Dim light at night affects the locomotor activity of nocturnal African pygmy mice (Mus minutoides) in an intensity-dependent manner.

Rodents are integral components of ecosystems as they provide several important ecosystem services. Despite their importance as prey, pollinators and seed distributors, African rodents are largely understudied. The effect of anthropogenic changes such as artificial light at night extends past urban areas to peri-urban and rural habitats, and can have profound effects on entire ecosystems. We investigated the effect of dim light at night (dLAN) on the locomotor activity rhythms of the African pygmy mouse (Mus minutoides). Pygmy mice showed a dramatic, intensity-dependent reduction in their locomotor activity when subjected to dLAN, which was accompanied by a delay in the activity onset. We also considered masking responses with a dark pulse (DP) during the day and a light pulse at night. All animals became inactive in response to a light pulse during the night, whereas approximately half of the animals showed activity during a DP in the day. Our results suggest that the African pygmy mouse is highly sensitive to light and that their activity is strongly masked by light. In their natural environment, vegetation could shield pygmy mice against high light levels; however, other anthropogenic disturbances can alter the behaviour of these animals and could affect their survival.

Adverse effects of heat stress during summer on broiler chickens production and antioxidant mitigating effects.

Broiler chicken meat is a good source of protein consumed universally, and is one of the most commonly farmed species in world. In addition to providing food, poultry non-edible byproducts also have value. A major advantage of broiler chicken production is their short production cycle, which results in a greater rate of production in comparison to other species. However, as with any production system, there are constraints in broiler production with one of the most pressing being energy requirements to keep the birds warm as chicks and cool later in the growth cycle, as a result of the cost needing mechanical heating and cooling. While this is feasible in more advanced economies, this is not readily affordable in developing economies. As a result, farmers rely on natural ventilation to cool the rearing houses, which generally becoming excessively warm with the resultant heat stress on the birds. Since little can be done without resorting to mechanical ventilation and cooling, exploring the use of other means to reduce heat stress is needed. For this review, we cover the various factors that induce heat stress, the physiological and behavioral responses of broiler chickens to heat stress. We also look at mitigating the adverse effect of heat stress through the use of antioxidants which possess either an anti-stress and/or antioxidant effects.

Flexibility in body temperature rhythms of free-living natal mole-rats (Cryptomys hottentotus natalensis).

The subterranean niche is a specialised and particularly challenging environment to obtain direct physiological and behavioural measurements from free-living animals. Rhythmicity has been examined in many mole-rat species in the laboratory, but field reports are relatively scarce. We implanted Natal mole-rats with temperature loggers in summer and winter to record core body temperature (Tb), before releasing the animals again. Animals were recaptured after two months to recover the loggers. Natal mole-rats can maintain rhythmicity of their Tb in their natural habitat and display seasonal differences in their Tb rhythms. During winter mole-rats have unimodal Tb rhythms, whereas in summer many animals have bimodal Tb patterns, which may be related to temperatures in the foraging burrows close to the soil surface. Individuals from the same colonies frequently exhibited similar rhythms, especially in the larger colonies, which may indicate social entrainment of rhythms. Males and females differ in their seasonal variation of Tb, with males having more variation in winter, while the opposite was true for females. Entire colonies may undergo sporadic torpor bouts, presumably to conserve energy, but the trigger for these events is unknown. This is the first report of torpor occurring in an African mole-rat species. The ability to respond to environmental and social cues, while rhythms remain flexible, can provide an adaptive advantage to animals living in challenging and energetically demanding habitats.

Oxidative stress in response to heat stress in wild caught Namaqua rock mice, Micaelamys namaquensis.

Modelling of anthropogenic induced climate suggests more frequent and severe heatwaves in the future, which are likely to result in the mass die-off of several species of organisms. Oxidative stress induced by severe heat stress has previously been associated with a reduction in animal cognitive performance, depressed reproduction and lower life expectancy. Little is known about the non-lethal consequences of species should they survive extreme heat exposure. We investigated the oxidative stress experienced by the Namaqua rock mouse, a nocturnal rodent, using two experimental heat stress protocols, a 6 hour acute heat stress protocol without access to water and a 3-day heatwave simulation with ad libitum water. Oxidative stress was determined in the liver, kidney and brain using malondialdehyde (MDA) and protein carbonyl (PC) as markers of oxidative damage, and superoxide dismutase (SOD) and total antioxidant capacity (TAC) as markers of antioxidant defence. Incubator heat stress (heat and dehydration stress) was brought about by increasing the body temperatures of animals to 39-40.8 °C for 6 hours. Following incubator heat stress, significantly higher levels of MDA were observed in the liver. Dehydration did not explain the variation in oxidative markers and is likely a combined effect of thermal and dehydration stress. Individual body mass was significantly negatively correlated to kidney SOD and lipid peroxidation. A heatwave was simulated using a temperature cycle that would naturally occur during a heatwave in the species' local habitat, with a maximal ambient temperature of 38 °C. Following the simulated heatwave, SOD activity of the kidney demonstrated significantly lowered activity suggesting oxidative stress. Current heat waves in this species have the potential of causing oxidative stress. Heat and dehydration stress following exacerbated temperatures are likely to incur significant oxidative stress in multiple tissues demonstrating the importance of water availability to allow for rehydration to prevent oxidative stress.

Locomotor activity in field captured crepuscular four-striped field mice, Rhabdomys dilectus and nocturnal Namaqua rock mice, Micaelamys namaquensis during a simulated heat wave.

Activity of animals is influenced by ambient temperature and increasing temperatures brought about by climate change may impose a heat stress risk. Previous studies investigating the effect of heat waves on activity usually measure animals at different, but constant temperatures, however, rarely are they studied under a natural temperature cycle. General activity, behavioural flexibility and frequency of water drinking counts during a normal day, hot day and a simulated heat wave temperature cycle were studied in the crepuscular four-striped field mouse, Rhabdomys dilectus, and the nocturnal Namaqua rock mouse, Micaelamys namaquensis. Both R. dilectus and M. namaquensis showed typical daily locomotor activity under control conditions. During the heat wave, peak activity times changed for R. dilectus, but both species exhibited higher bouts of activity for the heat wave during the day compared to the control, which was accompanied by an increased amount of time spent drinking water. The increased activity during the heat wave is likely due to enhanced water requirements and potentially a form of behavioural thermoregulation as animals may be uncomfortable and try to move to cooler areas. Thus, in the absence of a typical microclimate, access to water may allow rodents to overcome heat stress from extreme temperatures without having to shift their temporal active times.

Histomorphology, ultrastructure and fatty acid composition of the adipose tissue in pansteatitis, the potentials in understanding the underlying mechanism and diagnosis of pansteatitis in the Nile crocodile.

BACKGROUND: In an effort to characterize the fat body and other adipose tissue in the Nile crocodile and the effects of pansteatitis on the structure and composition of the adipose tissue, we evaluated the regional variation in structure and fatty acid composition of healthy farmed crocodiles and those affected by pansteatitis. METHODS: Adipose tissue samples were collected from the subcutaneous, visceral and intramuscular fat and the abdominal fat body of ten 4-year old juvenile crocodiles from Izinthaba Crocodile Farm, Pretoria, South Africa while pansteatitis samples were collected from visceral and intramuscular fat of crocodiles that had died of pansteatitis at the Olifant River, Mpumalanga, also in South Africa. Histomorphology, ultrastrustucture and fatty acid composition by fatty acid methyl ester (FAME) analysis were conducted. RESULTS: Histological examination showed regional variations in the adipose tissue especially in the collagen content of the ECM, tissue perfusion and division into lobes and lobules by fibrous capsule. Considerable fibrosis, mononuclear cell infiltration especially by macrophages and lymphocytes and toxic changes in the nucleus were observed in the pansteatitis samples. Regional variation in lipid composition especially in Myristoleic (C14:1), Erucic acid (C22:1n9), and Docosadienoic acid (C22:2n6) was observed. Most of the saturated and trans fatty acids were found in significant quantities in the pansteatitis samples, but had very low levels of the cis fatty acid and the essential fatty acids with C18 backbone. CONCLUSION: This study demonstrates that there exists some regional variation in histomorphology and fatty acid composition in the healthy adipose tissue of the Nile crocodile. It also showed that pansteatitis in the Nile crocodile might have been triggered by sudden change in energy balance from consumption of dead fish; and probable exposure to toxic environmental conditions with the evidence of up scaled monounsaturated long chain fatty acids composition and toxic changes in the leucocytes observed in pansteatitis in the present study.

Occurrence and molecular prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African wildlife: A systematic review and meta-analysis.

INTRODUCTION: Tick-borne pathogens (TBPs) constitute an emerging threat to public and animal health especially in the African continent, where land-use change, and wildlife loss are creating new opportunities for disease transmission. A review of TBPs with a focus on ticks determined the epidemiology of Rhipicephalus ticks in heartwater and the affinity of each Rickettsia species for different tick genera. We conducted a systematic review and meta-analysis to collect, map and estimate the molecular prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African wildlife. MATERIALS AND METHODS: Relevant scientific articles were retrieved from five databases: PubMed, ScienceDirect, Scopus, Ovid and OAIster. Publications were selected according to pre-determined exclusion criteria and evaluated for risk of bias using the appraisal tool for cross-sectional studies (AXIS). We conducted an initial descriptive analysis followed by a meta-analysis to estimate the molecular prevalence of each pathogen. Subgroup analysis and meta-regression models were employed to unravel associations with disease determinants. Finally, the quality of evidence of every estimate was finally assessed. RESULTS: Out of 577 retrieved papers, a total of 41 papers were included in the qualitative analysis and 27 in the meta-analysis. We retrieved 21 Anaplasmataceae species, six Rickettsiaceae species and Coxiella burnetii. Meta-analysis was performed for a total of 11 target pathogens. Anaplasma marginale, Ehrlichia ruminantium and Anaplasma centrale were the most prevalent in African bovids (13.9 %, CI: 0-52.4 %; 20.9 %, CI: 4.1-46.2 %; 13.9 %, CI: 0-68.7 %, respectively). Estimated TBPs prevalences were further stratified per animal order, family, species and sampling country. DISCUSSION: We discussed the presence of a sylvatic cycle for A. marginale and E. ruminantium in wild African bovids, the need to investigate A. phagocytophilum in African rodents and non-human primates as well as E. canis in the tissues of wild carnivores, and a lack of data and characterization of Rickettsia species and C. burnetii. CONCLUSION: Given the lack of epidemiological data on wildlife diseases, the current work can serve as a starting point for future epidemiological and/or experimental studies.

Differential locomotor activity responses to day-time light intensity in juvenile and adult solitary Cape mole-rats, Georychus capensis (Rodentia: Bathyergidae).

The Cape mole-rat (Georychus capensis) is a solitary, strictly subterranean rodent that is responsive to light and entrains to photic cues despite having a reduced visual system. Circadian entrainment is maintained throughout life, but age can alter the amplitude of the response and re-entrainment time. Mole-rats are long-lived for their size which raises questions regarding the robustness of their circadian rhythms and how impacts their locomotor activity rhythms. The locomotor activity rhythms of juvenile and adult Cape mole-rats were investigated. They were exposed to pre-experimental and post-experimental control cycles under fluorescent lights, six 12 h light:12 h dark cycles of decreasing intensities and a constant dark cycle (DD). All animals exhibited more activity during the dark phases of all light regimes. Juveniles were more active than adults and displayed more variable activity during both the light and dark phases. Adults exhibited relatively stable levels of activity under all experimental conditions, whereas juvenile activity decreased as the light intensity was reduced. The amplitude of Cape mole-rat rhythms was consistently low, but similar across light regimes and between adults and juveniles. Cape mole-rats have functional circadian systems, are primarily nocturnal and respond differentially to light intensity depending on their age. Light intensity does not affect the locomotor activity responses of Cape mole-rats in a predictable manner, and could indicate more complex interactions with light wavelengths. The circadian systems of juveniles appear to be more sensitive than those of adults, although the mechanism of the light response remains unclear.

Energetics reveals physiologically distinct castes in a eusocial mammal.

Eusociality, which occurs among mammals only in two species of African mole-rat, is characterized by division of labour between morphologically distinct 'castes'. In Damaraland mole-rats (Cryptomys damarensis), colony labour is divided between 'infrequent worker' and 'frequent worker' castes. Frequent workers are active year-round and together perform more than 95% of the total work of the colony, whereas infrequent workers typically perform less than 5% of the total work. Anecdotal evidence suggests that infrequent workers may act as dispersers, with dispersal being limited to comparatively rare periods when the soil is softened by moisture. Here we show that infrequent workers and queens increase their daily energy expenditure after rainfall whereas frequent workers do not. Infrequent workers are also fatter than frequent workers. We suggest that infrequent workers constitute a physiologically distinct dispersing caste, the members of which, instead of contributing to the work of the colony and helping the queen to reproduce, build up their own body reserves in preparation for dispersal and reproduction when environmental conditions are suitable.

Piroplasm parasites of white rhinoceroses (Ceratotherium simum) in the Kruger National Park, and their relation to anaemia.

As part of a larger survey to map the geographical distribution of Babesia and Theileria parasites in the southern African rhinoceros population, white rhinoceroses were sampled during routine immobilisations in the Kruger National Park. Polymerase chain reaction (PCR) and reverse line blot (RLB) hybridisation assays were used to screen for the presence of piroplasms and complete blood counts were used to assess associated changes in clinical parameters. Of the 195 rhinoceroses sampled, 71 (36.4 %) tested positive for the presence of Theileria bicornis, with no significant change in the haematological parameters measured, while 18 (9.2 %) tested positive for Theileria equi. None of the rhinoceroses sampled tested positive for Babesia bicornis, a parasite associated with mortalities in black rhinoceroses.

Laterality in the Cape mole-rat, Georychus capensis.

Behavioural lateralization, the differential use one side of the body, and/or the bilateral use of sensory organs or limbs, is common in many vertebrates. One way in which behavioural lateralization can be detected in animals is through turning biases, which is an inherent preference to either turn left or right. Mole-rats are a unique group of mammals that demonstrate a wide range of social organizations ranging from solitary to eusociality. Behavioural asymmetry has not previously been investigated in mole-rats. In this study, captive and wild solitary Cape-mole rats (Georychus capensis) were investigated for individual (relative laterality (LR)) and population-level (absolute laterality (LA)) laterality. Mole-rats in the captive group were in the laboratory for at least one year, whereas the wild group were captured and experimented on within 2 weeks of capture. Animals were placed in a Y-maze facing away from the centre of the maze, and the turn towards the centre of the maze was evaluated to determine individual turning biases. Lateralized individual turning biases were more apparent in wild (7/9), compared to captive (3/10) individuals. Both captive and wild populations demonstrated a left bias, which was higher in wild animals, but not significantly so. Cape mole-rats are extremely xenophobic and aggressive, and this aggressive behaviour may underlie the turning biases in these animals, as aggression is primarily a right hemisphere dominant process. The reduced lateralization observed in captive animals may be due to a reduced need for these behaviours as a result of different environments in captivity.

Temporal flexibility in activity rhythms of a diurnal rodent, the ice rat (Otomys sloggetti).

Diurnality in rodents is relatively rare and occurs primarily in areas with low nighttime temperatures such as at high altitudes and desert areas. However, many factors can influence temporal activity rhythms of animals, both in the field and the laboratory. The temporal activity patterns of the diurnal ice rat were investigated in the laboratory with, and without, access to running wheels, and in constant conditions with running wheels. Ice rats appeared to be fundamentally diurnal but used their running wheels during the night. In constant conditions, general activity remained predominantly diurnal while wheel running was either nocturnal or diurnal. In some animals, entrainment of the wheel running rhythm was evident, as demonstrated by free-running periods that were different from 24 h. In other animals, the wheel running activity abruptly switched from nocturnal to subjective day as soon as the animals entered DD, and reverted back to nocturnal once returned to LD, suggesting the rhythms were masked by light. Wheel running rhythms appears to be less robust and more affected by light compared to general activity rhythms. In view of present and future environmental changes, the existence of more unstable activity rhythms that can readily switch between temporal niches might be crucial for the survival of the species.

Heat and dehydration induced oxidative damage and antioxidant defenses following incubator heat stress and a simulated heat wave in wild caught four-striped field mice Rhabdomys dilectus.

Heat waves are known for their disastrous mass die-off effects due to dehydration and cell damage, but little is known about the non-lethal consequences of surviving severe heat exposure. Severe heat exposure can cause oxidative stress which can have negative consequences on animal cognition, reproduction and life expectancy. We investigated the current oxidative stress experienced by a mesic mouse species, the four striped field mouse, Rhabdomys dilectus through a heat wave simulation with ad lib water and a more severe temperature exposure with minimal water. Wild four striped field mice were caught between 2017 and 2019. We predicted that wild four striped field mice in the heat wave simulation would show less susceptibility to oxidative stress as compared to a more severe heat stress which is likely to occur in the future. Oxidative stress was determined in the liver, kidney and brain using malondialdehyde (MDA) and protein carbonyl (PC) as markers for oxidative damage, and superoxide dismutase (SOD) and total antioxidant capacity (TAC) as markers of antioxidant defense. Incubator heat stress was brought about by increasing the body temperatures of animals to 39-40.8°C for 6 hours. A heat wave (one hot day, followed by a 3-day heatwave) was simulated by using temperature cycle that wild four striped field mice would experience in their local habitat (determined through weather station data using temperature and humidity), with maximal ambient temperature of 39°C. The liver and kidney demonstrated no changes in the simulated heat wave, but the liver had significantly higher SOD activity and the kidney had significantly higher lipid peroxidation in the incubator experiment. Dehydration significantly contributed to the increase of these markers, as is evident from the decrease in body mass after the experiment. The brain only showed significantly higher lipid peroxidation following the simulated heat wave with no significant changes following the incubator experiment. The significant increase in lipid peroxidation was not correlated to body mass after the experiment. The magnitude and duration of heat stress, in conjunction with dehydration, played a critical role in the oxidative stress experienced by each tissue, with the results demonstrating the importance of measuring multiple tissues to determine the physiological state of an animal. Current heat waves in this species have the potential of causing oxidative stress in the brain with future heat waves to possibly stress the kidney and liver depending on the hydration state of animals.

An immunohistochemical study of the gonadotrophin-releasing hormone 1 system in solitary Cape mole-rats, Georychus capensis, and social Natal mole-rats, Cryptomys hottentotus natalensis.

Mole-rat species within the family Bathyergidae exhibit a wide range of reproductive strategies and social systems. Various forms of reproductive suppression are displayed within this family: in the solitary species, breeding is suspended for part of the year and in the social species, reproduction is suppressed in subordinate animals. This study investigated the gonadotrophin-releasing hormone 1 (GnHR-1) systems of breeding and non-breeding solitary Cape mole-rats and social Natal mole-rats for possible inter- and/or intra-species differences. In both species, GnRH-1 cell bodies are predominantly in the medial septum region of the diagonal band or the preoptic area, with relatively few in the mediobasal hypothalamus; a dense concentration of GnRH-1-immunoreactive (ir) processes is present in the region of the organum vasculosum of the lamina terminalis. In Cape mole-rats, GnRH-1-ir processes are particularly dense within the lateral margins of the median eminence, which is enfolded by a large pars tuberalis of the pituitary gland. Natal mole-rats display GnRH-1-ir processes across the breadth of the median eminence, which is abutted by a relatively small pars tuberalis. There are more GnRH-1-ir cell bodies in Natal mole-rats than in Cape mole-rats ( approximately 720 vs. approximately 420). No significant differences were found in the number, distribution or size of GnRH-1-ir cell bodies according to season in Cape mole-rats or according to reproductive status or sex in Natal mole-rats. In female and male Natal mole-rats, GnRH-1-immunoreactivity in the median eminence is less dense in the reproductive animals; no such difference was found in Cape mole-rats between the breeding and non-breeding seasons. These immunohistochemical results are discussed in the light of earlier studies which identified no functional neuroendocrine impediments underlying regulated reproduction in either Cape or Natal mole-rats. The cumulative findings suggest that the principal factors determining seasonal or socially induced suppression of reproduction in these species are behavioral rather than neuroendocrine.

Reproductive suppression and the seasonality of reproduction in the social Natal mole-rat (Cryptomys hottentotus natalensis).

Natal mole-rats are social subterranean rodents which exhibit a reproductive division of labour. Reproduction is confined to a single breeding female and one or more males; the remainder of the colony members is reproductively suppressed by the presence of the breeding animals. Apart from the discovery that female Natal mole-rats are induced ovulators, little is known about the reproductive biology of this species. Natal mole-rats are closely related to common and highveld mole-rats, both of which are induced ovulators and seasonal breeders. We therefore postulated that reproduction in Natal mole-rats is seasonally regulated. However, the results indicate that dominant Natal mole-rats are able to reproduce in the winter as well as in the summer. Furthermore, the increment in plasma LH in response to GnRH does not show marked seasonal differences in reproductive or non-reproductive mole-rats of either sex. Nevertheless, in all reproductive categories the level of plasma LH is significantly higher in the winter than in the summer. Seasonality in plasma LH levels dissociated from seasonality in breeding seems paradoxical. Further investigations will be required to elucidate this finding. We also investigated the processes underlying socially regulated reproduction in this species by determining basal and GnRH-evoked plasma LH in reproductive and non-reproductive animals of each sex in both seasons. The results failed to identify neuroendocrine differences consistent with an inhibited reproductive state in subordinates of either sex. Thus, the present findings suggest that behavioural interactions and/or inbreeding avoidance are the principal factors underlying suppression of reproduction in subordinate Natal mole-rats.

Detection of a Theileria species in dogs in South Africa.

A Theileria species was detected by PCR in blood samples collected from dogs in the Pietermaritzburg area and was also found in dogs presented at the Outpatients Clinic of the Onderstepoort Veterinary Academic Hospital (OVAH), in the Pretoria area, South Africa. In the Pietermaritzburg area, 79 of the 192 samples were positive, while 3 out of 1137 of the Onderstepoort samples were positive. Three positive samples from Pietermaritzburg were co-infected with Ehrlichia canis. PCR positive samples were further analysed by the Reverse Line Blot (RLB) and sequence analysis. Phylogenetic analysis of the 18S rRNA full-length gene sequences of one sample (VT12) from Pietermaritzburg and two samples from OVAH (BC281 and BC295) revealed a close relationship with sequences of Theileria species (sable). Clinical signs of the dogs that were examined at Pietermaritzburg and OVAH included an immune-mediated condition with severe thrombocytopenia. These findings identify a Theileria sp. in dogs for the first time in South Africa and add yet another microorganism to the growing list of haemoprotozoan parasites infecting dogs worldwide. The clinical significance of this infection in dogs is poorly resolved.

Gammaherpesvirus carrier status of black wildebeest (Connochaetes gnou) in South Africa.

Malignant catarrhal fever (MCF) is an economically important disease primarily of domestic cattle with a high case fatality rate. It is caused by either alcelaphine herpesvirus type 1 (AlHV-1) or ovine herpesvirus type 2 (OvHV-2). The major reservoir host of AlHV-1 is the blue wildebeest (Connochaetes taurinus), but it is generally accepted that the black wildebeest (Connochaetes gnou) is also a reservoir host. No viral studies in the black wildebeest have been reported and the carrier status of black wildebeest has not been documented. Specimens were collected from several game farms and conservation areas in central South Africa representing the geographical area historically linked to the natural habitat of the black wildebeest. Specimens were obtained from 304 black wildebeest of different ages and sex, as well as 51 black wildebeest foetuses at different stages of gestation. Virus was isolated from a black wildebeest calf. Morphological features and antigenic characteristics suggested it to be a gammaherpesvirus closely related to AlHV-1. All serum samples tested positive with a competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) for group-specific malignant catarrhal fever virus antibody. A SYBR Green real-time PCR assay was developed for the detection of gammaherpesviral DNA. Only 15.8 % of the animals tested positive with the real-time PCR assay whereas 90 % of the foetuses tested positive. This finding suggests that, unlike OvHV-2 infection in lambs in which the infection takes place after weaning, the virus in black wildebeest is mainly transmitted in utero or soon after birth. The results suggest that black wildebeest are latent carriers of a gammaherpesvirus similar or closely related to AlHV-1 present in blue wildebeest and that it is likely that all black wildebeest are persistently infected.

Occurrence of Theileria parva infection in cattle on a farm in the Ladysmith district, KwaZulu-Natal, South Africa.

Theileria parva causes widespread morbidity and mortality in cattle in endemic regions. An outbreak of theileriosis occurred on a farm near Ladysmith in KwaZulu-Natal, South Africa, which is not a declared Corridor disease-infected area. A survey of Red Brangus cattle from all age groups and areas of the farm was performed. Transmission of the parasite from infected animals on the farm to susceptible animals by tick transmission and tick-stabilate injection, was attempted. The survey indicated high numbers of animals with antibody titres to T. parva but only 6 infected animals, based on real-time PCR and RLB analysis. The transmission experiments failed to transmit the parasite. The study shows the difficulty in elucidating a source of infection and determining the dynamics of new infections in a herd where multiple possible sources are present and treatment with tetracyclines has taken place.

Factors influencing nurses' job satisfaction in selected private hospitals in England.

The quantitative descriptive survey used self-completion questionnaires to study factors influencing nurses' job satisfaction in selected private hospitals in England. Herzberg's Theory of Motivation was used to contextualise the results obtained from 85 completed questionnaires. In terms of Herzberg's Theory of Motivation, the most important extrinsic (hygiene) factor was no satisfaction with their salaries compared to nurses' salaries in other private hospitals in England, in the NHS and even at their own hospitals. However, most nurses were satisfied with the other extrinsic factors (organisation and administration policies, supervision and interpersonal relations). The most important intrinsic factors (motivators), influencing nurses' job satisfaction was their lack of satisfaction with promotions (including the fact that their qualifications were reportedly not considered for promotions), lack of advancement opportunities and being in dead-end jobs, and lack of involvement in decision- and policy-making activities. Nurses' levels of job satisfaction might be enhanced if promotion policies could be consistent, advancement opportunities implemented, qualifications considered for promotions, salary issues clarified, and if nurses could be involved in decision- and policy-making. Enhanced levels of job satisfaction could help to reduce turnover rates among registered nurses at the private hospitals in England that participated in this study.

A comparison of continuous clinical assessment and summative clinical assessment in restorative dentistry.

A possible measure of clinical competency for undergraduates may be students' continuous clinical assessment marks. This study compared each student's continuous clinical assessment (CCA) mark with their summative clinical assessments (SCA) in Paedodontics, Crown and Bridgework, Endodontics and Basic Restorative Dentistry. This was done in order to evaluate the predictive potential of the former against the latter, more conventional measure of assessment. The criterion to determine clinical competence was 60% and any assessment achieved above this would imply clinical competency. Comparisons were made between CCA and SCA for the 39 BChD V undergraduates in the disciplines of Crown and Bridgework, Paedodontics and Endodontics, as well as for the 59 BChD IV undergraduates in the discipline of Basic Restorative Dentistry, for the 2004 academic year. Data were analysed using a two-sample t-test and were also subjected to a Spearman Rank Order Correlation test. For the BChD V students, differences between the two assessment measures were significant for Crown and Bridgework (p=0.00) and Endodontics (p=0.03), but not so for Paedodontics (p=0.22). For the BChD IV students the difference between CCA and SCA for Basic Restorative Dentistry (p=0.00) was significant. The Spearman test produced generally weak correlation values (p<0.4), while the average assessment for Crown and Bridgework for the BChD V group of <60% suggests that, on the basis of the results of this study, continuous clinical assessment cannot be used as a predictor of clinical competence in this discipline.