Automated weighing by sequential inference in dynamic environments

We demonstrate sequential mass inference of a suspended bag of milk powder from simulated measurements of the vertical force component at the pivot while the bag is being filled. We compare the predictions of various sequential inference methods both with and without a physics model to capture the system dynamics. We find that non-augmented and augmented-state unscented Kalman filters (UKFs) in conjunction with a physics model of a pendulum of varying mass and length provide rapid and accurate predictions of the milk powder mass as a function of time. The UKFs outperform the other method tested - a particle filter. Moreover, inference methods which incorporate a physics model outperform equivalent algorithms which do not.Comment: 5 pages, 7 figures. Copyright IEEE (2015

Navigation by Induction-Based Magnetoreception in Elasmobranch Fishes

A quantitative frequency-domain model of induction-based magnetoreception is presented for elasmobranch fishes. We show that orientation with respect to the geomagnetic field can be determined by synchronous detection of electrosensory signals at harmonics of the vestibular frequency. The sensitivity required for this compass-sense mechanism is shown to be less than that known from behavioral experiments. Recent attached-magnet experiments have called into doubt the induction-based mechanism for magnetoreception. We show that the use of attached magnets would interfere with an induction-based mechanism unless relative movement between the electrosensory system and the attached magnet is less than 100 μm. This suggests that further experiments may be required to eliminate induction as a basis for magnetoreception

Nutritional status of patients in a long-stay hospital for people with mental handicap

Objective: To investigate the general nutritional status of patients in Alexandra Hospital, Cape Town, and to determine whether dietary copper deficiency was causing anaemia in hospital patients. Design: Descriptive and cross-sectional analytical studies. Setting: A long-stay hospital for people with mental handicap. Subjects: Information was obtained from the total hospital population. In addition, groups of 15 patients were selected from each of two specific wards, one with active and the other inactive patients. To determine whether copper deficiency was causing anaemia, sample of 30 patients, -f divided into three groups (a hypochromic microcytic, a normochromic anaemic and a non-anaemic group) was studied. Main outcome measures: Body mass indices (BMI) and daily dietary intakes were compared with Recommended Daily Allowance (RDA) values. Serum copper and serum caeruloplasmin levels were used to detect possible copper deficiency. Results: A considerable number of patients were found to be underweight (32% of males and 26% of females had BMIs < 20). A smaller number were obese (6% of males and 17% of females had BMIs > 30). Poor nutrition was more common in severely handicapped patients and those with acquired causes of their mental handicap. Subjects with Down syndrome were generally well nourished and occasionally obese. Poor dietary intakes of biotin, pantothenic acid, vitamin D and copper were encountered. The serum copper and caeruloplasmin values were found to be within normal limits. Patients with hypochromic, microcytic anaemia had higher serum copper and caeruloplasmin levels than those with normochromic anaemia and the control group. Conclusions: A number of nutritional problems among the inpatient population were found. Many were undernourished, while a smaller number of patients were overweight. In both the active and inactive wards macronutrient intakes were generally within normal limits. However, some micronutrient nutritional deficiencies were encountered. We were unable to establish that dietary copper deficiency was the cause of anaemia in our patients. Elevated serum copper and caeruloplasmin levels found in hypochromic, microcytic patients were thought to result from the existence of low-grade infection, associated with elevation of the acute-phase protein, caeruloplasmin.S Afr Med J 2000; 90: 1135-114

Evaluation of the infant at risk for neurodevelopmental disability

Background. Infants with neurodevelopmental abnormality need to start therapy early, and because of this they should be detected as soon as possible. Currently, no widely accepted method of early evaluation exists.Objectives_ To assess and compare, in terms of predicting neurodevelopmental outcome at 1 year of age: (i) a perinatal risk rating (PRR); (ii) the DubQwitz Neurological Assessment. (DNA); and (iii) the Infant Neuromotor Assessment (INA). Design and setting. A prospective neurodevelopmental followup study on graduates from the Groote Schuur Hospital (GSH) neonatal intensive care unit (NICU). Subjects. A cohort of 130 consecutive NICD graduates were selected according to high-risk criteria_Outcome measures. Each infant was examined at term gestational age on the DNAbefore discharge, and a PRR was allocated_ Study infants were seen again at 18 weeks of age when an INA was done, and at 1 year of age a Griffiths Developmental Assessment and full neurological examination was carried out.Results. All of the 130 infants assessed at term were seen at 18 weeks. Thereafter 5 were lost to follow-up and 2 died. The outcome for the remaining 123 is known.Conclusions. Prediction of a normal outcome at 1 year of age was 96% on the DNA and 98% for the PRR, but for an abnormal outcome they predicted only 56% and 42%, respectively. The INA done at 18 weeks predicted a normal outcome at 1 year in 99% of cases if 3 or less abnormal signs were present and an abnormal outcome in 82% of cases with 4 or more abnormal signs. Based on these findings a protocol for follow-up of these high-risk infants is suggested

The prevalence of mental disorders among children, adolescents and adults in the Western Cape, South Africa

Objective: To provide estimates of the prevalence of selected mental disorders in the Western Cape, based on the consensus achieved by a working group established for this purpose. Method: An expert working group was established to provide technical expertise for the project. Potential risk factors likely to influence local prevalence rates were identified. Annual prevalence rates for adults and for children and adolescents were derived by consensus, informed by a systematic literature review. Prevalence rates were derived for individual disorders and adjusted for comorbidity. Results: The overall prevalence was 25.0% for adults and 17.0% for children and adolescents. Conclusion: Prevalence rates of child, adolescent and adult mental disorders were derived in a short period of time and with the use of minimal resources. Although of unknown validity, they are useful for policy development and for planning service utilisation estimates, resource costing and targets for service development for local mental health needs. This in the absence of an existing methodologically sound national prevalence study. We recommend that policy and programme developers draw on the expertise of local academics and clinicians to promote research-informed planning and policy development in the public sector. South African Psychiatry Review Vol. 9(3) 2006: 157-16