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Sample records for namibian giraffe giraffa

  1. Monodontella giraffae infection in wild-caught southern giraffes (Giraffa camelopardalis giraffa).

    PubMed

    Bertelsen, Mads F; Østergaard, Kristine; Monrad, Jesper; Brøndum, Emil T; Baandrup, Ulrik

    2009-10-01

    Postmortem examination of seven wild-caught southern giraffes (Giraffa camelopardalis giraffa) from Namibia demonstrated focal discoloration, biliary thickening, and peribiliary fibrosis affecting mainly the left liver lobe. The giraffes were infected with Monodontella giraffae, previously associated with lethal infections in captive okapis (Okapia johnstoni) and giraffes. Contrary to this, all seven giraffes investigated in the present study were clinically healthy. Based on these findings, it is suggested that the nematode M. giraffae may not be an unusual parasite of the giraffe and that it does not necessarily cause detrimental liver disease.

  2. Surgical castration of subadult giraffe (Giraffa camelopardalis).

    PubMed

    Borkowski, Rose; Citino, Scott; Bush, Mitch; Wollenman, Paul; Irvine, Brenda

    2009-12-01

    Surgical castration of giraffe (Giraffa camelopardalis) has not been commonly performed. Large domestic animal castration has a significant complication rate that includes postoperative mortality. Documentation of castration techniques and complications in large domestic animals occurs regularly. However, literature describing castration experiences with large zoo mammals is sparse. In addition, a suitable anesthetic regimen for surgical castration of giraffe has not been confirmed. Open castration using an emasculator plus ligation was performed in three subadult giraffe weighing 555-711 kg. Scrotal incisions were left open and healed in about 6 wk. One animal developed scrotal dermatitis. No other complications occurred. As slow scrotal healing can increase the risk of ascending infection, partial or complete scrotal closure for giraffe may warrant consideration. Experiences with these animals also suggest that closed or modified closed castration may be considered for giraffe of this size. Thiafentanil, medetomidine, and ketamine plus local lidocaine provided suitable anesthesia for surgical castration.

  3. The giraffe (Giraffa camelopardalis) rumen microbiome.

    PubMed

    Roggenbuck, Michael; Sauer, Cathrine; Poulsen, Morten; Bertelsen, Mads F; Sørensen, Søren J

    2014-10-01

    Recent studies have shown that wild ruminants are sources of previously undescribed microorganisms, knowledge of which can improve our understanding of the complex microbial interactions in the foregut. Here, we investigated the microbial community of seven wild-caught giraffes (Giraffa camelopardalis), three of which were fed natural browse and four were fed Boskos pellets, leafy alfalfa hay, and cut savanna browse, by characterizing the 16S rRNA gene diversity using 454 FLX high-throughput sequencing. The microbial community composition varied according to diet, but differed little between the ruminal fluid and solid fraction. The giraffe rumen contained large levels of the phyla of Firmicutes and Bacteroidetes independent of diet, while Prevotella, Succinclasticium, and Methanobrevibacter accounted for the largest abundant taxonomic assigned genera. However, up to 21% of the generated sequences could not been assigned to any known bacterial phyla, and c. 70% not to genus, revealing that the giraffe rumen hosts a variety of previously undescribed bacteria.

  4. Behavioural inventory of the giraffe (Giraffa camelopardalis)

    PubMed Central

    2012-01-01

    Background Numerous factors like continuous habitat reduction or fragmentation for free-ranging giraffes (Giraffa camelopardalis) as well as e.g. suboptimal housing conditions for animals in captivity might lead to behavioural alterations as part of the overall adaptation process to the changing living conditions. In order to facilitate current and future studies on giraffe behaviour, a comprehensive ethogram was compiled based on existing literature, as well as observations on giraffes in the wild (Hwange National Park, Zimbabwe; Entabeni Game Reserve, South Africa), and in captivity (National Zoological Gardens of South Africa, Pretoria). Findings The resulting ethogram lists 65 different behavioural patterns, which were described and grouped into seven categories: General activities, Abnormal repetitive behaviours, General interactions, Bull-Cow behaviour, Bull-Bull behaviour, Cow-Bull behaviour, Maternal behaviours, and Interactions by calves. The behaviours were further described regarding a presumed purpose, particularly with respect to social interactions and sexual behaviour. Contradictory descriptions from previous studies were considered and discussed in comparison with our own observations. Conclusions This ethogram provides a basis for current and future studies by suggesting a terminology which can be used for harmonizing behavioural observations, thus helping to facilitate comparability of future results. Subsequently, a better understanding of the behavioural ecology of giraffes in the wild as well as in captivity could aid future conservation efforts. PMID:23173954

  5. Rumen content stratification in the giraffe (Giraffa camelopardalis).

    PubMed

    Sauer, Cathrine; Clauss, Marcus; Bertelsen, Mads F; Weisbjerg, Martin R; Lund, Peter

    2017-01-01

    Ruminants differ in the degree of rumen content stratification, with 'cattle-types' (i.e., the grazing and intermediate feeding ruminants) having stratified content, whereas 'moose-types' (i.e., the browsing ruminants) have unstratified content. The feeding ecology, as well as the digestive morphophysiology of the giraffe (Giraffa camelopardalis), suggest that it is a 'moose-type' ruminant. Correspondingly, the giraffe should have an unstratified rumen content and an even rumen papillation pattern. Digesta samples were collected from along the digestive tract of 27 wild-caught giraffes kept in bomas for up to 2months, and 10 giraffes kept in zoological gardens throughout their lives. Samples were analysed for concentration of dry matter, fibre fractions, volatile fatty acids and NH3, as well as mean particle size and pH. There was no difference between the dorsal and ventral rumen region in any of these parameters, indicating homogenous rumen content in the giraffes. In addition to the digesta samples, samples of dorsal rumen, ventral rumen and atrium ruminis mucosa were collected and the papillary surface enlargement factor was determined, as a proxy for content stratification. The even rumen papillation pattern observed also supported the concept of an unstratified rumen content in giraffes. Zoo giraffes had a slightly more uneven papillation pattern than boma giraffes. This finding could not be matched by differences in physical characteristics of the rumen content, probably due to an influence of fasting time ante mortem on these parameters.

  6. Helminths in a giraffe (Giraffa camelopardalis xgiraffa) from a zoo in Spain.

    PubMed

    Garijo, M M; Ortiz, J M; Ruiz de Ibáñez, M R

    2004-06-01

    A pregnant female Cape giraffe (Giraffa camelopardalis giraffa) died from an unknown cause in the Aitana Zoo, Alicante, Spain. Neither clinical signs nor macroscopic lesions were observed at necropsy. The alimentary tract was removed and examined for parasites. A total of 2 724 nematodes were found, including Camelostrongylus mentulatus, Trichostrongylus axei, Ostertagia ostertagi, Teladorsagia circumcincta, Teladorsagia trifurcata, Marshallagia marshalli, Trichostrongylus vitrinus, Trichostrongylus colubriformis, Spiculopteragia asymmetrica and Trichuris giraffae. Only T. giraffae and C. mentulatus have been previously reported from giraffes. The other nematodes are common in mouflons, fallow and red deer, which can usually be found in the same paddock as the giraffes in Aitana Zoo. Although its occurrence is unusual in this host, C. mentulatus was the most abundant nematode in our giraffe. This parasite has been related to disease, and even death, in several wild ruminants.

  7. Lung volumes in giraffes, Giraffa camelopardalis.

    PubMed

    Mitchell, G; Skinner, J D

    2011-01-01

    We have measured lung mass and trachea dimensions in 46 giraffes of both genders ranging in body mass from 147 kg to 1441 kg, calculated static and dynamic lung volumes, and developed allometric equations that relate changes in them to growth. We found that relative lung mass is 0.6±0.2% of body mass which is significantly less than it is in other mammals (1.1±0.1%). Total lung volume is significantly smaller (46.2±5.9 mL kg⁻¹) than in similar sized mammals (75.0±2.1 mL kg⁻¹). The lung volume:body mass ratio decreases during growth rather than increase as it does in other mammals. Tracheal diameter is significantly narrower than in similar sized mammals but dead space volume (2.9±0.5 mL kg⁻¹) is larger than in similar sized mammals (2.4±0.1 mL kg⁻¹). Our calculations suggest that tidal volume (10.5±0.2 mL kg⁻¹) is increased compared to that in other mammals(10.0±0.2 mL kg⁻¹) so that the dead space:tidal volume ratio is the same as in other mammals. Calculated Functional Residual Capacity is smaller than predicted (53.4±3.5 vs 33.7±0.6 mL kg⁻¹) as is Expiratory Reserve Volume (47.4±2.6 vs 27.2±1.0 mL kg⁻¹, but Residual Volume (6.0±0.4 mL kg⁻¹) is the same as in other similar sized mammals (6.0±0.9 mL kg⁻¹. Our calculations suggest that Inspiratory Reserve Volume is significantly reduced in size (11.6±1.6 vs 3.8±2.4 mL kg⁻¹), and, if so, the capacity to increase tidal volume is limited. Calculated dynamic lung volumes were the same as in similar sized mammals. We have concluded that giraffe morphology has resulted in lung volumes that are significantly different to that of similar sized mammals, but these changes do not compromise ventilatory capacity.

  8. Gross anatomy of the intestine in the giraffe (Giraffa camelopardalis).

    PubMed

    Pérez, W; Lima, M; Clauss, M

    2009-11-01

    We describe the macroscopic anatomy of the intestine of the giraffe (Giraffa camelopardalis). The small intestine was divided into duodenum, jejunum and ileum as usual. The caecum was attached to the ileum by a long ileocaecal fold, and to the proximal ansa of the ascending colon by a caecocolic fold. The ascending colon was the most developed portion of the gross intestine and had the most complex arrangement with three ansae: the proximal ansa, the spiral ansa and the distal ansa. The proximal ansa completely encircled the caecum, describing a 360 degrees gyrus, and represented the widest portion of the intestine. The spiral ansa was formed by three and a half centripetal gyri, a central flexure and three centrifugal gyri. The last centrifugal gyrus left the spiral and described nine flexures of different form and direction over the left side of the mesentery. The two portions that formed each of these flexures ran parallel to each other. The last part of this gyrus ran parallel to the jejunum. When compared with domestic cattle, giraffe had a comparatively short small intestine and a comparatively long large intestine, with a resulting small ratio of small:large intestine. Reasons are presented why this should be considered a peculiarity of cattle-like ruminants rather than a different representative of a browser-grazer dichotomy in general.

  9. Evaluation of progesterone levels in feces of captive reticulated giraffe (Giraffa camelopardalis reticulata).

    PubMed

    Dumonceaux, Genevieve A; Bauman, Joan E; Camilo, Gerardo R

    2006-09-01

    Fresh fecal samples were collected from seven adult female reticulated giraffe (Giraffa camelopardalis reticulata). Samples were collected for several weeks before, during, and for a few weeks after gestation. Fecal samples were analyzed for progesterone levels by radioimmunoassay. There were significant differences in progesterone levels between pregestational and gestational samples and between gestational and postgestational samples. These results demonstrate that fecal progesterone levels are useful in determining pregnant versus nonpregnant reticulated giraffe.

  10. OSTEOCHONDROSIS IN THE DISTAL FEMURS OF AN ADULT RETICULATED GIRAFFE (GIRAFFA CAMELOPARDALIS RETICULATA): MACROSCOPIC, RADIOLOGIC, AND HISTOLOGIC FINDINGS.

    PubMed

    Basu, Christopher; Stoll, Alexander L; Dixon, Jonathon; Molenaar, Fieke Marije; Flach, Edmund; Smith, Ken C

    2016-03-01

    An adult male reticulated giraffe (Giraffa camelopardalis reticulata) was presented for postmortem examination. During radiologic examination of the hindlimbs, osseous cyst-like lesions were detected in both medial femoral condyles. These lesions were subsequently examined macroscopically and histologically. The gross appearance suggested a diagnosis of bilateral osteochondrosis that was confirmed with histopathologic examination. This finding has not previously been reported in giraffes. Macroscopic visualization of the major limb joints, including the femorotibial joints, is therefore encouraged in future postmortem examinations of giraffes (Giraffa camelopardalis), and further assessment of clinical significance is required.

  11. Serum chemistry comparisons between captive and free-ranging giraffes (Giraffa camelopardalis).

    PubMed

    Schmidt, Debra A; Barbiers, Robyn B; Ellersieck, Mark R; Ball, Ray L; Koutsos, Elizabeth A; Griffin, Mark E; Grobler, Douw; Citino, Scott B; Bush, Mitchell

    2011-03-01

    Serum chemistry analyses were compared between captive and free-ranging giraffes (Giraffa camelopardalis) in an attempt to better understand some of the medical issues seen with captive giraffes. Illnesses, including peracute mortality, energy malnutrition, pancreatic disease, urolithiasis, hoof disease, and severe intestinal parasitism, may be related to zoo nutrition and management issues. Serum samples were collected from 20 captive giraffes at 10 United States institutions. Thirteen of the captive animal samples were collected from animals trained for blood collection; seven were banked samples obtained from a previous serum collection. These samples were compared with serum samples collected from 24 free-ranging giraffes in South Africa. Differences between captive and free-ranging giraffes, males and females, and adults and subadults were analyzed by using a 2 x 2 x 2 factorial and Fisher's least significant difference for mean separation; when necessary variables were ranked and analyzed via analysis of variance. Potassium and bilirubin concentrations and alanine aminotransferase (ALT) activities were different between captive and free-ranging giraffes, but all fell within normal bovid reference ranges. The average glucose concentration was significantly elevated in free-ranging giraffes (161 mg/dl) compared with captive giraffes (113 mg/dl). All giraffes in this study had glucose concentrations higher than bovine (42-75 mg/ dl) and caprine (48-76 mg/dl) reference ranges. Differences were also seen in lipase, chloride, and magnesium though these findings are likely not clinically significant. There were no differences detected between sexes. Adults had higher concentrations of potassium, total protein, globulins, and chloride and higher gamma glutamyltransferase activities, whereas subadults had higher concentrations of phosphorus. Within the captive group, nonimmobilized animals had higher concentrations of total protein and globulins. Captive giraffe diets

  12. MANAGEMENT OF OMPHALOPHLEBITIS AND UMBILICAL HERNIA IN THREE NEONATAL GIRAFFE (GIRAFFA CAMELOPARDALIS).

    PubMed

    Selig, Michael; Lewandowski, Albert; Burton, Michael S; Ball, Ray L

    2015-12-01

    Umbilical disorders, including omphalophlebitis, omphaloarteritis, external umbilical abscesses, urachal abscesses, patent urachus, and umbilical hernias, represent a significant challenge to the health and well-being of a neonate. The three neonatal giraffe (Giraffa camelopardalis) in this report were evaluated for umbilical swellings. Two developed omphalophlebitis, and one had an uncomplicated umbilical hernia. Omphalophlebitis is an inflammation and/or infection of the umbilical vein. Giraffe calves with a failure of passive transfer may be predisposed and should be thoroughly evaluated for the condition. Umbilical hernias result from a failure of the umbilical ring to close after parturition or from malformation of the umbilical ring during embryogenesis. These problems were surgically corrected for all three individuals, although one died due to postsurgical complications. The risks involved include anesthetic complications, surgical dehiscence, and maternal rejection. Early detection and surgical intervention are recommended for the correction of omphalophlebitis and umbilical hernias in neonatal giraffe.

  13. Histological features of the vomeronasal organ in the giraffe, Giraffa camelopardalis.

    PubMed

    Kondoh, Daisuke; Nakamura, Kentaro G; Ono, Yurie S; Yuhara, Kazutoshi; Bando, Gen; Watanabe, Kenichi; Horiuchi, Noriyuki; Kobayashi, Yoshiyasu; Sasaki, Motoki; Kitamura, Nobuo

    2017-01-17

    The vomeronasal organ (VNO) that preferentially detects species-specific substances is diverse among animal species, and its morphological properties seem to reflect the ecological features of animals. This histological study of two female reticulated giraffes (Giraffa camelopardalis reticulata) found that the VNO is developed in giraffes. The lateral and medial regions of the vomeronasal lumen were covered with sensory and nonsensory epithelia, respectively. The vomeronasal glands were positive for periodic acid-Schiff and alcian blue (pH 2.5) stains. The VNO comprises several large veins like others in the order Cetartiodactyla, suggesting that these veins function in a pumping mechanism in this order. In addition, numerous thin-walled vessels located immediately beneath the epithelia covering the lumen entirely surrounded the vomeronasal lumen. This sponge-like structure might function as a specific secondary pump in giraffes.

  14. Successful management of acute-onset torticollis in a giraffe (Giraffa camelopardalis reticulata).

    PubMed

    Dadone, Liza I; Haussler, Kevin K; Brown, Greg; Marsden, Melanie; Gaynor, James; Johnston, Matthew S; Garelle, Della

    2013-03-01

    A 2-yr-old male reticulated giraffe (Giraffa camelopardalis reticulata) presented with severe midcervical segmental torticollis upon arrival as an incoming shipment. Despite initial medical management, the giraffe developed marked neck sensitivity, focal muscle spasms, and decreased cervical range of motion. Using operant conditioning to assist patient positioning and tolerance to cervical manipulation, a series of manually applied chiropractic treatments were applied to the affected cervical vertebrae in an effort to restore normal cervical mobility. Laser therapy and cervical range of motion exercises were also used to reduce cervical muscle hypertonicity. The combined application of these nontraditional therapies produced marked clinical improvement. This case highlights the potential benefits of combining traditional medical management with chiropractic treatment and physical therapy techniques for management of severe acute-onset torticollis in a giraffe.

  15. Anthelmintic resistant Haemonchus contortus in a giraffe (Giraffa camelopardalis) in Florida.

    PubMed

    Garretson, Pamela D; Hammond, Elizabeth E; Craig, Thomas M; Holman, Patricia J

    2009-03-01

    A young male giraffe (Giraffa camelopardalis) recently acquired by the Lion Country Safari in Loxahatchee, Florida, was diagnosed and successfully treated for Haemonchus infection while in quarantine. Seven weeks after introduction into a group of resident giraffes, this giraffe presented with diarrhea. Fecal evaluation revealed an extremely high count of 16,700 eggs/g, with larval identification of the parasite as Haemonchus. A larval development assay showed resistance to the three classes of anthelmintics currently used to treat Haemonchus contortus: the benzimidazoles, imidazothiazoles, and macrocyclic lactones. The giraffe was treated with a combination of moxidectin topically and fenbendazole orally, and follow-up fecal examination 2 wk later showed a marked reduction in strongyle-type eggs. However, within 2 mo the giraffe had a packed cell volume of 22% and an eggs per gram count of 11,900. The animal was then treated with moxidectin topically and copper oxide wire particles orally and removed from the contaminated area. Because of the unusual host, molecular analysis of the parasite was employed, which confirmed the nematode as H. contortus. It is likely that the monthly rotational deworming schedule first implemented more than 5 yr earlier contributed to the development of multiple anthelmintic resistance in this H. contortus population. The proper use of anthelmintics and good pasture management are crucial to reducing the parasite burden in captive giraffe.

  16. A comparative assessment of the size of the frontal air sinus in the giraffe (Giraffa camelopardalis).

    PubMed

    Badlangana, N Ludo; Adams, Justin W; Manger, Paul R

    2011-06-01

    The current study examines the frontal air sinus of the giraffe (Giraffa camelopardalis) cranium with the aim of evaluating previously offered hypotheses as to why they have such an atypically voluminous frontal sinus relative to other artiodactyls. To date, no quantification of the frontal sinus in the adult or developing giraffe has been undertaken or compared to other artiodactyl species. Crania from eight species of adult artiodactyls, and giraffes varying in age from newborn to adult, were studied using CT scans to provide a volumetric assessment of the frontal sinus. Sinus volume was strongly correlated to cranial mass in the male giraffe ontogenetic series. The adult giraffe of both sexes were found to possess a far larger than predicted sinus volume relative to the relationship between frontal sinus volume and cranial mass observed in the other adult artiodactyls. Our results suggest that the volume of the frontal sinus in the giraffe is likely to be unique among artiodactyls, and the potential function and evolution we consider in light of several previously articulated hypotheses.

  17. Quantitative Macroscopic Anatomy of the Giraffe (Giraffa camelopardalis) Digestive Tract.

    PubMed

    Sauer, C; Bertelsen, M F; Lund, P; Weisbjerg, M R; Clauss, M

    2016-10-01

    Quantitative data on digestive anatomy of the world's largest ruminant, the giraffe, are scarce. Data were collected from a total of 25 wild-caught and 13 zoo-housed giraffes. Anatomical measures were quantified by dimension, area or weight and analysed by allometric regression. The majority of measures scaled positively and isometrically to body mass. Giraffes had lower tissue weight of all stomach compartments and longer large intestinal length than cattle. When compared to other ruminants, the giraffe digestive tract showed many of the convergent morphological adaptations attributed to browsing ruminants, for example lower reticular crests, thinner ruminal pillars and smaller surface area of the omasal laminae. Salivary gland weight of the giraffe, however, resembled that of grazing ruminants. This matches a previous finding of similarly small salivary glands in the other extant giraffid, the okapi (Okapia johnstoni), suggesting that not all convergent characteristics need be expressed in all species and that morphological variation between species is a combination of phylogenetic and adaptational signals.

  18. Lateralization of splay posture in reticulated giraffe (Giraffa camelopardalis reticulate).

    PubMed

    Svoke, Joseph T

    2017-02-01

    Motor laterality is quite often studied in non-human primates, but rarely has been investigated within ungulates. The aim of the study was to use the naturally occurring splay behavior in giraffe as a method to look for the presence of laterality. Four male giraffes housed at Zoo Atlanta were watched for three months, recording their first leg moved to begin the splay posture and the total number of leg movements to achieve a secure stance. All four giraffe significantly moved their left leg first to begin the stance, which suggests at least individual level laterality. However, using the number of leg movements overall, the last leg moved was only significant in one individual.

  19. Molecular cytogenetic insights to the phylogenetic affinities of the giraffe (Giraffa camelopardalis) and pronghorn (Antilocapra americana).

    PubMed

    Cernohorska, Halina; Kubickova, Svatava; Kopecna, Olga; Kulemzina, Anastasia I; Perelman, Polina L; Elder, Frederick F B; Robinson, Terence J; Graphodatsky, Alexander S; Rubes, Jiri

    2013-08-01

    Five families are traditionally recognized within higher ruminants (Pecora): Bovidae, Moschidae, Cervidae, Giraffidae and Antilocapridae. The phylogenetic relationships of Antilocapridae and Giraffidae within Pecora are, however, uncertain. While numerous fusions (mostly Robertsonian) have accumulated in the giraffe's karyotype (Giraffa camelopardalis, Giraffidae, 2n = 30), that of the pronghorn (Antilocapra americana, Antilocapridae, 2n = 58) is very similar to the hypothesised pecoran ancestral state (2n = 58). We examined the chromosomal rearrangements of two species, the giraffe and pronghorn, using a combination of fluorescence in situ hybridization painting probes and BAC clones derived from cattle (Bos taurus, Bovidae). Our data place Moschus (Moschidae) closer to Bovidae than Cervidae. Although the alternative (i.e., Moschidae + Cervidae as sister groups) could not be discounted in recent sequence-based analyses, cytogenetics bolsters conclusions that the former is more likely. Additionally, DNA sequences were isolated from the centromeric regions of both species and compared. Analysis of cenDNA show that unlike the pronghorn, the centromeres of the giraffe are probably organized in a more complex fashion comprising different repetitive sequences specific to single chromosomal pairs or groups of chromosomes. The distribution of nucleolar organiser region (NOR) sites, often an effective phylogenetic marker, were also examined in the two species. In the giraffe, the position of NORs seems to be autapomorphic since similar localizations have not been found in other species within Pecora.

  20. Scene from above: retinal ganglion cell topography and spatial resolving power in the giraffe (Giraffa camelopardalis).

    PubMed

    Coimbra, João Paulo; Hart, Nathan S; Collin, Shaun P; Manger, Paul R

    2013-06-15

    The giraffe (Giraffa camelopardalis) is a browser that uses its extensible tongue to selectively collect leaves during foraging. As the tallest extant terrestrial mammal, its elevated head height provides panoramic surveillance of the environment. These aspects of the giraffe's ecology and phenotype suggest that vision is of prime importance. Using Nissl-stained retinal wholemounts and stereological methods, we quantitatively assessed the retinal specializations in the ganglion cell layer of the giraffe. The mean total number of retinal ganglion cells was 1,393,779 and their topographic distribution revealed the presence of a horizontal visual streak and a temporal area. With a mean peak of 14,271 cells/mm(2), upper limits of spatial resolving power in the temporal area ranged from 25 to 27 cycles/degree. We also observed a dorsotemporal extension (anakatabatic area) that tapers toward the nasal retina giving rise to a complete dorsal arch. Using neurofilament-200 immunohistochemistry, we also detected a dorsal arch formed by alpha ganglion cells with density peaks in the temporal (14-15 cells/mm(2)) and dorsonasal (10 cells/mm(2)) regions. As with other artiodactyls, the giraffe shares the presence of a horizontal streak and a temporal area which, respectively, improve resolution along the horizon and in the frontal visual field. The dorsal arch is related to the giraffe's head height and affords enhanced resolution in the inferior visual field. The alpha ganglion cell distribution pattern is unique to the giraffe and enhances acquisition of motion information for the control of tongue movement during foraging and the detection of predators.

  1. Scaling of the appendicular skeleton of the giraffe (Giraffa camelopardalis).

    PubMed

    van Sittert, Sybrand; Skinner, John; Mitchell, Graham

    2015-05-01

    Giraffes have remarkably long and slender limb bones, but it is unknown how they grow with regard to body mass, sex, and neck length. In this study, we measured the length, mediolateral (ML) diameter, craniocaudal (CC) diameter and circumference of the humerus, radius, metacarpus, femur, tibia, and metatarsus in 10 fetuses, 21 females, and 23 males of known body masses. Allometric exponents were determined and compared. We found the average bone length increased from 340 ± 50 mm at birth to 700 ± 120 mm at maturity, while average diameters increased from 30 ± 3 to 70 ± 11 mm. Fetal bones increased with positive allometry in length (relative to body mass) and in diameter (relative to body mass and length). In postnatal giraffes bone lengths and diameters increased iso- or negatively allometric relative to increases in body mass, except for the humerus CC diameter which increased with positive allometry. Humerus circumference also increased with positive allometry, that of the radius and tibia isometrically and the femur and metapodials with negative allometry. Relative to increases in bone length, both the humerus and femur widened with positive allometry. In the distal limb bones, ML diameters increased isometrically (radius, metacarpus) or positively allometric (tibia, metatarsus) while the corresponding CC widths increased with negative allometry and isometrically, respectively. Except for the humerus and femur, exponents were not significantly different between corresponding front and hind limb segments. We concluded that the patterns of bone growth in males and females are identical. In fetuses, the growth of the appendicular skeleton is faster than it is after birth which is a pattern opposite to that reported for the neck. Allometric exponents seemed unremarkable compared to the few species described previously, and pointed to the importance of neck elongation rather than leg elongation during evolution. Nevertheless, the front limb bones

  2. Neocortical neuronal morphology in the newborn giraffe (Giraffa camelopardalis tippelskirchi) and African elephant (Loxodonta africana).

    PubMed

    Jacobs, Bob; Lee, Laura; Schall, Matthew; Raghanti, Mary Ann; Lewandowski, Albert H; Kottwitz, Jack J; Roberts, John F; Hof, Patrick R; Sherwood, Chet C

    2016-02-01

    Although neocortical neuronal morphology has been documented in the adult giraffe (Giraffa camelopardalis tippelskirchi) and African elephant (Loxodonta africana), no research has explored the cortical architecture in newborns of these species. To this end, the current study examined the morphology of neurons from several cortical areas in the newborn giraffe and elephant. After cortical neurons were stained with a modified Golgi technique (N = 153), dendritic branching and spine distributions were analyzed by using computer-assisted morphometry. The results showed that newborn elephant neurons were considerably larger in terms of all dendritic and spine measures than newborn giraffe neurons. Qualitatively, neurons in the newborns appeared morphologically comparable to those in their adult counterparts. Neurons in the newborn elephant differed considerably from those observed in other placental mammals, including the giraffe, particularly with regard to the morphology of spiny projection neurons. Projection neurons were observed in both species, with a much larger variety in the elephant (e.g., flattened pyramidal, nonpyramidal multipolar, and inverted pyramidal neurons). Although local circuit neurons (i.e., interneurons, neurogliaform, Cajal-Retzius neurons) resembled those observed in other eutherian mammals, these were usually spiny, which contrasts with their adult, aspiny equivalents. Newborn projection neurons were smaller than the adult equivalents in both species, but newborn interneurons were approximately the same size as their adult counterparts. Cortical neuromorphology in the newborn giraffe is thus generally consistent with what has been observed in other cetartiodactyls, whereas newborn and adult elephant morphology appears to deviate substantially from what is commonly observed in other placental mammals.

  3. Nocturnal behavior in captive giraffe (Giraffa camelopardalis)--A pilot study.

    PubMed

    Duggan, Graham; Burn, Charlotte C; Clauss, Marcus

    2016-01-01

    Captive giraffes (Giraffa camelopardalis) are known to perform oral and locomotor stereotypies. However, many studies do not consider the behavioral repertoire of these animals during the time when animals are confined to night quarters. At two zoological institutions, a total of six captive giraffes were observed via camera trap technology throughout six diurnal and nocturnal periods to record feeding, ruminating, and stereotypic behaviors. The effect of browse enrichment was assessed on alternate nights to determine how behaviors may be altered in the presence of natural forage. Results need to be interpreted with caution due to a high proportion of time when animals were out of camera range. For the observed time, stereotypical licking behavior was significantly higher at night compared to daytime at both facilities, while tongue play increased at the same time, but not significantly. The provision of browse enrichment during the night decreased the rate of tongue playing, but not significantly; however, browse did significantly reduce pacing behavior. Across treatments and institutions, observed oral stereotypies tended to correlate negatively with increased feeding behavior. Apart from a short-term effect of enrichment, this study indicates relevant differences in the frequencies of behaviors observed during the day and night, suggesting that assessing nocturnal behavior specifically may be important in many species.

  4. A comparison of postnatal arterial patterns in a growth series of giraffe (Artiodactyla: Giraffa camelopardalis)

    PubMed Central

    Gignac, Paul M.; Hieronymus, Tobin L.; Witmer, Lawrence M.

    2016-01-01

    Nearly all living artiodactyls (even-toed ungulates) possess a derived cranial arterial pattern that is highly distinctive from most other mammals. Foremost among a suite of atypical arterial configurations is the functional and anatomical replacement of the internal carotid artery with an extensive, subdural arterial meshwork called the carotid rete. This interdigitating network branches from the maxillary artery and is housed within the cavernous venous sinus. As the cavernous sinus receives cooled blood draining from the nasal mucosa, heat rapidly dissipates across the high surface area of the rete to be carried away from the brain by the venous system. This combination yields one of the most effective mechanisms of selective brain cooling. Although arterial development begins from the same embryonic scaffolding typical of mammals, possession of a rete is typically accompanied by obliteration of the internal carotid artery. Among taxa with available ontogenetic data, the point at which the internal carotid obliterates is variable throughout development. In small-bodied artiodactyls, the internal carotid typically obliterates prior to parturition, but in larger species, the vessel may remain patent for several years. In this study, we use digital anatomical data collection methods to describe the cranial arterial patterns for a growth series of giraffe (Giraffa camelopardalis), from parturition to senescence. Giraffes, in particular, have unique cardiovascular demands and adaptations owing to their exceptional body form and may not adhere to previously documented stages of cranial arterial development. We find the carotid arterial system to be conserved between developmental stages and that obliteration of the giraffe internal carotid artery occurs prior to parturition. PMID:26925324

  5. Analysis of the distal gut bacterial community by 454-pyrosequencing in captive giraffes (Giraffa camelopardalis).

    PubMed

    AlZahal, Ousama; Valdes, Eduardo V; McBride, Brian W

    2016-01-01

    The objective of this study was to characterize the structure of the fecal bacterial community of five giraffes (Giraffa camelopardalis) at Disney's Animal Kingdom, FL. Fecal genomic DNA was extracted and variable regions 1-3 of the 16S rRNA gene was PCR-amplified and then sequenced. The MOTHUR software-program was used for sequence processing, diversity analysis, and classification. A total of 181,689 non-chimeric bacterial sequences were obtained, and average number of sequences per sample was 36,338 -± 8,818. Sequences were assigned to 8,284 operational taxonomic units (OTU) with 95% of genetic similarity, which included 2,942 singletons (36%). Number of OTUs per sample was 2,554 ± 264. Samples were normalized and alpha (intra-sample) diversity indices; Chao1, Inverse Simpson, Shannon, and coverage were estimated as 3,712 ± 430, 116 -± 70, 6.1 ± 0.4, and 96 ± 1%, respectively. Thirteen phyla were detected and Firmicutes, Bacteroidetes, and Spirochaetes were the most dominant phyla (more than 2% of total sequences), and constituted 92% of the classified sequences, 66% of total sequences, and 43% of total OTUs. Our computation predicted that three OTUs were likely to be present in at least three of the five samples at greater than 1% dominance rate. These OTUs were Treponema, an unidentified OTU belonging to the order Bacteroidales, and Ruminococcus. This report was the first to characterize the bacterial community of the distal gut in giraffes utilizing fecal samples, and it demonstrated that the distal gut of giraffes is likely a potential reservoir for a number of undocumented species of bacteria.

  6. A comparison of postnatal arterial patterns in a growth series of giraffe (Artiodactyla: Giraffa camelopardalis).

    PubMed

    O'Brien, Haley D; Gignac, Paul M; Hieronymus, Tobin L; Witmer, Lawrence M

    2016-01-01

    Nearly all living artiodactyls (even-toed ungulates) possess a derived cranial arterial pattern that is highly distinctive from most other mammals. Foremost among a suite of atypical arterial configurations is the functional and anatomical replacement of the internal carotid artery with an extensive, subdural arterial meshwork called the carotid rete. This interdigitating network branches from the maxillary artery and is housed within the cavernous venous sinus. As the cavernous sinus receives cooled blood draining from the nasal mucosa, heat rapidly dissipates across the high surface area of the rete to be carried away from the brain by the venous system. This combination yields one of the most effective mechanisms of selective brain cooling. Although arterial development begins from the same embryonic scaffolding typical of mammals, possession of a rete is typically accompanied by obliteration of the internal carotid artery. Among taxa with available ontogenetic data, the point at which the internal carotid obliterates is variable throughout development. In small-bodied artiodactyls, the internal carotid typically obliterates prior to parturition, but in larger species, the vessel may remain patent for several years. In this study, we use digital anatomical data collection methods to describe the cranial arterial patterns for a growth series of giraffe (Giraffa camelopardalis), from parturition to senescence. Giraffes, in particular, have unique cardiovascular demands and adaptations owing to their exceptional body form and may not adhere to previously documented stages of cranial arterial development. We find the carotid arterial system to be conserved between developmental stages and that obliteration of the giraffe internal carotid artery occurs prior to parturition.

  7. The neocortex of cetartiodactyls. II. Neuronal morphology of the visual and motor cortices in the giraffe (Giraffa camelopardalis).

    PubMed

    Jacobs, Bob; Harland, Tessa; Kennedy, Deborah; Schall, Matthew; Wicinski, Bridget; Butti, Camilla; Hof, Patrick R; Sherwood, Chet C; Manger, Paul R

    2015-09-01

    The present quantitative study extends our investigation of cetartiodactyls by exploring the neuronal morphology in the giraffe (Giraffa camelopardalis) neocortex. Here, we investigate giraffe primary visual and motor cortices from perfusion-fixed brains of three subadults stained with a modified rapid Golgi technique. Neurons (n = 244) were quantified on a computer-assisted microscopy system. Qualitatively, the giraffe neocortex contained an array of complex spiny neurons that included both "typical" pyramidal neuron morphology and "atypical" spiny neurons in terms of morphology and/or orientation. In general, the neocortex exhibited a vertical columnar organization of apical dendrites. Although there was no significant quantitative difference in dendritic complexity for pyramidal neurons between primary visual (n = 78) and motor cortices (n = 65), there was a significant difference in dendritic spine density (motor cortex > visual cortex). The morphology of aspiny neurons in giraffes appeared to be similar to that of other eutherian mammals. For cross-species comparison of neuron morphology, giraffe pyramidal neurons were compared to those quantified with the same methodology in African elephants and some cetaceans (e.g., bottlenose dolphin, minke whale, humpback whale). Across species, the giraffe (and cetaceans) exhibited less widely bifurcating apical dendrites compared to elephants. Quantitative dendritic measures revealed that the elephant and humpback whale had more extensive dendrites than giraffes, whereas the minke whale and bottlenose dolphin had less extensive dendritic arbors. Spine measures were highest in the giraffe, perhaps due to the high quality, perfusion fixation. The neuronal morphology in giraffe neocortex is thus generally consistent with what is known about other cetartiodactyls.

  8. The Brain of the Giraffe (Giraffa Camelopardalis): Surface Configuration, Encephalization Quotient, and Analysis of the Existing Literature.

    PubMed

    Graïc, Jean-Marie; Peruffo, Antonella; Ballarin, Cristina; Cozzi, Bruno

    2017-03-27

    The anatomy of the giraffe (Giraffa camelopardalis Linnaeus, 1758) has been poorly studied, except for the circulatory system. In particular, only a handful of studies have concerned the brain of this species since the first description in 1839. Accordingly, only a very few articles discussing encephalization mentioned the giraffe or used it in their calculations. In this article, we performed a thorough examination of the literature including old and grey, regarding the central nervous system of the giraffe. Furthermore, we examined the brain of 3 giraffes, and calculated the encephalization quotient (EQ) of the species, based on our own data and the values found in the literature. We also revised the pre-existing literature and re-mapped the main sulci based on current comparative interpretation and anatomical nomenclature. Our results were compared to those of other selected significant mammals. The mean brain weight was of 719.9 ± 12.5 g. Our data indicate that the EQ of the giraffe is 0.64 and matches that of the typical ungulate, despite having the largest brain among terrestrial Cetartiodactyla. This emphasizes that the giraffe is a highly specialized mammal, within the limitations of its clad. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc.

  9. Mitochondrial DNA variability in Giraffa camelopardalis: consequences for taxonomy, phylogeography and conservation of giraffes in West and central Africa.

    PubMed

    Hassanin, Alexandre; Ropiquet, Anne; Gourmand, Anne-Laure; Chardonnet, Bertrand; Rigoulet, Jacques

    2007-03-01

    The giraffe (Giraffa camelopardalis) still survives in four countries of West and central Africa. The populations of Niger and Cameroon are generally assigned to the subspecies peralta, but those of Chad and the Central African Republic are taxonomically problematic, as they are referred to as either peralta, or antiquorum, or congoensis. In this study, a mitochondrial fragment of 1765 nucleotide sites, covering the complete cytochrome b gene, three transfer RNAs and a large part of the control region, was sequenced to assess the relationships between several populations of giraffe. The phylogenetic analyses performed on the 12 identified haplotypes indicate that northern giraffes constitute a natural group, distinct from that of southern giraffes. Surprisingly, the giraffes of Niger are found to be more closely related to the giraffes of East Africa (subspecies rothschildi and reticulata) than to those of central Africa. We conclude therefore that the subspecies peralta contains only the Niger giraffes, whereas the subspecies antiquorum includes all populations living in Cameroon, Chad, the Central African Republic, and southwestern Sudan. We suggest that the ancestor of the Nigerian giraffe dispersed from East to North Africa during the Quaternary period and thereafter migrated to its current Sahelian distribution in West Africa, in response to the development of the Sahara desert. This hypothesis implies that Lake Mega-Chad acted as a strong geographical barrier during the Holocene, preventing any contact between the subspecies peralta and antiquorum. Our study has direct implications for conservation management, as we show that no subspecies peralta is represented in any European zoos, only in Niger, with a small population of less than 200 individuals.

  10. The use of magnetic resonance imaging to better define hoof pathology in the reticulated giraffe (Giraffa camelopardalis reticulata).

    PubMed

    Wakeman, Kyle A; Sanchez, Carlos R; Lung, Nancy P; Hersman, Jake; Barrett, Myra F

    2014-09-01

    A 22-yr-old bull giraffe (Giraffa camelopardalis reticulata) with severely altered hoof conformation in both forelimbs was presented for necropsy following acute mortality. Due to multiple challenges that prevented safe immobilization, corrective hoof trimming procedures were never performed on this animal. To better define the extent of the damage of the soft tissue structures and bone within the hoof, a magnetic resonance imaging (MRI) system was used to obtain images of these structures. The MRI study found evidence of severe osteolysis, phalangeal fractures of both forelimbs, and tenosynovitis of several tendon sheaths. These findings help demonstrate the impact that hoof overgrowth can have on internal structures within the hoof. By managing hoof problems early in the course of disease and investing in appropriate facilities that make giraffe immobilization safer, morbidity and mortality associated with hoof disease and overgrowth can potentially be reduced.

  11. Genotypic variations in field isolates of Theileria species infecting giraffes (Giraffa camelopardalis tippelskirchi and Giraffa camelopardalis reticulata) in Kenya.

    PubMed

    Githaka, Naftaly; Konnai, Satoru; Skilton, Robert; Kariuki, Edward; Kanduma, Esther; Murata, Shiro; Ohashi, Kazuhiko

    2013-10-01

    Recently, mortalities among giraffes, attributed to infection with unique species of piroplasms were reported in South Africa. Although haemoparasites are known to occur in giraffes of Kenya, the prevalence, genetic diversity and pathogenicity of these parasites have not been investigated. In this study, blood samples from 13 giraffes in Kenya were investigated microscopically and genomic DNA extracted. PCR amplicons of the hyper-variable region 4 (V4) of Theileria spp. small subunit ribosomal RNA (18S rRNA) gene were hybridized to a panel of genus- and species-specific oligonucleotide probes by reverse line blot (RLB). Two newly designed oligonucleotide probes specific for previously identified Theileria spp. of giraffes found single infections in eight of the specimens and mixed infections in the remaining five samples. Partial 18S rRNA genes were successfully amplified from 9 samples and the PCR amplicons were cloned. A total of 28 plasmid clones representing the Kenyan isolates were analyzed in the present study and compared with those of closely-related organisms retrieved from GenBank. In agreement with RLB results, the nucleotide sequence alignment indicated the presence of mixed infections in the giraffes. In addition, sequence alignment with the obtained 18S rRNA gene sequences revealed extensive microheterogeneities within and between isolates, characterized by indels in the V4 regions and point mutations outside this region. Phylogeny with 18S rRNA gene sequences from the detected parasites and those of related organisms places Theileria of giraffes into two major groups, within which are numerous clades that include the isolates reported in South Africa. Collectively, these data suggest the existence of at least two distinct Theileria species among giraffes, and extensive genetic diversity within the two parasite groups.

  12. Ovarian ultrasonography correlated with fecal progestins and estradiol during the estrous cycle and early pregnancy in giraffes (Giraffa camelopardalis rothschildi).

    PubMed

    Lueders, Imke; Hildebrandt, Thomas B; Pootoolal, Jason; Rich, Peter; Gray, Charlie S; Niemuller, Cheryl A

    2009-11-01

    Fecal and urinary progestin analyses have shown that giraffes express a short reproductive cycle, averaging 15 days, compared with other large ruminants. However, actual ovarian events have not been correlated with the hormonal pattern. In this study, mature cycling female Rothschild giraffes (Giraffa camelopardalis rothschildi) were repeatedly examined by transrectal ultrasonography to correlate ovarian function with changes in fecal progestin (fP4 [n(c) = 6]) and estradiol (fE2 [n(c) = 6]) and serum progestin (n(c) = 2) as measured by enzyme immunoassay. Five females became pregnant and were monitored during early gestation. In this study, we discovered that hormone values for fP4 in cycling giraffes do not correlate with the classic profile of follicular development, ovulation, and luteogenesis. The corpus luteum (CL) and the next dominant follicle were forming simultaneously. A mean +/- SD peak in fE2 of 254.92 +/- 194.76 ng/g and subsequent ovulation occurred as early as 1 day after the fall in fP4. In pregnant giraffes, the CL reached a diameter significantly larger (mean +/- SD, 41.02 +/- 2.70 mm; P = 0.0126) than that during the cycle (33.48 +/- 2.80 mm), while follicular activity and fluctuating fE2 were still present. With this research, we demonstrated that the progesterone profile typically used to characterize the ovarian cycle does not correlate with luteal development in the ovaries of this species. Furthermore, we conclude that the giraffe could have evolved a short reproductive cycle because of the almost parallel order of ovarian events.

  13. Experimental infection of giraffe (Giraffa camelopardalis) with SAT-1 and SAT-2 foot-and-mouth disease virus.

    PubMed

    Vosloo, W; Swanepoel, S P; Bauman, M; Botha, B; Esterhuysen, J J; Boshoff, C I; Keet, D F; Dekker, A

    2011-04-01

    The potential role of giraffe (Giraffa camelopardalis) in the epidemiology and spread of foot-and-mouth disease (FMD) SAT types was investigated by experimental infection and detection of virus in excretions using virus isolation on primary pig kidney cell cultures. In two experiments separated by a period of 24 months, groups of four animals were needle infected with a SAT-1 or SAT-2 virus, respectively and two in-contact controls were kept with each group. Viraemia was detected 3-9 days post-infection and virus isolated from mouth washes and faeces only occasionally up to day 13. The SAT-1 virus was transmitted to only one in-contact control animal, probably via saliva that contained virus from vesicles in the mouth of a needle-infected animal. None of the animals infected with the SAT-2 virus had any vesicles in the mouth, and there was no evidence of transmission to the in-contact controls. No virus was detected in probang samples for the duration of the experiments (60 days post-infection), indicating that persistent infection probably did not establish with either of these isolates. Giraffe most likely do not play an important role in FMD dissemination. Transmission of infection would possibly occur only during close contact with other animals when mouth vesicles are evident.

  14. Serum concentration comparisons of amino acids, fatty acids, lipoproteins, vitamins A and E, and minerals between zoo and free-ranging giraffes (Giraffa camelopardalis).

    PubMed

    Schmidt, Debra A; Koutsos, Elizabeth A; Ellersieck, Mark R; Griffin, Mark E

    2009-03-01

    Serum concentrations of amino acids, fatty acids, lipoproteins, vitamins A and E, and minerals in zoo giraffes (Giraffa camelopardalis) were compared to values obtained from free-ranging giraffes in an effort to identify potential nutritional differences in the zoo population. Zoo giraffes have a specific set of maladies that may be nutritionally related, including peracute mortality, energy malnutrition, pancreatic disease, urolithiasis, hoof disease, and severe intestinal parasitism. Dietary requirements for giraffes are not known; invasive studies used with domestic animals cannot be performed on zoo animals. Though domestic animal standards are often used to evaluate nutritional health of exotic animals, they may not be the most appropriate standards to use. Serum samples from 20 zoo giraffes at 10 zoological institutions in the United States were compared to previously collected samples from 24 free-ranging giraffes in South Africa. Thirteen of the zoo animal samples were collected from animals trained for blood collection, and seven were banked samples obtained from a previous serum collection. Dietary information was also collected on each zoo giraffe; most zoo giraffe diets consisted of alfalfa-based pellets (acid detergent fiber-16), alfalfa hay, and browse in varying quantities. Differences between zoo and free-ranging giraffes, males and females, and adults and subadults were analyzed with the use of a 2 x 2 x 2 factorial and Fisher's Least Significant Difference (LSD) for mean separation. Of the 84 parameters measured, 54 (60%) were significantly different (P < or = 0.05) between zoo and free-ranging giraffes. Nine (11%) items were significantly different (P < or = 0.05) between adult and subadult animals. Only one parameter, sodium concentration, was found to be significantly different (P < or = 0.05) between genders. Further investigation in zoo giraffe diets is needed to address the differences seen in this study and the potentially related health

  15. Training giraffe (Giraffa camelopardalis reticulata) for front foot radiographs and hoof care.

    PubMed

    Dadone, Liza I; Schilz, Amy; Friedman, Susan G; Bredahl, Jason; Foxworth, Steve; Chastain, Bob

    2016-05-01

    For a large herd of reticulated giraffes, a mainly operant-based training program was created for front foot radiographs and hoof trims in an effort to diagnose and better manage lameness. Behaviors were shaped in a restricted contact set-up, using a positive reinforcement procedure to teach a series of mastered cued behaviors. This training was used to obtain lateral and lateral oblique front foot radiographs for the entire herd. Radiographs were diagnostic for multiple possible causes of lameness including fractures and osteitis of the distal phalangeal bone, hoof overgrowth, osteoarthritis of the distal interphalangeal joint, rotation of the distal phalangeal bone, sesamoid bone cysts, and sole foreign bodies. By training giraffe for foot radiographs and hoof trims, potential causes of lameness could be identified and better managed. Long-term, the results may help zoos identify best practices for managing and preventing lameness in giraffe. Zoo Biol. 35:228-236, 2016. © 2016 Wiley Periodicals, Inc.

  16. Tooth wear in captive giraffes (Giraffa camelopardalis): mesowear analysis classifies free-ranging specimens as browsers but captive ones as grazers.

    PubMed

    Clauss, Marcus; Franz-Odendaal, Tamara A; Brasch, Juliane; Castell, Johanna C; Kaiser, Thomas

    2007-09-01

    Captive giraffe (Giraffa camelopardalis) mostly do not attain the longevity possible for this species and frequently have problems associated with low energy intake and fat storage mobilization. Abnormal tooth wear has been among the causes suggested as an underlying problem. This study utilizes a tooth wear scoring method ("mesowear") primarily used in paleobiology. This scoring method was applied to museum specimens of free-ranging (n=20) and captive (n=41) giraffes. The scoring system allows for the differentiation between attrition--(typical for browsers, as browse contains little abrasive silica) and abrasion--(typical for grazers, as grass contains abrasive silica) dominated tooth wear. The dental wear pattern of the free-ranging population is dominated by attrition, resembles that previously published for free-ranging giraffe, and clusters within browsing herbivores in comparative analysis. In contrast, the wear pattern of the captive population is dominated by abrasion and clusters among grazing herbivores in comparative analyses. A potential explanation for this difference in tooth wear is likely related to the content of abrasive elements in zoo diets. Silica content (measured as acid insoluble ash) is low in browse and alfalfa. However, grass hay and the majority of pelleted compound feeds contain higher amounts of silica. It can be speculated that the abnormal wear pattern in captivity compromises tooth function in captive giraffe, with deleterious long-term consequences.

  17. Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis).

    PubMed

    Wilsher, S; Stansfield, F; Greenwood, R E S; Trethowan, P D; Anderson, R A; Wooding, F B W; Allen, W R

    2013-06-01

    Gross, histological and immunocytochemical examinations carried out on maternal and fetal reproductive tissues from two pregnant giraffes at an estimated 8 and 13.5 months of gestation (term=15 months) revealed a typically ruminant macrocotyledonary placenta with binucleate trophoblast cells scattered sparsely in the placentome where they stained intensely with a prolactin antiserum. Binucleate cells were present in greater numbers in the intercotyledonary allantochorion where they did not stain for prolactin whereas the uninucleate trophoblast still did. A single large corpus luteum of pregnancy and several small luteinised follicles were present in the maternal ovaries while the fetal ovaries at 13.5 months gestation showed an assortment of enlarging antral follicles and partially and completely lutenised follicles, the granulosa and luteal cells of which stained positively for 3β-hydroxysteroid dehydrogenase (3β-HSD), 17,20 lyase, prolactin, progesterone receptor and androgen receptor, but negatively for aromatase. The uninucleate trophoblast of the placentome and intercotyledonary allantochorion, the epithelium of the maternal endometrial glands, the seminiferous epithelium in the fetal testis at 8 months of gestation and the zonae fasciculata and reticularis of the fetal adrenal at 13.5 months also stained positively for 3β-HSD and negatively for aromatase. Endocrinologically, it appears that the giraffe placenta is more similar to that of the sheep than the cow with a placental lactogen as the likely driver of the considerable degree of luteinisation seen in both the maternal and the fetal ovaries.

  18. Daytime mother-calf relationships in reticulated giraffes (Giraffa cameloparadalis reticulate) at the Kyoto City Zoo.

    PubMed

    Nakamichi, Masayuki; Murata, Chisa; Eto, Ryo; Takagi, Naoko; Yamada, Kazunori

    2015-01-01

    The present study quantitatively assesses the relationships between a reticulated giraffe mother and her first- and second-born calves during the first 22 months of the older calf's and the first 12 months of the younger calf's life at the Kyoto City Zoo, Japan. The mother permitted her calves to suckle at over 70% of their suckling attempts in the first month after their births, and the calves ceased suckling spontaneously in 65 to 70% of the suckling bouts. From the second month on, she showed a clear tendency to reject the calves' suckling attempts and terminated almost all of their suckling bouts, which resulted in approximately 60 sec or less of suckling duration per bout. The frequency of proximity between the mother and her calves remained at 20 to 30% throughout the first year, with no apparent developmental changes being evident. The mother was mainly responsible for terminating proximity by walking away from her calves throughout their first year after birth, while both calves were mainly responsible for attempting proximity by approaching their mother after reaching 2 months of age. Our study also showed that the giraffe mother became pregnant again while nursing her calves and ceased lactation (i.e., weaned the calves) before the fetus's growth started accelerating.

  19. Karyotype evolution of giraffes (Giraffa camelopardalis) revealed by cross-species chromosome painting with Chinese muntjac (Muntiacus reevesi) and human (Homo sapiens) paints.

    PubMed

    Huang, L; Nesterenko, A; Nie, W; Wang, J; Su, W; Graphodatsky, A S; Yang, F

    2008-01-01

    Considering the giraffe (Giraffa camelopardalis, GCA, 2n = 30) as a primitive species, its comparative genomic data are critical for our understanding of the karyotype evolution of pecorans. Here, we have established genome-wide chromosomal homologies between giraffe, Chinese muntjac (Muntiacus reevesi, MRE, 2n = 46) and human (Homo sapiens, HSA, 2n = 46) with whole sets of chromosome-specific paints from Chinese muntjac and human, in addition to providing a high-resolution G-banding karyotype of giraffe. Chinese muntjac and human chromosome paints detected 32 and 45 autosomal homologs in the genome of giraffe, respectively. Our results suggest that it would require at least thirteen fissions, six fusions and three intrachromosomal rearrangements to 'transform' the 2n = 44 eutherian ancestral karyotype to the 2n = 58 pecoran ancestral karyotype. During giraffe evolution, some ancestral eutherian syntenies (i.e. association of HSA3/21, 4/8, 7/16, 14/15, 16/19 and two forms of 12/22) have been retained, while several derived syntenies (i.e. associations of human homologous segments 2/1, 2/9, 5/19, 4/12/22, 8/9, and 10/20) have been produced. The reduction of chromosome number in giraffe from the 2n = 58 pecoran ancestral karyotype could be primarily attributed to extensive Robertsonian translocations of ancestral chromosomal segments. More complex chromosomal rearrangements (including tandem fusion, centromere repositioning and pericentric inversion) have happened during the evolution of GCA2 and GCA8.

  20. Linking social and pathogen transmission networks using microbial genetics in giraffe (Giraffa camelopardalis).

    PubMed

    VanderWaal, Kimberly L; Atwill, Edward R; Isbell, Lynne A; McCowan, Brenda

    2014-03-01

    Although network analysis has drawn considerable attention as a promising tool for disease ecology, empirical research has been hindered by limitations in detecting the occurrence of pathogen transmission (who transmitted to whom) within social networks. Using a novel approach, we utilize the genetics of a diverse microbe, Escherichia coli, to infer where direct or indirect transmission has occurred and use these data to construct transmission networks for a wild giraffe population (Giraffe camelopardalis). Individuals were considered to be a part of the same transmission chain and were interlinked in the transmission network if they shared genetic subtypes of E. coli. By using microbial genetics to quantify who transmits to whom independently from the behavioural data on who is in contact with whom, we were able to directly investigate how the structure of contact networks influences the structure of the transmission network. To distinguish between the effects of social and environmental contact on transmission dynamics, the transmission network was compared with two separate contact networks defined from the behavioural data: a social network based on association patterns, and a spatial network based on patterns of home-range overlap among individuals. We found that links in the transmission network were more likely to occur between individuals that were strongly linked in the social network. Furthermore, individuals that had more numerous connections or that occupied 'bottleneck' positions in the social network tended to occupy similar positions in the transmission network. No similar correlations were observed between the spatial and transmission networks. This indicates that an individual's social network position is predictive of transmission network position, which has implications for identifying individuals that function as super-spreaders or transmission bottlenecks in the population. These results emphasize the importance of association patterns in

  1. Serum concentrations of amino acids, fatty acids, lipoproteins, vitamins A and E, and minerals in apparently healthy, free-ranging southern giraffe (Giraffa camelopardalis giraffe).

    PubMed

    Schmidt, Debra A; Ball, Ray L; Grobler, Douw; Ellersieck, Mark R; Griffin, Mark E; Citino, Scott B; Bush, Mitchell

    2007-01-01

    This pilot project began establishing a nutritional profile for free-ranging giraffe. The results will be used as a tool to begin assessing the nutritional status of captive giraffe. In October 2004 serum samples were collected opportunistically from seven adult and 17 sub-adult giraffe being anesthetized for different studies. Seventeen animals were from Double Drift Game Reserve and seven animals were from Kariega Private Game Reserve. The serum samples were analyzed for circulating concentrations of amino acids, fatty acids, lipoproteins, vitamins, and minerals. Information from 15 serum samples collected from anesthetized giraffe in Kruger National Park during April and August 2003 was included in the calcium and phosphorus concentration data. No significant differences were identified between genders. Significant differences between locations were identified for concentrations of certain amino acids, fatty acids, and lipoproteins. Differences between locations are likely due to different nutrient concentrations of foods and possibly the result of different animal densities forcing different food choices among locations. This pilot project may expand to include changes in circulating nutrient concentrations for free-ranging giraffe as is influenced by other locations, seasonal food availability, and different giraffe subspecies. Zoo Biol 0:1-13, 2007. (c) 2006 Wiley-Liss, Inc.

  2. Sonomorphology of the reproductive tract in male and pregnant and non-pregnant female Rothschild's giraffes (Giraffa camelopardalis rotschildi).

    PubMed

    Lueders, Imke; Niemuller, Cheryl; Pootoolal, Jason; Rich, Peter; Gray, Charlie; Streich, Wolf Jürgen; Hildebrandt, Thomas Bernd

    2009-07-01

    The application of real-time-B-mode ultrasonography to wild and zoo animal medicine has been shown to improve the understanding of reproductive physiology in many species. Ultrasound technology is especially helpful for monitoring urogenital health, which in turn has advantages for giraffe breeding and welfare in captivity. This study aimed to ultrasonographically describe the genital organs of reproductively healthy male and female giraffes. Through the use of a restrainer, repeated rectal ultrasound examinations were performed over a 2 year period in 2.6 Rothschild's giraffes. Changes in ovarian activity were monitored throughout four different reproductive stages in the females and included immature, mature-cycling, pregnancy, post-partum-period. In the immature giraffes the ovaries showed multiple follicles of which larger ones luteinized to form pseudo-corpora lutea. By comparison, in the mature giraffes the dominant follicle reached an ovulatory diameter of 18.5+/-0.89 mm. After ovulation, a single corpus luteum rapidly formed and reached a maximum diameter of 33.0+/-2.4mm on average. Pregnancy was detected for the first time by the embryonic vesicle, visualized around 28 days post copulation. Follicular development remained ongoing during early pregnancy. In the males, as in other ruminants, the bulbourethral glands and the seminal vesicles were prominent, whereas the prostate gland was indistinct. Knowledge about the reproductive tract morphology and physiology is necessary for diagnosing medical disorders and abnormalities in giraffes. The aim of this study was to help consolidate the current knowledge on basic reproductive parameters for this species.

  3. Phenotypical and Genotypical Properties of an Arcanobacterium pluranimalium Strain Isolated from a Juvenile Giraffe (Giraffa camelopardalis reticulata)

    PubMed Central

    Risse, Karin; Schlez, Karen; Eisenberg, Tobias; Geiger, Christina; Balbutskaya, Anna; Sammra, Osama; Lämmler, Christoph; Abdulmawjood, Amir

    2014-01-01

    The present study was designed to characterize phenotypically and genotypically an Arcanobacterium pluranimalium strain (A. pluranimalium 4868) following necropsy from a juvenile giraffe. The species identity could be confirmed by phenotypical investigations and by MALDI-TOF MS analysis, by sequencing the 16S rDNA, pluranimaliumlysin encoding gene pla, and glyceraldehyde-3-phosphate dehydrogenase encoding gene gap with sequence similarities to A. pluranimalium reference strain DSM 13483T of 99.2%, 89.9%, and 99.1%, respectively. To our knowledge, the present study is the first phenotypic and genotypic characterization of an A. pluranimalium strain isolated from a giraffe. PMID:26464930

  4. Influence of diet transition on serum calcium and phosphorus and fatty acids in zoo giraffe (Giraffa camelopardalis).

    PubMed

    Koutsos, E A; Armstrong, D; Ball, R; Dikeman, C; Hetherington, J; Simmons, L; Valdes, E V; Griffin, M

    2011-01-01

    In response to new recommendations for feeding giraffe in zoos, giraffe (n = 6) were transitioned from a typical hoofstock diet to diets containing reduced starch, protein, Ca and P and added n3 fatty acids. This diet was fed as a 50:50 mix with alfalfa and grass hay. Over the next 4 years, serum Ca, P, and fatty acids were measured every 6 months (summer and winter). Serum Ca was not affected by season (P = 0.67) or by diet (P = 0.12). Serum P was not affected season (P = 0.14), but was reduced by diet (P<0.01), and serum Ca:P was also increased by diet (P<0.01). The ratio of serum Ca:P tended to be affected by season (P = 0.07), in which animals tended to have greater Ca:P during the summer vs. the winter. The diet transition resulted in reduced serum saturated fatty acids (including lauric, myristic, palmitic, arachidic, and behenic acids), and increases in n6 fatty acids (including linolenic and arachidonic acids) and n3 fatty acids (docosahexaenoic acid) (P<0.05 for each). Overall, this diet transition resulted in blood nutrient profiles that more closely match that of values found in free-ranging giraffe.

  5. Distribution and morphology of putative catecholaminergic and serotonergic neurons in the medulla oblongata of a sub-adult giraffe, Giraffa camelopardalis.

    PubMed

    Badlangana, N Ludo; Bhagwandin, Adhil; Fuxe, Kjell; Manger, Paul R

    2007-11-01

    The current study details the nuclear parcellation and appearance of putative catecholaminergic and serotonergic neurons within the medulla oblongata of a sub-adult giraffe, using immunohistochemistry for tyrosine hydroxylase and serotonin. We hypothesized that the unusual phenotype of the giraffe, this being the long neck and potential axonal lengthening of these neurons, may pose specific problems in terms of the efficient functioning of these systems, as several groups of catecholaminergic and serotonergic neurons, especially of the medulla, are known to project to the entire spinal cord. This specific challenge may lead to observable differences in the nuclear parcellation and morphology of these systems in the giraffe. Our personal observations in the giraffe reveal that, as with other Artiodactyls, the spinal cord extends to the caudal end of the sacral vertebrae. Within the giraffe medulla we found evidence for five putative catecholaminergic (neurons containing tyrosine hydroxylase) and five serotonergic nuclei. In terms of both morphological appearance of the neurons and nuclear parcellation we did not find any evidence for features that may be considered affected by the phenotype of the giraffe. The nuclear parcellation and appearance of both the putative catecholaminergic and serotonergic systems in the medulla of the giraffe studied are strikingly similar to that seen in previous studies of other Artiodactyls. We interpret these findings in terms of a growing literature detailing order specific phylogenetic constraints in the evolution of these neuromodulatory systems.

  6. Identification of novel Babesia and Theileria species in South African giraffe (Giraffa camelopardalis, Linnaeus, 1758) and roan antelope (Hippotragus equinus, Desmarest 1804).

    PubMed

    Oosthuizen, Marinda C; Allsopp, Basil A; Troskie, Milana; Collins, Nicola E; Penzhorn, Barend L

    2009-07-07

    Blood specimens were received from five cases in which young adult giraffe, from different geographic origins in South Africa, showed sudden onset of disease and subsequently died. Additional specimens from two translocated giraffe, as well as one specimen from a roan antelope, were also included in the study. Blood slides from some of these animals showed the presence of piroplasms. DNA was extracted; the V4 hypervariable region of the 18S rRNA gene amplified and analyzed using the Reverse Line Blot (RLB) hybridization assay. PCR products failed to hybridize with any of the Babesia or Theileria species-specific probes, and only hybridized with the Babesia/Theileria genus-specific probe suggesting the presence of a novel species or variant of a species. Full-length 18S rDNA was amplified, cloned and the recombinants were sequenced. 18S rRNA gene sequence similarity analysis revealed the presence of novel piroplasm species in both healthy giraffe and a roan antelope and clinically sick or dead giraffe. Phylogenetic analysis grouped five of these organisms in the Babesia sensu stricto clade and three in the Theileria sensu stricto clade. Although parasites were observed in blood smears, there is no direct evidence that piroplasmosis caused the death of five giraffe, although it certainly seems to be likely.

  7. Insufficient colostrum ingestion is a risk factor for polyarthritis and/or phlegmon in hand-reared reticulated giraffes (Giraffa camelopardalis reticulata): 7 cases (2003-2012).

    PubMed

    Kido, Nobuhide; Nagakura, Kasumi; Itabashi, Masanori; Ono, Kaori; Dan, Mayuko; Matsumoto, Rei; Omiya, Tomoko

    2014-08-01

    Seven reticulated giraffes were hand-reared at Nogeyama Zoological Gardens, because the dam had agalactia. Six of the 7 calves exhibited polyarthritis and/or phlegmon in the lower legs. However, the cause of the disorder was unclear. The present study reviewed the clinical records of the 7 giraffes, including the type and amount of colostrum ingested during the first 72 hr. The disorder involved the fetlocks and carpal and tarsal joints in 6 of the 7 calves within an average of 8 days of birth. The average amount of fed bovine or powdered colostrum was 0-2.4 l in the first 24 hr and 2.0-6.2 l during the first 72 hr. Insufficient colostrum quantity might be a factor in polyarthritis and/or phlegmon.

  8. Organization and number of orexinergic neurons in the hypothalamus of two species of Cetartiodactyla: a comparison of giraffe (Giraffa camelopardalis) and harbour porpoise (Phocoena phocoena).

    PubMed

    Dell, Leigh-Anne; Patzke, Nina; Bhagwandin, Adhil; Bux, Faiza; Fuxe, Kjell; Barber, Grace; Siegel, Jerome M; Manger, Paul R

    2012-07-01

    The present study describes the organization of the orexinergic (hypocretinergic) neurons in the hypothalamus of the giraffe and harbour porpoise--two members of the mammalian Order Cetartiodactyla which is comprised of the even-toed ungulates and the cetaceans as they share a monophyletic ancestry. Diencephalons from two sub-adult male giraffes and two adult male harbour porpoises were coronally sectioned and immunohistochemically stained for orexin-A. The staining revealed that the orexinergic neurons could be readily divided into two distinct neuronal types based on somal volume, area and length, these being the parvocellular and magnocellular orexin-A immunopositive (OxA+) groups. The magnocellular group could be further subdivided, on topological grounds, into three distinct clusters--a main cluster in the perifornical and lateral hypothalamus, a cluster associated with the zona incerta and a cluster associated with the optic tract. The parvocellular neurons were found in the medial hypothalamus, but could not be subdivided, rather they form a topologically amorphous cluster. The parvocellular cluster appears to be unique to the Cetartiodactyla as these neurons have not been described in other mammals to date, while the magnocellular nuclei appear to be homologous to similar nuclei described in other mammals. The overall size of both the parvocellular and magnocellular neurons (based on somal volume, area and length) were larger in the giraffe than the harbour porpoise, but the harbour porpoise had a higher number of both parvocellular and magnocellular orexinergic neurons than the giraffe despite both having a similar brain mass. The higher number of both parvocellular and magnocellular orexinergic neurons in the harbour porpoise may relate to the unusual sleep mechanisms in the cetaceans.

  9. How many species of giraffe are there?

    PubMed

    Bercovitch, Fred B; Berry, Philip S M; Dagg, Anne; Deacon, Francois; Doherty, John B; Lee, Derek E; Mineur, Frédéric; Muller, Zoe; Ogden, Rob; Seymour, Russell; Shorrocks, Bryan; Tutchings, Andy

    2017-02-20

    In a recent paper in Current Biology, Fennessy and colleagues [1] conclude that there are four species of giraffe and that their numbers are declining in Africa. Giraffes (Giraffa camelopardalis) are presently classified as one species, with nine subspecies, which are considered 'Vulnerable' on the IUCN Red List [2]. The present consensus of one species divided into nine subspecies has previously been questioned (Supplemental information), and Fennessy and colleagues [1] provide another viewpoint on giraffe taxonomy. The fundamental reason for different taxonomic interpretations is that they are based upon different datasets that adopt different statistical techniques and follow different criteria for nomenclature.

  10. The Occurrence and Prevalence of Giraffe Skin Disease in Protected Areas of Northern Tanzania.

    PubMed

    Lee, Derek E; Bond, Monica L

    2016-07-01

    Giraffe skin disease (GSD) is a disorder of undetermined etiology that causes lesions on the forelimbs of Masai giraffe ( Giraffa camelopardalis tippelskirchi). We estimated occurrence and prevalence of GSD in six wildlife conservation areas of Tanzania. The disjunct spatial pattern of occurrence implies that environmental factors may influence GSD.

  11. Soil Correlates and Mortality from Giraffe Skin Disease in Tanzania.

    PubMed

    Bond, Monica L; Strauss, Megan K L; Lee, Derek E

    2016-10-01

    Giraffe skin disease (GSD) is a disorder of undetermined etiology that causes lesions on the forelimbs of Masai giraffe ( Giraffa camelopardalis tippelskirchi) in Tanzania, East Africa. We examined soil correlates of prevalence of GSD from 951 giraffe in 14 sites in Tanzania, and estimated mortality using 3 yr of longitudinal mark-recapture data from 382 giraffe with and without GSD lesions, in Tarangire National Park (TNP). Spatial variation in GSD prevalence was best explained by soil fertility, measured as cation exchange capacity. We found no mortality effect of GSD on adult giraffe in TNP. Based on our findings, GSD is unlikely to warrant immediate veterinary intervention, but continued monitoring is recommended to ensure early detection if GSD-afflicted animals begin to show signs of increased mortality or other adverse effects.

  12. Multi-locus Analyses Reveal Four Giraffe Species Instead of One.

    PubMed

    Fennessy, Julian; Bidon, Tobias; Reuss, Friederike; Kumar, Vikas; Elkan, Paul; Nilsson, Maria A; Vamberger, Melita; Fritz, Uwe; Janke, Axel

    2016-09-26

    Traditionally, one giraffe species and up to eleven subspecies have been recognized [1]; however, nine subspecies are commonly accepted [2]. Even after a century of research, the distinctness of each giraffe subspecies remains unclear, and the genetic variation across their distribution range has been incompletely explored. Recent genetic studies on mtDNA have shown reciprocal monophyly of the matrilines among seven of the nine assumed subspecies [3, 4]. Moreover, until now, genetic analyses have not been applied to biparentally inherited sequence data and did not include data from all nine giraffe subspecies. We sampled natural giraffe populations from across their range in Africa, and for the first time individuals from the nominate subspecies, the Nubian giraffe, Giraffa camelopardalis camelopardalis Linnaeus 1758 [5], were included in a genetic analysis. Coalescence-based multi-locus and population genetic analyses identify at least four separate and monophyletic clades, which should be recognized as four distinct giraffe species under the genetic isolation criterion. Analyses of 190 individuals from maternal and biparental markers support these findings and further suggest subsuming Rothschild's giraffe into the Nubian giraffe, as well as Thornicroft's giraffe into the Masai giraffe [6]. A giraffe survey genome produced valuable data from microsatellites, mobile genetic elements, and accurate divergence time estimates. Our findings provide the most inclusive analysis of giraffe relationships to date and show that their genetic complexity has been underestimated, highlighting the need for greater conservation efforts for the world's tallest mammal.

  13. Giraffe Stature and Neck Elongation: Vigilance as an Evolutionary Mechanism.

    PubMed

    Williams, Edgar M

    2016-09-12

    Giraffe (Giraffa camelopardalis), with their long neck and legs, are unique amongst mammals. How these features evolved is a matter of conjecture. The two leading ideas are the high browse and the sexual-selection hypotheses. While both explain many of the characteristics and the behaviour of giraffe, neither is fully supported by the available evidence. The extended viewing horizon afforded by increased height and a need to maintain horizon vigilance, as a mechanism favouring the evolution of increased height is reviewed. In giraffe, vigilance of predators whilst feeding and drinking are important survival factors, as is the ability to interact with immediate herd members, young and male suitors. The evidence regarding giraffe vigilance behaviour is sparse and suggests that over-vigilance has a negative cost, serving as a distraction to feeding. In woodland savannah, increased height allows giraffe to see further, allowing each giraffe to increase the distance between its neighbours while browsing. Increased height allows the giraffe to see the early approach of predators, as well as bull males. It is postulated that the wider panorama afforded by an increase in height and longer neck has improved survival via allowing giraffe to browse safely over wider areas, decreasing competition within groups and with other herbivores.

  14. Giraffe Stature and Neck Elongation: Vigilance as an Evolutionary Mechanism

    PubMed Central

    Williams, Edgar M.

    2016-01-01

    Giraffe (Giraffa camelopardalis), with their long neck and legs, are unique amongst mammals. How these features evolved is a matter of conjecture. The two leading ideas are the high browse and the sexual-selection hypotheses. While both explain many of the characteristics and the behaviour of giraffe, neither is fully supported by the available evidence. The extended viewing horizon afforded by increased height and a need to maintain horizon vigilance, as a mechanism favouring the evolution of increased height is reviewed. In giraffe, vigilance of predators whilst feeding and drinking are important survival factors, as is the ability to interact with immediate herd members, young and male suitors. The evidence regarding giraffe vigilance behaviour is sparse and suggests that over-vigilance has a negative cost, serving as a distraction to feeding. In woodland savannah, increased height allows giraffe to see further, allowing each giraffe to increase the distance between its neighbours while browsing. Increased height allows the giraffe to see the early approach of predators, as well as bull males. It is postulated that the wider panorama afforded by an increase in height and longer neck has improved survival via allowing giraffe to browse safely over wider areas, decreasing competition within groups and with other herbivores. PMID:27626454

  15. The Cervical Osteology of Okapia johnstoni and Giraffa camelopardalis.

    PubMed

    Danowitz, Melinda; Solounias, Nikos

    2015-01-01

    Giraffidae is the only family of ruminants that is represented by two extant species; Okapia johnstoni and Giraffa camelopardalis. Of these taxa, O. johnstoni represents a typical short-necked ungulate, and G. camelopardalis exemplifies the most extreme cervical elongation seen in any ruminant. We utilize these two species to provide a comprehensive anatomic description of the cervical vertebrae. In addition, we compare the serial morphologic characteristics of the okapi and giraffe cervical vertebrae, and report on several osteologic differences seen between the two taxa. The giraffe neck appears to exhibit homogenization of C3-C7; the position of the dorsal tubercle, thickness of the cranial articular process, shape of the ventral vertebral body, and orientation of the ventral tubercle are constant throughout these vertebrae, whereas these features are serially variable in the okapi. We also report on several specializations of the giraffe C7, which we believe relates to an atypical cervico-thoracic junction, corresponding to the substantial neck lengthening. The morphologic differences exhibited between the okapi and giraffe cervical vertebrae have implications on the function of the necks relating to both fighting and feeding.

  16. Detection and characterisation of papillomavirus in skin lesions of giraffe and sable antelope in South Africa.

    PubMed

    van Dyk, E; Bosman, A M; van Wilpe, E; Williams, J H; Bengis, R G; van Heerden, J; Venter, E H

    2011-06-01

    Papillomavirus was detected electron microscopically in cutaneous fibropapillomas of a giraffe (Giraffa camelopardalis) and a sable antelope (Hippotragus niger). The virus particles measured 45 nm in diameter. Histopathologically, the lesions showed histopathological features similar to those of equine sarcoid as well as positive immunoperoxidase-staining of tissue sections for papillomavirus antigen. Polymerase chain reaction (PCR) detected bovine papillomavirus (BPV) DNA. Bovine papillomavirus-1 was characterised by real-time PCR in the sable and giraffe, and cloning and sequencing of the PCR product revealed a similarity to BPV-1. As in the 1st giraffe, the lesions from a 2nd giraffe revealed locally malignant pleomorphism, possibly indicating the lesional end-point of papilloma infection. Neither virus particles nor positively staining papillomavirus antigen could be demonstrated in the 2nd giraffe but papillomavirus DNA was detected by real-time PCR which corresponded with BPV-1 and BPV-2.

  17. Androgen changes and flexible rutting behaviour in male giraffes.

    PubMed

    Seeber, Peter A; Duncan, Patrick; Fritz, Hervé; Ganswindt, André

    2013-10-23

    The social organization of giraffes (Giraffa camelopardalis) imposes a high-cost reproductive strategy on bulls, which adopt a 'roving male' tactic. Our observations on wild giraffes confirm that bulls indeed have unsynchronized rut-like periods, not unlike another tropical megaherbivore, the elephant, but on a much shorter timescale. We found profound changes in male sexual and social activities at the scale of about two weeks. This so far undescribed rutting behaviour is closely correlated with changes in androgen concentrations and appears to be driven by them. The short time scale of the changes in sexual and social activity may explain why dominance and reproductive status in male giraffe in the field seem to be unstable.

  18. Predicting the buoyancy, equilibrium and potential swimming ability of giraffes by computational analysis.

    PubMed

    Henderson, Donald M; Naish, Darren

    2010-07-21

    Giraffes (Giraffa camelopardalis) are often stated to be unable to swim, and while few observations supporting this have ever been offered, we sought to test the hypothesis that giraffes exhibited a body shape or density unsuited for locomotion in water. We assessed the floating capability of giraffes by simulating their buoyancy with a three-dimensional mathematical/computational model. A similar model of a horse (Equus caballus) was used as a control, and its floating behaviour replicates the observed orientations of immersed horses. The floating giraffe model has its neck sub-horizontal, and the animal would struggle to keep its head clear of the water surface. Using an isometrically scaled-down giraffe model with a total mass equal to that of the horse, the giraffe's proportionally larger limbs have much higher rotational inertias than do those of horses, and their wetted surface areas are 13.5% greater relative to that of the horse, thus making rapid swimming motions more strenuous. The mean density of the giraffe model (960 gm/l) is also higher than that of the horse (930 gm/l), and closer to that causing negative buoyancy (1000 gm/l). A swimming giraffe - forced into a posture where the neck is sub-horizontal and with a thorax that is pulled downwards by the large fore limbs - would not be able to move the neck and limbs synchronously as giraffes do when moving on land, possibly further hampering the animal's ability to move its limbs effectively underwater. We found that a full-sized, adult giraffe will become buoyant in water deeper than 2.8m. While it is not impossible for giraffes to swim, we speculate that they would perform poorly compared to other mammals and are hence likely to avoid swimming if possible.

  19. A new host record of Camelostrongylus mentulatus (Nematoda; Trichostrongyloidea) from abomasum of a giraffe at a zoo in Japan.

    PubMed

    Fukumoto, S; Uchida, T; Ohbayashi, M; Ikebe, Y; Sasano, S

    1996-12-01

    Camelostrongylus mentulatus (Railliet et Henry, 1909) Orloff, 1933 (Nematoda; Trichostrongyloidea) was found from the abomasum of a three-year-old female cape giraffe, Giraffa camelopardalis giraffa, born and died in a zoo park in Yamaguchi prefecture, Japan. This is the new host record from Giraffidae and geographical distribution of C. mentulatus. Present case of C. mentulatus might be infected from other ruminants, e.g., camels, antelopes and goats, kept at a same paddock in the zoo. Risk of imported parasitic diseases by the zoo animals from outside of Japan is discussed.

  20. Giraffe browsing in response to plant traits

    NASA Astrophysics Data System (ADS)

    Mahenya, Obeid; Ndjamba, Johannes Kambinda; Mathisen, Karen Marie; Skarpe, Christina

    2016-08-01

    Intake rates by large herbivores are governed by among other things plant traits. We used Masai giraffe (Giraffa camelopardalis tippelskirchi Matschie) as study animals, testing whether they as very large browsers would follow the Jarman-Bell principle and maximize intake rate while tolerating low forage quality. We worked in Arusha National Park, Tanzania. We investigated how intake rate was determined by bite mass and bite rate, and show that bite mass and bite rate were determined by plant characteristics, governed by inherent plant traits, plant traits acquired from previous years' browsing, and season. We predicted that; (1) bite mass would be larger in trees without spines than with (2) bite mass would be larger in the wet season than in the dry, (3) bite rate would be higher in spinescent trees than in non-spinescent, (4) bite rate and/or bite mass would increase with previous years' browsing, (5) bite mass, bite rate or browsing time per tree would be highest for high trees with large, although still available canopies. Visual observations were used to collect data on tree attributes, number of bites taken and time of browsing. Sample size was 132 observed giraffe. We found that bite mass was larger in spineless than in spinescent trees and was larger in the wet season than in the dry. Bite rate, but not bite mass, increased with increasing browsing in previous years and was highest on two to three meter high trees and in spinescent trees. Intake rate followed bite mass more than bite rate and was higher in spineless than in spinescent trees, higher in the wet season than in the dry, and tended to increase with tree height. Giraffe did not prioritize the highest intake rate, but browsed much on Acacias giving a high quality diet but a low intake rate.

  1. The weight of Rothschild giraffe-Is it really well known?

    PubMed

    Gloneková, Markéta; Brandlová, Karolína; Žáčková, Magdalena; Dobiášová, Barbora; Pechrová, Kateřina; Šimek, Jaroslav

    2016-09-01

    Despite being regularly bred in zoos, giraffes remain a challenge, especially in terms of feeding. Assessment of factors influencing growth and weight changes during ontogeny, as well as analysis of weight fluctuations in adult individuals, may become a critical point in captive diet evaluation. Knowledge about weight is a crucial husbandry tool; however, such data are rarely acquired. Using a unique dataset from regularly weighed Rothschild giraffes (Giraffa camelopardalis rothschildi) from Prague zoo, we determined the growth functions of male and female giraffes and calculated weight gains during giraffe ontogeny. The mean weights of adult males and females were 1307 ± 52 and 835 ± 45 kg, respectively confirming the large overall dimensions of G. c. rothschildi in comparison with other giraffe subspecies. As the giraffe is a polygynous species showing considerable sexual dimorphism, we expected male calves to have larger first weights and faster growth during the most intensive period of maternal care. Growth rates and daily weight gains were higher in males than in females during the whole postnatal period. Males grew faster and longer than females. However, differences in weight between males and females appeared as late as after 1 year of age. The weight of adult males and non-pregnant adult females fluctuated significantly across seasons, being the highest during the autumn and winter months, respectively which may reflect the different effects of sexual activity and feeding ratios in males and females. Zoo Biol. 35:423-431, 2016. © Wiley Periodicals, Inc.

  2. RESULTS OF THE MEGAVEREBRATE ANALGESIA SURVEY: GIRAFFE AND HIPPOPOTAMUS.

    PubMed

    Boothe, Matthew; Kottwitz, Jack; Harmon, Roy; Citino, Scott B; Zuba, Jeffery R; Boothe, Dawn M

    2016-12-01

    Results of an online survey posted on the American Association of Zoo Veterinarians listserv examined the patterns of analgesic medication and pain management modalities used for captive giraffe and hippopotami. Compiled data included signalment, drugs administered, dosing regimens, subjective efficacy scores, ease of administration, and adverse events. Nineteen institutions exhibiting hippopotami ( Hippopotamus amphibious ) and pygmy hippopotami (Choeropsis liberiensis) and 45 exhibiting giraffe ( Giraffa camelopardalis spp.) responded. Phenylbutazone was the most-commonly administered nonsteroidal anti-inflammatory drug (NSAID), followed by flunixin meglumine, but doses varied widely. Eight institutions reported adverse events from NSAID administration. Tramadol was the most-commonly administered opioid followed by butorphanol. Only one adverse event was reported for opioids. Twenty-three of 45 institutions exhibiting giraffe utilized alternative analgesia methods including gabapentin, glucosamine-chondroitin, local anesthetics, and low level laser therapy. Six of 19 institutions exhibiting hippopotami administered omega 3-6 fatty acids, gabapentin, glucosamine-chondroitin, and α-2 adrenergics to provide analgesia. While all reporting zoological institutions administered similar drugs, there was substantial variation and diversity in both dosing regimens and frequencies, indicating the need for both preclinical and clinical studies supporting dosing regimens.

  3. A Recycled Giraffe

    ERIC Educational Resources Information Center

    Diorio, Lucille

    1976-01-01

    Chicken wire, cardboard tubes, newspaper, scrap lumber and discontinued fabric samples were among the discarded materials used in the art classes at the Webster Hill Elementary School, West Hartford, Connecticut, to create an eight-foot giraffe. (Author/RK)

  4. On reconstructing Giraffa sivalensis, an extinct giraffid from the Siwalik Hills, India

    PubMed Central

    Mitchell, Graham

    2015-01-01

    Giraffa sivalensis occurred during the Plio-Pleistocene period and probably represents the terminal species of the genus in Southern Asia. The holotype is an almost perfectly preserved cervical vertebra of disputed anatomical location. Although there is also uncertainty regarding this animal’s size, other specimens that have been assigned to this species include fragments of two humeri, a radius, metacarpi and teeth. Here we estimate neck length, leg length and body mass using interspecific and, unusually, ontogenetic allometry of extant giraffe skeletal parameters. The appropriateness of each equation to estimate body mass was evaluated by calculating the prediction error incurred in both extant giraffes (G. camelopardalis) and okapis (Okapia johnstoni). It followed that the equations with the lowest prediction error in both species were considered robust enough to use in G. sivalensis. The size of G. sivalensis, based on the holotype, is proposed as 400 kg (range 228 kg–575 kg), with a neck length of approximately 147 cm and a height of 390 cm. The molar lengths of tooth specimens considered agree with this size estimate. The humerus was the most appropriate long bone to establish body mass, which estimates a heavier animal of ca 790 kg. The discrepancy with the vertebral body weight estimate might indicate sexual dimorphism. Radial and metacarpal specimens estimate G. sivalensis to be as heavy as extant giraffes. This may indicate that the radius and metacarpus are unsuitable for body mass predictions in Giraffa spp. Alternatively, certain long bones may have belonged to another long legged giraffid that occurred during the same period and locality as G. sivalensis. We have concluded that if sexual dimorphism was present then males would have been about twice the size of females. If sexual dimorphism was not present and all bones were correctly attributed to this species, then G. sivalensis had a slender neck with a relatively stocky body. PMID:26290791

  5. The first report of Anaplasma phagocytophilum and a novel Theileria spp. co-infection in a South African giraffe.

    PubMed

    Zhang, Yan; Li, Tongyi; Cui, Yanyan; Wang, Jinhong; Lv, Yali; Wang, Rongjun; Jian, Fuchun; Zhang, Longxian; Wang, Jiantang; Yang, Guangcheng; Ning, Changshen

    2016-08-01

    Organisms of the genera Anaplasma and Theileria are important intracellular bacteria and parasites that cause various tick-borne diseases, threatening the health of numerous animals as well as human beings. In the present study, a 12-month-old male wild South African giraffe (Giraffa camelopardalis giraffa) originating from South Africa, and living in Zhengzhou Zoo (located in the urban district of Zhengzhou in the provincial capital of Henan), suddenly developed an unknown fatal disease and died 1day after the onset of the clinical signs. By microscopic examination of Giemsa-stained blood smears combined with nested PCR and DNA sequence analysis, Anaplasma phagocytophilum, Anaplasma bovis and a novel Theileria spp. were found in the blood of this giraffe. The six other Cervidae animals in the zoo and three ruminants living in the same colony house with them were found to be negative for both Anaplasma and Theileria in their blood specimens. We report on the first case of an A. phagocytophilum infection and the occurrence of a novel Theileria spp. in the blood of a giraffe. This is the first reported case of a multi-infection of A. bovis, A. phagocytophilum and Theileria spp. in a giraffe, as revealed by microscopic examination of blood smears and the results of nested PCR and DNA sequencing.

  6. Fossil evidence and stages of elongation of the Giraffa camelopardalis neck

    PubMed Central

    Danowitz, Melinda; Vasilyev, Aleksandr; Kortlandt, Victoria; Solounias, Nikos

    2015-01-01

    Several evolutionary theories have been proposed to explain the adaptation of the long giraffe neck; however, few studies examine the fossil cervical vertebrae. We incorporate extinct giraffids, and the okapi and giraffe cervical vertebral specimens in a comprehensive analysis of the anatomy and elongation of the neck. We establish and evaluate 20 character states that relate to general, cranial and caudal vertebral lengthening, and calculate a length-to-width ratio to measure the relative slenderness of the vertebrae. Our sample includes cervical vertebrae (n=71) of 11 taxa representing all seven subfamilies. We also perform a computational comparison of the C3 of Samotherium and Giraffa camelopardalis, which demonstrates that cervical elongation occurs disproportionately along the cranial–caudal vertebral axis. Using the morphological characters and calculated ratios, we propose stages in cervical lengthening, which are supported by the mathematical transformations using fossil and extant specimens. We find that cervical elongation is anisometric and unexpectedly precedes Giraffidae. Within the family, cranial vertebral elongation is the first lengthening stage observed followed by caudal vertebral elongation, which accounts for the extremely long neck of the giraffe. PMID:26587249

  7. GIRAFFE test results summary

    SciTech Connect

    Yokobori, S.; Arai, K.; Oikawa, H.

    1996-03-01

    A passive system can provide engineered safety features enhancing safety system reliability and plant simplicity. Toshiba has conducted the test Program to demonstrate the feasibility of the SBWR passive safety system using a full-height, integral system test facility GIRAFFE. The test facility GIRAFFE models the SBWR in full height to correctly present the gravity driving head forces with a 1/400 volume scale. The GIRAFFE test Program includes the certification tests of the passive containment cooling system (PCCS) to remove the post-accident decay heat and the gravity driven cooling system (GDCS) to replenish the reactor coolant inventory during a LOCA. The test results have confirmed the PCCS and GDCS design and in addition, have demonstrated the operation of the pCCS with the presence of a lighter-than-steam noncondensable as well as with the presence of a heavier-than-steam, noncondensable. The GIRAFFE test Program has also provided the database to qualify a best estimate thermal-hydraulic computer code TRAC. The post test analysis results have shown that TRAC can accurately predict the PCCS heat removal Performance and the containment pressure response to a LOCA. This paper summarizes the GIRAFFE test results to investigate post-LOCA PCCS heat removal performance and post-test analysis using TRAC.

  8. A new species of Rhipicephalus (Acari: Ixodidae), a parasite of giraffes in Kenya.

    PubMed

    Horak, Ivan G; Apanaskevich, Dmitry A; Kariuki, Edward K

    2013-07-01

    A new tick species belonging to the genus Rhipicephalus Koch, 1844 (Acari: Ixodidae), namely, Rhipicephalus walkerae n. sp., is described. The male and female of this species are similar to those of several species in the Rhipicephalus appendiculatus group but can be distinguished from them by the very dense pattern of medium-sized punctations covering the conscutum and scutum, long and narrow dorsal prolongation of the spiracular plate, and relatively short dorsal cornua; in addition, the male has long and narrow adanal plates without a posterolateral angle. R. walkerae is known only from Kenya, where the adults were collected from giraffes, Giraffa camelopardalis (L.).

  9. The binucleate cell of okapi and giraffe placenta shows distinctive glycosylation compared with other ruminants: a lectin histochemical study.

    PubMed

    Jones, Carolyn J P; Wilsher, Sandra A; Wooding, F B P; Benirschke, K; Allen, W R

    2015-02-01

    The placenta of ruminants contains characteristic binucleate cells (BNC) with a highly conserved glycan structure which evolved early in Ruminant phylogenesis. Giraffe and Okapi placentae also contain these cells and it is not known whether they have a similar glycan array. We have used lectin histochemistry to examine the glycosylation of these cells in these species and compare them with bovine BNC which have a typical ruminant glycan composition. Two placentae, mid and near term, from Giraffe (Giraffa camelopardalis) and two term placenta of Okapi (Okapia johnstoni) were embedded in resin and stained with a panel of 23 lectins and compared with near-term bovine (Bos taurus) placenta. Significant differences were found in the glycans of Giraffe and Okapi BNC compared with those from the bovine, with little or no expression of terminal αN-acetylgalactosamine bound by Dolichos biflorus and Vicia villosa agglutinins which instead bound to placental blood vessels. Higher levels of N-acetylglucosamine bound by Lycopersicon esculentum and Phytolacca americana agglutinins were also apparent. Some differences between Okapi and Giraffe were evident. Most N-linked glycans were similarly expressed in all three species as were fucosyl residues. Interplacentomal areas in Giraffe and Bovine showed differences from the placentomal cells though no intercotyledonary BNC were apparent in Okapi. In conclusion, Giraffidae BNC developed different glycan biosynthetic pathways following their split from the Bovidae with further differences evolving as Okapi and Giraffe diverged from each other, affecting both inter and placentomal BNC which may have different functions during development.

  10. Forensic species identification of elephant (Elephantidae) and giraffe (Giraffidae) tail hair using light microscopy.

    PubMed

    Yates, Bonnie C; Espinoza, Edgard O; Baker, Barry W

    2010-09-01

    Here we present methods for distinguishing tail hairs of African elephants (Loxodonta africana), Asian elephants (Elephas maximus), and giraffes (Giraffa camelopardalis) from forensic contexts. Such hairs are commonly used to manufacture jewelry artifacts that are often sold illegally in the international wildlife trade. Tail hairs from these three species are easily confused macroscopically, and morphological methods for distinguishing African and Asian tail hairs have not been published. We used cross section analysis and light microscopy to analyze the tail hair morphology of 18 individual African elephants, 18 Asian elephants, and 40 giraffes. We found that cross-sectional shape, pigment placement, and pigment density are useful morphological features for distinguishing the three species. These observations provide wildlife forensic scientists with an important analytical tool for enforcing legislation and international treaties regulating the trade in elephant parts.

  11. How Giraffes Drink

    NASA Astrophysics Data System (ADS)

    Binder, P.-M.; Taylor, Dale L.

    2015-12-01

    Giraffes face unique challenges for drinking due to their long necks. In this article we use evidence from videos, size estimates, and elementary fluid mechanics to make a strong case for a plunger pump mechanism moving water up from their lips to their shoulders.

  12. How Giraffes Drink

    ERIC Educational Resources Information Center

    Binder, P.-M.; Taylor, Dale T.

    2015-01-01

    Giraffes face unique challenges for drinking due to their long necks. In this article we use evidence from videos, size estimates, and elementary fluid mechanics to make a strong case for a plunger pump mechanism moving water up from their lips to their shoulders.

  13. Namibian Extension Unit. A Brief Account of the Distance Education Programme for Namibians.

    ERIC Educational Resources Information Center

    Namibian Extension Unit, Lusaka (Zambia).

    The Namibian Extension Unit (NEU), a distance education program for Namibian refugees in Zambia and Angola, was established in 1981 and began teaching courses in mid-1982. Its purpose is to provide basic education to adult Namibian refugees using the distance education format. The NEU provides courses in study skills, introductory English and…

  14. Migratory herds of wildebeests and zebras indirectly affect calf survival of giraffes.

    PubMed

    Lee, Derek E; Kissui, Bernard M; Kiwango, Yustina A; Bond, Monica L

    2016-12-01

    In long-distance migratory systems, local fluctuations in the predator-prey ratio can exhibit extreme variability within a single year depending upon the seasonal location of migratory species. Such systems offer an opportunity to empirically investigate cyclic population density effects on short-term food web interactions by taking advantage of the large seasonal shifts in migratory prey biomass.We utilized a large-mammal predator-prey savanna food web to evaluate support for hypotheses relating to the indirect effects of "apparent competition" and "apparent mutualism" from migratory ungulate herds on survival of resident megaherbivore calves, mediated by their shared predator. African lions (Panthera leo) are generalist predators whose primary, preferred prey are wildebeests (Connochaetes taurinus) and zebras (Equus quagga), while lion predation on secondary prey such as giraffes (Giraffa camelopardalis) may change according to the relative abundance of the primary prey species.We used demographic data from five subpopulations of giraffes in the Tarangire Ecosystem of Tanzania, East Africa, to test hypotheses relating to direct predation and indirect effects of large migratory herds on calf survival of a resident megaherbivore. We examined neonatal survival via apparent reproduction of 860 adult females, and calf survival of 449 giraffe calves, during three precipitation seasons over 3 years, seeking evidence of some effect on neonate and calf survival as a consequence of the movements of large herds of migratory ungulates.We found that local lion predation pressure (lion density divided by primary prey density) was significantly negatively correlated with giraffe neonatal and calf survival probabilities. This supports the apparent mutualism hypothesis that the presence of migratory ungulates reduces lion predation on giraffe calves.Natural predation had a significant effect on giraffe calf and neonate survival, and could significantly affect giraffe population

  15. Molecular characterisation of a bovine-like rotavirus detected from a giraffe

    PubMed Central

    Mulherin, Emily; Bryan, Jill; Beltman, Marijke; O'Grady, Luke; Pidgeon, Eugene; Garon, Lucie; Lloyd, Andrew; Bainbridge, John; O'Shea, Helen; Whyte, Paul; Fanning, Séamus

    2008-01-01

    Background Rotavirus (RV), is a member of the Reoviridae family and an important etiological agent of acute viral gastroenteritis in the young. Rotaviruses have a wide host range infecting a broad range of animal species, however little is known about rotavirus infection in exotic animals. In this paper we report the first characterisation of a RV strain from a giraffe calf. Results This report describes the identification and detailed molecular characterisation of a rotavirus strain detected from a 14-day-old Giraffe (Giraffa camelopardalis), presenting with acute diarrhea. The RV strain detected from the giraffe was characterized molecularly as G10P[11]. Detailed sequence analysis of VP4 and VP7 revealed significant identity at the amino acid sequence level to Bovine RV (BoRV). Conclusion This study demonstrates the need for continuous surveillance of RV strains in various animal populations, which will facilitate the identification of rotavirus hosts not previously reported. Furthermore, extending typical epidemiology studies to a broader host range will contribute to the timely identification of new emerging strain types. PMID:19014526

  16. The Gravity of Giraffe Physiology

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.; Holton, Emily M. (Technical Monitor)

    1997-01-01

    By virtue of its tallness and terrestrial environment, the giraffe is a uniquely sensitive African animal to investigate tissue adaptations to gravitational stress. One decade ago, we studied transcapillary fluid balance and local tissue adaptations to high cardiovascular and musculoskeletal loads in adult and fetal giraffes. Previous studies by Goetz, Pattersson, Van Citters, Warren and their colleagues revealed that arterial pressure near the giraffe heart is about twice that in humans, to provide more normal blood pressure and perfusion to the brain. Another important question is how giraffes avoid pooling of blood and tissue fluid (edema) in dependent tissue of the extremities. As monitored by radiotelemetry, the blood and tissue fluid pressures that govern transcapillary exchange vary greatly with exercise. These pressures, combined with a tight skin layer, move fluid upward against gravity. Other mechanisms that prevent edema include precapillary vasoconstriction and low permeability of capillaries to plasma proteins. Other anatomical adaptations in dependent tissues of giraffes represent developmental adjustments to high and variable gravitational forces. These include vascular wall hypertrophy, thickened capillary basement membrane and other connective tissue adaptations. Our results in giraffe suggest avenues of future gravitational research in other animals including humans.

  17. Regional Differences in Seasonal Timing of Rainfall Discriminate between Genetically Distinct East African Giraffe Taxa

    PubMed Central

    Thomassen, Henri A.; Freedman, Adam H.; Brown, David M.; Buermann, Wolfgang; Jacobs, David K.

    2013-01-01

    Masai (Giraffa tippelskirchi), Reticulated (G. reticulata) and Rothschild's (G. camelopardalis) giraffe lineages in East Africa are morphologically and genetically distinct, yet in Kenya their ranges abut. This raises the question of how divergence is maintained among populations of a large mammal capable of long-distance travel, and which readily hybridize in zoos. Here we test four hypotheses concerning the maintenance of the phylogeographic boundaries among the three taxa: 1) isolation-by-distance; 2) physical barriers to dispersal; 3) general habitat differences resulting in habitat segregation; or 4) regional differences in the seasonal timing of rainfall, and resultant timing of browse availability. We used satellite remotely sensed and climate data to characterize the environment at the locations of genotyped giraffes. Canonical variate analysis, random forest algorithms, and generalized dissimilarity modelling were employed in a landscape genetics framework to identify the predictor variables that best explained giraffes' genetic divergence. We found that regional differences in the timing of precipitation, and resulting green-up associated with the abundance of browse, effectively discriminate between taxa. Local habitat conditions, topographic and human-induced barriers, and geographic distance did not aid in discriminating among lineages. Our results suggest that selection associated with regional timing of events in the annual climatic cycle may help maintain genetic and phenotypic divergence in giraffes. We discuss potential mechanisms of maintaining divergence, and suggest that synchronization of reproduction with seasonal rainfall cycles that are geographically distinct may contribute to reproductive isolation. Coordination of weaning with green-up cycles could minimize the costs of lactation and predation on the young. Our findings are consistent with theory and empirical results demonstrating the efficacy of seasonal or phenologically dictated

  18. Regional differences in seasonal timing of rainfall discriminate between genetically distinct East African giraffe taxa.

    PubMed

    Thomassen, Henri A; Freedman, Adam H; Brown, David M; Buermann, Wolfgang; Jacobs, David K

    2013-01-01

    Masai (Giraffa tippelskirchi), Reticulated (G. reticulata) and Rothschild's (G. camelopardalis) giraffe lineages in East Africa are morphologically and genetically distinct, yet in Kenya their ranges abut. This raises the question of how divergence is maintained among populations of a large mammal capable of long-distance travel, and which readily hybridize in zoos. Here we test four hypotheses concerning the maintenance of the phylogeographic boundaries among the three taxa: 1) isolation-by-distance; 2) physical barriers to dispersal; 3) general habitat differences resulting in habitat segregation; or 4) regional differences in the seasonal timing of rainfall, and resultant timing of browse availability. We used satellite remotely sensed and climate data to characterize the environment at the locations of genotyped giraffes. Canonical variate analysis, random forest algorithms, and generalized dissimilarity modelling were employed in a landscape genetics framework to identify the predictor variables that best explained giraffes' genetic divergence. We found that regional differences in the timing of precipitation, and resulting green-up associated with the abundance of browse, effectively discriminate between taxa. Local habitat conditions, topographic and human-induced barriers, and geographic distance did not aid in discriminating among lineages. Our results suggest that selection associated with regional timing of events in the annual climatic cycle may help maintain genetic and phenotypic divergence in giraffes. We discuss potential mechanisms of maintaining divergence, and suggest that synchronization of reproduction with seasonal rainfall cycles that are geographically distinct may contribute to reproductive isolation. Coordination of weaning with green-up cycles could minimize the costs of lactation and predation on the young. Our findings are consistent with theory and empirical results demonstrating the efficacy of seasonal or phenologically dictated

  19. Identification of a novel species of papillomavirus in giraffe lesions using nanopore sequencing.

    PubMed

    Vanmechelen, Bert; Bertelsen, Mads Frost; Rector, Annabel; Van den Oord, Joost J; Laenen, Lies; Vergote, Valentijn; Maes, Piet

    2017-03-01

    Papillomaviridae form a large family of viruses that are known to infect a variety of vertebrates, including mammals, reptiles, birds and fish. Infections usually give rise to minor skin lesions but can in some cases lead to the development of malignant neoplasia. In this study, we identified a novel species of papillomavirus (PV), isolated from warts of four giraffes (Giraffa camelopardalis). The sequence of the L1 gene was determined and found to be identical for all isolates. Using nanopore sequencing, the full sequence of the PV genome could be determined. The coding region of the genome was found to contain seven open reading frames (ORF), encoding the early proteins E1, E2 and E5-E7 as well as the late proteins L1 and L2. In addition to these ORFs, a region located within the E2 gene is thought, based on sequence similarities to other papillomaviruses, to encode an E4 protein, although no start codon could be identified. Based on the sequence of the L1 gene, this novel PV was found to be most similar to Capreolus capreolus papillomavirus 1 (CcaPV1), with 67.96% nucleotide identity. We therefore suggest that the virus identified here is given the name Giraffa camelopardalis papillomavirus 1 (GcPV1) and is classified as a novel species within the genus Deltapapillomavirus, in line with the current guidelines for the nomenclature and classification of PVs.

  20. Namibian Analogs To Titan Dunes

    NASA Astrophysics Data System (ADS)

    Wall, Stephen D.; Lopes, R.; Kirk, R.; Stofan, E.; Farr, T.; Van der Ploeg, P.; Lorenz, R.; Radebaugh, J.

    2009-09-01

    Titan's equatorial dunes, observed in Cassini SAR, have been described as longitudinal, similar to longitudinal dunes in the Namib sand sea in southern Africa. Their "Y” junctions and the way they divert around topography are used as evidence of equatorial wind flow direction. In two instances of such diversion they exhibit overlying or crosshatched patterns in two distinct directions that have been interpreted as a transition to transverse dunes. Here we describe field observations of the Namibian dunes and these comparisons, we present images of the dunes from terrestrial SAR missions, and we discuss implications to both the Titan dunes and the wind regime that created them. Selected portions of the Namibian dunes resemble Titan's dunes in peak-to-peak distance and length. They are morphologically similar to Titan, and specific superficial analogs are common, but they also differ. For example, when Titan dunes encounter topography they either terminate abruptly, "climb” the upslope, or divert around; only the latter behavior is seen in remote sensing images of Namibia. Namib linear dunes do transition to transverse as they divert, but at considerably smaller wavelength, while at Titan the wavelengths are of the same scale. Crosshatching of similar-wavelength dunes does occur in Namibia, but not near obstacles. Many additional aeolian features that are seen at Namibia such as star dunes, serpentine ridges and scours have not been detected on Titan, although they might be below the Cassini SAR's 300-m resolution. These similarities and differences allow us to explore mechanisms of Titan dune formation, in some cases giving us clues as to what larger scale evidence to look for in SAR images. Viewed at similar resolution, they provide interesting comparisons with the Titan dunes, both in likeness and differences. A part of this work was carried out at JPL under contract with NASA.

  1. Sexual segregation in foraging giraffe

    NASA Astrophysics Data System (ADS)

    Mramba, Rosemary Peter; Mahenya, Obeid; Siyaya, Annetjie; Mathisen, Karen Marie; Andreassen, Harry Peter; Skarpe, Christina

    2017-02-01

    Sexual segregation in giraffe is known to vary between savannas. In this study, we compared sexual segregation in giraffe in one nutrient-rich savanna, the Serengeti National Park, one nutrient-poor, Mikumi National Park, and one medium rich savanna, Arusha National Park, (from here on referred to just by name) based on effects of sexual size dimorphism and related hypotheses. Data were collected in the wet and dry seasons, by driving road transects and making visual observations of browsing giraffe. Additional data were collected from literature (plant chemistry; mammal communities). There was a noticeable difference in browsing by females and males and in browsing between the three savannas. Females browsed a higher diversity of tree species in Serengeti whereas males browsed a higher diversity in Arusha, while the diversity of species browsed in Mikumi was high and about the same in both sexes. Females selected for high concentrations of nitrogen and low concentrations of tannins and phenolics compared to males in Serengeti but selection in Mikumi was more complex. Males browsed higher in the canopy than females in all sites, but the browsing height was generally higher in Serengeti than Mikumi and Arusha. Season had an effect on the browsing height independent of sex in Mikumi, where giraffes browsed higher in the dry season compared to the wet season. Males spent more time browsing per tree compared to females in all three sites; however, browsing time in Mikumi was also affected by season, where giraffes had longer browsing bouts in the wet season compared to the dry season. We suggest that sexual differences in forage requirement and in foraging interacts with differences in tree chemistry and in competing herbivore communities between nutrient rich and nutrient poor savanna in shaping the sexual segregation.

  2. Pathology and immunohistochemistry of papillomavirus-associated cutaneous lesions in Cape mountain zebra, giraffe, sable antelope and African buffalo in South Africa.

    PubMed

    Williams, J H; van Dyk, E; Nel, P J; Lane, E; Van Wilpe, E; Bengis, R G; de Klerk-Lorist, L M; van Heerden, J

    2011-06-01

    Skin lesions associated with papillomaviruses have been reported in many animal species and man. Bovine papillomavirus (BVP) affects mainly the epidermis, but also the dermis in several species including bovine, the best-known example being equine sarcoid, which is associated with BVP types 1 and 2. This publication describes and illustrates the macroscopic and histological appearance of BPV-associated papillomatous, fibropapillomatous or sarcoid-like lesions in Cape mountain zebra (Equus zebra zebra) from the Gariep Dam Nature Reserve, 2 giraffes (Giraffa camelopardalis) from the Kruger National Park, and a sable antelope (Hippotragus niger) from the Kimberley area of South Africa. An African buffalo (Syncerus caffer) cow from Kruger National Park also had papillomatous lesions but molecular characterisation of lesional virus was not done. Immunohistochemical staining using polyclonal rabbit antiserum to chemically disrupted BPV-1, which cross-reacts with the L1 capsid of most known papillomaviruses, was positive in cells of the stratum granulosum of lesions in Giraffe 1, the sable and the buffalo and negative in those of the zebra and Giraffe 2. Fibropapillomatous and sarcoid-like lesions from an adult bovine were used as positive control for the immunohistochemistry and are described and the immunohistochemistry illustrated for comparison. Macroscopically, both adult female giraffe had severely thickened multifocal to coalescing nodular and occasionally ulcerated lesions of the head, neck and trunk with local poorly-circumscribed invasion into the subcutis. Necropsy performed on the 2nd giraffe revealed neither internal metastases nor serious underlying disease. Giraffe 1 had scattered, and Giraffe 2 numerous, large, anaplastic, at times indistinctly multinucleated dermal fibroblasts with bizarre nuclei within the sarcoid-like lesions, which were BPV-1 positive in Giraffe 1 and BPV-1 and -2 positive in Giraffe 2 by RT-PCR. The sable antelope presented with a

  3. The Language Question in Namibian Schools

    NASA Astrophysics Data System (ADS)

    Brock-Utne, Birgit

    1997-03-01

    Namibia, a country in southwest Africa with only 1.5 million inhabitants, officially has thirteen languages as languages of instruction in the first grades of schooling. Three of these are European, and ten African. Of the three European languages, two are connected with the colonial history of Namibia. Namibia was colonized by the Germans from 1884 to 1914 and German is still an important business language in Namibia and the language one hears most frequently among shop-keepers in Windhoek. The South African colonization, which was supposed to be a Trusteeship, lasted until 1990. In this period Afrikaans (a variety of Dutch) became the main official language and the language of instruction from grade 4 upwards. This article deals with the period after Independence and focuses especially on the Namibian languages of African origin. The role of English, a European language without a colonial history in Namibia, and now the official language, is also discussed. How much is the furthering of this language to the detriment of the Namibian languages? The article contains a description of the Namibian languages, the language policy and the status of the languages in Namibian schools. The article builds on a larger consultancy report written by the author.

  4. Manifestations of Namibian Boy's Underachievement in Education

    ERIC Educational Resources Information Center

    Zimba, Roderick F.

    2015-01-01

    An analysis of the 2012 grade 10 and grade 12 Namibian examination data indicate that girls received higher grades than boys across the then 13 education regions (Educational Management Information System, EMIS, 2012). University of Namibia graduation statistics for the period of 2002 to 2012 revealed that the institution consistently produced…

  5. The First Description of Dominance Hierarchy in Captive Giraffe: Not Loose and Egalitarian, but Clear and Linear

    PubMed Central

    Gloneková, Markéta

    2015-01-01

    Wild giraffes live in extensive groups in the fission fusion system, maintaining long social distances and loose social bonds. Within these groups, resources are widely distributed, agonistic encounters are scarce and the dominance hierarchy was reported in males only, while never deeply analysed. In captivity, the possibility to maintain inter-individual distances is limited and part of the resources is not evenly distributed. Consequently, we suggest that agonistic encounters should be more frequent, leading to the establishment of the dominance hierarchy. Based on the differences in resource-holding potential, we suggested that the rank of an individual would be affected by age and sex. Based on hypotheses of prior ownership, we tested whether rank was positively affected by the time spent in a herd and whether it was stable in adult females, which were present long-term in the same herd. We originally monitored four herds of Rothschild giraffes (Giraffa camelopardalis rothschildii) in Dvůr Králové zoo (n = 8), Liberec zoo (n = 6), and two herds in Prague zoo: Prague 1 (n = 8) and Prague 2 (n = 9). The Prague 1 and Prague 2 herds were then combined and the resulting fifth herd was observed over three consecutive years (2009, 2010, and 2011) (n = 14, 13, and 14, respectively). We revealed a significantly linear hierarchy in Dvůr Králové, Prague 2 and in the combined herd in Prague. Rank was significantly affected by age in all herds; older individuals dominated the younger ones. In females, rank was positively affected by the time spent in the herd and adult females in Prague maintained their rank during three consecutive years. This study represents the first analysis of the dominance hierarchy in the captive giraffe, and discusses the behavioural flexibility of the social structure in response to monopolisable resources in a captive environment. PMID:25970483

  6. The first description of dominance hierarchy in captive giraffe: not loose and egalitarian, but clear and linear.

    PubMed

    Horová, Edita; Brandlová, Karolína; Gloneková, Markéta

    2015-01-01

    Wild giraffes live in extensive groups in the fission fusion system, maintaining long social distances and loose social bonds. Within these groups, resources are widely distributed, agonistic encounters are scarce and the dominance hierarchy was reported in males only, while never deeply analysed. In captivity, the possibility to maintain inter-individual distances is limited and part of the resources is not evenly distributed. Consequently, we suggest that agonistic encounters should be more frequent, leading to the establishment of the dominance hierarchy. Based on the differences in resource-holding potential, we suggested that the rank of an individual would be affected by age and sex. Based on hypotheses of prior ownership, we tested whether rank was positively affected by the time spent in a herd and whether it was stable in adult females, which were present long-term in the same herd. We originally monitored four herds of Rothschild giraffes (Giraffa camelopardalis rothschildii) in Dvůr Králové zoo (n = 8), Liberec zoo (n = 6), and two herds in Prague zoo: Prague 1 (n = 8) and Prague 2 (n = 9). The Prague 1 and Prague 2 herds were then combined and the resulting fifth herd was observed over three consecutive years (2009, 2010, and 2011) (n = 14, 13, and 14, respectively). We revealed a significantly linear hierarchy in Dvůr Králové, Prague 2 and in the combined herd in Prague. Rank was significantly affected by age in all herds; older individuals dominated the younger ones. In females, rank was positively affected by the time spent in the herd and adult females in Prague maintained their rank during three consecutive years. This study represents the first analysis of the dominance hierarchy in the captive giraffe, and discusses the behavioural flexibility of the social structure in response to monopolisable resources in a captive environment.

  7. Tissue adaptations to gravitational stress - Newborn versus adult giraffes

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R; Gershuni, David H.; Danzig, Larry A.; Millard, Ronald W.; Pettersson, Knut

    1988-01-01

    Preliminary results on developmental alterations in load-bearing tissues of newborn and adult giraffes are presented. Attention is focused on vascular wall thickness in relation to local blood pressure, and on meniscal adaptations to increased load bearing in the developing giraffe. It is believed that the developing giraffe provides an excellent model for investigations of adaptive mechanisms of increased weight bearing.

  8. Sensorimotor responsiveness and resolution in the giraffe.

    PubMed

    More, Heather L; O'Connor, Shawn M; Brøndum, Emil; Wang, Tobias; Bertelsen, Mads F; Grøndahl, Carsten; Kastberg, Karin; Hørlyck, Arne; Funder, Jonas; Donelan, J Maxwell

    2013-03-15

    The ability of an animal to detect and respond to changes in the environment is crucial to its survival. However, two elements of sensorimotor control - the time required to respond to a stimulus (responsiveness) and the precision of stimulus detection and response production (resolution) - are inherently limited by a competition for space in peripheral nerves and muscles. These limitations only become more acute as animal size increases. In this paper, we investigated whether the physiology of giraffes has found unique solutions for maintaining sensorimotor performance in order to compensate for their extreme size. To examine responsiveness, we quantified three major sources of delay: nerve conduction delay, muscle electromechanical delay and force generation delay. To examine resolution, we quantified the number and size distribution of nerve fibers in the sciatic nerve. Rather than possessing a particularly unique sensorimotor system, we found that our measurements in giraffes were broadly comparable to size-dependent trends seen across other terrestrial mammals. Consequently, both giraffes and other large animals must contend with greater sensorimotor delays and lower innervation density in comparison to smaller animals. Because of their unconventional leg length, giraffes may experience even longer delays compared with other animals of the same mass when sensing distal stimuli. While there are certainly advantages to being tall, there appear to be challenges as well - our results suggest that giraffes are less able to precisely and accurately sense and respond to stimuli using feedback alone, particularly when moving quickly.

  9. The GIRAFFE Inner Bulge Survey (GIBS)

    NASA Astrophysics Data System (ADS)

    Zoccali, M.; Gonzalez, O. A.; Vasquez, S.; Hill, V.; Rejkuba, M.; Valenti, E.; Renzini, A.; Rojas-Arriagada, A.; Babusiaux, C.; Brown, T.; Minniti, D.; McWilliam, A.

    2015-03-01

    The GIRAFFE Inner Bulge Survey (GIBS) is a spectroscopic survey of ~ 6500 core helium burning (red clump) stars in the Milky Way Bulge, carried out with the FLAMES GIRAFFE spectrograph at the VLT. The aim of the GIBS survey is to derive the metallicity and radial velocity distributions of Bulge stars, across 31 fields in the region of Galactic longitude range -10° to +10° and latitude range -10° to +5°. This is the area also mapped by the VISTA Variables in the Vía Láctea (VVV) ESO Public Survey.

  10. Biologic, antigenic, and full-length genomic characterization of a bovine-like coronavirus isolated from a giraffe.

    PubMed

    Hasoksuz, Mustafa; Alekseev, Konstantin; Vlasova, Anastasia; Zhang, Xinsheng; Spiro, David; Halpin, Rebecca; Wang, Shiliang; Ghedin, Elodie; Saif, Linda J

    2007-05-01

    Coronaviruses (CoVs) possess large RNA genomes and exist as quasispecies, which increases the possibility of adaptive mutations and interspecies transmission. Recently, CoVs were recognized as important pathogens in captive wild ruminants. This is the first report of the isolation and detailed genetic, biologic, and antigenic characterization of a bovine-like CoV from a giraffe (Giraffa camelopardalis) in a wild-animal park in the United States. CoV particles were detected by immune electron microscopy in fecal samples from three giraffes with mild-to-severe diarrhea. From one of the three giraffe samples, a CoV (GiCoV-OH3) was isolated and successfully adapted to serial passage in human rectal tumor 18 cell cultures. Hemagglutination assays, receptor-destroying enzyme activity, hemagglutination inhibition, and fluorescence focus neutralization tests revealed close biological and antigenic relationships between the GiCoV-OH3 isolate and selected respiratory and enteric bovine CoV (BCoV) strains. When orally inoculated into a BCoV-seronegative gnotobiotic calf, GiCoV-OH3 caused severe diarrhea and virus shedding within 2 to 3 days. Sequence comparisons and phylogenetic analyses were performed to assess its genetic relatedness to other CoVs. Molecular characterization confirmed that the new isolate belongs to group 2a of the mammalian CoVs and revealed closer genetic relatedness between GiCoV-OH3 and the enteric BCoVs BCoV-ENT and BCoV-DB2, whereas BCoV-Mebus was more distantly related. Detailed sequence analysis of the GiCoV-OH3 spike gene demonstrated the presence of a deletion in the variable region of the S1 subunit (from amino acid 543 to amino acid 547), which is a region associated with pathogenicity and tissue tropism for other CoVs. The point mutations identified in the structural proteins (by comparing GiCoV-OH3, BCoV-ENT, BCoV-DB2, and BCoV-Mebus) were most conserved among GiCoV-OH3, BCoV-ENT, and BCoV-DB2, whereas most of the point mutations in the

  11. Who Said Giraffes Can't Dance?

    ERIC Educational Resources Information Center

    Lovett, Mary Lu

    2002-01-01

    Describes an art activity for third-grade students in which they learned about African animals in one class period and spent time in another class period creating a picture of a giraffe. Explains that the students learned about watercolor wash and the wet-on-wet technique. (CMK)

  12. Giraffe, a Computer Assisted Instruction Programme.

    ERIC Educational Resources Information Center

    Boekhorst, Albert K.; Groot, Tineke

    In 1989 a two year collaborative project, CAI (Computer Assisted Instruction) & Humanities, was initiated between the Faculty of Arts and IBM Netherlands during which General Information Retrieval All Faculties For Bibliographic Education (GIRAFFE), a program for the retrieval of information on general bibliographies, was developed. The…

  13. The GIRAFFE Archive: Reduced Spectra and Datacubes from the VLT FLAMES GIRAFFE Spectrograph

    NASA Astrophysics Data System (ADS)

    Royer, F.; Jégouzo, I.; Haigron, R.; Tajahmady, F.; Plassard, F.

    2014-12-01

    Since 2003, the intermediate- and high-resolution multi-fibre spectrograph GIRAFFE, part of the FLAMES facility, has been producing 1D spectra in its multi-object configuration and 3D spectra using its integral field unit configurations. Raw data are available in the ESO archive. The GIRAFFE archive (http://giraffe-archive.obspm.fr) offers the community, via a web interface and the Virtual Observatory (VO), access to reduced scientific data. The web interface to the database allows the use of a large range of selection criteria, including individual target positions, magnitudes and signal-to-noise ratios, together with an interactive quick look at the reduced data. Two collections are available in the VO: the 1D spectra (summed in the case of integral field observations) and the 3D field observations.

  14. Teachers' Use of Textbooks: Practice in Namibian Science Classrooms.

    ERIC Educational Resources Information Center

    Lubben, Fred; Campbell, Bob; Kasanda, Choshi; Kapenda, Hileni; Gaoseb, Noah; Kandjeo-Marenga, Utji

    2003-01-01

    Presents the results of a study that focused on incidences of prescribed textbook usage in Namibian science classrooms. Indicates teacher dominated textbook use and restricted range of textbook references per lesson. States that the teachers used textbooks for diagrams and data and to verify factual information. (CMK)

  15. Tongue twisters: feeding enrichment to reduce oral stereotypy in giraffe.

    PubMed

    Fernandez, Loraine Tarou; Bashaw, Meredith J; Sartor, Richard L; Bouwens, Nichole R; Maki, Todd S

    2008-05-01

    Stereotypic behavior has been well-studied and documented in a variety of animals including primates, carnivores, and domesticated ungulates. However, very little information is known about stereotypic behavior of captive exotic ungulates. Giraffe have been found to perform a wide range of stereotypic behaviors. According to a survey of zoological institutions, oral stereotypies, specifically the licking of nonfood objects are the most prevalent stereotypic behaviors observed in giraffe. Their performance appears to be related to feeding and rumination and may be a result of the inability of a highly motivated feeding behavior pattern, tongue manipulation, to be successfully completed. To test this hypothesis, the indoor and outdoor feeders for three giraffe housed at Zoo Atlanta were modified to require the giraffe to perform more naturalistic and complex foraging behaviors. Data were collected using instantaneous scan sampling in both exhibit and holding areas. Our results showed that, for the giraffe that engaged in the highest rates of oral stereotypic behavior in the baseline, more complex feeders that required tongue use to access grain or alfalfa had the greatest effect on behavior. For the giraffe that performed low baseline rates of oral stereotypic behavior, adding slatted tops to the alfalfa feeders indoors virtually eliminated the behavior. Although some changes in ruminating and feeding behavior were observed, the decreases in stereotypic behavior were not associated with the changes in ruminating or feeding behavior. These results provide evidence for the hypothesis that oral stereotypy in herbivores can be reduced by encouraging giraffe to engage in more naturalistic foraging behavior.

  16. Osteophagia provide giraffes with phosphorus and calcium?

    PubMed

    Bredin, I P; Skinner, J D; Mitchell, G

    2008-03-01

    The daily requirement for calcium and phosphorus by giraffes to sustain the growth and maintenance of their skeletons is large. The source of sufficient calcium is browse. The source of necessary phosphorus is obscure, but it could be osteophagia, a frequently observed behaviour in giraffes. We have assessed whether bone ingested as a result of osteophagia can be digested in the rumen. Bone samples from cancellous (cervical vertebrae) and dense bones (metacarpal shaft) were immersed in the rumens of five sheep, for a period of up to 30 days, and the effect compared to immersion in distilled water and in artificial saliva for 30 days. Distilled water had no effect on the bones. Dense bone samples were softened by exposure to the saliva and rumen fluid, but did not lose either calcium or phosphorus. In saliva and rumen fluid the cancellous bone samples also softened, and their mass and volume decreased as a result of exposure to saliva, but in neither fluid did they lose significant amounts of calcium and phosphorus. We conclude that although saliva and rumen fluid can soften ingested bones, there is an insignificant digestion of bones in the rumen.

  17. Response to "How many species of giraffe are there?"

    PubMed

    Fennessy, Julian; Winter, Sven; Reuss, Friederike; Kumar, Vikas; Nilsson, Maria A; Vamberger, Melita; Fritz, Uwe; Janke, Axel

    2017-02-20

    It is not unexpected that a proposal, such as ours [1], of four new mammalian species stirs up controversy, as evident in the correspondence by Bercovitch et al.[2]. We appreciate that their concerns are unrelated to the quality of the genetic data, the methodological approach or analyses, but are focused on the interpretation. Thus, we provided an analysis of giraffe speciation based on genomic sequence data, and not just "another viewpoint on giraffe taxonomy" [2]. We maintain our perspective that there is not only one but four species of giraffe (Figure 1).

  18. Review of Namibian legislation and policies pertinent to environmental flows

    NASA Astrophysics Data System (ADS)

    Bethune, Shirley; Amakali, Maria; Roberts, Kevin

    The rationale for evaluating Namibian environmental flows is essentially that of ensuring ‘the maintenance of ecosystems, essential ecological processes and biological diversity’ and the sustainable utilisation of natural resources as promoted in clause 95 of the Namibian Constitution. Recent policy and legislative reforms have created a unique opportunity for Namibia to incorporate environmental sensitivity clauses such as those to ensure adequate environmental flows for river systems. The Second National Development Plan and the National Water Policy White Paper form the basis for the new Water Resources Management Act, promulgated in December 2004. The National Water Policy includes a basic principle headed “Ecosystem values and sustainability” that stresses that the management of water resources needs to harmonise human and environmental requirements, recognising the role of water in supporting the ecosystem. One of the strategies given to ensure environmental and economic sustainability reads: “Ensure that in-stream flows are adequate both in terms of quality and quantity to sustain the ecosystem”. Although the water policy clearly states that: “The legislation will provide for determining an environmental water reserve for freshwater sources before they can be used to supply other demands than domestic and subsistence livestock watering”, there is now no direct mention of environmental flows in the new Water Act. This paper explores to what extent the need for the determination of environmental water needs has been incorporated into Namibian policies, legislation and development plans. It makes recommendations, pertinent to the Namibian situation, of what needs to be done to ensure that environmental water requirements are taken into account in future planning, operation and management of Namibia’s precious water resources.

  19. Hypertension and counter-hypertension mechanisms in giraffes.

    PubMed

    Zhang, Qiong Gus

    2006-03-01

    The giraffe is unique as its head is 2500-3000 millimeters above its heart, thus the giraffe's heart must pump hard enough to overcome the huge hydrostatic pressure generated by the tall column of blood in its neck in order to provide its head with sufficient nutrients and oxygen. Giraffes therefore have exceptionally high blood pressure (hypertension) by human standards. Interestingly, the "unnaturally" high blood pressure in giraffes does not culminate in severe vascular lesions, nor does it lead to heart and kidney failure, whereas in humans, the same blood pressure is exceedingly dangerous and will cause severe vascular damage. Intrinsically, natural selection likely has provided an important protective mechanism, because hypertension develops as soon as the giraffe stands up and erects its neck immediately after birth. Therefore, those individual giraffes who did not tolerate the burden of hypertension presumably developed acute heart failure and renal failure, not surviving to reproductive age. The genes and genotypes of animals that did not survive are thus predicted to have been gradually eliminated from the gene pool by natural selection. By the same process, genes that protect against hypertensive damage would be preserved and inherited from generation to generation. Some unique ingredients of the giraffe's diet may also provide an extrinsic mechanism for the prevention of hypertension and the prevention of fatal end-stage organ damage. The fascinating nature of the protective mechanisms in giraffes may provide a conceptual framework for further experimental investigations into mechanisms as well as prevention and treatment of human hypertension and cardiovascular disease.

  20. Giraffe genome sequence reveals clues to its unique morphology and physiology

    PubMed Central

    Agaba, Morris; Ishengoma, Edson; Miller, Webb C.; McGrath, Barbara C.; Hudson, Chelsea N.; Bedoya Reina, Oscar C.; Ratan, Aakrosh; Burhans, Rico; Chikhi, Rayan; Medvedev, Paul; Praul, Craig A.; Wu-Cavener, Lan; Wood, Brendan; Robertson, Heather; Penfold, Linda; Cavener, Douglas R.

    2016-01-01

    The origins of giraffe's imposing stature and associated cardiovascular adaptations are unknown. Okapi, which lacks these unique features, is giraffe's closest relative and provides a useful comparison, to identify genetic variation underlying giraffe's long neck and cardiovascular system. The genomes of giraffe and okapi were sequenced, and through comparative analyses genes and pathways were identified that exhibit unique genetic changes and likely contribute to giraffe's unique features. Some of these genes are in the HOX, NOTCH and FGF signalling pathways, which regulate both skeletal and cardiovascular development, suggesting that giraffe's stature and cardiovascular adaptations evolved in parallel through changes in a small number of genes. Mitochondrial metabolism and volatile fatty acids transport genes are also evolutionarily diverged in giraffe and may be related to its unusual diet that includes toxic plants. Unexpectedly, substantial evolutionary changes have occurred in giraffe and okapi in double-strand break repair and centrosome functions. PMID:27187213

  1. Giraffe genome sequence reveals clues to its unique morphology and physiology.

    PubMed

    Agaba, Morris; Ishengoma, Edson; Miller, Webb C; McGrath, Barbara C; Hudson, Chelsea N; Bedoya Reina, Oscar C; Ratan, Aakrosh; Burhans, Rico; Chikhi, Rayan; Medvedev, Paul; Praul, Craig A; Wu-Cavener, Lan; Wood, Brendan; Robertson, Heather; Penfold, Linda; Cavener, Douglas R

    2016-05-17

    The origins of giraffe's imposing stature and associated cardiovascular adaptations are unknown. Okapi, which lacks these unique features, is giraffe's closest relative and provides a useful comparison, to identify genetic variation underlying giraffe's long neck and cardiovascular system. The genomes of giraffe and okapi were sequenced, and through comparative analyses genes and pathways were identified that exhibit unique genetic changes and likely contribute to giraffe's unique features. Some of these genes are in the HOX, NOTCH and FGF signalling pathways, which regulate both skeletal and cardiovascular development, suggesting that giraffe's stature and cardiovascular adaptations evolved in parallel through changes in a small number of genes. Mitochondrial metabolism and volatile fatty acids transport genes are also evolutionarily diverged in giraffe and may be related to its unusual diet that includes toxic plants. Unexpectedly, substantial evolutionary changes have occurred in giraffe and okapi in double-strand break repair and centrosome functions.

  2. Consistency of captive giraffe behavior under two different management regimes.

    PubMed

    Bashaw, Meredith J

    2011-01-01

    Long-term animal behavior studies are sometimes conducted at a single site, leading to questions about whether effects are limited to animals in the same environment. Our ability to make general conclusions about behavior is improved when we can identify behaviors that are consistent across a range of environments. To extend Veasey and colleagues' ([1996b] Anim Welf 5:139-153) study, I compared not only activity budgets but also social behavior of an all-female group of giraffe at The Maryland Zoo in Baltimore (MZiB) to those previously observed in breeding groups at The San Diego Zoo's Wild Animal Park (SDZWAP; Bashaw et al. [2007] J Comp Psychol 121:46-53). Morning activity budgets and the maintenance of social relationships were consistent across groups. MZiB female giraffe interacted more frequently and the identity of animals that formed the strongest relationships was less predictable than at SDZWAP. Results support earlier findings that captive giraffe maintain social relationships and suggest that studies of giraffe social relationships and activity are generalizable across a range of captive conditions.

  3. Holocene sedimentation processes and environmental changes along the Namibian coastline

    NASA Astrophysics Data System (ADS)

    Schüller, Irka; Belz, Lukas; Wilkes, Heinz; Wehrmann, Achim

    2016-04-01

    The regional oceanic and atmospheric circulation patterns strongly control environmental conditions in southern Africa. Changes in the system may have significant consequences on climate and related processes. The hyper arid coast of Namibia is mainly influenced by (1) the cold Benguela upwelling, (2) the Benguela current and (3) the Angola current. The Benguela current transports the cool, upwelling water from south to north and interacts with the warm, contrary flowing Angola current at the Angola-Benguela Front (ABF). Today the ABF is located around the Namibian-Angolan border with minor seasonal changes. Therefore, climate and environment at the Namibian coast are affected by the cold water conditions. It is known evidently that the location of the ABF changed during the Holocene over several latitudes and enabled warm water species to expand their range farther south. Several (paleo-) lagoons (coastal salt pans) exist along the Namibian coastline. Most of them are already barred and filled by longshore sediment transport processes. Tidal flooding and active sedimentation processes are restricted to the southernmost lagoons. Two different types of sediments occur. The northern pans contain well sorted, siliciclastic medium sands. Fine-layered alternation refers to changes in mineral composition. The southern pans are dominated by typical tidal sediments with a high amount of benthic fauna (mainly bivalves and gastropods). At Cape Cross the distinct shift between both facies is documented in the cores. Age determinations of core material prove a very fast sediment filling of the distinct lagoons with high sedimentation rates. However, the age of closure differs from lagoon to lagoon. Northern pan sediments are much older (Cape Cross: ~ 5000 a BP) than southern (Sandwich Bay and Conception Bay: 1800 - 300 a BP). Additional information are supported by river clay deposits (~ 36600 a BP) and fossil reed systems (~ 47900 a BP) in Conception Bay and peat deposits at

  4. Effects of guest feeding programs on captive giraffe behavior.

    PubMed

    Orban, David A; Siegford, Janice M; Snider, Richard J

    2016-01-01

    Zoological institutions develop human-animal interaction opportunities for visitors to advance missions of conservation, education, and recreation; however, the animal welfare implications largely have yet to be evaluated. This behavioral study was the first to quantify impacts of guest feeding programs on captive giraffe behavior and welfare, by documenting giraffe time budgets that included both normal and stereotypic behaviors. Thirty giraffes from nine zoos (six zoos with varying guest feeding programs and three without) were observed using both instantaneous scan sampling and continuous behavioral sampling techniques. All data were collected during summer 2012 and analyzed using linear mixed models. The degree of individual giraffe participation in guest feeding programs was positively associated with increased time spent idle and marginally associated with reduced time spent ruminating. Time spent participating in guest feeding programs had no effect on performance of stereotypic behaviors. When time spent eating routine diets was combined with time spent participating in guest feeding programs, individuals that spent more time engaged in total feeding behaviors tended to perform less oral stereotypic behavior such as object-licking and tongue-rolling. By extending foraging time and complexity, guest feeding programs have the potential to act as environmental enrichment and alleviate unfulfilled foraging motivations that may underlie oral stereotypic behaviors observed in many captive giraffes. However, management strategies may need to be adjusted to mitigate idleness and other program consequences. Further studies, especially pre-and-post-program implementation comparisons, are needed to better understand the influence of human-animal interactions on zoo animal behavior and welfare.

  5. Protection against high intravascular pressure in giraffe legs.

    PubMed

    Petersen, Karin K; Hørlyck, Arne; Ostergaard, Kristine H; Andresen, Joergen; Broegger, Torbjoern; Skovgaard, Nini; Telinius, Niklas; Laher, Ismael; Bertelsen, Mads F; Grøndahl, Carsten; Smerup, Morten; Secher, Niels H; Brøndum, Emil; Hasenkam, John M; Wang, Tobias; Baandrup, Ulrik; Aalkjaer, Christian

    2013-11-01

    The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along the artery. Histology of the isolated median artery confirmed dense sympathetic innervation at the narrowing. Structure and contractility of small arteries from muscular beds in the leg and neck were compared. The arteries from the legs demonstrated an increased media thickness-to-lumen diameter ratio, increased media volume, and increased numbers of smooth muscle cells per segment length and furthermore, they contracted more strongly than arteries from the neck (500 ± 49 vs. 318 ± 43 mmHg; n = 6 legs and neck, respectively). Finally, the transient increase in interstitial fluid pressure following injection of saline was 5.5 ± 1.7 times larger (n = 8) in the leg than in the neck. We conclude that 1) tissue compliance in the legs is low; 2) large arteries of the legs function as resistance arteries; and 3) structural adaptation of small muscle arteries allows them to develop an extraordinary tension. All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure.

  6. Namibian Flood Early Warning SensorWeb Pilot

    NASA Technical Reports Server (NTRS)

    Mandl, Daniel; Policelli, Fritz; Frye, Stuart; Cappelare, Pat; Langenhove, Guido Van; Szarzynski, Joerg; Sohlberg, Rob

    2010-01-01

    The major goal of the Namibia SensorWeb Pilot Project is a scientifically sound, operational trans-boundary flood management decision support system for Southern African region to provide useful flood and waterborne disease forecasting tools for local decision makers. The Pilot Project established under the auspices of: Namibian Ministry of Agriculture Water and Forestry (MAWF), Department of Water Affairs; Committee on Earth Observing Satellites (CEOS), Working Group on Information Systems and Services (WGISS); and moderated by the United Nations Platform for Space-based Information for Disaster Management and Emergency Response (UN-SPIDER). The effort consists of identifying and prototyping technology which enables the rapid gathering and dissemination of both space-based and ground sensor data and data products for the purpose of flood disaster management and water-borne disease management.

  7. Gravitational haemodynamics and oedema prevention in the giraffe

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.; Millard, Ronald W.; Pettersson, Knut; Johansen, Kjell

    1987-01-01

    The question of how giraffes avoid pooling of blood and tissue fluid (edema) in dependent tissues of their extremities is addressed. As monitored by radiotelemetry, the blood and tissue fluid pressures that govern transcapillary exchange vary greatly with exercise. These pressures, combined with a tight skin layer, move fluid upward against gravity. The skin thus functions like a natural antigravity suit. Other mechanisms that prevent edema include precapillary vasoconstriction and low permeability of capillaries to plasma proteins.

  8. An allometric analysis of the giraffe cardiovascular system.

    PubMed

    Mitchell, G; Skinner, J D

    2009-12-01

    There has been co-evolution of a long neck and high blood pressure in giraffes. How the cardiovascular system (CVS) has adapted to produce a high blood pressure, and how it compares with other similar sized mammals largely is unknown. We have measured body mass and heart structure in 56 giraffes of both genders ranging in body mass from 18 kg to 1500 kg, and developed allometric equations that relate changes in heart dimensions to growth and to cardiovascular function. Predictions made from these equations match measurements made in giraffes. We have found that heart mass increases as body mass increases but it has a relative mass of 0.51+/-0.7% of body mass which is the same as that in other mammals. The left ventricular and interventricular walls are hypertrophied and their thicknesses are linearly related to neck length. Systemic blood pressure increases as body mass and neck length increase and is twice that of mammals of the same body mass. Cardiac output is the same as, but peripheral resistance double that predicted for similar sized mammals. We have concluded that increasing hydrostatic pressure of the column of blood during neck elongation results in cardiac hypertrophy and concurrent hypertrophy of arteriole walls raising peripheral resistance, with an increase in blood pressure following.

  9. The digestive morphophysiology of wild, free-living, giraffes.

    PubMed

    Mitchell, G; Roberts, D G; van Sittert, S J

    2015-09-01

    We have measured rumen-complex (rumen, reticulum, omasum, abomasum) and intestine (small and large combined) mass in 32 wild giraffes of both sexes with body masses ranging from 289 to 1441 kg, and parotid gland mass, tongue length and mass, masseter and mandible mass in 9 other giraffes ranging in body mass from 181 to 1396 kg. We have estimated metabolic and energy production rates, feed intake and home range size. Interspecific analysis of mature ruminants show that components of the digestive system increase linearly (Mb(1)) or positively allometric (Mb(>1)) with body mass while variables associated with feed intake scale with metabolic rate (Mb(.75)). Conversely, in giraffes ontogenetic increases in rumen-complex mass were negatively allometric (Mb(<1)), and increases in intestine mass, parotid gland mass, masseter mass, and mandible mass were isometric (Mb(1)). The relative masseter muscle mass (0.14% of Mb) and the relative parotid mass (0.03% of Mb) are smaller than in other ruminants. Increases in tongue length scale with head length(0.72) and Mb(.32) and tongue mass with Mb(.69). Absolute mass of the gastrointestinal tract increased throughout growth but its relative mass declined from 20% to 15% of Mb. Rumen-complex fermentation provides ca 43% of daily energy needs, large intestine fermentation 24% and 33% by digestion of soluble carbohydrates, proteins, and lipids. Dry matter intake (kg) was 2.4% of body mass in juveniles and 1.6% in adults. Energy requirements increased from 35 Mj/day to 190 Mj/day. Browse production rate sustains a core home range of 2.2-11.8 km(2).

  10. Multi-Method Provenance Analysis of Namibian Desert Sand

    NASA Astrophysics Data System (ADS)

    Vermeesch, P.; Garzanti, E.

    2014-12-01

    Mineralogical, geochemical and geochronological provenance proxies each have their own strengths and weaknesses: a. Bulk geochemistry, framework petrography and heavy mineral compositions can differentiate between source areas characterised by different lithologies, but are sensitive to hydraulic sorting and chemical alteration. b. Detrital zircon U-Pb geochronology is insensitive to winnowing effects, but is 'blind' to lithologies devoid of zircon and cannot differentiate between first cycle and recycled sediments. c. Cosmogenic neon isotopes can be used to identify different generations of surface exposure while simultaneously tracking different magmatic sources. The challenge is then to combine these different proxies into a self consistent story, and do so in as objective a manner as possible. We here present a case study of Namibia's Namib Sand Sea and Skeleton Coast ergs, in which all the aforementioned methods have been combined using a three-way multidimensional scaling (aka INDividual Differences SCALing or INDSCAL) analysis: 1. Each of the datasets was represented by a 'dissimilarity matrix' of pairwise distances between samples. 2. The set of these matrices was fed into the INDSCAL algorithm, which produces two pieces of graphical output: the 'group configuration', which is a scatter plot or 'map' in which similar samples plot close together and dissimilar samples plot far apart, and the 'proxy weights', in which not the samples but the proxies are plotted according to the weight they attached to the 'group configuration' axes. The INDSCAL map of the Namibia dataset indicates that (a) long-shore drift of Orange River sediments dominates the coastal sediment compositions all along the Namibian coast until Angola, and (b) that light and heavy minerals tell complementary parts of the provenance story.

  11. HIV/AIDS Educators: The Challenges and Issues for Namibian Bachelor of Education Students

    ERIC Educational Resources Information Center

    McGinty, Sara; Mundy, Karen

    2009-01-01

    The Life Skills course is offered to Namibian students in grades eight through twelve. It includes lessons on HIV/AIDS, imparting information and equipping them with the necessary psycho-social skills to assist in reducing the risk of becoming infected. Teachers are the impetus for the success of the course. As such, research was undertaken to…

  12. Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes

    PubMed Central

    Gunji, Megu; Endo, Hideki

    2016-01-01

    Here we examined the kinematic function of the morpho- logically unique first thoracic vertebra in giraffes. The first thoracic vertebra of the giraffe displayed similar shape to the seventh cervical vertebra in general ruminants. The flexion experiment using giraffe carcasses demonstrated that the first thoracic vertebra exhibited a higher dorsoventral mobility than other thoracic vertebrae. Despite the presence of costovertebral joints, restriction in the intervertebral movement imposed by ribs is minimized around the first thoracic vertebra by subtle changes of the articular system between the vertebra and ribs. The attachment area of musculus longus colli, mainly responsible for ventral flexion of the neck, is partly shifted posteriorly in the giraffe so that the force generated by muscles is exerted on the cervical vertebrae and on the first thoracic vertebra. These anatomical modifications allow the first thoracic vertebra to adopt the kinematic function of a cervical vertebra in giraffes. The novel movable articulation in the thorax functions as a fulcrum of neck movement and results in a large displacement of reachable space in the cranial end of the neck. The unique first thoracic vertebra in giraffes provides higher flexibility to the neck and may provide advantages for high browsing and/or male competition behaviours specific to giraffes. PMID:26998330

  13. Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes.

    PubMed

    Gunji, Megu; Endo, Hideki

    2016-02-01

    Here we examined the kinematic function of the morpho- logically unique first thoracic vertebra in giraffes. The first thoracic vertebra of the giraffe displayed similar shape to the seventh cervical vertebra in general ruminants. The flexion experiment using giraffe carcasses demonstrated that the first thoracic vertebra exhibited a higher dorsoventral mobility than other thoracic vertebrae. Despite the presence of costovertebral joints, restriction in the intervertebral movement imposed by ribs is minimized around the first thoracic vertebra by subtle changes of the articular system between the vertebra and ribs. The attachment area of musculus longus colli, mainly responsible for ventral flexion of the neck, is partly shifted posteriorly in the giraffe so that the force generated by muscles is exerted on the cervical vertebrae and on the first thoracic vertebra. These anatomical modifications allow the first thoracic vertebra to adopt the kinematic function of a cervical vertebra in giraffes. The novel movable articulation in the thorax functions as a fulcrum of neck movement and results in a large displacement of reachable space in the cranial end of the neck. The unique first thoracic vertebra in giraffes provides higher flexibility to the neck and may provide advantages for high browsing and/or male competition behaviours specific to giraffes.

  14. Evolutionary analysis of vision genes identifies potential drivers of visual differences between giraffe and okapi

    PubMed Central

    Agaba, Morris; Cavener, Douglas R.

    2017-01-01

    Background The capacity of visually oriented species to perceive and respond to visual signal is integral to their evolutionary success. Giraffes are closely related to okapi, but the two species have broad range of phenotypic differences including their visual capacities. Vision studies rank giraffe’s visual acuity higher than all other artiodactyls despite sharing similar vision ecological determinants with many of them. The extent to which the giraffe’s unique visual capacity and its difference with okapi is reflected by changes in their vision genes is not understood. Methods The recent availability of giraffe and okapi genomes provided opportunity to identify giraffe and okapi vision genes. Multiple strategies were employed to identify thirty-six candidate mammalian vision genes in giraffe and okapi genomes. Quantification of selection pressure was performed by a combination of branch-site tests of positive selection and clade models of selection divergence through comparing giraffe and okapi vision genes and orthologous sequences from other mammals. Results Signatures of selection were identified in key genes that could potentially underlie giraffe and okapi visual adaptations. Importantly, some genes that contribute to optical transparency of the eye and those that are critical in light signaling pathway were found to show signatures of adaptive evolution or selection divergence. Comparison between giraffe and other ruminants identifies significant selection divergence in CRYAA and OPN1LW. Significant selection divergence was identified in SAG while positive selection was detected in LUM when okapi is compared with ruminants and other mammals. Sequence analysis of OPN1LW showed that at least one of the sites known to affect spectral sensitivity of the red pigment is uniquely divergent between giraffe and other ruminants. Discussion By taking a systemic approach to gene function in vision, the results provide the first molecular clues associated with

  15. Immunogenetic Variation and Differential Pathogen Exposure in Free-Ranging Cheetahs across Namibian Farmlands

    PubMed Central

    Castro-Prieto, Aines; Wachter, Bettina; Melzheimer, Joerg; Thalwitzer, Susanne; Hofer, Heribert; Sommer, Simone

    2012-01-01

    Background Genes under selection provide ecologically important information useful for conservation issues. Major histocompatibility complex (MHC) class I and II genes are essential for the immune defence against pathogens from intracellular (e.g. viruses) and extracellular (e.g. helminths) origins, respectively. Serosurvey studies in Namibian cheetahs (Acinonyx juabuts) revealed higher exposure to viral pathogens in individuals from north-central than east-central regions. Here we examined whether the observed differences in exposure to viruses influence the patterns of genetic variation and differentiation at MHC loci in 88 free-ranging Namibian cheetahs. Methodology/Principal Findings Genetic variation at MHC I and II loci was assessed through single-stranded conformation polymorphism (SSCP) analysis and sequencing. While the overall allelic diversity did not differ, we observed a high genetic differentiation at MHC class I loci between cheetahs from north-central and east-central Namibia. No such differentiation in MHC class II and neutral markers were found. Conclusions/Significance Our results suggest that MHC class I variation mirrors the variation in selection pressure imposed by viruses in free-ranging cheetahs across Namibian farmland. This is of high significance for future management and conservation programs of this species. PMID:23145096

  16. The origin of mean arterial and jugular venous blood pressures in giraffes.

    PubMed

    Mitchell, Graham; Maloney, Shane K; Mitchell, Duncan; Keegan, D James

    2006-07-01

    Using a mechanical model of the giraffe neck and head circulation consisting of a rigid, ascending, 'carotid' limb, a 'cranial' circulation that could be rigid or collapsible, and a descending, 'jugular' limb that also could be rigid or collapsible, we have analyzed the origin of the high arterial and venous pressures in giraffe, and whether blood flow is assisted by a siphon. When the tubes were rigid and the 'jugular' limb exit was lower than the 'carotid' limb entrance a siphon operated, 'carotid' hydrostatic pressures became more negative, and flow was 3.3 l min(-1) but ceased when the 'cranial' and 'jugular' limbs were collapsible or when the 'jugular' limb was opened to the atmosphere. Pumping water through the model produced positive pressures in the 'carotid' limb similar to those found in giraffe. Applying an external 'tissue' pressure to the 'jugular' tube during pump flow produced the typical pressures found in the jugular vein in giraffe. Constriction of the lowest, 'jugular cuff', portion of the 'jugular' limb showed that the cuff may augment the orthostatic reflex during head raising. Except when all tubes were rigid, pressures were unaffected by a siphon. We conclude that mean arterial blood pressure in giraffes is a consequence of the hydrostatic pressure generated by the column of blood in the neck, that tissue pressure around the collapsible jugular vein produces the known jugular pressures, and that a siphon does not assist flow through the cranial circulation.

  17. Variations in the thickness and composition of the skin of the giraffe.

    PubMed

    Sathar, Farzana; Ludo Badlangana, N; Manger, Paul R

    2010-09-01

    This study examined the skin of two 1- to 2-year-old male giraffes and one adult male, determining skin thickness and histological structure with reference to it functioning as a component of the features required for the maintenance of blood pressure, dermal armor, or thermoregulation. It has been argued that a tight skin surrounding the extremities of the giraffe aids in the movement of fluid against gravity, hence preventing pooling of blood and tissue fluid (edema), but the skin has also been implicated in the thermoregulatory capacities and defensive anatomy of many mammalian species. In one of the younger giraffes, one-half of the skin was analyzed from which close to 170 sites were measured. In the other young and adult giraffes, spot tests to confirm the pattern observed in the fully analyzed individual were undertaken. It was discovered that the skin varied in thickness across the entire body and within regions of the body. Histological evaluation revealed that the skin was mostly collagenous, although interesting patterns of elastic fiber densities were also apparent. The skin in the neck and legs exhibited a morphology that may assist in cardiovascular regulation of blood flow to and from the head and legs, and the skin of the trunk and anterior neck has the possibility of functioning in a protective role. The analyses performed could not add any new data regarding the thermoregulatory role already described for giraffe skin.

  18. The opportunistic Sarcoptes scabiei: a new episode from giraffe in the drought-suffering Kenya.

    PubMed

    Alasaad, S; Ndeereh, D; Rossi, L; Bornstein, S; Permunian, R; Soriguer, R C; Gakuya, F

    2012-04-30

    The ubiquitous Sarcoptes mite is unexplainable emerging and re-emerging parasite, threatening biodiversity and human health. When a new outbreak occurs, it is not clear if it is a genuine emergence resulting from a new incidence or apparent emergence resulting from increased detection. In this paper we report, for the first time to our knowledge, an outbreak of sarcoptic mange in giraffes in the wild. Three decaying carcasses and five free-ranging subadult reticulated giraffes were observed to have mange-like lesions in the drought-suffering Wajir Region in North Eastern Kenya, while apparently all sympatric wild and domestic animals were mange-free. Affected giraffes were captured and successfully treated. The possible relations between this outbreak and annual seasons, animal age-classes and sex, and spatial distribution are discussed.

  19. Seroprevalences to Viral Pathogens in Free-Ranging and Captive Cheetahs (Acinonyx jubatus) on Namibian Farmland▿

    PubMed Central

    Thalwitzer, Susanne; Wachter, Bettina; Robert, Nadia; Wibbelt, Gudrun; Müller, Thomas; Lonzer, Johann; Meli, Marina L.; Bay, Gert; Hofer, Heribert; Lutz, Hans

    2010-01-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis. 40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts

  20. Serosurvey of viral infections in free-ranging Namibian cheetahs (Acinonyx jubatus).

    PubMed

    Munson, Linda; Marker, Laurie; Dubovi, Edward; Spencer, Jennifer A; Evermann, James F; O'Brien, Stephen J

    2004-01-01

    Cheetahs (Acinonyx jubatus) in captivity have unusually high morbidity and mortality from infectious diseases, a trait that could be an outcome of population homogeneity or the immunomodulating effects of chronic stress. Free-ranging Namibian cheetahs share ancestry with captive cheetahs, but their susceptibility to infectious diseases has not been investigated. The largest remaining population of free-ranging cheetahs resides on Namibian farmlands, where they share habitat with domestic dogs and cats known to carry viruses that affect cheetah health. To assess the extent to which free-ranging cheetahs are exposed to feline and canine viruses, sera from 81 free-ranging cheetahs sampled between 1992 and 1998 were evaluated for antibodies against canine distemper virus (CDV), feline coronavirus (feline infectious peritonitis virus; FCoV/ FIPV), feline herpesvirus 1 (FHV1), feline panleukopenia virus (FPV), feline immunodeficiency virus (FIV), and feline calicivirus (FCV) and for feline leukemia virus (FeLV) antigens. Antibodies against CDV, FCoV/FIPV, FHV1, FPV, and FCV were detected in 24, 29, 12, 48, and 65% of the free-ranging population, respectively, although no evidence of viral disease was present in any animal at the time of sample collection. Neither FIV antibodies nor FeLV antigens were present in any free-ranging cheetah tested. Temporal variation in FCoV/FIPV seroprevalence during the study period suggested that this virus is not endemic in the free-ranging population. Antibodies against CDV were detected in cheetahs of all ages sampled between 1995 and 1998, suggesting the occurrence of an epidemic in Namibia during the time when CDV swept through other parts of sub-Saharan Africa. This evidence in free-ranging Namibian cheetahs of exposure to viruses that cause severe disease in captive cheetahs should direct future guidelines for translocations, including quarantine of seropositive cheetahs and preventing contact between cheetahs and domestic pets.

  1. Seroprevalences to viral pathogens in free-ranging and captive cheetahs (Acinonyx jubatus) on Namibian Farmland.

    PubMed

    Thalwitzer, Susanne; Wachter, Bettina; Robert, Nadia; Wibbelt, Gudrun; Müller, Thomas; Lonzer, Johann; Meli, Marina L; Bay, Gert; Hofer, Heribert; Lutz, Hans

    2010-02-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis. 40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts.

  2. The Provision of a Health Promoting Environment for HIV/AIDS Education: The Case of Namibian Senior Secondary Schools

    ERIC Educational Resources Information Center

    Campbell, Bob; Lubben, Fred

    2003-01-01

    HIV/AIDS programmes in schools ultimately intend to decrease high risk sexual behaviour. One factor facilitating this outcome is a strong health promoting environment in the school. This paper reports a study surveying the health promoting environments supporting HIV/AIDS education in Namibian senior secondary schools. It develops a…

  3. Curriculum Review: Standing Tall. Teaching Guides for Kindergarten to Grade 12 from the Giraffe Project.

    ERIC Educational Resources Information Center

    Kuhmerker, Lisa

    1994-01-01

    Describes the development and content of teacher guides from The Giraffe Project, a social values and community service program. States that the teacher guides are available for grades K-2, 3-5, 6-9, and 10-12. Maintains that the materials would be appropriate for schools integrating a service component into the curriculum. (CFR)

  4. Attachment and sibling rivalry in Little Hans: the fantasy of the two giraffes revisited.

    PubMed

    Wakefield, Jerome C

    2007-01-01

    Freud's interpretation of Little Hans's "phantasy of the two giraffes" is pivotal to his oedipal analysis that Hans has inchoate desires for sexual intercourse with his mother. Bowlby argued that Freud's focus on his oedipal theory led him to ignore preoedipal attachment-related factors that have equal plausibility in explaining the clinical data. However, Bowlby did not attempt to apply the attachment perspective to the interpretation of Hans's fantasies that form the core of the case material. A microanalysis of Hans's giraffe fantasy and the evidence used to support Freud's claims about it yields an attachment-based sibling rivalry account arguably of greater explanatory power than the oedipal account. Consistent with Bowlby's hypothesis, the evidence suggests that Hans's giraffe fantasy is about the sibling rivalry triangle involved in caregiver attachment access, rather than (or in addition to) the oedipal triangle. The issue of multiple levels of meaning and the methodological challenges raised by multiple determination is also considered. The giraffe fantasy's attachment-theoretic explanation encourages a rethinking of this classic case and strengthens Bowlby's claim that the case is fruitfully viewed from an attachment perspective.

  5. Seasonal to interannual variability of water mass characteristics and currents on the Namibian shelf

    NASA Astrophysics Data System (ADS)

    Junker, Tim; Mohrholz, Volker; Siegfried, Lydia; van der Plas, Anja

    2017-01-01

    We present long-term current meter records from the Benguela system together with salinity and temperature observations gathered by a mooring on the Namibian shelf across 13 years (2002-2015). From this unique data set a climatological mean state is estimated enabling us to investigate seasonal to interannual variations of these variables on the Namibian shelf. The present study highlights the importance of the alongshore advection for the water mass characteristics in the Benguela system on a seasonal time scale. The annual cycle of the alongshore transport is characterized by a biannual flow reversal. Poleward directed currents dominate from October to April, and from May to September equatorward currents prevail. In addition, we present observational evidence for a biannual intrusion of tropical waters into the Benguela system with maxima in October and February. Based on the in situ temperature data, several anomalous events are described that affect the whole water column. During the outstanding warm event in austral fall 2011 the monthly temperature anomaly exceeds one Kelvin for five consecutive months peaking in March (2.4 K) in the upper layer of the water column. Our study suggests, that the occurrence of such extreme temperature events in the Benguela upwelling system is closely related to the strength of the alongshore advection in austral summer.

  6. Investigation of hydrogen sulphide eruptions along the Namibian coastline using different remote sensing systems

    NASA Astrophysics Data System (ADS)

    Ohde, Thomas

    2009-09-01

    Hydrogen sulphide eruptions with their typical turquoise discolorations at the water surface are a unique phenomenon along the Namibian coastline. The remote sensing techniques of ocean colour sensors and microwave scatterometers were used for the investigation of such events. The studies with ocean colour sensors showed that the turquoise discolorations near the Namibian coast were neither linked to dust deposition into the water column by desert storms nor to the reflection of bright material in shallow water areas. In addition, other coloured marine events like algae blooms and river outflows were differentiable from the hydrogen sulphide eruptions by their special optical properties. Quasi-true colour images and spectral identification methods were utilised to monitor and investigate the spatial and temporal distribution of sulphide events. In the past years, they were sometimes and locally limited discovered. Newest remote sensing observations including our own investigations have established that the occurrence of sulphide events is more frequent and longer lasting. The north-westerly direction of propagation and their velocity between 12 cm s-1 and 15 cm s1 were derived from an event on 14 April 2004. Lastly, the microwave scatterometer remote sensing was applied to investigate the relation of sulphide events to oceanographic conditions. The events from May 2004 were clearly related to strong coastal upwelling.

  7. Left ventricular morphology of the giraffe heart examined by stereological methods.

    PubMed

    Østergaard, Kristine H; Baandrup, Ulrik T; Wang, Tobias; Bertelsen, Mads F; Andersen, Johnnie B; Smerup, Morten; Nyengaard, Jens R

    2013-04-01

    The giraffe heart has a relative mass similar to other mammals, but generates twice the blood pressure to overcome the gravitational challenge of perfusing the cerebral circulation. To provide insight as to how the giraffe left ventricle (LV) is structurally adapted to tackle such a high afterload, we performed a quantitative structural study of the LV myocardium in young and adult giraffe hearts. Tissue samples were collected from young and adult giraffe LV. Design-based stereology was used to obtain unbiased estimates of numbers and sizes of cardiomyocytes, nuclei and capillaries. The numerical density of myocyte nuclei was 120 × 10(3) mm(-3) in the adult and 504 × 10(3) mm(-3) in the young LV. The total number (N) of myocyte nuclei was 1.3 × 10(11) in the adult LV and 4.9 × 10(10) in the young LV. In the adult LV the volume per myocyte was 39.5 × 10(3) µm(3) and the number of nuclei per myocyte was 4.2. The numerical density of myocytes was 24.1 × 10(6) cm(-3) and the capillary volume fraction of the adult giraffe ventricle was 0.054. The significantly higher total number of myocyte nuclei in the adult LV, the high density of myocyte nuclei in the LV, and the number of nuclei per myocyte (which was unusually high compared to other mammalian, including human data), all suggest the presence of myocyte proliferation during growth of the animal to increase wall thickness and normalize LV wall tension as the neck lengthens and the need for higher blood pressure ensues.

  8. A baseline study of metal contamination along the Namibian coastline for Perna perna and Choromytilus meridionalis.

    PubMed

    Dahms, S; van der Bank, F H; Greenfield, R

    2014-08-15

    The use of bivalves such as the brown mussel (Perna perna) and the black mussel (Choromytilus meridionalis) is common in the study of marine pollution and the effect of these pollutants on ecosystems and are important in both economic and ecological roles. Namibian marine ecosystems are threatened by pollution from mining, commercial fishing and population growth. The aims of this study were to determine baseline metal concentrations, spatial variation and variation between species. Metal levels in C. meridionalis from Guano Platform (GP) are the lowest of all the sites. The most polluted sites are Rocky Point (RP), Halifax Island (HIL) and between Walvis Bay and Swakopmund (WS). The bioaccumulation of metals between P. perna and C. meridionalis were not uniform for all metals. Overall the study indicates the condition of the coastline to be mostly normal, with Cd and Pb levels being of concern.

  9. Ejaculate traits in the Namibian cheetah (Acinonyx jubatus): influence of age, season and captivity.

    PubMed

    Crosier, Adrienne E; Marker, Laurie; Howard, JoGayle; Pukazhenthi, Budhan S; Henghali, Josephine N; Wildt, David E

    2007-01-01

    The objective was to examine the influence of animal age, season and captivity status on seminal quality in wild-born cheetahs (Acinonyx jubatus) in Namibia, Africa. Animals were divided into three age categories: juvenile (14-24 months; n = 16 males, 23 ejaculates); adult (25-120 months; n = 76 males, 172 ejaculates); and aged (>120 months; n = 5 males, 5 ejaculates). Seasons were categorised into hot-wet (January-April), cold-dry (May-August) and hot-dry (September-December). A comparison between freshly wild-caught (n = 29 males, 41 ejaculates) and captive-held cheetahs (n = 68 males, 159 ejaculates) was also conducted. Raw ejaculates contained 69.0 +/- 1.1% motile spermatozoa (mean +/- s.e.m.) with 73.6 +/- 1.5% of these cells containing an intact acrosome. Overall, 18.4 +/- 0.9% of spermatozoa were morphologically normal, with midpiece anomalies being the most prevalent (approximately 39%) defect. Juvenile cheetahs produced ejaculates with poorer sperm motility, forward progressive status, lower seminal volume and fewer total motile spermatozoa than adult and aged animals. Spermatogenesis continued unabated throughout the year and was minimally influenced by season. Proportions of sperm malformations were also not affected by season. Ejaculates from captive cheetahs had increased volume and intact acrosomes, but lower sperm density than wild-caught counterparts. In summary, Namibian cheetahs produce an extraordinarily high proportion of pleiomorphic spermatozoa regardless of age, season or living (captive versus free-ranging) status. Young males less than 2 years of age produce poorer ejaculate quality than adult and aged males. Because (1) all study animals were wild born and (2) there was little difference between freshly caught males and those maintained in captivity for protracted periods, our results affirm that teratospermia in the cheetah is mostly genetically derived. It also appears that an ex situ environment for the Namibian cheetah can ensure sperm

  10. Primary structure of pronghorn pancreatic ribonuclease: close relationship between giraffe and pronghorn.

    PubMed

    Beintema, J J; Gaastra, W; Munniksma, J

    1979-11-01

    Pancreatic ribonuclease from pronghorn (Antilocapra americana) was isolated and its amino acid sequence was determined from a tryptic digest of the performic acid-oxidized protein. Peptides were positioned by homology with other ribonucleases. Only peptides that differed in amino acid composition from the corresponding peptides of ox or goat ribonucleases were sequenced. In a most parsimonius tree of pancreatic ribonucleases, pronghorn and giraffe were placed together and these two were placed with the bovids, leaving the deer as a taxon separate from the other ruminants. The amino acid replacements that determine this tree topology are three rarely occurring replacements shared by pronghorn and giraffe. Notwithstanding their close phylogenetic relationship, both ribonucleases differ strongly in extent of glycosidation, net charge and antigenic properties.

  11. Of Caucasians, Asians, and Giraffes: The Influence of Categorization and Target Valence on Social Projection.

    PubMed

    Machunsky, Maya; Walther, Eva

    2015-09-01

    Past research has indicated that social projection is moderated by categorization, with more projection onto ingroups than onto outgroups. However, a few studies have reported elevated levels of projection even onto outgroups. In line with recent evidence, we hypothesized that positive target valence is the key feature of conditions that elicit projection onto outgroups. The present research extends previous findings by testing whether the effect of valence occurs independent of categorization, with increased levels of projection onto positive ingroup and non-ingroup targets alike. We designed two experiments in which target valence was manipulated by means of evaluative conditioning. Category membership was varied by using faces of Caucasians, Asians, and giraffes. The results supported our valence hypothesis. Counter-intuitively, we also found higher levels of projection onto giraffes than onto humans. These findings suggest that current cognition-based models of projection are not sufficient to account for the whole range of projection phenomena.

  12. VizieR Online Data Catalog: GIRAFFE Inner Bulge Survey (GIBS). I. (Zoccali+, 2014)

    NASA Astrophysics Data System (ADS)

    Zoccali, M.; Gonzalez, O. A.; Vasquez, S.; Hill, V.; Rejkuba, M.; Valenti, E.; Renzini, A.; Rojas-Arriagada, A.; Martinez-Valpuesta, I.; Babusiaux, C.; Brown, T.; Minniti, D.; McWilliam, A.

    2014-01-01

    Spectra for the selected targets have been collected with the GIRAFFE spectrograph fed by MEDUSA fibres (in some cases the observations were taken in the combined UVES+MEDUSA mode) of the FLAMES multi-fibre instrument at the ESO Very Large Telescope, between May 2011 and September 2012. Observations were carried out in service mode under programme 187.B-0909(A) and 187.B-0909(B), PI: Zoccali. (2 data files).

  13. Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe.

    PubMed

    Brøndum, E; Hasenkam, J M; Secher, N H; Bertelsen, M F; Grøndahl, C; Petersen, K K; Buhl, R; Aalkjaer, C; Baandrup, U; Nygaard, H; Smerup, M; Stegmann, F; Sloth, E; Ostergaard, K H; Nissen, P; Runge, M; Pitsillides, K; Wang, T

    2009-10-01

    How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended in the upright position so that we could lower the head. In the upright position, mean arterial pressure (MAP) was 193 +/- 11 mmHg (mean +/- SE), carotid flow was 0.7 +/- 0.2 l/min, and carotid cross-sectional area was 0.85 +/- 0.04 cm(2). Central venous pressure (CVP) was 4 +/- 2 mmHg, jugular flow was 0.7 +/- 0.2 l/min, and jugular cross-sectional area was 0.14 +/- 0.04 cm(2) (n = 4). Carotid arterial and jugular venous pressures at head level were 118 +/- 9 and -7 +/- 4 mmHg, respectively. When the head was lowered, MAP decreased to 131 +/- 13 mmHg, while carotid cross-sectional area and flow remained unchanged. Cardiac output was reduced by 30%, CVP decreased to -1 +/- 2 mmHg (P < 0.01), and jugular flow ceased as the jugular cross-sectional area increased to 3.2 +/- 0.6 cm(2) (P < 0.01), corresponding to accumulation of approximately 1.2 l of blood in the veins. When the head was raised, the jugular veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head is lowered, blood accumulates in the vein, affecting MAP.

  14. The control data "GIRAFFE" system for interactive graphic finite element analysis

    NASA Technical Reports Server (NTRS)

    Park, S.; Brandon, D. M., Jr.

    1975-01-01

    The Graphical Interface for Finite Elements (GIRAFFE) general purpose interactive graphics application package was described. This system may be used as a pre/post processor for structural analysis computer programs. It facilitates the operations of creating, editing, or reviewing all the structural input/output data on a graphics terminal in a time-sharing mode of operation. An application program for a simple three-dimensional plate problem was illustrated.

  15. Pressure profile and morphology of the arteries along the giraffe limb.

    PubMed

    Østergaard, Kristine Hovkjaer; Bertelsen, Mads F; Brøndum, Emil T; Aalkjaer, Christian; Hasenkam, J Michael; Smerup, Morten; Wang, Tobias; Nyengaard, Jens Randel; Baandrup, Ulrik

    2011-07-01

    Giraffes are the tallest animals on earth and the effects of gravity on their cardiovascular system have puzzled physiologists for centuries. The authors measured arterial and venous pressure in the foreleg of anesthetized giraffes, suspended in upright standing position, and determined the ratio between tunica media and lumen areas along the length of the femoral/tibial arteries in the hindleg. Volume fraction of elastin, density of vasa vasorum and innervations was estimated by stereology. Immunohistological staining with S100 was used to examine the innervation. The pressure increase in the artery and vein along the foreleg was not significantly different from what was expected on basis of gravity. The area of the arterial lumen in the hindleg decreased towards the hoof from 11.2 ± 4.2 to 0.6 ± 0.5 mm(2) (n = 10, P = 0.001), but most of this narrowing occurred within 2-4 cm immediately below the knee. This abrupt narrowing was associated with a marked increase in media to lumen area ratio (from 1.2 ± 0.5 to 7.8 ± 2.5; P = 0.001), and a decrease in mean volume fraction of elastin from 38 ± 6% proximal to the narrowing to 5.8 ± 1.1% distally (P = 0.001). The narrowing had a six-fold higher innervation density than the immediate distal and proximal regions. The sudden narrowing was also observed in the hind legs of neonates, indicating that it does not develop as an adaptation to the high transmural pressure in the standing giraffe. More likely it represents a preadaptation to the high pressures experienced by adult giraffes.

  16. Winning by a neck: tall giraffes avoid competing with shorter browsers.

    PubMed

    Cameron, Elissa Z; du Toit, Johan T

    2007-01-01

    With their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. They ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. We erected exclosures around individual Acacia nigrescens trees in the greater Kruger ecosystem, South Africa. After a complete growing season, we found no differences in leaf biomass per shoot across height zones in excluded trees but significant differences in control trees. We conclude that giraffes preferentially browse at high levels in the canopy to avoid competition with smaller browsers. Our findings are analogous with those from studies of grazing guilds and demonstrate that resource partitioning can be driven by competition when smaller foragers displace larger foragers from shared resources. This provides the first experimental support for the classic evolutionary hypothesis that vertical elongation of the giraffe body is an outcome of competition within the browsing ungulate guild.

  17. Why sauropods had long necks; and why giraffes have short necks.

    PubMed

    Taylor, Michael P; Wedel, Mathew J

    2013-01-01

    The necks of the sauropod dinosaurs reached 15 m in length: six times longer than that of the world record giraffe and five times longer than those of all other terrestrial animals. Several anatomical features enabled this extreme elongation, including: absolutely large body size and quadrupedal stance providing a stable platform for a long neck; a small, light head that did not orally process food; cervical vertebrae that were both numerous and individually elongate; an efficient air-sac-based respiratory system; and distinctive cervical architecture. Relevant features of sauropod cervical vertebrae include: pneumatic chambers that enabled the bone to be positioned in a mechanically efficient way within the envelope; and muscular attachments of varying importance to the neural spines, epipophyses and cervical ribs. Other long-necked tetrapods lacked important features of sauropods, preventing the evolution of longer necks: for example, giraffes have relatively small torsos and large, heavy heads, share the usual mammalian constraint of only seven cervical vertebrae, and lack an air-sac system and pneumatic bones. Among non-sauropods, their saurischian relatives the theropod dinosaurs seem to have been best placed to evolve long necks, and indeed their necks probably surpassed those of giraffes. But 150 million years of evolution did not suffice for them to exceed a relatively modest 2.5 m.

  18. Case Studies in Physiology: Ventilation and perfusion in a giraffe-does size matter?

    PubMed

    Nyman, Görel; Röken, Bengt; Hedin, Eva-Maria; Hedenstierna, Göran

    2016-12-01

    The trachea in the giraffe is long but narrow, and dead space ventilation is considered to be of approximately the same size as in other mammals. Less is known about the matching between ventilation and lung blood flow. The lungs in the giraffe are large, up to 1 m high and 0.7 m wide, and this may cause considerable ventilation/perfusion (VA/Q) mismatch due to the influence of gravitational forces, which could lead to hypoxemia. We studied a young giraffe under anesthesia using the multiple inert gas elimination technique to analyze the VA/Q distribution and arterial oxygenation and compared the results with those obtained in other species of different sizes, including humans. VA/Q distribution was broad but unimodal, and the shunt of blood flow through nonventilated lung regions was essentially absent, suggesting no lung collapse. The VA/Q match was as good as in the similarly sized horse and was even comparable to that in smaller sized animals, including rabbit and rat. The match was also similar to that in anesthetized humans. Arterial oxygenation was essentially similar in all studied species. The findings suggest that the efficiency of VA/Q matching is independent of lung size in the studied mammals that vary in weight from less than 1 to more than 400 kg.

  19. Why sauropods had long necks; and why giraffes have short necks

    PubMed Central

    Wedel, Mathew J.

    2013-01-01

    The necks of the sauropod dinosaurs reached 15 m in length: six times longer than that of the world record giraffe and five times longer than those of all other terrestrial animals. Several anatomical features enabled this extreme elongation, including: absolutely large body size and quadrupedal stance providing a stable platform for a long neck; a small, light head that did not orally process food; cervical vertebrae that were both numerous and individually elongate; an efficient air-sac-based respiratory system; and distinctive cervical architecture. Relevant features of sauropod cervical vertebrae include: pneumatic chambers that enabled the bone to be positioned in a mechanically efficient way within the envelope; and muscular attachments of varying importance to the neural spines, epipophyses and cervical ribs. Other long-necked tetrapods lacked important features of sauropods, preventing the evolution of longer necks: for example, giraffes have relatively small torsos and large, heavy heads, share the usual mammalian constraint of only seven cervical vertebrae, and lack an air-sac system and pneumatic bones. Among non-sauropods, their saurischian relatives the theropod dinosaurs seem to have been best placed to evolve long necks, and indeed their necks probably surpassed those of giraffes. But 150 million years of evolution did not suffice for them to exceed a relatively modest 2.5 m. PMID:23638372

  20. Organization of cholinergic, putative catecholaminergic and serotonergic nuclei in the diencephalon, midbrain and pons of sub-adult male giraffes.

    PubMed

    Bux, Faiza; Bhagwandin, Adhil; Fuxe, Kjell; Manger, Paul R

    2010-05-01

    The current study describes the nuclear organization and neuronal morphology of the cholinergic, putative catecholaminergic and serotonergic systems within the diencephalon, midbrain and pons of the giraffe using immunohistochemistry for choline acetyltransferase, tyrosine hydroxylase and serotonin. The giraffe has a unique phenotype (the long neck), a large brain (over 500 g) and is a non-domesticated animal, while previous studies examining the brains of other Artiodactyls have all been undertaken on domesticated animals. The aim of the present study was to investigate possible differences in the nuclear organization and neuronal morphology of the above-mentioned systems compared to that seen in other Artiodactyls and mammals. The nuclear organization of all three systems within the giraffe brain was similar to that of other Artiodactyls. Some features of interest were noted for the giraffe and in comparison to other mammals studied. The cholinergic neuronal somata of the laterodorsal tegmental nucleus were slightly larger than those of the pedunculopontine tegmental nucleus, a feature not described in other mammals. The putative catecholaminergic system of the giraffe appeared to lack an A15 dorsal nucleus, which is commonly seen in other mammals but absent in the Artiodactyls, had a large and expanded substantia nigra pars reticulata (A9 ventral), a small diffuse portion of the locus coerueleus (A6d), an expansive subcoeruleus (A7sc and A7d), and lacked the A4 nucleus of the locus coeruleus complex. The nuclear organization of the serotonergic system of the giraffe was identical to that seen in all other eutherian mammals studied to date. These observations in the giraffe demonstrate that despite significant changes in life history, phenotype, brain size and time of divergence, species within the same order show the same nuclear organization of the systems investigated.

  1. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    PubMed

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

    2016-02-01

    Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output.

  2. Remote camera-trap methods and analyses reveal impacts of rangeland management on Namibian carnivore communities

    USGS Publications Warehouse

    Kauffman, M.J.; Sanjayan, M.; Lowenstein, J.; Nelson, A.; Jeo, R.M.; Crooks, K.R.

    2007-01-01

    Assessing the abundance and distribution of mammalian carnivores is vital for understanding their ecology and providing for their long-term conservation. Because of the difficulty of trapping and handling carnivores many studies have relied on abundance indices that may not accurately reflect real abundance and distribution patterns. We developed statistical analyses that detect spatial correlation in visitation data from combined scent station and camera-trap surveys, and we illustrate how to use such data to make inferences about changes in carnivore assemblages. As a case study we compared the carnivore communities of adjacent communal and freehold rangelands in central Namibia. We used an index of overdispersion to test for repeat visits to individual camera-trap scent stations and a bootstrap simulation to test for correlations in visits to camera neighbourhoods. After distilling our presence-absence data to the most defensible spatial scale, we assessed overall carnivore visitation using logistic regression. Our analyses confirmed the expected pattern of a depauparate fauna on the communal rangelands compared to the freehold rangelands. Additionally, the species that were not detected on communal sites were the larger-bodied carnivores. By modelling these rare visits as a Poisson process we illustrate a method of inferring whether or not such patterns are because of local extinction of species or are simply a result of low sample effort. Our Namibian case study indicates that these field methods and analyses can detect meaningful differences in the carnivore communities brought about by anthropogenic influences. ?? 2007 FFI.

  3. Theory and use of GIRAFFE for analysis of decay characteristics of delayed-neutron precursors in an LMFBR

    SciTech Connect

    Gross, K. C.

    1980-07-01

    The application of the computer code GIRAFFE (General Isotope Release Analysis For Failed Elements) written in FORTRAN IV is described. GIRAFFE was designed to provide parameter estimates of the nonlinear discrete-measurement models that govern the transport and decay of delayed-neutron precursors in a liquid-metal fast breeder reactor (LMFBR). The code has been organized into a set of small, relatively independent and well-defined modules to facilitate modification and maintenance. The program logic, the numerical techniques, and the methods of solution used by the code are presented, and the functions of the MAIN program and of each subroutine are discussed.

  4. Harvey Cushing and the regulation of blood pressure in giraffe, rat and man: introducing 'Cushing's mechanism'.

    PubMed

    Paton, J F R; Dickinson, C J; Mitchell, G

    2009-01-01

    The fundamental mechanism that underlies essential hypertension is a high total peripheral resistance. We review here possible origins of high total peripheral resistance in physiologically hypertensive giraffes, spontaneously hypertensive rats and humans with essential hypertension. We propose that a common link could be reduced brainstem perfusion, as first suggested by Cushing in 1901. Any tendency towards reduction of cerebral blood flow to the cardiovascular control centres in rest and sleep will be prevented by activation of a response arising in the brainstem. The response will proportionately increase systemic blood pressure and return cerebral blood flow to a new homeostatic level. New evidence we review here supports this idea and leads us to suggest that central regulation of blood pressure has two components: the classic Cushing's response, which is a terminal event, and a Cushing's mechanism, which is a physiological mechanism for long-term control of mean arterial pressure. In giraffes, Cushing's mechanism is activated by increasing neck length during growth and subsequent gravitational hypotension that stimulates a rise in basal arterial blood pressure. In man and rats, the mechanism is activated by narrowing of the arteries supplying the brainstem. If we are correct, future successful treatment of essential hypertension in man will include methods of reducing cerebral arterial resistance.

  5. Gammaretrovirus-Specific Antibodies in Free-Ranging and Captive Namibian Cheetahs

    PubMed Central

    Krengel, Annika; Cattori, Valentino; Meli, Marina L.; Wachter, Bettina; Böni, Jürg; Bisset, Leslie R.; Thalwitzer, Susanne; Melzheimer, Jörg; Jago, Mark; Hofmann-Lehmann, Regina; Hofer, Heribert

    2015-01-01

    The cheetah population in Namibia is the largest free-ranging population in the world and a key population for research regarding the health status of this species. We used serological methods and quantitative real-time PCR to test free-ranging and captive Namibian cheetahs for the presence of feline leukemia virus (FeLV), a gammaretrovirus that can be highly aggressive in populations with low genetic diversity, such as cheetahs. We also assessed the presence of antibodies to other gammaretroviruses and the responses to a FeLV vaccine developed for domestic cats. Up to 19% of the free-ranging cheetahs, 27% of the captive nonvaccinated cheetahs, and 86% of the captive vaccinated cheetahs tested positive for FeLV antibodies. FeLV-antibody-positive free-ranging cheetahs also tested positive for Rauscher murine leukemia virus antibodies. Nevertheless, FeLV was not detectable by quantitative real-time PCR and no reverse transcriptase activity was detectable by product-enhanced reverse transcriptase assay in the plasma of cheetahs or the supernatants from cultures of peripheral blood mononuclear cells. The presence of antibodies to gammaretroviruses in clinically healthy specimens may be caused either by infection with a low-pathogenic retrovirus or by the expression of endogenous retroviral sequences. The strong humoral immune responses to FeLV vaccination demonstrate that cheetahs can respond to the vaccine and that vaccination against FeLV infection may be beneficial should FeLV infection ever become a threat, as was seen in Iberian lynx and Florida panthers. PMID:25809630

  6. Are Namibian “Fairy Circles” the Consequence of Self-Organizing Spatial Vegetation Patterning?

    PubMed Central

    Cramer, Michael D.; Barger, Nichole N.

    2013-01-01

    Causes of over-dispersed barren “fairy circles” that are often surrounded by ca. 0.5 m tall peripheral grasses in a matrix of shorter (ca. 0.2 m tall) grasses in Namibian grasslands remain mysterious. It was hypothesized that the fairy circles are the consequence of self-organizing spatial vegetation patterning arising from resource competition and facilitation. We examined the edaphic properties of fairy circles and variation in fairy circle size, density and landscape occupancy (% land surface) with edaphic properties and water availability at a local scale (<50 km) and with climate and vegetation characteristics at a regional scale. Soil moisture in the barren fairy circles declines from the center towards the periphery and is inversely correlated with soil organic carbon, possibly indicating that the peripheral grass roots access soil moisture that persists into the dry season within fairy circles. Fairy circle landscape occupancy is negatively correlated with precipitation and soil [N], consistent with fairy circles being the product of resource-competition. Regional fairy circle presence/absence is highly predictable using an empirical model that includes narrow ranges of vegetation biomass, precipitation and temperature seasonality as predictor variables, indicating that fairy circles are likely a climate-dependent emergent phenomenon. This dependence of fairy circle occurrence on climate explains why fairy circles in some locations may appear and disappear over time. Fairy circles are only over-dispersed at high landscape occupancies, indicating that inter-circle competition may determine their spacing. We conclude that fairy circles are likely to be an emergent arid-grassland phenomenon that forms as a consequence of peripheral grass resource-competition and that the consequent barren circle may provide a resource-reservoir essential for the survival of the larger peripheral grasses and provides a habitat for fossicking fauna. PMID:23976962

  7. Nitrogen utilization by phytoplankton in the Namibian upwelling region during an austral spring

    NASA Astrophysics Data System (ADS)

    Probyn, Trevor A.

    1988-08-01

    The uptake of NO 3-, NH 4+ and urea by phytoplankton populations was investigated off the Namibian coastline between 20° and 26°30'S during the spring, 1985. The region was characterized by intense upwelling with resultant penetration of high nutrient concentrations into adjacent oceanic waters. In spite of the high ambient NO 3- concentrations, nitrogen was taken up primarily as NH 4+ and urea in accordance with phytoplankton preference. Measured f-ratios (NO 3- uptake/total nitrogen uptake) were correspondingly lower than expected, with a mean value of 0.32. Ratios calculated from integrated data for the photic zone ( f'-ratio) proved to be positively correlated with phytoplankton biomass (Chl α) and production. Factors such as NO 3- concentration, light, temperature and recycled nutrient concentration were considered as potential influences on the f-ratio. No obvious relationship was evident between f-ratios and either NO 3- concentrations or concentration ratios. Temperature (mean upper mixed layer) was well correlated with nutrient uptake but not with the f-ratio. Temperature coefficients θ10) were considerably larger than expected, suggesting control of nutrient uptake by factors other than temperature. Light limitation, though probably influencing individual depth profiles of f-ratios, could not explain inter-station variability in f'-ratio, however, was negatively affected by increasing concentrations of recycled nutrients both for discrete depths and for depth-integrated values. It is proposed that the high nutrient and low chlorophyll conditions that prevailed over much of the region were the result of an inhibition of phytoplankton bloom development by zooplankton grazing and deep mixing. The nitrogen excretory products of zooplankton (NH 4+ and urea) in turn were preferentially utilized by phytoplankton with the resultant suppression of NO 3- uptake, explaining the low measured f-ratios.

  8. Gammaretrovirus-specific antibodies in free-ranging and captive Namibian cheetahs.

    PubMed

    Krengel, Annika; Cattori, Valentino; Meli, Marina L; Wachter, Bettina; Böni, Jürg; Bisset, Leslie R; Thalwitzer, Susanne; Melzheimer, Jörg; Jago, Mark; Hofmann-Lehmann, Regina; Hofer, Heribert; Lutz, Hans

    2015-06-01

    The cheetah population in Namibia is the largest free-ranging population in the world and a key population for research regarding the health status of this species. We used serological methods and quantitative real-time PCR to test free-ranging and captive Namibian cheetahs for the presence of feline leukemia virus (FeLV), a gammaretrovirus that can be highly aggressive in populations with low genetic diversity, such as cheetahs. We also assessed the presence of antibodies to other gammaretroviruses and the responses to a FeLV vaccine developed for domestic cats. Up to 19% of the free-ranging cheetahs, 27% of the captive nonvaccinated cheetahs, and 86% of the captive vaccinated cheetahs tested positive for FeLV antibodies. FeLV-antibody-positive free-ranging cheetahs also tested positive for Rauscher murine leukemia virus antibodies. Nevertheless, FeLV was not detectable by quantitative real-time PCR and no reverse transcriptase activity was detectable by product-enhanced reverse transcriptase assay in the plasma of cheetahs or the supernatants from cultures of peripheral blood mononuclear cells. The presence of antibodies to gammaretroviruses in clinically healthy specimens may be caused either by infection with a low-pathogenic retrovirus or by the expression of endogenous retroviral sequences. The strong humoral immune responses to FeLV vaccination demonstrate that cheetahs can respond to the vaccine and that vaccination against FeLV infection may be beneficial should FeLV infection ever become a threat, as was seen in Iberian lynx and Florida panthers.

  9. Genetic Diversity of Namibian Pennisetum glaucum (L.) R. BR. (Pearl Millet) Landraces Analyzed by SSR and Morphological Markers

    PubMed Central

    McBenedict, Billy; Chimwamurombe, Percy; Kwembeya, Ezekeil; Maggs-Kölling, Gillian

    2016-01-01

    Current Pennisetum glaucum (L.) R. BR. cultivars in Namibia have overall poor performance posing a threat to the nation's food security because this crop is staple for over 70% of the Namibian population. The crop suffers from undesirable production traits such as susceptibility to diseases, low yield, and prolonged reproductive cycle. This study aimed to understand the genetic diversity of the crop in Namibia by simple sequence repeats (SSRs) and morphology analysis. A total of 1441 genotypes were collected from the National Gene Bank representing all the Namibian landraces. A sample of 96 genotypes was further analyzed by SSR using Shannon-Wiener diversity index and revealed a value of 0.45 indicating low genetic diversity. Ordination using Principal Coordinate Analysis (PCoA) on SSR data confirmed clusters generated by UPGMA for the 96 P. glaucum accessions. UPGMA phenograms of 29 morphological characterized genotypes were generated for SSR and morphology data and the two trees revealed 78% resemblance. Lodging susceptibility, tillering attitude, spike density, fodder yield potential, early vigour, and spike shape were the phenotypic characters upon which some clusters were based in both datasets. It is recommended that efforts should be made to widen the current gene pool in Namibia. PMID:27433479

  10. Improved variability classification of CoRoT targets with Giraffe spectra

    NASA Astrophysics Data System (ADS)

    Sarro, L. M.; Debosscher, J.; Neiner, C.; Bello-García, A.; González-Marcos, A.; Prendes-Gero, B.; Ordieres, J.; León, G.; Aerts, C.; de Batz, B.

    2013-02-01

    Aims: We present an improved method for automated stellar variability classification, using fundamental parameters derived from high resolution spectra, with the goal to improve the variability classification obtained using information derived from CoRoT light curves only. Although we focus on Giraffe spectra and CoRoT light curves in this work, the methods are much more widely applicable. Methods: In order to improve the variability classification obtained from the photometric time series, only rough estimates of the stellar physical parameters (Teff and log (g)) are needed because most variability types that overlap in the space of time series parameters, are well separated in the space of physical parameters (e.g. γ Dor/SPB or δ Sct/β Cep). In this work, several state-of-the-art machine learning techniques are combined to estimate these fundamental parameters from high resolution Giraffe spectra. Next, these parameters are used in a multi-stage Gaussian-Mixture classifier to perform an improved supervised variability classification of CoRoT light curves. The variability classifier can be used independently of the regression module that estimates the physical parameters, so that non-spectroscopic estimates derived e.g. from photometric colour indices can be used instead. Results: Teff and log (g) are derived from Giraffe spectra, for 6832 CoRoT targets. The use of those parameters in addition to information extracted from the CoRoT light curves, significantly improves the results of our previous automated stellar variability classification. Several new pulsating stars are identified with high confidence levels, including hot pulsators such as SPB and β Cep, and several γ Dor-δ Sct hybrids. From our samples of new γ Dor and δ Sct stars, we find strong indications that the instability domains for both types of pulsators are larger than previously thought. The CoRoT space mission, launched on 27 December 2006, has been developed and is operated by CNES, with

  11. Identification and investigation of sulphur plumes along the Namibian coast using the MERIS sensor

    NASA Astrophysics Data System (ADS)

    Ohde, Thomas; Siegel, Herbert; Reißmann, Jan; Gerth, Monika

    2007-03-01

    In the upwelling area along the Namibian coast of SW-Africa sulphur discolorations were investigated to study the impact of hydrogen sulphide on the ecosystem using satellite imagery. The formation of colloidal sulphur in the upper water layer results from the oxidation of hydrogen sulphide. The occurrence of sulphur plumes as well as their temporal and spatial development was investigated in relation to the driving meteorological and oceanographic conditions. Because of the sporadic occurrence of sulphur events and the limited number of ship-borne investigations in that area remote sensing of ocean colour is the only method to follow these phenomena continuously and synoptically. In the past the sulphur plumes were studied by true colour images derived from ocean colour satellite data like sea-viewing wide field of view sensor or moderate resolution imaging spectroradiometer and identified by their typical milky turquoise discoloration. For the first time, medium resolution imaging spectrometer (MERIS) reduced resolution Level-2 products were applied to identify sulphur discoloration in the surface water off Namibia. Based on their high spectral resolution typical spectral water-leaving reflectances were identified for sulphur enriched waters and distinguished from other optical water types dominated by absorbing or scattering phytoplankton groups and suspended matter. This was the basis for the development of a classification algorithm for the identification of sulphur plumes. This algorithm was derived on available MERIS scenes from the first half of the year 2004 and extended to summer 2005 to study the occurrence, the temporal and spatial development, the extension, and the strength of such events as well as inter-annual differences in these years. Only near-shore sulphur occurrences were identified in the considered time period compared to other studies. A lifetime of sulphur patches between 1 and 6 days and a zonal extent of up to 21 km were determined. The

  12. Simulating magnetospheres with numerical relativity: The GiRaFFE code

    NASA Astrophysics Data System (ADS)

    Babiuc-Hamilton, Maria; Etienne, Zach

    2016-01-01

    Numerical Relativity has shown success over the past several years, especially in the simulation of black holes and gravitational waves. In recent years, teams have tackled the problem of the interaction of gravitational and electromagnetic waves. But where there are plasmas, the simulations often have trouble reproducing nature. Neutron stars, black hole accretion disks, astrophysical jets—all of these represent extreme environments both gravitationally and electromagnetically. We are creating the first open-source, dynamical spacetime general relativity force-free electrodynamics code: GiRaFFE.We present here the performance of GiRaFFE in testing. With this code, we will simulate neutron star magnetospheres, collisions between neutron stars and black holes, and particular attention will be paid to the production of jets through the Blandford-Znajek mechanism.GiRaFFE will be made available to the community.

  13. Complete genomic sequence analyses of the first group A giraffe rotavirus reveals close evolutionary relationship with rotaviruses infecting other members of the Artiodactyla.

    PubMed

    O'Shea, Helen; Mulherin, Emily; Matthijnssens, Jelle; McCusker, Matthew P; Collins, P J; Cashman, Olivia; Gunn, Lynda; Beltman, Marijke E; Fanning, Séamus

    2014-05-14

    Group A Rotaviruses (RVA) have been established as significant contributory agents of acute gastroenteritis in young children and many animal species. In 2008, we described the first RVA strain detected in a giraffe calf (RVA/Giraffe-wt/IRL/GirRV/2008/G10P[11]), presenting with acute diarrhoea. Molecular characterisation of the VP7 and VP4 genes revealed the bovine-like genotypes G10 and P[11], respectively. To further investigate the origin of this giraffe RVA strain, the 9 remaining gene segments were sequenced and analysed, revealing the following genotype constellation: G10-P[11]-I2-R2-C2-M2-A3-N2-T6-E2-H3. This genotype constellation is very similar to RVA strains isolated from cattle or other members of the artiodactyls. Phylogenetic analyses confirmed the close relationship between GirRV and RVA strains with a bovine-like genotype constellation detected from several host species, including humans. These results suggest that RVA strain GirRV was the result of an interspecies transmission from a bovine host to the giraffe calf. However, we cannot rule out completely that this bovine-like RVA genotype constellation may be enzootic in giraffes. Future RVA surveillance in giraffes may answer this intriguing question.

  14. Exaggerated Trait Allometry, Compensation and Trade-Offs in the New Zealand Giraffe Weevil (Lasiorhynchus barbicornis)

    PubMed Central

    Painting, Christina. J.; Holwell, Gregory I.

    2013-01-01

    Sexual selection has driven the evolution of exaggerated traits among diverse animal taxa. The production of exaggerated traits can come at a cost to other traits through trade-offs when resources allocated to trait development are limited. Alternatively some traits can be selected for in parallel to support or compensate for the cost of bearing the exaggerated trait. Male giraffe weevils (Lasiorhynchus barbicornis) display an extremely elongated rostrum used as a weapon during contests for mates. Here we characterise the scaling relationship between rostrum and body size and show that males have a steep positive allometry, but that the slope is non-linear due to a relative reduction in rostrum length for the largest males, suggesting a limitation in resource allocation or a diminishing requirement for large males to invest increasingly into larger rostra. We also measured testes, wings, antennae, fore- and hind-tibia size and found no evidence of a trade-off between these traits and rostrum length when comparing phenotypic correlations. However, the relative length of wings, antennae, fore- and hind-tibia all increased with relative rostrum length suggesting these traits may be under correlational selection. Increased investment in wing and leg length is therefore likely to compensate for the costs of flying with, and wielding the exaggerated rostrum of larger male giraffe weevils. These results provide a first step in identifying the potential for trait compensation and trades-offs, but are phenotypic correlations only and should be interpreted with care in the absence of breeding experiments. PMID:24312425

  15. Potential interactions of particle-associated anammox bacteria with bacterial and archaeal partners in the Namibian upwelling system.

    PubMed

    Woebken, Dagmar; Fuchs, Bernhard M; Kuypers, Marcel M M; Amann, Rudolf

    2007-07-01

    Recent studies have shown that the anaerobic oxidation of ammonium by anammox bacteria plays an important role in catalyzing the loss of nitrogen from marine oxygen minimum zones (OMZ). However, in situ oxygen concentrations of up to 25 microM and ammonium concentrations close to or below the detection limit in the layer of anammox activity are hard to reconcile with the current knowledge of the physiology of anammox bacteria. We therefore investigated samples from the Namibian OMZ by comparative 16S rRNA gene analysis and fluorescence in situ hybridization. Our results showed that "Candidatus Scalindua" spp., the typical marine anammox bacteria, colonized microscopic particles that were likely the remains of either macroscopic marine snow particles or resuspended particles. These particles were slightly but significantly (P < 0.01) enriched in Gammaproteobacteria (11.8% +/- 5.0%) compared to the free-water phase (8.1% +/- 1.8%). No preference for the attachment to particles could be observed for members of the Alphaproteobacteria and Bacteroidetes, which were abundant (12 to 17%) in both habitats. The alphaproteobacterial SAR11 clade, the Euryarchaeota, and group I Crenarchaeota, were all significantly depleted in particles compared to their presence in the free-water phase (16.5% +/- 3.5% versus 2.6% +/- 1.7%, 2.7% +/- 1.9% versus <1%, and 14.9% +/- 4.6% versus 2.2% +/- 1.8%, respectively, all P < 0.001). Sequence analysis of the crenarchaeotal 16S rRNA genes showed a 99% sequence identity to the nitrifying "Nitrosopumilus maritimus." Even though we could not observe conspicuous consortium-like structures of anammox bacteria with particle-enriched bacterioplankton groups, we hypothesize that members of Gammaproteobacteria, Alphaproteobacteria, and Bacteroidetes play a critical role in extending the anammox reaction to nutrient-depleted suboxic water layers in the Namibian upwelling system by creating anoxic, nutrient-enriched microniches.

  16. The South African and Namibian populations of the resurrection plant Myrothamnus flabellifolius are genetically distinct and display variation in their galloylquinic acid composition.

    PubMed

    Moore, John P; Farrant, Jill M; Lindsey, George G; Brandt, Wolf F

    2005-12-01

    The polyphenol contents and compositions in desiccated leaves of Myrothamnus flabellifolius plants collected in various locations in Namibia and South Africa were analyzed using UV spectroscopy and high-performance liquid chromatography-mass spectrometry. A study of the genetic relatedness of these populations was also performed by determination of the DNA sequence of the intergenic spacer region between the psbA and the trnH genes in the chloroplast genome. Namibian M. flabellifolius plants contained significantly more polyphenols than South African plants. Namibian plants essentially contained a single polyphenol, 3,4,5-tri-O-galloylquinic acid, whereas South African plants contained a variety of galloylquinic acids including 3,4,5-tri-O-galloylquinic acid together with higher molecular weight galloylquinic acids. Sequence analysis revealed a 1.4% divergence between Namibian and South African plants corresponding to the separation of these populations of approximately 4 x 10(6) years. The significance of the poly-phenol content and composition to the desiccation tolerance of the two populations is discussed.

  17. Weapon allometry varies with latitude in the New Zealand giraffe weevil.

    PubMed

    Painting, C J; Buckley, T R; Holwell, G I

    2014-12-01

    Animal body size commonly shows a relationship with latitude to the degree that this phenomenon is one of the few 'rules' discussed in evolutionary ecology: Bergmann's rule. Although exaggerated secondary sexual traits frequently exhibit interesting relationships with body size (allometries) and are expected to evolve rapidly in response to environmental variation, the way in which allometry might interact with latitude has not been addressed. We present data showing latitudinal variation in body size and weapon allometry for the New Zealand giraffe weevil (Lasiorhynchus barbicornis). Males display an extremely elongated rostrum used as a weapon during fights for access to females. Consistent with Bergmann's rule, mean body size increased with latitude. More interestingly, weapon allometry also varied with latitude, such that lower latitude populations exhibited steeper allometric slopes between weapon and body size. To our knowledge, this is the first study to document a latitudinal cline in weapon allometry and is therefore a novel contribution to the collective work on Bergmann's rule and secondary sexual trait variation.

  18. An assessment of RELAP5 MOD3.1.1 condensation heat transfer modeling with GIRAFFE heat transfer tests

    SciTech Connect

    Boyer, B.D.; Parlatan, Y.; Slovik, G.C.

    1995-09-01

    RELAP5 MOD3.1.1 is being used to simulate Loss of Coolant Accidents (LOCA) for the Simplified Boiling Water Reactor (SBWR) being proposed by General Electric (GE). One of the major components associated with the SBWR is the Passive Containment Cooling System (PCCS) which provides the long-term heat sink to reject decay heat. The RELAP5 MOD3.1.1 code is being assessed for its ability to represent accurately the PCCS. Data from the Phase 1, Step 1 Heat Transfer Tests performed at Toshiba`s Gravity-Driven Integral Full-Height Test for Passive Heat Removal (GIRAFFE) facility will be used for assessing the ability of RELAP5 to model condensation in the presence of noncondensables. The RELAP5 MOD3.1.1 condensation model uses the University of California at Berkeley (UCB) correlation developed by Vierow and Schrock. The RELAP5 code uses this heat transfer coefficient with the gas velocity effect multiplier being limited to 2. This heat transfer option was used to analyze the condensation heat transfer in the GIRAFFE PCCS heat exchanger tubes in the Phase 1, Step 1 Heat Transfer Tests which were at a pressure of 3 bar and had a range of nitrogen partial pressure fractions from 0.0 to 0.10. The results of a set of RELAP5 calculations at these conditions were compared with the GIRAFFE data. The effects of PCCS cell noding on the heat transfer process were also studied. The UCB correlation, as implemented in RELAP5, predicted the heat transfer to {plus_minus}5% of the data with a three--node model. The three-node model has a large cell in the entrance region which smeared out the entrance effects on the heat transfer, which tend to overpredict the condensation. Hence, the UCB correlation predicts condensation heat transfer correlation implemented in the code must be removed to allow for accurate calculations with smaller cell sizes.

  19. HIV risk behaviors, intentions, and perceptions among Namibian youth as assessed by a theory-based questionnaire.

    PubMed

    Stanton, B F; Fitzgerald, A M; Li, X; Shipena, H; Ricardo, I B; Galbraith, J S; Terreri, N; Strijdom, J; Hangula-Ndlovu, V; Kahihuata, J

    1999-04-01

    Considerable progress has been made in the United States and Europe regarding HIV risk prevention efforts targeting adolescents. However, in Africa less progress has been made to date. This article address three questions: Can risk assessment questionnaires developed in Western countries be modified so as to be appropriate for use in African countries? Are social cognitive models appropriate in African settings? Does covariation among risk behaviors occur among youth residing in African countries? The data was obtained from a cross-sectional survey conducted among 922 youth ages 12 to 18 years living in school-based hostels in Namibia. Data were collected using a theory-based risk assessment questionnaire. One third of the youth were sexually experienced, three quarters of whom had engaged in sexual intercourse in the previous 6 months. Over one third of these youth had had more that one sexual partner in the previous 6 months and over one half had not used a condom at last episode of intercourse. The psychometric properties of the questionnaire and the relationship between perceptions and behaviors provide evidence that theory-based questionnaires developed in Western countries can be modified for use in different cultural settings. The data also provide strong evidence of covariation between risk behaviors among Namibian youth.

  20. Isolation and characterization of avian paramyxovirus type 3b from farmed Namibian ostriches (Struthio camelus f. dom.).

    PubMed

    Kaleta, Erhard F; Werner, Ortrud; Hemberger, Yvonne

    2010-01-01

    Meat and skin from farmed ostriches are valuable products for European consumers. The EU regulations require that ostrich products deamed for export need to come from ostriches that are free of antibodies against Newcastle disease virus (avian paramxovirus type 1, aPMV-1). After the detection of antibodies against aPMV-1 in one of five ostrich farms in Namibia, attempts were made to isolate the causative virus. No aPMV-1 but an avian paramyxovirus type 3 (aPMV-3) was isolated from five pharyngeal/cloacal swabs of clinically healthy farmed Namibian ostriches. Subtype determination proved that all isolates are members of the subtype aPMV-3 of psittacine bird origin and were designated as aPMV-3b. In the haemagglutination inhibition test, the aPMV-3b isolates cross-reacted with aPMV-1. This allows the conclusion that the antibodies originally detected in sera of the ostriches are due to the cross-reaction with aPMV-3b, rather than to an infection with aPMV-1.To our knowledge, this is the first description of the occurrence of aPMV-3b in farmed ostriches.

  1. The contribution of the giraffe to hemodynamic knowledge: a unified physical principle for the circulation.

    PubMed

    Recordati, G

    1999-09-01

    Hemodynamics stands on three main physical principles: the hydrostatic pressure, firstly described by Stevino, the viscous flow pressure, described by Poiseuille and the total hydraulic energy, or Bernoulli's equation. However, neither of these physical principles gives a comprehensive description of the single pressure measurement in the cardiovascular system. Hence, all these principles should be used together to fully describe the physical forces acting in the circulation of blood. Experiments that measured the hydrostatic pressure in the jugular vein of the giraffe have shown that a few guidelines need to be followed to measure it correctly. Following these guidelines, it can be seen that hydrostatic and viscous flow pressures are strictly related to one another, and that this relationship is described in mathematical terms. In addition, it has been shown that hydrostatic and viscous pressures should be included in Bernoulli's principle, to give the combined Bernoulli-Poiseuille equation. This unified principle is helpful not only to measure correctly the pressure with a catheter connected to a pressure transducer, but also to give to the pressure measured in a patient with the mercury manometer, a strong connection with the description of the pressure as a physical force acting inside the circulation. In addition it provides a comprehensive view of the cardiovascular system as a closed hydrodynamic system, in which the heart is a pump, that does not normally work to overcome the force of gravity. The question at this point is: are there any pathophysiological conditions in which the heart needs to be confronted with the sudden appearance of the force of gravity inside the cardiovascular system?

  2. The GIRAFFE Inner Bulge Survey (GIBS). III. Metallicity distributions and kinematics of 26 Galactic bulge fields

    NASA Astrophysics Data System (ADS)

    Zoccali, M.; Vasquez, S.; Gonzalez, O. A.; Valenti, E.; Rojas-Arriagada, A.; Minniti, J.; Rejkuba, M.; Minniti, D.; McWilliam, A.; Babusiaux, C.; Hill, V.; Renzini, A.

    2017-02-01

    Context. Several recent studies have demonstrated that the Galactic bulge hosts two components with different mean metallicities, and possibly different spatial distribution and kinematics. As a consequence, both the metallicity distribution and the radial velocity of bulge stars vary across different lines of sight. Aims: We present here the metallicity distribution function of red clump stars in 26 fields spread across a wide area of the bulge, with special emphasis on fields close to Galactic plane, at latitudes b = -2° and b = -1°, that have not been explored before. Methods: This paper includes new metallicities from a sample of approximately 5000 K giant stars, observed at spectral resolution R 6500, in the Calcium II Triplet region. These represent the main dataset from the GIRAFFE Inner Bulge Survey. As part of the same survey we have previously published results for a sample of approximately 600 K giant stars, at latitude b -4°, derived from higher resolution spectra (R = 22 500). Results: The combined sample allows us to trace and characterize the metal poor and metal rich bulge populations down to the inner bulge. We present a density map for each of the two components. Contrary to expectations from previous works, we found the metal poor population to be more centrally concentrated than the metal rich one, and with a more axisymmetric spatial distribution. The metal rich population, on the other hand, is arranged in a boxy distribution, consistent with an edge-on bar. By coupling metallicities and radial velocities we show that the metal poor population has a velocity dispersion that varies rather mildly with latitude. On the contrary, the metal rich population has a low velocity dispersion far from the plane (b = -8.5°), yet has a steeper gradient with latitude, becoming higher than the metal poor one in the innermost field (b = -1°). Conclusions: This work provides new observational constraints on the actual chemodynamical properties of the

  3. Determinants of Persistence and Tolerance of Carnivores on Namibian Ranches: Implications for Conservation on Southern African Private Lands

    PubMed Central

    Lindsey, Peter Andrew; Havemann, Carl Peter; Lines, Robin; Palazy, Lucille; Price, Aaron Ernest; Retief, Tarryn Anne; Rhebergen, Tiemen; Van der Waal, Cornelis

    2013-01-01

    Changing land use patterns in southern Africa have potential to dramatically alter the prospects for carnivore conservation. Understanding these influences is essential for conservation planning. We interviewed 250 ranchers in Namibia to assess human tolerance towards and the distribution of large carnivores. Cheetahs (Acinonyx jubatus), leopards (Panthera pardus) and brown hyaenas (Hyaena brunnea) were widely distributed on Namibian farmlands, spotted hyaenas (Crocuta crocuta) had a narrower distribution, and wild dogs (Lycaon pictus) and lions (Panthera leo) are largely limited to areas near source populations. Farmers were most tolerant of leopards and least tolerant of lions, wild dogs and spotted hyaenas. Several factors relating to land use correlated consistently with carnivore-presence and landowner tolerance. Carnivores were more commonly present and/or tolerated where; wildlife diversity and biomass were higher; income from wildlife was higher; income from livestock was lower; livestock biomass was lower; in conservancies; game fencing was absent; and financial losses from livestock depredation were lower. Efforts to create conditions whereby the costs associated with carnivores are lowest, and which confer financial value to them are likely to be the most effective means of promoting carnivore conservation. Such conditions are achieved where land owners pool land to create conservancies where livestock are replaced with wildlife (or where livestock husbandry is improved) and where wildlife generates a significant proportion of ranch income. Additional measures, such as promoting improved livestock husbandry and educational outreach efforts may also help achieve coexistence with carnivores. Our findings provide insights into conditions more conducive to the persistence of and tolerance towards large carnivores might be increased on private (and even communal) lands in Namibia, elsewhere in southern and East Africa and other parts of the world where

  4. Determinants of persistence and tolerance of carnivores on Namibian ranches: implications for conservation on Southern African private lands.

    PubMed

    Lindsey, Peter Andrew; Havemann, Carl Peter; Lines, Robin; Palazy, Lucille; Price, Aaron Ernest; Retief, Tarryn Anne; Rhebergen, Tiemen; Van der Waal, Cornelis

    2013-01-01

    Changing land use patterns in southern Africa have potential to dramatically alter the prospects for carnivore conservation. Understanding these influences is essential for conservation planning. We interviewed 250 ranchers in Namibia to assess human tolerance towards and the distribution of large carnivores. Cheetahs (Acinonyx jubatus), leopards (Panthera pardus) and brown hyaenas (Hyaena brunnea) were widely distributed on Namibian farmlands, spotted hyaenas (Crocuta crocuta) had a narrower distribution, and wild dogs (Lycaon pictus) and lions (Panthera leo) are largely limited to areas near source populations. Farmers were most tolerant of leopards and least tolerant of lions, wild dogs and spotted hyaenas. Several factors relating to land use correlated consistently with carnivore-presence and landowner tolerance. Carnivores were more commonly present and/or tolerated where; wildlife diversity and biomass were higher; income from wildlife was higher; income from livestock was lower; livestock biomass was lower; in conservancies; game fencing was absent; and financial losses from livestock depredation were lower. Efforts to create conditions whereby the costs associated with carnivores are lowest, and which confer financial value to them are likely to be the most effective means of promoting carnivore conservation. Such conditions are achieved where land owners pool land to create conservancies where livestock are replaced with wildlife (or where livestock husbandry is improved) and where wildlife generates a significant proportion of ranch income. Additional measures, such as promoting improved livestock husbandry and educational outreach efforts may also help achieve coexistence with carnivores. Our findings provide insights into conditions more conducive to the persistence of and tolerance towards large carnivores might be increased on private (and even communal) lands in Namibia, elsewhere in southern and East Africa and other parts of the world where

  5. An assessment of RELAP5 MOD3.1.1 condensation heat transfer modeling with GIRAFFE heat transfer tests

    SciTech Connect

    Boyer, B.D.; Parlatan, Y.; Slovik, G.C.; Rohatgi, U.S.

    1995-09-01

    RELAP5 MOD3.1.1 is being used to simulate Loss of Coolant Accidents (LOCA) for the Simplified Boiling Water Reactor (SBWR) being proposed by General Electric (GE). One of the major components associated with the SBWR is the Passive Containment Cooling System (PCCS) which provides the long-term heat sink to reject decay heat. The RELAP5 MOD3.1.1 code is being assessed for its ability to represent accurately the PCCS. Data from the Phase 1, Step 1 Heat Transfer Tests performed at Toshiba`s Gravity-Driven Integral Full-Height Test for Passive Heat Removal (GIRAFFE) facility will be used for assessing the ability of RELAP5 to model condensation in the presence of noncondensables. The RELAP5 MOD3.1.1 condensation model uses the University of California at Berkeley (UCB) correlation developed by Vierow and Schrock. The RELAP5 code uses this heat transfer coefficient with the gas velocity effect multiplier being limited to 2. This heat transfer option was used to analyze the condensation heat transfer in the GIRAFFE PCCS heat exchanger tubes in the Phase 1, Step 1 Heat Transfer Tests which were at a pressure of 3 bar and had a range of nitrogen partial pressure fractions from 0.0 to 0.10. The results of a set of RELAP5 calculations al these conditions were compared with the GIRAFFE data. The effects of PCCS cell nodings on the heat transfer process were also studied. The UCB correlation, as implemented in RELAP5, predicted the heat transfer to {+-}5% of the data with a three-node model. The three-node model has a large cell in the entrance region which smeared out the entrance effects on the heat transfer, which tend to overpredict the condensation. Hence, the UCB correlation predicts condensation heat transfer in the presence of noncondensable gases with only a coarse mesh. The cell length term in the condensation heat transfer correlation implemented in the code must be removed to allow for accurate calculations with smaller cell sizes.

  6. Building new WDM regulations for the Namibian tourism sector on factors influencing current water-management practices at the enterprise level

    NASA Astrophysics Data System (ADS)

    Schachtschneider, Klaudia

    Namibia’s aridity is forcing its water sector to resort to new water resource management approaches, including water demand management (WDM). Such a change in management approach is facilitated through the country’s opportunity at independence to rewrite and adapt its old policies, including those for water and tourism. Legal support for WDM through the Water Act and other sector-specific Acts is crucial to plan the practical implementation of WDM throughout the different water use sectors of Namibia. In order to be able to put the policy into practice, it is imperative to understand which factors motivate people to adopt WDM initiatives. Within the Namibian tourism industry three main factors have been identified which influence the water-management approaches at tourist facilities. This paper discusses how the water and tourism decision makers can consider these factors when developing new regulations to introduce WDM in the tourism sector.

  7. VLT/GIRAFFE spectroscopic observations of the metal-poor blue compact dwarf galaxy SBS 0335-052E

    NASA Astrophysics Data System (ADS)

    Izotov, Y. I.; Schaerer, D.; Blecha, A.; Royer, F.; Guseva, N. G.; North, P.

    2006-11-01

    Aims.We present two-dimensional spectroscopy of the extremely metal-deficient blue compact dwarf (BCD) galaxy SBS 0335-052E to study physical conditions, element abundances and kinematical properties of the ionised gas in this galaxy. Methods: .Observations were obtained in the spectral range λ3620-9400 Å with the imaging spectrograph GIRAFFE on the UT2 of the Very Large Telescope (VLT). These observations are the first ones carried out so far with GIRAFFE in the ARGUS mode which allows one to simultaneously obtain 308 spectra covering a 11.4 arcsec×7.3 arcsec region. Results: .We produced images of SBS 0335-052E in the continuum and in emission lines of different stages of excitation. While the maximum of emission in the majority of lines, including the strong lines Hβ 4861 Å, Hα 6563 Å, [O iii] 4363,5007 Å, [O ii] 3726,3729 Å, coincides with the youngest south-eastern star clusters 1 and 2, the emission of He II 4686 Å line is offset to the more evolved north-west clusters 4, 5. This suggests that hard ionising radiation responsible for the He II λ4686 Å emission is not related to the most massive youngest stars, but rather is related to fast radiative shocks. This conclusion is supported by the kinematical properties of the ionised gas from the different emission lines as the velocity dispersion in the He II λ4686 Å line is systematically higher, by ~50-100%, than that in other lines. The variations of the emission line profiles suggest the presence of an ionised gas outflow in the direction perpendicular to the galaxy disk. We find a relatively high electron number density Ne of several hundred cm-3 in the brightest part of SBS 0335-052E. There is a small gradient of the electron temperature Te and oxygen abundance from the East to the West with systematically higher Te and lower 12+log O/H in the western part of the galaxy. The oxygen abundances for the whole H II region and its brightest part are 12 + log O/H = 7.29 ± 0.02 and 7.31 ± 0

  8. Nitrogen transfers off Walvis Bay: a 3-D coupled physical/biogeochemical modeling approach in the Namibian upwelling system

    NASA Astrophysics Data System (ADS)

    Gutknecht, E.; Dadou, I.; Marchesiello, P.; Cambon, G.; Le Vu, B.; Sudre, J.; Garçon, V.; Machu, E.; Rixen, T.; Kock, A.; Flohr, A.; Paulmier, A.; Lavik, G.

    2013-06-01

    Eastern boundary upwelling systems (EBUS) are regions of high primary production often associated with oxygen minimum zones (OMZs). They represent key regions for the oceanic nitrogen (N) cycle. By exporting organic matter (OM) and nutrients produced in the coastal region to the open ocean, EBUS can play an important role in sustaining primary production in subtropical gyres. However, losses of fixed inorganic N through denitrification and anammox processes take place in oxygen depleted environments such as EBUS, and can potentially mitigate the role of these regions as a source of N to the open ocean. EBUS can also represent a considerable source of nitrous oxide (N2O) to the atmosphere, affecting the atmospheric budget of N2O. In this paper a 3-D coupled physical/biogeochemical model (ROMS/BioEBUS) is used to investigate the N budget in the Namibian upwelling system. The main processes linked to EBUS and associated OMZs are taken into account. The study focuses on the northern part of the Benguela upwelling system (BUS), especially the Walvis Bay area (between 22° S and 24° S) where the OMZ is well developed. Fluxes of N off the Walvis Bay area are estimated in order to understand and quantify (1) the total N offshore export from the upwelling area, representing a possible N source that sustains primary production in the South Atlantic subtropical gyre; (2) export production and subsequent losses of fixed N via denitrification and anammox under suboxic conditions (O2 < 25 mmol O2 m-3); and (3) the N2O emission to the atmosphere in the upwelling area. In the mixed layer, the total N offshore export is estimated as 8.5 ± 3.9 × 1010 mol N yr-1 at 10° E off the Walvis Bay area, with a mesoscale contribution of 20%. Extrapolated to the whole BUS, the coastal N source for the subtropical gyre corresponds to 0.1 ± 0.04 mol N m-2 yr-1. This N flux represents a major source of N for the gyre compared with other N sources, and contributes 28% of the new primary

  9. The GIRAFFE Inner Bulge Survey (GIBS). II. Metallicity distributions and alpha element abundances at fixed Galactic latitude

    NASA Astrophysics Data System (ADS)

    Gonzalez, O. A.; Zoccali, M.; Vasquez, S.; Hill, V.; Rejkuba, M.; Valenti, E.; Rojas-Arriagada, A.; Renzini, A.; Babusiaux, C.; Minniti, D.; Brown, T. M.

    2015-12-01

    Aims: We investigate metallicity and α-element abundance gradients along a Galactic longitude strip, at latitude b ~ -4°, with the aim of providing observational constraints for the structure and origin of the Milky Way bulge. Methods: High-resolution (R ~ 22 500) spectra for 400 K giants, in four fields within -4.8° ≲ b ≲ -3.4° and -10° ≲ l ≲ +10°, were obtained within the GIRAFFE Inner Bulge Survey (GIBS) project. To this sample we added another ~400 stars in Baade's Window at (l,b) = (1°,-4°), observed with the identical instrumental configuration: FLAMES GIRAFFE in Medusa mode with HR13 setup. All target stars lie within the red clump of the bulge colour-magnitude diagram, thus minimising contamination from the disc or halo stars. The spectroscopic stellar surface parameters were derived with an automatic method based on the GALA code, while the [Ca/Fe] and [Mg/Fe] abundances as a function of [Fe/H] were derived through a comparison with the synthetic spectra using MOOG. We constructed the metallicity distributions for the entire sample, and for each field individually, in order to investigate the presence of gradients or field-to-field variations in the shape of the distributions. Results: The metallicity distributions in the five fields are consistent with being drawn from a single parent population, indicating the absence of a gradient along the major axis of the Galactic bar. The global metallicity distribution is nicely fitted by two Gaussians. The metal-poor component is rather broad, with a mean at ⟨ [Fe/H] ⟩ = -0.31 dex and σ = 0.31 dex. The metal-rich component is narrower, with mean ⟨ [Fe/H] ⟩ = + 0.26 and σ = 0.2 dex. The [Mg/Fe] ratio follows a tight trend with [Fe/H], with enhancement with respect to solar in the metal-poor regime similar to the value observed for giant stars in the local thick disc. [Ca/Fe] abundances follow a similar trend, but with a considerably larger scatter than [Mg/Fe]. A decrease in [Mg/Fe] is

  10. The GIRAFFE Inner Bulge Survey (GIBS). I. Survey description and a kinematical map of the Milky Way bulge

    NASA Astrophysics Data System (ADS)

    Zoccali, M.; Gonzalez, O. A.; Vasquez, S.; Hill, V.; Rejkuba, M.; Valenti, E.; Renzini, A.; Rojas-Arriagada, A.; Martinez-Valpuesta, I.; Babusiaux, C.; Brown, T.; Minniti, D.; McWilliam, A.

    2014-02-01

    Context. The Galactic bulge is a massive, old component of the Milky Way. It is known to host a bar, and it has recently been demonstrated to have a pronounced boxy/peanut structure in its outer region. Several independent studies suggest the presence of more than one stellar populations in the bulge, with different origins and a relative fraction changing across the bulge area. Aims: This is the first of a series of papers presenting the results of the Giraffe Inner Bulge Survey, carried out at the ESO-VLT with the multifibre spectrograph FLAMES. Spectra of ~5000 red clump giants in 24 bulge fields have been obtained at resolution R = 6500, in the infrared Calcium triplet wavelength region at ~8500 Å. They are used to derive radial velocities and metallicities, based on new calibration specifically devised for this project. Radial velocities for another ~1200 bulge red clump giants, obtained from similar archive data, have been added to the sample. Higher resolution spectra have been obtained for ~450 additional stars at latitude b = -3.5, with the aim of investigating chemical abundance patterns variations with longitude, across the inner bulge. In total we present here radial velocities for 6392 red clump stars. Methods: We present here the target selection criteria, observing strategy and the catalog with radial velocity measurements for all the target stars. Results: We derive a radial velocity, and velocity dispersion map of the Milky Way bulge, useful to be compared with similar maps of external bulges, and to infer the expected velocities and dispersion at any line of sight. The K-type giants kinematics is consistent with the cylindrical rotation pattern of M-giants from the BRAVA survey. Our sample enables to extend this result to latitude b = -2, closer to the Galactic plane than probed by previous surveys. Finally, we find strong evidence for a velocity dispersion peak at (0, -1) and (0, -2), possibily indicative of a high density peak in the central

  11. Evaluation of RELAP5 MOD 3.1.1 code with GIRAFFE Test Facility: Phase 1, Step 2 nitrogen venting tests

    SciTech Connect

    Boyer, B.D.; Slovik, G.C.; Rohatgl, U.S.

    1995-11-01

    The Simplified Boiling Water Reactor (SBWR) proposed by General Electric (GE) is an advanced light water reactor (ALWR) design that utilizes passive safety systems. The PCCS is a series of heat exchangers submerged in water and open to the containment. Since the containment is inerted with nitrogen during normal operation, the PCCS must condense the steam in the presence of noncondensable gases during an accident. To model the transient behavior of the SBWR with a system code, the code should properly simulate the expected phenomena. To validate the applicability of RELAP5 MOD 3.1.1, the data from three Phase 1, Step 2 nitrogen venting tests at Toshiba`s Gravity-Driven Integral Full-Height Test for Passive Heat Removal facility and RELAP5 calculations of these tests were compared. The comparison of the GIRAFFE data against the results from the RELAP5 calculations showed that it can predict condensation and gas purging phenomena occurring in the long-term decay heat rejection phase. In this phase of the transient, condensation in the PCCS is the only means to reject heat from the SBWR containment. In the two tests where the nitrogen purge vent line was at its deepest submergence in the Suppression Pool (SIP), the RELAP5 results mirrored the behavior of the containment pressures and of the water levels in the Horizontal Vent (HV) and the nitrogen purge line tube of the GIRAFFE data. However, in the test with the shallowest purge line submergence, there was appreciable direct contact condensation on the pool surface of the HV despite modeling efforts to deter these phenomena. This surface condensation, unobserved in the GIRAFFE tests, was a major cause of RELAP5 predicting early containment depressurization and the subsequent early rise in HV and nitrogen purge line water levels. The present RELAP5 MOD3.1.1 interfacial heat and mass transfer model does not properly degrade direct contact steam condensation in the presence of noncondensable gases sitting on a pool.

  12. Oligotyping reveals differences between gut microbiomes of free-ranging sympatric Namibian carnivores (Acinonyx jubatus, Canis mesomelas) on a bacterial species-like level

    PubMed Central

    Menke, Sebastian; Wasimuddin; Meier, Matthias; Melzheimer, Jörg; Mfune, John K. E.; Heinrich, Sonja; Thalwitzer, Susanne; Wachter, Bettina; Sommer, Simone

    2014-01-01

    Recent gut microbiome studies in model organisms emphasize the effects of intrinsic and extrinsic factors on the variation of the bacterial composition and its impact on the overall health status of the host. Species occurring in the same habitat might share a similar microbiome, especially if they overlap in ecological and behavioral traits. So far, the natural variation in microbiomes of free-ranging wildlife species has not been thoroughly investigated. The few existing studies exploring microbiomes through 16S rRNA gene reads clustered sequencing reads into operational taxonomic units (OTUs) based on a similarity threshold (e.g., 97%). This approach, in combination with the low resolution of target databases, generally limits the level of taxonomic assignments to the genus level. However, distinguishing natural variation of microbiomes in healthy individuals from “abnormal” microbial compositions that affect host health requires knowledge of the “normal” microbial flora at a high taxonomic resolution. This gap can now be addressed using the recently published oligotyping approach, which can resolve closely related organisms into distinct oligotypes by utilizing subtle nucleotide variation. Here, we used Illumina MiSeq to sequence amplicons generated from the V4 region of the 16S rRNA gene to investigate the gut microbiome of two free-ranging sympatric Namibian carnivore species, the cheetah (Acinonyx jubatus) and the black-backed jackal (Canis mesomelas). Bacterial phyla with proportions >0.2% were identical for both species and included Firmicutes, Fusobacteria, Bacteroidetes, Proteobacteria and Actinobacteria. At a finer taxonomic resolution, black-backed jackals exhibited 69 bacterial taxa with proportions ≥0.1%, whereas cheetahs had only 42. Finally, oligotyping revealed that shared bacterial taxa consisted of distinct oligotype profiles. Thus, in contrast to 3% OTUs, oligotyping can detect fine-scale taxonomic differences between microbiomes

  13. All giraffes have female-specific properties: influence of grammatical gender on deductive reasoning about sex-specific properties in German speakers.

    PubMed

    Imai, Mutsumi; Schalk, Lennart; Saalbach, Henrik; Okada, Hiroyuki

    2014-04-01

    Grammatical gender is independent of biological sex for the majority of animal names (e.g., any giraffe, be it male or female, is grammatically treated as feminine). However, there is apparent semantic motivation for grammatical gender classes, especially in mapping human terms to gender. This research investigated whether this motivation affects deductive inference in native German speakers. We compared German with Japanese speakers (a language without grammatical gender) when making inferences about sex-specific biological properties. We found that German speakers tended to erroneously draw inferences when the sex in the premise and grammatical gender of the target animal agreed. An over-generalization of the grammar-semantics mapping was found even when the sex of the target was explicitly indicated. However, these effects occurred only when gender-marking articles accompanied the nouns. These results suggest that German speakers project sex-specific biological properties onto gender-marking articles but not onto conceptual representations of animals per se.

  14. Teaching desertification: An investigation of teacher and classroom attributes, instructional strategies, locus of control, attitudes, and self-efficacy of Namibian junior secondary school teachers

    NASA Astrophysics Data System (ADS)

    Shimwooshili Shaimemanya, Cornelia Ndahambelela

    The purpose of this study was to investigate the direct and indirect effects of teacher attributes (teaching experience, age, and science content preparation), classroom attributes (grade level, class size, and teaching resources), and instructional strategies on Namibian junior secondary school teachers' locus of control, attitudes toward desertification, and self-efficacy. A multivariate analysis of variance (MANOVA) and path analysis strategy were used to test a hypothesized causal model that expressed the relationships among these factors. Sample data were collected from 221 teachers from 218 schools representing 4 northern education regions of Namibia. Overall MANOVA results were not significant and hence no follow-up analyses were conducted. However, when the causal model was retested in the absence of 13 variables, which were incorrectly specified, MANOVA results, although still not significant, improved considerably: The p-value decreased from 28.5% to 15%. As a result., follow-up analyses were conducted at an inflated alpha level relative to this alternative model. The results indicated that science content preparation, syllabus use, and Internet use had significant influences on teachers' self-efficacy, but none of the IVs had a significant relationship with either of the other two dependent measures. A follow-up exploratory analysis was also conducted using structural equation modeling (SEM) via LISREL. The resulting LISREL model indicated that (1) age and textbook use are positive measures that determine a teacher's ability to teach desertification, (2) Internet use is a negative measure of teachers' desertification teaching ability, and (3) self-efficacy and attitudes toward desertification are measures of teachers' motivation to teach desertification, with self-efficacy as the stronger measure. Findings suggest that: (1) teachers' desertification teaching can be improved by a stronger science content background as part of teacher training programs; (2

  15. Occallatibacter riparius gen. nov., sp. nov. and Occallatibacter savannae sp. nov., acidobacteria isolated from Namibian soils, and emended description of the family Acidobacteriaceae.

    PubMed

    Foesel, Bärbel U; Mayer, Susanne; Luckner, Manja; Wanner, Gerhard; Rohde, Manfred; Overmann, Jörg

    2016-01-01

    Three Gram-negative, non-spore-forming, encapsulated bacteria were isolated from a Namibian river-bank soil (strains 277T and 307) and a semiarid savannah soil (strain A2-1cT). 16S rRNA gene sequence analyses placed them within subdivision 1 of the Acidobacteria and revealed 100 % similarity between strains 277T and 307 and 98.2 % similarity between A2-1cT and the former two strains. The closest relatives with validly published names were Telmatobacter bradus, Acidicapsa borealis and Acidicapsa ligni (94.7-95.9 % similarity to the type strains). Cells of all three strains were rod-shaped and motile and divided by binary fission. Ultrastructural analyses revealed a thick cell envelope, resulting mainly from a thick periplasmic space. Colonies of strains 277T and 307 were white to cream and light pink, respectively, while strain A2-1cT displayed a bright pink colour. All three strains were aerobic, chemoheterotrophic mesophiles with a broad temperature range for growth and a moderately acidic pH optimum. Sugars and complex proteinaceous substrates were the preferred carbon and energy sources. A few polysaccharides were degraded. The major quinone in all three strains was MK-8; MK-7 occurred in strain A2-1cT as a minor compound. Major fatty acids were iso-C15 : 0 and iso-C17 : 1ω7c. In addition, iso-C17 : 0 occurred in significant amounts. The DNA G+C contents of strains 277T, 307 and A2-1cT were 59.6, 59.9 and 58.5 mol%, respectively. Based on these characteristics, the three isolates are assigned to two novel species of the novel genus Occallatibacter gen. nov., Occallatibacter riparius sp. nov. [type strain 277T ( = DSM 25168T = LMG 26948T) and reference strain 307 ( = DSM 25169 = LMG 26947)] and Occallatibacter savannae sp. nov. [type strain A2-1cT ( = DSM 25170T = LMG 26946T)]. Together with several other recently described taxa, the novel isolates provide the basis for an emended description of the established family

  16. Milk composition of free-ranging red hartebeest, giraffe, Southern reedbuck and warthog and a phylogenetic comparison of the milk of African Artiodactyla.

    PubMed

    Osthoff, G; Hugo, A; Madende, M; Deacon, F; Nel, P J

    2017-02-01

    The composition of major nutrients and fatty acids of the milk of three species, red hartebeest, Southern reedbuck and warthog, and milk fatty acids of giraffe, that have not been published before, are reported, and together with the same parameters of 11 species previously published, were incorporated in a phylogenetic comparison. Unique properties of milk composition have been observed. Southern reedbuck milk seems to have a complex casein composition, similar to that of sheep. Milk composition varies between species. Although some differences may be ascribed to biological condition, such as stage of lactation, or ecological factors, such as availability of certain nutrients, the contribution by evolutionary history is not well documented and the emphasis is usually on the composition of the macro nutrients. Phylogenetic comparisons often lack representatives of multiple species of taxonomic groups and sub-groups. To date phylogenetic comparisons of milk composition have been carried out by using data from different publications. The problem with this approach is that the ecological factors cannot be completely ruled out. A statistical phylogenetic comparison by PCA between 15 species representing 7 different suborders, families or subfamilies of African Artiodactyla was carried out. The phylogenetic properties showed that the milk composition of the Bovinae, represented here by the subfamilies Bovini and Tragelaphini, differs from the other taxonomic groups, in that the Alcelaphinae had a high milk fat content of the medium chain length fatty acids C8-C12 (>17% of total fatty acids) and the Hippotraginae high amounts of oligosaccharides (>0.4%).

  17. Impact of two types of complete pelleted, wild ungulate feeds and two pelleted feed to hay ratios on the development of urolithogenic compounds in meat goats as a model for giraffes.

    PubMed

    Sullivan, K; Freeman, S; van Heugten, E; Ange-van Heugten, K; Wolfe, B; Poore, M H

    2013-06-01

    Urolith formation has been documented in giraffes and goats. As research in giraffes poses logistical challenges, 16 buck goats were used as a model. The impact of two commercially available, pelleted feeds used for giraffes, ADF-16 and Wild Herbivore (WH), as well as the impact of alfalfa hay and pellet proportions (20% hay:80% pellets, 80P or 80% hay:20% pellet, 20P) on the formation of urolithogenic precursors in goat urine was accomplished in a 2 × 2 factorial balance study. Complete diets contained 0.60, 0.32, 0.35 and 0.26% phosphorus (P) with calcium:P ratios of 1.60, 4.16, 3.06 and 5.23, for 80P-ADF-16, 20P-ADF-16, 80P-WH and 20P-WH respectively. Total faeces and urine were collected over two 5-day periods to assess N and mineral balance. Fresh urine samples were collected and evaluated microscopically for urolithic crystal content. Urinary nitrogen (N) was lower and N retention was higher in goats fed 80P diets (p < 0.05). Intake of P was greatest for goats fed 80P-ADF-16; however, urinary P excretion and P retention were not affected by treatment. Crystal scores were higher in animals receiving 80P diets (p = 0.08), with crystals being composed predominantly of calcium phosphate. Urine pH was alkaline (>8) for all treatments. Urinary P concentration, a risk factor for urolithiasis, was highest (p ≤ 0.06) in the 80P-ADF-16 treatment (0.38 vs. 0.01, 0.02 and 0.04 mg/dl for 20P-ADF-16, 80P-WH and 20P-WH respectively), reflecting its highest dietary P level. Further investigation is recommended to determine the long-term effects of these diets on urolithogenic compound formation.

  18. Gaia-ESO Survey: Empirical classification of VLT/Giraffe stellar spectra in the wavelength range 6440-6810 Å in the γ Velorum cluster, and calibration of spectral indices

    NASA Astrophysics Data System (ADS)

    Damiani, F.; Prisinzano, L.; Micela, G.; Randich, S.; Gilmore, G.; Drew, J. E.; Jeffries, R. D.; Frémat, Y.; Alfaro, E. J.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Lanzafame, A. C.; Pancino, E.; Recio-Blanco, A.; Sacco, G. G.; Smiljanic, R.; Jackson, R. J.; de Laverny, P.; Morbidelli, L.; Worley, C. C.; Hourihane, A.; Costado, M. T.; Jofré, P.; Lind, K.; Maiorca, E.

    2014-06-01

    We present a study of spectral diagnostics available from optical spectra with R = 17 000 obtained with the VLT/Giraffe HR15n setup, using observations from the Gaia-ESO Survey, on the γ Vel young cluster, with the purpose of classifying these stars and finding their fundamental parameters. We define several spectroscopic indices, sampling the amplitude of TiO bands, the Hα line core and wings, and temperature- and gravity-sensitive sets of lines, each useful as a Teff or log g indicator over a limited range of stellar spectral types. Hα line indices are also useful as chromospheric activity or accretion indicators. Furthermore, we use all indices to define additional global Teff- and log g-sensitive indices τ and γ, valid for the entire range of types in the observed sample. We find a clear difference between gravity indices of main-sequence and pre-main-sequence stars, as well as a much larger difference between these and giant stars. The potentially great usefulness of the (γ,τ) diagram as a distance-independent age measurement tool for young clusters is discussed. We discuss the effect on the defined indices of classical T Tauri star veiling, which is however detected in only a few stars in the present sample. Then, we present tests and calibrations of these indices, on the basis of both photometry and literature reference spectra, from the UVES Paranal Observatory Projectand the ELODIE 3.1 Library. The known properties of these stars, spanning a wide range of stellar parameters, enable us to obtain a good understanding of the performances of our new spectral indices. For non-peculiar stars with known temperature, gravity, and metallicity, we are able to calibrate quantitatively our indices, and derive stellar parameters for a wide range of stellar types. To this aim, a new composite index is defined, providing a good metallicity indicator. The ability of our indices to select peculiar, or otherwise rare classes of stars is also established. For pre

  19. Giraffe and Clydesdale and Finless Fish

    ERIC Educational Resources Information Center

    Hall, Lincoln; Satin, Joseph

    1977-01-01

    A cooperative venture by the California State University and Colleges System (CSUCS) Consortium and the College of the Sequoias, a community college, is described in which students can pursue a liberal arts degree program with expanded community service. (LBH)

  20. Soil microbial communities following bush removal in a Namibian savanna

    NASA Astrophysics Data System (ADS)

    Buyer, Jeffrey S.; Schmidt-Küntzel, Anne; Nghikembua, Matti; Maul, Jude E.; Marker, Laurie

    2016-03-01

    Savanna ecosystems are subject to desertification and bush encroachment, which reduce the carrying capacity for wildlife and livestock. Bush thinning is a management approach that can, at least temporarily, restore grasslands and raise the grazing value of the land. In this study we examined the soil microbial communities under bush and grass in Namibia. We analyzed the soil through a chronosequence where bush was thinned at 9, 5, or 3 years before sampling. Soil microbial biomass, the biomass of specific taxonomic groups, and overall microbial community structure was determined by phospholipid fatty acid analysis, while the community structure of Bacteria, Archaea, and fungi was determined by multiplex terminal restriction fragment length polymorphism analysis. Soil under bush had higher pH, C, N, and microbial biomass than under grass, and the microbial community structure was also altered under bush compared to grass. A major disturbance to the ecosystem, bush thinning, resulted in an altered microbial community structure compared to control plots, but the magnitude of this perturbation gradually declined with time. Community structure was primarily driven by pH, C, and N, while vegetation type, bush thinning, and time since bush thinning were of secondary importance.

  1. Soil microbial communities following bush removal in a Namibian savanna

    NASA Astrophysics Data System (ADS)

    Buyer, J. S.; Schmidt-Küntzel, A.; Nghikembua, M.; Maul, J. E.; Marker, L.

    2015-12-01

    Savanna ecosystems are subject to desertification and bush encroachment, which reduce the carrying capacity for wildlife and livestock. Bush thinning is a management approach that can, at least temporarily, restore grasslands and raise the grazing value of the land. In this study we examined the soil microbial communities under bush and grass in Namibia. We analyzed the soil through a chronosequence where bush was thinned at 9, 5, or 3 years before sampling. Soil microbial biomass, the biomass of specific taxonomic groups, and overall microbial community structure was determined by phospholipid fatty acid analysis, while the community structure of Bacteria, Archaea, and fungi was determined by multiplex terminal restriction fragment length polymorphism analysis. Soil under bush had higher pH, C, N, and microbial biomass than under grass, and the microbial community structure was also altered under bush compared to grass. A major disturbance to the ecosystem, bush thinning, resulted in an altered microbial community structure compared to control plots, but the magnitude of this perturbation gradually declined with time. Community structure was primarily driven by pH, C, and N, while vegetation type, bush thinning, and time since bush thinning were of secondary importance.

  2. Soil microbial communities following bush removal in a Namibian savanna

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Savanna ecosystems are subject to desertification and bush encroachment, which reduce the grazing value of the land and hence the carrying capacity for wildlife and livestock. In this study we examined the soil microbial communities under bush and grass in Namibia. We analyzed the soil at a chronose...

  3. Experiments Testing the Causes of Namibian Fairy Circles.

    PubMed

    Tschinkel, Walter R

    2015-01-01

    The grasslands on the sandy soils of the eastern edge of the Namib Desert of Namibia are strikingly punctuated by millions of mostly regularly-spaced circular bare spots 2 to 10 m or more in diameter, generally with a margin of taller grasses. The causes of these so called fairy circles are unknown, but several hypotheses have been advanced. In October 2009, we set up experiments that specifically tested four hypothesized causes, and monitored these 5 times between 2009 and 2015. Grass exclusion in circles due to seepage of subterranean vapors or gases was tested by burying an impermeable barrier beneath fairy circles, but seedling density and growth did not differ from barrier-less controls. Plant germination and growth inhibition by allelochemicals or nutrient deficiencies in fairy circle soils were tested by transferring fairy circle soil to artificially cleared circles in the grassy matrix, and matrix soil to fairy circles (along with circle to circle and matrix to matrix controls). None of the transfers changed the seedling density and growth from the control reference conditions. Limitation of plant growth due to micronutrient depletion within fairy circles was tested by supplementing circles with a micronutrient mixture, but did not result in differences in plant seedling density and growth. Short-range vegetation competitive feedbacks were tested by creating artificially-cleared circles of 2 or 4 m diameter located 2 or 6 m from a natural fairy circle. The natural circles remained bare and the artificial circles revegetated. These four experiments provided evidence that fairy circles were not caused by subterranean vapors, that fairy circle soil per se did not inhibit plant growth, and that the circles were not caused by micronutrient deficiency. There was also no evidence that vegetative feedbacks affected fairy circles on a 2 to 10 m scale. Landscape-scale vegetative self-organization is discussed as a more likely cause of fairy circles.

  4. Experiments Testing the Causes of Namibian Fairy Circles

    PubMed Central

    Tschinkel, Walter R.

    2015-01-01

    The grasslands on the sandy soils of the eastern edge of the Namib Desert of Namibia are strikingly punctuated by millions of mostly regularly-spaced circular bare spots 2 to 10 m or more in diameter, generally with a margin of taller grasses. The causes of these so called fairy circles are unknown, but several hypotheses have been advanced. In October 2009, we set up experiments that specifically tested four hypothesized causes, and monitored these 5 times between 2009 and 2015. Grass exclusion in circles due to seepage of subterranean vapors or gases was tested by burying an impermeable barrier beneath fairy circles, but seedling density and growth did not differ from barrier-less controls. Plant germination and growth inhibition by allelochemicals or nutrient deficiencies in fairy circle soils were tested by transferring fairy circle soil to artificially cleared circles in the grassy matrix, and matrix soil to fairy circles (along with circle to circle and matrix to matrix controls). None of the transfers changed the seedling density and growth from the control reference conditions. Limitation of plant growth due to micronutrient depletion within fairy circles was tested by supplementing circles with a micronutrient mixture, but did not result in differences in plant seedling density and growth. Short-range vegetation competitive feedbacks were tested by creating artificially-cleared circles of 2 or 4 m diameter located 2 or 6 m from a natural fairy circle. The natural circles remained bare and the artificial circles revegetated. These four experiments provided evidence that fairy circles were not caused by subterranean vapors, that fairy circle soil per se did not inhibit plant growth, and that the circles were not caused by micronutrient deficiency. There was also no evidence that vegetative feedbacks affected fairy circles on a 2 to 10 m scale. Landscape-scale vegetative self-organization is discussed as a more likely cause of fairy circles. PMID:26510015

  5. The Life Cycle and Life Span of Namibian Fairy Circles

    PubMed Central

    Tschinkel, Walter R.

    2012-01-01

    In Namibia of southwestern Africa, the sparse grasslands that develop on deep sandy soils under rainfall between 50 and 100 mm per annum are punctuated by thousands of quasi-circular bare spots, usually surrounded by a ring of taller grass. The causes of these so-called “fairy circles” are unknown, although a number of hypotheses have been proposed. This paper provides a more complete description of the variation in size, density and attributes of fairy circles in a range of soil types and situations. Circles are not permanent; their vegetative and physical attributes allow them to be arranged into a life history sequence in which circles appear (birth), develop (mature) and become revegetated (die). Occasionally, they also enlarge. The appearance and disappearance of circles was confirmed from satellite images taken 4 years apart (2004, 2008). The frequency of births and deaths as a fraction of the total population of circles allowed the calculation of an approximate turnover rate, and from this, an estimate of circle lifespan. Lifespan appeared to vary with circle size, with small circles averaging about 24 years, and larger ones 43–75 years. Overall lifespan averaged about 41 yr. A second, independent estimate of lifespan was made by revisiting circles 2 to 9 years after their clear status had been confirmed. This resulted in a lifespan estimate of about 60 years. Any causal explanation of fairy circles must include their birth, development and death, their mean lifespan and the variation of their features under different conditions. PMID:22761663

  6. Evaluation of anthelmintic activity in captive wild ruminants by fecal egg reduction tests and a larval development assay.

    PubMed

    Young, K E; Jensen, J M; Craig, T M

    2000-09-01

    The effectiveness of anthelmintics was evaluated in four herds of captive ruminants, wapiti (Cervus elaphus), Armenian red sheep (Ovis orientalis), giraffe (Giraffa camelopardalis), and pronghorn (Antilocapra americana), by the use of fecal egg reduction tests (FERTs) and a commercial larval development assay (LDA) designed to evaluate susceptibility or resistance of nematodes to anthelmintics. Haemonchus sp. was the predominant nematode in the red sheep, giraffe, and pronghorn herds, whereas Ostertagia sp. and Trichostrongylus sp. were predominant in the wapiti. The LDA data indicated susceptibility by the worms to benzimidazoles except in the red sheep flock, which showed a high level of resistance. High levels of resistance to levamisole were seen in the worm populations from the wapiti and red sheep, moderate resistance in the pronghorn herd, and susceptibility in the giraffe herd. Worms were susceptible in all four herds to a combination of benzimidazole/levamisole. There was suspected avermectin resistance by Trichostrongylus sp. in the wapiti herd and by Haemonchus sp. in the giraffe. The FERTs agreed with the LDA in showing the Haemonchus in the giraffe was susceptible to fenbendazole and had suspected resistance to ivermectin, whereas Haemonchus in the red sheep and pronghorn were susceptible to ivermectin. There was correlation between the tests evaluating anthelmintics. The LDA is useful as a screening test in the selection of an anthelmintic for use in grazing ruminants, but the effectiveness of a drug in a host species may depend as much on the dose used, and the method of administration, as it does on the parasite's sensitivity to the anthelmintic.

  7. The Gifted Can't Weigh That Giraffe.

    ERIC Educational Resources Information Center

    Wassermann, Selma

    1982-01-01

    A professor's one-time observation of gifted and low-achieving students at one school leads to a startling conclusion. The gifted students were excessively anxious and unable to think creatively in the face of new problems; the low-achievers demonstrated high levels of creative problem-solving. (Author/WD)

  8. Seroprevalence of Toxoplasma gondii infection in zoo and domestic animals in Jiangxi Province, China

    PubMed Central

    Luo, Houqiang; Li, Kun; Zhang, Hui; Gan, Ping; Shahzad, Muhammad; Wu, Xiaoxing; Lan, Yanfang; Wang, Jiaxiang

    2017-01-01

    Toxoplasma gondii is a zoonotic protozoan parasite that infects a wide range of warm-blooded animals throughout the world. In the present study, antibodies to T. gondii were determined using a commercial indirect hemagglutination (IHA) test in wild animals in a zoo. Three of 11 giraffes (Giraffa camelopardalis) (27%), 1 of 5 wolves (Canis lupus laniger) (20%), 1 of 6 hippopotamuses (Hippopotamus amphibious) (17%), and 2 of 9 tundra swans (Cygnus columbianus) (22%) were found to be positive. No antibodies were detected in leopards (Panthera pardus), wild geese (Anser cygnoides), and Eastern grey kangaroos (Macropus giganteus). Domestic species from 13 counties of Jiangxi Province, China were also investigated by an indirect hemagglutination (IHA) test. Thirty-five of 340 goats (10%), 94 of 560 water buffaloes (17%), and 4 of 35 cattle (11%) were found to be seropositive. This is the first report of T. gondii infection in animals kept in zoos and domestic animals in this province. PMID:28224883

  9. A long life among ruminants: giraffids and other special cases.

    PubMed

    Müller, D W H; Zerbe, P; Codron, D; Clauss, M; Hatt, J-M

    2011-11-01

    In order to investigate differences in the relative maximum longevity and other life history parameter between ruminant species, we collated data on mean body mass, maximum longevity, gestation period and newborn mass in wild ruminant and camelid species. Among ruminants, giraffids (giraffe Giraffa camelopardalis and okapi Okapia johnstoni) have particularly high longevities, long gestation periods, and low intrauterine growth rates. A particularly high absolute and relative longevity is also achieved by the anoa (Bubalus depressicornis), a member of the bovinae (cattle-type ruminants) and an insular dwarf (inhabiting the Indonesian island of Sulawesi). The fact that some (but not all) other small ruminants also achieve surprisingly high longevities leads to the hypothesis that extreme relative longevities in this group are an indication for secondary body size reduction.

  10. Seroprevalence of Toxoplasma gondii infection in zoo and domestic animals in Jiangxi Province, China.

    PubMed

    Luo, Houqiang; Li, Kun; Zhang, Hui; Gan, Ping; Shahzad, Muhammad; Wu, Xiaoxing; Lan, Yanfang; Wang, Jiaxiang

    2017-01-01

    Toxoplasma gondii is a zoonotic protozoan parasite that infects a wide range of warm-blooded animals throughout the world. In the present study, antibodies to T. gondii were determined using a commercial indirect hemagglutination (IHA) test in wild animals in a zoo. Three of 11 giraffes (Giraffa camelopardalis) (27%), 1 of 5 wolves (Canis lupus laniger) (20%), 1 of 6 hippopotamuses (Hippopotamus amphibious) (17%), and 2 of 9 tundra swans (Cygnus columbianus) (22%) were found to be positive. No antibodies were detected in leopards (Panthera pardus), wild geese (Anser cygnoides), and Eastern grey kangaroos (Macropus giganteus). Domestic species from 13 counties of Jiangxi Province, China were also investigated by an indirect hemagglutination (IHA) test. Thirty-five of 340 goats (10%), 94 of 560 water buffaloes (17%), and 4 of 35 cattle (11%) were found to be seropositive. This is the first report of T. gondii infection in animals kept in zoos and domestic animals in this province.

  11. Unexpected rates of chromosomal instabilities and alterations of hormone levels in Namibian uranium miners

    SciTech Connect

    Zaire, R.; Notter, M.; Thiel, E.

    1997-05-01

    A common problem in determining the health consequences of radiation exposure is factoring out other carcinogenic influences. The conditions in Namibia provide a test case for distinguishing the effects of long-term low-dose exposure to uranium from the other environmental factors because of good air quality and the lack of other industries with negative health effects. Present records indicate a much higher prevalence of cancer among male workers in the open-pit uranium mine in Namibia compared with the general population. The objective of the present study was to determine whether long-term exposure to low doses of uranium increases the risk of a biological radiation damage which would lead to malignant diseases and to derive a dose-response model for these miners. To investigate this risk, we measured uranium excretion in urine, neutrophil counts and the serum level of FSH, LH and testosterone and analyzed chromosome aberrations in whole blood cells using fluorescence in situ hybridization. A representative cohort of 75 non-smoking, HIV-negative miners was compared to a control group of 31 individuals with no occupational history in mining. A sixfold increase in uranium excretion among the miners compared to the controls was recorded (P < 0.001). Furthermore, we determined a significant reduction in testosterone levels (P < 0.008) and neutrophil count (P < 0.0001). Most remarkably, cells with multiple aberrations such as {open_quotes}rogue{close_quotes} cells were observed for the first time in miners; these cells had previously been found only after short-term high-dose radiation exposure, e.g. from the Hiroshima atomic bomb or the Chernobyl accident. 19 refs., 1 fig., 3 tabs.

  12. Integrating small mammal community variables into aircraft-wildlife collision management plans at Namibian airports.

    PubMed

    Hauptfleisch, Morgan L; Avenant, Nico L

    2015-11-01

    Understanding ecosystems within and around airports can help to determine the causes and possible mitigation measures for collisions between aircraft and wildlife. Small mammal communities are an important component of the semi-arid savanna ecosystems of Namibia, its productivity and its ecosystem integrity. They are also a major direct attractant for raptors at airports. The present study compared the abundance and diversity of small mammals between Namibia's 2 main airport properties (Hosea Kutako International Airport and Eros Airport), and among areas of land used for various purposes surrounding the airports. A total of 2150 small mammals (3 orders, 11 species) were captured over 4 trapping seasons. Small mammal abundance was significantly higher at the end of the growing season than during the non-growing season. The grass mowing regimen in current management plans at the airports resulted in a significant reduction of small mammal abundance at Hosea Kutako during the non-growing season only, thus indicating that annual mowing is effective but insufficient to reduce the overall abundance of mammal prey species for raptors. Small mammal numbers were significantly higher at Hosea Kutako Airport compared to the cattle and game farming land surrounding the airport, while no differences in small mammal densities or diversity were found for areas with different land uses at and surrounding Eros. The study suggests that the fence around Hosea Kutako provides a refuge for small mammals, resulting in higher densities. It also indicates that different surrounding land use practices result in altered ecosystem function and productivity, an important consideration when identifying wildlife attractants at airports.

  13. Dietary plasticity of generalist and specialist ungulates in the Namibian Desert: a stable isotopes approach.

    PubMed

    Lehmann, David; Mfune, John Kazgeba Elijah; Gewers, Erick; Cloete, Johann; Brain, Conrad; Voigt, Christian Claus

    2013-01-01

    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.

  14. Chaetognatha of the Namibian upwelling region: taxonomy, distribution and trophic position.

    PubMed

    Bohata, Karolina; Koppelmann, Rolf

    2013-01-01

    In October 2010, the vertical distribution, biodiversity and maturity stages of Chaetognatha species were investigated at four stations located off Walvis Bay, Namibia. Seventeen species were detected and classified as pelagic, shallow-mesopelagic, deep-mesopelagic and bathypelagic species based upon the weighted mean depth derived from their average vertical distribution. High abundances of Chaetognatha were found in the upper 100 m at all stations of the Walvis Bay transect with a maximum value of 20837 ind. 1000 m(-3) at the outer shelf station near the surface. The community was dominated by species of the Serratodentata group. Furthermore, the distribution of Chaetognatha did not seem to be influenced by low oxygen concentrations. Stable isotope ratios of carbon and nitrogen in Chaetognatha were determined for seven different areas located off northern Namibia. The values of δ(15)N ranged from 6.05 ‰ to 11.39 ‰, while the δ(13)C values varied between -23.89 ‰ and -17.03 ‰. The highest values for δ(15)N were observed at the Walvis Bay shelf break station. The lowest δ(13)C values were found at the Rocky Point offshore station, which was statistically different from all other areas. Stable isotopes of carbon and nitrogen were determined for four taxa (Sagitta minima, Planctonis group, Sagitta enflata, Sagitta decipiens). In this case, the δ(15)N values ranged from 6.17 ‰ to 10.38 ‰, whereas the δ(13)C values varied from -22.70 ‰ to -21.56 ‰. The lowest δ(15)N values were found for S. minima. The C- and N-content revealed maximum C-values for S. decipiens and maximum N-values for the Planctonis group. The C:N ratio of Chaetognatha ranged between 5.25 and 6.20. Overall, Chaetognatha are a diverse group in the pelagic food web of the Benguela Upwelling System and act as competitors of fish larvae and jelly fish by preying on copepods.

  15. Prevalence and mitigation strategies of HIV/AIDS infection risks in Namibian tertiary education institutional hostels.

    PubMed

    Zimba, Roderick F; Likando, Gilbert N

    2014-01-01

    The purpose of this study was to investigate risk factors that could promote HIV infection amongst adolescents and young adults living in tertiary educational institutional hostels in Namibia. Employing structured questionnaires and focus group discussions, we sought to answer questions pertaining to factors, beliefs systems, values, traditions and sexual relations that could promote HIV infection in the student hostels. The data on these issues were gathered from 306 male and 314 female students aged 18-35 years living in eight hostels. Amongst other results, the data revealed that sexual promiscuity in the hostels was treated as the norm in the majority of cases, unauthorized access to hostel rooms by non-hostel dwellers was rampant, sexual harassment of female students by men who were under the influence of alcohol was reported to be common and there was general lack of support for victims of sexual abuse in the hostels. In addition, there was a general sense of insecurity in the hostels where more than 50% of the participants were afraid of being sexually attacked, some female hostel residents engaged in sexual activities for monetary and material gain and there was a general practice of older men from the community having sexual relations with young female hostel dwellers. To mitigate these and other risks it is recommended that there be provision of more HIV/AIDS prevention services, enhanced security, non-toxic entertainment (e.g. participation in sport and social clubs) and the banning of the sale of alcohol in student residences and on tertiary institution campuses. These and other results are discussed in the article and ways of mitigating the risks are proposed.

  16. Addressing the human resources crisis: a case study of the Namibian health service

    PubMed Central

    McCourt, Willy; Awases, Magda

    2007-01-01

    Background This paper addresses an important practical challenge to staff management. In 2000 the United Nations committed themselves to the ambitious targets embodied in the Millennium Development Goals (MDGs). Only five years later, it was clear that poor countries were not on track to achieve them. It was also clear that achieving the three out of the eight MDGs that concern health would only be possible if the appropriate human resources (HR) were in place. Methods We use a case study based on semi-structured interview data to explore the steps that Namibia, a country facing severe health problems that include an alarmingly high AIDS infection rate, has taken to manage its health workers. Results In the fifteen years since independence, Namibia has patiently built up a relatively good strategic framework for health policy in the context of government policy as a whole, including strong training arrangements at every level of health staffing, and it has brought HIV/AIDS under the strategic umbrella through its National Strategic Plan for HIV/AIDS. Its major weakness is that it has not kept pace with the rise in HIV/AIDS and TB infection: the community counselling service, still at the pilot stage at the time of this study, was the only specific response. That has created a tension between building long-term capacity in a strategic context and responding to the short-term demands of the AIDS and TB crisis, which in turn affects the ability of HR to contribute to improving health outcomes. Conclusion It is suggested that countries like Namibia need a new paradigm for staffing their health services. Building on the existing strategic framework, it should target the training of 'mid-level cadres'. Higher-level cadres should take on the role of supporting and monitoring the mid-level cadres. To do that, they will need management training and a performance management framework for staff support and monitoring. PMID:17224048

  17. Terriglobus albidus sp. nov., a member of the family Acidobacteriaceae isolated from Namibian semiarid savannah soil.

    PubMed

    Pascual, Javier; Wüst, Pia K; Geppert, Alicia; Foesel, Bärbel U; Huber, Katharina J; Overmann, Jörg

    2015-10-01

    A novel aerobic, chemo-organoheterotrophic bacterium, strain Ac_26_B10T, was isolated from a semiarid savannah soil collected in northern Namibia (Mashare, Kavango region). Based on analysis of its nearly full-length 16S rRNA gene sequence, the isolate belongs to the genus Terriglobus (family Acidobacteriaceae, order Acidobacteriales, class Acidobacteria) and shares 98.3 and 96.9 % 16S rRNA gene sequence similarity with its closest relatives, Terriglobus tenax DRP 35T and T. aquaticus O3SUJ4T. Cells were Gram-negative, coccoid to rod-shaped, non-motile and divided by binary fission. Strain Ac_26_B10T showed weak catalase activity and, in contrast to the other described species of the genus Terriglobus, was oxidase-positive. Compared with the already established species of the genus Terriglobus, the novel strain used a larger range of sugars and sugar alcohols for growth, lacked α-mannosidase activity and exhibited a higher temperature optimum of growth. DNA–DNA hybridization studies with its closest phylogenetic relative, T. tenax DSM 28898T, confirmed that strain Ac_26_B10T represents a distinct genomospecies. Its most abundant fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. Dominant polar lipids were phosphatidylethanolamine and diphosphatidylglycerol. The predominant menaquinone was MK-8; minor amounts of MK-7 and MK-8(H2) were also recorded. The G+C content of the genomic DNA was 58.5 mol%. On the basis of our polyphasic analysis, Ac_26_B10T represents a novel species of the genus Terriglobus, for which the name Terriglobus albidus sp. nov. is proposed. The type strain is Ac_26_B10T ( = DSM 26559T = LMG 27984T).

  18. Deep crustal structure of the Walvis Ridge at the junction with the Namibian coast

    NASA Astrophysics Data System (ADS)

    Fromm, Tanja; Jokat, Wilfried; Behrmann, Jan H.; Ryberg, Trond; Weber, Michael

    2013-04-01

    The Walvis Ridge perpendicular to the African coast offshore Namibia is believed to be caused by a long-lived hotspot, which started to erupt with the opening of the South Atlantic in mid Cretaceous. The ridge in combination with the large igneous provinces (Etendeka and Parana) in South America and Namibia is today considered to be a classical model for hotspot driven continental break-up. To unravel details on how the crust and mantle were modified by such a major thermal event, a large-scale geophysical on- and offshore experiment was conducted in 2011. We present p-wave velocity models of two active seismic profiles along and across Walvis Ridge. The profile along the ridge continues onshore, has a total length of ~730 km and consists of 28 ocean bottom stations, 50 land stations and 8 dynamite shots. This section reveals a complex structure with multiple buried seamounts, strong lateral velocity gradients and indication of a high velocity body at the crust-mantle boundary beneath the shelf area. Lower crustal velocities range from 6.5 km/s in the west to 7.0 km/s in the east while the crustal thickness is approximately 28 km at the coast thinning westwards. The second profile perpendicular to the ridge is located about 140 km west of the first profile, has a length of ~480 km and consists of 27 ocean bottom stations. The crustal thickness is well constrained by multiple Moho reflections showing a thickness of 20km under the crest of the ridge and gradually thinning to 8km towards north and south. A seamount marks the northern termination of the ridge leading to an abrupt thickening of the crust to 14km before reaching the Angola Basin. While crustal velocities of 5.5 km/s and 6.5 km/s in the upper and lower crust are similar to the first profile, lower crustal velocities north of the crest are approximately 6% higher.

  19. Dietary Plasticity of Generalist and Specialist Ungulates in the Namibian Desert: A Stable Isotopes Approach

    PubMed Central

    Lehmann, David; Mfune, John Kazgeba Elijah; Gewers, Erick; Cloete, Johann; Brain, Conrad; Voigt, Christian Claus

    2013-01-01

    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. PMID:23977249

  20. Chaetognatha of the Namibian Upwelling Region: Taxonomy, Distribution and Trophic Position

    PubMed Central

    Bohata, Karolina; Koppelmann, Rolf

    2013-01-01

    In October 2010, the vertical distribution, biodiversity and maturity stages of Chaetognatha species were investigated at four stations located off Walvis Bay, Namibia. Seventeen species were detected and classified as pelagic, shallow-mesopelagic, deep-mesopelagic and bathypelagic species based upon the weighted mean depth derived from their average vertical distribution. High abundances of Chaetognatha were found in the upper 100 m at all stations of the Walvis Bay transect with a maximum value of 20837 ind. 1000 m−3 at the outer shelf station near the surface. The community was dominated by species of the Serratodentata group. Furthermore, the distribution of Chaetognatha did not seem to be influenced by low oxygen concentrations. Stable isotope ratios of carbon and nitrogen in Chaetognatha were determined for seven different areas located off northern Namibia. The values of δ15N ranged from 6.05 ‰ to 11.39 ‰, while the δ13C values varied between −23.89 ‰ and −17.03 ‰. The highest values for δ15N were observed at the Walvis Bay shelf break station. The lowest δ13C values were found at the Rocky Point offshore station, which was statistically different from all other areas. Stable isotopes of carbon and nitrogen were determined for four taxa (Sagitta minima, Planctonis group, Sagitta enflata, Sagitta decipiens). In this case, the δ15N values ranged from 6.17 ‰ to 10.38 ‰, whereas the δ13C values varied from −22.70 ‰ to −21.56 ‰. The lowest δ15N values were found for S. minima. The C- and N-content revealed maximum C-values for S. decipiens and maximum N-values for the Planctonis group. The C:N ratio of Chaetognatha ranged between 5.25 and 6.20. Overall, Chaetognatha are a diverse group in the pelagic food web of the Benguela Upwelling System and act as competitors of fish larvae and jelly fish by preying on copepods. PMID:23342016

  1. Crustal structure of the Walvis Ridge at the junction with the Namibian coast

    NASA Astrophysics Data System (ADS)

    Fromm, Tanja; Jokat, Wilfried; Behrmann, Jan H.; Ryberg, Trond; Weber, Michael

    2014-05-01

    Continental breakup is commonly preceded or accompanied by massive volcanism and deposition of flood basalts. The large volumes of magma are thought to originate from hot upwelling mantle plumes arriving at the lithosphere. The following plume conduit often leaves a trail in form of volcanic islands or aseismic ridges on the newly created oceanic crust. Due to this correlation in space and time between plume-derived structures and continental breakup, plumes are considered to have a triggering effect or even cause continental breakups. The South Atlantic is a classical example for this model including the Parana (South America) and Etendeka (Africa) flood basalts as well as the aseismic ridges Rio Grande Rise and Walvis Ridge on both conjugate margins. The Walvis Ridge connects the Etendeka flood basalts with the active volcanic islands of Tristan da Cunha, the current hotspot position. To investigate the modification of the continent ocean transition (COT) by the arriving plume head, a large geophysical on- and offshore experiment was conducted in 2011 at the intersection of Walvis Ridge with the African continent. We present two P-wave velocity models of the deep crustal structure derived from seismic refraction data. One profile crosses the ridge ~500km away from the coastline, while the other one extends along the ridge and continues onshore. 27 ocean bottom stations (OBS, spacing 13 km) were deployed for the perpendicular profile, 28 OBS, 50 land stations and 8 dynamite shots were used for the longitudinal profile. Crustal velocities beneath Walvis Ridge range between 5.5 km/s and 7.0 km/s, which are typical velocities for oceanic crust. The thickness, however, is approximately three times than normal, 17 km in the western part and increasing to 22 km towards the continent. The COT is characterized by 30 km thick crust with a high velocity lower crustal body (HVLCB) with seismic velocities up to 7.5 km/s. The western boundary of the HVLCB is at a similar longitude as similar lower crustal bodies found more south. Towards the east the HVLCB terminates against the ~40 km thick crust of the Kaoko fold belt. Here, the variation of seismic velocities indicate that hot material intruded the continental crust during the initial rifting stage. However, beyond this relatively sharp boundary (40 km wide), the remaining continental crust seems not be affected by the hot material. The second line some 500 km west of the coast indicates that the Walvis Ridge might be broader than its topographic expression. The seismic velocities are similar to those closer to the coast, but the HVLCB is thinner.

  2. The foraging tunnel system of the Namibian desert termite, Baucaliotermes hainesi.

    PubMed

    Tschinkel, Walter R

    2010-01-01

    The harvester termite, Baucaliotermes hainesi (Fuller) (Termitidae: Nasutitermitinae), is an endemic in southern Namibia, where it collects and eats dry grass. At the eastern, landward edge of the Namib Desert, the nests of these termites are sometimes visible above ground surface, and extend at least 60 cm below ground. The termites gain access to foraging areas through underground foraging tunnels that emanate from the nest. The looseness of the desert sand, combined with the hardness of the cemented sand tunnels allowed the use of a gasoline-powered blower and soft brushes to expose tunnels lying 5 to 15 cm below the surface. The tunnels form a complex system that radiates at least 10 to 15 m from the nest with cross-connections between major tunnels. At 50 to 75 cm intervals, the tunnels are connected to the surface by vertical risers that can be opened to gain foraging access to the surrounding area. Foraging termites rarely need to travel more than a meter on the ground surface. The tunnels swoop up and down forming high points at riser locations, and they have a complex architecture. In the center runs a smooth, raised walkway along which termites travel, and along the sides lie pockets that act as depots where foragers deposit grass pieces harvested from the surface. Presumably, these pieces are transported to the nest by a second group of termites. There are also several structures that seem to act as vertical highways to greater depths, possibly even to moist soil. A census of a single nest revealed about 45,000 termites, of which 71% were workers, 9% soldiers and 6% neotenic supplementary reproductives. The nest consisted of a hard outer "carapace" of cemented sand, with a central living space of smooth, sweeping arches and surfaces. A second species of termite, Promirotermes sp. nested in the outer carapace.

  3. Impact of Land Use Management and Soil Properties on Denitrifier Communities of Namibian Savannas.

    PubMed

    Braker, Gesche; Matthies, Diethart; Hannig, Michael; Brandt, Franziska Barbara; Brenzinger, Kristof; Gröngröft, Alexander

    2015-11-01

    We studied potential denitrification activity and the underlying denitrifier communities in soils from a semiarid savanna ecosystem of the Kavango region in NE Namibia to help in predicting future changes in N(2)O emissions due to continuing changes of land use in this region. Soil type and land use (pristine, fallow, and cultivated soils) influenced physicochemical characteristics of the soils that are relevant to denitrification activity and N(2)O fluxes from soils and affected potential denitrification activity. Potential denitrification activity was assessed by using the denitrifier enzyme activity (DEA) assay as a proxy for denitrification activity in the soil. Soil type and land use influenced C and N contents of the soils. Pristine soils that had never been cultivated had a particularly high C content. Cultivation reduced soil C content and the abundance of denitrifiers and changed the composition of the denitrifier communities. DEA was strongly and positively correlated with soil C content and was higher in pristine than in fallow or recently cultivated soils. Soil type and the composition of both the nirK- and nirS-type denitrifier communities also influenced DEA. In contrast, other soil characteristics like N content, C:N ratio, and pH did not predict DEA. These findings suggest that due to greater availability of soil organic matter, and hence a more effective N cycling, the natural semiarid grasslands emit more N(2)O than managed lands in Namibia.

  4. Diversity and evolutionary patterns of immune genes in free-ranging Namibian leopards (Panthera pardus pardus).

    PubMed

    Castro-Prieto, Aines; Wachter, Bettina; Melzheimer, Joerg; Thalwitzer, Susanne; Sommer, Simone

    2011-01-01

    The genes of the major histocompatibility complex (MHC) are a key component of the mammalian immune system and have become important molecular markers for fitness-related genetic variation in wildlife populations. Currently, no information about the MHC sequence variation and constitution in African leopards exists. In this study, we isolated and characterized genetic variation at the adaptively most important region of MHC class I and MHC class II-DRB genes in 25 free-ranging African leopards from Namibia and investigated the mechanisms that generate and maintain MHC polymorphism in the species. Using single-stranded conformation polymorphism analysis and direct sequencing, we detected 6 MHC class I and 6 MHC class II-DRB sequences, which likely correspond to at least 3 MHC class I and 3 MHC class II-DRB loci. Amino acid sequence variation in both MHC classes was higher or similar in comparison to other reported felids. We found signatures of positive selection shaping the diversity of MHC class I and MHC class II-DRB loci during the evolutionary history of the species. A comparison of MHC class I and MHC class II-DRB sequences of the leopard to those of other felids revealed a trans-species mode of evolution. In addition, the evolutionary relationships of MHC class II-DRB sequences between African and Asian leopard subspecies are discussed.

  5. The Perceived Influence of School Leadership on Learner Behaviour in a Namibian Secondary School

    ERIC Educational Resources Information Center

    Smith, Clive; Amushigamo, Angelina

    2016-01-01

    Despite the deeply entrenched belief in and practice of corporal punishment to maintain learner control in schools, a secondary school in Namibia has for a number of years proven to be an exception to this practice. This is an interpretive account of the teachers' and learners' experiences and perceptions of the influence of their school…

  6. The Conflict between Cheetahs and Humans on Namibian Farmland Elucidated by Stable Isotope Diet Analysis

    PubMed Central

    Voigt, Christian C.; Thalwitzer, Susanne; Melzheimer, Jörg; Blanc, Anne-Sophie; Jago, Mark; Wachter, Bettina

    2014-01-01

    Large areas of Namibia are covered by farmland, which is also used by game and predator species. Because it can cause conflicts with farmers when predators, such as cheetahs (Acinonyx jubatus), hunt livestock, we assessed whether livestock constitutes a significant part of the cheetah diet by analysing the stable isotope composition of blood and tissue samples of cheetahs and their potential prey species. According to isotopic similarities, we defined three isotopic categories of potential prey: members of a C4 food web with high δ15N values (gemsbok, cattle, springhare and guinea fowl) and those with low δ15N values (hartebeest, warthog), and members of a C3 food web, namely browsers (eland, kudu, springbok, steenbok and scrub hare). We quantified the trophic discrimination of heavy isotopes in cheetah muscle in 9 captive individuals and measured an enrichment for 15N (3.2‰) but not for 13C in relation to food. We captured 53 free-ranging cheetahs of which 23 were members of groups. Cheetahs of the same group were isotopically distinct from members of other groups, indicating that group members shared their prey. Solitary males (n = 21) and males in a bachelor groups (n = 11) fed mostly on hartebeest and warthogs, followed by browsers in case of solitary males, and by grazers with high δ15N values in case of bachelor groups. Female cheetahs (n = 9) predominantly fed on browsers and used also hartebeest and warthogs. Mixing models suggested that the isotopic prey category that included cattle was only important, if at all, for males living in bachelor groups. Stable isotope analysis of fur, muscle, red blood cells and blood plasma in 9 free-ranging cheetahs identified most individuals as isotopic specialists, focussing on isotopically distinct prey categories as their food. PMID:25162403

  7. The conflict between cheetahs and humans on Namibian farmland elucidated by stable isotope diet analysis.

    PubMed

    Voigt, Christian C; Thalwitzer, Susanne; Melzheimer, Jörg; Blanc, Anne-Sophie; Jago, Mark; Wachter, Bettina

    2014-01-01

    Large areas of Namibia are covered by farmland, which is also used by game and predator species. Because it can cause conflicts with farmers when predators, such as cheetahs (Acinonyx jubatus), hunt livestock, we assessed whether livestock constitutes a significant part of the cheetah diet by analysing the stable isotope composition of blood and tissue samples of cheetahs and their potential prey species. According to isotopic similarities, we defined three isotopic categories of potential prey: members of a C4 food web with high δ15N values (gemsbok, cattle, springhare and guinea fowl) and those with low δ15N values (hartebeest, warthog), and members of a C3 food web, namely browsers (eland, kudu, springbok, steenbok and scrub hare). We quantified the trophic discrimination of heavy isotopes in cheetah muscle in 9 captive individuals and measured an enrichment for 15N (3.2‰) but not for 13C in relation to food. We captured 53 free-ranging cheetahs of which 23 were members of groups. Cheetahs of the same group were isotopically distinct from members of other groups, indicating that group members shared their prey. Solitary males (n = 21) and males in a bachelor groups (n = 11) fed mostly on hartebeest and warthogs, followed by browsers in case of solitary males, and by grazers with high δ15N values in case of bachelor groups. Female cheetahs (n = 9) predominantly fed on browsers and used also hartebeest and warthogs. Mixing models suggested that the isotopic prey category that included cattle was only important, if at all, for males living in bachelor groups. Stable isotope analysis of fur, muscle, red blood cells and blood plasma in 9 free-ranging cheetahs identified most individuals as isotopic specialists, focussing on isotopically distinct prey categories as their food.

  8. First evidence of hemoplasma infection in free-ranging Namibian cheetahs (Acinonyx jubatus).

    PubMed

    Krengel, Annika; Meli, Marina L; Cattori, Valentino; Wachter, Bettina; Willi, Barbara; Thalwitzer, Susanne; Melzheimer, Jörg; Hofer, Heribert; Lutz, Hans; Hofmann-Lehmann, Regina

    2013-03-23

    Infections with feline hemotropic mycoplasmas (hemoplasmas) have been documented in domestic cats and free-ranging feline species with high prevalences in Iberian lynxes (Lynx pardinus), Eurasian lynxes (Lynx lynx), European wildcats (Felis silvestris silvestris), African lions (Panthera leo) in Tanzania and domestic cats in South Africa. The prevalence of hemoplasmas has not yet been investigated in free-ranging felids in southern Africa. In this study we screened 73 blood samples from 61 cheetahs in central Namibia for the presence of hemoplasmas using quantitative real-time PCR. One of the cheetahs tested PCR-positive. Phylogenetic analysis based on partial sequencing of the 16S rRNA and RNAse P genes revealed that the isolate belongs to the Mycoplasma haemofelis/haemocanis group. This is the first molecular evidence of a hemoplasma infection in a free-ranging cheetah.

  9. A Purple Giraffe Is Faster than a Purple Elephant: Inconsistent Phonology Affects Determiner Selection in English

    ERIC Educational Resources Information Center

    Spalek, Katharina; Bock, Kathryn; Schriefers, Herbert

    2010-01-01

    The form of a determiner is dependent on different contextual factors: in some languages grammatical number and grammatical gender determine the choice of a determiner variant. In other languages, the phonological onset of the element immediately following the determiner affects selection, too. Previous work has shown that the activation of…

  10. "Do Giraffes Ever Sit?": A Study of Visitor Perceptions at the National Zoological Park, Smithsonian Institution.

    ERIC Educational Resources Information Center

    Wolf, Robert L.; Tymitz, Barbara L.

    This study explores why people come to the National Zoological Park, the value of their visit, what they learn, and how the overall experience of visiting the zoo affects them. The study was undertaken over six months. It is part of a series to evaluate how various bureaus of the Smithsonian Institutions influence the public through their diverse…

  11. VizieR Online Data Catalog: GIRAFFE Inner Bulge Survey (GIBS). II. (Gonzalez+, 2015)

    NASA Astrophysics Data System (ADS)

    Gonzalez, O. A.; Zoccali, M.; Vasquez, S.; Hill, V.; Rejkuba, M.; Valenti, E.; Rojas-Arriagada, A.; Renzini, A.; Babusiaux, C.; Minniti, D.; Brown, T.

    2015-09-01

    Coordinates, VIJHKs photometry, stellar surface parameters, [Fe/H], [Mg/Fe] and [Ca/Fe] abundance ratios for a sample of 400 red clump stars in the four high-resolution GIBS fields. The spectroscopic stellar surface parameters were derived with an automatic method based on the GALA code, while the [Ca/Fe] and [Mg/Fe] abundances as a function of[Fe/H] were derived through a comparison with the synthetic spectra using MOOG. (1 data file).

  12. A Comparison of Zoo Animal Behavior in the Presence of Familiar and Unfamiliar People.

    PubMed

    Martin, Rosemary Anne; Melfi, Vicky

    2016-01-01

    As recorded in domestic nonhuman animals, regular interactions between animals in zoos and keepers and the resulting relationship formed (human-animal relationship [HAR]) are likely to influence the animals' behaviors with associated welfare consequences. HAR formation requires that zoo animals distinguish between familiar and unfamiliar people. This ability was tested by comparing zoo animal behavioral responses to familiar (routine) keepers and unfamiliar keepers (participants in the "Keeper for the Day" program). Study subjects included 1 African elephant (Loxodonta Africana), 3 Rothschild's giraffes (Giraffa camelopardalis rothschildi), 2 Brazilian tapir (Tapirus terrestris), and 2 slender-tailed meerkats (Suricata suricatta). Different behavior was evident and observed as decreased avoidance behavior toward familiar keepers (t7 = 6.00, p <  .001). This finding suggests the zoo animals have a lower level of fear toward familiar keepers. Keeper familiarity did not significantly affect any other behavioral measure. This finding suggests that in the current study, unfamiliar keeper presence did not appear to have detrimental effects. Furthermore, unfamiliar keeper-animal interactions could provide an increased number of positive human-animal interactions and potentially enhance animal welfare.

  13. Use of advanced earth observation tools for the analyses of recent surface changes in Kalahari pans and Namibian coastal lagoons

    NASA Astrophysics Data System (ADS)

    Behling, Robert; Milewski, Robert; Chabrillat, Sabine; Völkel, Jörg

    2016-04-01

    The remote sensing analyses in the BMBF-SPACES collaborative project Geoarchives - Signals of Climate and Landscape Change preserved in Southern African Geoarchives - focuses on the use of recent and upcoming Earth Observation Tools for the study of climate and land use changes and its impact on the ecosystem. It aims at demonstrating the potential of recently available advanced optical remote sensing imagery with its extended spectral coverage and temporal resolution for the identification and mapping of sediment features associated with paleo-environmental archives as well as their recent dynamic. In this study we focus on the analyses of two ecosystems of major interest, the Kalahari salt pans as well as the lagoons at Namibia's west coast, that present high dynamic caused by combined hydrological and surface processes linked to climatic events. Multitemporal remote sensing techniques allow us to derive the recent surface dynamic of the salt pans and also provide opportunities to get a detailed understanding of the spatiotemporal development of the coastal lagoons. Furthermore spaceborne hyperspectral analysis can give insight to the current surface mineralogy of the salt pans on a physical basis and provide the intra pan distribution of evaporites. The soils and sediments of the Kalahari salt pans such as the Omongwa pan are a potentially significant storage of global carbon and also function as an important terrestrial climate archive. Thus far the surface distribution of evaporites have been only assessed mono-temporally and on a coarse regional scale, but the dynamic of the salt pans, especially the formation of evaporites, is still uncertain and poorly understood. For the salt pan analyses a change detection is applied using the Iterative-reweighted Multivariate Alteration Detection (IR-MAD) method to identify and investigate surface changes based on a Landsat time-series covering the period 1984-2015. Furthermore the current spatial distribution of evaporites is obtained using of EO-1 Hyperion hyperspectral imagery linked with geochemical field data. Results reveal a highly heterogeneous dynamic of the pan surface, which seems to be associated with varying surface crust types, halite or gypsum dominated. The lagoons at Namibia's west coast such as of Sandwich Harbour and Walvis Bay, are important habitats and also serve as a natural barrier to protect shipping and ports on an otherwise inhospitable coastline. Several studies have shown that these lagoons are highly dynamic and are known to have altered their shape in historical time. These changes occur due to sediment transport forced by aeolian processes or either by longshore or cross-shore drifts. A profound understanding of the spatiotemporal variations in the sand spits is of high relevance. In the lagoon environment the Landsat time-series is used to separate sand spits from open water. This way, changes in morphology of the sand spit are identified over time. The results reveal the presence of long-term and short-term changes as well as the presence of stable parts in the sand spits. These findings are linked to temporal patterns of forcing processes such as wind, tidal and ocean current data.

  14. Multicentric T-cell lymphoma associated with feline leukemia virus infection in a captive namibian cheetah (Acinonyx jubatus).

    PubMed

    Marker, Laurie; Munson, Linda; Basson, Peter A; Quackenbush, Sandra

    2003-07-01

    This case report describes a multicentric lymphoma in a 4 yr old female wildborn captive cheetah (Acinonyx jubatus) in Namibia after being housed in an enclosure adjacent to a feline leukemia virus (FeLV) infected cheetah that had previously been in contact with domestic cats. The year prior to the onset of clinical signs, the wild-born cheetah was FeLV antigen negative. The cheetah subsequently developed lymphoma, was found to be infected with FeLV, and then rapidly deteriorated and died. At necropsy, the liver, spleen, lymph nodes, and multiple other organs were extensively infiltrated with neoplastic T-lymphocytes. Feline leukemia virus DNA was identified in neoplastic lymphocytes from multiple organs by polymerase chain reaction and Southern blot analysis. Although the outcome of infection in this cheetah resembles that of FeLV infections in domestic cats, the transmission across an enclosure fence was unusual and may indicate a heightened susceptibility to infection in cheetahs. Caution should be exercised in holding and translocating cheetahs where contact could be made with FeLV-infected domestic, feral, or wild felids.

  15. The historical ecology of Namibian rangelands: vegetation change since 1876 in response to local and global drivers.

    PubMed

    Rohde, Richard F; Hoffman, M Timm

    2012-02-01

    The influence of both local and global drivers on long-term changes in the vegetation of Namibia's extensive rangelands was investigated. Fifty-two historical photographs of the Palgrave Expedition of 1876 were re-photographed and used to document changes over more than 130 years, in grass, shrub and tree cover within three major biomes along a 1200km climatic gradient in central and southern Namibia. We showed that patterns of change are correlated with mean annual precipitation (MAP) and that below a threshold of around 250mm, vegetation has remained remarkably stable regardless of land-use or tenure regime. Above this threshold, an increase in tree cover is linked to the rainfall gradient, the legacies of historical events in the late 19th century, subsequent transformations in land-use and increased atmospheric CO(2). We discuss these findings in relation to pastoral and settler societies, paleo- and historical climatic trends and predictions of vegetation change under future global warming scenarios. We argue that changes in land-use associated with colonialism (decimation of megaherbivores and wildlife browsers; fire suppression, cattle ranching), as well as the effects of CO(2) fertilisation provide the most parsimonious explanations for vegetation change. We found no evidence that aridification, as projected under future climate change scenarios, has started in the region. This study provided empirical evidence and theoretical insights into the relative importance of local and global drivers of change in the savanna environments of central and southern Namibia and global savanna ecosystems more generally.

  16. Cryopreservation of spermatozoa from wild-born Namibian cheetahs (Acinonyx jubatus) and influence of glycerol on cryosurvival.

    PubMed

    Crosier, Adrienne E; Pukazhenthi, Budhan S; Henghali, Josephine N; Howard, Jogayle; Dickman, Amy J; Marker, Laurie; Wildt, David E

    2006-04-01

    Sperm cryopreservation is a valuable tool for the genetic management of ex situ populations. This study was conducted to assess: (1) semen characteristics of wild-born cheetahs; and (2) the impact of three types of glycerol influence (duration of exposure, temperature, and method of addition) on sperm cryosensitivity. To evaluate the impact of duration of glycerol exposure, spermatozoa were incubated in Test Yolk Buffer (TYB) with 4% glycerol at ambient temperature (approximately 22 degrees C) for 15 vs. 60 min before cryopreservation. To evaluate the influence of temperature and method of glycerol addition, spermatozoa were resuspended at ambient temperature either in TYB with 0% glycerol followed by addition of 8% glycerol (1:1 v/v; at ambient temperature vs. 5 degrees C) or directly in TYB with 4% glycerol. All samples were cryopreserved in straws over liquid nitrogen vapor and evaluated for sperm motility and acrosomal integrity after thawing. Semen samples (n = 23; n = 13 males) contained a high proportion (78%) of pleiomorphic spermatozoa. Ejaculates also contained a high proportion of acrosome-intact (86%) and motile spermatozoa (78%). Immediately after thawing, a significant proportion of spermatozoa retained intact acrosomes (range, 48-67%) and motility (range, 40-49%). After thawing, incubation in glycerol for 60 min at ambient temperature before freezing decreased (p < 0.05) sperm motility and acrosomal integrity at one time-point each (pre-centrifugation and post-centrifugation, respectively). However, method or temperature of glycerol addition had no (p > 0.05) impact on sperm cryosurvival. In summary, (1) wild-born cheetahs produce high proportions of pleiomorphic spermatozoa but with a high proportion of intact acrosomes; and (2) resuspension in 4% glycerol, followed by exposure for up to 60 min at ambient temperature, had minimal effect on sperm motility and acrosomal integrity after cryopreservation. Results indicate the feasibility of cryopreserving cheetah spermatozoa under field conditions, providing a user-friendly method to capture and store gametes to enhance genetic management.

  17. Ecophysiological adaptations to dry thermal environments measured in two unrestrained Namibian scorpions, Parabuthus villosus (Buthidae) and Opisthophthalmus flavescens (Scorpionidae).

    PubMed

    Bridges, C R; le Roux, J M; van Aardt, W J

    1997-01-01

    The daily changes in body temperature experienced by Parabuthus villosus (Buthidae), a scorpion found on the gravel plains around Gobabeb, Namibia, and by Opisthophthalmus flavescens (Scorpionidae), a dune-dwelling species from the same area, were measured under similar field conditions. Thermocouples implanted under the segments of the mesosoma measured maximum temperatures as high as 43 degrees C in the shade. Air temperatures reached a maximum of 33 degrees C during the daytime and a minimum of 12 degrees C at night. Very low metabolic rates compared with those of other nonsedentary invertebrates were recorded in both species; oxygen consumption ranged from 8 microL g-1 h-1 at 16 degrees C to 115 microL g-1 h-1 at 40 degrees C. A pulsed Doppler system was used to measure heart rate in situ in free-moving scorpions. At night, heart rate declined to about 4 beats min-1 in resting undisturbed scorpions. During daylight excursions and while scorpions hunted for food, heart rates as high as 180 beats min-1 were observed. Heart rate was linearly correlated with temperature in P. villosus, with a slope of 2.37 (Q10 = 2.18), but in O. flavescens only a limited correlation was observed, with a slope of 1.18 (Q10 = 1.69). In O. flavescens, heart rate showed hysteresis as body temperature rose during daylight and then decreased during the late afternoon and evening; the reverse was observed in P. villosus. In both species, haemocyanin-oxygen affinity was independent of temperature, with a higher oxygen affinity and a larger pH sensitivity in O. flavescens. The Q10's of oxygen consumption and heart rate are quite different in O. flavescens but not as different in P. villosus. Although changes in the cardiovascular system, such as stroke volume, may also play a role in meeting increased oxygen demand, the features of the haemocyanin oxygen transport system, such as the absence of temperature sensitivity and a marked pH sensitivity, can also influence the maintenance of VO2 under temperature stress. The differences in the normal thermal habitats of the two species may be used to explain the distinctions between the evolved physiological responses to temperature increase shown by the two species.

  18. A Prominence Account of Syllable Reduction in Early Speech Development: The Child's Prosodic Phonology of "Tiger" and "Giraffe."

    ERIC Educational Resources Information Center

    Snow, David

    1998-01-01

    This paper tested a theory of syllable prominence with 11 children (ages 11 to 26 months). The theory proposes that syllable prominence is a product of two orthogonal suprasegmental systems: stress/accent peaks and phrase boundaries. Use of the developed prominence scale found it parsimoniously accounted for observed biases in syllable omissions…

  19. Differences in fecal particle size between free-ranging and captive individuals of two browser species.

    PubMed

    Hummel, Jürgen; Fritz, Julia; Kienzle, Ellen; Medici, E Patricia; Lang, Stefanie; Zimmermann, Waltraut; Streich, W Jürgen; Clauss, Marcus

    2008-01-01

    Data from captive animals indicated that browsing (BR) ruminants have larger fecal particles-indicative of lesser chewing efficiency-than grazers (GR). To answer whether this reflects fundamental differences between the animal groups, or different reactions of basically similar organisms to diets fed in captivity, we compared mean fecal particle size (MPS) in a GR and a BR ruminant (aurox Bos primigenius taurus, giraffe Giraffa camelopardalis) and a GR and a BR hindgut fermenter (Przewalski's horse Equus ferus przewalskii, lowland tapir Tapirus terrestris), both from captivity and from the wild. As would be expected owing to a proportion of finely ground, pelleted feeds in captive diets, MPS was smaller in captive than free-ranging GR. In contrast, MPS was drastically higher in captive than in free-ranging BR of either digestion type. Thus, the difference in MPS between GR and BR was much more pronounced among captive than free-ranging animals. The results indicate that BR teeth have adapted to their natural diet so that in the wild, they achieve a particle size reduction similar to that of GR. However, although GR teeth seem equally adapted to food ingested in captivity, the BR teeth seem less well suited to efficiently chew captive diets. In the case of ruminants, less efficient particle size reduction could contribute to potential clinical problems like "rumen blockage" and bezoar formation. Comparisons of MPS between free-ranging and captive animals might offer indications for the physical suitability of zoo diets. Zoo Biol 27:70-77, 2008. (c) 2007 Wiley-Liss, Inc.

  20. The host status of African buffaloes, Syncerus caffer, for Rhipicephalus (Boophilus) decoloratus.

    PubMed

    Horak, I G; Golezardy, H; Uys, A C

    2006-09-01

    The objective of this study was to assess the host status of African buffaloes, Syncerus caffer, for the one-host tick Rhipicephalus (Boophilus) decoloratus. To this end the R. (B.) decoloratus burdens of ten buffaloes examined in three north-eastern KwaZulu-Natal Province (KZN) nature reserves were compared with those of medium-sized to large antelope species in these reserves and in the southern Kruger National Park (KNP), Mpumalanga Province. The R. (B.) decoloratus burdens of the buffaloes were considerably smaller than those of the antelopes in the KNP, but not those in the KZN reserves. The life-stage structure of the R. (B.) decoloratus populations on the buffaloes, in which larvae predominated, was closer to that of this tick on blue wildebeest, Connochaetes taurinus, a tick-resistant animal, than to that on other antelopes. A single buffalo examined in the KNP was not infested with R. (B.) decoloratus, whereas a giraffe, Giraffa camelopardalis, examined at the same locality and time, harboured a small number of ticks. In a nature reserve in Mpumalanga Province adjacent to the KNP, two immobilized buffaloes, from which only adult ticks were collected, were not infested with R. (B.) decoloratus, whereas greater kudus, Tragelaphus strepsiceros, examined during the same time of year in the KNP harboured large numbers of adult ticks of this species. African buffaloes would thus appear to be resistant to infestation with R. (B.) decoloratus, and this resistance is expressed as the prevention of the majority of tick larvae from developing to nymphs.

  1. Effects of sediment discharge from Namibian diamond mines on intertidal and subtidal rocky-reef communities and the rock lobster Jasus lalandii

    NASA Astrophysics Data System (ADS)

    Pulfrich, Andrea; Branch, George M.

    2014-10-01

    Extensive terrestrial diamond mining occurs on the southern coast of Namibia, and at Elizabeth Bay near Lüderitz sediment tailings totalling about 2 million tons.yr-1, have been discharged onto the beach. We report here on monitoring spanning 2004-2012 to assess (1) the impacts of increased tailings discharges following an expansion of the mine in 2005, and (2) recovery after discharges halted in 2009. Sampling covered three levels of wave exposure, and compared impacted sites with comparable unmined reference sites. Benthic communities were quantified on both intertidal and subtidal reefs, and kelp densities and rock-lobster abundances, lengths and sex ratios on subtidal reefs. Prior to intensification of mining, deposition of tailings significantly influenced intertidal communities only at sheltered localities where wave action was insufficient to disperse them. Following the mine expansion, effects spread to both semi-exposed and exposed sites. After mining was suspended, recovery of the biota was limited, even three years later. Reductions of intertidal diversity and grazers, proliferation of macroalgae, and increased dominance by filter feeders were recorded at the impacted sites and were persistent, but the affects of wave exposure on community composition generally exceeded those of mining discharges. On subtidal reefs, tailings deposition reduced predators and grazers, increased filter feeders and ephemeral green algae, and decreased all other algae, possibly driven by light reduction due to plumes of suspended fine sediments. Increased discharges post-2005 also substantially influenced bathymetry, wave and current regimes, transforming 2 km of previously wave-exposed rocky coastline into a semi-exposed sandy beach. Tailings discharge appeared to influence community composition in four ways: (1) inundation and blanketing; (2) increased suspended particulate materials; (3) indirect top-down ripple effects, and (4) light reduction. Throughout the period 2004-2007, tailings-deposition had no detectable effects on the sex ratio, sizes or density of rock lobsters, but following suspension of mining activities, densities in 2010-2012 at impact sites exceeded those at reference sites. High natural variability in the abundance of rock lobsters may mask mining impacts, but the data strongly indicate an absence of any negative effects on rock lobsters.

  2. Home range and use of diurnal shelters by the Etendeka round-eared sengi, a newly discovered Namibian endemic desert mammal

    PubMed Central

    Dumbacher, John P.

    2015-01-01

    To understand habitat use by the newly described Etendeka round-eared sengi (Macroscelides micus) in northwestern Namibia, we radio-tracked five individuals for nearly a month. Home ranges (100% convex polygons) in the rocky desert habitat were remarkably large (mean 14.9 ha) when compared to sengi species in more mesic habitats (<1.5 ha). The activity pattern of M. micus was strictly nocturnal, which contrasts to the normal diurnal or crepuscular activity of other sengis. The day shelters of M. micus were under single rocks and they likely were occupied by single sengis. One tagged sengi used 22 different day shelters during the study. On average, only 7% of the day shelters were used more than once by the five tagged sengis. The shelters were also unusual for a small mammal in that they were unmodified in terms of excavation or nesting material. Shelter entrances were significantly oriented to face south by south west (average 193°), away from the angle of the prevailing midday sun. This suggests that solar radiation is probably an important aspect of M. micus thermal ecology, similar to other sengis. Compared to published data on other sengis, M. micus generally conforms to the unique sengi adaptive syndrome, but with modifications related to its hyper-arid habitat. PMID:26557433

  3. Electrical conductivity images across the Namibian passive margin: Implications for tectonic processes along the Kaoko Belt, the western Kongo Craton and the Walvis Ridge

    NASA Astrophysics Data System (ADS)

    Weckmann, Ute; Meqbel, Naser; Kapinos, Gerhard; Jegen-Kulcsar, Marion; Ritter, Oliver

    2014-05-01

    The Special Priority Programme SAMPLE of the German Science Foundation DFG is focussed on investigating processes related to the breakup of supercontinent Gondwana and the post breakup evolution of the passive continental margins of Africa and South America. Within this framework an amphibian magnetotelluric (MT) experiment was conducted at the Southern African passive continental margin, starting at the Walvis Ridge in the Atlantic Ocean and crossing onshore the entire Kaoko Belt and the western boundary of the Kongo Craton in Northern Namibia. High-quality MT data at 167 onshore and xx offshore sites show a strong variability within short distances and indicate complex subsurface structures in parts of the Kaoko Belt and along some of the major thrust and fault zones. To identify the main conductivity features and resolve their properties in more spatial detail we started our modelling procedure with 2D inversion for a sub-set of the data where the 3D effects are less dominant along the amphibian profile. However, to account for 3D effects in the MT data and to assess robustness of conductivity anomalies revealed in the 2D model we used the entire data set for the 3D inversion using ModEM. 2D and 3D inversion models show zones of high electrical conductivity that correlate with surface expressions of prominent faults such as the Purros Mylonite Zone and the Three Palm Mylonite Zone of the Kaoko Belt. Outcropping Etendeka flood basalts in the Western Kaoko Zones are imaged by 10-15km deep reaching zones of high resistivity. Additionally, the inversion models reveal a spatial correlation of resistive zones with the cratonic Northern Platform; however, the geologically defined onset of the Kongo Craton appears as an area of high conductivity. Compared with other craton boundaries in Southern Africa this is very untypical.

  4. QUINCE System; State-of-the-Art Review

    DTIC Science & Technology

    1978-06-01

    NOUN 3. VP -" VERB/INTRANS 4. VP -► VERB/TRANS 5. DET "* the 6. NOUN -* giraffe 7. NOUN -* apple 8. VERB/INTRANS "* dreams 9. VERB/TRANS...agreement for subjects, thus giving: The giraffes eat the apple. The giraffe eats the apple, but not: *The giraffes eats the apple. *The giraffe eat...the terminal 70 ,-..—-Wl-l., »Itv.!/«..:-^.»^^^^-^^..»»«....^,.-. /..-».A--^^. :M vocabulary. We must add rules: 6a. NOUN/SG -* giraffe 6b. NOUN

  5. Large herbivores facilitate savanna tree establishment via diverse and indirect pathways.

    PubMed

    Goheen, Jacob R; Palmer, Todd M; Keesing, Felicia; Riginos, Corinna; Young, Truman P

    2010-03-01

    1. Savanna ecosystems are defined largely by tree-grass mixtures, and tree establishment is a key driver of community structure and ecosystem function in these systems. The factors controlling savanna tree establishment are understudied, but likely involve some combination of seed, microsite and predator/fire limitation. In African savannas, suppression and killing of adult trees by large mammals like elephants (Loxodonta africana Blumenbach, 1797) and giraffes (Giraffa camelopardalis Linnaeus, 1758) can maintain tree-grass co-dominance, although the impacts of even these conspicuous herbivores on tree establishment also are poorly understood. 2. We combined seed addition and predator exclusion experiments with a large-scale, long-term field manipulation of large herbivores to investigate the relative importance of seeds, microsites and predators in limiting establishment of a monodominant tree (Acacia drepanolobium Sjostedt) in a Kenyan savanna. 3. Both wild and domestic (i.e. cattle; Bos taurus Linnaeus, 1758) large herbivores facilitated tree establishment by suppressing abundances of rodents, the most important seed and seedling predators. However, this indirect, positive effect of wild herbivores was negated by wild herbivores' suppression of seed production. Cattle did not have this direct, negative impact; rather, they further assisted tree establishment by reducing cover of understorey grasses. Thus, the impacts of both groups of large herbivores on tree establishment were largely routed through other taxa, with a negligible net effect of wild herbivores and a positive net effect of cattle on tree establishment. 4. The distinction between the (positive) net effect of cattle and (neutral) net effect of wild herbivores is due to the inclusion of browsers and mixed feeders within the assemblage of wild herbivores. Browsing by wild herbivores limited seed production, which reduced tree recruitment; grazing by cattle was more pronounced than that by wild

  6. A-10s over Kosovo. The Victory of Airpower over a Fielded Army as Told by the Airmen Who Fought in Operation Allied Force

    DTIC Science & Technology

    2003-12-01

    Chapter Page The Giraffe . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 Capt Ron “Stu” Stuewe Attack on Montenegro...194 1st Lt Johnny “CBU” Hamilton A Monkey and a Giraffe . . . . . . . . . . . . . . . . . . 197 Capt Joe “Joe Bro” Brosious 7 TACTICAL...204 Satellite photo of Giraffe radar area . . . . . . . . . . . 205 Plot of initial coordinates for Vega 31 . . . . . . . . . 217 Actual

  7. Fine-scale analysis of an assassin bug's behaviour: predatory strategies to bypass the sensory systems of prey

    PubMed Central

    2016-01-01

    Some predators sidestep environments that render them conspicuous to the sensory systems of prey. However, these challenging environments are unavoidable for certain predators. Stenolemus giraffa is an assassin bug that feeds on web-building spiders; the web is the environment in which this predator finds its prey, but it also forms part of its preys' sophisticated sensory apparatus, blurring the distinction between environment and sensory systems. Stenolemus giraffa needs to break threads in the web that obstruct its path to the spiders, and such vibrations can alert the spiders. Using laser vibrometry, this study demonstrates how S. giraffa avoids alerting the spiders during its approach. When breaking threads, S. giraffa attenuates the vibrations produced by holding on to the loose ends of the broken thread and causing them to sag prior to release. In addition, S. giraffa releases the loose ends of a broken thread one at a time (after several seconds or minutes) and in this way spaces out the production of vibrations in time. Furthermore, S. giraffa was found to maximally reduce the amplitude of vibrations when breaking threads that are prone to produce louder vibrations. Finally, S. giraffa preferred to break threads in the presence of wind, suggesting that this araneophagic insect exploits environmental noise that temporarily impairs the spiders' ability to detect vibrations. The predatory behaviour of S. giraffa seems to be adaptated in intricate manner for bypassing the sophisticated sensory systems of web-building spiders. These findings illustrate how the physical characteristics of the environment, along with the sensory systems of prey can shape the predatory strategies of animals. PMID:27853576

  8. Fine-scale analysis of an assassin bug's behaviour: predatory strategies to bypass the sensory systems of prey.

    PubMed

    Soley, Fernando G

    2016-10-01

    Some predators sidestep environments that render them conspicuous to the sensory systems of prey. However, these challenging environments are unavoidable for certain predators. Stenolemus giraffa is an assassin bug that feeds on web-building spiders; the web is the environment in which this predator finds its prey, but it also forms part of its preys' sophisticated sensory apparatus, blurring the distinction between environment and sensory systems. Stenolemus giraffa needs to break threads in the web that obstruct its path to the spiders, and such vibrations can alert the spiders. Using laser vibrometry, this study demonstrates how S. giraffa avoids alerting the spiders during its approach. When breaking threads, S. giraffa attenuates the vibrations produced by holding on to the loose ends of the broken thread and causing them to sag prior to release. In addition, S. giraffa releases the loose ends of a broken thread one at a time (after several seconds or minutes) and in this way spaces out the production of vibrations in time. Furthermore, S. giraffa was found to maximally reduce the amplitude of vibrations when breaking threads that are prone to produce louder vibrations. Finally, S. giraffa preferred to break threads in the presence of wind, suggesting that this araneophagic insect exploits environmental noise that temporarily impairs the spiders' ability to detect vibrations. The predatory behaviour of S. giraffa seems to be adaptated in intricate manner for bypassing the sophisticated sensory systems of web-building spiders. These findings illustrate how the physical characteristics of the environment, along with the sensory systems of prey can shape the predatory strategies of animals.

  9. Human Information Processing of Targets and Real-World Scenes.

    DTIC Science & Technology

    1985-07-30

    a typewriter, banana, or giraffe (Roach, Mervis, Gray, & Boyes-Braem 1976). Much of our knowledge about objects is organized at this level of...animal, e.g., a Giraffe . But the thesis proposed here would hold that the identifications of objects that were distinguished only by the aspect...Almost all natural categories, appear to have one or only a few instances, such as elephants or giraffes , in that we know of few (one?) componential

  10. Development of a High Throughput Assay for Indirectly Measuring Phage Growth Using the OmniLog (trademark) System

    DTIC Science & Technology

    2012-09-01

    and phage Giraffe exhibits a similar morphology (Fig. 1A). Phage BA39 (Fig. 1E) appears to belong to the Myoviridae family (icosahedral head and...see later) but this assignment is tentative. Monitoring the kinetics of bacterial growth using OmniLogTM system upon infection with Giraffe phage...spores with and without infection by Giraffe phage are shown in Figure 2A and B respectively. The growth of 7702 without phage infection followed a

  11. Acquisition of a Static Human Target in Complex Terrain: Study of Perceptual Learning Utilizing Virtual Environments

    DTIC Science & Technology

    2008-09-01

    or features), and the target (or signal) of interest. Image information about the signal, such as 3D description of a giraffe , is typically...confounded by uncertainties (or noise) introduced by rendering and projection… image details such as the precise shapes of the spots on the giraffe or the...the particular giraffe or the kind of bush, then the shapes of the spots and leaves would become important (Olman & Dersten, 2004). This point is

  12. Overview of Shipboard Data Fusion and Resource Management R&D Results and Rationale for Its Real-Time Implementation in the ASCACT Testbed

    DTIC Science & Technology

    1996-04-01

    and IRST sensor simulations. More specifically, the CPF radars currently supported by the CASE_ATTI sensor module are the SG-150 Sea Giraffe and the...specifications. The current A WW sensor suite of the CPF comprises the SPS-49 long range 2-D radar, the Sea Giraffe medium range 2-D radar, the CANEWS ESM...Sea Giraffe . This represents an original novelty of our simulation environment. P435278.PDF [Page: 66 of 128] UNCLASSIFIED 50 The baseline

  13. The Littoral Combat Ship: How We Got Here, and Why

    DTIC Science & Technology

    2014-01-01

    Giraffe 3D air and surface search radar and an eleven-cell SeaRAM anti-missile system.144 Both variants also received electronic warfare systems...The Sea Giraffe radar uses agile multi-beam technology to detect air and surface targets. It can simultaneously handle multiple threats approaching...from different directions and altitudes, including diving anti-ship missiles. Like the TRS-3D radar, the Sea Giraffe is specialized for rapidly

  14. Effective Bayesian Transfer Learning

    DTIC Science & Technology

    2010-03-01

    class •!Classes: llama, deer, horse, giraffe , elephant, anteater •!Transferred knowledge: •!Location of keypoints (landmarks) •!Variability of...Elephant Deer-Horse Deer- Giraffe Deer-Llama Giraffe -Deer Elephant-Deer Llama-Deer Horse-Deer TL7 Average Curve for deer-llama One class to another...class Transfer No Transfer TL7 Average Curves for pairs One class to another class Deer-Elephant Deer-Horse Deer- Giraffe Deer-Llama Llama-Deer

  15. Fires. A Joint Publication for U.S. Artillery Professionals. March - April 2010

    DTIC Science & Technology

    2010-03-01

    Russo LCMR: Not just an additional dutyPage 53 By MAJ Benjamin R. Luper and CW4 Dallas C. Whitney The Giraffe : The multi-mission radar gets it all...validate their training on the LCMR.” Fires55 March-April 2010 • The Giraffe : The Giraffe agile multi-beam air defense search radar at a...decathlete system than the Giraffe agile multi-beam air defense search radar. Challenges. His- torically, radars were specialized and used for

  16. VizieR Online Data Catalog: VLT-FLAMES Tarantula Survey (Evans+, 2011)

    NASA Astrophysics Data System (ADS)

    Evans, C. J.; Taylor, W. D.; Henault-Brunet, V.; Sana, H.; de Koter, A.; Simon-Diaz, S.; Carraro, G.; Bagnoli, T.; Bastian, N.; Bestenlehner, J. M.; Bonanos, A. Z.; Bressert, E.; Brott, I.; Campbell, M. A.; Cantiello, M.; Clark, J. S.; Costa, E.; Crowther, P. A.; de Mink, S. E.; Doran, E.; Dufton, P. L.; Dunstall, P. R.; Friedrich, K.; Garcia, M.; Gieles, M.; Graefener, G.; Herrero, A.; Howarth, I. D.; Izzard, R. G.; Langer, N.; Lennon, D. J.; Maiz Apellaniz, J.; Markova, N.; Najarro, F.; Puls, J.; Ramirez, O. H.; Sabin-Sanjulian, C.; Smartt, S. J.; Stroud, V. E.; van Loon, J. T.; Vink, J. S.; Walborn, N. R.

    2011-09-01

    The Tarantula Survey employs three modes of the Fibre Large Array Multi-Element Spectrograph (FLAMES) instrument on the VLT: Medusa-Giraffe, ARGUS-Giraffe and UVES. Most of the Medusa observations were obtained over the period 2008 October to 2009 February. (2 data files).

  17. Image Understanding Research

    DTIC Science & Technology

    1991-02-01

    investigating the possibility of parallel cutting out - look at the ears of the giraffe ). The recognition implementation. The data structure of a...0.1, 311 model segments -line fit. tol. -super segments/ giraffe 310 l .4,2,3,4,5,6,8 310 (b) Scene (c) Detected Animals panther 298 1.4,2,3.4,5,6,8 282

  18. Analysis of Global Properties of Shapes

    DTIC Science & Technology

    2010-06-01

    separate segments, some of the hoofs are outlying segments, and the back of the horse is merged with the tail of the giraffe . To improve the results...of the giraffe . Third, we consider only low-level cues: adjacency and point correspondences. Better segmenta- tions may be achieved by expanding the

  19. The Great Orange Hope: Ukraine, NATO, and the Dilemma of European Integration After the Orange Revolution

    DTIC Science & Technology

    2005-12-01

    122 Philip Shishkin. “Weighty Business: A Cold-War Plane lifts Ukrainian in Cargo Market; Antonov’s Rulsans Transport Armor, oil Rigs, Giraffes ...Antonov’s Rulsans Transport Armor, oil Rigs, Giraffes ; Playing Soccer in the Hold; A Legal Snag Grounds Flights.” The Wall Street Journal. New York

  20. Exploring Ways to Improve DTAG Deployment Success Rates with the ARTS Pneumatic Launcher

    DTIC Science & Technology

    2011-09-30

    spring, four springs, no spring), and a different shock absorber system has been developed, (the giraffe leg technique or GL, Figure 2), which has...GL ( giraffe leg technique) with 3 studs (right) WORK COMPLETED During the testing period various dummy whale targets were constructed for

  1. Components of Individual Differences in Human Intelligence.

    DTIC Science & Technology

    1983-02-01

    giraffe would be high on size but low on ferocity and human- ness. Examples of the items we used are shown in Table 1. Insert Table 1 about here Thus...series.] Classification Zebra Giraffe Goat (1) Dog (2) Cow (3) Mouse (4) Deer [The subject’s task is to rank-order the options in terms of theft

  2. Exploring Ways to Improve DTAG Deployment Success Rates With the ARTS Pneumatic Launcher

    DTIC Science & Technology

    2010-01-01

    absorber system has been developed, (the giraffe leg technique or GL, Figure 2), which has the shock absorbing component in front of the tag. The ARTS...3 Figure 2: the new 1- and 4-spring shock absorbing robot (left) and the GL ( giraffe leg technique) with 3 studs (right) WORK

  3. Aircraft Survivability: Susceptibility Reduction, Spring 2003

    DTIC Science & Technology

    2003-01-01

    jamming. [4] Additional anti-jamming capability arrived in the 1990s with the intro- duction of radars such as the Giraffe 75. Electronic protection (EP...Coherent Electronic Attack Aiding Aircraft Survivability C o m pl ex it y 1961 1966 1987 1991 1995 20xx SA–3 SA–6 SA–12 SA–15 Giraffe 75

  4. Public Participation Guide: Skorpion Zinc Project Case Study - Namibia

    EPA Pesticide Factsheets

    This case study describes the efforts of an independent professional team working with South African and Namibian specialists to identify and address environmental and public health and safety concerns related to a zinc mine and refinery.

  5. Warship Combat System Selection Methodology Based on Discrete Event Simulation

    DTIC Science & Technology

    2010-09-01

    Mk 2 1 20 mm Vulcan Phalanx Mk 15 Mod 1 16 RIM- 162 8 Harpoon Block 1C (2 quad) 4 Mk 46 Mod 5 Independ ence (LCS) US 2790 Ton Sea Giraffe VDS...DPG 35 mm 1 SGE-30 Goalkee per 30 mm 16 RIM 7P 8 Harpoon Block 1C (2 quad) 2 Mk 46 Mod 5 Lekiu Malaysia 1845 Ton DA08; Sea Giraffe 150HC...Oto Melara 76/62 Super Rapid 2 DS 30M Mk 2 30 mm No 12 MM40 Block 3 N/A Baynunah United Arab Emirates 830 Ton Sea Giraffe ; Scanter 2001

  6. US Navy Littoral Combat Ship (LCS) Capabilities, Risks, Possible Missions, and Modules to Support Future USMC Operating Concepts

    DTIC Science & Technology

    2011-07-29

    significantly earlier detection and more consistent track on attackers in the clutter." 50 "Sea Giraffe Amb- 3D Naval Surveillance Radar," SAAB...accessed February 09, 2011, http://www. saabgroup .co miN a v a liS ituational-Awareness/Multi -role-Surveillance- Radar/Sea Giraffe AMB/. 51 "MK 36...Weapon System." Accessed February 09, 2011. http://www .ra ytheon.com/capabili ties/products/ram/. SAAB. "Sea Giraffe Amb- 3D Naval Surveillance Radar

  7. Spectroscopy of quasar host galaxies at the VLT: stellar populations and dynamics down to the central kiloparsec

    NASA Astrophysics Data System (ADS)

    Courbin, F.; Letawe, G.; Magain, P.; Wisotzki, L.; Jablonka, P.; Alloin, D.; Jahnke, K.; Kuhlbrodt, B.; Meylan, G.; Minniti, D.

    2002-03-01

    1. Scientific Context 2. VLT Spectroscopic Observations 3. Spectra Decomposition and Stellar Population 4. Dynamics of the Host 5. Towards 2D Spectroscopy and High Spatial Resolution: GIRAFFE, SINFONI and FALCON

  8. VizieR Online Data Catalog: Low-mass stars spectroscopy in NGC 2516 (Jackson+, 2012)

    NASA Astrophysics Data System (ADS)

    Jackson, R. J.; Jeffries, R. D.

    2013-04-01

    Targets for our spectroscopic survey were selected from Irwin et al. (2007, Cat. J/MNRAS/377/741) with 14GIRAFFE and UVES spectrographs. Multiple targets were observed with GIRAFFE in eight separate fibre configurations. (2 data files).

  9. Implementation of an Education Technology Policy in Namibia's High Schools: Through the Eyes of the Teacher

    ERIC Educational Resources Information Center

    Boer, Perien Joniell

    2012-01-01

    The purpose of this study was to explore how Namibian high school teachers experienced the ICT policy for education in their schools. This mixed methods sequential explanatory design consists of two distinct phases: quantitative followed by qualitative (Creswell & Plano Clark, 2011). Quantitative data collection involved the distribution and…

  10. Voices of Divergence: Resistance, Contestation and the Shaping of Namibia's Teacher Education, 1990-2010

    ERIC Educational Resources Information Center

    Nyambe, John; Wilmot, Di

    2015-01-01

    This paper reports on an aspect of a broader study that investigated teacher educators' uptake of learner-centred pedagogy in post-apartheid Namibia. The paper shares part of the study that illuminated the path traversed by Namibian teacher education policy from 1990 to 2010, two decades into the country's post-apartheid self-rule. It argues that,…

  11. Consultancy Report: Assessment of the Zambia College of Distance Education (ZACODE)

    ERIC Educational Resources Information Center

    Ellis, Justin

    2009-01-01

    This study was carried out at the request of the Ministry of Education, Zambia. The Commonwealth of Learning contracted Turning Points Consultancy CC, a Namibian company, who provided the services of the author, to "carry out an evaluation of the Zambia College of Distance Education (ZACODE) and submit recommendations to the Ministry of…

  12. Modeling and Measuring Acoustic Backscatter from Fish Aggregations

    DTIC Science & Technology

    1999-09-30

    of the abundance, spatial distribution, schooling behaviour and acoustic backscatter of the Namibian pilchard. Cruise Report 99-4, Dr. Fridtjof ... Nansen . 103 pp. Rudstam, L, Horne, J., Fleischer, G. Report from the Great Lakes Acoustic Workshop III: Translation of acoustic data to fish abundance

  13. Innovation Management Issues Raised by a Distance-Learning Project in Eritrea: Can Such Projects Be Successfully Transplanted from One Developing Country to Another?

    ERIC Educational Resources Information Center

    Guariento, W. A.

    1997-01-01

    This paper is based on a case study of an audiotape/book based package designed to improve, via distance learning, the English of Namibian teachers of English, which was adapted in 1994-95 for use in Eritrea. (five references) (Author/CK)

  14. 50 CFR 23.35 - What are the requirements for an import permit?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) CONVENTION ON INTERNATIONAL TRADE IN ENDANGERED SPECIES OF WILD... Elephant, and Namibian Southern White Rhinoceros Sport-hunted Trophies Appendix-I Plants Appendix-I... CITES:ESA Plants ESA Sport-hunted Trophies ESA Wildlife 3-200-36 3-200-20 3-200-37 (3) Marine...

  15. 50 CFR 23.35 - What are the requirements for an import permit?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) CONVENTION ON INTERNATIONAL TRADE IN ENDANGERED SPECIES OF WILD... Elephant, and Namibian Southern White Rhinoceros Sport-hunted Trophies Appendix-I Plants Appendix-I... CITES:ESA Plants ESA Sport-hunted Trophies ESA Wildlife 3-200-36 3-200-20 3-200-37 (3) Marine...

  16. Working on the Impossible: Early Childhood Policies in Namibia

    ERIC Educational Resources Information Center

    Penn, Helen

    2008-01-01

    This article discusses the complexities of aid-giving using the example of early childhood policies in Namibia. It supports a critical view of aid processes and of World Bank endeavours in particular. Using an analysis of the World Bank funded education sector-wide improvement plan (ETSIP) in Namibia and three Namibian local case studies, it shows…

  17. San Language Development for Education in Namibia: Progress and Challenges

    ERIC Educational Resources Information Center

    Davids, Laurentius

    2011-01-01

    After Namibian independence, the government introduced an education system aimed at providing equal education to all and fostering the establishment of a nonracial society. The formulation of the language policy was one of major initiatives of the democratically elected government of Namibia after independence. The goal of this policy is to foster…

  18. Markedness and Salience in Language Contact and Second-Language Acquisition: Evidence from a Non-Canonical Contact Language.

    ERIC Educational Resources Information Center

    Deumert, Ana

    2003-01-01

    Argues that the study of contact varieties of a language are relevant to understanding of second language acquisition and use, because non-canonical contact languages are often situated on a continuum between pidginization and the more general processes of untutored second language acquisition. Data on participle regularization in Namibian Black…

  19. Plasticity of Human Spatial Cognition: Spatial Language and Cognition Covary across Cultures

    ERIC Educational Resources Information Center

    Haun, Daniel B. M.; Rapold, Christian J.; Janzen, Gabriele; Levinson, Stephen C.

    2011-01-01

    The present paper explores cross-cultural variation in spatial cognition by comparing spatial reconstruction tasks by Dutch and Namibian elementary school children. These two communities differ in the way they predominantly express spatial relations in language. Four experiments investigate cognitive strategy preferences across different levels of…

  20. Lessons Learned and Global Partnerships: Stories of Sexual and Reproductive Health from Namibia

    ERIC Educational Resources Information Center

    Maurer, Lis; Kelly, Maureen

    2005-01-01

    Through a Global Partnership Project, Planned Parenthood of the Southern Finger Lakes in Ithaca, New York and the Namibian Planned Parenthood Association (NAPPA) in Windhoek, Namibia have joined together to share best practices, technical assistance, support, and resources. The Global Partners share the common goal of increasing awareness,…

  1. Phylogenetic implications of the first African Middle Miocene hominoid frontal bone from Otavi, Namibia

    NASA Astrophysics Data System (ADS)

    Pickford, Martin; Sola, Salvador Moya; Köhler, Meike

    1997-09-01

    The discovery of a hominoid frontal at Berg Aukas, Namibia, aged 13-12 Ma, permits an analysis of the phylogenetic relations between fossil and extant great apes. The Namibian specimen is closer morphologically to African apes and humans (AAH), whereas all fossil Eurasian great apes differ markedly from AAH but are closer to the Pongo clade.

  2. The Development of National Standards for Adult Educators in Namibia

    ERIC Educational Resources Information Center

    Ellis, Justin; Richardson, Brent H.

    2012-01-01

    Since gaining independence from South Africa in 1990, Namibia has placed considerable emphasis on education, including adult learning. As a means of improving the quality of adult learning, the Namibian Ministry of Education commissioned the development of national standards in 2010 to express competency requirements for adult educators.…

  3. The Choice of English as Medium of Instruction and Its Effects on the African Languages in Namibia.

    ERIC Educational Resources Information Center

    Brock-Utne, Birgit; Holmarsdottir, Halla B.

    2001-01-01

    Discusses two studies that examine the effects of English, and its status as the official language, on Namibian languages. Finds that the numbers of students in African language classes in Namibia have been dropping significantly--in 1995 there were 100 students taking Oshindonga, and in 1999-2000 there was one. (Contains 66 references.) (NB)

  4. 78 FR 60317 - Notice of Updates to the Department of Labor's List of Goods Produced by Child Labor or Forced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-01

    ... qualitative research to determine the current situation of child labor in the Namibian charcoal industry. The... eliminated. In the 2012-2013 research period, ILAB staff reviewed four items currently on the List to... these items, as discussed below, and continues to conduct research on the fourth item, salt...

  5. The Education of Refugees in Africa: The Role of Distance and Open Learning.

    ERIC Educational Resources Information Center

    Dodds, Tony

    1988-01-01

    Description of education services to refugees in Africa focuses on three case studies: Institute of In-Service Teacher Training (IITT) in Somalia; Sudan Extension Unit (SEU); and Namibian Extension Unit (NEU) in Angola and Zambia. Highlights include refugee problems, the relevance of distance and open learning approaches, and international…

  6. Endoparasites of exotic ungulates from the Giraffidae and Camelidae families kept ex situ.

    PubMed

    Nosal, Paweł; Kowal, Jerzy; Kornaś, Sławomir; Wyrobisz, Anna; Skotnicki, Józef; Basiaga, Marta; Plucińska, Natalia E

    2016-01-01

    Giraffes and camels are popular attractions at zoological gardens. In order to present the diversity of parasites infecting exotic ungulates from zoos, faecal samples from three giraffes and six camels from both the Silesian Zoological Garden in Chorzów, and Kraków Zoological Garden, were examined. The research was carried out over a ten-month period in 2013 and 2014. In total, 100 faecal samples from 18 animals were analysed with the use of the McMaster method. Moreover, coccidian oocysts were incubated to investigate their development and larvoscopic examination was conducted to detect the presence of nematode species. Giraffes were infected with coccidia from the genus Eimeria, and gastrointestinal nematodes from the Strongylida order, and Trichuris and Aonhotheca genera. One male giraffe was uninfected. The level of infection in giraffes was low when compared to camels kept in both of the zoos. Limited contact with other animal species contributed greatly to the lower level of infection in camels from Kraków Zoo than those from Chorzów, which were kept in the same enclosure as alpacas and Shetland ponies.

  7. Application of a monoclonal antibody to a comparative study of alpha-lactalbumins from various species

    SciTech Connect

    Kaminogawa, S.; Shimoda, M.; Kurisaki, J.; Yamauchi, K.

    1989-05-01

    A monoclonal antibody to bovine alpha-lactalbumin was prepared and purified. The binding ability of alpha-lactalbumin from different species (cow, goat, giraffe, horse, pig, human, monkey, and guinea pig) was examined by a competitive radioimmunoassay. The order in strength of the binding affinity was cow goat, giraffe, horse, cynomolgus monkey and human, pig, and guinea pig. The order of evolutional divergence calculated from the amino acid composition was cow, goat, giraffe, horse, pig, guinea pig and human, and monkey. The orders in both cases were similar. Hence, it is suggested that immunological divergence as deduced by a monoclonal antibody is likely to be close to the evolutional divergence of alpha-lactalbumin.

  8. VizieR Online Data Catalog: Carina Project VIII. α-element abundances (Fabrizio+, 2015)

    NASA Astrophysics Data System (ADS)

    Fabrizio, M.; Nonino, M.; Bono, G.; Primas, F.; Thevenin, F.; Stetson, P. B.; Cassisi, S.; Buonanno, R.; Coppola, G.; da Silva, R. O.; Dall'Ora, M.; Ferraro, I.; Genovali, K.; Gilmozzi, R.; Iannicola, G.; Marconi, M.; Monelli, M.; Romaniello, M.; Walker, A. R.

    2015-05-01

    We present an extension of the analysis for the high-resolution (R~40000) UVES and FLAMES/UVES red-arm spectra presented in Fabrizio et al. (2012, Cat. J/PASP/124/519, Paper V), where we obtained the FeI and FeII abundances of 44 red giant Carina stars (hereafter UVES). File table2 contains the list of cross-identified spectroscopic targets. File table3 contains the equivalent widths and their errors for individual UVES stars. File table4 contains the equivalent widths and their errors for stacked stars in Giraffe HR grisms. File table5 contains the individual abundances and errors for old population stacked stars in Giraffe LR08 grism. File table6 contains the individual abundances and errors for intermediate-age population stacked stars in Giraffe LR08 grism. File table8 contains the mean chemical abundances and dispersions of Carina stars. (6 data files).

  9. VizieR Online Data Catalog: NGC 6121 turnoff and subgiant stars abundances (Spite+, 2016)

    NASA Astrophysics Data System (ADS)

    Spite, M.; Spite, F.; Gallagher, A. J.; Monaco, L.; Bonifacio, P.; Caffau, E.; Villanova, S.

    2016-08-01

    Observations were conducted at the Very Large Telescope (VLT) (Paranal, Chile) between April and July 2010 using the LR2 setting from 400 to 456nm with a resolving power R=6000, the HR12 setting from 583 to 614nm, and the HR15N setting from 666 to 679nm, both with a resolving power of about R=20000. The frames were processed using the FLAMES-GIRAFFE reduction pipeline. More information can be found in Monaco et al. (2012A&A...539A.157M, Cat. J/A+A/539/A157). The spectroscopic data are available through the Giraffe archive at Paris Observatory (http://giraffe-archive.obspm.fr/). (2 data files).

  10. VizieR Online Data Catalog: NGC 2808 HB stars abundances (Marino+, 2014)

    NASA Astrophysics Data System (ADS)

    Marino, A. F.; Milone, A. P.; Przybilla, N.; Bergemann, M.; Lind, K.; Asplund, M.; Cassisi, S.; Catelan, M.; Casagrande, L.; Valcarce, A. A. R.; Bedin, L. R.; Cortes, C.; D'Antona, F.; Jerjen, H.; Piotto, G.; Schlesinger, K.; Zoccali, M.; Angeloni, R.

    2014-11-01

    To identify our stellar sample, we use the photometric catalogue of Momany et al. (2004), which has been obtained from U, B and V images collected with the Wide-Field Imager (WFI) mounted at the 2.2m ESO-MPI (Max-Planck-Institut) telescope at La Silla observatory, Chile. Our spectroscopic data consist of FLAMES/GIRAFFE and FLAMES/UVES data collected under the ESO programme 086.D-0141 (PI: Marino). The GIRAFFE fibres were used with the HR12 setup, covering the spectral range from ~5820 to ~6140Å with a resolution of ~18700. (6 data files).

  11. VizieR Online Data Catalog: VLT-FLAMES Tarantula Survey: B supergiants (McEvoy+, 2015)

    NASA Astrophysics Data System (ADS)

    McEvoy, C. M.; Dufton, P. L.; Evans, C. J.; Kalari, V. M.; Markova, N.; Simon-Diaz, S.; Vink, J. S.; Walborn, N. R.; Crowther, P. A.; de Koter, A.; de Mink, S. E.; Dunstall, P. R.; Henault-Brunet, V.; Herrero, A.; Langer, N.; Lennon, D. J.; Maiz Apellaniz, J.; Najarro, F.; Puls, J.; Sana, H.; Schneider, F. R. N.; Taylor, W. D.

    2015-06-01

    The majority of the VFTS data were obtained using the Medusa mode of FLAMES, which uses fibres to feed the light from up to 130 targets simultaneously to the Giraffe spectrograph. Nine Medusa configurations (Fields A to I) were observed in the 30 Dor region, with the targets sampling its different clusters and the local field population. The analysis presented here employs the FLAMES-Medusa observations obtained with two of the standard Giraffe settings (LR02 and LR03), giving coverage of the λλ3960-5050Å region at a resolving power of ~7000. (5 data files).

  12. Bioaugmentation of the anaerobic digestion of food waste by dungs of herbivore, carnivore, and omnivore zoo animals.

    PubMed

    Ariunbaatar, Javkhlan; Ozcan, Onur; Bair, Robert; Esposito, Giovanni; Ball, Ray; Lens, Piet N L; Yeh, Daniel H

    2017-03-27

    The potential improvement of biomethanation of food waste (FW) by adding dung of herbivore (giraffe, llama, koala), carnivore (tiger), and omnivore (sloth bear) animals to anaerobic sludge (AnS) was investigated. Adding 30% giraffe, sloth bear or koala dung to the AnS inoculum yielded, respectively, a 11.17 (±4.51), 10.10 (±1.23), and 1.41 (±0.56)% higher biomethane production, as compared to the control (FW with solely AnS). The highest biomethane production of 564.00 (±3.88) ml CH4/gVSadded obtained with 30% giraffe dung and 70% AnS was attributed to a higher solubilization of proteins (6.96 ± 2.76%) and recalcitrant carbohydrates (344.85 ± 54.31 mg/L as compared to zero). The biomethanation process could have been stimulated by the microorganisms or enzymes newly introduced, and/or the trace elements (Ni, Zn, and Co) present in the giraffe dung. These results indicate that bioaugmentation with zoo animals dung is worthy of further investigation as a strategy for improving the biomethane recovery from organic wastes.

  13. Habitat Is Where It's At. A Coloring Book about Wildlife Habitat.

    ERIC Educational Resources Information Center

    Hernbrode, Bob

    This coloring book provides illustrations of 18 animals in their habitats. Animals presented include: beavers; bears; bats; housecats; elephants; moose; tigers; geese; chimpanzees; rabbits; butterflies; giraffes; fish; kangaroos; gnus; bugs and bees; and humans. Two additional illustrations are provided which show that the sun and air are part of…

  14. 9 CFR 94.0 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Cervid. All members of the family Cervidae and hybrids, including deer, elk, moose, caribou, reindeer... whether the flesh and juices have lost all red and pink color. Port of arrival. Any place in the United..., buffaloes, sheep, goats, deer, antelopes, camels, llamas and giraffes. Sentinel bird. A chicken that...

  15. Development of Teleological Explanations in Peruvian Quechua-Speaking and U.S. English-Speaking Preschoolers and Adults

    ERIC Educational Resources Information Center

    Sánchez Tapia, Ingrid; Gelman, Susan A.; Hollander, Michelle A.; Manczak, Erika M.; Mannheim, Bruce; Escalante, Carmen

    2016-01-01

    Teleological reasoning involves the assumption that entities exist for a purpose (giraffes have long necks for reaching leaves). This study examines how teleological reasoning relates to cultural context, by studying teleological reasoning in 61 Quechua-speaking Peruvian preschoolers (M[subscript age] = 5.3 years) and adults in an indigenous…

  16. Camelopardalis

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (formerly sometimes spelled Camelopardus; the Giraffe; abbrev. Cam, gen. Camelopardalis; area 757 sq. deg.) A northern constellation which lies between Auriga and the north celestial pole, and culminates at midnight in late December. It represents the animal upon which Rebecca rode in Canaan to become the wife of Isaac, and was introduced by the Dutch theologian and geographer Petrus Plancius, who...

  17. The cervical anatomy of Samotherium, an intermediate-necked giraffid

    PubMed Central

    Danowitz, Melinda; Domalski, Rebecca; Solounias, Nikos

    2015-01-01

    Giraffidae are represented by many extinct species. The only two extant taxa possess diametrically contrasting cervical morphology, as the okapi is short-necked and the giraffe is exceptionally long-necked. Samotherium major, known from the Late Miocene of Samos in Greece and other Eurasian localities, is a key extinct giraffid; it possesses cervical vertebrae that are intermediate in the evolutionary elongation of the neck. We describe detailed anatomical features of the cervicals of S. major, and compare these characteristics with the vertebrae of the two extant giraffid taxa. Based on qualitative morphological characters and a quantitative analysis of cervical dimensions, we find that the S. major neck is intermediate between that of the okapi and the giraffe. Specifically, the more cranial (C2–C3) vertebrae of S. major represent a mosaic of features shared either with the giraffe or with the okapi. The more caudal (C5–C7) S. major vertebrae, however, appear transitional between the two extant taxa, and hence are more unique. Notably, the C6 of S. major exhibits a partially excavated ventral lamina that is strong cranially but completely absent on the caudal half of the ventral vertebral body, features between those seen in the giraffe and the okapi. Comprehensive anatomical descriptions and measurements of the almost-complete cervical column reveal that S. major is a truly intermediate-necked giraffid. Reconstructions of the neck display our findings. PMID:26716010

  18. VizieR Online Data Catalog: Blue stragglers in ω Cen (Mucciarelli+, 2014)

    NASA Astrophysics Data System (ADS)

    Mucciarelli, A.; Lovisi, L.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.; Monaco, L.

    2016-11-01

    The spectroscopic data set analyzed in this paper includes two samples of high-resolution spectra acquired with the multi-object spectrograph FLAMES-GIRAFFE mounted at the Very Large Telescope of the European Southern Observatory (ESO). (1 data file).

  19. VizieR Online Data Catalog: Horizontal branch stars in NGC 6723 (Gratton+, 2015)

    NASA Astrophysics Data System (ADS)

    Gratton, R. G.; Lucatello, S.; Sollima, A.; Carretta, E.; Bragaglia, A.; Momany, Y.; D'Orazi, V.; Salaris, M.; Cassisi, S.; Stetson, P. B.

    2015-02-01

    We observed a total of 58 candidate HB stars of NGC 6723 with FLAMES + GIRAFFE at the VLT. The instrument was used in MEDUSA mode, with fibres pointing to each star and several (~20) fibres used for determining the local sky background. Observations were made between 2011-07-11 and 2011-08-27. (5 data files).

  20. VizieR Online Data Catalog: SEP stars radial velocities (Fremat+, 2017)

    NASA Astrophysics Data System (ADS)

    Fremat, Y.; Altmann, M.; Pancino, E.; Soubiran, C.; Jofre, P.; Damerdji, Y.; Heiter, U.; Royer, F.; Seabroke, G.; Sordo, R.; Blanco-Cuaresma, S.; Jasniewicz, G.; Martayan, C.; Thevenin, F.; Vallenari, A.; Blomme, R.; David, M.; Gosset, E.; Katz, D.; Viala, Y.; Boudreault, S.; Cantat-Gaudin, T.; Lobel, A.; Meisenheimer, K.; Nordlander, T.; Raskin, G.; Royer, P.; Zorec, J.

    2016-10-01

    The tables contain a description of the observations we performed with the GIRAFFE and UVES spectrographs of a sample of targets found in the South Ecliptic Pole. Radial velocities and astrophysical parameters were derived, and the variability of the RVs was assessed. (7 data files).

  1. Portraits of Learning 2007: We Present This Year's Winning Student Photos

    ERIC Educational Resources Information Center

    Technology & Learning, 2007

    2007-01-01

    This year's more than 4,000 Portraits of Learning entries attest to the growing comfort with digital technologies and visual arts that today's kids have. This article presents 12 winning student photos of the Portraits of Learning 2007. The winners emerged from the selection of subjects that varied wildly--from grasshoppers, giraffes, zebras, and…

  2. Benefits and Costs of Lexical Decomposition and Semantic Integration during the Processing of Transparent and Opaque English Compounds

    ERIC Educational Resources Information Center

    Ji, Hongbo; Gagne, Christina L.; Spalding, Thomas L.

    2011-01-01

    Six lexical decision experiments were conducted to examine the influence of complex structure on the processing speed of English compounds. All experiments revealed that semantically transparent compounds (e.g., "rosebud") were processed more quickly than matched monomorphemic words (e.g., "giraffe"). Opaque compounds (e.g., "hogwash") were also…

  3. VizieR Online Data Catalog: Gaia-ESO Survey: NGC6705 (Cantat-Gaudin+, 2014)

    NASA Astrophysics Data System (ADS)

    Cantat-Gaudin, T.; Vallenari, A.; Zaggia, S.; Bragaglia, A.; Sordo, R.; Drew, J. E.; Eisloeffel, J.; Farnhill, H. J.; Gonzalez-Solares, E.; Greimel, R.; Irwin, M. J.; Kupcu-Yoldas, A.; Jordi, C.; Blomme, R.; Sampedro, L.; Costado, M. T.; Alfaro, E.; Smiljanic, R.; Magrini, L.; Donati, P.; Friel, E. D.; Jacobson, H.; Abbas, U.; Hatzidimitriou, D.; Spagna, A.; Vecchiato, A.; Balaguer-Nunez, L.; Lardo, C.; Tosi, M.; Pancino, E.; Klutsch, A.; Tautvaisiene, G.; Drazdauskas, A.; Puzeras, E.; Jimenez-Esteban, F.; Maiorca, E.; Geisler, D.; San, I.; Villanova, S.; Gilmore, G.; Randich, S.; Bensby, T.; Flaccomio, E.; Lanzafame, A.; Recio-Blanco, A.; Damiani, F.; Hourihane, A.; Jofre, P.; Delaverny, P.; Masseron, T.; Morbidelli, L.; Prisinzano, L.; Sacco, G. G.; Sbordone, L.; Worley, C. C.

    2014-07-01

    We combine new BV photometry with the spectroscopic observations of the Gaia-ESO Survey to study the open cluster NGC6 705. 1028 stars were observed with the HR15n grating of the GIRAFFE instrument at VLT/UT2. The radial velocities obtained for those stars were used to derive membership probabilities. (1 data file).

  4. VizieR Online Data Catalog: Radial velocities in seven globular clusters (Lardo+, 2015)

    NASA Astrophysics Data System (ADS)

    Lardo, C.; Pancino, E.; Bellazzini, M.; Bragaglia, A.; Donati, P.; Gilmore, G.; Randich, S.; Feltzing, S.; Jeffries, R. D.; Vallenari, A.; Alfaro, E. J.; Allende Prieto, C.; Flaccomio, E.; Koposov, S. E.; Recio-Blanco, A.; Bergemann, M.; Carraro, G.; Costado, M. T.; Damiani, F.; Hourihane, A.; Jofree, P.; de Laverny, P.; Marconi, G.; Masseron, T.; Morbidelli, L.; Sacco, G. G.; Worley, C. C.

    2014-11-01

    Velocities are given for 1826 stars in the field of the globular clusters NGC 1851, NGC 2808, NGC 4372, NGC 4833, NGC 5927, NGC 6752, and NGC 7078 observed with FLAMES/GIRAFFE@VLT. The table provides the individual identifications, coordinates, V magnitudes, velocities and their associated uncertainties for each star. (2 data files).

  5. VizieR Online Data Catalog: Abundances of 47 Tuc turn-off stars (Dobrovolskas+, 2014)

    NASA Astrophysics Data System (ADS)

    Dobrovolskas, V.; Kucinskas, A.; Bonifacio, P.; Korotin, S. A.; Steffen, M.; Sbordone, L.; Caffau, E.; Ludwig, H.-G.; Royer, F.; Prakapavicius, D.

    2014-07-01

    Spectra of the TO stars in 47 Tuc investigated in this work were obtained with the GIRAFFE spectrograph in August-September, 2008, under the programme 081.D-0287(A) (PI: Shen). The same data set was independently analysed by D'Orazi et al. (2010ApJ...713L...1D, Cat. J/ApJ/713/L1). (1 data file).

  6. VizieR Online Data Catalog: CaIIK spectra of 7 Galactic and MC open clusters (Smoker+, 2015)

    NASA Astrophysics Data System (ADS)

    Smoker, J.; Keenan, F. P.; Fox, A. J.

    2015-07-01

    The data on which the current paper is based were extracted from the ESO archive and are FLAMES-GIRAFFE observations towards three open clusters located in the Milky Way, and two in each of the Large and Small Magellanic Clouds, plus FEROS and UVES observations towards stars located in the Magellanic system and Milky Way. (18 data files).

  7. VizieR Online Data Catalog: Abundances in outer parts of Fornax dSph (Hendricks+, 2014)

    NASA Astrophysics Data System (ADS)

    Hendricks, B.; Koch, A.; Walker, M.; Johnson, C. I.; Penarrubia, J.; Gilmore, G.

    2014-10-01

    The spectra for this study have been obtained in November 2008 with FLAMES at the VLT (programme ID 082.B-0940(A)) , where we used GIRAFFE in MEDUSA high-resolution mode (HR21, R~16000, 8484-9001Å). Tables A1-A3 are presented here in combined tables. (2 data files).

  8. Misconceived Causal Explanations for Emergent Processes

    ERIC Educational Resources Information Center

    Chi, Michelene T. H.; Roscoe, Rod D.; Slotta, James D.; Roy, Marguerite; Chase, Catherine C.

    2012-01-01

    Studies exploring how students learn and understand science processes such as "diffusion" and "natural selection" typically find that students provide misconceived explanations of how the patterns of such processes arise (such as why giraffes' necks get longer over generations, or how ink dropped into water appears to "flow"). Instead of…

  9. Laboratory information management system: an example of international cooperation in Namibia.

    PubMed

    Colangeli, Patrizia; Ferrilli, Monica; Quaranta, Fabrizio; Malizia, Elio; Mbulu, Rosa-Stella; Mukete, Esther; Iipumbu, Lukas; Kamhulu, Anna; Tjipura-Zaire, Georgina; Di Francesco, Cesare; Lelli, Rossella; Scacchia, Massimo

    2012-01-01

    The authors describe the project undertaken by the Istituto G. Caporale to provide a laboratory information management system (LIMS) to the Central Veterinary Laboratory (CVL) in Windhoek, Namibia. This robust laboratory management tool satisfies Namibia's information obligations under international quality standard ISO 17025:2005. The Laboratory Information Management System (LIMS) for Africa was designed to collect and manage all necessary information on samples, tests and test results. The system involves the entry of sample data on arrival, as required by Namibian sampling plans, the tracking of samples through the various sections of the CVL, the collection of test results, generation of test reports and monitoring of outbreaks through data interrogation functions, eliminating multiple registrations of the same data on paper records. It is a fundamental component of the Namibian veterinary information system.

  10. Epidemiology, pathology, and genetic analysis of a canine distemper epidemic in Namibia.

    PubMed

    Gowtage-Sequeira, Sonya; Banyard, Ashley C; Barrett, Tom; Buczkowski, Hubert; Funk, Stephan M; Cleaveland, Sarah

    2009-10-01

    Severe population declines have resulted from the spillover of canine distemper virus (CDV) into susceptible wildlife, with both domestic and wild canids being involved in the maintenance and transmission of the virus. This study (March 2001 to October 2003) collated case data, serologic, pathologic, and molecular data to describe the spillover of CDV from domestic dogs (Canis familiaris) to black-backed jackals (Canis mesomelas) during an epidemic on the Namibian coast. Antibody prevalence in jackals peaked at 74.1%, and the clinical signs and histopathologic observations closely resembled those observed in domestic dog cases. Viral RNA was isolated from the brain of a domestic dog from the outbreak area. Sequence data from the phosphoprotein (P) gene and the hemagglutinin (H) genes were used for phylogenetic analyses. The P gene sequence from the domestic dog shared 98% identity with the sequence data available for other CDV isolates of African carnivores. For the H gene, the two sequences available from the outbreak that decimated the lion population in Tanzania in 1994 were the closest match with the Namibian sample, being 94% identical across 1,122 base pairs (bp). Phylogenetic analyses based on this region clustered the Namibian sample with the CDV that is within the morbilliviruses. This is the first description of an epidemic involving black-backed jackals in Namibia, demonstrating that this species has the capacity for rapid and large-scale dissemination of CDV. This work highlights the threat posed to endangered wildlife in Namibia by the spillover of CDV from domestic dog populations. Very few sequence data are currently available for CDV isolates from African carnivores, and this work provides the first sequence data from a Namibian CDV isolate.

  11. Massive emissions of toxic gas in the Atlantic.

    PubMed

    Weeks, Scarla J; Currie, Bronwen; Bakun, Andrew

    2002-01-31

    Recurrent eruptions of toxic hydrogen sulphide gas in the waters along the Namibian coast off southwestern Africa have been considered to be local features with only limited ecosystem-scale consequences. But satellite remote sensing has revealed that these naturally occurring events are much more extensive and longer-lasting than previously suspected, and that the resultant hypoxia may last for much longer. The effects on the marine ecology and valuable coastal fisheries of this region are likely to be important.

  12. Complete Genome and Molecular Epidemiological Data Infer the Maintenance of Rabies among Kudu (Tragelaphus strepsiceros) in Namibia

    PubMed Central

    Scott, Terence P.; Fischer, Melina; Khaiseb, Siegfried; Freuling, Conrad; Höper, Dirk; Hoffmann, Bernd; Markotter, Wanda; Müller, Thomas; Nel, Louis H.

    2013-01-01

    Rabies in kudu is unique to Namibia and two major peaks in the epizootic have occurred since it was first noted in 1977. Due to the large numbers of kudu that were affected, it was suspected that horizontal transmission of rabies occurs among kudu and that rabies was being maintained independently within the Namibian kudu population – separate from canid cycles, despite geographic overlap. In this study, it was our aim to show, through phylogenetic analyses, that rabies was being maintained independently within the Namibian kudu population. We also tested, through complete genome sequencing of four rabies virus isolates from jackal and kudu, whether specific mutations occurred in the virus genome due to host adaptation. We found the separate grouping of all rabies isolates from kudu to those of any other canid species in Namibia, suggesting that rabies was being maintained independently in kudu. Additionally, we noted several mutations unique to isolates from kudu, suggesting that these mutations may be due to the adaptation of rabies to a new host. In conclusion, we show clear evidence that rabies is being maintained independently in the Namibian kudu population – a unique phenomenon with ecological and economic impacts. PMID:23527015

  13. Aging of marine organic matter during cross-shelf lateral transport in the Benguela upwelling system revealed by compound-specific radiocarbon dating

    NASA Astrophysics Data System (ADS)

    Mollenhauer, Gesine; Inthorn, Maik; Vogt, Thomas; Zabel, Matthias; Sinninghe Damsté, Jaap S.; Eglinton, Timothy I.

    2007-09-01

    Organic matter accumulation and burial on the Namibian shelf and upper slope are spatially heterogeneous and strongly controlled by lateral transport in subsurface nepheloid layers. Much of the material deposited in depo-centers on the slope ultimately derives from the shelf. Supply of organic matter from the shelf involves selective transport of organic matter. We studied these selective transport processes by analyzing the radiocarbon content of co-occurring sediment fractions. Here we present radiocarbon data for total organic carbon as well as three tracers of surface ocean productivity (phytoplankton-derived alkenones, membrane lipids of pelagic crenarchaeota (crenarchaeol), and calcareous microfossils of planktic foraminifera) in core-top and near-surface sediment samples. The samples were collected on the Namibian margin along a shelf-slope transect (85 to 1040 m) at 24°S and from the upper slope depo-center at 25.5°S. In core-top sediments, alkenone ages gradually increased from modern to 3490 radiocarbon years with distance from shore and with water depth. Crenarchaeol, while younger than alkenones, also increased in age with distance offshore. It was concluded that the observed ages were a consequence of cross-shelf transport and associated aging of organic matter. Radiocarbon ages of preserved lipid biomarkers in sediments thus at least partially depend on the relative amount of laterally supplied, pre-aged material present in a sample, highlighting the importance of nepheloid transport for the sedimentation of organic matter over the Namibian margin.

  14. Isolation of Bartonella henselae, Bartonella koehlerae subsp. koehlerae, Bartonella koehlerae subsp. bothieri and a new subspecies of B. koehlerae from free-ranging lions (Panthera leo) from South Africa, cheetahs (Acinonyx jubatus) from Namibia and captive cheetahs from California.

    PubMed

    Molia, S; Kasten, R W; Stuckey, M J; Boulouis, H J; Allen, J; Borgo, G M; Koehler, J E; Chang, C C; Chomel, B B

    2016-11-01

    Bartonellae are blood- and vector-borne Gram-negative bacteria, recognized as emerging pathogens. Whole-blood samples were collected from 58 free-ranging lions (Panthera leo) in South Africa and 17 cheetahs (Acinonyx jubatus) from Namibia. Blood samples were also collected from 11 cheetahs (more than once for some of them) at the San Diego Wildlife Safari Park. Bacteria were isolated from the blood of three (5%) lions, one (6%) Namibian cheetah and eight (73%) cheetahs from California. The lion Bartonella isolates were identified as B. henselae (two isolates) and B. koehlerae subsp. koehlerae. The Namibian cheetah strain was close but distinct from isolates from North American wild felids and clustered between B. henselae and B. koehlerae. It should be considered as a new subspecies of B. koehlerae. All the Californian semi-captive cheetah isolates were different from B. henselae or B. koehlerae subsp. koehlerae and from the Namibian cheetah isolate. They were also distinct from the strains isolated from Californian mountain lions (Felis concolor) and clustered with strains of B. koehlerae subsp. bothieri isolated from free-ranging bobcats (Lynx rufus) in California. Therefore, it is likely that these captive cheetahs became infected by an indigenous strain for which bobcats are the natural reservoir.

  15. Propagation of coastally trapped waves in the Northern Benguela studied with hydrographic moorings and a regional circulation model

    NASA Astrophysics Data System (ADS)

    Siegfried, Lydia; Junker, Tim; Mohrholz, Volker; Schmidt, Martin; van der Plas, Anja

    2015-04-01

    Upwelling in the Northern Benguela is mainly driven by local winds but nutrient and oxygen conditions on the shelf are largely determined by the intrusion of South Atlantic Central Water (SACW) through the Angola-Benguela Front (ABF). The poleward spreading of tropical waters is related to the propagation of Kelvin and continental shelf waves originating from the Equatorial Atlantic and bending poleward at the African coast. The strength of this remote forcing is thought to be especially relevant to the interannual variability of the upwelling system. We test the hypothesis that the poleward spreading of tropical water is driven by the combined action of both I) coastally trapped waves of equatorial origin bringing tropical water to the ABF zone and II) locally forced waves generating the undercurrent which advects SACW onto the shelf. Signals of poleward propagating waves were found in satellite altimeter data up to 12°S. To detect the propagation of coastally trapped waves further south in-situ measurements have been conducted. Three hydrographic moorings equipped inter alia with ADCPs have been deployed and maintained within the framework of the projects GENUS, SACUS and PREFACE. For the first time, simultaneous current measurements on the Namibian shelf have been realized at three different positions. The moorings are located in the Cunene cell, the Northern Namibian cell and the Central Namibian cell. By means of a regional circulation model based on MOM the propagation of coastally trapped waves are investigated with high spatial and temporal resolution (about 8km along the Namibian coast, 2-hour averages). It has been demonstrated that modelled meridional transports correspond well with long term measurements obtained by a mooring off Walvis Bay. The power spectral density shows sharp peaks for the tidal and inertial frequencies. A large proportion of kinetic energy accounts for the sub-inertial frequency range. Meridional transport signals were found to

  16. VizieR Online Data Catalog: Gaia-ESO Survey: Halpha emission stars catalogue (Traven+, 2015)

    NASA Astrophysics Data System (ADS)

    Traven, G.; Zwitter, T.; van Eck, S.; Klutsch, A.; Bonito, R.; Lanzafame, A. C.; Alfaro, E. J.; Bayo, A.; Bragaglia, A.; Costado, M. T.; Damiani, F.; Flaccomio, E.; Frasca, A.; Hourihane, A.; Jimenez-Esteban, F.; Lardo, C.; Morbidelli, L.; Pancino, E.; Prisinzano, L.; Sacco, G. G.; Worley, C. C.

    2015-07-01

    The GES employs the VLT-UT2 FLAMES high-resolution multiobject spectrograph . FLAMES has two instruments, the higher-resolution UVES, fed by 8 fibres, and GIRAFFE, with about 130 fibres. In the present paper we concentrate on the much more numerous GIRAFFE spectra to thoroughly test our classification scheme; a similar analysis of the UVES spectra will follow later. We use only spectra obtained in the wavelength range with Hα line - HR15N setting (6470-6790Å, R=17000), for which the majority of targets selected by GES are open cluster stars. Along with ongoing GES observations, we also use all relevant ESO archive data, which are included to be analysed as part of GES. (3 data files).

  17. VizieR Online Data Catalog: Metallicity of the γ Vel cluster (Spina+, 2014)

    NASA Astrophysics Data System (ADS)

    Spina, L.; Randich, S.; Palla, F.; Sacco, G. G.; Magrini, L.; Franciosini, E.; Morbidelli, L.; Prisinzano, L.; Alfaro, E. J.; Biazzo, K.; Frasca, A.; Gonzalez Hernandez, J. I.; Sousa, S. G.; Adibekyan, V.; Delgado-Mena, E.; Montes, D.; Tabernero, H.; Klutsch, A.; Gilmore, G.; Feltzing, S.; Jeffries, R. D.; Micela, G.; Vallenari, A.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Koposov, S.; Lanzafame, A. C.; Pancino, E.; Recio-Blanco, A.; Smiljanic, R.; Costado, M. T.; Damiani, F.; Hill, V.; Hourihane, A.; Jofre, P.; de Laverny, P.; Masseron, T.; Worley, C.

    2014-05-01

    Atmospheric parameters, radial velocities, lithium equivalent widths are products of the Gaia-ESO Survey that were used for our membership analysis of the 48 UVES targets observed in the Gamma Velorum fields. Also photometry from Jeffries et al. (2009MNRAS.393..538J) has been used. Iron abundances of these stars have been used to determine the metal content of the cluster. We also discussed the metallicity derived through the iron abundances of the 208 cluster members targeted with GIRAFFE and identified by Jeffries et al. (2014A&A...563A..94J). Stellar parameters of 39 stars targeted by both UVES and GIRAFFE have been used to check the quality of the data. (4 data files).

  18. VizieR Online Data Catalog: VFTS. B-type stars classification and RV (Evans+, 2015)

    NASA Astrophysics Data System (ADS)

    Evans, C. J.; Kennedy, M. B.; Dufton, P. L.; Howarth, I. D.; Walborn, N. R.; Markova, N.; Clark, J. S.; de Mink, S. E.; de Koter, A.; Dunstall, P. R.; Henault-Brunet, V.; Maiz Apellaniz, J.; McEvoy, C. M.; Sana, H.; Simon-Diaz, S.; Taylor, W. D.; Vink, J. S.

    2015-03-01

    All of the VFTS data discussed here were obtained using the Medusa-Giraffe mode of the Fibre Large Array Multi-Element Spectrograph (FLAMES) instrument on the Very Large Telescope (VLT). The Medusa fibres (which subtend 1.2" on the sky) were used to relay light from up to 130 targets simultaneously to the Giraffe spectrograph (see Pasquini et al., 2002Msngr.110....1P). Full details of the observational strategy and reduction of the data are given in Paper I (Evans et al., 2011A&A...530A.108E). In brief, the ESO Common Pipeline Library FLAMES recipes were used to undertake bias subtraction, fibre location, summed extractions of each object, division by a normalised flat-field, and wavelength calibration. Subsequent processing included correction of the spectra to the heliocentric frame, sky subtraction, and rejection of significant cosmic rays. (5 data files).

  19. VizieR Online Data Catalog: Abundances of NGC 6362 member stars (Mucciarelli+, 2016)

    NASA Astrophysics Data System (ADS)

    Mucciarelli, A.; Dalessandro, E.; Massari, D.; Bellazzini, M.; Ferraro, F. R.; Lanzoni, B.; Lardo, C.; Salaris, M.; Cassisi, S.

    2016-08-01

    A total of 219 stars have been selected along the RGB and the red horizontal branch (RHB) from the ACS@HST and WFI@2.2m ESO catalogs presented in Paper I (Dalessandro et al. 2014ApJ...791L...4D). The observations have been performed with the multiplex facility FLAMES@ESO-VLT in the UVES+GIRAFFE combined mode (PID:093.D-0618, PI:Dalessandro). The employed gratings are the UVES Red Arm CD#3 580, which covers the spectral range between ~4800 and ~6800Å with a spectral resolution of ~45000, and the GIRAFFE setups HR11 (5597-5840Å and R~24000) and HR13 (6120-6405Å and R~22000). (1 data file).

  20. The Gaia-ESO Survey: detailed abundances for thousands of FGK-type stars

    NASA Astrophysics Data System (ADS)

    Smiljanic, R.

    2014-10-01

    The Gaia-ESO Survey is using FLAMES at the VLT to observe more than 10^{5} stars. Giraffe medium-resolution spectra is being obtained for ˜ 10^{5} stars and high-resolution UVES spectra is being obtained for ˜ 5000 stars. Here I present a short summary of the Survey with emphasis on the sample of FGK-type stars being observed with UVES.

  1. VizieR Online Data Catalog: Nebular emission lines towards NGC3372 center (Damiani+, 2016)

    NASA Astrophysics Data System (ADS)

    Damiani, F.; Bonito, R.; Magrini, L.; Prisinzano, L.; Mapelli, M.; Micela, G.; Kalari, V.; Maiz Apellaniz, J.; Gilmore, G.; Randich, S.; Alfaro, E.; Flaccomio, E.; Koposov, S.; Klutsch, A.; Lanzafame, A. C.; Pancino, E.; Sacco, G. G.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Franciosini, E.; Hourihane, A.; Lardo, C.; Lewis, J.; Monaco, L.; Morbidelli, L.; Worley, C.; Zaggia, S.; Zwitter, T.; Dorda, R.

    2016-04-01

    Nebular emission lines of H-alpha, [NII] 6584Å, HeI 6678Å, [SII] 6717Å, [SII] 6731Å, towards the center of Carina nebula, are modeled with two gaussians each ('blue' and 'red' components). Best-fit parameters are given in the table. Line widths include the instrumental width of the Giraffe spectrograph (7km/s). Radial velocities are heliocentric. (1 data file).

  2. [The stability of progesterone in feces of different wild animal species kept in a zoological garden].

    PubMed

    Neumann, G; Gottschalk, J; Eulenberger, K; Grün, E

    2002-05-01

    Methodical investigations were carried out to monitor especially in what respect external factors (dry mass of faeces, time point of freezing, duration of storage of the frozen samples, multiple defrosting of the samples) influence the progesterone concentration of the faeces of several wild animal species (Baringo giraffe, Black rhinoceros, Dama gazelle, Mountain goat) living in a zoological garden. With reference to one animal species the dry mass of the faeces showed only small variations. Therefore, it is possible to estimate comparable progesterone levels in several faecal samples of the same animal species without drying the samples. In all cases the progesterone concentration was increased after 24 and 48 hour storage of the faecal samples at room temperature compared with samples frozen directly (significant differences for giraffes and rhinoceroses). Samples of rhinoceroses and gazelles showed no significant changes of their progesterone concentration after a long time of storage (one and three months) in the freezing state (-20 degrees C). On the other hand, in faeces of giraffes with high progesterone levels a significant decrease of the initial level was pointed out. In comparison of single and multiple defrosting of the faecal samples, the latter caused a decrease of the progesterone concentration of the faeces of all animal species investigated (significant differences for rhinoceroses and gazelles).

  3. Developmental adaptations to gravity in animals

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.

    1991-01-01

    Terrestrial animals have adapted to a constant gravitational stress over millions of years. Tissues of the cardiovascular system and lumbar spine in tall species of animals such as the giraffe are particularly well adapted to high and variable vectors of gravitational force. Swelling of the leg tissues in the giraffe is prevented by a variety of physiological mechanisms including (1) a natural 'antigravity suit', (2) impermeable capillaries, (3) arterial-wall hypertrophy, (4) variable blood pressures during normal activity, and (5) a large-capacity lymphatic system. These adaptations, as well as a natural hypertension, maintain blood perfusion to the giraffe's brain. The intervertebral disk is another tissue that is uniquely adapted to gravitational stress. Tall and large terrestrial animals have higher swelling pressures than their smaller or aquatic counterparts. Finally, the meniscus of the rabbit knee provides information on the effects of aging and load-bearing on cartilaginous tissues. Such tissues within the joints of animals are important for load-bearing on Earth; these connective tissues may degenerate during long-duration space flight.

  4. Comparison of Infiltrability Measurements in the Thornbush Savanna, Namibia

    NASA Astrophysics Data System (ADS)

    Classen, Nikolaus; Gröngröft, Alexander; Eschenbach, Annette

    2010-05-01

    Large proportions of Namibian Savannas are affected by strong bush encroachment leading to a reduction in grazing capacity. Especially woody plant encroachment is expected to have an impact on hydrology by increasing plant transpiration, bare soil evaporation and reducing soil water availability (HUXMAN et al. 2005). Although the processes are not fully understood, the role of soil water balance is highlighted by many studies. Especially the small-scale interactions of vegetation and soil are of high relevance. To characterize the water balance of different sites in the Namibian thornbush savanna long-term studies were conducted. In addition we applied three methods to quantify the infiltration rate (IR) at four central Namibian thornbush savanna sites differing in soil texture and vegetation type: a single ring (own construction, 14 cm inner diameter), a disc-infiltrometer (Eijkelkamp Agrisearch Equipment BV) and a hood infiltrometer (UGT Umwelt-Geräte-Technik GmbH). At each site, the measurements we conducted along short transect lines (15 m) in positions with differing plant influence (canopy of Acacia trees and shrubs, grass and dwarf-shrub tussocks, bare soil, termitaria). All three methods resulted in different mean IR as well as spatial distribution patterns. Using statistical analysis by ANOVA, dominant controlling variables were elaborated. The poster will demonstrate which of the methods is defensible with respect to the research question. References : HUXMAN, T. E., B. P. WILCOX, et al. (2005): Ecohydrological implications of woody plant encroachment. Ecology 86(2): 308-319. Acknowledgment: The work was founded by BMBF within the Project Biota South (support code 01LC 0624 A2).

  5. Naturally acquired antibodies to Bacillus anthracis protective antigen in vultures of southern Africa.

    PubMed

    Turnbull, P C B; Diekmann, M; Kilian, J W; Versfeld, W; De Vos, V; Arntzen, L; Wolter, K; Bartels, P; Kotze, A

    2008-06-01

    Sera from 19 wild caught vultures in northern Namibia and 15 (12 wild caught and three captive bred but with minimal histories) in North West Province, South Africa, were examined by an enzyme-linked immunosorbent assay (ELISA) for antibodies to the Bacillus anthracis toxin protective antigen (PA). As assessed from the baseline established with a control group of ten captive reared vultures with well-documented histories, elevated titres were found in 12 of the 19 (63%) wild caught Namibian birds as compared with none of the 15 South African ones. There was a highly significant difference between the Namibian group as a whole and the other groups (P < 0.001) and no significant difference between the South African and control groups (P > 0.05). Numbers in the Namibian group were too small to determine any significances in species-, sex- or age-related differences within the raw data showing elevated titres in four out of six Cape Vultures, Gyps coprotheres, six out of ten White-backed Vultures, Gyps africanus, and one out of three Lappet-faced Vultures, Aegypius tracheliotus, or in five of six males versus three of seven females, and ten of 15 adults versus one of four juveniles. The results are in line with the available data on the incidence of anthrax in northern Namibia and South Africa and the likely contact of the vultures tested with anthrax carcasses. It is not known whether elevated titre indicates infection per se in vultures or absorption of incompletely digested epitopes of the toxin or both. The results are discussed in relation to distances travelled by vultures as determined by new tracking techniques, how serology can reveal anthrax activity in an area and the issue of the role of vultures in transmission of anthrax.

  6. Reflecting on interprofessional education in the design of space and place: lessons from Namibia.

    PubMed

    Wessels, Quenton; Rennie, Timothy

    2013-09-01

    Education at the University of Namibia, School of Medicine and School of Pharmacy relies on a community-centred curriculum. The aim is to nurture "7-star" doctors and pharmacists that will address the current social and health needs within the country. A sound understanding of the interplay between learning and the learning environment is said to improve interprofessional educational activities. This relationship is dependent on constrictive alignment of not only the aspects of pedagogy, but also that of educational leadership in context of the current and social health needs. In this report, we reflect on the interprofessional-learning environment that was created out of necessity within a Namibian context.

  7. No Matter How Long the Night, the Day is Sure to Come: Culture and Educational Transformation in Post-Colonial Namibia and Post-Apartheid South Africa

    NASA Astrophysics Data System (ADS)

    Nekhwevha, Fhulu

    1999-11-01

    Following the defeat of Apartheid, the 1990s have witnessed serious attempts by Namibians and South Africans alike to reconstruct their social institutions along democratic lines. While education has not been excluded from these efforts, there is evidence that the new curricula are primarily influenced by western educational models. For example, prescriptions of the International Monetary Fund and the World Bank have been uncritically incorporated into the new educational programme. Consequently the curricula lack an indigenous ingredient, namely the cultural capital of the African masses. It is suggested in this article that the much acclaimed African cultural renaissance in education will only become a reality when educationalists embrace the "pedagogy of hope".

  8. Fences and grazing management in northern Namibia

    NASA Astrophysics Data System (ADS)

    Prudat, Brice; Bloemertz, Lena; Kuhn, Nikolaus J.

    2016-04-01

    Since Namibian independence, many fences have been erected in the communal land of the Ohangwena region in northern Namibia. Most fencing issues discussed so far in the region concern large-scale fencing of communal land by the new Namibian elite. Rarely discussed are the fences erected around small-scale farmers' parcels. This paper will discuss the impact of such increased small-scale fencing activities in northern Namibia. Fencing of land has different functions, including protection of fields against livestock and securing property rights. However, not all community members can afford the monetary and labor costs involved. In the annual agricultural cycle of the study area, livestock is left un-herded after the harvest of most crops. They can then feed on available crop remains and grass on the fields. The livestock then freely utilizes unfenced and unprotected land. This system has the advantage to accelerate crop degradation and fertilize the soils. However, by erecting efficient fences, the new middle-class community members concentrate fertility in their own field, thereby degrading agricultural soils of poorer farmers. Potentially, such small-scale fencing of land has therefore an impact on sol quality and thus fosters degradation of unfenced cropland. By using fences as features to determine the limits of the new land rights, the ongoing Communal Land Reform may not only promote the erection of fences, but may also have a negative impact on soil quality and potentially food security of small-scale farmers without cattle.

  9. Ammonia‐oxidizing Bacteria of the N itrosospira cluster 1 dominate over ammonia‐oxidizing Archaea in oligotrophic surface sediments near the South Atlantic Gyre

    PubMed Central

    Lagostina, Lorenzo; Goldhammer, Tobias; Røy, Hans; Evans, Thomas W.; Lever, Mark A.; Jørgensen, Bo B.; Petersen, Dorthe G.; Schreiber, Lars

    2015-01-01

    Summary Sediments across the Namibian continental margin feature a strong microbial activity gradient at their surface. This is reflected in ammonium concentrations of < 10 μM in oligotrophic abyssal plain sediments near the South Atlantic Gyre compared with ammonium concentrations of > 700 μM in upwelling areas near the coast. Here we address changes in apparent abundance and structure of ammonia‐oxidizing archaeal and bacterial communities (AOA and AOB) along a transect of seven sediment stations across the Namibian shelf by analysing their respective ammonia monooxygenase genes (amoA). The relative abundance of archaeal and bacterial amoA (g−1 DNA) decreased with increasing ammonium concentrations, and bacterial amoA frequently outnumbered archaeal amoA at the sediment–water interface [0–1 cm below seafloor (cmbsf)]. In contrast, AOA were apparently as abundant as AOB or dominated in several deeper (> 10 cmbsf), anoxic sediment layers. Phylogenetic analyses showed a change within the AOA community along the transect, from two clusters without cultured representatives at the gyre to N itrososphaera and N itrosopumilus clusters in the upwelling region. AOB almost exclusively belonged to the N itrosospira cluster 1. Our results suggest that this predominantly marine AOB lineage without cultured representatives can thrive at low ammonium concentrations and is active in the marine nitrogen cycle. PMID:25581373

  10. Genetic connectivity across marginal habitats: the elephants of the Namib Desert.

    PubMed

    Ishida, Yasuko; Van Coeverden de Groot, Peter J; Leggett, Keith E A; Putnam, Andrea S; Fox, Virginia E; Lai, Jesse; Boag, Peter T; Georgiadis, Nicholas J; Roca, Alfred L

    2016-09-01

    Locally isolated populations in marginal habitats may be genetically distinctive and of heightened conservation concern. Elephants inhabiting the Namib Desert have been reported to show distinctive behavioral and phenotypic adaptations in that severely arid environment. The genetic distinctiveness of Namibian desert elephants relative to other African savanna elephant (Loxodonta africana) populations has not been established. To investigate the genetic structure of elephants in Namibia, we determined the mitochondrial (mt) DNA control region sequences and genotyped 17 microsatellite loci in desert elephants (n = 8) from the Hoanib River catchment and the Hoarusib River catchment. We compared these to the genotypes of elephants (n = 77) from other localities in Namibia. The mtDNA haplotype sequences and frequencies among desert elephants were similar to those of elephants in Etosha National Park, the Huab River catchment, the Ugab River catchment, and central Kunene, although the geographically distant Caprivi Strip had different mtDNA haplotypes. Likewise, analysis of the microsatellite genotypes of desert-dwelling elephants revealed that they were not genetically distinctive from Etosha elephants, and there was no evidence for isolation by distance across the Etosha region. These results, and a review of the historical record, suggest that a high learning capacity and long-distance migrations allowed Namibian elephants to regularly shift their ranges to survive in the face of high variability in climate and in hunting pressure.

  11. Confronting 'scale-down': assessing Namibia's human resource strategies in the context of decreased HIV/AIDS funding.

    PubMed

    Cairney, Liita-Iyaloo; Kapilashrami, Anuj

    2014-01-01

    In Namibia, support through the Global Fund and President's Emergency Plan for AIDS Relief has facilitated an increase in access to HIV and AIDS services over the past 10 years. In collaboration with the Namibian government, these institutions have enabled the rapid scale-up of prevention, treatment and care services. Inadequate human resources capacity in the public sector was cited as a key challenge to initial scale-up; and a substantial portion of donor funding has gone towards the recruitment of new health workers. However, a recent scale-down of donor funding to the Namibian health sector has taken place, despite the country's high HIV and AIDS burden. With a specific focus on human resources, this paper examines the extent to which management processes that were adopted at scale-up have proven sustainable in the context of scale-down. Drawing on data from 43 semi-structured interviews, we argue that human resources planning and management decisions made at the onset of the country's relationship with the two institutions appear to be primarily driven by the demands of rapid scale-up and counter-productive to the sustainability of interventions.

  12. Benthic remineralisation rates in shelf and slope sediments of the northern Benguela upwelling margin

    NASA Astrophysics Data System (ADS)

    Neumann, Andreas; Lahajnar, Niko; Emeis, Kay-Christian

    2016-02-01

    The Benguela Upwelling System off Namibia is a region of intensive plankton production. Remineralisation of this biomass frequently causes the formation of an oxygen minimum zone. A part of the organic matter is further deposited on the broad shelf in form of an extensive mudbelt with high TOC concentrations. During February 2011 we retrieved sediment samples from shelf and slope sediment along the Namibian coast to establish fluxes of nutrients, oxygen, and N2 on the basis of pore water concentrations. In mudbelt sediment, fluxes were estimated as high as 8 mmol NH4+ m-2 d-1 and 0.9 mmol PO43 - m-2 d-1, which is probably attributable to the activity of large sulphur bacteria. Especially phosphate is mobilised from sediment overlain by oxygen deficient bottom water when and where bottom water oxygen concentrations fall below 50 μmol l-1. In comparison to nutrient transport by Southern Atlantic Central Water flowing onto the Namibian shelf, benthic nutrient fluxes of the mudbelt contribute less than 5% to the nutrient budget of the shelf.

  13. The impact of stigma, experience, and group referent on HIV risk assessments and HIV testing intentions in Namibia.

    PubMed

    Smith, Rachel A; Morrison, Daniel

    2006-11-01

    People often perceive risks for others and themselves differently. This study examines whether personal beliefs about HIV and experience with those living with HIV influence personal risk assessments of contracting HIV in an interview sample of northern Namibians (N=400), but not others' assessments as explained by singular-distribution theory [Klar, Medding, & Sarel (1996). Nonunique invulnerability: Singular versus distributional probabilities and unrealistic optimism in comparative risk judgments. Organizational Behavior and Human Decision Processes, 67, 229-245]. Findings indicate that personal risk perceptions decrease with more HIV stigmatizing beliefs and increase with greater experience, but that those characteristics had no impact on assessments for others' risk. The study also examines whether the size and characteristics of the referent group, peers and the general Namibian population, influence others' risk assessments. Optimistic biases for personal risk versus others' risk appear with the highest discrepancy emerging between personal and general population risk assessments. Further, we found that personal risk perceptions did not mediate the relationship between personal characteristics, beliefs and experiences, and intentions to seek HIV testing.

  14. Assessment of HIV transmission risks in clinical situations in health care students from Germany, Lithuania and Namibia.

    PubMed

    Klewer, J; Lauschke, H; Raulinaviciute, J; Sasnauskaite, L; Pavilonis, A; Kugler, J

    2001-03-01

    Due to the increasing global HIV prevalence, comprehensive knowledge about clinical HIV transmission risks in health care professionals is essential. Mainly medical and nursing students are at risk, because they are working close to infected patients. By using an anonymous questionnaire, the study analysed the assessments of German medical/dental students (n = 182), Lithuanian medical students (n = 176) and Namibian student nurses (n = 135) on the risk of getting HIV infected in different clinical situations. It became obvious that the Namibian student nurses overestimated the risk of HIV transmission in several situations (eg changing dirty linen, physical examination). In comparison, the Lithuanian students showed the most realistic assessments, while the German students also tended to overestimate the risks of HIV transmission. The results indicate that assessments on the risk of HIV transmission in clinical situations are influenced by the national prevalence and daily contacts with HIV patients. Education of health care students should consider this and focus more on epidemiological aspects and infection control procedures, to avoid endangering students and patients.

  15. Extrinsic factors significantly affect patterns of disease in free-ranging and captive cheetah (Acinonyx jubatus) populations.

    PubMed

    Munson, Linda; Terio, Karen A; Worley, Michael; Jago, Mark; Bagot-Smith, Arthur; Marker, Laurie

    2005-07-01

    The cheetah (Acinonyx jubatus) has been considered a paradigm for disease vulnerability due to loss of genetic diversity. This species monomorphism has been suspected to be the basis for their general poor health and dwindling populations in captivity. North American and South African captive populations have high prevalences of hepatic veno-occlusive disease, glomerulosclerosis, gastritis, and systemic amyloidosis, diseases that are rare in other species. Unusually severe inflammatory reactions to common infectious agents have also been documented in captive cheetahs. The current study compared disease prevalences in free-ranging Namibian cheetahs with those in two captive populations of similar ages. The occurrence of diseases in the free-ranging population was determined from 49 necropsies and 27 gastric biopsies obtained between 1986 and 2003 and compared with prevalences in 147 North American and 80 South African captive cheetahs. Except for two cheetahs, the free-ranging population was in robust health with only mild lesions present, in contrast with significantly higher prevalences in the captive populations. Despite widespread heavy Helicobacter colonization in wild cheetahs, only 3% of the free-ranging population had moderate to severe gastritis, in contrast with 64% of captive cheetahs. No severe inflammatory reactions to viral infections were detected in the free-ranging animals. Because free-ranging Namibian cheetahs are as genetically impoverished as captive cheetahs, these findings caution against attributing loss of fitness solely to genetic factors and attest to the fundamental importance of extrinsic factors in wildlife health.

  16. Chemical tagging with Gaia-ESO Survey and Gaia-RVS data

    NASA Astrophysics Data System (ADS)

    Guiglion, G.; Recio-Blanco, A.; de Laverny, P.

    2014-01-01

    We present a new method devoted to chemical tagging for Galactic Archeology. In the context of the Gaia-ESO Survey (GES) and the Gaia Data Processing and Analysis Consortium (DPAC), we aim at preparing the Gaia-Radial Velocity Spectrograph analysis, which will provide ~ 2×106 spectra covering the IR CaII triplet domain (R ~ 11 500), with sufficient SNR to perform chemical tagging. Our method will be integrated in the Gaia DPAC Apsis pipeline (CU8, Astrophysical Parameters) and we test it with GES GIRAFFE spectra (MEDUSA mode, HR10 & HR21) deriving abundances of MgI in 168 stars.

  17. VizieR Online Data Catalog: Sgr dSph stars spectral classification (McDonald+, 2012)

    NASA Astrophysics Data System (ADS)

    McDonald, I.; White, J. R.; Zijlstra, A. A.; Guzman Ramirez, L.; Szyszka, C.; van Loon, J. T.; Lagadec, E.; Jones, O. C.

    2013-08-01

    The bulk of our observed spectra were obtained using the ESO VLT/FLAMES+MEDUSA multi-fibre spectrograph in GIRAFFE+UVES mode. These cover nine fields of the Sgr dSph core, each taken in four settings (L714.2, L682.2, H651.5B and H710.5). Simultaneous spectra were taken using the UVES instrument using the red arm, cross-disperser CD3 and a central wavelength of 580nm. (2 data files).

  18. Installation and first results of FLAMES, the VLT multifibre facility

    NASA Astrophysics Data System (ADS)

    Pasquini, Luca; Alonso, Jaime; Avila, Gerardo; Barriga, Pablo; Biereichel, Peter; Buzzoni, Bernard; Cavadore, Cyril; Cumani, Claudio; Dekker, Hans; Delabre, Bernard; Kaufer, Andreas; Kotzlowski, Heinz; Hill, Vanessa; Lizon, Jean-Luis; Nees, Walter; Santin, Paolo; Schmutzer, Ricardo; Kesteren, A. V.; Zoccali, Manuela

    2003-03-01

    FLAMES is the VLT Fibre Facility, installed and being commissioned at the Nasmyth A of UT2 (Kueyen Telescope). FLAMES has been built and assembled at the VLT telescope in about 4 years through an international collaboration between 10 institutes in 6 countries and 3 continents. It had first light with the fibre link to the red arm of UVES on April 1, and with the GIRAFFE spectrograph on July 3. We have not yet enough data to compare the observed vs. expected astronomical performances, although these first data are encouraging in many respects. We aim at proceeding soon with the remaining tests

  19. Refinement Of Hexahedral Cells In Euler Flow Computations

    NASA Technical Reports Server (NTRS)

    Melton, John E.; Cappuccio, Gelsomina; Thomas, Scott D.

    1996-01-01

    Topologically Independent Grid, Euler Refinement (TIGER) computer program solves Euler equations of three-dimensional, unsteady flow of inviscid, compressible fluid by numerical integration on unstructured hexahedral coordinate grid refined where necessary to resolve shocks and other details. Hexahedral cells subdivided, each into eight smaller cells, as needed to refine computational grid in regions of high flow gradients. Grid Interactive Refinement and Flow-Field Examination (GIRAFFE) computer program written in conjunction with TIGER program to display computed flow-field data and to assist researcher in verifying specified boundary conditions and refining grid.

  20. Indirect measurement of nuclear reactions of astrophysical interest

    SciTech Connect

    Liu, W. P.; Li, Z. H.; Bai, X. X.; Wang, Y. B.; Guo, B.; Lian, G.; Su, J.; Zeng, S.; Wang, B. X.; Yan, S. Q.; Li, Y. J.; Li, E. T.; Jin, S. J.

    2010-05-12

    Systematic indirect measurements of nuclear astrophysical reactions using the unstable ion beam facility GIRAFFE in CIAE were performed. We have measured the angular distributions of transfer reactions, such as {sup 8}Li(d,p){sup 9}Li, {sup 8}Li(d,n){sup 9}Be and {sup 8}Li(p,d){sup 7}Li in inverse kinematics, and derived the astrophysical S-factors or reaction rates for {sup 8}Li(n,gamma){sup 9}Li and {sup 8}Li(p,gamma){sup 9}Be by using asymptotic normalization coefficient (ANC) or spectroscopic factor methods.

  1. NGC 3293 revisited by the Gaia-ESO Survey

    NASA Astrophysics Data System (ADS)

    Semaan, Thierry; Morel, Thierry; Gosset, Eric; Zorec, Juan; Frémat, Yves; Blomme, Ronny; Lobel, Alex

    2015-01-01

    In the framework of the Gaia-ESO survey we have determined the fundamental parameters of a large number of B-type stars in the Galactic, young open cluster NGC 3293. The determination of the stellar parameters is based on medium-resolution spectra obtained with FLAMES/GIRAFFE at ESO-VLT. As a second step, we adopted the accurate parameters to determine the chemical abundances of these hot stars. We present a comparison of our results with those obtained by the 'VLT-FLAMES survey of massive stars' (Evans et al. 2005). Our study increases the number of objects analysed and provides an extended view of this cluster.

  2. VizieR Online Data Catalog: Classification of stellar spectra 644-681nm (Damiani+, 2014)

    NASA Astrophysics Data System (ADS)

    Damiani, F.; Prisinzano, L.; Micela, G.; Randich, S.; Gilmore, G.; Drew, J. E.; Jeffries, R. D.; Fremat, Y.; Alfaro, E. J.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Lanzafame, A. C.; Pancino, E.; Recio-Blanco, A.; Sacco, G. G.; Smiljanic, R.; Jackson, R. J.; de Laverny, P.; Morbidelli, L.; Worley, C. C.; Hourihane, A.; Costado, M. T.; Jofre, P.; Lind, K.; Maiorca, E.

    2014-05-01

    A set of newly-defined spectral indices is presented for all stars in the field of the γ Vel cluster, observed within the Gaia-ESO Survey. All indices are based exclusively on the spectral range 6440-6810 Angstroms, corresponding to the VLT/FLAMES Giraffe setup HR15N. Fundamental stellar parameters can be derived from these indices as explained in the paper. Stars with either high cluster membership probability, or/and SB2 binaries, are flagged. (2 data files).

  3. Gaia-ESO Survey: Analysis of pre-main sequence stellar spectra

    NASA Astrophysics Data System (ADS)

    Lanzafame, A. C.; Frasca, A.; Damiani, F.; Franciosini, E.; Cottaar, M.; Sousa, S. G.; Tabernero, H. M.; Klutsch, A.; Spina, L.; Biazzo, K.; Prisinzano, L.; Sacco, G. G.; Randich, S.; Brugaletta, E.; Delgado Mena, E.; Adibekyan, V.; Montes, D.; Bonito, R.; Gameiro, J. F.; Alcalá, J. M.; González Hernández, J. I.; Jeffries, R.; Messina, S.; Meyer, M.; Gilmore, G.; Asplund, M.; Binney, J.; Bonifacio, P.; Drew, J. E.; Feltzing, S.; Ferguson, A. M. N.; Micela, G.; Negueruela, I.; Prusti, T.; Rix, H.-W.; Vallenari, A.; Alfaro, E. J.; Allende Prieto, C.; Babusiaux, C.; Bensby, T.; Blomme, R.; Bragaglia, A.; Flaccomio, E.; Francois, P.; Hambly, N.; Irwin, M.; Koposov, S. E.; Korn, A. J.; Smiljanic, R.; Van Eck, S.; Walton, N.; Bayo, A.; Bergemann, M.; Carraro, G.; Costado, M. T.; Edvardsson, B.; Heiter, U.; Hill, V.; Hourihane, A.; Jackson, R. J.; Jofré, P.; Lardo, C.; Lewis, J.; Lind, K.; Magrini, L.; Marconi, G.; Martayan, C.; Masseron, T.; Monaco, L.; Morbidelli, L.; Sbordone, L.; Worley, C. C.; Zaggia, S.

    2015-04-01

    Context. The Gaia-ESO Public Spectroscopic Survey is obtaining high-quality spectroscopy of some 100 000 Milky Way stars using the FLAMES spectrograph at the VLT, down to V = 19 mag, systematically covering all the main components of the Milky Way and providing the first homogeneous overview of the distributions of kinematics and chemical element abundances in the Galaxy. Observations of young open clusters, in particular, are giving new insights into their initial structure, kinematics, and their subsequent evolution. Aims: This paper describes the analysis of UVES and GIRAFFE spectra acquired in the fields of young clusters whose population includes pre-main sequence (PMS) stars. The analysis is applied to all stars in such fields, regardless of any prior information on membership, and provides fundamental stellar atmospheric parameters, elemental abundances, and PMS-specific parameters such as veiling, accretion, and chromospheric activity. Methods: When feasible, different methods were used to derive raw parameters (e.g. line equivalent widths) fundamental atmospheric parameters and derived parameters (e.g. abundances). To derive some of these parameters, we used methods that have been extensively used in the past and new ones developed in the context of the Gaia-ESO survey enterprise. The internal precision of these quantities was estimated by inter-comparing the results obtained by these different methods, while the accuracy was estimated by comparison with independent external data, such as effective temperature and surface gravity derived from angular diameter measurements, on a sample of benchmarks stars. A validation procedure based on these comparisons was applied to discard spurious or doubtful results and produce recommended parameters. Specific strategies were implemented to resolve problems of fast rotation, accretion signatures, chromospheric activity, and veiling. Results: The analysis carried out on spectra acquired in young cluster fields during

  4. Current progress of nuclear astrophysics experiments at CIAE

    SciTech Connect

    Liu Weiping; Li Zhihong; Su Jun; Bai Xixiang; Wang Youbao; Lian Gang; Guo Bing; Zeng Sheng; Yan Shengquan; Wang Baoxiang; Shu Nengchuan; Chen Yongshou

    2006-07-12

    This paper described current progress of nuclear astrophysical studies using the unstable ion beam facility GIRAFFE. We measured the angular distributions for some low energy reactions, such as 11C(d,n)12N, 8Li(d,p)9Li and 17F(d,n)18Ne in inverse kinematics, and indirectly derived the astrophysical S-factors or reaction rates of 11C(p,{gamma})12N, 8Li(n,{gamma})9Li, 8B(p,{gamma})9C at astrophysically relevant energies.

  5. VizieR Online Data Catalog: M54 and Sgr dSph red giants abundances (Mucciarelli+, 2014)

    NASA Astrophysics Data System (ADS)

    Mucciarelli, A.; Salaris, M.; Bonifacio, P.; Monaco, L.; Villanova, S.

    2015-04-01

    High-resolution spectra of lower RGB stars in M54 have been secured with the multi-object spectrograph FLAMES at the ESO Very Large Telescope, in the GIRAFFE/MEDUSA mode. The observations have been performed with the setups HR12 (to sample the Na D lines, with a resolution of 18700) and HR15N (to sample the Li doublet at 6707Å, with a resolution of 17000). The same target configuration has been used for both gratings and each target has been observed for a total time of 26 and 4h, for HR15N and HR12, respectively. (1 data file).

  6. Blocking of Pseudomonas aeruginosa and Chromobacterium violaceum lectins by diverse mammalian milks.

    PubMed

    Zinger-Yosovich, K D; Iluz, D; Sudakevitz, D; Gilboa-Garber, N

    2010-02-01

    Pseudomonas aeruginosa and Chromobacterium violaceum morbid and mortal infections are initiated by bacterial adherence to host-cell receptors via their adhesins, including lectins (which also contribute to bacterial biofilm formation). Pseudomonas aeruginosa produces a galactophilic lectin, PA-IL (LecA), and a fucophilic (Lewis-specific) lectin, PA-IIL (LecB), and C. violaceum produces a fucophilic (H-specific) lectin, CV-IIL. The antibiotic resistance of these bacteria prompted the search for glycosylated receptor-mimicking compounds that would function as glycodecoys for blocking lectin attachment to human cell receptors. Lectins PA-IL and PA-IIL have been shown to be useful for such glycodecoy probing, clearly differentiating between human and cow milks. This article describes their usage, together with CV-IIL and the plant lectin concanavalin A, for comparing the anti-lectin-dependent adhesion potential of diverse mammalian milks. The results show that the diverse milks differ in blocking (hemagglutination inhibition) and differential binding (Western blots) of these lectins. Human milk most strongly inhibited the 3 bacterial lectins (with PA-IIL superiority), followed by alpaca, giraffe, and monkey milks, whereas cow milk was a weak inhibitor. Lectin PA-IL was inhibited strongly by human, followed by alpaca, mare, giraffe, buffalo, and monkey milks, weakly by camel milk, and not at all by rabbit milk. Lectins PA-IIL and CV-IIL were also most sensitive to human milk, followed by alpaca, monkey, giraffe, rabbit, and camel milks but negligibly sensitive to buffalo and mare milks. Plant lectin concanavalinA, which was used as the reference, differed from them in that it was much less sensitive to human milk and was equally as sensitive to cow milk. These results have provided important information on the anti-lectin-dependent adhesion potential of the diverse milks examined. They showed that human followed by alpaca, giraffe, and Rhesus monkey milks efficiently

  7. VizieR Online Data Catalog: Metallicity and kinematics in Galactic bar (Babusiaux+, 2014)

    NASA Astrophysics Data System (ADS)

    Babusiaux, C.; Katz, D.; Hill, V.; Royer, F.; Gomez, A.; Arenou, F.; Combes, F.; Di Matteo, P.; Gilmore, G.; Haywood, M.; Robin, A. C.; Rodriguez-Fernandez, N.; Sartoretti, M.; Schultheis, P.

    2014-01-01

    We observe red clump stars in four fields along the Galactic bar major axis (l=10°, -6°, 6° and b=0°, plus a field at l=0°, b=1°) with low-resolution spectroscopy from FLAMES/GIRAFFE (setup LR08) at the VLT, observing around the CaII triplet. We developed robust methods to extract radial velocity and metallicity estimates from these low signal-to-noise spectra. Results have been derived by fixing atmospheric parameters typical of a red clump star (Teff=4750K, logg=2.5). For some targets, the metallicity could not be derived. (1 data file).

  8. Compact Instruments Measure Heat Potential

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Based in Huntsville, Alabama, AZ Technology Inc. is a woman- and veteran-owned business that offers expertise in electromechanical-optical design and advanced coatings. AZ Technology has received eight Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center for the development of spectral reflectometers and the measurement of surface thermal properties. The company uses a variety of measurement services and instruments, including the Spectrafire, a portable spectral emissometer it used to assist General Electric with the design of its award-winning Giraffe Warmer for neonatal intensive care units.

  9. Emerging pestiviruses infecting domestic and wildlife hosts.

    PubMed

    Ridpath, Julia F

    2015-06-01

    Until the early 1990 s there were just three recognized species in the pestivirus genus, bovine viral diarrhea virus (BVDV), border disease virus (BDV) and classical swine fever virus (CSFV). Subsequently BVDV were divided into two different species, BVDV1 and BVDV2 and four additional putative pestivirus species have been identified, based on phylogenetic analysis. The four putative pestivirus specices, listed in chronological order of published reports, are Giraffe (isolated from one of several giraffes in the Nanyuki District of Kenya suffering from mucosal disease-like symptoms), HoBi (first isolated from fetal bovine serum originating in Brazil and later from samples originating in Southeast Asia), Pronghorn (isolated from an emaciated blind pronghorn antelope in the USA), and Bungowannah (isolated following an outbreak in pigs, resulting in still birth and neonatal death, in Australia). In addition to the emergence of putative new species of pestivirus, changes in host and virulence of recognized or 'classic' pestiviruses have led to reevaluation of disease control programs and management of domestic and wildlife populations.

  10. Phylogeny of ruminants secretory ribonuclease gene sequences of pronghorn (Antilocapra americana).

    PubMed

    Beintema, Jaap J; Breukelman, Heleen J; Dubois, Jean-Yves F; Warmels, Hayo W

    2003-01-01

    Phylogenetic analyses based on primary structures of mammalian ribonucleases, indicated that three homologous enzymes (pancreatic, seminal and brain ribonucleases) present in the bovine species are the results of gene duplication events, which occurred in the ancestor of the ruminants after divergence from other artiodactyls. In this paper sequences are presented of genes encoding pancreatic and brain-type ribonuclease genes of pronghorn (Antilocapra americana). The seminal-type ribonuclease gene could not be detected in this species, neither by PCR amplification nor by Southern blot analyses, indicating that it may be deleted completely in this species. Previously we demonstrated of a study of amino acid sequences of pancreatic ribonucleases of a large number of ruminants the monophyly of bovids and cervids, and that pronghorn groups with giraffe. Here we present phylogenetic analyses of nucleotide sequences of ribonucleases and other molecules from ruminant species and compare these with published data. Chevrotain (Tragulus) always groups with the other ruminants as separate taxon from the pecora or true ruminants. Within the pecora the relationships between Bovidae, Cervidae, Giraffidae, and pronghorn (Antilocapra) cannot be decided with certainty, although in the majority of analyses Antilocapra diverges first, separately or joined with giraffe. Broad taxon sampling and investigation of specific sequence features may be as important for reliable conclusions in phylogeny as the lengths of analyzed sequences.

  11. Musical structure modulates semantic priming in vocal music.

    PubMed

    Poulin-Charronnat, Bénédicte; Bigand, Emmanuel; Madurell, François; Peereman, Ronald

    2005-01-01

    It has been shown that harmonic structure may influence the processing of phonemes whatever the extent of participants' musical expertise [Bigand, E., Tillmann, B., Poulin, B., D'Adamo, D. A., & Madurell, F. (2001). The effect of harmonic context on phoneme monitoring in vocal music. Cognition, 81, B11-B20]. The present study goes a step further by investigating how musical harmony may potentially interfere with the processing of words in vocal music. Eight-chord sung sentences were presented, their last word being either semantically related (La girafe a un tres grand cou, The giraffe has a very long neck) or unrelated to the previous linguistic context (La girafe a un tres grand pied, The giraffe has a very long foot). The target word was sung on a chord that acted either as a referential tonic chord or as a congruent but less referential subdominant chord. Participants performed a lexical decision task on the target word. A significant interaction was observed between semantic and harmonic relatedness suggesting that music modulates semantic priming in vocal music. Following Jones' dynamic attention theory, we argue that music can modulate semantic priming in vocal music, by modifying the allocation of attentional resource necessary for linguistic computation.

  12. Metrical expectations from preceding prosody influence perception of lexical stress

    PubMed Central

    Brown, Meredith; Salverda, Anne Pier; Dilley, Laura C.; Tanenhaus, Michael K.

    2015-01-01

    Two visual-world experiments tested the hypothesis that expectations based on preceding prosody influence the perception of suprasegmental cues to lexical stress. The results demonstrate that listeners’ consideration of competing alternatives with different stress patterns (e.g., ‘jury/gi’raffe) can be influenced by the fundamental frequency and syllable timing patterns across material preceding a target word. When preceding stressed syllables distal to the target word shared pitch and timing characteristics with the first syllable of the target word, pictures of alternatives with primary lexical stress on the first syllable (e.g., jury) initially attracted more looks than alternatives with unstressed initial syllables (e.g., giraffe). This effect was modulated when preceding unstressed syllables had pitch and timing characteristics similar to the initial syllable of the target word, with more looks to alternatives with unstressed initial syllables (e.g., giraffe) than to those with stressed initial syllables (e.g., jury). These findings suggest that expectations about the acoustic realization of upcoming speech include information about metrical organization and lexical stress, and that these expectations constrain the initial interpretation of suprasegmental stress cues. These distal prosody effects implicate on-line probabilistic inferences about the sources of acoustic-phonetic variation during spoken-word recognition. PMID:25621583

  13. Connecting the person with dementia and family: a feasibility study of a telepresence robot

    PubMed Central

    2014-01-01

    Background Maintenance of communication is important for people with dementia living in long-term care. The purpose of this study was to assess the feasibility of using “Giraff”, a telepresence robot to enhance engagement between family and a person with dementia living in long-term care. Methods A mixed-methods approach involving semi-structured interviews, call records and video observational data was used. Five people with dementia and their family member participated in a discussion via the Giraff robot for a minimum of six times over a six-week period. A feasibility framework was used to assess feasibility and included video analysis of emotional response and engagement. Results Twenty-six calls with an average duration of 23 mins took place. Residents showed a general state of positive emotions across the calls with a high level of engagement and a minimal level of negative emotions. Participants enjoyed the experience and families reported that the Giraff robot offered the opportunity to reduce social isolation. A number of software and hardware challenges were encountered. Conclusions Participants perceived this novel approach to engage families and people with dementia as a feasible option. Participants were observed and also reported to enjoy the experience. The technical challenges identified have been improved in a newer version of the robot. Future research should include a feasibility trial of longer duration, with a larger sample and a cost analysis. PMID:24456417

  14. Seasonal acclimatization determined by non-invasive measurements of coat insulation.

    PubMed

    Langman, Vaughan A; Langman, Sarah L; Ellifrit, Nancy

    2015-01-01

    Seasonal acclimatization in terrestrial mammals in the Northern Hemisphere involves changes in coat insulation. It is more economical to provide increased insulation than increased heat production for protection against the cold. This study was done to test a technique for the non-invasive measurement of mammal coat insulation and to measure coat insulation over several seasons on captive exotics. The working hypothesis was that species that have no coat or have a coat that does not change seasonally do not acclimatize seasonally. Three surface temperature readings were measured from the torso area. The insulation was calculated using measured metabolic rates and body temperature when possible. The African elephants, giraffe and okapi did not acclimatize with average maximum insulation values of 0.256°Cm(2)  W(-1) . The Amur tigers and mountain goats acclimatized to seasonal ambient conditions by increasing the insulation values of the hair coats in the cold with an average maximum insulation values of 0.811°Cm(2)  W(-1) . The cold adapted species are more than three times more insulated in the cold than the equatorial species. The husbandry implications of exotics that have no ability to acclimatize to Northern Hemisphere seasonal ambient changes are profound. Giraffe, African elephants, and okapi when exposed to cold conditions with ambient air temperatures below 21°C will use body energy reserves to maintain a heat balance and will require housing that provides ambient conditions of 21°C.

  15. Coxiella burnetii DNA detected in domestic ruminants and wildlife from Portugal.

    PubMed

    Cumbassá, Aminata; Barahona, Maria J; Cunha, Mónica V; Azórin, Beatriz; Fonseca, Carlos; Rosalino, Luís Miguel; Tilburg, Jeroen; Hagen, Ferry; Santos, Ana S; Botelho, Ana

    2015-10-22

    Coxiella burnetii is the etiological agent of Q fever or Coxiellosis, a zoonosis mainly affecting domestic ruminants. Information on the population structure and epidemiology of C. burnetii in animals is scarce in Portugal. Evidence of C. burnetti infection was sought in domestic, wild and captive animals based on the detection of bacterial DNA. Tissue samples from 152 domestic animals (cattle=24, goats=51, sheep=76 and swine=1), 55 wild carnivores (Egyptian mongoose=45, red fox=4, common genet=3, weasel=2 and European badger=1) and 22 zoo animals (antelopes=15, impala=1; rhinoceros=1, deer=2, zebras=2 and giraffe=1) were screened by nested-touchdown PCR. Cloacae swabs from 19 griffon vultures were also analysed. Among the domestic ruminants, goats presented the highest prevalence of infection (23.53%), followed by cattle, (20.83%) and sheep (10.53%). C. burnetii DNA was also detected in five Egyptian mongooses and two antelopes and one giraffe. Using a 6-locus multiple-locus variable-number tandem repeat analysis (MLVA-6) six complete genotypes, T, I and CM and the first reported CN, CO and CP, were identified, respectively, in small ruminants and Egyptian mongooses. Clustering analysis of genotypes exposed four distinct groups, according to detection source, enlightening an apparent association between C. burnetii genotype and host.

  16. VizieR Online Data Catalog: VLTS. B stars multiplicity (Dunstall+, 2015)

    NASA Astrophysics Data System (ADS)

    Dunstall, P. R.; Dufton, P. L.; Sana, H.; Evans, C. J.; Howarth, I. D.; Simon-Diaz, S.; de Mink, S. E.; Langer, N.; Maiz Apellaniz, J.; Taylor, W. D.

    2015-05-01

    The VFTS spectra were obtained with the Fibre Large Array Multi-Element Spectrograph (FLAMES) on the Very Large Telescope (VLT). Classifications for the 438 B-type stars observed in the VFTS were given by Evans et al. (2015, cat. J/A+A/574/A13). These are located in the main clusters in the 30 Dor region (i.e. NGC 2070, NGC 2060, Hodge 301, SL 639) and the local field population (see Fig. 4 from Evans et al.). All of the spectra were obtained using the fibre-fed Medusa-Giraffe mode of FLAMES, so the sample does not include stars in R136, the young massive cluster at the core of 30 Dor, which is too densely populated for effective use of the Medusa fibres. This paper presents a radial-velocity (RV) analysis of the multiple observations of the B-type stars with the LR02 setting of the Giraffe spectrograph. The observations spanned 10-12 months for most targets, with an extended baseline of 22 months for 31 targets, due to a reobservation for operational reasons. Two or three consecutive exposures were obtained on any given night, with the longer-term sampling designed to optimise detection of binaries with periods up to ~200d, given scheduling constraints. (3 data files).

  17. Gradual regime shifts in fairy circles

    PubMed Central

    Zelnik, Yuval R.; Meron, Ehud; Bel, Golan

    2015-01-01

    Large responses of ecosystems to small changes in the conditions—regime shifts—are of great interest and importance. In spatially extended ecosystems, these shifts may be local or global. Using empirical data and mathematical modeling, we investigated the dynamics of the Namibian fairy circle ecosystem as a case study of regime shifts in a pattern-forming ecosystem. Our results provide new support, based on the dynamics of the ecosystem, for the view of fairy circles as a self-organization phenomenon driven by water–vegetation interactions. The study further suggests that fairy circle birth and death processes correspond to spatially confined transitions between alternative stable states. Cascades of such transitions, possible in various pattern-forming systems, result in gradual rather than abrupt regime shifts. PMID:26362787

  18. The development of national standards for adult educators in Namibia

    NASA Astrophysics Data System (ADS)

    Ellis, Justin; Richardson, Brent H.

    2012-06-01

    Since gaining independence from South Africa in 1990, Namibia has placed considerable emphasis on education, including adult learning. As a means of improving the quality of adult learning, the Namibian Ministry of Education commissioned the development of national standards in 2010 to express competency requirements for adult educators. Particular attention was paid to the views of adult learners who participated through thirty focus groups. The participatory process revealed that the work of an adult educator is more complex and demanding than had previously been appreciated. The required competencies were categorised under four headings: (1) Knowledge as an adult educator, (2) Practice as an adult educator, (3) Relationships as an adult educator and (4) Ethics and professionalism as an adult educator. The Namibia Qualifications Authority, acting under its legislative mandate of setting occupational standards for occupations, jobs, posts and positions, approved the national standards in 2011.

  19. Forcings of nutrient, oxygen, and primary production interannual variability in the southeast Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Bachèlery, M.-L.; Illig, S.; Dadou, I.

    2016-08-01

    The recurrent occurrences of interannual warm and cold events along the coast of Africa have been intensively studied because of their striking effects on climate and fisheries. Using sensitivity experimentation based on a coupled physical/biogeochemical model, we show that the oceanic remote equatorial forcing explains more than 85% of coastal interannual nitrate and oxygen fluctuations along the Angolan and Namibian coasts up to the Benguela Upwelling System (BUS). These events, associated with poleward propagations of upwelling and downwelling Coastal Trapped Waves (CTW), are maximum in subsurface and controlled by physical advection processes. Surprisingly, an abrupt change in the CTW biogeochemical signature is observed in the BUS, associated with mixed vertical gradients due to the strong local upwelling dynamics. Coastal modifications of biogeochemical features result in significant primary production variations that may affect fisheries habitats and coastal biodiversity along the southwestern African coasts and in the BUS.

  20. Plasticity of human spatial cognition: spatial language and cognition covary across cultures.

    PubMed

    Haun, Daniel B M; Rapold, Christian J; Janzen, Gabriele; Levinson, Stephen C

    2011-04-01

    The present paper explores cross-cultural variation in spatial cognition by comparing spatial reconstruction tasks by Dutch and Namibian elementary school children. These two communities differ in the way they predominantly express spatial relations in language. Four experiments investigate cognitive strategy preferences across different levels of task-complexity and instruction. Data show a correlation between dominant linguistic spatial frames of reference and performance patterns in non-linguistic spatial memory tasks. This correlation is shown to be stable across an increase of complexity in the spatial array. When instructed to use their respective non-habitual cognitive strategy, participants were not easily able to switch between strategies and their attempts to do so impaired their performance. These results indicate a difference not only in preference but also in competence and suggest that spatial language and non-linguistic preferences and competences in spatial cognition are systematically aligned across human populations.

  1. Welwitschiaceae from the Lower Cretaceous of northeastern Brazil.

    PubMed

    Dilcher, David L; Bernardes-De-Oliveira, Mary E; Pons, Denise; Lott, Terry A

    2005-08-01

    Welwitschiaceae, a family in the Gnetales, is known today from only one extant species, Welwitschia mirabilis. This species is distributed in the Namibian desert, along the western coast of southern Africa, about 10 km inland from the coast. Very little is known about the fossil record of this family. Lower Cretaceous megafossils of various organs, assigned to Welwitschiaceae, are presented here. These fossils include young stems with paired cotyledons attached (Welwitschiella austroamericana n. gen. et sp.), isolated leaves (Welwitschiophyllum brasiliense n. gen. et sp.), and axes bearing male cones (Welwitschiostrobus murili n. gen. et sp.). They were collected in the Crato Formation, which is dated by palynomorphs and ostracods as Late Aptian (114 to 112 million years ago). These sediments are exposed in the Araripe Basin of northeastern Brazil. This study brings together new information of the megafossil record of Welwitschia-like plants and also reports of pollen said to be similar to that of Welwitschia from Lower Cretaceous sediments.

  2. Gradual regime shifts in fairy circles.

    PubMed

    Zelnik, Yuval R; Meron, Ehud; Bel, Golan

    2015-10-06

    Large responses of ecosystems to small changes in the conditions--regime shifts--are of great interest and importance. In spatially extended ecosystems, these shifts may be local or global. Using empirical data and mathematical modeling, we investigated the dynamics of the Namibian fairy circle ecosystem as a case study of regime shifts in a pattern-forming ecosystem. Our results provide new support, based on the dynamics of the ecosystem, for the view of fairy circles as a self-organization phenomenon driven by water-vegetation interactions. The study further suggests that fairy circle birth and death processes correspond to spatially confined transitions between alternative stable states. Cascades of such transitions, possible in various pattern-forming systems, result in gradual rather than abrupt regime shifts.

  3. Moving beyond a destructive past to a decolonised and inclusive future: The role of ubuntu-style education in providing culturally relevant pedagogy for Namibia

    NASA Astrophysics Data System (ADS)

    Biraimah, Karen L.

    2016-02-01

    Namibia has one of the most dehumanising and destructive colonial pasts of any nation in Africa, or, for that matter, the world. Before colonisation, the area now known as Namibia was home to diverse cultural groups. The successive colonial regimes of Germany and South Africa inflicted genocide, brutality and apartheid on the region. Namibia finally fought for and won its independence in 1990 - over three decades after Ghana became the first independent sub-Saharan nation in 1957. Today, Namibia strives to leave behind its troubled past and harness the power of education to provide greater equality of opportunity and quality of life for all of its citizens. The concept of ubuntu, with its emphasis on inclusiveness, equity and equality, is central to Namibia's pursuit of this goal. Significant challenges stand in its way, including extreme poverty, an emerging economy struggling with drought and a competitive world market, and a populace with multiple mother tongues and cultural traditions. After a brief summary of Namibia's colonial past, this study examines these challenges, noting that the same factors that provide Namibia with a rich and diverse cultural tapestry also pose great difficulties for educators determined to provide equitable education for all. Current inequities in Namibian education are assessed, with a particular focus on the divide between urban and rural Namibia and between the four major ethnic and cultural groupings: the White Afrikaans speakers, the Black African majority, the Coloured population, and the Basters. The study concludes by suggesting multiple ways in which education could be brought closer into line with ubuntu values. The author argues that the very same factors that currently pose challenges to the quality and equity of Namibian education (ethnicity, urban/rural location, gender and socioeconomic class) might, if seen from a new perspective, become the basis for educational transformation.

  4. Rhizobia Indigenous to the Okavango Region in Sub-Saharan Africa: Diversity, Adaptations, and Host Specificity

    PubMed Central

    Grönemeyer, Jann L.; Kulkarni, Ajinkya; Berkelmann, Dirk; Hurek, Thomas

    2014-01-01

    The rhizobial community indigenous to the Okavango region has not yet been characterized. The isolation of indigenous rhizobia can provide a basis for the formulation of a rhizobial inoculant. Moreover, their identification and characterization contribute to the general understanding of species distribution and ecology. Isolates were obtained from nodules of local varieties of the pulses cowpea, Bambara groundnut, peanut, hyacinth bean, and common bean. Ninety-one of them were identified by BOX repetitive element PCR (BOX-PCR) and sequence analyses of the 16S-23S rRNA internally transcribed spacer (ITS) and the recA, glnII, rpoB, and nifH genes. A striking geographical distribution was observed. Bradyrhizobium pachyrhizi dominated at sampling sites in Angola which were characterized by acid soils and a semihumid climate. Isolates from the semiarid sampling sites in Namibia were more diverse, with most of them being related to Bradyrhizobium yuanmingense and Bradyrhizobium daqingense. Host plant specificity was observed only for hyacinth bean, which was nodulated by rhizobia presumably representing yet-undescribed species. Furthermore, the isolates were characterized with respect to their adaptation to high temperatures, drought, and local host plants. The adaptation experiments revealed that the Namibian isolates shared an exceptionally high temperature tolerance, but none of the isolates showed considerable adaptation to drought. Moreover, the isolates' performance on different local hosts showed variable results, with most Namibian isolates inducing better nodulation on peanut and hyacinth bean than the Angolan strains. The local predominance of distinct genotypes implies that indigenous strains may exhibit a better performance in inoculant formulations. PMID:25239908

  5. Discovery of fairy circles in Australia supports self-organization theory

    PubMed Central

    Getzin, Stephan; Yizhaq, Hezi; Bell, Bronwyn; Erickson, Todd E.; Postle, Anthony C.; Katra, Itzhak; Tzuk, Omer; Zelnik, Yuval R.; Wiegand, Kerstin; Wiegand, Thorsten; Meron, Ehud

    2016-01-01

    Vegetation gap patterns in arid grasslands, such as the “fairy circles” of Namibia, are one of nature’s greatest mysteries and subject to a lively debate on their origin. They are characterized by small-scale hexagonal ordering of circular bare-soil gaps that persists uniformly in the landscape scale to form a homogeneous distribution. Pattern-formation theory predicts that such highly ordered gap patterns should be found also in other water-limited systems across the globe, even if the mechanisms of their formation are different. Here we report that so far unknown fairy circles with the same spatial structure exist 10,000 km away from Namibia in the remote outback of Australia. Combining fieldwork, remote sensing, spatial pattern analysis, and process-based mathematical modeling, we demonstrate that these patterns emerge by self-organization, with no correlation with termite activity; the driving mechanism is a positive biomass–water feedback associated with water runoff and biomass-dependent infiltration rates. The remarkable match between the patterns of Australian and Namibian fairy circles and model results indicate that both patterns emerge from a nonuniform stationary instability, supporting a central universality principle of pattern-formation theory. Applied to the context of dryland vegetation, this principle predicts that different systems that go through the same instability type will show similar vegetation patterns even if the feedback mechanisms and resulting soil–water distributions are different, as we indeed found by comparing the Australian and the Namibian fairy-circle ecosystems. These results suggest that biomass–water feedbacks and resultant vegetation gap patterns are likely more common in remote drylands than is currently known. PMID:26976567

  6. The 1911 Quadrant offshore Namibia; Exploration in a virgin basin

    SciTech Connect

    Holtar, E.; Forsberg, A.

    1995-08-01

    As a result of the first licensing round in independent Namibia, the Namibian authorities in 1992 awarded five offshore licenses to five different companies or groups of companies. License no. 001 was awarded in 1992 to a group consisting of three Norwegian oil companies, Norsk Hydro, Saga Petroleum and Statoil, with Hydro as the operator. Somewhat later Bow Valley Energy (now Talisman Energy) farmed in. Since 1992 a seismic survey of 7200 km has been acquired over the license area that covers 11.619 sq. Km of the Walvis Basin. This basin was undrilled until the 1911/15-1 well was finished at a depth of 4586mRKB in early 1994. The sedimentary succession of the 1911/15-1 well reflects a depositional history that postdates the Neocorman Etendeka plateau basalts found onshore Namibia. After the onset of the drift phase in late Hauterivian times, the Walvis Basin subsided and eventually a marine transgression took place. Shallow marine platform sedimentation then prevailed until an Albian tectonic event resulted in complex block faulting and the formation of several sub basins. Subsequent volcanic activity created a series of volcanic centres localized on the Walvis Ridge bathymetric feature. In early Late Cretaceous the Southern African craton was uplifted relative to the shelf, leading to the formation of large scale westward prograding wedges. Later sedimentation largely followed the evolution of a passive continental margin, responding to relative sealevel changes and paleoclimate. A stratigraphic breakdown of the Northern Namibian offshore is proposed, and compared to South African and Angolan nomenclature.

  7. "I do what I have to do to survive": An investigation into the perceptions, experiences and economic considerations of women engaged in sex work in Northern Namibia

    PubMed Central

    2011-01-01

    Background There is little published research investigating sex work in Namibia, particularly in rural areas. Therefore, the aim of this paper was to determine the views of women engaged in sex work in the Oshakati area of Namibia concerning the main factors influencing their use, or non-use, of male condoms during transactional sexual exchanges. Methods Qualitative interviews were used to better understand the perceptions, experiences and economic considerations of female sex workers in Namibia who were involved in a Behavior Change Communication Program encouraging safer sex practices among high-risk populations in 2006 and 2007. Results While the Behavior Change Communication Program has made significant strides in educating and empowering young women to negotiate more consistent condom use with sexual partners, the gendered economic inequalities and power imbalances within rural and semi-urban Namibian society that favor men hinder further advancement towards positive behavioral change for HIV prevention and also hinder the development of the loving relationships sought by some sex workers. Conclusion This study found that sex workers and transactional sex encounters are heterogeneous entities dependent upon the characteristics of the man (known, stranger, wealthy, attractive to the woman) and the woman (in financial need, desiring love). These features all influence condom use. The 3 E's 'education, empowerment and economic independence' are critical factors needed to encourage and facilitate consistent condom use to prevent HIV transmission. Without financial independence and occupational alternatives building on their health education and empowerment, women who engage in sex work-and transactional sex more generally-will remain largely marginalized from Namibian society, and will continue engaging in risky sexual practices that facilitate HIV acquisition and transmission throughout the community. PMID:21813006

  8. Rhizobia Indigenous to the Okavango Region in Sub-Saharan Africa: Diversity, Adaptations, and Host Specificity.

    PubMed

    Grönemeyer, Jann L; Kulkarni, Ajinkya; Berkelmann, Dirk; Hurek, Thomas; Reinhold-Hurek, Barbara

    2014-12-01

    The rhizobial community indigenous to the Okavango region has not yet been characterized. The isolation of indigenous rhizobia can provide a basis for the formulation of a rhizobial inoculant. Moreover, their identification and characterization contribute to the general understanding of species distribution and ecology. Isolates were obtained from nodules of local varieties of the pulses cowpea, Bambara groundnut, peanut, hyacinth bean, and common bean. Ninety-one of them were identified by BOX repetitive element PCR (BOX-PCR) and sequence analyses of the 16S-23S rRNA internally transcribed spacer (ITS) and the recA, glnII, rpoB, and nifH genes. A striking geographical distribution was observed. Bradyrhizobium pachyrhizi dominated at sampling sites in Angola which were characterized by acid soils and a semihumid climate. Isolates from the semiarid sampling sites in Namibia were more diverse, with most of them being related to Bradyrhizobium yuanmingense and Bradyrhizobium daqingense. Host plant specificity was observed only for hyacinth bean, which was nodulated by rhizobia presumably representing yet-undescribed species. Furthermore, the isolates were characterized with respect to their adaptation to high temperatures, drought, and local host plants. The adaptation experiments revealed that the Namibian isolates shared an exceptionally high temperature tolerance, but none of the isolates showed considerable adaptation to drought. Moreover, the isolates' performance on different local hosts showed variable results, with most Namibian isolates inducing better nodulation on peanut and hyacinth bean than the Angolan strains. The local predominance of distinct genotypes implies that indigenous strains may exhibit a better performance in inoculant formulations.

  9. The Gaia-ESO Survey: processing FLAMES-UVES spectra

    NASA Astrophysics Data System (ADS)

    Sacco, G. G.; Morbidelli, L.; Franciosini, E.; Maiorca, E.; Randich, S.; Modigliani, A.; Gilmore, G.; Asplund, M.; Binney, J.; Bonifacio, P.; Drew, J.; Feltzing, S.; Ferguson, A.; Jeffries, R.; Micela, G.; Negueruela, I.; Prusti, T.; Rix, H.-W.; Vallenari, A.; Alfaro, E.; Allende Prieto, C.; Babusiaux, C.; Bensby, T.; Blomme, R.; Bragaglia, A.; Flaccomio, E.; Francois, P.; Hambly, N.; Irwin, M.; Koposov, S.; Korn, A.; Lanzafame, A.; Pancino, E.; Recio-Blanco, A.; Smiljanic, R.; Van Eck, S.; Walton, N.; Bergemann, M.; Costado, M. T.; de Laverny, P.; Heiter, U.; Hill, V.; Hourihane, A.; Jackson, R.; Jofre, P.; Lewis, J.; Lind, K.; Lardo, C.; Magrini, L.; Masseron, T.; Prisinzano, L.; Worley, C.

    2014-05-01

    The Gaia-ESO Survey is a large public spectroscopic survey that aims to derive radial velocities and fundamental parameters of about 105 Milky Way stars in the field and in clusters. Observations are carried out with the multi-object optical spectrograph FLAMES, using simultaneously the medium-resolution (R ~ 20 000) GIRAFFE spectrograph and the high-resolution (R ~ 47 000) UVES spectrograph. In this paper we describe the methods and the software used for the data reduction, the derivation of the radial velocities, and the quality control of the FLAMES-UVES spectra. Data reduction has been performed using a workflow specifically developed for this project. This workflow runs the ESO public pipeline optimizing the data reduction for the Gaia-ESO Survey, automatically performs sky subtraction, barycentric correction and normalisation, and calculates radial velocities and a first guess of the rotational velocities. The quality control is performed using the output parameters from the ESO pipeline, by a visual inspection of the spectra and by the analysis of the signal-to-noise ratio of the spectra. Using the observations of the first 18 months, specifically targets observed multiple times at different epochs, stars observed with both GIRAFFE and UVES, and observations of radial velocity standards, we estimated the precision and the accuracy of the radial velocities. The statistical error on the radial velocities is σ ~ 0.4 km s-1 and is mainly due to uncertainties in the zero point of the wavelength calibration. However, we found a systematic bias with respect to the GIRAFFE spectra (~0.9 km s-1) and to the radial velocities of the standard stars (~0.5 km s-1) retrieved from the literature. This bias will be corrected in the future data releases, when a common zero point for all the set-ups and instruments used for the survey is be established. Based on observations made with the ESO/VLT, at Paranal Observatory, under programme 188.B-3002 (The Gaia-ESO Public

  10. System Integral Test by BWR Drywell Cooler Applied as Phase-II Accident Management

    SciTech Connect

    Nagasaka, Hideo; Tobimatsu, Toshimi; Tahara, Mika; Yokobori, Seiichi; Akinaga, Makoto

    2002-07-01

    This paper deals with the system interaction performance using the BWR drywell local cooler (DWC) in combination with containment spray as a Japanese Phase-II accident management (AM). By using almost full height simulation test facility (GIRAFFE-DWC) with scaling ratio of 1/600, the system integral tests simulating BWR low pressure vessel failure sequence were accomplished during about 14 hours. In case of DWC application, the containment pressure increase was found milder due to DWC heat removal performance. Initial spray timing was delayed about 3 hours and each spray period was reduced almost by half. It was concluded that the application of a BWR DWC to Phase-II AM measure is quite promising from the point of delaying or preventing the containment venting. (authors)

  11. Massive spectroscopic analysis of the stellar populations in three of the CoRoT/Exoplanet fields

    NASA Astrophysics Data System (ADS)

    Gazzano, J.-C.; Deleuil, M.; de Laverny, P.; Kordopatis, G.; Moutou, C.; Recio-Blanco, A.; Bijaoui, A.; Bouchy, F.; Ordenovic, C.

    2010-12-01

    We derived the atmospheric parameters (teff, logg, met, alf), řad, and šini for 1227 CoRoT/Exoplanet targets in three of the fields observed by CoRoT. We derived the corresponding absolute magnitude using evolutionary models. We combined 2MASS colours with a new implementation of the infrared flux method, and the teff from matisse to constrain the interstellar extinction. These steps allowed us to measure the stellar distances, hence deriving kinematics information. This opened the path to the study of the stellar populations found in these \\corot fields.These studies showed the potential of combining a multi-fiber instrument like FLAMES/GIRAFFE, with an automatic tool to determine efficiently atmospheric stellar parameters, as MATISSE.

  12. Estimation of Human Toxicity From Animal Inhalation Toxicity Data: 1. Minute Volume-Body Weight Relationships Between Animals And Man.

    DTIC Science & Technology

    1997-10-01

    the data. These included the cat studies of Wang [152], the cotton rat data of Guyton [2] and the spiny anteater study by Bentley et al [62] which are...Baboon 4.424,1 1.61 0.365 *Cotton rat 0.07727,1 0.040 0.516 Monkey 4.27311.15 1.40 0.374 *Spiny 3.473.1 0.527 0.150 ±2.69 ±0.42 ±0.125 anteater ±0.177...Restrained 170 1 19 0.112 56 Pig, female 225 37 0.164 53, 71 Giraffe Free standing 544 2 74.3 0.136 141 **Spiny Anteater Y, Quiet, restrained, asleep? 3.35 2

  13. New algorithms for reducing cross-dispersed echelle spectra

    NASA Astrophysics Data System (ADS)

    Piskunov, N. E.; Valenti, J. A.

    2002-04-01

    We describe advanced image processing algorithms, implemented in a data analysis package for conventional and cross-dispersed echelle spectra. Comparisons with results from other packages illustrate the outstanding quality of the new REDUCE package, particularly in terms of resulting noise level and treatment of CCD defects and cosmic ray spikes. REDUCE can be adapted relatively easily to handle a variety of instrument types, including spectrographs with prism or grating cross-dispersers, possibly fed by a fiber or image slicer, etc. In addition to reduced spectra, an accurate spatial profile is recovered, providing valuable information about the spectrograph PSF and simplifying scattered light corrections. Based on data obtained with the VLT UVES and SAAO Giraffe spectrometers.

  14. Uncovering mental representations with Markov chain Monte Carlo.

    PubMed

    Sanborn, Adam N; Griffiths, Thomas L; Shiffrin, Richard M

    2010-03-01

    A key challenge for cognitive psychology is the investigation of mental representations, such as object categories, subjective probabilities, choice utilities, and memory traces. In many cases, these representations can be expressed as a non-negative function defined over a set of objects. We present a behavioral method for estimating these functions. Our approach uses people as components of a Markov chain Monte Carlo (MCMC) algorithm, a sophisticated sampling method originally developed in statistical physics. Experiments 1 and 2 verified the MCMC method by training participants on various category structures and then recovering those structures. Experiment 3 demonstrated that the MCMC method can be used estimate the structures of the real-world animal shape categories of giraffes, horses, dogs, and cats. Experiment 4 combined the MCMC method with multidimensional scaling to demonstrate how different accounts of the structure of categories, such as prototype and exemplar models, can be tested, producing samples from the categories of apples, oranges, and grapes.

  15. Preliminary Results of Detailed Chemical Abundance Analysis of Milky Way Satellite Galaxy Reticulum II Discovered in the Dark Energy Survey

    NASA Astrophysics Data System (ADS)

    Nagasawa, Daniel; Marshall, Jennifer L.; Li, Ting; Dark Energy Survey Milky Way Science Group

    2016-01-01

    We present preliminary results from abundance analysis of stars in Milky Way satellite galaxies found in the Dark Energy Survey (DES). DES has discovered 16 candidate satellite galaxies of the Milky Way in its first two years of operation. Since January 2015, three candidates have subsequently been revealed to be dark matter-dominated by spectroscopic follow-up studies of their kinematics, confirming their status as satellite galaxies. Spectroscopic follow-up of the remaining 13 candidates is underway. We have analyzed high resolution VLT/GIRAFFE spectra of member stars in one of these satellite galaxies, Reticulum II. Using equivalent width measurement and spectral synthesis methods, we measure the abundances of Iron and other species in order to begin to understand the chemical content of these Milky Way satellites.

  16. VizieR Online Data Catalog: NGC 2808 AGB and RGB stars Na abundance (Wang+, 2016)

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Primas, F.; Charbonnel, C.; van der Swaelmen, M.; Bono, G.; Chantereau, W.; Zhao, G.

    2016-05-01

    The high-resolution spectra of our sample of AGB and RGB stars in the Galactic globular cluster NGC 2808 were obtained with the high-resolution multi-object spectrograph FLAMES, mounted on ESO/VLT-UT2. A combined mode was used where the brightest five objects was observed with UVES-fibre and the remaining targets with GIRAFFE/Medusa. The basic information of our sample stars are listed in Table 2, including the evolutionary phase, instrument used for observation, coordinates, photometry and barycentric radial velocity. Our Fe abundances were derived from the equivalent widths of Fe lines, while the Na abundances were determined with spectra synthesis. Both FeI and Na abundances have been corrected for the non-LTE effect. In Table 4 we show the derived stellar parameters of our sample stars, and the Na abundances are shown in Table 6. (3 data files).

  17. Searching for IMBHs in Galactic globular clusters through radial velocities of individual stars

    NASA Astrophysics Data System (ADS)

    Lanzoni, Barbara

    2016-02-01

    I present an overview of our ongoing project aimed at building a new generation of velocity dispersion profiles ad rotation curves for a representative sample of Galactic globular clusters, from the the radial velocity of hundreds of individual stars distributed at different distances from the cluster center. The innermost portion of the profiles will be used to constrain the possible presence of intermediate-mass black holes. The adopted methodology consists of combining spectroscopic observations acquired with three different instruments at the ESO-VLT: the adaptive-optics assisted, integral field unit (IFU) spectrograph SINFONI for the innermost and highly crowded cluster cores, the multi-IFU spectrograph KMOS for the intermediate regions, and the multi-fiber instrument FLAMES/GIRAFFE-MEDUSA for the outskirts. The case of NGC 6388, representing the pilot project that motivated the entire program, is described in some details.

  18. VizieR Online Data Catalog: CaT/[Fe/H] calibration for Galactic bulge stars (Vasquez+, 2015)

    NASA Astrophysics Data System (ADS)

    Vasquez, S.; Zoccali, M.; Hill, V.; Gonzalez, O. A.; Saviane, I.; Rejkuba, M.; Battaglia, G.

    2015-07-01

    The target stars we used to construct the CaT calibration are all located in Baade's Window, and they consist of two samples: 80 stars in the bulge RC and 68 stars on the RGB, which are ~0.7mag brigther than the RC. The medium-resolution spectra analysed here were taken with the FLAMES-GIRAFFE multifibre spectrograph at the VLT, in Medusa mode, within the ESO program ID 385.B-0735(B). Bulge data used to compute the metallicity calibration are presented. For each bulge star we provided the coordinates, magnitude difference respect to the red clump, equivalent widths for the two strongest calcium lines and the corresponding metallicity derived from high resolution spectroscopy. (1 data file).

  19. A kinematic analysis of the Giant star-forming Region of N11

    NASA Astrophysics Data System (ADS)

    Torres-Flores, Sergio; Barbá, Rodolfo; Maíz Apellániz, Jesús; Rubio, Mónica; Bosch, Guillermo

    2015-02-01

    In this work we present high resolution spectroscopic data of the giant star-forming region of N11, obtained with the GIRAFFE instrument at the Very Large Telescope. By using this data set, we find that most of the Hα emission lines profiles in this complex can be fitted by a single Gaussian, however, multiple emission line profiles can be observed in the central region of N11. By adding all the spectra, we derive the integrated Hα profile of this complex, which displays a width (σ) of about 12 km s-1 (corrected by instrumental and thermal width). We find that a single Gaussian fit on the integrated Hα profile leaves remaining wings, which can be fitted by a secondary broad Gaussian component. In addition, we find high velocity features, which spatially correlate with soft diffuse X-ray emission.

  20. VizieR Online Data Catalog: NGC 288 hot horizontal branch stars abundances (Moehler+, 2014)

    NASA Astrophysics Data System (ADS)

    Moehler, S.; Dreizler, S.; Leblanc, F.; Khalack, V.; Michaud, G.; Richer, J.; Sweigart, A. V.; Grundahl, F.

    2014-03-01

    Temperatures, surface gravities, and abundances for hot (Teff>9000K) horizontal branch stars in NGC 288 as derived from medium-resolution FLAMES-GIRAFFE spectra (resolution about 0.7Å). Effective temperatures and surface gravities are derived from line profile fits. The abundances were derived via spectrum synthesis, using the presviously defined effective temperature and surface gravity. Errors are about ±5% in Teff, ±0.1 in logg, ±0.2 (He), ±0.28 (Mg), ±0.34 (Si, P, Fe), ±0.58 (Ti, Mn, Ni). 0.00 means that no abundance could be determined. (2 data files).

  1. Evolution of the chemical element abundances with age in open clusters: The Hyades, Pleiades, Coma Berenices and M6

    NASA Astrophysics Data System (ADS)

    Kiliçoǧlu, T.; Monier, R.; Gebran, M.; Fossati, L.

    2014-12-01

    We compare the averaged photospheric abundances of A and F stars in open clusters of different ages: M6 (˜80 Myr), Pleiades (˜100 Myr), Coma Berenices (˜450 Myr), and the Hyades (˜800 Myr). The variation in the averaged abundances among F stars generally reflects the differences between the initial compositions of the clusters in their various birthplaces. The differences of the averaged chemical composition of A stars may also reveal the effects of radiative difussion for the stars of different ages. We also discuss the methods, resolutions and wavelength coverages of spectra and discrepancies in the derived microturbulent velocities among the various studies to check if these studies are comparable. We also present the pattern of mean abundances and metallicity for the M6 cluster determined by spectral analysis of GIRAFFE spectra acquired with the VLT, Paranal Observatory.

  2. Elemental abundances in RGB stars of the Large Magellanic Cloud.

    NASA Astrophysics Data System (ADS)

    Van der Swaelmen, M.; Hill, V.; Primas, F.

    The present work is based on a high-resolution spectroscopic survey of two LMC fields located in the bar and the inner disc, observed at ESO/VLT with FLAMES/GIRAFFE. We confront the results in the LMC inner disc and bar fields and discuss their similarities/differences in the light of the origin of the LMC bar. Both fields show that the LMC has a SFH slower than the MW, resulting in a chemical evolution dominated by SNIa and metal-poor AGB winds. Chemical anomalies for Eu, Ba and La are detected in the most metal-rich field stars, as it has been before in LMC GC stars, and cannot be explained by canonical nucleosynthesis processes.

  3. Studies of Long Period Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Ratajczak, M.; Hełminiak, K. G.; Konacki, M.

    2015-07-01

    The survey of long period eclipsing binaries from the All Sky Automated Survey (ASAS) catalog aims at searching for and characterizing subgiants and red giants in double-lined detached binary systems. Absolute physical and orbital parameters are presented based on radial velocities from high-quality optical spectra obtained with the following telescope/instrument combinations: 8.2 m Subaru/HDS, ESO 3.6 m/HARPS, 1.9 m Radcliffe/GIRAFFE, CTIO 1.5 m/CHIRON, and 1.2 m Euler/CORALIE. Photometric data from ASAS, SuperWASP, and the Solaris Project were also used. We discuss the derived uncertainties for the individual masses and radii of the components (better than 3% for several systems), as well as results from the spectral analysis performed for components of systems whose spectra we disentangled.

  4. Sky background subtraction with fiber-fed spectrographs

    NASA Astrophysics Data System (ADS)

    Puech, M.; Rodrigues, M.; Yang, Y.; Flores, H.; Royer, F.; Disseau, K.; Gonçalves, T.; Hammer, F.; Cirasuolo, M.; Evans, C. J.; Li Causi, G.; Maiolino, R.; Melo, C.

    2014-08-01

    Fiber-fed spectrographs can now have throughputs equivalent to slit spectrographs. However, the sky subtraction accuracy that can be reached on such instruments has often been pinpointed as one of their major issues, in relation to difficulties in scattered light and flat-field corrections or throughput losses associated with fibers. Using technical time observations with FLAMES-GIRAFFE, two observing techniques, namely dual staring and cross beam switching modes, were tested and the resulting sky subtraction accuracy reached in both cases was quantified. Results indicate that an accuracy of 0.6% on the sky subtraction can be reached, provided that the cross beam switching mode is used. This is very encouraging regarding the detection of very faint sources with future fiber-fed spectrographs such as VLT/MOONS or E-ELT/MOSAIC.

  5. Indirect measurements of nuclear astrophysics reactions at CIAE

    SciTech Connect

    Liu Weiping; Li Zhihong; Bai Xixiang; Wang Youbao; Lian Gang; Guo Bing; Zeng Sheng; Yan Shengquan; Wang Baoxiang; Su Jun; Shu Nengchuan; Chen Yongshou

    2006-11-02

    This paper described the nuclear astrophysical studies using the unstable ion beam facility GIRAFFE, by indirect measurements. We measured the angular distributions for some single proton or neutron transfer reactions, such as 7Be(d,n)8B, 11C(d,n)12N, 8Li(d,n)9Be, 8Li(d,p)9Li and 13N(d,n)14O in inverse kinematics, and derived the astrophysical S-factors or reaction rates of 7Be(p,{gamma})8B, 11C(p,{gamma})12N, 8Li(n,{gamma})9Li, 13N(p,{gamma})14O by asymptotic normalization coefficient, spectroscopic factor, and R-matrix approach at astrophysically relevant energies.

  6. VizieR Online Data Catalog: Sulphur in the Sculptor dSph (Skuladottir+, 2015)

    NASA Astrophysics Data System (ADS)

    Skuladottir, A.; Andrievsky, S. M.; Tolstoy, E.; Hill, V.; Salvadori, S.; Korotin, S. A.; Pettini, M.

    2015-11-01

    From the DART survey (Tolstoy et al., 2006Msngr.123...33T), detailed abundance measurements are known for ~100 stars spread over a 25' diameter field of view in the Sculptor dSph (Tolstoy et al., 2009ARA&A..47..371T; Hill et al., in prep.). Because of the distance to Sculptor, only the brightest stars are available for HR spectroscopy. This sample, therefore, consists of relatively cool red giant branch (RGB) stars, with Teff<~4700K. For an overlapping sample of 86 stars in Sculptor, ESO VLT/GIRAFFE spectroscopy was carried out to measure sulphur. The observations presented here were taken in service mode in July and August of 2012, all using the HR22B grating, which covers the wavelength range 8960-9420Å th resolution R~19000 . (2 data files).

  7. VizieR Online Data Catalog: Radial velocity and photometry in NGC 4372 (Kacharov+, 2014)

    NASA Astrophysics Data System (ADS)

    Kacharov, N.; Bianchini, P.; Koch, A.; Frank, M. J.; Martin, N. F.; van de Ven, G.; Puzia, T. H.; McDonald, I.; Johnson, C. I.; Zijlstra, A. A.

    2014-06-01

    We present the radial velocities of 220 stars in the field of the globular cluster NGC 4372 measured from high resolution FLAMES/GIRAFFE spectra. We have confirm 131 cluster member stars from radial velocity and metallicity constraints. The rest are foreground contaminants. We also present a BVI photometric catalogue in a field of view covering 30x30arcmin, centred on NGC 4372. We used archival imaging obtained with the Wide Field Imager (WFI) at the 2.2m MPG/ESO telescope at La Silla. We used the 2MASS point source catalog as astrometric reference. Photometric zero points were fixed to standard stars in the same field from the standard star database of Stetson (2000PASP..112..925S, 2005PASP..117..563S). We have estimated individual reddening for each star in the catalogue. (2 data files).

  8. Sperm preservation by freeze-drying for the conservation of wild animals.

    PubMed

    Kaneko, Takehito; Ito, Hideyuki; Sakamoto, Hidefusa; Onuma, Manabu; Inoue-Murayama, Miho

    2014-01-01

    Sperm preservation is a useful technique for the maintenance of biological resources in experimental and domestic animals, and in wild animals. A new preservation method has been developed that enables sperm to be stored for a long time in a refrigerator at 4 °C. Sperm are freeze-dried in a solution containing 10 mM Tris and 1 mM EDTA. Using this method, liquid nitrogen is not required for the storage and transportation of sperm. We demonstrate that chimpanzee, giraffe, jaguar, weasel and the long-haired rat sperm remain viable after freeze-drying. In all species, pronuclei were formed after the injection of freeze-dried sperm into the mouse oocytes. Although preliminary, these results may be useful for the future establishment of "freeze-drying zoo" to conserve wild animals.

  9. Membership, lithium and chromospheric activity of the young open clusters IC 2391, IC 2602 and IC 4665 from GES (Gaia-ESO Survey) observations

    NASA Astrophysics Data System (ADS)

    Gómez Garrido, M.; Montes, D.; Gutiérrez Albarrán, M. L.; Tabernero, H. M.; Gónzalez Hernández, J. I.; GES Survey Builders

    2017-03-01

    We conduct a comparative study of the main properties of the of the young open clusters IC 2391, IC 2602 and IC 4665, focusing on their membership, lithium abundance and level of chromospheric activity and possible accretion. We use the fundamental parameters (effective temperature, surface gravity, and radial velocity) delivered by the Gaia-ESO survey (GES - https://www.gaia-eso.eu/) consortium in the four internal data release (iDR4) to select the members of these clusters among the UVES and GIRAFFE spectroscopic observations. Chromospheric activity criterium, and iterative process between radial velocity distribution and lithium-temperature diagram are applied to determinate what objects are members or non members of the clusters. All this information allowed us to characterize the properties of the members of these clusters and identify some field contaminant lithium-rich giants.

  10. VizieR Online Data Catalog: Velocities and photometry in Trumpler 20 (Donati+, 2014)

    NASA Astrophysics Data System (ADS)

    Donati, P.; Gaudin, Cantat; Bragaglia, A.; Friel, E.; Magrini, L.; Smiljanic, R.; Vallenari, A.; Tosi, M.; Sordo, R.; Tautvaisiene, G.; Blanco-Cuaresma, S.; Costado, M. T.; Geisler, D.; Klutsch, A.; Mowlavi, N.; Munoz, C.; San, Roman I.; Zaggia, S.; Gilmore, G.; Randich, S.; Bensby, T.; Flaccomio, E.; Koposov, S. E.; Korn, A. J.; Pancino, E.; Recio-Blanco, A.; Franciosini, E.; de Laverny, P.; Lewis, J.; Morbidelli, L.; Prisinzano, L.; Sacco, G.; Worley, C. C.; Hourihane, A.; Jofre, P.; Lardo, C.; Maiorca, E.

    2013-11-01

    We combined high quality photometry available in literature (Carraro et al., 2010AJ....140..954C, hereafter C10, and Platais et al., 2008, Cat. J/MNRAS/391/1482, hereafter P08) and the spectroscopic observations of the Gaia-ESO Survey to reevaluate the parameters of the open cluster Trumpler 20. 1370 star spectra, taken with UVES and GIRAFFE spectrograph at VLT/UT2, of both main sequence and red clump stars were exploited to estimate the radial velocity distribution of the cluster stars and select the most probable cluster members. 13 red clump stars observed with UVES were used to determine the cluster metallicity. With the improved information on metallicity and membership we used the photometric catalogues to estimate age, distance and average galactic reddening by means of the isochrone fitting method. We estimated the differential reddening on the cluster face and found to play a not negligible role on the CMD morphology. (2 data files).

  11. Numerical taxonomy of the genus Pestivirus: new software for genotyping based on the palindromic nucleotide substitutions method.

    PubMed

    Giangaspero, Massimo; Apicella, Claudio; Harasawa, Ryô

    2013-09-01

    The genus Pestivirus from the family Flaviviridae is represented by four established species; Bovine viral diarrhea virus 1 (BVDV-1); Bovine viral diarrhea virus 2 (BVDV-2); Border disease virus (BDV); and Classical swine fever virus (CSFV); as well a tentative species from a Giraffe. The palindromic nucleotide substitutions (PNS) in the 5' untranslated region (UTR) of Pestivirus RNA has been described as a new, simple and practical method for genotyping. New software is described, also named PNS, that was prepared specifically for this PNS genotyping procedure. Pestivirus identification using PNS was evaluated on five hundred and forty-three sequences at genus, species and genotype level using this software. The software is freely available at www.pns-software.com.

  12. How name descriptiveness impacts proper name learning in young and older adults.

    PubMed

    Fogler, Kethera A; James, Lori E; Crandall, Elizabeth A

    2010-09-01

    To elucidate the impact of name descriptiveness and aging on learning new names, 26 young and 26 healthy older participants learned visibly-descriptive (e.g., Lengthy for a giraffe), psychologically-descriptive (e.g., Classy), and non-descriptive (e.g., Sam) proper names for previously-unknown cartoon characters. More visibly-descriptive names were learned than psychologically- or non-descriptive names, which did not differ from each other. There was also a differential benefit for older adults when the name was visibly-descriptive of the referent, such that older adults learned visibly-descriptive names as well as young adults but there were substantial age-related deficits in learning psychologically- and non-descriptive names.

  13. How Name Descriptiveness Impacts Proper Name Learning in Young and Older Adults

    PubMed Central

    Fogler, Kethera A.; James, Lori E.; Crandall, Elizabeth A.

    2009-01-01

    To elucidate the impact of name descriptiveness and aging on learning new names, 26 young and 26 healthy older participants learned visibly-descriptive (e.g., Lengthy for a giraffe), psychologically-descriptive (e.g., Classy), and non-descriptive (e.g., Sam) proper names for previously-unknown cartoon characters. More visibly-descriptive names were learned than psychologically- or non-descriptive names, which did not differ from each other. There was also a differential benefit for older adults when the name was visibly-descriptive of the referent, such that older adults learned visibly-descriptive names as well as young adults but there were substantial age-related deficits in learning psychologically- and non-descriptive names. PMID:20349368

  14. The helminth parasites of various artiodactylids from some South African nature reserves.

    PubMed

    Boomker, J; Horak, I G; De Vos, V

    1986-06-01

    The helminth species composition and helminth burdens of 4 grey duikers, 12 bushbuck, 2 nyala, 2 giraffe, a steenbok, an oribi, a waterbuck and a tsessebe from the Kruger National Park (KNP); of a steenbok and a greater kudu from the farm Riekerts Laager, Transvaal; of a single blue duiker from the Tsitsikama Forest National Park, and of a blue wildebeest, a red hartebeest, a gemsbok and 2 springbok from the Kalahari Gemsbok National Park (KGNP) were collected, counted and identified. New parasite records are: Agriostomum equidentatum from the gemsbok, Cooperia neitzi from the bushbuck, Cooperia sp. from the gemsbok and the red hartebeest, Cooperia yoshidai from the waterbuck and the tsessebe, Dictyocaulus viviparus from the bushbuck, Haemonchus bedfordi from the waterbuck, Haemonchus contortus from the gemsbok, Haemonchus krugeri from the steenbok from the KNP, Impalaia nudicollis from the gemsbok and the red hartebeest, Impalaia tuberculata from the oribi and the waterbuck, Impalaia spp. from the kudu, Longistrongylus meyeri from the steenbok from Riekerts Laager and the gemsbok, Longistrongylus sabie from the steenbok from the KNP, Longistrongylus schrenki from the tsessebe, Parabronema sp. from the tsessebe and the red hartebeest, Paracooperia serrata from the gemsbok and the steenbok from the KGNP, Pneumostrongylus calcaratus from the bushbuck, Strongyloides sp. from the gemsbok, Trichostrongylus sp. from the gemsbok, the red hartebeest and the steenbok from the KGNP, Trichostrongylus axei from the blue duiker, Trichostrongylus falculatus from the bushbuck and the oribi, Trichostrongylus instabilis from the bushbuck, the steenbok from the KNP and the oribi and Trichostrongylus thomasi from the grey duikers and tsessebe. Host specificity of the parasites was not marked and crossinfestation was common. This was not true for the giraffe, since none of the helminths of these animals were found in the antelope and vice versa.

  15. Buffalo, Bush Meat, and the Zoonotic Threat of Brucellosis in Botswana

    PubMed Central

    Alexander, Kathleen Anne; Blackburn, Jason Kenna; Vandewalle, Mark Eric; Pesapane, Risa; Baipoledi, Eddie Kekgonne; Elzer, Phil H.

    2012-01-01

    Background Brucellosis is a zoonotic disease of global importance infecting humans, domestic animals, and wildlife. Little is known about the epidemiology and persistence of brucellosis in wildlife in Southern Africa, particularly in Botswana. Methods Archived wildlife samples from Botswana (1995–2000) were screened with the Rose Bengal Test (RBT) and fluorescence polarization assay (FPA) and included the African buffalo (247), bushbuck (1), eland (5), elephant (25), gemsbok (1), giraffe (9), hartebeest (12), impala (171), kudu (27), red lechwe (10), reedbuck (1), rhino (2), springbok (5), steenbok (2), warthog (24), waterbuck (1), wildebeest (33), honey badger (1), lion (43), and zebra (21). Human case data were extracted from government annual health reports (1974–2006). Findings Only buffalo (6%, 95% CI 3.04%–8.96%) and giraffe (11%, 95% CI 0–38.43%) were confirmed seropositive on both tests. Seropositive buffalo were widely distributed across the buffalo range where cattle density was low. Human infections were reported in low numbers with most infections (46%) occurring in children (<14 years old) and no cases were reported among people working in the agricultural sector. Conclusions Low seroprevalence of brucellosis in Botswana buffalo in a previous study in 1974 and again in this survey suggests an endemic status of the disease in this species. Buffalo, a preferred source of bush meat, is utilized both legally and illegally in Botswana. Household meat processing practices can provide widespread pathogen exposure risk to family members and the community, identifying an important source of zoonotic pathogen transmission potential. Although brucellosis may be controlled in livestock populations, public health officials need to be alert to the possibility of human infections arising from the use of bush meat. This study illustrates the need for a unified approach in infectious disease research that includes consideration of both domestic and wildlife

  16. Analysis of panthers full-scale heat transfer tests with RELAP5

    SciTech Connect

    Parlatan, Y.; Boyer, B.D.; Jo, J.; Rohatgi, S.

    1996-01-01

    The RELAP5 code is being assessed on the full-scale Passive Containment Cooling System (PCCS) in the Performance ANalysis and Testing of HEat Removal Systems (PANTHERS) facility at Societa Informazioni Termoidrauliche (SIET) in Italy. PANTHERS is a test facility with fall-size prototype beat exchangers for the PCCS in support of the General Electric`s (GE) Simplified Boiling Water Reactor (SBWR) program. PANTHERS tests with a low noncondensable gas concentration and with a high noncondensable gas concentration were analyzed with RELAP5. The results showed that beat transfer rate decreases significantly along the PCCS tubes. In the test case with a higher inlet noncondensable gas fraction, the PCCS removed 35% less heat than in the test case with the lower noncondensable gas fraction. The dominant resistance to the overall heat transfer is the condensation beat transfer resistance inside the tubes. This resistance increased by about 5-fold between the inlet and exit of the tube due to the build up of noncondensable gases along the tube. The RELAP5 calculations also predicted that 4% to 5% of the heat removed to the PCCS pool occurs in the inlet steam piping and PCCS upper and lower headers. These piping needs to be modeled for other tests systems. The full-scale PANTHERS predictions are also compared against 1/400 scale GIRAFFE tests. GIRAFFE has 33% larger heat surface area, but its efficiency is only 15% and 23% higher than PANTHERS for the two cases analyzed This was explained by the high heat transfer resistance inside the tubes near the exit.

  17. On the accretion properties of young stellar objects in the L1615/L1616 cometary cloud

    NASA Astrophysics Data System (ADS)

    Biazzo, K.; Alcalá, J. M.; Frasca, A.; Zusi, M.; Getman, F.; Covino, E.; Gandolfi, D.

    2014-12-01

    We present the results of FLAMES/UVES and FLAMES/GIRAFFE spectroscopic observations of 23 low-mass stars in the L1615/L1616 cometary cloud, complemented with FORS2 and VIMOS spectroscopy of 31 additional stars in the same cloud. L1615/L1616 is a cometary cloud in which the star formation was triggered by the impact of massive stars in the Orion OB association. From the measurements of the lithium abundance and radial velocity, we confirm the membership of our sample to the cloud. We use the equivalent widths of the Hα, Hβ, and the He i λ5876, λ6678, λ7065 Å emission lines to calculate the accretion luminosities, Lacc, and the mass accretion rates, Ṁacc. We find in L1615/L1616 a fraction of accreting objects (~30%), which is consistent with the typical fraction of accretors in T associations of similar age (~3 Myr). The mass accretion rate for these stars shows a trend with the mass of the central object similar to that found for other star-forming regions, with a spread at a given mass that depends on the evolutionary model used to derive the stellar mass. Moreover, the behavior of the 2MASS/WISE colors with Ṁacc indicates that strong accretors with log Ṁacc ≳ -8.5 dex show large excesses in the JHKs bands, as in previous studies. We also conclude that the accretion properties of the L1615/L1616 members are similar to those of young stellar objects in T associations, like Lupus. Based on FLAMES (UVES+GIRAFFE) observations collected at the Very Large Telescope (VLT; Paranal, Chile). Program 076.C-0385(A).Tables 3-6 and Appendices are available in electronic form at http://www.aanda.org

  18. Helium enhanced stars and multiple populations along the horizontal branch of NGC 2808: direct spectroscopic measurements

    NASA Astrophysics Data System (ADS)

    Marino, A. F.; Milone, A. P.; Przybilla, N.; Bergemann, M.; Lind, K.; Asplund, M.; Cassisi, S.; Catelan, M.; Casagrande, L.; Valcarce, A. A. R.; Bedin, L. R.; Cortés, C.; D'Antona, F.; Jerjen, H.; Piotto, G.; Schlesinger, K.; Zoccali, M.; Angeloni, R.

    2014-01-01

    We present an abundance analysis of 96 horizontal branch (HB) stars in NGC 2808, a globular cluster exhibiting a complex multiple stellar population pattern. These stars are distributed in different portions of the HB and cover a wide range of temperature. By studying the chemical abundances of this sample, we explore the connection between HB morphology and the chemical enrichment history of multiple stellar populations. For stars lying on the red HB, we use GIRAFFE and UVES spectra to determine Na, Mg, Si, Ca, Sc, Ti, Cr, Mn, Fe, Ni, Zn, Y, Ba and Nd abundances. For colder, blue HB stars, we derive abundances for Na, primarily from GIRAFFE spectra. We were also able to measure direct non-local thermodynamic equilibrium He abundances for a subset of these blue HB stars with temperature higher than ˜9000 K. Our results show that: (i) HB stars in NGC 2808 show different content in Na depending on their position in the colour-magnitude diagram, with blue HB stars having higher Na than red HB stars; (ii) the red HB is not consistent with a uniform chemical abundance, with slightly warmer stars exhibiting a statistically significant higher Na content; and (iii) our subsample of blue HB stars with He abundances shows evidence of enhancement with respect to the predicted primordial He content by ΔY = +0.09 ± 0.01 ± 0.05 (internal plus systematic uncertainty). Our results strongly support theoretical models that predict He enhancement among second-generation(s) stars in globular clusters and provide observational constraints on the second-parameter governing HB morphology.

  19. Geoscience communication in Namibia: YES Network Namibia spreading the message to young scientists

    NASA Astrophysics Data System (ADS)

    Mhopjeni, Kombada

    2015-04-01

    The Young Earth Scientists (YES) Network is an international association for early-career geoscientists under the age of 35 years that was formed as a result of the International Year of Planet Earth (IYPE) in 2007. YES Network aims to establish an interdisciplinary global network of early-career geoscientists to solve societal issues/challenges using geosciences, promote scientific research and interdisciplinary networking, and support professional development of early-career geoscientists. The Network has several National Chapters including one in Namibia. YES Network Namibia (YNN) was formed in 2009, at the closing ceremony of IYPE in Portugal and YNN was consolidated in 2013 with the current set-up. YNN supports the activities and goals of the main YES Network at national level providing a platform for young Namibian scientists with a passion to network, information on geoscience opportunities and promoting earth sciences. Currently most of the members are geoscientists from the Geological Survey of Namibia (GSN) and University of Namibia. In 2015, YNN plans to carry out two workshops on career guidance, establish a mentorship program involving alumni and experienced industry experts, and increase involvement in outreach activities, mainly targeting high school pupils. Network members will participate in a range of educational activities such as school career and science fairs communicating geoscience to the general public, learners and students. The community outreach programmes are carried out to increase awareness of the role geosciences play in society. In addition, YNN will continue to promote interactive collaboration between the University of Namibia, Geological Survey of Namibia (GSN) and Geological Society of Namibia. Despite the numerous potential opportunities YNN offers young scientists in Namibia and its presence on all major social media platforms, the Network faces several challenges. One notable challenge the Network faces is indifference among

  20. Millennial Scale Events Of The Last 40 Ky In The South Atlantic: From The Tropics To The Subantarctic

    NASA Astrophysics Data System (ADS)

    Vazquez Riveiros, N.; Waelbroeck, C.; Arz, H. W.; Gottschalk, J.; Skinner, L. C.; Dokken, T. M.

    2015-12-01

    We present sub-millennially resolved time series from core MD08-3167, retrieved at 23°S and 1950 m water depth on the Namibian margin during 2008 RETRO cruise. At present, this region is characterised by upwelling of waters from 150-500 m depth. Stable isotopes (d18O and d13C) and Mg/Ca were measured on the planktonic foraminifer Globigerina bulloides, which may be assumed to thrive in upwelled waters. Stable isotopes were also measured on the benthic foraminifer Cibicides wuellerstorfi. Core MD08-3167 records were dated based on 23 14C dates covering the last 30 ky. These records are compared with new and published surface and deep water records from cores from the North-East Brazil margin (MD09-3257, 4.3°S, 2340 m, and MD09-3256Q, 3.33°S, 3537 m; Burckel et al., 2015) and the South Atlantic (core MD07-3076Q, 44°S, 3770 m; Gottschalk et al., 2015). Our comparison of surface records indicates that sea surface temperature increases, in phase with Antarctic warming during the Younger Dryas (YD), Heinrich Stadial (HS) 1 and HS4, took place everywhere in the South Atlantic, form equatorial Brazil to the Subantarctic region. In addition, the planktonic d18O records from the Namibian margin indicate that rapid changes in surface ocean circulation and upwelling intensity took place in that region at the beginning of HS1, possibly in response to sea-ice retreat around Antarctica and/or changes in the intensity or position of the westerlies. The deep water records show that water mass ventilation during the YD and Heinrich stadials in the South Atlantic was very similar between 1800 and 2900 m, but a chemical divide seems to be present below this depth before HS1. The comparison of these records demonstrates that the large ocean circulation changes observed during the YD and HS1 (e.g., Waelbroeck et al., 2011) also prevailed during preceding Heinrich stadials and are thus not characteristic of terminations.

  1. Aerobic Microbial Respiration in Oceanic Oxygen Minimum Zones

    NASA Astrophysics Data System (ADS)

    Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene M.; Revsbech, Niels Peter; Schunck, Harald; Loescher, Carolin; Desai, Dhwani K.; LaRoche, Julie; Schmitz-Streit, Ruth; Kuypers, Marcel M. M.

    2014-05-01

    In the oxygen minimum zones (OMZs) of the tropical oceans, sluggish ventilation combined with strong microbial respiration of sinking organic matter results in the depletion of oxygen (O2). When O2 concentrations drop below ~5 µmol/L, organic matter is generally assumed to be respired with nitrate, ultimately leading to the loss of fixed inorganic nitrogen via anammox and denitrification. However, direct measurements of microbial O2 consumption at low O2 levels are - apart from a single experiment conducted in the OMZ off Peru - so far lacking. At the same time, consistently observed active aerobic ammonium and nitrite oxidation at non-detectable O2 concentrations (<1 µmol/L) in all major OMZs, suggests aerobic microorganisms, likely including heterotrophs, to be well adapted to near-anoxic conditions. Consequently, microaerobic (≤5 µmol/L) remineralization of organic matter, and thus release of ammonium, in low- O2 environments might be significantly underestimated at present. Here we present extensive measurements of microbial O2 consumption in OMZ waters, combined with highly sensitive O2 (STOX) measurements and meta-omic functional gene analyses. Short-term incubation experiments with labelled O2 (18-18O2) carried out in the Namibian and Peruvian OMZ, revealed persistent aerobic microbial activity at depths with non-detectable concentrations of O2 (≤50 nmol/L). In accordance, examination of metagenomes and metatranscriptomes from Chilean and Peruvian OMZ waters identified genes encoding for terminal respiratory oxidases with high O2 affinities as well as their expression by diverse microbial communities. Oxygen consumption was particularly enhanced near the upper OMZ boundaries and could mostly (~80%) be assigned to heterotrophic microbial activity. Compared to previously identified anaerobic microbial processes, microaerobic organic matter respiration was the dominant remineralization pathway and source of ammonium (~90%) in the upper Namibian and

  2. Short-term patterns of vertical particle flux in northern Benguela: a comparison between sinking POC and respiratory carbon consumption

    NASA Astrophysics Data System (ADS)

    Osma, N.; Fernández-Urruzola, I.; Packard, T. T.; Postel, L.; Gómez, M.; Pollehne, F.

    2014-11-01

    Short-term variability of vertical carbon flux (C-flux) was assessed by two approaches at two stations on the Namibian shelf upwelling system (20°S). The first approach was based on modeling water-column respiratory CO2 production (Fc) by integrating vertical profiles of the respiratory electron transport system. The second approach was based on automated sediment trap sampling daily. In both cases, temporal variability at the same station proved to be greater than the spatial variability between stations. Comparison of the two methods yielded higher C-flux values from the sediment traps in the presence of upwelling filaments (7.85 vs 3.67 mmol C m- 2 d- 1). Contrarily, in the post-filament stage of the upwelling system, the values from the Fc models were higher (1.43 vs 2.57 mmol C m- 2 d- 1). This difference was attributed to compositional changes in sinking particles and their settling velocities. In combination, both approaches served to increase current understanding of the short-term particle fluxes in this northern Benguela upwelling system. The Fc approach was further applied to zooplankton from the same area in order to quantify their importance in attenuating the particulate organic C-flux. This attenuation, as measured by fractional consumption of the primary productivity, ranged from 2% to 20%.

  3. Land scarcity in Northern Namibia

    NASA Astrophysics Data System (ADS)

    Bloemertz, Lena; Dobler, Gregor; Graefe, Olivier; Kuhn, Nikolaus J.; Nghitevelekwa, Romie; Prudat, Brice; Weidmann, Laura

    2015-04-01

    Land access is a major topic in the Namibian population, which can also be seen in political discourses. In North-Central Namibia, the ongoing Communal Land Reform aims at improving tenure security and thereby also hopes to promote sustainable investment in land. Within this context, it is often argued that population growth is leading to an increased scarcity of land. However, this argument falls short of actual issues determining land scarcity in Namibia. In a context, where a large part of the population is still seen as depending on agricultural production, land scarcity has to be measured by different means to assess physical scarcity (population density, farm density, proportion of cultivated areas, or yield per person) as well as the perception of these different scarcities. This paper aims to discuss the different notions of land scarcity and argues that by focusing only on the physical realities of increasing pressure on land because of population growth, important other aspects are neglected. In order to scrutinize those measures, the study will further look at the distribution of different land uses, changing land use practices as connected to changing labour availability and mobility. Special attention will thereby be given to the difference between land scarcity and fertile soil scarcity and their relation to labour availability.

  4. Lithostratigraphy of the Kalahari Group in northeastern Namibia

    NASA Astrophysics Data System (ADS)

    Wanke, Heike; Wanke, Ansgar

    2007-08-01

    The Kalahari Group in northeastern Namibia consists of terrestrial sediments deposited in a tectonically active basin that was formed by flexural uplift of the African continental margin and independent structures related to rifting. The thickness of the sequence varies from a few meters to around 400 m. Greatest thicknesses occur where the NW-SE trending Kalahari basin axis conjugates with NE-SW trending grabens. Repeated phases of flooding and desiccation dominate the depositional environments of the Kalahari Group in northeastern Namibia. Associations of lithofacies allow recognition of distinct depositional settings such as proximal debris flows, braided streams and sand fans, and pans and sandflats. The northeastern Namibian Kalahari Group rests unconformable on the pre-Kalahari surface which showed a relatively pronounced relief in the Epukiro area. The succession starts with conglomerates, breccias and pebbly sandstones, followed by carbonates, sandstones of various maturities, and silcretes. Ferruginous sandstones and ferricretes occur locally. The onset of Kalahari Group deposition was likely a basin-wide event and therefore the basal lithostratigraphic units can be correlated with confidence. Conversely, the correlation of the succeeding lithostratigraphic units remains fairly speculative.

  5. Healthcare and Warfare. Medical Space, Mission and Apartheid in Twentieth Century Northern Namibia

    PubMed Central

    Nord, Catharina

    2014-01-01

    In the year 1966, the first government hospital, Oshakati hospital, was inaugurated in northern South-West Africa. It was constructed by the apartheid regime of South Africa which was occupying the territory. Prior to this inauguration, Finnish missionaries had, for 65 years, provided healthcare to the indigenous people in a number of healthcare facilities of which Onandjokwe hospital was the most important. This article discusses these two agents’ ideological standpoints. The same year, the war between the South-West African guerrillas and the South African state started, and continued up to 1988. The two hospitals became involved in the war; Oshakati hospital as a part of the South African war machinery, and Onandjokwe hospital as a ‘terrorist hospital’ in the eyes of the South Africans. The missionary Onandjokwe hospital was linked to the Lutheran church in South-West Africa, which became one of the main critics of the apartheid system early in the liberation war. Warfare and healthcare became intertwined with apartheid policies and aggression, materialised by healthcare provision based on strategic rationales rather than the people’s healthcare needs. When the Namibian state took over a ruined healthcare system in 1990, the two hospitals were hubs in a healthcare landscape shaped by missionary ambitions, war and apartheid logic. PMID:25045182

  6. Distribution of zooplankton biomass and potential metabolic activities across the northern Benguela upwelling system

    NASA Astrophysics Data System (ADS)

    Fernández-Urruzola, I.; Osma, N.; Packard, T. T.; Gómez, M.; Postel, L.

    2014-11-01

    The distribution of zooplankton biomass and potential metabolic rates, in terms of electron transport system (ETS) and glutamate dehydrogenase (GDH), were analyzed along a cross-shelf transect in waters off Namibia. The highly variable dynamics of upwelling filaments promoted short-term fluctuations in the zooplankton biomass and metabolism. Maximum values were characteristically found over the shelf-break, where zooplankton biomass as dry mass (DM) reached peaks of 64.5 mg m- 3 within the upper 200 m in late August. Two weeks later, the zooplankton-DM decreased by more than a third (19 mg DM m- 3). Zooplankton potential respiration and NH4+ excretion averaged 234 μmol O2 m- 3 d- 1 and 169 μmol NH4+ m- 3 d- 1 in the Namibian shelf, respectively. High protein-specific ETS activities even in the low-chlorophyll waters outside the filament suggested a shift into greater omnivory seaward. In this light, zooplankton elemental and isotopic compositions were used to investigate the pelagic food web interactions. They evidenced spatial changes in the carbon resource for zooplankton as well as changes in the form of nitrogen that fueled the biological production in aging advected waters. Overall, both aspects of zooplankton metabolism impacted the primary productivity at a level less than 10% under all the different oceanographic conditions.

  7. Prevalence of hepatitis C virus antibodies and genotypes in asymptomatic, first-time blood donors in Namibia.

    PubMed Central

    Vardas, E.; Sitas, F.; Seidel, K.; Casteling, A.; Sim, J.

    1999-01-01

    Reported is the prevalence of hepatitis C virus (HCV) in Namibia as determined using a third-generation enzyme-linked immunosorbent assay (ELISA) on samples of blood collected from all asymptomatic, first-time blood donors between 1 February and 31 July 1997 (n = 1941). The HCV seroprevalence was 0.9% (95% confidence interval (CI): 0.5-1.5%) and no associations were detected between a positive HCV serostatus and the person's sex, region of residence, or previous hepatitis B exposure or hepatitis B carrier status, as determined by hepatitis B surface antigen (HBsAg). The only significant association in a logistic regression model was an increase in HCV positivity with increasing age (P = 0.04). Viral RNA was amplified from 2 out of 18 (11.1%) specimens that were ELISA positive. Genotyping of these specimens, by restriction fragment length polymorphism (RFLP), showed the presence of genotypes 5 and 1a. The positive predictive value of using HBsAg positivity as a surrogate screening marker for HCV in Namibian blood donors was poor (1.6%), with low sensitivity (16.7%) and specificity (89.3%), and detecting only 3 out of 18 serologically HCV-positive specimens. The results of this first study of the prevalence and epidemiology of HCV infection in Namibia suggest that donor blood should be screened for HCV by ELISA in order to prevent the transmission of hepatitis C virus. PMID:10680243

  8. Use of Highly Specific Molecular Markers Reveals Positive Correlation between Abundances of Mesodinium cf. major and its Preferred Prey, Teleaulax amphioxeia, During Red Water Blooms in the Columbia River Estuary.

    PubMed

    Herfort, Lydie; Maxey, Katie; Vorhees, Ian; Simon, Holly M; Grobler, Kolette; Peterson, Tawnya D; Zuber, Peter

    2017-03-04

    In a previous study, Teleaulax amphioxeia-the preferred prey of Mesodinium in the Columbia River estuary-were undetectable within intense annual blooms, suggesting blooms are prey-limited or prey are acquired outside of bloom patches. We used a novel molecular approach specifically targeting the prey (i.e. Unique Sequence Element [USE] within the ribosomal RNA 28S D2 regions of Teleaulax amphioxeia nucleus and nucleomorph) in estuarine water samples acquired autonomously with an Environmental Sample Processor integrated within a monitoring network (ESP-SATURN). This new approach allowed for both more specific detection of the prey and better constraint of sample variability. A positive correlation was observed between abundances of M. cf. major and T. amphioxeia during bloom periods. The correlation was stronger at depth (>8.2 m) and weak or non-existent in the surface, suggesting that predator-prey dynamics become uncoupled when stratification is strong. We confirmed exclusive selectivity for T. amphioxeia by M. cf. major and observed the incorporation of the prey nucleus into a 4-nuclei complex, where it remained functionally active. The specific biomarker for T. amphioxeia was also recovered in M. cf. major samples from a Namibian coastal bloom, suggesting that a specific predator-prey relationship might be widespread between M. cf. major and T. amphioxeia. This article is protected by copyright. All rights reserved.

  9. The Choice of English as Medium of Instruction and Its Effects on the African Languages in Nambia

    NASA Astrophysics Data System (ADS)

    Brock-Utne, Birgit; Holmarsdottir, Halla B.

    2001-07-01

    In 1995 Birgit Brock-Utne was asked by NIED (National Institute for Education and Development) in Namibia to make a study of the situation of the African languages after Independence in 1990. Five years later the study was followed up by Halla Holmarsdottir as her thesis for the degree of Master of Philosophy in Comparative and International Education. The study was supported by the Nordic Institute of African Studies. This article is built on both these studies, which shows that the enormous work that has gone into making English the official language of Namibia, has born fruits. However, Holmarsdottir in her 2000 study also found that teachers overestimate their knowledge of English and in fact recent teacher graduates are not significantly more proficient in English than those who have been teaching for some time. Both studies reveal that many people around the country have grave concerns that the Namibian languages are losing a battle against English. One notable example of this development is the drop in the number of students studying African languages at the University of Namibia. In 1995 there were 100 students taking Oshindonga, and in the academic year 1999-2000 there was one.

  10. A molecular epidemiological study of rabies epizootics in kudu (Tragelaphus strepsiceros) in Namibia

    PubMed Central

    Mansfield, Karen; McElhinney, Lorraine; Hübschle, Otto; Mettler, Felix; Sabeta, Claude; Nel, Louis H; Fooks, Anthony R

    2006-01-01

    Background A panel of 37 rabies virus isolates were collected and studied, originating mainly from the northern and central regions of Namibia, between 1980 and 2003. Results These virus isolates demonstrated a high degree of genetic similarity with respect to a 400 bp region of the nucleoprotein gene, with the virus isolates originating from kudu antelope (n = 10) sharing 97.2–100% similarity with jackal isolates, and 97–100% similarity with those isolated from domestic dogs. Phylogenetic analysis suggested that these viruses were all of the canid rabies biotype of southern Africa. The viruses from kudu were closely associated with jackal isolates (n = 6), bat-eared fox isolates (n = 2) and domestic dog isolates (n = 2) at the genetic level and identical at the amino acid level, irrespective of the year of isolation. Conclusion These data suggest that jackal and kudu may form part of the same epidemiological cycle of rabies in Namibian wildlife, and might demonstrate the close-relationship between rabies virus strains that circulate within Namibia and those that circulate between Namibia and its neighbouring countries such as Botswana and South Africa. PMID:16412222

  11. MODIS Retrievals of Cloud Optical Thickness and Particle Radius

    NASA Technical Reports Server (NTRS)

    Platnick, S.; King, M. D.; Ackerman, S. A.; Gray, M.; Moody, E.; Arnold, G. T.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) provides an unprecedented opportunity for global cloud studies with 36 spectral bands from the visible through the infrared, and spatial resolution from 250 m to 1 km at nadir. In particular, all solar window bands useful for simultaneous retrievals of cloud optical thickness and particle size (0.67, 0.86, 1.2, 1.6, 2.1, and 3.7 micron bands) are now available on a single satellite instrument/platform for the first time. An operational algorithm for the retrieval of these optical and cloud physical properties (including water path) have been developed for both liquid and ice phase clouds. The product is archived into two categories: pixel-level retrievals at 1 km spatial resolution (referred to as a Level-2 product) and global gridded statistics (Level-3 product). An overview of the MODIS cloud retrieval algorithm and early level-2 and -3 results will be presented. A number of MODIS cloud validation activities are being planned, including the recent Southern Africa Regional Science Initiative 2000 (SAFARI-2000) dry season campaign conducted in August/September 2000. The later part of the experiment concentrated on MODIS validation in the Namibian stratocumulus regime off the southwest coast of Africa. Early retrieval results from this regime will be discussed.

  12. Land degradation monitoring in Namibia: a first approximation.

    PubMed

    Klintenberg, Patrik; Seely, Mary

    2004-12-01

    This paper presents development of a first approximation of a Namibian, national level, land degradation monitoring system. The process involved a large number of stakeholders and led to the definition of four primary indicators that were regarded as related to land degradation in Namibia: population pressure, livestock pressure, seasonal rainfall and erosion hazards. These indicators were calculated annually for the period 1971-1997. Annual land degradation risk maps were produced for the same period by combining the indicators. A time series analysis of results generated by indicators was undertaken at two sites. The analysis revealed a general trend towards an increased land degradation risk over the period 1971-1997. A decrease in annual rainfall and an increase in livestock numbers caused this negative trend at one site, while decreased annual rainfall and increased human population were the causes at a second site. Evaluation of resulting maps through direct field observations and long-term monitoring at selected study sites with different conditions relevant for the indicators defined, is an essential next step.

  13. Sulfur Upwelling off the African Coast

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Though these aquamarine clouds in the waters off the coast of northern Namibia may look like algae blooms, they are in fact clouds of sulfur produced by anaerobic bacteria on the ocean's floor. This image of the sulfur-filled water was taken on April 24, 2002, by the Sea-viewing Wide Field-of-View Sensor (SeaWiFS), flying aboard the Orbview-2 satellite. The anaerobic bacteria (bacteria that can live without oxygen) feed upon algae carcasses that exist in abundance on the ocean's floor off of Namibia. As the bacteria ingest the algae husks, they produce hydrogen sulfide, which slowly builds up in the sea-floor sediments. Eventually, the hydrogen sulfide reaches the point where the sediment can no longer contain it, and it bubbles forth. When this poisonous chemical reaches the surface, it combines with the oxygen in the upper layers of the ocean to create clouds of pure sulfur. The sulfur causes the Namibian coast to smell like rotten eggs, and the hydrogen sulfide will often kill fish and drive lobsters away. For more information, read: A Bloom By Any Other Name A high-resolution (250 meters per pixel) image earlier on the 24th taken from the Moderate-Resolution Imaging Spectroradiometer (MODIS) shows additional detail in the plumes. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE. MODIS image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  14. Structure and genesis of the Cubango Megafan in northern Namibia: implications for its hydrogeology

    NASA Astrophysics Data System (ADS)

    Lindenmaier, F.; Miller, R.; Fenner, J.; Christelis, G.; Dill, H. G.; Himmelsbach, T.; Kaufhold, S.; Lohe, C.; Quinger, M.; Schildknecht, F.; Symons, G.; Walzer, A.; van Wyk, B.

    2014-09-01

    An exploration strategy for groundwater was established and followed in the northern Namibian Cuvelai-Etosha Basin (CEB). The data derived from transient electromagnetics, rotary-drilling, coring and sample investigation were used to refine stratigraphy and hydrostratigraphy, and to develop a 3D map of aquifers within the Cubango Megafan. The results have delineated three major aquifers. The newly found, deep-seated Ohangwena II Aquifer (KOH-2) has the potential of providing significant additional water to the water supply of northern Namibia and Angola. While near-surface aquifers carry predominantly brackish water, freshwater in the deep-seated aquifer is further extended and features good hydraulic properties. To date, only a small part of the hydrogeological potential of arid CEB has been explored and an extension of exploration is needed, including southern Angola. The combination of structural, sedimentological and hydrogeological approaches greatly advanced both the geological and hydrogeological understanding. With regard to the deep-seated aquifer, strict measures need to be applied to ensure that the water in the KOH-2 reservoir is exploited sustainably. Water control areas need to be established to ensure long-term preservation of this newly explored aquifer.

  15. A Bayesian Two Part Model Applied to Analyze Risk Factors of Adult Mortality with Application to Data from Namibia

    PubMed Central

    Kazembe, Lawrence N.

    2013-01-01

    Despite remarkable gains in life expectancy and declining mortality in the 21st century, in many places mostly in developing countries, adult mortality has increased in part due to HIV/AIDS or continued abject poverty levels. Moreover many factors including behavioural, socio-economic and demographic variables work simultaneously to impact on risk of mortality. Understanding risk factors of adult mortality is crucial towards designing appropriate public health interventions. In this paper we proposed a structured additive two-part random effects regression model for adult mortality data. Our proposal assumed two processes: (i) whether death occurred in the household (prevalence part), and (ii) number of reported deaths, if death did occur (severity part). The proposed model specification therefore consisted of two generalized linear mixed models (GLMM) with correlated random effects that permitted structured and unstructured spatial components at regional level. Specifically, the first part assumed a GLMM with a logistic link and the second part explored a count model following either a Poisson or negative binomial distribution. The model was used to analyse adult mortality data of 25,793 individuals from the 2006/2007 Namibian DHS data. Inference is based on the Bayesian framework with appropriate priors discussed. PMID:24066052

  16. Healthcare and warfare. Medical space, mission and apartheid in twentieth century northern Namibia.

    PubMed

    Nord, Catharina

    2014-07-01

    In the year 1966, the first government hospital, Oshakati hospital, was inaugurated in northern South-West Africa. It was constructed by the apartheid regime of South Africa which was occupying the territory. Prior to this inauguration, Finnish missionaries had, for 65 years, provided healthcare to the indigenous people in a number of healthcare facilities of which Onandjokwe hospital was the most important. This article discusses these two agents' ideological standpoints. The same year, the war between the South-West African guerrillas and the South African state started, and continued up to 1988. The two hospitals became involved in the war; Oshakati hospital as a part of the South African war machinery, and Onandjokwe hospital as a 'terrorist hospital' in the eyes of the South Africans. The missionary Onandjokwe hospital was linked to the Lutheran church in South-West Africa, which became one of the main critics of the apartheid system early in the liberation war. Warfare and healthcare became intertwined with apartheid policies and aggression, materialised by healthcare provision based on strategic rationales rather than the people's healthcare needs. When the Namibian state took over a ruined healthcare system in 1990, the two hospitals were hubs in a healthcare landscape shaped by missionary ambitions, war and apartheid logic.

  17. Differences in the Visual Perception of Symmetric Patterns in Orangutans (Pongo pygmaeus abelii) and Two Human Cultural Groups: A Comparative Eye-Tracking Study.

    PubMed

    Mühlenbeck, Cordelia; Liebal, Katja; Pritsch, Carla; Jacobsen, Thomas

    2016-01-01

    Symmetric structures are of importance in relation to aesthetic preference. To investigate whether the preference for symmetric patterns is unique to humans, independent of their cultural background, we compared two human populations with distinct cultural backgrounds (Namibian hunter-gatherers and German town dwellers) with one species of non-human great apes (Orangutans) in their viewing behavior regarding symmetric and asymmetric patterns in two levels of complexity. In addition, the human participants were asked to give their aesthetic evaluation of a subset of the presented patterns. The results showed that humans of both cultural groups fixated on symmetric patterns for a longer period of time, regardless of the pattern's complexity. On the contrary, Orangutans did not clearly differentiate between symmetric and asymmetric patterns, but were much faster in processing the presented stimuli and scanned the complete screen, while both human groups rested on the symmetric pattern after a short scanning time. The aesthetic evaluation test revealed that the fixation preference for symmetric patterns did not match with the aesthetic evaluation in the Hai//om group, whereas in the German group aesthetic evaluation was in accordance with the fixation preference in 60 percent of the cases. It can be concluded that humans prefer well-ordered structures in visual processing tasks, most likely because of a positive processing bias for symmetry, which Orangutans did not show in this task, and that, in humans, an aesthetic preference does not necessarily accompany the fixation preference.

  18. Cultural and Species Differences in Gazing Patterns for Marked and Decorated Objects: A Comparative Eye-Tracking Study

    PubMed Central

    Mühlenbeck, Cordelia; Jacobsen, Thomas; Pritsch, Carla; Liebal, Katja

    2017-01-01

    Objects from the Middle Paleolithic period colored with ochre and marked with incisions represent the beginning of non-utilitarian object manipulation in different species of the Homo genus. To investigate the visual effects caused by these markings, we compared humans who have different cultural backgrounds (Namibian hunter–gatherers and German city dwellers) to one species of non-human great apes (orangutans) with respect to their perceptions of markings on objects. We used eye-tracking to analyze their fixation patterns and the durations of their fixations on marked and unmarked stones and sticks. In an additional test, humans evaluated the objects regarding their aesthetic preferences. Our hypotheses were that colorful markings help an individual to structure the surrounding world by making certain features of the environment salient, and that aesthetic appreciation should be associated with this structuring. Our results showed that humans fixated on the marked objects longer and used them in the structural processing of the objects and their background, but did not consistently report finding them more beautiful. Orangutans, in contrast, did not distinguish between object and background in their visual processing and did not clearly fixate longer on the markings. Our results suggest that marking behavior is characteristic for humans and evolved as an attention-directing rather than aesthetic benefit. PMID:28167923

  19. A Bayesian two part model applied to analyze risk factors of adult mortality with application to data from Namibia.

    PubMed

    Kazembe, Lawrence N

    2013-01-01

    Despite remarkable gains in life expectancy and declining mortality in the 21st century, in many places mostly in developing countries, adult mortality has increased in part due to HIV/AIDS or continued abject poverty levels. Moreover many factors including behavioural, socio-economic and demographic variables work simultaneously to impact on risk of mortality. Understanding risk factors of adult mortality is crucial towards designing appropriate public health interventions. In this paper we proposed a structured additive two-part random effects regression model for adult mortality data. Our proposal assumed two processes: (i) whether death occurred in the household (prevalence part), and (ii) number of reported deaths, if death did occur (severity part). The proposed model specification therefore consisted of two generalized linear mixed models (GLMM) with correlated random effects that permitted structured and unstructured spatial components at regional level. Specifically, the first part assumed a GLMM with a logistic link and the second part explored a count model following either a Poisson or negative binomial distribution. The model was used to analyse adult mortality data of 25,793 individuals from the 2006/2007 Namibian DHS data. Inference is based on the Bayesian framework with appropriate priors discussed.

  20. Understanding early-stage dune development: morphodynamics of aeolian protodunes

    NASA Astrophysics Data System (ADS)

    Baddock, Matthew; Wiggs, Giles; Nield, Joanna

    2016-04-01

    For such a fundamental aspect of bedform development, the initiation and early-stage growth of sand dunes remain poorly understood. Protodunes are bedforms within the continuum of early-stage depositional aeolian features that exist between flat sand patches and small dunes. As transitory bedforms with the potential to develop into dunes, the detailed study of protodune morphodynamics can provide significant insights into nascent dune development. As part of a multi-annual study investigating bedform change through repeat morphological surveys of bedforms with differing maturity, measurements of near-surface airflow and sand transport were conducted over a protodune in a small Namibian barchan dune field. The protodune was approximately 85 m in length and 1 m high, and was without a slipface. Data show that over the course of a week, patterns of airflow and transport flux variation were linked with accretion at the crest, and erosion of the leeside edge showing an increase in protodune height, and providing evidence of the dune's vertical development. Surveys reveal the longer term evolution of the protodune, in the context of changes exhibited by nearby, fully developed barchan dunes, and long term monitoring of wind regime at the site.

  1. Possible ctenophoran affinities of the Precambrian "sea-pen" Rangea.

    PubMed

    Dzik, Jerzy

    2002-06-01

    The Namibian Kuibis Quartzite fossils of Rangea are preserved three-dimensionally owing to incomplete collapse of the soft tissues under the load of instantaneously deposited sand. The process of fossilization did not reproduce the original external morphology of the organism but rather the inner surface of collapsed organs, presumably a system of sacs connected by a medial canal. The body of Rangea had tetraradial symmetry, a body plan shared also by the White Sea Russian fossil Bomakellia and possibly some other Precambrian frond-like fossils. They all had a complex internal anatomy, smooth surface of the body, and radial membranes, making their alleged colonial nature unlikely. Despite a different style of preservation, the Middle Cambrian Burgess Shale frond-like Thaumaptilon shows several anatomical similarities to Rangea. The body plan of the Burgess Shale ctenophore Fasciculus, with its numerous, pinnately arranged comb organs, is in many respects transitional between Thaumaptilon and the Early Cambrian ctenophore Maotianoascus from the Chengjiang fauna of South China. It is proposed that the irregularly distributed dark spots on the fusiform units of the petaloid of Thaumaptilon represent a kind of macrocilia and that the units are homologous with the ctenophoran comb organs. These superficial structures were underlain by the complex serial organs, well represented in the fossils of Rangea. The Precambrian "sea-pens" were thus probably sedentary ancestors of the ctenophores.

  2. Differences in the Visual Perception of Symmetric Patterns in Orangutans (Pongo pygmaeus abelii) and Two Human Cultural Groups: A Comparative Eye-Tracking Study

    PubMed Central

    Mühlenbeck, Cordelia; Liebal, Katja; Pritsch, Carla; Jacobsen, Thomas

    2016-01-01

    Symmetric structures are of importance in relation to aesthetic preference. To investigate whether the preference for symmetric patterns is unique to humans, independent of their cultural background, we compared two human populations with distinct cultural backgrounds (Namibian hunter-gatherers and German town dwellers) with one species of non-human great apes (Orangutans) in their viewing behavior regarding symmetric and asymmetric patterns in two levels of complexity. In addition, the human participants were asked to give their aesthetic evaluation of a subset of the presented patterns. The results showed that humans of both cultural groups fixated on symmetric patterns for a longer period of time, regardless of the pattern’s complexity. On the contrary, Orangutans did not clearly differentiate between symmetric and asymmetric patterns, but were much faster in processing the presented stimuli and scanned the complete screen, while both human groups rested on the symmetric pattern after a short scanning time. The aesthetic evaluation test revealed that the fixation preference for symmetric patterns did not match with the aesthetic evaluation in the Hai//om group, whereas in the German group aesthetic evaluation was in accordance with the fixation preference in 60 percent of the cases. It can be concluded that humans prefer well-ordered structures in visual processing tasks, most likely because of a positive processing bias for symmetry, which Orangutans did not show in this task, and that, in humans, an aesthetic preference does not necessarily accompany the fixation preference. PMID:27065184

  3. Two vicariant Semispathidium species from tropical Africa and central Europe: S. fraterculum nov. spec. and S. pulchrum nov. spec. (Ciliophora, Haptorida).

    PubMed

    Foissner, Wilhelm; Hess, Sebastian; Al-Rasheid, Khaled

    2010-01-01

    Using standard methods, we describe two new Semispathidium species from semiterrestrial habitats of tropical Africa and central Europe. Semispathidium fraterculum nov. spec. and S. pulchrum nov. spec. differ from each other and from two Namibian (Southwest African) congeners by body size, the shape and location of the extrusomes; the shape of the macronucleus, the number of ciliary rows, the number of cilia within the rows, and the number of dikinetids comprising the dorsal brush rows. The globular resting cyst of S. fraterculum is unique in having countless granules on the inside of the external layer, forming sharp-angled rows. The distribution of these and two further, not yet described south African species indicates that the genus Semispathidium evolved in subtropical Africa. Semispathidium fraterculum and S. pulchrum are highly similar, both morphologically and ecologically, differing in mainly one important feature: the shape and location of the extrusomes used for prey capture. This suggests that they evolved from a common ancestor whose areal was divided by a vicariant event, causing an independent evolution of the split populations. We argue that this and other species pairs indicate that the vicariance speciation model is applicable to protists.

  4. Novel genotype of Tritrichomonas foetus from cattle in Southern Africa.

    PubMed

    Casteriano, Andrea; Molini, Umberto; Kandjumbwa, Kornelia; Khaiseb, Siegfried; Frey, Caroline F; Šlapeta, Jan

    2016-12-01

    Bovine trichomonosis caused by Tritrichomonas foetus is a significant reproductive disease of cattle. Preputial samples were collected using sheath washing technique in bulls in Namibia. Thirty-six trichomonad cultures were characterized using the TaqMan-probe commercial real-time polymerase chain reaction (PCR) diagnostic assay (VetMAX™-Gold Trich Detection Kit) and CYBR real-time PCR assay based on TFR3/4 primers. Diagnostic real-time PCRs and DNA sequencing of the internal transcribed region confirmed presence of T. foetus in 35 out of 36 samples. Multilocus genotyping using cysteine proteases (CP1, CP2, CP4, CP5, CP6, CP7, CP8, CP9) and malate dehydrogenase (MDH1) gene sequences demonstrate that the T. foetus in Namibia are genetically distinct from those characterized elsewhere. We report the discovery of a novel genotype of T. foetus in Namibian cattle, distinct from other T. foetus genotypes in Europe, South and North America and Australia. We suggest recognition of a 'Southern African' genotype of T. foetus. Identification of the new genotype of T. foetus demonstrates the need for wider global sampling to fully understand the diversity and origin of T. foetus causing disease in cattle or cats.

  5. The Cosmic Dance of Distant Galaxies

    NASA Astrophysics Data System (ADS)

    2006-03-01

    GIRAFFE at VLT reveals the turbulent life of distant galaxies Studying several tens of distant galaxies, an international team of astronomers found that galaxies had the same amount of dark matter relative to stars 6 billion years ago as they have now. If confirmed, this suggests a much closer interplay between dark and normal matter than previously believed. The scientists also found that as many as 4 out of 10 galaxies are out of balance. These results shed a new light on how galaxies form and evolve since the Universe was only half its current age. ESO PR Photo 10a/06 ESO PR Photo 10a/06 Collision Between Galaxies (Artist's Impression) "This may imply that collisions and merging are important in the formation and evolution of galaxies", said François Hammer, Paris Observatory, France, and one of the leaders of the team [1]. The scientists were interested in finding out how galaxies that are far away - thus seen as they were when the Universe was younger - evolved into the ones nearby. In particular, they wanted to study the importance of dark matter in galaxies. "Dark matter, which composes about 25% of the Universe, is a simple word to describe something we really don't understand," said Hector Flores, co-leader. "From looking at how galaxies rotate, we know that dark matter must be present, as otherwise these gigantic structures would just dissolve." In nearby galaxies, and in our own Milky Way for that matter, astronomers have found that there exists a relation between the amount of dark matter and ordinary stars: for every kilogram of material within a star there is roughly 30 kilograms of dark matter. But does this relation between dark and ordinary matter still hold in the Universe's past? ESO PR Photo 10b/06 ESO PR Photo 10b/06 Mapping Distant Galaxies (FLAMES-GIRAFFE/VLT) This required measuring the velocity in different parts of distant galaxies, a rather tricky experiment: previous measurements were indeed unable to probe these galaxies in sufficient

  6. Hubble and ESO's VLT provide unique 3D views of remote galaxies

    NASA Astrophysics Data System (ADS)

    2009-03-01

    Astronomers have obtained exceptional 3D views of distant galaxies, seen when the Universe was half its current age, by combining the twin strengths of the NASA/ESA Hubble Space Telescope's acute eye, and the capacity of ESO's Very Large Telescope to probe the motions of gas in tiny objects. By looking at this unique "history book" of our Universe, at an epoch when the Sun and the Earth did not yet exist, scientists hope to solve the puzzle of how galaxies formed in the remote past. ESO PR Photo 10a/09 A 3D view of remote galaxies ESO PR Photo 10b/09 Measuring motions in 3 distant galaxies ESO PR Video 10a/09 Galaxies in collision For decades, distant galaxies that emitted their light six billion years ago were no more than small specks of light on the sky. With the launch of the Hubble Space Telescope in the early 1990s, astronomers were able to scrutinise the structure of distant galaxies in some detail for the first time. Under the superb skies of Paranal, the VLT's FLAMES/GIRAFFE spectrograph (ESO 13/02) -- which obtains simultaneous spectra from small areas of extended objects -- can now also resolve the motions of the gas in these distant galaxies (ESO 10/06). "This unique combination of Hubble and the VLT allows us to model distant galaxies almost as nicely as we can close ones," says François Hammer, who led the team. "In effect, FLAMES/GIRAFFE now allows us to measure the velocity of the gas at various locations in these objects. This means that we can see how the gas is moving, which provides us with a three-dimensional view of galaxies halfway across the Universe." The team has undertaken the Herculean task of reconstituting the history of about one hundred remote galaxies that have been observed with both Hubble and GIRAFFE on the VLT. The first results are coming in and have already provided useful insights for three galaxies. In one galaxy, GIRAFFE revealed a region full of ionised gas, that is, hot gas composed of atoms that have been stripped of

  7. The Carina Project. VIII. The α-element abundances

    NASA Astrophysics Data System (ADS)

    Fabrizio, M.; Nonino, M.; Bono, G.; Primas, F.; Thévenin, F.; Stetson, P. B.; Cassisi, S.; Buonanno, R.; Coppola, G.; da Silva, R. O.; Dall'Ora, M.; Ferraro, I.; Genovali, K.; Gilmozzi, R.; Iannicola, G.; Marconi, M.; Monelli, M.; Romaniello, M.; Walker, A. R.

    2015-08-01

    We have performed a new abundance analysis of Carina red giant (RG) stars from spectroscopic data collected with UVES (high spectral resolution) and FLAMES/GIRAFFE (high and medium resolution) at ESO/VLT. The former sample includes 44 RGs, while the latter consists of 65 (high-resolution) and ~800 (medium-resolution) RGs, covering a significant fraction of the galaxy's RG branch, and red clump stars. To improve the abundance analysis at the faint magnitude limit, the FLAMES/GIRAFFE data were divided into ten surface gravity and effective temperature bins. The spectra of the stars belonging to the same gravity and temperature bin were stacked. This approach allowed us to increase the signal-to-noise ratio in the faint magnitude limit (V≥ 20.5 mag) by at least a factor of five. We took advantage of the new photometry index cU,B,I introduced recently as an age and probably a metallicity indicator to split stars along the red giant branch. These two stellar populations display distinct [Fe/H] and [Mg/H] distributions: their mean iron abundances are -2.15 ± 0.06 dex (σ = 0.28), and -1.75 ± 0.03 dex (σ = 0.21), respectively. The two iron distributions differ at the 75% level. This supports preliminary results. Moreover, we found that the old and intermediate-age stellar populations have mean [Mg/H] abundances of -1.91 ± 0.05 dex (σ = 0.22) and -1.35 ± 0.03 dex (σ = 0.22); these differ at the 83% level. Carina's α-element abundances agree, within 1σ, with similar abundances for field halo stars and for cluster (Galactic and Magellanic) stars. The same outcome applies to nearby dwarf spheroidals and ultra-faint dwarf galaxies in the iron range covered by Carina stars. Finally, we found evidence of a clear correlation between Na and O abundances, thus suggesting that Carina's chemical enrichment history is quite different from that in the globular clusters. Based on spectra retrieved from the ESO/ST-ECF Science Archive Facility and collected either with UVES at

  8. A 12-month survey of the gastro-intestinal helminths of antelopes, gazelles and giraffids kept at two zoos in Belgium.

    PubMed

    Goossens, Els; Dorny, Pierre; Boomker, Joop; Vercammen, Francis; Vercruysse, Jozef

    2005-02-28

    Faecal egg count patterns and clinical signs associated with gastro-intestinal (GI) nematodes of 107 zoo ruminants were monitored at fortnightly intervals for 1 year. The ruminants in this study were kept under different husbandry conditions at two sites of the Royal Zoological Society of Antwerp, the Antwerp Zoo and the Animal Park Planckendael. Artiodactylids involved were Arabian oryx (Oryx leucoryx), scimitar-horned oryx (Oryx dammah), bongos (Tragelaphus euryceros isaaci), sitatungas (Tragelaphus spekii gratus), common eland (Taurotragus oryx), impala (Aepyceros melampus), slender-horned gazelles, (Gazella leptoceros), blue wildebeest (Connochaetes taurinus taurinus), Kordofan giraffes (Giraffe camelopardalis antiquorum) and okapi (Okapia johnstoni). Nematode eggs were recovered from 586 of 1606 (36.5%) individual faecal samples, using flotation techniques. Infection levels were distinctly low at Antwerp Zoo, probably due to zero grazing and daily dung removal. At Planckendael, the herds of Arabian oryx, scimitar-horned oryx and slender-horned gazelles showed markedly higher egg counts than the other herds, with more than 10% of the faecal egg counts having more than 100 eggs per gram (epg) and maximum faecal egg counts of 600, 750 and 1350 epg, respectively. Faecal egg counts increased during the mid-grazing season (July) and peaked at the end of the grazing season (October). No clinical signs, such as loss of faecal consistency, could be correlated with faecal egg counts (P > 0.05). With the exception of significantly more Nematodirus spp. eggs that were present in juvenile eland, no differences in faecal egg counts could be found between the sexes and different age groups. Abomasa and intestines of 17 animals that died during the survey were available for total worm counts. In one Arabian oryx, four slender-horned gazelles and one sitatunga low burdens ranging from 200 to 14,300 were found. Nematode species recovered were Camelostrongylus mentulatus from

  9. Climate processes shape the evolution of populations and species leading to the assembly of modern biotas - examples along a continuum from shallow to deep time

    NASA Astrophysics Data System (ADS)

    Jacobs, D. K.

    2014-12-01

    California experiences droughts, so lets begin with the effects of streamflow variation on population evolution in a coastal lagoon-specialist endangered fish, the tidewater goby. Streamflow controls the closing and opening of lagoons to the sea determining genetic isolation or gene flow. Here evolution is a function of habitat preference for closing lagoons. Other estuarine fishes, with different habitat preferences, differentiate at larger spatial scales in response to longer glacio-eustatic control of estuarine habitat. Species of giraffes in Africa are a puzzle. Why do the ranges of large motile, potentially interbreeding, species occur in contact each other without hybridization? The answer resides in the timing of seasonal precipitation. Although the degree of seaonality of climate does not vary much between species, the timing of precipitation and seasonal "greenup" does. This provides a selective advantage to reproductive isolation, as reproductive timing can be coordinated in each region with seasonal browse availability for lactating females. Convective rainfall in Africa follows the sun and solar intensity is influenced by the precession cycle such that more extensive summer rains fell across the Sahara and South Asia early in the Holocene, this may also contribute to the genetic isolation and speciation of giraffes and others savanna species. But there also appears to be a correlation with rarity (CITES designation) of modern wetland birds, as the dramatic drying of the late Holocene landscape contributes to this conservation concern. Turning back to the West Coast we find the most diverse temperate coastal fauna in the world, yet this diversity evolved and is a relict of diversity accumulation during the apex of upwelling in the late Miocene, driven by the reglaciation of Antarctica. Lastly we can see that the deep-sea evolution is broadly constrained by the transitions from greenhouse to icehouse worlds over the last 90 mya as broad periods of warm

  10. Quantifying Heterogeneity in Host-Vector Contact: Tsetse (Glossina swynnertoni and G. pallidipes) Host Choice in Serengeti National Park, Tanzania

    PubMed Central

    Auty, Harriet; Cleaveland, Sarah; Malele, Imna; Masoy, Joseph; Lembo, Tiziana; Bessell, Paul; Torr, Stephen; Picozzi, Kim; Welburn, Susan C.

    2016-01-01

    Background Identifying hosts of blood-feeding insect vectors is crucial in understanding their role in disease transmission. Rhodesian human African trypanosomiasis (rHAT), also known as acute sleeping sickness is caused by Trypanosoma brucei rhodesiense and transmitted by tsetse flies. The disease is commonly associated with wilderness areas of east and southern Africa. Such areas hold a diverse range of species which form communities of hosts for disease maintenance. The relative importance of different wildlife hosts remains unclear. This study quantified tsetse feeding preferences in a wilderness area of great host species richness, Serengeti National Park, Tanzania, assessing tsetse feeding and host density contemporaneously. Methods Glossina swynnertoni and G. pallidipes were collected from six study sites. Bloodmeal sources were identified through matching Cytochrome B sequences amplified from bloodmeals from recently fed flies to published sequences. Densities of large mammal species in each site were quantified, and feeding indices calculated to assess the relative selection or avoidance of each host species by tsetse. Results The host species most commonly identified in G. swynnertoni bloodmeals, warthog (94/220), buffalo (48/220) and giraffe (46/220), were found at relatively low densities (3-11/km2) and fed on up to 15 times more frequently than expected by their relative density. Wildebeest, zebra, impala and Thomson’s gazelle, found at the highest densities, were never identified in bloodmeals. Commonly identified hosts for G. pallidipes were buffalo (26/46), giraffe (9/46) and elephant (5/46). Conclusions This study is the first to quantify tsetse host range by molecular analysis of tsetse diet with simultaneous assessment of host density in a wilderness area. Although G. swynnertoni and G. pallidipes can feed on a range of species, they are highly selective. Many host species are rarely fed on, despite being present in areas where tsetse are

  11. Effects of large mammalian herbivores and ant symbionts on condensed tannins of Acacia drepanolobium in Kenya.

    PubMed

    Ward, David; Young, Truman P

    2002-05-01

    Condensed tannins have been considered to be important inducible defenses against mammalian herbivory. We tested for differences in condensed tannin defenses in Acacia drepanolobium in Kenya over two years among different large mammalian herbivore treatments [total exclusion, antelope only, and megaherbivore (elephants and giraffes) + antelope] and with four different ant symbiont species on the trees. We predicted that (1) condensed tannin concentrations would be lowest in the mammal treatment with the lowest level of herbivory (total exclusion), (2) trees occupied by mutualist ants that protect the trees most aggressively would have lower levels of tannins, and (3) if chemical defense production is costly, there would be a trade-off between tannin concentrations, growth, and mechanical defenses. Mean tannin concentrations increased from total exclusion treatments to wildlife-only treatments to megaherbivore + antelope treatments. In 1997, condensed tannin concentrations were significantly lower in trees occupied by the ant Crematogaster nigriceps, the only ant species that actively removed axillary buds. Contrary to our prediction, trees occupied by ant species that protect the trees more aggressively against mammalian herbivores did not have lower overall levels of condensed tannins. There was no consistent evidence of a trade-off between tannin concentrations and growth rate, but there was a positive correlation between mean thorn length and mean tannin concentrations across species of ant inhabitants and across herbivore treatments in 1997. Contrary to our expectation, trees had higher tannin concentrations in the upper parts of the canopy where there is little herbivory by mammals.

  12. Optical bi-stable shutter development/improvement

    NASA Astrophysics Data System (ADS)

    Lizon, J. L.; Haddad, N.; Castillo, R.

    2012-09-01

    Two of the VLT instruments (Giraffe and VIMOS) are using the large magnetic E/150 from Prontor (with an aperture diameter of 150 mm). As we were facing an unacceptable number of failures with this component some improvement plan was discussed already in 2004. The final decision for starting this program was conditioned by the decision from the constructor to stop the production. The opportunity was taken to improve the design building a fully bi-stable mechanism in order to reduce the thermal dissipation. The project was developed in collaboration between the two main ESO sites doing the best use of the manpower and of the technical capability available at the two centers. The project took advantage of the laser Mask Manufacturing Unit and the invar sheets used to prepare the VIMOS MOS mask to fabricate the shutter petals. Our paper describes the development including the intensive and long optimization period. To conclude this optimization we proceed with a long life test on two units. These units have demonstrate a very high level of reliability (up to 100 000 cycles without failure which can be estimated to an equivalent 6 years of operation of the instrument) A new bi-stable shutter driver and controller have also been developed. Some of the highlights of this unit are the fully configurable coil driving parameters, usage of braking strategy to dump mechanical vibration and reduce mechanical wearing, configurable usage of OPEN and CLOSE sensors, non volatile storage of parameters, user friendly front panel interface.

  13. Dynamic Imbalance Analysis and Stability Control of Galloping Gait for a Passive Quadruped Robot

    PubMed Central

    Wang, Chunlei; Zhang, Ting; Wei, Xiaohui; Long, Yongjun; Wang, Shigang

    2015-01-01

    Some imbalance and balance postures of a passive quadruped robot with a simplified mathematical model are studied. Through analyzing the influence of the touchdown angle of the rear leg on the posture of the trunk during the flight phase, the stability criterion is concluded: the closer are the two moments which are the zero time of the pitching angle and the peak time of the center of mass, the better is the stability of the trunk posture during the flight phase. Additionally, the validity of the stability criterion is verified for the cat, greyhound, lion, racehorse, basset hound, and giraffe. Furthermore, the stability criterion is also applicable when the center of the mass of body is shifted. Based on the stability criterion, the necessary and sufficient condition of the galloping stability for the quadruped robot is proposed to attain a controlled thrust. The control strategy is designed by an optimization dichotomy algorithm for seeking the zero point of the balance condition. Through the control results, it is demonstrated that the imbalance posture of the trunk could be stabilized by adjusting the stiffness of four legs. PMID:27110095

  14. FALCON: a concept to extend adaptive optics corrections to cosmological fields

    NASA Astrophysics Data System (ADS)

    Hammer, Francois; Puech, Mathieu; Assemat, Francois F.; Gendron, Eric; Sayede, Frederic; Laporte, Philippe; Marteaud, Michel; Liotard, Arnaud; Zamkotsian, Frederic

    2004-07-01

    FALCON is an original concept for a next generation spectrograph at ESO VLT or at future ELTs. It is a spectrograph including multiple small integral field units (IFUs) which can be deployed within a large field of view such as that of VLT/GIRAFFE. In FALCON, each IFU features an adaptive optics correction using off-axis natural reference stars in order to combine, in the 0.8 - 1.8 μm wavelength range, spatial and spectral resolutions (0.1 - 0.15 arcsec and R = 1000 +/- 5000). These conditions are ideally suited for distant galaxy studies, which should be done within fields of view larger than the galaxy clustering scales (4 - 9 Mpc), i.e. foV > 100 arcmin. Instead of compensating the whole field, the adaptive correction will be performed locally on each IFU. This implies to use small miniaturized devices both for adaptive optics correction and wavefront sensing. Applications to high latitude fields imply to use atmospheric tomography because the stars required for wavefront sensing will be in most of the cases far outside the isoplanatic patch.

  15. Comparisons of Salmonella conjugation and virulence gene hyperexpression mediated by rumen protozoa from domestic and exotic ruminants.

    PubMed

    Brewer, Matt T; Xiong, Nalee; Dier, Jeffery D; Anderson, Kristi L; Rasmussen, Mark A; Franklin, Sharon K; Carlson, Steve A

    2011-08-05

    Recent studies have identified a phenomenon in which ciliated protozoa engulf Salmonella and the intra-protozoal environment hyperactivates virulence gene expression and provides a venue for conjugal transfer of antibiotic resistance plasmids. The former observation is relegated to Salmonella bearing the SGI1 multiresistance integron while the latter phenomenon appears to be a more generalized event for recipient Salmonella. Our previous studies have assessed virulence gene hyperexpression only with protozoa from the bovine rumen while conjugal transfer has been demonstrated in rumen protozoa from cattle and goats. The present study examined virulence gene hyperexpression for Salmonella exposed to rumen protozoa obtained from cattle, sheep, goats, or two African ruminants (giraffe and bongo). Conjugal transfer was also assessed in these protozoa using Salmonella as the recipient. Virulence gene hyperexpression was only observed following exposure to the rumen protozoa from cattle and sheep while elevated virulence was also observed in these animals. Conjugal transfer events were, however, observed in all protozoa evaluated. It therefore appears that the protozoa-based hypervirulence is not universal to all ruminants while conjugal transfer is more ubiquitous.

  16. Adaptation to Space: An Introduction

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.

    1995-01-01

    The cardiovascular and musculoskeletal systems are normally exposed to gradients of blood pressure and weight on Earth. These gradients increase blood pressure and tissue weight in dependent tissues of the body. Exposure to actual and simulated microgravity causes blood and tissue fluid to shift from the legs to the head. Studies of humans in space have documented facial edema, space motion sickness, decreased plasma volume, muscle atrophy, and loss of bone strength. Return of astronauts to Earth is accompanied by orthostatic intolerance, decreased neuromuscular coordination, and reduced exercise capacity. These factors decrease performance during descent from orbit and increase risk during emergency egress from the spacecraft. Models of simulated microgravity include 6 deg head-down tilt, immersion, and prolonged horizontal bedrest. Head-down tilt is the most accepted model and studies using this model of up to one year have been performed in Russia. Animal models which offer clear insights into the role of gravity on vertebrates include the developing giraffe and snakes from various habitats. Finally, possible countermeasures to speed readaptation of astronauts to gravity after prolonged space flight will be discussed.

  17. Ethically sound technology? Guidelines for interactive ethical assessment of personal health monitoring.

    PubMed

    Palm, Elin; Nordgren, Anders; Verweij, Marcel; Collste, Göran

    2013-01-01

    Novel care-technologies possess a transformational potential. Future care and support may be provided via monitoring technologies such as smart devices, sensors, actors (robots) and Information and Communication Technologies. Such technologies enable care provision outside traditional care institutions, for instance in the homes of patients. Health monitoring may become "personalized" i.e. tailored to the needs of individual care recipients' but may also alter relations between care providers and care recipents, shape and form the care environment and influence values central to health-care. Starting out from a social constructivist theory of technology, an interactive ethical assessment-model is offered. The suggested model supplements a traditional analysis based on normative ethical theory (top-down approach) with interviews including relevant stakeholders (a bottom-up approach). This method has been piloted by small-scale interviews encircling stakeholder perspectives on three emerging technologies: (1) Careousel, a smart medicine-management device, (2) Robot Giraff, an interactive and mobile communication-device and (3) I-Care, a care-software that combines alarm and register system. By incorporating stakeholder perspectives into the analysis, the interactive ethical assessment model provides a richer understanding of the impact of PHM-technologies on ethical values than a traditional top-down model. If the assessment is conducted before the technology has reached the market - preferably in close interaction with developers and users - ethically sound technologies may be obtained.

  18. Caught in Formation: The Nuclear-Cluster-to-Be in NGC 2139

    NASA Astrophysics Data System (ADS)

    Andersen, David R.; Walcher, C. Jakob; Böker, Torsten; Ho, Luis C.; van der Marel, Roeland P.; Rix, Hans-Walter; Shields, Joseph C.

    2008-12-01

    Close to its center, the bulgeless galaxy NGC 2139 hosts a star cluster that is younger and less massive than any nuclear star cluster (NC) studied so far. We have measured the Hα velocity field around the photometric center of this galaxy using the VLT ARGUS integral field unit and the GIRAFFE spectrograph in order to constrain different proposed theories of NC formation. We observe that the best-fit kinematic center and the candidate NC appear to be separated by 2.8'' (320 pc). Indeed, the kinematic center is also offset from the galaxy's photometric center and a possible bar or extended region of star formation in which the young cluster resides, implying that this galaxy is not in dynamic equilibrium. The Hα flux map also reveals other regions of strong star formation in the possible bar. These observations suggest that a nascent NC is forming away from the kinematic center of NGC 2139, which may come to rest there on a timescale of a few 100 Myr. Based on observations collected at the European Southern Observatory, Chile, proposal 74.B-0264.

  19. VizieR Online Data Catalog: Kinematics of the Gamma Vel cluster (Jeffries+, 2014)

    NASA Astrophysics Data System (ADS)

    Jeffries, R. D.; Jackson, R. J.; Cottaar, M.; Koposov, S. E.; Lanzafame, A. C.; Meyer, M. R.; Prisinzano, L.; Randich, S.; Sacco, G. G.; Brugaletta, E.; Caramazza, M.; Damiani, F.; Franciosini, E.; Frasca, A.; Gilmore, G.; Feltzing, S.; Micela, G.; Alfaro, E.; Bensby, T.; Pancino, E.; Recio-Blanco, A.; de Laverny, P.; Lewis, J.; Magrini, L.; Morbidelli, L.; Costado, M. T.; Jofre, P.; Klutsch, A.; Lind, K.; Maiorca, E.

    2014-01-01

    The positions, photometry, radial velocities, projected equatorial velocities and lithium equivalent widths for 208 members of the Gamma2 Velorum cluster. These members were selected on the basis of their positions in the V versus V-I colour-magnitude diagram and the strength of lithium absorption in their spectra. The photometry is from Jeffries et al. (2009MNRAS.393..538J). The radial velocities, projected equatorial velocities and equivalent widths of the 6708 angstrom LiI feature are from spectra taken with FLAMES/GIRAFFE at the VLT as part of the Gaia-ESO spectroscopic survey. Although values of projected equatorial velocity less than 10km/s are reported, these should be treated as upper limits at 10km/s. Masses are estimated from the $V-I$ colour and models of Baraffe et al. (1998A&A...337..403B) for an assumed age of 10Myr. Two kinematic populations are reported in the paper; P(A) reports the probability that a star belongs to population "A". (1 data file).

  20. A genome survey sequencing of the Java mouse deer (Tragulus javanicus) adds new aspects to the evolution of lineage specific retrotransposons in Ruminantia (Cetartiodactyla).

    PubMed

    Gallus, S; Kumar, V; Bertelsen, M F; Janke, A; Nilsson, M A

    2015-10-25

    Ruminantia, the ruminating, hoofed mammals (cow, deer, giraffe and allies) are an unranked artiodactylan clade. Around 50-60 million years ago the BovB retrotransposon entered the ancestral ruminantian genome through horizontal gene transfer. A survey genome screen using 454-pyrosequencing of the Java mouse deer (Tragulus javanicus) and the lesser kudu (Tragelaphus imberbis) was done to investigate and to compare the landscape of transposable elements within Ruminantia. The family Tragulidae (mouse deer) is the only representative of Tragulina and phylogenetically important, because it represents the earliest divergence in Ruminantia. The data analyses show that, relative to other ruminantian species, the lesser kudu genome has seen an expansion of BovB Long INterspersed Elements (LINEs) and BovB related Short INterspersed Elements (SINEs) like BOVA2. In comparison the genome of Java mouse deer has fewer BovB elements than other ruminants, especially Bovinae, and has in addition a novel CHR-3 SINE most likely propagated by LINE-1. By contrast the other ruminants have low amounts of CHR SINEs but high numbers of actively propagating BovB-derived and BovB-propagated SINEs. The survey sequencing data suggest that the transposable element landscape in mouse deer (Tragulina) is unique among Ruminantia, suggesting a lineage specific evolutionary trajectory that does not involve BovB mediated retrotransposition. This shows that the genomic landscape of mobile genetic elements can rapidly change in any lineage.

  1. a Study of Sasin-Animal Sky Map on Chonmunryucho

    NASA Astrophysics Data System (ADS)

    Yang, Hong-Jin; Park, Myeong-Gu

    2003-03-01

    Chon-Mun-Ryu-Cho, written (edited) by Lee Sun-Ji during the period of King Se-Jong, is a representative astronomy book of Cho-Sun (A.D. 1392 -1910) Dynasty. We find and study in the first page of the book; the description of 28 oriental constellations as a Sasin (four mythical oriental animals)-animal sky map which is not widely known yet. The map consists of four groups of constellations, each of which represents the Sasin: Chang-Ryong (dragon), Baek-Ho (tigers with Ki-Rin [Oriental giraffe]), Ju-Jak (Chinese phoenix), Hyun-Mu (a tortoise interwined with a snake). Each group (animals) spans 2˜7 of 28 oriental constellations As we know from the illustration of the Chon-Sang-Yol-Cha-Bun-Ya-Ji-Do a representative sky map of Cho-Sun Dynasty, astronomy in Cho-Sun Dynasty is closely related to that in Go-Gu-Ryer (B.C. 37 -A.D. 668) Dynasty. Since these Sasin-animals appear in most mural paintings of Go-Gu-Ryer tombs, visualization of sky with these animal constellations could have been established as early as in Go-Gu-Ryer Dynasty. We also reconstruct this ''A Sasin-animal Korean sky map'' based on the shapes of the Sasin and Ki-Rin from Go-Gu-Ryer paintings and 28 oriental constellations in Chon-Sang-Yol-Cha-Bun-Ya-Ji-Do.

  2. Spinning like a blue straggler: the population of fast rotating blue straggler stars in ω Centauri

    SciTech Connect

    Mucciarelli, A.; Lovisi, L.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.

    2014-12-10

    By using high-resolution spectra acquired with FLAMES-GIRAFFE at the ESO/VLT, we measured the radial and rotational velocities for 110 blue straggler stars (BSSs) in ω Centauri, the globular cluster-like stellar system harboring the largest known BSS population. According to their radial velocities, 109 BSSs are members of the system. The rotational velocity distribution is very broad, with the bulk of BSSs spinning at less than ∼40 km s{sup –1} (in agreement with the majority of such stars observed in other globular clusters) and a long tail reaching ∼200 km s{sup –1}. About 40% of the sample has v{sub e} sin i > 40 km s{sup –1} and about 20% has v{sub e} sin i > 70 km s{sup –1}. Such a large fraction is very similar to the percentage of fast rotating BSSs observed in M4. Thus, ω Centauri is the second stellar cluster, beyond M4, with a surprisingly high population of fast spinning BSSs. We found a hint of radial behavior for a fraction of fast rotating BSSs, with a mild peak within one core radius, and a possible rise in the external regions (beyond four core radii). This may suggest that recent formation episodes of mass transfer BSSs occurred preferentially in the outskirts of ω Centauri, or that braking mechanisms able to slow down these stars are least efficient in the lowest density environments.

  3. ACCURATE STELLAR KINEMATICS AT FAINT MAGNITUDES: APPLICATION TO THE BOOeTES I DWARF SPHEROIDAL GALAXY

    SciTech Connect

    Koposov, Sergey E.; Gilmore, G.; Walker, M. G.; Belokurov, V.; Evans, N. Wyn; Okamoto, S.; Penarrubia, J.; Fellhauer, M.; Gieren, W.; Geisler, D.; Monaco, L.; Norris, J. E.; Wilkinson, M.; Wyse, R. F. G.; Zucker, D. B.

    2011-08-01

    We develop, implement, and characterize an enhanced data reduction approach which delivers precise, accurate, radial velocities from moderate resolution spectroscopy with the fiber-fed VLT/FLAMES+GIRAFFE facility. This facility, with appropriate care, delivers radial velocities adequate to resolve the intrinsic velocity dispersions of the very faint dwarf spheroidal (dSph) galaxies. Importantly, repeated measurements let us reliably calibrate our individual velocity errors (0.2 kms{sup -1} {<=} {delta}{sub V} {<=} 5 km s{sup -1}) and directly detect stars with variable radial velocities. We show, by application to the Booetes I dSph, that the intrinsic velocity dispersion of this system is significantly below 6.5 km s{sup -1} reported by previous studies. Our data favor a two-population model of Booetes I, consisting of a majority 'cold' stellar component, with velocity dispersion 2.4{sup +0.9}{sub -0.5} km s{sup -1}, and a minority 'hot' stellar component, with velocity dispersion {approx}9 km s{sup -1}, although we cannot completely rule out a single component distribution with velocity dispersion 4.6{sup 0.8}{sub -0.6} km s{sup -1}. We speculate that this complex velocity distribution actually reflects the distribution of velocity anisotropy in Booetes I, which is a measure of its formation processes.

  4. SBWR design update: Passively safe, nuclear power generation for the twenty first century

    SciTech Connect

    Upton, H.A.; Torbeck, J.E.; Billig, P.F.; Duncan, J.D.; Herzog, M.

    1996-07-01

    This paper describes the current state of design, development and testing of a new generation of Boiling Water Reactors, the SBWR. The SBWR is a plant that will be significantly simpler to build, operate and maintain compared to operating plants. In this paper, the design and performance of the reference 670 MWe SBWR is summarized, the economics of SBWR power generation is addressed and the current developments in component testing and integrated system testing are given. This paper specifically discusses the current innovations and key reference design features of the SBWR including the RPV, depressurization system, pressure suppression system, flammability control system (based on passive autocatalytic recombiners), gravity driven cooling system, the passive containment cooling system, isolation condenser system and other unique engineered safety features that rely on gravity or stored energy to ensure core cooling, decay heat removal, and ATWS mitigation. The component and integrated system development testing summarized includes key results of recently concluded PANTHERS condenser tests conducted at SIET in Italy, GIRAFFE non-condensable gas testing by Toshiba in Japan, and the ongoing testing at the PANDA facility at PSI in Switzerland.

  5. Eclipsing Binary B-Star Mass Determinations

    NASA Astrophysics Data System (ADS)

    Townsend, Amanda; Eikenberry, Stephen S.

    2016-01-01

    B-stars in binary pairs provide a laboratory for key astrophysical measurements of massive stars, including key insights for the formation of compact objects (neutron stars and black holes). In their paper, Martayan et al (2004) find 23 Be binary star pairs in NGC2004 in the Large Magellanic Cloud, five of which are both eclipsing and spectroscopic binaries with archival data from VLT-Giraffe and photometric data from MACHO. By using the Wilson eclipsing binary code (e.g., Wilson, 1971), we can determine preliminary stellar masses of the binary components. We present the first results from this analysis. This study also serves as proof-of-concept for future observations with the Photonic Synthesis Telescope Array (Eikenberry et al., in prep) that we are currently building for low-cost, precision spectroscopic observations. With higher resolution and dedicated time for observations, we can follow-up observations of these Be stars as well as Be/X-ray binaries, for improved mass measurements of neutron stars and black holes and better constraints on their origin/formation.

  6. Automated procedure to derive fundamental parameters of B and A stars: Application to the young cluster NGC 3293

    NASA Astrophysics Data System (ADS)

    Aydi, E.; Gebran, M.; Monier, R.; Royer, F.; Lobel, A.; Blomme, R.

    2014-12-01

    This work describes a procedure to derive several fundamental parameters such as the effective temperature, surface gravity, equatorial rotational velocity and microturbulent velocity. In this work, we have written a numerical procedure in Python which finds the best fit between a grid of synthetic spectra and the observed spectra by minimizing a standard chi-square. LTE model atmospheres were calculated using the ATLAS9 code and were used as inputs to the spectrum synthesis code SYNSPEC48 in order to compute a large grid of synthetic Balmer line profiles. This new procedure has been applied to a large number of new observations (GIRAFFE spectra) of B and A stars members of the young open cluster NGC3293. These observations are part of the GAIA ESO Survey. Takeda's procedure was also used to derive rotational velocities and microturbulent velocities. The results have been compared to previous determinations by other authors and are found to agree with them. As a first result, we concluded that using this procedure, an accuracy of ± 200 K could be achieved in effective temperature and ± 0.2 dex in surface gravities.

  7. Radiological air quality in a depleted uranium storage vault

    SciTech Connect

    Robinson, T.; Cucchiara, A.L.

    1999-03-01

    The radiological air quality of two storage vaults, one with depleted uranium (DU) and one without, was evaluated and compared. The intent of the study was to determine if the presence of stored DU would significantly contribute to the gaseous/airborne radiation level compared to natural background. Both vaults are constructed out of concrete and are dimensionally similar. The vaults are located on the first floor of the same building. Neither vault has air supply or air exhaust. The doors to both vaults remained closed during the evaluation period, except for brief and infrequent access by the operational group. One vault contained 700 KG of depleted uranium, and the other vault contained documents inside of file cabinets. Radon detectors and giraffe air samplers were used to gather data on the quantity of gaseous/airborne radionuclides in both vaults. The results of this study indicated that there was no significant difference in the quantity of gaseous/airborne radionuclides in the two vaults. This paper gives a discussion of the effects of the stored DU on the air quality, and poses several theories supporting the results.

  8. Elemental abundance analysis of the early-type members of the open cluster M6: Preliminary results

    NASA Astrophysics Data System (ADS)

    Kılıçoǧlu, T.; Monier, R.; Fossati, L.

    2014-11-01

    Differences in chemical composition among main sequence stars within a given cluster are probably due to differences in their masses and other effects such as radiative diffusion, magnetic field, rotation, mixing mechanisms, mass loss, accretion and multiplicity. The early type main-sequence members of open clusters of different ages support studies of the competition between radiative diffusion and mixing mechanisms. We have analysed low- and high-resolution spectra covering the spectral range λ 4500-5840 Å of late B-, A- and F-type members of the open cluster M6 (age ˜100 Myr). The spectra were obtained with the FLAMES/GIRAFFE spectrograph mounted at UT2, the 8-m VLT telescope. The effective temperatures, surface gravities and microturbulent velocities of the stars were derived from both photometric and spectral methods. We have also performed a chemical abundance analysis using synthetic spectra. Abundances were determined for the elements C, O, Mg, Si, Ca, Sc, Ti, Cr, Mn, Fe, Ni, Y and Ba. The star-to-star variations in element abundances among the members of M6 are discussed.

  9. SODIUM-OXYGEN ANTICORRELATION AND NEUTRON-CAPTURE ELEMENTS IN OMEGA CENTAURI STELLAR POPULATIONS

    SciTech Connect

    Marino, A. F.; Milone, A. P.; Piotto, G.; Bellini, A.; Villanova, S.; Geisler, D.; Gratton, R.; Renzini, A.; D'Antona, F.; Anderson, J.; Bedin, L. R.; Cassisi, S.; Zoccali, M. E-mail: anna.marino@unipd.it

    2011-04-10

    Omega Centauri is no longer the only globular cluster known to contain multiple stellar populations, yet it remains the most puzzling. Due to the extreme way in which the multiple stellar population phenomenon manifests in this cluster, it has been suggested that it may be the remnant of a larger stellar system. In this work, we present a spectroscopic investigation of the stellar populations hosted in the globular cluster {omega} Centauri to shed light on its still puzzling chemical enrichment history. With this aim, we used FLAMES+GIRAFFE-VLT to observe 300 stars distributed along the multimodal red giant branch of this cluster, sampling with good statistics the stellar populations of different metallicities. We determined chemical abundances for Fe, Na, O, and n-capture elements Ba and La. We confirm that {omega} Centauri exhibits large star-to-star variations in iron with [Fe/H] ranging from {approx}-2.0 to {approx}-0.7 dex. Barium and lanthanum abundances of metal-poor stars are correlated with iron, up to [Fe/H] {approx}-1.5, while they are almost constant (or at least have only a moderate increase) in the more metal-rich populations. There is an extended Na-O anticorrelation for stars with [Fe/H] {approx}<-1.3 while more metal-rich stars are almost all Na-rich. Sodium was found to mildly increase with iron over the entire metallicity range.

  10. About the new B- and A-type periodic variable stars

    NASA Astrophysics Data System (ADS)

    Mowlavi, Nami; Saesen, Sophie; Barblan, Fabio; Semaan, Thierry; Eyer, Laurent

    2015-08-01

    New periodic variable stars of type B and A were discovered in 2013 in the open cluster NGC 3766 (Mowlavi et al. 2013), in a region of the Hertzsprung-Rusell diagram on the main sequence, between delta-Scuti and Slowly Pulsating B stars, where no periodic star was expected to be found. The observational properties of the potentially new class of variability challenged model predictions of pulsating stars that were available at the time of their discovery, and triggered new theoretical developments in the field.Meanwhile, we obtained additional observational elements that shed new light on these new periodic variable stars. First, we analyzed photometric data of three other young clusters with ages between about 15 to about 70 million years, for which we had up to seven years of observations. The analysis reveals the presence of the new periodic B- and A-type stars in those clusters as well, with properties similar to those found in NGC 3766, but with also new features. Second, we took spectra of all new periodic variables found in NGC 3766, using Giraffe multi-fiber spectrometer mounted on the VLT. Those data enable a better characterization of the nature of those stars.We present in this contribution the results of those two new studies, and their impacts on our understanding of the new periodic stars.

  11. VizieR Online Data Catalog: Gamma Vel cluster membership and IMF (Prisinzano+, 2016)

    NASA Astrophysics Data System (ADS)

    Prisinzano, L.; Damiani, F.; Micela, G.; Jeffries, R. D.; Franciosini, E.; Sacco, G. G.; Frasca, A.; Klutsch, A.; Lanzafame, A.; Alfaro, E. J.; Biazzo, K.; Bonito, R.; Bragaglia, A.; Caramazza, M.; Vallenari, A.; Carraro, G.; Costado, M. T.; Flaccomio, E.; Jofre, P.; Lardo, C.; Monaco, L.; Morbidelli, L.; Mowlavi, N.; Pancino, E.; Randich, S.; Zaggia, S.

    2016-04-01

    We derived a list as complete as possible of confirmed members of the young open cluster Gamma Velorum, with the aim of deriving general cluster properties such as the IMF. We used all available spectroscopic membership indicators within the Gaia-ESO public archive, based on spectra acquired with FLAMES a the VLT using the GIRAFFE intermediate-resolution spectrograph. In addition, we used literature photometry and X-ray data. For each membership criterion, we derived the most complete list of candidate cluster members. Then, we considered photometry, gravity, and radial velocities as necessary conditions for selecting a subsample of candidates whose membership was confirmed by using the lithium and Halpha lines and X-rays as youth indicators. Table 5 lists the fundamental parameters of the confirmed and possible members in Gamma Velorum, i.e. photometry, radial velocities, equivalent widths of the lithium line, the Halpha activity index, the X-ray flag, the gravity gamma index and the stellar masses. Finally the binarity and membership flags are given. (1 data file).

  12. Before the Giants: APASS Support to Ambitious Ground-based Galaxy Investigations and Space Missions Serching for Exo-Earths (Abstract)

    NASA Astrophysics Data System (ADS)

    Munari, U.

    2015-06-01

    (Abstract only) A huge, worldwide effort is underway to reconstruct the structure, kinematics and evolution of our Galaxy with optical spectroscopic techniques, which provide radial velocities and individual chemical abundances in addition to derive fundamental stellar parameters like surface temperature and gravity. RAVE has used for ten years (2003-2013) the 6dF 150-fiber positioner at the 1.3-meter UK Schmidt telescope in Siding Spring, ESO-Gaia has hundreds of nights allocated at the VLT telescopes in Chile with UVES and GIRAFFE multi-fiber instruments, GALAH has been allocated 400 nights in five years with the 400-fiber HERMES spectrograph at the 4-meter Australian telescope. Common to the millions of stars targeted by these surveys (over the range 10 < V < 16 mag) is the lack of suitable, multi-band, accurate optical photometry. In this talk, I review the fundamental role played by APASS in providing such missing photometric information for the stars targeted by these gigantic spectroscopic surveys. The APASS BVgri data are fundamental to support the spectroscopic effort, for example to constrain (when modelled together with 2MASS infrared JHK photometry) the stellar temperature. The APASS data are also crucial in fixing the interstellar reddening and the distance to the target stars, and their importance will be further expanded when APASS ultraviolet (u) and far red (z,Y) magnitudes will become available, as well the unsaturated APASS extension to brighter stars so that most of the bright spectroscopic standards will become within photometric reach.

  13. In Vitro Dissolution Tests of Plutonium and Americium Containing Contamination Originating From ZPPR Fuel Plates

    SciTech Connect

    William F. Bauer; Brian K. Schuetz; Gary M. Huestis; Thomas B. Lints; Brian K. Harris; R. Duane Ball; Gracy Elias

    2012-09-01

    Assessing the extent of internal dose is of concern whenever workers are exposed to airborne radionuclides or other contaminants. Internal dose determinations depend upon a reasonable estimate of the expected biological half-life of the contaminants in the respiratory tract. One issue with refractory elements is determining the dissolution rate of the element. Actinides such as plutonium (Pu) and Americium (Am) tend to be very refractory and can have biological half-lives of tens of years. In the event of an exposure, the dissolution rates of the radionuclides of interest needs to be assessed in order to assign the proper internal dose estimates. During the November 2011 incident at the Idaho National Laboratory (INL) involving a ZPPR fuel plate, air filters in a constant air monitor (CAM) and a giraffe filter apparatus captured airborne particulate matter. These filters were used in dissolution rate experiments to determine the apparent dissolution half-life of Pu and Am in simulated biological fluids. This report describes these experiments and the results. The dissolution rates were found to follow a three term exponential decay equation. Differences were noted depending upon the nature of the biological fluid simulant. Overall, greater than 95% of the Pu and 93% of the Am were in a very slow dissolving component with dissolution half-lives of over 10 years.

  14. Ba STARS AND OTHER BINARIES IN FIRST AND SECOND GENERATION STARS IN GLOBULAR CLUSTERS

    SciTech Connect

    D'Orazi, Valentina; Gratton, Raffaele; Lucatello, Sara; Carretta, Eugenio; Bragaglia, Angela; Marino, Anna F.

    2010-08-20

    The determination of the Ba abundance in globular cluster (GC) stars is a very powerful test to address several issues in the framework of multiple population scenarios. We measured the Ba content for a sample of more than 1200 stars in 15 Galactic GCs, using high-resolution FLAMES/Giraffe spectra. We found no variation in [Ba/Fe] ratios for different stellar populations within each cluster; this means that low-mass asymptotic giant branch stars do not significantly contribute to the intracluster pollution. Very interestingly, we found that the fraction of Ba stars in first generation (FG) stars is close to the values derived for field stars ({approx}2%); on the other hand, second generation (SG) stars present a significantly lower fraction. An independent and successful test, based on radial velocity variations among giant stars in NGC 6121, confirms our finding: the binary fraction among FG stars is about {approx}12%, to be compared with {approx}1% of SG stars. This is an evidence that SG stars formed in a denser environment, where infant mortality of binary systems was particularly efficient.

  15. Stellar density profile and mass of the Milky Way bulge from VVV data

    NASA Astrophysics Data System (ADS)

    Valenti, E.; Zoccali, M.; Gonzalez, O. A.; Minniti, D.; Alonso-García, J.; Marchetti, E.; Hempel, M.; Renzini, A.; Rejkuba, M.

    2016-03-01

    We present the first stellar density profile of the Milky Way bulge that reaches latitude b = 0°. The profile was derived by counting red clump stars within the colour-magnitude diagram that was constructed using the new PSF-fitting photometry from VISTA Variables in the Vía Láctea (VVV) survey data. The new stellar density map covers the area between | l | ≤ 10° and | b | ≤ 4.5° with unprecedented accuracy, allowing the stellar kinematics from the Giraffe Inner Bulge Spectroscopic Survey (GIBS) to be linked to the stellar mass density distribution. In particular, the location of the central velocity-dispersion peak from GIBS matches a high over-density in the VVV star count map. By scaling the total luminosity function (LF) obtained from all VVV fields to the LF from Zoccali et al.(2003), we obtain the first fully empirical estimate of the mass in stars and in remnants of the Galactic bulge. Within (| b | < 9.5°, | l | < 10°), the Milky Way bulge stellar mass is 2.0 ± 0.3 × 1010M⊙. Based on observations taken within the ESO/VISTA Public Survey VVV under the programme ID 179.B-2002 (PI: Minniti).

  16. Kinematics of a globular cluster with an extended profile: NGC 5694

    NASA Astrophysics Data System (ADS)

    Bellazzini, M.; Mucciarelli, A.; Sollima, A.; Catelan, M.; Dalessandro, E.; Correnti, M.; D'Orazi, V.; Cortés, C.; Amigo, P.

    2015-01-01

    We present a study of the kinematics of the remote globular cluster NGC 5694 based on GIRAFFE@VLT medium-resolution spectra. A sample of 165 individual stars selected to lie on the red giant branch in the cluster colour-magnitude diagram was considered. Using radial velocity and metallicity from Calcium triplet, we were able to select 83 bona fide cluster members. The addition of six previously known members leads to a total sample of 89 cluster giants with typical uncertainties ≤1.0 km s-1 in their radial velocity estimates. The sample covers a wide range of projected distances from the cluster centre, from ˜0.2 arcmin to 6.5 arcmin ≃ 23 half-light radii (rh). We find only very weak rotation, as typical of metal-poor globular clusters. The velocity dispersion gently declines from a central value of σ = 6.1 km s-1 to σ ≃ 2.5 km s-1 at ˜2 arcmin ≃ 7.1rh, then it remains flat out to the next (and last) measured point of the dispersion profile, at ˜4 arcmin ≃ 14.0rh, at odds with the predictions of isotropic King models. We show that both isotropic single-mass non-collisional models and multimass anisotropic models can reproduce the observed surface brightness and velocity dispersion profiles.

  17. Calibrating the lithium-age relation with open clusters observed with GES (Gaia-ESO Survey)

    NASA Astrophysics Data System (ADS)

    Gutiérrez Albarrán, M. L.; Montes, D.; Gómez Garrido, M.; Tabernero, H. M..; González Hernández, J. I.; GES Survey Builders

    2017-03-01

    Li depletion is strongly age-dependent but currently available data have shown a complex pattern of Li depletion on the pre- and main-sequence stars that is not yet understood. The lithium abundance observed in late-type stars depend not only of the age and the temperature but also on metallicity, mixing mechanisms, convection structure, rotation and magnetic activity. The large number of stars observed within the Gaia-ESO survey (GES - https://www.gaia-eso.eu/) for many open clusters and associations can be used to calibrate the lithium-age relation and its dependence with other parameters that can be derived from the UVES and GIRAFFE spectroscopic observations. We present here the preliminary results of the analysis of membership and Li abundance of the young clusters and associations, as well as of the intermediate-age and old open clusters, observed until now in GES (iDR4) in order to conduct a comparative study. All this information allowed us to characterize the properties of the members of these clusters and identify a series of field contaminant stars, both lithium-rich giants and non-giant outliers.

  18. Distinct and Diverse: Range-Wide Phylogeography Reveals Ancient Lineages and High Genetic Variation in the Endangered Okapi (Okapia johnstoni)

    PubMed Central

    Stanton, David W. G.; Hart, John; Galbusera, Peter; Helsen, Philippe; Shephard, Jill; Kümpel, Noëlle F.; Wang, Jinliang; Ewen, John G.; Bruford, Michael W.

    2014-01-01

    The okapi is an endangered, evolutionarily distinctive even-toed ungulate classified within the giraffidae family that is endemic to the Democratic Republic of Congo. The okapi is currently under major anthropogenic threat, yet to date nothing is known about its genetic structure and evolutionary history, information important for conservation management given the species' current plight. The distribution of the okapi, being confined to the Congo Basin and yet spanning the Congo River, also makes it an important species for testing general biogeographic hypotheses for Congo Basin fauna, a currently understudied area of research. Here we describe the evolutionary history and genetic structure of okapi, in the context of other African ungulates including the giraffe, and use this information to shed light on the biogeographic history of Congo Basin fauna in general. Using nuclear and mitochondrial DNA sequence analysis of mainly non-invasively collected samples, we show that the okapi is both highly genetically distinct and highly genetically diverse, an unusual combination of genetic traits for an endangered species, and feature a complex evolutionary history. Genetic data are consistent with repeated climatic cycles leading to multiple Plio-Pleistocene refugia in isolated forests in the Congo catchment but also imply historic gene flow across the Congo River. PMID:25007188

  19. Independent effects of heart-head distance and caudal blood pooling on blood pressure regulation in aquatic and terrestrial snakes.

    PubMed

    Seymour, Roger S; Arndt, Joachim O

    2004-03-01

    Changes in orientation in a gravitational field markedly alter the patterns of blood pressure and flow in animals, especially tall or long ones such as giraffes or snakes. Vertical orientation tends to reduce blood flow and pressure in the head for two major reasons. First, the increased vertical blood column above the heart creates a gravitational hydrostatic pressure against which the heart must work. Second, expansion of dependent vessels in the lower extremities causes blood pooling and reduces return of venous blood to the heart, thereby lowering flow and pressure. For most animals, it is difficult to separate these two effects, but snakes offer the possibility of bending the animal in the region of the heart and manipulating the two ends of the body independently. We studied baroregulatory responses in terrestrial pythons (Liasis fuscus) and aquatic file snakes (Acrochordus arafurae) by tilting only the front or rear parts and then the whole animal. Changes in head blood pressure during partial tilts added up to the change during full tilt. The vertical distance to the head had twice as much influence on head blood pressure than did blood pooling in the pythons and four times as much in file snakes. This accounts for the cephalad location of the heart in terrestrial species compared with aquatic ones.

  20. Sensor network infrastructure for a home care monitoring system.

    PubMed

    Palumbo, Filippo; Ullberg, Jonas; Stimec, Ales; Furfari, Francesco; Karlsson, Lars; Coradeschi, Silvia

    2014-02-25

    This paper presents the sensor network infrastructure for a home care system that allows long-term monitoring of physiological data and everyday activities. The aim of the proposed system is to allow the elderly to live longer in their home without compromising safety and ensuring the detection of health problems. The system offers the possibility of a virtual visit via a teleoperated robot. During the visit, physiological data and activities occurring during a period of time can be discussed. These data are collected from physiological sensors (e.g., temperature, blood pressure, glucose) and environmental sensors (e.g., motion, bed/chair occupancy, electrical usage). The system can also give alarms if sudden problems occur, like a fall, and warnings based on more long-term trends, such as the deterioration of health being detected. It has been implemented and tested in a test environment and has been deployed in six real homes for a year-long evaluation. The key contribution of the paper is the presentation of an implemented system for ambient assisted living (AAL) tested in a real environment, combining the acquisition of sensor data, a flexible and adaptable middleware compliant with the OSGistandard and a context recognition application. The system has been developed in a European project called GiraffPlus.

  1. Numerical taxonomy of the genus Pestivirus based on palindromic nucleotide substitutions in the 5' untranslated region.

    PubMed

    Giangaspero, Massimo; Harasawa, Ryô

    2007-12-01

    The palindromic nucleotide substitutions (PNS) at the three variable loci (V1, V2 and V3) in the 5' untranslated region (UTR) of Pestivirus RNA have been considered for taxonomical segregation of species, through the evaluation of 430 genomic sequences. On the basis of qualitative and quantitative secondary structure characteristics, six species have been identified: Bovine viral diarrhea virus 1 (BVDV-1), Bovine viral diarrhea virus 2 (BVDV-2), Classical swine fever virus (CSFV), Border disease virus (BDV), the tentative species Giraffe and a new proposed taxon named Pronghorn. The first step was qualitative and consisted in the characterization of the different positions of the three stems and loops in the 5' UTR sequences of all the strains under consideration belonging to the genus. Secondary structure sequences showing divergent base-pair combinations have been aligned for comparison. Palindromic positions have been characterized according to changes in nucleotide base-pairs identifying low-variable positions (LVP) including base-pairs present in less than 80% of the genus. The second step was quantitative, allowing the identification of genomic groups by clustering the base-pair combinations according to LVP. Relatedness among types was evaluated to identify homogeneous groups. Cross comparisons between types within the genus have been evaluated by computing the divergence percentage thus clarifying borderline and multirelated sequences.

  2. Extreme morphological and ecological homoplasy in tropical salamanders

    PubMed Central

    Parra-Olea, Gabriela; Wake, David B.

    2001-01-01

    Fossorial salamanders typically have elongate and attenuated heads and bodies, diminutive limbs, hands and feet, and extremely elongate tails. Batrachoseps from California, Lineatriton from eastern México, and Oedipina from southern México to Ecuador, all members of the family Plethodontidae, tribe Bolitoglossini, resemble one another in external morphology, which has evolved independently. Whereas Oedipina and Batrachoseps are elongate because there are more trunk vertebrae, a widespread homoplasy (parallelism) in salamanders, the genus Lineatriton is unique in having evolved convergently by an alternate “giraffe-neck” developmental program. Lineatriton has the same number of trunk vertebrae as related, nonelongated taxa, but individual trunk vertebrae are elongated. A robust phylogenetic hypothesis, based on sequences of three mtDNA genes, finds Lineatriton to be deeply nested within a clade characterized by generalized ecology and morphology. Lineatriton lineolus, the only currently recognized taxon in the genus, shows unanticipated genetic diversity. Surprisingly, geographically separated populations of L. lineolus are not monophyletic, but are sister taxa of different species of the morphologically generalized genus Pseudoeurycea. Lineatriton, long thought to be a unique monospecific lineage, is polyphyletic. Accordingly, the specialized morphology of Lineatriton displays homoplasy at two hierarchical levels: (i) with respect to other elongate lineages in the family (convergence), and (ii) within what is currently recognized as a single taxon (parallelism). These evolutionary events are of adaptive significance because to invade the lowland tropics salamanders must be either arboreal or fossorial; the repeated evolution of elongation and attenuation has led to multiple lowland invasions. PMID:11427707

  3. Pulsations and metallicity of the pre-main sequence eclipsing spectroscopic binary RS Cha

    NASA Astrophysics Data System (ADS)

    Alecian, E.; Catala, C.; van't Veer-Menneret, C.; Goupil, M.-J.; Balona, L.

    2005-11-01

    We present new spectroscopic observations of the pre-main sequence eclipsing spectroscopic binary RS Cha. A sample of 174 spectra were obtained with the GIRAFFE spectrograph at the SAAO at 32 000 resolution. The radial velocity curves derived from these spectra were combined with previous observations spanning a period of about 30 years to correct the ephemeris of the system, and the result indicates that the orbital period is not constant. Residuals of the binary radial velocity curve for both components with amplitudes up to a few km s-1 and periods on the order of 1 h are clearly seen in our data, which we interpret as the signatures of delta-Scuti type pulsations. We revisited the masses of both components and determined the surface metallicity Z of both components of the RS Cha system by fitting synthetic spectra to observed spectra in a set of selected spectral regions. The synthetic spectra are calculated with the SYNTH code using stellar atmosphere models computed with the Kurucz ATLAS 9 code, along with a list of lines obtained from the VALD database. A selection of the best spectra and the most relevant spectral regions allowed us to determine Z = 0.028 ± 0.005. We also derived new values of v sin i: 64 ± 6 km s-1 and 70 ± 6 km s-1 for the primary and the secondary star, respectively. Finally, we observationally confirm that the RS Cha system is a synchronized and circularized system.

  4. Sensor Network Infrastructure for a Home Care Monitoring System

    PubMed Central

    Palumbo, Filippo; Ullberg, Jonas; Štimec, Ales; Furfari, Francesco; Karlsson, Lars; Coradeschi, Silvia

    2014-01-01

    This paper presents the sensor network infrastructure for a home care system that allows long-term monitoring of physiological data and everyday activities. The aim of the proposed system is to allow the elderly to live longer in their home without compromising safety and ensuring the detection of health problems. The system offers the possibility of a virtual visit via a teleoperated robot. During the visit, physiological data and activities occurring during a period of time can be discussed. These data are collected from physiological sensors (e.g., temperature, blood pressure, glucose) and environmental sensors (e.g., motion, bed/chair occupancy, electrical usage). The system can also give alarms if sudden problems occur, like a fall, and warnings based on more long-term trends, such as the deterioration of health being detected. It has been implemented and tested in a test environment and has been deployed in six real homes for a year-long evaluation. The key contribution of the paper is the presentation of an implemented system for ambient assisted living (AAL) tested in a real environment, combining the acquisition of sensor data, a flexible and adaptable middleware compliant with the OSGistandard and a context recognition application. The system has been developed in a European project called GiraffPlus. PMID:24573309

  5. Distinct and diverse: range-wide phylogeography reveals ancient lineages and high genetic variation in the endangered okapi (Okapia johnstoni).

    PubMed

    Stanton, David W G; Hart, John; Galbusera, Peter; Helsen, Philippe; Shephard, Jill; Kümpel, Noëlle F; Wang, Jinliang; Ewen, John G; Bruford, Michael W

    2014-01-01

    The okapi is an endangered, evolutionarily distinctive even-toed ungulate classified within the giraffidae family that is endemic to the Democratic Republic of Congo. The okapi is currently under major anthropogenic threat, yet to date nothing is known about its genetic structure and evolutionary history, information important for conservation management given the species' current plight. The distribution of the okapi, being confined to the Congo Basin and yet spanning the Congo River, also makes it an important species for testing general biogeographic hypotheses for Congo Basin fauna, a currently understudied area of research. Here we describe the evolutionary history and genetic structure of okapi, in the context of other African ungulates including the giraffe, and use this information to shed light on the biogeographic history of Congo Basin fauna in general. Using nuclear and mitochondrial DNA sequence analysis of mainly non-invasively collected samples, we show that the okapi is both highly genetically distinct and highly genetically diverse, an unusual combination of genetic traits for an endangered species, and feature a complex evolutionary history. Genetic data are consistent with repeated climatic cycles leading to multiple Plio-Pleistocene refugia in isolated forests in the Congo catchment but also imply historic gene flow across the Congo River.

  6. Lessons learned from the integration of local stakeholders in water management approaches in central-northern Namibia

    NASA Astrophysics Data System (ADS)

    Jokisch, A.; Urban, W.

    2012-04-01

    Water is the main limiting factor for economic and agricultural development in central-northern Namibia, where approximately 50% of the Namibian population lives on less than 10% of the country's surface area. The climate in the region can be characterized as semi-arid, with distinctive rainy and dry seasons and an average precipitation of 470 mm/a. Central-northern Namibia can furthermore be characterized by a system of so-called Oshanas, very shallow ephemeral river streams which drain the whole region from north to south towards the Etosha-Saltpan. Water quality within these ephemeral river streams rapidly decreases towards the end of the dry season due to high rates of evaporation (2,700 mm/a) which makes the water unsuitable for human consumption and in certain times of the year also for irrigation purposes. Other local water resources are scarce or of low quality. Therefore, the local water supply is mainly secured via a pipeline scheme which is fed by the Namibian-Angolan border river Kunene. Within the research project CuveWaters - Integrated Water Resources Management in central-northern Namibia different small scale water supply and sanitation technologies are implemented and tested as part of the projects multi-resource mix. The aim is to decentralize the regional water supply and make it more sustainable especially in the face of climate change. To gain understanding and to create ownership within the local population for the technologies implemented, stakeholder participation and capacity development are integral parts of the project. As part of the implementation process of rainwater harvesting and water harvesting from ephemeral river streams, pilot plants for the storage of water were constructed with the help of local stakeholders who will also be the beneficiaries of the pilot plants. The pilot plants consist of covered storage tanks and infrastructure for small scale horticultural use of the water stored. These small scale horticultural

  7. GIRAF 2009 - Taking action on geoscience information across Africa

    NASA Astrophysics Data System (ADS)

    Asch, Kristine

    2010-05-01

    A workshop in Windhoek Between 16 and 20 March 2009 97 participants from 26 African nations, plus four European countries, and representatives from UNESCO, ICSU and IUGS-CGI, held a workshop at the Namibian Geological Survey in Windhoek. The workshop - GIRAF 2009 - Geoscience InfoRmation In Africa - was organised by the Federal Institute for Geosciences and Natural Resources (BGR) and the Geological Survey of Namibia (GSN) at the Namibian Ministry for Mines and Energy and was mainly financed by the German Federal Ministry for Economic Cooperation and Development (BMZ), supported by the IUGS Commission for the Management and Application of Geoscience Information (CGI). The participants came to Namibia to discuss one of the most topical issues in the geological domain - geoscience information and informatics. A prime objective was to set up a pan-African network for exchanging knowledge about geoscience information. GIRAF 2009 builds on the results of a preparatory workshop organised by the CGI and funded by the IUGS, which was held in June 2006 in Maputo at the 21st Colloquium on African Geology - CAG21. This preparatory workshop concentrated on identifying general problems and needs of African geological institutions in discussion with representatives of African geological surveys, universities, private companies and non-governmental organisations. The GIRAF 2009 workshop used the results of this discussion to plan and design its programme Aims In detail the five aims of the GIRAF2009 workshop were: to bring together relevant African authorities, national experts and stakeholders in geoscience information; to initiate the building of a pan-African geoscience information knowledge network to exchange and share geoscience information knowledge and best practice; to integrate the authorities, national experts and experts across Africa into global geoinformation initiatives; to develop a strategic plan for Africa's future in geoscience information; to make Africa a

  8. Mitigating Climate Change in the Arid Lands of Namibia

    NASA Astrophysics Data System (ADS)

    Schneider, Martin B.; Sorensen, Marten

    2014-05-01

    Mitigating Climate Change in the Arid Lands of Namibia Namibia is the most arid country south of the Sahara, with scarce rainfall and perennial rivers only at its borders, > 80% of the area relies solely on groundwater. This has had devastating economic effects limiting opportunities for sustainable rural livelihoods that keep the population majority living below the World Bank poverty line (IFAD, 2013). A primary example of climatic variability which affects agrarian productivity is increased bush encroachment of Namibia's arid grazing land. The result has been a severe biodiversity loss, increased desertification and diminished water-use efficiency and underground water tables. Given these factors, Namibia's arid lands provide a unique opportunity to assess and test innovative / appropriate adaptation and mitigation strategies. Working toward sustainable management, restoration, and maintenance of balanced, resilient arid ecosystems in Namibia will also be a means to support and expand economic sectors incl. opportunities for job creation and potentially provide a model for similar arid regions. Main vegetation zones are: desert (46%), savannah (37%), and dry woodlands and forests (17%), i.e. < 2% is arable. Also, government protected areas cover 13.8% of the land surface. Current climate models suggest that Namibia faces serious risks, e.g. increased temperatures, hyper-arid conditions, and more frequent and extreme weather events (Pamaccafrica, 2013). The Namibian government, civil society organizations, and the scientific community attempt to address these risks and a certain level of institutional and human capacities are already in place. However, overall climate variability appears significantly higher than current plans and policies take into account. To improve livelihoods, reduce poverty, and food insecurity for rural Namibians in marginal/hyper-arid lands through sustainable climate change adaptation these objectives will be implemented: 1. Identify

  9. Optical and Microphysical Retrievals of Marine Stratocumulus Clouds off the Coast of Namibia from Satellite and Aircraft

    NASA Technical Reports Server (NTRS)

    Platnick, Steven E.

    2010-01-01

    Though the emphasis of the Southern Africa Regional Science Initiative 2000 (SAFARI-2000) dry season campaign was largely on emission sources and transport, the assemblage of aircraft (including the high altitude NASA ER-2 remote sensing platform and the University of Washington CV-580, UK MRF C-130, and South African Weather Bureau JRA in situ aircrafts) provided a unique opportunity for cloud studies. Therefore, as part of the SAFARI initiative, investigations were undertaken to assess regional aerosol-cloud interactions and cloud remote sensing algorithms. In particular, the latter part of the experiment concentrated on marine boundary layer stratocumulus clouds off the southwest coast of Africa. Associated with cold water upwelling along the Benguela current, the Namibian stratocumulus regime has received limited attention but appears to be unique for several reasons. During the dry season, outflow of continental fires and industrial pollution over this area can be extreme. From below, upwelling provides a rich nutrient source for phytoplankton (a source of atmospheric sulfur through DMS production as well as from decay processes). The impact of these natural and anthropogenic sources on the microphysical and optical properties of the stratocumulus is unknown. Continental and Indian Ocean cloud systems of opportunity were also studied during the campaign. SAFARI 2000 aircraft flights off the coast of Namibia were coordinated with NASA Terra Satellite overpasses for synergy with the Moderate Resolution Imaging Spectroradiometer (MODIS) and other Terra instruments. MODIS was developed by NASA and launched onboard the Terra spacecraft on December 18, 1999 (and Aqua spacecraft on May 4, 2002). Among the remote sensing algorithms developed and applied to this sensor are cloud optical and microphysical properties that include cloud thermodynamic phase, optical thickness, and effective particle radius of both liquid water and ice clouds. The archived products from

  10. Hand dug wells in Namibia: An underestimated water source or a threat to human health?

    NASA Astrophysics Data System (ADS)

    Wanke, H.; Nakwafila, A.; Hamutoko, J. T.; Lohe, C.; Neumbo, F.; Petrus, I.; David, A.; Beukes, H.; Masule, N.; Quinger, M.

    The rural population of parts of northern and western Namibia uses hand dug wells for their domestic water supply, partly because no other source (e.g., deep tube wells) is available, but also as a substitute for pipeline water that is often perceived as being too expensive. The water quality of these wells is usually not monitored or controlled, thus a study has been carried out in four study areas in Namibia: southern Omusati/Oshana area, Okongo/Ohangwena area, Omatjete/Omaruru area, Okanguati/Kunene area. Hand dug wells have been tested for on-site parameters: electric conductivity, pH and temperature while samples were taken for major inorganic constituents and several minor and trace constituents including fluoride and nitrate. In addition a sampling campaign in 2010 included the determination of coliform bacteria and Escherichia coli. Results were classified according to the Namibian Water Guidelines. The constituents making the water unfit for human consumption are fluoride, nitrate, sulphate and total dissolved solids. Contamination by E. coli was indicated in nearly all wells that are used for livestock watering. For the Omatjete/Omaruru study area an isotope based study on the source of nitrate has indicated manure as a source. The range of recharge values obtained for the studied villages ranges from 1 mm/a to locally more than 100 mm/a. Overall the water resource in the shallow perched aquifers in the study areas is in many places inappropriate for human consumption. Treatment to improve the quality or introduction of protection measures is necessary to bring this resource to an acceptable quality according to national and/or international standards.

  11. Spatial Access to Emergency Services in Low- and Middle-Income Countries: A GIS-Based Analysis

    PubMed Central

    Tansley, Gavin; Schuurman, Nadine; Amram, Ofer; Yanchar, Natalie

    2015-01-01

    Injury is a leading cause of the global disease burden, accounting for 10 percent of all deaths worldwide. Despite 90 percent of these deaths occurring in low and middle-income countries (LMICs), the majority of trauma research and infrastructure development has taken place in high-income settings. Furthermore, although accessible services are of central importance to a mature trauma system, there remains a paucity of literature describing the spatial accessibility of emergency services in LMICs. Using data from the Service Provision Assessment component of the Demographic and Health Surveys of Namibia and Haiti we defined the capabilities of healthcare facilities in each country in terms of their preparedness to provide emergency services. A Geographic Information System-based network analysis method was used to define 5- 10- and 50-kilometer catchment areas for all facilities capable of providing 24-hour care, higher-level resuscitative services or tertiary care. The proportion of a country’s population with access to each level of service was obtained by amalgamating the catchment areas with a population layer. A significant proportion of the population of both countries had poor spatial access to lower level services with 25% of the population of Haiti and 51% of the population of Namibia living further than 50 kilometers from a facility capable of providing 24-hour care. Spatial access to tertiary care was considerably lower with 51% of Haitians and 72% of Namibians having no access to these higher-level services within 50 kilometers. These results demonstrate a significant disparity in potential spatial access to emergency services in two LMICs compared to analogous estimates from high-income settings, and suggest that strengthening the capabilities of existing facilities may improve the equity of emergency services in these countries. Routine collection of georeferenced patient and facility data in LMICs will be important to understanding how spatial

  12. [Ophthalmologic short-term operations in Africa--Namibia und Mali: what makes sense?].

    PubMed

    Künster, A; Schwarz, T

    2012-08-01

    Many people even in the more prosperous countries of Africa have no opportunity to receive the necessary eye operations because of socioeconomical aspects. Personal contacts made it possible for our association called "Kids' and Poors' Eyes International e. V." to take part in an international operation camp in Namibia and enter into a cooperation with the German "Mali-Hilfe" organization. Organized by the Namibian Ministry of Health, three operation camps with international surgeons are held annually in remote places in Namibia. Operation materials, such as intraocular lenses, viscoelastics, suturing and draping materials and operation instruments are brought by the operation teams themselves, the microscopes are supplied by the central eye hospital in the capital city of Windhoek. The operation camps last for 4-5 days plus 2 days for travelling, setting up and dismantling the operation settings. Most patients have in fact become blind by dense cataract and are therefore severely impaired. To treat the mostly mature cataracts, an extracapsular technique with a wide lamellar tunnel cut, use of vision blue, expression of the nucleus and intraocular lens (IOL) implantation has been proven as a routine method and in some cases phacoemulsification is possible. In Mali, one of the poorest countries of the world, we achieved initial promising results with the implementation of an educational system to train resident surgeons. We got in touch with Mali via the help of the German-Mali humanitarian organisation "Malihilfe" and direct contacts to the Mali Minister of the Interior. Our presentation is about the experiences we made in our surgical work in both countries and answers questions about what is expedient and reasonable in high-volume surgical humanitarian aid and in the implementation of a system for self-help.

  13. Palynological records of Gondwana's mid-Permian climate amelioration: New insights from black shale deposits (Collingham Formation, South Africa)

    NASA Astrophysics Data System (ADS)

    Götz, Annette E.

    2015-04-01

    Permian black shale deposits of the southern Karoo Basin were studied with respect to palynostratigraphy, palaeoenvironment, and palaeoclimate signatures recorded in palynomorph assemblages. The 28 m thick black shales of the Collingham Formation, exposed along road cuttings of the Ecca Pass north of Grahamstown (Eastern Cape Province, South Africa), are rich in sedimentary organic matter with a high content of amorphous organic matter and prasinophytes, characteristic of a deep, stratified marine basin. Moderately preserved pollen grains of the lower part of the formation reveal a mid-Permian (Roadian) age, corresponding to the stratigraphic position of the Collingham Formation in the Namibian part of the Karoo with an absolute age of 270 Ma obtained from a tuff (Stollhofen et al., 2000). The samples from the lower Collingham Formation show a very similar composition as samples from coal seams of the upper Vryheid Formation in the northeastern part of the Karoo Basin. Additionally, a similar stratigraphic trend in changes of palynomorph assemblages was detected, showing a striking increase in taeniate bissacate pollen grains up section. This signature points to a warm-temperate bisaccate-producing plant community in the hinterland, replacing cool-temperate floras of the underlying Whitehill Formation (Ruckwied et al., 2014). The detected palaeoclimate signatures document Gondwana's mid-Permian climate amelioration and have proved to be a powerful tool for high-resolution basin-wide correlation of marine and non-marine successions. References Ruckwied, K., Götz, A.E., Jones, P. 2014. Palynological records of the Permian Ecca Group (South Africa): Utilizing climatic icehouse-greenhouse signals for cross basin correlations. Palaeogeography, Palaeoclimatology, Palaeoecology 413, 167-172. Stollhofen, H., Stanistreet, I.G., Bangert, B., Grill, H. 2000. Tuffs, tectonism and glacially related sea-level changes, Carboniferous-Permian, southern Namibia. Palaeogeography

  14. Insights on crustal growth from detrital zircons in ancient glacial deposits

    NASA Astrophysics Data System (ADS)

    Gaschnig, R. M.; Rudnick, R. L.; McDonough, W. F.; Kaufman, A. J.; Vervoort, J. D.; Fisher, C. M.

    2015-12-01

    Continental ice sheets can erode vast areas and carry unsorted sediment great distances before being deposited en masse. The resulting glacial diamictites can provide important information on the integrated geologic history of continents. Detrital mineral analysis, such as U-Pb geochronological and Hf isotope geochemical characterization of zircon, is one way of interrogating this sedimentary archive, and here we apply this approach to glacial diamictites of Mesoarchean and Neoproterozoic age in southern Africa and Paleoproterozoic age in North America. Several major magmatic events between 3.3 and 2.9 Ga, most notably at 3.08 Ga are recorded in detrital zircons from several of the Mesoarchean diamictites. Hf isotopes in these zircons are almost exclusively superchondritic, indicating that these are major juvenile crust forming events. In contrast, Neoproterozoic Namibian diamictites are almost devoid of Archean zircons and record a major 1.9 Ga population with subchondritic epsilon Hf, consistent with the reworking of Neoarchean (2.5-2.7 Ga) crust. Paleoproterozoic diamictites from North America (Ontario and Wyoming) are all dominated by a common age peak at 2.7 Ga with a narrow superchondritic Hf isotopic range, consistent with a major crustal growth event at this time in North America. Major globally recognized crust forming events that occurred at 2.7 Ga and orogenic events that occurred at 1.9 Ga are recorded by these diamictites. Lack of pre-Mesoarchean U-Pb ages and the superchondritic epsilon Hf of the Neoarchean and Mesoarchean detrital zircons are suggestive of minimal emergent continental crust prior to ~3.6 Ga or reflect significant preservation and/or recycling issues for the early Earth that are not well understood.

  15. Explaining Marital Patterns and Trends in Namibia: A Regression Analysis of 1992, 2000 and 2006 Demographic and Survey Data

    PubMed Central

    Pazvakawambwa, Lillian; Indongo, Nelago; Kazembe, Lawrence N.

    2013-01-01

    becoming distinctive in the Namibian society. PMID:23967073

  16. Modeling downward particulate organic nitrogen flux from zooplankton ammonium regeneration in the northern Benguela

    NASA Astrophysics Data System (ADS)

    Fernández-Urruzola, I.; Osma, N.; Gómez, M.; Pollehne, F.; Postel, L.; Packard, T. T.

    2016-12-01

    The vertical fluxes of particulate organic matter play a crucial role in the distribution of nutrients throughout the oceans. Although they have been the focus of intensive research, little effort has been made to explore alternative approaches that quantify the particle export at a high spatial resolution. In this study, we assess the minimum nitrogen flux (FN) required to sustain the heterotrophic metabolism in the water column from ocean depth profiles of zooplankton NH4+ excretion (RNH4+). The reduction of RNH4+ as a function of depth was described by a power law fit, RNH4+ = (RNH4+)m (z /zm)b , whereby the b-value determines the net particulate nitrogen loss with increasing depth. Integrating these excretory functions from the base of the euphotic zone to the ocean bottom, we calculated FN at two stations located over the Namibian outer shelf. Estimates of FN (ranging between 0.52 and 1.14 mmol N m-2 d-1) were compared with the sinking fluxes of particles collected in sediment traps (0.15-1.01 mmol N m-2 d-1) 50 m over the seafloor. We found a reasonable agreement between the two approaches when fast-sinking particles dominated the ecosystem, but the FN was somewhat at odds with the measured gravitational flux during a low-sedimentation regime. Applying our conceptual model to the mesozooplankton RNH4+ we further constructed a section of FN along a cross-shelf transect at 20° S, and estimated the efficiency of the epipelagic ecosystem to retain nutrients. Finally, we address the impact of the active flux driven by the migrant mesozooplankton to the total nitrogen export. Depending on the sedimentation regime, the downward active flux (0.86 mmol N m-2 d-1 at 150 m) accounted for between 50 and 307% of the gravitational flux.

  17. Kalman filter physical retrieval of surface emissivity and temperature from SEVIRI infrared channels: a validation and intercomparison study

    NASA Astrophysics Data System (ADS)

    Masiello, G.; Serio, C.; Venafra, S.; Liuzzi, G.; Göttsche, F.; Trigo, I. F.; Watts, P.

    2015-07-01

    A Kalman filter-based approach for the physical retrieval of surface temperature and emissivity from SEVIRI (Spinning Enhanced Visible and Infrared Imager) infrared observations has been developed and validated against in situ and satellite observations. Validation for land has been provided based on in situ observations from the two permanent stations at Evora and Gobabeb operated by Karlsruhe Institute of Technology (KIT) within the framework of EUMETSAT's Satellite Application Facility on Land Surface Analysis (LSA SAF). Sea surface retrievals have been intercompared on a broad spatial scale with equivalent satellite products (MODIS, Moderate Resolution Imaging Spectroradiometer, and AVHRR, Advanced Very High Resolution Radiometer) and ECMWF (European Centre for Medium-Range Weather Forecasts) analyses. For surface temperature, the Kalman filter yields a root mean square accuracy of ≍ ±1.5 °C for the two land sites considered and ≍ ±1.0 °C for the sea. Comparisons with polar satellite instruments over the sea surface show nearly zero temperature bias. Over the land surface the retrieved emissivity follows the seasonal vegetation cycle and permits identification of desert sand regions using the SEVIRI channel at 8.7 μm due to the strong quartz reststrahlen bands around 8-9 μm. Considering the two validation stations, we have found that emissivity retrieved in SEVIRI channel 10.8 μm over the gravel plains of the Namibian desert is in excellent agreement with in situ observations. Over Evora, the seasonal variation of emissivity with vegetation is successfully retrieved and yields emissivity values for green and dry vegetation that are in good agreement with spectral library data. The algorithm has been applied to the SEVIRI full disk, and emissivity maps on that global scale have been physically retrieved for the first time.

  18. Parents’ Participation in the Sexuality Education of Their Children in Rural Namibia: A Situational Analysis

    PubMed Central

    Lukolo, Linda Ndeshipandula; van Dyk, Agnes

    2015-01-01

    Talking about sexuality has never been easy in most Namibians cultures and it seems that most parents feel uncomfortable and embarrassed to talk openly with their children about sexuality. They do not participate in the sexuality education of their children, because they believe they are unable to provide quality and adequate sexuality information due to their lack of knowledge about human sexuality or their perceived inability to explain what they do know. The ultimate purpose of this study was to develop, describe, implement and evaluate an educational programme to empower rural parents to participate in the sexuality education of their children. The study was designed to be qualitative, explorative, descriptive and contextual in nature. It was performed in three phases. Phase 1 consisted of a situational analysis to explore and describe how parents provide sexuality education. Phase 2 consisted of the development of a conceptual framework that facilitated the development of an educational programme. In phase 3 the programme was implemented and evaluated, recommendations were made and conclusions drawn. The main findings revealed two themes: factors influencing parental participation in their children’s sexuality education, and the need for parental participation in their children’s sexuality education. This article is part of series of three article stems from a study on the topic of sexuality education empowerment programme of rural parents in Namibia. The three articles have the following titles: one: parent’s participation in sexuality education of their children: a situational analysis; two: conceptual framework developments that facilitate the development of an educational programme and three: programme implementation and evaluation. This article dealt with parent’s participation in sexuality education of their children: a situational analysis. PMID:25560329

  19. Associations Between Orphan and Vulnerable Child Caregiving, Household Wealth Disparities, and Women's Overweight Status in Three Southern African Countries Participating in Demographic Health Surveys.

    PubMed

    Kanamori, Mariano J; Carter-Pokras, Olivia D; Madhavan, Sangeetha; Lee, Sunmin; He, Xin; Feldman, Robert H

    2015-08-01

    This study examines whether orphan and vulnerable children (OVC) primary caregivers are facing absolute household wealth (AWI) disparities, the association between AWI and women's overweight status, and the modifying role of OVC primary caregiving status on this relationship. Demographic Health Surveys data (2006-2007) from 20 to 49 year old women in Namibia (n = 6,305), Swaziland (n = 2,786), and Zambia (n = 4,389) were analyzed using weighted marginal means and logistic regressions. OVC primary caregivers in Namibia and Swaziland had a lower mean AWI than other women in the same country. In Zambia, OVC primary caregivers had a lower mean AWI score than non-primary caregivers living with an OVC but a higher mean AWI score than non-OVC primary caregivers. In Swaziland and Zambia, even small increases in household wealth were associated with higher odds for being overweight regardless of women's caregiving status. Only in Namibia, OVC primary caregiving modified the effect of the previous association. Among Namibian OVC primary caregivers, women who had at least medium household wealth (4 or more AWI items) were more likely to be overweight than their poorest counterparts (0 or 1 AWI items). OVC primary caregivers are facing household wealth disparities as compared to other women from their communities. Future studies/interventions should consider using population-based approaches to reach women from every household wealth level to curb overweight in Swaziland and Zambia and to focus on specific household wealth characteristics that are associated with OVC primary caregivers' overweight status in Namibia.

  20. Reproductive tactics of male bearded goby (Sufflogobius bibarbatus) in anoxic and hypoxic waters

    NASA Astrophysics Data System (ADS)

    Seivåg, Maria Larsen; Salvanes, Anne Gro Vea; Utne-Palm, Anne Christine; Kjesbu, Olav Si'gurd

    2016-03-01

    The bearded goby (Sufflogobius bibarbatus), a key species in the northern Benguela Upwelling Ecosystem, tolerates extremely low levels of oxygen. Yet little is known about how its reproduction is affected by these harsh living conditions. The distribution patterns of alternative reproductive tactics of male bearded goby across the continental shelf off Namibia were investigated. Histology and stereology were for the first time used to validate macroscopic maturity development by estimating volume fraction of the different stages of spermatogenesis using "Delesse principle", an approach so far for teleosts barely used in studies on testes but applied in advanced oocyte estimation. The macroscopic scale appeared suitable for the purpose, and the prevalence of territorial and sneaker tactics could therefore be documented. The sneakers had relative large testes and small seminal vesicles (SV), with the opposite being the case for the territorials. A third, numerous category with intermediate sized testes and SV was also recognized with unclear underlying tactical rationale, although regression analyses indicated similar investment in testes weight in relation to somatic weight as for the territorials. Low oxygen levels were the most important factor limiting spawning activity in territorial males. Our data suggested the existence of a spawning site on the outer shelf of the central Namibian shelf where the bottom water is hypoxic (oxygen saturation of 6.2-6.7%) while the anoxic middle shelf area (oxygen saturation of 1.7-2.9%) appeared to show too low oxygen levels for spawning to take place. Hence, significant parts of this large shelf area appear unsuited for successful reproduction of the bearded goby, in particular for nest building by the territorials.

  1. A theoretical foundation for multi-scale regular vegetation patterns.

    PubMed

    Tarnita, Corina E; Bonachela, Juan A; Sheffer, Efrat; Guyton, Jennifer A; Coverdale, Tyler C; Long, Ryan A; Pringle, Robert M

    2017-01-18

    Self-organized regular vegetation patterns are widespread and thought to mediate ecosystem functions such as productivity and robustness, but the mechanisms underlying their origin and maintenance remain disputed. Particularly controversial are landscapes of overdispersed (evenly spaced) elements, such as North American Mima mounds, Brazilian murundus, South African heuweltjies, and, famously, Namibian fairy circles. Two competing hypotheses are currently debated. On the one hand, models of scale-dependent feedbacks, whereby plants facilitate neighbours while competing with distant individuals, can reproduce various regular patterns identified in satellite imagery. Owing to deep theoretical roots and apparent generality, scale-dependent feedbacks are widely viewed as a unifying and near-universal principle of regular-pattern formation despite scant empirical evidence. On the other hand, many overdispersed vegetation patterns worldwide have been attributed to subterranean ecosystem engineers such as termites, ants, and rodents. Although potentially consistent with territorial competition, this interpretation has been challenged theoretically and empirically and (unlike scale-dependent feedbacks) lacks a unifying dynamical theory, fuelling scepticism about its plausibility and generality. Here we provide a general theoretical foundation for self-organization of social-insect colonies, validated using data from four continents, which demonstrates that intraspecific competition between territorial animals can generate the large-scale hexagonal regularity of these patterns. However, this mechanism is not mutually exclusive with scale-dependent feedbacks. Using Namib Desert fairy circles as a case study, we present field data showing that these landscapes exhibit multi-scale patterning-previously undocumented in this system-that cannot be explained by either mechanism in isolation. These multi-scale patterns and other emergent properties, such as enhanced resistance to

  2. Cloud and Radiation Studies during SAFARI 2000

    NASA Technical Reports Server (NTRS)

    Platnick, Steven; King, M. D.; Hobbs, P. V.; Osborne, S.; Piketh, S.; Bruintjes, R.; Lau, William K. M. (Technical Monitor)

    2001-01-01

    Though the emphasis of the Southern Africa Regional Science Initiative 2000 (SAFARI-2000) dry season campaign was largely on emission sources and transport, the assemblage of aircraft (including the high altitude NASA ER-2 remote sensing platform and the University of Washington CV-580, UK MRF C130, and South African Weather Bureau JRA in situ aircrafts) provided a unique opportunity for cloud studies. Therefore, as part of the SAFARI initiative, investigations were undertaken to assess regional aerosol-cloud interactions and cloud remote sensing algorithms. In particular, the latter part of the experiment concentrated on marine boundary layer stratocumulus clouds off the southwest coast of Africa. Associated with cold water upwelling along the Benguela current, the Namibian stratocumulus regime has received limited attention but appears to be unique for several reasons. During the dry season, outflow of continental fires and industrial pollution over this area can be extreme. From below, upwelling provides a rich nutrient source for phytoplankton (a source of atmospheric sulphur through DMS production as well as from decay processes). The impact of these natural and anthropogenic sources on the microphysical and optical properties of the stratocumulus is unknown. Continental and Indian Ocean cloud systems of opportunity were also studied during the campaign. Aircraft flights were coordinated with NASA Terra Satellite overpasses for synergy with the Moderate Resolution Imaging Spectroradiometer (MODIS) and other Terra instruments. An operational MODIS algorithm for the retrieval of cloud optical and physical properties (including optical thickness, effective particle radius, and water path) has been developed. Pixel-level MODIS retrievals (11 km spatial resolution at nadir) and gridded statistics of clouds in th SAFARI region will be presented. In addition, the MODIS Airborne Simulator flown on the ER-2 provided high spatial resolution retrievals (50 m at nadir

  3. Individual variation of isotopic niches in grazing and browsing desert ungulates.

    PubMed

    Lehmann, D; Mfune, J K E; Gewers, E; Brain, C; Voigt, C C

    2015-09-01

    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.

  4. The Effect of Crustal Strength on Volcanism During Continental Breakup

    NASA Astrophysics Data System (ADS)

    Armitage, J. J.; Petersen, K. D.; Perez-Gussinye, M.; Collier, J.; Pik, R.

    2015-12-01

    Segmentation is a fundamental property of rifted margins which is thought to be inherited from pre-breakup lithospheric structure. The volume of melt emplaced during rifting typically varies across these segments. Notable examples are the Gulf of California, break-up in the South Atlantic, and the Afar depression. For example in Afar there is a clear north south transition from break-up in the Erta Ale segment, where there is localised young (<1 Ma) volcanism, to the Dabbahu segment where there is the 4-1 Ma Stratoid volcanic series and distributed faulting. Along the Namibian and conjugate Argentinian margin there is evidence that surface area of seaward dipping reflectors change across segments. Such lateral changes in volcanism over a relatively short spatial scale are hard to explain by change in mantle temperature. We will demonstrate that crustal strength places a crucial control on the volume and composition of melt generated during break-up. We have compared models of extension with a weaker and strong lower crust based on observed rock rheologies. Melt composition and volume is found to be a function of the lower crustal rheology as it effects the shape of the melt zone during extension. By comparing a suite models we find that Afar volcanism can be matched by models with both a weak or strong lower crust. If however the crust is weaker then the equivalent volume and composition is created with less crustal thinning but over a greater period of time. The difference in time required to generate significant volcanic rock may explain the change in surface area of sub-areal volcanism in both Afar, where there is a transition of strong to weak crust from Erta Ale to Dabbahu, and off-shore Namibia. Lateral variation in volcanism between segments may therefore be fundamentally controlled by the crust.

  5. Combining FastScape χ Values and 10Be Erosion Rates to Evaluate Topographic Equilibrium in Evolving Landscapes: Examples from Namibia and the Central Himalaya

    NASA Astrophysics Data System (ADS)

    Fenton, C.; Codilean, A.; Braun, J.; Merrall, S.

    2015-12-01

    The FastScape landscape evolution model is a powerful and user-friendly tool that can be used in concert with catchment-wide cosmogenic 10Be erosion rates to assess states of dynamic equilibrium in landscapes with respect to their tectonic and climatic settings. FastScape was used to compute chi (χ), a proxy for steady-state river channel elevation (Willet et al., 2014), for model domains in Namibia (e.g., desert climate and passive continental margin) and the central Himalaya (e.g., active mountain building and a wet, monsoonal climate). Namibian and central Himalayan landscapes are eroding at widely different rates (e.g., 101 mm/ka and 103 mm/ka, respectively). Chi values are sensitive to both DEM domain size and base level, cell resolution, and time, thus, chi values can only be evaluated and directly compared within a given domain. Chi values indicate areas or regions of equilibrium or disequilibrium within a given model domain, and not between domains in different geographic study areas. Chi can be used to ascertain if anomalously high 10Be erosion rates are affected by the addition of youthful sediment from landslides, debris flows, or glaciation of river catchments or tributary basins. In this study, glacial settings with high erosion rates show no relationship to chi values. For unglaciated tributary basins in a given catchment, chi values are related to cosmogenic 10Be erosion rates in the following ways: (1) basins in equilibrium have chi values that remain constant with increasing cosmogenic erosion rates; (2) basins in disequilibrium have an inverse relationship between chi values and erosion rates in a setting where erosion is driven predominantly by precipitation; and (3) basins in disequilibrium have a positive correlation between chi values and erosion rates in a setting where tectonic uplift is the dominant force driving erosion.

  6. A web-based survey of horse owners' perceptions and network analysis of horse movements relating to African horse sickness distribution in Namibia and South Africa.

    PubMed

    Liebenberg, Danica; Piketh, Stuart; van Hamburg, Huib

    2016-06-01

    Africa horse sickness (AHS) is the most lethal infectious non-contagious horse disease and has accordingly been declared notifiable by the World Organisation for Animal Health. AHS is endemic to sub-Saharan Africa and causes considerable losses to the equestrian industry. The effect of diseases in livestock on socio-economic factors is well researched, but the effect of anthropogenic factors on the distribution of a disease is poorly understood. The purpose of the study was to assess Namibian and South African horse owners' perceptions and the effect of horse movement on AHS distribution. A cross-sectional study was conducted to collect information from horse owners in Namibia and South Africa. To that end 'Fluid survey' was used for survey development. The survey was launched on Facebook and the link shared to horse related focus groups in Namibia and South Africa. A total of 508 responses were collected during the survey period. Of the 417 completed questionnaires received, 22% were from Namibia and 78% from South Africa. The participants comprised of 71% social and 29% professional riders. The most popular precautionary measures used, in addition to vaccination, were chemical repellents (64%) and stabling of horses during dusk and dawn (59%). A network analysis was performed in Gephi 0.8.2.B to illustrate the movement of horses between countries and districts/provinces. Network analysis results indicate that areas with the highest movement of horses corresponded to the areas with a high occurrence of AHS. Although 93% of the participants were aware that AHS is a notifiable and controlled disease, the process and efficiency of reporting is mostly unknown. With this snapshot of horse owners' perceptions and the effect of horse movement on the distribution of AHS, it is clear that a more holistic approach is needed. To that end, all environmental and social factors must be taken into account in effective management strategies.

  7. Cheetah paradigm revisited: MHC diversity in the world's largest free-ranging population.

    PubMed

    Castro-Prieto, Aines; Wachter, Bettina; Sommer, Simone

    2011-04-01

    For more than two decades, the cheetah (Acinonyx jubatus) has been considered a paradigm of disease vulnerability associated with low genetic diversity, particularly at the immune genes of the major histocompatibility complex (MHC). Cheetahs have been used as a classic example in numerous conservation genetics textbooks as well as in many related scientific publications. However, earlier studies used methods with low resolution to quantify MHC diversity and/or small sample sizes. Furthermore, high disease susceptibility was reported only for captive cheetahs, whereas free-ranging cheetahs show no signs of infectious diseases and a good general health status. We examined whether the diversity at MHC class I and class II-DRB loci in 149 Namibian cheetahs was higher than previously reported using single-strand conformation polymorphism analysis, cloning, and sequencing. MHC genes were examined at the genomic and transcriptomic levels. We detected ten MHC class I and four class II-DRB alleles, of which nine MHC class I and all class II-DRB alleles were expressed. Phylogenetic analyses and individual genotypes suggested that the alleles belong to four MHC class I and three class II-DRB putative loci. Evidence of positive selection was detected in both MHC loci. Our study indicated that the low number of MHC class I alleles previously observed in cheetahs was due to a smaller sample size examined. On the other hand, the low number of MHC class II-DRB alleles previously observed in cheetahs was further confirmed. Compared with other mammalian species including felids, cheetahs showed low levels of MHC diversity, but this does not seem to influence the immunocompetence of free-ranging cheetahs in Namibia and contradicts the previous conclusion that the cheetah is a paradigm species of disease vulnerability.

  8. Associations Between Orphan and Vulnerable Child Caregiving, Household Wealth Disparities, and Women's Overweight Status in Three Southern African Countries Participating in Demographic Health Surveys

    PubMed Central

    Kanamori, Mariano J.; Carter-Pokras, Olivia D.; Madhavan, Sangeetha; Lee, Sunmin; He, Xin; Feldman, Robert H.

    2015-01-01

    Objectives This study examines whether orphan and vulnerable children (OVC) primary caregivers are facing absolute household wealth (AWI) disparities, the association between AWI and women’s overweight status, and the modifying role of OVC primary caregiving status on this relationship. Methods Demographic Health Surveys (DHS) data (2006–2007) from 20–49 year old women in Namibia (n=6,305), Swaziland (n=2,786), and Zambia (n=4,389) were analyzed using weighted marginal means and logistic regressions. Results OVC primary caregivers in Namibia and Swaziland had a lower mean AWI than other women in the same country. In Zambia, OVC primary caregivers had a lower mean AWI score than non-primary caregivers living with an OVC but a higher mean AWI score than non-OVC primary caregivers. In Swaziland and Zambia, even small increases in household wealth were associated with higher odds for being overweight regardless of women’s caregiving status. Only in Namibia, OVC primary caregiving modified the effect of the previous association. Among Namibian OVC primary caregivers, women who had at least medium household wealth (4 or more AWI items) were more likely to be overweight than their poorest counterparts (0 or 1 AWI items). Conclusions OVC primary caregivers are facing household wealth disparities as compared to other women from their communities. Future studies/interventions should consider using population-based approaches to reach women from every household wealth level to curb overweight in Swaziland and Zambia and to focus on specific household wealth characteristics that are associated with OVC primary caregivers’ overweight status in Namibia. PMID:25630405

  9. Model and experiences of initiating collaboration with traditional healers in validation of ethnomedicines for HIV/AIDS in Namibia

    PubMed Central

    Chinsembu, Kazhila C

    2009-01-01

    Many people with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) in Namibia have access to antiretroviral drugs but some still use traditional medicines to treat opportunistic infections and offset side-effects from antiretroviral medication. Namibia has a rich biodiversity of indigenous plants that could contain novel anti-HIV agents. However, such medicinal plants have not been identified and properly documented. Various ethnomedicines used to treat HIV/AIDS opportunistic infections have not been scientifically validated for safety and efficacy. These limitations are mostly attributable to the lack of collaboration between biomedical scientists and traditional healers. This paper presents a five-step contextual model for initiating collaboration with Namibian traditional healers in order that candidate plants that may contain novel anti-HIV agents are identified, and traditional medicines used to treat HIV/AIDS opportunistic infections are subjected to scientific validation. The model includes key structures and processes used to initiate collaboration with traditional healers in Namibia; namely, the National Biosciences Forum, a steering committee with the University of Namibia (UNAM) as the focal point, a study tour to Zambia and South Africa where other collaborative frameworks were examined, commemorations of the African Traditional Medicine Day (ATMD), and consultations with stakeholders in north-eastern Namibia. Experiences from these structures and processes are discussed. All traditional healers in north-eastern Namibia were willing to collaborate with UNAM in order that their traditional medicines could be subjected to scientific validation. The current study provides a framework for future collaboration with traditional healers and the selection of candidate anti-HIV medicinal plants and ethnomedicines for scientific testing in Namibia. PMID:19852791

  10. Environmental Domains and Range-Limiting Mechanisms: Testing the Abundant Centre Hypothesis Using Southern African Sandhoppers

    PubMed Central

    Baldanzi, Simone; McQuaid, Christopher D.; Cannicci, Stefano; Porri, Francesca

    2013-01-01

    Predicting shifts of species geographical ranges is a fundamental challenge for conservation ecologists given the great complexity of factors involved in setting range limits. Distributional patterns are frequently modelled to “simplify” species responses to the environment, yet the central mechanisms that drive a particular pattern are rarely understood. We evaluated the distributions of two sandhopper species (Crustacea, Amphipoda, Talitridae), Talorchestia capensis and Africorchestia quadrispinosa along the Namibian and South African coasts, encompassing three biogeographic regions influenced by two different oceanographic systems, the Benguela and Agulhas currents. We aimed to test whether the Abundant Centre Hypothesis (ACH) can explain the distributions of these species’ abundances, sizes and sex ratios and examined which environmental parameters influence/drive these distributions. Animals were collected during a once-off survey at 29 sites over c.3500 km of coastline. The ACH was tested using a non-parametric constraint space analysis of the goodness of fit of five hypothetical models. Distance Based Linear Modelling (DistLM) was performed to evaluate which environmental traits influenced the distribution data. Abundance, size and sex ratio showed different patterns of distribution. A ramped model fitted the abundance (Ramped North) and size (Ramped South) distribution for A. quadrispinosa. The Inverse Quadratic model fitted the size distribution of T. capensis. Beach slope, salinity, sand temperature and percentage of detritus found on the shore at the time of collection played important roles in driving the abundance of A. quadrispinosa. T. capensis was mainly affected by salinity and the morphodynamic state of the beach. Our results provided only some support for the ACH predictions. The DistLM confirmed that the physical state of the beach is an important factor for sandy beach organisms. The effect of salinity and temperature suggest metabolic

  11. Alpha-1-antitrypsin deficiency in the Cape Verde islands (Northwest Africa): High prevalence in a sub-Saharan population.

    PubMed

    Spínola, Carla; Brehm, António; Spínola, Hélder

    2010-07-01

    Alpha-1-antitrypsin (AAT) deficiency results from mutations on the Protease Inhibitor (PI) locus located in chromosome 14 and has been associated with pulmonary early-onset emphysema and chronic obstructive pulmonary disease (COPD). African populations show a lower prevalence of AAT deficiency compared to Europeans. Two hundred and two (202) unrelated samples from the Cape Verde archipelago (Northwest Africa) were genotyped for the two most common AAT deficiency alleles, PI*S and PI*Z, using PCR - Mediated Site-Directed Mutagenesis. PI*S mutation in Cape Verde (3.2%) presents one of the highest frequencies in sub-Saharans, similar to South Africa (3.3%) but lower than Angolans (18.8%), Namibians (14.7%), Nigerians (6.4%) and Botswains (4.5%). The PI*Z mutation shows lower values (0.2%) than other sub-Saharan populations, namely Somalia (1.15%), Mali (0.98%)or Nigeria (0.36%). However, many other sub-Saharan populations, like Botswana, Congo, Cameroon, Angola, Gambia, South Africa, Mozambique and Namibia, lack the PI*Z mutation. The frequency of all the AAT deficiency genotypes in the Cape Verde archipelago (PI*ZZ, PI*SS, and PI*SZ) was estimated to be one of the highest in sub-Saharans (15 per 1000), only lower than Angola (54 per 1000) and Namibia (22 per 1000). The results obtained show a high prevalence of the AAT deficiency in Cape Verdeans when compared to other sub-Saharans a condition that can be explained by a heavy European genetic influence, characteristic of that population.

  12. Corazonin in insects.

    PubMed

    Predel, Reinhard; Neupert, Susanne; Russell, William K; Scheibner, Olaf; Nachman, Ronald J

    2007-01-01

    Corazonin is a peptidergic neurohormone of insects that is expressed in neurosecretory neurons of the pars lateralis of the protocerebrum and transported via nervi corporis cardiaci to the storage lobes of the corpora cardiaca. This peptide occurs with a single isoform in all insects studied so far, with the exception of the Coleoptera in which no corazonin form could be detected. Very few modifications of [Arg(7)]-corazonin, originally isolated from cockroaches, are known, namely [His(7)]-corazonin which is expressed in certain locusts and the stick insect Carausius morosus, and [Thr(4), His(7)]-corazonin recently described from the honey bee Apis mellifera. In this study, we performed a comprehensive screening for corazonin in the different insect groups after detecting of a fourth isoform in a crane fly, Tipula sp. ([Gln(10)]-corazonin). [Arg(7)]-corazonin is distributed in most major lineages of insects, and is thus the ancient form which was present at the time the phylum Insecta evolved. The replacement of Arg with His at position 7 from the N-terminus occurred several times in the evolution of insects. The third isoform, [Thr(4), His(7)]-corazonin, seems to be restricted to bees (Apidae); whereas wasps (Vespidae) and a bumble bee (Apidae) express other corazonins, specifically [His(7)]-corazonin and [Tyr(3), Gln(7), Gln(10)]-corazonin, respectively. A novel corazonin form, [His(4), Gln(7)]-corazonin, was also detected in all South African members of the newly described insect order Mantophasmatodea. The [His(4), Gln(7)]-corazonin separates these species from the Namibian Mantophasmatodea which express [Arg(7)]-corazonin and can be used as a distinct character to distinguish these morphologically similar insects.

  13. Reference intervals for selected serum biochemistry analytes in cheetahs Acinonyx jubatus.

    PubMed

    Hudson-Lamb, Gavin C; Schoeman, Johan P; Hooijberg, Emma H; Heinrich, Sonja K; Tordiffe, Adrian S W

    2016-02-26

    Published haematologic and serum biochemistry reference intervals are very scarce for captive cheetahs and even more for free-ranging cheetahs. The current study was performed to establish reference intervals for selected serum biochemistry analytes in cheetahs. Baseline serum biochemistry analytes were analysed from 66 healthy Namibian cheetahs. Samples were collected from 30 captive cheetahs at the AfriCat Foundation and 36 free-ranging cheetahs from central Namibia. The effects of captivity-status, age, sex and haemolysis score on the tested serum analytes were investigated. The biochemistry analytes that were measured were sodium, potassium, magnesium, chloride, urea and creatinine. The 90% confidence interval of the reference limits was obtained using the non-parametric bootstrap method. Reference intervals were preferentially determined by the non-parametric method and were as follows: sodium (128 mmol/L - 166 mmol/L), potassium (3.9 mmol/L - 5.2 mmol/L), magnesium (0.8 mmol/L - 1.2 mmol/L), chloride (97 mmol/L - 130 mmol/L), urea (8.2 mmol/L - 25.1 mmol/L) and creatinine (88 µmol/L - 288 µmol/L). Reference intervals from the current study were compared with International Species Information System values for cheetahs and found to be narrower. Moreover, age, sex and haemolysis score had no significant effect on the serum analytes in this study. Separate reference intervals for captive and free-ranging cheetahs were also determined. Captive cheetahs had higher urea values, most likely due to dietary factors. This study is the first to establish reference intervals for serum biochemistry analytes in cheetahs according to international guidelines. These results can be used for future health and disease assessments in both captive and free-ranging cheetahs.

  14. Reference intervals for selected serum biochemistry analytes in cheetahs (Acinonyx jubatus).

    PubMed

    Hudson-Lamb, Gavin C; Schoeman, Johan P; Hooijberg, Emma H; Heinrich, Sonja K; Tordiffe, Adrian S W

    2016-02-26

    Published haematologic and serum biochemistry reference intervals are very scarce for captive cheetahs and even more for free-ranging cheetahs. The current study was performed to establish reference intervals for selected serum biochemistry analytes in cheetahs. Baseline serum biochemistry analytes were analysed from 66 healthy Namibian cheetahs. Samples were collected from 30 captive cheetahs at the AfriCat Foundation and 36 free-ranging cheetahs from central Namibia. The effects of captivity-status, age, sex and haemolysis score on the tested serum analytes were investigated. The biochemistry analytes that were measured were sodium, potassium, magnesium, chloride, urea and creatinine. The 90% confidence interval of the reference limits was obtained using the non-parametric bootstrap method. Reference intervals were preferentially determined by the non-parametric method and were as follows: sodium (128 mmol/L - 166 mmol/L), potassium (3.9 mmol/L - 5.2 mmol/L), magnesium (0.8 mmol/L - 1.2 mmol/L), chloride (97 mmol/L - 130 mmol/L), urea (8.2 mmol/L - 25.1 mmol/L) and creatinine (88 µmol/L - 288 µmol/L). Reference intervals from the current study were compared with International Species Information System values for cheetahs and found to be narrower. Moreover, age, sex and haemolysis score had no significant effect on the serum analytes in this study. Separate reference intervals for captive and free-ranging cheetahs were also determined. Captive cheetahs had higher urea values, most likely due to dietary factors. This study is the first to establish reference intervals for serum biochemistry analytes in cheetahs according to international guidelines. These results can be used for future health and disease assessments in both captive and free-ranging cheetahs.

  15. Data reduction, radial velocities and stellar parameters from spectra in the very low signal-to-noise domain

    NASA Astrophysics Data System (ADS)

    Malavolta, Luca

    2013-10-01

    Large astronomical facilities usually provide data reduction pipeline designed to deliver ready-to-use scientific data, and too often as- tronomers are relying on this to avoid the most difficult part of an astronomer job Standard data reduction pipelines however are usu- ally designed and tested to have good performance on data with av- erage Signal to Noise Ratio (SNR) data, and the issues that are related with the reduction of data in the very low SNR domain are not taken int account properly. As a result, informations in data with low SNR are not optimally exploited. During the last decade our group has collected thousands of spec- tra using the GIRAFFE spectrograph at Very Large Telescope (Chile) of the European Southern Observatory (ESO) to determine the ge- ometrical distance and dynamical state of several Galactic Globular Clusters but ultimately the analysis has been hampered by system- atics in data reduction, calibration and radial velocity measurements. Moreover these data has never been exploited to get other informa- tions like temperature and metallicity of stars, because considered too noisy for these kind of analyses. In this thesis we focus our attention on data reduction and analysis of spectra with very low SNR. The dataset we analyze in this thesis comprises 7250 spectra for 2771 stars of the Globular Cluster M 4 (NGC 6121) in the wavelength region 5145-5360Å obtained with GIRAFFE. Stars from the upper Red Giant Branch down to the Main Sequence have been observed in very different conditions, including nights close to full moon, and reaching SNR - 10 for many spectra in the dataset. We will first review the basic steps of data reduction and spec- tral extraction, adapting techniques well tested in other field (like photometry) but still under-developed in spectroscopy. We improve the wavelength dispersion solution and the correction of radial veloc- ity shift between day-time calibrations and science observations by following a completely

  16. A test field for Gaia. Radial velocity catalogue of stars in the South Ecliptic Pole

    NASA Astrophysics Data System (ADS)

    Frémat, Y.; Altmann, M.; Pancino, E.; Soubiran, C.; Jofré, P.; Damerdji, Y.; Heiter, U.; Royer, F.; Seabroke, G.; Sordo, R.; Blanco-Cuaresma, S.; Jasniewicz, G.; Martayan, C.; Thévenin, F.; Vallenari, A.; Blomme, R.; David, M.; Gosset, E.; Katz, D.; Viala, Y.; Boudreault, S.; Cantat-Gaudin, T.; Lobel, A.; Meisenheimer, K.; Nordlander, T.; Raskin, G.; Royer, P.; Zorec, J.

    2017-01-01

    Context. Gaia is a space mission that is currently measuring the five astrometric parameters, as well as spectrophotometry of at least 1 billion stars to G = 20.7 mag with unprecedented precision. The sixth parameter in phase space (i.e., radial velocity) is also measured thanks to medium-resolution spectroscopy that is being obtained for the 150 million brightest stars. During the commissioning phase, two fields, one around each ecliptic pole, have been repeatedly observed to assess and to improve the overall satellite performances, as well as the associated reduction and analysis software. A ground-based photometric and spectroscopic survey was therefore initiated in 2007, and is still running to gather as much information as possible about the stars in these fields. This work is of particular interest to the validation of the radial velocity spectrometer outputs. Aims: The paper presents the radial velocity measurements performed for the Southern targets in the 12-17 R magnitude range on high- to mid-resolution spectra obtained with the GIRAFFE and UVES spectrographs. Methods: Comparison of the South Ecliptic Pole (SEP) GIRAFFE data to spectroscopic templates observed with the HERMES (Mercator in La Palma, Spain) spectrograph enabled a first coarse characterisation of the 747 SEP targets. Radial velocities were then obtained by comparing the results of three different methods. Results: In this paper, we present an initial overview of the targets to be found in the 1 sq. deg SEP region that was observed repeatedly by Gaia ever since its commissioning. In our representative sample, we identified one galaxy, six LMC S-stars, nine candidate chromospherically active stars, and confirmed the status of 18 LMC Carbon stars. A careful study of the 3471 epoch radial velocity measurements led us to identify 145 RV constant stars with radial velocities varying by less than 1 km s-1. Seventy-eight stars show significant RV scatter, while nine stars show a composite spectrum

  17. Wildlife Population Dynamics in Human-Dominated Landscapes under Community-Based Conservation: The Example of Nakuru Wildlife Conservancy, Kenya.

    PubMed

    Ogutu, Joseph O; Kuloba, Bernard; Piepho, Hans-Peter; Kanga, Erustus

    2017-01-01

    Wildlife conservation is facing numerous and mounting challenges on private and communal lands in Africa, including in Kenya. We analyze the population dynamics of 44 common wildlife species in relation to rainfall variation in the Nakuru Wildlife Conservancy (NWC), located in the Nakuru-Naivasha region of Kenya, based on ground total counts carried out twice each year from March 1996 to May 2015. Rainfall in the region was quasi-periodic with cycle periods dependent on the rainfall component and varying from 2.8 years for the dry season to 10.9 years for the wet season. These oscillations are associated with frequent severe droughts and food scarcity for herbivores. The trends for the 44 wildlife species showed five general patterns during 1996-2015. 1) Steinbuck, bushbuck, hartebeest and greater kudu numbers declined persistently and significantly throughout 1996-2015 and thus merit the greatest conservation attention. 2) Klipspringer, mongoose, oribi, porcupine, cheetah, leopard, ostrich and Sykes monkey numbers also decreased noticeably but not significantly between 1996 and 2015. 3) Dik dik, eland, African hare, Jackal, duiker, hippo and Thomson's gazelle numbers first increased and then declined between 1996 and 2015 but only significantly for duiker and hippo. 4) Aardvark, serval cat, colobus monkey, bat-eared fox, reedbuck, hyena and baboon numbers first declined and then increased but only the increases in reedbuck and baboon numbers were significant. 5) Grant's gazelle, Grevy's zebra, lion, spring hare, Burchell's zebra, bushpig, white rhino, rock hyrax, topi, oryx, vervet monkey, guinea fowl, giraffe, and wildebeest numbers increased consistently between 1996 and 2015. The increase was significant only for rock hyrax, topi, vervet monkey, guinea fowl, giraffe and wildebeest. 6) Impala, buffalo, warthog, and waterbuck, numbers increased significantly and then seemed to level off between 1996 and 2015. The aggregate biomass of primates and carnivores

  18. Wildlife Population Dynamics in Human-Dominated Landscapes under Community-Based Conservation: The Example of Nakuru Wildlife Conservancy, Kenya

    PubMed Central

    Ogutu, Joseph O.; Kuloba, Bernard; Piepho, Hans-Peter; Kanga, Erustus

    2017-01-01

    Wildlife conservation is facing numerous and mounting challenges on private and communal lands in Africa, including in Kenya. We analyze the population dynamics of 44 common wildlife species in relation to rainfall variation in the Nakuru Wildlife Conservancy (NWC), located in the Nakuru-Naivasha region of Kenya, based on ground total counts carried out twice each year from March 1996 to May 2015. Rainfall in the region was quasi-periodic with cycle periods dependent on the rainfall component and varying from 2.8 years for the dry season to 10.9 years for the wet season. These oscillations are associated with frequent severe droughts and food scarcity for herbivores. The trends for the 44 wildlife species showed five general patterns during 1996–2015. 1) Steinbuck, bushbuck, hartebeest and greater kudu numbers declined persistently and significantly throughout 1996–2015 and thus merit the greatest conservation attention. 2) Klipspringer, mongoose, oribi, porcupine, cheetah, leopard, ostrich and Sykes monkey numbers also decreased noticeably but not significantly between 1996 and 2015. 3) Dik dik, eland, African hare, Jackal, duiker, hippo and Thomson’s gazelle numbers first increased and then declined between 1996 and 2015 but only significantly for duiker and hippo. 4) Aardvark, serval cat, colobus monkey, bat-eared fox, reedbuck, hyena and baboon numbers first declined and then increased but only the increases in reedbuck and baboon numbers were significant. 5) Grant’s gazelle, Grevy’s zebra, lion, spring hare, Burchell’s zebra, bushpig, white rhino, rock hyrax, topi, oryx, vervet monkey, guinea fowl, giraffe, and wildebeest numbers increased consistently between 1996 and 2015. The increase was significant only for rock hyrax, topi, vervet monkey, guinea fowl, giraffe and wildebeest. 6) Impala, buffalo, warthog, and waterbuck, numbers increased significantly and then seemed to level off between 1996 and 2015. The aggregate biomass of primates and

  19. The effect of intervertebral cartilage on neutral posture and range of motion in the necks of sauropod dinosaurs.

    PubMed

    Taylor, Michael P; Wedel, Mathew J

    2013-01-01

    The necks of sauropod dinosaurs were a key factor in their evolution. The habitual posture and range of motion of these necks has been controversial, and computer-aided studies have argued for an obligatory sub-horizontal pose. However, such studies are compromised by their failure to take into account the important role of intervertebral cartilage. This cartilage takes very different forms in different animals. Mammals and crocodilians have intervertebral discs, while birds have synovial joints in their necks. The form and thickness of cartilage varies significantly even among closely related taxa. We cannot yet tell whether the neck joints of sauropods more closely resembled those of birds or mammals. Inspection of CT scans showed cartilage:bone ratios of 4.5% for Sauroposeidon and about 20% and 15% for two juvenile Apatosaurus individuals. In extant animals, this ratio varied from 2.59% for the rhea to 24% for a juvenile giraffe. It is not yet possible to disentangle ontogenetic and taxonomic signals, but mammal cartilage is generally three times as thick as that of birds. Our most detailed work, on a turkey, yielded a cartilage:bone ratio of 4.56%. Articular cartilage also added 11% to the length of the turkey's zygapophyseal facets. Simple image manipulation suggests that incorporating 4.56% of neck cartilage into an intervertebral joint of a turkey raises neutral posture by 15°. If this were also true of sauropods, the true neutral pose of the neck would be much higher than has been depicted. An additional 11% of zygapophyseal facet length translates to 11% more range of motion at each joint. More precise quantitative results must await detailed modelling. In summary, including cartilage in our models of sauropod necks shows that they were longer, more elevated and more flexible than previously recognised.

  20. Enough is enough: the effects of symbiotic ant abundance on herbivory, growth, and reproduction in an African acacia.

    PubMed

    Palmer, Todd M; Brody, Alison K

    2013-03-01

    Understanding how cooperative interactions evolve and persist remains a central challenge in biology. Many mutualisms are thought to be maintained by "partner fidelity feedback," in which each partner bases their investment on the benefits they receive. Yet, we know little about how benefits change as mutualists vary their investment, which is critical to understanding the balance between mutualism and antagonism in any given partnership. Using an obligate ant-plant mutualism, we manipulated the density of symbiotic acacia ants (Crematogaster mimosae) and examined how the costs and benefits to Acacia drepanolobium trees scaled with ant abundance. Benefits of ants to plants saturated with increasing ant abundance for protection from branch browsing by elephants and attack by branch galling midges, while varying linearly for protection from cerambycid beetles. In addition, the risk of catastrophic whole-tree herbivory by elephants was highest for trees with very low ant abundance. However, there was no relationship between ant abundance and herbivory by leaf-feeding invertebrates, nor by vertebrate browsers such as giraffe, steinbuck, and Grant's gazelle. Ant abundance did not significantly influence rates of branch growth on acacias, but there was a significant negative relationship between ant abundance and the number of fruits produced by host plants, suggesting that maintaining high-density ant colonies is costly. Because benefits to plants largely saturated with increasing colony size, while costs to plant reproduction increased, we suggest that ant colonies may achieve abundances that are higher than optimal for host plants. Our results highlight the conflicts of interest inherent in many mutualisms, and demonstrate the value of examining the shape of curves relating costs and benefits within these globally important interactions.

  1. Construction of chimeric bovine viral diarrhea viruses containing glycoprotein E rns of heterologous pestiviruses and evaluation of the chimeras as potential marker vaccines against BVDV.

    PubMed

    Luo, Yugang; Yuan, Ying; Ankenbauer, Robert G; Nelson, Lynn D; Witte, Steven B; Jackson, James A; Welch, Siao-Kun W

    2012-06-06

    Bovine viral diarrhea virus (BVDV) infections are enzootic in the cattle population and continue to cause significant economic losses to the beef and dairy industries worldwide. Extent of the damages has stimulated increasing interest in control programs directed at eradicating BVDV infections. Use of a BVDV marker vaccine would facilitate eradication efforts as a negatively marked vaccine would enable differentiation of infected from vaccinated animals (DIVA). We describe here the construction of three chimeric BVDVs containing glycoprotein E(rns) of heterologous pestiviruses and the evaluation of the chimera viruses as potential marker vaccines against BVDV infections. Chimeric NADL/G-E(rns), NADL/R-E(rns), and NADL/P-E(rns) were constructed by replacing the E(rns) gene of the full-length BVDV (NADL strain) genome with the E(rns) genes of giraffe (G-E(rns)), reindeer (R-E(rns)), or pronghorn antelope (P-E(rns)) pestiviruses, respectively. Each chimeric NADL virus was viable and infectious in RD 420 (bovine testicular) and BK-6 (bovine kidney) cells. By immunohistochemistry assays, NADL/G-E(rns) and NADL/R-E(rns) chimeric viruses reacted to BVDV E(rns) specific monoclonal antibody (mAb) 15C5, whereas the NADL/P-E(rns) chimeric virus did not. In an animal vaccination study, inactivated vaccines made from two chimeric viruses and the wild type NADL BVDV induced similar neutralizing antibody responses. NADL/P-E(rns)-vaccinated animals were distinguished from animals vaccinated with the wild type virus by means of a companion serological DIVA assay. These results show that chimeric NADL/P-E(rns) virus containing the E(rns) gene of pronghorn antelope pestivirus could be a potential marker vaccine candidate for use in a BVDV control and eradication program.

  2. The AVES adaptive optics spectrograph for the VLT: status report

    NASA Astrophysics Data System (ADS)

    Pallavicini, Roberto; Delabre, Bernard; Pasquini, Luca; Zerbi, Filippo M.; Bonanno, Giovanni; Comari, Maurizio; Conconi, Paolo; Mazzoleni, Ruben; Santin, Paolo; Damiani, Francesco; Di Marcantonio, Paolo; Franchini, Mariagrazia; Spano, Paolo; Bonifacio, P.; Catalano, Santo; Molaro, Paolo P.; Randich, S.; Rodono, Marcello

    2003-03-01

    We report on the status of AVES, the Adaptive-optics Visual Echelle Spectrograph proposed for the secondary port of the Nasmyth Adaptive Optics System (NAOS) recently installed at the VLT. AVES is an intermediate resolution (R ≍ 16,000) high-efficiency fixed- format echelle spectrograph which operates in the spectral band 500 - 1,000 nm. In addition to a high intrinsic efficiency, comparable to that of ESI at Keck II, it takes advantage of the adaptive optics correction provided by NAOS to reduce the sky and detector contribution in background-limited observations of weak sources, thus allowing a further magnitude gain with respect to comparable non-adaptive optics spectrographs. Simulations show that the instrument will be capable of reaching a magnitude V = 22.5 at S/N > 10 in two hours, two magnitudes weaker than GIRAFFE at the same resolution and 3 magnitudes weaker than the higher resolution UVES spectrograph. Imaging and coronographic functions have also been implemented in the design. We present the results of the final design study and we dicuss the technical and operational issues related to its implementation at the VLT as a visitor instrument. We also discuss the possibility of using a scaled-up non-adaptive optics version of the same design as an element of a double- or triple-arm intermediate-resolution spectrograph for the VLT. Such an option looks attractive in the context of a high-efficiency large-bandwidth (320 - 1,500 nm) spectrograph ("fast-shooter") being considered by ESO as a 2nd-generation VLT instrument.

  3. Gravity of Living Systems: May the Force Be With You

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.; Holton, Emily M. (Technical Monitor)

    1998-01-01

    Gravity, the force which shapes the architecture of organisms from single cells to dinosaurs, has been the most constant environmental factor during the evolution of species on Earth. With long-duration space flight, an understanding of how gravity affects living systems gains greater urgency in order to maintain the health and performance of crews who will explore the solar system. For example, the cardiovascular and musculoskeletal systems are normally exposed to gravitational gradients of blood pressure and weight on Earth. Such gradients increase blood pressure and tissue weight in dependent tissues of the body. Thus, from a physiologic standpoint, these systems are greatly affected by altered gravity. Exposure to actual and simulated microgravity causes blood and tissue fluid to shift from the legs to the head. Studies of humans in space have documented facial edema, space adaptation syndrome, decreased plasma volume, muscle atrophy, and loss of bone strength. Return of astronauts to Earth is accompanied by orthostatic intolerance, decreased neuromuscular coordination, and reduced exercise capacity. These factors decrease performance during descent from orbit and increase risk during emergency egress from the space craft. Models of simulated microgravity include 60 head-down tilt, immersion, and prolonged horizontal bedrest. Head-down tilt and dry immersion are the most accepted models and studies using these models of up to one year have been performed in Russia. Sensitive animal models which offer clear insights into the role of gravity on structure and function include the developing giraffe and snakes from various habitats. Finally, possible countermeasures to speed readaptation of astronauts to gravity after prolonged space flight include exercise, lower body negative pressure, and centrifugation.

  4. Na-O anticorrelation and horizontal branches. IV. Detection of He-rich and He-poor stellar populations in the globular cluster NGC 6218

    NASA Astrophysics Data System (ADS)

    Carretta, E.; Bragaglia, A.; Gratton, R. G.; Catanzaro, G.; Leone, F.; Sabbi, E.; Cassisi, S.; Claudi, R.; D'Antona, F.; François, P.; James, G.; Piotto, G.

    2007-03-01

    We used the multifiber spectrograph FLAMES on the ESO Very Large Telescope UT2 to derive atmospheric parameters, metallicities and abundances of O and Na for 79 red giant stars in the Galactic globular cluster NGC 6218 (M 12). We analyzed stars in the magnitude range from about 1 mag below the bump to the tip of the Red Giant Branch. The average metallicity we derive is [Fe/H]=-1.31± 0.004± 0.028 dex (random and systematic errors, respectively), with a very small star-to-star scatter (rms=0.033 dex), from moderately high-resolution Giraffe spectra. This is the first extensive spectroscopic abundance analysis in this cluster. Our results indicate that NGC 6218 is very homogeneous as far as heavy elements are concerned. On the other hand, light elements involved in the well known proton-capture reactions of H-burning at high temperature, such as O and Na, show large variations, anticorrelated with each other, at all luminosities along the red giant branch. The conclusion is that the Na-O anticorrelation must be established in early times at the cluster formation. We interpret the variation of Na found near the RGB-bump as the effect of two distinct populations having different bump luminosities, as predicted for different He content. To our knowledge, NGC 6218 is the first GC where such a signature has been spectroscopically detected, when combined with consistent and homogeneous data obtained for NGC 6752 to gain in statistical significance. Based on observations collected at ESO telescopes under programme 073.D-0211. Full Tables 2, 3, and 5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/464/939

  5. Stellar kinematics and metallicities in the ultra-faint dwarf galaxy Reticulum II

    SciTech Connect

    Simon, J. D.

    2015-07-23

    With this study, we present Magellan/M2FS, Very Large Telescope/GIRAFFE, and Gemini South/GMOS spectroscopy of the newly discovered Milky Way satellite Reticulum II. Based on the spectra of 25 Ret II member stars selected from Dark Energy Survey imaging, we measure a mean heliocentric velocity of $62.8\\pm 0.5\\;\\mathrm{km}\\;{\\rm{s}}^{-1}$ and a velocity dispersion of $3.3\\pm 0.7\\;\\mathrm{km}\\;{\\rm{s}}^{-1}$. The mass-to-light ratio of Ret II within its half-light radius is $470\\pm 210\\ {M}_{\\odot }/{L}_{\\odot }$, demonstrating that it is a strongly dark matter-dominated system. Despite its spatial proximity to the Magellanic Clouds, the radial velocity of Ret II differs from that of the LMC and SMC by 199 and 83 $\\mathrm{km}\\ {{\\rm{s}}}^{-1}$, respectively, suggesting that it is not gravitationally bound to the Magellanic system. The likely member stars of Ret II span 1.3 dex in metallicity, with a dispersion of 0.28 ± 0.09 dex, and we identify several extremely metal-poor stars with ${\\rm{[Fe/H]}}\\lt -3$. In combination with its luminosity, size, and ellipticity, these results confirm that Ret II is an ultra-faint dwarf galaxy. With a mean metallicity of ${\\rm{[Fe/H]}}=-2.65\\pm 0.07$, Ret II matches Segue 1 as the most metal-poor galaxy known. Although Ret II is the third-closest dwarf galaxy to the Milky Way, the line-of-sight integral of the dark matter density squared is ${\\mathrm{log}}_{10}(J)=18.8\\pm 0.6\\;\\;\\mathrm{GeV}{\\;}^{2}\\;{\\mathrm{cm}}^{-5}\\;$ within 0fdg2, indicating that the predicted gamma-ray flux from dark matter annihilation in Ret II is lower than that of several other dwarf galaxies.

  6. Uncertain links in host–parasite networks: lessons for parasite transmission in a multi-host system

    PubMed Central

    2017-01-01

    For many parasites, the full set of hosts that are susceptible to infection is not known, and this could lead to a bias in estimates of transmission. We used counts of individual adult parasites from historical parasitology studies in southern Africa to map a bipartite network of the nematode parasites of herbivore hosts that occur in Botswana. Bipartite networks are used in community ecology to represent interactions across trophic levels. We used a Bayesian hierarchical model to predict the full set of host–parasite interactions from existing data on parasitic gastrointestinal nematodes of wild and domestic ungulates given assumptions about the distribution of parasite counts within hosts, while accounting for the relative uncertainty of less sampled species. We used network metrics to assess the difference between the observed and predicted networks, and to explore the connections between hosts via their shared parasites using a host–host unipartite network projected from the bipartite network. The model predicts a large number of missing links and identifies red hartebeest, giraffe and steenbok as the hosts that have the most uncertainty in parasite diversity. Further, the unipartite network reveals clusters of herbivores that have a high degree of parasite sharing, and these clusters correspond closely with phylogenetic distance rather than with the wild/domestic boundary. These results provide a basis for predicting the risk of cross-species transmission of nematode parasites in areas where livestock and wildlife share grazing land. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289262

  7. Influence of Aesthetic Appreciation of Wildlife Species on Attitudes towards Their Conservation in Kenyan Agropastoralist Communities

    PubMed Central

    de Pinho, Joana Roque; Grilo, Clara; Boone, Randall B.; Galvin, Kathleen A.; Snodgrass, Jeffrey G.

    2014-01-01

    The influence of human aesthetic appreciation of animal species on public attitudes towards their conservation and related decision-making has been studied in industrialized countries but remains underexplored in developing countries. Working in three agropastoralist communities around Amboseli National Park, southern Kenya, we investigated the relative strength of human aesthetic appreciation on local attitudes towards the conservation of wildlife species. Using semi-structured interviewing and free listing (n = 191) as part of a mixed methods approach, we first characterized local aesthetic judgments of wildlife species. With a Generalized Linear Mixed Models (GLMM) approach, we then determined the influence of perceiving four species as beautiful on local support for their protection (“rescuing them”), and of perceiving four other species as ugly on support for their removal from the area, while controlling for informant personal and household socioeconomic attributes. Perceiving giraffe, gazelles and eland as beautiful is the strongest variable explaining support for rescuing them. Ugliness is the strongest variable influencing support for the removal of buffalo, hyena, and elephant (but not lion). Both our qualitative and quantitative results suggest that perceptions of ugly species could become more positive through direct exposure to those species. We propose that protected areas in developing countries facilitate visitation by local residents to increase their familiarity with species they rarely see or most frequently see in conflict with human interests. Since valuing a species for its beauty requires seeing it, protected areas in developing countries should connect the people who live around them with the animals they protect. Our results also show that aesthetic appreciation of biodiversity is not restricted to the industrialized world. PMID:24551176

  8. Phenotypic and Genotypic Characterization of Salmonella enterica in Captive Wildlife and Exotic Animal Species in Ohio, USA.

    PubMed

    Farias, L F P; Oliveira, C J B; Medardus, J J; Molla, B Z; Wolfe, B A; Gebreyes, W A

    2015-09-01

    The purpose of this study was to investigate the occurrence, antimicrobial resistance patterns, phenotypic and genotypic relatedness of Salmonella enterica recovered from captive wildlife host species and in the environment in Ohio, USA. A total of 319 samples including faecal (n = 225), feed (n = 38) and environmental (n = 56) were collected from 32 different wild and exotic animal species in captivity and their environment in Ohio. Salmonellae were isolated using conventional culture methods and tested for antimicrobial susceptibility with the Kirby-Bauer disc diffusion method. Salmonella isolates were serotyped, and genotyping was performed using the pulsed-field gel electrophoresis (PFGE). Salmonella was detected in 56 of 225 (24.9%) faecal samples; six of 56 (10.7%) environmental samples and six of 38 (15.8%) feed samples. Salmonella was more commonly isolated in faecal samples from giraffes (78.2%; 36/46), cranes (75%; 3/4) and raccoons (75%; 3/4). Salmonella enterica serotypes of known public health significance including S. Typhimurium (64.3%), S. Newport (32.1%) and S. Heidelberg (5.3%) were identified. While the majority of the Salmonella isolates were pan-susceptible (88.2%; 60 of 68), multidrug-resistant strains including penta-resistant type, AmStTeKmGm (8.8%; six of 68) were detected. Genotypic diversity was found among S. Typhimurium isolates. The identification of clonally related Salmonella isolates from environment and faeces suggests that indirect transmission of Salmonella among hosts via environmental contamination is an important concern to workers, visitors and other wildlife. Results of this study show the diversity of Salmonella serovars and public health implications of human exposure from wildlife reservoirs.

  9. Isolation and characterization of Babesia pecorum sp. nov. from farmed red deer (Cervus elaphus).

    PubMed

    Jouglin, Maggy; Fernández-de-Mera, Isabel G; de la Cotte, Nathalie; Ruiz-Fons, Francisco; Gortázar, Christian; Moreau, Emmanuelle; Bastian, Suzanne; de la Fuente, José; Malandrin, Laurence

    2014-08-26

    The diversity of Babesia species infecting cervids in parts of central and southern Spain was analyzed by collecting blood from farmed red deer (Cervus elaphus). Babesia sp. was isolated in vitro from two red deer herds in Cádiz and Ciudad Real. The number of Babesia sp. carriers differed between the two herds: 36/77 in Cádiz and 1/35 in Ciudad Real. Hyalomma lusitanicum was the most prevalent tick species identified on the Cádiz farm vegetation and on sampled animals, and is therefore a candidate vector. The molecular characteristics of 21 isolates were determined by complete (8 isolates) or partial (13 isolates) 18S rRNA gene sequencing. The sequences were highly similar (over 99.4% identity) and 6 sequence types were identified at the level of one herd only, demonstrating a rather high genetic diversity. They formed a monophyletic clade, and members of the three main sequence types shared a similar morphology and the same erythrocyte susceptibility pattern. This clade also included Babesia sp. Xinjiang isolated from sheep in China and Babesia sp. identified in giraffe in South Africa, with identities higher than 98.3% and statistically relevant phylogenetic support. None of the biological properties analyzed for both Babesia from red deer and Babesia sp. Xinjiang allowed their differentiation (ability to develop in vitro in erythrocytes from cattle and sheep, as well as in erythrocytes from different cervids, unsuccessful infection of calves). We propose the Babesia isolated from red deer as a new species named B. pecorum. Whether Babesia sp. Xinjiang and the Babesia characterized in South Africa belong to the same species is debated.

  10. Common Functional Correlates of Head-Strike Behavior in the Pachycephalosaur Stegoceras validum (Ornithischia, Dinosauria) and Combative Artiodactyls

    PubMed Central

    Snively, Eric; Theodor, Jessica M.

    2011-01-01

    Background Pachycephalosaurs were bipedal herbivorous dinosaurs with bony domes on their heads, suggestive of head-butting as seen in bighorn sheep and musk oxen. Previous biomechanical studies indicate potential for pachycephalosaur head-butting, but bone histology appears to contradict the behavior in young and old individuals. Comparing pachycephalosaurs with fighting artiodactyls tests for common correlates of head-butting in their cranial structure and mechanics. Methods/Principal Findings Computed tomographic (CT) scans and physical sectioning revealed internal cranial structure of ten artiodactyls and pachycephalosaurs Stegoceras validum and Prenocephale prenes. Finite element analyses (FEA), incorporating bone and keratin tissue types, determined cranial stress and strain from simulated head impacts. Recursive partition analysis quantified strengths of correlation between functional morphology and actual or hypothesized behavior. Strong head-strike correlates include a dome-like cephalic morphology, neurovascular canals exiting onto the cranium surface, large neck muscle attachments, and dense cortical bone above a sparse cancellous layer in line with the force of impact. The head-butting duiker Cephalophus leucogaster is the closest morphological analog to Stegoceras, with a smaller yet similarly rounded dome. Crania of the duiker, pachycephalosaurs, and bighorn sheep Ovis canadensis share stratification of thick cortical and cancellous layers. Stegoceras, Cephalophus, and musk ox crania experience lower stress and higher safety factors for a given impact force than giraffe, pronghorn, or the non-combative llama. Conclusions/Significance Anatomy, biomechanics, and statistical correlation suggest that some pachycephalosaurs were as competent at head-to-head impacts as extant analogs displaying such combat. Large-scale comparisons and recursive partitioning can greatly refine inference of behavioral capability for fossil animals. PMID:21738658

  11. Protozoan and bacterial pathogens in tick salivary glands in wild and domestic animal environments in South Africa.

    PubMed

    Berggoetz, M; Schmid, M; Ston, D; Wyss, V; Chevillon, C; Pretorius, A-M; Gern, L

    2014-03-01

    A total of 7364 ticks belonging to 13 species was collected from 64 game animals (belonging to 11 species) and from 64 livestock animals (cattle and sheep) living in close vicinity at 6 localities in 3 South African Provinces (Free State, Mpumalanga, and Limpopo). The geographic distribution of all tick species was congruent with the literature except for Haemaphysalis silacea. From each infested host, a maximum of 10 males and 10 females of each tick species were dissected to isolate the salivary glands. Salivary glands were screened for tick-borne pathogens using polymerase chain reaction followed by reverse line blotting and sequencing. This approach allowed us to evaluate the exposure of wild and domestic hosts to tick-borne pathogens in their respective environments. Among the 2117 examined ticks, 329 (15.5%), belonging to 8 species, were infected and harboured 397 infections. Among those, 57.7% were identified to species level and were assigned to 23 pathogen species of the genera Babesia, Theileria, Anaplasma, and Ehrlichia. In 3 out of 6 localities, salivary glands from ticks infesting wild ruminants displayed significantly higher infection prevalence and pathogen mean density than salivary glands from ticks infesting livestock animals. Four piroplasm species [Theileria bicornis, Babesia sp. (sable), Theileria sp. (giraffe), and Theileria sp. (kudu)] were detected for the first time in ticks. The tick species Rhipicephalus evertsi evertsi, Rhipicephalus (Boophilus) decoloratus, Hyalomma rufipes, Rhipicephalus appendiculatus, and Amblyomma hebraeum were associated with a broader pathogen range than previously known, and thus new vector-pathogen combinations are described. In addition, previously unknown coinfection patterns in tick salivary glands are reported.

  12. Seasonal diet and prey preference of the African lion in a waterhole-driven semi-arid savanna.

    PubMed

    Davidson, Zeke; Valeix, Marion; Van Kesteren, Freya; Loveridge, Andrew J; Hunt, Jane E; Murindagomo, Felix; Macdonald, David W

    2013-01-01

    Large carnivores inhabiting ecosystems with heterogeneously distributed environmental resources with strong seasonal variations frequently employ opportunistic foraging strategies, often typified by seasonal switches in diet. In semi-arid ecosystems, herbivore distribution is generally more homogeneous in the wet season, when surface water is abundant, than in the dry season when only permanent sources remain. Here, we investigate the seasonal contribution of the different herbivore species, prey preference and distribution of kills (i.e. feeding locations) of African lions in Hwange National Park, Zimbabwe, a semi-arid African savanna structured by artificial waterholes. We used data from 245 kills and 74 faecal samples. Buffalo consistently emerged as the most frequently utilised prey in all seasons by both male (56%) and female (33%) lions, contributing the most to lion dietary biomass. Jacobs' index also revealed that buffalo was the most intensively selected species throughout the year. For female lions, kudu and to a lesser extent the group "medium Bovidae" are the most important secondary prey. This study revealed seasonal patterns in secondary prey consumption by female lions partly based on prey ecology with browsers, such as giraffe and kudu, mainly consumed in the early dry season, and grazers, such as zebra and suids, contributing more to female diet in the late dry season. Further, it revealed the opportunistic hunting behaviour of lions for prey as diverse as elephants and mice, with elephants taken mostly as juveniles at the end of the dry season during droughts. Jacobs' index finally revealed a very strong preference for kills within 2 km from a waterhole for all prey species, except small antelopes, in all seasons. This suggested that surface-water resources form passive traps and contribute to the structuring of lion foraging behaviour.

  13. Testing the effects of perimeter fencing and elephant exclosures on lion predation patterns in a Kenyan wildlife conservancy.

    PubMed

    Dupuis-Desormeaux, Marc; Davidson, Zeke; Pratt, Laura; Mwololo, Mary; MacDonald, Suzanne E

    2016-01-01

    The use of fences to segregate wildlife can change predator and prey behaviour. Predators can learn to incorporate fencing into their hunting strategies and prey can learn to avoid foraging near fences. A twelve-strand electric predator-proof fence surrounds our study site. There are also porous one-strand electric fences used to create exclosures where elephant (and giraffe) cannot enter in order to protect blocs of browse vegetation for two critically endangered species, the black rhinoceros (Diceros bicornis) and the Grevy's zebra (Equus grevyi). The denser vegetation in these exclosures attracts both browsing prey and ambush predators. In this study we examined if lion predation patterns differed near the perimeter fencing and inside the elephant exclosures by mapping the location of kills. We used a spatial analysis to compare the predation patterns near the perimeter fencing and inside the exclosures to predation in the rest of the conservancy. Predation was not over-represented near the perimeter fence but the pattern of predation near the fence suggests that fences may be a contributing factor to predation success. Overall, we found that predation was over-represented inside and within 50 m of the exclosures. However, by examining individual exclosures in greater detail using a hot spot analysis, we found that only a few exclosures contained lion predation hot spots. Although some exclosures provide good hunting grounds for lions, we concluded that exclosures did not necessarily create prey-traps per se and that managers could continue to use this type of exclusionary fencing to protect stands of dense vegetation.

  14. Investigations of Allerton-type herpes virus infection in East African game animals and cattle.

    PubMed

    Plowright, W; Jessett, D M

    1971-06-01

    Neutralization tests with a strain (BA) of Allerton-type herpes virus, derived from a buffalo (Syncerus caffer) were carried out on 924 sera from 17 species of E. African game animals and on cattle sera from Tanzania (2001), Kenya (792) and Uganda (410).Buffalo populations throughout E. Africa showed a very high rate of infection, with all animals over 2 years of age serologically positive. Antibody was present in some giraffe, waterbuck and hippopotamus sera and, less frequently, in impala, eland, bushbuck and oryx. Data are provided on the titres of positive samples; the mean titre of buffalo sera increased with age.Cattle in many localities of N. Tanzania and S. Kenya showed a very high rate of infection, 85-95% of sera from animals more than 2-years old containing antibody; the titres recorded were lower than those in buffaloes. Very high infection rates were also found in Karamoja and Teso (Uganda) and also in some other areas of Kenya, whilst a considerably lower incidence of infection was detected in W. Nile Province of Uganda and in central Tanzania. Differences in infection rates may have been related to herd size and husbandry practices.It was shown that a wave of infection was probably spreading through cattle in N. Tanzania at about the same time as an outbreak of disease occurred in buffaloes and it is suggested that virus transmission may have been by biting flies.No clinical signs attributable to the virus were reported in cattle but mouth lesions similar to those recorded in buffaloes, or nasal lesions, could have passed undetected. Allerton-type virus probably produces a range of clinical syndromes in cattle, closely resembling those associated with some herpes viruses in primates but infection is seldom related in the field to either pseudo-lumpy skin disease, mammillitis or stomatitis.

  15. Spinning Like a Blue Straggler: The Population of Fast Rotating Blue Straggler Stars in ω Centauri

    NASA Astrophysics Data System (ADS)

    Mucciarelli, A.; Lovisi, L.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.; Monaco, L.

    2014-12-01

    By using high-resolution spectra acquired with FLAMES-GIRAFFE at the ESO/VLT, we measured the radial and rotational velocities for 110 blue straggler stars (BSSs) in ω Centauri, the globular cluster-like stellar system harboring the largest known BSS population. According to their radial velocities, 109 BSSs are members of the system. The rotational velocity distribution is very broad, with the bulk of BSSs spinning at less than ~40 km s-1 (in agreement with the majority of such stars observed in other globular clusters) and a long tail reaching ~200 km s-1. About 40% of the sample has ve sin i > 40 km s-1 and about 20% has ve sin i > 70 km s-1. Such a large fraction is very similar to the percentage of fast rotating BSSs observed in M4. Thus, ω Centauri is the second stellar cluster, beyond M4, with a surprisingly high population of fast spinning BSSs. We found a hint of radial behavior for a fraction of fast rotating BSSs, with a mild peak within one core radius, and a possible rise in the external regions (beyond four core radii). This may suggest that recent formation episodes of mass transfer BSSs occurred preferentially in the outskirts of ω Centauri, or that braking mechanisms able to slow down these stars are least efficient in the lowest density environments. Based on observations collected at the ESO-VLT under the programs 077.D-0696(A), 081.D-0356(A), and 089.D-0298(A).

  16. Large- and small-scale structure of the intermediate- and high-velocity clouds towards the LMC and SMC

    NASA Astrophysics Data System (ADS)

    Smoker, J. V.; Fox, A. J.; Keenan, F. P.

    2015-08-01

    We employ Ca II K and Na I D interstellar absorption-line spectroscopy of early-type stars in the Large and Small Magellanic Clouds (LMC, SMC) to investigate the large- and small-scale structure in foreground intermediate- and high-velocity clouds (I/HVCs). Data include FLAMES-GIRAFFE Ca II K observations of 403 stars in four open clusters, plus FEROS or UVES spectra of 156 stars in the LMC and SMC. The FLAMES observations are amongst the most extensive probes to date of Ca II struct