bluuebunny/crossref_metadata_2025 huggingface dataset:
The idea of a gradient index intraocular lens (IOL)
Authors: Siedlecki Damian , Pierscionek Barbara K.
Published: August 2010

Aim:  The usual treatment of an eye affected by cataract is the extraction of the crystalline lens from the capsular bag and replacing it with an artificial implant – an intraocular lens (IOL). Such a procedure usually helps the patient to regain his vision, however its quality is far from perfection. The most important element that affects the quality of vision of such a pseudophakic eye is the spherical aberration (SA) which is significantly higher than the SA of a healthy eye. One of the ways to minimize the SA is to involve the gradient index distribution in the medium of IOL. The aim of this study was to find the optimal radial gradient index distribution and to estimate its image quality.

Methods:  The theoretical model of the eye was used and its crystalline lens was replaced with the radial gradient index medium. The distribution of the refractive index was optimized in order to give the best possible retinal image quality.

Results:  Our theoretical studies showed that the SA of the eye with the Gaussian radial gradient IOL is much lower than the SA of the eye with any other IOL implanted and therefore the image quality is significantly higher.

Conclusions:  The implementation of the gradient index in the IOL implantation minimized the SA of a pseudophakic eye. The parameters of the gradient index distribution can be adjusted using an algorithm to the dimensions of a patient's eye.
Visually evoked potential (VEP) measurement of neural suppression during dynamic accommodation
Authors: Laird S. K. , Mucke S. , Manahilov V. , Strang N. C. , Seidel D.
Published: August 2010

Purpose:  Previous work using psychophysical procedures has found evidence of high spatial frequency suppression during step accommodation responses. In this experiment we use VEPs to provide an objective measure of this suppression.

Method:  VEPs to horizontal sinusoidal gratings were measured in one young subject in both dynamic and static conditions. The gratings were presented for 40 ms on a monitor placed at 1 m. In the dynamic mode the grating was presented at various time intervals over the course of an accommodation response (1–3D). These measures were compared with static VEP measures taken at defocus equivalent points across the accommodation response range.

Results:  The results show VEP amplitudes decreasing with defocus (due to accommodation) in both the static and the dynamic conditions. However, at the time of peak accommodation response acceleration, a decrease in amplitude is seen in the dynamic compared with static condition. The latency of both the dynamic and static recordings increased with the amount of defocus.

Conclusion:  The results support the suggestion that neural high spatial frequency suppression occurs during an accommodation step response.
Cortical suppression during accommodation step responses
Authors: Mucke Sven , Manahilov Velitchko , Strang Niall C. , Seidel Dirk
Published: August 2010

Purpose:  Step changes in accommodation from distance to near take approximately 500 ms, during which time it is uncertain what visual information we perceive. A process of visual suppression seems to occur as we do not notice any blurring. In the present study we examine the visual processing capabilities by measuring contrast sensitivity during accommodation responses.

Methods:  Contrast thresholds were measured for two viewing conditions (dynamic and static) using a 2‐alternative forced‐choice staircase procedure. Sinusoidal [1, 4 cycles per degree (cpd)] and square wave (9 cpd) gratings were presented on a monitor at 1 m for the duration of 26 ms. In the dynamic condition a 2 dioptre (1–3D) far to near accommodation step response (ASR) was induced while contrast threshold measurements were taken every 100 ms after onset of the ASR. Results were compared to measurements taken in the static condition, where steady state accommodation responses were induced for five stimulus distances ranging from 1 m–33 cm.

Results:  We found that contrast sensitivity in the high spatial frequency condition (9 cpd) was significantly reduced in dynamic compared with static conditions. Differences found between the dynamic and static thresholds at low and mid spatial frequencies (1, 4 cpd) were inconsistent.

Conclusion:  The results suggest that the visual system employs high spatial frequency suppression during ASRs in order to minimize blur. These findings support a theory of oculomotor control in which the various oculomotor subsystems have both fast and slow components. The fast component exhibits pre‐programming and suppression of fine spatial detail, while the slow component shows continuous feedback control.
Validation of aberrometry‐based relative peripheral refraction measurements
Authors: Berntsen David A. , Mutti Donald O. , Zadnik Karla
Published: August 2010

Purpose:  To validate aberrometry‐based relative peripheral refraction (RPR) measurements and to examine RPR differences in the nasal and temporal horizontal visual field.

Methods:  Thirty subjects underwent cycloplegia in the right eye. Ten measurements each were made centrally, 30° nasally on the retina and 30° temporally on the retina using the Complete Ophthalmic Analysis System (COAS) aberrometer and the Grand Seiko WR‐5100K autorefractor in random order. A 2‐mm COAS analysis diameter was used to approximate the Grand Seiko autorefractor measurement beam diameter. Nasal and temporal RPR were calculated as the difference between the average nasal or temporal spherical equivalent and the average central spherical equivalent. Repeated measures ANOVAs were used to test for significant differences between the RPR readings of each instrument in each retinal location (nasal or temporal) and to examine refractive error in each direction of gaze for both instruments.

Results:  Central spherical equivalent refractive error as measured by the Grand Seiko autorefractor ranged from +0.63 D to −8.41 D (mean ± S.D. = −2.63 D ± 2.05 D). There were no significant differences between the instruments for RPR measurements (p = 0.34). The nasal RPR was significantly more hyperopic than the temporal RPR (mean ± S.D. = +0.45 D ± 1.04 D, p = 0.02). Spherical equivalent refractive error in all directions of gaze was more myopic with the COAS than with the Grand Seiko autorefractor (mean ± S.D. = −0.41 D ± 0.61 D, p < 0.0001).

Conclusions:  RPR measurements with the COAS are feasible and equivalent to those made with the Grand Seiko autorefractor. The COAS can be used to simultaneously collect RPR and peripheral aberration data. Nasal and temporal RPR measurements were significantly different in our sample.
Tear sample collection using cellulose acetate absorbent filters
Authors: Esmaeelpour Marieh , Cai Jun , Watts Patrick , Boulton Mike , Murphy Paul J.
Published: August 2010

Purpose:  To assess the use of cellulose acetate filter rods as a technique for tear collection.

Method:  The cellulose acetate rod (CR) was compared with the ‘standard’ glass capillary tube (CT), in a series of experiments, to assess: sample collection by collected volume size; the effect of tear stimulation on total tear protein concentration and major tear protein concentrations; and technique invasiveness.

Results:  No difference was found in concentrations for total protein, IgA (secretory immunoglobulin A), lactoferrin and lysozyme (p > 0.05) with no clinically significant increase in serum albumin to show serum leakage. Sample volume was higher for CR (p < 0.005) and sample volume increased for stimulated collection with CR (p = 0.001). Dilution effect of a stimulated sample size was reliably shown only with CR (r = −0.66, p = 0.011). Using bovine albumin standard with CR and CT, a smaller sample volume (p < 0.001) and a higher protein concentration (p < 0.001) were extracted with CR.

Conclusion:  The cellulose rod offers a suitable alternative to the glass CT. It is able to quickly absorb a sample, allowing use for a wide range of sample sizes, while being minimally invasive.
Flipped optical systems
Authors: Harris W. F.
Published: August 2010

In the standard refraction routine, a Jackson cross‐cylinder is reversed in front of the eye by the process of flipping it about its handle. Reverse telescopes have applications in low vision. In ophthalmoscopy, the practitioner views a patient's retina using light that traverses the eye in a direction opposite to that involved in vision. These represent examples of flipped systems that are involved in optometry. The purpose of this paper is to examine what happens to the optical character of an arbitrary optical system when it is flipped in this manner. The analysis is in terms of the ray transference of the system and, because the transference completely characterises the first‐order optics of a system, is complete within the limitations of linear optics. It allows for elements in the system to be astigmatic and decentred. An expression is derived for the transference of the flipped system in terms of the transference of the system itself. Expressions are also obtained for the fundamental first‐order optical properties and the dioptric power of the flipped system. Three numerical examples are given in the Appendix.
Temporal trends in bromide release following rewetting of a naturally drained gully mire
Authors: Hughes S. , Reynolds B. , Brittain S. A. , Hudson J. A. , Freeman C.
Published: August 2010

Abstract. Recently, there has been interest in the occurrence of bromide (Br‐) in natural waters since it has been demonstrated that Br‐, in association with humic substances in raw waters, is readily incorporated into haloacetic acids in the form of organically bound bromine (Br) during water chlorination. We report results of the effects of experimentally rewetting a naturally drained gully mire on the hydrochemistry of Br‐, iron (Fe) and dissolved organic carbon (DOC) in the peat water. Results obtained over a three year period showed that rewetting substantially increased the concentrations of these solutes in the pore water, with peak values of 1 mg dm‐3 (Br‐), > 60 mg dm‐3 (Fe) and > 300 mg dm‐3 (DOC) detected in some samples after rewetting, compared with typical values < 0.05 mg dm‐3 (Br‐), < 1 mg dm‐3 (Fe) and < 15 mg dm‐3 (DOC) under the drained conditions. Bromide, Fe and DOC release were highly seasonal, with the largest concentrations observed in late‐summer to autumn. However, whereas seasonal peak concentrations of Fe and DOC have since remained at these higher levels, seasonal peak concentrations of Br‐ were progressively attenuated over time, suggesting the latter phenomenon is a flush effect, with no longer‐term consequences for water quality.
Interpreting pH and nitrate concentration in solutions drained from acid soils. Possible artefacts of lysimeters
Authors: Rufyikiri G. , Dufey J.E. , Hennebert P.A.
Published: August 2010

Abstract. Solutions collected from lysimeters of acid soils can show pH values close to or even above neutral. Laboratory experiments on an acid soil from Burundi were planned to test if denitrification or CO2 degassing might explain such a paradox. In the first experiment, soil profiles were reconstituted in columns and leached with 55 μm Ca(NO3)2 solutions at 30 °C and 4 °C. Two drainage regimes were applied: intermittent suction or no suction at the bottom of the columns. In the second experiment, pH values were measured in solutions drained from different horizons at 30 °C, before and after equilibration with ambient air. Sterilized soil was also tested in the same way. Results from experiment 1 showed that despite the accumulation of water in the bottom of soil profiles when no suction was applied, aeration still existed so that reduction reactions, namely denitrification, are not expected to affect greatly the percolate composition. Indeed nitrate concentration was similar in both drainage regimes and was close to the input value. The pH values in percolates were close to 7 at 30 °C and they dropped to about 5.5 when the columns were at 4 °C. In experiment 2, equilibration of percolates with ambient air resulted in pH increase which was greater for the top horizon (C‐rich) but negligible when the soil was first sterilized. These convergent results illustrate the very important effect of CO2 degassing on pH of drained solutions when microbial activity is stimulated at high temperatures, in C‐rich soil. This is of prime importance when interpreting results from lysimeter experiments. By chance, this study also showed that large quantities of nitrate can be produced in soil at low temperatures.
Nitrous oxide emission from soils after incorporating crop residues
Authors: Baggs E.M. , Rees R.M. , Smith K.A. , Vinten A.J.A.
Published: August 2010

Abstract. Emissions of N2O were measured from different agricultural systems in SE Scotland. N2O emissions increased temporarily after fertilization of arable crops, cultivation of bare soil, ploughing up of grassland and incorporation of arable and horticultural crop residues, but the effect was short‐lived. Most of the emission occurred during the first two weeks, returning to ‘background’ levels after 30–40 days. The highest flux was from N‐rich lettuce residues, 1100 g N2O‐N ha−1 being emitted over the first 14 days after incorporation by rotary tillage. The magnitude and pattern of emissions was strongly influenced by rainfall, soil mineral N, cultivation technique and C∶N ratio of the residue. Comparatively large emissions were measured after incorporation of material with low C∶N ratios. Management practices are recommended that would increase N‐use efficiency and reduce N2O emissions from agricultural soils.
Porosity and soil water properties of Caribbean volcanic ash soils
Authors: Dorel M. , Roger‐Estrade J. , Manichon H. , Delvaux B.
Published: August 2010

Abstract. Volcanic ash soils are generally recognized as soils with excellent and stable physical properties. Here we characterized the porosity and water properties of volcanic ash Andosols and Nitisols from Guadeloupe in contrasting banana systems: (1) perennial crop without mechanization, (2) mechanized and regularly replanted crop. Desiccation from 1 kPa to 1550 kPa moisture tension leads to significant shrinkage in the Andosol, representing a 50% reduction of the void space. The clayey Nitisol exhibited limited shrinkage. Soil clods from the mechanized plots had a significantly smaller macroporosity than that from perennial plots. The soil hydraulic conductivity was also drastically reduced in the compacted layers of the mechanized plots. However, Nitisols appeared to be less affected than Andosols. Laboratory compression tests showed that both soils were susceptible to compaction at soil moisture close to field capacity. The shrinkage properties of the Andosol were due to microaggregation of non‐crystalline components upon drying. The relative stability of the macroporosity in the Nitisol was probably related to the presence of stable microaggregates made of halloysite and iron oxide. Two major processes promote soil structure degradation in the Andosol under mechanized banana cropping, surface desiccation and soil compaction. They are both induced by repeated tillage after clearing.
A survey of the production and use of animal manures in England and Wales. III. Cattle manures
Authors: Smith K.A. , Brewer A.J. , Crabb J. , Dauven A.
Published: August 2010

Abstract. A survey of cattle manure management was undertaken in England and Wales, in 1997, by postal questionnaire sent out to a stratified sample (by unit size) of 1750 dairy and 1750 beef producers. The level of response obtained, with 471 dairy farmers (27%) and 515 beef farmers (29%) returning questionnaires, reflects well on the interest shown by the industry and on the survey design. The survey provided information on manure production and storage, when and how applied and nutrient value. Dairy farms are estimated to produce manures in the form of c. 65% slurry and 35% farmyard manures (FYM) and, beef units, 80%FYM and 20%slurry (based on survey response data, animal numbers and calculations of undiluted outputs of excreta). Slurry storage within both dairy and beef systems is typically up to 3–6 months capacity, although there is no storage for an estimated 16% of dairy and 25% of beef slurry. Autumn and winter spreading is common practice, with 40–50% of slurry and 50–60% of FYM applied at that time. Although some evidence suggests that farmers make little allowance for the nutrient content of manures in planning fertilizer inputs, the results of this survey suggest that many farmers do make some effort to utilize manure nutrients. However, they currently fail to be assured by the advice available to them or they lack confidence in manures as nutrient sources for a number of technical reasons. Information provided by the survey may be important to policy makers, researchers and consultants, as well as farmers.
Removal of rock fragments and its effect on soil loss and crop yield, Tigray, Ethiopia
Authors: Nyssen J. , Haile Mitiku , Poesen J. , Deckers J. , Moeyersons J.
Published: August 2010

Abstract. When the farmers of the Highlands of Tigray (northern Ethiopia) consider rock fragment cover in their fields to be excessive, they remove some of them. In addition, large amounts of rock fragments of all sizes are removed from fields for building stone bunds. Semi‐structured interviews indicate that the farmers are often reluctant to take away the smaller rock fragments (i.e. < 5 cm across) from their fields, since they believe these benefit soil moisture conservation and protect topsoil from erosion. A field experiment was carried out on a Vertic Cambisol (average slope: 0.125 m m–1), 2 km east of Hagere Selam (subhumid climate). Rock fragments were totally, partially or not removed from the 12 runoff plots (5 m × 6 m) before the beginning of the 1999 cropping season, during which a local mixture of wheat varieties (Triticum spp.) was sown. After harvest, erosion rates were assessed by measuring deposited sediment volume in trenches at the lower side of each subplot, and grain and straw yields were assessed. We found a significant negative relationship between rock fragment cover and soil loss by water erosion. However, the resulting positive relationship between rock fragment cover and grain and straw yield was weak. This might be explained by the fact that the plot did not suffer from drought due to soil and climatic conditions. Detailed analysis showed that cover by medium and large rock fragments (> 2 cm diameter) showed an optimum percentage cover above which crop yields decrease. A recommendation resulting from this study is to rely on the farmers’ experience: smaller rock fragments should never be removed from the surface of fields during soil and water conservation works; instead rock fragment rich soil can be used to top the stone bunds.
Simulating nitrate leaching under crops fertilized with pig slurry in lysimeters
Authors: Marchetti R. , Ponzoni G. , Spallacci P.
Published: August 2010

Abstract. Regions in the Po Valley, Northern Italy, are characterized by intensive crop‐livestock farming systems. A simulation model has been chosen for an inter‐regional project, which should help in defining groundwater vulnerability and pollution risk on a regional scale, in relation to agricultural land use, by allowing the prediction of nitrate leaching under different climate, soil, crop and management scenarios. The model derives from the coupling of a hydrological model, MACRO, simulating water flow and solute transport in structured soils, with a model simulating soil N dynamics, SOILN. The aim of this work was to test the model's ability to simulate nitrate leaching through soil after land spreading of pig slurries. A dataset obtained from lysimeter experiments which had been carried out in the period 1976–1981 was used for this purpose. Four soil types were compared (silty clay, sandy loam, loam and sand) in factorial combination with four rates of pig slurry (0, 142, 284, 426 g of N m–2, accumulated values from 1976 to 1979) for a seven crop sequence. The efficiency of the MACRO model ranged from 0.96, in the sandy‐loam soil, to 0.81, in the sand. Percolation was usually under‐estimated, the relative error ranging from 0.7 to 14.6, depending on the soil. The low efficiency of the SOILN model in simulating nitrate leaching is attributed to the lack of knowledge of the mechanisms regulating N transformation processes and especially the mineralization of pig slurry N. This lack of knowledge hampers the correct setting of the N transformation parameter values. A remarkable improvement of the model's performance was obtained by changing a few coefficients which control the mineralization‐immobilization turnover of the faeces‐organic N. The model efficiency, following this recalibration, ranged from –0.62 to 0.84, and the relative error ranged from –56 to 35, depending on soil and treatment. N leaching was under‐estimated at the low pig slurry N application rates and over‐estimated at the high ones.
Impact of land use changes on the hydrological properties of volcanic ash soils in South Ecuador
Authors: Buytaert W. , Deckers J. , Dercon G. , de Bièvre B. , Poesen J. , Govers G.
Published: August 2010

Abstract. The effect of land use on the water retention capacity of Umbric Andosols in south Ecuador was studied. The objective was to acquire a better insight into the hydrological processes of the ecosystem and the role of the soil, in order to assess the impact of changing soil properties due to land use change on the hydrology of the high Andes region. Field data on the water retention capacity at wilting point of Umbric Andosols were collected for both cultivated field conditions and original bush vegetation. The pH in water and in NaF, texture, organic matter content and dry bulk density were measured to show which physicochemical soil characteristics are responsible for the water retention of the Umbric Andosols and for the irreversible loss in water retention due to air drying. Organic matter content appears to be very important and certainly more important than allophane clay content. Water retention of the organic litter layer was calculated to be 16 mm, this would be lost when vegetation was cleared and the land cultivated.
Amelioration of calcareous saline sodic soils through phytoremediation and chemical strategies
Authors: Qadir M. , Qureshi R.H. , Ahmad N.
Published: August 2010

Abstract. The worldwide occurrence of saline sodic and sodic soils on more than half a billion hectares warrants attention for their efficient, inexpensive and environmentally acceptable management. These soils can be ameliorated by providing a source of calcium (Ca2+) to replace excess sodium (Na+) from the cation exchange sites. Although chemical amendments have long been used to ameliorate such soils, the chemical process has become costly during the last two decades in several developing countries. As a low‐cost and environmentally acceptable strategy, the cultivation of certain salt tolerant forage species on calcareous sodic and saline sodic soils, i.e. phytoremediation, has gained interest among scientists and farmers in recent years. In a field study conducted at three calcareous saline sodic sites (pHs=8.1–8.8, ECe=7.8–12.5 dS m–1, SAR=30.6–76.1) in the Indus Plains of Pakistan, we compared chemical and phytoremediation methods. There were four treatments; two involved plants: Kallar grass (Leptochloa fusca (L.) Kunth), and sesbania (Sesbania bispinosa (Jacq.) W. Wight). The other two treatments were uncropped: soil application of gypsum and an untreated control. All treatments were irrigated with canal water (EC=0.22–0.28 dS m–1). The plant species were grown for one season (5–6 months). Sesbania produced more forage yield (34 t ha–1) than Kallar grass (23 t ha–1). Phytoremediation and chemical treatments resulted in similar decreases in soil salinity and sodicity, indicating that phytoremediation may replace or supplement the more costly chemical approach. The soil amelioration potential of sesbania was similar to that of the Kallar grass, which suggests that moderately saline sodic calcareous soils can be improved by growing a forage legume with market value.
Long‐term changes in soil organic matter under conventional tillage and no‐tillage systems in semiarid Morocco
Authors: Bessam F. , Mrabet R.
Published: August 2010

Abstract. A no‐tillage (NT) system was developed in semiarid Morocco to improve the soil fertility and stabilize yield through conservation of water. Results in two long‐term trials (4 and 11 years) were able to show the effects of a no‐tillage system in increasing total soil organic matter and total nitrogen. Over time, the quality of the NT soil surface was improved compared with that under conventional tillage (CT) with disc harrows. This effect was the result of an increase in soil organic carbon (SOC) and a slight decline in pH. However, over time, nitrogen decreased in both tillage practices, especially in the 0–25 mm layer (from 0.59 to 0.57 t ha−1 and from 0.44 to 0.42 t ha−1 under NT and CT, respectively). After 4 years of NT an extra 5.62 t ha−1 of SOC was sequestered in the 0–25 mm layer, and after 11 years the SOC increased further to 7.21 t ha−1.
Impacts of land management on fluxes of trace greenhouse gases
Authors: Smith K. A. , Conen F.
Published: August 2010

Abstract. Land use change and land management practices affect the net emissions of the trace gases methane (CH4) and nitrous oxide (N2O), as well as carbon sources and sinks. Changes in CH4 and N2O emissions can substantially alter the overall greenhouse gas balance of a system. Drainage of peatlands for agriculture or forestry generally increases N2O emission as well as that of CO2, but also decreases CH4 emission. Intermittent drainage or late flooding of rice paddies can greatly diminish the seasonal emission of CH4 compared with continuous flooding. Changes in N2O emissions following land use change from forest or grassland to agriculture vary between climatic zones, and the net impact varies with time. In many soils, the increase in carbon sequestration by adopting no‐till systems may be largely negated by associated increases in N2O emission. The promotion of carbon credits for the no‐till system before we have better quantification of its net greenhouse gas balance is naïve. Applying nitrogen fertilizers to forests could increase the forest carbon sink, but may be accompanied by a net increase in N2O; conversely, adding lime to acid forest soils can decrease the N2O emission.
An approach for estimating when soils will reach maximum nitrogen storage
Authors: Schipper L.A. , Percival H.J. , Sparling G.P.
Published: August 2010

Abstract. Net accumulation of organic nitrogen in soil is constrained by the amount of organic matter and its minimum C:N ratio. Our objective was to estimate the potential for New Zealand soils to continue accumulating nitrogen within the soil organic pool. We calculated total carbon and nitrogen in the top metre of 138 representative soil profiles from the New Zealand National Soils Database. Carbon in these mainly pasture soils was assumed to be at steady state. The maximum nitrogen storage capacity was estimated by calculating the amount of nitrogen stored under assumed minimum soil C:N ratios of either 9, 10 or 11. The storage capacity remaining was determined as the difference between the amount of nitrogen currently stored and the maximum storage capacity. The length of time before a soil profile will reach the maximum capacity for nitrogen storage was calculated assuming net accumulation of 20, 50 and 100 kg N ha−1 yr−1. A C:N ratio of 9 (giving most storage capacity) and a conservative accumulation rate of 20 kg N ha−1 yr−1 showed that 12% of these soils would be at maximum storage within 40 years. A C:N ratio of 10 and a storage rate of 50 kg N ha−1 yr−1 would result in 54% of the soils reaching maximum storage within the next 40 years. As the capacity for nitrogen storage in soils declines, nitrate leaching is likely to increase with associated risk to the environment.
Potassium balances for arable soils in southern England 1986–1999
Authors: Heming S.D.
Published: August 2010

Abstract. The behaviour of potassium (K) in a range of arable soils was examined by plotting the change in exchangeable K of the topsoil (Δ Kex) at the end of a 3–5 year period against the K balance over the same period (fertilizer K applied minus offtake in crops, estimated from farmers' records of yield and straw removal). Based on the assumption that values for offtake per tonne of crop yield used for UK arable crops MAFF 2000) are valid averages, 10–50% of Δ Kex was explained by the balance, relationships being stronger on shallow/stony soils. Excess fertilizer tended to increase Kex and reduced fertilization decreased it, requiring between 1.2 and 5.4 kg K ha−1 for each mg L−1Δ Kex. However, merely to prevent Kex falling required an extra 20 kg K ha−1 yr−1 fertilizer on Chalk soils and soils formed in the overlying Tertiary and Quaternary deposits, despite clay contents >18%. Whereas, on older geological materials, medium soils needed no extra K and clays gained 17 kg K ha−1 yr−1. It is unlikely that the apparent losses on some soil types are anomalies due to greater crop K contents. Theory and the literature suggest leaching from the topsoil as a major factor; accumulation in the subsoil was not measured. Recommendations for K fertilization of UK soils might be improved by including loss or gain corrections for certain soil types.
A review of nitrogen fertilizer and conservation tillage effects on soil organic carbon storage
Authors: Alvarez R.
Published: August 2010

Abstract. The effects of nitrogen fertilizer and tillage systems on soil organic carbon (SOC) storage have been tested in many field experiments worldwide. The published results of this research are here compiled for evaluation of the impact of management practices on carbon sequestration. Paired data from 137 sites with varying nitrogen rates and 161 sites with contrasting tillage systems were included. Nitrogen fertilizer increased SOC but only when crop residues were returned to the soil; a multiple regression model accounted for just over half the variance (R2=0.56, P=0.001). The model included as independent variables: cumulative nitrogen fertilizer rate; rainfall; temperature; soil texture; and a cropping intensity index, calculated as a combination of the number of crops per year and percentage of corn in the rotation. Carbon sequestration increased as more nitrogen was applied to the system, and as rainfall or cropping intensity increased. At sites with higher mean temperatures and also in fine textured soils, carbon sequestration decreased. When the carbon costs of production, transportation and application of fertilizer are subtracted from the carbon sequestration predicted by the model, it appears that nitrogen fertilizer‐use in tropical regions results in no additional carbon sequestration, whereas in temperate climates, it appears to promote net carbon sequestration. No differences in SOC were found between reduced till (chisel, disc, and sweep till) and no‐till, whereas conventional tillage (mouldboard plough, disc plough) was associated with less SOC. The accumulation of SOC under conservation tillage (reduced and no till) was an S‐shape time dependent process, which reached a steady state after 25–30 years, but this relationship only accounted for 26% of the variance. Averaging out SOC differences in all the experiments under conservation tillage, there was an increase of 2.1 t C ha−1 over ploughing. However, when only those cases that had apparently reached equilibrium were included (all no till vs. conventional tillage comparisons from temperate regions), mean SOC increased by approximately 12 t C ha−1. This estimate is larger than others previously reported. Carbon sequestration under conservation tillage was not significantly related to climate, soil texture or rotation.
Insulin resistance and hepatitis C virus: a case–control study of non‐obese, non‐alcoholic and non‐steatotic hepatitis virus carriers with persistently normal serum aminotransferase
Authors: Tanaka Naoki , Nagaya Tadanobu , Komatsu Michiharu , Horiuchi Akira , Tsuruta Goro , Shirakawa Haruaki , Umemura Takeji , Ichijo Tetsuya , Matsumoto Akihiro , Yoshizawa Kaname , Aoyama Toshifumi , Kiyosawa Kendo , Tanaka Eiji
Published: August 2010

Background/Aims: Recent studies using transgenic mouse models have demonstrated that the presence of hepatitis C virus (HCV) singularly induces insulin resistance (IR). When evaluated in humans, the exclusion of other factors influencing IR, such as obesity, alcohol intake, hepatic inflammation and steatosis is needed, but only few studies have been performed to these ends. Therefore, we aimed at exploring the singular effects of HCV on glucose metabolism through analysis of HCV carriers with persistently normal serum aminotransferase.

Methods: Non‐obese, non‐diabetic and non‐alcoholic HCV carriers (n=30) were enrolled with 30 hepatitis B virus carriers matched by age, gender, body mass index and waist‐to‐hip ratio. All patients maintained normal serum aminotransferase (<30 U/L), hyaluronic acid (<50 ng/ml) and platelet count (>150 × 103/μl) for more than 5 years without additional treatments, and had no signs of steatosis. We then compared fasting plasma glucose, serum insulin and adiponectin, and homoeostasis model assessment of IR (HOMA‐IR) and HOMA‐β indices between the groups.

Results: There were no significant differences in IR/secretion‐associated markers or serum adiponectin. Multivariate analysis demonstrated that the presence of HCV was not an independent predictor of IR. HOMA‐IR was strongly correlated with waist circumferences and serum γ‐glutamyltransferase in HCV carriers, but not with serum aminotransferase, high‐sensitivity C‐reactive protein, hyaluronic acid or HCV core antigen.

Conclusions: These results suggest that the presence of HCV alone does not affect IR. Coexistence of hepatitis, steatosis and/or fibrosis may be important to the pathogenesis of IR induced by chronic HCV infection.
Role of cortical dysplasia in epileptogenesis following prolonged febrile seizure
Authors: Park Kyung‐Il , Chu Kon , Jung Keun‐Hwa , Kim Jin‐Hee , Kang Kyung‐Muk , Lee Soon‐Tae , Park Hee‐Kwon , Kim Manho , Lee Sang Kun , Roh Jae‐Kyu
Published: August 2010

Purpose:  Hippocampal sclerosis, characterized by prominent neuronal loss and reactive gliosis, is the most common pathology in human temporal lobe epilepsy (TLE). Although prolonged febrile convulsion (FC) is a risk factor of TLE, it is not clear whether FC provokes hippocampal sclerosis and subsequent TLE. Given that underlying brain lesions, such as cortical dysplasia (CD), in the immature brain predispose patients to FC, CD may link FC and TLE. However, the role of CD in epileptogenesis after FC is also unclear. Here, we investigated whether inborn CD increases the risk of later epilepsy induced by prolonged FC using a rat model.

Methods:  Experimental CD was induced by in utero exposure of methylazoxymethanol (MAM). Rat pups from MAM‐treated or control rats were then subjected to prolonged FC. We examined morphologic changes in the hippocampi with respect to neuronal loss, reactive gliosis, and synaptogenesis, and evaluated spontaneous recurrent seizures (SRS) by long‐term video‐EEG (electroencephalography).

Results:  The MAM+FC group had a significantly lower hippocampal neuronal density in the CA1 and dentate hilus than other control groups. A robust increase in glial cells and synaptic reorganization was also detected in the MAM+FC groups. Furthermore, later SRS occurred in all rats in the MAM+FC group and in 50% and 25% of the rats in the FC‐only and MAM‐only group, respectively. The frequency and total duration of SRS was highest in the MAM+FC group.

Discussion:  Our results suggest that preexisting CD in the immature brain augments the proepileptogenic effects of prolonged FC, leading to TLE.
Mixed Red Cell Populations
Authors: Huestis Douglas W.
Published: August 2010

Letters to be considered for publication should be sent to D.W. Huestis, The University of Arizona, Arizona Health Sciences Center, Clinical Pathology Department, Tucson, Arizona 85724. Two copies of clearly typed (double‐spaced) manuscript are required. Authors are requested to submit manuscripts consistent in style and format with letters published in this Journal.
Transfusion Classics
Authors: Oberman Harold A.
Published: August 2010

Dr. Croone told me, that at the meeting of Gresham College tonight, which it seems they now have every Wednesday, there was a pretty experiment of the blood of one dog let out till he died, into the body of another on one side, while all his own run out on the other side. The first died upon the place, and the other very well and likely to do well. This did give occasion to many pretty wishes, as of the blood of a Quaker to be let into an Archbishop, and such like; but, as Dr. Croone says, may, if it takes, be of mighty use to man's health, for the amending of bad blood by borrowing from a better body.
A randomized crossover trial comparing three plateletpheresis machines
Authors: Bueno José Luis , García Fernando , Castro Emma , Barea Luisa , González Rocío
Published: August 2010

BACKGROUND: The aim of the study was to compare three different apheresis machines with the same donors regarding the processing time required to obtain a 3.5 × 1011 platelet (PLT) dose and acceptance by donors.

STUDY DESIGN AND METHODS: A randomized crossover trial was performed to evaluate the differences between the Amicus Crescendo (Baxter Biotech Corp.), the MCS Plus (Haemonetics Corp.), and the Trima Accel (Gambro BCT). Donations from 51 donors were compared for time adjusted to obtain a standard 3.5 × 1011 PLT dose (TSD3.5), efficiency, adverse reactions, yield, leukodepletion, machine accuracy, and donor preferences. Processing times were measured by chronometer. The same vein access was used during all three processes in each donor. In the statistical analysis, to take into account the nonindependence of several measurements from the same donor, generalized estimating equations were used with an autoregressive correlation matrix.

RESULTS: The Accel produced a TSD3.5 (mean ± SEM) of 47.9 ± 1.0 min; the Amicus, 60.3 ± 1.0 min; and the MCS Plus, 66.7 ± 1.0 (p < 0.0001). The Amicus presented the greatest efficiency (87.5%; p < 0.0028). The MCS Plus demonstrated the highest capacity for leukodepletion (p < 0.0002) despite one process presenting more than 1 × 106 white blood cells per unit. The MCS Plus also measured the processing time with the greatest accuracy. No severe adverse effects were observed. The donors preferred the Accel (61%) followed by the Amicus (35%) and the MCS Plus (4%; p < 0.0001) and the processing speed was the most highly valued measure (55%).

CONCLUSIONS: The Accel is the fastest and, because of this advantage, the machine preferred by donors. The Amicus was the most efficient and the MCS Plus was the only one not to underestimate the processing time.
Fresh frozen plasma prepared with amotosalen HCl (S‐59) photochemical pathogen inactivation: transfusion of patients with congenital coagulation factor deficiencies
Authors: De Alarcon Pedro , Benjamin Richard , Dugdale Marion , Kessler Craig , Shopnick Rinah , Smith Peter , Abshire Thomas , Hambleton Julie , Matthew Prasad , Ortiz Idith , Cohen Alice , Konkle Barbara A. , Streiff Michael , Lee Martin , Wages David , Corash Laurence
Published: August 2010

BACKGROUND: Photochemical treatment (PCT) with amotosalen HCl (S‐59) was developed to inactivate pathogens and white blood cells in plasma (PCT‐FFP) used for transfusion support.

STUDY DESIGN AND METHODS: An open‐label, multicenter trial was conducted in patients with congenital coagulation factor deficiencies (factors [F]I, FII, FV, FVII, FX, FXI, and FXIII and protein C) to measure the kinetics of specific coagulation factors, hemostatic efficacy, and safety of PCT‐FFP. Posttransfusion prothrombin time (PT), partial thromboplastin time (PTT), and clinical hemostasis were evaluated before and after PCT‐FFP transfusions.

RESULTS: Thirty‐four patients received 107 transfusions of PCT‐FFP for kinetic studies or therapeutic indications (mean dose, 12.8 ± 8.5 mL/kg). Incremental factor recoveries ranged from 0.9 to 2.4 IU per dL per IU per kg (FII, FV, FVII, FX, FXI, and protein C). Mean pretransfusion PT (20.7 ± 22.2 sec) corrected after PCT‐FFP (13.8 ± 2.4 sec, p < 0.001). Mean pretransfusion PTT (51.2 ± 29.3 sec) corrected after PCT‐FFP (32.0 ± 5.1 sec, p < 0.001). Thirteen patients required 77 transfusions for therapeutic indications. PCT‐FFP provided effective hemostasis and was well tolerated.

CONCLUSIONS: Replacement coagulation factors in PCT‐FFP exhibited kinetics and therapeutic efficacy consistent with conventional FFP.
Anti‐D and anti‐i activities are inseparable in V4‐34‐encoded monoclonal anti‐D: the same framework 1 residues are required for both reactivities
Authors: Thorpe Susan J. , Ball Christine , Fox Bernard , Thompson Keith M. , Thorpe Robin , Bristow Adrian
Published: August 2010

BACKGROUND: The heavy‐chain V4‐34 germline gene segment is mandatory for pathologic cold‐reacting autoantibodies with anti‐I/i specificity (cold agglutinins) and is also preferentially used by monoclonal immunoglobulin M alloantibodies against D and other Rh antigens. The use of the V4‐34 segment by monoclonal anti‐D has previously been shown to also confer anti‐I/i reactivity (cold agglutinin activity), which has implications for the use of such antibodies for Rh blood typing. V4‐34 framework 1 (FR1) sequence is believed to be critical for cold agglutinin activity of cold agglutinins.

STUDY DESIGN AND METHODS: The aim of this investigation was to use site‐directed mutagenesis of a recombinant V4‐34‐encoded anti‐D to determine the contribution of V4‐34 FR1 sequence to anti‐D activity and whether mutational modifications in the FR1 region could separately alter anti‐D and anti‐i activities.

RESULTS: The results show that amino acid changes in V4‐34 FR1 at W7, A23, and Y25 have a profound effect on anti‐D activity as well as on anti‐i activity. It was not possible to substantially reduce or remove anti‐i activity without reducing anti‐D activity to a comparable extent.

CONCLUSIONS: The same nonpolar hydrophobic amino acids in FR1 are critical for maintaining both anti‐D and anti‐i activity. It is proposed that these residues influence the conformation of the antigen‐binding site.
Chromatography of Food Dyes: A Simple Demonstration for Actively Engaging High School Students in the Chemistry of Foods
Authors: Chism Grady W.
Published: August 2010

ABSTRACT: A simple demonstration of the chromatography of food dyes suitable for high school students is presented. Reversed phase mini‐columns are utilized to separate dyes in grape and lime drinks. The exercise introduces chromatography and reinforces the concept of polarity. It has been successfully used to actively engage students for periods of 30 to 60 min.
A Model for Developing and Testing Custom‐Made Laboratory Manuals to Use with Food Chemistry and Food Analysis Courses
Authors: Bell L.N. , Hsieh Y‐H.P.
Published: August 2010

ABSTRACT: This project reports on a model for preparing food chemistry and food analysis laboratory manuals that provide a closer link between lecture material and laboratory exercises. Teaching effectiveness was also improved by evaluating the composition and eliminating duplication between these complementary courses. Utilizing the combination of personal experience and the scientific literature, laboratory exercises were developed and modified to fit with the lecture material. Labs were initially performed and critiqued by a graduate student. After making appropriate revisions, undergraduate students tested the labs under the graduate student's supervision and completed a questionnaire about their experiences. Based on the undergraduate feed‐back, final revisions were made and custom laboratory manuals were printed. This project demonstrates one effective way for developing custom food science labs to parallel with lecture material.
Integration of Team‐Building Skills into Food Chemistry Team Research Projects
Authors: Boylston T.D. , Wang T.
Published: August 2010

ABSTRACT: As professionals, food scientists are expected to communicate effectively in interpersonal and team contexts. The objective of this study was to evaluate the impact of structured teambuilding activities on the development of interpersonal and team‐work skills through team research projects in a food chemistry course. Team‐building skills and the assessment of team performance were integrated into team research projects for a food chemistry course. Through these activities, teams exhibited the characteristics of effective teams. Students recognized that the development of good teamwork and communication skills are important for their future careers.
National Science Foundation Graduate Teaching Fellows Promote Food Science Education in K‐12 Schools in Maine
Authors: Calder B. , Brawley S.H. , Bagley M.
Published: August 2010

ABSTRACT: The Univ. of Maine is participating in the National Science Foundation's (NSF) GK‐12 Teaching Fellows program. Between 2000 and 2003, 4 food science graduate students demonstrated food‐ and nutrition‐related science lessons, among other innovative activities. This article includes details of an activity on natural dyes to help students understand plant pigments. Assessment of the NSF GK‐12 program is ongoing both locally and nationally. NSF's goals are being met, including one of the most important, which is the effect of NSF Fellows as role models on K‐12 students.
Phytochemicals in Fruits and Vegetables: Use of Interactive Videoconferencing and the World Wide Web for Teaching a Multidisciplinary Course
Authors: Patil B.S. , Lineberger R. Daniel , Dooley Kim E. , Vanamala Jairam
Published: August 2010

ABSTRACT: An evaluation of interactive video conferencing and Web‐assisted instruction to deliver a multidisciplinary course entitled Phytochemicals in Fruits and Vegetables to Improve Human Health was conducted during the spring semesters of 1999 and 2001. This course was taught by 20 instructors from 11 institutions to 49 students during spring 2001, which was an increase of 53% over spring 1999. Weekly 3‐h lectures were delivered by the Trans‐Texas Videoconference Network integrated with PowerPoint® or HTML slides available on the course Web site (http://phytochemicals.tamu.edu). Qualitative and quantitative data were collected through formative and summative methods. Participants expressed their satisfaction with course format and the need for technical support for interactive videoconferencing.
Identifying the Learning Styles and Instructional Tool Preferences of Beginning Food Science and Human Nutrition Majors
Authors: Bohn D.M. , Rasmussen C.N. , Schmidt S.J.
Published: August 2010

ABSTRACT: :

Learning styles vary among individuals, and understanding which instructional tools certain learning styles prefer can be utilized to enhance student learning. Students in the introductory Food Science and Human Nutrition course (FSHN 101), taught at the Univ. of Illinois at Urbana‐Champaign, were asked to complete Gregorc's Learning Style DelineatorTM, which identifies dominant learning style(s). In addition, students were asked to complete a survey that asked them to identify which instructional tools used in FSHN 101 they preferred and which they did not. All students, regardless of learning style, preferred the in‐class lecture, outlined lecture notes, the WebCT site as a whole, lecture study guide questions, and example exam questions.
PASSIVE ÜBERFÜHRUNG VON IDIOSYNKRASIE
Authors: BAAGØE K. H.
Published: August 2010

Von 7 Versuchen, die Idiosynkrasie von Asthmatikern mit positiver Kutanreaktion auf den betreffenden Stoff auf Tiere zu übertragen, gelang nur ein Versuch (Übertragung von Fischidiosynkrasie).

Von 14 Versuchen, Idiosynkrasie von 6 Asthmatikern mit positiver Kutanreaktion auf gesunde Menschenhaut zu übertragen, gelangen 8, während 6 ein negatives oder ein zweifelhaftes Resultat ergaben. Ebenfalls erhielt man einen negativen Ausfall bei 2 Fällen mit Injektion von Serum von »normalen« Kindern mit positiver Kutanreaktion aber ohne klinische Idiosynkrasie.