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Sample records for namibian giraffe giraffa

  1. 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. PMID:25087453

  2. 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

  3. 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. PMID:27010303

  4. 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. PMID:26667556

  5. 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. PMID:23505724

  6. 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. PMID:27593556

  7. 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. PMID:23896647

  8. 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. PMID:23595815

  9. 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

  10. 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. PMID:26104263

  11. 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. PMID:26479272

  12. 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

  13. 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. PMID:26925324

  14. 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. PMID:26584008

  15. 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. PMID:25048683

  16. 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. PMID:25314840

  17. 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. PMID:23792245

  18. 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. PMID:26353052

  19. 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. PMID:26991999

  20. 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. PMID:25678184

  1. 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. PMID:23550169

  2. 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. PMID:17939353

  3. 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

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

    PubMed

    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 13483(T) 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

  5. 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

  6. 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. PMID:24758869

  7. 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 Central

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

    2012-01-01

    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. PMID:22683547

  8. 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. PMID:27310168

  9. 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. PMID:26302156

  10. 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. PMID:23925833

  11. Subependymal glioneuronal hamartoma in the mesencephalic aqueduct of a giraffe.

    PubMed

    Koehler, Jennifer; Cox, Nancy; Passler, Thomas; Wolfe, Dwight

    2012-09-01

    A 1-day-old male giraffe calf (Giraffa camelopardalis) was submitted for necropsy examination after sustaining postnatal head trauma from the cow. In addition to the expected findings of severe cerebral edema and epidural and subarachnoid hemorrhage, there also was present an incidental finding of a subependymal glioneuronal aqueductal hamartoma. Reports of this type of congenital lesion are rare in the human literature, and the lesion has not, to the authors' knowledge, previously been reported in this or any other veterinary species. PMID:23082530

  12. 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.

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

    PubMed

    van Sittert, Sybrand J; 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

  14. 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

  15. 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)

  16. 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. PMID:27109775

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

    PubMed

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

    2015-10-01

    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

  18. 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

  19. 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.). PMID:23926765

  20. 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.

  1. 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. PMID:25527317

  2. 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. PMID:20549391

  3. 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.

  4. Namibian women and land.

    PubMed

    Andima, J J

    1994-03-01

    More than 50% of Namibia's 1.5 million inhabitants live in reserved communal areas; most of these are women who make up a third of the country's total population. Women are the main food producers, but access to land, livestock, water, and fuelwood is determined for women by marriage arrangements and settlements. In some parts of the country, women can obtain land in their own right, but they suffer from such subtle discouragements as receiving inferior land or having their stock mysteriously disappear. In some villages, a fee must be paid to a village head upon the allocation of land. This fee guarantees land tenure until the death or eviction of the person who paid the fee. In some areas, only men or widows (and sometimes divorced women) are eligible, and widows must reapply for permission to stay on their husband's land. Women also have a heavy labor burden. Since most of the men migrate to the urban areas for wage employment, the women must tend livestock and harvest and store the grain as well as run their households. Woman also may be evicted from commercial farms if their husbands die. In some areas, all property reverts to a husband's family upon his death, and the wife must return to her own relative. In some tribes, widows must leave their houses empty-handed; their sisters-in-law inherit any stored grain or clothing available. Other tribes are more liberal, and property remains with the widow. In this case, a male relative will be assigned to help the widow manage the property. Reform efforts which attempt to end such abuses by bringing common and customary law in compliance with the Namibian constitution are having an effect. The Women and Law Committee of the Law Reform and the Development Commission is working with the Customary Law Commission to involve traditional leaders in the adaptation of customary law to modern requirements which make discrimination against women unlawful. Until woman have security of land tenure, they are unwilling to invest

  5. 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.

  6. Morphology of the lingual papillae in the giraffe.

    PubMed

    Emura, Shoichi; Okumura, Toshihiko; Chen, Huayue

    2013-01-01

    We examined the dorsal lingual surfaces of an adult giraffe (giraffa camelopardalis) by scanning electron microscopy. The filiform papillae on the lingual apex consisted of slender and thick conical papillae. The connective tissue core of the filiform papilla was flower-bud-like in shape. The filiform papillae on the lingual body consisted of large conical papillae and the fungiform papillae were round in shape. The connective tissue core of the fungiform papilla was rose-like in shape. The filiform papillae on the lingual prominence consisted of more large conical papillae than that of the lingual body. The connective tissue core of the filiform papilla was trianglar in shape. The large lenticular papillae were limited on the lingual prominence. The connective tissue core of the lenticular papilla consisted of small spines. The vallate papillae were located on both sides of the posterolateral aspects. The vallate papillae were flattened-oval in shape and the papillae were surrounded by a semicircular trench. The top of the connective tissue core of the vallate papilla had a rough surface with no spines. PMID:23614981

  7. 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

  8. 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

  9. GIRAFFE Reaches towards the Stars

    NASA Astrophysics Data System (ADS)

    2002-07-01

    "First Light" of New Powerful Spectrograph at the VLT Summary The first observations of stellar spectra have just been performed with the new GIRAFFE multi-object spectrograph on the ESO Very Large Telescope (VLT) at the Paranal Observatory in Chile. This milestone event was achieved in the early morning of July 3, 2002. It signifies another important step towards the full implementation of the extremely powerful Fibre Large Array Multi-Element Spectrograph (FLAMES) , one of the main instruments for the ESO VLT. This project is co-ordinated by ESO and incorporates many complex components that have been constructed at various research institutions in Europe and Australia. The GIRAFFE spectrograph provides unique possibilities for detailed observations of the properties of individual stars located in our Milky Way galaxy ( PR 16b/02 ) as well as in other galaxies of the Local Group. PR Photo 16a/02 : A series of stellar spectra recorded by GIRAFFE during "First Light" . PR Photo 16b/02 : Details of some of these stellar spectra . FLAMES and GIRAFFE ESO PR Photo 16a/02 ESO PR Photo 16a/02 [Preview - JPEG: 756 x 400 pix - 363k] [Normal - JPEG: 1511 x 800 pix - 1.2M] ESO PR Photo 16b/02 ESO PR Photo 16b/02 [Preview - JPEG: 461 x 400 pix - 196k] [Normal - JPEG: 921 x 800 pix - 606k] Caption : PR Photo 16a/02 : "First Light" test observation with the GIRAFFE spectrograph of about 50 high-quality spectra (10 min exposure at spectral resolution 7,000) of stars in the Milky Way disk, in the early morning of July 3, 2002. The stars have magnitudes of 12 - 16 and are all of solar type. The photo shows part of the image recorded with a 2000 x 4000 pixel CCD detector at the focal plane of the spectrograph. Each stellar spectrum is seen as one vertical line - some of the absorption lines can be seen as dark horizontal features. PR Photo 16b/02 shows a small part of this image. The three strong absorption lines that are visible as horizontal, dark lines in the lower part of the

  10. 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.

  11. 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…

  12. 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. PMID:25970483

  13. 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

  14. 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. PMID:23447665

  15. 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.

  16. 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.

  17. 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 program,…

  18. 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)

  19. 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.

  20. The GIRAFFE Archive: 1D and 3D Spectra

    NASA Astrophysics Data System (ADS)

    Royer, F.; Jégouzo, I.; Tajahmady, F.; Normand, J.; Chilingarian, I.

    2013-10-01

    The GIRAFFE Archive (http://giraffe-archive.obspm.fr) contains the reduced spectra observed with the intermediate and high resolution multi-fiber spectrograph installed at VLT/UT2 (ESO). In its multi-object configuration and the different integral field unit configurations, GIRAFFE produces 1D spectra and 3D spectra. We present here the status of the archive and the different functionalities to select and download both 1D and 3D data products, as well as the present content. The two collections are available in the VO: the 1D spectra (summed in the case of integral field observations) and the 3D field observations. These latter products can be explored using the VO Paris Euro3D Client (http://voplus.obspm.fr/ chil/Euro3D).

  1. 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)

  2. 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

    2016-01-01

    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

  3. 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

  4. 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. PMID:24005251

  5. 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. PMID:26910772

  6. Nitrite oxidation in the Namibian oxygen minimum zone

    PubMed Central

    Füssel, Jessika; Lam, Phyllis; Lavik, Gaute; Jensen, Marlene M; Holtappels, Moritz; Günter, Marcel; Kuypers, Marcel MM

    2012-01-01

    Nitrite oxidation is the second step of nitrification. It is the primary source of oceanic nitrate, the predominant form of bioavailable nitrogen in the ocean. Despite its obvious importance, nitrite oxidation has rarely been investigated in marine settings. We determined nitrite oxidation rates directly in 15N-incubation experiments and compared the rates with those of nitrate reduction to nitrite, ammonia oxidation, anammox, denitrification, as well as dissimilatory nitrate/nitrite reduction to ammonium in the Namibian oxygen minimum zone (OMZ). Nitrite oxidation (⩽372 nM NO2− d−1) was detected throughout the OMZ even when in situ oxygen concentrations were low to non-detectable. Nitrite oxidation rates often exceeded ammonia oxidation rates, whereas nitrate reduction served as an alternative and significant source of nitrite. Nitrite oxidation and anammox co-occurred in these oxygen-deficient waters, suggesting that nitrite-oxidizing bacteria (NOB) likely compete with anammox bacteria for nitrite when substrate availability became low. Among all of the known NOB genera targeted via catalyzed reporter deposition fluorescence in situ hybridization, only Nitrospina and Nitrococcus were detectable in the Namibian OMZ samples investigated. These NOB were abundant throughout the OMZ and contributed up to ∼9% of total microbial community. Our combined results reveal that a considerable fraction of the recently recycled nitrogen or reduced NO3− was re-oxidized back to NO3− via nitrite oxidation, instead of being lost from the system through the anammox or denitrification pathways. PMID:22170426

  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. 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

  9. 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.

  10. 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). PMID:26021980

  11. 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. PMID:26998330

  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. Sex, love and money along the Namibian-Angolan border.

    PubMed

    Pinho, Adriana de Araujo; Sampaio, Camila Alves Machado; Monteiro, Simone Souza; Murray, Laura Rebecca; Bastos, Francisco Inácio

    2016-08-01

    In sub-Saharan Africa, young women engaged in relationships with multiple partners in order to gain material benefits play a key role in local HIV dynamics. This paper is based upon field observations and interviews with 38 young women who live along the Angolan-Namibian border. In the last 10 years, rapid urbanisation has attracted migrants in search of opportunities to do business in the region. Our findings show that sexual-affective economic networks reflect these socioeconomic changes. Women, particularly those from particular ethnic groups and/or from Namibia, with low levels of formal education and social support are often excluded from the labour market and turn to emotional-sexual male-centred networks for material and financial benefits. Men in these networks tend to be older, have higher socioeconomic status and greater geographic mobility. This 'capitalisation' of intimate relationships is material and symbolic; it enables women to acquire goods and access to services identified with an urban and globalised lifestyle. It is also emotional because relationships include affection and pleasure. Engaging in these relationships involves some social risks (bad reputation, family rejection, discrimination and violence), but maintaining ties often takes priority over safer sex and social sanctions. PMID:26950415

  14. A Water Demand Management Strategy For The Namibian Tourism Sector

    NASA Astrophysics Data System (ADS)

    Schachtschneider, K.; Winter, K.

    The arid conditions of Namibia are forcing its decision-makers to resort to new wa- ter resource management approaches, including Water Demand Management (WDM). When Namibia achieved its independence from South Africa 1990, a new opportunity arose to rewrite certain restrictive laws and policies in order to bring about redress, development and transformation. The new Water Policy is one example in which the mindset is changed from a supply to a demand oriented water management ap- proach. Legal support for WDM within the new Water Act is a critical component that will support the implementation of WDM in all economic sectors, such as agri- culture, mining and tourism. It is argued that an appropriate WDM strategy should be designed specifically for each sector, once the typical water use patterns in a sec- tor are understood and key water resource managers at all levels are identified. The Namibian tourism sector is geographically dispersed and control over its operations is compounded by the fact that it is frequently located in extremely remote areas that are arid and ecologically sensitive. In general, WDM is rarely practised, because it is not yet supported by law and there are currently no institutional arrangements to con- trol water use in this geographically dispersed industrial sector through which WDM could be enforced either through metering and/or payments. Managers of tourist en- terprises undertake most of the water management themselves, and have been identi- fied as being crucial to the implementation of WDM strategies. A study of six tourist facilities determined the willingness and motivation of these managers to undertake various WDM initiatives. The study identified three factors which appear to influence the actions of managers, namely external controls, economics and company ethics. It is recommended that a tourism sector WDM strategy should focus on these three factors in order to transform the WDM aims and objectives on the policy level into

  15. 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…

  16. 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. PMID:22137348

  17. 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

  18. 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)

  19. 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. PMID:17915649

  20. 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. PMID:23420662

  1. 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

  2. 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

  3. 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…

  4. 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.

  5. 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. PMID:26160332

  6. 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).

  7. 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.

  8. 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. PMID:21207038

  9. 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. PMID:23638372

  10. 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

  11. 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. PMID:26643090

  12. 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.

  13. A purple giraffe is faster than a purple elephant: inconsistent phonology affects determiner selection in English.

    PubMed

    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 opposing determiner forms by a noun's grammatical properties leads to slower naming latencies in a picture naming task, as does the activation of opposing forms by the interaction between a noun's gender and the phonological context. The present paper addresses the question of whether phonological context alone is sufficient to evoke competition between determiner forms. Participants produced English phrases in which a noun phrase's phonology required a determiner that was the same as or differed from the determiner required by the noun itself (e.g., apurple giraffe; an orange giraffe). Naming latencies were slower when the phrase-initial determiner differed from the determiner required by the noun in isolation than when the phrase-initial determiner matched the isolated-noun determiner. This was true both for definite and indefinite determiners. The data show that during the production of a determiner-noun phrase, nouns automatically activate the phonological forms of their determiners, which can compete with the phonological forms that are generated by an assimilation rule. PMID:19853845

  14. Molybdenum Cycling in Upwelling Sediments: An Example from Namibian Margin Sediments

    NASA Astrophysics Data System (ADS)

    Arnold, G. L.; Goldhammer, T.; Formolo, M.; Brunner, B.; Ferdelman, T.

    2008-12-01

    The paleo-redox application of molybdenum (Mo) isotopes is strongly tied to our knowledge of the modern marine Mo cycle. Elemental mass balance indicates that ~47% of the Mo supplied to the oceans is removed to deep sea sediments, leaving the remaining Mo to "near-shore" reducing sediments (1). The Black Sea is likely the best studied reducing environment with regards to Mo isotopes, yet accounts for only a small fraction of the Mo mass balance. The accumulation of Mo in continental margin sediments has been recently re-assessed and may account for a larger fraction of the marine Mo reservoir than previously thought (2). In the presence of sulfide, the molybdate anion is transformed, by the replacement of oxygen with sulfur, to particle reactive oxy-thiomolybdates (3). This is often cited as the mechanism by which Mo removal proceeds in the Black Sea where sulfide concentrations in the water are high. In contrast, in continental margin settings, the removal mechanism is poorly understood, and the extent to which sulfur cycling plays a role remains un-quantified. To better understand removal/cycling processes in a continental margin setting, where sulfide may only be present in the pore waters and not in the water column, Mo was studied in an array of marine settings off the Namibian coast. Surface sediments were collected across a transect from near-shore/high productivity to deep water/low productivity sediments. These sediments were incubated in bag experiments to study the relationship between sulfur and Mo cycling. Molybdenum concentrations in the Namibian sediments range from detrital values at the lowest productivity site to 25 ppm in surface sediments with high productivity. Preliminary results allude to a correlation between sulfate reduction rates and Mo accumulation in these sediments. Detailed studies of Mo, Mo isotopes, other trace metals, and sulfur investigations from both sediment cores and bag experiments will be presented. (1)Bertine and Turekian

  15. Complete Genome Sequence of Bovine Pestivirus Strain PG-2, a Second Member of the Tentative Pestivirus Species Giraffe.

    PubMed

    Becher, Paul; Fischer, Nicole; Grundhoff, Adam; Stalder, Hanspeter; Schweizer, Matthias; Postel, Alexander

    2014-01-01

    We report the complete genome sequence of bovine pestivirus strain PG-2. The sequence data from this virus showed that PG-2 is closely related to the giraffe pestivirus strain H138. PG-2 and H138 belong to one pestivirus species that should be considered an approved member of the genus Pestivirus. PMID:24831142

  16. 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.

  17. 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.

  18. Exaggerated trait allometry, compensation and trade-offs in the New Zealand giraffe weevil (Lasiorhynchus barbicornis).

    PubMed

    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

  19. 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. PMID:24582453

  20. 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

  1. 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. PMID:25809630

  2. 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

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

    PubMed

    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

  4. 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

  5. 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

  6. 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. PMID:25303121

  7. Morphogenesis of pestiviruses: new insights from ultrastructural studies of strain Giraffe-1.

    PubMed

    Schmeiser, Stefanie; Mast, Jan; Thiel, Heinz-Jürgen; König, Matthias

    2014-03-01

    Knowledge on the morphogenesis of pestiviruses is limited due to low virus production in infected cells. In order to localize virion morphogenesis and replication sites of pestiviruses and to examine intracellular virion transport, a cell culture model was established to facilitate ultrastructural studies. Based on results of virus growth kinetic analysis and quantification of viral RNA, pestivirus strain Giraffe-1 turned out to be a suitable candidate for studies on virion generation and export from culture cells. Using conventional transmission electron microscopy and single-tilt electron tomography, we found virions located predominately in the lumen of the endoplasmic reticulum (ER) in infected cells and were able to depict the budding process of virions at ER membranes. Colocalization of the viral core protein and the envelope glycoprotein E2 with the ER marker protein disulfide isomerase (PDI) was demonstrated by immunogold labeling of cryosections. Moreover, pestivirions could be shown in transport vesicles and the Golgi complex and during exocytosis. Interestingly, viral capsid protein and double-stranded RNA (dsRNA) were detected in multivesicular bodies (MVBs), which implies that the endosomal compartment plays a role in pestiviral replication. Significant cellular membrane alterations such as those described for members of the Flavivirus and Hepacivirus genera were not found. Based on the gained morphological data, we present a consistent model of pestivirus morphogenesis. PMID:24352462

  8. Morphogenesis of Pestiviruses: New Insights from Ultrastructural Studies of Strain Giraffe-1

    PubMed Central

    Mast, Jan; Thiel, Heinz-Jürgen; König, Matthias

    2014-01-01

    Knowledge on the morphogenesis of pestiviruses is limited due to low virus production in infected cells. In order to localize virion morphogenesis and replication sites of pestiviruses and to examine intracellular virion transport, a cell culture model was established to facilitate ultrastructural studies. Based on results of virus growth kinetic analysis and quantification of viral RNA, pestivirus strain Giraffe-1 turned out to be a suitable candidate for studies on virion generation and export from culture cells. Using conventional transmission electron microscopy and single-tilt electron tomography, we found virions located predominately in the lumen of the endoplasmic reticulum (ER) in infected cells and were able to depict the budding process of virions at ER membranes. Colocalization of the viral core protein and the envelope glycoprotein E2 with the ER marker protein disulfide isomerase (PDI) was demonstrated by immunogold labeling of cryosections. Moreover, pestivirions could be shown in transport vesicles and the Golgi complex and during exocytosis. Interestingly, viral capsid protein and double-stranded RNA (dsRNA) were detected in multivesicular bodies (MVBs), which implies that the endosomal compartment plays a role in pestiviral replication. Significant cellular membrane alterations such as those described for members of the Flavivirus and Hepacivirus genera were not found. Based on the gained morphological data, we present a consistent model of pestivirus morphogenesis. PMID:24352462

  9. 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.

  10. 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.

  11. 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. PMID:20329642

  12. 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

  13. 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

  14. Cross-sectional study assessing HIV related knowledge, attitudes and behavior in Namibian public sector employees in capital and regional settings.

    PubMed

    Kiderlen, Til R; Conteh, Michael; Roll, Stephanie; Seeling, Stefanie; Weinmann, Stefan

    2013-01-01

    The study objective was to assess the current status of HIV knowledge, attitudes and behavior (KAB) among employees of Namibian ministries. As most HIV campaigning takes place in the capital of Windhoek, an additional aim was to compare Windhoek to four regions (Hardap, Erongo, Oshana, and Caprivi). Between January and March 2011 a cross-sectional survey was conducted in two Namibian ministries, with participants selected randomly from the workforce. Data collection was based on questionnaires. 832 participants were included in the study (51.6% male). Nearly 90% of participants reported to have been tested for HIV before. Knowledge about HIV transmission ranged from 67% to 95% of correct answers, with few differences between the capital and regions. However, a knowledge gap regarding HIV transmission and prevention was seen. In particular, we found significantly lower knowledge regarding transmission from mother-to-child during pregnancy and higher rate of belief in a supernatural role in HIV transmission. In addition, despite many years of HIV prevention activities, a substantial proportion of employees had well-known HIV risk factors including multiple concurrent partnership rates (21%), intergenerational sex (19%), and lower testing rates for men (82% compared to women with 91%). PMID:24073273

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. Cross-sectional study assessing HIV-related knowledge, attitudes and behavior in the Namibian truck transport sector: Readjusting HIV prevention programs in the workplace.

    PubMed

    Kiderlen, Til R; Conteh, Michael; Roll, Stephanie; Seeling, Stefanie; Weinmann, Stefan

    2015-01-01

    The objectives of this study were to assess the current status of HIV-related knowledge, attitudes, and behavior (KAB) of employees in the private transport sector in Namibia and to compare companies with established HIV workplace program (WPPs) with those that have recently initiated the implementation of such programs. The study was designed as a cross-sectional questionnaire-based survey. Between January and March 2011, the survey was conducted in the Namibian truck transport sector in six companies of different sizes. The participants were selected randomly from the workforce. Data collection was based on a KAB questionnaire. The range of correct answers to the survey concerning the knowledge of HIV transmission was 67-95%. Twenty percent of the employees had never been tested for HIV. Additionally, risky sexual behaviors were quite prevalent and included having multiple concurrent partners and the use of sex for incentives. This study revealed that drivers and laborers were especially at risk for such behaviors. The employees of companies with established WPPs were tested for HIV more often than those of companies with new WPPs; however, aside from this difference, only minor differences were observed between the two groups. The findings of this study highlight the need for on-going HIV information and prevention campaigns that focus on the special needs of mobile and low-income workers. WPPs should be tailored accordingly and shift their focus to more practical approaches, such as voluntary counseling and testing (VCT), to increase their effectiveness. PMID:25805432

  1. 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

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

    PubMed

    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. PMID

  3. 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. PMID:23957504

  4. 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

  5. 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

  6. Dyke emplacement at the incipient Namibian margin - structural and anisotropy of magnetic susceptibility (AMS) studies in the Henties Bay - Outjo Dyke Swarm

    NASA Astrophysics Data System (ADS)

    Wiegand, Miriam; Trumbull, Robert; Greiling, Reinhard O.

    2010-05-01

    During the Cretaceous breakup of western Gondwana, the conjugate Namibian and South American margins were the site of flood basalts, mafic dyke swarms and subvolcanic intrusive complexes which make up the South Atlantic Large Igneous Province and the volcanic margin of northwestern Namibia. This contribution presents data on internal fabrics in mafic dykes (mostly subalkaline tholeiitic dolerites) from the major Henties Bay-Outjo dyke swarm (HOD) in coastal and inland NW Namibia, which are discussed in terms of magma emplacement. The HOD is some 100 km wide and extends at least 500 km from the continental margin. The dykes were emplaced in Neoproterozoic (Panafrican) Damara mobile belt, which is bounded by the Angola/Congo craton on the north and the Kalahari craton on the south. Field relations and radiometric dates indicate Early Cretaceous emplacement ages for the dykes. In coastal exposures north of the HOD, dolerite dykes are mainly coast-parallel (NNW-SSE) and syn-tectonic with normal faults that offset Etendeka lavas. Coast-parallel dykes are also common within the HOD, but the great majority of dykes strike NE-SW. We observed the latter dykes to crosscut coast-parallel ones. But the opposite relationship is also found locally. The dominant NE-SW strike of HOD indicates the influence of the Damara Belt structural grain at a regional scale, but locally the dykes commonly crosscut basement foliations and lithologic contacts. Depending on dyke thickness, which varies in the HOD from a few cm to about 50 m), the dykes are variably fine grained with chilled margins. Vesiculation is seldom observed. Typical textures are intersertal to subophitic, with plagioclase, clinopyroxene and olivine being the main mineral phases. Common minor minerals include opaque oxides and acicular apatite. Linear dykes are composed of segments, 10 m to some km in length, which are connected by transfer zones. Often a minor horizontal displacement can be observed between these segments

  7. Na-O anticorrelation and HB. VII. The chemical composition of first and second-generation stars in 15 globular clusters from GIRAFFE spectra

    NASA Astrophysics Data System (ADS)

    Carretta, E.; Bragaglia, A.; Gratton, R. G.; Lucatello, S.; Catanzaro, G.; Leone, F.; Bellazzini, M.; Claudi, R.; D'Orazi, V.; Momany, Y.; Ortolani, S.; Pancino, E.; Piotto, G.; Recio-Blanco, A.; Sabbi, E.

    2009-10-01

    We present abundances of Fe, Na, and O for 1409 red giant stars in 15 galactic globular clusters (GCs), derived from the homogeneous analysis of high-resolution FLAMES/GIRAFFE spectra. Combining the present data with results from our FLAMES/UVES spectra and from previous studies within the project, we obtained a total sample of 1958 stars in 19 clusters, the largest and most homogeneous database of this kind to date. The programme clusters cover a range in metallicity from [Fe/H] = -2.4 dex to [Fe/H] = -0.4 dex, with a wide variety of global parameters (morphology of the horizontal branch, mass, concentration, etc.). For all clusters we find the Na-O anticorrelation, the classical signature of the operation of proton-capture reactions in H-burning at high temperature in a previous generation of more massive stars that are now extinct. Using quantitative criteria (from the morphology and extension of the Na-O anticorrelation), we can define three different components of the stellar population in GCs. We separate a primordial component (P) of first-generation stars, and two components of second-generation stars, that we name intermediate (I) and extreme (E) populations from their different chemical composition. The P component is present in all clusters, and its fraction is almost constant at about one third. The I component represents the bulk of the cluster population. On the other hand, E component is not present in all clusters, and it is more conspicuous in some (but not in all) of the most massive clusters. We discuss the fractions and spatial distributions of these components in our sample and in two additional clusters (M 3 = NGC 5272 and M 13 = NGC6205) with large sets of stars analysed in the literature. We also find that the slope of the anti-correlation (defined by the minimum O and maximum Na abundances) changes from cluster-to-cluster, a change that is represented well by a bilinear relation on cluster metallicity and luminosity. This second dependence

  8. 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. PMID:22497558

  9. Crustal architecture and deep structure of the Namibian continental shelf and adjacent oceanic basins around the landfall of Walvis Ridge from wide-angle seismic and marine magnetotelluric data

    NASA Astrophysics Data System (ADS)

    Planert, L.; Behrmann, J.; Jegen, M.; Heincke, B.; Jokat, W.; Bialas, J.; Marti, A.

    2012-12-01

    The opening of the South Atlantic ocean basin resulted in voluminous magmatism on the conjugate continental margins of Africa and South America, including the formation of the Parana and Entendeka large igneous provinces (LIPs), the formation of up to 100 km wide volcanic wedges characterized by seaward dipping reflector sequences (SDRs), as well as the formation of paired hotspot tracks on the rifted African and South American plates, the Walvis Ridge and the Rio Grande Rise. Hence, the passive margins bordering the South Atlantic are today considered as type examples for models involving hotspot related continental break-up. However, the presence of volcanic features (SDRs, LIPs) appears to be limited south of the hotspot trails. The resulting segmentation of the margins offers a prime opportunity to study the magmatic signal in space and time, and investigate the interrelation with rift-related deformation. A globally significant question to be adressed here is whether magmatism is the driving force for continental break-up, or whether even rifting with abundant hotspot related magmatism is in principle in response to crustal and lithospheric stretching. In 2010/11, a combination of on-/offshore wide-angle seismic, marine magnetotelluric and on-/offshore seismological data were acquired around the landfall of Walvis Ridge at the Namibian passive continental margin. The set of experiments was designed to provide crustal velocity and conductivity information and to investigate the structure of the upper mantle. In particular, we aimed at identifying deep fault zones and variations in Moho depth, the presence of interleaved sediment layers in SDR sequences as well as magmatic intrusions and underplated material near the continent-ocean transition. The sedimentary portions down to the igneous basement were additionally constrained by coincident single-channel reflection seismic data. Here, we present preliminary results for two wide-angle seismic transects and first

  10. 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)

  11. 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

  12. Severe laminitis in multiple zoo species.

    PubMed

    Wiedner, Ellen; Holland, Jeff; Trupkiewicz, John; Uzal, Francisco

    2014-01-01

    A 10-year record review from a zoological institution in the western USA identified four cases of severe laminitis resulting in rotation and protrusion of the third phalanx through the sole. Laminitis is reported in a Masai giraffe (Giraffa camelopardalis tippelskirchi), a Sichuan takin (Budorcas taxicolor tibetana), a greater Malayan chevrotain (Tragulus napu) and a giant eland (Taurotragus derbianus). This is the first report of severe laminitis with pedal bone rotation and protrusion in multiple species of non-domestic hoofstock, and the first report of this disease in three of these species (takin, chevrotain, and giant eland). PMID:24730432

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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...

  18. Namibian prisoners describe barriers to HIV antiretroviral therapy adherence.

    PubMed

    Shalihu, Nauyele; Pretorius, Louise; van Dyk, Agnes; Vander Stoep, Ann; Hagopian, Amy

    2014-01-01

    Little is available in scholarly literature about how HIV-positive prisoners, especially in low-income countries, access antiretroviral therapy (ART) medication. We interviewed 18 prisoners at a large prison in Namibia to identify barriers to medication adherence. The lead nurse researcher was a long-standing clinic employee at the prison, which afforded her access to the population. We identified six significant barriers to adherence, including (1) the desire for privacy and anonymity in a setting where HIV is strongly stigmatized; (2) the lack of simple supports for adherence, such as availability of clocks; (3) insufficient access to food to support the toll on the body of ingesting taxing ART medications; (4) commodification of ART medication; (5) the brutality and despair in the prison setting, generally leading to discouragement and a lack of motivation to strive for optimum health; and (6) the lack of understanding about HIV, how it is transmitted, and how it is best managed. Because most prisoners eventually transition back to communitysettings when their sentences are served, investments in prison health represent important investments in public health. PMID:24499371

  19. 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)

  20. Ticks associated with the three largest wild ruminant species in southern Africa.

    PubMed

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

    2007-09-01

    The objective of this study was to assess the host status of the three largest southern African wild ruminants, namely giraffes, Giraffa camelopardalis, African buffaloes, Syncerus caffer, and eland, Taurotragus oryx for ixodid ticks. To this end recently acquired unpublished data are added here to already published findings on the tick burdens of these animals, and the total numbers and species of ticks recorded on 12 giraffes, 18 buffaloes and 36 eland are summarized and discussed. Twenty-eight ixodid tick species were recovered. All stages of development of ten species, namely Amblyomma hebraeum, Rhipicephalus (Boophilus) decoloratus, Haemaphysalis silacea, Ixodes pilosus group, Margaropus winthemi, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus glabroscutatum, Rhipicephalus maculatus and Rhipicephalus muehlensi were collected. The adults of 13 species, of which the immature stages use small mammals as hosts, namely Haemaphysalis aciculifer, Hyalomma glabrum, Hyalomma marginatum rufipes, Hyalomma truncatum, Ixodes rubicundus, Rhipicephalus capensis, Rhipicephalus exophthalmos, Rhipicephalus follis, Rhipicephalus gertrudae, Rhipicephalus lounsburyi, Rhipicephalus lunulatus, Rhipicephalus pravus group and Rhipicephalus simus, were also collected. PMID:17933365

  1. Changes in serum calcium, phosphorus, and magnesium levels in captive ruminants affected by diet manipulation.

    PubMed

    Miller, Michele; Weber, Martha; Valdes, Eduardo V; Neiffer, Donald; Fontenot, Diedre; Fleming, Gregory; Stetter, Mark

    2010-09-01

    A combination of low serum calcium (Ca), high serum phosphorus (P), and low serum magnesium (Mg) has been observed in individual captive ruminants, primarily affecting kudu (Tragelaphus strepsiceros), eland (Taurotragus oryx), nyala (Tragelaphus angasii), bongo (Tragelaphus eurycerus), and giraffe (Giraffa camelopardalis). These mineral abnormalities have been associated with chronic laminitis, acute tetany, seizures, and death. Underlying rumen disease secondary to feeding highly fermentable carbohydrates was suspected to be contributing to the mineral deficiencies, and diet changes that decreased the amount of starch fed were implemented in 2003. Serum chemistry values from before and after the diet change were compared. The most notable improvement after the diet change was a decrease in mean serum P. Statistically significant decreases in mean serum P were observed for the kudu (102.1-66.4 ppm), eland (73.3-58.4 ppm), and bongo (92.1-64.2 ppm; P < 0.05). Although not statistically significant, mean serum P levels also decreased for nyala (99.3-86.8 ppm) and giraffe (82.6-68.7 ppm). Significant increases in mean serum Mg were also observed for kudu (15.9-17.9 ppm) and eland (17.1-19.7 ppm). A trend toward increased serum Mg was also observed in nyala, bongo, and giraffe after the diet change. No significant changes in mean serum Ca were observed in any of the five species evaluated, and Ca was within normal ranges for domestic ruminants. The mean Ca:P ratio increased to greater than one in every species after the diet change, with kudu, eland, and bongo showing a statistically significant change. The results of this study indicate that the diet change had a generally positive effect on serum P and Mg levels. PMID:20945636

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

    PubMed

    Zaire, R; Notter, M; Riedel, W; 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 < 0.004) in miners compared to the unexposed controls. A threefold increase in chromosome aberrations in the miners compared to the nonexposed controls was recorded (P < 0.0001). Most remarkably, cells with multiple aberrations such as "rogue" 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. We conclude that the miners exposed to uranium are at an increased risk to acquire various degrees of genetic damage, and that the damage may be associated with an increased risk for malignant transformation. As expected, the chronic radiation injury of the hematopoietic system resulted in low neutrophil counts. Also, low hormone levels probably reflect damage to the gonadal endocrine system. PMID:9146703

  3. 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

  4. 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. PMID:26331534

  5. Predictors of Reading among Herero-English Bilingual Namibian School Children

    ERIC Educational Resources Information Center

    Veii, Kazuvire; Everatt, John

    2005-01-01

    Predictions derived from the central processing and script dependent hypotheses were assessed by measuring the reading ability of 116 Grade 2-5 Herero-English bilingual children in Namibia ranging in age from 7 to 12 and investigating possible predictors of word reading among measures of cognitive/linguistic processes. Tasks included measures of…

  6. 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.

  7. 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. PMID:23977249

  8. 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

  9. 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. PMID:23342016

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

    PubMed Central

    Zimba, Roderick F.; Likando, Gilbert N.

    2014-01-01

    Abstract 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. PMID:24814659

  11. 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

  12. 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. PMID:25162403

  13. 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. PMID:23123173

  14. 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. PMID:24814659

  15. 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). PMID:26297491

  16. The Foraging Tunnel System of the Namibian Desert Termite, Baucaliotermes hainesi

    PubMed Central

    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 gasolinepowered 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 crossconnections 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. PMID:20672982

  17. "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…

  18. 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…

  19. 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).

  20. 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. PMID:26960022

  1. 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.

  2. A study to verify a reported excess of chromosomal aberrations in blood lymphocytes of Namibian uranium miners.

    PubMed

    Lloyd, D C; Lucas, J N; Edwards, A A; Deng, W; Valente, E; Hone, P A; Moquet, J E

    2001-06-01

    This report describes a study to verify an earlier report of excess chromosomal damage in the blood lymphocytes of uranium miners. Coded blood samples from 10 miners and 10 controls were analyzed conventionally for unstable aberrations and by FISH for translocations. Conventional analysis, scoring 1000 metaphases per subject, showed no significant difference between miners and controls in the frequencies of chromosome- and chromatid-type aberrations. Investigators at two laboratories undertook FISH analyses, each scoring 4000 metaphases per subject. When the data from each laboratory were examined separately, one found slightly more translocations in the miners while the other found fewer. In neither case was the difference significant at the 95% level of confidence. Combining the data likewise showed no significant excess of damage in the miners. This applied to simple one- and two-way translocations and to cells with complex exchanges. There was no correlation between levels of translocations and total lifetime doses from occupational and/or background irradiation. A borderline significant excess of rogue cells was found in the miners. This may be a chance observation, as these rare, highly abnormal cells are considered to be unrelated to radiation exposure and are probably due to a virus. The overall conclusion is that the frequency of chromosomal damage in the miners did not exceed that in the controls. Therefore, the result of the earlier study was not confirmed. PMID:11352763

  3. 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. PMID:9231398

  4. The geochemical similarity of Oligocene and recent phosphorites from the Chiatura deposit (Georgia) and the Namibian shelf

    NASA Astrophysics Data System (ADS)

    Baturin, G. N.; Zhegallo, E. A.; Shkolnik, E. L.

    2014-12-01

    Detailed studies of the distribution of macro- and microelements in phosphorites associated with Oligocene manganese ores of the Chiatura deposit revealed their geochemical similarity to the Late Quaternary phosphorites on the recent shelf of Namibia in the Atlantic Ocean. This shows that the Chiatura nodular phosphorites were formed in the shallow-water bioproductive zone of the Oligocene basin by biogenic supply of phosphorus onto the bottom and its subsequent diagenetic concentrating similarly to the granular-nodular phosphorites on the shelf of the recent ocean. The Chiatura phosphorites were later subjected to the epigenetic impact of hydrogeological processes, which modified the initial composition of the contained rareearth elements.

  5. Bradyrhizobium kavangense sp. nov., a symbiotic nitrogen-fixing bacterium from root nodules of traditional Namibian pulses.

    PubMed

    Lasse Grönemeyer, Jann; Hurek, T; Reinhold-Hurek, Barbara

    2015-12-01

    Eight strains of symbiotic bacteria from root nodules of local races of cowpea (Vigna unguiculata) and Bambara groundnut (Vigna subterranea) grown on subsistence farmers' fields in the Kavango region, Namibia, were previously characterized and identified as a novel group within the genus Bradyrhizobium. To clarify their taxonomic status, these strains were further characterized using a polyphasic approach. In phylogenetic analysis of the 16S rRNA gene sequence the novel group was most closely related to Bradyrhizobium iriomotense EK05T and Bradyrhizobium ingae BR 10250T, and to 'Bradyrhizobium arachidis' CCBAU 051107 in the ITS sequence analysis. Phylogenetic analysis of concatenated glnII-recA-rpoB-dnaK sequences placed the strains in a lineage distinct from named species of the genus Bradyrhizobium. The species status was validated by results of DNA-DNA hybridization. Phylogenetic analysis of nifH and nodC genes placed the novel strains in a group with 'B. arachidis' CCBAU 051107. The combination of phenotypic characteristics from several tests including carbon source utilization and antibiotic resistance could be used to differentiate representative strains from recognized species of the genus Bradyrhizobium. Novel strain 14-3T induces effective nodules on Vigna subterranea, Vigna unguiculata, Arachis hypogaea and Lablab purpureus. Based on the data presented, it is concluded that the strains represent a novel species of the genus Bradyrhizobium, for which the name Bradyrhizobium kavangense sp. nov. is proposed. The type strain is 14-3T [ = DSM 100299T = LMG 28790T = NTCCM 0012T (Windhoek)]. The DNA G+C content of strain 14-3T is 63.8 mol% (Tm). PMID:26446190

  6. Upwelling Dynamics and Nitrogen Cycling on the Namibian Shelf and Slope over the last two Climatic Cycles

    NASA Astrophysics Data System (ADS)

    Pichevin, L. E.; Martinez, P.; Bertrand, P.

    2003-12-01

    The Benguela upwelling system is the world's most productive eastern boundary current. Whether local paleoproductivity was mainly supported by new or recycled nutrients is a tricky issue. Solving this question is, however, an essential prerequisite for estimates of the net CO2 pumping attributable to this upwelling through the past and, ultimately, for forecasts of the future climate changes. In this regard, the mechanisms that control the local nutrient budget and their variations with climate changes must be addressed. We interpret the δ 15N signals of three cores distributed from the upper to the lower continental slope of Namibia (25° 6S) as reflecting an interplay of changes in local nitrogen cycling and regional denitrification during the last 250 kyrs. Detrital grain-size distributions and SST records were used as proxies for wind stress and upwelling dynamics, respectively, and TOC and MAR Corg values as indicators of paleoproduction. The upper slope core displays a noisy δ 15N signal without obvious glacial-interglacial variability, whereas the lower slope cores display low δ 15N during cold periods and high δ 15N during climatic optima. This dissimilarity results from the segregation of the upwelling structure in two cells, decoupling nutrient dynamics of the shelf from those beyond the shelf-edge. We hypothesize that, for the coastal cell, denitrification and nutrient recycling change little over time, though regenerated production may be more intense during sea level high-stands. The coastal cell d15N seems insensitive to wind stress variations. Changes in nutrient availability in the shelf-edge cell waters, however, may be partly mediated by the strength and zonality of the wind, impacting off-shore productivity, though this cannot explain the full range of variability. Positive δ 15N peaks during full interglacial periods, namely stages 7.5, 5.5 and 1, are concurrent with δ 15N maxima from other upwelling systems adjoining OMZs. We suggest that, during full interglacial periods, some degree of water column denitrification occurs in the Benguela region: globally lower oxygen concentrations in intermediate waters at these times, possibily in combination with sporadic intrusions from a poleward, oxygen depleted undercurrent, led to suboxia in the OMZ.

  7. 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…

  8. It takes a giraffe to see the big picture - citizens' view on decision makers in health care rationing.

    PubMed

    Broqvist, Mari; Garpenby, Peter

    2015-03-01

    Previous studies show that citizens usually prefer physicians as decision makers for rationing in health care, while politicians are downgraded. The findings are far from clear-cut due to methodological differences, and as the results are context sensitive they cannot easily be transferred between countries. Drawing on methodological experiences from previous research, this paper aims to identify and describe different ways Swedish citizens understand and experience decision makers for rationing in health care, exclusively on the programme level. We intend to address several challenges that arise when studying citizens' views on rationing by (a) using a method that allows for reflection, (b) using the respondents' nomination of decision makers, and (c) clearly identifying the rationing level. We used phenomenography, a qualitative method for studying variations and changes in perceiving phenomena. Open-ended interviews were conducted with 14 Swedish citizens selected by standard criteria (e.g. age) and by their attitude towards rationing. The main finding was that respondents viewed politicians as more legitimate decision makers in contrast to the results in most other studies. Interestingly, physicians, politicians, and citizens were all associated with some kind of risk related to self-interest in relation to rationing. A collaborative solution for decision making was preferred where the views of different actors were considered important. The fact that politicians were seen as appropriate decision makers could be explained by several factors: the respondents' new insights about necessary trade-offs at the programme level, awareness of the importance of an overview of different health care needs, awareness about self-interest among different categories of decision-makers, including physicians, and the national context of long-term political accountability for health care in Sweden. This study points to the importance of being aware of contextual and methodological issues in relation to research on how citizens experience arrangements for rationing in health care. PMID:25638017

  9. 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. PMID:19360605

  10. 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.

  11. 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

  12. Fosmids of novel marine Planctomycetes from the Namibian and Oregon coast upwelling systems and their cross-comparison with planctomycete genomes.

    PubMed

    Woebken, Dagmar; Teeling, Hanno; Wecker, Patricia; Dumitriu, Alexandra; Kostadinov, Ivaylo; Delong, Edward F; Amann, Rudolf; Glöckner, Frank O

    2007-09-01

    Planctomycetes are widely distributed in marine environments, where they supposedly play a role in carbon recycling. To deepen our understanding about the ecology of this sparsely studied phylum six planctomycete fosmids from two marine upwelling systems were investigated and compared with all available planctomycete genomic sequences including the as yet unpublished near-complete genomes of Blastopirellula marina DSM 3645(T) and Planctomyces maris DSM 8797(T). High numbers of sulfatase genes (41-109) were found on all marine planctomycete genomes and on two fosmids (2). Furthermore, C1 metabolism genes otherwise only known from methanogenic Archaea and methylotrophic Proteobacteria were found on two fosmids and all planctomycete genomes, except for 'Candidatus Kuenenia stuttgartiensis'. Codon usage analysis indicated high expression levels for some of these genes. In addition, novel large families of planctomycete-specific paralogs with as yet unknown functions were identified, which are notably absent from the genome of 'Candidatus Kuenenia stuttgartiensis'. The high numbers of sulfatases in marine planctomycetes characterizes them as specialists for the initial breakdown of sulfatated heteropolysaccharides and indicate their importance for recycling carbon from these compounds. The almost ubiquitous presence of C1 metabolism genes among Planctomycetes together with codon usage analysis and information from the genomes suggest a general importance of these genes for Planctomycetes other than formaldehyde detoxification. The notable absence of these genes in Candidatus K. stuttgartiensis plus the surprising lack of almost any planctomycete-specific gene within this organism reveals an unexpected distinctiveness of anammox bacteria from all other Planctomycetes. PMID:18043661

  13. Rainfall influences on ungulate population abundance in the Mara-Serengeti ecosystem.

    PubMed

    Ogutu, J O; Piepho, H-P; Dublin, H T; Bhola, N; Reid, R S

    2008-07-01

    1. Rainfall is the prime climatic factor underpinning the dynamics of African savanna ungulates, but no study has analysed its influence on the abundance of these ungulates at monthly to multiannual time scales. 2. We report relationships between rainfall and changes in age- and sex-structured abundances of seven ungulate species monitored monthly for 15 years using vehicle ground counts in the Maasai Mara National Reserve, Kenya. 3. Abundance showed strong and curvilinear relationships with current and cumulative rainfall, with older topi, Damaliscus korrigum (Ogilby); warthog, Phacochoerus aethiopicus (Pallas); waterbuck, Kobus ellipsyprimnus (Ogilby); and impala, Aepyceros melampus (Lichtenstein) responding to longer lags than younger animals, portraying carryover effects of prior habitat conditions. 4. The abundances of newborn calves were best correlated with monthly rainfall averaged over the preceding 5-6 months for topi, waterbuck, warthog, and 2 months for the migratory zebra Equus burchelli (Gray), but with seasonal rainfall averaged over 2-5 years for giraffe, Giraffa camelopardalis (L.); impala; and kongoni, Alcelaphus busephalus (Pallas). The cumulative late wet-season rainfall was the best predictor of abundance for quarter- to full-grown animals for most species. Monthly rainfall exerted both negative and positive effects on the abundances of zebra, impala and waterbuck. Ignoring age, both sexes responded similarly to rainfall. 5. Births were strongly seasonal only for warthog and topi, but peaked between August and December for most species. Hence abundance was strongly seasonal for young topi and warthog and the migratory zebra. Pronounced seasonality in births for warthog and topi obliterated otherwise strong relationships between abundance and rainfall when both month and rainfall were included in the same model. Aggregated density produced relationships with rainfall similar to those for fully grown animals, emphasizing the necessity of

  14. 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).

  15. 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…

  16. The Values Manifesto Project

    ERIC Educational Resources Information Center

    Euvrard, George

    2006-01-01

    South Africa and Namibia, two countries building young democracies, face the task of transforming their public education systems to support the values articulated in their new constitutions. This article describes a project designed to incorporate these values into schools. A group of 50 Namibian teachers, who were enrolled in the author's…

  17. 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…

  18. 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.…

  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. 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…

  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. 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,…

  3. 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 Education,…

  4. 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. PMID:27262960

  5. Diamond provenance studies from 40Ar/ 39Ar dating of clinopyroxene inclusions: An example from the west coast of Namibia

    NASA Astrophysics Data System (ADS)

    Phillips, D.; Harris, J. W.

    2009-11-01

    The west coast of Namibia is host to substantive detrital diamond deposits located in onshore and offshore beach gravels, desert deflation deposits and lower Orange river terraces. The origin of the Namibian diamonds is controversial, with some studies favouring derivation from distal Cretaceous/Jurassic kimberlites on the Kaapvaal craton, and others arguing that most diamonds originated from proximal Dwyka glacial deposits (~ 300 Ma), which incorporated diamonds from older (≥ 500 Ma), pre-Karoo kimberlites. Previous studies have demonstrated that clinopyroxene inclusions extracted from their host diamonds give 40Ar/ 39Ar ages approaching the time of source kimberlite eruption. This behaviour is attributed to diffusion of argon to lattice defect sites and the diamond/inclusion interface region during mantle residence, with subsequent loss of the latter component on cleaving of the diamond to release the inclusion(s). In this study, we measured 40Ar/ 39Ar ages of extracted clinopyroxene inclusions from Namibian detrital diamonds, in order to determine potential kimberlite sources, craton erosion histories and palaeo-drainage evolution in southern Africa. 40Ar/ 39Ar step-heating data were obtained for eclogitic and peridotitic clinopyroxene inclusions from 50 Namibian diamonds. Low temperature steps produced older apparent ages than high temperature (fusion) steps, consistent with partial retention of pre-eruption argon in defect sites. With one exception, fusion steps yielded younger ages, ranging from 62 ± 30 Ma to 1441 ± 700 Ma. The majority (80%) of inclusions have fusion ages < 300 Ma, indicating that most Namibian detrital diamonds originated from post-Dwyka (< 300 Ma) kimberlites. Six inclusion aliquots (13%) produced ages unique to Cretaceous Group I kimberlites, confirming erosion of diamonds from these sources. The proportion of diamonds sourced from Group II kimberlites is uncertain, although forward modelling suggests roughly equal quantities from

  6. 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).

  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: 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).

  9. 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).

  10. 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…

  11. 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…

  12. 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).

  13. 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

  14. 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).

  15. 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).

  16. 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).

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

    PubMed

    Danowitz, Melinda; Domalski, Rebecca; Solounias, Nikos

    2015-11-01

    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: 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).

  19. 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).

  20. 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…

  1. VizieR Online Data Catalog: Iron abundances of red giants in Carina gal. (Fabrizio+, 2012)

    NASA Astrophysics Data System (ADS)

    Fabrizio, M.; Merle, T.; Thevenin, F.; Nonino, M.; Bono, G.; Stetson, P. B.; Ferraro, I.; Iannicola, G.; Monelli, M.; Walker, A. R.; Buonanno, R.; Caputo, F.; Corsi, E.; Dall'Ora, M.; Degl'Innocenti, S.; Francois, P.; Gilmozzi, R.; Marconi, M.; Pitrinferni, A.; Prada Moroni, P. G.; Primas, F.; Pulone, L.; Ripepi, V.; Romaniello, M.

    2013-03-01

    The high-resolution spectra for Carina RGs adopted in this investigation were retrieved from the ESO Science Archive. We selected spectra from four different ESO/VLT observing programs collected with either UVES (slit mode, nine RGs) or FLAMES/GIRAFFE-UVES (multifiber mode, 80 RGs). (2 data files).

  2. 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…

  3. Abundance analysis of B, A and F dwarfs in the M6 open cluster: Spectrum synthesis method

    NASA Astrophysics Data System (ADS)

    Kiliçoğlu, T.; Monier, R.; Fossati, L.

    2012-12-01

    The chemical abundances of 10 stars in the M6 open cluster (˜100 Myr) were derived using spectrum synthesis. The stars were observed using the FLAMES/GIRAFFE spectrograph. We found star-to-star variations in abundances for A type stars. General enrichment of Si, Cr, and Y were obtained for the cluster.

  4. VizieR Online Data Catalog: Horizontal branch stars in NGC 1851 (Gratton+, 2012)

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    We acquired spectra for 35 stars on the BHB, 1 RR Lyrae variable, 57 stars on the RHB, and 13 on the lower RGB (luminosity below the bump) of NGC 1851 using the GIRAFFE fibre-fed spectrograph at VLT . (3 data files).

  5. VizieR Online Data Catalog: Horizontal branch stars in 47 Tuc and M5 (Gratton+, 2013)

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    Tables with basic data and abundances for 110 HB stars in 47 Tuc and 92 Horizontal-Branch (HB) stars in M5. The observations were made with the GIRAFFE fibre-fed spectrograph at the VLT in March 2011 (47 Tuc) and June 2011 (M5). (5 data files).

  6. 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…

  7. 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. PMID:19901377

  8. Complete genome and molecular epidemiological data infer the maintenance of rabies among kudu (Tragelaphus strepsiceros) in Namibia.

    PubMed

    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

  9. 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

  10. 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

  11. 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).

  12. 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).

  13. 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).

  14. Chromosome conservation among the advanced pecorans and determination of the primitive bovid karyotype.

    PubMed

    Gallagher, D S; Derr, J N; Womack, J E

    1994-01-01

    Extensive monobrachial QFH-band homologies were found among cattle (Bovidae), pronghorn (Antilocapridae), Masai giraffe (Giraffidae), and mule and whitetail deer (Cervidae). The deer species had identical karyotypes (2n = 70, NAA = 70). Interfamily comparisons demonstrated that cattle (2n = 60, NAA = 58) and pronghorn (2n = 58, NAA = 60) were karyotypically the most similar. The giraffe possessed a 2n = 30, NAA = 54, and differed from the other artiodactyls by having a preponderance of biarmed autosomes. The primarily acrocentric deer karyotypes showed several chromosome arm disruptions relative to the other species. Comparative cytogenetic data among the advanced pecorans strongly suggest that the 2n = 60, NAA = 58 karyotype found in several species of the tribe Bovini is probably near the primitive condition for the Bovidae. However, the ancestral conditions of the sex chromosomes within the Bovidae and among the advanced pecorans remain in question. PMID:8014460

  15. 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.

  16. 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).

  17. 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.

  18. 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).

  19. 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. PMID:18788202

  20. 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".

  1. Genetic markers reveal a gradient of hybridization between cape hakes (Merluccius capensis and Merluccius paradoxus) in their sympatric geographic distribution

    NASA Astrophysics Data System (ADS)

    Miralles, Laura; Machado-Schiaffino, Gonzalo; Garcia-Vazquez, Eva

    2014-02-01

    The cape hakes Merluccius capensis and Merluccius paradoxus are important fishing resources for African countries such as Namibia and South Africa. In this study we have genetically analyzed adult samples from the overlapping distribution of these species. Eight microsatellite loci, the nuclear 5S rDNA locus and the Cytochrome Oxidase subunit I (COI) gene were employed as molecular markers. A North-South gradient of interspecific hybridization was found, with discordant mitochondrial and nuclear genotypes at the northernmost edge of M. paradoxus distribution. These results suggest intense introgression in North Benguela off the Namibian coast. Independent hake stock assessment is recommended in this region for sustainable management of this valuable resource.

  2. Ammonia-oxidizing Bacteria of the Nitrosospira cluster 1 dominate over ammonia-oxidizing Archaea in oligotrophic surface sediments near the South Atlantic Gyre.

    PubMed

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

    2015-06-01

    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 Nitrososphaera and Nitrosopumilus clusters in the upwelling region. AOB almost exclusively belonged to the Nitrosospira 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

  3. 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.

  4. 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.

  5. Early-type objects in NGC 6611 and the Eagle Nebula

    NASA Astrophysics Data System (ADS)

    Martayan, C.; Floquet, M.; Hubert, A. M.; Neiner, C.; Frémat, Y.; Baade, D.; Fabregat, J.

    2008-10-01

    Aims: An important question about Be stars is whether they are born as such or whether they have become Be stars during their evolution. It is necessary to observe young clusters to answer this question. Methods: To this end, observations of stars in NGC 6611 and the star-formation region of Eagle Nebula were carried out with the ESO-WFI in slitless spectroscopic mode and at the VLT-GIRAFFE (R ≃ 6400-17 000). The targets for the GIRAFFE observations were pre-selected from the literature and our catalogue of emission-line stars based on the WFI study. GIRAFFE observations allowed us to study the population of the early-type stars accurately both with and without emission lines. For this study, we determined the fundamental parameters of OBA stars thanks to the GIRFIT code. We also studied the status of the objects (main sequence or pre-main sequence stars) by using IR data, membership probabilities, and location in HR diagrams. Results: The nature of the early-type stars with emission-line stars in NGC 6611 and its surrounding environment is derived. The slitless observations with the WFI clearly indicate a small number of emission-line stars in M16. We observed with GIRAFFE 101 OBA stars, among them 9 are emission-line stars with circumstellar emission in Hα. We found that W080 could be a new He-strong star, like W601. W301 is a possible classical Be star, W503 is a mass-transfer eclipsing binary with an accretion disk, and the other ones are possible Herbig Ae/Be stars. We also found that the rotational velocities of main sequence B stars are 18% lower than those of pre-main sequence B stars, in good agreement with theory about the evolution of rotational velocities. Combining adaptive optics, IR data, spectroscopy, and radial velocity indications, we found that 27% of the B-type stars are binaries. We also redetermined the age of NGC 6611 found equal to 1.2-1.8 Myears, in good agreement with the most recent determinations.

  6. 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).

  7. 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

  8. 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).

  9. 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.

  10. 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.

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Drosophila myogenesis.

    PubMed

    Bothe, Ingo; Baylies, Mary K

    2016-09-12

    The skeletal muscle system is the largest organ in motile animals, constituting between 35 and 55% of the human body mass, and up to 75% of the body mass in flying organisms like Drosophila. The flight muscles alone in flying insects comprise up to 65% of total body mass. Not only is the musculature the largest organ system, it is also exquisitely complex, with single muscles existing in different shapes and sizes. These different morphologies allow for such different functions as the high-frequency beating of a wing in a hummingbird, the dilation of the pupil in a human eye, or the maintenance of posture in a giraffe's neck. PMID:27623256

  17. Optimizing the neonatal thermal environment.

    PubMed

    Sherman, Tami Irwin; Greenspan, Jay S; St Clair, Nancy; Touch, Suzanne M; Shaffer, Thomas H

    2006-01-01

    Devices used to maintain thermal stability in preterm infants have advanced over time from the first incubator reported by Jean-Louis-Paul Denuce in 1857 to the latest Versalet Incuwarmer and Giraffe Omnibed devices today. Optimizing the thermal environment has proven significant for improving the chances of survival for small infants. Understanding the basic physiologic principles and current methodology of thermoregulation is important in the clinical care of these tiny infants. This article highlights principles of thermoregulation and the technologic advances that provide thermal support to our vulnerable PMID:16913236

  18. 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

  19. Chemical abundances of A-type dwarfs in the young open cluster M6

    NASA Astrophysics Data System (ADS)

    Kílíçoǧlu, T.; Monier, R.; Fossati, L.

    2011-12-01

    Elemental abundance analysis of five members in the open cluster M6 (age ˜90 myr) were performed using FLAMES-GIRAFFE spectrograph mounted on 8-meter class VLT telescopes. The abundances of 14 chemical elements were derived. Johnson and Geneva photometric systems, hydrogen line profile fittings, and ionization equilibrium were used to derive the atmospheric parameters of the stars. Synthetic spectra were compared to the observed spectra to derive chemical abundances. The abundance analysis of these five members shows that these stars have an enhancement (or solar composition) of metals in general, with some exceptions. C, O, Ca, Sc, Ni, Y, and Ba exhibit the largest star-to-star abundance variations.

  20. 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

  1. 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. PMID:15617668

  2. 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. PMID:26345258

  3. 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. PMID:26050572

  4. 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. PMID:26087320

  5. Metrical expectations from preceding prosody influence perception of lexical stress.

    PubMed

    Brown, Meredith; Salverda, Anne Pier; Dilley, Laura C; Tanenhaus, Michael K

    2015-04-01

    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 online probabilistic inferences about the sources of acoustic-phonetic variation during spoken-word recognition. PMID:25621583

  6. The Rotation of Subpopulations in ω Centauri

    NASA Astrophysics Data System (ADS)

    Pancino, E.; Galfo, A.; Ferraro, F. R.; Bellazzini, M.

    2007-06-01

    We present the first result of the Ital-FLAMES survey of red giant branch (RGB) stars in ω Cen. Radial velocities with a precision of ~0.5 km s-1 are presented for 650 members of ω Cen observed with FLAMES-GIRAFFE at the Very Large Telescope. We found that stars belonging to the metal-poor (RGB-MP), metal-intermediate (RGB-MInt), and metal-rich (RGB-a) subpopulations of ω Cen are all compatible with having the same rotational pattern. Our results appear to contradict past findings by Norris et al., who could not detect any rotational signature for metal-rich stars. The slightly higher precision of the present measurements and the much larger sample size, especially for the stars richer in metals, appear as the most likely explanations for this discrepancy. The result presented here weakens the body of evidence in favor of a merger event in the past history of ω Cen. Based on data obtained with the Giraffe-FLAMES facility of ESO Very Large Telescope during the Ital-FLAMES GTO program 71.D-0217(A). Also based on data from the VALD and GEISA databases.

  7. 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

  8. 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).

  9. 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

  10. 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.

  11. 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

  12. Effects of Culture and the Urban Environment on the Development of the Ebbinghaus Illusion.

    PubMed

    Bremner, Andrew J; Doherty, Martin J; Caparos, Serge; de Fockert, Jan; Linnell, Karina J; Davidoff, Jules

    2016-05-01

    The development of visual context effects in the Ebbinghaus illusion in the United Kingdom and in remote and urban Namibians (UN) was investigated (N = 336). Remote traditional Himba children showed no illusion up until 9-10 years, whereas UK children showed a robust illusion from 7 to 8 years of age. Greater illusion in UK than in traditional Himba children was stable from 9 to 10 years to adulthood. A lesser illusion was seen in remote traditional Himba children than in UN children growing up in the nearest town to the traditional Himba villages across age groups. We conclude that cross-cultural differences in perceptual biases to process visual context emerge in early childhood and are influenced by the urban environment. PMID:27059268

  13. The Search Finds an End: Colpodidiids Belong to the Class Nassophorea (Ciliophora)

    PubMed Central

    BREINER, HANS-WERNER; FOISSNER, WILHELM; STOECK, THORSTEN

    2010-01-01

    At its discovery in 1982, the ciliate genus Colpodidium was assigned to the Class Colpodea. Redescriptions of the type species Colpodidium caudatum caused the establishment of a new family (Colpodidiidae). Based on ontogenetic data, eventually a new order—Colpodidiida—was established and hypothesized to belong to the Class Nassophorea. Despite a remarkable increase in the number of colpodidiid species, no sequence data were available to confirm or reject either class assignment or to assess the phylogenetic validity of the Colpodidiidae and the Colpodidiida. We here retrieved and phylogenetically analyzed the SSrDNA sequences of C. caudatum from a Namibian soil and an as-yet undescribed colpodidiid ciliate from the Chobe River floodplain, Botswana. Bayesian inference methods and evolutionary distance analyses confirmed the assignment of these taxa to the class Nassophorea. PMID:18318862

  14. Gradual regime shifts in fairy circles.

    PubMed

    Zelnik, Yuval R; Meron, Ehud; Bel, Golan

    2015-10-01

    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

  15. 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. PMID:21238953

  16. Dispelling "heterosexual African AIDS" in Namibia: same-sex sexuality in the township of Katutura.

    PubMed

    Lorway, Robert

    2006-01-01

    This paper questions international public health theories that characterize AIDS in Africa as an unambiguous heterosexual epidemic. It does so by describing the daily sexual lives of a community of Namibian youth who engage in same-sex sexual practices. The author outlines how the ongoing vilification of "homosexuals" by ruling State officials serves as a stigmatizing backdrop against which young people experience and practice their sexuality. Drawing upon 20 months of ethnographic research, the paper discusses the HIV sexual risk perceptions and practices of young men, highlighting the complexities in sexual subjectivity that form within the cultural politics of competing masculinities, state-sponsored anti-homosexual rhetoric and transnational queer rights protest. Bounded and monolithic notions of gender and sexual identity do not lend themselves to HIV risk and vulnerability analysis in this community. PMID:16923647

  17. Cross-cultural recognition of basic emotions through nonverbal emotional vocalizations

    PubMed Central

    Sauter, Disa A.; Eisner, Frank; Ekman, Paul; Scott, Sophie K.

    2010-01-01

    Emotional signals are crucial for sharing important information, with conspecifics, for example, to warn humans of danger. Humans use a range of different cues to communicate to others how they feel, including facial, vocal, and gestural signals. We examined the recognition of nonverbal emotional vocalizations, such as screams and laughs, across two dramatically different cultural groups. Western participants were compared to individuals from remote, culturally isolated Namibian villages. Vocalizations communicating the so-called “basic emotions” (anger, disgust, fear, joy, sadness, and surprise) were bidirectionally recognized. In contrast, a set of additional emotions was only recognized within, but not across, cultural boundaries. Our findings indicate that a number of primarily negative emotions have vocalizations that can be recognized across cultures, while most positive emotions are communicated with culture-specific signals. PMID:20133790

  18. 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.

  19. Understanding long-term (1982-2013) multi-decadal change in the equatorial and subtropical South Atlantic climate

    NASA Astrophysics Data System (ADS)

    Vizy, Edward K.; Cook, Kerry H.

    2016-04-01

    High-resolution observations along with atmospheric and oceanic reanalyses are diagnosed to understand how and why southeastern Atlantic SSTs have changed over the 1982-2013 period. Multiple datasets are used to evaluate confidence. Results indicate significant SST warming trends (0.5-1.5 K per 32-years) along the Guinean and Angolan/Namibian Coasts, and a cooling trend (-0.10 to -0.60 K per 32-years) over the subtropical South Atlantic between 18°S and 28°S. SST trends are shown to vary over the annual cycle with the greatest changes occurring during November-January. Analysis of the ocean surface heat balance reveals that the austral summer SST warming trend along the Angolan/Namibian Coast is associated with an increase in the net downward atmospheric heat flux. In addition, there is a decrease in coastal upwelling due to circulation changes related to a poleward shift of the South Atlantic subtropical anticyclone and an intensification of the southwestern African thermal low. The cooling trend over the subtropical South Atlantic is also associated with the poleward shift of the South Atlantic anticyclone, as stronger surface winds enhance latent heat loss from the ocean over this region. Positive SST trends along the Guinean coast are found to be primarily associated with changes internal to the ocean, specifically, reduced coastal upwelling, diffusion, and enhanced horizontal transport of warmer water. These results highlight the need to better understand South Atlantic subtropical anticyclone and the continental thermal low interactions and their implications for present day climate variability and future climate change.

  20. 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.

  1. Discovery of fairy circles in Australia supports self-organization theory.

    PubMed

    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

    2016-03-29

    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

  2. "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

  3. 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

  4. 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

  5. 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.

  6. 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. PMID:25409172

  7. 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.

  8. 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).

  9. 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).

  10. 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.

  11. 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.

  12. 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).

  13. 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.

  14. 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).

  15. 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.

  16. 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).

  17. 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. PMID:23684846

  18. 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)

  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. 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.

  1. 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).

  2. Symmetry breaking and adaptation: evidence from a 'toy model' of a virus.

    PubMed

    Vargas, J M; Stephens, C R; Waelbroeck, H; Zertuche, F

    1999-07-01

    We argue that an induced breaking of the genetic synonym symmetry due to the action of genetic operators such as mutation can enhance the adaptability of a species to changes in the environment. In the case of a virus, the claim is that the codon bias in the neutralization epitope improves the virus' ability to generate mutants that evade the induced immune response. We support our claim with a simple 'toy model' of a viral epitope evolving in competition with the immune system. The effective selective advantage of a higher mutability leads to a dominance of codons that favor non-synonymous mutations. As further evidence we present a simple model for a genetic regulatory network that leads to adaptive evolution in a population of giraffes by means of an induced symmetry breaking rather than through any direct selective advantage. PMID:10426468

  3. The AMBRE Project: Stellar Parameterisation of ESO Archived Spectra

    NASA Astrophysics Data System (ADS)

    de Laverny, P.; Recio-Blanco, A.; Worley, C. C.; De Pascale, M.; Hill, V.; Bijaoui, A.

    2013-09-01

    AMBRE is a Galactic archaeology project set up by ESO and the Observatoire de la Côte d'Azur in order to determine the stellar atmospheric parameters for the archived spectra from the ESO spectrographs FEROS, HARPS, UVES and GIRAFFE. A total of about 230000 spectra have now been homogeneously analysed and, for most (i.e., the slow-rotating FGKM-type stars), parameterised by their effective temperatures, surface gravities, global metallicities, α-element to iron abundance ratios and radial velocities. The determination of the stellar parameters is carried out using a pipeline that has been specifically developed for AMBRE. This pipeline is based on the MATISSE algorithm initially developed for the analysis of the Gaia Radial Velocity Spectrometer data.

  4. Evaluation of wild herbivore faeces from South Africa as a potential source of hydrolytically active microorganisms.

    PubMed

    Ndlela, Luyanda L; Schmidt, Stefan

    2016-01-01

    This study assessed faecal matter from three indigenous South African herbivores-zebra, giraffe and impala-as a potential source for hydrolytically active aerobic and facultatively anaerobic bacteria. Herbivore droppings were collected freshly in a local nature reserve in Pietermaritzburg, South Africa. Soil samples adjacent to faecal collection sites and faeces from a domestic herbivore, the Nguni cow, were included as controls. Hydrolase and dehydrogenase activity in faecal matter and soil samples were measured by the fluorescein diacetate and the triphenyltetrazolium chloride assay. Viable counts and counts for amylase, cellulase, esterase and protease producers were established using plate count agar and solid media containing cellulose, skim milk, starch and Tween 80. Zebra droppings produced the highest hydrolase and dehydrogenase activity. Faecal matter of the three indigenous herbivores generally produced higher hydrolytic activity than Nguni cow faeces and soil controls, thereby confirming that these materials are potential targets for hydrolytic enzyme mining. PMID:26900540

  5. Sperm Preservation by Freeze-Drying for the Conservation of Wild Animals

    PubMed Central

    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. PMID:25409172

  6. Chemical Analysis of Fornax dwarf spheroidal with VLT/FLAMES

    NASA Astrophysics Data System (ADS)

    Letarte, B.; Hill, V.; Tolstoy, E.

    The Fornax dSph is a nearby dwarf spheroidal galaxy with five globular clusters and a complex star formation history. It is one of the most massive dwarf spheroidal galaxies in the Local Group. Using the FLAMES/GIRAFFE spectrograph on the VLT, we have obtained high resolution (R˜20 000) spectra for 80 Red Giant Branch stars in the central 25' of the Fornax dSph. We present abundance ratios for some of the elements we have in our analysis, including alpha (Mg and Ca), iron-peak (Fe and Ni) and heavy (Y, Ba, Eu) elements. We compare our results with the Milky Way (MW) and our recent VLT/UVES abundance determinations of nine individual stars in Fornax globular clusters.

  7. Chemical abundances in the Galactic bulge

    NASA Astrophysics Data System (ADS)

    Zoccali, M.; Lecureur, A.; Hill, V.; Barbuy, B.; Renzini, A.; Minniti, D.; Gómez, A.; Ortolani, S.

    We spectroscopically characterize the Galactic Bulge to infer its star formation timescale, compared to the other Galactic components, through the chemical signature on its individual stars. O, Na, Mg, Al were obtained for 50 K giants in four fields towards the Galactic bulge from UVES spectra (R=45,000), while Fe was measured in more than 400 stars with a slightly low resolution (R=20,000) and the GIRAFFE spectrograph at VLT. Oxygen and Magnesium show a well defined trend with [Fe/H], with abundances larger than those measured in both thin and thick disk stars, supporting a scenario in which the bulge formed before and more rapidly than the disk. On the other hand the iron distribution peaks at solar metallicity and it is slightly narrower than that measured in previous works. Part of the present results have been published by \\citet{Zoccali06} and \\citet{Lecureur07}, and part will be discussed in forthcoming papers.

  8. VizieR Online Data Catalog: Hot HB stars in ω Cen (Moehler+, 2011)

    NASA Astrophysics Data System (ADS)

    Moehler, S.; Dreizler, S.; Lanz, T.; Bono, G.; Sweigart, A. V.; Calamida, A.; Nonino, M.

    2011-05-01

    Moderately high resolution spectra of hot HB stars in the globular cluster omega Cen were analysed for radial velocity variations, atmospheric parameters, and abundances using LTE and non-LTE model atmospheres. The spectroscopic data were obtained in 2005 (4 observations) and in 2006 (5 observations) in Service Mode using the MEDUSA mode of the multi-object fiber spectrograph FLAMES + GIRAFFE on the UT2 Telescope of the VLT. We used the low spectroscopic resolution mode with the spectral range 3964Å-4567Å (LR2, R=6400) and observed spectra for a total of 109 blue hook and canonical blue HB/EHB star candidates (see Table 1) and for 17 sky background positions. Each observation had an exposure time of 2550s to keep the total execution time of the observing block shorter than one hour. (3 data files).

  9. 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

  10. 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.

  11. 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

  12. Terzan 8: a Sagittarius-flavoured globular cluster

    NASA Astrophysics Data System (ADS)

    Carretta, E.; Bragaglia, A.; Gratton, R. G.; D'Orazi, V.; Lucatello, S.; Sollima, A.

    2014-01-01

    Massive globular clusters (GCs) contain at least two generations of stars with slightly different ages and clearly distinct light element abundances. The Na-O anticorrelation is the best studied chemical signature of multiple stellar generations. Instead, low-mass clusters usually appear to be chemically homogeneous. We are investigating low-mass GCs to understand what the lower mass limit is where multiple populations can form, mainly using the Na and O abundance distribution. We used VLT/FLAMES spectra of giants in the low-mass, metal-poor GC Terzan 8 that belongs to the Sagittarius dwarf galaxy to determine abundances of Fe, O, Na, α-, Fe-peak, and neutron-capture elements in six stars observed with UVES and 14 observed with GIRAFFE. The average metallicity is [Fe/H] = -2.27 ± 0.03 (rms = 0.08), based on the six high-resolution UVES spectra. Only one star, observed with GIRAFFE, shows an enhanced abundance of Na and we tentatively assign it to the second generation. In this cluster, unlike what happens in more massive GCs, the second generation seems to represent at most a minority fraction. We discuss the implications of our findings, comparing Terzan 8 with the other Sgr dSph GCs, and to GCs and field stars in the Large Magellanic Cloud, Fornax, and in other dwarfs galaxies. Based on observations collected at ESO telescopes under programme 087.B-0086Tables 2, 3, 7-10 are available in electronic form at http://www.aanda.orgFull Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/561/A87

  13. 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.

  14. 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

  15. 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

  16. Namibia [South-West Africa].

    PubMed

    1983-01-01

    Namibia, a country of 1,051,700 inhabitants of whom 85.6% are blacks of diverse ethnic and linguistic origins, 7.5% are white, and the rest are of mixed ancestry, has been illegally administered by South Africa since 1966, when a League of Nations mandate was revoked by the UN. The Namibian Desert was a barrier to European expansion until the late 18th century, when the area came under German and British influence. Efforts to bring about an orderly and peaceful transition to independent status are hampered at present by the lack of parallel progress toward withdrawal of Cuban combat forces from Angola. Beginning in 1980, considerable executive power was transferred from the administrator general appointed by the South African Government to an interim 3-tier system of elected representatives dividing responsibility between central, ethnic, and local authorities. The judicial structure has separate overlapping systems for whites, westernized blacks and coloreds and for indigenous blacks. Namibian society is highly politicized, with 4 white and about 40 nonwhite political groups. The South West Africa People's Organization (SWAPO) remains an active party inside Namibia despite simultaneous detention of its entire leadership in 1979 by the South African Government. Namibia's economy is dual, with a modern market sector of mining, ranching and fishing producing most of the wealth and a traditional subsistence sector supporting most of the labor force. About 60% of the work force of 500,000 in 1981 worked in agriculture, 19% in industry and commerce, 6% in mining, 8% in services, and 7% in government. Namibia's gross domestic product in 1980 was $1.712 billion, representing an average growth rate of 2.5% from 1970-80. However, real growth since 1978 has been negative because of persistent drought, political uncertainty, low demand for mineral products, and previous overfishing. Namibia has no separate representation in any international body. The country may have the

  17. 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.

  18. Lithostratigraphy and depositional environments in the Waterberg-Erongo area, central Namibia, and correlation with the main Karoo Basin, South Africa

    NASA Astrophysics Data System (ADS)

    Holzförster, Frank; Stollhofen, Harald; Stanistreet, Ian G.

    1999-07-01

    The dissected landscape of the Waterberg-Erongo area, central Namibia, exposes Karoo-equivalent strata deposited in basins that occur throughout sub-Saharan Africa. Although many are of economic interest, including coal-bearing strata, their depositional history is not well understood. This study of the Waterberg-Erongo area provides detailed lithostratigraphical data, which suggest sedimentation from the late Early Triassic to the Early Jurassic in a fault-bounded depository. Subsidence and sediment supply were controlled predominantly by the northeast-southwest trending Waterberg-Omaruru Fault Zone, which defines the northwestern margin of the depository. Facies development and thickness distribution of the Karoo strata in the Waterberg-Erongo area, perhaps the most continuous of any of the Karoo basins, indicate a northeastwardly-migrating depocentre alongside that fault, in response to major extensional movements in the early pre-South Atlantic rift zone. Periodic fault movements repeatedly caused basinward progradation of the alluvial facies, which are reflected by stacked fining-upward cycles in the lithological record. On a broader scale, the results of this study suggest that the northward propagation of the rift zone between Southern Africa and South America, was partially accommodated by transfer lineaments. Local depocentres developed along these lineaments, such as those in the Waterberg-Erongo area, with localised enhanced subsidence greater than that revealed in other Namibian onshore exposures, dominated by the rifting itself.

  19. 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

  20. 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. PMID:11948678

  1. Economic and demographic consequences of AIDS in Namibia: rapid assessment of the costs.

    PubMed

    Ojo, K; Delaney, M

    1997-01-01

    Recent announcements by the Government of Namibia to provide financial support to people living with AIDS (and their family members) have received considerable media attention. However, given the fact that government budgets are already stretched, and the need for resources to devote the prevention efforts remains, there is an urgent need to assign some values to the support the government is considering within the context of an explosive epidemic. It is against this background that this study attempts to provide a rapid assessment of the economic costs of HIV/AIDS in Namibia over the next 5 years of the First National Development Plan. The estimates include the direct and indirect costs. The direct costs are costs to the economy for inpatient and outpatient medical services, as well as the costs of support payments to people living with AIDS, their families and children orphaned by AIDS. Government and donor expenditure on national prevention and control efforts are also included. The study concludes that no sector of the Namibian economy will escape the impact of AIDS. The epidemic will definitely tax hospital, public health, private and community resources, and these substantial burdens underscore the need for coordinated long-term planning. PMID:10177418

  2. 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.

  3. Sediment volume in the north polar sand seas of Mars

    SciTech Connect

    Lancaster, N.; Greeley, R. )

    1990-07-10

    Data from studies of the cross-sectional area of terrestrial transverse dunes have been combined with maps of dune morphometry derived from Viking orbiter images to generate new estimates of sediment thickness and dune sediment volume in the north polar sand seas of Mars. A relationship between dune spacing and equivalent sediment thickness (EST) was developed from field data on Namibian and North American dunes and was applied to data on dune spacing and dune cover measured on Viking orbiter images to generate maps of dune sediment thickness for Martian north polar sand seas. There are four major sand seas in the north polar region of Mars, covering an area of 6.8 x 10{sup 5} km{sup 2}. Equivalent sediment thickness ranges between 0.5 and 6.1 m with a mean of 1.8 m. The sand seas contain a total of 1158 km{sup 3} of dune sediment, which may have been derived by erosion of polar layered deposits and concentrated in its present location by winds that change direction seasonally.

  4. 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.

  5. Seasonal and interannual phytoplankton dynamics and forcing mechanisms in the Northern Benguela upwelling system

    NASA Astrophysics Data System (ADS)

    Louw, Deon C.; van der Plas, Anja K.; Mohrholz, Volker; Wasmund, Norbert; Junker, Tim; Eggert, Anja

    2016-05-01

    Seasonal phytoplankton blooms are one of the key features of the productive northern Benguela upwelling system (nBUS), however they are not well described thus far. In this study twelve years (2000-2012) of in situ chlorophyll-a data from a monitoring transect off the Namibian coast were analysed to assess the long-term and seasonal variability in chlorophyll-a as a measure of phytoplankton biomass and the occurrence of phytoplankton blooms. On the shelf, low chlorophyll-a concentrations were identified in 2001/2002, 2005/2006, and 2011/2012. The concentrations on the shelf were highest in 2008/2009 and 2010/2011. Major phytoplankton blooms defined at chlorophyll-a concentrations > 18 mg m- 3 occurred in five of the 12 years (2002/2003, 2004/2005, 2008/2009, 2009/2010 and 2010/2011) while minor blooms (> 13 mg m- 3) occurred in almost every year. The calculated climatology of the chlorophyll-a time series revealed a clear seasonality. Three chlorophyll-a maxima typically develop inshore over the year: an austral winter peak (August), an early austral summer peak (December) and a late summer/autumn peak (April). The analysis of synoptic hydrographic, nutrient and wind data revealed three different forcing mechanisms that all initiate an influx of nutrients into the surface mixed layer.

  6. 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.

  7. Microbial sequestration of phosphorus in anoxic upwelling sediments

    NASA Astrophysics Data System (ADS)

    Goldhammer, Tobias; Brüchert, Volker; Ferdelman, Timothy G.; Zabel, Matthias

    2010-08-01

    Phosphorus is an essential nutrient for life. In the ocean, phosphorus burial regulates marine primary production. Phosphorus is removed from the ocean by sedimentation of organic matter, and the subsequent conversion of organic phosphorus to phosphate minerals such as apatite, and ultimately phosphorite deposits. Bacteria are thought to mediate these processes, but the mechanism of sequestration has remained unclear. Here, we present results from laboratory incubations in which we labelled organic-rich sediments from the Benguela upwelling system, Namibia, with a 33P-radiotracer, and tracked the fate of the phosphorus. We show that under both anoxic and oxic conditions, large sulphide-oxidizing bacteria accumulate 33P in their cells, and catalyse the nearly instantaneous conversion of phosphate to apatite. Apatite formation was greatest under anoxic conditions. Nutrient analyses of Namibian upwelling waters and sediments suggest that the rate of phosphate-to-apatite conversion beneath anoxic bottom waters exceeds the rate of phosphorus release during organic matter mineralization in the upper sediment layers. We suggest that bacterial apatite formation is a significant phosphorus sink under anoxic bottom-water conditions. Expanding oxygen minimum zones are projected in simulations of future climate change, potentially increasing sequestration of marine phosphate, and restricting marine productivity.

  8. 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.

  9. 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

  10. 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

  11. 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. PMID:25045182

  12. Identification of a new strain of hepatitis E virus from an outbreak in Namibia in 1995.

    PubMed

    Maila, Hazel T; Bowyer, Sheila M; Swanepoel, Robert

    2004-01-01

    Endemic circulation of hepatitis E virus (HEV) in Namibia was suspected from serological data during an outbreak of non-A, non-B hepatitis in Rundu in 1995. The source of the outbreak was suspected to be the water supply, which had been compromised approximately 6 months earlier. Four HEV isolates from four different persons in this outbreak were successfully amplified, sequenced and analysed over a 451 bp region of a subgenomic fragment from the 3' end of the genome in ORF2. Phylogenetic analysis showed that the four Namibian HEV isolates clustered with a Mexican isolate in genotype II and shared 85.8-86.3 % nucleotide identity with the 1987 Mexican isolate, but were only 77.6-79.6 % similar to other African isolates. HEV isolated from the same region of Namibia in 1983 was reported to cluster in genotype I. However, virus isolates from sporadic cases of HEV isolated in 1997/8 in Nigeria were also from genotype II. PMID:14718623

  13. Namibia updates its figures -- what more should it do as a response?

    PubMed

    1997-06-01

    Namibia has conducted a sentinel survey of antenatal clinic attenders every 2 years since 1992. The most recent survey was conducted during July-August 1996. In 1992, 4.2% of antenatal clinic attenders were infected with HIV; 8.4% in 1994 and 15.4% in 1996. There is considerable geographic variation in the prevalence of HIV infection, and very small sample sizes in some areas demand caution in interpreting the data. Available data indicate that an estimated 108,325 Namibians aged 15-44 years are infected with HIV. 4441 cumulative cases of AIDS had been reported at the time of the 1996 survey. The epidemic is worst in urban areas, with the 1996 prevalence of HIV infection at 16% and 17.4% in Windhoek and Swakopmund, respectively. There is evidence that the epidemic may be stabilizing in some locations in the north of the country, where 60% of the population lives, at a high of 24.2% in Katimo Mulilo and a lower 8.4% in more rural Rundu. Age-specific prevalence shows a marked increase in infection at all ages, except ages 35-39, possibly due to sample size. There has been a poor response to the HIV/AIDS epidemic in Namibia. PMID:12347941

  14. 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

  15. Causes of cattle bruising during handling and transport in Namibia.

    PubMed

    Hoffman, Louwrens C; Lühl, Juljane

    2012-10-01

    Numerous risks associated with transport and handling of livestock cause bruising and poor welfare to animals. Variables having an influence on the level of bruising under Namibian transport conditions include animal factors (breed type, age, sex, condition and subcutaneous fat cover), pre-transport handling (re-branding of animals), transport related risks (loading density, animals lying down during transit) and lairage factors (fit of truck floor to off-loading ramp, moving to holding pen, pen size and minimum temperatures). Although no single factor was the dominant driver of bruise prevalence; load density, gravel roads, and cattle running after disembarking had a cumulative effect on bruising. Surprisingly, transport duration (3 vs 8h) had minimal effect. The overall incidence of bruising is high, with the highest levels on the hips, around the butt and pin areas. In the event of animals transported to slaughter in the central areas of Namibia, conditions surrounding transport are more important than the distance transported or journey duration. PMID:22571972

  16. 3-D magnetotelluric image of offshore magmatism at the Walvis Ridge and rift basin

    NASA Astrophysics Data System (ADS)

    Jegen, Marion; Avdeeva, Anna; Berndt, Christian; Franz, Gesa; Heincke, Björn; Hölz, Sebastian; Neska, Anne; Marti, Anna; Planert, Lars; Chen, J.; Kopp, Heidrun; Baba, Kiyoshi; Ritter, Oliver; Weckmann, Ute; Meqbel, Naser; Behrmann, Jan

    2016-06-01

    The Namibian continental margin marks the starting point of the Tristan da Cunha hotspot trail, the Walvis Ridge. This section of the volcanic southwestern African margin is therefore ideal to study the interaction of hotspot volcanism and rifting, which occurred in the late Jurassic/early Cretaceous. Offshore magnetotelluric data image electromagnetically the landfall of Walvis Ridge. Two large-scale high resistivity anomalies in the 3-D resistivity model indicate old magmatic intrusions related to hot-spot volcanism and rifting. The large-scale resistivity anomalies correlate with seismically identified lower crustal high velocity anomalies attributed to magmatic underplating along 2-D offshore seismic profiles. One of the high resistivity anomalies (above 500 Ωm) has three arms of approximately 100 km width and 300 km to 400 km length at 120° angles in the lower crust. One of the arms stretches underneath Walvis Ridge. The shape is suggestive of crustal extension due to local uplift. It might indicate the location where the hot-spot impinged on the crust prior to rifting. A second, smaller anomaly of 50 km width underneath the continent ocean boundary may be attributed to magma ascent during rifting. We attribute a low resistivity anomaly east of the continent ocean boundary and south of Walvis Ridge to the presence of a rift basin that formed prior to the rifting.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. Na-O anticorrelation and HB. VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra

    NASA Astrophysics Data System (ADS)

    Carretta, E.; Bragaglia, A.; Gratton, R.; Lucatello, S.

    2009-10-01

    We present homogeneous abundance determinations for iron and some of the elements involved in the proton-capture reactions (O, Na, Mg, Al, and Si) for 202 red giants in 17 Galactic globular clusters (GCs) from the analysis of high-resolution UVES spectra obtained with the FLAMES facility at the ESO VLT2 telescope. Our programme clusters span almost the whole range of the metallicity distribution of GCs and were selected to sample the widest range of global parameters (horizontal-branch morphology, masses, concentration, etc.). In this paper we focus on the discussion of the Na-O and Mg-Al anticorrelations and related issues. Our study finds clear Na and O star-to-star abundance variations, exceeding those expected from the error in the analysis, in all clusters. Variations in Al are present in all but a few GCs. Finally, a spread in abundances of Mg and Si are also present in a few clusters. Mg is slightly less overabundant and Si slightly more overabundant in the most Al-rich stars. The correlation between Si and Al abundances is a signature of production of 28Si leaking from the Mg-Al cycle in a few clusters. The cross sections required for the proper reactions to take over in the cycle point to temperatures in excess of about 65 million K for the favoured site of production. We used a dilution model to infer the total range of Al abundances starting from the Na and Al abundances in the FLAMES-UVES spectra, and the Na abundance distributions found from analysis of the much larger set of stars for which FLAMES-GIRAFFE spectra were available. We found that the maximum amount of additional Al produced by first-generation polluters contributing to the composition of the second-generation stars in each cluster is closely correlated with the same combination of metallicity and cluster luminosity that reproduced the minimum O-abundances found from GIRAFFE spectra. We then suggest that the high temperatures required for the Mg-Al cycle are only reached in the most

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:25007188

  8. 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.

  9. 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. PMID:26123917

  10. 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.

  11. 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.

  12. 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).

  13. Testing the embodied account of object naming: a concurrent motor task affects naming artifacts and animals.

    PubMed

    Matheson, Heath E; White, Nicole; McMullen, Patricia A

    2014-01-01

    Embodied theories of object representation propose that the same neural networks are involved in encoding and retrieving object knowledge. In the present study, we investigated whether motor programs play a causal role in the retrieval of object names. Participants performed an object-naming task while squeezing a sponge with either their right or left hand. The objects were artifacts (e.g. hammer) or animals (e.g. giraffe) and were presented in an orientation that favored a grasp or not. We hypothesized that, if activation of motor programs is necessary to retrieve object knowledge, then concurrent motor activity would interfere with naming manipulable artifacts but not non-manipulable animals. In Experiment 1, we observed naming interference for all objects oriented towards the occupied hand. In Experiment 2, we presented the objects in more 'canonical orientations'. Participants named all objects more quickly when they were oriented towards the occupied hand. Together, these interference/facilitation effects suggest that concurrent motor activity affects naming for both categories. These results also suggest that picture-plane orientation interacts with an attentional bias that is elicited by the objects and their relationship to the occupied hand. These results may be more parsimoniously accounted for by a domain-general attentional effect, constraining the embodied theory of object representations. We suggest that researchers should scrutinize attentional accounts of other embodied cognitive effects. PMID:24291119

  14. The Gaia-ESO Large Public Spectroscopic Survey

    NASA Astrophysics Data System (ADS)

    Randich, S.; Gilmore, G.; Gaia-ESO Consortium

    2013-12-01

    The Gaia-ESO Public Spectroscopic Survey has completed about one third of the data taking and continues to acquire high-quality spectroscopy, with both Giraffe and UVES, of representative samples of all Galactic stellar populations, including open clusters — young and old, nearby and distant, interior and exterior to the Sun — and field stars in the Galactic Halo, the thick Disc, the thin Disc and the Galactic Bulge. A large sample of stars in the Solar Neighbourhood, selected to include all possible ages and metallicities, is also being observed with UVES. This will be the first such large internally homogeneous study of the Milky Way stellar populations. Besides the intrinsic range of exciting scientific results, the Gaia-ESO Survey is also a pathfinder for future massive Gaia follow-up. Equally importantly, we are building an ESO-wide community of stellar spectroscopists, sharing, optimising, refining and cross-calibrating complementary approaches, strengths and experience. Internal Science Verification (SV) has started with several results demonstrating the huge potential of the survey and the first release of spectra to ESO has occurred.

  15. Stroop-like interference in the real animal size test and the pictorial animal size test in 5- to 12-year-old children and young adults.

    PubMed

    Ikeda, Yoshifumi; Okuzumi, Hideyuki; Kokubun, Mitsuru

    2014-01-01

    This study examined prepotent response inhibition among 653 5- to 12-year-old children and young adults divided into five age groups: forty-six 5- to 6-year-olds, one hundred fifty-eight 7- to 8-year-olds, one hundred ninety-six 9- to 10-year-olds, one hundred eighty-three 11- to 12-year-olds, and 70 young adults (19- to 22-year-olds). Two paper-and-pencil versions of Stroop-like tasks were administered: the Real Animal Size Test and the Pictorial Animal Size Test. In these tests, participants are presented with pictures of animals (large animals such as an elephant, a giraffe, and a whale vs. small animals such as a frog, a bird, and a squirrel) printed as either big or small images that are mismatched with the animal's real size. Participants are required to decide the size of the animals (big vs. small) based on either the size in real life or the size of the picture. The results indicated the following: (a) The Pictorial Animal Size Test elicited robust interference, whereas the Real Animal Size Test elicited no interference; (b) prepotent response inhibition develops markedly in childhood and between children and young adults; and (c) error correction increased rapidly after age 8. The mechanism of interference and the influence of metacognition on prepotent response inhibition are discussed. PMID:24716870

  16. Dynamic Imbalance Analysis and Stability Control of Galloping Gait for a Passive Quadruped Robot.

    PubMed

    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

  17. Elemental abundance analysis of the early-type members of the open cluster M6: Preliminary results

    NASA Astrophysics Data System (ADS)

    Kııçoǧlu, 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.

  18. 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.

  19. 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).

  20. 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.

  1. 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.

  2. 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.

  3. 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).

  4. 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.

  5. 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.

  6. The arteries of brain base in species of the cervid family.

    PubMed

    Kiełtyka-Kurc, Agata; Frąckowiak, Hieronim; Brudnicki, Witold

    2015-04-01

    The aim of the article was to describe the pattern of main arteries at the encephalon base, their connections, and varieties. This study included 106 specimens of the head and cerebral arteries of the following eight species of the cervid family: reindeer, chital, Eld's deer, wapiti, sika deer, fallow deer, Pere David's deer or milu, and Reeve's or Chinese muntjac. The arteries of the animals under study were filled with acetone-dissolved stained vinyl superchloride or stained latex LBS3060. The analysis of the specimens revealed that the vascular system of the species of the studied cervid family was similar to the system described in other ruminant species. A branch diverging from the condylar artery to the rostral epidural rete mirabile is present in all studied cervids, but it can be found also in giraffe and eland. The pattern of the arterial vascularization of the encephalon base, which we observed in our analysis, confirms the morphological similarity between those animals and the correct placement of the cervid family in species taxonomy. PMID:25399744

  7. Bilateral Diffuse Uveal Melanocytic Proliferation Presenting as a Giant Unilateral Choroidal Nevus: A Case Report

    PubMed Central

    Menezes, Carlos; Carvalho, Rui; Neves-Martins, Joana; Teixeira, Carla

    2015-01-01

    Background/Aims The aim of our study was to report a case of bilateral diffuse uveal melanocytic proliferation (BDUMP) with a markedly asymmetric presentation and fundoscopic response to palliative chemotherapy. Case Report We report a 67-year-old Caucasian man who presented with vision loss in his right eye. The best-corrected visual acuities were 2/10 in the right eye and 10/10 in the left eye, and biomicroscopy revealed bilateral mild cataracts. Fundoscopy of the right eye showed a macular flat and pigmented lesion extending beyond the posterior pole with areas of giraffe-type pigmentation and an overlying exudative retinal detachment. Nothing remarkable was detected in the left eye apart from a small round hypopigmented area of retinal pigment epithelium atrophy in the papillomacular bundle. BDUMP was diagnosed, and the workup for systemic malignancy revealed a pulmonary adenocarcinoma. After chemotherapy, not only did the right eye's visual acuity improve and the serous detachment resolve, but also the pigmentation decreased. Conclusion BDUMP presentation can be markedly asymmetric and resemble a giant unilateral choroidal nevus. Response to chemotherapy was unique not only for the usual retinal detachment resolution, but also because of an evident regression of pigmentation. PMID:27171585

  8. 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.

  9. Insights from stable light isotopes on enamel defects and weaning in Pliocene herbivores.

    PubMed

    Franz-Odendaal, Tamara A; Lee-Thorp, Julia A; Chinsamy, Anusuya

    2003-12-01

    A high prevalence of enamel hypoplasia in several herbivores from the early Pliocene Langebaanweg locality, South Africa, indicates general systemic stress during the growing years of life. The presence of several linear enamel hypoplasias per tooth crown in many teeth further suggest that these stress events may be episodic. The delta18O values along tooth crowns of mandibular second molars of Sivatherium hendeyi (Artiodactyla, Giraffidae) were used to investigate the cause of the stress events in this tooth type. Results show that weaning in this fossil giraffid occurred at a similar ontogenetic age to that in extant giraffes, and that the observed enamel hypoplasia towards the base of this tooth type manifested post-weaning. Further, high-resolution oxygen isotope analyses across S. hendeyi third molars suggest that the entire development of defective tooth crowns occurred under conditions of increased aridity in which the cool, rainy part of the seasonal cycle was missing. The high prevalence of this defect in many herbivores suggests that climatic conditions were not favourable. This study reiterates the value of stable isotope analyses in determining both the behaviour of fossil animals and the environmental conditions that prevailed during tooth development. PMID:14660876

  10. Evapotranspiration partitioning in a semi-arid African savanna using stable isotopes of water vapor

    NASA Astrophysics Data System (ADS)

    Soderberg, K.; Good, S. P.; O'Connor, M.; King, E. G.; Caylor, K. K.

    2012-04-01

    Evapotranspiration (ET) represents a major flux of water out of semi-arid ecosystems. Thus, understanding ET dynamics is central to the study of African savanna health and productivity. At our study site in central Kenya (Mpala Research Centre), we have been using stable isotopes of water vapor to partition ET into its constituent parts of plant transpiration (T) and soil evaporation (E). This effort includes continuous measurement (1 Hz) of δ2H and δ18O in water vapor using a portable water vapor isotope analyzer mounted on a 22.5 m eddy covariance flux tower. The flux tower has been collecting data since early 2010. The isotopic end-member of δET is calculated using a Keeling Plot approach, whereas δT and δE are measured directly via a leaf chamber and tubing buried in the soil, respectively. Here we report on a two recent sets of measurements for partitioning ET in the Kenya Long-term Exclosure Experiment (KLEE) and a nearby grassland. We combine leaf level measurements of photosynthesis and water use with canopy-scale isotope measurements for ET partitioning. In the KLEE experiment we compare ET partitioning in a 4 ha plot that has only seen cattle grazing for the past 15 years with an adjacent plot that has undergone grazing by both cattle and wild herbivores (antelope, elephants, giraffe). These results are compared with a detailed study of ET in an artificially watered grassland.

  11. 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

  12. SPADES: a Stellar PArameters DEtermination Software

    NASA Astrophysics Data System (ADS)

    Posbic, H.; Katz, D.; Caffau, E.; Bonifacio, P.; Sbordone, L.; Gomez, A.; Arenou, F.

    2011-12-01

    With the large amounts of spectroscopic data available today and the very large surveys to come (e.g. Gaia), the need for automatic data analysis software is unquestionable. We thus developed an automatic spectra analysis program for the determination of stellar parameters: radial velocity, effective temperature, surface gravity, micro-turbulence, metallicity and the elemental abundances of the elements present in the spectral range. Target stars for this software should include all types of stars. The analysis method relies on a line by line comparison of the spectrum of a target star to a library of synthetic spectra. The idea is built on the experience acquired in developing the TGMET (Katz et al. 1998, Soubiran et al. 2003), ETOILE (Katz 2001) and Abbo (Bonifacio & Caffau 2003) software.The method is presented and the performances are illustrated with GIRAFFE-like simulated spectra with high resolution (R = 25000), with high and low signal to noise ratios (down to SNR = 30). These spectra should be close to what could be targeted by the Gaia-ESO Survey (GCDS).

  13. Neck length and mean arterial pressure in the sauropod dinosaurs.

    PubMed

    Hughes, Stephen; Barry, John; Russell, Jeremy; Bell, Robert; Gurung, Som

    2016-04-15

    How blood was able to reach the heads of the long-necked sauropod dinosaurs has long been a matter of debate and several hypotheses have been presented. For example, it has been proposed that sauropods had exceptionally large hearts, multiple 'normal' sized hearts spaced at regular intervals up the neck or held their necks horizontal, or that the siphon effect was in operation. By means of an experimental model, we demonstrate that the siphon principle is able to explain how blood was able to adequately perfuse the sauropod brain. The return venous circulation may have been protected from complete collapse by a structure akin to the vertebral venous plexus. We derive an equation relating neck height and mean arterial pressure, which indicates that with a mean arterial pressure similar to that of the giraffe, the maximum safe vertical distance between heart and head would have been about 12 m. A hypothesis is presented that the maximum neck length in the fossil record is due to the siphon height limit. The equation indicates that to migrate over high ground, sauropods would have had to either significantly increase their mean arterial pressure or keep their necks below a certain height dependent on altitude. PMID:26944489

  14. 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. PMID:23920461

  15. 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. PMID:12049231

  16. 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

  17. Sensor network infrastructure for a home care monitoring system.

    PubMed

    Palumbo, Filippo; Ullberg, Jonas; Stimec, 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

  18. [Right tracheal bronchus with anomalous ramification of the bronchial artery disclosed during an episode of hemoptysis].

    PubMed

    Kyo, S; Maeda, H; Yahata, T; Kawashima, T; Takada, T; Ohnishi, K; Adachi, K

    2000-01-01

    A 63-year-old woman was referred to our hospital on June 18th, 1998 during an episode of hemoptysis that had lasted for 6 days. She had no hemorrhagic diathesis and no history of pulmonary disease. Chest X-ray films disclosed a ground-glass opacity in the right upper lung field. Bronchoscopic examination revealed bleeding from an anomalous ectopic orifice on the right lateral trachea, about 1 cm above the carina. Chest computed tomographic examinations by conventional and spiral methods readily disclosed an ectopic bronchus. Bronchial arteriography showed that the tracheal bronchus was fed by a branched vessel of the thyrocervical artery arising from the brachiocephalic artery. Atypical mycobacterium was detected in bronchoalveolar lavage fluid from the ectopic bronchus. A shunt had formed with the pulmonary artery and peripheral parts of the bronchial artery that fed the tracheal bronchus. It was speculated that the hemoptysis in this case might be due to the combined phenomena of infection and abnormal vessel formation in the tracheal bronchus. In our patient, the system of blood supply to the tracheal bronchus may have been a manifestation of atavism because it closely resembled the circulatory structure of the tracheal bronchi normally observed in sheep and giraffes. The tracheal bronchus should be taken into consideration as a potential cause of hemoptysis, inflammatory changes, and atelectasis during intubation. PMID:10723948

  19. GYES, A Multifibre Spectrograph for the CFHT

    NASA Astrophysics Data System (ADS)

    Bonifacio, P.; Mignot, S.; Dournaux, J.-L.; François, P.; Caffau, E.; Royer, F.; Babusiaux, C.; Arenou, F.; Balkowski, C.; Bienaymé, O.; Briot, D.; Carlberg, R.; Cohen, M.; Dalton, G. B.; Famaey, B.; Fasola, G.; Frémat, Y.; Gómez, A.; Guinouard, I.; Haywood, M.; Hill, V.; Huet, J.-M.; Katz, D.; Horville, D.; Kudritzky, R.; Lallement, R.; Laporte, Ph.; de Laverny, P.; Lemasle, B.; Lewis, I. J.; Martayan, C.; Monier, R.; Mourard, D.; Nardetto, N.; Recio Blanco, A.; Robichon, N.; Robin, A. C.; Rodrigues, M.; Soubiran, C.; Turon, C.; Venn, K.; Viala, Y.

    2011-02-01

    We have chosen the name of GYES, one of the mythological giants with one hundred arms, offspring of Gaia and Uranus, for our instrument study of a multifibre spectrograph for the prime focus of the Canada-France-Hawaii Telescope. Such an instrument could provide an excellent ground-based complement for the Gaia mission and a northern complement to the HERMES project on the AAT. The CFHT is well known for providing a stable prime focus environment, with a large field of view, which has hosted several imaging instruments, but has never hosted a multifibre spectrograph. Building upon the experience gained at GÉPI with FLAMES-Giraffe and X-Shooter, we are investigating the feasibility of a high multiplex spectrograph (about 500 fibres) over a field of view one degree in diameter. We are investigating an instrument with resolution in the range 15 000 to 30 000, which should provide accurate chemical abundances for stars down to 16th magnitude and radial velocities, accurate to 1 km s-1 for fainter stars. The study is led by GÉPI-Observatoire de Paris with a contribution from Oxford for the study of the positioner. The financing for the study comes from INSU CSAA and Observatoire de Paris. The conceptual study will be delivered to CFHT for review by October 1st 2010.

  20. 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

  1. Nonprobative photographs (or words) inflate truthiness.

    PubMed

    Newman, Eryn J; Garry, Maryanne; Bernstein, Daniel M; Kantner, Justin; Lindsay, D Stephen

    2012-10-01

    When people evaluate claims, they often rely on what comedian Stephen Colbert calls "truthiness," or subjective feelings of truth. In four experiments, we examined the impact of nonprobative information on truthiness. In Experiments 1A and 1B, people saw familiar and unfamiliar celebrity names and, for each, quickly responded "true" or "false" to the (between-subjects) claim "This famous person is alive" or "This famous person is dead." Within subjects, some of the names appeared with a photo of the celebrity engaged in his or her profession, whereas other names appeared alone. For unfamiliar celebrity names, photos increased the likelihood that the subjects would judge the claim to be true. Moreover, the same photos inflated the subjective truth of both the "alive" and "dead" claims, suggesting that photos did not produce an "alive bias" but rather a "truth bias." Experiment 2 showed that photos and verbal information similarly inflated truthiness, suggesting that the effect is not peculiar to photographs per se. Experiment 3 demonstrated that nonprobative photos can also enhance the truthiness of general knowledge claims (e.g., Giraffes are the only mammals that cannot jump). These effects add to a growing literature on how nonprobative information can inflate subjective feelings of truth. PMID:22869334

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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

  7. Major Paleostress Field Differences on Complementary Margins of the South Atlantic

    NASA Astrophysics Data System (ADS)

    Salomon, E.; Koehn, D.; Passchier, C. W.; Hackspacher, P. C.; Glasmacher, P. A.

    2013-12-01

    We present a detailed study of paleostress fields of the Namibian and Brazilian passive continental margins of the South Atlantic to address a general debate on whether or not these complementary margins experienced similar tectonic histories (e.g. Cobbold et al., 2001; Al-Hajri et al., 2009; Japsen et al., 2012). In our study, we compare the NW of Namibia and the SE of Brazil with each other. These areas are largely covered by the flood basalts of the Paraná-Etendeka-Large Igneous Province overlying Neo-Proterozoic basement of the Pan-African orogeny. With an age of ~133 Ma the basalts were emplaced just before or during the onset of the South Atlantic opening and thus serve as a good time marker for rift- and post-rift-related tectonics. We studied mainly fault planes and associated striations within the flood basalts and compared the resulting stress patterns of both margins. Results reveal remarkable differences in the stress patterns for SE Brazil and NW Namibia. In NW Namibia, a WSW-ENE directed extensional stress field dominates and fits well with extension of the original continental rift and the passive margin. A second extensional stress field (σ3 SSW oriented) and a strike-slip system (σ1 NW oriented) appear only subdued. In contrast, the SE of Brazil is mainly characterized by two strike-slip systems (σ1 oriented SW and E, respectively) whereas an extensional stress field is almost non-existent. The strike-slip faulting of the Brazilian study area occur widespread across SE Brazil as they are also evident in other paleostress studies of the region and might thus be the result of far-field stresses. Margin-parallel faults are scarce, so it appears that rift-related extension was restricted to a narrower strip along the continent-ocean boundary, now lying offshore. In NW Namibia, the faults of the extensional stress regime run parallel to the sub-margin-parallel basement structure (i.e. shear zones and foliation) and hence indicate a reactivation of

  8. 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

  9. Seasonal export and sediment preservation of diatomaceous, foraminiferal and organic matter mass fluxes in a trophic gradient across the SE Atlantic

    NASA Astrophysics Data System (ADS)

    Lončarić, Neven; van Iperen, Jolanda; Kroon, Dick; Brummer, Geert-Jan A.

    2007-04-01

    productivity and deposition at the Namibian margin relative to the oligotrophic central gyre. From the open ocean toward coastal upwelling, small and weakly silicified diatoms were substituted by other, larger and more heavily silicified species, possibly in response to decreased silica limitation. Foraminiferal deposition fluxes were increasingly dominated by G. inflata, accompanied by a change-over from many warm- to few cold-water minor species. The late winter maximum at the Namibian margin and the early spring maximum at the central Walvis Ridge were generated by the same process of collapsing surface productivity in response to the shut down of nutrient entrainment at the winter to summer transition, although delayed by up to 2 months in the Central Gyre. At the sediment-water interface, intense degradation of organic matter and biogenic silica resulted in poor preservation accompanied by pronounced changes in the species composition of siliceous phytoplankton. Of all particle groups at the central Walvis Ridge, only the export of foraminiferal shells appeared to be fully transferred into the sediment, and through their species assemblage to provide a sedimentary record of past seasonal productivity conditions of the upper ocean.

  10. 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

  11. 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

  12. 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. PMID:25630405

  13. Carotenoid diagenesis in recent marine sediments: II. Degradation of fucoxanthin to loliolide

    NASA Astrophysics Data System (ADS)

    Repeta, Daniel J.

    1989-03-01

    The quantitative distributions of loliolide and the major phytoplankton carotenoids: fucoxanthin, diadinochrome, diatoxanthin, and β-carotene in two cores of anoxic marine sediment recovered from the Peru continental shelf are reported. Our results demonstrate that the rapid degradation of carotenoids in sediments is not a result of their high degree of unsaturation as has been previously suggested. Instead, carotenoids exhibit a wide range of degradation rates that are proportional to the ability of specific pigments to form unstable bicyclic furanoxides. Carotenoid furanoxides undergo subsequent fragmentation to loliolide, isololiolide, dihydroactinidiolide and other, as yet undetermined, low molecular weight products. This degradation pathway accounts for the relative rates of removal for specific carotenoids (fucoxanthin = fucoxanthinol > diadinoxanthin > diatoxanthin = carotene), the distribution of carotenoids reported by Wpatts and Maxwell (1977) and C ARDOSOet al. (1978) in ancient sediments, the occurrence of novel carotenoid transformation products in surface sediments reported by r pidout et al. (1984), and the distribution of loliolides in recent sediments recovered from the Namibian shelf reported by k plok et al. (1984a,b). We predict that loliolide and isololiolide will inherit a specific stereochemistry from their carotenoid precursors, but that dihydroactinidiolide will be racemic. For every μmole of fucoxanthin degraded in Peru sediments, 0.7-1.1 μmole of loliolide is produced. Summation of fucoxanthin and loliolide at each subsurface horizon yields an estimate of the total deposition of fucoxanthin at t = 0. Throughout the 0-20 cm depth of our samples, this parameter is remarkably constant to ±16%. Individual horizons exhibit excursions which may reflect changes in surface productivity. Extrapolation of our measurements to deeper sediments may therefore be of some value in deciphering questions on environmental conditions of deposition and

  14. 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.

  15. 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.

  16. Spatial Access to Emergency Services in Low- and Middle-Income Countries: A GIS-Based Analysis.

    PubMed

    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 access

  17. Dune Morphometry in the Age of Digital Elevation Models

    NASA Astrophysics Data System (ADS)

    Lancaster, N.

    2014-12-01

    Dune patterns can be characterized in many different ways. Relationships between dune height, width and spacing, and the spatial variation in these parameters have been widely employed to provide quantitative information that can be used to describe dune patterns and make comparisons between dunes in widely separated areas, as well as to identify different generations of dunes. Digital elevation models (e.g. ASTER GDEM) provide a rich resource of data for analyses of dune patterns at landscape scales in several ways, including: (1) more extensive analyses using traditional measures, such as relationships between dune height and spacing, and the spatial variation in these parameters; and (2) estimation of sediment thickness on a regional scale. Analyses of data for Arabian and Namibian sand seas and dune fields show that dune height and spacing relationships are much more variable than previously reported and call into question existing models. Regional patterns of sediment thickness reveal areas of erosion, bypass, and accumulation that can be related to transport pathways and wind regimes. The widespread occurrence of complex dune patterns as well as the magnitude of the newly available data sets however requires more sophisticated analyses than simple extraction of dune morphometric parameters using GIS approaches. Geostatistical analyses using spatial autocorrelation, Fourier, and Wavelet methods have been employed in analyses of sub-aqueous bedforms and show promise for dune systems. Automated or semi-automated identification of dune length, width, spacing, and trends using advanced image analysis techniques such as linear segment detection is a potentially transformative approach. The strengths and weaknesses of these methods to provide pertinent geomorphic information are currently being evaluated, but they have the potential to provide new insights into the nature of dune patterns.

  18. 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.

  19. 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

  20. Exposure and Risk Factors to Coxiella burnetii, Spotted Fever Group and Typhus Group Rickettsiae, and Bartonella henselae among Volunteer Blood Donors in Namibia

    PubMed Central

    Noden, Bruce H.; Tshavuka, Filippus I.; van der Colf, Berta E.; Chipare, Israel; Wilkinson, Rob

    2014-01-01

    Background The role of pathogen-mediated febrile illness in sub-Saharan Africa is receiving more attention, especially in Southern Africa where four countries (including Namibia) are actively working to eliminate malaria. With a high concentration of livestock and high rates of companion animal ownership, the influence of zoonotic bacterial diseases as causes of febrile illness in Namibia remains unknown. Methodology/Principal Findings The aim of the study was to evaluate exposure to Coxiella burnetii, spotted fever and typhus group rickettsiae, and Bartonella henselae using IFA and ELISA (IgG) in serum collected from 319 volunteer blood donors identified by the Blood Transfusion Service of Namibia (NAMBTS). Serum samples were linked to a basic questionnaire to identify possible risk factors. The majority of the participants (64.8%) had extensive exposure to rural areas or farms. Results indicated a C. burnetii prevalence of 26.1% (screening titre 1∶16), and prevalence rates of 11.9% and 14.9% (screening titre 1∶100) for spotted fever group and typhus group rickettsiae, respectively. There was a significant spatial association between C. burnetii exposure and place of residence in southern Namibia (P<0.021). Donors with occupations involving animals (P>0.012), especially cattle (P>0.006), were also significantly associated with C. burnetii exposure. Males were significantly more likely than females to have been exposed to spotted fever (P<0.013) and typhus (P<0.011) group rickettsiae. Three (2.9%) samples were positive for B. henselae possibly indicating low levels of exposure to a pathogen never reported in Namibia. Conclusions/Significance These results indicate that Namibians are exposed to pathogenic fever-causing bacteria, most of which have flea or tick vectors/reservoirs. The epidemiology of febrile illnesses in Namibia needs further evaluation in order to develop comprehensive local diagnostic and treatment algorithms. PMID:25259959

  1. 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. PMID:26970371

  2. An investigation into vocal expressions of emotions: the roles of valence, culture, and acoustic factors

    NASA Astrophysics Data System (ADS)

    Sauter, Disa

    This PhD is an investigation of vocal expressions of emotions, mainly focusing on non-verbal sounds such as laughter, cries and sighs. The research examines the roles of categorical and dimensional factors, the contributions of a number of acoustic cues, and the influence of culture. A series of studies established that naive listeners can reliably identify non-verbal vocalisations of positive and negative emotions in forced-choice and rating tasks. Some evidence for underlying dimensions of arousal and valence is found, although each emotion had a discrete expression. The role of acoustic characteristics of the sounds is investigated experimentally and analytically. This work shows that the cues used to identify different emotions vary, although pitch and pitch variation play a central role. The cues used to identify emotions in non-verbal vocalisations differ from the cues used when comprehending speech. An additional set of studies using stimuli consisting of emotional speech demonstrates that these sounds can also be reliably identified, and rely on similar acoustic cues. A series of studies with a pre-literate Namibian tribe shows that non-verbal vocalisations can be recognized across cultures. An fMRI study carried out to investigate the neural processing of non-verbal vocalisations of emotions is presented. The results show activation in pre-motor regions arising from passive listening to non-verbal emotional vocalisations, suggesting neural auditory-motor interactions in the perception of these sounds. In sum, this thesis demonstrates that non-verbal vocalisations of emotions are reliably identifiable tokens of information that belong to discrete categories. These vocalisations are recognisable across vastly different cultures and thus seem to, like facial expressions of emotions, comprise human universals. Listeners rely mainly on pitch and pitch variation to identify emotions in non verbal vocalisations, which differs with the cues used to comprehend

  3. 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.

  4. 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

  5. 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

  6. Geochemical characteristics of Cretaceous carbonatites from Angola

    NASA Astrophysics Data System (ADS)

    Alberti, A.; Castorina, F.; Censi, P.; Comin-Chiaramonti, P.; Gomes, C. B.

    1999-12-01

    The Early Cretaceous (138-130 Ma) carbonatites and associated alkaline rocks of Angola belong to the Paraná-Angola-Etendeka Province and occur as ring complexes and other central-type intrusions along northeast trending tectonic lineaments, parallel to the trend of coeval Namibian alkaline complexes. Most of the Angolan carbonatite-alkaline bodies are located along the apical part of the Moçamedes Arch, a structure representing the African counterpart of the Ponta Grossa Arch in southern Brazil, where several alkaline-carbonatite complexes were also emplaced in the Early Cretaceous. Geochemical and isotopic (C, 0, Sr and Nd) characteristics determined for five carbonatitic occurrences indicate that: (1) the overall geochemical composition, including the OC isotopes, is within the range of the Early and Late Cretaceous Brazilian occurrences from the Paraná Basin; (2) the La versus {La}/{Yb} relationships are consistent with the exsolution of CO i2-rich melts from trachyphonolitic magmas; and (3) the {143Nd}/{144Nd} and {87Sr}/{86Sr} initial ratios are similar to the initial isotopic ratios (129 Ma) of alkaline complexes in northwest Namibia. In contrast, the Lupongola carbonatites have a distinctly different {143Nd}/{144Nd} initial ratio, suggesting a different source. The Angolan carbonatites have SrNd isotopic compositions ranging from bulk earth to time-integrated depleted sources. Since those from eastern Paraguay (at the western fringe of the Paraná-Angola-Etendeka Province) and Brazil appear to be related to mantle-derived melts with time-integrated enriched or B.E. isotopic characteristics, it is concluded that the carbonatites of the Paraná-Angola-Etendeka Province have compositionally distinct mantle sources. Such mantle heterogeneity is attributed to 'metasomatic processes', which would have occurred at ca 0.6-0.7 Ga (Angola, northwest Namibia and Brazil) and ca 1.8 Ga (eastern Paraguay), as suggested by Nd-model ages.

  7. Southeast Atlantic warm events and southern african rainfall

    NASA Astrophysics Data System (ADS)

    Rouault, M.

    2003-04-01

    From January to May 2001, several countries of Southern Africa experienced above normal rainfall and floods. 23 000 people were displaced in Southern Angola after a flood in April. In March, an inundation killed several people and displaced 5,000 others in eastern Zambia's. The situation in Zambia was aggravated when authorities had to open the spillway gates at the Kariba Dam, the main source of electricity for Zambia and Zimbabwe. Water discharged from the Kariba dam ran into neighbouring Mozambique, aggravating floods in that country. At the same time warm sea surface anomalies were measured off the Angolan and Namibian coast. Warm events in the Southeast Tropical Atlantic off Angola and Namibia called "Benguela Nino" are known to affect the fisheries of the region but they also affect the rainfall. In 1995, the warmest recorded Benguela Nino happened with anomalies off up to 8°C extending 300 km offshore with a southward extension to 27°S. During the 1984, 1986, 1995 and 2001 warm events, above average rainfall occurred near the sea surface temperature anomalies and extended inland from the coast to an extent that appeared to depend on the intensity of the regional moisture convergence and atmospheric circulation anomalies. Rainfall over western Angola / Namibia is greatest for those events for which the local circulation anomalies act to strengthen the climatological westwards flux of Indian Ocean sourced moisture across low latitude southern Africa and which flow anticyclonically over the warmest SST off the northern coast. The significance of the warm events occurring during the February to April period is that this is the time when SST reaches its maximum in the annual cycle (up to 28oC off northern Angola) and this favours more intense local evaporation and convection and a greater impact on late austral summer rainfall.

  8. 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. PMID:25953117

  9. [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. PMID:22911356

  10. Parents' participation in the sexuality education of their children in rural Namibia: a situational analysis.

    PubMed

    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

  11. 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

    2016-01-01

    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. PMID:26974036

  12. 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

  13. 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. PMID:21183613

  14. 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.

  15. 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

  16. 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

  17. 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

  18. Effects of metallicity, star-formation conditions, and evolution on the B and Be stars populations in the Magellanic Clouds.

    NASA Astrophysics Data System (ADS)

    Martayan, Christophe

    2005-02-01

    If in the Milky Way, the B & Be star populations are relatively well known, this is not the same case in the Magellanic Clouds. The Large and Small Magellanic Clouds are galaxies satellites of our proper Galaxy and they are known for having a low metallicity. In order to study the effects of metal under abundances in the hot stars, we have observed large samples of stars in the Magellanic Clouds with the multifibers spectrograph GIRAFFE at the VLT. In this thesis, we present the creation of astrometric and photometric catalogues and the process of B & Be stIf in the Milky Way, the B & Be star populations are relatively well known, this is not the same case in the Magellanic Clouds. The Large and Small Magellanic Clouds are galaxies satellites of our proper Galaxy and they are known for having a low metallicity. In order to study the effects of metal under abundances in the hot stars, we have observed large samples of stars in the Magellanic Clouds with the multifibers spectrograph GIRAFFE at the VLT. In this thesis, we present the creation of astrometric and photometric catalogues and the process of B & Be stars selection. Then, we present the fundamental parameters determination and we examine the consequences of the metallicity on the rotational velocities. For the first time, we show the ZAMS rotational velocities distributions of Be stars and their implications on their behaviour. Afterwards, we compare the evolutionary status of Be stars in the Magellanic Clouds with the Milky Way and we give answers to understand the differences seen. Finally, we give an estimate of the surface carbon abundances and we show differences between the fast rotators like the Be stars and the slow rotators like B stars.ars selection. Then, we present the fundamental parameters determination and we examine the consequences of the metallicity on the rotational velocities. For the first time, we show the ZAMS rotational velocities distributions of Be stars and their implications on

  19. 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.

  20. Physical and computational fluid dynamics models for the hemodynamics of the artiodactyl carotid rete.

    PubMed

    O'Brien, Haley D; Bourke, Jason

    2015-12-01

    In the mammalian order Artiodactyla, the majority of arterial blood entering the intracranial cavity is supplied by a large arterial meshwork called the carotid rete. This vascular structure functionally replaces the internal carotid artery. Extensive experimentation has demonstrated that the artiodactyl carotid rete drives one of the most effective selective brain cooling mechanisms among terrestrial vertebrates. Less well understood is the impact that the unique morphology of the carotid rete may have on the hemodynamics of blood flow to the cerebrum. It has been hypothesized that, relative to the tubular internal carotid arteries of most other vertebrates, the highly convoluted morphology of the carotid rete may increase resistance to flow during extreme changes in cerebral blood pressure, essentially protecting the brain by acting as a resistor. We test this hypothesis by employing simple and complex physical models to a 3D surface rendering of the carotid rete of the domestic goat, Capra hircus. First, we modeled the potential for increased resistance across the carotid rete using an electrical circuit analog. The extensive branching of the rete equates to a parallel circuit that is bound in series by single tubular arteries, both upstream and downstream. This method calculated a near-zero increase in resistance across the rete. Because basic equations do not incorporate drag, shear-stress, and turbulence, we used computational fluid dynamics to simulate the impact of these computationally intensive factors on resistance. Ultimately, both simple and complex models demonstrated negligible changes in resistance and blood pressure across the arterial meshwork. We further tested the resistive potential of the carotid rete by simulating blood pressures known to occur in giraffes. Based on these models, we found resistance (and blood pressure mitigation as a whole) to be an unlikely function for the artiodactyl carotid rete. PMID:26403501

  1. SODIUM-OXYGEN ANTICORRELATION AMONG HORIZONTAL BRANCH STARS IN THE GLOBULAR CLUSTER M4

    SciTech Connect

    Marino, A. F.; Lind, K.; Villanova, S.; Geisler, D.; Milone, A. P.; Piotto, G.; Stetson, P. B.

    2011-04-01

    The horizontal branch (HB) morphology of globular clusters (GCs) is mainly governed by metallicity. The second parameter problem, well known since the 1960s, states that metallicity alone is not enough to describe the observed HB morphology of many GCs. Despite many efforts to resolve this issue, the second parameter phenomenon still remains without a satisfactory explanation. We have analyzed blue-HB, red-HB, and RR-Lyrae stars in the GC M4 and studied their Fe, Na, and O abundances. Our goal is to investigate possible connections between the bimodal HB of M4 and the chemical signatures of the two stellar populations recently discovered among red giants of this cluster. We obtained FLAMES-UVES/GIRAFFE spectra of a sample of 22 stars covering the HB from the red to the blue region. While iron has the same abundance in both the red-HB and blue-HB segments, the red-HB is composed of stars with scaled-solar sodium abundances, while the blue-HB stars are all sodium enhanced and oxygen depleted. The RR-Lyrae are Na-poor, as the red-HB stars, and O-rich. This is what we expect if the blue-HB consists of a second generation of stars formed from the ejecta produced by an earlier stellar population through high-temperature hydrogen-burning processes that include the CNO, NeNa, and MgAl cycles and are therefore expected to be He-rich. According to this scenario, the sodium and oxygen pattern detected in the blue-HB and red-HB segments suggests helium as the second parameter that rules the HB morphology in M4.

  2. Seasonal patterns of mixed species groups in large East African mammals.

    PubMed

    Kiffner, Christian; Kioko, John; Leweri, Cecilia; Krause, Stefan

    2014-01-01

    Mixed mammal species groups are common in East African savannah ecosystems. Yet, it is largely unknown if co-occurrences of large mammals result from random processes or social preferences and if interspecific associations are consistent across ecosystems and seasons. Because species may exchange important information and services, understanding patterns and drivers of heterospecific interactions is crucial for advancing animal and community ecology. We recorded 5403 single and multi-species clusters in the Serengeti-Ngorongoro and Tarangire-Manyara ecosystems during dry and wet seasons and used social network analyses to detect patterns of species associations. We found statistically significant associations between multiple species and association patterns differed spatially and seasonally. Consistently, wildebeest and zebras preferred being associated with other species, whereas carnivores, African elephants, Maasai giraffes and Kirk's dik-diks avoided being in mixed groups. During the dry season, we found that the betweenness (a measure of importance in the flow of information or disease) of species did not differ from a random expectation based on species abundance. In contrast, in the wet season, we found that these patterns were not simply explained by variations in abundances, suggesting that heterospecific associations were actively formed. These seasonal differences in observed patterns suggest that interspecific associations may be driven by resource overlap when resources are limited and by resource partitioning or anti-predator advantages when resources are abundant. We discuss potential mechanisms that could drive seasonal variation in the cost-benefit tradeoffs that underpin the formation of mixed-species groups. PMID:25470495

  3. Mixed-host aggregations and helminth parasite sharing in an East African wildlife-livestock system.

    PubMed

    VanderWaal, Kimberly; Omondi, George Paul; Obanda, Vincent

    2014-09-15

    Parasitic infections transmitted between livestock and wildlife pose a significant risk to wildlife conservation efforts and constrain livestock productivity in tropical regions of the world. Gastrointestinal helminths are among the most ubiquitous parasites, and many parasites within this taxon can readily infect a wide range of host species. Factors shaping bidirectional transmission of parasites in wildlife-livestock systems are understudied. In this study, we investigate the prevalence and diversity of helminth infections in an East African community of wild and domestic ungulates. We also identify pairs of host species between which transmission may be possible based on shared parasite taxa, and explore the role of multi-host aggregations in shaping patterns of parasite sharing. Helminth taxa detected included Trichostrongylus, Trichuris, Paramphistomum, Skrjabinema, Strongyloides, Strongylus spp., and other strongyle-type nematodes. We found that nearly 50% of individuals harbored at least one species of helminth, but certain species, such as zebra and impala, exhibited higher prevalence than others. High canopy feeders, like giraffe, had lower prevalence than hosts feeding at medium and low foraging heights. For helminths, patterns of parasite sharing likely emerge from shared space use, which is mediated in part by mixed-species aggregations. The frequency with which host species associated together in mixed-species aggregations was positively correlated with the number of parasite taxa shared. We suggest that variation among species in their tendency to form mixed-species aggregations creates heterogeneity in transmission opportunities, and consequently, parasite sharing across ungulate species. These results enhance our understanding of the role of spatiotemporal relationships among host species in shaping parasite communities in mixed wildlife-livestock grazing systems. PMID:25086496

  4. Stellar Kinematics and Metallicities in the Ultra-faint Dwarf Galaxy Reticulum II

    NASA Astrophysics Data System (ADS)

    Simon, J. D.; Drlica-Wagner, A.; Li, T. S.; Nord, B.; Geha, M.; Bechtol, K.; Balbinot, E.; Buckley-Geer, E.; Lin, H.; Marshall, J.; Santiago, B.; Strigari, L.; Wang, M.; Wechsler, R. H.; Yanny, B.; Abbott, T.; Bauer, A. H.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Dodelson, S.; Cunha, C. E.; Estrada, J.; Evrard, A. E.; Fausti Neto, A.; Fernandez, E.; Finley, D. A.; Flaugher, B.; Frieman, J.; Gaztanaga, E.; Gerdes, D.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; March, M.; Martini, P.; Miller, C. J.; Miquel, R.; Ogando, R.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sako, M.; Sanchez, E.; Schubnell, M.; Sevilla, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Tucker, D.; Vikram, V.; Walker, A. R.; Wester, W.; DES Collaboration

    2015-07-01

    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+/- 0.5 {km} {{{s}}}-1 and a velocity dispersion of 3.3+/- 0.7 {km} {{{s}}}-1. The mass-to-light ratio of Ret II within its half-light radius is 470+/- 210 {M}⊙ /{L}⊙ , 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 {km} {{{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 {{[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 {{[Fe/H]}}=-2.65+/- 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 {{log}}10(J)=18.8+/- 0.6 {GeV}{ }2 {{cm}}-5 within 0.°2, indicating that the predicted gamma-ray flux from dark matter annihilation in Ret II is lower than that of several other dwarf galaxies. Based on data obtained from the ESO Science Archive Facility under request number 157689.

  5. Correlation of Twin Creek limestone with Arapien shale in Arapien embayment, Utah - preliminary appraisal

    SciTech Connect

    Sprinkel, D.A.; Waanders, G.L.

    1984-07-01

    Striking and important stratigraphic patterns have emerged as a result of recent work during which members of the Twin Creek Limestone were correlated with the Arapien Shale, all of Middle Jurassic age. These correlations, determined first on the basis of electric and lithologic logs, are supported by recent palynologic work. Three distinct dinoflagellate assemblages, assigned to the Bajocian(.), Bathonian, and Callovian stages, form the paleontologic basis for these correlations. The Bajocian(.) assemblage is found in rocks of the Sliderock and Rich Members of the Twin Creek Limestone. The Bathonian assemblage is found in units of the Boundary Ridge and Watton Canyon Members of the Twin Creek, and also in units of the lower Arapien Shale (lower Leeds Creek Member of the Twin Creek of Wyoming). The Callovian assemblage is found in rocks of the upper Arapien (upper Leeds Creek and Giraffe Creek Members of the Twin Creek of Wyoming). Isopach maps, based on these correlations, indicate that most of central Utah was the site of a large marine embayment - the Arapien embayment -that was flanked on the west, south, and east by highlands. The maps also suggest that the ancestral Uinta Mountains, a submerged feature, affected sedimentation as early as Bajocian time, and became a significant barrier from the late Bathonian through Callovian. In central Utah, marine carbonates were deposited in the Arapien embayment during deposition of the Gypsum Spring through Watton Canyon Members of the Twin Creek Limestone. During deposition of the Arapien Shale, a major northward regression occurred; the embayment shrank to form a smaller basin - the Arapien basin - that lay directly south of the ancestral Uinta Mountains. Most of the Arapien Shale is shallow-water deposits that formed in the basin under hypersaline conditions.

  6. The Metallicity Spread and the Age-Metallicity Relation of ω Centauri

    NASA Astrophysics Data System (ADS)

    Villanova, S.; Geisler, D.; Gratton, R. G.; Cassisi, S.

    2014-08-01

    ω Centauri is a peculiar globular cluster formed by a complex stellar population. To investigate it, we studied 172 stars belonging to the five SGBs that we can identify in our photometry, in order to measure their [Fe/H] content as well as estimate their age dispersion and the age-metallicity relation. The first important result is that all of these SGBs have a distribution in metallicity with a spread that exceeds the observational errors and typically displays several peaks that indicate the presence of several subpopulations. We were able to identify at least six of them based on their mean [Fe/H] content. These metallicity-based subpopulations are seen to varying extents in each of the five SGBs. Taking advantage of the age sensitivity of the SGB, we showed that, first of all, at least half of the subpopulations have an age spread of at least 2 Gyr. Then, we obtained an age-metallicity relation that is the most complete to date for this cluster. Interpretation of the age-metallicity relation is not straightforward, but it is possible that the cluster (or what we can call its progenitor) was initially composed of two populations with different metallicities. Because of their age, it is very unlikely that the most metal-rich derives from the most metal-poor by some kind of chemical evolution process, so they can be assumed to be two independent primordial objects, or perhaps two separate parts of a single larger object, that merged in the past to form the present-day cluster. Based on FLAMES+GIRAFFE@VLT observations under the program 082.D-0424(A).

  7. The Na-O anticorrelation in horizontal branch stars. V. NGC 6723

    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.

    2015-01-01

    We used FLAMES+GIRAFFE (Medusa mode) at the VLT to obtain moderately high resolution spectra for 30 red horizontal branch (RHB) stars, 4 RR Lyrae variables, and 17 blue horizontal branch (BHB) stars in the low-concentration, moderately metal-rich globular cluster NGC 6723 ([Fe/H] = -1.22 ± 0.08 from our present sample). The spectra were optimized to derive O and Na abundances. In addition, we obtained abundances for other elements, including N, Fe, Mg, Ca, Ni, and Ba. We used these data to discuss the evidence of a connection between the distribution of stars along the horizontal branch (HB) and the multiple populations that are typically present in globular clusters. We found that all RHB and most (13 out of 17) BHB stars are O-rich, Na-poor, and N-poor; these stars probably belong to the first stellar generation in this cluster. Only the four warmest observed stars are (moderately) O-poor, Na-rich, and N-rich, and they probably belong to the second generation. While our sample is not fully representative of the whole HB population in NGC 6723, our data suggest that in this cluster only HB stars warmer than ~9000 K, that is one fourth of the total, belong to the second generation, if at all. Since in many other clusters this fraction is about two thirds, we conclude that the fraction of first/second generation in globular clusters may be strongly variable. In addition, the wide range in colour of chemically homogeneous first-generation HB stars requires a considerable spread in mass loss (>0.10 M⊙). The reason for this spread is yet to be understood. Finally, we found a high Ba abundance, with a statistically significant radial abundance gradient. Based on observations collected at ESO telescopes under programme 087.D-0230.Tables 2, 3, 5, 7, and 8 are available in electronic form at http://www.aanda.org

  8. 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

    2014-01-01

    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. PMID:25155988

  9. Kinematics and Chemistry of Recently Discovered Reticulum 2 and Horologium 1 Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Koposov, Sergey E.; Casey, Andrew R.; Belokurov, Vasily; Lewis, James R.; Gilmore, Gerard; Worley, Clare; Hourihane, Anna; Randich, S.; Bensby, T.; Bragaglia, A.; Bergemann, M.; Carraro, G.; Costado, M. T.; Flaccomio, E.; Francois, P.; Heiter, U.; Hill, V.; Jofre, P.; Lando, C.; Lanzafame, A. C.; de Laverny, P.; Monaco, L.; Morbidelli, L.; Sbordone, L.; Mikolaitis, Š.; Ryde, N.

    2015-09-01

    We report on VLT/GIRAFFE spectra of stars in two recently discovered ultra-faint satellites, Reticulum 2 and Horologium 1, obtained as part of the Gaia-ESO Survey. We identify 18 members in Reticulum 2 and five in Horologium 1. We find Reticulum 2 to have a velocity dispersion of {3.22}-0.49+1.64 {km} {{{s}}}-1, implying a mass-to-light ratio (M/L) of ∼500. The mean metallicity of Reticulum 2 is [{Fe}/{{H}}]=-2.46, with an intrinsic dispersion of ∼0.3 dex and α-enhancement of ∼0.4 dex. We conclude that Reticulum 2 is a dwarf galaxy. We also report on the serendipitous discovery of four stars in a previously unknown stellar substructure near Reticulum 2 with [{Fe}/{{H}}]∼ -2 and {V}{hel}∼ 220 {km} {{{s}}}-1, far from the systemic velocity of Reticulum 2. For Horologium 1 we infer a velocity dispersion of σ ≤ft(V\\right)={4.9}-0.9+2.8 {km} {{{s}}}-1 and a M/L ratio of ∼600, leading us to conclude that Horologium 1 is also a dwarf galaxy. Horologium 1 is slightly more metal-poor than Reticulum 2 ([{Fe}/{{H}}]=-2.76) and is similarly α-enhanced: [α /{Fe}]∼ 0.3 {dex} with a significant spread of metallicities of 0.17 dex. The line-of-sight velocity of Reticulum 2 is offset by 100 km s‑1 from the prediction of the orbital velocity of the Large Magellanic Cloud (LMC), thus making its association with the Cloud uncertain. However, at the location of Horologium 1, both the backward-integrated orbit of the LMC and its halo are predicted to have radial velocities similar to that of the dwarf. Therefore, it is possible that Horologium 1 is or once was a member of the Magellanic family.

  10. The M 4 Core Project with HST - IV. Internal kinematics from accurate radial velocities of 2771 cluster members★

    NASA Astrophysics Data System (ADS)

    Malavolta, L.; Piotto, G.; Bedin, L. R.; Sneden, C.; Nascimbeni, V.; Sommariva, V.

    2015-12-01

    We present a detailed study of the internal kinematics of the Galactic globular cluster M 4 (NGC 6121), by deriving the radial velocities from 7250 spectra for 2771 stars distributed from the upper part of the red giant branch down to the main sequence. We describe new approaches to determine the wavelength solution from day-time calibrations and to determine the radial velocity drifts that can occur between calibration and science observations when observing with the GIRAFFE spectrograph at Very Large Telescope. Two techniques to determine the radial velocity are compared, after a qualitative description of their advantages with respect to other commonly used algorithm, and a new approach to remove the sky contribution from the spectra obtained with fibre-fed spectrograph and further improve the radial velocity precision is presented. The average radial velocity of the cluster is = 71.08 ± 0.08 km s-1 with an average dispersion of μ _{v_c} = 3.97 km s-1. Using the same data set and the same statistical approach of previous analyses, 20 additional binary candidates are found, for a total of 87 candidates. A new determination of the internal radial velocity dispersion as a function of cluster distance is presented, resulting in a dispersion of 4.5 km s-1 within 2 arcmin from the centre of cluster and steadily decreasing outward. We statistically confirm the small amplitude of the cluster rotation, as suggested in the past by several authors. This new analysis represents a significant improvement with respect to previous results in literature and provides a fundamental observational input for the modelling of the cluster dynamics.

  11. Comparative neuronal morphology of the cerebellar cortex in afrotherians, carnivores, cetartiodactyls, and primates.

    PubMed

    Jacobs, Bob; Johnson, Nicholas L; Wahl, Devin; Schall, Matthew; Maseko, Busisiwe C; Lewandowski, Albert; Raghanti, Mary A; Wicinski, Bridget; Butti, Camilla; Hopkins, William D; Bertelsen, Mads F; Walsh, Timothy; Roberts, John R; Reep, Roger L; Hof, Patrick R; Sherwood, Chet C; Manger, Paul R

    2014-01-01

    Although the basic morphological characteristics of neurons in the cerebellar cortex have been documented in several species, virtually nothing is known about the quantitative morphological characteristics of these neurons across different taxa. To that end, the present study investigated cerebellar neuronal morphology among eight different, large-brained mammalian species comprising a broad phylogenetic range: afrotherians (African elephant, Florida manatee), carnivores (Siberian tiger, clouded leopard), cetartiodactyls (humpback whale, giraffe) and primates (human, common chimpanzee). Specifically, several neuron types (e.g., stellate, basket, Lugaro, Golgi, and granule neurons; N = 317) of the cerebellar cortex were stained with a modified rapid Golgi technique and quantified on a computer-assisted microscopy system. There was a 64-fold variation in brain mass across species in our sample (from clouded leopard to the elephant) and a 103-fold variation in cerebellar volume. Most dendritic measures tended to increase with cerebellar volume. The cerebellar cortex in these species exhibited the trilaminate pattern common to all mammals. Morphologically, neuron types in the cerebellar cortex were generally consistent with those described in primates (Fox et al., 1967) and rodents (Palay and Chan-Palay, 1974), although there was substantial quantitative variation across species. In particular, Lugaro neurons in the elephant appeared to be disproportionately larger than those in other species. To explore potential quantitative differences in dendritic measures across species, MARSplines analyses were used to evaluate whether species could be differentiated from each other based on dendritic characteristics alone. Results of these analyses indicated that there were significant differences among all species in dendritic measures. PMID:24795574

  12. Calcium triplet metallicity calibration for stars in the Galactic bulge

    NASA Astrophysics Data System (ADS)

    Vásquez, S.; Zoccali, M.; Hill, V.; Gonzalez, O. A.; Saviane, I.; Rejkuba, M.; Battaglia, G.

    2015-08-01

    Aims: We present a new calibration of the calcium II triplet equivalent widths versus [Fe/H], constructed upon K giant stars in the Galactic bulge. This calibration will be used to derive iron abundances for the targets of the GIBS survey, and is in general especially well suited for solar and supersolar metallicity giants, which are typical of external massive galaxies. Methods: About 150 bulge K giants were observed with the GIRAFFE spectrograph at the VLT with a resolution of R ~ 20 000 and at R ~ 6000. In the first case, the spectra allowed us to directly determine the Fe abundances from several unblended Fe lines, deriving what we call here high-resolution [Fe/H] measurements. The low-resolution spectra allowed us to measure equivalent widths of the two strongest lines of the near-infrared calcium II triplet at 8542 and 8662 Å. Results: By comparing the two measurements, we derived a relation between calcium equivalent widths and [Fe/H] that is linear over the metallicity range probed here, - 1 < [Fe/H] < +0.7. By adding a small second-order correction based on literature globular cluster data, we derived the unique calibration equation [Fe/H] CaT = -3.150 + 0.432W' + 0.006W'2, with an rms dispersion of 0.197 dex, valid across the whole metallicity range -2.3 < [Fe/H] < +0.7. Based on observations taken with ESO telescopes at the La Silla Paranal Observatory under programme ID 385.B-0735(B).Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/580/A121

  13. 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. PMID:25388917

  14. Influence of aesthetic appreciation of wildlife species on attitudes towards their conservation in Kenyan agropastoralist communities.

    PubMed

    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

  15. The Gaia-ESO Survey: the first abundance determination of the pre-main-sequence cluster gamma Velorum

    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.; González Hernández, 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.; Jofré, P.; de Laverny, P.; Masseron, T.; Worley, C.

    2014-07-01

    Context. Knowledge of the abundance distribution of star forming regions and young clusters is critical to investigate a variety of issues, from triggered star formation and chemical enrichment by nearby supernova explosions to the ability to form planetary systems. In spite of this, detailed abundance studies are currently available for relatively few regions. Aims: In this context, we present the analysis of the metallicity of the gamma Velorum cluster, based on the products distributed in the first internal release of the Gaia-ESO Survey. Methods: The gamma Velorum candidate members have been observed with FLAMES, using both UVES and Giraffe, depending on the target brightness and spectral type. In order to derive a solid metallicity determination for the cluster, membership of the observed stars must be first assessed. To this aim, we use several membership criteria including radial velocities, surface gravity estimates, and the detection of the photospheric lithium line. Results: Out of the 80 targets observed with UVES, we identify 14 high-probability members. We find that the metallicity of the cluster is slightly subsolar, with a mean [ Fe/H ] = -0.057 ± 0.018 dex. Although J08095427-4721419 is one of the high-probability members, its metallicity is significantly larger than the cluster average. We speculate about its origin as the result of recent accretion episodes of rocky bodies of ~60 M⊕ hydrogen-depleted material from the circumstellar disk. Based on observations collected at the ESO telescopes under programme 188.B3002, the Gaia-ESO large public spectroscopic survey.Full Tables 1-4 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/567/A55

  16. 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. PMID:24205163

  17. 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. PMID:23687894

  18. Sulphur in the Sculptor dwarf spheroidal galaxy. Including NLTE corrections

    NASA Astrophysics Data System (ADS)

    Skúladóttir, Á.; Andrievsky, S. M.; Tolstoy, E.; Hill, V.; Salvadori, S.; Korotin, S. A.; Pettini, M.

    2015-08-01

    In Galactic halo stars, sulphur has been shown to behave like other α-elements, but until now, no comprehensive studies have been done on this element in stars of other galaxies. Here, we use high-resolution ESO VLT/FLAMES/GIRAFFE spectra to determine sulphur abundances for 85 stars in the Sculptor dwarf spheroidal galaxy, covering the metallicity range -2.5 ≤ [ Fe / H ] ≤ -0.8. The abundances are derived from the S I triplet at 9213, 9228, and 9238 Å. These lines have been shown to be sensitive to departure from local thermodynamic equilibrium, i.e. NLTE effects. Therefore, we present new NLTE corrections for a grid of stellar parameters covering those of the target stars. The NLTE-corrected sulphur abundances in Sculptor show the same behaviour as other α-elements in that galaxy (such as Mg, Si, and Ca). At lower metallicities ([ Fe / H ] ≲ -2) the abundances are consistent with a plateau at [ S / Fe ] ≈ + 0.16, similar to what is observed in the Galactic halo, [ S / Fe ] ≈ + 0.2. With increasing [Fe/H], the [S/Fe] ratio declines, reaching negative values at [ Fe / H ] ≳ -1.5. The sample also shows an increase in [S/Mg] with [Fe/H], most probably because of enrichment from Type Ia supernovae. Based on observations made with ESO/VLT/FLAMES at the La Silla Paranal observatory under program ID 089.B-0304(B).Appendix is available in electronic form at http://www.aanda.org

  19. 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. PMID:24378080

  20. 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. PMID:26893967

  1. 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).

  2. Atmospheric parameters and metallicities for 2191 stars in the globular cluster M4

    SciTech Connect

    Malavolta, Luca; Piotto, Giampaolo; Nascimbeni, Valerio; Sneden, Christopher; Milone, Antonino P.; Bedin, Luigi R. E-mail: giampaolo.piotto@unipd.it E-mail: luigi.bedin@oapd.inaf.it E-mail: milone@mso.anu.edu.au

    2014-02-01

    We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V ≤ 14.7, we obtain a nearly constant metallicity, ([Fe/H]) = –1.07 (σ = 0.02). No difference in the metallicity at the level of 0.01 dex is observed between the two RGB sequences identified by Monelli et al. For 1869 subgiant and main-sequence stars with V > 14.7, we obtain ([Fe/H]) = –1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions.

  3. Atmospheric Parameters and Metallicities for 2191 Stars in the Globular Cluster M4

    NASA Astrophysics Data System (ADS)

    Malavolta, Luca; Sneden, Christopher; Piotto, Giampaolo; Milone, Antonino P.; Bedin, Luigi R.; Nascimbeni, Valerio

    2014-02-01

    We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V <= 14.7, we obtain a nearly constant metallicity, lang[Fe/H]rang = -1.07 (σ = 0.02). No difference in the metallicity at the level of 0.01 dex is observed between the two RGB sequences identified by Monelli et al. For 1869 subgiant and main-sequence stars with V > 14.7, we obtain lang[Fe/H]rang = -1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions.

  4. Early primate evolution in Afro-Arabia.

    PubMed

    Seiffert, Erik R

    2012-11-01

    The peculiar mammalian fauna that inhabited Afro-Arabia during the Paleogene first came to the attention of the scientific community in the early part of the twentieth century, when Andrews1 and Schlosser2 published their landmark descriptions of fossil mammals from the Fayum Depression in northern Egypt. Their studies revealed a highly endemic assemblage of land mammals that included the first known Paleogene records of hyraxes, proboscideans, and anthropoid primates, but which lacked ancestors of many iconic mammalian lineages that are found in Africa today, such as rhinos, zebras, bovids, giraffes, and cats. Over the course of the last century, the Afro-Arabian Paleogene has yielded fossil remains of several other endemic mammalian lineages,3 as well as a diversity of prosimian primates,4 but we are only just beginning to understand how the continent's faunal composition came to be, through ancient processes such as the movement of tectonic plates, changes in climate and sea level, and early phylogenetic splits among the major groups of placental mammals. These processes, in turn, made possible chance dispersal events that were critical in determining the competitive landscape--and, indeed, the survival--of our earliest anthropoid ancestors. Newly discovered fossils indicate that the persistence and later diversification of Anthropoidea was not an inevitable result of the clade's competitive isolation or adaptive superiority, as has often been assumed, but rather was as much due to the combined influences of serendipitous geographic conditions, global cooling, and competition with a group of distantly related extinct strepsirrhines with anthropoid-like adaptations known as adapiforms. Many of the important details of this story would not be known, and could never have been predicted, without the fossil evidence that has recently been unearthed by field paleontologists. PMID:23280921

  5. 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.

  6. Co-infection with Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum in a veterinarian

    PubMed Central

    2013-01-01

    Background During a two year period, a 27-year-old female veterinarian experienced migraine headaches, seizures, including status epilepticus, and other neurological and neurocognitive abnormalities. Prior to and during her illness, she had been actively involved in hospital-based work treating domestic animals, primarily cats and dogs, in Grenada and Ireland and anatomical research requiring the dissection of wild animals (including lions, giraffe, rabbits, mongoose, and other animals), mostly in South Africa. The woman reported contact with fleas, ticks, lice, biting flies, mosquitoes, spiders and mites and had also been scratched or bitten by dogs, cats, birds, horses, reptiles, rabbits and rodents. Prior diagnostic testing resulted in findings that were inconclusive or within normal reference ranges and no etiological diagnosis had been obtained to explain the patient’s symptoms. Methods PCR assays targeting Anaplasma spp. Bartonella spp. and hemotopic Mycoplasma spp. were used to test patient blood samples. PCR positive amplicons were sequenced directly and compared to GenBank sequences. In addition, Bartonella alpha Proteobacteria growth medium (BAPGM) enrichment blood culture was used to facilitate bacterial growth and Bartonella spp. serology was performed by indirect fluorescent antibody testing. Results Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum DNA was amplified and sequenced from the woman’s blood, serum or blood culture samples. Her serum was variably seroreactive to several Bartonella sp. antigens. Despite symptomatic improvement, six months of doxycycline most likely failed to eliminate the B. henselae infection, whereas A. platys and Candidatus M. haematoparvum DNA was no longer amplified from post-treatment samples. Conclusions As is typical of many veterinary professionals, this individual had frequent exposure to arthropod vectors and near daily contact with persistently bacteremic reservoir hosts, including

  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. Testing the effects of perimeter fencing and elephant exclosures on lion predation patterns in a Kenyan wildlife conservancy

    PubMed Central

    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. PMID:26893967

  9. 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. PMID:23405121

  10. LIMITS ON [O III] 5007 EMISSION FROM NGC 4472'S GLOBULAR CLUSTERS: CONSTRAINTS ON PLANETARY NEBULAE AND ULTRALUMINOUS BLACK HOLE X-RAY BINARIES IN GLOBULAR CLUSTERS

    SciTech Connect

    Peacock, Mark B.; Zepf, Stephen E.; Maccarone, Thomas J.

    2012-06-20

    We have searched for [O III] 5007 emission in high-resolution spectroscopic data from FLAMES/GIRAFFE Very Large Telescope observations of 174 massive globular clusters (GCs) in NGC 4472. No planetary nebulae (PNe) are observed in these clusters, constraining the number of PNe per bolometric luminosity, {alpha} < 0.8 Multiplication-Sign 10{sup -7} PN/L{sub Sun }. This is significantly lower than the rate predicted from stellar evolution, if all stars produce PNe. Comparing our results to populations of PNe in galaxies, we find most galaxies have a higher {alpha} than these GCs (more PNe per bolometric luminosity-though some massive early-type galaxies do have similarly low {alpha}). The low {alpha} required in these GCs suggests that the number of PNe per bolometric luminosity does not increase strongly with decreasing mass or metallicity of the stellar population. We find no evidence for correlations between the presence of known GC PNe and either the presence of low-mass X-ray binaries (LMXBs) or the stellar interaction rates in the GCs. This, and the low {alpha} observed, suggests that the formation of PNe may not be enhanced in tight binary systems. These data do identify one [O III] emission feature, this is the (previously published) broad [O III] emission from the cluster RZ 2109. This emission is thought to originate from the LMXB in this cluster, which is accreting at super-Eddington rates. The absence of any similar [O III] emission from the other clusters favors the hypothesis that this source is a black hole LMXB, rather than a neutron star LMXB with significant geometric beaming of its X-ray emission.

  11. Multi-Scale Clustering by Building a Robust and Self Correcting Ultrametric Topology on Data Points

    PubMed Central

    Fushing, Hsieh; Wang, Hui; VanderWaal, Kimberly; McCowan, Brenda; Koehl, Patrice

    2013-01-01

    The advent of high-throughput technologies and the concurrent advances in information sciences have led to an explosion in size and complexity of the data sets collected in biological sciences. The biggest challenge today is to assimilate this wealth of information into a conceptual framework that will help us decipher biological functions. A large and complex collection of data, usually called a data cloud, naturally embeds multi-scale characteristics and features, generically termed geometry. Understanding this geometry is the foundation for extracting knowledge from data. We have developed a new methodology, called data cloud geometry-tree (DCG-tree), to resolve this challenge. This new procedure has two main features that are keys to its success. Firstly, it derives from the empirical similarity measurements a hierarchy of clustering configurations that captures the geometric structure of the data. This hierarchy is then transformed into an ultrametric space, which is then represented via an ultrametric tree or a Parisi matrix. Secondly, it has a built-in mechanism for self-correcting clustering membership across different tree levels. We have compared the trees generated with this new algorithm to equivalent trees derived with the standard Hierarchical Clustering method on simulated as well as real data clouds from fMRI brain connectivity studies, cancer genomics, giraffe social networks, and Lewis Carroll's Doublets network. In each of these cases, we have shown that the DCG trees are more robust and less sensitive to measurement errors, and that they provide a better quantification of the multi-scale geometric structures of the data. As such, DCG-tree is an effective tool for analyzing complex biological data sets. PMID:23424653

  12. 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.

  13. Seasonal Patterns of Mixed Species Groups in Large East African Mammals

    PubMed Central

    Kiffner, Christian; Kioko, John; Leweri, Cecilia; Krause, Stefan

    2014-01-01

    Mixed mammal species groups are common in East African savannah ecosystems. Yet, it is largely unknown if co-occurrences of large mammals result from random processes or social preferences and if interspecific associations are consistent across ecosystems and seasons. Because species may exchange important information and services, understanding patterns and drivers of heterospecific interactions is crucial for advancing animal and community ecology. We recorded 5403 single and multi-species clusters in the Serengeti-Ngorongoro and Tarangire-Manyara ecosystems during dry and wet seasons and used social network analyses to detect patterns of species associations. We found statistically significant associations between multiple species and association patterns differed spatially and seasonally. Consistently, wildebeest and zebras preferred being associated with other species, whereas carnivores, African elephants, Maasai giraffes and Kirk's dik-diks avoided being in mixed groups. During the dry season, we found that the betweenness (a measure of importance in the flow of information or disease) of species did not differ from a random expectation based on species abundance. In contrast, in the wet season, we found that these patterns were not simply explained by variations in abundances, suggesting that heterospecific associations were actively formed. These seasonal differences in observed patterns suggest that interspecific associations may be driven by resource overlap when resources are limited and by resource partitioning or anti-predator advantages when resources are abundant. We discuss potential mechanisms that could drive seasonal variation in the cost-benefit tradeoffs that underpin the formation of mixed-species groups. PMID:25470495

  14. Multi-scale clustering by building a robust and self correcting ultrametric topology on data points.

    PubMed

    Fushing, Hsieh; Wang, Hui; Vanderwaal, Kimberly; McCowan, Brenda; Koehl, Patrice

    2013-01-01

    The advent of high-throughput technologies and the concurrent advances in information sciences have led to an explosion in size and complexity of the data sets collected in biological sciences. The biggest challenge today is to assimilate this wealth of information into a conceptual framework that will help us decipher biological functions. A large and complex collection of data, usually called a data cloud, naturally embeds multi-scale characteristics and features, generically termed geometry. Understanding this geometry is the foundation for extracting knowledge from data. We have developed a new methodology, called data cloud geometry-tree (DCG-tree), to resolve this challenge. This new procedure has two main features that are keys to its success. Firstly, it derives from the empirical similarity measurements a hierarchy of clustering configurations that captures the geometric structure of the data. This hierarchy is then transformed into an ultrametric space, which is then represented via an ultrametric tree or a Parisi matrix. Secondly, it has a built-in mechanism for self-correcting clustering membership across different tree levels. We have compared the trees generated with this new algorithm to equivalent trees derived with the standard Hierarchical Clustering method on simulated as well as real data clouds from fMRI brain connectivity studies, cancer genomics, giraffe social networks, and Lewis Carroll's Doublets network. In each of these cases, we have shown that the DCG trees are more robust and less sensitive to measurement errors, and that they provide a better quantification of the multi-scale geometric structures of the data. As such, DCG-tree is an effective tool for analyzing complex biological data sets. PMID:23424653

  15. Comparative neuronal morphology of the cerebellar cortex in afrotherians, carnivores, cetartiodactyls, and primates

    PubMed Central

    Jacobs, Bob; Johnson, Nicholas L.; Wahl, Devin; Schall, Matthew; Maseko, Busisiwe C.; Lewandowski, Albert; Raghanti, Mary A.; Wicinski, Bridget; Butti, Camilla; Hopkins, William D.; Bertelsen, Mads F.; Walsh, Timothy; Roberts, John R.; Reep, Roger L.; Hof, Patrick R.; Sherwood, Chet C.; Manger, Paul R.

    2014-01-01

    Although the basic morphological characteristics of neurons in the cerebellar cortex have been documented in several species, virtually nothing is known about the quantitative morphological characteristics of these neurons across different taxa. To that end, the present study investigated cerebellar neuronal morphology among eight different, large-brained mammalian species comprising a broad phylogenetic range: afrotherians (African elephant, Florida manatee), carnivores (Siberian tiger, clouded leopard), cetartiodactyls (humpback whale, giraffe) and primates (human, common chimpanzee). Specifically, several neuron types (e.g., stellate, basket, Lugaro, Golgi, and granule neurons; N = 317) of the cerebellar cortex were stained with a modified rapid Golgi technique and quantified on a computer-assisted microscopy system. There was a 64-fold variation in brain mass across species in our sample (from clouded leopard to the elephant) and a 103-fold variation in cerebellar volume. Most dendritic measures tended to increase with cerebellar volume. The cerebellar cortex in these species exhibited the trilaminate pattern common to all mammals. Morphologically, neuron types in the cerebellar cortex were generally consistent with those described in primates (Fox et al., 1967) and rodents (Palay and Chan-Palay, 1974), although there was substantial quantitative variation across species. In particular, Lugaro neurons in the elephant appeared to be disproportionately larger than those in other species. To explore potential quantitative differences in dendritic measures across species, MARSplines analyses were used to evaluate whether species could be differentiated from each other based on dendritic characteristics alone. Results of these analyses indicated that there were significant differences among all species in dendritic measures. PMID:24795574

  16. Planetary Nebulae and their parent stellar populations. Tracing the mass assembly of M87 and Intracluster light in the Virgo cluster core

    NASA Astrophysics Data System (ADS)

    Arnaboldi, Magda; Longobardi, Alessia; Gerhard, Ortwin

    2016-08-01

    The diffuse extended outer regions of galaxies are hard to study because they are faint, with typical surface brightness of 1% of the dark night sky. We can tackle this problem by using resolved star tracers which remain visible at large distances from the galaxy centers. This article describes the use of Planetary Nebulae as tracers and the calibration of their properties as indicators of the star formation history, mean age and metallicity of the parent stars in the Milky Way and Local Group galaxies. We then report on the results from a deep, extended, planetary nebulae survey in a 0.5 deg2 region centered on the brightest cluster galaxy NGC 4486 (M87) in the Virgo cluster core, carried out with SuprimeCam@Subaru and FLAMES-GIRAFFE@VLT. Two planetary nebulae populations are identified out to 150 kpc distance from the center of M87. One population is associated with the M87 halo and the second one with the intracluster light in the Virgo cluster core. They have different line-of-sight velocity and spatial distributions, as well as different planetary nebulae specific frequencies and luminosity functions. The intracluster planetary nebulae in the surveyed region correspond to a luminosity of four times the luminosity of the Large Magellanic Cloud. The M87 halo planetary nebulae trace an older, more metal-rich, parent stellar population. A substructure detected in the projected phase-space of the line-of-sight velocity vs. major axis distance for the M87 halo planetary nebulae provides evidence for the recent accretion event of a satellite galaxy with luminosity twice that of M33. The satellite stars were tidally stripped about 1 Gyr ago, and reached apocenter at a major axis distance of 60-90 kpc from the center of M87. The M87 halo is still growing significantly at the distances where the substructure is detected.

  17. Five Groups of Red Giants with Distinct Chemical Composition in the Globular Cluster NGC 2808

    NASA Astrophysics Data System (ADS)

    Carretta, Eugenio

    2015-09-01

    The chemical composition of multiple populations in the massive globular cluster (GC) NGC 2808 is addressed with the homogeneous abundance reanalysis of 140 red giant branch stars. UVES spectra for 31 stars and GIRAFFE spectra for the other giants were analyzed with the same procedures used for about 2500 giants in 23 GCs in our FLAMES survey, deriving abundances of Fe, O, Na, Mg, Si, Ca, Ti, Sc, Cr, Mn, and Ni. Iron, elements from α capture, and those in the Fe group do not show intrinsic scatter. On our UVES scale, the metallicity of NGC 2808 is [Fe/H] =\\-1.129+/- 0.005+/- 0.034 (± statistical ± systematic error) with σ = 0.030 (31 stars). The main features related to proton-capture elements are retrieved, but the improved statistics and the smaller associated internal errors allow us to uncover five distinct groups of stars along the Na-O anticorrelation. We observe large depletions in Mg, anticorrelated with enhancements of Na and also Si, suggestive of unusually high temperatures for proton captures. About 14% of our sample is formed by giants with solar or subsolar [Mg/Fe] ratios. Using the [Na/Mg] ratios, we confirm the presence of five populations with different chemical compositions that we call P1, P2, I1, I2, and E in order of decreasing Mg and increasing Na abundances. Statistical tests show that the mean ratios in any pair of groups cannot be extracted from the same parent distribution. The overlap with the five populations recently detected from UV photometry is good but not perfect, confirming that more distinct components probably exist in this complex GC. Based on data collected at the ESO telescopes under program 072.D-0507 and during the FLAMES Science Verification program.

  18. Kinematics and Chemistry of Recently Discovered Reticulum 2 and Horologium 1 Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Koposov, Sergey E.; Casey, Andrew R.; Belokurov, Vasily; Lewis, James R.; Gilmore, Gerard; Worley, Clare; Hourihane, Anna; Randich, S.; Bensby, T.; Bragaglia, A.; Bergemann, M.; Carraro, G.; Costado, M. T.; Flaccomio, E.; Francois, P.; Heiter, U.; Hill, V.; Jofre, P.; Lando, C.; Lanzafame, A. C.; de Laverny, P.; Monaco, L.; Morbidelli, L.; Sbordone, L.; Mikolaitis, Š.; Ryde, N.

    2015-09-01

    We report on VLT/GIRAFFE spectra of stars in two recently discovered ultra-faint satellites, Reticulum 2 and Horologium 1, obtained as part of the Gaia-ESO Survey. We identify 18 members in Reticulum 2 and five in Horologium 1. We find Reticulum 2 to have a velocity dispersion of {3.22}-0.49+1.64 {km} {{{s}}}-1, implying a mass-to-light ratio (M/L) of ˜500. The mean metallicity of Reticulum 2 is [{Fe}/{{H}}]=-2.46, with an intrinsic dispersion of ˜0.3 dex and α-enhancement of ˜0.4 dex. We conclude that Reticulum 2 is a dwarf galaxy. We also report on the serendipitous discovery of four stars in a previously unknown stellar substructure near Reticulum 2 with [{Fe}/{{H}}]˜ -2 and {V}{hel}˜ 220 {km} {{{s}}}-1, far from the systemic velocity of Reticulum 2. For Horologium 1 we infer a velocity dispersion of σ ≤ft(V\\right)={4.9}-0.9+2.8 {km} {{{s}}}-1 and a M/L ratio of ˜600, leading us to conclude that Horologium 1 is also a dwarf galaxy. Horologium 1 is slightly more metal-poor than Reticulum 2 ([{Fe}/{{H}}]=-2.76) and is similarly α-enhanced: [α /{Fe}]˜ 0.3 {dex} with a significant spread of metallicities of 0.17 dex. The line-of-sight velocity of Reticulum 2 is offset by 100 km s-1 from the prediction of the orbital velocity of the Large Magellanic Cloud (LMC), thus making its association with the Cloud uncertain. However, at the location of Horologium 1, both the backward-integrated orbit of the LMC and its halo are predicted to have radial velocities similar to that of the dwarf. Therefore, it is possible that Horologium 1 is or once was a member of the Magellanic family.

  19. Five Groups of Red Giants with Distinct Chemical Composition in the Globular Cluster NGC 2808

    NASA Astrophysics Data System (ADS)

    Carretta, Eugenio

    2015-09-01

    The chemical composition of multiple populations in the massive globular cluster (GC) NGC 2808 is addressed with the homogeneous abundance reanalysis of 140 red giant branch stars. UVES spectra for 31 stars and GIRAFFE spectra for the other giants were analyzed with the same procedures used for about 2500 giants in 23 GCs in our FLAMES survey, deriving abundances of Fe, O, Na, Mg, Si, Ca, Ti, Sc, Cr, Mn, and Ni. Iron, elements from α capture, and those in the Fe group do not show intrinsic scatter. On our UVES scale, the metallicity of NGC 2808 is [Fe/H] =\\-1.129+/- 0.005+/- 0.034 (± statistical ± systematic error) with σ = 0.030 (31 stars). The main features related to proton-capture elements are retrieved, but the improved statistics and the smaller associated internal errors allow us to uncover five distinct groups of stars along the Na–O anticorrelation. We observe large depletions in Mg, anticorrelated with enhancements of Na and also Si, suggestive of unusually high temperatures for proton captures. About 14% of our sample is formed by giants with solar or subsolar [Mg/Fe] ratios. Using the [Na/Mg] ratios, we confirm the presence of five populations with different chemical compositions that we call P1, P2, I1, I2, and E in order of decreasing Mg and increasing Na abundances. Statistical tests show that the mean ratios in any pair of groups cannot be extracted from the same parent distribution. The overlap with the five populations recently detected from UV photometry is good but not perfect, confirming that more distinct components probably exist in this complex GC. Based on data collected at the ESO telescopes under program 072.D-0507 and during the FLAMES Science Verification program.

  20. 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 structures on ˜20 arcsec scales in Magellanic I/HVCs. From the FLAMES data within a 0.5° field of view, the Ca II K equivalent width in the I/HVC components towards three clusters varies by factors of ≥10. There are no detections of molecular gas in absorption at intermediate or high velocities, although molecular absorption is present at LMC and Galactic velocities towards some sightlines. The FEROS/UVES data show Ca II K I/HVC absorption in ˜60 per cent of sightlines. The range in the Ca II/Na I ratio in I/HVCs is from -0.45 to +1.5 dex, similar to previous measurements for I/HVCs. In 10 sightlines we find Ca II/O I ratios in I/HVC gas ranging from 0.2 to 1.5 dex below the solar value, indicating either dust or ionization effects. In nine sightlines I/HVC gas is detected in both H I and Ca II at similar velocities, implying that the two elements form part of the same structure.

  1. An extensive radial velocity survey towards NGC 6253

    NASA Astrophysics Data System (ADS)

    Montalto, M.; Melo, C. H. F.; Santos, N. C.; Queloz, D.; Piotto, G.; Desidera, S.; Bedin, L. R.; Momany, Y.; Saviane, I.

    2016-04-01

    The old and metal-rich open cluster NGC 6253 was observed with the Fibre Large Array Multi Element Spectrograph (FLAMES) multi-object spectrograph during an extensive radial velocity campaign monitoring 317 stars with a median of 15 epochs per object. All the targeted stars are located along the upper main sequence of the cluster between 14.8 < V < 16.5. Fifty nine stars are confirmed cluster members both by radial velocities and proper motions and do not show evidence of variability. We detected 45 variable stars among which 25 belong to NGC 6253. We were able to derive an orbital solution for four cluster members (and for two field stars) yielding minimum masses in between ˜90 MJ and ˜460 MJ and periods between 3 and 220 d. Simulations demonstrated that this survey was sensitive to objects down to 30 MJ at 10 days orbital periods with a detection efficiency equal to 50 per cent. On the basis of these results we concluded that the observed frequency of binaries down to the hydrogen burning limit and up to 20 d orbital period is around (1.5 ± 1.3) per cent in NGC 6253. The overall observed frequency of binaries around the sample of cluster stars is (13 ± 3) per cent. The median radial velocity precision achieved by the GIRAFFE spectrograph in this magnitude range was around ˜240 m s- 1 (˜180 m s- 1 for UVES). Based on a limited follow-up analysis of seven stars in our sample with the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph we determined that a precision of 35 m s- 1 can be reached in this magnitude range, offering the possibility to further extend the variability analysis into the substellar domain. Prospects are even more favourable once considering the upcoming ESPRESSO spectrograph at VLT.

  2. Tracking the Feeding Patterns of Tsetse Flies (Glossina Genus) by Analysis of Bloodmeals Using Mitochondrial Cytochromes Genes

    PubMed Central

    Muturi, Catherine N.; Ouma, Johnson O.; Malele, Imna I.; Ngure, Raphael M.; Rutto, Jane J.; Mithöfer, Klaus M.; Enyaru, John; Masiga, Daniel K.

    2011-01-01

    Tsetse flies are notoriously difficult to observe in nature, particularly when populations densities are low. It is therefore difficult to observe them on their hosts in nature; hence their vertebrate species can very often only be determined indirectly by analysis of their gut contents. This knowledge is a critical component of the information on which control tactics can be developed. The objective of this study was to determine the sources of tsetse bloodmeals, hence investigate their feeding preferences. We used mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) gene sequences for identification of tsetse fly blood meals, in order to provide a foundation for rational decisions to guide control of trypanosomiasis, and their vectors. Glossina swynnertoni were sampled from Serengeti (Tanzania) and G. pallidipes from Kenya (Nguruman and Busia), and Uganda. Sequences were used to query public databases, and the percentage identities obtained used to identify hosts. An initial assay showed that the feeds were from single sources. Hosts identified from blood fed flies collected in Serengeti ecosystem, included buffaloes (25/40), giraffes (8/40), warthogs (3/40), elephants (3/40) and one spotted hyena. In Nguruman, where G. pallidipes flies were analyzed, the feeds were from elephants (6/13) and warthogs (5/13), while buffaloes and baboons accounted for one bloodmeal each. Only cattle blood was detected in flies caught in Busia and Uganda. Out of four flies tested in Mbita Point, Suba District in western Kenya, one had fed on cattle, the other three on the Nile monitor lizard. These results demonstrate that cattle will form an integral part of a control strategy for trypanosomiasis in Busia and Uganda, while different approaches are required for Serengeti and Nguruman ecosystems, where wildlife abound and are the major component of the tsetse fly food source. PMID:21386971

  3. Minimizing predation risk in a landscape of multiple predators: effects on the spatial distribution of African ungulates.

    PubMed

    Thaker, Maria; Vanak, Abi T; Owen, Cailey R; Ogden, Monika B; Niemann, Sophie M; Slotow, Rob

    2011-02-01

    Studies that focus on single predator-prey interactions can be inadequate for understanding antipredator responses in multi-predator systems. Yet there is still a general lack of information about the strategies of prey to minimize predation risk from multiple predators at the landscape level. Here we examined the distribution of seven African ungulate species in the fenced Karongwe Game Reserve (KGR), South Africa, as a function of predation risk from all large carnivore species (lion, leopard, cheetah, African wild dog, and spotted hyena). Using observed kill data, we generated ungulate-specific predictions of relative predation risk and of riskiness of habitats. To determine how ungulates minimize predation risk at the landscape level, we explicitly tested five hypotheses consisting of strategies that reduce the probability of encountering predators, and the probability of being killed. All ungulate species avoided risky habitats, and most selected safer habitats, thus reducing their probability of being killed. To reduce the probability of encountering predators, most of the smaller prey species (impala, warthog, waterbuck, kudu) avoided the space use of all predators, while the larger species (wildebeest, zebra, giraffe) only avoided areas where lion and leopard space use were high. The strength of avoidance for the space use of predators generally did not correspond to the relative predation threat from those predators. Instead, ungulates used a simpler behavioral rule of avoiding the activity areas of sit-and-pursue predators (lion and leopard), but not those of cursorial predators (cheetah and African wild dog). In general, selection and avoidance of habitats was stronger than avoidance of the predator activity areas. We expect similar decision rules to drive the distribution pattern of ungulates in other African savannas and in other multi-predator systems, especially where predators differ in their hunting modes. PMID:21618919

  4. An aluminium tool for multiple stellar generations in the globular clusters 47 Tucanae and M 4

    NASA Astrophysics Data System (ADS)

    Carretta, E.; Gratton, R. G.; Bragaglia, A.; D'Orazi, V.; Lucatello, S.

    2013-02-01

    We present aluminium abundances for a sample of about 100 red giant stars in each of the Galactic globular clusters 47 Tuc (NGC 104) and M 4 (NGC 6121). We have derived homogeneous abundances from intermediate-resolution FLAMES/GIRAFFE spectra. Aluminium abundances are from the strong doublet Al i 8772-8773 Å, as in previous works done for giants in NGC 6752 and NGC 1851, and nitrogen abundances are extracted from a large number of features of the CN molecules by assuming a suitable carbon abundance. We added previous homogeneous abundances of O and Na and newly derived abundances of Mg and Si for our samples of 83 stars in M 4 and 116 stars in 47 Tuc to obtain the full set of elements from proton-capture reactions produced by different stellar generations in these clusters. By simultaneously studying the Ne-Na and Mg-Al cycles of H-burning at high temperature, our main aims are to understand the nature of the polluters at work in the first generation and to ascertain whether the second generation of cluster stars was formed in one or, rather, several episodes of star formation. Our data confirm that in M 4 only two stellar populations are visible. On the other hand, for 47 Tuc a cluster analysis performed on our full dataset suggests that at least three distinct groups of stars are present on the giant branch. The abundances of O, Na, Mg, and Al in the intermediate group can be produced within a pollution scenario; results for N are ambiguous, depending on the C abundance we adopt for the three groups. Based on observations collected at ESO telescopes under program 085.D-0205 and on public data from the ESO/ST-ECF Science Archive Facility.Tables 2 and 3 are available in electronic form at http://www.aanda.org

  5. Earthquake damage scenario simulation of a water supply system in Taipei

    NASA Astrophysics Data System (ADS)

    Lin, Ji-Hao; Chen, Walter W.

    2008-10-01

    Taiwan is located in the Circum-Pacific Belt and at the junction of the Philippine Sea Plate and the Eurasian Plate. The island is squeezed over a long period of time, so the frequency of the occurrence of earthquakes is very high. Changes of terrain due to seismic forces such as fault ruptures and surface uplifts could cause extensive damage to water pipeline networks. The 921 Ji-Ji earthquake was one of the most serious disasters in recent years in Taiwan, and it indeed resulted in the most severe damage of water supply systems. The urban water supply network is very important for municipal water management in Taiwan. If the water supply systems break down, hospitals and fire stations will not have enough water to carry out the rescue work, and the results may worsen the disasters. This study took the water supply system of the West District in Taipei City as an example. First, the metro-Taipei area was split into three hundred and twenty-seven 1 km by 1 km cells. Second, the location of a simulated earthquake was determined. Third, the Peak Ground Acceleration (PGA) value of each cell was calculated by an empirical formula. Fourth, the Repair Rate (RR) of each cell was calculated based on its PGA value. Fifth, using the GIRAFFE software developed by Cornell University, the Monte Carlo simulation method was used to simulate the possible damage to the water supply system. And finally, the EPANET program developed by the US Environmental Protection Agency was applied to compute the distribution of flow volumes and water pressures of the damaged water supply system. Results of the pipeline network under different scenarios of earthquake magnitudes are shown in this study, and they provide an evaluation basis to decision makers to improve the pipeline infrastructures for fire protection after major earthquakes.

  6. The Effect of Intervertebral Cartilage on Neutral Posture and Range of Motion in the Necks of Sauropod Dinosaurs

    PubMed Central

    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. PMID:24205163

  7. Some avian and mammalian hosts of Amblyomma hebraeum and Amblyomma marmoreum (Acari: Ixodidae).

    PubMed

    Horak, I G; MacIvor, K M; Petney, T N; De Vos, V

    1987-09-01

    Large numbers of birds, wild mammals and domestic stock from a variety of localities within the Republic of South Africa were examined for infestation with the ixodid ticks Amblyomma hebraeum and Amblyomma marmoreum. Every warthog (Phacochoerus aethiopicus), Burchell's zebra (Equus burchelli), impala (Aepyceros melampus) and kudu (Tragelaphus strepsiceros) from the Kruger National Park in the north-eastern Transvaal Lowveld was infested with A. hebraeum. In the eastern Cape Province every helmeted guinea fowl (Numida meleagris), scrub hare (Lepus saxatilis) and kudu from the Andries Vosloo Kudu Reserve; all but 1 of the 22 domestic cattle examined on the farm "Bucklands"; and all Angora goats plus nearly all Boer goats examined on the farm "Brakhill" were infested with this tick. Most animals examined appeared to be good hosts of the immature stages, and the larger the host species the greater the chances of it harbouring large numbers of adult ticks. The largest animals examined, such as eland, buffalo, giraffe and rhinoceros, harboured very large numbers of adult A. hebraeum. No adult A. marmoreum was recovered from any host. However, 50% or more of helmeted guinea fowl and kudu from the Andries Vosloo Kudu Reserve; helmeted guinea fowl, scrub hares and eland (Taurotragus oryx) from the Mountain Zebra National Park; helmeted guinea fowl, kudu, domestic sheep, goats and cattle on the farm "Bucklands", and caracal (Felis caracal) from the Cradock and Southwell areas of the eastern Cape Province were infested with immature A. marmoreum. In the Bontebok National Park in the south-western Cape Province more than 35% of scrub hares, vaal ribbok (Pelea capreolus) and bontebok (Damaliscus dorcas dorcas) were infested with immature ticks. PMID:3329327

  8. Using diamond-mined sediment discharges to test the paradigms of sandy-beach ecology

    NASA Astrophysics Data System (ADS)

    Pulfrich, Andrea; Branch, George M.

    2014-10-01

    The prevailing view of sandy-shore ecosystems is that they are controlled largely by physical conditions, particularly particle size, slope and wave regime, but it is rarely possible to test this view by experimentally manipulating these attributes. We report a unique opportunity to accomplish this because large-scale alteration of these properties has taken place on the Namibian coast, associated with diamond mining. Elizabeth Bay diamond mine, near Lüderitz, started modern operations in 1991. Since then, 30.8 million tonnes of sediment with a particle size (<1.4 mm) coarser than the native beach sand have been discharged as slurry onto the beach as part of the treatment process. The physical and biological effects of this were monitored on seven occasions between 1993 and 2012, spanning three phases: (1) an initial pre-upgrade phase (1994-2004) with discharges of moderate intensity; (2) doubling of discharges during upgrade of the mine (2005-2008); (3) temporary cessation of mining (2009-2011). These vicissitudes resulted in both spatial and temporal physical changes, including massive beach accretion (350-620 m), overall increases in mean sand particle size and slope and decreases in Dean's Parameter, east-to-west gradients in beach slope, wave height and erosion, and changes in the beach state from dissipative towards reflective conditions. Alteration of physical conditions led to significant macrofaunal changes, with the community structure in the centre of the bay opposite the discharge points shifting from a state dominated by sand mussels to one dominated by peracarid crustaceans, accompanied by reductions in diversity, biomass and abundance. Grossebucht, which lies nearby and is not mined, provided comparative reference samples: physical conditions there changed little, and biotic communities were constant, significantly more diverse and had greater abundances and biomasses than at Elizabeth Bay. The changes in physical conditions and ensuing biological

  9. Fe Isotope Composition of Neoproterozoic Post-Glacial "Cap Dolostones"

    NASA Astrophysics Data System (ADS)

    Halverson, G. P.

    2005-12-01

    The largest variations in the Fe isotope composition in the geological record are found in sedimentary rocks, presumably as the result of redox transformations of iron during mineral precipitation, microbial processing, and diagenesis (Johnson et al., Cont. Min. Petrol., 2003). Systematic trends in the variability of the Fe isotope composition of sulfide minerals formed in ancient marine black shales broadly mirror patterns in sulfur isotope data (Δ33S, Δ34S), which are consistent with geological and other geochemical evidence for the progressive oxidation of the earth's surface during the Precambrian (Rouxel et al., Science, 2005). Therefore, the record of the Fe isotope composition of minerals formed in the marine environment appears to be a promising proxy for the redox evolution of the ocean. We have developed a method to extract the marine Fe isotope composition from carbonates in an attempt to establish higher resolution records of changes in marine redox changes than permitted by black shale geochemistry. We have applied this method to the study of ca. 635 Ma iron-rich dolostones, which are found in Neoproterozoic successions worldwide and immediately post-date a purported snowball (Marinoan) glaciation during which time the deep ocean is thought to have become anoxic (Hoffman et al., Science, 1998), allowing its Fe isotopic composition to evolve towards the composition of relatively light (δ57Fe vs. IRMM-14 ~ -0.6‰) hydrothermal iron (Beard et al., Geology, 2003). Fe isotope compositions were measured relative to IRMM-14 in medium-resolution mode on a Neptune MC-ICP-MS with a long-term external (2σ) reproducibility of < 0.04‰/amu. Preliminary data on dolomite samples from Svalbard, northern Namibia and northwest Canada show a range in δ57Fe values from -0.65 to 0.04‰, similar to the range found in siderite and Fe-rich dolomite in ancient BIFs (Johsnon et al., 2003) and to values for the Namibian cap dolostone reported by Leighton et al

  10. Emergence of the Namib Desert During the Neogene, and Correlations With Global Palaeoclimate Changes

    NASA Astrophysics Data System (ADS)

    Segalen, L.; Renard, M.; Lee-Thorp, J. A.; Senut, B.; Pickford, M.

    2004-12-01

    The Namib is one of the oldest known desert systems, hence its formation and maintenance are of considerable regional and global importance. Fluctuations in Atlantic climate and oceanic circulation patterns directly affect the ecology of the Namibian desert, and the entire South African west coast area, on a variety of timescales. The discovery of mammalian fossils and ratite eggshells has provided a biochronology, while the ratite eggshells have allowed stable oxygen and carbon isotope studies of this material to pinpoint the plant dietary base of these birds and to provide clues about changing environments through time. The results of the existing multidisciplinary study provide a sequence showing that during the lower Miocene, prior to 17 Ma, (fluviatile environments, terraces of the Proto-Orange river) a tropical/subtropical climate existed. The onset of aridification is correlated with appearance of the first aeolianites in the basal middle Miocene period. In the Southern Namib, cross-stratification in aeolianites represent the lower slipface of crescent dunes. The predominant northeast-northwest azimuths of the cross-bedded strata indicate deposition under a prevailing southerly wind regime. This regime remained in place throughout the Neogene. The aeolianites of the Northern Namib present different lithologies from those in the south: sand sheet deposits rich in cemented roots (stabilization phase of the arid system), cross-stratification of complex dunes and deflation surfaces related to water flowing from nearby inselbergs. The azimuths of these cross-bedded strata indicate deposition under westerly/southerly winds and also easterly and northeasterly winds during the Late Miocene (at present the bergwinds produce similar conditions). Isotopic data from the ratite eggshells shows advance of C4 grasses in this region at the end of the Miocene, and emergent differences in the plant cover of the southern versus northern sectors. Eggshell carbon isotope

  11. Radar scattering of linear dunes and mega-yardangs: Application to Titan

    NASA Astrophysics Data System (ADS)

    Paillou, Philippe; Seignovert, Benoît; Radebaugh, Jani; Wall, Stephen

    2016-05-01

    Cassini RADAR T8 acquisitions over the Belet Sand Sea on Titan, and show that the linear dunes encountered there are likely to be of both Egyptian and Namibian type. We also show that the radar-bright linear features observed in Cassini RADAR T64 and T83 acquisitions are very likely to be mega-yardangs, possible remnants of ancient lake basins at mid-latitude, formed when Titan's climate was different.

  12. Tracing incipient continental breakup from dike swarms: application of high-resolution aeromagnetics in Namibia

    NASA Astrophysics Data System (ADS)

    Trumbull, R.; Vietor, T.; Hahne, K.; Wackerle, R.; Kamati, T.; Ledru, P.

    2003-04-01

    High-resolution aeromagnetic data reveals a major Mesozoic dike swarm in north-central Namibia (the Henties Bay-Outjo Dikes or HOD), which extends NE at least 600 km inland from the Atlantic coast and 800 km from the continental shelf edge. Field relations and radiometric dates indicate emplacement ages of 120 to 140 Ma for the predominantly basic dikes, which agrees with ages of flood basalts and alkaline igneous complexes in the same region, and with similar rocks on the conjugate margin of Brazil and Uruguay. The density (number per unit area) and orientation of dikes in the HOD vary with distance from the coast, reflecting structural changes in the crustal basement and perhaps also proximity to a magma source at the developing continent-ocean boundary. In the coastal section (to ca. 100 km inland) the density of dikes is highest and orientations are dominantly NE-SW, with subordinate but important coast-parallel components. In the central section, the density of dikes decreases continuously inland and coast-parallel orientations are rare. In the northern section close to the boundary of the Congo Craton, the density of dikes increases again and orientations become more irregular and increasingly discordant to the structures of the Neoproterzoic Damara Belt. Some of the dikes propagate across the craton boundary in a fan-like array extending to beneath the Etosha Basin. Within the craton, the density of dikes is lower and individual dikes are longer and more continuous than in the Damara Belt, probably reflecting the more rigid and thicker crust. We interpret the HOD as one arm of a triple junction formed at the intersection of the NE-trending Damara Belt and the Namibian shelf edge west of Walfish Bay. This rift geometry is unlikely to reflect doming over a mantle plume since plate reconstructions place the Tristan plume head under southern Congo in the Early Cretaceous. Instead, it may represent reactivation of much older structures at the juncture between the

  13. A groundwater quality index map for Namibia

    NASA Astrophysics Data System (ADS)

    Bergmann, Thomas; Schulz, Oliver; Wanke, Heike; Püttmann, Wilhelm

    2016-04-01

    Groundwater quality and contamination is a huge concern for the population of Namibia, especially for those living in remote areas. There, most farmers use their own wells to supply themselves and their animals with drinking water. In many cases, except for a few studies that were done in some areas, the only groundwater quality measurements that took place were taken at the time the well was drilled. These data were collected and are available through the national GROWAS-Database. Information on measurements determining the amount of contaminants such as fluoride, TDS, other major ions and nitrate for several thousand wells are provided there. The aim of this study was I) to check the database for its reliability by comparing it to results from different studies and statistical analysis, II) to analyze the database on groundwater quality using different methods (statistical-, pattern- and correlation analysis) and III) to embed our own field work that took place within a selected Namibian region into that analysis. In order to get a better understanding of the groundwater problems in different areas of Namibia, a groundwater quality index map based on GROWAS was created using GIS processing techniques. This map uses several indicators for groundwater quality in relation to selected guidelines and combines them into an index, thus enabling the assessment of groundwater quality with regard to more than one pollutant. The goal of the groundwater quality map is to help identify where the overall groundwater quality is problematic and to communicate these problems. Additionally, suggestions for an enhancement of the database and for new field surveys will be given. The field work was focusing on three farms within an area known for its problematic nitrate concentration in groundwater. There, 23 wells were probed. In order to identify the sources of the contamination, isotopic measurements were executed for three of these wells with high nitrate concentrations

  14. Coupled physical/biogeochemical modeling including O2-dependent processes in the Eastern Boundary Upwelling Systems: application in the Benguela

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    The Eastern Boundary Upwelling Systems (EBUS) contribute to one fifth of the global catches in the ocean. Often associated with Oxygen Minimum Zones (OMZs), EBUS represent key regions for the oceanic nitrogen (N) cycle. Important bioavailable N loss due to denitrification and anammox processes as well as greenhouse gas emissions (e.g, N2O) occur also in these EBUS. However, their dynamics are currently crudely represented in global models. In the climate change context, improving our capability to properly represent these areas is crucial due to anticipated changes in the winds, productivity, and oxygen content. We developed a biogeochemical model (BioEBUS) taking into account the main processes linked with EBUS and associated OMZs. We implemented this model in a 3-D realistic coupled physical/biogeochemical configuration in the Namibian upwelling system (northern Benguela) using the high-resolution hydrodynamic ROMS model. We present here a validation using in situ and satellite data as well as diagnostic metrics and sensitivity analyses of key parameters and N2O parameterizations. The impact of parameter values on the OMZ off Namibia, on N loss, and on N2O concentrations and emissions is detailed. The model realistically reproduces the vertical distribution and seasonal cycle of observed oxygen, nitrate, and chlorophyll a concentrations, and the rates of microbial processes (e.g, NH4+ and NO2- oxidation, NO3- reduction, and anammox) as well. Based on our sensitivity analyses, biogeochemical parameter values associated with organic matter decomposition, vertical sinking, and nitrification play a key role for the low-oxygen water content, N loss, and N2O concentrations in the OMZ. Moreover, the explicit parameterization of both steps of nitrification, ammonium oxidation to nitrate with nitrite as an explicit intermediate, is necessary to improve the representation of microbial activity linked with the OMZ. The simulated minimum oxygen concentrations are driven by

  15. Prevalence and Knowledge Assessment of HIV and Non-Communicable Disease Risk Factors among Formal Sector Employees in Namibia

    PubMed Central

    Guariguata, Leonor; de Beer, Ingrid; Hough, Rina; Mulongeni, Pancho; Feeley, Frank G.; Rinke de Wit, Tobias F.

    2015-01-01

    Introduction The burden of non-communicable diseases (NCDs) is growing in sub-Saharan Africa combined with an already high prevalence of infectious disease, like HIV. Engaging the formal employment sector may present a viable strategy for addressing both HIV and NCDs in people of working age. This study assesses the presence of three of the most significant threats to health in Namibia among employees in the formal sector: elevated blood pressure, elevated blood glucose, and HIV and assesses the knowledge and self-perceived risk of employees for these conditions. Methods A health and wellness screening survey of employees working in 13 industries in the formal sector of Namibia was conducted including 11,192 participants in the Bophelo! Project in Namibia, from January 2009 to October 2010. The survey combined a medical screening for HIV, blood glucose and blood pressure with an employee-completed survey on knowledge and risk behaviors for those conditions. We estimated the prevalence of the three conditions and compared to self-reported employee knowledge and risk behaviors and possible determinants. Results 25.8% of participants had elevated blood pressure, 8.3% of participants had an elevated random blood glucose measurement, and 8.9% of participants tested positive for HIV. Most participants were not smokers (80%), reported not drinking alcohol regularly (81.2%), and had regular condom use (66%). Most participants could not correctly identify risk factors for hypertension (57.2%), diabetes (57.3%), or high-risk behaviors for HIV infection (59.5%). In multivariate analysis, having insurance (OR:1.15, 95%CI: 1.03 – 1.28) and a managerial position (OR: 1.29, 95%CI: 1.13 – 1.47) were associated with better odds of knowledge of diabetes. Conclusion The prevalence of elevated blood pressure, elevated blood glucose, and HIV among employees of the Namibian formal sector is high, while risk awareness is low. Attention must be paid to improving the knowledge of

  16. Ethnobotanical knowledge on indigenous fruits in Ohangwena and Oshikoto regions in Northern Namibia

    PubMed Central

    2013-01-01

    Background Indigenous communities in Namibia possess a rich indigenous knowledge expressed within many practices of these communities. Indigenous wild edible fruits are available along the Namibian 13 regions of which it forms a rich source of vitamins, fibres, minerals and a heterogeneous collection of bioactive compounds referred to as phytochemicals for indigenous people’s diet. The aim of this study was to record the different IKS practices on the indigenous fruit trees in Ohangwena and Oshikoto regions of Namibia. Methods An ethnobotanical survey was undertaken to collect information from local communities from 23-29 October 2011. Data was collected through the use of questionnaires and personal interviews during field trips in the Ohangwena and Oshikoto regions. A total of 65 respondents were interviewed; 54%; women, 38%; men and 8%; both in group interviews. Results The majority of the people interviewed were in their thirty’s, with the youngest being 18 years old and the oldest being 98 years old. Forty three plant specimens were collected from the two regions; these specimens belong to 20 genera and 25 species. Regarding to the indigenous knowledge; 87%; of the respondents indicated that their knowledge on indigenous fruits was learnt mainly through their parent. Indigenous people’s perception on declining indigenous fruits revealed that 56.3%; of the respondents reported that indigenous fruits were declining. Only a 42.2%; indicated that the indigenous fruits populations are increasing. Regarding to the management practices to improve the production of these indigenous fruit trees; 38.6%; reported that there are some efforts on management practices; on the other hand 61.4%; reported there are no management practices on the indigenous fruit trees in their areas. Four species were found to be the most frequently used and mentioned fruits which need to be given high preference in terms of conservation are: Berchemia discolor, Hyphaene petersiana

  17. Use of the Earth Observing One (EO-1) Satellite for the Namibia SensorWeb Flood Early Warning Pilot

    NASA Technical Reports Server (NTRS)

    Mandl, Daniel; Frye, Stuart; Cappelaere, Pat; Handy, Matthew; Policelli, Fritz; Katjizeu, McCloud; Van Langenhove, Guido; Aube, Guy; Saulnier, Jean-Francois; Sohlberg, Rob; Silva, Julie; Kussul, Nataliia; Skakun, Sergii; Ungar, Stephen; Grossman, Robert

    2012-01-01

    The Earth Observing One (EO-1) satellite was launched in November 2000 as a one year technology demonstration mission for a variety of space technologies. After the first year, it was used as a pathfinder for the creation of SensorWebs. A SensorWeb is the integration of variety of space, airborne and ground sensors into a loosely coupled collaborative sensor system that automatically provides useful data products. Typically, a SensorWeb is comprised of heterogeneous sensors tied together with a messaging architecture and web services. Disasters are the perfect arena to use SensorWebs. One SensorWeb pilot project that has been active since 2009 is the Namibia Early Flood Warning SensorWeb pilot project. The Pilot Project was established under the auspices of the Namibian Ministry of Agriculture Water and Forestry (MAWF)/Department of Water Affairs, the 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 began by identifying and prototyping technologies which enabled 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. This was followed by an international collaboration to build small portions of the identified system which was prototyped during that past few years during the flood seasons which occurred in the February through May timeframe of 2010 and 2011 with further prototyping to occur in 2012. The SensorWeb system features EO-1 data along with other data sets from such satellites as Radarsat, Terra and Aqua. Finally, the SensorWeb team also began to examine the socioeconomic component to determine the impact of the SensorWeb technology and how best to assist in the infusion of this technology in lesser affluent areas with low levels of basic

  18. VNIR-SWIR-TIR hyperspectral airborne campaign for soil and sediment mapping in semi-arid south african environments

    NASA Astrophysics Data System (ADS)

    Milewski, Robert; Chabrillat, Sabine; Eisele, Andreas

    2016-04-01

    Airborne hyperspectral remote sensing techniques has been proven to offer efficient procedures for soil and sediment mineralogical mapping in arid areas on larger scales. Optical methods based on traditional remote sensing windows using the solar reflective spectral wavelength range from the visible-near infrared (VNIR: 0.4-1.1 μm) to the short-wave infrared region (SWIR: 1.1-2.5 μm) allow mapping of common soil properties such as iron oxides, textural characteristics and organic carbon. However, soil mapping in semi-arid environments using VNIR-SWIR is currently limited due to specific spectral characteristics. Challenges appear in such environments due to the common presence of sandy soils (coarse textured) which grain size distribution is driven by the dominant mineral, quartz (SiO2), and which lacks any distinctive Si-O bond related spectral features within the VNIR-SWIR. Furthermore, another challenge is represented by the common presence of other specific spectral features due to different salts (gypsum, halite) or coatings of different forms (cyanobacteria, iron-oxides and/or -oxyhydroxides) for which few studies exists or that oft prevent detection of any other potential spectral feature of e.g. soil organics. In this context, more methodological developments are needed to overcome current limitations of hyperspectral remote sensing for arid areas, and to extent its scope using the thermal infrared (TIR) wavelength region within the atmospheric window between 8 and 14 μm (longwave infrared). In 2015 an extensive VNIR-SWIR-TIR airborne hyperspectral dataset consisting of HySpex-VNIR, HySpex-SWIR (NEO) and Hyper-Cam (TELOPS) data has been acquired in various Namibian and South African landscapes part of the Dimap/GFZ campaign in the frame of the BMBF-SPACES Geoarchive project. Research goals are 1) to demonstrate the capabilities to extract information from such a dataset and 2) to demonstrate the potential of advanced hyperspectral remote sensing

  19. Multiple nuclide cosmogenic dating of very old desert pavements on the Puna Plateau, Northwest Argentina

    NASA Astrophysics Data System (ADS)

    Dortch, J.; Schoenbohm, L. M.

    2011-12-01

    Wind erosion of bedrock has been suggested to be responsible for the removal of more than 800 m of strata in the Qaidam Basin while wind deposition creates large-scale landforms such as the loess plateau. Wind eroded landforms, such as desert pavements in the Namibian Desert, Africa, form relic landscapes that are stable for more than 5 Ma. Desert pavements are of particular importance because of their widespread occurrence on terraces and fans, in mountains and coastal areas, and in hot and cold deserts including: Southwestern Africa, Antartic Dry valleys, Southwest USA, Denmark, Ireland, Israel, Sweden, and Central Tibet. Moreover, greater than 95 % of ventifacts on desert pavements are suspected to be late Quaternary to Holocene in age and are located on surfaces suitable for cosmogenic radionuclide dating. In spite of this, glacial, fluvial, and mass wasting systems have received far more attention than wind as an important geomorphic agent of erosion, deposition, and rock mass redistribution. Our goal is to: 1) quantify bedrock wind erosion rates; 2) quantify the ages of old, stable desert pavements; 3) and to identify which lithology-isotope pair provides the most accurate exposure ages for desert pavements in arid landscapes. The Puna Plateau, Argentina, is an ideal area to undertake this study because numerous wind eroded/deposited landforms are present, rates of fluvial erosion are low, and glaciation is limited. Mapping using remote sensed images shows that a significant portion of the Puna Plateau surface is covered by wind eroded or wind deposited landforms. These landforms align with the dominant wind direction (southeast) determined from ~450 ventifact measurements from 9 locations on the plateau. Twelve amalgamated samples sets that span six lithologies (granite, gneiss, quartzite, rhyolite, diabase, and basalt) using four cosmogenic isotopes (10Be, 26Al, 36Cl, 3He) on ventifacted clasts were collected from two surfaces to identify the most

  20. Oxygen Sensitivity of Anammox and Coupled N-Cycle Processes in Oxygen Minimum Zones

    PubMed Central

    Kalvelage, Tim; Jensen, Marlene M.; Contreras, Sergio; Revsbech, Niels Peter; Lam, Phyllis; Günter, Marcel; LaRoche, Julie; Lavik, Gaute; Kuypers, Marcel M. M.

    2011-01-01

    Nutrient measurements indicate that 30–50% of the total nitrogen (N) loss in the ocean occurs in oxygen minimum zones (OMZs). This pelagic N-removal takes place within only ∼0.1% of the ocean volume, hence moderate variations in the extent of OMZs due to global warming may have a large impact on the global N-cycle. We examined the effect of oxygen (O2) on anammox, NH3 oxidation and NO3− reduction in 15N-labeling experiments with varying O2 concentrations (0–25 µmol L−1) in the Namibian and Peruvian OMZs. Our results show that O2 is a major controlling factor for anammox activity in OMZ waters. Based on our O2 assays we estimate the upper limit for anammox to be ∼20 µmol L−1. In contrast, NH3 oxidation to NO2− and NO3− reduction to NO2− as the main NH4+ and NO2− sources for anammox were only moderately affected by changing O2 concentrations. Intriguingly, aerobic NH3 oxidation was active at non-detectable concentrations of O2, while anaerobic NO3− reduction was fully active up to at least 25 µmol L−1 O2. Hence, aerobic and anaerobic N-cycle pathways in OMZs can co-occur over a larger range of O2 concentrations than previously assumed. The zone where N-loss can occur is primarily controlled by the O2-sensitivity of anammox itself, and not by any effects of O2 on the tightly coupled pathways of aerobic NH3 oxidation and NO3− reduction. With anammox bacteria in the marine environment being active at O2 levels ∼20 times higher than those known to inhibit their cultured counterparts, the oceanic volume potentially acting as a N-sink increases tenfold. The predicted expansion of OMZs may enlarge this volume even further. Our study provides the first robust estimates of O2 sensitivities for processes directly and indirectly connected with N-loss. These are essential to assess the effects of ocean de-oxygenation on oceanic N-cycling. PMID:22216239

  1. Warm water events in the southeast Atlantic and their impact on regional and large-scale atmospheric conditions in the CMIP5 model output

    NASA Astrophysics Data System (ADS)

    Ott, Irena; Lutz, Karin; Rathmann, Joachim; Jacobeit, Jucundus

    2013-04-01

    Two types of El Niño-like events are described in the South Atlantic: the Atlantic Niño in the equatorial Atlantic and the Benguela Niño off the Namibian and Angolan coast. These warm water events are known to be associated with rainfall anomalies at the West and Southwest African coastal region and harm marine ecosystems and fish populations. The two phenomena are handled separately so far, but the identification of warm water events in our study - via similar variabilities of sea surface temperatures (SST) - based on observed SST data (HadISST1.1) as well as global climate model output from CMIP5, involved the definition of an area mean index that includes both Niño types from the Atlantic region. A multi-model ensemble of the CMIP5 output is used to investigate the impact of Atlantic Niño events on regional atmospheric conditions. Based on the Atlantic SST index, composite analyses give information about anomalous precipitation, air pressure, humidity, evaporation, horizontal wind and vertical air motion patterns over the African continent and the South Atlantic. The Atlantic variability mode is similar to the Pacific El Niño system, but more irregular and less intense. However, recent studies show that the Atlantic influences the El Niño Southern Oscillation (ENSO) in the Pacific Ocean by the modification of the Walker and Hadley circulations and associated wind stress, thermocline and SST anomalies, further amplified by the Bjerknes positive feedback. As a result, an Atlantic Niño is followed by a La Niña-like phenomenon in the Pacific area with a lag of six months. In our study, the CMIP5 output is considered with respect to its ability of describing the complex connection between the Atlantic and Pacific variability modes. For that purpose, the inter-ocean teleconnection is studied with correlation analyses of the ensemble members of the CMIP5 output by means of the Atlantic index, the Southern Oscillation (SOI) and the Pacific El Niño indices (Ni

  2. Nitrogen transfers and air-sea N2O fluxes in the upwelling off Namibia within the oxygen minimum zone: a 3-D model approach

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

    As regions of high primary production and being often associated to Oxygen Minimum Zones (OMZs), Eastern Boundary Upwelling Systems (EBUS) represent key regions for the oceanic nitrogen (N) cycle. Indeed, by exporting the 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. Losses of fixed inorganic N, through denitrification and anammox processes and through nitrous oxide (N2O) emissions to the atmosphere, take place in oxygen depleted environments such as EBUS, and alleviate the role of these regions as a source of N. In the present study, we developed a 3-D coupled physical/biogeochemical (ROMS/BioBUS) model for investigating the full N budget in the Namibian sub-system of the Benguela Upwelling System (BUS). The different state variables of a climatological experiment have been compared to different data sets (satellite and in situ observations) and show that the model is able to represent this biogeochemical oceanic region. The N transfer is investigated in the Namibian upwelling system using this coupled model, especially in the Walvis Bay area between 22° S and 24° S where the OMZ is well developed (O2 < 0.5 ml O2 l-1). The upwelling process advects 24.2 × 1010 mol N yr-1 of nitrate enriched waters over the first 100 m over the slope and over the continental shelf. The meridional advection by the alongshore Benguela current brings also nutrient-rich waters with 21.1 × 1010 mol N yr-1. 10.5 × 1010 mol N yr-1 of OM are exported outside of the continental shelf (between 0 and 100-m depth). 32.4% and 18.1% of this OM are exported by advection in the form of Dissolved and Particulate Organic Matters (DOM and POM), respectively, however vertical sinking of POM represents the main contributor (49.5%) to OM export outside of the first 100-m depth of the water column on the continental shelf. The continental slope also represents a net N export

  3. Stellar kinematics and metallicities in the ultra-faint dwarf galaxy Reticulum II

    DOE PAGESBeta

    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 ofmore » $$62.8\\pm 0.5\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$$ 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.« less

  4. A study of rotating globular clusters. The case of the old, metal-poor globular cluster NGC 4372

    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.

    2014-07-01

    Context. NGC 4372 is a poorly studied old, very metal-poor globular cluster (GC) located in the inner Milky Way halo. Aims: We present the first in-depth study of the kinematic properties and derive the structural parameters of NGC 4372 based on the fit of a Plummer profile and a rotating, physical model. We explore the link between internal rotation to different cluster properties and together with similar studies of more GCs, we put these in the context of globular cluster formation and evolution. Methods: We present radial velocities for 131 cluster member stars measured from high-resolution FLAMES/GIRAFFE observations. Their membership to the GC is additionally confirmed from precise metallicity estimates. We build a velocity dispersion profile and a systemic rotation curve using this kinematic data set. Additionally, we obtain an elliptical number density profile of NGC 4372 based on optical images using a Markov chain Monte Carlo fitting algorithm. From this, we derive the cluster's half-light radius and ellipticity as rh = 3.44' ± 0.04' and ɛ = 0.08 ± 0.01. Finally, we give a physical interpretation of the observed morphological and kinematic properties of this GC by fitting an axisymmetric, differentially rotating, dynamical model. Results: Our results show that NGC 4372 has an unusually high ratio of rotation amplitude to velocity dispersion (1.2 vs. 4.5 km s-1) for its metallicity. This puts it in line, however, with two other exceptional, very metal-poor GCs: M 15 and NGC 4590. We also find a mild flattening of NGC 4372 in the direction of its rotation. Given its old age, this suggests that the flattening is indeed caused by the systemic rotation rather than tidal interactions with the Galaxy. Additionally, we estimate the dynamical mass of the GC Mdyn = 2.0 ± 0.5 × 105M⊙ based on the dynamical model, which constrains the mass-to-light ratio of NGC 4372 between 1.4 and 2.3 M⊙/L⊙, representative of an old, purely stellar population. Based on

  5. The Gaia-ESO Survey: Catalogue of Hα emission stars

    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.

    2015-09-01

    We discuss the properties of Hα emission stars across the sample of 22035 spectra from the Gaia-ESO Survey internal data release, observed with the GIRAFFE instrument and largely belonging to stars in young open clusters. Automated fits using two independent Gaussian profiles and a third component that accounts for the nebular emission allow us to discern distinct morphological types of Hα line profiles with the introduction of a simplified classification scheme. All in all, we find 3765 stars with intrinsic emission and sort their spectra into eight distinct morphological categories: single-component emission, emission blend, sharp emission peaks, double emission, P-Cygni, inverted P-Cygni, self-absorption, and emission in absorption. We have more than one observation for 1430 stars in our sample, thus allowing a quantitative discussion of the degree of variability of Hα emission profiles, which is expected for young, active objects. We present a catalogue of stars with properties of their Hα emission line profiles, morphological classification, analysis of variability with time and the supplementary information from the SIMBAD, VizieR, and ADS databases. The records in SIMBAD indicate the presence of Hα emission for roughly 25% of all stars in our catalogue, while at least 305 of them have already been more thoroughly investigated according to the references in ADS. The most frequently identified morphological categories in our sample of spectra are emission blend (23%), emission in absorption (22%), and self-absorption (16%). Objects with repeated observations demonstrate that our classification into discrete categories is generally stable through time, but categories P-Cygni and self-absorption seem less stable, which is the consequence of discrete classification rules, as well as of the fundamental change in profile shape. Such records of emission stars can be valuable for automatic pipelines in large surveys, where it may prove very useful for

  6. The Metal-poor Knee in the Fornax Dwarf Spheroidal Galaxy

    NASA Astrophysics Data System (ADS)

    Hendricks, Benjamin; Koch, Andreas; Lanfranchi, Gustavo A.; Boeche, Corrado; Walker, Matthew; Johnson, Christian I.; Peñarrubia, Jorge; Gilmore, Gerard

    2014-04-01

    We present α-element abundances of Mg, Si, and Ti for a large sample of field stars in two outer fields of the Fornax dwarf spheroidal (dSph) galaxy, obtained with Very Large Telescope/GIRAFFE (R ~ 16, 000). Due to the large fraction of metal-poor (MP) stars in our sample, we are able to follow the α-element evolution from [Fe/H] ≈ -2.5 continuously to [Fe/H] ≈ -0.7. For the first time we are able to resolve the turnover from the Type II supernovae (SNe) dominated, α-enhanced plateau down to subsolar [α/Fe] values, due to the onset of SNe Ia, and thus to trace the chemical enrichment efficiency of the galaxy. Our data support the general concept of an α-enhanced plateau at early epochs, followed by a well-defined "knee" caused by the onset of SNe Ia, and finally a second plateau with sub-solar [α/Fe] values. We find the position of this knee to be at [Fe/H] ≈ -1.9 and therefore significantly more MP than expected from comparison with other dSphs and standard evolutionary models. Surprisingly, this value is rather comparable to the knee in Sculptor, a dSph ~10 times less luminous than Fornax. Using chemical evolution models, we find that the position of the knee and the subsequent plateau at the sub-solar level can hardly be explained unless the galaxy experienced several discrete star formation (SF) events with a drastic variation in SF efficiency, while a uniform SF can be ruled out. One possible evolutionary scenario is that Fornax experienced one or several major accretion events from gas-rich systems in the past, so that its current stellar mass is not indicative of the chemical evolution environment at ancient times. If Fornax is the product of several smaller buildings blocks, this may also have implications for the understanding of the formation process of dSphs in general. This article is based on observations made with ESO Telescopes at the Paranal Observatory under program 082.B-0940(A).

  7. VizieR Online Data Catalog: Activity and accretion in γ Vel and Cha I (Frasca+, 2015)

    NASA Astrophysics Data System (ADS)

    Frasca, A.; Biazzo, K.; Lanzafame, A. C.; Alcala, J. M.; Brugaletta, E.; Klutsch, A.; Stelzer, B.; Sacco, G. G.; Spina, L.; Jeffries, R. D.; Montes, D.; Alfaro, E. J.; Barentsen, G.; Bonito, R.; Gameiro, J. F.; Lopez-Santiago, J.; Pace, G.; Pasquini, L.; Prisinzano, L.; Sousa, S. G.; Gilmore, G.; Randich, S.; Micela, G.; Bragaglia, A.; Flaccomio, E.; Bayo, A.; Costado, M. T.; Franciosini, E.; Hill, V.; Hourihane, A.; Jofre, P.; Lardo, C.; Maiorca, E.; Masseron, T.; Morbidelli, L.; Worley, C. C.

    2014-11-01

    We use the fundamental parameters (effective temperature, surface gravity, lithium abundance, and radial velocity) delivered by the GES consortium in the first internal data release to select the members of Gamma Vel and Cha I among the UVES and GIRAFFE spectroscopic observations. A total of 140 Gamma Vel members and 74 Cha I members were studied. The procedure adopted by the GES to derive stellar fundamental parameters provided also measures of the projected rotational velocity (vsini). We calculated stellar luminosities through spectral energy distributions, while stellar masses were derived by comparison with evolutionary tracks. The spectral subtraction of low-activity and slowly rotating templates, which are rotationally broadened to match the vsini of the targets, enabled us to measure the equivalent widths (EWs) and the fluxes in the Hα and Hβ lines. The Hα line was also used for identifying accreting objects, on the basis of its equivalent width and the width at the 10% of the line peak (10%W), and for evaluating the mass accretion rate (Macc). The distribution of vsini for the members of Gamma Vel displays a peak at about 10km/s with a tail toward faster rotators. There is also some indication of a different vsini distribution for the members of its two kinematical populations. Most of these stars have Hα fluxes corresponding to a saturated activity regime. We find a similar distribution, but with a narrower peak, for Cha I. Only a handful of stars in Gamma Vel display signatures of accretion, while many more accretors were detected in the younger Cha I, where the highest Hα fluxes are mostly due to accretion, rather than to chromospheric activity. Accreting and active stars occupy two different regions in a T_eff-flux diagram and we propose a criterion for distinguishing them. We derive M_acc in the ranges 10-11-10-9M⊙/yr and 10-10-10-7M⊙/yr for Gamma Vel and Cha I accretors, respectively. (4 data files).

  8. The extreme chemistry of multiple stellar populations in the metal-poor globular cluster NGC 4833

    NASA Astrophysics Data System (ADS)

    Carretta, E.; Bragaglia, A.; Gratton, R. G.; D'Orazi, V.; Lucatello, S.; Momany, Y.; Sollima, A.; Bellazzini, M.; Catanzaro, G.; Leone, F.

    2014-04-01

    Our FLAMES survey of Na-O anticorrelation in globular clusters (GCs) is extended to NGC 4833, a metal-poor GC with a long blue tail on the horizontal branch (HB). We present the abundance analysis for a large sample of 78 red giants based on UVES and GIRAFFE spectra acquired at the ESO-VLT. We derived abundances of Na, O, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Ba, La, and Nd. This is the first extensive study of this cluster from high resolution spectroscopy. On the scale of our survey, the metallicity of NGC 4833 is [Fe/H] = -2.015 ± 0.004 ± 0.084 dex (rms = 0.014 dex) from 12 stars observed with UVES, where the first error is from statistics and the second one refers to the systematic effects. The iron abundance in NGC 4833 is homogeneous at better than 6%. On the other hand, the light elements involved in proton-capture reactions at high temperature show the large star-to-star variations observed in almost all GCs studied so far. The Na-O anticorrelation in NGC 4833 is quite extended, as expected from the high temperatures reached by stars on the HB, and NGC 4833 contains a conspicuous fraction of stars with extreme [O/Na] ratios. More striking is the finding that large star-to-star variations are also seen for Mg, which spans a range of more than 0.5 dex in this GC. Depletions in Mg are correlated to the abundances of O and anti-correlated with Na, Al, and Si abundances. This pattern suggests the action of nuclear processing at unusually high temperatures, producing the extreme chemistry observed in the stellar generations of NGC 4833. These extreme changes are also seen in giants of the much more massive GCs M 54 and ω Cen, and our conclusion is that NGC 4833 has probably lost a conspicuous fraction of its original mass due to bulge shocking, as also indicated by its orbit. Based on observations collected at ESO telescopes under programmes 083.D-0208 and 68.D-0265.Full Tables 2, 6-11 are only available at the CDS via anonymous ftp to http

  9. The normal chemistry of multiple stellar populations in the dense globular cluster NGC 6093 (M 80)

    NASA Astrophysics Data System (ADS)

    Carretta, E.; Bragaglia, A.; Gratton, R. G.; D'Orazi, V.; Lucatello, S.; Sollima, A.; Momany, Y.; Catanzaro, G.; Leone, F.

    2015-06-01

    We present the abundance analysis of 82 red giant branch stars in the dense, metal-poor globular cluster NGC 6093 (M 80), the largest sample of stars analysed in this way for this cluster. From high-resolution UVES spectra of 14 stars and intermediate resolution GIRAFFE spectra for the other stars we derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu. On our UVES metallicity scale the mean metal abundance of M 80 is [Fe/H] = -1.791 ± 0.006 ± 0.076 (±statistical ±systematic error) with σ = 0.023 (14 stars). M 80 shows star-to-star variations in proton-capture elements, and the extension of the Na-O anti-correlation perfectly fit the relations with (i) total cluster mass; (ii) horizontal branch morphology; and (iii) cluster concentration previously found by our group. The chemistry of multiple stellar populations in M 80 does not look extreme. The cluster is also a representative of halo globular clusters concerning the pattern of α-capture and Fe-group elements. However we found that a significant contribution from the s-process is required to account for the distribution of neutron-capture elements. A minority of stars in M 80 seem to exhibit slightly enhanced abundances of s-process species, compatible with those observed in M 22 and NGC 1851, although further confirmation from larger samples is required. Based on observations collected at ESO telescopes under programme 083.D-0208.Full Tables 2, 3, 5-9 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/578/A116Appendix A is available in electronic form at http://www.aanda.org

  10. Pencil beam proton radiography using a multilayer ionization chamber.

    PubMed

    Farace, Paolo; Righetto, Roberto; Meijers, Arturs

    2016-06-01

    A pencil beam proton radiography (PR) method, using a commercial multilayer ionization chamber (MLIC) integrated with a treatment planning system (TPS) was developed. A Giraffe (IBA Dosimetry) MLIC (±0.5 mm accuracy) was used to obtain pencil beam PR by delivering spots uniformly positioned at a 5.0 mm distance in a 9  ×  9 square of spots. PRs of an electron-density (with tissue-equivalent inserts) phantom and a head phantom were acquired. The integral depth dose (IDD) curves of the delivered spots were computed by the TPS in a volume of water simulating the MLIC, and virtually added to the CT at the exit side of the phantoms. For each spot, measured and calculated IDD were overlapped in order to compute a map of range errors. On the head-phantom, the maximum dose from PR acquisition was estimated. Additionally, on the head phantom the impact on the range errors map was estimated in case of a 1 mm position misalignment. In the electron-density phantom, range errors were within 1 mm in the soft-tissue rods, but greater in the dense-rod. In the head-phantom the range errors were  -0.9  ±  2.7 mm on the whole map and within 1 mm in the brain area. On both phantoms greater errors were observed at inhomogeneity interfaces, due to sensitivity to small misalignment, and inaccurate TPS dose computation. The effect of the 1 mm misalignment was clearly visible on the range error map and produced an increased spread of range errors (-1.0  ±  3.8 mm on the whole map). The dose to the patient for such PR acquisitions would be acceptable as the maximum dose to the head phantom was  <2cGyE. By the described 2D method, allowing to discriminate misalignments, range verification can be performed in selected areas to implement an in vivo quality assurance program. PMID:27164479

  11. The metal-poor knee in the Fornax dwarf spheroidal galaxy

    SciTech Connect

    Hendricks, Benjamin; Koch, Andreas; Lanfranchi, Gustavo A.; Boeche, Corrado; Walker, Matthew; Johnson, Christian I.; Peñarrubia, Jorge; Gilmore, Gerard

    2014-04-20

    We present α-element abundances of Mg, Si, and Ti for a large sample of field stars in two outer fields of the Fornax dwarf spheroidal (dSph) galaxy, obtained with Very Large Telescope/GIRAFFE (R ∼ 16, 000). Due to the large fraction of metal-poor (MP) stars in our sample, we are able to follow the α-element evolution from [Fe/H] ≈ –2.5 continuously to [Fe/H] ≈ –0.7. For the first time we are able to resolve the turnover from the Type II supernovae (SNe) dominated, α-enhanced plateau down to subsolar [α/Fe] values, due to the onset of SNe Ia, and thus to trace the chemical enrichment efficiency of the galaxy. Our data support the general concept of an α-enhanced plateau at early epochs, followed by a well-defined 'knee' caused by the onset of SNe Ia, and finally a second plateau with sub-solar [α/Fe] values. We find the position of this knee to be at [Fe/H] ≈ –1.9 and therefore significantly more MP than expected from comparison with other dSphs and standard evolutionary models. Surprisingly, this value is rather comparable to the knee in Sculptor, a dSph ∼10 times less luminous than Fornax. Using chemical evolution models, we find that the position of the knee and the subsequent plateau at the sub-solar level can hardly be explained unless the galaxy experienced several discrete star formation (SF) events with a drastic variation in SF efficiency, while a uniform SF can be ruled out. One possible evolutionary scenario is that Fornax experienced one or several major accretion events from gas-rich systems in the past, so that its current stellar mass is not indicative of the chemical evolution environment at ancient times. If Fornax is the product of several smaller buildings blocks, this may also have implications for the understanding of the formation process of dSphs in general.

  12. Effects of wildlife and cattle on tick abundance in central Kenya.

    PubMed

    Keesing, Felicia; Allan, Brian F; Young, Truman P; Ostfeld, Richard S

    2013-09-01

    In African savannas, large mammals, both wild and domestic, support an abundant and diverse population of tick ectoparasites. Because of the density of ticks and the many pathogens that they vector, cattle in East Africa are often treated with acaricides. While acaricides are known to be effective at reducing tick burdens on cattle, their effects on the overall abundance and community composition of ticks in savanna ecosystems are less well understood. It is also not known how well tick populations can be maintained in the absence of large mammals. We evaluated the effects of wildlife and of acaricide-treated cattle on host-seeking tick populations in a long-term, exclusion experiment in central Kenya. Over seven years, we sampled larval, nymphal, and adult ticks monthly on replicated treatment plots that controlled for the presence of cattle and for the presence of two guilds of large wild mammals: megaherbivores (giraffes and elephants) and all other large wild herbivores (> 15 kg). Two species of ticks were found in this habitat; across all surveys, 93% were Rhipicephalus pulchellus and 7% were R. praetextatus. The presence of acaricide-treated cattle dramatically reduced the abundance of host-seeking nymphal and adult ticks but did not affect the abundance of host-seeking larval ticks. The abundance of larval ticks was determined by the presence of large wild mammals, which appear to import gravid female ticks into the experimental plots. On plots with no large mammals, either wild or domestic, larval and nymphal ticks were rare. Adult R. pulchellus were most abundant in plots that allowed wildlife but excluded cattle. Adult R. praetextatus were relatively abundant in plots without any large mammals. These differences suggest that these ticks utilize different members of the host community. The reduction in ticks that results from the presence of acaricide-treated cattle has potential health benefits for humans and wildlife, but these benefits must be weighed

  13. Physical parameters of NGC6705 (M11) open cluster using Strömgren photometry

    NASA Astrophysics Data System (ADS)

    Casamiquela, L.; Balaguer-Núñez, L.; Jordi, C.; Masana, E.

    2015-05-01

    NGC 6705 (M11) is a middle-age well-studied open cluster. Its location in an area where the interstellar extinction is relatively low, its exceptional stellar density and richness, and the presence of both early type and evolved stars makes this cluster an interesting target for many scientific issues. Although NGC 6705 has been widely studied, Strömgren photometry was missing. The observations by our team have yielded uvbyH photometry for 51293 stars in an area of 34'×34' and with V_{lim}˜21. Observed stars with complete photometry (9308) are classified into photometric regions and their physical parameters are determined using standard relations among color indices for each of the photometric regions of the HR diagram. That allows us to provide an astrophysical characterization of the cluster: E(b-y)=0.31±0.05 (E(B-V)=0.42); V_{0}-M_{V}=11.9±0.7 (d˜2000pc); [Fe/H]=-0.2±0.4 (Z=0.009). In addition, we discuss the accuracy of the physical parameters through comparison with those recently determined by Beaver et al. (2013) with Strömgren photometry. We find mean systematic differences of Δ V=-0.015±0.038, Δ (b-y)=-0.017±0.046, Δ m_{1}=-0.014±0.092, Δ c_{1}=+0.014±0.131, and Δ β=-0.036±0.042. These are caused by different selection of reference stars for the instrumental-to-standard transformation. We also compare our results with those from the spectroscopic Gaia-ESO Survey (GES) to assess the quality of the photometric determinations. This work can be useful to give input astrophysical parameters to the spectral analyses being made by GES. We find out clear different trends for the stars bluer and redder than (b-y)=0.4 (T_{eff}˜8000 K), due to the different instrumental setups used for the GIRAFFE observations (HR3 and HR15N). We find that mean differences in effective temperatures and gravities for both works are compatible within the errors. However, mean difference in metallicity for stars with (b-y)>0.4 is discrepant by -0.65 dex.

  14. Light, Alpha, and Fe-peak Element Abundances in the Galactic Bulge

    NASA Astrophysics Data System (ADS)

    Johnson, Christian I.; Rich, R. Michael; Kobayashi, Chiaki; Kunder, Andrea; Koch, Andreas

    2014-10-01

    We present radial velocities and chemical abundances of O, Na, Mg, Al, Si, Ca, Cr, Fe, Co, Ni, and Cu for a sample of 156 red giant branch stars in two Galactic bulge fields centered near (l, b) = (+5.25,-3.02) and (0,-12). The (+5.25,-3.02) field also includes observations of the bulge globular cluster NGC 6553. The results are based on high-resolution (R ~ 20,000), high signal-to-noise ration (S/N >~ 70) FLAMES-GIRAFFE spectra obtained through the European Southern Observatory archive. However, we only selected a subset of the original observations that included spectra with both high S/N and that did not show strong TiO absorption bands. This work extends previous analyses of this data set beyond Fe and the α-elements Mg, Si, Ca, and Ti. While we find reasonable agreement with past work, the data presented here indicate that the bulge may exhibit a different chemical composition than the local thick disk, especially at [Fe/H] >~ -0.5. In particular, the bulge [α/Fe] ratios may remain enhanced to a slightly higher [Fe/H] than the thick disk, and the Fe-peak elements Co, Ni, and Cu appear enhanced compared to the disk. There is also some evidence that the [Na/Fe] (but not [Al/Fe]) trends between the bulge and local disk may be different at low and high metallicity. We also find that the velocity dispersion decreases as a function of increasing [Fe/H] for both fields, and do not detect any significant cold, high-velocity populations. A comparison with chemical enrichment models indicates that a significant fraction of hypernovae may be required to explain the bulge abundance trends, and that initial mass functions that are steep, top-heavy (and do not include strong outflow), or truncated to avoid including contributions from stars >40 M ⊙ are ruled out, in particular because of disagreement with the Fe-peak abundance data. For most elements, the NGC 6553 stars exhibit abundance trends nearly identical to comparable metallicity bulge field stars. However, the

  15. The DART Imaging And CaT Survey of the Fornax Dwarf Spheroidal Galaxy

    SciTech Connect

    Battaglia, Giuseppina; Tolstoy, E.; Helmi, A.; Irwin, M.J.; Letarte, B.; Jablonka, P.; Hill, V.; Venn, K.A.; Shetrone, M.D.; Arimoto, N.; Primas, F.; Kaufer, A.; Francois, P.; Szeifert, T.; Abel, T.; Sadakane, K.; /Osaka Kyoiku U.

    2006-08-28

    As part of the DART project we have used the ESO/2.2m Wide Field Imager in conjunction with the VLT/FLAMES* GIRAFFE spectrograph to study the detailed properties of the resolved stellar population of the Fornax dwarf spheroidal galaxy out to and beyond its tidal radius. Fornax dSph has had a complicated evolution and contains significant numbers of young, intermediate age and old stars. We investigate the relation between these different components by studying their photometric, kinematic and abundance distributions. We re-derived the structural parameters of the Fornax dwarf spheroidal using our wide field imaging covering the galaxy out to its tidal radius, and analyzed the spatial distribution of the Fornax stars of different ages as selected from Colour-Magnitude Diagram analysis. We have obtained accurate velocities and metallicities from spectra in the Ca II triplet wavelength region for 562 Red Giant Branch stars which have velocities consistent with membership in Fornax dwarf spheroidal. We have found evidence for the presence of at least three distinct stellar components: a young population (few 100 Myr old) concentrated in the center of the galaxy, visible as a Main Sequence in the Colour-Magnitude Diagram; an intermediate age population (2-8 Gyr old); and an ancient population (> 10Gyr), which are distinguishable from each other kinematically, from the metallicity distribution and in the spatial distribution of stars found in the Colour-Magnitude Diagram. From our spectroscopic analysis we find that the ''metal rich'' stars ([Fe/H] > -1.3) show a less extended and more concentrated spatial distribution, and display a colder kinematics than the ''metal poor'' stars ([Fe/H] < -1.3). There is tentative evidence that the ancient stellar population in the center of Fornax does not exhibit equilibrium kinematics. This could be a sign of a relatively recent accretion of external material, such as the merger of another galaxy or other means of gas accretion at

  16. Chemical Composition of Intermediate-mass Star Members of the M6 (NGC 6405) Open Cluster

    NASA Astrophysics Data System (ADS)

    Kılıçoğlu, T.; Monier, R.; Richer, J.; Fossati, L.; Albayrak, B.

    2016-03-01

    We present here the first abundance analysis of 44 late B-, A-, and F-type members of the young open cluster M6 (NGC 6405, age about 75 Myr). Low- and medium-resolution spectra, covering the 4500-5840 Å wavelength range, were obtained using the FLAMES/GIRAFFE spectrograph attached to the ESO Very Large Telescopes. We determined the atmospheric parameters using calibrations of the Geneva photometry and by adjusting the Hβ profiles to synthetic ones. The abundances of up to 20 chemical elements, from helium to mercury, were derived for 19 late B, 16 A, and 9 F stars by iteratively adjusting synthetic spectra to the observations. We also derived a mean cluster metallicity of [Fe/H] = 0.07 ± 0.03 dex from the iron abundances of the F-type stars. We find that for most chemical elements, the normal late B- and A-type stars exhibit larger star-to-star abundance variations than the F-type stars probably because of the faster rotation of the B and A stars. The abundances of C, O, Mg, Si, and Sc appear to be anticorrelated with that of Fe, while the opposite holds for the abundances of Ca, Ti, Cr, Mn, Ni, Y, and Ba as expected if radiative diffusion is efficient in the envelopes of these stars. In the course of this analysis, we discovered five new peculiar stars: one mild Am, one Am, and one Fm star (HD 318091, CD-32 13109, GSC 07380-01211, CP1), one HgMn star (HD 318126, CP3), and one He-weak P-rich (HD 318101, CP4) star. We also discovered a new spectroscopic binary, most likely a SB2. We performed a detailed modeling of HD 318101, the new He-weak P-rich CP star, using the Montréal stellar evolution code XEVOL which self-consistently treats all particle transport processes. Although the overall abundance pattern of this star is properly reproduced, we find that detailed abundances (in particular the high P excess) resisted modeling attempts even when a range of turbulence profiles and mass-loss rates were considered. Solutions are proposed which are still under

  17. A selective deficit in imageable concepts: a window to the organization of the conceptual system.

    PubMed

    Gvion, Aviah; Friedmann, Naama

    2013-01-01

    Nissim, a 64 years old Hebrew-speaking man who sustained an ischemic infarct in the left occipital lobe, exhibited an intriguing pattern. He could hold a deep and fluent conversation about abstract and complex issues, such as the social risks in unemployment, but failed to retrieve imageable words such as ball, spoon, carrot, or giraffe. A detailed study of the words he could and could not retrieve, in tasks of picture naming, tactile naming, and naming to definition, indicated that whereas he was able to retrieve abstract words, he had severe difficulties when trying to retrieve imageable words. The same dissociation also applied for proper names-he could retrieve names of people who have no visual image attached to their representation (such as the son of the biblical Abraham), but could not name people who had a visual image (such as his own son, or Barack Obama). When he tried to produce imageable words, he mainly produced perseverations and empty speech, and some semantic paraphasias. He did not produce perseverations when he tried to retrieve abstract words. This suggests that perseverations may occur when the phonological production system produces a word without proper activation in the semantic lexicon. Nissim evinced a similar dissociation in comprehension-he could understand abstract words and sentences but failed to understand sentences with imageable words, and to match spoken imageable words to pictures or to semantically related imageable words. He was able to understand proverbs with imageable literal meaning but abstract figurative meaning. His comprehension was impaired also in tasks of semantic associations of pictures, pointing to a conceptual, rather than lexical source of the deficit. His visual perception as well as his phonological input and output lexicons and buffers (assessed by auditory lexical decision, word and sentence repetition, and writing to dictation) were intact, supporting a selective conceptual system impairment. He was able

  18. The Gaia-ESO Survey: Kinematics of seven Galactic globular clusters

    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.; Jofré, P.; de Laverny, P.; Marconi, G.; Masseron, T.; Morbidelli, L.; Sacco, G. G.; Worley, C. C.

    2015-01-01

    The Gaia-ESO survey is a large public spectroscopic survey aimed at investigating the origin and formation history of our Galaxy by collecting spectroscopy of representative samples (about 105 Milky Way stars) of all Galactic stellar populations, in the field and in clusters. The survey uses globular clusters as intra- and inter-survey calibrators, deriving stellar atmospheric parameters and abundances of a significant number of stars in clusters, along with radial velocity determinations. We used precise radial velocities of a large number of stars in seven globular clusters (NGC 1851, NGC 2808, NGC 4372, NGC 4833, NGC 5927, NGC 6752, and NGC 7078) to validate pipeline results and to preliminarily investigate the cluster internal kinematics. Radial velocity measurements were extracted from FLAMES/GIRAFFE spectra processed by the survey pipeline as part of the second internal data release of data products to ESO. We complemented our sample with ESO archival data obtained with different instrument configurations. Reliable radial velocity measurements for 1513 bona fide cluster star members were obtained in total. We measured systemic rotation, estimated central velocity dispersions, and present velocity dispersion profiles of all the selected clusters, providing the first velocity dispersion curve and the first estimate of the central velocitydispersion for the cluster NGC 5927. Finally, we explore the possible link between cluster kinematics and other physical parameters. The analysis we present here demonstrates that Gaia-ESO survey data are sufficiently accurate to be used in studies of kinematics of stellar systems and stellar populations in the Milky Way. Full Table 3 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/A115Based on data products from observations made with ESO telescopes at the La Silla Paranal Observatory under programme 188.B-3002 (the

  19. Atomic diffusion and mixing in old stars. V. A deeper look into the globular cluster NGC 6752

    NASA Astrophysics Data System (ADS)

    Gruyters, Pieter; Nordlander, Thomas; Korn, Andreas J.

    2014-07-01

    Context. Abundance trends in heavier elements with evolutionary phase have been shown to exist in the globular cluster NGC 6752 ([Fe / H] = -1.6). These trends are a result of atomic diffusion and additional (non-convective) mixing. Studying such trends can provide us with important constraints on the extent to which diffusion modifies the internal structure and surface abundances of solar-type, metal-poor stars. Aims: Taking advantage of a larger data sample, we investigate the reality and the size of these abundance trends and address questions and potential biases associated with the various stellar populations that make up NGC 6752. Methods: We perform an abundance analysis by combining photometric and spectroscopic data of 194 stars located between the turnoff point and the base of the red giant branch. Stellar parameters are derived from uvby Strömgren photometry. Using the quantitative-spectroscopy package SME, stellar surface abundances for light elements such as Li, Na, Mg, Al, and Si as well as heavier elements such as Ca, Ti, and Fe are derived in an automated way by fitting synthetic spectra to individual lines in the stellar spectra, obtained with the VLT/FLAMES-GIRAFFE spectrograph. Results: Based on uvby Strömgren photometry, we are able to separate three stellar populations in NGC 6752 along the evolutionary sequence from the base of the red giant branch down to the turnoff point. We find weak systematic abundance trends with evolutionary phase for Ca, Ti, and Fe which are best explained by stellar-structure models including atomic diffusion with efficient additional mixing. We derive a new value for the initial lithium abundance of NGC 6752 after correcting for the effect of atomic diffusion and additional mixing which falls slightly below the predicted standard BBN value. Conclusions: We find three stellar populations by combining photometric and spectroscopic data of 194 stars in the globular cluster NGC 6752. Abundance trends for groups of

  20. Manganese abundances in Galactic bulge red giants

    NASA Astrophysics Data System (ADS)

    Barbuy, B.; Hill, V.; Zoccali, M.; Minniti, D.; Renzini, A.; Ortolani, S.; Gómez, A.; Trevisan, M.; Dutra, N.

    2013-11-01

    Context. Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut between the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy. Manganese is also produced in type Ia SNe. Aims: The aim of this work is the study of abundances of the iron-peak element Mn in 56 bulge giants, among which 13 are red clump stars. Four bulge fields along the minor axis are inspected. The study of abundances of Mn-over-Fe as a function of metallicity in the Galactic bulge may shed light on its production mechanisms. Methods: High-resolution spectra were obtained using the FLAMES+UVES spectrograph on the Very Large Telescope. The spectra were obtained within a program to observe 800 stars using the GIRAFFE spectrograph, together with the present UVES spectra. Results: We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Galactic bulge. We find [Mn/Fe] ~ -0.7 at [Fe/H] ~ -1.3, increasing to a solar value at metallicities close to solar, and showing a spread around - 0.7 ≲ [Fe/H] ≲ -0.2, in good agreement with other work on Mn in bulge stars. There is also good agreement with chemical evolution models. We find no clear difference in the behaviour of the four bulge fields. Whereas [Mn/Fe] vs. [Fe/H] could be identified with the behaviour of the thick disc stars, [Mn/O] vs. [O/H] has a behaviour running parallel, at higher metallicities, compared to thick disc stars, indicating that the bulge enrichment might have proceeded differently from that of the thick disc. Observations collected at the European Southern Observatory, Paranal, Chile (ESO programmes 71.B-0617A, 73.B0074A, and GTO 71.B-0196).Tables 1-6 and Figs. 1-6 are available in electronic form at http://www.aanda.org

  1. Metallicity and kinematics of the bar in situ

    NASA Astrophysics Data System (ADS)

    Babusiaux, C.; Katz, D.; Hill, V.; Royer, F.; Gómez, A.; Arenou, F.; Combes, F.; Di Matteo, P.; Gilmore, G.; Haywood, M.; Robin, A. C.; Rodriguez-Fernandez, N.; Sartoretti, P.; Schultheis, M.

    2014-03-01

    Context. Constraints on the Galactic bulge and bar structures and on their formation history from stellar kinematics and metallicities mainly come from relatively high-latitude fields (|b| > 4°) where a complex mix of stellar population is seen. Aims: We aim here to constrain the formation history of the Galactic bar by studying the radial velocity and metallicity distributions of stars in situ (|b| ≤ 1°). Methods: We observed red clump stars in four fields along the bar's major axis (l = 10°, -6°, 6° and b = 0° plus a field at l = 0°, b = 1°) with low-resolution spectroscopy from FLAMES/GIRAFFE at the VLT, observing around the Ca ii triplet. We developed robust methods for extracting radial velocity and metallicity estimates from these low signal-to-noise spectra. We derived distance probability distributions using Bayesian methods rigorously handling the extinction law. Results: We present radial velocities and metallicity distributions, as well as radial velocity trends with distance. We observe an increase in the radial velocity dispersion near the Galactic plane. We detect the streaming motion of the stars induced by the bar in fields at l = ±6°, the highest velocity components of this bar stream being metal-rich ([Fe/H] ~ 0.2 dex). Our data is consistent with a bar that is inclined at 26 ± 3° from the Sun-Galactic centre line. We observe a significant fraction of metal-poor stars, in particular in the field at l = 0°, b = 1°. We confirm the flattening of the metallicity gradient along the minor axis when getting closer to the plane, with a hint that it could actually be inverted. Conclusions: Our stellar kinematics corresponds to the expected behaviour of a bar issued from the secular evolution of the Galactic disc. The mix of several populations, seen further away from the plane, is also seen in the bar in situ since our metallicity distributions highlight a different spatial distribution between metal-poor and metal-rich stars, the more

  2. Pencil beam proton radiography using a multilayer ionization chamber

    NASA Astrophysics Data System (ADS)

    Farace, Paolo; Righetto, Roberto; Meijers, Arturs

    2016-06-01

    A pencil beam proton radiography (PR) method, using a commercial multilayer ionization chamber (MLIC) integrated with a treatment planning system (TPS) was developed. A Giraffe (IBA Dosimetry) MLIC (±0.5 mm accuracy) was used to obtain pencil beam PR by delivering spots uniformly positioned at a 5.0 mm distance in a 9  ×  9 square of spots. PRs of an electron-density (with tissue-equivalent inserts) phantom and a head phantom were acquired. The integral depth dose (IDD) curves of the delivered spots were computed by the TPS in a volume of water simulating the M