The crystal structure of perfluorononanoic acid (PFNA) was solved via parallel tempering using synchrotron powder diffraction data obtained from the Brockhouse X-ray Diffraction and Scattering (BXDS) Wiggler Lower Energy (WLE) beamline at the Canadian Light Source. PFNA crystallizes in monoclinic space group P21/c (#14) with lattice parameters a = 26.172(1) Å, b = 5.6345(2) Å, c = 10.9501(4) Å, and β = 98.752(2)°. The crystal structure is composed of dimers, with pairs of PFNA molecules connected by hydrogen bonds via the carboxylic acid functional groups. The Rietveld-refined structure was compared to a density functional theory-optimized structure, and the root-mean-square Cartesian difference was larger than normally observed for correct powder structures. The powder data likely exhibited evidence of disorder which was not successfully modeled.

Field trials were conducted at two sites in 1996 and 1997 to evaluate weed control and crop response to herbicide programs in no-till soybean that include flumioxazin or sulfentrazone alone and each herbicide tank-mixed with either chlorimuron or imazaquin. A prepackaged mixture of metribuzin plus chlorimuron also was included for comparison. Cool, wet conditions after herbicide application in both years were conducive to soybean injury up to 21% at 3 wk after planting (WAP). Flumioxazin and sulfentrazone alone provided ≥ 89% control of velvetleaf, Pennsylvania smartweed, and common cocklebur. Sulfentrazone alone provided greater control of common waterhemp, common cocklebur, and ivyleaf and pitted morningglories than flumioxazin. Flumioxazin provided greater control of common ragweed than sulfentrazone. The addition of chlorimuron to flumioxazin or sulfentrazone provided greater control of velvetleaf than flumioxazin or sulfentrazone alone. The addition of imazaquin or chlorimuron to flumioxazin provided greater control of common cocklebur than flumioxazin alone. The addition of imazaquin or chlorimuron to sulfentrazone provided greater control of common ragweed than sulfentrazone alone. The addition of chlorimuron or imazaquin to sulfentrazone or flumioxazin provided little or no additional control of pitted morningglory, common waterhemp, or Pennsylvania smartweed. Metribuzin plus chlorimuron provided control of velvetleaf, Pennsylvania smartweed, common ragweed, and common cocklebur that was equal to or better than the control provided by sulfentrazone or flumioxazin plus chlorimuron or imazaquin.

Cosmic radiation is capable of depositing significant quantities of energy and momentum in gravitational wave antennas at times that will generally be random with respect to gravitational signals. Such cosmic ray effects may generate noise signals at detectable levels compared to antenna design thresholds at rates of a few per year but, since antennas will not be capable of absorbing all the cosmic ray energy, it should be readily possible to construct vetoing cosmic ray detectors. For proposed interferometer antennas, a deposition of a few hundred GeV will produce a detectable noise signal and the veto will require about 100 MeV of energy deposition outside the antenna. We consider here some of the principles involved in the generation of gravitational antenna noise by cosmic ray particles and we describe a veto system to be installed at the Perth gravitational wave observatory.

Human campylobacteriosis exhibits a distinctive seasonality in temperate regions. This paper aims to identify the origins of this seasonality. Clinical isolates [typed by multi-locus sequence typing (MLST)] and epidemiological data were collected from Scotland. Young rural children were found to have an increased burden of disease in the late spring due to strains of non-chicken origin (e.g. ruminant and wild bird strains from environmental sources). In contrast the adult population had an extended summer peak associated with chicken strains. Travel abroad and UK mainland travel were associated with up to 17% and 18% of cases, respectively. International strains were associated with chicken, had a higher diversity than indigenous strains and a different spectrum of MLST types representative of these countries. Integrating empirical epidemiology and molecular subtyping can successfully elucidate the seasonal components of human campylobacteriosis. The findings will enable public health officials to focus strategies to reduce the disease burden.

Three known species of scale insects belonging to the genus Matsucoccus occur on pine trees in northeastern North America: M. gallicolis Morr., on pitch pine, Pinus rigida Mill., and scrub pine, Pinus virginiana Mill. (Parr, 1939); M. resinosae Bean and Godwin on red pine, P. resinosa Ait. (Bean and Godwin, 1955); and M. macrocicatrices Richards on eastern white pine, P. strobus L. (Richards, 1960). This last species. in contrast with the others, is closely associated with the fungus Septobasidium pinicola Snell. From 1957 to 1959 personnel of the Forest Insect Laboratory, Sault Ste. Marie, and the Forest Biology Laboratory, Fredericton, collected some 500 specimens from 21 areas in Ontario and the Maritime Provinces. These collections, augmented by herbarium specimens provided by the Forest Pathology Laboratory, Maple, from five other areas in Ontario, not only the insect specimens necessary for the dercription of the species, but information on its biology and distribution.

An experimental X-ray powder diffraction pattern was produced and analyzed for imipenem monohydrate, an antimicrobial pharmaceutical agent. Although there are no experimental powder patterns in the ICDD PDF-4/Organics Database, there is one powder pattern calculated with single-crystal X-ray diffraction data from the Cambridge Structural Database. Here, we report the refined experimental powder diffraction data for imipenem monohydrate. These data for imipenem monohydrate are consistent with an orthorhombic crystal system having reduced unit-cell parameters of a = 8.2534(3) Å, b = 11.1293(4) Å, and c = 15.4609(6) Å. The resulting unit-cell volume, 1420.15(15) Å3, indicates four formula units per unit cell. Observed peaks are consistent with the P212121 space group.

A total of 41 ticks were collected from 15 quokkas on Bald Island and 2 ticks from a Gilbert's potoroo from Two Peoples Bay. Three species of Ixodid ticks Ixodes australiensis, Ixodes hirsti and Ixodes myrmecobii were identified on the quokkas known to have a high prevalence of Trypanosoma copemani. Tick faeces from ticks isolated from 8 individual quokkas and a Gilbert's potoroo were examined with one identified as positive for trypanosomes. Faecal examination revealed trypanosomes similar to in vitro life-cycle stages of T. copemani. In total 12 ticks were dissected and trypanosomes found in sections of their midgut and haemolymph, 49 and 117 days after collection. Tick faeces, salivary glands and midguts from I. australiensis were screened using an 18S rRNA PCR with amplification seen only from the midguts. Sequencing showed 100% homology to T. copemani (genotype A) and 99·9% homology to the wombat (AII) isolate of T. copemani. Trypanosomes were only detected in I. australiensis as neither I. hirsti nor I. myrmecobii survived the initial 30-day storage conditions. We therefore identify a vector for T. copemani as I. australiensis and, given the detection of trypanosomes in the faeces, suggest that transmission is via the faecal-oral route.

During a 15-month period in Scotland a small but important number of human Campylobacter cases (3·2%) arose from 91 putative household outbreaks. Of the 26 outbreaks with known strain composition, 89% were composed of the same MLST which supports the potential use of MLST in public health epidemiology. The number of cases associated with household outbreaks is much larger than general outbreaks and there is some evidence to indicate that there may be secondary transmission, although this is relatively rare.

Distinctive flask-shaped cysts have been observed within the loricae of the tintinnids Favella serrata (Mobius),Helicostomella subulata (Ehrenberg), Parundella caudata (Ostenfeld) and Leprotintinnus pellucidus (Cleve) from samples taken by the Continuous Plankton Recorder. Similar cysts occur as a common element in palynological preparations of intertidal sediments from the British Isles. Encystment in tintinnids is now known for over 20 species and appears to be a more important process in the tintinnid life-cycle than previously believed. A possible relationship between tintinnid cysts and the extinct microfossil order Chitinozoa is proposed.

Results from the Continuous Plankton Recorder (CPR) Survey have been used to extend the observation by Boalch & Harbour (1977 a) of the occurrence in January 1977 of a diatom Coscinodiscus nobilis (Grunow), new to British waters. Samples have been taken by the CPR to the west of the British Isles since 1948 and along the English Channel since 1957. C. nobilis was not identified until the spring of 1977, thus confirming the observations by Boalch & Harbour. It reappeared in 1978 when it was found further north in the Irish Sea.

Chaffed lucerne hay of 64% apparent organic matter (OM) digestibility was fed to wether sheep under four feeding regimens: two levels of dry matter (D.M.) intake (700 (L) and 1050 (H) g/day) and within each level two feeding frequencies (once a day (daily) and once an hour (hourly)). Three separate groups of sheep were used concurrently: a slaughter group was used to obtain feeding behaviour data and to measure pool sizes and obtain samples from the reticulo-rumen; a digestion group, in which each sheep was prepared with a rumen and a duodenal cannula, was used to measure duodenal digesta flow, rumen microbial growth and reticulo-rumen motility; a balance group was used to measure digestibility and nutrient balances.

High D.M. intake increased reticulo-rumen pool sizes and flow rates but it did not affect apparent digestibilities or the proportions of OM, fibre, cellulose, hemicellulose, lipid and nitrogen digested in the stomach and intestines. Increased feeding frequency had a major effect on reticulo-rumen pool sizes but did not affect apparent digestibilities or partition of digestion of non-nitrogenous constituents. Daily feeding resulted in increased total-N flow to the duodenum; however, N retention was significantly greater with frequent feeding. It is suggested that this was due to a more efficient tissue utilization of N.

The kinetics of digesta flow within the reticulo-rumen, expressed as fractional flow rates, were studied with data from sheep fed hourly. The fractional inflow, outflow and disappearance rates for OM, fibre, cellulose and hemicellulose did not change with an increase in intake because of an equivalent increase in reticulo-rumen volume. Increasing D.M. intake by 50% resulted in a 24% increase in water intake, a 19% increase in reticulo-rumen water volume, and a 49% increase in water outflow rate. The data suggest that the increased outflow of water was achieved by increasing the net flow of water across the mucosa into the reticulo-rumen, rather than by increasing salivation.

There was no difference between treatments in the frequency of reticulo-rumen contractions. It was calculated that for each A sequence contraction, OM flow was 0·26 and 0·37 g and water flow was 4·38 and 0·36 g on L and H intakes respectively. A 50% increase in intake resulted in a 42% increase in OM passage per A sequence contraction. This increased passage with intake was not accompanied by an increase in reticulorumen contraction frequency.

1. The object of the experiment was to determine the effects on the diet and production of grazing dairy cows of providing different quantities of herbage over a relatively long period.

2. Three groups of five Ayrshire cows were strip grazed on areas supplying (A) 25, (B) 35 or (C) 45 lb D.M. per cow per day, for a total of 11 weeks. Three swards were used in succession, and measurements of herbage intake, milk production and live-weight changes were made over the last 10 weeks.

3. Mean intakes for treatments A–C, respectively, were 23·9, 25·6 and 26·4 lb organic matter per cow per day, and milk yields were 30·4, 30·8 and 32·8 lb. Differences in digestibility between treatments were small, even when the cows grazed poor herbage in which the organic matter was only 68 % digestible.

4. The treatments had no significant effects on milk composition or live-weight gain, although the latter was less for treatment A.

For phase I of a rotational grazing experiment (three grazing cycles; May–July) a group of nine cows (group S) were ‘conditioned’ to eat fouled herbage by being allowed to graze only on slurry-treated pasture (area 1), and two further groups of nine (groups H and C) grazed on an adjacent area (2) of untreated pasture. One-third of area 2 was harrowed after each grazing. During phase II (the fourth grazing cycle; August) group H grazed on the harrowed part and groups S and C grazed on the remainder of area 2. The herbage allowance was 15 kg dry matter per cow per day in phase I and 12 kg in phase II.

In phase I, group S cows ate significantly less than groups C and H combined (9·2 v. 10·5 kg organic matter per day), and lost weight (– 0·37 v. + 0–03 kg/day), but their milk yields were not significantly lower (16·1 v.16–6 kg/day). In phase II neither intake nor milk yield differed significantly between the three groups, but group S cows gained weight while the other two groups lost weight.

It was concluded that neither conditioning the cows nor harrowing the pasture was an effective means of avoiding rejection of fouled pasture.

1. In each of 6 digestibility trials, comprising a total of 21 measurement periods of 3-4 days, two steers were fed on herbage cut from the top of the sward, two on the remaining bottom growth and two on a mixture of equal parts of these fractions. Within each period the fractions were similar in digestibility although the top growth had a higher content of nitrogen.

2. The trials were divided into three groups, according to time of year, for the purpose of calculating regressions of digestibility on faecal nitrogen concentration. Regressions calculated in the usual manner on a between-period basis (i.e. within animals) had constant terms which differed significantly among animals but not from one fraction of the herbage to another.

Two experiments were made, each with 35 autumn-calving cows fed on complete diets containing 40–70% hay and 60–30% concentrates. In both experiments, cows fed to appetite on a diet containing 11 MJ metabolizable energy/kg D.M. for weeks 7–24 of lactation ate about 20% more than cows rationed according to yield, but produced only about 3% more milk. The cows fed to appetite gained more in live weight, but lost their weight advantage during the subsequent grazing season.

In Expt 1, a further group of cows were fed to appetite on diets progressively reduced in metabolizable energy content from 11·0 to 9·2 MJ/kg. Dry-matter intake decreased by about 1·2 kg/day per 1 MJ reduction in energy content. The lower dry-matter and energy intakes of cows on this treatment did not significantly reduce their milk yield, but their response when turned out to grass suggested under-nutrition in late winter. In Expt 2, increasing the energy content of the diet in early lactation (weeks 7–12) and reducing it thereafter had no significant effect on milk yield.

Within each treatment group there were reasonably close relationships between energy intake and energy requirement. Nevertheless, it seems likely that the efficiency of feed utilization of cows fed on complete diets will be low unless intake is controlled by energy dilution.

Chaffed lucerne hay was fed to wether sheep at two feeding frequencies (once a day (daily) and once an hour (hourly)) and at two levels of dry matter (D.M.) intake (700 (L) and 1020 (H) g/day). Sheep fed daily were slaughtered either prior to eating, immediately after eating ceased or 10 h after eating ceased to compare rumen, reticulum, omasum and abomasum pool sizes and particle size distributions within pools.

Effects of level of intake, feeding frequency and time after feeding were confined mainly to the rumen which contained 77–91% of stomach D.M. Once-daily feeding resulted in a 2·6 fold variation in rumen D.M. pool size. Sheep fed hourly had a relatively small rumen and comparatively large reticulum D.M. pool. Diurnal changes in reticulo-rumen particle size pools are discussed in relation to the effectiveness of chewing.

Particle size distribution in digesta was estimated by wet sieving. On average the proportion of D.M. retained on a sieve 1 mm or larger comprised 35, 28, 4 and 4% of D.M. in the rumen, reticulum, omasum and abomasum, respectively, D.M. passing a 0·25 mm sieve comprised 40, 46, 57 and 61% of D.M. in the respective organs.

The reticulum usually contained significantly less D.M. retained on a 4 mm sieve than the rumen, and reticulum D.M. percentage was usually 3–5 units lower than rumen D.M. percentage. Reticulum digesta composition is discussed in relation to the efflux of particulate D.M. to the omasum.

Chemical composition of rumen particulate D.M. retained on sieves > 0·25 mm was comparatively unaffected by intake level and feeding frequency. Analyses of particle composition showed a rapid loss of non cell wall constituents after feeding and an increasing contribution of rumination toward particle size reduction.

Artificially reared sambar (tropical) deer and red (temperate) deer were confined indoors in metabolism cages and fed chaffed lucerne hay ad libitum for 4-week periods during summer and winter at Flock House Agricultural Centre, New Zealand, during 1992. Measurements were made of voluntary feed intake (VFI), apparent digestibility, faeces particle size distribution, eating and ruminating time and the rate of chewing during eating and ruminating. Red deer reduced VFI (kg DMI/day) markedly from summer to winter, associated with a reduction in the duration of each eating bout. Sambar deer slightly increased VFI over this time, associated with an increase in chewing frequency. Digestive efficiency was similar in both species, and the critical particle size for leaving the rumen was passage through a 1 mm sieve for both species. Time spent eating/g DMI was greater for sambar deer than for red deer during summer, but there was no difference during winter. Relative to red deer, sambar deer consistently spent more time ruminating/g DMI, and spent a greater proportion of total ruminating time as daytime ruminating and had more daytime ruminating bouts. Duration of each ruminating bout (min) was similar for the two deer species, but sambar deer had less chews/bolus ruminated but more rumination boli/h than red deer. Differences between sambar deer and red deer were more pronounced in ruminating than in eating behaviour, and sambar deer may have evolved a different rumination pattern to break down low-quality tropical forages more effectively.