Ungulates are famous for large-scale movements in response to local and regional changes in plant productivity. However, it is poorly understood how non-migratory ungulates respond towards shortages in plant availability. In the arid Kunene Region of Namibia, we studied the variation of home ranges and habitat use of gemsbok during a period of severe drought that led to a critical food shortage. We then related the spatiotemporal behaviour of gemsbok to relative plant greenness and local plant productivity, using local Normalized Differenced Vegetation Indices (NDVI) as a proxy, and to satellite images to assess habitat types and topography. Core home range sizes of gemsbok did not vary with decreasing local NDVI values, while total home-ranges increased with decreasing NDVI values. Gemsbok responded to resource fluctuations by using a combination of habitats differing in plant productivity, topography and vegetation cover. Gemsbok increased the number of habitats used when NDVI values decreased. Individuals remained non-migratory even during the period of peak drought. Non-migratory gemsboks are capable of exploiting local resources efficiently by adjusting their habitat use, when facing declining resources and unpredictable food shortages. Our study provides important information on the habitat use of gemsbok for the sustainable management of populations in arid environments.

Classical galactosaemia (OMIM 230400) is an inherited disorder of galactose metabolism. The toxic potential of ingested galactose (derived predominantly from lactose) and build-up of intermediates was recognised over 100 years ago. The most common and most severe form is classical galactosaemia, resulting from galactose-1-phosphate uridyl transferase deficiency (GALT). In the UK, patients are usually diagnosed only after they become symptomatic – galactosaemia is not included in the newborn screening programme. Treatment is based on restriction of galactose in the diet, mainly by excluding lactose which is found in milk, milk products and manufactured foods containing milk. Early diagnosis is crucial to prevent acute life threatening complications. Long-term outcome in classical galactosaemia in the overall patients' population remains disappointing. This review gives a summary of current practises, updated recommendations and highlights potential disease burden.

Ungulates often adjust their diet when food availability varies over time. However, it is poorly understood when and to what extent individuals change their diet and, if they do so, if all individuals of a population occupy distinct or similar dietary niches. In the arid Namibian Kunene Region, we studied temporal variations of individual niches in grazing gemsbok (Oryx gazella gazella) and predominantly browsing springbok (Antidorcas marsupialis). We used variation in stable C and N isotope ratios of tail hair increments as proxies to estimate individual isotopic dietary niches and their temporal plasticity. Isotopic dietary niches of populations of the two species were mutually exclusive, but similar in breadth. Isotopic niche breadth of gemsbok was better explained by within-individual variation than by between-individual variation of stable isotope ratios, indicating that gemsbok individuals were facultative specialists in using isotopically distinct local food resources. In contrast, inter- and intra-individual variations contributed similarly to the isotopic niche breadth of the springbok population, suggesting a higher degree of individual isotopic segregation in a more generalist ungulate. In both species, between-individual variation was neither explained by changes in plant primary productivity, sex, geographical position nor by group size. Within species, individual dietary niches overlapped partially, suggesting that both populations included individuals with distinct isotopic dietary niches. Our study provides the first evidence for isotopic dietary niche segregation in individuals of two distinct desert ungulates. Similar, yet isotopically distinct dietary niches of individuals may facilitate partitioning of food resources and thus individual survival in desert ecosystems.

Desert ungulates live in adverse ecosystems that are particularly sensitive to degradation and global climate change. Here, we asked how two ungulate species with contrasting feeding habits, grazing gemsbok (Oryx g. gazella) and browsing springbok (Antidorcas marsupialis), respond to an increase in food availability during a pronounced rain period. We used a stable isotope approach to delineate the feeding habits of these two ungulates in the arid Kunene Region of Namibia. Our nineteen months field investigation included two time periods of drought when food availability for ungulates was lowest and an intermediate period with extreme, unusual rainfalls. We documented thirteen isotopically distinct food sources in the isotopic space of the study area. Our results indicated a relatively high dietary plasticity of gemsbok, which fed on a mixture of plants, including more than 30% of C3 plants during drought periods, but almost exclusively on C4 and CAM plant types when food was plentiful. During drought periods, the inferred gemsbok diets also consisted of up to 25% of Euphorbia damarana; an endemic CAM plant that is rich in toxic secondary plant compounds. In contrast, springbok were generalists, feeding on a higher proportion of C3 than C4/CAM plants, irrespective of environmental conditions. Our results illustrate two dietary strategies in gemsbok and springbok which enable them to survive and coexist in the hostile Kunene arid ecosystem.

While galactosaemia was originally documented over 100 hundred years ago, it still remains poorly understood and recognized. Classical galactosaemia is an inherited disorder of galactose metabolism, whose main dietary source is lactose. In the UK which does not currently screen for Galactosaemia lack of recognition of key symptoms can lead to delays in diagnosis. However it has become clearer that Galactosaemia is not only an acute disease of the neonatal period but affected children potential are prone to a number of chronic problems later in life. This review looks at the current thinking concerning the pathogenesis and complications of galactosaemia and summaries our current management of patients.

African Journal of EcologyVolume 37, Issue 1 p. 107-109 Lion predation on black rhinoceros (Diceros bicornis) in Etosha National Park C. Brain, C. Brain Etosha Ecological Institute, P.O. Okaukuejo Via Outjo, Namibia 9000. Fax: 067 229853. E-male: [email protected]Search for more papers by this authorO. Forge, O. Forge Etosha Ecological Institute, P.O. Okaukuejo Via Outjo, Namibia 9000. Fax: 067 229853. E-male: [email protected]Search for more papers by this authorP. Erb, P. Erb Etosha Ecological Institute, P.O. Okaukuejo Via Outjo, Namibia 9000. Fax: 067 229853. E-male: [email protected]Search for more papers by this author C. Brain, C. Brain Etosha Ecological Institute, P.O. Okaukuejo Via Outjo, Namibia 9000. Fax: 067 229853. E-male: [email protected]Search for more papers by this authorO. Forge, O. Forge Etosha Ecological Institute, P.O. Okaukuejo Via Outjo, Namibia 9000. Fax: 067 229853. E-male: [email protected]Search for more papers by this authorP. Erb, P. Erb Etosha Ecological Institute, P.O. Okaukuejo Via Outjo, Namibia 9000. Fax: 067 229853. E-male: [email protected]Search for more papers by this author First published: 24 December 2001 https://doi.org/10.1046/j.1365-2028.1999.00137.xCitations: 19Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume37, Issue1March 1999Pages 107-109 RelatedInformation

We surgically implanted temperature sensitive telemeters intraperitonealy in free-ranging baboons. Thereafter, we recorded body temperature changes while the baboons were free-ranging and under visual observation. Two distinct patterns of daily body temperature fluctuations occurred; they were related to the availability of drinking water. Core body temperature fluctuated by as much as 5.3°C and regularly exceeded 41°C. Behavioral adaptations of the baboons, notably sandbathing, appeared to be associated with the regulation of body temperature.

Objectives-To investigate the relation between cranial irradiation received during treatment for childhood leukaemia and obesity at final height.Design-Retrospective cross sectional study.Setting-Paediatric oncology centres at Great Ormond Street Hospital for Children and the Royal Marsden Hospital.Subjects-Survivors of childhood leukaemia who received cranial irradiation, were in continuous first remission, and had reached final height. An unirradiated group of patients fi om the United Kingdom acute lymphoblastic leukaemia XI trial was also included; these patients were in continuous first remission and had been followed for at least four years from diagnosis.Main outcome measures-Body mass index standard deviation score (BMI z score) at final height for irradiated patients and at most recent follow up for unirradiated patients. Regression analysis was used to examine the effect on BMI z score of sex, age at diagnosis, and the dose of radiation received.Results-For cranially irradiated patients, an increase in the BMI z score at final height was associated with female sex and lower radiation dose, but not with age at diagnosis. Severe obesity, defined as a BMI z score of > 3 at final height, was only present in girls who received 18-20 Gy irradiation and had a prevalence of 8%. Both male and female unirradiated patients had raised BMI z scores at latest follow up and there was no association with age at diagnosis.Conclusions-These data are further evidence for a sexually dimorphic and dose dependent effect. of radiation on the human brain.

Proopiomelanocortin (POMC) is the precursor of a number of hormones and neuropeptides. It is cleaved tissue-specifically to yield peptides with diverse functions, such as adrenocorticotrophin (ACTH), a, b, and g-melanocyte stimulating hormone (MSH), b-lipotrophin, and b-endorphin (1). The most clearly defined physiological role of these peptides is the control of adrenal steroidogenesis by anterior pituitaryderived ACTH, as well as skin pigmentation by a-MSH. Evidence for a role of POMC gene products in the control of human energy balance is accumulating rapidly. Thus, Krude et al. reported two families in which mutations in the POMC gene result in congenital ACTH deficiency with extreme early-onset obesity (2), and two groups have just reported mutations in the melanocortin-4 receptor (MC4R) that are associated with morbid obesity (3, 4). The MC4R is highly expressed in the hypothalamus and binds a-MSH with high affinity (5). These human discoveries add to the substantial body of murine evidence for a key role of melanocortin signaling in energy homeostasis. This includes the obesity seen with MC4R “knock-out” (6), the inhibition of hypothalamic melanocortin signaling due to ectopic expression of Agouti protein (7), and transgenic overexpression of Agouti-related peptide (Agrp) (8). Thus, mechanisms leading to human and murine obesity include defects that affect the function and/or expression of POMC-derived ligands, their receptors, and their antagonists. An additional molecular mechanism for defective melanocortin signaling leading to obesity may be impaired proteolytic processing of POMC to its effector hormones and neuropeptides. Thus, in fat/fat mice, obesity is associated with mutations of carboxypeptidase E and a failure to process POMC normally (9). Jackson et al. reported a woman with compound heterozygous mutations in prohormone convertase 1 (PC1), in whom marked impairment of POMC processing was associated with severe early-onset obesity (10). However, in both cases the specific linkage of impaired POMC processing to obesity is complicated by the widespread roles that PC1 and CPE have in propeptide processing. In this regard, we would like to report a novel form of human early-onset obesity, in which defective prohormone processing appears to be confined to POMC. The patient is a 9-yr-old caucasian female who is the second child of healthy, non consanguineous parents. Her early clinical and biochemical features, before development of obesity, have been described previously (11, 12). Briefly, she presented at 11 h of age with hypoglycemia associated with undetectable plasma cortisol and ACTH. Despite this, plasma POMC concentrations were markedly elevated and responded appropriately to corticotrophin releasing hormone and dexamethasone, suggesting a prohormone processing defect. However, the sequence of the POMC gene was normal. Unlike the fat/fat mouse and the PC1-defective human, the ratio of proinsulin to insulin in her plasma was also normal, suggesting that PC1 and CPE are intact because they are critical for proinsulin processing. The responses of serum glucagon to glucose and glucagon-like peptide 1 (GLP1) to a test meal were also normal. We have now established that her PC1 genomic sequence is normal in all 14 exons, the exon/intron boundaries, and the promoter region. Strikingly, despite only physiological cortisol replacement (mean daily cortisol dose from age 2–9 yr was 14.8 mg/m) and normal linear growth (10 centile height at age 2 yr, 50 at 5.5 yr, and 75 at age 9 yr), marked obesity has developed (Fig. 1). She displays hyperphagia and foodseeking behavior such that access to food has to be restricted, and efforts to implement stringent dietary control (Fig. 1, arrows) result in marked social difficulties. The cause of the severe and specific impairment of POMC processing in this child remains obscure. The absence of circulating ACTH indicates that the defect is expressed in the corticotrophs of the anterior pituitary, and the progressive obesity suggests that it is also present in the hypothalamus. In contrast to the children with defects in the POMC gene itself, this child does not have red hair, suggesting that some bioactive melanocortin activity is present in the hair follicle. In conclusion, the early-onset obesity seen in this child is further evidence for the role of impaired prohormone processing in mammalian obesity. Additionally, the specificity of the processing defect provides evidence for the importance of melanocortin signaling in the control of energy balance in man.

OBJECTIVE Conventional treatment of familial hypophosphataemic rickets with oral phosphate and 1α‐hydroxycholecalciferol (1αHCC) does not satisfactorily correct the metabolic or physical defects of the disease and can have adverse effects, such as nephrocalcinosis. Hyperoxaluria from increased oral phosphate intake may contribute to nephrocalcinosis. Growth hormone enhances renal tubular phosphate reabsorption and 1,25‐dihydroxycholecalciferol production in normal and in GH deficient individuals, and may thus be of benefit to patients with familial hypophosphataemic rickets. PATIENTS We have assessed the acute effects of GH on phosphate and calcium metabolism in 6 children (age 4–14 years) with familial hypophosphataemic rickets. DESIGN Each patient served as his/her own control and received the following in a sequential non‐randomized design: conventional treatment with oral phosphate 1.0–3.4 mmol/kg/day in 3–6 divided doses and 1αHCC 18–31 ng/kg/day—no treatment—GH 0.05 mg/kg daily—GH and 1αHCC—and GH with phosphate and 1αHCC. Each treatment was given for 7 days with 7 day periods of no treatment in between. MEASUREMENTS AND RESULTS Glomerular filtration rate, tubular maximum rate of phosphate reabsorption per litre of glomerular filtrate (TmP/GFR) and serum 1,25‐dihydroxycholecalciferol increased with GH. Mean 24‐hour plasma phosphate concentrations did not increase with GH but were higher in the treatment phases which included phosphate and 1αHCC (P = 0.002). Serum PTH was higher when GH was given in combination with phosphate and 1αHCC compared to other phases. Urine oxalate excretion did not differ between the treatment phases. CONCLUSIONS GH seemed to partially correct the defects in renal tubular phosphate transport and 1α‐hydroxylation of 25‐hydroxycholecalciferol. We speculate that the net effect of GH treatment was an increase in body phosphate, although this was not reflected in a change in plasma phosphate. Therefore, GH in combination with 1αHCC may act as a phosphate sparing agent, permitting treatment with lower and less frequent doses of oral phosphate and reducing adverse effects such as nephrocalcinosis.

Stable carbon and nitrogen isotope ratios have been determined for bone collagen from samples of chacma baboons (Papio cynocephalus ursinus) from a rang of environments in southern Africa. The results are compared with data for ungulates and Homo sapiens from southern and East Africa. Regression analyses demonstrate relationships between carbon and nitrogen isotope ratios in baboons and H. sapiens, similar to those previously found in ungulates. Modern baboon samples indicate that a single primate species can display a considerable degree of variation in stable carbon isotope ratios over a range of environmental conditions, but variability within the same species in a particular environment at any one time is generally confined to less than 3 parts per thousand. This is the kind of variability found in enamel samples of hominid teeth attributed to Australopithecus robustus and fossil baboon teeth attributed to Papio robinsoni from Swartkrans in the Sterkfontein valley.

Summary The gastro‐intestinal parasites of baboons in the Namib Desert, Namibia, were shown, using scat analysis, to be predominantly protozoans, notably amoebae, in contrast to those of baboons from South Africa, which harbour a helminth‐dominated fauna. Due to the extreme abiotic characteristics of both soil and water in the desert, these baboons harbour only parasite species which can complete their life‐cycles without prolonged exposure to the outside environment: forms transmitted either directly via the faecal‐oral or trans‐placental/mammary (vertical) routes or indirectly via arthropod intermediate hosts which are eaten. Résumé On a montré par des analyses d'excréments que les parasites gastrointestinaux des babouins du Désert du Namib, Namibie, sont majoritairement des protozoaires, notamment des amibes, contrairement aux babouins d'Afrique du Sud qui hébergent une faune dominée par les helminthes. En raison des caractéristiques extrêmement abiotiques du sol et de l'eau dans le désert, ces babouins n'hébergent que des espèces de parasites qui peuvent completer leur cycle vital sans exposition prolongée à l'environnempent extérieur: ce sont soit des formes qui sont transmises directement par la voie excréments‐nourriture, à travers le placenta ou par le lait maternel, soit indirectement, par l'intermédiaire d'arthropodes‐hôtes qui sont consommes.

Chacma baboons (Papio ursinus) living in an arid environment in Namibia were heavily infested with ticks of the genus Rhipicephalus. A survey to assess tick numbers and identity was undertaken in the baboons' habitat. It appears that there is a strong correlation between the number of ticks and the amount of time the baboons spend in an area. It is speculated that tick infestations were responsible for more than half (n = 18) of recorded infant deaths amongst these baboons.

Three separate periods of observation totalling 1504 h were carried out on the baboons (Papio ursinus) resident in the Central Namib desert environment of the Kuiseb River canyon. The three troops resident in the canyon occupy highly linear ranges that overlap at the extremities. Troop interactions occur when troops are forced into close proximity as resources fail. The spatial separation of food resources and water has resulted in one of the troops spending up to 11 days in food-rich areas without drinking. This adaptation has numerous advantages, such as decreasing mean daily travel by 41% and reducing the chance of troop interactions. Individual's rank in the troop determines the order but not the quantity of resource aquisition. Tactics employed by low ranking individuals frequently result in their more successful utilization of available resources in this desert environment.

In this paper, a process control-based inventory control methodology is developed for a yarn spinning plant. The technique attempts to control the inventory at a specified level using separate proportional/derivative control equations for each product (yarn) type. The system is unique in that the controlling variable (number of spinning frames producing a yarn type) is discrete while the output of the control equation is continuous. Additionally, each controller is contending for a common set of resources (spinning frames). The approach is compared with a traditional min/max system via computer simulation for the case of uncorrelated demand.