Tolworth Hospital

OBJECTIVE: To examine the dental health of community dwelling people with schizophrenia and to compare results with those in the general population. METHOD: Dental health of 428 people with schizophrenia in six different areas of the UK was assessed by a self-report questionnaire. RESULTS: Compared with the general population, significantly more of the younger patients were edentate (3-39% vs. 1-20%) and fewer had more than 20 teeth (70% vs. 83%). None of four dental health targets had been achieved in the patient population. More patients had last visited the dentist because of trouble with their teeth; fewer had visited for a check-up. Fewer patients cleaned their teeth daily; this group had more negative symptoms. CONCLUSION: The dental health of people with schizophrenia is poor. Community mental health teams should encourage them to attend their community dentist regularly.

Records of 186 suicides among male prisoners in England between 1958 and 1971 emphasize the differences between the prison population and the population at large. The suicide rate may well be three times greater. The records show that sentence of more than 18 months' duration, whether anticipated or actually received, is associated with a greater risk of suicide than shorter sentence, and that suicide is most likely to be committed during the first few weeks in custody.

Laboratory feeding tests were carried out to determine the efficacy of the anticoagulant rodenticide bromadiolone against Rattus norvegicus, R. rattus and Mus musculus. Using 0.005% bromadiolone, complete kills of R. norvegicus and R. rattus not resistant to warfarin were obtained after exposure to the poison for 1 and 5 days respectively. Warfarin-resistant R. norvegicus were all killed in 4 days, and resistant M. musculus in 12 days. In general, the results resembled those obtained with difenacoum. Acceptance of bromadiolone was very good.

INTRODUCTION: Theories of delusions often underplay the role of their content. With respect to persecutory delusions, taking threat as fundamental suggests that models of threat-related, aversive learning, such as the Conditioned Avoidance Response (CAR) task, might offer valid insights into the underlying normal and abnormal processes. In this study, we reappraise the psychological significance of the CAR model of antipsychotic drug action; and we relate this to contemporary psychological theories of paranoia. METHODS: Review and synthesis of literature. RESULTS: Anticipation and recall of aversive events are abnormally accentuated in paranoia. Safety (avoidance) behaviours may help perpetuate and fix persecutory ideas by preventing their disconfirmation. In addition, patients may explain negative events in a paranoid way instead of making negative self-attributions (i.e., in an attempt to maintain self-esteem). This defensive function only predominates in the overtly psychotic patients. The "safety behaviours" of paranoid patients, their avoidance of negative self-attributions, and the antiparanoid effect of antipsychotic medication all resonate with aspects of the CAR. CONCLUSIONS: The CAR appears to activate some normal psychological and biological processes that are pathologically activated in paranoid psychosis. Paranoid psychological defences may be a result of basic aversive learning mechanisms, which are accentuated during acute psychosis.

Summary This paper discusses how to compare the utility of soil maps. For three contrasting areas, in Southern England, it compares the utilities of a number of single‐property and general purpose (series) soil maps, produced by free and grid survey, at map scales from 1 :20,000–1:70,000. The‘ purity ’of series mapping units increases with survey effort. Where the soil boundaries had fairly clear external expression free survey was superior to grid survey. On average the purity of maps by grid survey was higher than for maps by free survey at comparable survey effort. The uniformity of soil properties within mapping units was measured by relative variance (RV)= within‐unit variance/total variance, (1–RV) indicates the increased precision achieved by the soil map. It increased with survey effort. For series maps by free or grid survey (1–RV) depended on how closely soil properties were associated with profile classes, and on the extent to which soil boundaries could be mapped on their external expression. Free survey was preferred at scales between 1: 100,000 and 1:30,000, when the soil boundaries could be mapped on their external expression, (1–RV) for the profile classes on which the mapping units are defined puts a ceiling to the utility of series maps (grid or free) which is already nearly achieved at map scales near 1:25,000. Except for properties very poorly associated with profile classes, single property maps do not have great advantage over series maps at medium map scales, but they attain higher values of (1–RV) at scales greater than 1: 25,000.

Aversive processing plays a central role in human phobic fears and may also be important in some symptoms of psychosis. We developed a temporal-difference model of the conditioned avoidance response, an important experimental model for aversive learning which is also a central pharmacological model of psychosis. In the model, dopamine neurons reported outcomes that were better than the learner expected, typically coming from reaching safety states, and thus controlled the acquisition of a suitable policy. The model accounts for normal conditioned avoidance learning, the persistence of responding in extinction, and critical effects of dopamine blockade, notably that subjects experiencing shocks under dopamine blockade, and hence failing to avoid them, nevertheless develop avoidance responses when both shocks and dopamine blockade are subsequently removed. These postulated roles of dopamine in aversive learning can thus account for many of the effects of dopaminergic modulation seen in laboratory models of psychopathological processes.

Background: Mental health professionals have been shown to have negative attitudes towards substance misuse. This impacts on the quality of care provided to mentally ill substance-using service users. Aims: To investigate mental health professionals' attitudes to substance misusers. Associations between attitude and demographic factors, such as age, experience, professional status, additional training, educational level and own substance use were also investigated. Method: The Substance Abuse Attitude Survey (SAAS) was completed by a convenience sample of mental health professionals from an outer London Borough. The SAAS measures five factors; non-stereotyping, permissiveness, non-moralism, treatment optimism and treatment intervention. Results: Fifty-six (54%) of the 103 sampled professionals returned usable questionnaires. Participants who were educated to a postgraduate level were less moralistic in their approach and had greater treatment optimism. Participants who were qualified social workers had greater permissiveness scores than nurses. Personal use of tobacco, cannabis and illicit drug use was associated with greater treatment intervention scores. Age, gender, level of experience in mental health or substance misuse, and number of substance misuse training days were not associated with any SAAS subscores. Conclusion: The results indicate that there are elements of postgraduate courses that contribute to less moralistic attitudes and a higher level of treatment optimism when working with substance misusers. Further research needs to ascertain what elements of post-graduate education contribute towards constructive attitudes in relation to working with substance misusers. Declaration of interest: Neither author has any conflicting interests to declare whilst conducting and writing up this research.

Laboratory and field trials were conducted to determine the efficacy of the anticoagulant rodenticide bromadiolone against the house mouse (Mus musculus). In laboratory feeding tests, family groups of warfarin-resistant mice maintained in pens and conditioned to feeding on plain foods were offered pinhead oatmeal bait containing bromadiolone at 0.005%. Overall mortality in replicated 21-day poison treatments was 55/58 or 94.8%. Six field trials were carried out, using the same poison bait, against mice infesting farm buildings. Treatment success, estimated from the results of census baitings conducted before and after treatment, ranged between 60.4% and 100%, mean 92.4%. In equivalent field trials using difenacoum, another newly developed anticoagulant rodenticide, the control achieved ranged between 70.2% and 100%, mean 96.0%. Five field trials, three involving bromadiolone and two difenacoum, were not completely successful and the surviving mice were removed for laboratory examination. In 21-day toxicity tests, each animal was fed the poison bait offered to it earlier in the field. Bromadiolone and difenacoum gave kills of 12/21 (57.1%) and 9/11 (81.8%) respectively. The possible emergence of mouse populations resistant to these anticoagulants is considered.

SUMMARY Aggressive behaviour was observed to be rare in small family groups of confined wild house mice, Mus musculus L. Unrelated mice were attacked when they were introduced to a family group and in their presence intra‐family aggressive behaviour increased. When two family groups of mice were allowed to meet there were frequent aggressive encounters between unrelated animals and the two groups remained separate. Resident mice were found to be aggressive towards males and females individually isolated and returned to their own family after 2 or 3 weeks absence but not after 1 week. The possibility is discussed that in wild mice odour discrimination influences the dispersal and build‐up of free‐living populations.

(1968). An Outbreak of Rats in Agricultural Areas of Kenya in 1962. East African Agricultural and Forestry Journal: Vol. 34, No. 1, pp. 66-77.

Summary Errors of measurement of soil water content with the neutron probe can be made small enough for most water balance studies; and apart from the possible damage resulting from access tube implacement, they can be readily specified. A more important problem is estimating how much water is lost from soil by drainage. A simple, graphical method is described to distinguish between drainage and evaporation from soil, based upon identification of the maximum depth at which measurable quantities of water are extracted by roots. As a result of errors in soil water measurements and uncertainties in the distinction between drainage and evaporation, estimates of soil water deficit and hence evaporation for a single profile are likely to have a precision of about ±5 mm. Larger variability is commonly found in soil water storage changes measured in replicate profiles partly because of uneven wetting of the soil during rain and partly because of non‐uniform losses by drainage and root extraction. This variability requires careful attention to replication and location of access tubes when assessing the evaporation for a particular site.

Between January 6 and April 23, 1997, 11 outbreaks of Newcastle disease were confirmed in Great Britain, four in broiler chickens and seven in turkeys. Although the viruses isolated gave intracerebral pathogenicity indices in day-old chicks between 1.65 and 1.95, the clinical signs of disease in field infections were variable and not always associated with high mortality, especially in turkeys. Epidemiological investigations indicated that the majority of the outbreaks occurred as a result of secondary spread by human agency from two or more primary infected flocks. The presence of similar outbreaks in Scandinavian countries in 1996 and the unusual patterns of movement of migratory birds at the end of 1996 and beginning of 1997 suggest they may have been responsible for the primary introduction of the causative virus into Great Britain.

The 2-stage determination is based on changes in blood coaggulation activity brought about both by the administration of warfarin in conjunction with vitamin K1 epoxide and by feeding a vitamin K-free diet for 4 days. When it was applied to laboratory-bred rats of known warfarin-resistance genotype, 35/35 homozygous susceptible, 44/44 homozygous resistant and 131/133 heterozygous rats were correctly classified. This method was equally effective in identifying the genotype of wild rats carrying the warfarin-resistance gene, Rw2. The procedure is rapid and accurate.

Summary In the Cayman Islands a core of Miocene and Oligocene crystalline limestones is overlain unconformably by limestones of the Pleistocene Ironshore Formation. Within this Formation five separate depositional environments are recognized. A reef facies contains corals still in their growth position. This reef facies is succeeded by a back reef facies, followed by a lagoonal facies. The lagoonal facies contains a diverse molluskan fauna of 75 species which differs considerably from that found in the present lagoons around the island. Rocks of these facies are overlain in places by ridges of calcarenite, considered to be shoal deposits. Higher ridges which overlie the Tertiary limestones and reef facies rocks are interpreted as beach ridges. It is thought that the Pleistocene sediments were deposited around a gradually subsiding core of Tertiary rocks.

The differences between individuals at the centre and at the periphery of social groupings of birds have been demonstrated, but night‐time roosts have received little attention. Here, the effects of age, sex and physical condition on the structure of Starling roosts were investigated. It was found that the dispersion of different age and sex categories was heterogeneous; proportionately more adult males occurred in the centre compared with the periphery, and proportionately more first‐year females occurred on the periphery compared with the centre. Birds in the centre were heavier than peripheral ones irrespective of differences in body‐size. We propose that the centre of the roost is the preferred location and that the observed dispersion reflects dominance.

Gonad development, moult and seasonal changes in body weight and composition in the Tawny owl Strix aluco were studied by examining the carcasses of 369 owls (mostly road casualties) supplemented by 112 weights of live birds. In breeding females laying was preceded by the accumulation of fat and to a lesser extent protein which meant that they weighed more at this time (February/March) than at any other. Females declined in weight after laying but were still heavy during incubation. In contrast, males and non‐breeding females did not increase in weight before the start of the breeding season. Juveniles reached or even exceeded adult weight well before independence due to the deposition of fat. Even after the exclusion of diseased or contaminated individuals, 9·4% of the birds examined were identified as starving; most of these were in the autumn and were probably newly‐independent young wandering in search of territories. In both sexes gonad maturation was of brief duration coinciding with the period (mid‐March to mid‐April) in which eggs are normally laid. Ovarian growth was biphasic. In the three months prior to the breeding season ovarian condition in different birds was positively correlated with body weight and it appeared that the largest ovarian follicles of females in poor condition failed to attain the size from which rapid growth to final ovulation occurs. in males testis size in the breeding season was correlated with pectoral muscle weight (an index to protein condition) but not body weight. The majority of adults commenced wing moult in June. The average duration of primary moult was estimated to be 77 days. Healthy birds replaced the primaries of both wings at the same rate but most diseased birds moulted asymmetrically and/or out of season. First‐year birds renewed their body feathers between September and November. In the Tawny owl territory establishment, breeding and moult are temporally separated.

Trials of rodenticidal baits containing 50 p.p.m. difenacoum, 50 p.p.m. bromadiolone or 20 p.p.m. brodifacoum were carried out on farmsteads against populations of Rattus norvegicus containing difenacoum-resistant individuals. Six difenacoum treatments failed in 14--42 days of baiting. Two treatments with bromadiolone succeeded in 23 and 33 days, but four further treatments lasting 35--56 days failed to eradicate the populations. Brodifacoum gave virtually complete control of six populations in 21--73 days and of the ten residual populations left behind by the other two compounds, after baiting for a further 11--85 days. The performance of both bromadiolone and brodifacoum was well below that reported by previous investigators, indicating the possibility of low-grade resistance to these compounds in the difenacoum-resistant strain.

Variations in egg‐size (weight, or an index of volume derived from the length and breadth of eggs) were analysed for four years' data from a colony of Starlings in southern England. Variation was much greater among clutches than within clutches. There were no consistent trends for egg‐size to increase or decrease through the laying sequence, but the first‐ and last‐laid eggs tended to be smaller than the clutch mean. Loss of single nestlings (perhaps by starvation) was more frequent if the smallest, or last‐laid egg was particularly small. Effects of egg‐size on the growth of surviving chicks were slight‐most variation in development was attributable to factors such as clutch or brood size, and nestlings' relative weights fluctuated so that they continually changed ranks during the nestling period. In Starlings, egg‐size was inversely correlated with clutch size, but three open‐nesting species (Bullfinch, Song Thrush and Blackbird) showed the opposite pattern. These results are discussed in relation to their implications for understanding the adaptive aspects of egg‐size variation.

SUMMARY In a population of Plodia interpunctella living on 4 tons of bagged American maize stored in a Nissen hut, fewer adults than expected emerged in the spring, as many pupae were killed by high temperatures close to the roof. In spite of this, a population of approximately eighteen adults gave rise 3 months later to 643 larvae. There were indications that the life cycle might be completed in 9 weeks, as a second generation of adults started to emerge within this period. Larvae preferred bags stacked flat to those stacked upright. They tended to occur in the upper parts of stacks, to spin their cocoons in the necks of bags and to remain in their existing sites without showing any indication of migrating. Of four food materials tested in laboratory studies, no. 3 N. Manitoba Tough wheat induced quickest development, followed by sultanas, American yellow corn and almonds. Of four types of wheat, Australian was more suitable than no. I N. Manitoba or U.S. Northern Spring; English wheat was the least suitable. Milo (N. American sorghum) was as good as no. I N. Manitoba and U.S. Northern Spring wheats, and Plate maize was comparable to English wheat. Groundnuts were less satisfactory and maize meal gave poorer results than any other food. The main period of emergence of adults was short on those foods which induced the most rapid development but prolonged on those on which the development period was longer. The life cycle was unusually long in a proportion of individuals which were reared on American yellow corn, no. I N. Manitoba wheat and almonds. In these examples the fully grown larvae underwent a long period of rest within the cocoon, suggesting a facultative diapause. Mortality of pre‐adult stages appeared to be higher when the period of development was longer.

Abstract In England during the spring, commencing in the year 1956, numbers of deaths occurred amongst wild birds and the insecticides used to dress cereal seeds were suspected. Pigeons were fed with dieldrin, aldrin, heptachlor and y‐BHC and the toxicities and residues in flesh and organs measured. Following this, birds from the field were examined during the 1960/61 sowing season. The results of analyses support the view that dieldrin, aldrin and heptachlor had been mainly responsible for the deaths. An ecological section includes an explanation for the predominance of casualties in the spring time.