The role of wild birds and the environment in the epidemiology of Yersiniae in New Zealand

A survey was carried out to determine the prevalence of Yersiniae in wild passerines in the lower half of the North island of New Zealand over a period of 12 months. Samples of soil, water and foliage were also collected. Out of a total of 1370 avian samples, only two strains of Y. pseudotuberculosis were isolated and a total of 98 strains of environmental yersiniae were identified, including Y. enterocolitica biotype 1a, Y. frederiksenii, Y. kristensenii and Y. intermedia. No strains of Y. pseudotuberculosis were isolated from 1032 non-avian samples collected, which included 100 samples taken from wild mammals. From the non-avian samples, 51 strains of environmental Yersiniae were identified, of which the relative prevalence of Yersinia enterocolitica, biotype 1a, Y. frederiksenii, Y. kristensenii and Y. intermedia was similar to that in the rural passerines. The prevalence of Yersiniae in soil samples was greater in rural areas than in urban areas of the survey region. In both rural and urban passerine populations, the prevalence of Yersiniae was greater in the winter and early summer than at other times of the vear.     

The hen's egg: Relationship between shell thickness and the amount of organic matter in the shell

Percentage weight loss on ashing was measured in 110 shell segments: 4 segments per shell—broad polar cap, narrow polar cap and two halves of the “barrel” —from 28 shells from 4 strains of chicken. The membranes had been removed, by hand, from each shell segment and shell thickness measured with a biconvex anvil micrometer. For each segment the function γ = T (1 + Wodm/Wmdo) was calculated, where T is the mean thickness, Wo the weight loss upon ashing, Wm the ash weight, d0 the density of the organic matter in the shell (assumed to be 1.0075 g/cm3) and dm the density of the mineral matter (2.386 g/cm3). Govariance analysis of the regression of T on T for each shell segment within each strain showed that the regression was linear, that the lines did not differ in slope, but that there were significant differences between the adjusted means for strains and for segments. This is interpreted as demonstrating that (a) the amount of organic matter in incremental shell is constant, estimated at 0.68 per cent by weight, and (b) the amount of organic matter outside incremental shell is variable. The equivalent thickness of the latter was estimated for each segment of each shell with a standard deviation of 0.4 μm. Other evidence suggests that the variation in organic matter outside incremental shell is due mainly to variation in cuticle thickness. Implications for poultry breeding and for future research are discussed.     

The Morphology of the Ureter in the Duck (Anas platyrhynchos)

The morphology of the ureter of the duck was investigated, using histological, SEM and TEM techniques. The inner perimeter, the total thickness of the ureteral wall and the thickness of each uretral layer were measured. The epithelium was tall columnar and pseudostratified along all the tracts of the ureter and showed a high muco-secretive activity. The lamina propria contained numerous capillaries and aggregates of leucocytes and macrophages. Throughout the lamina propria there was a dense plexus of nerves. Some denuded single nerve fibres were observed between the epithelial basal cells. A plexus of nerves was also observed in the tunica muscularis. The ostium cloacale ureteris opened on a well-developed papilla in the dorsal region of the urodeum. The total thickness of the ureteral wall, the thickness of the lamina propria and the tunica muscularis, and the inner perimeter progressively increased towards the ostium. The above observations suggest that the avian ureter plays an important role in the modification of the urine coming from medullary cones, and in emission of the urine into the cloaca.     

The Foramina of the Cervical Vertebrae of the Ox

All the macroscopically visible foramina of the atlas and axis in 20 oxen are examined and their size, incidence and connections described. The atlas possesses a canal connecting the atlantal fossa with the vertebral foramen. It is suggested that it be named “Canalis vertebroalaris”. The axis contains a prominent transverse canal rather than a foramen, with “cranial” and “caudal transverse foramina”. The canal occurs in an atypical location in 25 % of cases.     

The expression pattern,polymorphisms and association analyses of the porcine NREP gene

NREP (neuronal regeneration related protein homolog) plays a role in the transformation of neural, muscle, and fibroblast cells and in smooth muscle myogenesis. The NREP gene was selected for detailed study as an expressional and functional candidate gene on the basis of data from the expression microarray, which detected the differences in gene expression between Czech Large White pigs and wild boars in the longissimus lumborum et thoracis and biceps femoris muscle tissues. Quantitative real-time PCR results confirmed that porcine NREP was expressed in both skeletal muscles and significantly overexpressed in Czech Large White pigs compared with wild boars (14.5- and 11.6-fold; p < .05). We identified 9 polymorphic sites in the genomic DNA of NREP. Six of these polymorphisms were in complete linkage disequilibrium, and therefore, only 4 loci were informative. The associations of the HF571253:g.103G>A, HF571253:g.134G>A, HF571253:g.179T>C and HF571253:g.402_409delT polymorphisms with backfat thickness, lean meat content and average daily gain were assessed in Czech Large White pigs. The GG genotypes HF571253:g.103G>A and HF571253:g.134G>A, the TT genotypes HF571253:g.179T>C and 67 HF571253:g.402_409delT genotypes had favourable effects on the studied traits. Our results indicate the possibility of utilizing the variability of the NREP gene in marker-assisted selection in order to improve meat production in pigs.     

The anthelmintic effects of five plant extracts on the viability of Parascaris equorum larvae

Ascariasis is a very common parasitic disease in equids, especially in young horses. Despite the use of anthelmintic drugs, resistance has been frequently reported in populations of Parascaris equorum. As a result, herbal preparations are proposed for current control strategies. In this study, a modified method was used for hatching the eggs of P. equorum. After hatching, the effects of methanolic extract of Artemisia dracunculus, Eucalyptus camadulensis, Mentha pulegium, Zataria multiflora and Allium sativum (garlic) were investigated on the recovered larvae. For each extract, the anthelmintic effects of different concentrations (50, 75, 100 and 125 mg/mL) were evaluated at 0, 10, 20, 30 and 40 min after the challenge. The results showed that our modifications to the older method could enhance the hatching rate for the eggs of P. equorum (to an average of 98%). Potassium dichromate was also demonstrated in this study to be a favourable medium during embryonation. In addition, all the concentrations of A. dracunculus and M. pulegium and higher levels (≥100 mg/mL concentrations) of Z. multiflora extracts had significant lethal effects on larvae from the first to the fourth 10 min of the experiment. In contrast, E. camadulensis and A. sativum had not marked effects on larvae viability at any time of the challenge. In conclusion, our data suggest that A. dracunculus, M. pulegium and Z. multiflora have potential to be used as anthelmintic for the control of ascariasis in equid host; however, these effects remain to be confirmed through in vivo studies.     

The importance of the ecological view of agriculture

Abstract

Marked populations of Themeda triandra and Sporobolus fimbriatus tillers were sequentially harvested at fortnightly intervals both under irrigation and under unamended moisture conditions. Sampling covered a period from tiller initiation through to senescence after flowering.

Tiller masses and green leaf areas were used to derive absolute growth rates, relative growth rates, net assimilation rates and leaf area ratios respectively. Growth rates of Themeda triandra were higher, or were maintained at high levels for longer than those of Sporobolus fimbriatus. Moisture stress resulted in considerably depressed growth rates. Photosynthetic efficiency of spring emerging tillers was potentially greatest in midsummer, but this seasonal influence was masked by moisture stress on non‐irrigated treatments.     

The rough-toothed dolphin genome provides new insights into the genetic mechanism of its rough teeth

The rough-toothed dolphin (Steno bredanensis) is characterized by having teeth covered in finely wrinkled vertical ridges, which is a general manifestation of amelogenesis imperfecta. The rough surfaces are hypothesized to be an evolutionary morphological trait of feeding adaptation to increase the dolphin's grip on prey. Here, we assembled a rough-toothed dolphin genome and performed the comparative genomic analysis to reveal the genetic basis of the special enamel. Results showed that genes related to enamel development or dental diseases have undergone diversified adaptive changes that may shape the special enamel morphology of this dolphin species, including positive selection (CLDN19, PRKCE, SSUH2, and WDR72), rapid evolution (LAMB3), or unique amino acid substitutions (AMTN, ENAM, MMP20, and KLK4). Meanwhile, the historical demography of rough-toothed dolphin indicated several distinct population fluctuations associated with climate change. The genome-wide heterozygosity of this dolphin is in the middle of all published data for cetaceans. Although the population is considerable, there may be population or subspecies differentiation, and with the global warming and the increasing disturbance of human activities, we should pay more attention to protection in the future. Together, our study brings new insights into the genetic mechanisms that may have driven the evolution of the special enamel morphology in rough-toothed dolphins and provides the first results of genetic heterozygosity and population historical dynamics of this species, which have important guiding implications for the conservation of this dolphin species.     

The effects of physostigmine on the electroretinogram in the beagle dog

The purpose of the study was to correlate electroretinogram (ERG) parameters with increasing levels of plasma, erythrocyte and ocular tissue cholinesterase inhibition using the beagle dog as a model for human neurovisual toxicity. The anticholinesterase compound physostigmine was administered at various steady-state intravenous infusion rates based on pharmacokinetic estimates of plasma and red blood cell cholinesterase inhibition. The most sensitive parameter was the b-wave amplitude of the rod response, which was significantly depressed compared to pretreatment at all levels of acute cholinesterase depression. The overall maximal ERG response demonstrated a trend of declining a-and b-wave amplitudes, which corresponded with the increased levels of cholinesterase depression, but these differences were not significant. The depression of the electroretinogram rod and cone amplitudes appeared to parallel plasma cholinesterase inhibition more closely than erythrocyte cholinesterase activity. Ocular tissue cholinesterase activity was significantly depressed in the retina (70%), cornea (60%) and dorsal rectus extraocular muscle (46%). Electroretinography may be a useful physiological tool for evaluating the ocular toxicity of certain chemicals or pharmaceuticals associated with cholinesterase biomarker activity.Abbreviations AChE acetylcholinesterase - Amp amplitude - BuChE butyrylcholinesterase - C _p plasma level - C _ss steady-state plasma concentration - D _L loading dose - e ^–kt the rate of elimination over time (t) - ERG electroretinogram - k elimination rate constant - Lat latency - MBW metabolic body weight - O₁–O₅ consecutive oscillatory potential wavelets - PreTx pretreatment - R rate of infusion - R _Inf rate of infusion - V _d volume of distribution     

The effect of breed,sex, and drug concentration on the pharmacokinetic profile of ivermectin in cattle

Ivermectin (IVM) is one of the most widely used antiparasitic drugs worldwide and has become the drug of choice for anthelmintic and tick treatment in beef cattle production. It is known that pharmacokinetic parameters are fundamental to the rational use of a drug and food safety and these parameters are influenced by different factors. The aim of this study was to evaluate the pharmacokinetic profile of IVM in Bos indicus, Bos taurus, and crossbreed cattle (B. indicus × B. taurus) kept under same field conditions and the possible impacts of sex and IVM formulation (1% and 3.15%). It was observed that IVM concentration was significantly affected by breed. The plasma concentrations of IVM, AUC, C_max, and t_1/2β were significantly higher in B. indicus compared to B. taurus. Crossbreed animals showed an intermediate profile between European and Indian cattle. No alteration in pharmacokinetics parameters was detected when comparing different gender. Concerning the pharmacokinetic data of IVM formulation, it was verified that T_max, AUC, and t_1/2β were higher in 3.15% IVM animals than those from 1% IVM formulation. The results clearly indicated that the IVM plasma concentrations in B. indicus were higher than that in B. taurus.     

The Anatomy and Venom-Emitting Mechanism of the Globiferous Pedicellariae of the Urchin Parechinus Angulosus (Leske) With Notes on Their Behaviour

The freshwater snails belonging to the genus Melanoides Olivier, 1804 are widespread across tropical regions of the world and endemic species have evolved in the African Lakes Malawi, Mweru and Tanganyika. The endemic Melanoides species of Lake Malawi have been investigated several times during the last century, due to their large conchological variation, but no unambiguous answer regarding the number of species has been given. The phylogenetic relationship between morphs or genetic clones of Melanoides in Lake Malawi was inferred by phylogenetic analyses of DNA sequence data from the mitochondrial genes 16S and COI. Additional sequences from GenBank were included to investigate the relationship to other morphs from different parts of the world. For the first time, a putative secondary structure was developed for a partial region of 16S in this genus to identify the variability of the secondary structure in stems and loops. The molecular analyses indicated that several genetic clones exist in Lake Malawi and that M. tuberculata is a paraphyletic taxon. It is not clear from the results whether invasions or dispersals account for the complex situation in Lake Malawi. The basal position of M. admirabilis, endemic to Lake Tanganyika, in the inferred phylogeny indicates that Africa might be the origin of the genus. The results further indicate that three major clades of Melanoides, consisting of several genetic clones, are present in Lake Malawi; one clade consisting of invasive M. tuberculata, another of native M. tuberculata and a third consisting of the M. polymorpha- complex. It appears as if the unique development of morphs within the Melanoides genus in Lake Malawi has evolved primarily by divergence of genetic clones instead of species differentiation.     

The timing of oviposition and ovulation in the quail (Coturnix coturnix japonica)

An extensive series of experiments was performed to assess the common Coturnix quail as a laboratory bird for research on ovulation. The results indicate that the timing of the sequential events of ovulation, egg formation and lay in Coturnix is sufficiently constant to permit access to the physiological processes which determine ovulation and to provide convenient means for assessment of results. Special problems of method and limitations in the use of the quail are discussed. Differences in the timing of sequential ovulations in chickens and Coturnix are described. It is concluded that Coturnix will be a valuable subject for comparative studies on ovulation in birds.     

The Chimpanzees of the Taï Forest.

This paper reports a previously undescribed form of predation upon the angulate tortoise, Chersina angulata, in the West Coast National Park, South Africa. Twelve recently killed C. angulata were found, within an area of 4–5 hectares, during April 2000. The head and neck were missing from all individuals, while the rest of the body was undamaged. Spoor of the large grey mongoose, Herpestes ichneumon, was observed at a freshly killed tortoise and it is argued that this was the predator responsible.     

The significance of the gastrointestinal parasites of Asian buffalo in Sri Lanka

Buffalo aged 3–15 months on institutional farms and in the villages of an irrigation project were monitored for gastrointestinal nematodes by faecal egg counts over two years. Apart from treatment for Toxocara vitulorum at 10–16 days of age, no anthelmintics were used. Half of the strongylid egg counts were zero and 90% were less than 500 epg of faeces on the institutional farms, and 67% were zero and 97% less than 500 epg in the villages. No problems arose during four years without anthelmintics on the institutional farms and during two years in the villages. Autopsies demonstrated that the eggs which were present were produced by mixed infections of small numbers of Haemonchus spp., Mecistocirrus digitatus, Trichostrongylus spp., Bunostomum phlebotomum and Cooperia spp. High egg counts of Strongyloides papillosus occurred in calves up to six months old, but were not pathogenic.     

The hen's egg: Relationship of mean strain energy at shell fracture to shell compression speed,the nature of the compressing body and the location on the shell of the point of contact

1. The mean energy, E_f, required for fracture of an egg shell at its equator by a flat plate is known to depend on shell compression speed, v_m, for speeds in the range 20 μm/s to 2.lb5 mm/s; analysis of published data shows that E_f bears a linear relationship to log (v_m ) throughout the industrially important speed range from 20 μm/s to 1.lb1 m/s, increasing from 1.lb3 to 5.lb0 mJ.

2. At lower speeds down to 2 μm/s E_f is constant.

3. E_f is reduced if the flat plate is replaced by a sphere or cylinder; the greater its curvature, the smaller E_f.

4. E_f for the narrow pole is greater and for the broad pole smaller than that for the equator but these differences may be due in part to . systematic differences in shell thickness as well as curvature.     

The influence of Trypanosoma congolense infection on the disposition kinetics of diminazene aceturate in the dog

Diminazene aceturate was administered intravenously at 3.5 mg/kg body weight to mongrel dogs before and after infection with Trypanosoma congolense. Plasma and urine were collected at varying intervals thereafter and analysed for the compound. The mean are under the concentration-time curve (AUC) of diminazene in healthy dogs was 25.8 h.g/ml but was significantly increased (p<0.05) to 35.7 h.g/ml after infection with T. congolense. The distribution half-life was significantly reduced (p<0.05) in dogs after infection, being 0.12 h compared to 0.17 h in the same dogs before infection. The mean proportion of the diminazene recovered in the urine of infected dogs (25.1%) was not significantly different from that recovered in the urine of healthy dogs (26.8%). These results indicate that infection with T. congolense increases the rate at which diminazene is distributed in the body but that the infection has no marked influence on the urinary excretion of the drug.     

The Ecology of Patella From the Cape Peninsula South Africa

Forty-six species were recorded in association with Patella spp., but most of these are casual associates, seeking temporary shelter. The shell surface offers an important substrate for algae.

The amphipod Hyale grandicornis is often associated with Patella, particularly in the juvenile stages. It is a facultative inquiline which vacates its hosts at high tide. The isopods Dynamenella australis and D. scabricula are predominantly associated with limpets and complete their life cycles under limpets. Choice chamber experiments demonstrate their preference for sheltering under limpets. The copepod Scutellidium patellarum is similar, but the association is more marked.

Calliopiella michaelseni (Amphipoda) is commensal and show a preference for certain limpet species. Its colour changes in relation to the host species. Feeding occurs on limpet faeces and algal fragments. The life cycle is completed under the limpet, two reproductive peaks occurring each year. Adults usually occur in pairs and there is a positive correlation between host and amphipod size. Juveniles remain with their parents initially, and then disperse to other limpets. Adult pairs may defend their host, excluding other amphipods. Calliopiella is strongly photonegative and thigmotactic.

The turbellarian Notoplanapatellarum is preferentially commensal with Patella oculus. This can be experimentally demonstrated. It feeds on small Crustacea, including Scutellidium.     

The 2006 outbreak of bluetongue in northern Europe—The entomological perspective

After bluetongue (BT) appeared in northern Europe in August 2006 entomological studies were implemented in all five affected Member States (MSs) to establish which species of Culicoides had acted as vectors. The findings can be summarised as follows: (i) C. imicola the principal southern European/African vector of BTV has not penetrated into northern Europe, (ii) three pools of C. obsoletus/C. scoticus and one of C. dewulfi assayed RT-PCR-positive to BTV-8, (iii) in support of these results it was found that both potential vectors had also high parity rates (approximately 40%) indicating increased longevity favouring BTV virogenesis and transmission, (iv) furthermore, C. obsoletus/C. scoticus and C. dewulfi occurred also widely and abundantly on sheep and cattle holdings across the entire affected region, (v) and during the latter part of the season showed strong endophily readily entering livestock buildings in significant numbers to bite the animals inside (endophagy), (vi) which demonstrates that housing at best offers only limited protection to livestock from Culicoides attacks, (vii) in contrast the potential vector C. pulicaris sensu stricto was restricted geographically, was captured rarely, had a low parity rate (10%) and was exophilic indicating it played no role in the outbreak of BT, (viii) the incrimination of C. dewulfi as a novel vector is significant because it breeds in cattle and horse dung this close association raising its vectorial potential, but (ix) problems with its taxonomy (and that of the Obsoletus and Pulicaris species complexes) illustrates the need for morphological and molecular techniques to become more fully integrated to ensure progress in the accurate identification of vector Culicoides, (x) midge densities (as adjudged by light traps) were generally low indicating northern European Culicoides to have a high vector potential and/or that significant numbers of midges are going undetected because they are biting (and transmitting BTV) during the day when light traps are not effective, and (xi) the sporadic capture of Culicoides in the winter of 2007 invites re-examination of the current definition of a vector-free period. The re-emergence of BT over a wide front in 2007 raises anew questions as to precisely how the virus overwinters and asks also that we scrutinise our monitoring systems in terms of their sensitivity and early warning capability.     

The detection of Mycobacterium paratuberculosis in bovine faeces by isolation and the comparison of isolation with the examination of stained smears by light microscopy

The detection of Mycobacterium paratuberculosis organisms in bovine faeces by isolation was compared with that by the microscopical examination of Ziehl-Neelsen stained faecal smears for the presence of clumps of acid-fast M. paratuberculosis organisms. Faeces were obtained from cattle naturally or experimentally infected with M. paratuberculosis as well as from uninfected cattle. Microscopical examination was an unreliable method for the detection of M. paratuberculosis organisms since the organisms were only detected in 99 (=55.9%) of 177 culturally positive faecal samples. In addition, clumps of acid-fast organisms indistinguishable from M. paratuberculosis were also observed in three of 18 samples from cattle free from Johne's disease and in 18 of 37 culturally negative samples from paratuberculous cattle. When M. paratuberculosis organisms were added to faeces from an uninfected cow, results showed that isolation attempts should be positive when 15 or more M. paratuberculosis organisms per gram of faeces are present.