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Summary The ‘substantial equivalence’ of three transgenic wheats expressing additional highmolecular-weight subunit genes and the corresponding parental lines (two lines plus a null transformant) was examined using metabolite profiling of samples grown in replicate field trials on two UK sites (Rothamsted, Hertfordshire and Long Ashton, near Bristol) for 3 years. Multivariate comparison of the proton nuclear magnetic resonance spectra of polar metabolites extracted with deuterated methanol–water showed a stronger influence of site and year than of genotype. Nevertheless, some separation between the transgenic and parental lines was observed, notably between the transgenic line B73-6-1 (which had the highest level of transgene expression) and its parental line L88-6. Comparison of the spectra showed that this separation resulted from increased levels of maltose and/or sucrose in this transgenic line, and that differences in free amino acids were also apparent. More detailed studies of the amino acid composition of material grown in 2000 were carried out using gas chromatography-mass spectrometry. The most noticeable difference was that the samples grown at Rothamsted consistently contained larger amounts of acidic amino acids (glutamic, aspartic) and their amides (glutamine, asparagine). In addition, the related lines, L88-6 and B73-6-1, both contained larger amounts of proline and γ -aminobutyric acid when grown at Long Ashton than at Rothamsted. The results clearly demonstrate that the environment affects the metabolome and that any differences between the control and transgenic lines are generally within the same range as the differences observed between the control lines grown on different sites and in different years.

Leaf, fruit, stem, bark and root of Zanthoxylum americanum were investigated for antifungal activity with 11 strains of fungi representing diverse opportunistic and systemic pathogens, including Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. All extracts demonstrated a broad spectrum of antifungal activity and inhibited at least eight fungal species in a disk diffusion assay (600 microg/disk). Antifungal activity was light-dependent, with fruit and leaf extracts most active in general. The presence of light-mediated compounds, such as psoralen, 8-methoxypsoralen and imperatorin in extracts of different organs was confirmed by RP-HPLC. A high furanocoumarin content was detected in fruit and leaf and low furanocoumarin levels were found in bark and wood. A high positive correlation was observed between total furanocoumarin content and fungal inhibition zones (r2=0.902, p0.001). The results provide a phytochemical basis for the very widespread use of Z. americanum in indigenous North American ethnomedical tradition for conditions that may be related to fungal infections.

Professor Jourdan has chosen a poor target for her critique of sign regulation. Every article, book, or message is written with an expected audience in mind. Professor Daniel Mandelker's work is no exception. That audience includes, among others,planners and lawyers who want the land use regulations they craft to regulate in a constitutional way. Writing a book or article that considers the needs of an important segment of his likely audience should not be troubling. That is not a “fundamental problem “that reflects a “belief that a municipality is obligated to undertake the regulation of signage in the interests of the general public health, safety, and welfare. “

Maintaining crop production levels with reductions in terrestrial greenhouse gases requires strategic residue and nitrogen (N) fertilizer management. Our objectives were to: (1) quantify the effect of nitrogen N application rate on N losses; (2) examine the role of residue returned on N transformation and losses; and (3) verify the capability of the NCSWAP/NCSOIL model to simulate the dynamics of N and 15N in the soil–plant system. Data obtained from a long-term continuous corn study on a silt loam soil, with two N levels (20 and 200 kg N/ha), with two types of residue management (residue harvested, −R; and residue returned, +R) was used to calibrate the model. The model accurately predicted 15N in the plant and soil organic matter (SOM) at the 0- to 15-cm and 15- to 30-cm depths for both fertilizer rates and residue managements. Concentrations of 15N in the corn and SOM were higher for the 20 than 200 kg N/ha treatments. Greater dilution of the 15N with nontracer fertilizer added at the higher fertilizer rate was responsible for differences in 15N concentrations in the plant. The predicted cumulative N loss during a 30-year simulation indicates more nitrate leaching past the 1-m depth for −R than +R treatments, while higher denitrification rates were predicted for the +R than −R. The simulated cumulative effect of residue returned on denitrification over 30 years predicted increased cumulative N losses from 1320 to 1705 kg N/ha and 1333 to 2574 kg N/ha for the low and high N application rates, respectively. Better synchronization of N release from residue and addition of N fertilizer with plant-N uptake would minimize leaching and denitrification.

Short wavelength (C-band) radar backscatter intensity from forests is insufficient for estimating age related tree parameters because the microwave radiation does not penetrate far into the forest canopy. However, extra information that is not available in the SAR image tone may be provided by the image texture, the spatial variation in image intensity. This paper demonstrates that a simple measure of texture in high spatial resolution C-band airborne SAR imagery of a tropical forest region can assist in the discrimination of forest age classes that have very similar average backscatter responses. As this effect is not seen in similar studies of a temperate coniferous forest, it is suggested that the relationship between texture and age is associated with the process of forest development particular to tropical forests. >

The closed form system of equations governing a positive-displacement pump with a cylindrical fluid chamber and a brushless DC motor that relates the pump geometry to its mechanical efficiency have been determined with the use of some simplifications. The resulting system was used to predict the efficiency of the pump given specific operating conditions for different geometries and vice versa. The closed-form system that the simplifications facilitated properly predicted the trends of the efficiency over different geometries and operating conditions.

We present the first results in a new program intended to make the best use of all available technologies to provide an effective understanding of waves from inspiralling black hole binaries in time for imminent observations. In particular, we address the problem of combining the close-limit approximation describing ringing black holes and full numerical relativity, required for essentially nonlinear interactions. We demonstrate the effectiveness of our approach using general methods for a model problem, the head-on collision of black holes. Our method allows a more direct physical understanding of these collisions indicating clearly when non-linear methods are important. The success of this method supports our expectation that this unified approach will be able to provide astrophysically relevant results for black hole binaries in time to assist gravitational wave observations., Comment: 4 pages, 3 eps figures, Revtex

This work consists of two distinct parts. In the first part we present a new method for solving the initial value problem of general relativity. Given any spatial metric with a surface orthogonal Killing field and two freely specified components of the extrinsic curvature we solve for extrinsic curvature's remaining components. For the second part, after noting that initial data for the Kerr spacetime can be derived within our formalism we construct data for axisymmetric configurations of spinning black holes. Though our method is limited to axisymmetry, it offers an advantage over the Bowen-York proceedure that our data approach those for Kerr holes in the limit of large separations and in the close limit., 10 pages

We solve the problem of expressing the Weyl scalars $\psi $ that describe gravitational perturbations of a Kerr black hole in terms of Cauchy data. To do so we use geometrical identities (like the Gauss-Codazzi relations) as well as Einstein equations. We are able to explicitly express $\psi $ and $\partial _t\psi $ as functions only of the extrinsic curvature and the three-metric (and geometrical objects built out of it) of a generic spacelike slice of the spacetime. These results provide the link between initial data and $\psi $ to be evolved by the Teukolsky equation, and can be used to compute the gravitational radiation generated by two orbiting black holes in the close limit approximation. They can also be used to extract waveforms from spacetimes completely generated by numerical methods., Comment: 5 pages, REVTEX, no figures

This study describes the development of a semiempirical model for the retrieval of above-ground biomass density of regenerating tropical forest using JERS-1 Synthetic Aperture Radar (SAR). The magnitude and variability of the response of the L-band SAR to above-ground biomass density was quantified using field data collected at Tapajos in central Amazonia and imagery from a series of dates. A simple backscatter model was fitted to this response and validated using image and field data acquired independently at Manaus, 500 km to the west of Tapajos. The sources of variability in biomass density and SAR backscatter were investigated so as to determine confidence limits for the subsequent retrieval of biomass density using the model. This analysis suggested that only three broad classes of regenerating forest biomass density may be positively distinguished. While the backscatter appears to saturate at around 60 tonnes per hectare, the biomass limit for retrieval purposes which is tolerant to both speckle and image texture is only 31 tonnes per hectare. The spatial distribution of biomass density in central Amazonia was estimated by applying the model to a mosaic of 90 JERS-1 images. A favorable comparison of this distribution to a map of regeneration derived from NOAA AVHRR imagery suggested that L-band SAR will provide a useful method of monitoring tropical forests on a regional scale.

OBJECTIVE: An analysis was performed to evaluate early patterns of recurrence and survival in patients undergoing laparoscopic-assisted colectomies for primary colorectal cancer. Thirty-nine patients are available with a minimum of 24 months postoperative follow-up. SUMMARY BACKGROUND DATA: The techniques and expected surgical outcomes for patients undergoing laparoscopically assisted colectomies are slowly being defined as these procedures become more common and more widely available. One of the areas of greatest concern is the use of laparoscopic-assisted colectomy for the surgical treatment of patients with primary colorectal cancer. There are anecdotal reports in the literature describing both port site recurrence and wound recurrence in patients undergoing laparoscopic-assisted colectomies for colorectal cancer. This raises concerns about whether these recurrences are more common in patients undergoing laparoscopic procedures and whether overall survival is compromised. Wound recurrences and laparoscopic port site recurrences have been described with numerous other intra-abdominal tumors, but the precise incidence remains unknown. The authors reviewed data from 39 patients to determine early patterns of recurrence and overall survival. METHODS: Two-hundred thirty-eight laparoscopic-assisted colectomies were performed by the Norfolk Surgical Group between June 1992 and September 1995. Thirty-nine of the patients who underwent resection for colorectal cancer between June 1992 and September 1993 currently are available for at least a 2-year follow-up. Preoperative evaluation included physical examination, liver function studies, carcinoembryonic antigen, chest x-ray, computed tomography scans, and endoscopies with biopsy. Postoperative follow-up data consisted of physical examination, liver function tests, CEA, chest X-ray, computed tomography scan of the abdomen, and endoscopy of the colon. No patients have been lost to follow-up. Survival rates and patterns of recurrence were compared between node-negative and node-positive patients and compared with conventional data after open surgery. RESULTS: There were 22 men and 17 women ranging in age from 33 to 89 years. Mean follow-up was 30 months, with a range of 24 to 40 months. There were three patients with recurrence and nine deaths. Recurrence and tumor-related death rates, respectively, for each Dukes' stage were 0/1 and 0/1 for stage A, 0/7 and 0/7 for stage B-1, 1/16 and 2/16 for stage B-2, 0/1 and 0/1 for stage C-1, and 2/8 and 1/8 for Stage C-2. All six patients with Dukes' stage D disease died of metastatic colorectal cancer within 4 to 14 months of surgery. There were two patients with anastomotic recurrence. No unusual patterns of recurrent disease were noted, and there were no wound or port site recurrences. CONCLUSIONS: In this group of patients undergoing laparoscopic-assisted colectomies for primary colorectal malignancy, no adverse patterns of recurrence or decreased survival has been noted at 2-year follow-up when compared with standard open colorectal cancer surgery statistics. Prospective randomized studies with long-term follow-up will be required to better define the potential benefits and adverse effects of laparoscopic surgery for colorectal malignancy.

MnFe/NiFe exchange structures have been prepared in an ultra-high vacuum sputtering/surface analysis system. Controlled introduction of residual gas impurities such as O2 and H2O at the MnFe/NiFe interface is studied by in-situ x-ray photoelectron spectroscopy (XPS) and the exchange structures are magnetically characterized. Due to the extreme reactivity of the NiFe surface towards O2, the exchange coupling is severely degraded by only small exposures of this molecule to the NiFe surface. In contrast, H2O does not oxidize the NiFe surface and therefore can be tolerated in greater quantities in the sputtering chamber without detrimental loss of exchange. This understanding of the basic surface chemistry of the MnFe and NiFe surfaces can lead to improved sputtering practices in actual manufacturing applications.

Tilman et al . (Reports, 8 December 2006, p. 1598) argued that low-input high-diversity grasslands can provide a substantial proportion of global energy needs. We contend that their conclusions are not substantiated by their experimental protocol. The authors understated the management inputs required to establish prairies, extrapolated globally from site-specific results, and presented potentially misleading energy accounting.

Evaluating the impact of land use practices on ground water quality has been difficult because few techniques are capable of monitoring the quality and quantity of soil water flow below the root zone without disturbing the soil profile and affecting natural flow processes. A recently introduced method, known as equilibrium tension lysimetry, was a major improvement but it was not a true equilibrium since it still required manual intervention to maintain proper lysimeter suction. We addressed this issue by developing an automated equilibrium tension lysimeter (AETL) system that continuously matches lysimeter tension to soil-water matric potential of the surrounding soil. The soil-water matric potential of the bulk soil is measured with a heat-dissipation sensor, and a small DC pump is used to apply suction to a lysimeter. The improved automated approach reported here was tested in the field for a 12-mo period. Powered by a small 12-V rechargeable battery, the AETLs were able to continuously match lysimeter suction to soil-water matric potential for 2-wk periods with minimal human attention, along with the added benefit of collecting continuous soil-water matric potential data. We also demonstrated, in the laboratory, methods for continuous measurement of water depth in the AETL, a capability that quantifies drainage on a 10-min interval, making it a true water-flux meter. Equilibrium tension lysimeters have already been demonstrated to be a reliable method of measuring drainage flux, and the further improvements have created a more effective device for studying water drainage and chemical leaching through the soil matrix.

The use of soil heat flux as a critical component of the surface energy balance is routine; however, its accurate quantification is not. The direct measurement of soil heat flux is generally accomplished with soil heat flux plates. However, the presence of heat flux plates causes perturbations in heat and fluid flow in the soil that may give rise to measurement errors. We describe here the direct measurement of soil heat flux with the gradient technique using a tri-needle instrument, where soil heat flux is the product of the soil thermal conductivity measured by transient heating of the center needle and the soil temperature gradient measured between the outer needles. Soil heat fluxes measured this way were compared with those obtained from commercially available soil heat flux plates. Laboratory trials revealed good precision and accuracy (error generally

The use of net radiation as a critical variable in models of surface-atmosphere exchange is routine; however, its measurement is not. The discrete measurement of incoming and outgoing solar radiation with pyranometers and long-wave radiation with pyrgeometers is widely thought to be the most accurate method for estimating net radiation, but deployment at multiple sites is cost prohibitive. A recently developed single-sensor net radiometer differs from other commonly used net radiometers in that it has no domes covering the thermopile sensor. Long-term field data from this net radiometer were compared to reference net radiation calculated as the sum of the four independently measured components. The domeless net radiometer agreed well with the reference measurements, out-performing a similarly priced, widely used, domed net radiometer under most conditions. However, our analyses suggest that the domeless net radiometer has differing sensitivities to short and long-wave radiation, which is not accounted for in the calibration. Additionally, precipitation affected the domeless net radiometer much more severely than the domed model, which could be a significant limitation in areas with frequent rainfall. Despite these shortfalls, the domeless net radiometer evaluated here could be useful in a variety of field settings.

Fine‐grained, 200 nm thick films of Pb–In(12 wt%)–Au(4 wt%) have been obtained by depositing sequential layers of Pb, Au, Pb, and In at 95 K in high vacuum. The use of such films as base electrodes for Josephson tunnel junctions has enabled achievement of an ≊100× improvement in junction stability during repeated thermal cycling between 300 K and 4.2 K. However, the morphology and microstructure of such films were found to be strongly dependent on the level and composition of the residual gas during deposition. This effect was studied in an ultrahigh vacuum system by intentionally introducing H2O, CO2, and CO individually and in mixtures at pressures between 7×10−6 and 3×10−4 Pa. The films were then examined with Scanning Electron Microscopy (SEM) and Transmission Elecron Microscopy (TEM). Whereas the presence of the individual gases caused relatively minor changes in the films, the combination of H2O and CO2 caused holes and hillocks to form at a level that increased strongly with gas exposure. A factor ...

Many models in a variety of disciplines require air temperature throughout the day as an input, yet often the only data available are daily extrema. Several methods for estimating the diurnal change in temperature from daily extrema have been reported. This paper compares the performance of three such algorithms (a sine wave, a sine-exponential, and a linear model) at all times of the year. Each was used to generate four years of hourly temperatures using as input the daily highs and lows recorded by the National Weather Service at the Minneapolis-St. Paul International Airport for the years 1970, 1971, 1973 and 1974. The output from the models was compared with the actual hourly values recorded at the same site. Residual sums and standard errors computed for all three models, both as functions of day and month of the year, showed that all three were more accurate in summer than in winter. Differences in the overall standard errors of estimate among the three models were small relative to the sta...

Reicosky, D.C., Winkelman, L.J., Baker, J.M. and Baker, D.G., 1989. Accuracy of hourly air temperatures calculated from daily minima and maxima. Agric. For. Meteorol., 46: 193-209. Temperature is one of the critical variables that drives biological systems and is of fundamental importance in crop growth models. The objective of this work was to determine the accuracy of several methods for calculating hourly air temperatures from daily maxima and minima. Methods that have as inputs daily minimum and maximum temperature were selected from the literature based on their use in existing growth models and simplicity. Four years of hourly air temperature data collected during the growing season at 2 m over well-watered grass were used to test the various methods. Six days from each growing season were randomly selected for detailed analysis, and an additional 9 days were selected to cover a range of daily maximum temperatures and solar radiation. The absolute mean error within a 24-h period ranged from 0.5 to 9.3 ° C for the 6 randomly selected days for all 4 years of the data. All methods worked reasonably well on clear days but with limited success on overcast days. Daily maximum temperature did not appear to affect the accuracy of any of the methods. If accurate timing of temperature input to models is critical, the results indicate direct measurement of hourly temperature may be necessary.

Oxides grown on PbInAu alloys using a combined thermal and rf oxidation process have been examined with x‐ray photoemission spectroscopy (XPS or ESCA) and ellipsometry. The oxides were prepared on alloy films deposited at 300 K containing 13 and 26 at. % In in the PbIn phase and on fine‐grain alloy films deposited at 95 K containing 13 at. % In. Following an in situ thermal oxidation at 75 °C, the films were rf‐plasma oxidized while mounted on an electrode coated with either In or photoresist. The XPS spectra showed that both lead oxide and indium oxide were present, in agreement with previous findings that the bulk of such oxides consists of a layer of In2O3 overlying a layer of PbO. The binding energy of the Pb 4f peak from the oxide was shifted by 0.9–1 eV from the metal peak, a shift characteristic of PbO. Analysis of the XPS intensities based on a layered structure indicated that oxides on the films deposited at 300 K consisted of about 2.7 nm of In2O3 on top of 1.6 nm of PbO. Oxides on the fine‐grai...

There is considerable interest in understanding the surface oxidation reactions of transition‐metal alloys with potentially useful magnetic properties. These reactions can either lead to passivation or corrosion of the magnetic film under normal atmospheric conditions. Little is known, however, about the surface oxidation reactions of MnFe. In the present study, thin films of MnFe prepared by dc magnetron sputter deposition onto Si, Cu, and Ni80Fe20 have been characterized magnetically by superconducting quantum interference device (SQUID) and vibrating sample magnetometer measurements and their surface chemistry has been followed by angle resolved x‐ray photoelectron spectroscopy and ellipsometry. The reactivity of the clean MnFe surface with O2, H2O, and N2 was investigated. The interaction of MnFe with O2 proceeds by preferential oxidation and surface segregation of Mn oxide. The final products of oxidation after a 66 000‐L exposure are MnO and Fe2O3, in agreement with thermodynamic considerations. Com...

With any method for measuring soil water content it is useful to know the spatial sensitivity of the measurement, i.e., what volume of soil is measured and what the distribution of sensitivity is within that volume. We determined this information for the method of time-domain reflectometry (TDR), us

(...) When the potential gradient between center and outer compartments reached 1.0 MPa, the gamma readings showed overnight movement of water from wet to dry soil that could only have taken place through the root systems of the outer row plants. The overnight transfer of water, while significant, was not sufficient to fully supply the day-time transpiration demand of the unirrigated center row plants (...)

A mechanism is considered for oxide growth on an electrically isolated metal sample in the presence of an rf‐excited oxygen plasma. The assumption is made that the rate of rf oxidation is limited by transport of ionic species through the already‐formed oxide layer. Thermally activated hopping of ionic defects in the presence of electric fields due to the surface potential established by the rf discharge and modified by the space charge of the mobile ionic defects is hypothesized. The origin of the voltage across the oxide is discussed in terms of a balance between the transport of negatively charged O ions and transport of electron holes created by ion neutralization of positive ions from the plasma. This model is developed analytically and evaluated numerically by employing the continuum limit of hopping transport equations valid for the very‐high‐field limit. A three parameter fit gives excellent agreement of the theory with the published data of Greiner for the rf oxidation of lead. The fitting parameters are the voltage across the oxide film, the ionic diffusivity, and the rate at which the oxide is removed by sputtering. The resulting parameter values are shown to be in reasonable accord with available experimental data. Parametric curves are presented to illustrate the dependence of the kinetics on the various microscopic parameters. The dependence of the limiting thickness on the primary parameters is likewise presented. It is shown that the growth rate may be significantly retarded by high levels of space charge in the oxide.

Heat balance methods of stem flow measurement offer the opportunity to measure directly the mass flow rate of water in plants. We have tested one such approach; the constant power heat balance method of Sakuratani (1981). The results supported his statement of an approximate accuracy of 10% when measuring the transpiration rate of herbaceous plants. The response to sudden changes in stem flow rate is not instantaneous, but investigation of the time constant shows that it decreases as stem flow increases, to the extent that, at flow rates typical of daytime conditions the system is capable of accurately tracking changes in stem flow within 5 min or less. We describe a new gauge design that is relatively rugged, simple to use with an appropriate digital datalogger and suitable for field use over prolonged periods of time. It does not injure or penetrate the stem, is amenable to continuous and direct recording of the mass flow rate of water in the stem and requires no calibration. A further refinement, which should improve both the accuracy and the dynamic response of the system, is proposed.

An axisymmetric finite element model of heat flow was used to evaluate some of the assumptions inherent in the steady-state heat balance method for measuring sap flow in herbaceous plants. Results indicate that the gauge slightly overestimates conduction up and down the stem when sap flow is nearly zero, causing a corresponding underestimate of the sheath conductance and the radial outward heat flux. As sap flow rates increase, the temperature distribution in the stem and gauge is altered to the point that the one-dimensional Fourier equations are no longer applicable and the individual heat fluxes in the system are poorly estimated. However, the errors are largely self-compensating, so that the resulting gauge estimate of the heat absorbed by the sap stream is reasonably accurate. The model indicates that stem vascular anatomy affects the accuracy of the method, predicting that, in general, the method should be more accurate with dicots than with monocots.

A process for fabricating experimental Josephson integrated circuits is described that is based primarily on the use of vacuum-deposited Pb-alloy and SiO films patterned by photoresist stencil lift-off. The process has evolved from one previously reported, with changes having occurred in junction electrodes, tunnel barrier formation, layer patterning, device geometry, and minimum linewidths. Films of Pb-In(12 wt%)-Au(4 wt%) alloy (200-800 nm thick) are used for forming junction base electrodes, interferometer controls, and interconnection lines. Tunnel barriers are formed on the base electrode films by thermal oxidation and subsequent sputter-etching in an rf-oxygen plasma. Junction counter electrodes are formed from 400-nm-thick Pb-Bi(29 wt%) alloy films. Ground planes are formed from 300-nm-thick Nb films patterned by subtractive etching and insulated in part by a Nb2O5 layer formed by liquid anodization. Films of the intermetallic compound AuIn2(30-43 nm thick) are used for forming terminating, load, and damping resistors. The Si0 films are used for interlayer insulation, for defining junction areas in interferometers, and as protective coatings. Layer patterning is achieved mainly by means of photoresist lift-off stencils. By utilizing this process, experimental logic and memory circuits containing ≅100 interferometers with lines as small as 2.5 µm in width have been successfully fabricated.

1. The reported 22 cases of unilobar obstructive emphysema in infancy are reviewed. Eighteen of these cases were successfully treated by lobectomy or segmental resection. No cause of the obstruction was found in over 50% of the cases reported. 2. Two cases of unilobar obstructive emphysema in the newborn are presented. These patients were successfully treated by selectively decompressing the emphysematous lobe. 3. The non-surgical method of treatment is advocated in the newborn when lobar emphysema is newly established and reversible. It may be of value when surgery is indicated to improve the patient who is a poor risk. 4. The mechanism, by which selective decompression alleviates the partially obstructed bronchus, is open to conjecture. However, we postulate that the bronchus, is kinked by an overdistended emphysematous lobe and that retained viscid secretions augment the bronchial obstruction in the new born.

Dynamic equilibrium of Van Allen belts studied for self-consistency through saturation of trapped plasma

Differences exist concerning the parameters and their effect on trickling filter efficiency and volume requirements among the work of different investigators. The formulas for trickling filter efficiency proposed by the National Research Council, Eckenfelder, and Galler and Gotaas are compared. Design charts for single-stage filters by each of the three formulas are presented. Modifications of the Eckenfelder and Galler-Gotaas formulas similar to the NRC formula for second-stage filters are proposed, and design charts are presented for each of the formulas. A computer program to optimize the two-stage filter volume has been developed. It is indicated that the optimum (minimum) volume will occur when the volumes of each stage are approximately equal, using the NRC formula and modified Eckenfelder formulas, and with a ratio of first to second stage of 1:2 using the Galler-Gotaas formula.

The effects of several sources of phosphorus on the emergence of winter wheat (Triticum aestivum L.) were compared when applied in a band with the seed under controlled temperature and moisture conditions. The detrimental effects of a given fertilizer treatment on emergence increased as temperature increased from 15 to 25C. Increasing soil moisture stress from 1 to 3 bars also reduced emergence. The harmful effects of increasing the temperature from 15 to 25C were greater than the harmful effects of increasing moisture tension from 1 to 3 bars. Emergence was reduced to a much greater extent on a sandy soil than on a medium textured soil for a given fertilizer treatment. The effects of temperature, moisture, and soil texture appeared to be cumulative. Ammonium polyphosphate, ordinary superphosphate, and concentrated superphosphate had approximately equal effects on emergence and were much less detrimental than monoammonium and diammonium phosphate which were about equal. Ammonium phosphate sulfate decreased emergence to a much greater extent than any other source. Banding of concentrated superphosphate with the seed reduced emergence as much as 40% in the field. This reduced emergence, however, had no effect on yield of grain.

International audience; In any metabolomics experiment, robustness and reproducibility of data collection is of vital importance. These become more important in collaborative studies where data is to be collected on multiple instruments. With minimisation of variance in sample preparation and instrument performance it is possible to elucidate even subtle differences in metabolite fingerprints due to genotype or biological treatment. In this paper we report on an inter laboratory comparison of plant derived samples by [1H]-NMR spectroscopy across five different sites and within those sites utilising instruments with different probes and magnetic field strengths of 9.4 T (400 MHz), 11.7 T (500 MHz) and 14.1 T (600 MHz). Whilst the focus of the study is on consistent data collection across laboratories, aspects of sample stability and the requirement for sample rotation within the NMR magnet are also discussed. Comparability of the datasets from participating laboratories was exceptionally good and the data were amenable to comparative analysis by multivariate statistics. Field strength differences can be adjusted for in the data pre-processing and multivariate analysis demonstrating that [1H]-NMR fingerprinting is the ideal technique for large scale plant metabolomics data collection requiring the participation of multiple laboratories.

Using current, improved commercial equipment, the authors reexamined the calibration procedure of the dual-probe gamma soil densitometer, using exact density standards. When each instrument is individually calibrated, the procedure, as originally designed, gives consistent and accurate results.