Effect of reforestation on turnover of ¹⁵N-labelled nitrate and ammonium in relation to changes in soil microflora     

J.M. Jones  B.N. Richards 《Soil biology & biochemistry》1977,9(6):383-392

The effects of incubation time, vegetation type (represented by a pine plantation, a protected and a periodically burnt eucalypt forest), lime and finely ground pine needles on the transformation of (¹⁵NH₄)₂SO₄ and K¹⁵NO₃ were studied in incubation experiments with a sandy lateritic podzolic soil from south-east Queensland. Microorganisms were counted so as to relate N transformations to particular groups of microorganisms.The heterotrophic miroflora utilized NH⁺₄ as a source of N in preference to NO^?₃, and autotrophic nitrifiers seemed to be weak competitors for NH⁺₄. Lime caused a slight loss of NO^?₃ and this was accompanied by an increase in the population of denitrifying bacteria.Lime promoted immobilization of NH⁺₄ by heterotrophic bacteria and subsequent mineralization by nitrifying bacteria, but when pine needles were also added the nitrifiers were suppressed and immobilization by heterotrophic bacteria dominated. Pine needles alone stimulated fungi to immobilize NH⁺₄.While reforestation with exotic pines caused a loss of total-N there was evidence of increased turnover, i.e. more rapid immobilization and nitrification, in pine plantation soils. Prescribed burning also promoted nitrification while reducing total-N.  相似文献   

The effects of limb posture on relationships between in vitro radial hoof strain,load and joint angles     

S. J. Hobbs  J. Mather  C. Rolph  J. Richards 《Equine veterinary journal》2009,41(3):229-232

Reasons for performing study: Radial strain in normal hooves has been found to vary with strain gauge location, limb posture and sample limb but reported magnitudes were considered to be low. More accurate measurement of radial strain may enhance the understanding of hoof function. Objectives: To explore in vitro radial hoof strain in relation other kinetic and kinematic variables that may be related. Methods: Five normal forelimbs were removed at the proximal articular surface of the third metacarpal bone (McIII). The limbs were loaded using a modified Instron test machine. Six calibrated infrared cameras captured movement from markers on the hoof and bone fixed markers on the second and first phalanxes and McIII, whilst radial hoof strain was measured using a calibrated instrumented plug. Change in strain, joint angle and load were found at simulated walking postures and bivariate correlations were used to compare the relationships between them. Results: Radial strain was moderately correlated with proximal interphalangeal joint (PIPJ) rotation (r =?0.519). Large reductions in radial strain were found in loading and midstance with 10° of heel lift postures. Conclusions and potential relevance: PIPJ rotation has previously been linked to the magnitude of deep digital flexor tendon (DDFT) loads and it is therefore suspected that these loads may have the greatest influence on radial strain magnitudes. Further investigation of radial strain is needed to describe the patterns fully during the stance phase in vivo.  相似文献   

THE HOT BLAST IN MAKING IRON     

Richards RH 《Science (New York, N.Y.)》1884,3(50):72-73

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CERTAIN PROVISIONS OF CONTINENENTAL LEGISLATION CONCERNING FOOD ADULTERATION     

Richards E 《Science (New York, N.Y.)》1889,14(353):308-310

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Letter to the Editor          下载免费PDF全文

A. D. Richards 《Equine veterinary journal》2015,47(3):376-376

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Assessment of caecal parameters in layer hens fed on diets containing wheat distillers dried grains with solubles     

G. A. White  P. J. Richards  S. Wu  K. H. Mellits  J. Wiseman 《British poultry science》2015,56(4):494-502

1. There is much interest in quantifying the nutritional value of UK wheat distillers dried grains with solubles (W-DDGS) for livestock species. A study was designed to evaluate caecal parameters (pH, short chain fatty acids (SCFAs) and bacterial diversity) in layer hens fed on balanced diets containing graded concentrations of W-DDGS.

2. A total of 32 layer hens (Bovans Brown strain at 27 weeks of age) were randomly allocated to one of 4 dietary treatments containing W-DDGS at 0, 60, 120 or 180 g/kg. Each treatment was fed to 8 replicate individually housed layer hens over a 5-d acclimatisation period, followed by a 4-week trial. Individual feed intakes were monitored and all eggs were collected daily for weeks 2, 3 and 4 of the trial, weighed and an assessment of eggshell “dirtiness” made. All hens were culled on d 29 and caecal pH and SCFAs measured. Polymerase chain reaction denaturing gradient gel electrophoresis of the bacterial 16 S rDNA gene was used to assess total bacterial diversity of luminal caecal content from hens fed the 0 and 180 g W-DDGS/kg diets. Unweighted pair group method with arithmetic mean (UPGMA) dendrograms were generated from DGGE banding patterns.

3. Increasing W-DDGS dietary concentrations resulted in a more acidic caecal environment. Caecal SCFAs were unaffected by diet aside from a quadratic effect for molar proportions of isobutyric acid. Diversity profiles of the bacterial 16S rRNA gene from luminal caecal contents were unaffected by W-DDGS inclusion.

4. The results of the current study suggest that W-DDGS can be successfully formulated into nutritionally balanced layer diets (supplemented with xylanase and phytase) at up to 180 g/kg with no detrimental effects to the caecal environment.

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Methyl bromide fumigation and delayed mortality: safe trade of live pests?     

Phillips  C. B.  Iline  I. I.  Novoselov  M.  McNeill  M. R.  Richards  N. K.  van Koten  C.  Stephenson  B. P. 《Journal of pest science》2015,88(1):121-134

Journal of Pest Science - Live organisms intercepted from treated commodities during phytosanitary inspections usually arouse suspicions of treatment failure, sub-standard treatment application, or...  相似文献   

Marine shrimp aquaculture: a novel waste treatment system     

C. S. Lee  J. N. Sweeney  W. K. Richards  Jr. 《Aquacultural Engineering》1986,5(2-4):147-160

Ecuadorian Penaeus vannamei were cultured in dirt ponds (each of approximately 163 m²) at four different stocking densities, i.e. 5 shrimp m⁻², 10 shrimp m⁻², 15 shrimp m⁻² and 20 shrimp m⁻². Experiments were carried out over three different periods during the year. Each experiment lasted for 11–14 weeks. No commercial feed was given to the shrimp. The only input to the ponds was about 30 kg of cattle manure per pond per week. Chemical composition of the cattle manure was analyzed. Water quality parameters such as temperature, pH, DO and turbidity were recorded twice daily for each experiment; nutrients (nitrite, nitrate, ammonium and phosphate), water ATP, sediment ATP, H₂S and chlorophyll were measured twice weekly for each experiment. Shrimp were sampled either weekly or bi-weekly for body weight measurements.

The results showed a negative correlation between stocking density and growth. Weekly growth ranged from 0·44 to 1·58 g week⁻¹. Survival was over 50% in all treatments and averaged at 70·8%. Under these stocking densities, shrimp production ranged from 4·4 to 18·8 kg ha⁻¹ day⁻¹. The stocking density of 15 shrimps m⁻² provides better production than the other stocking densities.

Water quality data did not relate to any shrimp growth. Water nutrient levels in pond discharge water were less than or equal to the nutrients in the incoming water in spite of the weekly addition of cattle manure and did not increase with the addition of cattle manure. No coliform bacteria were detected in any pond water samples through the study period. This indicates digestion of cattle manure in marine shrimp ponds would not pollute the environment with high concentrations of dissolved nutrients.

Thus, a marine shrimp pond can be considered a dissolved nutrient marine treatment plant converting unwanted cattle manure (1841 kg cattle manure ha⁻¹ week⁻¹ in this study) into a valuable commodity — shrimp.  相似文献   

VH1-44 gene usage defines a subset of canine B-cell lymphomas associated with better patient survival     

Hsiao-Wei Chen  George W. Small  Alison Motsinger-Reif  Steven E. Suter  Kristy L. Richards 《Veterinary immunology and immunopathology》2014,157(3-4):125-130

The use of specific immunoglobulin heavy chain variable region (VH) genes has been associated with increased patient survival in human B-cell lymphomas (hBCL). Given the similarity of human and canine BCL (cBCL) in morphology and clinical treatment, we examined the choice of VH in cBCL and determined whether VH gene selection was a distinct feature associated with survival time in dogs. VH gene selection and mutational status in 52 cBCL, including 29 diffuse large B-cell lymphomas (cDLBCL, the most common subtype of cBCL), were analyzed by comparison with the 80 published canine germline VH gene sequences. We further examined the prognostic impact of the subgroups defined by these features on canine survival. We found that VH1-44 was preferentially expressed in the majority of the 52 cBCLs (60%) as well as in the majority of the cDLBCL subset (59%). VH1-44 gene expression was associated with a statistically better overall survival (p = 0.039) in cBCL patients, as well as in the cDLBCL subset of patients (p = 0.038). These findings suggest that VH gene selection in cBCL is not random and may therefore have functional implications for cBCL lymphomagenesis, in addition to being a useful prognostic biomarker.  相似文献   

Use of activity monitors for assessment of pruritus in an acute model of canine atopic dermatitis     

Rachel Schwab‐Richards  Christine Prost  Jean Steffan  Wolfgang Seewald  Chiara Nenci  Petra Roosje 《Veterinary dermatology》2014,25(5):441-e69

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