A note on the structure and iron‐binding properties of egg‐shell membranes

1. When a solution of ferric ammonium sulphate was added to shell membranes of the domestic fowl, iron infiltrated the mantle (cortex) surrounding the cores of the individual fibres of the membranes.

2. Contraction of warm eggs in ice‐cold colloidal iron caused flooding of pore canals and contamination of the underlying shell membranes with this element.

3. Appreciable contamination of the inner shell membrane with iron persisted for 25 d in infertile eggs stored at 37.5 °C.     

A 31P topical magnetic resonance study of embryonic development in hens' eggs

1. A ³¹P topical magnetic resonance study of whole chicken's eggs in vivo is described.

2. Resonances from adenosine triphosphate, phosphocreatine, inorganic phosphate and phosphorous storage protein were observed. These changed in relative intensity as the embryo developed.

3. No ill effects due to exposure to radiofrequency radiation or magnetic fields were observed.

4. It is concluded that topical magnetic resonance can make a useful contribution to the study of embryonic development in avian eggs.     

Diagnostic value of intestinal alkaline phosphatase in horse serum

Antiserum directed against equine intestinal Alkaline Phosphatase (ALP) was produced in rabbits and used to develop a sensitive and quantitative assay for the detection of intestinal ALP in equine serum. This assay was then used to measure the half-life of intravenously injected intestinal ALP and to determine if the intestinal ALP was present in normal horse sera, sera from horses presented for lesions not involving the gastrointestinal tract and sera from horses presented with lesions involving the gastrointestinal tract. The results suggest that intestinal ALP is not likely to appear in equine serum even when gastrointestinal disease is present and, therefore, appears to be of no diagnostic value.     

Kinematics of the equine thoracolumbar spine

At least three types of movement take place in the joint complexes of the equine thoracolumbar spine: dorsoventral flexion and extension, axial rotation and lateral bending. Using the standard right-handed Cartesian coordinate system, these movements may be defined as rotation about the x, y and z axes respectively. Except in cases of intervertebral fusion, all three types of movement occur in each joint complex of the equine back. The greatest amount of dorsoventral movement takes place at the lumbosacral and the first thoracic intervertebral joints. The greatest amount of axial rotation and lateral bending was measured in the mid-thoracolumbar spine at the level of the 11th or 12th thoracic intervertebral joints. The caudal thoracic and the lumbar spine is the least mobile region of the equine back. In the mid-thoracic spine, lateral bending was always accompanied by a "coupled" axial rotation. The presence of the rib cage stabilised the cranial thoracic vertebrae against axial rotation.     

Further characterization of dandelion yellow mosaic virus from lettuce and dandelion

A damaging virus isolated in the Netherlands from lettuce was studied and compared with a virus isolated from dandelion orginating from Czechoslovakia. It was found to biologically resemble dandelion yellow mosaic virus incompletely described from dandelion and lettuce in Great Britain (Kassanis, 1944, 1947) and from dandelion in Germany (Hein, 1963). Mechanical transmission was greatly improved by buffer solution and transmission byMyzus persicae seemed to be in the non-persistent manner. Longevity in vitro of the virus hardly exceeded one day. Thermal inactivation was between 60 and 65 °C and the dilution end-point was between 10 000 and 100 000. It was still infectious in leaf material dried and stored over CaCl₂ at 4 °C for 6 1/2 years. The virus was isolated and purified with difficulty and was found to consist of one type of spherical particle of ca 30 nm diameter, with a sedimentation coefficient of 159 S, a buoyant density of 1.42 g.cm^?3 and an A₂₆₀/A₂₈₀ ratio of 1.67. An antiserum was prepared with a titre of 256 in the agar double-diffusion test. The virus could be identified in crude extracts from lettuce andChenopodium amaranticolor by enzyme-linked immunosorbent assay (ELISA), but not by agar double diffusion. It could only be visualized in crude sap in the electron microscope after trapping of virus particles on antiserum-coated grids. The virus cannot yet be assigned to any known virus group. It is of potential economic importance to lettuce because of its occurrence in widely differing regions in Europe, its aggressiveness and virulence on 22 out of 23 lettuce cultivars tested (and on endive) and its pathogenicity toLactuca genotypes which are resistant to lettuce mosaic virus and other important pathogens of lettuce. ‘Laibacher Eis’ was the only cultivar showing some tolerance.     

Synthetic pyrethroids and avermectin for controlling the grapevine pestsLobesia botrana,Cryptoblabes gnidiella andDrosophila melanogaster

Field treatments in a vineyard with 0.015 or 0.01% a.i. of cypermethrin, fenvalerate, fenpropathrin or AC-222,705 were more efficient in controlling the grape-berry moth (Lobesia botrana Schiff.) and the honeydew moth (Cryptoblabes gnidiella Mill.) than four standard treatments consisting of two with 0.05% a.i. fenitrothion and two with 0.075% a.i. diazinon. In pyrethroid-treated plots, infestation at the end of the trials ranged between 2.5 and 12%, compared with 21% in the standard treatment plots and 34% in the untreated plots. Cypermethrin, fenpropathrin and AC-222,705 exhibited similar field activity, while that of fenvalerate was somewhat lower. Under laboratory conditions, cypermethrin at 0.005 and 0.01% a.i. was significantly more potent than fenvalerate, fenpropathrin and AC-222,705; at a higher concentration, 0.015% a.i., all pyrethroids were highly active, with mortality ranging between 75 and 95%. Under laboratory conditions the vinegar fly (Drosophila melanogaster Meig.) was in general more susceptible to pyrethroids than was the grape-berry moth. Cypermethrin and AC-222,705 at 0.005% a.i. and avermectin at 0.0035% a.i. were potent compounds against the vinegar fly and more active than fenvalerate and fenpropathrin.     

FACTORS AFFECTING THE LOSS OF TRI-ALLATE FROM SOILS

Summary. Electron-capture gas chromatography was used to detect tri-allate residues in persistence studies with two soils. At rates equivalent to 0–75, 15 and 3 Ib/ac, 50% of the amount applied was degraded in 8–11 weeks at 25°C in moist Regina heavy clay and Weyburn loam. No loss occurred in sterile soils, indicating that microbial degradation may be a, major factor contributing to tri-allate breakdown.
When aqueous solutions buffered at pH 4–8 were held at 25° G, only 10–15% of the tri-allate was chemically degraded during 24 weeks.
At the normal field rate of 1·25 Ib/ac, tri-allate was not readily leached. From soil columns of Weyburn loam, 5–7% was eluted by 9 in. of water; with clay the corresponding value was 12–13% of the amount applied. When field plots were sprayed with 125 lb/ac in April, tri-allate could still be detected until the soil froze in November.
Facteurs agissant sur la perte de tri-allate dans les sots