominant leg, power, four-line sprint, and three-corner run performances (p<0.05). Triple-hop in dominant leg performance correlated with foam surface, tandem leg and total BESS score (r = 0.755, p < 0.01; r = 0.664, p < 0.05; r = 0.713, p< 0.01, respectively). Standing broad jump performance correlated with foam surface, tandem leg and total BESS score (r = 0.737, p < 0.01; r = 0.692, p < 0.05; r = 0.617, p< 0.05, respectively). There was a statistically significant relationship among the single leg BESS score and vertical jumping performance (r = -0.596, p<0.05). In conclusion, the activities requiring explosive power may reflect the ability of managing a balanced posture but the activities in which time period is longer may not.
Biomechanical, Neuro-muscular and Methodical Aspects of Running Speed Development
Authors: Coh Milan , Babic Vesna , Maćkała Krzysztof
Published: January 2011

Biomechanical, Neuro-muscular and Methodical Aspects of Running Speed Development

The purpose of present review article is to gather the most important findings in the field of speed development including biomechanical, motor and neuro-muscular factors. Maximum speed is a complex motor ability, which manifests itself in real sports situations and is an important factor in various sports disciplines. Efficiency of maximum running is defined with frequency and the length of stride. Both variables are mutually dependant; they also depend on the processes of central regulation of motor stereotype. From the biomechanical point of view, a running stride as a basic structural unit depends on eccentric-concentric muscular cycle of take-off action. Utilisation of elastic strength in muscular-tendon complex and pre-activation of the gastrocnemius muscle is highly important in this element. Maximum running is very limited hereditary motor ability with characteristic of reduced possibility for controlling movement. Cerebellum, co-activation of muscles in kinetic chain and the frequency of activation of motor units play important roles in controlling the activation of agonists and antagonists. The prime goal of training is to create an optimal model of motor stereotype in the zone of maximum speed. Such process has to be long term and methodical.
Physical Characteristics and Somatotype of Soccer Players according to Playing Level and Position
Authors: Hazir Tahir
Published: January 2011

Physical Characteristics and Somatotype of Soccer Players according to Playing Level and Position

The purpose of this study was to assess the physical characteristics of soccer players according to playing level and position. A total of 305 professional male soccer players [Turkish Super League (SL) (n = 161) and Turkish First League (FL) (n = 144)] were involved in this study. All data were gathered at the beginning of preparatory period of mid-season. Height, weight, flexed and tensed upper arm and calf girths, humerus and femur biepicondylar breadths, and four skinfold thicknesses (triceps, subscapular, supraspinale, and medial calf) were measured. Somatotypes were estimated using the Heath-Carter method. SL players were older (p≥0.002), and heavier (p≥0.007) than FL players, while height (p ≤ 0.497) was similar between SL and FL groups. There were significant differences for BW (p≥=0.000), and height (p≥0.000) between playing positions. Goalkeepers were taller (p≥0.000), and heavier (p≥0.001) than other players. Midfielders were shorter (p≥0.013) than other players, however, they were lighter than forwards (p≥0.008). The mean somatotype of the overall players was 2.4-4.8-2.3 (0.9-0.8-0.7) in SL and was 3.0-4.5-2.6 (0.9-0.9-0.8) in FL. SL players were more mesomorphic (p≥0.01), less endomorphic (p≥0.000), and less ectomorphic (p≥0.001) than FL players. Except for goalkeepers, there were significant differences in paired means between whole somatotype means of the SL and FL according to playing positions. The results of the present study demonstrate that both physical characteristics and somatotype of players were significantly different between playing levels and positions. Although the somatotype of soccer players in both levels was dominated by the mesomorph category, players at the higher playing level were more mesomorphic, and less endomorphic and ectomorphic than players at the lower level at all playing positions.
Perfectionism and Achievement Goals in Adult Male Elite Athletes who Compete at the National Level and above
Authors: Zarghmi Mehdi , Ghamary Amin , ShaykhShabani Sayed , Varzaneh Ahmad
Published: January 2011

Perfectionism and Achievement Goals in Adult Male Elite Athletes who Compete at the National Level and above

Different views on perfectionism, and different approaches about achievement goals, have led to studies on relationships between perfectionism and achievement goals. Stoeber et al. (2009) found relationship patterns from perfectionism and achievement goals in young Finnish ice-hockey players' under-16, in which it was found that perfectionistic strivings were associated with mastery-approach and performance-approach goals, and perfectionistic concerns with mastery-avoidance, performance-approach, and performance-avoidance goals. Thus, as Stoeber et al. (2009) noted, findings can be generalized to older age-groups, as researchers have pointed out that achievement goal orientations in athletes may change when athletes become older (Elliot & Conroy, 2005; Spray & Keegan, 2005). Thus, we examined the theoretical model by Stoeber et al. (2009), to investigate relationships between perfectionism and achievement goals in adult elite athletes. For this purpose, 134 adult elite athletes completed questionnaires of MIPS (Stoeber, Otto & Stoll, English version, 2006), sport - MPS - 2 (Gotwals & Dunn, 2009), and AGQ - S (Conroy et al., 2003). On the assumption of the final theoretical model as based on a few significant indices, perfectionistic strivings was associated with mastery-approach and performance-approach goals, while perfectionistic concerns was associated with mastery-avoidance and performance-avoidance goals. Contrary to expectations, there was no relationship between perfectionistic concerns and performance-approach goals. In fact, the present research results put in ambiguity the concept of perfectionism and the relationship between perfectionism and achievement goals, which were the main aims of our research. Moreover, a number of indices obtained structural equation modeling, which showed marginal to no significant effects. Thus, such equivocal results clearly imply that further research on context is needed. However, it appears that positive and negative aspects of perfectionism have complex relationships with each other
Breeding density of the Scops Owl Otus scops in urban settlements on the island of Brač (Central Dalmatia)
Authors: Bordjan Dejan , Rozoničnik Anja
Published: January 2011

Gnezditvena gostota velikega skovika Otus scops v naseljih otoka Brača (srednja Dalmacija)
The tectonic evolution of Lake Eğirdir, West Turkey
Authors: Karaman M.
Published: January 2011

The tectonic evolution of Lake Eğirdir, West Turkey

Lake Eğirdir is one of the most important fresh-water lakes of Turkey. It has a tectonics-related origin. The area formed under a roughly N-S compressional tectonic regime during the Middle Miocene. The stresses caused slip faults west and east of Isparta Angle, and the lake formed at the junction of these faults. The area subsided between normal faults, thus creating the topographic condition required for a lake. The lacustrine sediments have fundamentally different lithologies. After the Late Miocene, central Anatolia started to move westwards, but western Anatolia moved in a SW direction along the South-western Anatolian Fault, which we suggest to have a left lateral slip, which caused that the Hoyran Basin moved t7 km towards the SW and rotated 40° counterclockwise relative to Lake Eğirdir.
Feasibility of Bioethanol Production From Lignocellulosic Biomass
Authors: Aunina Zane , Bazbauers Gatis , Valters Karlis
Published: January 2011

Feasibility of Bioethanol Production From Lignocellulosic Biomass

The objective of the paper is to discuss the potential of cellulosic ethanol production processes and compare them, to find the most appropriate production method for Latvia's situation, to perform theoretical calculations and to determine the potential ethanol price. In addition, price forecasts for future cellulosic and grain ethanol are compared. A feasibility estimate to determine the price of cellulosic ethanol in Latvia, if production were started in 2010, was made. The grain and cellulosic ethanol price comparison (future forecast) was made through to the year 2018.
Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects
Authors: Jaunzems Dzintars , Veidenbergs Ivars
Published: January 2011

Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects

The paper contributes to the analyses from the environmental and economical point of view of small scale solar cooling system in climate conditions of Latvia. Cost analyses show that buildings with a higher cooling load and full load hours have lower costs. For high internal gains, cooling costs are around 1,7 €/kWh and 2,5 €/kWh for buildings with lower internal gains. Despite the fact that solar cooling systems have significant potential to reduce CO2 emissions due to a reduction of electricity consumption, the economic feasibility and attractiveness of solar cooling system is still low.
Use of Benchmark Methodology in Environmental Impact Assessment
Authors: Pubule Jelena , Blumberga Dagnija
Published: January 2011

Use of Benchmark Methodology in Environmental Impact Assessment

Every industrial activity and procedure influences the environment and climate change. This impact has to be assessed and therefore the procedure of Environmental Impact Assessment (EIA) including the application of a benchmark methodology has been developed. The developed benchmark methodology can be used in the initial assessment as a screening method. The article surveys the developed benchmark methodology for impact assessment of the projects providing extraction of dolomite in the deposits of mineral resources. The benchmark methodology developed makes it possible to assess the impacts caused by the provided activity by objective considerations, to conduct comparison of different projects and evaluate whether the provided activity corresponds to the principles of sustainable development.
Controlling Flow Rate and Fluid Level by Variable Frequency Drive Unit
Authors: Gürbüz Riza
Published: January 2011

Controlling Flow Rate and Fluid Level by Variable Frequency Drive Unit

The Variable Frequency Drive (VFD) is used to control the speed of the pumpmotor to attain the desired flow rate and fluid level in a fluid system. An AC drive provides efficient flow control by varying the pump-motor speed. The comparison of energy requirements and costs in a system where a throttling device is used for flow control on a centrifugal pump with the power used when an variable frequency drive (VFD) is used to control the same flow, evidently shows potential savings. In this system, AC Motor Frequency drive and static pressure transmitter, turbine type flowmeter and Analog/Digital cards, micro-control unit and computer connection are designed specially to control flow rate, fluid flow type (turbulence or laminar) and water level at the different conditions with different PID parameters.
Model of a Combined Pump and Drive System for Advanced Control and Diagnosis
Authors: Kleinmann Stefan , Dąbrowska Anna , Koller-Hodac Agathe , Leonardo Domenico , Stetter Ralf
Published: January 2011

Model of a Combined Pump and Drive System for Advanced Control and Diagnosis

An elaborate study executed in the direction of exploring energy saving potential shows that more than 20% of electrical energy used in industry is used for pump systems. Experts calculate that more than 30% of this energy can be saved by improving control and diagnosis for pump systems. Unfortunately, the application ratio of such system is small and consequently a large demand for such technological advanced systems can still be observed in the pump industry. Because of this reason and still growing demand of saving energy in industry, two Universities in Germany and Switzerland together with leading German pump manufacturer decided to join their knowledge and skill to work on the project called "Smart Pump". This paper presents one of the first results of this project, which goal is the development of future control methods and diagnosis systems for intelligent pumps.
Coccidioidomycosis: knowledge, attitudes, and practices among healthcare providers — Arizona, 2007
Authors: Chen Sanny , Erhart Laura M. , Anderson Shoana , Komatsu Ken , Park Benjamin , Chiller Tom , Sunenshine Rebecca
Published: January 2011

Coccidioidomycosis presumably causes ≤ 33% of community-acquired pneumonias cases, although < 15% of the patients are tested for coccidioidomycosis. We assessed healthcare providers' knowledge, attitudes, and practices regarding coccidioidomycosis diagnosis and treatment in Arizona. A survey was mailed to 7,608 eligible healthcare providers licensed by the Arizona medical, osteopathic, and nursing boards in October and December 2007. We used weights to adjust for non-response and multivariate logistic regression models to identify predictors of ≥ 70% correct regarding knowledge and treatment practices. Of 1,823 (24%) respondents, 53% were physicians, 52% were male, and the mean age was 51 years. Approximately 50% reported confidence in their ability to treat coccidioidomycosis, and 21% correctly answered all four treatment questions. Predictors of ≥ 70% correct concerning knowledge and treatment practices included always counseling patients after diagnosis (adjusted odds ratio [AOR] = 4.4; 95% confidence interval [CI]: 2.8–7.1); specializing in infectious diseases (AOR = 2.4; 95% CI: 1.0–5.7); and having received coccidioidomycosis continuing medical education (CME) in the last year (AOR = 1.8; 95% CI: 1.2–2.6). These findings demonstrate that coccidioidomycosis CME improves knowledge of disease diagnosis and management, underscoring the need for a comprehensive coccidioidomycosis education campaign for healthcare providers in Arizona.
Corrective Feedback and L2 Vocabulary Development: Prompts and Recasts in the Adult ESL Classroom
Authors: Dilans Gatis
Published: January 2011

This study investigates the effects of corrective feedback in the form of prompts and recasts on second language vocabulary development. The study employed pre-test/post-test/delayed post-test design. Intermediate adult ESL learners (N = 23) in a community college located in the southwestern United States were categorized into three groups: prompts, recasts, and control. The treatment consisted of a four-step vocabulary activity during which either prompts, recasts, or no feedback was provided. The outcomes were tested using measures based on a three-dimensional L2 vocabulary development model. The findings appear to indicate that prompts and recasts were equally beneficial in the short term and that prompts were slightly more advantageous in the longer term. However, the prompts group was the only one that demonstrated significant increases over time on all three dimensions of vocabulary development as they were operationalized for this study.