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Institution

The Hertz Corporation

About: The Hertz Corporation is a based out in . It is known for research contribution in the topics: Population & Soil water. The organization has 9562 authors who have published 11044 publications receiving 447929 citations. The organization is also known as: Hertz Rental Car & Hertz Rent-a-Car.


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Journal ArticleDOI
TL;DR: In this paper, the effects of fumigation on organic C extractable by 0.5 m K2SO4 were examined in a contrasting range of soils and it was shown that both ATP and organic C rendered decomposable by CHCl3 came from the soil microbial biomass.
Abstract: The effects of fumigation on organic C extractable by 0.5 M K2SO4 were examined in a contrasting range of soils. EC (the difference between organic C extracted by 0.5 M K2SO4 from fumigated and non-fumigated soil) was about 70% of FC (the flush of CO2-C caused by fumigation during a 10 day incubation), meaned for ten soils. There was a close relationship between microbial biomass C, measured by fumigation-incubation (from the relationship Biomass C = FC/0.45) and EC given by the equation: Biomass C = (2.64 ± 0.060) EC that accounted for 99.2% of the variance in the data. This relationship held over a wide range of soil pH (3.9–8.0). ATP and microbial biomass N concentrations were measured in four of the soils. The (ATP)(EC) ratios were very similar in the four soils, suggesting that both ATP and the organic C rendered decomposable by CHCl3 came from the soil microbial biomass. The C:N ratio of the biomass in a strongly acid (pH 4.2) soil was greater (9.4) than in the three less-acid soils (mean C:N ratio 5.1). We propose that the organic C rendered extractable to 0.5 m K2SO4 after a 24 h CHCl3-fumigation (EC) comes from the cells of the microbial biomass and can be used to estimate soil microbial biomass C in both neutral and acid soils.

9,975 citations

Journal ArticleDOI
01 May 1972
TL;DR: In this paper, the authors used iterative weighted linear regression to obtain maximum likelihood estimates of the parameters with observations distributed according to some exponential family and systematic effects that can be made linear by a suitable transformation.
Abstract: JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Blackwell Publishing and Royal Statistical Society are collaborating with JSTOR to digitize, preserve and extend access to Journal of the Royal Statistical Society. Series A (General). SUMMARY The technique of iterative weighted linear regression can be used to obtain maximum likelihood estimates of the parameters with observations distributed according to some exponential family and systematic effects that can be made linear by a suitable transformation. A generalization of the analysis of variance is given for these models using log-likelihoods. These generalized linear models are illustrated by examples relating to four distributions; the Normal, Binomial (probit analysis, etc.), Poisson (contingency tables) and gamma (variance components). The implications of the approach in designing statistics courses are discussed.

8,793 citations

Journal ArticleDOI
TL;DR: To improve stain penetration and clearing in whole mycorrhizal roots of onion and other host plants, and in roots infected by other fungi, the following two procedures are developed, which give deeply stained fungal structures which show distinctly against the outlines of the cells in the cortex of intact roots.
Abstract: During studies on the effect of vesicular-arbuscular (VA) mycorrhiza, caused by species of Endogene, on plant growth, we needed to estimate the amount of mycorrhizal infection in the root cortex. Such infections in gramineous roots stain fairly clearly with standard procedures such as simmering in o·I % trypan blue in lactophenol (Hayman, 1970), or cotton blue and Sudan IV in lactophenol (Nicolson, 1959), and in some dicotyledonous roots by boiling for 10 min in 0'0 I % acid fuchsin in saturated chloral hydrate (Gerdemann, 1955), or standing cold overnight in any of these stains. Infection in onion, our main test plant (Hayman & Mosse, 1970), is difficult to estimate using these methods because, although external hyphae and entry points are strongly stained, internal hyphae, arbuscules and vesicles are usually only well defined near the cut ends of the root segments. To improve stain penetration and clearing in whole mycorrhizal roots of onion and other host plants, and in roots infected by other fungi, we developed...two procedures, which give deeply stained fungal structures which show distinctly against the outlines of the cells in the cortex of intact roots.

7,796 citations

Journal ArticleDOI
TL;DR: It is shown that a satisfactory account can be given of open water evaporation at four widely spaced sites in America and Europe, the results for bare soil receive a reasonable check in India, and application of theresults for turf shows good agreement with estimates of evapolation from catchment areas in the British Isles.
Abstract: Two theoretical approaches to evaporation from saturated surfaces are outlined, the first being on an aerodynamic basis in which evaporation is regarded as due to turbulent transport of vapour by a process of eddy diffusion, and the second being on an energy basis in which evaporation is regarded as one of the ways of degrading incoming radiation. Neither approach is new, but a combination is suggested that eliminates the parameter measured with most difficulty—surface temperature—and provides for the first time an opportunity to make theoretical estimates of evaporation rates from standard meteorological data, estimates that can be retrospective. Experimental work to test these theories shows that the aerodynamic approach is not adequate and an empirical expression, previously obtained in America, is a better description of evaporation from open water. The energy balance is found to be quite successful. Evaporation rates from wet bare soil and from turf with an adequate supply of water are obtained as fractions of that from open water, the fraction for turf showing a seasonal change attributed to the annual cycle of length of daylight. Finally, the experimental results are applied to data published elsewhere and it is shown that a satisfactory account can be given of open water evaporation at four widely spaced sites in America and Europe, the results for bare soil receive a reasonable check in India, and application of the results for turf shows good agreement with estimates of evaporation from catchment areas in the British Isles.

6,711 citations

Journal ArticleDOI
TL;DR: The standard error of four methods of assessment based on observations of stained root samples either randomly arranged in a petri dish or mounted on microscope slides are calculated.
Abstract: Summary Assessment of infection is an essential part of many studies involving VA mycorrhiza. A summary is given of the range of techniques that have been used. We calculated the standard error of four methods of assessment based on observations of stained root samples either randomly arranged in a petri dish or mounted on microscope slides. The methods are based on presence or absence of infection at root/grid intersect points, on a visual estimate of percentage cortex occupied by fungus or on estimates of length, or presence or absence of infection in root pieces mounted on slides. The number of replicate observations required for a given standard error % infection can be read from the curves provided. The advantages of the different methods of assessment are discussed and reasons given why they all probably overestimate the true values.

5,355 citations


Authors

Showing all 9562 results

NameH-indexPapersCitations
Pete Smith1562464138819
J. H. Hough11790489697
Christine H. Foyer11649061381
Steve P. McGrath11548346326
Nial R. Tanvir11287753784
Fang-Jie Zhao10737239328
Martin R Turner9850334965
Peter R. Shewry9784540265
Helen E. Heslop9752336292
Stephen E. Harris9542146780
Brian C. J. Moore9371138036
Ken E. Giller9255536374
Kingston H. G. Mills9231329630
Alex B. McBratney9255234770
David M. Glover9230124620
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20222
202145
202046
201939
201855
201757