Citrullinaemia in Friesian calves

Six Friesian calves from a pedigree herd died or were killed within 1 week of birth because of progressive central nervous disease in which the only consistent lesion was cerebral oedema. The cause was citrullinaemia, resulting from an autosomally inherited dysfunction of the urea cycle enzyme arginosuccinate synthetase. Citrullinaemia was diagnosed by demonstrating markedly elevated concentrations of citrulline in the blood of one calf and in the cerebral spinal fluid of another. One of two sires used in the herd was a heterozygous carrier of the disease. Heterozygocity was demonstrated using a polymerase chain reaction/restriction endonuclease test designed to detect the genetic mutation that causes citrullinaemia in cattle.     

Comparative studies of BHV-1 variants by in vivo--in vitro tests.

The new encephalitogenic BHV-1.3 and previously characterized BHV-1 strains were studied with reference to their immunogenic and protective potency and their antigenic relationships using "in vitro" and "in vivo" tests. The "in vitro" results obtained by neutralization kinetics showed that the Los Angeles (LA) strain (BHV-1.1) and a vaginal isolate L-114 strain (BHV-1.2) had antigenic similarities. Conversely, the behavior of the encephalitogenic strain A-663 (BHV-1.3), was significantly distinct. The "in vivo" protection test was carried out in calves using LA and A-663 strains. Post-vaccination antibodies and challenge with A-663 strain showed that the immunogenic behavior and protective capacities of both strains were similar. Neutralization kinetics differences between BHV-1.1 and BHV-1.3 did not alter the "in vivo" protection against BHV-1.3 challenge.     

Covalently protein-bound bilirubin conjugates in cholestatic disease of dogs

We investigated the occurrence of covalently protein-bound bilirubins in the plasma of dogs with hyperbilirubinemia attributable to hepatobiliary diseases or Coombs test-positive hemolysis. The bilirubins in plasma were measured with the conventional Van den Bergh reaction, by treatment with diazotized p-iodoaniline, and by high-performance liquid chromatography of bilirubin and its methylesters after alkaline methanolysis. All but one dog had covalently protein-bound bilirubin conjugates. The concentration and the fraction of total bilirubins varied in all diseases investigated, but they tended to be low in primary hemolysis. The "biliprotein" complex accounted for 2 to 94% of total plasma bilirubins. Because biliprotein usually is not cleared by the liver, but has a half-life comparable with that of albumin, it prevents the evaluation of the actual state of the underlying disease. Measurement of the total bilirubin concentration exclusively with the Van den Bergh reaction, therefore, is clinically useless. Other methods should be introduced for routine bilirubin assays, permitting the measurement of noncovalently bound pigment as a meaningful estimate of the course of the disease.     

Thermodynamic efficiency of brittle frictional mountain building

An active fold-and-thrust belt in unchanging tectonic and climatic conditions attains a dynamic steady-state in which the influx of accreted material at the toe is balanced by the erosive efflux off the top. The overall balance of energy in such a steady-state fold-and-thrust belt is described by the equation E = W(G) + Q, where E is the rate at which both mechanical and heat energy are added from external sources, W(G) is the rate of work performed against gravitational body forces, and Q is the rate at which waste heat flows out of the upper and lower boundaries. The total amount of power being supplied to the active Taiwan fold-and-thrust belt by the subducting Eurasian plate and in situ radioactivity is 4.2 gigawatts. Because only 0.5 gigawatts are expended in doing useful work against gravity and the remaining 3.7 gigawatts are ejected as heat, the efficiency of brittle frictional mountain building in Taiwan is 11 percent.     

Infection process of Rhizoctonia solani on Solanum tuberosum and effects of granular nematicides

The infection process ofRhizoctonia solani AG-3 was studied on potato sprouts, cv. Bintje, in growth chamber trials at 15 °C. Initially hyphae ofR. solani grew predominantly in the longitudinal direction of the sprouts (runner hyphae). They tended to follow the junctions between epidermis cells as was observed by SEM. The hyphae formed side-branches mainly half-way of the subterranean parts of the sprouts. They branched several times with short swollen cells to form infection cushions. Lesions developed only underneath the infection cushions and were first observed five days after inoculation. The necrotic area was proportional to the area covered with infection cushions on the sprouts. Depth of the lesions could extend up to the vascular bundle. Sprouts were colonized only in healthy tissue in the epidermal layer underneath the infection cushion and in necrotic tissue. A few days after appearance of the lesions,R. solani formed brown, uninfective mycelium on and in the circumference of these lesions.Aldicarb did not influence any part of the infection process. Ethoprophos delayed the emergence of sprouts, but increased the number of sprouts per tuber. As soon as sprouts had emerged, growth was considerably promoted by ethoprophos. Ethoprophos delayed the appearance of lesions and reduced their size. Oxamyl showed the same effects to a smaller extent.As the size of lesions appears to be proportional to the size of the infection cushions, any agents that change the size of the infection cushions, such as pesticides or antagonists, may alter the severity of the disease.Samenvatting Het infectieproces vanRhizoctonia solani AG-3 werd bestudeerd op aardappelspruiten, cv. Bintje, in een klimaatcel bij 15C. Aanvankelijk groeide de schimmel met runnerhyfen voornamelijk in de lengterichting van de spruit. Via SEM kon waargenomen worden, dat de hyfen hierbij vooral over de begrenzingen van de epidermiscellen groeiden. Het mycelium vormde veel zijvertakkingen, bestaande uit iets gezwollen korte cellen, welke voornamelijk halverwege op het ondergrondse deel van de spruit gevormd werden. Een dichte massa van deze cellen vormde een infectiekussentje. Lesies, welke vanaf vijf dagen na inoculatie werden waargenomen, bevonden zich slechts onder spruitoppervlak bezet met infectiekussentjes. De lesiegrootte was recht evenredig met het spruitoppervlak dat bezet was met infectiekussentjes. De diepte van de lesies reikte tot aan de vaatbundels. De spruit werd alleen door de schimmel gekoloniseerd in gezond epidermisweefsel onder het infectiekussentje en in necrotisch weefsel. Enkele dagen na verschijning van lesies vormde R.solani bruin, niet infectieus, mycelium op en rondom de lesies.Aldicarb had geen effect op het infectieproces. Ethoprophos vertraagde de opkomst en verhoogde het aantal tot ontwikkeling gekomen spruiten per knol in gestoomd zand. Direct na opkomst had ethoprophos echter een sterk groeistimulerend effect. Ethoprophos vertraagde de lesievorming en reduceerde de lesiegrootte, vergeleken met onbehandelde planten. Oxamyl vertoonde deze effecten in geringere mate.Daar de lesiegrootte direct gecorreleerd blijkt met de grootte van het infectiekussentje, mag verwacht worden dat elke beïnvloeding van de ontwikkeling van het mycelium van R.solani, bijvoorbeeld door pesticiden of antagonisten, een verandering van de lesiegrootte ten gevolge heeft.     

Dynamic properties of molecularly thin liquid films

An experimental technique is described for simultaneously measuring the static and dynamic interactions of very thin liquid films between two surfaces as they are moved normally or laterally relative to each other. Film thickness can be measured and controlled to 1 angstrom. Initial results are presented of the transition in the physical properties of liquid films only one molecular layer thick to thicker films whose properties are practically indistinguishable from the bulk. In particular, the results show that two molecularly smooth surfaces, when close together in simple liquids, slide (shear) past each other while separated by a discrete number of molecular layers, and that the frictional force is "quantized" with the number of layers.     

Nitrogen metabolism in growing swine receiving a bacterial protein supplement (Alcaligenes eutrophus) instead of soybean meal

In a balance trial with 10 pigs (mean body mass 50 kg) the influence of a bacterial protein supplement (Alcaligenes eutrophus) on N-metabolism was investigated. The bacteria were included into the diet at levels of 7 and 14% at the expense of extracted soyabean meal. Thus bacterial "pure protein" (bacterial non-nucleic acid N X X 6.25) amounted to 30 and 60% of the protein of the ration. Consuming 2 kg of feed dry matter per day the animals of the control group (I) and the experimental groups (II and III) ingested 48 g, 52 g and 55 g of total N respectively. The difference in N-intake is explained by the additional nucleic acid-N, amounting to 19,8% of total bacterial N. Daily weight gain (on average 1054 g) and feed conversion efficiency (feed ingested/weight gain; on average 1,9) were relatively improved at the highest dietary level of bacterial cell mass. Faecal N-excretion was increased significantly, whereas renal N-excretion remained unchanged. Mean apparent N-digestibility was 87,4% showing no significant difference between the experimental groups. N-balance values were noticibly increased following the intake of the bacterial protein supplement. The excretion of urinary urea-N was slightly reduced whereas 4-6 times as much allantoin-N was excreted when bacteria were fed. It is calculated that about 80% of the bacterial purines are renally excreted as allantoin and uric acid.