Toxicological studies with the 1,3,5-triazine herbicide cyanazine

Acute and long-term mammalian toxicity studies were carried out with the 1,3,5-triazine herbicide cyanazine (I) and its two major plant and soil metabolites DW 43 85 (II) and DW 4394 (III). Depending upon the species used, the acute oral LD50 values for cyanazine ranged from 140-750 mg/kg, the values in any one species not being influenced by formulation. The acute, percutaneous LD50 values were greater than 1000 mg/kg, the maximum dose which could be administered. Cyanazine was non-irritant to eyes and skin and a non-sensitiser to skin. The acute oral LD50 in rats for (II) was 789 mg/kg and for (III) was >2000 mg/kg. In 13-week studies on cyanazine, reduced growth rates and organ weight changes were the most sensitive criteria of exposure, 25 parts/million in the diet of rats and 5 mg/kg orally dosed to dogs being considered to be without toxicological effect. In two year studies 12 parts/million in the diet of rats and 1.25 mg/kg, orally dosed to dogs produced no changes of toxicological significance. In 13-week studies with (II) and (III), intakes of up to 10 000 parts/million in the diet failed to produce any toxicologically significant changes.     

Rabies surveillance in the United States during 2004

During 2004, 49 states and Puerto Rico reported 6,836 cases of rabies in nonhuman animals and 8 cases in human beings to the CDC, representing a 4.6% decrease from the 7,170 cases in nonhuman animals and 3 cases in human beings reported in 2003. Approximately 92% of the cases were in wildlife, and 8% were in domestic animals (compared with 91% and 9%, respectively, in 2003). Relative contributions by the major animal groups were as follows: 2,564 raccoons (37.5%), 1,856 skunks (27.1%), 1,361 bats (19.9%), 389 foxes (5.7%), 281 cats (4.1%), 115 cattle (1.7%), and 94 dogs (1.4%). Compared with the numbers of reported cases in 2003, cases in 2004 decreased among all groups, except bats, cattle, human beings, and "other domestics" (1 llama). Decreases in numbers of rabid raccoons during 2004 were reported by 12 of the 20 eastern states in which raccoon rabies was enzootic. In the East, Massachusetts reported the first cases of raccoon rabies detected beyond the Cape Cod oral rabies vaccine barrier. Along the western edge of the raccoon rabies epizootic (Ohio in the north and Tennessee in the south), cases of rabies were reported from unexpected new foci beyond oral rabies vaccine zones. On a national level, the number of rabies cases in skunks during 2004 decreased by 12.1% from the number reported in 2003. Once again, Texas reported the greatest number (n = 534) of rabid skunks and the greatest overall state total of rabies cases (913). Texas reported only 1 case of rabies in a dog that was infected with the dog/coyote rabies virus variant and only 22 cases associated with theTexas gray fox rabies virus variant (compared with 61 cases in 2003). The total number of cases of rabies reported nationally in foxes and raccoons declined 14.7% and 2.7%, respectively, during 2004. The 1,361 cases of rabies reported in bats during 2004 represented a 12.3% increase over the previous year's total of 1,212 cases for this group of mammals. Cases of rabies reported in cats, dogs, horses and mules, and sheep and goats decreased 12.5%, 19.7%, 31.8%, and 16.7%, respectively, whereas cases reported in cattle increased 174%. In Puerto Rico, reported cases of rabies in mongooses decreased 4.1% and rabies in dogs (9 cases) remained unchanged from those reported in 2003. Among the 8 cases of rabies in human beings, 1 person from Oklahoma and 3 from Texas died following receipt of infected organs and tissues from an Arkansas donor. In California, a person originally from El Salvador and, in Florida, a person originally from Haiti both died of canine rabies infections acquired outside the United States. In Wisconsin, a teenager contracted rabies from a bat bite and became the first known person to survive rabies despite not having received rabies vaccine prior to symptom onset.     

Control of Microdochium majus in winter wheat with botanicals – from laboratory to the field

The fungal pathogen Microdochium majus, causing snow mould, seedling blight and foot rot, results in severe yield losses in small grain cereals. There are few options to control this pathogen in organic production. In this study, aqueous extracts or botanical powders prepared from chamomile, meadowsweet, thyme and Chinese galls were tested in vitro against M. majus conidia germination and mycelial growth, respectively. Subsequently, three botanicals were chosen, applied as powders with different seed coating adhesives, and tested for their effect on the incidence of M. majus from naturally infected wheat seed lots and on seedling emergence from soil under controlled environmental conditions. Furthermore, seed treatments with warm water, a bacterial product or one chosen botanical were tested in a growth chamber and in a field experiment over three consecutive years. Of the botanicals tested, Chinese galls showed the highest efficacy in controlling M. majus, reducing conidia germination and mycelial growth by up to 97 and 100%, respectively, and reducing the incidence from infested seeds by up to 59%. In two growth chamber experiments, total seedling emergence increased by up to 30 and 59% compared with the control treatments following an application with Chinese galls. Under field conditions, yield increase through Chinese galls, the bacterial product and the warm water treatment was 19, 10 and 37% compared with the untreated control, respectively. This study demonstrates the potential of Chinese galls to control M. majus in wheat. Options for improved formulations or combinations of heat‐based treatments with Chinese galls are discussed.     

The effect of three space allowances on the physiology and behavior of weaned pigs during transportation

Stocking density is an important aspect of transport, which could affect animal health and welfare, especially in pigs simultaneously experiencing weaning stress. The objective of this research was to evaluate the effect of three different space allowances on the physiology and behavior of weaned pigs during transport. A commercial semi-trailer with compartments that provided 0.05, 0.06 and 0.07 m²/pig was used throughout the study. All three space allowances were represented on both the upper and lower decks during each replicate. A constant of 100 pigs were loaded into each experimental compartment. Pigs were then transported for 112.5 ± 6.5 min to the wean-to-finishing site using the same route for each replication. This experiment was replicated 4 times. The experimental unit was the compartment. Prior to and after transport, blood samples were taken from a sub-set of pigs (n = 32 pigs/space allowance) for analysis of physiological and immune measures, and body weights and lesion scores were also recorded. Data loggers were fitted inside the trailer to record temperature, humidity, and wind speed. Cameras were placed in each experimental compartment to record behavior and postures of pigs during transport. The frequencies of standing, lying, sitting, standing-rearing on another pig, lying/huddling on top of another pig, total active and total inactive behaviors were recorded using 1-min scan samples during the entire duration of transport. Inside trailer temperature ranged from − 2.4 to 21.7 °C and inside trailer relative humidity ranged from 28.4 to 89.2% during transport. Cortisol, the neutrophil:lymphocyte (N:L) ratio, blood urea nitrogen, total bilirubin, total protein, albumin, aspartate aminotransferase, and creatine kinase were higher (p < 0.05) in pigs after transport regardless of space allowance. Skin lesions were more severe (p < 0.001) in pigs after transport regardless of space allowance. Pigs spent more (p < 0.001) time active during the first 75 min of transport compared with the last 30 min, regardless of space allowance. Pigs spent less (p < 0.01) time standing on another pig during transport at 0.07 m²/pig compared with pigs transported at 0.06 m²/pig. Higher cortisol concentrations and N:L ratio in weaned pigs after transport suggest that these pigs experienced stress, however space allowance did not appear to influence this response. Space allowances of 0.05, 0.06 or 0.07 m²/pig did not differentially influence pig well-being during a 112-min transport period as measured by changes in physiological measures.     

Ingestion of deep-sea mining discharge by five species of tropical copepods

Five species of tropical copepods were exposed to samples of mining discharge and the fecal pellets produced were collected for chemical comparisons with mining discharge and with fecal pellets produced when the same species were held in ambient sea water. Chemical compositions were compared by means of Energy Dispersive Analysis of X-rays (EDAX). Chemical composition of fecal pellets and mining discharge indicates uptake of mining discharge inUndinula vulgaris,Euchaeta rimana, andLabidocera acutifrons, possible uptake inUndinula darwinii and no apparent uptake inOncaea venusta. The total difference between the elemental ratios, standardized to Ca, observed for mining discharge and fecal pellets are 22.9 and 6.8 inUndinula vulgaris, 23.9 and 13.6 inEuchaeta rimana, 23.3 and 2.9 inLabidocera acutifrons, 19.8 and 13.7 inUndinula darwinii, and 18.2 and 4.0 inOncaea venusta for fecal pellets produced by copepods held in ambient sea water and for fecal pellets produced when exposed to a sample of mining discharge respectively. The application of EDAX to chemical analysis of fecal pellets is described and discussed.     

A manganese(IV)/iron(III) cofactor in Chlamydia trachomatis ribonucleotide reductase

In a conventional class I ribonucleotide reductase (RNR), a diiron(II/II) cofactor in the R2 subunit reacts with oxygen to produce a diiron(III/IV) intermediate, which generates a stable tyrosyl radical (Y*). The Y* reversibly oxidizes a cysteine residue in the R1 subunit to a cysteinyl radical (C*), which abstracts the 3'-hydrogen of the substrate to initiate its reduction. The RNR from Chlamydia trachomatis lacks the Y*, and it had been proposed that the diiron(III/IV) complex in R2 directly generates the C* in R1. By enzyme activity measurements and spectroscopic methods, we show that this RNR actually uses a previously unknown stable manganese(IV)/iron(III) cofactor for radical initiation.