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Sample records for african monarch danaus

  1. Color vision and learning in the monarch butterfly, Danaus plexippus (Nymphalidae).

    PubMed

    Blackiston, Douglas; Briscoe, Adriana D; Weiss, Martha R

    2011-02-01

    The monarch butterfly, Danaus plexippus, is well known for its intimate association with milkweed plants and its incredible multi-generational trans-continental migrations. However, little is known about monarch butterflies' color perception or learning ability, despite the importance of visual information to butterfly behavior in the contexts of nectar foraging, host-plant location and mate recognition. We used both theoretical and experimental approaches to address basic questions about monarch color vision and learning ability. Color space modeling based on the three known spectral classes of photoreceptors present in the eye suggests that monarchs should not be able to discriminate between long wavelength colors without making use of a dark orange lateral filtering pigment distributed heterogeneously in the eye. In the context of nectar foraging, monarchs show strong innate preferences, rapidly learn to associate colors with sugar rewards and learn non-innately preferred colors as quickly and proficiently as they do innately preferred colors. Butterflies also demonstrate asymmetric confusion between specific pairs of colors, which is likely a function of stimulus brightness. Monarchs readily learn to associate a second color with reward, and in general, learning parameters do not vary with temporal sequence of training. In addition, monarchs have true color vision; that is, they can discriminate colors on the basis of wavelength, independent of intensity. Finally, behavioral trials confirm that monarchs do make use of lateral filtering pigments to enhance long-wavelength discrimination. Our results demonstrate that monarchs are proficient and flexible color learners; these capabilities should allow them to respond rapidly to changing nectar availabilities as they travel over migratory routes, across both space and time.

  2. Establishment of a Monarch Butterfly (Danaus plexippus, Lepidoptera: Danaidae) Cell Line and its Susceptibility to Insect Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A cell line from the monarch butterfly Danaus plexippus designated BCIRL-DP-AM/JG was established from adult ovaries. The cell line consisted mainly of round cells and took a prolonged period of time in the growth medium ExCell 401 containing 10% fetal bovine serum and antibiotics before it could be...

  3. Climate Change May Alter Breeding Ground Distributions of Eastern Migratory Monarchs (Danaus plexippus) via Range Expansion of Asclepias Host Plants

    PubMed Central

    Lemoine, Nathan P.

    2015-01-01

    Climate change can profoundly alter species’ distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  4. Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus) via range expansion of Asclepias host plants.

    PubMed

    Lemoine, Nathan P

    2015-01-01

    Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  5. Migratory Connectivity of the Monarch Butterfly (Danaus plexippus): Patterns of Spring Re-Colonization in Eastern North America

    PubMed Central

    Miller, Nathan G.; Wassenaar, Leonard I.; Hobson, Keith A.; Norris, D. Ryan

    2012-01-01

    Each year, millions of monarch butterflies (Danaus plexippus) migrate up to 3000 km from their overwintering grounds in central Mexico to breed in eastern North America. Malcolm et al. (1993) articulated two non-mutually exclusive hypotheses to explain how Monarchs re-colonize North America each spring. The ‘successive brood’ hypothesis proposes that monarchs migrate from Mexico to the Gulf Coast, lay eggs and die, leaving northern re-colonization of the breeding range to subsequent generations. The ‘single sweep’ hypothesis proposes that overwintering monarchs continue to migrate northward after arriving on the Gulf coast and may reach the northern portion of the breeding range, laying eggs along the way. To examine these hypotheses, we sampled monarchs throughout the northern breeding range and combined stable-hydrogen isotopes (δD) to estimate natal origin with wing wear scores to differentiate between individuals born in the current vs. previous year. Similar to Malcolm et al. (1993), we found that the majority of the northern breeding range was re-colonized by the first generation of monarchs (90%). We also estimated that a small number of individuals (10%) originated directly from Mexico and, therefore adopted a sweep strategy. Contrary to Malcolm et al. (1993), we found that 62% of monarchs sampled in the Great Lakes originated from the Central U.S., suggesting that this region is important for sustaining production in the northern breeding areas. Our results provide new evidence of re-colonization patterns in monarchs and contribute important information towards identifying productive breeding regions of this unique migratory insect. PMID:22427813

  6. Migratory connectivity of the monarch butterfly (Danaus plexippus): patterns of spring re-colonization in eastern North America.

    PubMed

    Miller, Nathan G; Wassenaar, Leonard I; Hobson, Keith A; Norris, D Ryan

    2012-01-01

    Each year, millions of monarch butterflies (Danaus plexippus) migrate up to 3000 km from their overwintering grounds in central Mexico to breed in eastern North America. Malcolm et al. (1993) articulated two non-mutually exclusive hypotheses to explain how Monarchs re-colonize North America each spring. The 'successive brood' hypothesis proposes that monarchs migrate from Mexico to the Gulf Coast, lay eggs and die, leaving northern re-colonization of the breeding range to subsequent generations. The 'single sweep' hypothesis proposes that overwintering monarchs continue to migrate northward after arriving on the Gulf coast and may reach the northern portion of the breeding range, laying eggs along the way. To examine these hypotheses, we sampled monarchs throughout the northern breeding range and combined stable-hydrogen isotopes (δD) to estimate natal origin with wing wear scores to differentiate between individuals born in the current vs. previous year. Similar to Malcolm et al. (1993), we found that the majority of the northern breeding range was re-colonized by the first generation of monarchs (90%). We also estimated that a small number of individuals (10%) originated directly from Mexico and, therefore adopted a sweep strategy. Contrary to Malcolm et al. (1993), we found that 62% of monarchs sampled in the Great Lakes originated from the Central U.S., suggesting that this region is important for sustaining production in the northern breeding areas. Our results provide new evidence of re-colonization patterns in monarchs and contribute important information towards identifying productive breeding regions of this unique migratory insect.

  7. Quasi-extinction risk and population targets for the Eastern, migratory population of monarch butterflies (Danaus plexippus).

    PubMed

    Semmens, Brice X; Semmens, Darius J; Thogmartin, Wayne E; Wiederholt, Ruscena; López-Hoffman, Laura; Diffendorfer, Jay E; Pleasants, John M; Oberhauser, Karen S; Taylor, Orley R

    2016-03-21

    The Eastern, migratory population of monarch butterflies (Danaus plexippus), an iconic North American insect, has declined by ~80% over the last decade. The monarch's multi-generational migration between overwintering grounds in central Mexico and the summer breeding grounds in the northern U.S. and southern Canada is celebrated in all three countries and creates shared management responsibilities across North America. Here we present a novel Bayesian multivariate auto-regressive state-space model to assess quasi-extinction risk and aid in the establishment of a target population size for monarch conservation planning. We find that, given a range of plausible quasi-extinction thresholds, the population has a substantial probability of quasi-extinction, from 11-57% over 20 years, although uncertainty in these estimates is large. Exceptionally high population stochasticity, declining numbers, and a small current population size act in concert to drive this risk. An approximately 5-fold increase of the monarch population size (relative to the winter of 2014-15) is necessary to halve the current risk of quasi-extinction across all thresholds considered. Conserving the monarch migration thus requires active management to reverse population declines, and the establishment of an ambitious target population size goal to buffer against future environmentally driven variability.

  8. Quasi-extinction risk and population targets for the Eastern, migratory population of monarch butterflies (Danaus plexippus)

    USGS Publications Warehouse

    Semmens, Brice X.; Semmens, Darius J.; Thogmartin, Wayne E.; Wiederholt, Ruscena; Lopez-Hoffman, Laura; Diffendorfer, James E.; Pleasants, John M; Oberhauser, Karen S.; Taylor, Orley R

    2016-01-01

    The Eastern, migratory population of monarch butterflies (Danaus plexippus), an iconic North American insect, has declined by ~80% over the last decade. The monarch’s multi-generational migration between overwintering grounds in central Mexico and the summer breeding grounds in the northern U.S. and southern Canada is celebrated in all three countries and creates shared management responsibilities across North America. Here we present a novel Bayesian multivariate auto-regressive state-space model to assess quasi-extinction risk and aid in the establishment of a target population size for monarch conservation planning. We find that, given a range of plausible quasi-extinction thresholds, the population has a substantial probability of quasi-extinction, from 11–57% over 20 years, although uncertainty in these estimates is large. Exceptionally high population stochasticity, declining numbers, and a small current population size act in concert to drive this risk. An approximately 5-fold increase of the monarch population size (relative to the winter of 2014–15) is necessary to halve the current risk of quasi-extinction across all thresholds considered. Conserving the monarch migration thus requires active management to reverse population declines, and the establishment of an ambitious target population size goal to buffer against future environmentally driven variability.

  9. Quasi-extinction risk and population targets for the Eastern, migratory population of monarch butterflies (Danaus plexippus)

    PubMed Central

    Semmens, Brice X.; Semmens, Darius J.; Thogmartin, Wayne E.; Wiederholt, Ruscena; López-Hoffman, Laura; Diffendorfer, Jay E.; Pleasants, John M.; Oberhauser, Karen S.; Taylor, Orley R.

    2016-01-01

    The Eastern, migratory population of monarch butterflies (Danaus plexippus), an iconic North American insect, has declined by ~80% over the last decade. The monarch’s multi-generational migration between overwintering grounds in central Mexico and the summer breeding grounds in the northern U.S. and southern Canada is celebrated in all three countries and creates shared management responsibilities across North America. Here we present a novel Bayesian multivariate auto-regressive state-space model to assess quasi-extinction risk and aid in the establishment of a target population size for monarch conservation planning. We find that, given a range of plausible quasi-extinction thresholds, the population has a substantial probability of quasi-extinction, from 11–57% over 20 years, although uncertainty in these estimates is large. Exceptionally high population stochasticity, declining numbers, and a small current population size act in concert to drive this risk. An approximately 5-fold increase of the monarch population size (relative to the winter of 2014–15) is necessary to halve the current risk of quasi-extinction across all thresholds considered. Conserving the monarch migration thus requires active management to reverse population declines, and the establishment of an ambitious target population size goal to buffer against future environmentally driven variability. PMID:26997124

  10. Strength in numbers: high parasite burdens increase transmission of a protozoan parasite of monarch butterflies (Danaus plexippus).

    PubMed

    de Roode, Jacobus C; Chi, Jean; Rarick, Rachel M; Altizer, Sonia

    2009-08-01

    Parasites often produce large numbers of offspring within their hosts. High parasite burdens are thought to be important for parasite transmission, but can also lower host fitness. We studied the protozoan Ophryocystis elektroscirrha, a common parasite of monarch butterflies (Danaus plexippus), to quantify the benefits of high parasite burdens for parasite transmission. This parasite is transmitted vertically when females scatter spores onto eggs and host plant leaves during oviposition; spores can also be transmitted between mating adults. Monarch larvae were experimentally infected and emerging adult females were mated and monitored in individual outdoor field cages. We provided females with fresh host plant material daily and quantified their lifespan and lifetime fecundity. Parasite transmission was measured by counting the numbers of parasite spores transferred to eggs and host plant leaves. We also quantified spores transferred from infected females to their mating partners. Infected monarchs had shorter lifespans and lower lifetime fecundity than uninfected monarchs. Among infected females, those with higher parasite loads transmitted more parasite spores to their eggs and to host plant leaves. There was also a trend for females with greater parasite loads to transmit more spores to their mating partners. These results demonstrate that high parasite loads on infected butterflies confer a strong fitness advantage to the parasite by increasing between-host transmission.

  11. Population Genetics of Overwintering Monarch Butterflies, Danaus plexippus (Linnaeus), from Central Mexico Inferred from Mitochondrial DNA and Microsatellite Markers.

    PubMed

    Pfeiler, Edward; Nazario-Yepiz, Nestor O; Pérez-Gálvez, Fernan; Chávez-Mora, Cristina Alejandra; Laclette, Mariana Ramírez Loustalot; Rendón-Salinas, Eduardo; Markow, Therese Ann

    2017-03-01

    Population genetic variation and demographic history in Danaus plexippus (L.), from Mexico were assessed based on analyses of mitochondrial cytochrome c oxidase subunit I (COI; 658 bp) and subunit II (COII; 503 bp) gene segments and 7 microsatellite loci. The sample of 133 individuals included both migratory monarchs, mainly from 4 overwintering sites within the Monarch Butterfly Biosphere Reserve (MBBR) in central Mexico (states of Michoacán and México), and a nonmigratory population from Irapuato, Guanajuato. Haplotype (h) and nucleotide (π) diversities were relatively low, averaging 0.466 and 0.00073, respectively, for COI, and 0.629 and 0.00245 for COII. Analysis of molecular variance of the COI data set, which included additional GenBank sequences from a nonmigratory Costa Rican population, showed significant population structure between Mexican migratory monarchs and nonmigratory monarchs from both Mexico and Costa Rica, suggesting limited gene flow between the 2 behaviorally distinct groups. Interestingly, while the COI haplotype frequencies of the nonmigratory populations differed from the migratory, they were similar to each other, despite the great physical distance between them. Microsatellite analyses, however, suggested a lack of structure between the 2 groups, possibly owing to the number of significant deviations from Hardy-Weinberg equilibrium resulting from heterzoygote deficiencies found for most of the loci. Estimates of demographic history of the combined migratory MBBR monarch population, based on the mismatch distribution and Bayesian skyline analyses of the concatenated COI and COII data set (n = 89) suggested a population expansion dating to the late Pleistocene (~35000-40000 years before present) followed by a stable effective female population size (Nef) of about 6 million over the last 10000 years.

  12. Chasing migration genes: a brain expressed sequence tag resource for summer and migratory monarch butterflies (Danaus plexippus).

    PubMed

    Zhu, Haisun; Casselman, Amy; Reppert, Steven M

    2008-01-09

    North American monarch butterflies (Danaus plexippus) undergo a spectacular fall migration. In contrast to summer butterflies, migrants are juvenile hormone (JH) deficient, which leads to reproductive diapause and increased longevity. Migrants also utilize time-compensated sun compass orientation to help them navigate to their overwintering grounds. Here, we describe a brain expressed sequence tag (EST) resource to identify genes involved in migratory behaviors. A brain EST library was constructed from summer and migrating butterflies. Of 9,484 unique sequences, 6068 had positive hits with the non-redundant protein database; the EST database likely represents approximately 52% of the gene-encoding potential of the monarch genome. The brain transcriptome was cataloged using Gene Ontology and compared to Drosophila. Monarch genes were well represented, including those implicated in behavior. Three genes involved in increased JH activity (allatotropin, juvenile hormone acid methyltransfersase, and takeout) were upregulated in summer butterflies, compared to migrants. The locomotion-relevant turtle gene was marginally upregulated in migrants, while the foraging and single-minded genes were not differentially regulated. Many of the genes important for the monarch circadian clock mechanism (involved in sun compass orientation) were in the EST resource, including the newly identified cryptochrome 2. The EST database also revealed a novel Na+/K+ ATPase allele predicted to be more resistant to the toxic effects of milkweed than that reported previously. Potential genetic markers were identified from 3,486 EST contigs and included 1599 double-hit single nucleotide polymorphisms (SNPs) and 98 microsatellite polymorphisms. These data provide a template of the brain transcriptome for the monarch butterfly. Our "snap-shot" analysis of the differential regulation of candidate genes between summer and migratory butterflies suggests that unbiased, comprehensive transcriptional

  13. Chasing Migration Genes: A Brain Expressed Sequence Tag Resource for Summer and Migratory Monarch Butterflies (Danaus plexippus)

    PubMed Central

    Zhu, Haisun; Casselman, Amy; Reppert, Steven M.

    2008-01-01

    North American monarch butterflies (Danaus plexippus) undergo a spectacular fall migration. In contrast to summer butterflies, migrants are juvenile hormone (JH) deficient, which leads to reproductive diapause and increased longevity. Migrants also utilize time-compensated sun compass orientation to help them navigate to their overwintering grounds. Here, we describe a brain expressed sequence tag (EST) resource to identify genes involved in migratory behaviors. A brain EST library was constructed from summer and migrating butterflies. Of 9,484 unique sequences, 6068 had positive hits with the non-redundant protein database; the EST database likely represents ∼52% of the gene-encoding potential of the monarch genome. The brain transcriptome was cataloged using Gene Ontology and compared to Drosophila. Monarch genes were well represented, including those implicated in behavior. Three genes involved in increased JH activity (allatotropin, juvenile hormone acid methyltransfersase, and takeout) were upregulated in summer butterflies, compared to migrants. The locomotion-relevant turtle gene was marginally upregulated in migrants, while the foraging and single-minded genes were not differentially regulated. Many of the genes important for the monarch circadian clock mechanism (involved in sun compass orientation) were in the EST resource, including the newly identified cryptochrome 2. The EST database also revealed a novel Na+/K+ ATPase allele predicted to be more resistant to the toxic effects of milkweed than that reported previously. Potential genetic markers were identified from 3,486 EST contigs and included 1599 double-hit single nucleotide polymorphisms (SNPs) and 98 microsatellite polymorphisms. These data provide a template of the brain transcriptome for the monarch butterfly. Our “snap-shot” analysis of the differential regulation of candidate genes between summer and migratory butterflies suggests that unbiased, comprehensive transcriptional profiling

  14. Monarch butterflies (Danaus plexippus L.) use a magnetic compass for navigation.

    PubMed

    Etheredge, J A; Perez, S M; Taylor, O R; Jander, R

    1999-11-23

    Fall migratory monarch butterflies, tested for their directional responses to magnetic cues under three conditions, amagnetic, normal, and reversed magnetic fields, showed three distinct patterns. In the absence of a magnetic field, monarchs lacked directionality as a group. In the normal magnetic field, monarchs oriented to the southwest with a group pattern typical for migrants. When the horizontal component of the magnetic field was reversed, the butterflies oriented to the northeast. In contrast, nonmigratory monarchs lacked directionality in the normal magnetic field. The results are a direct demonstration of magnetic compass orientation in migratory insects.

  15. Experimental Examination of Intraspecific Density-Dependent Competition during the Breeding Period in Monarch Butterflies (Danaus plexippus)

    PubMed Central

    Flockhart, D. T. Tyler; Martin, Tara G.; Norris, D. Ryan

    2012-01-01

    A central goal of population ecology is to identify the factors that regulate population growth. Monarch butterflies (Danaus plexippus) in eastern North America re-colonize the breeding range over several generations that result in population densities that vary across space and time during the breeding season. We used laboratory experiments to measure the strength of density-dependent intraspecific competition on egg laying rate and larval survival and then applied our results to density estimates of wild monarch populations to model the strength of density dependence during the breeding season. Egg laying rates did not change with density but larvae at high densities were smaller, had lower survival, and weighed less as adults compared to lower densities. Using mean larval densities from field surveys resulted in conservative estimates of density-dependent population reduction that varied between breeding regions and different phases of the breeding season. Our results suggest the highest levels of population reduction due to density-dependent intraspecific competition occur early in the breeding season in the southern portion of the breeding range. However, we also found that the strength of density dependence could be almost five times higher depending on how many life-stages were used as part of field estimates. Our study is the first to link experimental results of a density-dependent reduction in vital rates to observed monarch densities in the wild and show that the effects of density dependent competition in monarchs varies across space and time, providing valuable information for developing robust, year-round population models in this migratory organism. PMID:22984614

  16. Experimental examination of intraspecific density-dependent competition during the breeding period in monarch butterflies (Danaus plexippus).

    PubMed

    Flockhart, D T Tyler; Martin, Tara G; Norris, D Ryan

    2012-01-01

    A central goal of population ecology is to identify the factors that regulate population growth. Monarch butterflies (Danaus plexippus) in eastern North America re-colonize the breeding range over several generations that result in population densities that vary across space and time during the breeding season. We used laboratory experiments to measure the strength of density-dependent intraspecific competition on egg laying rate and larval survival and then applied our results to density estimates of wild monarch populations to model the strength of density dependence during the breeding season. Egg laying rates did not change with density but larvae at high densities were smaller, had lower survival, and weighed less as adults compared to lower densities. Using mean larval densities from field surveys resulted in conservative estimates of density-dependent population reduction that varied between breeding regions and different phases of the breeding season. Our results suggest the highest levels of population reduction due to density-dependent intraspecific competition occur early in the breeding season in the southern portion of the breeding range. However, we also found that the strength of density dependence could be almost five times higher depending on how many life-stages were used as part of field estimates. Our study is the first to link experimental results of a density-dependent reduction in vital rates to observed monarch densities in the wild and show that the effects of density dependent competition in monarchs varies across space and time, providing valuable information for developing robust, year-round population models in this migratory organism.

  17. Mortality of the Monarch Butterfly (Danaus plexippus L.): Avian Predation at Five Overwintering Sites in Mexico.

    PubMed

    Calvert, W H; Hedrick, L E; Brower, L P

    1979-05-25

    Analyses of predated butterflies on the forest floor at five monarch overwintering sites in Mexico and observations of birds foraging in mixed flocks indicate that individual birds of several species have learned to penetrate the monarch's cardenolide-based chemical defense. Predation is inversely proportional to colony size and appears to be one evolutionary explanation of the dense aggregations.

  18. Effects of the protozoan parasite ophryocystis elektroscirrha on the fitness of monarch butterflies (Danaus plexippus)

    PubMed

    Altizer; Oberhauser

    1999-07-01

    We evaluated the effects of the protozoan parasite Ophryocystis elektroscirrha on the survival and reproduction of monarch butterflies. Because larvae in natural populations are likely to experience a wide range of natural parasite population densities, we examined the effects of increasing spore density (0, 10, 100, or 1000 spores per larva) on host fitness. Parasites had little effect on monarch survival or reproduction, except at the highest dose. Monarchs inoculated with 1000 spores per larva had decreased survival to eclosion, and this effect was more severe when larvae were inoculated at an earlier stage (first versus third instar). Monarchs inoculated with higher spore densities also emerged with smaller wingspans and lower body mass than noninoculated adults. Infection with the highest dose of O. elektroscirrha led to decreased male lifespan and reproductive success, but females infected with O. elektroscirrha did not experience a significant decline in lifetime fecundity. However, heavily infected females in outdoor enclosures were less active than uninfected females and gained weight during their adult lifespan. Among samples of adult monarchs captured in natural populations, parasite loads were associated with butterfly condition and activity. Heavily infected adults captured breeding in western North America and southern Florida were smaller than uninfected monarchs. Among overwintering adults in Mexico and California, mating activity was positively associated with higher parasite loads. In addition, the proportion of adults with low and intermediate spore loads (as opposed to no spores) was higher among adults with greater wing tatter and scale loss. Our findings of minor effects of O. elektroscirrha on the survival and reproduction of monarch butterflies are consistent with the expectation that maternally transmitted parasites should have little or no effect on host fitness compared with horizontally transmitted parasites. However, because our

  19. Secondary Defense Chemicals in Milkweed Reduce Parasite Infection in Monarch Butterflies, Danaus plexippus.

    PubMed

    Gowler, Camden D; Leon, Kristoffer E; Hunter, Mark D; de Roode, Jacobus C

    2015-06-01

    In tri-trophic systems, herbivores may benefit from their host plants in fighting parasitic infections. Plants can provide parasite resistance in two contrasting ways: either directly, by interfering with the parasite, or indirectly, by increasing herbivore immunity or health. In monarch butterflies, the larval diet of milkweed strongly influences the fitness of a common protozoan parasite. Toxic secondary plant chemicals known as cardenolides correlate strongly with parasite resistance of the host, with greater cardenolide concentrations in the larval diet leading to lower parasite growth. However, milkweed cardenolides may covary with other indices of plant quality including nutrients, and a direct experimental link between cardenolides and parasite performance has not been established. To determine if the anti-parasitic activity of milkweeds is indeed due to secondary chemicals, as opposed to nutrition, we supplemented the diet of infected and uninfected monarch larvae with milkweed latex, which contains cardenolides but no nutrients. Across three experiments, increased dietary cardenolide concentrations reduced parasite growth in infected monarchs, which consequently had longer lifespans. However, uninfected monarchs showed no differences in lifespan across treatments, confirming that cardenolide-containing latex does not increase general health. Our results suggest that cardenolides are a driving force behind plant-derived resistance in this system.

  20. Preliminary characterization of iron-containing material and of neuronal assembles responsive to magnetic stimulation in the monarch butterfly (Danaus plexippus)

    NASA Astrophysics Data System (ADS)

    Fuentes, A.; Barrera, J.; Rizi, A.; Urrutia, J.; Gutierrez, G.

    2007-05-01

    Migration is a common process among animal groups. Most of the biological events underlying migratory behavior are yet unknown. This is especially true for the neural mechanisms and the sensory information used by migratory species to define their routes. Hence, the present work aimed at demonstrating that the Monarch butterflies (Danaus plexippus) may use magnetic cues to define their route of migration by mapping neuronal assembles responsive to magnetic stimuli. Because research conducted in other insect species suggests that magnetite-based receptors may transduce the magnetic information into neuronal codes, we also evaluated the presence of magnetite in the body of the monarch butterfly. Our electron microscopy results demonstrate that the butterfly's head, abdomen and thorax contain iron particles of about 1-5 mm in diameter. Accordingly, Prussian blue histochemical techniques revealed the presence of abundant ferric deposits in diverse regions of the nervous system and the ventral abdomen. In contrast, the thoracic segments have only a few deposits. Finally, magneto metric measures concord with the morphological results. With regard to the mapping of the neuronal assembles responsive to magnetic stimuli, we were able to revealed c-fos immunoreactivity in groups of neurons located in the retina, lamina, lobula and deutero-cerebrum in butterflies subjected to magnetic stimuli. In sum, we believe that our results provide preliminary evidence supporting the existence of 1) a neural pathway capable of processing magnetic information in the monarch butterfly and 2) the presence of magnetite-like material in the various segments of its body.

  1. Directions of migrating monarch butterflies (Danaus Plexippus; Danaidae; Lepidoptera) in some parts of the eastern United States.

    PubMed

    Schmidt-Koenig, K

    1979-04-01

    In September 1977, the directions of 477 migrating monarch butterflies were recorded at five locations in the Eastern United States. The monarchs moved highly directed generally to the southwest, roughly in accordance with the orthodrome direction, to their assumed winter quarter in Mexico. Deviations from the precise direction seemed to be due at least partly to wind drift; major drift required navigational compensation.

  2. The influence of eastern North American autumnal migrant monarch butterflies (Danaus plexippus L.) on continuously breeding resident monarch populations in southern Florida.

    PubMed

    Knight, Amy; Brower, Lincoln P

    2009-07-01

    In Florida, the eastern North American population of the monarch butterfly exhibits geographic variability in population structure and dynamics. This includes the occurrence of migrants throughout the peninsula during the autumnal migration, occasional overwintering clusters that form along the Gulf Coast, remigrants from Mexico that breed in north-central Florida during the spring, and what have been assumed to be year-round, resident breeding populations in southern Florida. The work reported here focused on two monarch populations west of Miami and addressed four questions: Are there permanent resident populations of monarchs in southern Florida? Do these breed continuously throughout the year? Do they receive northern monarchs moving south during the autumn migration? Do they receive overwintered monarchs returning via Cuba or the Yucatan during the spring remigration from the Mexican overwintering area? Monthly collections and counts of spermatophores in the bursa copulatrices of females established that a resident population of continuously breeding monarchs exists year-round in southern Florida. It was determined through cardenolide fingerprinting that most of the butterflies had bred on the local southern Florida milkweed species, Asclepias curassavica. During the autumn migration period, however, some monarchs had fed on the northern milkweed, Asclepias syriaca. It appears that instead of migrating to Mexico, these individuals travel south through peninsular Florida, break diapause, mate with and become incorporated into the resident breeding populations. None of the monarchs captured in spring had the A. syriaca cardenolide fingerprint, which is evidence against the southern Florida populations receiving overwintered remigrants from Cuba, Central America or Mexico.

  3. Purification and Characterization of the Danaus Plexippus Cryptochromes

    DTIC Science & Technology

    2006-01-01

    independent transcriptional repressor activity (mammalian). Recently, two cryptochromes from the monarch butterfly (Danaus plexippus) have been identified...have been identified in the monarch butterfly , Danaus plexippus: DpCryl which shows moderate sequence homology to dCry (62), and DpCry2 which shows...Danaus plexippus ( monarch butterfly ). Therefore, I purified insect-like DpCryl and mammalian-like DpCry2 from a bacterial expression system using low

  4. Complete mitochondrial genome recovered from the gut metagenome of overwintering monarch butterflies, Danaus plexippus (L.) (Lepidoptera: Nymphalidae, Danainae).

    PubMed

    Servín-Garcidueñas, Luis E; Martínez-Romero, Esperanza

    2014-12-01

    We present a 15,314 bp mitochondrial genome (mitogenome) sequence from monarch butterflies overwintering in Mexico. The complete mitogenome was generated by next generation sequencing techniques and was reconstructed by iterative assembly of reads from a metagenomic study of pooled butterfly gut DNA. The mitogenome codes for 13 putative protein coding genes, 22 tRNA genes, the large and small rRNA genes, and contains the A + T-rich sequence corresponding to the control region. The consensus sequence presented here has a depth of coverage of 142-fold and only three putative single nucleotide polymorphisms could be detected. The recovered D. plexippus mitogenome represents the second analyzed for the subfamily Danainae and accordingly, the closest available sequenced mitogenome was found to be the one corresponding to Euploea mulciber (Lepidoptera: Nymphalidae, Danainae).

  5. Selection of Reference Genes for RT-qPCR Analysis in the Monarch Butterfly, Danaus plexippus (L.), a Migrating Bio-Indicator

    PubMed Central

    Bidne, Keith; Hellmich, Richard L.; Siegfried, Blair D.; Zhou, Xuguo

    2015-01-01

    Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) is a powerful technique to quantify gene expression. To facilitate gene expression study and obtain accurate results, normalization relative to stably expressed reference genes is crucial. The monarch butterfly, Danaus plexippus (L.), is one of the most recognized insect species for its spectacular annual migration across North America. Besides its great voyages, D. plexippus has drawn attention to its role as a bio-indicator, ranging from genetically modified organisms (GMOs) to natural ecosystems. In this study, nine reference genes from D. plexippus genome were selected as the candidate reference genes. The expression profiles of these candidates under various biotic and abiotic conditions were evaluated using the four readily available computational programs, BestKeeper, Normfinder, geNorm, and ΔCt method, respectively. Moreover, RefFinder, a web-based computational platform integrating the four above mentioned algorisms, provided a comprehensive ranking of the stability of these reference genes. As a result, a suite of reference genes were recommended for each experimental condition. Specifically, elongation factor 1α (EF1A) and ribosomal protein 49 (RP49) were the most stable reference genes, respectively, under biotic (development, tissue, and sex) and abiotic (photoperiod, temperature, and dietary RNAi) conditions. With the recent release of a 273-million base pair draft genome, results from this study allow us to establish a standardized RT-qPCR analysis and lay a foundation for the subsequent genomic and functional genomic research in D. plexippus, a major bio-indicator and an emerging model for migratory animals. PMID:26030778

  6. Selection of Reference Genes for RT-qPCR Analysis in the Monarch Butterfly, Danaus plexippus (L.), a Migrating Bio-Indicator.

    PubMed

    Pan, Huipeng; Yang, Xiaowei; Bidne, Keith; Hellmich, Richard L; Siegfried, Blair D; Zhou, Xuguo

    2015-01-01

    Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) is a powerful technique to quantify gene expression. To facilitate gene expression study and obtain accurate results, normalization relative to stably expressed reference genes is crucial. The monarch butterfly, Danaus plexippus (L.), is one of the most recognized insect species for its spectacular annual migration across North America. Besides its great voyages, D. plexippus has drawn attention to its role as a bio-indicator, ranging from genetically modified organisms (GMOs) to natural ecosystems. In this study, nine reference genes from D. plexippus genome were selected as the candidate reference genes. The expression profiles of these candidates under various biotic and abiotic conditions were evaluated using the four readily available computational programs, BestKeeper, Normfinder, geNorm, and ΔCt method, respectively. Moreover, RefFinder, a web-based computational platform integrating the four above mentioned algorisms, provided a comprehensive ranking of the stability of these reference genes. As a result, a suite of reference genes were recommended for each experimental condition. Specifically, elongation factor 1α (EF1A) and ribosomal protein 49 (RP49) were the most stable reference genes, respectively, under biotic (development, tissue, and sex) and abiotic (photoperiod, temperature, and dietary RNAi) conditions. With the recent release of a 273-million base pair draft genome, results from this study allow us to establish a standardized RT-qPCR analysis and lay a foundation for the subsequent genomic and functional genomic research in D. plexippus, a major bio-indicator and an emerging model for migratory animals.

  7. Clocks, cryptochromes and Monarch migrations.

    PubMed

    Kyriacou, Charalambos P

    2009-01-01

    The annual migration of the Monarch butterfly (Danaus plexippus) from eastern North America to central Mexico is one of nature's most inspiring spectacles. Recent studies including one in BMC Biology, have begun to dissect the molecular and neurogenetic basis for this most complex behavior.

  8. Neurobiology of Monarch Butterfly Migration.

    PubMed

    Reppert, Steven M; Guerra, Patrick A; Merlin, Christine

    2016-01-01

    Studies of the migration of the eastern North American monarch butterfly (Danaus plexippus) have revealed mechanisms behind its navigation. The main orientation mechanism uses a time-compensated sun compass during both the migration south and the remigration north. Daylight cues, such as the sun itself and polarized light, are processed through both eyes and integrated through intricate circuitry in the brain's central complex, the presumed site of the sun compass. Monarch circadian clocks have a distinct molecular mechanism, and those that reside in the antennae provide time compensation. Recent evidence shows that migrants can also use a light-dependent inclination magnetic compass for orientation in the absence of directional daylight cues. The monarch genome has been sequenced, and genetic strategies using nuclease-based technologies have been developed to edit specific genes. The monarch butterfly has emerged as a model system to study the neural, molecular, and genetic basis of long-distance animal migration.

  9. Plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,Danaus plexippus reared on the milkweed,Asclepias eriocarpa in California.

    PubMed

    Brower, L P; Seiber, J N; Nelson, C J; Lynch, S P; Tuskes, P M

    1982-03-01

    This paper is the first in a series on cardenolide fingerprinting of the monarch butterfly. New methodologies are presented which allow both qualitative and quantitative descriptions of the constituent cardenolides which these insects derive in the wild from specificAsclepias foodplants. Analyses of thin-layer Chromatographic profiles ofAsclepias eriocarpa cardenolides in 85 individual plant-butterfly pairs collected at six widely separate localities in California indicate a relatively invariant pattern of 16-20 distinct cardenolides which we here define as theAsclepias eriocarpa cardenolide fingerprint profile. Cardenolide concentrations vary widely in the plant samples, but monarchs appear able to regulate total storage by increasing their concentrations relative to their larval host plant when reared on plants containing low concentrations, and vice versa. Forced-feeding of blue jays with powdered butterfly and plant material and with one of the constituent plant cardenolides, labriformin, established that theA. eriocarpa cardenolides are extremely emetic, and that monarchs which have fed on this plant contain an average of 16 emetic-dose fifty (ED50) units. The relatively nonpolar labriformin and labriformidin in the plant are not stored by the monarch but are metabolized in vivo to desglucosyrioside which the butterfly does store. This is chemically analogous to the way in which monarchs and grasshoppers metabolize another series of milkweed cardenolides, those found inA. curassavica. It appears that the sugar moiety through functionality at C-3' determines which cardenolides are metabolized and which are stored. The monarch also appears able to store several lowR f cardenolides fromA. eriocarpa without altering them. Differences in the sequestering process in monarchs and milkweed bugs (Oncopeltus) may be less than emphasized in the literature. The monarch is seen as a central organism involved in a coevolutionary triad simultaneously affecting and affected

  10. MonarchBase: the monarch butterfly genome database

    PubMed Central

    Zhan, Shuai; Reppert, Steven M.

    2013-01-01

    The monarch butterfly (Danaus plexippus) is emerging as a model organism to study the mechanisms of circadian clocks and animal navigation, and the genetic underpinnings of long-distance migration. The initial assembly of the monarch genome was released in 2011, and the biological interpretation of the genome focused on the butterfly’s migration biology. To make the extensive data associated with the genome accessible to the general biological and lepidopteran communities, we established MonarchBase (available at http://monarchbase.umassmed.edu). The database is an open-access, web-available portal that integrates all available data associated with the monarch butterfly genome. Moreover, MonarchBase provides access to an updated version of genome assembly (v3) upon which all data integration is based. These include genes with systematic annotation, as well as other molecular resources, such as brain expressed sequence tags, migration expression profiles and microRNAs. MonarchBase utilizes a variety of retrieving methods to access data conveniently and for integrating biological interpretations. PMID:23143105

  11. MonarchBase: the monarch butterfly genome database.

    PubMed

    Zhan, Shuai; Reppert, Steven M

    2013-01-01

    The monarch butterfly (Danaus plexippus) is emerging as a model organism to study the mechanisms of circadian clocks and animal navigation, and the genetic underpinnings of long-distance migration. The initial assembly of the monarch genome was released in 2011, and the biological interpretation of the genome focused on the butterfly's migration biology. To make the extensive data associated with the genome accessible to the general biological and lepidopteran communities, we established MonarchBase (available at http://monarchbase.umassmed.edu). The database is an open-access, web-available portal that integrates all available data associated with the monarch butterfly genome. Moreover, MonarchBase provides access to an updated version of genome assembly (v3) upon which all data integration is based. These include genes with systematic annotation, as well as other molecular resources, such as brain expressed sequence tags, migration expression profiles and microRNAs. MonarchBase utilizes a variety of retrieving methods to access data conveniently and for integrating biological interpretations.

  12. Monarch Migration.

    ERIC Educational Resources Information Center

    Williamson, Brad; Taylor, Orley

    1996-01-01

    Describes the Monarch Watch program that tracks the migration of the monarch butterfly. Presents activities that introduce students to research and international collaboration between students and researchers. Familiarizes students with monarchs, stimulates their interest, and helps them generate questions that can lead to good research projects.…

  13. The genetics of monarch butterfly migration and warning colouration.

    PubMed

    Zhan, Shuai; Zhang, Wei; Niitepõld, Kristjan; Hsu, Jeremy; Haeger, Juan Fernández; Zalucki, Myron P; Altizer, Sonia; de Roode, Jacobus C; Reppert, Steven M; Kronforst, Marcus R

    2014-10-16

    The monarch butterfly, Danaus plexippus, is famous for its spectacular annual migration across North America, recent worldwide dispersal, and orange warning colouration. Despite decades of study and broad public interest, we know little about the genetic basis of these hallmark traits. Here we uncover the history of the monarch's evolutionary origin and global dispersal, characterize the genes and pathways associated with migratory behaviour, and identify the discrete genetic basis of warning colouration by sequencing 101 Danaus genomes from around the globe. The results rewrite our understanding of this classic system, showing that D. plexippus was ancestrally migratory and dispersed out of North America to occupy its broad distribution. We find the strongest signatures of selection associated with migration centre on flight muscle function, resulting in greater flight efficiency among migratory monarchs, and that variation in monarch warning colouration is controlled by a single myosin gene not previously implicated in insect pigmentation.

  14. Fire creates host plant patches for monarch butterflies.

    PubMed

    Baum, Kristen A; Sharber, Wyatt V

    2012-12-23

    Monarch butterflies (Danaus plexippus) depend on the presence of host plants (Asclepias spp.) within their breeding range for reproduction. In the southern Great Plains, Asclepias viridis is a perennial that flowers in May and June, and starts to senesce by August. It is locally abundant and readily used by monarchs as a host plant. We evaluated the effects of summer prescribed fire on A. viridis and the use of A. viridis by monarch butterflies. Summer prescribed fire generated a newly emergent population of A. viridis that was absent in other areas. Pre-migrant monarch butterflies laid eggs on A. viridis in summer burned plots in late August and September, allowing adequate time for a new generation of adult monarchs to emerge and migrate south to their overwintering grounds. Thus, summer prescribed fire may provide host plant patches and/or corridors for pre-migrant monarchs during a time when host plant availability may be limited in other areas.

  15. Do Healthy Monarchs Migrate Farther? Tracking Natal Origins of Parasitized vs. Uninfected Monarch Butterflies Overwintering in Mexico.

    PubMed

    Altizer, Sonia; Hobson, Keith A; Davis, Andrew K; De Roode, Jacobus C; Wassenaar, Leonard I

    2015-01-01

    Long-distance migration can lower parasite prevalence if strenuous journeys remove infected animals from wild populations. We examined wild monarch butterflies (Danaus plexippus) to investigate the potential costs of the protozoan Ophryocystis elektroscirrha on migratory success. We collected monarchs from two wintering sites in central Mexico to compare infection status with hydrogen isotope (δ2H) measurements as an indicator of latitude of origin at the start of fall migration. On average, uninfected monarchs had lower δ2H values than parasitized butterflies, indicating that uninfected butterflies originated from more northerly latitudes and travelled farther distances to reach Mexico. Within the infected class, monarchs with higher quantitative spore loads originated from more southerly latitudes, indicating that heavily infected monarchs originating from farther north are less likely to reach Mexico. We ruled out the alternative explanation that lower latitudes give rise to more infected monarchs prior to the onset of migration using citizen science data to examine regional differences in parasite prevalence during the summer breeding season. We also found a positive association between monarch wing area and estimated distance flown. Collectively, these results emphasize that seasonal migrations can help lower infection levels in wild animal populations. Our findings, combined with recent declines in the numbers of migratory monarchs wintering in Mexico and observations of sedentary (winter breeding) monarch populations in the southern U.S., suggest that shifts from migratory to sedentary behavior will likely lead to greater infection prevalence for North American monarchs.

  16. Do Healthy Monarchs Migrate Farther? Tracking Natal Origins of Parasitized vs. Uninfected Monarch Butterflies Overwintering in Mexico

    PubMed Central

    Altizer, Sonia; Hobson, Keith A.; Davis, Andrew K.; De Roode, Jacobus C.; Wassenaar, Leonard I.

    2015-01-01

    Long-distance migration can lower parasite prevalence if strenuous journeys remove infected animals from wild populations. We examined wild monarch butterflies (Danaus plexippus) to investigate the potential costs of the protozoan Ophryocystis elektroscirrha on migratory success. We collected monarchs from two wintering sites in central Mexico to compare infection status with hydrogen isotope (δ2H) measurements as an indicator of latitude of origin at the start of fall migration. On average, uninfected monarchs had lower δ2H values than parasitized butterflies, indicating that uninfected butterflies originated from more northerly latitudes and travelled farther distances to reach Mexico. Within the infected class, monarchs with higher quantitative spore loads originated from more southerly latitudes, indicating that heavily infected monarchs originating from farther north are less likely to reach Mexico. We ruled out the alternative explanation that lower latitudes give rise to more infected monarchs prior to the onset of migration using citizen science data to examine regional differences in parasite prevalence during the summer breeding season. We also found a positive association between monarch wing area and estimated distance flown. Collectively, these results emphasize that seasonal migrations can help lower infection levels in wild animal populations. Our findings, combined with recent declines in the numbers of migratory monarchs wintering in Mexico and observations of sedentary (winter breeding) monarch populations in the southern U.S., suggest that shifts from migratory to sedentary behavior will likely lead to greater infection prevalence for North American monarchs. PMID:26606389

  17. Occurrence and host specificity of a neogregarine protozoan in four milkweed butterfly hosts (Danaus spp.).

    PubMed

    Barriga, Paola A; Sternberg, Eleanore D; Lefèvre, Thierry; de Roode, Jacobus C; Altizer, Sonia

    2016-10-01

    Throughout their global range, wild monarch butterflies (Danaus plexippus) are infected with the protozoan Ophryocystis elektroscirrha (OE). In monarchs, OE infection reduces pupal eclosion, adult lifespan, adult body size and flight ability. Infection of other butterfly hosts with OE is rare or unknown, and the only previously published records of OE infection were on monarch and queen butterflies (D. gilippus). Here we explored the occurrence and specificity of OE and OE-like parasites in four Danaus butterfly species. We surveyed wild D. eresimus (soldier), D. gilippus (queen), D. petilia (lesser wanderer), and D. plexippus (monarch) from five countries to determine the presence of infection. We conducted five cross-infection experiments, on monarchs and queen butterflies and their OE and OE-like parasites, to determine infection probability and the impact of infection on their hosts. Our field survey showed that OE-like parasites were present in D. gilippus, D. petilia, and D. plexippus, but were absent in D. eresimus. Infection probability varied geographically such that D. gilippus and D. plexippus populations in Puerto Rico and Trinidad were not infected or had low prevalence of infection, whereas D. plexippus from S. Florida and Australia had high prevalence. Cross-infection experiments showed evidence for host specificity, in that OE strains from monarchs were more effective at infecting monarchs than queens, and monarchs were less likely to be infected by OE-like strains from queens and lesser wanderers relative to their own natal strains. Our study showed that queens are less susceptible to OE and OE-like infection than monarchs, and that the reduction in adult lifespan following infection is more severe in monarchs than in queens.

  18. The genetics of monarch butterfly migration and warning coloration

    PubMed Central

    Zhan, Shuai; Zhang, Wei; Niitepõld, Kristjan; Hsu, Jeremy; Haeger, Juan Fernández; Zalucki, Myron P.; Altizer, Sonia; de Roode, Jacobus C.; Reppert, Steven M.; Kronforst, Marcus R.

    2014-01-01

    The monarch butterfly, Danaus plexippus, is famous for its spectacular annual migration across North America, recent worldwide dispersal, and orange warning coloration. Despite decades of study and broad public interest, we know little about the genetic basis of these hallmark traits. By sequencing 101 monarch genomes from around the globe, we uncover the history of the monarch's evolutionary origin and global dispersal, characterize the genes and pathways associated with migratory behavior, and identify the discrete genetic basis of warning coloration. The results rewrite our understanding of this classic system, showing that D. plexippus was ancestrally migratory and dispersed out of North America to occupy its broad distribution. We find the strongest signatures of selection associated with migration center on flight muscle function, resulting in greater flight efficiency among migratory monarchs, and that variation in monarch warning coloration is controlled by a single myosin gene not previously implicated in insect pigmentation. PMID:25274300

  19. A magnetic compass aids monarch butterfly migration.

    PubMed

    Guerra, Patrick A; Gegear, Robert J; Reppert, Steven M

    2014-06-24

    Convincing evidence that migrant monarch butterflies (Danaus plexippus) use a magnetic compass to aid their fall migration has been lacking from the spectacular navigational capabilities of this species. Here we use flight simulator studies to show that migrants indeed possess an inclination magnetic compass to help direct their flight equatorward in the fall. The use of this inclination compass is light-dependent utilizing ultraviolet-A/blue light between 380 and 420 nm. Notably, the significance of light <420 nm for inclination compass function was not considered in previous monarch studies. The antennae are important for the inclination compass because they appear to contain light-sensitive magnetosensors. For migratory monarchs, the inclination compass may serve as an important orientation mechanism when directional daylight cues are unavailable and may also augment time-compensated sun compass orientation for appropriate directionality throughout the migration.

  20. A magnetic compass aids monarch butterfly migration

    PubMed Central

    Guerra, Patrick A; Gegear, Robert J; Reppert, Steven M

    2014-01-01

    Convincing evidence that migrant monarch butterflies (Danaus plexippus) use a magnetic compass to aid their fall migration has been lacking from the spectacular navigational capabilities of this species. Here we use flight simulator studies to show that migrants indeed possess an inclination magnetic compass to help direct their flight equatorward in the fall. The use of this inclination compass is light-dependent utilizing ultraviolet-A/blue light between 380 and 420 nm. Notably, the significance of light <420 nm for inclination compass function was not considered in previous monarch studies. The antennae are important for the inclination compass because they appear to contain light-sensitive magnetosensors. For migratory monarchs, the inclination compass may serve as an important orientation mechanism when directional daylight cues are unavailable and may also augment time-compensated sun compass orientation for appropriate directionality throughout the migration. PMID:24960099

  1. Plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,Danaus plexippus L. Reared on milkweed plants in California: 2.Asclepias speciosa.

    PubMed

    Brower, L P; Seiber, J N; Nelson, C J; Lynch, S P; Holland, M M

    1984-04-01

    The pattern of variation in gross cardenolide concentration of 111Asclepias speciosa plants collected in six different areas of California is a positively skewed distribution which ranges from 19 to 344 μg of cardenolide per 0.1 g dry weight with a mean of 90 μg per 0.1 g. Butterflies reared individually on these plants in their native habitats ranged from 41 to 547 μg of cardenolide per 0.1 g dry weight with a mean of 179 μg. Total cardenolide per butterfly ranged from 54 to 1279 μg with a mean of 319 μg. Differences in concentrations and total cardenolide contents in the butterflies from the six geographic areas appeared minor, and there were no differences between the males and the females, although the males did weigh significantly more than females. The uptake of cardenolide by the butterflies was found to be a logarithmic function of the plant concentration. This results in regulation: larvae which feed on low-concentration plants produce butterflies with increased cardenolide concentrations relative to those of the plants, and those which feed on high-concentration plants produce butterflies with decreased concentrations. No evidence was adduced that high concentrations of cardenolides in the plants affected the fitness of the butterflies. The mean emetic potencies of the powdered plant and butterfly material were 5.62 and 5.25 blue jay emetic dose fifty units per milligram of cardenolide and the number of ED50 units per butterfly ranged from 0.28 to 6.7 with a mean of 1.67. Monarchs reared onA. speciosa, on average, are only about one tenth as emetic as those reared onA. eriocarpa. UnlikeA. eriocarpa which is limited to California,A. speciosa ranges from California to the Great Plains and is replaced eastwards byA. syriaca L. These two latter milkweed species appear to have a similar array of chemically identical cardenolides, and therefore both must produce butterflies of relatively low emetic potency to birds, with important ecological implications

  2. Monarch butterfly migration and parasite transmission in eastern North America.

    PubMed

    Bartel, Rebecca A; Oberhauser, Karen S; De Roode, Jacobus C; Altizer, Sonia M

    2011-02-01

    Seasonal migration occurs in many animal systems and is likely to influence interactions between animals and their parasites. Here, we focus on monarch butterflies (Danaus plexippus) and a protozoan parasite (Ophryocystis elektroscirrha) to investigate how host migration affects infectious disease processes. Previous work showed that parasite prevalence was lower among migratory than nonmigratory monarch populations; two explanations for this pattern are that (1) migration allows animals to periodically escape contaminated habitats (i.e., migratory escape), and (2) long-distance migration weeds out infected animals (i.e., migratory culling). We combined field-sampling and analysis of citizen science data to examine spatiotemporal trends of parasite prevalence and evaluate evidence for these two mechanisms. Analysis of within-breeding-season variation in eastern North America showed that parasite prevalence increased from early to late in the breeding season, consistent with the hypothesis of migratory escape. Prevalence was also positively related to monarch breeding activity, as indexed by larval density. Among adult monarchs captured at different points along the east coast fall migratory flyway, parasite prevalence declined as monarchs progressed southward, consistent with the hypothesis of migratory culling. Parasite prevalence was also lower among monarchs sampled at two overwintering sites in Mexico than among monarchs sampled during the summer breeding period. Collectively, these results indicate that seasonal migration can affect parasite transmission in wild animal populations, with implications for predicting disease risks for species with threatened migrations.

  3. Southern Monarchs do not Develop Learned Preferences for Flowers With Pyrrolizidine Alkaloids.

    PubMed

    de Oliveira, Marina Vasconcelos; Trigo, José Roberto; Rodrigues, Daniela

    2015-07-01

    Danaus butterflies sequester pyrrolizidine alkaloids (PAs) from nectar and leaves of various plant species for defense and reproduction. We tested the hypothesis that the southern monarch butterfly Danaus erippus shows innate preferences for certain flower colors and has the capacity to develop learned preferences for artificial flowers presenting advantageous floral rewards such as PAs. We predicted that orange and yellow flowers would be innately preferred by southern monarchs. Another prediction is that flowers with both sucrose and PAs would be preferred over those having sucrose only, regardless of flower color. In nature, males of Danaus generally visit PA sources more often than females, so we expected that males of D. erippus would exhibit a stronger learned preference for PA sources than the females. In the innate preference tests, adults were offered artificial non-rewarding yellow, orange, blue, red, green, and violet flowers. Orange and yellow artificial flowers were most visited by southern monarchs, followed by blue and red ones. No individual visited either green or violet flowers. For assessing learned preferences for PA flowers over flowers with no PAs, southern monarchs were trained to associate orange flowers with sucrose plus the PA monocrotaline vs. yellow flowers with sucrose only; the opposite combination was used to train another set of butterflies. In the tests, empty flowers were offered to trained butterflies. Neither males nor females showed learned preferences for flower colors associated with PAs in the training set. Thus, southern monarchs resemble the sister species Danaus plexippus in their innate preferences for orange and yellow flowers. Southern monarchs, similarly to temperate monarchs, might not be as PA-demanding as are other danaine species.

  4. Polarized light helps monarch butterflies navigate.

    PubMed

    Reppert, Steven M; Zhu, Haisun; White, Richard H

    2004-01-20

    During their spectacular migratory journey in the fall, North American monarch butterflies (Danaus plexippus) use a time-compensated sun compass to help them navigate to their overwintering sites in central Mexico. One feature of the sun compass mechanism not fully explored in monarchs is the sunlight-dependent parameters used to navigate. We now provide data suggesting that the angle of polarized skylight (the e-vector) is a relevant orientation parameter. By placing butterflies in a flight simulator outdoors and using a linear polarizing filter, we show that manipulating the e-vector alters predictably the direction of oriented flight. Butterflies studied in either the morning or afternoon showed similar responses to filter rotation. Monarch butterflies possess the anatomical structure needed for polarized skylight detection, as rhabdoms in the dorsalmost row of photoreceptor cells in monarch eye show the organization characteristic of polarized-light receptors. The existence of polarized-light detection could allow migrants to accurately navigate under a variety of atmospheric conditions and reveals a critical input pathway into the sun compass mechanism.

  5. Host plant species affects virulence in monarch butterfly parasites.

    PubMed

    de Roode, Jacobus C; Pedersen, Amy B; Hunter, Mark D; Altizer, Sonia

    2008-01-01

    1. Studies have considered how intrinsic host and parasite properties determine parasite virulence, but have largely ignored the role of extrinsic ecological factors in its expression. 2. We studied how parasite genotype and host plant species interact to determine virulence of the protozoan parasite Ophryocystis elektroscirrha (McLaughlin & Myers 1970) in the monarch butterfly Danaus plexippus L. We infected monarch larvae with one of four parasite genotypes and reared them on two milkweed species that differed in their levels of cardenolides: toxic chemicals involved in predator defence. 3. Parasite infection, replication and virulence were affected strongly by host plant species. While uninfected monarchs lived equally long on both plant species, infected monarchs suffered a greater reduction in their life spans (55% vs. 30%) on the low-cardenolide vs. the high-cardenolide host plant. These life span differences resulted from different levels of parasite replication in monarchs reared on the two plant species. 4. The virulence rank order of parasite genotypes was unaffected by host plant species, suggesting that host plant species affected parasite genotypes similarly, rather than through complex plant species-parasite genotype interactions. 5. Our results demonstrate that host ecology importantly affects parasite virulence, with implications for host-parasite dynamics in natural populations.

  6. A trans-national monarch butterfly population model and implications for regional conservation priorities

    USGS Publications Warehouse

    Oberhauser, Karen; Wiederholt, Ruscena; Diffendorfer, James E.; Semmens, Darius J.; Ries, Leslie; Thogmartin, Wayne E.; Lopez-Hoffman, Laura; Semmens, Brice

    2017-01-01

    1. The monarch has undergone considerable population declines over the past decade, and the governments of Mexico, Canada, and the United States have agreed to work together to conserve the species.2. Given limited resources, understanding where to focus conservation action is key for widespread species like monarchs. To support planning for continental-scale monarch habitat restoration, we address the question of where restoration efforts are likely to have the largest impacts on monarch butterfly (Danaus plexippus Linn.) population growth rates.3. We present a spatially explicit demographic model simulating the multi-generational annual cycle of the eastern monarch population, and use the model to examine management scenarios, some of which focus on particular regions of North America.4. Improving the monarch habitat in the north central or southern parts of the monarch range yields a slightly greater increase in the population growth rate than restoration in other regions. However, combining restoration efforts across multiple regions yields population growth rates above 1 with smaller simulated improvements in habitat per region than single-region strategies.5. Synthesis and applications: These findings suggest that conservation investment in projects across the full monarch range will be more effective than focusing on one or a few regions, and will require international cooperation across many land use categories.

  7. National valuation of monarch butterflies indicates an untapped potential for incentive-based conservation

    USGS Publications Warehouse

    Diffendorfer, Jay E.; Loomis, John B.; Ries, Leslie; Oberhauser, Karen; Semmens, Darius; Semmens, Brice; Butterfield, Bruce; Bagstad, Ken; Goldstein, Josh; Wiederholt, Ruscena; Mattsson, Brady; Thogmartin, Wayne E.

    2013-01-01

    The annual migration of monarch butterflies (Danaus plexippus) has high cultural value and recent surveys indicate monarch populations are declining. Protecting migratory species is complex because they cross international borders and depend on multiple regions. Understanding how much, and where, humans place value on migratory species can facilitate market-based conservation approaches. We performed a contingent valuation study of monarchs to understand the potential for such approaches to fund monarch conservation. The survey asked U.S. respondents about the money they would spend, or have spent, growing monarch-friendly plants, and the amount they would donate to monarch conservation organizations. Combining planting payments and donations, the survey indicated U.S. households valued monarchs as a total one-time payment of $4.78–$6.64 billion, levels similar to many endangered vertebrate species. The financial contribution of even a small percentage of households through purchases or donations could generate new funding for monarch conservation through market-based approaches.

  8. Ecological niches in sequential generations of eastern North American monarch butterflies (Lepidoptera: Danaidae): the ecology of migration and likely climate change implications.

    PubMed

    Batalden, Rebecca V; Oberhauser, Karen; Peterson, A Townsend

    2007-12-01

    Eastern North American monarch butterflies (Danaus plexippus L.) show a series of range shifts during their breeding season. Using ecological niche modeling, we studied the environmental context of these shifts by identifying the ecological conditions that monarchs use in successive summer months. Monarchs use a consistent ecological regimen through the summer, but these conditions contrast strikingly with those used during the winter. Hence, monarchs exhibit niche-following among sequential breeding generations but niche-switching between the breeding and overwintering stages of their annual cycle. We projected their breeding ecological niche onto monthly future climate scenarios, which indicated northward shifts, particularly at the northern extreme of their summer movements, over the next 50 yrs; if both monarchs and their milkweed host plants cannot track these changing climates, monarchs could lose distributional area during critical breeding months.

  9. Monarch butterfly oviposition on swallow-worts (Vincetoxicum spp.).

    PubMed

    Casagrande, R A; Dacey, J E

    2007-06-01

    As black swallow-wort, Vincetoxicum nigrum L. Moench, and pale swallow-wort, V. rossicum (Kleopow) Barbar., spread throughout the northeastern United States and southern Canada, there is concern about the impact of these invasive plants on populations of the native North American monarch butterfly Danaus plexippus L. Recent laboratory studies in New York and Ontario, Canada, have found little or no oviposition by monarch butterflies on the two Vincetoxicum species. In Rhode Island, we found 10.5-21.7% oviposition on Vincetoxicum species relative to common milkweed Asclepias syriaca L. in choice tests and 11.9-20.3% in no-choice tests in 2 yr of laboratory testing. These results were supported by field cage trials where monarchs given a choice between V. nigrum and A. syriaca laid 24.5% of their eggs on V. nigrum. In surveys of three pasture fields in Rhode Island where relative coverage of A. syriaca exceeded that of V. nigrum by a 0.77:0.23 ratio, 15.4% of monarch eggs were found on V. nigrum plants. In V. nigrum stands with very little A. syriaca (6.25 stems/ha), monarch egg density on V. nigrum was found to be over five times greater than in the three mixed pasture fields. In none of our laboratory or field evaluations was there any survival of monarch larvae on Vincetoxicum species. It seems that in Rhode Island, Vincetoxicum species serve as an oviposition sink for monarch butterflies. These findings suggest that East Coast butterflies may differ in host selection from those in central New York and southern Ontario, Canada.

  10. Sun compass integration of skylight cues in migratory monarch butterflies.

    PubMed

    Heinze, Stanley; Reppert, Steven M

    2011-01-27

    Migrating monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate from eastern North America to their overwintering grounds in central Mexico. Here we describe the neuronal layout of those aspects of the butterfly's central complex likely to establish part of the internal sun compass and find them highly homologous to those of the desert locust. Intracellular recordings from neurons in the monarch sun compass network reveal responses tuned to specific E-vector angles of polarized light, as well as azimuth-dependent responses to unpolarized light, independent of spectral composition. The neural responses to these two stimuli in individual neurons are mediated through different regions of the compound eye. Moreover, these dual responses are integrated to create a consistent representation of skylight cues in the sun compass throughout the day. The results advance our understanding of how ambiguous sensory signals are processed by the brain to elicit a robust behavioral response.

  11. Non-target effects of clothianidin on monarch butterflies

    NASA Astrophysics Data System (ADS)

    Pecenka, Jacob R.; Lundgren, Jonathan G.

    2015-04-01

    Monarch butterflies ( Danaus plexippus) frequently consume milkweed in and near agroecosystems and consequently may be exposed to pesticides like neonicotinoids. We conducted a dose response study to determine lethal and sublethal doses of clothianidin using a 36-h exposure scenario. We then quantified clothianidin levels found in milkweed leaves adjacent to maize fields. Toxicity assays revealed LC10, LC50, and LC90 values of 7.72, 15.63, and 30.70 ppb, respectively. Sublethal effects (larval size) were observed at 1 ppb. Contaminated milkweed plants had an average of 1.14 ± 0.10 ppb clothianidin, with a maximum of 4 ppb in a single plant. This research suggests that clothianidin could function as a stressor to monarch populations.

  12. Non-target effects of clothianidin on monarch butterflies.

    PubMed

    Pecenka, Jacob R; Lundgren, Jonathan G

    2015-04-01

    Monarch butterflies (Danaus plexippus) frequently consume milkweed in and near agroecosystems and consequently may be exposed to pesticides like neonicotinoids. We conducted a dose response study to determine lethal and sublethal doses of clothianidin using a 36-h exposure scenario. We then quantified clothianidin levels found in milkweed leaves adjacent to maize fields. Toxicity assays revealed LC10, LC50, and LC90 values of 7.72, 15.63, and 30.70 ppb, respectively. Sublethal effects (larval size) were observed at 1 ppb. Contaminated milkweed plants had an average of 1.14±0.10 ppb clothianidin, with a maximum of 4 ppb in a single plant. This research suggests that clothianidin could function as a stressor to monarch populations.

  13. Efficient targeted mutagenesis in the monarch butterfly using zinc-finger nucleases

    PubMed Central

    Merlin, Christine; Beaver, Lauren E.; Taylor, Orley R.; Wolfe, Scot A.; Reppert, Steven M.

    2013-01-01

    The development of reverse-genetic tools in “nonmodel” insect species with distinct biology is critical to establish them as viable model systems. The eastern North American monarch butterfly (Danaus plexippus), whose genome is sequenced, has emerged as a model to study animal clocks, navigational mechanisms, and the genetic basis of long-distance migration. Here, we developed a highly efficient gene-targeting approach in the monarch using zinc-finger nucleases (ZFNs), engineered nucleases that generate mutations at targeted genomic sequences. We focused our ZFN approach on targeting the type 2 vertebrate-like cryptochrome gene of the monarch (designated cry2), which encodes a putative transcriptional repressor of the monarch circadian clockwork. Co-injections of mRNAs encoding ZFNs targeting the second exon of monarch cry2 into “one nucleus” stage embryos led to high-frequency nonhomologous end-joining-mediated, mutagenic lesions in the germline (up to 50%). Heritable ZFN-induced lesions in two independent lines produced truncated, nonfunctional CRY2 proteins, resulting in the in vivo disruption of circadian behavior and the molecular clock mechanism. Our work genetically defines CRY2 as an essential transcriptional repressor of the monarch circadian clock and provides a proof of concept for the use of ZFNs for manipulating genes in the monarch butterfly genome. Importantly, this approach could be used in other lepidopterans and “nonmodel” insects, thus opening new avenues to decipher the molecular underpinnings of a variety of biological processes. PMID:23009861

  14. Efficient targeted mutagenesis in the monarch butterfly using zinc-finger nucleases.

    PubMed

    Merlin, Christine; Beaver, Lauren E; Taylor, Orley R; Wolfe, Scot A; Reppert, Steven M

    2013-01-01

    The development of reverse-genetic tools in "nonmodel" insect species with distinct biology is critical to establish them as viable model systems. The eastern North American monarch butterfly (Danaus plexippus), whose genome is sequenced, has emerged as a model to study animal clocks, navigational mechanisms, and the genetic basis of long-distance migration. Here, we developed a highly efficient gene-targeting approach in the monarch using zinc-finger nucleases (ZFNs), engineered nucleases that generate mutations at targeted genomic sequences. We focused our ZFN approach on targeting the type 2 vertebrate-like cryptochrome gene of the monarch (designated cry2), which encodes a putative transcriptional repressor of the monarch circadian clockwork. Co-injections of mRNAs encoding ZFNs targeting the second exon of monarch cry2 into "one nucleus" stage embryos led to high-frequency nonhomologous end-joining-mediated, mutagenic lesions in the germline (up to 50%). Heritable ZFN-induced lesions in two independent lines produced truncated, nonfunctional CRY2 proteins, resulting in the in vivo disruption of circadian behavior and the molecular clock mechanism. Our work genetically defines CRY2 as an essential transcriptional repressor of the monarch circadian clock and provides a proof of concept for the use of ZFNs for manipulating genes in the monarch butterfly genome. Importantly, this approach could be used in other lepidopterans and "nonmodel" insects, thus opening new avenues to decipher the molecular underpinnings of a variety of biological processes.

  15. Juvenile hormone regulation of longevity in the migratory monarch butterfly.

    PubMed

    Herman, W S; Tatar, M

    2001-12-22

    Monarch butterflies (Danaus plexippus) of eastern North America are well known for their long-range migration to overwintering roosts in south-central Mexico. An essential feature of this migration involves the exceptional longevity of the migrant adults; individuals persist from August/September to March while their summer counterparts are likely to live less than two months as adults. Migrant adults persist during a state of reproductive diapause in which both male and female reproductive development is arrested as a consequence of suppressed synthesis of juvenile hormone. Here, we describe survival in monarch butterflies as a function of the migrant syndrome. We show that migrant adults are longer lived than summer adults when each are maintained under standard laboratory conditions, that the longevity of migrant adults is curtailed by treatment with juvenile hormone and that the longevity of summer adults is increased by 100% when juvenile hormone synthesis is prevented by surgical removal of its source, the corpora allatum. Thus, monarch butterfly persistence through a long winter season is ensured in part by reduced ageing that is under endocrine regulation, as well as by the unique environmental properties of their winter roost sites. Phenotypic plasticity for ageing is an integral component of the monarch butterflies' migration-diapause syndrome.

  16. The Monarch Watch.

    ERIC Educational Resources Information Center

    Brown, Ken

    1994-01-01

    Science education can be an exciting process of observation and discovery. This article describes the use of the Monarch Watch project by environmental educators to study migratory behavior and scientific research through the tagging of Monarch butterflies. Discusses reasons the national project has been successful. (LZ)

  17. Antennal circadian clocks coordinate sun compass orientation in migratory monarch butterflies.

    PubMed

    Merlin, Christine; Gegear, Robert J; Reppert, Steven M

    2009-09-25

    During their fall migration, Eastern North American monarch butterflies (Danaus plexippus) use a time-compensated Sun compass to aid navigation to their overwintering grounds in central Mexico. It has been assumed that the circadian clock that provides time compensation resides in the brain, although this assumption has never been examined directly. Here, we show that the antennae are necessary for proper time-compensated Sun compass orientation in migratory monarch butterflies, that antennal clocks exist in monarchs, and that they likely provide the primary timing mechanism for Sun compass orientation. These unexpected findings pose a novel function for the antennae and open a new line of investigation into clock-compass connections that may extend widely to other insects that use this orientation mechanism.

  18. Migratory monarchs wintering in California experience low infection risk compared to monarchs breeding year-round on non-native milkweed.

    PubMed

    Satterfield, Dara A; Villablanca, Francis X; Maerz, John C; Altizer, Sonia

    2016-08-01

    Long-distance migration can lower infection risk for animal populations by removing infected individuals during strenuous journeys, spatially separating susceptible age classes, or allowing migrants to periodically escape from contaminated habitats. Many seasonal migrations are changing due to human activities including climate change and habitat alteration. Moreover, for some migratory populations, sedentary behaviors are becoming more common as migrants abandon or shorten their journeys in response to supplemental feeding or warming temperatures. Exploring the consequences of reduced movement for host-parasite interactions is needed to predict future responses of animal pathogens to anthropogenic change. Monarch butterflies (Danaus plexippus) and their specialist protozoan parasite Ophryocystis elektroscirrha (OE) provide a model system for examining how long-distance migration affects infectious disease processes in a rapidly changing world. Annual monarch migration from eastern North America to Mexico is known to reduce protozoan infection prevalence, and more recent work suggests that monarchs that forego migration to breed year-round on non-native milkweeds in the southeastern and south central Unites States face extremely high risk of infection. Here, we examined the prevalence of OE infection from 2013 to 2016 in western North America, and compared monarchs exhibiting migratory behavior (overwintering annually along the California coast) with those that exhibit year-round breeding. Data from field collections and a joint citizen science program of Monarch Health and Monarch Alert showed that infection frequency was over nine times higher for monarchs sampled in gardens with year-round milkweed as compared to migratory monarchs sampled at overwintering sites. Results here underscore the importance of animal migrations for lowering infection risk and motivate future studies of pathogen transmission in migratory species affected by environmental change.

  19. An Evaluation of Butterfly Gardens for Restoring Habitat for the Monarch Butterfly (Lepidoptera: Danaidae).

    PubMed

    Cutting, Brian T; Tallamy, Douglas W

    2015-10-01

    The eastern migratory monarch butterfly (Danaus plexippus L.) population in North America hit record low numbers during the 2013-2014 overwintering season, prompting pleas by scientists and conservation groups to plant the butterfly's milkweed host plants (Asclepias spp.) in residential areas. While planting butterfly gardens with host plants seems like an intuitive action, no previous study has directly compared larval survival in gardens and natural areas to demonstrate that gardens are suitable habitats for Lepidoptera. In this study, milkweed was planted in residential gardens and natural areas. In 2009 and 2010, plants were monitored for oviposition by monarch butterflies and survival of monarch eggs and caterpillars. Monarchs oviposited significantly more frequently in gardens than in natural sites, with 2.0 and 6.2 times more eggs per plant per observation in 2009 and 2010, respectively. There were no significant differences in overall subadult survival between gardens and natural areas. Significant differences in survival were measured for egg and larval cohorts when analyzed separately, but these were not consistent between years. These results suggest that planting gardens with suitable larval host plants can be an effective tool for restoring habitat for monarch butterflies. If planted over a large area, garden plantings may be useful as a partial mitigation for dramatic loss of monarch habitat in agricultural settings.

  20. The monarch butterfly genome yields insights into long-distance migration

    PubMed Central

    Zhan, Shuai; Merlin, Christine; Boore, Jeffrey L.; Reppert, Steven M.

    2011-01-01

    SUMMARY We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16, 866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals: a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration. PMID:22118469

  1. Extreme heterogeneity in parasitism despite low population genetic structure among monarch butterflies inhabiting the Hawaiian Islands.

    PubMed

    Pierce, Amanda A; de Roode, Jacobus C; Altizer, Sonia; Bartel, Rebecca A

    2014-01-01

    Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus) are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed year-round in milder climates such as Hawaii and other tropical locations. Prior work showed an inverse relationship between monarch migratory propensity and the prevalence of the protozoan parasite, Ophryocystis elektroscirrha. Here, we sampled monarchs from replicate sites within each of four Hawaiian Islands to ask whether these populations show consistently high prevalence of the protozoan parasite as seen for monarchs from several other non-migratory populations. Counter to our predictions, we observed striking spatial heterogeneity in parasite prevalence, with infection rates per site ranging from 4-85%. We next used microsatellite markers to ask whether the observed variation in infection might be explained by limited host movement and spatial sub-structuring among sites. Our results showed that monarchs across the Hawaiian Islands form one admixed population, supporting high gene flow among sites. Moreover, measures of individual-level genetic diversity did not predict host infection status, as might be expected if more inbred hosts harbored higher parasite loads. These results suggest that other factors such as landscape-level environmental variation or colonization-extinction processes might instead cause the extreme heterogeneity in monarch butterfly infection observed here.

  2. The monarch butterfly genome yields insights into long-distance migration.

    PubMed

    Zhan, Shuai; Merlin, Christine; Boore, Jeffrey L; Reppert, Steven M

    2011-11-23

    We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16,866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration.

  3. Extreme Heterogeneity in Parasitism Despite Low Population Genetic Structure among Monarch Butterflies Inhabiting the Hawaiian Islands

    PubMed Central

    Pierce, Amanda A.; de Roode, Jacobus C.; Altizer, Sonia; Bartel, Rebecca A.

    2014-01-01

    Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus) are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed year-round in milder climates such as Hawaii and other tropical locations. Prior work showed an inverse relationship between monarch migratory propensity and the prevalence of the protozoan parasite, Ophryocystis elektroscirrha. Here, we sampled monarchs from replicate sites within each of four Hawaiian Islands to ask whether these populations show consistently high prevalence of the protozoan parasite as seen for monarchs from several other non-migratory populations. Counter to our predictions, we observed striking spatial heterogeneity in parasite prevalence, with infection rates per site ranging from 4–85%. We next used microsatellite markers to ask whether the observed variation in infection might be explained by limited host movement and spatial sub-structuring among sites. Our results showed that monarchs across the Hawaiian Islands form one admixed population, supporting high gene flow among sites. Moreover, measures of individual-level genetic diversity did not predict host infection status, as might be expected if more inbred hosts harbored higher parasite loads. These results suggest that other factors such as landscape-level environmental variation or colonization-extinction processes might instead cause the extreme heterogeneity in monarch butterfly infection observed here. PMID:24926796

  4. Genomic Access to Monarch Migration Using TALEN and CRISPR/Cas9-Mediated Targeted Mutagenesis.

    PubMed

    Markert, Matthew J; Zhang, Ying; Enuameh, Metewo S; Reppert, Steven M; Wolfe, Scot A; Merlin, Christine

    2016-04-07

    The eastern North American monarch butterfly, Danaus plexippus, is an emerging model system to study the neural, molecular, and genetic basis of animal long-distance migration and animal clockwork mechanisms. While genomic studies have provided new insight into migration-associated and circadian clock genes, the general lack of simple and versatile reverse-genetic methods has limited in vivo functional analysis of candidate genes in this species. Here, we report the establishment of highly efficient and heritable gene mutagenesis methods in the monarch butterfly using transcriptional activator-like effector nucleases (TALENs) and CRISPR-associated RNA-guided nuclease Cas9 (CRISPR/Cas9). Using two clock gene loci, cryptochrome 2 and clock (clk), as candidates, we show that both TALENs and CRISPR/Cas9 generate high-frequency nonhomologous end-joining (NHEJ)-mediated mutations at targeted sites (up to 100%), and that injecting fewer than 100 eggs is sufficient to recover mutant progeny and generate monarch knockout lines in about 3 months. Our study also genetically defines monarch CLK as an essential component of the transcriptional activation complex of the circadian clock. The methods presented should not only greatly accelerate functional analyses of many aspects of monarch biology, but are also anticipated to facilitate the development of these tools in other nontraditional insect species as well as the development of homology-directed knock-ins.

  5. The Redder the Better: Wing Color Predicts Flight Performance in Monarch Butterflies

    PubMed Central

    Davis, Andrew K.; Chi, Jean; Bradley, Catherine; Altizer, Sonia

    2012-01-01

    The distinctive orange and black wings of monarchs (Danaus plexippus) have long been known to advertise their bitter taste and toxicity to potential predators. Recent work also showed that both the orange and black coloration of this species can vary in response to individual-level and environmental factors. Here we examine the relationship between wing color and flight performance in captive-reared monarchs using a tethered flight mill apparatus to quantify butterfly flight speed, duration and distance. In three different experiments (totaling 121 individuals) we used image analysis to measure body size and four wing traits among newly-emerged butterflies prior to flight trials: wing area, aspect ratio (length/width), melanism, and orange hue. Results showed that monarchs with darker orange (approaching red) wings flew longer distances than those with lighter orange wings in analyses that controlled for sex and other morphometric traits. This finding is consistent with past work showing that among wild monarchs, those sampled during the fall migration are darker in hue (redder) than non-migratory monarchs. Together, these results suggest that pigment deposition onto wing scales during metamorphosis could be linked with traits that influence flight, such as thorax muscle size, energy storage or metabolism. Our results reinforce an association between wing color and flight performance in insects that is suggested by past studies of wing melansim and seasonal polyphenism, and provide an important starting point for work focused on mechanistic links between insect movement and color. PMID:22848463

  6. Tracking multi-generational colonization of the breeding grounds by monarch butterflies in eastern North America

    PubMed Central

    Flockhart, D. T. Tyler; Wassenaar, Leonard I.; Martin, Tara G.; Hobson, Keith A.; Wunder, Michael B.; Norris, D. Ryan

    2013-01-01

    Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the breeding grounds of monarch butterflies (Danaus plexippus) in eastern North America. We found that monarch breeding occurrence was best modelled with geographical and climatic variables resulting in an annual breeding distribution of greater than 12 million km2 that encompassed 99% occurrence probability. Combining occurrence models with stable isotope measurements to estimate natal origin, we show that butterflies which overwintered in Mexico came from a wide breeding distribution, including southern portions of the range. There was a clear northward progression of monarchs over successive generations from May until August when reproductive butterflies began to change direction and moved south. Fifth-generation individuals breeding in Texas in the late summer/autumn tended to originate from northern breeding areas rather than regions further south. Although the Midwest was the most productive area during the breeding season, monarchs that re-colonized the Midwest were produced largely in Texas, suggesting that conserving breeding habitat in the Midwest alone is insufficient to ensure long-term persistence of the monarch butterfly population in eastern North America. PMID:23926146

  7. Genomic Access to Monarch Migration Using TALEN and CRISPR/Cas9-Mediated Targeted Mutagenesis

    PubMed Central

    Markert, Matthew J.; Zhang, Ying; Enuameh, Metewo S.; Reppert, Steven M.; Wolfe, Scot A.; Merlin, Christine

    2016-01-01

    The eastern North American monarch butterfly, Danaus plexippus, is an emerging model system to study the neural, molecular, and genetic basis of animal long-distance migration and animal clockwork mechanisms. While genomic studies have provided new insight into migration-associated and circadian clock genes, the general lack of simple and versatile reverse-genetic methods has limited in vivo functional analysis of candidate genes in this species. Here, we report the establishment of highly efficient and heritable gene mutagenesis methods in the monarch butterfly using transcriptional activator-like effector nucleases (TALENs) and CRISPR-associated RNA-guided nuclease Cas9 (CRISPR/Cas9). Using two clock gene loci, cryptochrome 2 and clock (clk), as candidates, we show that both TALENs and CRISPR/Cas9 generate high-frequency nonhomologous end-joining (NHEJ)-mediated mutations at targeted sites (up to 100%), and that injecting fewer than 100 eggs is sufficient to recover mutant progeny and generate monarch knockout lines in about 3 months. Our study also genetically defines monarch CLK as an essential component of the transcriptional activation complex of the circadian clock. The methods presented should not only greatly accelerate functional analyses of many aspects of monarch biology, but are also anticipated to facilitate the development of these tools in other nontraditional insect species as well as the development of homology-directed knock-ins. PMID:26837953

  8. Tracking multi-generational colonization of the breeding grounds by monarch butterflies in eastern North America.

    PubMed

    Flockhart, D T Tyler; Wassenaar, Leonard I; Martin, Tara G; Hobson, Keith A; Wunder, Michael B; Norris, D Ryan

    2013-10-07

    Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the breeding grounds of monarch butterflies (Danaus plexippus) in eastern North America. We found that monarch breeding occurrence was best modelled with geographical and climatic variables resulting in an annual breeding distribution of greater than 12 million km(2) that encompassed 99% occurrence probability. Combining occurrence models with stable isotope measurements to estimate natal origin, we show that butterflies which overwintered in Mexico came from a wide breeding distribution, including southern portions of the range. There was a clear northward progression of monarchs over successive generations from May until August when reproductive butterflies began to change direction and moved south. Fifth-generation individuals breeding in Texas in the late summer/autumn tended to originate from northern breeding areas rather than regions further south. Although the Midwest was the most productive area during the breeding season, monarchs that re-colonized the Midwest were produced largely in Texas, suggesting that conserving breeding habitat in the Midwest alone is insufficient to ensure long-term persistence of the monarch butterfly population in eastern North America.

  9. The redder the better: wing color predicts flight performance in monarch butterflies.

    PubMed

    Davis, Andrew K; Chi, Jean; Bradley, Catherine; Altizer, Sonia

    2012-01-01

    The distinctive orange and black wings of monarchs (Danaus plexippus) have long been known to advertise their bitter taste and toxicity to potential predators. Recent work also showed that both the orange and black coloration of this species can vary in response to individual-level and environmental factors. Here we examine the relationship between wing color and flight performance in captive-reared monarchs using a tethered flight mill apparatus to quantify butterfly flight speed, duration and distance. In three different experiments (totaling 121 individuals) we used image analysis to measure body size and four wing traits among newly-emerged butterflies prior to flight trials: wing area, aspect ratio (length/width), melanism, and orange hue. Results showed that monarchs with darker orange (approaching red) wings flew longer distances than those with lighter orange wings in analyses that controlled for sex and other morphometric traits. This finding is consistent with past work showing that among wild monarchs, those sampled during the fall migration are darker in hue (redder) than non-migratory monarchs. Together, these results suggest that pigment deposition onto wing scales during metamorphosis could be linked with traits that influence flight, such as thorax muscle size, energy storage or metabolism. Our results reinforce an association between wing color and flight performance in insects that is suggested by past studies of wing melansim and seasonal polyphenism, and provide an important starting point for work focused on mechanistic links between insect movement and color.

  10. The ancestral circadian clock of monarch butterflies: role in time-compensated sun compass orientation.

    PubMed

    Reppert, S M

    2007-01-01

    The circadian clock has a vital role in monarch butterfly (Danaus plexippus) migration by providing the timing component of time-compensated sun compass orientation, which contributes to navigation to the overwintering grounds. The location of circadian clock cells in monarch brain has been identified in the dorsolateral protocerebrum (pars lateralis); these cells express PERIOD, TIMELESS, and a Drosophila-like cryptochrome designated CRY1. Monarch butterflies, like all other nondrosophilid insects examined so far, express a second cry gene (designated insect CRY2) that encodes a vertebrate-like CRY that is also expressed in pars lateralis. An ancestral circadian clock mechanism has been defined in monarchs, in which CRY1 functions as a blue light photoreceptor for photic entrainment, whereas CRY2 functionswithin the clockwork as themajor transcriptional repressor of an intracellular negative transcriptional feedback loop. A CRY1-staining neural pathway has been identified that may connect the circadian (navigational) clock to polarized light input important for sun compass navigation, and a CRY2-positive neural pathway has been discovered that may communicate circadian information directly from the circadian clock to the central complex, the likely site of the sun compass. The monarch butterfly may thus use the CRY proteins as components of the circadian mechanism and also as output molecules that connect the clock to various aspects of the sun compass apparatus.

  11. Monarch butterflies cross the Appalachians from the west to recolonize the east coast of North America.

    PubMed

    Miller, Nathan G; Wassenaar, Leonard I; Hobson, Keith A; Norris, D Ryan

    2011-02-23

    Each spring, millions of monarch butterflies (Danaus plexippus) migrate from overwintering sites in Mexico to recolonize eastern North America. However, few monarchs are found along the east coast of the USA until mid-summer. Brower (Brower, L. P. 1996 J. Exp. Biol. 199, 93-103.) proposed that east coast recolonization is accomplished by individuals migrating from the west over the Appalachians, but to date no evidence exists to support this hypothesis. We used hydrogen (δD) and carbon (δ(13)C) stable isotope measurements to estimate natal origins of 90 monarchs sampled from 17 sites along the eastern United States coast. We found the majority of monarchs (88%) originated in the mid-west and Great Lakes regions, providing, to our knowledge, the first direct evidence that second generation monarchs born in June complete a (trans-) longitudinal migration across the Appalachian mountains. The remaining individuals (12%) originated from parents that migrated directly from the Gulf coast during early spring. Our results provide evidence of a west to east longitudinal migration and provide additional rationale for conserving east coast populations by identifying breeding sources.

  12. Let Monarchs Rule

    ERIC Educational Resources Information Center

    Shimkanin, John; Murphy, Amy

    2007-01-01

    Many teachers bring caterpillars into their class for their students to see the transformation from caterpillar to butterfly. This is exciting and educational, but more can be done using Monarchs across the curriculum. This article describes an integrated butterfly unit for students in grades four to six that starts with identifying the Monarch…

  13. The Effect of Wing Scales on Monarch Butterfly Flight Characteristics

    NASA Astrophysics Data System (ADS)

    Shaw, Angela; Jones, Robert; Lang, Amy

    2010-11-01

    Recent research has shown that the highly flexible wings of butterflies in flapping flight develop vortices along their leading and trailing edges. Butterfly scales (approximately 100 microns in length) have a shingled pattern and extend into the boundary layer. These scales, which make up approximately 3% of the body weight or less, could play a part in controlling separation and vortex formation in this unsteady, three-dimensional complex flow field. A better understanding of this mechanism may lead to bio-inspired applications for flapping wing micro-air vehicles. In this study, the flight performance of Monarch (Danaus plexippus) butterflies with and without scales was analyzed. Scales were removed from the upper and lower wing surfaces and specimens were videotaped at 600 frames per second. Variation in flapping patterns and flight fitness were observed.

  14. An experimental displacement and over 50 years of tag-recoveries show that monarch butterflies are not true navigators.

    PubMed

    Mouritsen, Henrik; Derbyshire, Rachael; Stalleicken, Julia; Mouritsen, Ole Ø; Frost, Barrie J; Norris, D Ryan

    2013-04-30

    Monarch butterflies (Danaus plexippus) breeding in eastern North America are famous for their annual fall migration to their overwintering grounds in Mexico. However, the mechanisms they use to successfully reach these sites remain poorly understood. Here, we test whether monarchs are true navigators who can determine their location relative to their final destination using both a "compass" and a "map". Using flight simulators, we recorded the orientation of wild-caught monarchs in southwestern Ontario and found that individuals generally flew in a southwest direction toward the wintering grounds. When displaced 2,500 km to the west, the same individuals continued to fly in a general southwest direction, suggesting that monarchs use a simple vector-navigation strategy (i.e., use a specific compass bearing without compensating for displacement). Using over 5 decades of field data, we also show that the directional concentration and the angular SD of recoveries from tagged monarchs largely conformed to two mathematical models describing the directional distribution of migrants expected under a vector-navigation strategy. A third analysis of tagged recoveries shows that the increasing directionality of migration from north to south is largely because of the presence of geographic barriers that guide individuals toward overwintering sites. Our work suggests that monarchs breeding in eastern North America likely combine simple orientation mechanisms with geographic features that funnel them toward Mexican overwintering sites, a remarkable achievement considering that these butterflies weigh less than a gram and travel thousands of kilometers to a site they have never seen.

  15. Stable isotopes (δD and δ(13)C) are geographic indicators of natal origins of monarch butterflies in eastern North America.

    PubMed

    Hobson, Keith A; Wassenaar, Leonard I; Taylor, Orley R

    1999-08-01

    Wing membranes of laboratory and field-reared monarch butterflies (Danaus plexippus) were analyzed for their stable-hydrogen (δD) and carbon (δ(13)C) isotope ratios to determine whether this technique could be used to identify their natal origins. We hypothesized that the hydrogen isotopic composition of monarch butterfly wing keratin would reflect the hydrogen isotope patterns of rainfall in areas of natal origin where wings were formed. Monarchs were reared in the laboratory on milkweed plants (Asclepias sp.) grown with water of known deuterium content, and, with the assistance of volunteers, on native milkweeds throughout eastern North America. The results show that the stable hydrogen isotopic composition of monarch butterflies is highly correlated with the isotopic composition of the milkweed host plants, which in turn corresponds closely with the long-term geographic patterns of deuterium in rainfall. Stable-carbon isotope values in milkweed host plants were similarly correlated with those values in monarch butterflies and showed a general pattern of enrichment along a southwest to northeast gradient bisecting the Great Lakes. These findings indicate that natal origins of migratory and wintering monarchs in Mexico can be inferred from the combined δD and δ(13)C isotopic signatures in their wings. This relationship establishes that analysis of hydrogen and carbon isotopes can be used to answer questions concerning the biology of migratory monarch butterflies and provides a new approach to tracking similar migratory movements of other organisms.

  16. Dynamic mechanical oscillations during metamorphosis of the monarch butterfly.

    PubMed

    Pelling, Andrew E; Wilkinson, Paul R; Stringer, Richard; Gimzewski, James K

    2009-01-06

    The mechanical oscillation of the heart is fundamental during insect metamorphosis, but it is unclear how morphological changes affect its mechanical dynamics. Here, the micromechanical heartbeat with the monarch chrysalis (Danaus plexippus) during metamorphosis is compared with the structural changes observed through in vivo magnetic resonance imaging (MRI). We employ a novel ultra-sensitive detection approach, optical beam deflection, in order to measure the microscale motions of the pupae during the course of metamorphosis. We observed very distinct mechanical contractions occurring at regular intervals, which we ascribe to the mechanical function of the heart organ. Motion was observed to occur in approximately 15 min bursts of activity with frequencies in the 0.4-1.0 Hz range separated by periods of quiescence during the first 83 per cent of development. In the final stages, the beating was found to be uninterrupted until the adult monarch butterfly emerged. Distinct stages of development were characterized by changes in frequency, amplitude, mechanical quality factor and de/repolarization times of the mechanical pulsing. The MRI revealed that the heart organ remains functionally intact throughout metamorphosis but undergoes morphological changes that are reflected in the mechanical oscillation.

  17. Coldness triggers northward flight in remigrant monarch butterflies.

    PubMed

    Guerra, Patrick A; Reppert, Steven M

    2013-03-04

    Each fall, eastern North American monarch butterflies (Danaus plexippus) migrate from their northern range to their overwintering grounds in central Mexico. Fall migrants are in reproductive diapause, and they use a time-compensated sun compass to navigate during the long journey south. Eye-sensed directional cues from the daylight sky (e.g., the horizontal or azimuthal position of the sun) are integrated in the sun compass in the midbrain central complex region. Sun compass output is time compensated by circadian clocks in the antennae so that fall migrants can maintain a fixed flight direction south. In the spring, the same migrants remigrate northward to the southern United States to initiate the northern leg of the migration cycle. Here we show that spring remigrants also use an antenna-dependent time-compensated sun compass to direct their northward flight. Remarkably, fall migrants prematurely exposed to overwintering-like coldness reverse their flight orientation to the north. The temperature microenvironment at the overwintering site is essential for successful completion of the migration cycle, because without cold exposure, aged migrants continue to orient south. Our discovery that coldness triggers the northward flight direction in spring remigrants solves one of the long-standing mysteries of the monarch migration.

  18. Serial founder effects and genetic differentiation during worldwide range expansion of monarch butterflies.

    PubMed

    Pierce, Amanda A; Zalucki, Myron P; Bangura, Marie; Udawatta, Milan; Kronforst, Marcus R; Altizer, Sonia; Haeger, Juan Fernández; de Roode, Jacobus C

    2014-12-22

    Range expansions can result in founder effects, increasing genetic differentiation between expanding populations and reducing genetic diversity along the expansion front. However, few studies have addressed these effects in long-distance migratory species, for which high dispersal ability might counter the effects of genetic drift. Monarchs (Danaus plexippus) are best known for undertaking a long-distance annual migration in North America, but have also dispersed around the world to form populations that do not migrate or travel only short distances. Here, we used microsatellite markers to assess genetic differentiation among 18 monarch populations and to determine worldwide colonization routes. Our results indicate that North American monarch populations connected by land show limited differentiation, probably because of the monarch's ability to migrate long distances. Conversely, we found high genetic differentiation between populations separated by large bodies of water. Moreover, we show evidence for serial founder effects across the Pacific, suggesting stepwise dispersal from a North American origin. These findings demonstrate that genetic drift played a major role in shaping allele frequencies and created genetic differentiation among newly formed populations. Thus, range expansion can give rise to genetic differentiation and declines in genetic diversity, even in highly mobile species.

  19. Anatomical basis of sun compass navigation I: the general layout of the monarch butterfly brain.

    PubMed

    Heinze, Stanley; Reppert, Steven M

    2012-06-01

    Each fall, eastern North American monarch butterflies (Danaus plexippus) use a time-compensated sun compass to migrate to their overwintering grounds in central Mexico. The sun compass mechanism involves the neural integration of skylight cues with timing information from circadian clocks to maintain a constant heading. The neuronal substrates for the necessary interactions between compass neurons in the central complex, a prominent structure of the central brain, and circadian clocks are largely unknown. To begin to unravel these neural substrates, we performed 3D reconstructions of all neuropils of the monarch brain based on anti-synapsin labeling. Our work characterizes 21 well-defined neuropils (19 paired, 2 unpaired), as well as all synaptic regions between the more classically defined neuropils. We also studied the internal organization of all major neuropils on brain sections, using immunocytochemical stainings against synapsin, serotonin, and γ-aminobutyric acid. Special emphasis was placed on describing the neuroarchitecture of sun-compass-related brain regions and outlining their homologies to other migratory species. In addition to finding many general anatomical similarities to other insects, interspecies comparison also revealed several features that appear unique to the monarch brain. These distinctive features were especially apparent in the visual system and the mushroom body. Overall, we provide a comprehensive analysis of the brain anatomy of the monarch butterfly that will ultimately aid our understanding of the neuronal processes governing animal migration.

  20. Impact of Bt corn pollen on monarch butterfly populations: a risk assessment.

    PubMed

    Sears, M K; Hellmich, R L; Stanley-Horn, D E; Oberhauser, K S; Pleasants, J M; Mattila, H R; Siegfried, B D; Dively, G P

    2001-10-09

    A collaborative research effort by scientists in several states and in Canada has produced information to develop a formal risk assessment of the impact of Bt corn on monarch butterfly (Danaus plexippus) populations. Information was sought on the acute toxic effects of Bt corn pollen and the degree to which monarch larvae would be exposed to toxic amounts of Bt pollen on its host plant, the common milkweed, Asclepias syriaca, found in and around cornfields. Expression of Cry proteins, the active toxicant found in Bt corn tissues, differed among hybrids, and especially so in the concentrations found in pollen of different events. In most commercial hybrids, Bt expression in pollen is low, and laboratory and field studies show no acute toxic effects at any pollen density that would be encountered in the field. Other factors mitigating exposure of larvae include the variable and limited overlap between pollen shed and larval activity periods, the fact that only a portion of the monarch population utilizes milkweed stands in and near cornfields, and the current adoption rate of Bt corn at 19% of North American corn-growing areas. This 2-year study suggests that the impact of Bt corn pollen from current commercial hybrids on monarch butterfly populations is negligible.

  1. Serial founder effects and genetic differentiation during worldwide range expansion of monarch butterflies

    PubMed Central

    Pierce, Amanda A.; Zalucki, Myron P.; Bangura, Marie; Udawatta, Milan; Kronforst, Marcus R.; Altizer, Sonia; Haeger, Juan Fernández; de Roode, Jacobus C.

    2014-01-01

    Range expansions can result in founder effects, increasing genetic differentiation between expanding populations and reducing genetic diversity along the expansion front. However, few studies have addressed these effects in long-distance migratory species, for which high dispersal ability might counter the effects of genetic drift. Monarchs (Danaus plexippus) are best known for undertaking a long-distance annual migration in North America, but have also dispersed around the world to form populations that do not migrate or travel only short distances. Here, we used microsatellite markers to assess genetic differentiation among 18 monarch populations and to determine worldwide colonization routes. Our results indicate that North American monarch populations connected by land show limited differentiation, probably because of the monarch's ability to migrate long distances. Conversely, we found high genetic differentiation between populations separated by large bodies of water. Moreover, we show evidence for serial founder effects across the Pacific, suggesting stepwise dispersal from a North American origin. These findings demonstrate that genetic drift played a major role in shaping allele frequencies and created genetic differentiation among newly formed populations. Thus, range expansion can give rise to genetic differentiation and declines in genetic diversity, even in highly mobile species. PMID:25377462

  2. Cryptochromes Define a Novel Circadian Clock Mechanism in Monarch Butterflies That May Underlie Sun Compass Navigation

    PubMed Central

    Zhu, Haisun; Sauman, Ivo; Yuan, Quan; Casselman, Amy; Emery-Le, Myai; Emery, Patrick; Reppert, Steven M

    2008-01-01

    The circadian clock plays a vital role in monarch butterfly (Danaus plexippus) migration by providing the timing component of time-compensated sun compass orientation, a process that is important for successful navigation. We therefore evaluated the monarch clockwork by focusing on the functions of a Drosophila-like cryptochrome (cry), designated cry1, and a vertebrate-like cry, designated cry2, that are both expressed in the butterfly and by placing these genes in the context of other relevant clock genes in vivo. We found that similar temporal patterns of clock gene expression and protein levels occur in the heads, as occur in DpN1 cells, of a monarch cell line that contains a light-driven clock. CRY1 mediates TIMELESS degradation by light in DpN1 cells, and a light-induced TIMELESS decrease occurs in putative clock cells in the pars lateralis (PL) in the brain. Moreover, monarch cry1 transgenes partially rescue both biochemical and behavioral light-input defects in cryb mutant Drosophila. CRY2 is the major transcriptional repressor of CLOCK:CYCLE-mediated transcription in DpN1 cells, and endogenous CRY2 potently inhibits transcription without involvement of PERIOD. CRY2 is co-localized with clock proteins in the PL, and there it translocates to the nucleus at the appropriate time for transcriptional repression. We also discovered CRY2-positive neural projections that oscillate in the central complex. The results define a novel, CRY-centric clock mechanism in the monarch in which CRY1 likely functions as a blue-light photoreceptor for entrainment, whereas CRY2 functions within the clockwork as the transcriptional repressor of a negative transcriptional feedback loop. Our data further suggest that CRY2 may have a dual role in the monarch butterfly's brain—as a core clock element and as an output that regulates circadian activity in the central complex, the likely site of the sun compass. PMID:18184036

  3. Cryptochromes define a novel circadian clock mechanism in monarch butterflies that may underlie sun compass navigation.

    PubMed

    Zhu, Haisun; Sauman, Ivo; Yuan, Quan; Casselman, Amy; Emery-Le, Myai; Emery, Patrick; Reppert, Steven M

    2008-01-01

    The circadian clock plays a vital role in monarch butterfly (Danaus plexippus) migration by providing the timing component of time-compensated sun compass orientation, a process that is important for successful navigation. We therefore evaluated the monarch clockwork by focusing on the functions of a Drosophila-like cryptochrome (cry), designated cry1, and a vertebrate-like cry, designated cry2, that are both expressed in the butterfly and by placing these genes in the context of other relevant clock genes in vivo. We found that similar temporal patterns of clock gene expression and protein levels occur in the heads, as occur in DpN1 cells, of a monarch cell line that contains a light-driven clock. CRY1 mediates TIMELESS degradation by light in DpN1 cells, and a light-induced TIMELESS decrease occurs in putative clock cells in the pars lateralis (PL) in the brain. Moreover, monarch cry1 transgenes partially rescue both biochemical and behavioral light-input defects in cry(b) mutant Drosophila. CRY2 is the major transcriptional repressor of CLOCK:CYCLE-mediated transcription in DpN1 cells, and endogenous CRY2 potently inhibits transcription without involvement of PERIOD. CRY2 is co-localized with clock proteins in the PL, and there it translocates to the nucleus at the appropriate time for transcriptional repression. We also discovered CRY2-positive neural projections that oscillate in the central complex. The results define a novel, CRY-centric clock mechanism in the monarch in which CRY1 likely functions as a blue-light photoreceptor for entrainment, whereas CRY2 functions within the clockwork as the transcriptional repressor of a negative transcriptional feedback loop. Our data further suggest that CRY2 may have a dual role in the monarch butterfly's brain-as a core clock element and as an output that regulates circadian activity in the central complex, the likely site of the sun compass.

  4. Consequences of Food Restriction for Immune Defense, Parasite Infection, and Fitness in Monarch Butterflies.

    PubMed

    McKay, Alexa Fritzsche; Ezenwa, Vanessa O; Altizer, Sonia

    2016-01-01

    Organisms have a finite pool of resources to allocate toward multiple competing needs, such as development, reproduction, and enemy defense. Abundant resources can support investment in multiple traits simultaneously, but limited resources might promote trade-offs between fitness-related traits and immune defenses. We asked how food restriction at both larval and adult life stages of the monarch butterfly (Danaus plexippus) affected measures of immunity, fitness, and immune-fitness interactions. We experimentally infected a subset of monarchs with a specialist protozoan parasite to determine whether parasitism further affected these relationships and whether food restriction influenced the outcome of infection. Larval food restriction reduced monarch fitness measures both within the same life stage (e.g., pupal mass) as well as later in life (e.g., adult lifespan); adult food restriction further reduced adult lifespan. Larval food restriction lowered both hemocyte concentration and phenoloxidase activity at the larval stage, and the effects of larval food restriction on phenoloxidase activity persisted when immunity was sampled at the adult stage. Adult food restriction reduced only adult phenoloxidase activity but not hemocyte concentration. Parasite spore load decreased with one measure of larval immunity, but food restriction did not increase the probability of parasite infection. Across monarchs, we found a negative relationship between larval hemocyte concentration and pupal mass, and a trade-off between adult hemocyte concentration and adult life span was evident in parasitized female monarchs. Adult life span increased with phenoloxidase activity in some subsets of monarchs. Our results emphasize that food restriction can alter fitness and immunity across multiple life stages. Understanding the consequences of resource limitation for immune defense is therefore important for predicting how increasing constraints on wildlife resources will affect fitness and

  5. Behavioural resistance against a protozoan parasite in the monarch butterfly.

    PubMed

    Lefèvre, Thierry; Chiang, Allen; Kelavkar, Mangala; Li, Hui; Li, James; de Castillejo, Carlos Lopez Fernandez; Oliver, Lindsay; Potini, Yamini; Hunter, Mark D; de Roode, Jacobus C

    2012-01-01

    1. As parasites can dramatically reduce the fitness of their hosts, there should be strong selection for hosts to evolve and maintain defence mechanisms against their parasites. One way in which hosts may protect themselves against parasitism is through altered behaviours, but such defences have been much less studied than other forms of parasite resistance. 2. We studied whether monarch butterflies (Danaus plexippus L.) use altered behaviours to protect themselves and their offspring against the protozoan parasite Ophryocystis elektroscirrha (McLaughlin & Myers (1970), Journal of Protozoology, 17, p. 300). In particular, we studied whether (i) monarch larvae can avoid contact with infectious parasite spores; (ii) infected larvae preferentially consume therapeutic food plants when given a choice or increase the intake of such plants in the absence of choice; and (iii) infected female butterflies preferentially lay their eggs on medicinal plants that make their offspring less sick. 3. We found that monarch larvae were unable to avoid infectious parasite spores. Larvae were also not able to preferentially feed on therapeutic food plants or increase the ingestion of such plants. However, infected female butterflies preferentially laid their eggs on food plants that reduce parasite growth in their offspring. 4. Our results suggest that animals may use altered behaviours as a protection against parasites and that such behaviours may be limited to a single stage in the host-parasite life cycle. Our results also suggest that animals may use altered behaviours to protect their offspring instead of themselves. Thus, our study indicates that an inclusive fitness approach should be adopted to study behavioural defences against parasites.

  6. Monarch Caterpillar Changes to a Chrysalis

    SciTech Connect

    2015-06-25

    The annual monarch migration is underway! Should you happen to spot a monarch caterpillar impersonating the letter 'J', watch it carefully. It might change from a caterpillar (the larva) to a chrysalis (the pupa) before your very eyes!

  7. Monarch Caterpillar Changes to a Chrysalis

    ScienceCinema

    None

    2016-07-12

    The annual monarch migration is underway! Should you happen to spot a monarch caterpillar impersonating the letter 'J', watch it carefully. It might change from a caterpillar (the larva) to a chrysalis (the pupa) before your very eyes!

  8. Monarchs in decline: a collateral landscape-level effect of modern agriculture.

    PubMed

    Stenoien, Carl; Nail, Kelly R; Zalucki, Jacinta M; Parry, Hazel; Oberhauser, Karen S; Zalucki, Myron P

    2016-09-21

    We review the postulated threatening processes that may have affected the decline in the eastern population of the monarch butterfly, Danaus plexippus L. (Lepidoptera: Nymphalidae), in North America. Although there are likely multiple contributing factors, such as climate and resource-related effects on breeding, migrating, and overwintering populations, the key landscape-level change appears to be associated with the widespread use of genetically modified herbicide resistant crops that have rapidly come to dominate the extensive core summer breeding range. We dismiss misinterpretations of the apparent lack of population change in summer adult count data as logically flawed. Glyphosate-tolerant soybean and maize have enabled the extensive use of this herbicide, generating widespread losses of milkweed (Asclepias spp.), the only host plants for monarch larvae. Modeling studies that simulate lifetime realized fecundity at a landscape scale, direct counts of milkweeds, and extensive citizen science data across the breeding range suggest that a herbicide-induced, landscape-level reduction in milkweed has precipitated the decline in monarchs. A recovery will likely require a monumental effort for the re-establishment of milkweed resources at a commensurate landscape scale.

  9. Effects of Cry1Ab-expressing corn anthers on the movement of monarch butterfly larvae.

    PubMed

    Prasifka, Patricia L; Hellmich, Richard L; Prasifka, Jarrad R; Lewis, Leslie C

    2007-02-01

    Decreased larval feeding and weight of the monarch butterfly, Danaus plexippus L., have been detected after 4 d of exposure in the laboratory to a high density of Bacillus thuringiensis (Bt)-expressing anthers. One hypothesis is that larvae exposed to Bt anthers exhibit increased wandering, resulting in less feeding and lower weight gain. To test this hypothesis, 2-d-old monarch butterfly larvae exposed to milkweed leaf disks with no anthers, anthers that express Bt (Cry1Ab, event MON810), or other non-Bt anthers were observed using a video-tracking system. As had been shown in previous studies, larvae exposed to Bt anthers fed less and gained less weight than larvae exposed to non-Bt or no anthers, yet there was no evidence of feeding on anthers. Total distance moved, maximum displacement from release point, percentage of time spent moving or near anthers, or mean turn angle did not differ across treatments. However, larvae exposed to Bt anthers spent more time off milkweed leaf disks than those exposed to no anthers and were more likely to move off the leaf than larvae exposed to non-Bt anthers. Results suggest that larvae exposed to Bt anthers behave differently and that ingestion may not be the only way Bt can affect nontarget insects like the monarch butterfly.

  10. An experimental displacement and over 50 years of tag-recoveries show that monarch butterflies are not true navigators

    PubMed Central

    Mouritsen, Henrik; Derbyshire, Rachael; Stalleicken, Julia; Mouritsen, Ole Ø.; Frost, Barrie J.; Norris, D. Ryan

    2013-01-01

    Monarch butterflies (Danaus plexippus) breeding in eastern North America are famous for their annual fall migration to their overwintering grounds in Mexico. However, the mechanisms they use to successfully reach these sites remain poorly understood. Here, we test whether monarchs are true navigators who can determine their location relative to their final destination using both a “compass” and a “map”. Using flight simulators, we recorded the orientation of wild-caught monarchs in southwestern Ontario and found that individuals generally flew in a southwest direction toward the wintering grounds. When displaced 2,500 km to the west, the same individuals continued to fly in a general southwest direction, suggesting that monarchs use a simple vector-navigation strategy (i.e., use a specific compass bearing without compensating for displacement). Using over 5 decades of field data, we also show that the directional concentration and the angular SD of recoveries from tagged monarchs largely conformed to two mathematical models describing the directional distribution of migrants expected under a vector-navigation strategy. A third analysis of tagged recoveries shows that the increasing directionality of migration from north to south is largely because of the presence of geographic barriers that guide individuals toward overwintering sites. Our work suggests that monarchs breeding in eastern North America likely combine simple orientation mechanisms with geographic features that funnel them toward Mexican overwintering sites, a remarkable achievement considering that these butterflies weigh less than a gram and travel thousands of kilometers to a site they have never seen. PMID:23569228

  11. Fitness costs of animal medication: antiparasitic plant chemicals reduce fitness of monarch butterfly hosts.

    PubMed

    Tao, Leiling; Hoang, Kevin M; Hunter, Mark D; de Roode, Jacobus C

    2016-09-01

    The emerging field of ecological immunology demonstrates that allocation by hosts to immune defence against parasites is constrained by the costs of those defences. However, the costs of non-immunological defences, which are important alternatives to canonical immune systems, are less well characterized. Estimating such costs is essential for our understanding of the ecology and evolution of alternative host defence strategies. Many animals have evolved medication behaviours, whereby they use antiparasitic compounds from their environment to protect themselves or their kin from parasitism. Documenting the costs of medication behaviours is complicated by natural variation in the medicinal components of diets and their covariance with other dietary components, such as macronutrients. In the current study, we explore the costs of the usage of antiparasitic compounds in monarch butterflies (Danaus plexippus), using natural variation in concentrations of antiparasitic compounds among plants. Upon infection by their specialist protozoan parasite Ophryocystis elektroscirrha, monarch butterflies can selectively oviposit on milkweed with high foliar concentrations of cardenolides, secondary chemicals that reduce parasite growth. Here, we show that these antiparasitic cardenolides can also impose significant costs on both uninfected and infected butterflies. Among eight milkweed species that vary substantially in their foliar cardenolide concentration and composition, we observed the opposing effects of cardenolides on monarch fitness traits. While high foliar cardenolide concentrations increased the tolerance of monarch butterflies to infection, they reduced the survival rate of caterpillars to adulthood. Additionally, although non-polar cardenolide compounds decreased the spore load of infected butterflies, they also reduced the life span of uninfected butterflies, resulting in a hump-shaped curve between cardenolide non-polarity and the life span of infected butterflies

  12. Uncovering patterns of spring migration in the monarch butterfly using stable isotopes and demographic models

    NASA Astrophysics Data System (ADS)

    Norris, R.; Miller, N.; Wassenaar, L.; Hobson, K.

    2010-12-01

    Each spring, millions of monarch butterflies (Danaus plexippus) migrate up to 3000 km from central Mexico to re-colonize eastern North America. However, despite centuries of research, the patterns of re-colonization are not well understood. We combined stable-hydrogen (δD) and -carbon (δ13C) isotope measurements with demographic models to test (1) whether individuals sampled in the northern part of the breeding range in the Great Lakes originate directly from Mexico or are second generation individuals born in the southern US and (2) to estimate whether populations on the eastern seaboard migrate longitudinally over the Appalachians or originate directly from the Gulf Coast. In the Great Lakes, we found that the majority of individuals were second-generation monarchs born in the Gulf Coast and Central regions of the US. However, 25% individuals originated directly from Mexico and we estimated that these individuals produced the majority of offspring born in the Great Lakes region during June. On the eastern seaboard, we found the majority of monarchs (88%) originated in the mid-west and Great Lakes regions, providing the first direct evidence that second generation monarchs born in June complete a (trans-) longitudinal migration across the Appalachian mountains. The remaining individuals (12%) originated from parents that migrated directly from the Gulf coast during early spring. Our results demonstrate how stable isotopes, when combined with ecological data, can provide insights into patterns of connectivity in migratory insects that have been impossible to test using conventional techniques. The migration patterns presented here have important implications for predicting future changes in population size and for developing effective conservation plans for this species.

  13. Connecting the navigational clock to sun compass input in monarch butterfly brain.

    PubMed

    Sauman, Ivo; Briscoe, Adriana D; Zhu, Haisun; Shi, Dingding; Froy, Oren; Stalleicken, Julia; Yuan, Quan; Casselman, Amy; Reppert, Steven M

    2005-05-05

    Migratory monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate to their overwintering grounds in Mexico. Although polarized light is one of the celestial cues used for orientation, the spectral content (color) of that light has not been fully explored. We cloned the cDNAs of three visual pigment-encoding opsins (ultraviolet [UV], blue, and long wavelength) and found that all three are expressed uniformly in main retina. The photoreceptors of the polarization-specialized dorsal rim area, on the other hand, are monochromatic for the UV opsin. Behavioral studies support the importance of polarized UV light for flight orientation. Next, we used clock protein expression patterns to identify the location of a circadian clock in the dorsolateral protocerebrum of butterfly brain. To provide a link between the clock and the sun compass, we identified a CRYPTOCHROME-staining neural pathway that likely connects the circadian clock to polarized light input entering brain.

  14. Discordant timing between antennae disrupts sun compass orientation in migratory monarch butterflies.

    PubMed

    Guerra, Patrick A; Merlin, Christine; Gegear, Robert J; Reppert, Steven M

    2012-07-17

    To navigate during their long-distance migration, monarch butterflies (Danaus plexippus) use a time-compensated sun compass. The sun compass timing elements reside in light-entrained circadian clocks in the antennae. Here we show that either antenna is sufficient for proper time compensation. However, migrants with either antenna painted black (to block light entrainment) and the other painted clear (to permit light entrainment) display disoriented group flight. Remarkably, when the black-painted antenna is removed, re-flown migrants with a single, clear-painted antenna exhibit proper orientation behaviour. Molecular correlates of clock function reveal that period and timeless expression is highly rhythmic in brains and clear-painted antennae, while rhythmic clock gene expression is disrupted in black-painted antennae. Our work shows that clock outputs from each antenna are processed and integrated together in the monarch time-compensated sun compass circuit. This dual timing system is a novel example of the regulation of a brain-driven behaviour by paired organs.

  15. Genetic variation in resistance, but not tolerance, to a protozoan parasite in the monarch butterfly.

    PubMed

    Lefèvre, Thierry; Williams, Amanda Jo; de Roode, Jacobus C

    2011-03-07

    Natural selection should strongly favour hosts that can protect themselves against parasites. Most studies on animals so far have focused on resistance, a series of mechanisms through which hosts prevent infection, reduce parasite growth or clear infection. However, animals may instead evolve tolerance, a defence mechanism by which hosts do not reduce parasite infection or growth, but instead alleviate the negative fitness consequences of such infection and growth. Here, we studied genetic variation in resistance and tolerance in the monarch butterfly (Danaus plexippus) to its naturally occurring protozoan parasite, Ophryocystis elektroscirrha. We exposed 560 monarch larvae of 19 different family lines to one of five different parasite inoculation doses (0, 1, 5, 10 and 100 infective spores) to create a range of parasite loads in infected butterflies. We then used two proxies of host fitness (adult lifespan and body mass) to quantify: (i) qualitative resistance (the ability to prevent infection; also known as avoidance or anti-infection resistance); (ii) quantitative resistance (the ability to limit parasite growth upon infection; also known as control or anti-growth resistance); and (iii) tolerance (the ability to maintain fitness with increasing parasite infection intensity). We found significant differences among host families in qualitative and quantitative resistance, indicating genetic variation in resistance. However, we found no genetic variation in tolerance. This may indicate that all butterflies in our studied population have evolved maximum tolerance, as predicted by some theoretical models.

  16. Genetic variation in resistance, but not tolerance, to a protozoan parasite in the monarch butterfly

    PubMed Central

    Lefèvre, Thierry; Williams, Amanda Jo; de Roode, Jacobus C.

    2011-01-01

    Natural selection should strongly favour hosts that can protect themselves against parasites. Most studies on animals so far have focused on resistance, a series of mechanisms through which hosts prevent infection, reduce parasite growth or clear infection. However, animals may instead evolve tolerance, a defence mechanism by which hosts do not reduce parasite infection or growth, but instead alleviate the negative fitness consequences of such infection and growth. Here, we studied genetic variation in resistance and tolerance in the monarch butterfly (Danaus plexippus) to its naturally occurring protozoan parasite, Ophryocystis elektroscirrha. We exposed 560 monarch larvae of 19 different family lines to one of five different parasite inoculation doses (0, 1, 5, 10 and 100 infective spores) to create a range of parasite loads in infected butterflies. We then used two proxies of host fitness (adult lifespan and body mass) to quantify: (i) qualitative resistance (the ability to prevent infection; also known as avoidance or anti-infection resistance); (ii) quantitative resistance (the ability to limit parasite growth upon infection; also known as control or anti-growth resistance); and (iii) tolerance (the ability to maintain fitness with increasing parasite infection intensity). We found significant differences among host families in qualitative and quantitative resistance, indicating genetic variation in resistance. However, we found no genetic variation in tolerance. This may indicate that all butterflies in our studied population have evolved maximum tolerance, as predicted by some theoretical models. PMID:20843849

  17. Regional climate on the breeding grounds predicts variation in the natal origin of monarch butterflies overwintering in Mexico over 38 years.

    PubMed

    Flockhart, D T Tyler; Brower, Lincoln P; Ramirez, M Isabel; Hobson, Keith A; Wassenaar, Leonard I; Altizer, Sonia; Norris, D Ryan

    2017-01-03

    Addressing population declines of migratory insects requires linking populations across different portions of the annual cycle and understanding the effects of variation in weather and climate on productivity, recruitment, and patterns of long-distance movement. We used stable H and C isotopes and geospatial modeling to estimate the natal origin of monarch butterflies (Danaus plexippus) in eastern North America using over 1000 monarchs collected over almost four decades at Mexican overwintering colonies. Multinomial regression was used to ascertain which climate-related factors best-predicted temporal variation in natal origin across six breeding regions. The region producing the largest proportion of overwintering monarchs was the US Midwest (mean annual proportion = 0.38; 95% CI: 0.36-0.41) followed by the north-central (0.17; 0.14-0.18), northeast (0.15; 0.11-0.16), northwest (0.12; 0.12-0.16), southwest (0.11; 0.08-0.12), and southeast (0.08; 0.07-0.11) regions. There was no evidence of directional shifts in the relative contributions of different natal regions over time, which suggests these regions are comprising the same relative proportion of the overwintering population in recent years as in the mid-1970s. Instead, interannual variation in the proportion of monarchs from each region covaried with climate, as measured by the Southern Oscillation Index and regional-specific daily maximum temperature and precipitation, which together likely dictate larval development rates and food plant condition. Our results provide the first robust long-term analysis of predictors of the natal origins of monarchs overwintering in Mexico. Conservation efforts on the breeding grounds focused on the Midwest region will likely have the greatest benefit to eastern North American migratory monarchs, but the population will likely remain sensitive to regional and stochastic weather patterns.

  18. Monarch Butterflies: Spirits of Loved Ones

    ERIC Educational Resources Information Center

    Crumpecker, Cheryl

    2011-01-01

    The study of the beautiful monarch butterfly lends itself to a vast array of subject matter, and offers the opportunity to meet a large and varied number of standards and objectives for many grade levels. Art projects featuring monarchs may include many cross-curricular units such as math (symmetry and number graphing), science (adaptation and…

  19. Cardenolide fingerprint of monarch butterflies reared on common milkweed,Asclepias syriaca L.

    PubMed

    Malcolm, S B; Cockrell, B J; Brower, L P

    1989-03-01

    Monarch butterfly,Danaus plexippus (L.), larvae were collected during August 1983 from the common milkweed,Asclepias syriaca L., across its extensive North American range from North Dakota, east to Vermont, and south to Virginia. This confirms that the late summer distribution of breeding monarchs in eastern North America coincides with the range of this extremely abundant milkweed resource. Plant cardenolide concentrations, assayed by spectrophotometry in 158 samples from 27 collection sites, were biased towards plants with low cardenolide, and ranged from 4 to 229 μg/ 0.1 g dry weight, with a mean of 50 μg/0.1 g. Monarch larvae reared on these plants stored cardenolides logarithmically, and produced 158 adults with a normally distributed concentration range from 0 to 792 μg/0. l g dry butterfly, with a mean of 234 μg/0.1 g. Thus butterflies increased the mean plant cardenolide concentration by 4.7. The eastern plants and their resultant butterflies had higher cardenolide concentrations than those from the west, and in some areas monarchs sequestered more cardenolide from equivalent plants. Plants growing in small patches had higher cardenolide concentrations than those in larger patches, but this did not influence butterfly concentration. However, younger plants and those at habitat edges had higher cardenolide concentrations than either older, shaded, or open habitat plants, and this did influence butterfly storage. There were no apparent topographical differences reflected in the cardenolides of plants and butterflies. Twenty-eight cardenolides were recognized by thin-layer chromatography, with 27 in plants and 21 in butterflies. Butterflies stored cardenolides within the more polar 46% of the plantR d range, these being sequestered in higher relative concentrations than they occurred in the plants. By comparison with published TLC cardenolide mobilities, spots 3, 4, 9, 16, 24 or 25, 26, and 27, may be the cardenolides syrioside, uzarin, syriobioside

  20. Are female monarch butterflies declining in eastern North America? Evidence of a 30-year change in sex ratios at Mexican overwintering sites.

    PubMed

    Davis, Andrew K; Rendón-Salinas, Eduardo

    2010-02-23

    Every autumn the entire eastern North American population of monarch butterflies (Danaus plexippus) undergoes a spectacular migration to overwintering sites in the mountains of central Mexico, where they form massive clusters and can number in the millions. Since their discovery, these sites have been extensively studied, and in many of these studies, monarchs were captured and sexes recorded. In a recent effort to compile the sex ratio data from these published records, a surprising trend was found, which appears to show a gradual decline in proportion of females over time. Sex ratio data from 14 collections of monarchs, all spanning 30 years and totaling 69 113 individuals, showed a significant negative correlation between proportion of females and year (r = -0.69, p = 0.007). Between 1976 and 1985, 53 per cent of overwintering monarchs were female, whereas in the last decade, 43 per cent were female. The relationship was significant with and without weighting the analyses by sampling effort. Moreover, analysis of a recent three-year dataset of sex ratios revealed no variation among nine separate colonies, so differences in sampling location did not influence the trend. Additional evidence from autumn migration collections appears to confirm that proportions of females are declining, and also suggests the sex ratio is shifting on breeding grounds. While breeding monarchs face a number of threats, one possibility is an increase in prevalence of the protozoan parasite, Ophryocystis elektroscirrha, which recent evidence shows affects females more so than males. Further study will be needed to determine the exact cause of this trend, but for now it should be monitored closely.

  1. Are female monarch butterflies declining in eastern North America? Evidence of a 30-year change in sex ratios at Mexican overwintering sites

    PubMed Central

    Davis, Andrew K.; Rendón-Salinas, Eduardo

    2010-01-01

    Every autumn the entire eastern North American population of monarch butterflies (Danaus plexippus) undergoes a spectacular migration to overwintering sites in the mountains of central Mexico, where they form massive clusters and can number in the millions. Since their discovery, these sites have been extensively studied, and in many of these studies, monarchs were captured and sexes recorded. In a recent effort to compile the sex ratio data from these published records, a surprising trend was found, which appears to show a gradual decline in proportion of females over time. Sex ratio data from 14 collections of monarchs, all spanning 30 years and totaling 69 113 individuals, showed a significant negative correlation between proportion of females and year (r = −0.69, p = 0.007). Between 1976 and 1985, 53 per cent of overwintering monarchs were female, whereas in the last decade, 43 per cent were female. The relationship was significant with and without weighting the analyses by sampling effort. Moreover, analysis of a recent three-year dataset of sex ratios revealed no variation among nine separate colonies, so differences in sampling location did not influence the trend. Additional evidence from autumn migration collections appears to confirm that proportions of females are declining, and also suggests the sex ratio is shifting on breeding grounds. While breeding monarchs face a number of threats, one possibility is an increase in prevalence of the protozoan parasite, Ophryocystis elektroscirrha, which recent evidence shows affects females more so than males. Further study will be needed to determine the exact cause of this trend, but for now it should be monitored closely. PMID:19776062

  2. Monarch butterfly spatially discrete advection model.

    PubMed

    Yakubu, Abdul-Aziz; Sáenz, Roberto; Stein, Julie; Jones, Laura E

    2004-08-01

    We study the population cycles of the Monarch butterfly using one of the simplest systems incorporating both migration and local dynamics. The annual migration of the Monarch involves four generations. Members of Generations 1-3 (occasionally 4) migrate from the over-wintering site in Central Mexico to breeding grounds that extend as far north as the Northern United States and Southern Canada. A portion of the Generation 3 and all members of the Generation 4 butterflies begin their return to the over-wintering grounds in August through October where they enter reproductive diapause for several months. We developed a simple discrete-time island chain model in which different fecundity functions are used to model the reproductive strategies of each generation. The fecundity functions are selected from broad classes of functions that capture the effects of either contest or scramble intraspecific competition in the Monarch population. The objectives of our research are multiple and include the study of the generationally dependent intraspecific competition and its effect on the pool size of migrants as well as the persistence of the overall butterfly populations. The stage structure used in modeling the Monarch butterfly dynamics and their generationally dependent reproductive strategies naturally support fluctuating patterns and multiple attractors. The implications of these fluctuations and attractors on the long-term survival of the Monarch butterfly population are explored.

  3. Trends in deforestation and forest degradation after a decade of monitoring in the Monarch Butterfly Biosphere Reserve in Mexico.

    PubMed

    Vidal, Omar; López-García, José; Rendón-Salinas, Eduardo

    2014-02-01

    We used aerial photographs, satellite images, and field surveys to monitor forest cover in the core zones of the Monarch Butterfly Biosphere Reserve in Mexico from 2001 to 2012. We used our data to assess the effectiveness of conservation actions that involved local, state, and federal authorities and community members (e.g., local landowners and private and civil organizations) in one of the world's most iconic protected areas. From 2001 through 2012, 1254 ha were deforested (i.e., cleared areas had <10% canopy cover), 925 ha were degraded (i.e., areas for which canopy forest decreased), and 122 ha were affected by climatic conditions. Of the total 2179 ha of affected area, 2057 ha were affected by illegal logging: 1503 ha by large-scale logging and 554 ha by small-scale logging. Mexican authorities effectively enforced efforts to protect the monarch reserve, particularly from 2007 to 2012. Those efforts, together with the decade-long financial support from Mexican and international philanthropists and businesses to create local alternative-income generation and employment, resulted in the decrease of large-scale illegal logging from 731 ha affected in 2005-2007 to none affected in 2012, although small-scale logging is of growing concern. However, dire regional social and economic problems remain, and they must be addressed to ensure the reserve's long-term conservation. The monarch butterfly (Danaus plexippus) overwintering colonies in Mexico-which engage in one of the longest known insect migrations-are threatened by deforestation, and a multistakeholder, regional, sustainable-development strategy is needed to protect the reserve.

  4. Trends in Deforestation and Forest Degradation after a Decade of Monitoring in the Monarch Butterfly Biosphere Reserve in Mexico

    PubMed Central

    VIDAL, OMAR; LÓPEZ-GARCÍA, JOSÉ; RENDÓN-SALINAS, EDUARDO

    2014-01-01

    We used aerial photographs, satellite images, and field surveys to monitor forest cover in the core zones of the Monarch Butterfly Biosphere Reserve in Mexico from 2001 to 2012. We used our data to assess the effectiveness of conservation actions that involved local, state, and federal authorities and community members (e.g., local landowners and private and civil organizations) in one of the world’s most iconic protected areas. From 2001 through 2012, 1254 ha were deforested (i.e., cleared areas had <10% canopy cover), 925 ha were degraded (i.e., areas for which canopy forest decreased), and 122 ha were affected by climatic conditions. Of the total 2179 ha of affected area, 2057 ha were affected by illegal logging: 1503 ha by large-scale logging and 554 ha by small-scale logging. Mexican authorities effectively enforced efforts to protect the monarch reserve, particularly from 2007 to 2012. Those efforts, together with the decade-long financial support from Mexican and international philanthropists and businesses to create local alternative-income generation and employment, resulted in the decrease of large-scale illegal logging from 731 ha affected in 2005–2007 to none affected in 2012, although small-scale logging is of growing concern. However, dire regional social and economic problems remain, and they must be addressed to ensure the reserve’s long-term conservation. The monarch butterfly (Danaus plexippus) overwintering colonies in Mexico—which engage in one of the longest known insect migrations—are threatened by deforestation, and a multistakeholder, regional, sustainable-development strategy is needed to protect the reserve. PMID:24001209

  5. Navigational Mechanisms of Migrating Monarch Butterflies

    PubMed Central

    Reppert, Steven M.; Gegear, Robert J.; Merlin, Christine

    2010-01-01

    Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind the navigation south, using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and likely integrated in the brain’s central complex, the presumed site of the sun compass. Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae. Monarchs may also use a magnetic compass, because they possess two cryptochromes that have the molecular capability for light-dependent magnetoreception. Multiple genomic approaches are being utilized to ultimately identify navigation genes. Monarch butterflies are thus emerging as an excellent model organism to study the molecular and neural basis of long-distance migration. PMID:20627420

  6. Navigational mechanisms of migrating monarch butterflies.

    PubMed

    Reppert, Steven M; Gegear, Robert J; Merlin, Christine

    2010-09-01

    Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind their southward navigation while using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and are probably integrated in the brain's central complex, the presumed site of the sun compass. Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae. Monarchs might also use a magnetic compass because they possess two cryptochromes that have the molecular capability for light-dependent magnetoreception. Multiple genomic approaches are now being used with the aim of identifying navigation genes. Monarch butterflies are thus emerging as an excellent model organism in which to study the molecular and neural basis of long-distance migration.

  7. Physiological characterization of the compound eye in monarch butterflies with focus on the dorsal rim area.

    PubMed

    Stalleicken, Julia; Labhart, Thomas; Mouritsen, Henrik

    2006-03-01

    The spectral, angular and polarization sensitivities of photoreceptors in the compound eye of the monarch butterfly (Danaus plexippus) are examined using electrophysiological methods. Intracellular recordings reveal a spectrally homogenous population of UV receptors with optical axes directed upwards and >or=10 degrees to the contralateral side. Based on optical considerations and on the opsin expression pattern (Sauman et al. 2005), we conclude that these UV receptors belong to the anatomically specialized dorsal rim area (DRA) of the eye. Photoreceptors in the main retina with optical axes <10 degrees contralateral or ipsilateral have maximal sensitivities in the UV (lambda(max)

  8. Combining stochastic models with experiments to understand the dynamics of monarch butterfly colonization.

    PubMed

    Drury, Kevin L S; Dwyer, Greg

    2005-12-01

    Stochastic models are of increasing importance in ecology but are usually only applied to observational data. Here we use a stochastic population model to combine experimental and observational data to understand the colonization of old fields by monarch butterflies Danaus plexippus. We experimentally tested for density dependence in oviposition rates when predators were excluded, and we measured predation rates under natural conditions. Significance tests on the resulting data showed that both oviposition and predation were density dependent but could not show how oviposition and mortality combine to determine egg densities in nature. We therefore used our data to calculate the Akaike Information Criterion to choose between a nested suite of stochastic models that differed in their oviposition and mortality terms. When we simply fit the models to the observational data, the best model assumed density independence in both oviposition and predation. When we instead first estimated the oviposition rate at low density from experimental data, however, the best model included density dependence in oviposition, and a model that included density dependence in both oviposition and predation performed nearly as well. This result is consistent with our experiments and suggests that experiments can enhance the usefulness of stochastic models in ecology.

  9. Does skipping a meal matter to a butterfly's appearance? Effects of larval food stress on wing morphology and color in monarch butterflies.

    PubMed

    Johnson, Haley; Solensky, Michelle J; Satterfield, Dara A; Davis, Andrew K

    2014-01-01

    In animals with complex life cycles, all resources needed to form adult tissues are procured at the larval stage. For butterflies, the proper development of wings involves synthesizing tissue during metamorphosis based on the raw materials obtained by larvae. Similarly, manufacture of pigment for wing scales also requires resources acquired by larvae. We conducted an experiment to test the effects of food deprivation in the larval stage on multiple measures of adult wing morphology and coloration of monarch butterflies (Danaus plexippus), a species in which long-distance migration makes flight efficiency critical. In a captive setting, we restricted food (milkweed) from late-stage larvae for either 24 hrs or 48 hrs, then after metamorphosis we used image analysis methods to measure forewing surface area and elongation (length/width), which are both important for migration. We also measured the brightness of orange pigment and the intensity of black on the wing. There were correlations between several wing features, including an unexpected association between wing elongation and melanism, which will require further study to fully understand. The clearest effect of food restriction was a reduction in adult wing size in the high stress group (by approximately 2%). Patterns observed for other wing traits were ambiguous: monarchs in the low stress group (but not the high) had less elongated and paler orange pigmentation. There was no effect on wing melanism. Although some patterns obtained in this study were unclear, our results concerning wing size have direct bearing on the monarch migration. We show that if milkweed is limited for monarch larvae, their wings become stunted, which could ultimately result in lower migration success.

  10. Does Skipping a Meal Matter to a Butterfly's Appearance? Effects of Larval Food Stress on Wing Morphology and Color in Monarch Butterflies

    PubMed Central

    Johnson, Haley; Solensky, Michelle J.; Satterfield, Dara A.; Davis, Andrew K.

    2014-01-01

    In animals with complex life cycles, all resources needed to form adult tissues are procured at the larval stage. For butterflies, the proper development of wings involves synthesizing tissue during metamorphosis based on the raw materials obtained by larvae. Similarly, manufacture of pigment for wing scales also requires resources acquired by larvae. We conducted an experiment to test the effects of food deprivation in the larval stage on multiple measures of adult wing morphology and coloration of monarch butterflies (Danaus plexippus), a species in which long-distance migration makes flight efficiency critical. In a captive setting, we restricted food (milkweed) from late-stage larvae for either 24 hrs or 48 hrs, then after metamorphosis we used image analysis methods to measure forewing surface area and elongation (length/width), which are both important for migration. We also measured the brightness of orange pigment and the intensity of black on the wing. There were correlations between several wing features, including an unexpected association between wing elongation and melanism, which will require further study to fully understand. The clearest effect of food restriction was a reduction in adult wing size in the high stress group (by approximately 2%). Patterns observed for other wing traits were ambiguous: monarchs in the low stress group (but not the high) had less elongated and paler orange pigmentation. There was no effect on wing melanism. Although some patterns obtained in this study were unclear, our results concerning wing size have direct bearing on the monarch migration. We show that if milkweed is limited for monarch larvae, their wings become stunted, which could ultimately result in lower migration success. PMID:24695643

  11. Animal behaviour: monarchs catch a cold.

    PubMed

    Kyriacou, Charalambos P

    2013-03-18

    The spectacular migration of the Monarch from northeastern America to its overwintering grounds in Mexico requires the butterfly to set its time-compensated compass south in the autumn, then north in the spring for its return home. The stimulus responsible for compass resetting has been identified as a reduction in temperature.

  12. The Transformation: Monarch Institute for Neurological Differences

    ERIC Educational Resources Information Center

    Reclaiming Children and Youth, 2013

    2013-01-01

    Those utilizing the Monarch Institute and its powerful website include educational and mental health professionals looking for training, or employers seeking qualified workers who happen to have neurological differences. Most are students and their parents who are worried and in pain because they have a problem. The young person is not progressing…

  13. Unravelling the annual cycle in a migratory animal: breeding-season habitat loss drives population declines of monarch butterflies.

    PubMed

    Flockhart, D T Tyler; Pichancourt, Jean-Baptiste; Norris, D Ryan; Martin, Tara G

    2015-01-01

    Threats to migratory animals can occur at multiple periods of the annual cycle that are separated by thousands of kilometres and span international borders. Populations of the iconic monarch butterfly (Danaus plexippus) of eastern North America have declined over the last 21 years. Three hypotheses have been posed to explain the decline: habitat loss on the overwintering grounds in Mexico, habitat loss on the breeding grounds in the United States and Canada, and extreme weather events. Our objectives were to assess population viability, determine which life stage, season and geographical region are contributing the most to population dynamics and test the three hypotheses that explain the observed population decline. We developed a spatially structured, stochastic and density-dependent periodic projection matrix model that integrates patterns of migratory connectivity and demographic vital rates across the annual cycle. We used perturbation analysis to determine the sensitivity of population abundance to changes in vital rate among life stages, seasons and geographical regions. Next, we compared the singular effects of each threat to the full model where all factors operate concurrently. Finally, we generated predictions to assess the risk of host plant loss as a result of genetically modified crops on current and future monarch butterfly population size and extinction probability. Our year-round population model predicted population declines of 14% and a quasi-extinction probability (<1000 individuals) >5% within a century. Monarch abundance was more than four times more sensitive to perturbations of vital rates on the breeding grounds than on the wintering grounds. Simulations that considered only forest loss or climate change in Mexico predicted higher population sizes compared to milkweed declines on the breeding grounds. Our model predictions also suggest that mitigating the negative effects of genetically modified crops results in higher population size and

  14. Temporal and spatial overlap between monarch larvae and corn pollen.

    PubMed

    Oberhauser, K S; Prysby, M D; Mattila, H R; Stanley-Horn, D E; Sears, M K; Dively, G; Olson, E; Pleasants, J M; Lam, W K; Hellmich, R L

    2001-10-09

    To assess the likelihood that monarch larvae will be exposed to Bacillus thuringiensis (Bt) pollen, we studied milkweed and monarch densities in habitats which comprise much of the land available to breeding monarchs, e.g., cornfields, cornfield edges, other agricultural fields, and nonagricultural areas, in four regions of the monarch breeding range. We found that monarchs use milkweed in cornfields throughout their breeding season, and that per plant densities are as high or higher in agricultural habitats as in nonagricultural habitats. As a result of the prevalence of agricultural land, most of the monarchs produced in the upper Midwest are likely to originate in cornfields or other agricultural habitats. There was a greater temporal overlap between susceptible monarchs and corn anthesis in the northern than the southern part of the summer breeding range, because of earlier pollen shed in the south. The importance of agricultural habitats to monarch production suggests that, regardless of the impact of genetically modified crops, agricultural practices such as weed control and foliar insecticide use could have large impacts on monarch populations.

  15. Specialized ommatidia of the polarization-sensitive dorsal rim area in the eye of monarch butterflies have non-functional reflecting tapeta.

    PubMed

    Labhart, Thomas; Baumann, Franziska; Bernard, Gary D

    2009-12-01

    Many insects exploit sky light polarization for navigation or cruising-course control. The detection of polarized sky light is mediated by the ommatidia of a small specialized part of the compound eye: the dorsal rim area (DRA). We describe the morphology and fine structure of the DRA in monarch butterflies (Danaus plexippus). The DRA consists of approximately 100 ommatidia forming a narrow ribbon along the dorsal eye margin. Each ommatidium contains two types of photoreceptor with mutually orthogonal microvilli orientations occurring in a 2:6 ratio. Within each rhabdomere, the microvilli are well aligned. Rhabdom structure and orientation remain constant at all retinal levels, but the rhabdom profiles, as seen in tangential sections through the DRA, change their orientations in a fan-like fashion from the frontal to the caudal end of the DRA. Whereas these properties (two microvillar orientations per rhabdom, microvillar alignment along rhabdomeres, ommatidial fan array) are typical for insect DRAs in general, we also report and discuss here a novel feature. The ommatidia of monarch butterflies are equipped with reflecting tapeta, which are directly connected to the proximal ends of the rhabdoms. Although tapeta are also present in the DRA, they are separated from the rhabdoms by a space of approximately 55 mum effectively inactivating them. This reduces self-screening effects, keeping polarization sensitivity of all photoreceptors of the DRA ommatidia both high and approximately equal.

  16. Attenuation of the jasmonate burst, plant defensive traits, and resistance to specialist monarch caterpillars on shaded common milkweed (Asclepias syriaca).

    PubMed

    Agrawal, Anurag A; Kearney, Emily E; Hastings, Amy P; Ramsey, Trey E

    2012-07-01

    Plant responses to herbivory and light competition are often in opposing directions, posing a potential conflict for plants experiencing both stresses. For sun-adapted species, growing in shade typically makes plants more constitutively susceptible to herbivores via reduced structural and chemical resistance traits. Nonetheless, the impact of light environment on induced resistance has been less well-studied, especially in field experiments that link physiological mechanisms to ecological outcomes. Accordingly, we studied induced resistance of common milkweed (Asclepias syriaca, a sun-adapted plant), and linked hormonal responses, resistance traits, and performance of specialist monarch caterpillars (Danaus plexippus) in varying light environments. In natural populations, plants growing under forest-edge shade showed reduced levels of resistance traits (lower leaf toughness, cardenolides, and trichomes) and enhanced light-capture traits (higher specific leaf area, larger leaves, and lower carbon-to-nitrogen ratio) compared to paired plants in full sun. In a field experiment repeated over two years, only milkweeds growing in full sun exhibited induced resistance to monarchs, whereas plants growing in shade were constitutively more susceptible and did not induce resistance. In a more controlled field experiment, plant hormones were higher in the sun (jasmonic acid, salicylic acid, abscisic acid, indole acidic acid) and were induced by herbivory (jasmonic acid and abscisic acid). In particular, the jasmonate burst following herbivory was halved in plants raised in shaded habitats, and this correspondingly reduced latex induction (but not cardenolide induction). Thus, we provide a mechanistic basis for the attenuation of induced plant resistance in low resource environments. Additionally, there appears to be specificity in these interactions, with light-mediated impacts on jasmonate-induction being stronger for latex exudation than cardenolides.

  17. Dietary Risk Assessment of v-ATPase A dsRNAs on Monarch Butterfly Larvae

    PubMed Central

    Pan, Huipeng; Yang, Xiaowei; Bidne, Keith; Hellmich, Richard L.; Siegfried, Blair D.; Zhou, Xuguo

    2017-01-01

    By suppressing the expression of genes with essential biological functions, in planta RNAi can negatively affect the development and survival of target pests. As a part of a concerted effort to assess the risks of RNAi transgenic crops on non-target organisms, we developed an in vivo toxicity assay to examine the impacts of ingested dsRNAs incurred to the monarch butterfly, Danaus plexippus (L.), an iconic eco-indicator in North America. To create the worst case scenario, the full-length v-ATPase A cDNAs from the target pest, western corn rootworm, Diabrotica virgifera virgifera, and the non-target D. plexippus were respectively cloned. A 400 bp fragment with the highest sequence similarity between the two species was used as the template to synthesize dsRNAs for the subsequent dietary RNAi toxicity assay. Specifically, newly hatched neonates were provisioned with leaf disks surface-coated with v-ATPase A dsRNAs synthesized from D. v. virgifera and D. plexippus, respectively, a control dsRNA, β-glucoruronidase, from plants, and H2O. The endpoint measurements included gene expressions and life history traits. The 2283 bp D. plexippus v-ATPase A cDNA contains a 99 bp 5′-untranslated region, a 330 bp 3′-untranslated region, and an 1851 bp ORF encoding 617 amino acids. The temporal RNAi study did not detect any impact to D. plexippus v-ATPase A expression by the assay days and treatments. This was reflected in the phenotypic impacts of dietary RNAi, in which both survival rate and development time were not affected by the uptake of ingested dsRNAs. These combined results suggest that D. plexippus larvae are not susceptible to dietary RNAi, therefore, the impact of transgenic RNAi plants on this non-target organism is, likely, negligible. PMID:28275381

  18. Formation and function of flavin anion radical in cryptochrome 1 blue-light photoreceptor of monarch butterfly.

    PubMed

    Song, Sang-Hun; Oztürk, Nuri; Denaro, Tracy R; Arat, N Ozlem; Kao, Ya-Ting; Zhu, Haisun; Zhong, Dongping; Reppert, Steven M; Sancar, Aziz

    2007-06-15

    The monarch butterfly (Danaus plexippus) cryptochrome 1 (DpCry1) belongs in the class of photosensitive insect cryptochromes. Here we purified DpCry1 expressed in a bacterial host and obtained the protein with a stoichiometric amount of the flavin cofactor in the two-electron oxidized, FAD(ox), form. Exposure of the purified protein to light converts the FAD(ox) to the FAD*(-) flavin anion radical by intraprotein electron transfer from a Trp residue in the apoenzyme. To test whether this novel photoreduction reaction is part of the DpCry1 physiological photocycle, we mutated the Trp residue that acts as the ultimate electron donor in flavin photoreduction. The mutation, W328F, blocked the photoreduction entirely but had no measurable effect on the light-induced degradation of DpCry1 in vivo. In light of this finding and the recently published action spectrum of this class of Crys, we conclude that DpCry1 and similar insect cryptochromes do not contain flavin in the FAD(ox) form in vivo and that, most likely, the [see text] photoreduction reaction is not part of the insect cryptochrome photoreaction that results in proteolytic degradation of the photopigment.

  19. Fueling the fall migration of the monarch butterfly.

    PubMed

    Brower, Lincoln P; Fink, Linda S; Walford, Peter

    2006-12-01

    Monarch butterflies in eastern North America accumulate lipids during their fall migration to central Mexico, and use them as their energy source during a 5 month overwintering period. When and where along their migratory journey the butterflies accumulate these lipids has implications for the importance of fall nectar sources in North America. We analyzed the lipid content of 765 summer breeding and fall migrant monarch butterflies collected at 1 nectaring site in central Virginia over 4 years (1998-2001), and compared them with 16 additional published and unpublished datasets from other sites, dating back to 1941. Virginia migrants store significantly more lipid than summer butterflies, and show significant intraseason and between-year variation. None of the Virginia samples, and none of the historical samples, with one exception, had lipid levels comparable with those found in migrants that had reached Texas and northern Mexico. This evidence suggests that upon reaching Texas, the butterflies undergo a behavioral shift and spend more time nectaring. The one exceptional sample led us to the discovery that monarchs that form roosts along their migratory routes have higher lipid contents than monarchs collected while nectaring at flowers. We propose that for much of their journey monarchs are opportunistic migrants, and the variation within and between samples reflects butterflies' individual experiences. The stored lipids appear to be of less importance as fuel for the butterflies' migration than for their survival during their overwintering period, in part because soaring on favorable winds reduces the energetic cost of flying. The conservation of nectar plants in Texas and northern Mexico is crucial to sustaining the monarch's migratory spectacle, and nectar abundance throughout eastern North America is also important. As generalists in their selection of nectar sources and nectaring habitats, monarchs are unlikely to be affected by small changes in plant

  20. Selection of reference genes for RT-qPCR analysis in the monarch butterfly, Danaus plexippus (L.), a migrating bio-indicator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative real-time PCR (qRT-PCR) is a reliable and reproducible technique for measuring and evaluating changes in gene expression. To facilitate gene expression studies and obtain more accurate qRT-PCR data, normalization relative to stable housekeeping genes is required. In this study, expres...

  1. Listening to their voices: The essence of the experience of special and regular education students as they learn monarch, Danaus plexippus, biology and ecology

    NASA Astrophysics Data System (ADS)

    Koomen, Michele Jean Hollingsworth

    This dissertation reports on a phenomenological study of nine regular and special education students as they studied insect biology and ecology in their inclusive seventh grade life science class. Three fundamental data collection methods of interpretive research (student observations, interviews and artifact analysis) framed the data collection of this study. Hermeneutic phenomenological analysis and a seven-step framework, beginning with establishment of the unit of analysis and ending in theory generation, were used to systematically analyze the data resulting in the emergence of four main themes. The essence of the lived experience of the study participants reveal a variety of ways working with others in groups supported their learning. Students reported that it was easier to share ideas, ask questions and complete their work when they worked together with other classmates. A second finding of this study, It's kind of hard in learning science, exposes some of the anxiety and the challenges that are part of the experiences of both regular and special education students in learning science. A third finding reveals that for the students in this study the practice of inquiry learning in science is fragile. Despite daily opportunities in inquiry activities, many students are fixated in finding the "right" answers and just getting their "work done." The practice of inquiry is also fragile because of the perceptions of how we go about doing and learning science. The perception of practicing science for the special education students was moderated and limited by their viewpoint that science is coupled with language arts. The last major theme describes the manner in which both student groups navigate through science learning using various strategies that contribute to their learning or engaging in behaviors that seem to conceal their learning differences. The results of this research have implication for inclusive classroom teachers, special educators, teacher educators and administrators. Listening to their voices serves to "prime" us to consider and value their perspectives as we make decisions that affect their learning and their lives.

  2. Populations of Monarch butterflies with different migratory behaviors show divergence in wing morphology.

    PubMed

    Altizer, Sonia; Davis, Andrew K

    2010-04-01

    The demands of long-distance flight represent an important evolutionary force operating on the traits of migratory species. Monarchs are widespread butterflies known for their annual migrations in North America. We examined divergence in wing morphology among migratory monarchs from eastern and western N. America, and nonmigratory monarchs in S. Florida, Puerto Rico, Costa Rica, and Hawaii. For the three N. American populations, we also examined monarchs reared in four common environment experiments. We used image analysis to measure multiple traits including forewing area and aspect ratio; for laboratory-reared monarchs we also quantified body area and wing loading. Results showed wild monarchs from all nonmigratory populations were smaller than those from migratory populations. Wild and captive-reared eastern monarchs had the largest and most elongated forewings, whereas monarchs from Puerto Rico and Costa Rica had the smallest and roundest forewings. Eastern monarchs also had the largest bodies and high measures of wing loading, whereas western and S. Florida monarchs had less elongated forewings and smaller bodies. Among captive-reared butterflies, family-level effects provided evidence that genetic factors contributed to variation in wing traits. Collectively, these results support evolutionary responses to long-distance flight in monarchs, with implications for the conservation of phenotypically distinct wild populations.

  3. The monarch butterfly controversy: scientific interpretations of a phenomenon.

    PubMed

    Shelton, A M; Sears, M K

    2001-09-01

    The future development and use of agricultural biotechnology has been challenged by two preliminary studies indicating potential risk to monarch butterfly populations by pollen from corn engineered to express proteins from Bacillus thuringiensis. Likewise, these studies have also challenged the way in which science should be performed, published in scientific journals and communicated to the public at large. Herein, we provide a history of the monarch controversy to date. We believe a retrospective view may be useful for providing insights into the proper roles and responsibilities of scientists, the media and public agencies and the consequences when they go awry.

  4. Illuminating the circadian clock in monarch butterfly migration.

    PubMed

    Froy, Oren; Gotter, Anthony L; Casselman, Amy L; Reppert, Steven M

    2003-05-23

    Migratory monarch butterflies use a time-compensated Sun compass to navigate to their overwintering grounds in Mexico. Here, we report that constant light, which disrupts circadian clock function at both the behavioral and molecular levels in monarchs, also disrupts the time-compensated component of flight navigation. We further show that ultraviolet light is important for flight navigation but is not required for photic entrainment of circadian rhythms. Tracing these distinct light-input pathways into the brain should aid our understanding of the clock-compass mechanisms necessary for successful migration.

  5. Effects of altitude on the climbing performance of Monarch butterflies

    NASA Astrophysics Data System (ADS)

    Kang, Chang-Kwon; Sridhar, Madhu; Landrum, David; Aono, Hikaru

    2016-11-01

    Millions of Monarchs annually travel up to 4,000km, the longest migration distance among insects. They fly and overwinter at high altitudes. However, the aerodynamic mechanism enabling the long-range flight of Monarch butterflies is unknown. To study the effects of altitude on the aerodynamic performance of Monarch butterflies, a unique combination of a motion tracking system and a variable pressure chamber that allows controlling the density is used. The condition inside the chamber is systematically varied to simulate high altitude conditions up to 3,000 m. An optical tracking technique is used to characterize the climbing trajectories of freely flying Monarch butterflies. Customized reflective markers are designed to minimize the effects of marker addition. Flapping amplitude and frequency as well as climbing trajectories are measured. Lift acting on the butterfly is also determined by considering the force balance. Results show that the average flight speed and the Reynolds number, in general, decreased with the altitude, whereas, interestingly, the lift coefficient increased with the altitude. More detailed measurements and analyses will be performed in the future to explain the lift enhancement by flying at higher altitudes. This work is partly supported by NSF Grant CBET-1335572 and in part by CK's startup fund provided by UAH.

  6. EPA Grant Supports New York City Monarch Butterfly Project

    EPA Pesticide Factsheets

    (New York, N.Y.) The U.S. Environmental Protection Agency has awarded a $91,000 environmental education grant to Queens College to support the Queens College Metropolitan Monarch Alliance Project. The project is a community-based program to study and prote

  7. 34. Credit JTL. Second floor, view of Monarch Co. Corn ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. Credit JTL. Second floor, view of Monarch Co. Corn cracking machine, by Sprout, Waldron and Co., (Muncy, PA), which cut and diced corn to a uniform size, then separated it into three grades of cracked corn and corn meal and removed chaff. - Bunker Hill Mill, County Route 26, Bunker Hill, Berkeley County, WV

  8. Do monarch butterflies use polarized skylight for migratory orientation?

    PubMed

    Stalleicken, Julia; Mukhida, Maya; Labhart, Thomas; Wehner, Rüdiger; Frost, Barrie; Mouritsen, Henrik

    2005-06-01

    To test if migratory monarch butterflies use polarized light patterns as part of their time-compensated sun compass, we recorded their virtual flight paths in a flight simulator while the butterflies were exposed to patches of naturally polarized blue sky, artificial polarizers or a sunny sky. In addition, we tested butterflies with and without the polarized light detectors of their compound eye being occluded. The monarchs' orientation responses suggested that the butterflies did not use the polarized light patterns as a compass cue, nor did they exhibit a specific alignment response towards the axis of polarized light. When given direct view of the sun, migratory monarchs with their polarized light detectors painted out were still able to use their time-compensated compass: non-clockshifted butterflies, with their dorsal rim area occluded, oriented in their typical south-southwesterly migratory direction. Furthermore, they shifted their flight course clockwise by the predicted approximately 90 degrees after being advance clockshifted 6 h. We conclude that in migratory monarch butterflies, polarized light cues are not necessary for a time-compensated celestial compass to work and that the azimuthal position of the sun disc and/or the associated light-intensity and spectral gradients seem to be the migrants' major compass cue.

  9. Monarch larvae sensitivity to Bacillus thuringiensis- purified proteins and pollen.

    PubMed

    Hellmich, R L; Siegfried, B D; Sears, M K; Stanley-Horn, D E; Daniels, M J; Mattila, H R; Spencer, T; Bidne, K G; Lewis, L C

    2001-10-09

    Laboratory tests were conducted to establish the relative toxicity of Bacillus thuringiensis (Bt) toxins and pollen from Bt corn to monarch larvae. Toxins tested included Cry1Ab, Cry1Ac, Cry9C, and Cry1F. Three methods were used: (i) purified toxins incorporated into artificial diet, (ii) pollen collected from Bt corn hybrids applied directly to milkweed leaf discs, and (iii) Bt pollen contaminated with corn tassel material applied directly to milkweed leaf discs. Bioassays of purified Bt toxins indicate that Cry9C and Cry1F proteins are relatively nontoxic to monarch first instars, whereas first instars are sensitive to Cry1Ab and Cry1Ac proteins. Older instars were 12 to 23 times less susceptible to Cry1Ab toxin compared with first instars. Pollen bioassays suggest that pollen contaminants, an artifact of pollen processing, can dramatically influence larval survival and weight gains and produce spurious results. The only transgenic corn pollen that consistently affected monarch larvae was from Cry1Ab event 176 hybrids, currently <2% corn planted and for which re-registration has not been applied. Results from the other types of Bt corn suggest that pollen from the Cry1Ab (events Bt11 and Mon810) and Cry1F, and experimental Cry9C hybrids, will have no acute effects on monarch butterfly larvae in field settings.

  10. Lack of genetic differentiation between monarch butterflies with divergent migration destinations.

    PubMed

    Lyons, Justine I; Pierce, Amanda A; Barribeau, Seth M; Sternberg, Eleanore D; Mongue, Andrew J; De Roode, Jacobus C

    2012-07-01

    Monarch butterflies are best known for their spectacular annual migration from eastern North America to Mexico. Monarchs also occur in the North American states west of the Rocky Mountains, from where they fly shorter distances to the California Coast. Whether eastern and western North American monarchs form one genetic population or are genetically differentiated remains hotly debated, and resolution of this debate is essential to understand monarch migration patterns and to protect this iconic insect species. We studied the genetic structure of North American migratory monarch populations, as well as nonmigratory populations in Hawaii and New Zealand. Our results show that eastern and western migratory monarchs form one admixed population and that monarchs from Hawaii and New Zealand have genetically diverged from North American butterflies. These findings suggest that eastern and western monarch butterflies maintain their divergent migrations despite genetic mixing. The finding that eastern and western monarchs form one genetic population also suggests that the conservation of overwintering sites in Mexico is crucial for the protection of monarchs in both eastern and western North America.

  11. Sensory basis of lepidopteran migration: focus on the monarch butterfly.

    PubMed

    Guerra, Patrick A; Reppert, Steven M

    2015-10-01

    In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compass and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources.

  12. Sensory basis of lepidopteran migration: Focus on the monarch butterfly

    PubMed Central

    Guerra, Patrick A.; Reppert, Steven M.

    2015-01-01

    In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compasses and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources. PMID:25625216

  13. Monarch butterfly orientation: missing pieces of a magnificent puzzle

    PubMed

    Brower

    1996-01-01

    From late August to early September, millions of adult monarch butterflies of the eastern North American population cease reproducing, become highly gregarious and begin migrating southwards. By mid-October, they migrate through central Texas into Mexico where they follow the Sierra Madre Oriental across the Tropic of Cancer. They then shift direction westwards towards the Transverse Neovolcanic Belt of mountains where they overwinter without breeding. A rapid exodus northwards occurs at the spring equinox, and by early April both sexes reach the Gulf Coast states where the females lay eggs on the resurgent spring milkweed (Asclepias) flora and die. Adults of the new generation continue the migration to the northernmost breeding range, arriving by early June. Two or more short-lived breeding generations are produced over the summer, spread eastwards across the Appalachian Mountains and, by September, the autumn migration is again under way. This paper presents a new hypothesis that the orientation of adult monarchs undergoes a continual clockwise shifting throughout the 3-5 generations, rotating by 360 in the course of the year. This hypothesis is consistent with the timing of arrivals and the relative abundances of the successive generations of monarchs throughout eastern North America, with the directions of movement of their spring, summer and autumn generations, and with the timing of their arrival at the overwintering area in central Mexico.

  14. Natal origins of migratory monarch butterflies at wintering colonies in Mexico: new isotopic evidence.

    PubMed

    Wassenaar, L I; Hobson, A

    1998-12-22

    Each year, millions of monarch butterflies from eastern North America migrate to overwinter in 10-13 discrete colonies located in the Oyamel forests of central Mexico. For decades efforts to track monarch migration have relied on observations and tag-recapture methods, culminating with the discovery of the wintering colonies in 1975. Monarch tag returns from Mexico, however, are few and primarily from two accessible colonies, and therefore tag-recapture techniques have not quantified natal origins or distinctiveness among monarch populations at wintering sites. Such information would be invaluable in the conservation of the monarch and its migration phenomenon since the wintering sites currently are threatened by habitat alteration. Here we show that stable hydrogen (deltaD) and carbon (delta13C) isotope ratios of wintering monarchs can be used to evaluate natal origins on the summer breeding range. Stable-hydrogen and carbon isotopic values of 597 wintering monarchs from 13 wintering roost sites were compared with isotopic patterns measured in individuals at natal sites across their breeding range over a single migration cycle. We determined that all monarch wintering colonies were composed of individuals originating mainly from the Midwest, United States, thereby providing evidence for a panmictic model of wintering colony composition. However, two colonies showed more northerly origins, suggesting possible priority colonies for conservation efforts.

  15. Natal origins of migratory monarch butterflies at wintering colonies in Mexico: New isotopic evidence

    PubMed Central

    Wassenaar, Leonard I.; Hobson, Keith A.

    1998-01-01

    Each year, millions of monarch butterflies from eastern North America migrate to overwinter in 10–13 discrete colonies located in the Oyamel forests of central Mexico. For decades efforts to track monarch migration have relied on observations and tag-recapture methods, culminating with the discovery of the wintering colonies in 1975. Monarch tag returns from Mexico, however, are few and primarily from two accessible colonies, and therefore tag-recapture techniques have not quantified natal origins or distinctiveness among monarch populations at wintering sites. Such information would be invaluable in the conservation of the monarch and its migration phenomenon since the wintering sites currently are threatened by habitat alteration. Here we show that stable hydrogen (δD) and carbon (δ13C) isotope ratios of wintering monarchs can be used to evaluate natal origins on the summer breeding range. Stable-hydrogen and carbon isotopic values of 597 wintering monarchs from 13 wintering roost sites were compared with isotopic patterns measured in individuals at natal sites across their breeding range over a single migration cycle. We determined that all monarch wintering colonies were composed of individuals originating mainly from the Midwest, United States, thereby providing evidence for a panmictic model of wintering colony composition. However, two colonies showed more northerly origins, suggesting possible priority colonies for conservation efforts. PMID:9860986

  16. Cardenolide connection between overwintering monarch butterflies from Mexico and their larval food plant,Asclepias syriaca.

    PubMed

    Seiber, J N; Brower, L P; Lee, S M; McChesney, M M; Cheung, H T; Nelson, C J; Watson, T R

    1986-05-01

    The majority (85%) of 394 monarch butterflies sampled from overwintering sites in Mexico contain the same epoxy cardenolide glycosides, including most conspicuously a novel polar glycoside with a single genin-sugar bridge (aspecioside), as occur in the milkweedsAsclepias speciosa andA. syriaca. This cardenolide commonality was established by isolating aspecioside and syriobioside from the wings of overwintering monarchs and the two plant species, and comparing Chromatographie and NMR spectrometric characteristics of the isolates. When combined with the migratory pattern of monarchs and the distribution of these two milkweed species, this chemical evidence lends strong support to the hypothesis thatA. syriaca is the major late summer food plant of monarchs in eastern North America. This finding may be of ecological importance, forA. syriaca contributes less cardenolide and cardenolides of lower emetic potency to monarchs than most milkweeds studied to date.

  17. Tracking climate impacts on the migratory monarch butterfly

    USGS Publications Warehouse

    Zipkin, Elise F.; Ries, Leslie; Reeves, Rick; Regetz, James; Oberhauser, Karen S.

    2012-01-01

    Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad-scale climate metric can explain summer breeding phenology or the substantial year-to-year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state-wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to

  18. Phylogenetic incongruence and the evolutionary origins of cardenolide-resistant forms of Na(+) ,K(+) -ATPase in Danaus butterflies.

    PubMed

    Aardema, Matthew L; Andolfatto, Peter

    2016-08-01

    Many distantly related insect species are specialized feeders of cardenolide-containing host plants such as milkweed (Asclepias spp.). Previous studies have revealed frequent, parallel substitution of a functionally important amino acid substitution (N122H) in the alpha subunit of Na(+) ,K(+) -ATPase in a number of these species. This substitution facilitates the ability of these insects to feed on their toxic hosts and sequester cardenolides for their own use in defense. Among milkweed butterflies of the genus Danaus, the previously established phylogeny for this group suggests that N122H arose independently and fixed in two distinct lineages. We reevaluate this conclusion by examining Danaus phylogenetic relationships using >400 orthologous gene sequences assembled from transcriptome data. Our results indicate that the three Danaus species known to harbor the N122H substitution are more closely related than previously thought, consistent with a single, common origin for N122H. However, we also find evidence of both incomplete lineage sorting and post-speciation genetic exchange among these butterfly species, raising the possibility of collateral evolution of cardenolide-insensitivity in this species group.

  19. Virtual migration in tethered flying monarch butterflies reveals their orientation mechanisms.

    PubMed

    Mouritsen, Henrik; Frost, Barrie J

    2002-07-23

    A newly developed flight simulator allows monarch butterflies to fly actively for up to several hours in any horizontal direction while their fall migratory flight direction can be continuously recorded. From these data, long segments of virtual flight paths of tethered, flying, migratory monarch butterflies were reconstructed, and by advancing or retarding the butterflies' circadian clocks, we have shown that they possess a time-compensated sun compass. Control monarchs on local time fly approximately southwest, those 6-h time-advanced fly southeast, and 6-h time-delayed butterflies fly in northwesterly directions. Moreover, butterflies flown in the same apparatus under simulated overcast in natural magnetic fields were randomly oriented and did not change direction when magnetic fields were rotated. Therefore, these experiments do not provide any evidence that monarch butterflies use a magnetic compass during migration.

  20. Unravelling the Costs of Flight for Immune Defenses in the Migratory Monarch Butterfly.

    PubMed

    Fritzsche McKay, Alexa; Ezenwa, Vanessa O; Altizer, Sonia

    2016-08-01

    Migratory animals undergo extreme physiological changes to prepare for and sustain energetically costly movements; one potential change is reduced investment in immune defenses. However, because some migrants have evolved to minimize the energetic demands of movement (for example, through the temporary atrophy of non-essential organs such as those involved in reproduction), migratory animals could potentially avoid immunosuppression during long-distance journeys. In this study, we used a tethered flight mill to examine immune consequences of experimentally induced powered flight in eastern North American monarch butterflies. These butterflies undergo an annual two-way long-distance migration each year from as far north as Canada to wintering sites in Central Mexico. We quantified immune measures as a function of categorical flight treatment (flown versus control groups) and continuous measures of flight effort (e.g., flight distance, duration, and measures of efficiency). We also examined whether relationships between flight and immune measures depended on reproductive investment by experimentally controlling whether monarchs were reproductive or in state of reproductive diapause (having atrophied reproductive organs) prior to flight. Of the three immune responses we measured, hemocyte concentration (the number of immune cells) was lower in flown monarchs relative to controls but increased with flight distance among flown monarchs; the other two immune measures showed no relationship to monarch flight. We also found that monarchs that were reproductively active were less efficient fliers, as they exerted more power during flight than monarchs in reproductive diapause. However, reproductive status did not modify relationships between flight and immune measures. Results of this study add to a growing body of work suggesting that migratory monarchs-like some other animals that travel vast distances-can complete their journeys with efficient use of resources and

  1. The Effects of Scales on Autorotation of Monarch Butterfly Forewings

    NASA Astrophysics Data System (ADS)

    Dechello, Nicole; Lang, Amy

    2014-11-01

    The wings of Monarch butterflies (Danus plexippus) have scales of approximately 100 micrometers that cover their wings in a roof-shingle pattern, and these scales are hypothesized to help improve flight efficiency for their long migration. The aerodynamic effects of the scales, particularly involving the leading edge vortex formation and resulting lift, were investigated by observing the natural autorotation of forewing specimen when dropped in quiescent air. A high-speed camera recorded drop tests of 32 forewings both with scales and after removal of the scales. It was found that the scales, on average, comprised 17% of the forewing mass. Tracking software was used to analyze the videos for several parameters, including descent speed and radius of rotation. NSF ECE Grant #1358991 supported the first author as an research experience for undergraduate (REU) student.

  2. Scales affect performance of Monarch butterfly forewings in autorotational flight

    NASA Astrophysics Data System (ADS)

    Demko, Anya; Lang, Amy

    2012-11-01

    Butterfly wings are characterized by rows of scales (approximately 100 microns in length) that create a shingle-like pattern of cavities over the entire surface. It is hypothesized that these cavities influence the airflow around the wing and increase aerodynamic performance. A forewing of the Monarch butterfly (Danus plexippus) naturally undergoes autorotational flight in the laminar regime. Autorotational flight is an accurate representation of insect flight because the rotation induces a velocity gradient similar to that found over a flapping wing. Drop test flights of 22 forewings before and after scale removal were recorded with a high-speed camera and flight behavior was quantified. It was found that removing the scales increased the descent speed and decreased the descent factor, a measure of aerodynamic efficacy, suggesting that scales increased the performance of the forewings. Funded by NSF REU Grant 1062611.

  3. Soil-Applied Imidacloprid Translocates to Ornamental Flowers and Reduces Survival of Adult Coleomegilla maculata, Harmonia axyridis, and Hippodamia convergens Lady Beetles, and Larval Danaus plexippus and Vanessa cardui Butterflies

    PubMed Central

    Krischik, Vera; Rogers, Mary; Gupta, Garima; Varshney, Aruna

    2015-01-01

    Integrated Pest Management (IPM) is a decision making process used to manage pests that relies on many tactics, including cultural and biological control, which are practices that conserve beneficial insects and mites, and when needed, the use of conventional insecticides. However, systemic, soil-applied neonicotinoid insecticides are translocated to pollen and nectar of flowers, often for months, and may reduce survival of flower-feeding beneficial insects. Imidacloprid seed-treated crops (0.05 mg AI (active ingredient) /canola seed and 1.2 mg AI/corn seed) translocate less than 10 ppb to pollen and nectar. However, higher rates of soil-applied imidacloprid are used in nurseries and urban landscapes, such as 300 mg AI/10 L (3 gallon) pot and 69 g AI applied to the soil under a 61 (24 in) cm diam. tree. Translocation of imidacloprid from soil (300 mg AI) to flowers of Asclepias curassavica resulted in 6,030 ppb in 1X and 10,400 ppb in 2X treatments, which are similar to imidacloprid residues found in another plant species we studied. A second imidacloprid soil application 7 months later resulted in 21,000 ppb in 1X and 45,000 ppb in 2X treatments. Consequently, greenhouse/nursery use of imidacloprid applied to flowering plants can result in 793 to 1,368 times higher concentration compared to an imidacloprid seed treatment (7.6 ppb pollen in seed- treated canola), where most research has focused. These higher imidacloprid levels caused significant mortality in both 1X and 2X treatments in 3 lady beetle species, Coleomegilla maculata, Harmonia axyridis, and Hippodamia convergens, but not a fourth species, Coccinella septempunctata. Adult survival were not reduced for monarch, Danaus plexippus and painted lady, Vanessa cardui, butterflies, but larval survival was significantly reduced. The use of the neonicotinoid imidacloprid at greenhouse/nursery rates reduced survival of beneficial insects feeding on pollen and nectar and is incompatible with the principles of IPM

  4. Soil-applied imidacloprid translocates to ornamental flowers and reduces survival of adult Coleomegilla maculata, Harmonia axyridis, and Hippodamia convergens lady beetles, and larval Danaus plexippus and Vanessa cardui butterflies.

    PubMed

    Krischik, Vera; Rogers, Mary; Gupta, Garima; Varshney, Aruna

    2015-01-01

    Integrated Pest Management (IPM) is a decision making process used to manage pests that relies on many tactics, including cultural and biological control, which are practices that conserve beneficial insects and mites, and when needed, the use of conventional insecticides. However, systemic, soil-applied neonicotinoid insecticides are translocated to pollen and nectar of flowers, often for months, and may reduce survival of flower-feeding beneficial insects. Imidacloprid seed-treated crops (0.05 mg AI (active ingredient) /canola seed and 1.2 mg AI/corn seed) translocate less than 10 ppb to pollen and nectar. However, higher rates of soil-applied imidacloprid are used in nurseries and urban landscapes, such as 300 mg AI/10 L (3 gallon) pot and 69 g AI applied to the soil under a 61 (24 in) cm diam. tree. Translocation of imidacloprid from soil (300 mg AI) to flowers of Asclepias curassavica resulted in 6,030 ppb in 1X and 10,400 ppb in 2X treatments, which are similar to imidacloprid residues found in another plant species we studied. A second imidacloprid soil application 7 months later resulted in 21,000 ppb in 1X and 45,000 ppb in 2X treatments. Consequently, greenhouse/nursery use of imidacloprid applied to flowering plants can result in 793 to 1,368 times higher concentration compared to an imidacloprid seed treatment (7.6 ppb pollen in seed- treated canola), where most research has focused. These higher imidacloprid levels caused significant mortality in both 1X and 2X treatments in 3 lady beetle species, Coleomegilla maculata, Harmonia axyridis, and Hippodamia convergens, but not a fourth species, Coccinella septempunctata. Adult survival were not reduced for monarch, Danaus plexippus and painted lady, Vanessa cardui, butterflies, but larval survival was significantly reduced. The use of the neonicotinoid imidacloprid at greenhouse/nursery rates reduced survival of beneficial insects feeding on pollen and nectar and is incompatible with the principles of IPM.

  5. Assimilation of MODIS Dark Target and Deep Blue Observations in the Dust Aerosol Component of NMMB-MONARCH version 1.0

    NASA Technical Reports Server (NTRS)

    Di Tomaso, Enza; Schutgens, Nick A. J.; Jorba, Oriol; Perez Garcia-Pando, Carlos

    2017-01-01

    A data assimilation capability has been built for the NMMB-MONARCH chemical weather prediction system, with a focus on mineral dust, a prominent type of aerosol. An ensemble-based Kalman filter technique (namely the local ensemble transform Kalman filter - LETKF) has been utilized to optimally combine model background and satellite retrievals. Our implementation of the ensemble is based on known uncertainties in the physical parametrizations of the dust emission scheme. Experiments showed that MODIS AOD retrievals using the Dark Target algorithm can help NMMB-MONARCH to better characterize atmospheric dust. This is particularly true for the analysis of the dust outflow in the Sahel region and over the African Atlantic coast. The assimilation of MODIS AOD retrievals based on the Deep Blue algorithm has a further positive impact in the analysis downwind from the strongest dust sources of the Sahara and in the Arabian Peninsula. An analysis-initialized forecast performs better (lower forecast error and higher correlation with observations) than a standard forecast, with the exception of underestimating dust in the long-range Atlantic transport and degradation of the temporal evolution of dust in some regions after day 1. Particularly relevant is the improved forecast over the Sahara throughout the forecast range thanks to the assimilation of Deep Blue retrievals over areas not easily covered by other observational datasets.The present study on mineral dust is a first step towards data assimilation with a complete aerosol prediction system that includes multiple aerosol species.

  6. Assimilation of MODIS Dark Target and Deep Blue observations in the dust aerosol component of NMMB-MONARCH version 1.0

    NASA Astrophysics Data System (ADS)

    Di Tomaso, Enza; Schutgens, Nick A. J.; Jorba, Oriol; Pérez García-Pando, Carlos

    2017-03-01

    A data assimilation capability has been built for the NMMB-MONARCH chemical weather prediction system, with a focus on mineral dust, a prominent type of aerosol. An ensemble-based Kalman filter technique (namely the local ensemble transform Kalman filter - LETKF) has been utilized to optimally combine model background and satellite retrievals. Our implementation of the ensemble is based on known uncertainties in the physical parametrizations of the dust emission scheme. Experiments showed that MODIS AOD retrievals using the Dark Target algorithm can help NMMB-MONARCH to better characterize atmospheric dust. This is particularly true for the analysis of the dust outflow in the Sahel region and over the African Atlantic coast. The assimilation of MODIS AOD retrievals based on the Deep Blue algorithm has a further positive impact in the analysis downwind from the strongest dust sources of the Sahara and in the Arabian Peninsula. An analysis-initialized forecast performs better (lower forecast error and higher correlation with observations) than a standard forecast, with the exception of underestimating dust in the long-range Atlantic transport and degradation of the temporal evolution of dust in some regions after day 1. Particularly relevant is the improved forecast over the Sahara throughout the forecast range thanks to the assimilation of Deep Blue retrievals over areas not easily covered by other observational datasets. The present study on mineral dust is a first step towards data assimilation with a complete aerosol prediction system that includes multiple aerosol species.

  7. Modeling current and future potential wintering distributions of eastern North American monarch butterflies.

    PubMed

    Oberhauser, Karen; Peterson, A Townsend

    2003-11-25

    Monarch butterflies overwinter in restricted areas in montane oyamel fir forests in central Mexico with specific microclimates that allow the butterflies to survive for up to 5 months. We use ecological niche modeling (ENM) to identify areas adequate for overwintering monarch colonies under both current and future climate scenarios. The ENM approach permits testing and validation of model predictivity, and yields quantitative, testable predictions regarding likely future climate change effects. Our models predicted monarch presence with a high degree of accuracy, and indicated that precipitation and diurnal temperature range were key environmental factors in making locations suitable for monarchs. When we projected monarch distribution onto future climate scenarios (Hadley Centre climate models), we found that conditions were likely to be inadequate across the entire current winter range, particularly owing to increased cool-weather precipitation that could cause increased mortality. This study applies ENM to understanding the seasonal dynamics of a migratory species under climate change, and uses ENM to identify key limiting environmental parameters in species' responses to climate change.

  8. Modeling current and future potential wintering distributions of eastern North American monarch butterflies

    PubMed Central

    Oberhauser, Karen; Peterson, A. Townsend

    2003-01-01

    Monarch butterflies overwinter in restricted areas in montane oyamel fir forests in central Mexico with specific microclimates that allow the butterflies to survive for up to 5 months. We use ecological niche modeling (ENM) to identify areas adequate for overwintering monarch colonies under both current and future climate scenarios. The ENM approach permits testing and validation of model predictivity, and yields quantitative, testable predictions regarding likely future climate change effects. Our models predicted monarch presence with a high degree of accuracy, and indicated that precipitation and diurnal temperature range were key environmental factors in making locations suitable for monarchs. When we projected monarch distribution onto future climate scenarios (Hadley Centre climate models), we found that conditions were likely to be inadequate across the entire current winter range, particularly owing to increased cool-weather precipitation that could cause increased mortality. This study applies ENM to understanding the seasonal dynamics of a migratory species under climate change, and uses ENM to identify key limiting environmental parameters in species' responses to climate change. PMID:14612569

  9. Decline of Monarch Butterflies Overwintering in Mexico- Is the Migratory Phenomenon at Risk?

    NASA Technical Reports Server (NTRS)

    Brower, Lincoln; Taylor, Orley R.; Williams, Ernest H.; Slayback, Daniel; Zubieta, Raul R.; Ramirez, M. Isabel

    2012-01-01

    1.During the 2009-2010 overwintering season and following a 15-year downward trend, the total area in Mexico occupied by the eastern North American population of overwintering monarch butterflies reached an all-time low. Despite an increase, it remained low in 2010-2011. 2. Although the data set is small, the decline in abundance is statistically significant using both linear and exponential regression models. 3. Three factors appear to have contributed to reduce monarch abundance: degradation of the forest in the overwintering areas; the loss of breeding habitat in the United States due to the expansion ofGM herbicide-resistant crops, with consequent loss of milkweed host plants, as well as continued land development; and severe weather. 4. This decline calls into question the long-term survival of the monarchs' migratory phenomenon

  10. Impact of Consuming ‘Toxic’ Monarch Caterpillars on Adult Chinese Mantid Mass Gain and Fecundity

    PubMed Central

    Rafter, Jamie L.; Gonda-King, Liahna; Niesen, Daniel; Seeram, Navindra P.; Rigsby, Chad M.; Preisser, Evan L.

    2017-01-01

    Predators that feed on chemically-defended prey often experience non-lethal effects that result in learned avoidance of the prey species. Some predators are able to consume toxic prey without ill-effect. The Chinese mantid is able to consume cardenolide-containing monarch caterpillars without immediate adverse effects. Although they discard the caterpillars’ gut contents, mantids consume sequestered cardenolides. Although consumption of these cardenolides does not elicit an acute response, there may be long-term costs associated with cardenolide consumption. We tested the hypothesis that consumption of monarch caterpillars will adversely affect adult mantid biomass gain and reproductive condition. We reared mantids from egg to adult and assigned them to one of four toxicity groups that differed in the number of monarch caterpillars offered over a 15-day period. Mantids consumed similar amounts of prey biomass during the experiment. Yet, mantids in the high-toxicity group had a higher conversion efficiency and gained more biomass than mantids in other groups. Mantids in all treatment groups produced similar numbers of eggs. However, mantids in the high-toxicity group produced heavier eggs and devoted a greater portion of their biomass toward egg production than those in the control group. This increase in reproductive condition is probably driven by variation in prey nutritional value and/or the nutritional advantages inherent in eating multiple food types. Our results demonstrate the mantid is able to incorporate ‘toxic’ monarch prey into its diet without acute or chronic ill-effects. PMID:28218646

  11. Milkweed: A resource for increasing stink bug parasitism and aiding insect pollinator and monarch butterfly conservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The flowers of milkweed species can produce a rich supply of nectar, and therefore, planting an insecticide-free milkweed habitat in agricultural farmscapes could possibly conserve monarch butterflies, bees and other insect pollinators, as well as enhance parasitism of insect pests. In peanut-cotton...

  12. Impact of Consuming 'Toxic' Monarch Caterpillars on Adult Chinese Mantid Mass Gain and Fecundity.

    PubMed

    Rafter, Jamie L; Gonda-King, Liahna; Niesen, Daniel; Seeram, Navindra P; Rigsby, Chad M; Preisser, Evan L

    2017-02-17

    Predators that feed on chemically-defended prey often experience non-lethal effects that result in learned avoidance of the prey species. Some predators are able to consume toxic prey without ill-effect. The Chinese mantid is able to consume cardenolide-containing monarch caterpillars without immediate adverse effects. Although they discard the caterpillars' gut contents, mantids consume sequestered cardenolides. Although consumption of these cardenolides does not elicit an acute response, there may be long-term costs associated with cardenolide consumption. We tested the hypothesis that consumption of monarch caterpillars will adversely affect adult mantid biomass gain and reproductive condition. We reared mantids from egg to adult and assigned them to one of four toxicity groups that differed in the number of monarch caterpillars offered over a 15-day period. Mantids consumed similar amounts of prey biomass during the experiment. Yet, mantids in the high-toxicity group had a higher conversion efficiency and gained more biomass than mantids in other groups. Mantids in all treatment groups produced similar numbers of eggs. However, mantids in the high-toxicity group produced heavier eggs and devoted a greater portion of their biomass toward egg production than those in the control group. This increase in reproductive condition is probably driven by variation in prey nutritional value and/or the nutritional advantages inherent in eating multiple food types. Our results demonstrate the mantid is able to incorporate 'toxic' monarch prey into its diet without acute or chronic ill-effects.

  13. Population status of the Tinian Monarch (Monarcha takatsukasae) on Tinian, Commonwealth of the Northern Mariana Islands

    USGS Publications Warehouse

    Lusk, Michael; Hess, Steve; Reynolds, Michelle H.; Johnston, Scott

    2000-01-01

    We conducted surveys to evaluate the current population status of the Tinian Monarch (Monarcha takatsukasae), an insectivorous forest bird restricted to the island of Tinian, Commonwealth of the Northern Mariana Islands. In 1996, we recounted transects surveyed in 1982 and used the same analysis procedure to compare 1982 and 1996 population estimates. The 1996 population estimate was 55,721 ± 3,846 SE (48,345–63,495 95% CI), which is 57% higher than our estimate of 35,846 ± 2,211 SE (31,668–40,337 95% CI) for 1982. Vegetation density, measured by canopy cover and lateral visibility at each station, has also increased since 1982. Our data suggest that the Tinian Monarch population has increased possibly due to increased habitat availability, but remains at risk both from an accidental introduction of brown tree snakes (Boiga irregularis) to the island and stochastic processes.

  14. Poor sequestration of toxic host plant cardenolides and their rapid loss in the milkweed butterfly Danaus chrysippus (Lepidoptera: Nymphalidae: Danainae: Danaini).

    PubMed

    Mebs, Dietrich; Wunder, Cora; Toennes, Stefan W

    2017-03-09

    Butterflies of the genus Danaus are known to sequester toxic cardenolides from milkweed host plants (Apocynaceae). In particular, Danaus plexippus efficiently sequesters and stores these compounds, whereas D. chrysippus, is considered to poorly sequester cardenolides. To estimate its sequestration capability compared with that of D. plexippus, larvae of both species were jointly reared on Asclepias curassavica and the major cardenolides of the host plant, calotropin and calactin, were analyzed in adults sampled at different time intervals after eclosion. Both cardenolides were detected in body and wings of D. plexippus. Whereas the calotropin-concentration remained constant over a period of 24 days, that of calactin steadily decreased. In the body, but not in the wings of D. chrysippus, calactin only was detected in low amounts, which was then almost completely lost during the following 8 days after eclosion, suggesting that in contrast to D. plexippus, cardenolides seem to be less important for that butterfly's defence against predators.

  15. Mapping Topoclimate and Microclimate in the Monarch Butterfly Biosphere Reserve, Mexico

    NASA Astrophysics Data System (ADS)

    Weiss, S. B.

    2006-12-01

    Overwintering monarch butterflies in Mexico select areas of the high elevation Oyamel fir -pine forest providing a canopy that protects them from extremes of cold, heat, sun, and wind. These exacting microclimatic conditions are found in relatively small areas of forest with appropriate topography and canopy cover. The major goal of this investigation is to map topoclimatic and microclimatic conditions within the Monarch Butterfly Biosphere Reserve by combining temperature monitoring (iButton Thermochrons), hemispherical canopy photography, multiple regression, and GIS modeling. Temperature measurements included base weather stations and arrays of Thermochrons (on the north-side of trees at 2m height) across local topographic and canopy cover gradients. Topoclimatic models of minimum temperatures included topographic position, slope, and elevation, and predicted that thermal belts on slopes and cold air drainage into canyons create local minimum temperature gradients of 2°C. Topoclimatic models of maximum temperatures models included elevation, topographic position, and relative solar exposure, with local gradients of 3°C. These models, which are independent of forest canopy structure, were then projected across the entire region. Forest canopy structure, including direct and diffuse solar radiation, was assessed with hemispherical photography at each Thermochron site. Canopy cover affected minimum temperatures primarily on the calmest, coldest nights. Maximum temperatures were predicted by direct radiation below the canopy. Fine- scale grids (25 m spacing) at three overwintering sites characterized effects of canopy gaps and edges on temperature and wind exposure. The effects of temperature variation were considered for lipid loss rates, ability to take flight, and freezing mortality. Lipid loss rates were estimated by measured hourly temperatures. Many of the closed canopy sites allowed for substantial lipid reserves at the end of the season (March 15), but

  16. Analysis of whole blood for drugs of abuse using EMIT d.a.u. reagents and a Monarch 1000 Chemistry Analyzer.

    PubMed

    Diosi, D T; Harvey, D C

    1993-01-01

    This paper describes refinements in procedures coupling methanolic extraction-precipitation of whole blood with subsequent screening for commonly encountered drugs of abuse using EMIT d.a.u. reagents on a Monarch Chemistry Analyzer. The automation capabilities inherent in the Monarch make batch processing of samples convenient and cost effective. The small sample volume requirement of the Monarch allows greater sensitivities and use of lower cutoffs than previously reported. Subsequent analysis of EMIT positives by GC/MS confirmed the presence of the indicated drugs of abuse 86.7% of the time.

  17. Draft Genome Sequence of Commensalibacter papalotli MX01, a Symbiont Identified from the Guts of Overwintering Monarch Butterflies.

    PubMed

    Servín-Garcidueñas, Luis E; Sánchez-Quinto, Andrés; Martínez-Romero, Esperanza

    2014-03-06

    We report the draft genome sequence of Commensalibacter papalotli strain MX01, isolated from the intestines of an overwintering monarch butterfly. The 2,332,652-bp AT-biased genome of C. papalotli MX01 is the smallest genome for a member of the Acetobacteraceae family and provides the first evidence of plasmids in Commensalibacter.

  18. Draft Genome Sequence of Commensalibacter papalotli MX01, a Symbiont Identified from the Guts of Overwintering Monarch Butterflies

    PubMed Central

    Sánchez-Quinto, Andrés; Martínez-Romero, Esperanza

    2014-01-01

    We report the draft genome sequence of Commensalibacter papalotli strain MX01, isolated from the intestines of an overwintering monarch butterfly. The 2,332,652-bp AT-biased genome of C. papalotli MX01 is the smallest genome for a member of the Acetobacteraceae family and provides the first evidence of plasmids in Commensalibacter. PMID:24604647

  19. Aphids indirectly increase virulence and transmission potential of a monarch butterfly parasite by reducing defensive chemistry of a shared food plant.

    PubMed

    de Roode, Jacobus C; Rarick, Rachel M; Mongue, Andrew J; Gerardo, Nicole M; Hunter, Mark D

    2011-05-01

    Parasites and hosts live in communities consisting of many interacting species, but few studies have examined how communities affect parasite virulence and transmission. We studied a food web consisting of two species of milkweed, two milkweed herbivores (monarch butterfly and oleander aphid) and a monarch butterfly-specific parasite. We found that the presence of aphids increased the virulence and transmission potential of the monarch butterfly's parasite on one milkweed species. These increases were associated with aphid-induced decreases in the defensive chemicals of milkweed plants. Our experiment suggests that aphids can indirectly increase the virulence and transmission potential of monarch butterfly parasites, probably by altering the chemical composition of a shared food plant. These results indicate that species that are far removed from host-parasite interactions can alter such interactions through cascading indirect effects in the food web. As such, indirect effects within ecological communities may drive the dynamics and evolution of parasites.

  20. Neural Integration Underlying a Time-Compensated Sun Compass in the Migratory Monarch Butterfly.

    PubMed

    Shlizerman, Eli; Phillips-Portillo, James; Forger, Daniel B; Reppert, Steven M

    2016-04-13

    Migrating eastern North American monarch butterflies use a time-compensated sun compass to adjust their flight to the southwest direction. Although the antennal genetic circadian clock and the azimuth of the sun are instrumental for proper function of the compass, it is unclear how these signals are represented on a neuronal level and how they are integrated to produce flight control. To address these questions, we constructed a receptive field model of the compound eye that encodes the solar azimuth. We then derived a neural circuit model that integrates azimuthal and circadian signals to correct flight direction. The model demonstrates an integration mechanism, which produces robust trajectories reaching the southwest regardless of the time of day and includes a configuration for remigration. Comparison of model simulations with flight trajectories of butterflies in a flight simulator shows analogous behaviors and affirms the prediction that midday is the optimal time for migratory flight.

  1. The stabilizing role of the Sabbath in pre-monarchic Israel: a mathematical model.

    PubMed

    Livni, Joseph; Stone, Lewi

    2015-03-01

    The three monotheistic cultures have many common institutions and some of them germinated in pre-monarchic Israel. Reasonably, the essential institutions were in place at that starting point; this work explores the possibility that the Sabbath is one of these institutions. Our mathematical examination points to the potential cultural, civic, and social role of the weekly Sabbath, that is, the Sabbath institution, in controlling deviation from social norms. It begins with an analogy between spread of transgression (defined as lack of conformity with social norms) and of biological infection. Borrowing well-known mathematical methods, we derive solution sets of social equilibrium and study their social stability. The work shows how a weekly Sabbath could in theory enhance social resilience in comparison with a similar assembly with a more natural and longer period, say between New Moon and Full Moon. The examination reveals that an efficient Sabbath institution has the potential to ensure a stable organization and suppress occasional appearances of transgression from cultural norms and boundaries. The work suggests the existence of a sharp threshold governed by the "Basic Sabbath Number ש0"-a critical observance of the Sabbath, or large enough ש0, is required to ensure suppression of transgression. Subsequently, the model is used to explore an interesting question: how old is the Sabbath? The work is interdisciplinary, combining anthropological concepts with mathematical analysis and with archaeological parallels in regards to the findings.

  2. The Monarch Initiative: an integrative data and analytic platform connecting phenotypes to genotypes across species

    PubMed Central

    Mungall, Christopher J.; McMurry, Julie A.; Köhler, Sebastian; Balhoff, James P.; Borromeo, Charles; Brush, Matthew; Carbon, Seth; Conlin, Tom; Dunn, Nathan; Engelstad, Mark; Foster, Erin; Gourdine, J.P.; Jacobsen, Julius O.B.; Keith, Dan; Laraway, Bryan; Lewis, Suzanna E.; NguyenXuan, Jeremy; Shefchek, Kent; Vasilevsky, Nicole; Yuan, Zhou; Washington, Nicole; Hochheiser, Harry; Groza, Tudor; Smedley, Damian; Robinson, Peter N.; Haendel, Melissa A.

    2017-01-01

    The correlation of phenotypic outcomes with genetic variation and environmental factors is a core pursuit in biology and biomedicine. Numerous challenges impede our progress: patient phenotypes may not match known diseases, candidate variants may be in genes that have not been characterized, model organisms may not recapitulate human or veterinary diseases, filling evolutionary gaps is difficult, and many resources must be queried to find potentially significant genotype–phenotype associations. Non-human organisms have proven instrumental in revealing biological mechanisms. Advanced informatics tools can identify phenotypically relevant disease models in research and diagnostic contexts. Large-scale integration of model organism and clinical research data can provide a breadth of knowledge not available from individual sources and can provide contextualization of data back to these sources. The Monarch Initiative (monarchinitiative.org) is a collaborative, open science effort that aims to semantically integrate genotype–phenotype data from many species and sources in order to support precision medicine, disease modeling, and mechanistic exploration. Our integrated knowledge graph, analytic tools, and web services enable diverse users to explore relationships between phenotypes and genotypes across species. PMID:27899636

  3. The Monarch Initiative: an integrative data and analytic platform connecting phenotypes to genotypes across species.

    PubMed

    Mungall, Christopher J; McMurry, Julie A; Köhler, Sebastian; Balhoff, James P; Borromeo, Charles; Brush, Matthew; Carbon, Seth; Conlin, Tom; Dunn, Nathan; Engelstad, Mark; Foster, Erin; Gourdine, J P; Jacobsen, Julius O B; Keith, Dan; Laraway, Bryan; Lewis, Suzanna E; NguyenXuan, Jeremy; Shefchek, Kent; Vasilevsky, Nicole; Yuan, Zhou; Washington, Nicole; Hochheiser, Harry; Groza, Tudor; Smedley, Damian; Robinson, Peter N; Haendel, Melissa A

    2017-01-04

    The correlation of phenotypic outcomes with genetic variation and environmental factors is a core pursuit in biology and biomedicine. Numerous challenges impede our progress: patient phenotypes may not match known diseases, candidate variants may be in genes that have not been characterized, model organisms may not recapitulate human or veterinary diseases, filling evolutionary gaps is difficult, and many resources must be queried to find potentially significant genotype-phenotype associations. Non-human organisms have proven instrumental in revealing biological mechanisms. Advanced informatics tools can identify phenotypically relevant disease models in research and diagnostic contexts. Large-scale integration of model organism and clinical research data can provide a breadth of knowledge not available from individual sources and can provide contextualization of data back to these sources. The Monarch Initiative (monarchinitiative.org) is a collaborative, open science effort that aims to semantically integrate genotype-phenotype data from many species and sources in order to support precision medicine, disease modeling, and mechanistic exploration. Our integrated knowledge graph, analytic tools, and web services enable diverse users to explore relationships between phenotypes and genotypes across species.

  4. Flight testing of live Monarch butterflies to determine the aerodynamic benefit of butterfly scales

    NASA Astrophysics Data System (ADS)

    Lang, Amy; Cranford, Jacob; Conway, Jasmine; Slegers, Nathan; Dechello, Nicole; Wilroy, Jacob

    2014-11-01

    Evolutionary adaptations in the morphological structure of butterfly scales (0.1 mm in size) to develop a unique micro-patterning resulting in a surface drag alteration, stem from a probable aerodynamic benefit of minimizing the energy requirement to fly a very lightweight body with comparably large surface area in a low Re flow regime. Live Monarch butterflies were tested at UAHuntsville's Autonomous Tracking and Optical Measurement (ATOM) Laboratory, which uses 22 Vicon T40 cameras that allow for millimeter level tracking of reflective markers at 515 fps over a 4 m × 6 m × 7 m volume. Data recorded included the flight path as well as the wing flapping angle and wing-beat frequency. Insects were first tested with their scales intact, and then again with the scales carefully removed. Differences in flapping frequency and/or energy obtained during flight due to the removal of the scales will be discussed. Initial data analysis indicates that scale removal in some specimens leads to increased flapping frequencies for similar energetic flight or reduced flight speed for similar flapping frequencies. Both results point to the scales providing an aerodynamic benefit, which is hypothesized to be linked to leading-edge vortex formation and induced drag. Funding from the National Science Foundation (CBET and REU) is gratefully acknowledged.

  5. Host-parasite genetic interactions and virulence-transmission relationships in natural populations of monarch butterflies.

    PubMed

    de Roode, Jacobus C; Altizer, Sonia

    2010-02-01

    Evolutionary models predict that parasite virulence (parasite-induced host mortality) can evolve as a consequence of natural selection operating on between-host parasite transmission. Two major assumptions are that virulence and transmission are genetically related and that the relative virulence and transmission of parasite genotypes remain similar across host genotypes. We conducted a cross-infection experiment using monarch butterflies and their protozoan parasites from two populations in eastern and western North America. We tested each of 10 host family lines against each of 18 parasite genotypes and measured virulence (host life span) and parasite transmission potential (spore load). Consistent with virulence evolution theory, we found a positive relationship between virulence and transmission across parasite genotypes. However, the absolute values of virulence and transmission differed among host family lines, as did the rank order of parasite clones along the virulence-transmission relationship. Population-level analyses showed that parasites from western North America caused higher infection levels and virulence, but there was no evidence of local adaptation of parasites on sympatric hosts. Collectively, our results suggest that host genotypes can affect the strength and direction of selection on virulence in natural populations, and that predicting virulence evolution may require building genotype-specific interactions into simpler trade-off models.

  6. Rural aquaculture as a sustainable alternative for forest conservation in the Monarch Butterfly Biosphere Reserve, Mexico.

    PubMed

    López-García, José; Manzo-Delgado, Lilia L; Alcántara-Ayala, Irasema

    2014-06-01

    Forest conservation plays a significant role in environmental sustainability. In Mexico only 8.48 million ha of forest are used for conservation of biodiversity. Payment for Environmental Services in the Monarch Butterfly Biosphere Reserve, one of the most important national protected areas, contributes to the conservation of these forests. In the Reserve, production of rainbow trout has been important for the rural communities who need to conserve the forest cover in order to maintain the hibernation cycle of the butterfly. Aquaculture is a highly productive activity for these protected areas, since it harnesses the existing water resources. In this study, changes from 1999 to 2012 in vegetation and land-use cover in the El Lindero basin within the Reserve were evaluated in order to determine the conservation status and to consider the feasibility of aquaculture as a means of sustainable development at community level. Evaluation involved stereoscopic interpretation of digital aerial photographs from 1999 to 2012 at 1:10,000 scale, comparative analysis by orthocorrected mosaics and restitution on the mosaics. Between 1999 and 2012, forested land recovered by 28.57 ha (2.70%) at the expense of non-forested areas, although forest degradation was 3.59%. Forest density increased by 16.87%. In the 46 ha outside the Reserve, deforestation spread by 0.26%, and land use change was 0.11%. The trend towards change in forest cover is closely related to conservation programmes, particularly payment for not extracting timber, reforestation campaigns and surveillance, whose effects have been exploited for the development of rural aquaculture; this is a new way to improve the socio-economic status of the population, to avoid logging and to achieve environmental sustainability in the Reserve.

  7. Anatomical basis of sun compass navigation II: the neuronal composition of the central complex of the monarch butterfly.

    PubMed

    Heinze, Stanley; Florman, Jeremy; Asokaraj, Surainder; El Jundi, Basil; Reppert, Steven M

    2013-02-01

    Each fall, eastern North American monarch butterflies in their northern range undergo a long-distance migration south to their overwintering grounds in Mexico. Migrants use a time-compensated sun compass to determine directionality during the migration. This compass system uses information extracted from sun-derived skylight cues that is compensated for time of day and ultimately transformed into the appropriate motor commands. The central complex (CX) is likely the site of the actual sun compass, because neurons in this brain region are tuned to specific skylight cues. To help illuminate the neural basis of sun compass navigation, we examined the neuronal composition of the CX and its associated brain regions. We generated a standardized version of the sun compass neuropils, providing reference volumes, as well as a common frame of reference for the registration of neuron morphologies. Volumetric comparisons between migratory and nonmigratory monarchs substantiated the proposed involvement of the CX and related brain areas in migratory behavior. Through registration of more than 55 neurons of 34 cell types, we were able to delineate the major input pathways to the CX, output pathways, and intrinsic neurons. Comparison of these neural elements with those of other species, especially the desert locust, revealed a surprising degree of conservation. From these interspecies data, we have established key components of a conserved core network of the CX, likely complemented by species-specific neurons, which together may comprise the neural substrates underlying the computations performed by the CX.

  8. Environmental Assessment, Los Angeles AFB Parking Structure

    DTIC Science & Technology

    2007-08-01

    Skipper Panoquina errans El Segundo Blue Butterfly Euphilotes battoides allyni Endangered Monarch Butterfly Danaus plexipus Mimic Tryonia...aculeatus williamsoni Endangered Quino Checker-Spot Butterfly Euphydryas editha quino Endangered Riverside Fairy Shrimp Streptocephalus woottoni

  9. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  10. African Pentecostalism

    ERIC Educational Resources Information Center

    Garrard, David J.

    2009-01-01

    The diversity of African Pentecostalism, its early colonial and missionary history and its current characteristics are described and analysed. Reference is made to methods of training and forms of leadership, and suggestions are made about the reasons for its growth and persistence. (Contains 19 notes.)

  11. Virulence evolution in response to anti-infection resistance: toxic food plants can select for virulent parasites of monarch butterflies.

    PubMed

    de Roode, J C; de Castillejo, C Lopez Fernandez; Faits, T; Alizon, S

    2011-04-01

    Host resistance to parasites can come in two main forms: hosts may either reduce the probability of parasite infection (anti-infection resistance) or reduce parasite growth after infection has occurred (anti-growth resistance). Both resistance mechanisms are often imperfect, meaning that they do not fully prevent or clear infections. Theoretical work has suggested that imperfect anti-growth resistance can select for higher parasite virulence by favouring faster-growing and more virulent parasites that overcome this resistance. In contrast, imperfect anti-infection resistance is thought not to select for increased parasite virulence, because it is assumed that it reduces the number of hosts that become infected, but not the fitness of parasites in successfully infected hosts. Here, we develop a theoretical model to show that anti-infection resistance can in fact select for higher virulence when such resistance reduces the effective parasite dose that enters a host. Our model is based on a monarch butterfly-parasite system in which larval food plants confer resistance to the monarch host. We carried out an experiment and showed that this environmental resistance is most likely a form of anti-infection resistance, through which toxic food plants reduce the effective dose of parasites that initiates an infection. We used these results to build a mathematical model to investigate the evolutionary consequences of food plant-induced resistance. Our model shows that when the effective infectious dose is reduced, parasites can compensate by evolving a higher per-parasite growth rate, and consequently a higher intrinsic virulence. Our results are relevant to many insect host-parasite systems, in which larval food plants often confer imperfect anti-infection resistance. Our results also suggest that - for parasites where the infectious dose affects the within-host dynamics - vaccines that reduce the effective infectious dose can select for increased parasite virulence.

  12. African-American Biography.

    ERIC Educational Resources Information Center

    Martin, Ron

    1995-01-01

    Suggests sources of information for African American History Month for library media specialists who work with students in grades four through eight. Gale Research's "African-American Reference Library," which includes "African-America Biography,""African-American Chronology," and "African-American Almanac,"…

  13. African Trypanosomiasis

    DTIC Science & Technology

    2011-06-01

    infection by protozoan hemo- flagellates of the Trypanosoma brucei complex, 2 subspe- cies of which cause disease in humans: Trypanosoma bru- cei gambiense...public release; distribution unlimited 13. SUPPLEMENTARY NOTES See also ADA545141. Chapter 3 from e-book, Topics on the Pathology of Protozoan and...the brief ferry crossing. 2 3 • Topics on The paThology of proTozoan and invasive arThropod diseases Three severe epidemics of African trypanosomiasis

  14. Milkweed (Gentianales: Apocynaceae): a farmscape resource for increasing parasitism of stink bugs (Hemiptera: Pentatomidae) and providing nectar to insect pollinators and monarch butterflies.

    PubMed

    Tillman, P G; Carpenter, J E

    2014-04-01

    In peanut-cotton farmscapes in Georgia, the stink bugs Nezara viridula (L.) and Chinavia hilaris (Say) (Hemiptera: Pentatomidae) and the leaffooted bug, Leptoglossus phyllopus (L.) (Hemiptera: Coreidae), disperse at crop-to-crop interfaces to feed on bolls in cotton. The main objective of this study was to determine whether insecticide-free tropical milkweed (Asclepias curassavica L.), a nectar-producing plant, can increase parasitism of these bugs by Trichopoda pennipes (F.) (Diptera: Tachinidae) and provide nectar to monarch butterflies and insect pollinators in these farmscapes. Peanut-cotton plots with and without flowering milkweed plants were established in 2009 and 2010. Adult T. pennipes, monarch butterflies, honey bees, and native insect pollinators readily fed on floral nectar of milkweed. Monarch larvae feeding on milkweed vegetation successfully developed into pupae. In 2009, N. viridula was the primary host of T. pennipes in cotton, and parasitism of this pest by the parasitoid was significantly higher in milkweed cotton (61.6%) than in control cotton (13.3%). In 2010, parasitism of N. viridula, C. hilaris, and L. phyllopus by T. pennipes was significantly higher in milkweed cotton (24.0%) than in control cotton (1.1%). For both years of the study, these treatment differences were not owing to a response by the parasitoid to differences in host density, because density of hosts was not significantly different between treatments. In conclusion, incorporation of milkweed in peanut-cotton plots increased stink bug parasitism in cotton and provided nectar to insect pollinators and monarch butterflies.

  15. Environmental Assessment: Base Realignment and Closure (BRAC) 2005 Mission Realignments to Vandenberg AFB

    DTIC Science & Technology

    2007-02-01

    become established in a few of the trees. The eucalyptus groves also provide roost sites for the Monarch butterfly . The man-made structures provide...VAFB Breeders only) Additional Comments Insects Monarch butterfly Danaus plexippus SA O Wintering Monterey pine and Eucalyptus groves

  16. Environmental Assessment: Military Housing Privatization Initiative, Los Angeles Air Force Base, California

    DTIC Science & Technology

    2006-11-01

    California ground squirrel (USAF 2001). Bat species and monarch butterflies may use buildings in urban areas for roosting, but this is not likely to be...near the base. Table 5. Sensitive Species Species Status Terrestrial Invertebrates Monarch butterfly (Danaus plexippus) Species of local concern...Palos Verdes blue butterfly (Glaucopsyche lygdamus palosverdesensis) Federally listed as endangered Reptiles San Diego horned lizard (Phrynosoma

  17. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  18. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  19. Role of forest conservation in lessening land degradation in a temperate region: the Monarch Butterfly Biosphere Reserve, Mexico.

    PubMed

    Manzo-Delgado, Lilia; López-García, José; Alcántara-Ayala, Irasema

    2014-06-01

    With international concern about the rates of deforestation worldwide, particular attention has been paid to Latin America. Forest conservation programmes in Mexico include Payment for Environmental Services (PES), a scheme that has been successfully introduced in the Monarch Butterfly Biosphere Reserve. To seek further evidence of the role of PES in lessening land degradation processes in a temperate region, the conservation state of the Cerro Prieto ejido within the Reserve was assessed by an analysis of changes in vegetation cover and land-use between 1971 and 2013. There were no changes in the total forest surface area, but the relative proportions of the different classes of cover density had changed. In 1971, closed and semi-closed forest occupied 247.81 ha and 5.38 ha, 82.33% and 1.79% of the total area of the ejido, respectively. By 2013, closed forest had decreased to 230.38 ha (76.54% of the ejido), and semi-closed cover was 17.23 ha (5.72% of the ejido), suggesting that some semi-closed forest had achieved closed status. The final balance between forest losses and recovery was: 29.63 ha were lost, whereas 13.72 ha were recovered. Losses were mainly linked to a sanitation harvest programme to control the bark beetle Scolytus mundus. Ecotourism associated with forest conservation in the Cerro Prieto ejido has been considered by inhabitants as a focal alternative for economic development. Consequently, it is essential to develop a well-planned and solidly structured approach based on social cohesion to foster a community-led sustainable development at local level.

  20. African Americans and Glaucoma

    MedlinePlus

    ... Involved News About Us Donate In This Section African Americans and Glaucoma email Send this article to a ... glaucoma is the leading cause of blindness in African Americans. Half of those with glaucoma don't know ...

  1. Black African Traditional Mathematics

    ERIC Educational Resources Information Center

    Zaslavsky, Claudia

    1970-01-01

    Discusses the traditional number systems and the origin of the number names used by several African peoples living south of the Sahara. Also included are limitations in African mathematical development, and possible topics for research. (RP)

  2. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  3. The African superswell

    NASA Technical Reports Server (NTRS)

    Nyblade, Andrew A.; Robinson, Scott W.

    1994-01-01

    Maps of residual bathymetry in the ocean basins around the African continent reveal a broad bathymetric swell in the southeastern Atlantic Ocean with an amplitude of about 500 m. We propose that this region of anomalously shallow bathymetry, together with the contiguous eastern and southern African plateaus, form a superswell which we refer to as the African superswell. The origin of the African superswell is uncertain. However, rifting and volcanism in eastern Africa, as well as heat flow measurements in southern Africa and the southeastern Atlantic Ocean, suggest that the superswell may be attributed, at least in part, to heating of the lithosphere.

  4. Understanding African American Males

    ERIC Educational Resources Information Center

    Bell, Edward Earl

    2010-01-01

    The purpose of this study was to assess the socialization skills, self-esteem, and academic readiness of African American males in a school environment. Discussions with students and the School Perceptions Questionnaire provided data for this investigation. The intended targets for this investigation were African American students; however, there…

  5. Africans Away from Home.

    ERIC Educational Resources Information Center

    Clarke, John Henrik

    Africans who were brought across the Atlantic as slaves never fully adjusted to slavery or accepted its inevitability. Resistance began on board the slave ships, where many jumped overboard or committed suicide. African slaves in South America led the first revolts against tyranny in the New World. The first slave revolt in the Caribbean occurred…

  6. Educating African American Males

    ERIC Educational Resources Information Center

    Bell, Edward E.

    2010-01-01

    Background: Schools across America spend money, invest in programs, and sponsor workshops, offer teacher incentives, raise accountability standards, and even evoke the name of Obama in efforts to raise the academic achievement of African American males. Incarceration and college retention rates point to a dismal plight for many African American…

  7. 16 Extraordinary African Americans.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    This collection for children tells the stories of 16 African Americans who helped make America what it is today. African Americans can take pride in the heritage of these contributors to society. Biographies are given for the following: (1) Sojourner Truth, preacher and abolitionist; (2) Frederick Douglass, abolitionist; (3) Harriet Tubman, leader…

  8. Keeping African Masks Real

    ERIC Educational Resources Information Center

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  9. Neotropical Africanized honey bees have African mitochondrial DNA.

    PubMed

    Smith, D R; Taylor, O R; Brown, W M

    1989-05-18

    Non-indigenous African honey bees have invaded most of South and Central America in just over 30 years. The genetic composition of this population and the means by which it rapidly colonizes new territory remain controversial. In particular, it has been unclear whether this 'Africanized' population has resulted from interbreeding between African and domestic European bees, or is an essentially pure African population. Also, it has not been known whether this population expanded primarily by female or by male migration. Restriction site mapping of 62 mitochondrial DNAs of African bees from Brazil, Venezuela and Mexico reveals that 97% were of African (Apis mellifera scutellata) type. Although neotropical European apiary populations are rapidly Africanized by mating with neotropical African males, there is little reciprocal gene flow to the neotropical African population through European females. These are the first genetic data to indicate that the neotropical African population could be expanding its range by female migration.

  10. African American Suicide

    MedlinePlus

    ... accounted for 83.8% of Caucasian elderly suicides. • Firearms were the predominant method of suicide among African ... per 100,000 annually. Source: Centers for Disease Control and Prevention. National Vital Statistics System. Mortality Data. ...

  11. Obesity and African Americans

    MedlinePlus

    ... and Management System Report to Congress Knowledge Center Capacity Building Information Services Events Calendar Resource Guide Justice ... Workforce Diversity Grants Youth Program Grants Other Grants Planning and Evaluation Grantee Best Practices Black/African American ...

  12. Description and evaluation of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry model (NMMB-MONARCH) version 1.0: gas-phase chemistry at global scale

    NASA Astrophysics Data System (ADS)

    Badia, Alba; Jorba, Oriol; Voulgarakis, Apostolos; Dabdub, Donald; Pérez García-Pando, Carlos; Hilboll, Andreas; Gonçalves, María; Janjic, Zavisa

    2017-02-01

    This paper presents a comprehensive description and benchmark evaluation of the tropospheric gas-phase chemistry component of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry model (NMMB-MONARCH), formerly known as NMMB/BSC-CTM, that can be run on both regional and global domains. Here, we provide an extensive evaluation of a global annual cycle simulation using a variety of background surface stations (EMEP, WDCGG and CASTNET), ozonesondes (WOUDC, CMD and SHADOZ), aircraft data (MOZAIC and several campaigns), and satellite observations (SCIAMACHY and MOPITT). We also include an extensive discussion of our results in comparison to other state-of-the-art models. We note that in this study, we omitted aerosol processes and some natural emissions (lightning and volcano emissions). The model shows a realistic oxidative capacity across the globe. The seasonal cycle for CO is fairly well represented at different locations (correlations around 0.3-0.7 in surface concentrations), although concentrations are underestimated in spring and winter in the Northern Hemisphere, and are overestimated throughout the year at 800 and 500 hPa in the Southern Hemisphere. Nitrogen species are well represented in almost all locations, particularly NO2 in Europe (root mean square error - RMSE - below 5 ppb). The modeled vertical distributions of NOx and HNO3 are in excellent agreement with the observed values and the spatial and seasonal trends of tropospheric NO2 columns correspond well to observations from SCIAMACHY, capturing the highly polluted areas and the biomass burning cycle throughout the year. Over Asia, the model underestimates NOx from March to August, probably due to an underestimation of NOx emissions in the region. Overall, the comparison of the modeled CO and NO2 with MOPITT and SCIAMACHY observations emphasizes the need for more accurate emission rates from anthropogenic and biomass burning sources (i.e., specification of temporal variability). The resulting

  13. Patterns of host-parasite adaptation in three populations of monarch butterflies infected with a naturally occurring protozoan disease: virulence, resistance, and tolerance.

    PubMed

    Sternberg, Eleanore D; Li, Hui; Wang, Rebecca; Gowler, Camden; de Roode, Jacobus C

    2013-12-01

    Many studies have used host-parasite systems to study local adaptation, but few of these studies have found unequivocal evidence for adaptation. One potential reason is that most studies have focused on limited measures of host and parasite fitness that are generally assumed to be under negative frequency-dependent selection. We have used reciprocal cross-infection experiments to test for local adaptation in Hawaiian, south Floridian, and eastern North American populations of monarch butterflies and their protozoan parasites. Sympatric host-parasite combinations did not result in greater host or parasite fitness, as would be expected under coevolutionary dynamics driven by negative frequency-dependent selection. Instead, we found that Hawaiian hosts were more resistant and carried more infective and virulent parasites, which is consistent with theoretical predictions for virulence evolution and coevolutionary arms race dynamics. We also found that Hawaiian hosts were more tolerant, particularly of Hawaiian parasites, indicating that increased resistance does not preclude increased tolerance within a population and that hosts may be more tolerant of local parasites. We did not find a similar pattern in the south Floridian or eastern populations, possibly because host-parasite adaptation occurs within the context of a greater ecological community.

  14. Coccidioidomycosis in African Americans

    PubMed Central

    Ruddy, Barbara E.; Mayer, Anita P.; Ko, Marcia G.; Labonte, Helene R.; Borovansky, Jill A.; Boroff, Erika S.; Blair, Janis E.

    2011-01-01

    Coccidioidomycosis is caused by Coccidioides species, a fungus endemic to the desert regions of the southwestern United States, and is of particular concern for African Americans. We performed a PubMed search of the English-language medical literature on coccidioidomycosis in African Americans and summarized the pertinent literature. Search terms were coccidioidomycosis, Coccidioides, race, ethnicity, African, black, and Negro. The proceedings of the national and international coccidioidomycosis symposia were searched. All relevant articles and their cited references were reviewed; those with epidemiological, immunologic, clinical, and therapeutic data pertaining to coccidioidomycosis in African Americans were included in the review. Numerous studies documented an increased predilection for severe coccidioidal infections, coccidioidomycosis-related hospitalizations, and extrapulmonary dissemination in persons of African descent; however, most of the published studies are variably problematic. The immunologic mechanism for this predilection is unclear. The clinical features and treatment recommendations are summarized. Medical practitioners need to be alert to the possibility of coccidioidomycosis in persons with recent travel to or residence in an area where the disease is endemic. PMID:21193657

  15. Mental Health and African Americans

    MedlinePlus

    ... Minority Population Profiles > Black/African American > Mental Health Mental Health and African Americans Poverty level affects mental health ... compared to 120% of non-Hispanic whites. 1 MENTAL HEALTH STATUS Serious psychological distress among adults 18 years ...

  16. The Struggles over African Languages

    ERIC Educational Resources Information Center

    Maseko, Pam; Vale, Peter

    2016-01-01

    In this interview, African Language expert Pam Maseko speaks of her own background and her first encounter with culture outside of her mother tongue, isiXhosa. A statistical breakdown of South African languages is provided as background. She discusses Western (originally missionary) codification of African languages and suggests that this approach…

  17. Narcolepsy in African Americans

    PubMed Central

    Kawai, Makoto; O'Hara, Ruth; Einen, Mali; Lin, Ling; Mignot, Emmanuel

    2015-01-01

    Study Objectives: Although narcolepsy affects 0.02–0.05% of individuals in various ethnic groups, clinical presentation in different ethnicities has never been fully characterized. Our goal was to study phenotypic expression across ethnicities in the United States. Design/Setting: Cases of narcolepsy from 1992 to 2013 were identified from searches of the Stanford Center for Narcolepsy Research database. International Classification of Sleep Disorders, Third Edition diagnosis criteria for type 1 and type 2 narcolepsy were used for inclusion, but subjects were separated as with and without cataplexy for the purpose of data presentation. Information extracted included demographics, ethnicity and clinical data, HLA-DQB1*06:02, polysomnography (PSG), multiple sleep latency test (MSLT) data, and cerebrospinal fluid (CSF) hypocretin-1 level. Patients: 182 African-Americans, 839 Caucasians, 35 Asians, and 41 Latinos with narcolepsy. Results: Sex ratio, PSG, and MSLT findings did not differ across ethnicities. Epworth Sleepiness Scale (ESS) score was higher and age of onset of sleepiness earlier in African Americans compared with other ethnicities. HLA-DQB1*06:02 positivity was higher in African Americans (91.0%) versus others (76.6% in Caucasians, 80.0% in Asians, and 65.0% in Latinos). CSF hypocretin-1 level, obtained in 222 patients, was more frequently low (≤ 110 pg/ml) in African Americans (93.9%) versus Caucasians (61.5%), Asians (85.7%) and Latinos (75.0%). In subjects with low CSF hypocretin-1, African Americans (28.3%) were 4.5 fold more likely to be without cataplexy when compared with Caucasians (8.1%). Conclusions: Narcolepsy in African Americans is characterized by earlier symptom onset, higher Epworth Sleepiness Scale score, higher HLA-DQB1*06:02 positivity, and low cerebrospinal fluid hypocretin-1 level in the absence of cataplexy. In African Americans, more subjects without cataplexy have type 1 narcolepsy. Citation: Kawai M, O'Hara R, Einen M, Lin L

  18. The genetic structure and history of Africans and African Americans.

    PubMed

    Tishkoff, Sarah A; Reed, Floyd A; Friedlaender, Françoise R; Ehret, Christopher; Ranciaro, Alessia; Froment, Alain; Hirbo, Jibril B; Awomoyi, Agnes A; Bodo, Jean-Marie; Doumbo, Ogobara; Ibrahim, Muntaser; Juma, Abdalla T; Kotze, Maritha J; Lema, Godfrey; Moore, Jason H; Mortensen, Holly; Nyambo, Thomas B; Omar, Sabah A; Powell, Kweli; Pretorius, Gideon S; Smith, Michael W; Thera, Mahamadou A; Wambebe, Charles; Weber, James L; Williams, Scott M

    2009-05-22

    Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (approximately 71%), European (approximately 13%), and other African (approximately 8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies.

  19. Elective: African Literature.

    ERIC Educational Resources Information Center

    Jenkins, Kenneth V.

    The make-up of a course in African literature for high school students is discussed. It is pointed out that the course can be constructed on already familiar lines. High school students will be able to describe clearly, for example, the relationship between environment and character or the dilemma of characters caught between traditional values…

  20. African Americans and Agriculture.

    ERIC Educational Resources Information Center

    Morgan, Joan

    2000-01-01

    Reviews the opportunities available in the field of agriculture for African American students and notes efforts of the 136 colleges of agriculture to publicize their offerings and recruit students. Profiles six black leaders in agriculture, highlighting their achievements in research and aid to developing countries. A table provides data on annual…

  1. African Literature: Selected Resources.

    ERIC Educational Resources Information Center

    Deschenes, Martin O.; Waters, Harold A.

    This bibliography of resources for the teaching of African literature includes over 100 citations of books, textbooks, anthologies, plays, novels, short stories, and periodicals in French and English. Publishing house addresses, audiovisual aids, professional organizations, and a course list are also cited. The books are listed under the following…

  2. Competition: Butterflies eliminate milkweed bugs from a Caribbean Island.

    PubMed

    Blakley, Nigel R; Dingle, Hugh

    1978-01-01

    By eliminating the food plant, Asclepias curassavica, monarch butterflies, Danaus plexippus, have virtually eliminated milkweed bugs, Oncopeltus spp., from the island of Barbados. The relatively open terrain of Barbados means the plants have no refuge; the butterflies survive on an alternate milkweed food plant, Calotropis procera, whose thick-walled pods make seeds unavailable to the bugs.

  3. Understanding traditional African healing

    PubMed Central

    MOKGOBI, M.G.

    2015-01-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists. PMID:26594664

  4. Ectoparasites of African Mammals.

    DTIC Science & Technology

    1976-11-30

    This study consisted of ectoparasites from approximately 100,000 African small mammals, representing probably more than 500 species of which many are...study of ectoparasites may provide information concerning interactions among animal reservoirs of disease, and (3) an understanding of ecological...parameters for ectoparasites and their hosts may enhance understanding of epidemiological patterns. Of the four major groups dealt with, considerably more

  5. Diversity among African Pygmies

    PubMed Central

    Ramírez Rozzi, Fernando V.; Sardi, Marina L.

    2010-01-01

    Although dissimilarities in cranial and post-cranial morphology among African pygmies groups have been recognized, comparative studies on skull morphology usually pull all pygmies together assuming that morphological characters are similar among them and different with respect to other populations. The main aim of this study is to compare cranial morphology between African pygmies and non-pygmies populations from Equatorial Africa derived from both the Eastern and the Western regions in order to test if the greatest morphological difference is obtained in the comparison between pygmies and non-pygmies. Thirty three-dimensional (3D) landmarks registered with Microscribe in four cranial samples (Western and Eastern pygmies and non-pygmies) were obtained. Multivariate analysis (generalized Procrustes analysis, Mahalanobis distances, multivariate regression) and complementary dimensions of size were evaluated with ANOVA and post hoc LSD. Results suggest that important cranial shape differentiation does occur between pygmies and non-pygmies but also between Eastern and Western populations and that size changes and allometries do not affect similarly Eastern and Western pygmies. Therefore, our findings raise serious doubt about the fact to consider African pygmies as a homogenous group in studies on skull morphology. Differences in cranial morphology among pygmies would suggest differentiation after divergence. Although not directly related to skull differentiation, the diversity among pygmies would probably suggest that the process responsible for reduced stature occurred after the split of the ancestors of modern Eastern and Western pygmies. PMID:21049030

  6. Human African trypanosomiasis.

    PubMed

    Lejon, Veerle; Bentivoglio, Marina; Franco, José Ramon

    2013-01-01

    Human African trypanosomiasis or sleeping sickness is a neglected tropical disease that affects populations in sub-Saharan Africa. The disease is caused by infection with the gambiense and rhodesiense subspecies of the extracellular parasite Trypanosoma brucei, and is transmitted to humans by bites of infected tsetse flies. The disease evolves in two stages, the hemolymphatic and meningoencephalitic stages, the latter being defined by central nervous system infection after trypanosomal traversal of the blood-brain barrier. African trypanosomiasis, which leads to severe neuroinflammation, is fatal without treatment, but the available drugs are toxic and complicated to administer. The choice of medication is determined by the infecting parasite subspecies and disease stage. Clinical features include a constellation of nonspecific symptoms and signs with evolving neurological and psychiatric alterations and characteristic sleep-wake disturbances. Because of the clinical profile variability and insidiously progressive central nervous system involvement, disease staging is currently based on cerebrospinal fluid examination, which is usually performed after the finding of trypanosomes in blood or other body fluids. No vaccine being available, control of human African trypanosomiasis relies on diagnosis and treatment of infected patients, assisted by vector control. Better diagnostic tools and safer, easy to use drugs are needed to facilitate elimination of the disease.

  7. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  8. Elder Abuse among African Americans

    ERIC Educational Resources Information Center

    Tauriac, Jesse J.; Scruggs, Natoschia

    2006-01-01

    Perceptions of extreme, moderate, and mild forms of elder abuse among African-American women (n=25) and men (n=10) were examined. African-American respondents emphasized physical abuse when giving examples of extremely abusive behavior. Along with physical abuse, verbal abuse was the most frequently identified form of abuse, and was significantly…

  9. African ethics and voluntary euthanasia.

    PubMed

    Omonzejele, P F

    2004-01-01

    This paper outlines the relationship between euthanasia and its ethical norms and practices in a part of West Africa. The various sub-types of euthanasia are described in detail, parallel with the role of African ethical theories in determining their relevance. The author discusses the implications of this approach relative to the social and economic state of African communities.

  10. African American Administrators and Staff

    ERIC Educational Resources Information Center

    Wright, Dianne; Taylor, Janice D.; Burrell, Charlotte; Stewart, Gregory

    2006-01-01

    This article explores the issues of African American participation in the administrative ranks of the academy. The authors find that African Americans tend to hold positions that are marginal in academic organizations, lacking power and influence, and that not much has changed over recent decades. Forces influencing this condition are explored,…

  11. African-Americans and Alcoholism.

    ERIC Educational Resources Information Center

    Sigmon, Scott B.

    To better serve people in a counseling relationship, it is useful to understand them not only culturally, but demographically as well. This paper traces historical, religious, demographic aspects and treatment of alcohol abuse in African Americans. Historically, alcohol abuse and alcohol dependence have varied for African Americans. During the…

  12. Africanization in the United States

    PubMed Central

    Pinto, M. Alice; Rubink, William L.; Patton, John C.; Coulson, Robert N.; Johnston, J. Spencer

    2005-01-01

    The expansion of Africanized honeybees from South America to the southwestern United States in <50 years is considered one of the most spectacular biological invasions yet documented. In the American tropics, it has been shown that during their expansion Africanized honeybees have low levels of introgressed alleles from resident European populations. In the United States, it has been speculated, but not shown, that Africanized honeybees would hybridize extensively with European honeybees. Here we report a continuous 11-year study investigating temporal changes in the genetic structure of a feral population from the southern United States undergoing Africanization. Our microsatellite data showed that (1) the process of Africanization involved both maternal and paternal bidirectional gene flow between European and Africanized honeybees and (2) the panmitic European population was replaced by panmitic mixtures of A. m. scutellata and European genes within 5 years after Africanization. The post-Africanization gene pool (1998–2001) was composed of a diverse array of recombinant classes with a substantial European genetic contribution (mean 25–37%). Therefore, the resulting feral honeybee population of south Texas was best viewed as a hybrid swarm. PMID:15937139

  13. Cancer statistics for African Americans.

    PubMed

    Ghafoor, Asma; Jemal, Ahmedin; Cokkinides, Vilma; Cardinez, Cheryll; Murray, Taylor; Samuels, Alicia; Thun, Michael J

    2002-01-01

    The American Cancer Society provides estimates on the number of new cancer cases and deaths, and compiles health statistics on African Americans in a biennial publication, Cancer Facts and Figures for African Americans. The compiled statistics include cancer incidence, mortality, survival, and lifestyle behaviors using the most recent data on incidence and survival from the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) program, mortality data from the National Center for Health Statistics (NCHS), and behavioral information from the Behavior Risk Factor Surveillance System (BRFSS), Youth Risk Behavior Surveillance System (YRBSS), and National Health Interview Survey (NHIS). It is estimated that 132,700 new cases of cancer and 63,100 deaths will occur among African Americans in the year 2003. Although African Americans have experienced higher incidence and mortality rates of cancer than whites for many years, incidence rates have declined by 2.7 percent per year in African-American males since 1992, while stabilizing in African-American females. During the same period, death rates declined by 2.1 percent and 0.4 percent per year among African-American males and females, respectively. The decrease in both incidence and death rates from cancer among African-American males was the largest of any racial or ethnic group. Nonetheless, African Americans still carry the highest cancer burden among US racial and ethnic groups. Most cancers detectable by screening are diagnosed at a later stage and survival rates are lower within each stage of disease in African Americans than in whites. The extent to which these disparities reflect unequal access to health care versus other factors is an active area of research.

  14. East African ROAD

    NASA Astrophysics Data System (ADS)

    Tekle, Kelali

    2016-10-01

    In the developing world astronomy had been treated as the science of elites. As a result of this overwhelming perception, astronomy compared with other applied sciences has got less attention and its role in development has been insignificant. However, the IAU General Assembly decision in 2009 opened new opportunity for countries and professionals to deeply look into Astronomy and its role in development. Then, the subsequent establishment of regional offices in the developing world is helping countries to integrate astronomy with other earth and space based sciences so as to progressively promote its scientific and development importance. Gradually nations have come to know that space is the frontier of tomorrow and the urgency of preeminence on space frontier starts at primary school and ascends to tertiary education. For this to happen, member nations in east African region have placed STEM education at the center of their education system. For instance, Ethiopian has changed University enrollment strategy to be in favor of science and engineering subjects, i.e. every year seventy percent of new University entrants join science and engineering fields while thirty percent social science and humanities. Such bold actions truly promote astronomy to be conceived as gateway to science and technology. To promote the concept of astronomy for development the East African regional office has actually aligned it activities to be in line with the focus areas identified by the IAU strategy (2010 to 2020).

  15. African oil plays

    SciTech Connect

    Clifford, A.J. )

    1989-09-01

    The vast continent of Africa hosts over eight sedimentary basins, covering approximately half its total area. Of these basins, only 82% have entered a mature exploration phase, 9% have had little or no exploration at all. Since oil was first discovered in Africa during the mid-1950s, old play concepts continue to bear fruit, for example in Egypt and Nigeria, while new play concepts promise to become more important, such as in Algeria, Angola, Chad, Egypt, Gabon, and Sudan. The most exciting developments of recent years in African oil exploration are: (1) the Gamba/Dentale play, onshore Gabon; (2) the Pinda play, offshore Angola; (3) the Lucula/Toca play, offshore Cabinda; (4) the Metlaoui play, offshore Libya/Tunisia; (5) the mid-Cretaceous sand play, Chad/Sudan; and (6) the TAG-I/F6 play, onshore Algeria. Examples of these plays are illustrated along with some of the more traditional oil plays. Where are the future oil plays likely to develop No doubt, the Saharan basins of Algeria and Libya will feature strongly, also the presalt of Equatorial West Africa, the Central African Rift System and, more speculatively, offshore Ethiopia and Namibia, and onshore Madagascar, Mozambique, and Tanzania.

  16. Bioenergy and African transformation.

    PubMed

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures.

  17. A Bibliography of African Languages and Linguistics.

    ERIC Educational Resources Information Center

    Murphy, John D., Comp.; Goff, Harry, Comp.

    The present bibliography of African languages and linguistics includes not only works relating to the "Negro-African" languages, but also those dealing with the African varieties of Arabic, the Hamitic languages, Malagasy, Afrikaans, and various Creoles. (The greater part of the entries relate to the indigenous languages of the African continent…

  18. The African Millennium Villages

    PubMed Central

    Sanchez, Pedro; Palm, Cheryl; Sachs, Jeffrey; Denning, Glenn; Flor, Rafael; Harawa, Rebbie; Jama, Bashir; Kiflemariam, Tsegazeab; Konecky, Bronwen; Kozar, Raffaela; Lelerai, Eliud; Malik, Alia; Modi, Vijay; Mutuo, Patrick; Niang, Amadou; Okoth, Herine; Place, Frank; Sachs, Sonia Ehrlich; Said, Amir; Siriri, David; Teklehaimanot, Awash; Wang, Karen; Wangila, Justine; Zamba, Colleen

    2007-01-01

    We describe the concept, strategy, and initial results of the Millennium Villages Project and implications regarding sustainability and scalability. Our underlying hypothesis is that the interacting crises of agriculture, health, and infrastructure in rural Africa can be overcome through targeted public-sector investments to raise rural productivity and, thereby, to increased private-sector saving and investments. This is carried out by empowering impoverished communities with science-based interventions. Seventy-eight Millennium Villages have been initiated in 12 sites in 10 African countries, each representing a major agroecological zone. In early results, the research villages in Kenya, Ethiopia, and Malawi have reduced malaria prevalence, met caloric requirements, generated crop surpluses, enabled school feeding programs, and provided cash earnings for farm families. PMID:17942701

  19. [African population in history].

    PubMed

    Yang, S

    1984-11-29

    The growth rate of the African population has been fluctuating throughout history, affected by political, social, and economic events. 6000 years ago, the majority of the population was based in North Africa, because farming had been developed there. However, between the 11th and the 16th centuries, there was a constant decline in the population of that region, due to invasions from Europe and the black plague. During the same period, the population in the area south of the Sahara grew rapidly, as people there had gone into the iron tool period and farming had been developed. From the 16th to the mid-17th Century, population growth was considerable in Africa; more people had learned the technology of irrigation, corn and potatoes had been introduced from South America, and colonialism was not yet an issue. From the mid-17th to the mid-19th Century, there was no growth, due to the slave trade and wars between tribes. One estimate sets the direct and indirect loss during this period, as a result of the slave trade, at 100 million people. From the 1850s to the end of World War I, population growth started up again, chiefly influenced by the fact that the slave trade had essentially come to a half and modern medical care had become available on the continent. However, in central Africa, the region which suffered the worst blow from the slave trade, growth was very slow, while in East Africa the population was declining because of wars between colonists and natives, as well as natural disasters. Increases in population during this period were a result of immigration from Europe and India. From the end of World War I to the present, growth has been rapid, given improvements in medical services and standards of living, while most of the former colonies became independent after the 1950s. Consequently, almost all African countries are under great pressure now with regard to their populations.

  20. Central African Republic.

    PubMed

    1989-11-01

    The Central African Republic contains 242,000 square miles, which rolling terrain almost 2000 feet above sea level. The climate is tropical, and it has a population of 2.8 million people with a 2.5% growth rate. There are more than 80 ethnic groups including Baya 34%, Banda 28%, Sara 10%, Mandja 9%, Mboum 9%, and M'Baka 7%. The religions are traditional African 35%, protestant 25%, Roman Catholic 25%, and Muslim 15%, and the languages are French and Sangho. The infant mortality rate is 143/1000, with expectancy at 49 years and a 40% literacy rate. The work force of 1 million is 70% agricultural, industry 6% and commerce and service 6% and government 3%. The government consists of a president assisted by cabinet ministers and a single party. Natural resources include diamonds, uranium, timber, gold, and oil, and major industries are beverages, textiles, and soap. Agricultural products feature coffee, cotton, peanuts, tobacco, food crops and livestock. Most of the population live in rural areas and most of the 80 ethnic groups have their own language. This is one of the world's least developed countries, with a per capita income of $375/year. The main problems with development are the poor transportation infrastructure, and the weak internal and international marketing systems. The US and various international organizations have aided in agriculture development, health programs, and family planning. US investment is mainly in diamond and gold mining, and although oil drilling has been successful it is not economically feasible at current prices.

  1. African Passages: Journaling through Archetypes.

    ERIC Educational Resources Information Center

    Spencer, Patricia

    1990-01-01

    Explores how students (through an awareness of literary archetypes and journal writing) can use African stories to cross cultures, time, and continents, making connections between their worlds and the worlds of others. (MG)

  2. Early African Hominids: Pedagogic Patterns.

    ERIC Educational Resources Information Center

    Newman, James L.

    1984-01-01

    By studying early African hominids, students can learn about the interactive testing and creative aspects of scientific thinking and sharpen their geographical skills. It is impossible to study this topic without giving prominence to space and time. (RM)

  3. African-Americans and Alzheimer's

    MedlinePlus

    ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of Alzheimer's, ... two times more likely to develop late-onset Alzheimer's disease than whites and less likely to have a ...

  4. Hepatitis C in African Americans.

    PubMed

    Saab, Sammy; Jackson, Christian; Nieto, Jose; Francois, Fritz

    2014-10-01

    The care of hepatitis C virus (HCV) in African Americans represents an opportunity to address a major health disparity in medicine. In all facets of HCV infection, African Americans are inexplicably affected, including in the prevalence of the virus, which is higher among them compared with most of the racial and ethnic groups. Ironically, although fibrosis rates may be slow, hepatocellular carcinoma and mortality rates appear to be higher among African Americans. Sustained viral response (SVR) rates have historically significantly trailed behind Caucasians. The reasons for this gap in SVR are related to both viral and host factors. Moreover, low enrollment rates in clinical trials hamper the study of the efficacy of anti-viral therapy. Nevertheless, the gap in SVR between African Americans and Caucasians may be narrowing with the use of direct-acting agents. Gastroenterologists, hepatologists, primary care physicians, and other health-care providers need to address modifiable risk factors that affect the natural history, as well as treatment outcomes, for HCV among African Americans. Efforts need to be made to improve awareness among health-care providers to address the differences in screening and referral patterns for African Americans.

  5. The African Pediatric Fellowship Program: Training in Africa for Africans.

    PubMed

    Wilmshurst, Jo M; Morrow, Brenda; du Preez, Avril; Githanga, David; Kennedy, Neil; Zar, Heather J

    2016-01-01

    Africa has a significant burden of childhood disease, with relatively few skilled health care professionals. The African Paediatric Fellowship Programme was developed by the Department of Pediatrics and Child Health at the University of Cape Town to provide relevant training for African child health professionals, by Africans, within Africa. Trainees identified by partner academic institutions spend 6 months to 2 years training in the Department of Pediatrics and allied disciplines. They then return to their home institution to build practice, training, research, and advocacy. From 2008 to 2015, 73 physicians have completed or are completing training in general pediatrics or a pediatric subspecialty. At 1 year posttraining, 98% to 100% are practicing back in their home institution. The impact of the returning fellows is evident from their practice interventions, research collaborations, and positions as stakeholders who can change health care policies. Thirty-three centers in 13 African countries are partners with the program, and the program template is now followed by other partner sites in Africa. Increasing and retaining the skills pool of African child health specialists is building a network of motivated, highly skilled clinicians who are equipped to advance child health in Africa.

  6. Phylogenomics of African guenons.

    PubMed

    Moulin, Sibyle; Gerbault-Seureau, Michèle; Dutrillaux, Bernard; Richard, Florence Anne

    2008-01-01

    The karyotypes of 28 specimens belonging to 26 species of Cercopithecinae have been compared with each other and with human karyotype by chromosome banding and, for some of them, by Zoo-FISH (human painting probes) techniques. The study includes the first description of the karyotypes of four species and a synonym of Cercopithecus nictitans. The chromosomal homologies obtained provide us with new data on a large number of rearrangements. This allows us to code chromosomal characters to draw Cercopithecini phylogenetic trees, which are compared to phylogenetic data based on DNA sequences. Our findings show that some of the superspecies proposed by Kingdon (1997 The Kingdon Field Guide to African Mammals, Academic Press.) and Groves (2001 Primates Taxonomy, Smithsonian Institution Press) do not form homogeneous groups and that the genus Cercopithecus is paraphyletic, in agreement with previous molecular analyses. The evolution of Cercopithecini karyotypes is mainly due to non-centromeric chromosome fissions and centromeric shifts or inversions. Non-Robertsonian translocations occurred in C. hamlyni and C. neglectus. The position of chromosomal rearrangements in the phylogenetic tree leads us to propose that the Cercopithecini evolution proceeded by either repeated fission events facilitated by peculiar genomic structures or successive reticulate phases, in which heterozygous populations for few rearranged chromosomes were present, allowing the spreading of chromosomal forms in various combinations, before the speciation process.

  7. An African ethic for nursing?

    PubMed

    Haegert, S

    2000-11-01

    This article derives from a doctoral thesis in which a particular discourse was used as a 'paradigm case'. From this discourse an ethic set within a South African culture arose. Using many cultural 'voices' to aid the understanding of this narrative, the ethic shows that one can build on both a 'justice' and a 'care' ethic. With further development based on African culture one can take the ethic of care deeper and reveal 'layers of understanding'. Care, together with compassion, forms the foundation of morality. Nursing ethics has followed particular western moral philosophers. Often nursing ethics has been taught along the lines of Kohlberg's theory of morality, with its emphasis on rules, rights, duties and general obligations. These principles were universalistic, masculine and noncontextual. However, there is a new ethical movement among Thomist philosophers along the lines to be expounded in this article. Nurses such as Benner, Bevis, Dunlop, Fry and Gadow--to name but a few--have welcomed the concept of an 'ethic of care'. Gilligan's work gave a feminist view and situated ethics in the everyday aspects of responsiveness, responsibility, context and concern. Shutte's search for a 'philosophy for Africa' has resulted in finding similarities in Setiloane and in Senghor with those of Thomist philosophers. Using this African philosophy and a research participant's narrative, an African ethic evolves out of the African proverb: 'A person is a person through other persons', or its alternative rendering: 'I am because we are: we are because I am.' This hermeneutic narrative reveals 'the way affect imbues activity with ethical meaning' within the context of a black nursing sister in a rural South African hospital. It expands upon the above proverb and incorporates the South African constitutional idea of 'Ubuntu' (compassion and justice or humanness).

  8. African American Preschoolers' Language, Emergent Literacy Skills, and Use of African American English: A Complex Relation

    ERIC Educational Resources Information Center

    Connor, Carol McDonald; Craig, Holly K.

    2006-01-01

    Purpose: This study examined the relation between African American preschoolers' use of African American English (AAE) and their language and emergent literacy skills in an effort to better understand the perplexing and persistent difficulties many African American children experience learning to read proficiently. Method: African American…

  9. Technical Consulting: The African-American Perspective

    ERIC Educational Resources Information Center

    Whitfield, Tracy N.

    2010-01-01

    The qualitative research study explored the organizational characteristics necessary in addressing the low concentration of African American technical consultants employed in the information technology industry. Using research participants' professional experience, participants responded to a developed questionnaire. African American technical…

  10. African N Assessment

    NASA Astrophysics Data System (ADS)

    Bekunda, M.; Galford, G. L.; Hickman, J. E.; Palm, C.

    2011-12-01

    Africa's smallholder agricultural systems face unique challenges in planning for reducing poverty, concurrent with adaptation and mitigation to climate change. At continental level, policy seeks to promote a uniquely African Green Revolution to increase crop yields and food production, and improve local livelihoods. However, the consequences on the environment and climate are not clear; these pro-economic development measures should be linked to climate change adaptation and mitigation measures, and research is required to help achieve these policy proposals by identifying options, and testing impacts. In particular, increased nitrogen (N) inputs are essential for increasing food production in Africa, but are accompanied by inevitable increases in losses to the environment. These losses appear to be low at input levels promoted in agricultural development programs, while the increased N inputs both increase current food production and appear to reduce the vulnerability of food production to changes in climate. We present field and remote sensing evidence from Malawi that subsidizing improved seed and fertilizers increases resilience to drought without adding excess N to the environment. In Kenya, field research identified thresholds in N2O losses, where emissions are very low at fertilization rates of less than 200 kg ha-1. Village-scale models have identified potential inefficiencies in the food production process where the largest losses of reactive N occur, and which could be targeted to reduce the amount of N released to the environment. We further review some on-going research activities and progress in Africa that compare different methods of managing resources that target resilience in food production and adaptation to climate change, using nutrient N as an indicator, while evaluating the effects of these resource management practices on ecosystems and the environment.

  11. Plio-pleistocene African climate

    SciTech Connect

    deMenocal, P.B.

    1995-10-06

    Marine records of African climate variability document a shift toward more arid conditions after 2.8 million years ago (Ma), evidently resulting from remote forcing by cold North Atlantic sea-surface temperatures associated with the onset of Northern Hemisphere glacial cycles. African climate before 2.8 Ma was regulated by low-latitude insolation forcing of monsoonal climate due to Earth orbital precession. Major steps in the evolution of African hominids and other vertebrates are coincident with shifts to more arid, open conditions near 2.8 Ma, 1.7 Ma, and 1.0 Ma, suggesting that some Pliocene (Plio)-Pleistocene speciation events may have been climatically mediated. 65 refs., 6 figs.

  12. Plio-Pleistocene African Climate

    NASA Astrophysics Data System (ADS)

    Demenocal, Peter B.

    1995-10-01

    Marine records of African climate variability document a shift toward more arid conditions after 2.8 million years ago (Ma), evidently resulting from remote forcing by cold North Atlantic sea-surface temperatures associated with the onset of Northern Hemisphere glacial cycles. African climate before 2.8 Ma was regulated by low-latitude insolation forcing of monsoonal climate due to Earth orbital precession. Major steps in the evolution of African hominids and other vertebrates are coincident with shifts to more arid, open conditions near 2.8 Ma, 1.7 Ma, and 1.0 Ma, suggesting that some Pliocene (Plio)-Pleistocene speciation events may have been climatically mediated.

  13. African perceptions of female attractiveness.

    PubMed

    Coetzee, Vinet; Faerber, Stella J; Greeff, Jaco M; Lefevre, Carmen E; Re, Daniel E; Perrett, David I

    2012-01-01

    Little is known about mate choice preferences outside Western, educated, industrialised, rich and democratic societies, even though these Western populations may be particularly unrepresentative of human populations. To our knowledge, this is the first study to test which facial cues contribute to African perceptions of African female attractiveness and also the first study to test the combined role of facial adiposity, skin colour (lightness, yellowness and redness), skin homogeneity and youthfulness in the facial attractiveness preferences of any population. Results show that youthfulness, skin colour, skin homogeneity and facial adiposity significantly and independently predict attractiveness in female African faces. Younger, thinner women with a lighter, yellower skin colour and a more homogenous skin tone are considered more attractive. These findings provide a more global perspective on human mate choice and point to a universal role for these four facial cues in female facial attractiveness.

  14. The African Cultural Astronomy Project

    NASA Astrophysics Data System (ADS)

    Urama, Johnson O.; Holbrook, Jarita C.

    2011-06-01

    Indigenous, endogenous, traditional, or cultural astronomy focuses on the many ways that people and cultures interact with celestial bodies. In most parts of Africa, there is very little or no awareness about modern astronomy. However, like ancient people everywhere, Africans wondered at the sky and struggled to make sense of it. The African Cultural Astronomy Project aims to unearth the body of traditional knowledge of astronomy possessed by peoples of the different ethnic groups in Africa and to consider scientific interpretations when appropriate for cosmogonies and ancient astronomical practices. Regardless of scientific validity, every scientist can relate to the process of making observations and creating theoretical mechanisms for explaining what is observed. Through linking the traditional and the scientific, it is believed that this would be used to create awareness and interest in astronomy in most parts of Africa. This paper discusses the vision, challenges and prospects of the African Cultural Astronomy Project in her quest to popularize astronomy in Africa.

  15. Towards a Norm in South African Englishes.

    ERIC Educational Resources Information Center

    van der Walt, Johann L.; van Rooy, Bertus

    2002-01-01

    Investigates the perception and application of the norm in South African English with specific reference to Black South African English. Hypothesizes that South African English is in the hibernation and expansion phase. Three sets of data are presented and analyzed. (Author/VWL)

  16. African American Teaching and the Matriarchal Performance.

    ERIC Educational Resources Information Center

    Jeffries, Rhonda Baynes

    This paper discusses the role of matriarchs in African-American culture, explaining that traditionally, African-American matriarchs arise from a combination of African norms and American social positions that naturally forces them to assume leadership conditions. The roles these women assume are a response to the desire to survive in a society…

  17. Freedom Road: Adult Education of African Americans.

    ERIC Educational Resources Information Center

    Peterson, Elizabeth A., Ed.

    This book contains six chapters by various authors about the history of African Americans' contributions and participation in adult education. The book reports on how some African American leaders saw the connection between education and the eventual freedom or uplift of the African American people. Following a foreword (Phyllis M. Cunningham) and…

  18. Engaging African Americans in Smoking Cessation Programs

    ERIC Educational Resources Information Center

    Wallen, Jacqueline; Randolph, Suzanne; Carter-Pokras, Olivia; Feldman, Robert; Kanamori-Nishimura, Mariano

    2014-01-01

    Background: African Americans are disproportionately exposed to and targeted by prosmoking advertisements, particularly menthol cigarette ads. Though African Americans begin smoking later than whites, they are less likely to quit smoking than whites. Purpose: This study was designed to explore African American smoking cessation attitudes,…

  19. Increasing Reading Engagement in African American Boys

    ERIC Educational Resources Information Center

    Husband, Terry

    2014-01-01

    Much has been written concerning the challenges many teachers face in engaging African American males in reading practices. While much of this extant scholarship focuses on African American males at the pre-adolescent stage of development and beyond, little has been written regarding increasing reading engagement in African American boys in P-5…

  20. African Expressions in Hispano-American Literature.

    ERIC Educational Resources Information Center

    Coleman, Ben C.

    This revised version of a lecture on the relationship of African language and Hispano-American literature illustrates the historical influence of the African slave on representative literature and modern culture of the Caribbean Islands. Introductory remarks focus on the migratory patterns of the African slaves. The concept of negritude is then…

  1. An Introduction to West African Literature.

    ERIC Educational Resources Information Center

    Taiwo, Oladele

    Intended to provide help for those interested in studying West African literature, this book is divided into three parts. Part One provides background information: the various African oral traditions are discussed, related to the way of life of the people, and examined for the extent to which they form the basis of present West African literary…

  2. Empowering African genomics for infectious disease control.

    PubMed

    Folarin, Onikepe A; Happi, Anise N; Happi, Christian T

    2014-11-07

    At present, African scientists can only participate minimally in the genomics revolution that is transforming the understanding, surveillance and clinical treatment of infectious diseases. We discuss new initiatives to equip African scientists with knowledge of cutting-edge genomics tools, and build a sustainable critical mass of well-trained African infectious diseases genomics scientists.

  3. Heart failure in African Americans.

    PubMed

    Yancy, Clyde W

    2005-10-10

    The demographics of the United States are changing, and in the next few decades there will no longer be a racial/ethnic majority population. Increased awareness of cardiovascular disease (CVD) in special populations is warranted as these populations increase. Heart failure carries a substantial burden on those affected, particularly African Americans, who have a disproportionate burden of heart disease. Current treatments for heart failure include angiotensin-converting enzyme inhibitors, beta-blockers, angiotensin II-receptor antagonists, and vasodilating agents. This review discusses the unique characteristics of CVD in African Americans and addresses the need for targeted treatments to reduce the excess burden found in this population.

  4. The Role of the African Union in African Peacekeeping Operations

    DTIC Science & Technology

    2008-03-26

    Government in Sirte , Libya, on 9 September 1999. The AU was formed to address some of the issues identified during the analysis of the OAU PKOs. The...Establishment of the African Union The Sirte Declaration led to the establishment of the AU in 2002. One of the AU’s objectives was to enhance the security

  5. African-American spirituality: a concept analysis.

    PubMed

    Newlin, Kelley; Knafl, Kathleen; Melkus, Gail D'Eramo

    2002-12-01

    Culturally competent care for African Americans requires sensitivity to spirituality as a component of the cultural context. To foster understanding, measurement, and delivery of the spiritual component of culturally competent care, this article presents an evolutionary concept analysis of African-American spirituality. The analysis is based on a sample of multidisciplinary research studies reflecting spirituality of African Americans. Findings indicate that African-American spirituality involves quintessential, internal, external, consoling, and transformative attributive dimensions. Findings are considered in relation to previous conceptual analyses of spirituality and suggest that defining attributes of African-American spirituality are both global and culturally prominent. Implications for practice and research are discussed.

  6. Cryptococcal meningitis in African children.

    PubMed

    Subramanyam, V R; Mtitimila, E; Hart, C A; Broadhead, R L

    1997-06-01

    Three cases of cryptococcal meningitis in Malawian children aged 6 weeks, 3 years and 9 years are described. Only 23 cases of cryptococcal meningitis in children have been described previously, but in children from Europe and the USA. These are therefore the first cases of cryptococcosis to be described in African children.

  7. Wellness among African American Counselors

    ERIC Educational Resources Information Center

    Day-Vines, Norma L.; Holcomb-McCoy, Cheryl

    2007-01-01

    Although there are various definitions of wellness, few conceptual definitions have addressed the contextual dimensions of wellness relative to African American counselors. The authors present an overview of generic models of wellness, discuss factors that both inhibit and promote wellness, offer some culture-specific models of wellness, and…

  8. African American Men in College

    ERIC Educational Resources Information Center

    Cuyjet, Michael J., Ed.

    2006-01-01

    This book is a much-needed resource that includes examples of real-world programs and activities to enhance academic success in the college environment for African American men. The examples are collected from a variety of institutions across the country. With contributions from leading practitioners and scholars in the field, this book explores…

  9. Improvisation in West African Musics.

    ERIC Educational Resources Information Center

    Locke, David

    1980-01-01

    Discussed is music of the sub-Sahara. Vocal, instrumental, and dance drumming from the Sudan Desert, the North Coast, East Horn, Central and West Africa, and contrapuntal yodeling of Pygmies is described. For African musicians, the ability to improvise, and creativity, are gifts from God. Includes selected readings and recordings. (KC)

  10. Developing anatomical terms in an African language.

    PubMed

    Madzimbamuto, Farai Daniel

    2012-02-23

    Clinical and technical information imparted in most African languages involves inexact terminology and code switching, so it lacks the explanatory power characterised by the English language. African languages are absent in the tertiary science education environment and forums where African scientists could present scientific material in the medium of African languages. This limits the development of African languages in the scientific domain. There has recently been a trend in several African languages to develop and intellectualise them, especially in the field of medical sciences. The ChiShona language is used to explore the ability of an African language to develop new terminology, to name the vertebral skeleton and describe it scientifically. It uses word compounding to demonstrate terminology development. ChiShona has similarities with several hundred other Bantu languages in East, Central and Southern Africa. Advancing this language can promote similar developments in others, making them more explanatory for the lay public and health professionals.

  11. Some African American Males' Perspectives on the Black Woman.

    ERIC Educational Resources Information Center

    Burrow, Rufus, Jr.

    1992-01-01

    Presents views of Frederick Douglass, W. E. B. Du Bois, Malcolm X, and James Hal Cone (African-American male leaders) toward African-American women in the United States. Discusses the role of African-American men in addressing and eradicating sexism in African-American churches and the African-American community. (SLD)

  12. The UCAR Africa Initiative: Enabling African Solutions to African Needs

    NASA Astrophysics Data System (ADS)

    Pandya, R.; Bruintjes, R.; Foote, B.; Heck, S.; Hermann, S.; Hoswell, L.; Konate, M.; Kucera, P.; Laing, A.; Lamptey, B.; Moncrieff, M.; Ramamurthy, M.; Roberts, R.; Spangler, T.; Traoré, A.; Yoksas, T.; Warner, T.

    2007-12-01

    The University Corporation for Atmospheric Research (UCAR) Africa Initiative (AI) is a coordinated effort aimed at building sustainable partnerships between UCAR and African institutions in order to pursue research and applications for the benefit of the African people. The initiative is based on four fundamental operating principles, concisely summarized by the overall philosophy of enabling African solutions to African needs. The four principles are: • Collaborate with African institutions • Focus on institutional capacity building and research support • Explore science research themes critical to Africa and important for the world • Leverage the research infrastructure in UCAR to add value These principles are realized in a set of pilot activities, chosen for their high probability of short-term results and ability to set the stage for longer-term collaboration. The three pilot activities are listed below. 1. A modest radar network and data-distribution system in Mali and Burkina Faso, including a data-sharing MOU between the Mail and Burkina Faso Weather Services. 2. A partnership among UCAR, the Ghana Meteorological Agency, and the Ghana university community to develop an operational Weather Research and Forecasting (WRF) model for West Africa. The output is used by researchers and operational forecasters in Africa. Model output is also part of a demonstration project that aims to allow humanitarian agencies to share geo-referenced information in Africa via a web portal. 3. A workshop in Ouagadougou, Burkina Faso from April 2-6, 2007, with the theme Improving Lives by Understanding Weather. The workshop, co-organized with Programme SAAGA and the Commité Permanent Inter-Etats de Lutte Contre la Sécheresse dans le Sahel (CILSS), included over 80 participants from 18 countries, and produced a set of recommendations for continued collaboration. Our presentation will provide an update of these pilot activities and point to future directions. Recognizing

  13. [Return of African sleeping sickness].

    PubMed

    Stingl, Peter

    2006-09-14

    At present there is a steady rise in African sleeping sickness (trypanosomiasis) transmitted by the Tsetse fly, and which if left untreated, is fatal. Thanks to more than so years of neglect by research, our therapeutic repertoire is limited to medications with a high level of toxicity. Both WHO and international aid organizations are pushing hard for the development of new, more efficient drugs that can be readily applied in the field.

  14. Genome-wide patterns of population structure and admixture in West Africans and African Americans.

    PubMed

    Bryc, Katarzyna; Auton, Adam; Nelson, Matthew R; Oksenberg, Jorge R; Hauser, Stephen L; Williams, Scott; Froment, Alain; Bodo, Jean-Marie; Wambebe, Charles; Tishkoff, Sarah A; Bustamante, Carlos D

    2010-01-12

    Quantifying patterns of population structure in Africans and African Americans illuminates the history of human populations and is critical for undertaking medical genomic studies on a global scale. To obtain a fine-scale genome-wide perspective of ancestry, we analyze Affymetrix GeneChip 500K genotype data from African Americans (n = 365) and individuals with ancestry from West Africa (n = 203 from 12 populations) and Europe (n = 400 from 42 countries). We find that population structure within the West African sample reflects primarily language and secondarily geographical distance, echoing the Bantu expansion. Among African Americans, analysis of genomic admixture by a principal component-based approach indicates that the median proportion of European ancestry is 18.5% (25th-75th percentiles: 11.6-27.7%), with very large variation among individuals. In the African-American sample as a whole, few autosomal regions showed exceptionally high or low mean African ancestry, but the X chromosome showed elevated levels of African ancestry, consistent with a sex-biased pattern of gene flow with an excess of European male and African female ancestry. We also find that genomic profiles of individual African Americans afford personalized ancestry reconstructions differentiating ancient vs. recent European and African ancestry. Finally, patterns of genetic similarity among inferred African segments of African-American genomes and genomes of contemporary African populations included in this study suggest African ancestry is most similar to non-Bantu Niger-Kordofanian-speaking populations, consistent with historical documents of the African Diaspora and trans-Atlantic slave trade.

  15. African-Centered Education: An Approach to Schooling for Social Justice for African American Students

    ERIC Educational Resources Information Center

    Marks, Jay B.; Tonso, Karen L.

    2006-01-01

    This essay argues that offering African American students an African-centered education is one way to promote social justice in public education. We begin with a summary of the inadequate educations offered to many African American students, and then use philosophical interpretations of equal educational opportunity to delineate the requirements…

  16. Investigating Instructional Practices of an African American Male Mathematics Teacher with Underachieving African American Male Students

    ERIC Educational Resources Information Center

    Muhammad, Rhonda K.

    2012-01-01

    This qualitative study examined the instructional practices of an experienced African American mathematics teacher to determine his perceived capabilities in augmenting academic proficiency for his African American male students. Provided in this descriptive case study are the lived experiences of an African American male teacher working to move…

  17. 75 FR 2844 - African Development Foundation, Board of Directors Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ...; ] AFRICAN DEVELOPMENT FOUNDATION African Development Foundation, Board of Directors Meeting Time: Tuesday, January 26, 2010, 8:30 a.m. to 1 p.m. Place: African Development Foundation, Conference Room, 1400...

  18. 75 FR 45600 - African Development Foundation, Board of Directors Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ...; ] AFRICAN DEVELOPMENT FOUNDATION African Development Foundation, Board of Directors Meeting Time: Tuesday, August 17, 2010, 8:30 a.m. to 1 p.m. Place: African Development Foundation, Conference Room, 1400...

  19. Race, health, and the African Diaspora.

    PubMed

    Spigner, Clarence

    Health inequalities exist throughout the African Diaspora and are viewed in this article as largely color-coded. In developed, developing, and undeveloped nations today, "racial" stratification is consistently reflected in an inability to provide adequate health regardless of national policy or ideology. For instance, African Americans experience less than adequate health care very similar to Blacks in Britain, in spite of each nations differing health systems. Latin America's Africana Negra communities experience poorer health similar to Blacks throughout the Caribbean. The African continent itself is arguably the poorest on earth. A common history of racism correlates with health disparities across the African Diaspora.

  20. African American girls and the challenges ahead.

    PubMed

    Rozie-Battle, Judith L

    2002-01-01

    The research on the psychosocial development of African American girls is limited. Information that is available focuses on teen pregnancy and health issues such as nutrition and physical activity. African American girls are facing challenges, including poverty, crime, poor self-esteem, and peer pressure. Despite some of the negative characteristics attributed to African American girls, many are achieving some success. Policy makers and service providers need to recognize the resiliency and unique needs of African American girls and develop services that ensure their needs are being fully met.

  1. Rhinoplasty in the African-American patient.

    PubMed

    Rohrich, Rod J; Muzaffar, Arshad R

    2003-03-01

    Because of the increasing popularity of rhinoplasty in the African-American patient, we delineate how a rhinoplasty surgeon can perform this challenging technique to obtain uniform and consistent results. First, we address how one can appreciate and analyze the various aesthetic concepts of beauty and the unique anatomic characteristics of the African-American nose. Second, we present a pragmatic, systematic analysis of the African-American nose. Last, we describe the techniques consistently used to modify the African-American nose while achieving or maintaining facial harmony using the open approach to rhinoplasty. Specific case analyses are presented to demonstrate utilization of the technique.

  2. The African diaspora: history, adaptation and health.

    PubMed

    Rotimi, Charles N; Tekola-Ayele, Fasil; Baker, Jennifer L; Shriner, Daniel

    2016-12-01

    The trans-Atlantic slave trade brought millions of Africans to the New World. Advances in genomics are providing novel insights into the history and health of Africans and the diasporan populations. Recent examples reviewed here include the unraveling of substantial hunter-gatherer and 'Eurasian' admixtures across sub-Saharan Africa, expanding our understanding of ancestral African genetics; the global ubiquity of mixed ancestry; the revealing of African ancestry in Latin Americans that likely derived from the slave trade; and understanding of the ancestral backgrounds of APOL1 and LPL found to influence kidney disease and lipid levels, respectively, providing specific insights into disease etiology and health disparities.

  3. Gentle Africanized bees on an oceanic island.

    PubMed

    Rivera-Marchand, Bert; Oskay, Devrim; Giray, Tugrul

    2012-11-01

    Oceanic islands have reduced resources and natural enemies and potentially affect life history traits of arriving organisms. Among the most spectacular invasions in the Western hemisphere is that of the Africanized honeybee. We hypothesized that in the oceanic island Puerto Rico, Africanized bees will exhibit differences from the mainland population such as for defensiveness and other linked traits. We evaluated the extent of Africanization through three typical Africanized traits: wing size, defensive behavior, and resistance to Varroa destructor mites. All sampled colonies were Africanized by maternal descent, with over 65% presence of European alleles at the S-3 nuclear locus. In two assays evaluating defense, Puerto Rican bees showed low defensiveness similar to European bees. In morphology and resistance to mites, Africanized bees from Puerto Rico are similar to other Africanized bees. In behavioral assays on mechanisms of resistance to Varroa, we directly observed that Puerto Rican Africanized bees groomed-off and bit the mites as been observed in other studies. In no other location, Africanized bees have reduced defensiveness while retaining typical traits such as wing size and mite resistance. This mosaic of traits that has resulted during the invasion of an oceanic island has implications for behavior, evolution, and agriculture.

  4. Gentle Africanized bees on an oceanic island

    PubMed Central

    Rivera-Marchand, Bert; Oskay, Devrim; Giray, Tugrul

    2012-01-01

    Oceanic islands have reduced resources and natural enemies and potentially affect life history traits of arriving organisms. Among the most spectacular invasions in the Western hemisphere is that of the Africanized honeybee. We hypothesized that in the oceanic island Puerto Rico, Africanized bees will exhibit differences from the mainland population such as for defensiveness and other linked traits. We evaluated the extent of Africanization through three typical Africanized traits: wing size, defensive behavior, and resistance to Varroa destructor mites. All sampled colonies were Africanized by maternal descent, with over 65% presence of European alleles at the S-3 nuclear locus. In two assays evaluating defense, Puerto Rican bees showed low defensiveness similar to European bees. In morphology and resistance to mites, Africanized bees from Puerto Rico are similar to other Africanized bees. In behavioral assays on mechanisms of resistance to Varroa, we directly observed that Puerto Rican Africanized bees groomed-off and bit the mites as been observed in other studies. In no other location, Africanized bees have reduced defensiveness while retaining typical traits such as wing size and mite resistance. This mosaic of traits that has resulted during the invasion of an oceanic island has implications for behavior, evolution, and agriculture. PMID:23144660

  5. Studies on the cardenolide sequestration in African milkweed butterflies (Danaidae).

    PubMed

    Mebs, Dietrich; Reuss, Esther; Schneider, Michael

    2005-04-01

    Butterflies of the Danaidae family are considered to be toxic or distasteful due to the presence of cardiac glycosides sequestered from their larval food plants. Alcoholic extracts of specimens of Danaus chrysippus aegyptius and Amauris ochlea ochlea from southern Africa (Namibia, S.-Africa, Mozambique) were analyzed by thin-layer chromatography for these cardenolides. But only 4 of 75 specimens of D. chrysippus aegyptius contained trace amounts, all others including 13 specimens of A. ochlea ochlea were negative. Genetic analysis of the ouabain binding site of the Na(+), K(+)-ATPase revealed that both species do not present an amino acid replacement at the position 122, which otherwise makes the enzyme insensitive to cardenolides suggesting that other strategies of toxin tolerance must have been developed.

  6. Impacts of ultra-low volume resmethrin applications on non-target insects.

    PubMed

    Oberhauser, Karen S; Manweiler, Stephen A; Lelich, Rosemary; Blank, Meredith; Batalden, Rebecca V; de Anda, Alma

    2009-03-01

    We studied the impacts of exposure to ultra-low volume (ULV) applications of resmethrin (Scourge) on monarch butterfly (Danaus plexippus) larvae and adults. In a series of 3 experiments, we measured short- and long-term survival of monarch larvae and adults, and the impacts of consuming previously exposed host plants on monarch larvae. We measured efficacy during all experiments with caged sentinel mosquitoes, and during Experiments 1 and 2 with pretreatment, treatment, and posttreatment measurements of mosquito abundance in CO2 traps. Downwind monarch larval and adult mortality were higher than upwind or control mortality up to 120 m, but not 170 m, from the spray path. In 1 experiment, monarchs exposed to spray as larvae developed into smaller adults, suggesting sublethal impacts. Milkweed host plants sprayed 1, but not 2 or 4 days previously, resulted in increased monarch larval mortality. Sentinel mosquito mortality was generally high, and CO2 traps revealed substantially lower mosquito abundance immediately after the treatment (>90% reduction) but <20% reduction 24 h after treatment. Our results suggest that ULV resmethrin applications will impact lepidopteran larvae and adults that are directly exposed to the spray but that generalizations about other nontarget taxa will require additional research. The magnitude of population-level impacts on monarchs will depend on the proportion of the population that is exposed.

  7. Conflict and human African trypanosomiasis.

    PubMed

    Berrang-Ford, Lea; Lundine, Jamie; Breau, Sebastien

    2011-02-01

    Human African Trypanosomiasis (HAT) has reemerged in sub-Saharan Africa as a disease of major public health importance. The success of HAT elimination in sub-Saharan Africa is subject to the feasibility of controlling, eliminating, or mitigating the determinants of incidence in affected countries. Conflict has been widely recognized and cited as a contributing factor to the resurgence of HAT in many countries, as well as to continuing HAT incidence in politically unstable and resource-poor regions. Despite extensive anecdotal and qualitative recognition of the role of conflict, there has been no quantitative research of this topic at the population level in affected African countries. We characterize the qualitative and quantitative associations between HAT incidence and conflict-related processes in HAT-affected African countries over the past 30 years. HAT and conflict-related data were collected for 35 affected countries in sub-Saharan Africa for the years 1976-2004. Descriptive and univariate inferential statistics, as well as negative binomial regression modeling, are used to assess the associations between HAT and conflict. A space-time scan statistic is used to identify significant incidence clusters. Clusters of HAT incidence over the past 30 years have predominantly coincided with periods of conflict or socio-political instability. HAT cases occurred significantly more often in countries and during years with conflict, high political terror, and internationalized civil war. The results indicate a lag period between the start of conflict events and a peak in incidence of approximately 10 years. We recommend explicit consideration and quantification of socio-political measures such as conflict and terror indices in GIS (Geographic Information Systems)-based risk assessments for HAT policy and intervention.

  8. Hydrogenotrophic microbiota distinguish native Africans from African and European Americans.

    PubMed

    Nava, Gerardo M; Carbonero, Franck; Ou, Junhai; Benefiel, Ann C; O'Keefe, Stephen J; Gaskins, H Rex

    2012-06-01

    Reduced susceptibility to sporadic colorectal cancer in native Africans (NA) is correlated with low consumption of animal products and greater microbial production of colonic methane. In this context, two hydrogenotrophic microbial groups are of interest, methanogenic Archaea (MA) utilizing H2 to produce methane and sulfate-reducing bacteria (SRB) generating hydrogen sulfide, which has been linked with chronic inflammatory disorders of the colon. In the present study, stool samples from NA, consuming a diet high in resistant starch and low in animal products, and from African Americans (AA) and European Americans (EA), both consuming a typical Western diet, were examined for genetic diversity and structure of Archaea, MA and SRB communities. In general, a greater proportion of NA than AA and EA harboured the full range of targeted hydrogenotrophic groups. Terminal restriction fragment length polymorphism analysis of 16S rRNA genes and specific functional genes, combined with multivariate statistical analyses, revealed that NA harboured more diverse and different Archaea and MA populations than AA and EA. Also, NA harboured significantly distinct SRB populations compared with AA and EA. Taken together, these data are consistent with diet selecting for distinct hydrogenotrophic microbiota.

  9. France: Africans and the French Revolution.

    ERIC Educational Resources Information Center

    Fatunde, Tunde

    1989-01-01

    The French Revolution had profound and long-term effects for Africans, both in Africa and throughout the Western hemisphere. Revolutionary leaders not only opposed the emancipation of slaves in French territories but supported an intensified slave trade, sparking numerous rebellions. French exploitation of Africans extended well into the twentieth…

  10. African (Black) Psychology: Issues and Synthesis.

    ERIC Educational Resources Information Center

    Baldwin, Joseph A.

    1986-01-01

    Reviews the recent attempts of Black psychologists and social scientists to formulate a conceptual-operational framework for the study of psychological phenomena as they bear on the cultural-survival conditions of Black-African people. Outlines issues and problems in the attempt to define African (Black) psychology and discusses its relation to…

  11. Kunta Kinte's Struggle to be African

    ERIC Educational Resources Information Center

    Courlander, Harold

    1986-01-01

    This article reveals the differences between the character Kunta Kinte and the historical record concerning African males in the preslavery period. Kunta's non-African behaviors include displays of blind anger and rage, prudishness, and actions unknown in his Mandinka culture. These represent the many misrepresentations and ambiguities in Alex…

  12. Multicultural Curriculum: African American Children's Literature.

    ERIC Educational Resources Information Center

    Harris, Violet J.

    1991-01-01

    Traces and analyzes the history of African American children's literature defined as "culturally conscious," an authentic body of literature written about and for African American children. Discusses the current status of this literature and indicates a change in focus in the last century. Authors' perspectives, and the implications for…

  13. African American Undergraduates and the Academic Library

    ERIC Educational Resources Information Center

    Whitmire, Ethelene

    2006-01-01

    This study examines the academic library experiences of African American undergraduates attending a research university in the Midwest. Data collection techniques included questionnaires and ethnographic observations. The results indicated that African American undergraduates are using the academic library primarily to read and to study with their…

  14. African Education and Globalization: Critical Perspectives

    ERIC Educational Resources Information Center

    Abdi, Ali A., Ed.; Puplampu, Korbla P., Ed.; Dei, George J. Sefa, Ed.

    2006-01-01

    Containing both theoretical discussions of globalization and specific case analyses of individual African countries, this collection of essays examines the intersections of African education and globalization with multiple analytical and geographical emphases and intentions. The 11 essays critically analyze the issues from historical, cultural,…

  15. Smoking Cessation in African-Americans.

    ERIC Educational Resources Information Center

    Ahluwalia, Jasjit S.

    1996-01-01

    Because the smoking behavior of African Americans differs considerably from that of other groups, researchers examined differences between African Americans who did and did not use the nicotine patch as an adjunct to counseling and education for smoking cessation. Results indicated the nicotine patch significantly improved six-month cessation…

  16. Genetics Home Reference: African iron overload

    MedlinePlus

    ... of a genetic condition? Genetic and Rare Diseases Information Center Frequency African iron overload is common in rural areas of central and ... more about the gene associated with African iron overload SLC40A1 Related Information What is a gene? What is a gene ...

  17. Cultural Expressions of the African American Child.

    ERIC Educational Resources Information Center

    Akbar, Na'im

    Interpretations of the differences between the African American child and the Caucasian child in North America follow two major trends. In one the differences in the African American child are viewed as deviance from the Euro-American norm and therefore inferior or pathological. In the other, the differences are viewed as deviant but adaptive…

  18. A Mirror Image African American Student Reflections

    ERIC Educational Resources Information Center

    Cannon Dawson, Candice

    2012-01-01

    This dissertation is a narrative inquiry research project that focuses on the collegiate experiences of African American students at both historically black colleges and universities (HBCUs) and predominantly white institutions (PWIs). I look at how African American college students who engage in race or culturally specific activities, the degree…

  19. Syntactic Variation in West African English.

    ERIC Educational Resources Information Center

    Bamiro, Edmund O.

    1995-01-01

    Describes syntactic variation in West African English with examples from West African English literature and identifies and describes subjectless sentences, deletion of the -ly morpheme in manner adjuncts, omission of function words, reduplication, tag questions, substitution of prepositions in idiomatic usage, and focus constructions. (53…

  20. Experiences of African American College Graduates

    ERIC Educational Resources Information Center

    Green, Aundria Chephan

    2014-01-01

    The purpose of this study was to explore the reasons that African-American alumni from a historically Black university (HBCU) and a predominantly White university (PWI) chose to attend, remain in, and graduate from college. The central research question was how do African Americans describe their college experiences? The secondary research…

  1. Hidden Education among African Americans during Slavery

    ERIC Educational Resources Information Center

    Gundaker, Grey

    2007-01-01

    Background/Context: Historical studies examine aspects of African American education in and out of school in detail (Woodson 1915, 1933, Bullock 1970, Anderson 1988, Morris 1982, Rachal 1986, Rose 1964, Webber 1978, Williams 2005). Scholars of African American literacy have noted ways that education intersects other arenas such as religion and…

  2. African Americans in the Early Republic.

    ERIC Educational Resources Information Center

    Nash, Gary B.

    2000-01-01

    Discusses five topics on African Americans that are essential to studying United States History in the years between 1760 and 1830: (1) African Americans in the Revolutionary War ; (2) the rise of free black communities; (3) early abolitionism; (4) the spread of slavery; and (5) black resistance to slavery. (CMK)

  3. A Reader's Guide to African Literature.

    ERIC Educational Resources Information Center

    Zell, Hans M., Ed.; Silver, Helene, Ed.

    This annotated bibliography lists 820 literary works by black African authors south of the Sahara writing in English and in French. Reference material, critical works, and anthologies (many by non-Africans) are also included. The bibliography--excluding reference and critical works and anthologies--is divided into two sections. "Writings in…

  4. Precolonial African History. AHA Pamphlets, 501.

    ERIC Educational Resources Information Center

    Curtin, Philip D.

    This pamphlet surveys western historiography of precolonial Africa. Prior to World War II, African history emphasized the European role in Africa, relegating African history before European colonization to minor importance. Only after the increase in university enrollments and funding in the 1960's did opportunities for innovative research and new…

  5. New data on African health professionals abroad

    PubMed Central

    Clemens, Michael A; Pettersson, Gunilla

    2008-01-01

    Background The migration of doctors and nurses from Africa to developed countries has raised fears of an African medical brain drain. But empirical research on the causes and effects of the phenomenon has been hampered by a lack of systematic data on the extent of African health workers' international movements. Methods We use destination-country census data to estimate the number of African-born doctors and professional nurses working abroad in a developed country circa 2000, and compare this to the stocks of these workers in each country of origin. Results Approximately 65,000 African-born physicians and 70,000 African-born professional nurses were working overseas in a developed country in the year 2000. This represents about one fifth of African-born physicians in the world, and about one tenth of African-born professional nurses. The fraction of health professionals abroad varies enormously across African countries, from 1% to over 70% according to the occupation and country. Conclusion These numbers are the first standardized, systematic, occupation-specific measure of skilled professionals working in developed countries and born in a large number of developing countries. PMID:18186916

  6. Depression, Sociocultural Factors, and African American Women

    ERIC Educational Resources Information Center

    Hunn, Vanessa Lynn; Craig, Carlton David

    2009-01-01

    The authors discuss depression in African American women from a sociocultural perspective, including aspects of oppression and racism that affect symptom manifestation. The authors highlight John Henryism as a coping mechanism, the history and continuing role of the African American church as a safe haven, and strategies for culturally competent…

  7. An African Perspective on Human Rights.

    ERIC Educational Resources Information Center

    Shiman, David

    1992-01-01

    Presents a series of classroom activities comparing differing views of human rights in the United Nations Universal Declaration of Human Rights and the African Charter on Human and People's Rights. Includes excerpts from the African Charter on Human and People's Rights and the full text of the Universal Declaration of Human Rights. (CFR)

  8. Prostate Cancer Genetics in African Americans

    DTIC Science & Technology

    2015-11-01

    AWARD NUMBER: W81XWH-11-1-0566 TITLE: Prostate Cancer Genetics in African Americans PRINCIPAL INVESTIGATOR: Henry T. Lynch, MD CONTRACTING...W81XWH-11-1-0566 November 2015 Final 15Aug2011 - 14Aug2015 Prostate Cancer Genetics in African Americans Henry T. Lynch Nothing listed 36

  9. South African Students' Views of the Universe.

    ERIC Educational Resources Information Center

    Lemmer, M.; Lemmer, T. N.; Smit, J. J. A.

    2003-01-01

    Investigates perceptions of the universe of (n=232) first-year physics students from two South African universities. Compared results with Aristotelian and Newtonian views as well as with those of children as revealed in a literature survey. Results also showed that a statistically significant larger number of African than European students have…

  10. Supporting Change: Working with South African Universities.

    ERIC Educational Resources Information Center

    Moran, Anne D.; Volmink, John

    1986-01-01

    University and pre-university education in South Africa is briefly described, along with areas where U.S. universities can assist South African organizations working to promote equal access to quality education. Three basic areas are explored: financial aid for South African students; manpower support to help in tutorials and academic research;…

  11. British African Caribbean Women and Depression

    ERIC Educational Resources Information Center

    Adkison-Bradley, Carla; Maynard, Donna; Johnson, Phillip; Carter, Stephaney

    2009-01-01

    Depression is a common condition among women in the United Kingdom. However, little is known about the context of depression among British African Caribbean women. This article offers a preliminary discussion regarding issues and information pertaining to depression among British African Caribbean women. Characteristics and symptoms of depression…

  12. The Process of Africanizing the Social Studies.

    ERIC Educational Resources Information Center

    Merryfield, Merry M.; Tlou, Josiah

    1995-01-01

    Investigates social studies curriculum reform in Botswana, Kenya, Malawi, Nigeria, and Zimbabwe. Reports on each country contain a brief overview of the historical situation and current syllabus, and a discussion of the ongoing "Africanization" process. Concludes with a definition of "Africanization," its purpose, and…

  13. Improving African American Achievement in Geometry Honors

    ERIC Educational Resources Information Center

    Mims, Adrian B.

    2010-01-01

    This case study evaluated the significance of implementing an enrichment mathematics course during the summer to rising African American ninth graders entitled, "Geometry Honors Preview." In the past, 60 to 70 percent of African American students in this school district had withdrawn from Geometry Honors by the second academic quarter. This study…

  14. A Reevaluation of African Education: Woodson Revisited.

    ERIC Educational Resources Information Center

    Okafor, Victor Oguejiofor

    1992-01-01

    Reviews the ideas of C. G. Woodson (1875-1950) about the inappropriate education received by African Americans. Although Woodson's book, "The Mis-Education of the Negro," was written in 1933, his diagnosis of the state of the African-American community appears to hold up well today. (SLD)

  15. African Americans and World War II.

    ERIC Educational Resources Information Center

    Kersten, Andrew E.

    2002-01-01

    Focuses on the experience of African Americans during World War II on the homefront and in the armed forces. States that African Americans not only fought fascism overseas but also apartheid in the United States, also known as the "Double V." (CMK)

  16. Prostate cancer in men of African origin.

    PubMed

    McGinley, Kathleen F; Tay, Kae Jack; Moul, Judd W

    2016-02-01

    Men of African origin are disproportionately affected by prostate cancer: prostate cancer incidence is highest among men of African origin in the USA, prostate cancer mortality is highest among men of African origin in the Caribbean, and tumour stage and grade at diagnosis are highest among men in sub-Saharan Africa. Socioeconomic, educational, cultural, and genetic factors, as well as variations in care delivery and treatment selection, contribute to this cancer disparity. Emerging data on single-nucleotide-polymorphism patterns, epigenetic changes, and variations in fusion-gene products among men of African origin add to the understanding of genetic differences underlying this disease. On the diagnosis of prostate cancer, when all treatment options are available, men of African origin are more likely to choose radiation therapy or to receive no definitive treatment than white men. Among men of African origin undergoing surgery, increased rates of biochemical recurrence have been identified. Understanding differences in the cancer-survivorship experience and quality-of-life outcomes among men of African origin are critical to appropriately counsel patients and improve cultural sensitivity. Efforts to curtail prostate cancer screening will likely affect men of African origin disproportionately and widen the racial disparity of disease.

  17. The TG/HDL-C ratio does not predict insulin resistance in overweight women of African descent: a study of South African, African American and West African women.

    PubMed

    Knight, Michael G; Goedecke, Julia H; Ricks, Madia; Evans, Juliet; Levitt, Naomi S; Tulloch-Reid, Marshall K; Sumner, Anne E

    2011-01-01

    Women of African descent have a high prevalence of diseases caused by insulin resistance. To positively impact cardiometabolic health in Black women, effective screening tests for insulin resistance must be identified. Recently, the TG/HDL-C ratio has been recommended as a tool to predict insulin resistance in overweight people. While the ratio predicts insulin resistance in White women, it is ineffective in African American women. As there are no data for African women, we tested the ability of the TG/HDL-C ratio to predict insulin resistance in Black women from South Africa, West Africa and the United States. For comparison, the ratio was also tested in White women from South Africa. Participants were 801 women (157 Black South African, 382 African American, 119 West African, 143 White South African, age 36 +/- 9y [mean +/- SD]). Standardized scores were created from log-transformed homeostasis model assessment-insulin resistance values from each population. Participants in the upper third of their population distribution were classified as insulin-resistant. To predict insulin resistance by the TC/HDL-C ratio, area under the receiver operating characteristic (AUC-ROC) curve was used and criteria were: 0.50 for no discrimination and > or = 0.70 for acceptable. Seventy-one percent of the Black women were overweight vs 51% of White women (P<.01). In overweight White women, AUC-ROC curve for prediction of insulin resistance by TG/HDL-C was 0.76 +/- 0.06, but below the 0.70 threshold in each group of overweight Black women (Black South African: 0.64 +/- 0.06, African American: 0.66 +/- 0.03, and West African: 0.63 +/- 0.07). Therefore, TG/HDL-C does not predict insulin resistance in overweight African American women and this investigation extends that finding to overweight Black South African and West African women. Resources to identify effective markers of insulin resistance are needed to improve cardiometabolic health in women of African descent.

  18. The extent of burning in African savanna

    NASA Technical Reports Server (NTRS)

    Cahoon, D. R. JR.; Levine, J. S.; Cofer, W. R. Iii; Stocks, B. J.

    1994-01-01

    The temporal and spatial distribution of African savanna grassland fires has been examined, and the areal extent of these fires has been estimated for the subequatorial African continent. African savanna fires have been investigated using remote sensing techniques and imagery collected by low-light sensors on Defense Meteorological Satellite Program (DMSP) satellites and by the Advanced Very High Resolution Radiometer (AVHRR) which is aboard polar orbiting National Oceanic and Atmospheric Administration (NOAA) satellites. DMSP imagery has been used to map the evolution of savanna burning over all of the African continent and the analysis of AVHRR imagery has been used to estimate the areal extent of the burning in the southern hemispheric African savannas. The work presented primarily reflects the analysiscompleted for the year 1987. However, comparisons have been made with other years and the representativeness of the 1987 analysis is discussed.

  19. Intimate partner violence in African American women.

    PubMed

    Campbell, Doris Williams; Sharps, Phyllis W; Gary, Faye A; Campbell, Jacquelyn C; Lopez, Loretta M

    2002-01-01

    Violence against African American women, specifically intimate partner abuse, has a significant impact on their health and well being. Intimate partner femicide and near fatal intimate partner femicide are the major causes of premature death and disabling injuries for African American women. Yet, despite this, there is a paucity of research and interventions specific and culturally relevant for these women. This article focuses on issues relevant to intimate partner violence and abuse against African American women by examining existing empirical studies of prevalence and health outcomes of intimate partner violence against women in general, plus what limited research there is about African American women, specifically. It includes a discussion of specific recommendations for research, practice, education, and policy to reduce and prevent intimate partner violence against African American women.

  20. African Americans and the medical establishment.

    PubMed

    Smith, C

    1999-09-01

    The African American community's response to the AIDS epidemic has reflected the profound mistrust of the medical establishment which many African Americans feel. Among African Americans, the belief that the epidemic originated in a genocidal plot is widespread. It is thought that organized medicine has been significantly involved in this plot. If we look at African Americans' historical relationship to the medical establishment from the era of slavery to the recent past, the suspicious attitudes which make such beliefs possible can be seen as an intelligible response to a new disease which disproportionately affects African Americans. Successful medical and public health responses to the epidemic have depended and will continue to depend upon overcoming the historical legacy of suspicion and gaining the trust of the community.

  1. HMO employment and African-American physicians.

    PubMed Central

    Briscoe, Forrest; Konrad, Thomas R.

    2006-01-01

    OBJECTIVES: To assess the level and determinants of African-American physicians' employment in health maintenance organizations (HMOs), particularly early in their careers. METHODS: We analyzed data from the 1991 and 1996 Young Physicians Surveys to assess racial differences in the likelihood of HMO employment (n = 3,705). Using multinomial logistic regression, we evaluated four explanations for an observed relationship between African-American physicians and HMO employment: human capital stratification among organizations, race-based affinity between physicians and patients, financial constraints due to debt burden, and different organizational hiring practices. Using binomial logistic regression, we also evaluated differences in the odds of being turned down for a prior practice position, of subsequently leaving the current practice organization and of later having career doubts. RESULTS: Without any controls, African-American physicians were 4.52 times more likely to practice in HMOs than Caucasian physicians. After controlling for human capital stratification, racial concordance and financial constraints, African-American physicians remained 2.48 times more likely to practice in HMOs than Caucasian physicians. In addition, 19.2% of African-American physicians in HMOs reported being turned down for another job, far more than any other racial/ethnic group in the HMO setting and any racial/ethnic group, including African-American physicians in the non-HMO setting (including all other practice locations). Five years later, those same African-American physicians from HMOs also reported significantly more turnover (7.50 times more likely than non-HMO African-American physicians to leave their current practice) and doubt about their careers (2.17 times more likely than non-HMO African-American physicians to express serious career doubts). CONCLUSIONS: African-American physicians were disproportionately hired into HMO settings, impacting their subsequent careers. PMID

  2. The African Folktale. An Instructional Unit for Seventh Grade English.

    ERIC Educational Resources Information Center

    Dobbs, Sherry

    The document presents a 3-week seventh grade English unit on the African folktale. The guide is one of a number of products developed by a summer workshop for teachers on African curriculum development. The objectives are to help students develop respect for African cultures and lifestyles, compare values of African and American ethnic…

  3. School Counseling for African American Adolescents: The Alfred Adler Approach

    ERIC Educational Resources Information Center

    Sapp, Marty

    2010-01-01

    This article discusses how Adlerian counseling can be used as a form of school counseling for African American adolescents. Moreover, school counseling for African American adolescents is discussed within the context of African American culture. Due to the strength-based nature of Adlerian approach, it can capitalize on African American…

  4. Towards an Africological Pedagogical Approach to African Civilization.

    ERIC Educational Resources Information Center

    Okafor, Victor Oguejiofor

    1996-01-01

    Presents a case study of controversies related to African studies and makes the case for an Africological pedagogical approach to African Civilization. The title "African Civilization" reflects the African place in the whole of world civilization even though that place is itself a multiple entity. (SLD)

  5. African American cancer patients' pain experience.

    PubMed

    Im, Eun-Ok; Lim, Hyun-Ju; Clark, Maresha; Chee, Wonshik

    2008-01-01

    Although very little is known about African American cancer patients' pain experience, a few studies have indicated that their cancer pain experience is unique and somewhat different from that of other ethnic groups. The purpose of the study reported in this article was to explore African American cancer patients' pain experience using an online forum. This study was a qualitative online forum designed from a feminist perspective and conducted among 11 African American cancer patients who were recruited through both Internet and real settings. Nine online forum topics were used to administer the 6-month online forum, and the data were analyzed using thematic analysis. Four themes emerged through the data analysis process. First, participants viewed cancer as a challenge in life that they should fight against. Second, cancer pain was differentiated from ordinary pain because cancer was stigmatized in their culture. Third, participants viewed that African Americans, especially women, were culturally raised to be strong, and this African American cultural heritage inhibited cancer patients from expressing pain and seeking help for pain management. Finally, the findings indicated certain changes in perspectives among African American cancer patients during the disease process, which might make them tolerate pain through praying to God and reading the Bible. Based on the findings, we suggest further studies among diverse groups of African American cancer patients, with a focus on cultural attitudes toward cancer pain and influences of family on cancer pain experience.

  6. Enslaved Africans and doctors in South Carolina.

    PubMed

    Goodson, Martia Graham

    2003-03-01

    This interpretation of the relationship between enslavement and American medicine in 19th century South Carolina reveals the intimacy that existed between Africans enslaved in that state and the doctors who practiced and taught there. Enslaved Africans were resourceful and reliable medical figures in the slave community. Their knowledge of medical botany permeated the slave quarters and plantation hospitals and was appropriated into southern medical knowledge. The trajectories of the careers of three South Carolina physicians are tied to their practice around and on the enslaved. The beginnings of gynecological surgery are linked to 1840s experimentation on enslaved African women performed by one of them.

  7. Henipavirus RNA in African Bats

    PubMed Central

    Gloza-Rausch, Florian; Seebens, Antje; Annan, Augustina; Ipsen, Anne; Kruppa, Thomas; Müller, Marcel A.; Kalko, Elisabeth K. V.; Adu-Sarkodie, Yaw; Oppong, Samuel; Drosten, Christian

    2009-01-01

    Background Henipaviruses (Hendra and Nipah virus) are highly pathogenic members of the family Paramyxoviridae. Fruit-eating bats of the Pteropus genus have been suggested as their natural reservoir. Human Henipavirus infections have been reported in a region extending from Australia via Malaysia into Bangladesh, compatible with the geographic range of Pteropus. These bats do not occur in continental Africa, but a whole range of other fruit bats is encountered. One of the most abundant is Eidolon helvum, the African Straw-coloured fruit bat. Methodology/Principal Findings Feces from E. helvum roosting in an urban setting in Kumasi/Ghana were tested for Henipavirus RNA. Sequences of three novel viruses in phylogenetic relationship to known Henipaviruses were detected. Virus RNA concentrations in feces were low. Conclusions/Significance The finding of novel putative Henipaviruses outside Australia and Asia contributes a significant extension of the region of potential endemicity of one of the most pathogenic virus genera known in humans. PMID:19636378

  8. Enhancing the African bioethics initiative

    PubMed Central

    Ogundiran, Temidayo O

    2004-01-01

    Background Medical ethics has existed since the time of Hippocrates. However, formal training in bioethics did not become established until a few decades ago. Bioethics has gained a strong foothold in health sciences in the developed world, especially in Europe and North America. The situation is quite different in many developing countries. In most African countries, bioethics – as established and practiced today in the west- is either non-existent or is rudimentary. Discussion Though bioethics has come of age in the developed and some developing countries, it is still largely "foreign" to most African countries. In some parts of Africa, some bioethics conferences have been held in the past decade to create research ethics awareness and ensure conformity to international guidelines for research with human participants. This idea has arisen in recognition of the genuine need to develop capacity for reviewing the ethics of research in Africa. It is also a condition required by external sponsors of collaborative research in Africa. The awareness and interest that these conferences have aroused need to be further strengthened and extended beyond research ethics to clinical practice. By and large, bioethics education in schools that train doctors and other health care providers is the hook that anchors both research ethics and clinical ethics. Summary This communication reviews the current situation of bioethics in Africa as it applies to research ethics workshops and proposes that in spite of the present efforts to integrate ethics into biomedical research in Africa, much still needs to be done to accomplish this. A more comprehensive approach to bioethics with an all-inclusive benefit is to incorporate formal ethics education into health training institutions in Africa. PMID:15488145

  9. Chronic lymphocytic leukemia in African Americans.

    PubMed

    Coombs, Catherine C; Falchi, Lorenzo; Weinberg, J Brice; Ferrajoli, Alessandra; Lanasa, Mark C

    2012-11-01

    Chronic lymphocytic leukemia (CLL) is the most prevalent leukemia in the United States with almost 4390 attributable deaths per year. Epidemiologic data compiled by the Surveillance, Epidemiology and End Results (SEER) program identifies important differences in incidence and survival for African Americans with CLL. Although the incidence of CLL is lower among African Americans than among Caucasians (4.6 and 6.2 per 100 000 men, respectively), age-adjusted survival is inferior. African American patients with CLL are almost twice as likely to die from a CLL-related complication in the first 5 years after diagnosis as are Caucasian patients with CLL. The biologic basis for these observations is almost entirely unexplored, and a comprehensive clinical analysis of African American patients with CLL is lacking. This is the subject of the present review.

  10. HIV/AIDS among African Americans

    MedlinePlus

    ... person’s chance of getting or transmitting HIV. The poverty rate is higher among African Americans than other racial/ethnic groups. The socioeconomic issues associated with poverty—including limited access to high-quality health care, ...

  11. Cardiac assessment of African hedgehogs (Atelerix albiventris).

    PubMed

    Black, Peter A; Marshall, Cecilia; Seyfried, Alice W; Bartin, Anne M

    2011-03-01

    Cardiomyopathy is a common finding in captive African hedgehogs (Atelerix albiventris) at postmortem exam. To date, treatment attempts have been mostly empirical and unrewarding. The objective of this study was to determine reference cardiac values for captive African hedgehogs based on echocardiogram, electrocardiogram (ECG), and radiographs. Adult African hedgehogs with no clinical signs of cardiac disease (n = 13) were selected. Each animal was anesthetized with isoflurane via facemask and an echocardiogram, ECG, and radiographs were performed. Standard measurements were taken and the descriptive statistics performed. Values were comparable to limited data available in other hedgehog species and other similar-sized exotic species. Two animals were removed from consideration of reference values due to valvular defects that were considered significant. These data are the first establishing cardiac parameters in normal African hedgehogs using radiographic cardiac measurement, echocardiogram, and ECG. Evaluating animals with possible cardiomyopathy may allow for earlier diagnosis and more successful treatment.

  12. Mellonee Burnim on African American Music.

    ERIC Educational Resources Information Center

    Campbell, Patricia Shehan

    1995-01-01

    Describes the role and influence of Mellonee Burnim on U.S. music education. Discusses the origins and impact of African American gospel music. Includes a list of selected resources and two lesson plans featuring gospel music. (CFR)

  13. What physicians should know about Africanized honeybees.

    PubMed Central

    Sherman, R A

    1995-01-01

    The Africanized honeybee, popularly known as the "killer bee," is already well established in Texas and has recently entered California and Arizona. As the Africanized honeybee spreads in North America, the medical community must become aware of the problems associated with this insect and ensure that sting emergencies can be handled quickly and appropriately. The major differences between Africanized and European honeybees are that the former are more irritable, they swarm more readily and frequently, they defend their hives more vehemently, and they sting more collectively. It is not the composition nor the volume of an individual bee's venom, but rather the cumulative dose of multiple stings that accounts for the morbidity and mortality associated with Africanized honeybee-sting incidents. Even nonallergic persons are susceptible to the toxic effects of these large combined venom loads. Africanized honeybee-sting victims are treated the same as victims of European honeybee stings. Authorities will prepare for the bees' arrival by expanding public awareness, teaching risk-avoidance behavior, providing for the removal of troublesome hives, and developing sting treatment protocols that can be initiated rapidly in the field or emergency departments. Health care professionals should participate in the educational efforts and in the development of needed emergency response protocols so that the effects of the Africanized honeybee will be merely a nuisance rather than a plague. PMID:8553637

  14. Partiality and distributive justice in African bioethics.

    PubMed

    Wareham, Christopher Simon

    2017-04-01

    African ethical theories tend to hold that moral agents ought to be partial, in the sense that they should favour members of their family or close community. This is considered an advantage over the impartiality of many Western moral theories, which are regarded as having counterintuitive implications, such as the idea that it is unethical to save a family member before a stranger. The partiality of African ethics is thought to be particularly valuable in the context of bioethics. Thaddeus Metz, in particular, argues that his African-derived theory best accounts for a number of plausible intuitions, such as the intuition that health care practitioners ought to be biased towards the patients for whom they are directly responsible. In this article, I claim that the plausible intuitions drawn on in favour of partiality can be satisfactorily explained on the basis of impartial moral theories. Moreover, I argue that blanket acceptance of partiality has problematic consequences for distributive justice in resource allocation in biomedical contexts. By contrast, impartial theories can justify plausible instances of partiality whilst avoiding the pitfalls of fully partial moral theories. Although this provides grounds for abandoning partiality in principle, I claim that this finding should not be seen as damaging to African medical ethics. Instead, it prompts investigation of underexplored possibilities of impartial African moral theories. To demonstrate the value of this direction, I sketch some novel and attractive conceptions that combine impartiality with elements of African ethics.

  15. Port of Sanctuary: The Aesthetic of the African/African American and the Barnes Foundation.

    ERIC Educational Resources Information Center

    Hollingsworth, Charles H.

    1994-01-01

    Asserts that, although it has been ignored by most art historians and art educators, the Barnes Foundation was founded upon a unique African/African American esthetic influence. Describes influences on the life of Dr. Albert C. Barnes, his world view, and the decision to establish the Barnes Foundation and its art collection. (CFR)

  16. Trade in Educational Services: Reflections on the African and South African Higher Education System

    ERIC Educational Resources Information Center

    Sehoole, Chika Trevor

    2004-01-01

    This article discusses and analyses the emergence of globalisation and its impact on developments within the African continent. Africa's response at a regional level through the New Partnership for Africa's Development and at a subregional level through the Southern African Development Community's "Protocol on Education" come under…

  17. "Women ... Mourn and Men Carry on": African Women Storying Mourning Practices--A South African Example

    ERIC Educational Resources Information Center

    Kotze, Elmarie; Els, Lishje; Rajuili-Masilo, Ntsiki

    2012-01-01

    African mourning of loss of lives in South Africa has been shaped by discursive practices of both traditional African cultures and the sociopolitical developments under apartheid and in post-apartheid South Africa. This article reports on changes in mourning practices on the basis of a literature review and uses a collection of examples to…

  18. African American Pastors' Beliefs and Actions Regarding Childhood Incest in the African American Community

    ERIC Educational Resources Information Center

    Wells, Tesia Denis

    2012-01-01

    This quantitative study sought to explore African American pastors' beliefs and actions regarding childhood incest in the African American community and their decisions to inform the proper authorities. This exploratory study was developed in order to draw both public and academic attention to the understudied phenomenon of childhood incest within…

  19. An Ambivalent Community: International African Students in Residence at a South African University

    ERIC Educational Resources Information Center

    Weber, Everard

    2016-01-01

    This is a qualitative case study of the experiences and perceptions of South African and especially international, African students living in university residences in South Africa. The concept, community, is used to interpret interview data. This community was characterised by ambivalent social relations: There was discrimination by South Africans…

  20. The Pedagogy of African American Parents: Learning from Educational Excellence in the African American Community

    ERIC Educational Resources Information Center

    Watkins, Audrey P.

    2006-01-01

    This qualitative study of how parents teach their children to excel academically in the African American community seeks to establish the validity of the pedagogical practices of working class African American families by investigating the educational leadership of two families on Chicago's south side. The study acknowledges the significance of…

  1. African swine fever virus serotype-specific proteins are significant protective antigens for African swine fever

    Technology Transfer Automated Retrieval System (TEKTRAN)

    African swine fever (ASF) is an emerging disease threat for the swine industry worldwide. No ASF vaccine is available and progress is hindered by lack of knowledge concerning the extent of African swine fever virus (ASFV) strain diversity and the viral antigens conferring type specific protective im...

  2. Changing Fatherhood: An Exploratory Qualitative Study with African and African Caribbean Men in England

    ERIC Educational Resources Information Center

    Williams, Robert; Hewison, Alistair; Wildman, Stuart; Roskell, Carolyn

    2013-01-01

    This paper presents findings from a qualitative study undertaken with 46 African and African Caribbean men exploring their experiences of fatherhood. Data analysis was informed by Connell's theoretical work on changing gender relations. Findings indicate that fathers' lives were mediated by masculinities, racism, gender, migration and generational…

  3. A SNP test to identify Africanized honeybees via proportion of 'African' ancestry.

    PubMed

    Chapman, Nadine C; Harpur, Brock A; Lim, Julianne; Rinderer, Thomas E; Allsopp, Michael H; Zayed, Amro; Oldroyd, Benjamin P

    2015-11-01

    The honeybee, Apis mellifera, is the world's most important pollinator and is ubiquitous in most agricultural ecosystems. Four major evolutionary lineages and at least 24 subspecies are recognized. Commercial populations are mainly derived from subspecies originating in Europe (75-95%). The Africanized honeybee is a New World hybrid of A. m. scutellata from Africa and European subspecies, with the African component making up 50-90% of the genome. Africanized honeybees are considered undesirable for bee-keeping in most countries, due to their extreme defensiveness and poor honey production. The international trade in honeybees is restricted, due in part to bans on the importation of queens (and semen) from countries where Africanized honeybees are extant. Some desirable strains from the United States of America that have been bred for traits such as resistance to the mite Varroa destructor are unfortunately excluded from export to countries such as Australia due to the presence of Africanized honeybees in the USA. This study shows that a panel of 95 single nucleotide polymorphisms, chosen to differentiate between the African, Eastern European and Western European lineages, can detect Africanized honeybees with a high degree of confidence via ancestry assignment. Our panel therefore offers a valuable tool to mitigate the risks of spreading Africanized honeybees across the globe and may enable the resumption of queen and bee semen imports from the Americas.

  4. African Games of Strategy: A Teaching Manual. African Outreach Series, No. 2.

    ERIC Educational Resources Information Center

    Crane, Louise

    Appreciation of African games has increased in this country; especially board games which have been popularized through commercial versions. African games are invaluable resources for studying subjects requiring mathematical concepts, as well as social studies, history, geography, and languages. This manual presents some of the better known…

  5. Genetic Factors and Host Traits Predict Spore Morphology for a Butterfly Pathogen

    PubMed Central

    Sander, Sarah E.; Altizer, Sonia; de Roode, Jacobus C.; Davis, Andrew K.

    2013-01-01

    Monarch butterflies (Danaus plexippus) throughout the world are commonly infected by the specialist pathogen Ophryocystis elektroscirrha (OE). This protozoan is transmitted when larvae ingest infectious stages (spores) scattered onto host plant leaves by infected adults. Parasites replicate internally during larval and pupal stages, and adult monarchs emerge covered with millions of dormant spores on the outsides of their bodies. Across multiple monarch populations, OE varies in prevalence and virulence. Here, we examined geographic and genetic variation in OE spore morphology using clonal parasite lineages derived from each of four host populations (eastern and western North America, South Florida and Hawaii). Spores were harvested from experimentally inoculated, captive-reared adult monarchs. Using light microscopy and digital image analysis, we measured the size, shape and color of 30 replicate spores per host. Analyses examined predictors of spore morphology, including parasite source population and clone, parasite load, and the following host traits: family line, sex, wing area, and wing color (orange and black pigmentation). Results showed significant differences in spore size and shape among parasite clones, suggesting genetic determinants of morphological variation. Spore size also increased with monarch wing size, and monarchs with larger and darker orange wings tended to have darker colored spores, consistent with the idea that parasite development depends on variation in host quality and resources. We found no evidence for effects of source population on variation in spore morphology. Collectively, these results provide support for heritable variation in spore morphology and a role for host traits in affecting parasite development. PMID:26462429

  6. Antigenic variation in African trypanosomes

    PubMed Central

    Horn, David

    2014-01-01

    Studies on Variant Surface Glycoproteins (VSGs) and antigenic variation in the African trypanosome, Trypanosoma brucei, have yielded a remarkable range of novel and important insights. The features first identified in T. brucei extend from unique to conserved-among-trypanosomatids to conserved-among-eukaryotes. Consequently, much of what we now know about trypanosomatid biology and much of the technology available has its origin in studies related to VSGs. T. brucei is now probably the most advanced early branched eukaryote in terms of experimental tractability and can be approached as a pathogen, as a model for studies on fundamental processes, as a model for studies on eukaryotic evolution or often all of the above. In terms of antigenic variation itself, substantial progress has been made in understanding the expression and switching of the VSG coat, while outstanding questions continue to stimulate innovative new approaches. There are large numbers of VSG genes in the genome but only one is expressed at a time, always immediately adjacent to a telomere. DNA repair processes allow a new VSG to be copied into the single transcribed locus. A coordinated transcriptional switch can also allow a new VSG gene to be activated without any detectable change in the DNA sequence, thereby maintaining singular expression, also known as allelic exclusion. I review the story behind VSGs; the genes, their expression and switching, their central role in T. brucei virulence, the discoveries that emerged along the way and the persistent questions relating to allelic exclusion in particular. PMID:24859277

  7. African female sexuality and the heterosexual form.

    PubMed

    Mcfadden, P

    1994-03-01

    All women find sexuality problematical, especially women living in countries that were colonized or colonized others. The stereotype of repressed sexuality in Victorian England found its antithesis in the stereotype of promiscuous African sexuality which had to be "civilized" and controlled through religion and repression. Colonizing nations have seen the discourse on sexuality move from the private to the public domain, while Africa maintains its silence on the subject. Sexuality is a difficult topic because it embraces the most intimate and individual of our human emotions, thus, it is difficult even to voice sexual preferences to a lifetime partner. In addition, especially in Africa, sexuality is a very gender-specific social construct. Africans foster heterosexuality through socialization from early childhood and discourage any sign of sexual stimulation in their children. After teaching that humans are "naturally" heterosexual, Africans teach their children that marriage is essential for the moral uprightness of society, although most Africans are, in fact, raised in many types of alternative families. Critique of the heterosexual form is literally nonexistent in African feminist genre because African sexuality is really male sexuality. When people assert that an African culture exists, they really mean that patriarchal constructs about maleness and femaleness pervade the continent. Women are not expected to experience sexual satisfaction, and, indeed, the practice of female genital mutilation assures that they will never experience sexual pleasure. This practice assures that female sexuality exists only through men. It represents a misogynist point of view about the female body and is equally repulsive whether it takes the form of "excision" of a part of the clitoris or removal of all of the external genitalia. This practice controls female sexuality by depriving women of the opportunity to masturbate or to engage in homosexual relations. The resulting option

  8. Afriphone Literature as a Prototypical Form of African Literature: Insights from Prototype Theory

    ERIC Educational Resources Information Center

    Bodomo, Adams

    2016-01-01

    What is the most prototypical form of African literature? Shouldn't we be using African languages to produce African literary texts, shouldn't we produce more Afriphone African literature compared to Europhone African literature or Afro-Europhone literature? This issue underlies the reality that the vast majority of African writers presumably…

  9. Pattern of breast cancer among white-American, African-American, and nonimmigrant west-African women.

    PubMed Central

    Ijaduola, T. G.; Smith, E. B.

    1998-01-01

    This study reviews the current understanding of the pattern of breast cancer among whites, African Americans, and West Africans who have never immigrated to the US to find better ways of improving the prevention, early detection, and care of breast cancer world-wide. In the United States, the behavior pattern of breast cancer in African-American women differs from that of white women. Among the three populations, breast cancer appears to be least common in nonimmigrant West-African women. The peak incidence in African Americans and West Africans occurs around the premenopausal period while it occurs postmenopausal period in whites. Also, unlike white women, West-African and African-American women present late for treatment with a greater cancer burden and consequently lower survival rates. The predominant histological type is infiltrating ductal carcinoma in the three groups but the highest percentage (33%) of infiltrating poorly differentiated anaplastic carcinoma occurs in West Africans. Menstrual and obstetric history, obesity, and high body mass index status appear to be greater specific risk factors among African Americans than among West Africans. African Americans and West Africans have three "Ls" in common: late stage in seeking treatment, lower age at peak incidence with severe tumor burden, and consequently lower survival rates. There is a need for more detailed population-based research at molecular levels to elucidate the basis for some of these features. PMID:9770955

  10. The African University and the Duty to Co-Operate.

    ERIC Educational Resources Information Center

    Agblemagnon, N'Sougan

    1984-01-01

    Because of their history rooted in human rights, African universities can now practically and politically undertake international and interinstitutional cooperative projects for human rights and intercultural understanding, especially through such alliances as the Association of African Universities. (MSE)

  11. Men of African Descent and Carcinoma of the Prostate Consortium

    Cancer.gov

    The Men of African Descent and Carcinoma of the Prostate Consortium collaborates on epidemiologic studies to address the high burden of prostate cancer and to understand the causes of etiology and outcomes among men of African ancestry.

  12. What about African Americans and High Blood Pressure?

    MedlinePlus

    ANSWERS by heart Lifestyle + Risk Reduction High Blood Pressure What About African Americans and High Blood Pressure? The prevalence of high blood pressure in African Americans is among the highest in ...

  13. Chemotherapy of human African trypanosomiasis.

    PubMed

    Burchmore, Richard J S; Ogbunude, Patrick O J; Enanga, Bertin; Barrett, Michael P

    2002-01-01

    Human African trypanosomiasis or sleeping sickness is resurgent [1,2]. The disease is caused by subspecies of the parasitic haemoflagellate, Trypanosoma brucei. Infection starts with the bite of an infected tsetse fly (Glossina spp.). Parasites move from the site of infection to the draining lymphatic vessels and blood stream. The parasites proliferate within the bloodstream and later invade other tissues including the central nervous system. Once they have established themselves within the CNS, a progressive breakdown of neurological function accompanies the disease. Coma precedes death during this late phase. Two forms of the disease are recognised, one caused by Trypanosoma brucei rhodesiense, endemic in Eastern and Southern Africa, in which parasites rapidly invade the CNS causing death within weeks if untreated. T. b. gambiense, originally described in West Africa, but also widespread in Central Africa, proliferates more slowly and can take several years before establishing a CNS-involved infection. Many countries are in the midst of epidemics caused by gambiense-type parasites. Four drugs have been licensed to treat the disease [3]; two of them, pentamidine and suramin, are used prior to CNS involvement. The arsenic-based drug, melarsoprol is used once parasites are established in the CNS. The fourth, eflornithine, is effective against late stage disease caused by T. b. gambiense, but is ineffective against T. b. rhodesiense. Another drug, nifurtimox is licensed for South American trypanosomiasis but also been used in trials against melarsoprol-refractory late sage disease. This review focuses on what is known about modes of action of current drugs and discusses targets for future drug development.

  14. KSC kicks off African-American History Month

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Clothed in her traditional African garb, Michelle Amos, mistress of ceremonies, welcomes the audience on Feb. 3 at the kick-off of African-American History Month. The theme for this year's observation is 'Heritage and Horizons: The African-American Legacy and the Challenges of the 21st Century.' February is designated each year as a time to celebrate the achievements and contributions of African Americans to Kennedy Space Center, NASA and the nation.

  15. Lift every voice: voices of African-American lesbian elders.

    PubMed

    Woody, Imani

    2015-01-01

    Old lesbians of African descent have experienced racism, heterosexism, homophobia, and ageism. This article explores the topics of aging, ageism, heterosexism, and minority stress among older African-American lesbians. The narratives and subsequent analysis offer significant contributions to the dialogue regarding Black aging lesbians in the aging and lesbian, gay, bisexual, and transgender (LGBT) communities generally and in the African-American and African-American lesbian communities specifically.

  16. Population Genomics of sub-saharan Drosophila melanogaster: African diversity and non-African admixture.

    PubMed

    Pool, John E; Corbett-Detig, Russell B; Sugino, Ryuichi P; Stevens, Kristian A; Cardeno, Charis M; Crepeau, Marc W; Duchen, Pablo; Emerson, J J; Saelao, Perot; Begun, David J; Langley, Charles H

    2012-01-01

    Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia), while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa F(ST) were found to be enriched in genomic regions of locally elevated

  17. Antineoplastic constituents of some Southern African plants.

    PubMed

    Charlson, A J

    1980-12-01

    Extracts of several Southern African plants which have been used in folk remedies have been prepared, and the extracts were tested in a variety of experimental tumour test-systems. Raphionacme hirsuta and Cheilanthes contracta have been used in African anticancer medicines. Extracts of these plants showed antitumor activity in some rodent test-systems, but the results were not confirmed. In the folk-lore, Haemanthus natalensis has been used in emetics and Urginea capitata preparations have been used to vaccinate African chiefs. Extracts of these plants showed significant cytotoxicity in the KB cell culture test-system. Infusions of Brunsvigia radulosa have been used as folk remedies for abdominal troubles. An extract of this Amaryllis plant increased the life span of P-388 leukaemic mice. Amaryllis bellandonna has also been investigated. Extracts of Amaryllis belladonna had to be fractionated in order to produce significant antitumour activity in the P-388 lymphocytic leukaemia test-system.

  18. IDEAL Symposium on the East African Lakes

    NASA Astrophysics Data System (ADS)

    Johnson, T. C.; Kelts, K.; Lehman, J. T.; Wuest, A.

    A vast array of interdisciplinary problems presented by the African Great Lakes were highlighted at the International Symposium on the Limnology, Climatology and Paleoclimatology of the East African Lakes, organized by the International Decade for the East African Lakes (IDEAL) February 17-21 in Jinja, Uganda. Approximately 125 scientists attended from North America, Europe, Africa, and New Zealand. Jinja is located on the northern shore of Lake Victoria at the head-waters of the Nile and is the site of the host institution for the symposium, the Uganda Freshwater Fisheries Research Organization (UFFRO). The conveners of the symposium were Tom Johnson of Duke University, George Kitaka of UNESCO-ROSTA, and Eric Odada of the University of Nairobi.

  19. Trichomonas vaginalis, HIV, and African-Americans.

    PubMed Central

    Sorvillo, F.; Smith, L.; Kerndt, P.; Ash, L.

    2001-01-01

    Trichomonas vaginalis may be emerging as one of the most important cofactors in amplifying HIV transmission, particularly in African-American communities of the United States. In a person co-infected with HIV, the pathology induced by T. vaginalis infection can increase HIV shedding. Trichomonas infection may also act to expand the portal of entry for HIV in an HIV-negative person. Studies from Africa have suggested that T. vaginalis infection may increase the rate of HIV transmission by approximately twofold. Available data indicate that T. vaginalis is highly prevalent among African-Americans in major urban centers of the United States and is often the most common sexually transmitted infection in black women. Even if T. vaginalis increases the risk of HIV transmission by a small amount, this could translate into an important amplifying effect since Trichomonas is so common. Substantial HIV transmission may be attributable to T. vaginalis in African-American communities of the United States. PMID:11747718

  20. Cancer statistics for African Americans, 2013.

    PubMed

    DeSantis, Carol; Naishadham, Deepa; Jemal, Ahmedin

    2013-05-01

    In this article, the American Cancer Society estimates the number of new cancer cases and deaths for African Americans and compiles the most recent data on cancer incidence, mortality, survival, and screening prevalence based upon incidence data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data from the National Center for Health Statistics. It is estimated that 176,620 new cases of cancer and 64,880 deaths will occur among African Americans in 2013. From 2000 to 2009, the overall cancer death rate among males declined faster among African Americans than whites (2.4% vs 1.7% per year), but among females, the rate of decline was similar (1.5% vs 1.4% per year, respectively). The decrease in cancer death rates among African American males was the largest of any racial or ethnic group. The reduction in overall cancer death rates since 1990 in men and 1991 in women translates to the avoidance of nearly 200,000 deaths from cancer among African Americans. Five-year relative survival is lower for African Americans than whites for most cancers at each stage of diagnosis. The extent to which these disparities reflect unequal access to health care versus other factors remains an active area of research. Overall, progress in reducing cancer death rates has been made, although more can and should be done to accelerate this progress through ensuring equitable access to cancer prevention, early detection, and state-of-the-art treatments.

  1. The management of hypertension in African Americans.

    PubMed

    Ferdinand, Keith C; Armani, Annemarie M

    2007-06-01

    The prevalence of hypertension in blacks in the United States is among the highest in the world. Compared with whites, blacks develop hypertension at an earlier age, their average blood pressures are much higher and they experience worse disease severity. Consequently, blacks have a 1.3 times greater rate of nonfatal stroke, 1.8 times greater rate of fatal stroke, 1.5 times greater rate of heart disease death, 4.2 times greater rate of end-stage kidney disease, and a 50% higher frequency of heart failure; overall, mortality due to hypertension and its consequences is 4 to 5 times more likely in African Americans than in whites. The increased prevalence of hypertension and excessive target organ damage is due to a combination of genetic and, most likely, environmental factors. There are no clinical trial data at present to suggest that lower-than-usual BP targets should be set for high-risk demographic groups such as African Americans. The primary means of prevention and early treatment of hypertension in African Americans will be the appropriate use of lifestyle modification. The International Society of Hypertension in Blacks guidelines realize that most patients will require combination therapy, many of them first-line, to reach appropriate BP goals. Although certain classes and combinations of antihypertensive agents have been well-established to be effective, the choice of drugs for combination therapy in African American patients may be different. Within the African American group, the responsiveness to monotherapy with ACE inhibitors, angiotensin receptor blockers, and beta blockers may be less than the responsiveness to diuretics and calcium channel blockers, but these differences are corrected when diuretics are added to the neurohormonal antagonists. Of note, African American patients with systolic BP >15 mm Hg or a diastolic BP >10 mm Hg above goal should be treated with first-line combination therapy.

  2. Assessing the contributions of East African and West Pacific warming to the 2014 boreal spring East African drought

    USGS Publications Warehouse

    Funk, Christopher C.; Shukla, Shraddhanand; Hoell, Andrew; Livneh, Ben

    2015-01-01

    Anthropogenic warming contributed to the 2014 East African drought by increasing East African and west Pacific temperatures, and increasing the gradient between standardized western and central Pacific SST causing reduced rainfall, evapotranspiration, and soil moisture.

  3. Oral Cancer in African Americans: Addressing Health Disparities

    ERIC Educational Resources Information Center

    Dodd, Virginia J.; Watson, Jennifer M.; Choi, Youjin; Tomar, Scott L.; Logan, Henrietta L.

    2008-01-01

    Objectives: To explore factors underlying African Americans' perceptions of oral cancer and the oral cancer exam. Study findings were used to guide development of oral cancer messages designed to increase oral cancer exams among African Americans. Methods: Focus groups were conducted to understand African Americans' attitudes and expectations…

  4. African American Acculturation and Black Racial Identity: A Preliminary Investigation.

    ERIC Educational Resources Information Center

    Pope-Davis, Donald B.; Liu, William M.; Ledesma-Jones, Shannon; Nevitt, Jonathan

    2000-01-01

    Examines the relationship between acculturation and racial identity among African Americans. One hundred eighty-seven African American students completed the Black Racial Identity Attitude Scale and the African American Acculturation Scale (AAAS). Acculturation was associated with three of the five AAAS subscales: Dissonance, Immersion, and…

  5. Exposure of African-American Youth to Alcohol Advertising.

    ERIC Educational Resources Information Center

    2003

    The marketing of alcohol products in African-American communities has, on occasion, stirred national controversy and met with fierce resistance from African Americans and others. Despite occasional media and community spotlights on the marketing of alcohol products in the African-American community, there has been no systematic review of the…

  6. Teaching African Politics at American Colleges and Universities: A Survey.

    ERIC Educational Resources Information Center

    Kenski, Henry C.; Kenski, Margaret C.

    Political scientists who teach African politics courses at U.S. colleges and universities were surveyed in 1973 to (1) discover successful teaching techniques, approaches, and texts; (2) determine the popularity of courses in African politics; and (3) collect data on the status of African politics as a research area. A questionnaire was mailed to…

  7. Neo-African Literature: A History of Black Writing.

    ERIC Educational Resources Information Center

    Jahn, Janheinz

    Chapters in this book classify the literature reflecting the overlap of African and Western cultures according to its content, stylistic features, and patterns of literary expression. Areas covered are (1) early writers of African descent; (2) the African scene--oral, Afro-Arabic, "apprentice" and "protest," and Southern Bantu literatures; (3) the…

  8. Exploring How African American Faculty Cope with Classroom Racial Stressors

    ERIC Educational Resources Information Center

    Pittman, Chavella T.

    2010-01-01

    This study was an examination of how African American faculty discussed their coping with racially stressful classrooms. Despite aims for racial equality in higher education, the classroom has been a significant site of racial stressors for African American facility. Analysis of interviews with 16 (8 women, 8 men) African American faculty at a…

  9. Engaging Youth through African-Derived Dance and Culture

    ERIC Educational Resources Information Center

    Franklin, Kikora

    2013-01-01

    This article provides a brief history of African and African-derived dance and culture and highlights the physical health, dance education, historical, and cultural benefits of a school-based program that incorporates African dance as its core component. The article also includes the phases of the programming and brings attention to potential…

  10. The Notion of Ubuntu and Communalism in African Educational Discourse

    ERIC Educational Resources Information Center

    Venter, Elza

    2004-01-01

    The notion of "ubuntu" and "communalism" is of great importance in an African educational discourse, as well as in African Philosophy of Education and in African philosophical discourse. "Ubuntu" is a philosophy that promotes the common good of society and includes humanness as an essential element of human growth. In…

  11. Achievement and Underachievement: The Experiences of African Caribbeans

    ERIC Educational Resources Information Center

    Rhamie, Jasmine

    2012-01-01

    The disproportionate representation of African Caribbeans in all the negative educational statistics has been well documented. Despite this, there are African Caribbeans who achieve academically but relatively few studies have explored this area. This study aimed to investigate the factors that contribute to African Caribbean academic success,…

  12. African-American Males' Health Perceptions and Knowledge

    ERIC Educational Resources Information Center

    McNeal, CoSandra; Perkins, Isaac; Lyons, Shenia

    2006-01-01

    Research on African American men's health is limited. Perception and knowledge of health may have a significant effect on health seeking behavior and self care. This study was designed to examine factors that may influence health perception and knowledge among African American males. This is a cross-sectional study of 343 African American males…

  13. Perceptions of Domestic Violence: A Dialogue with African American Women

    ERIC Educational Resources Information Center

    Bent-Goodley, Tricia B.

    2004-01-01

    Although empirical research has accumulated over the past 20 years regarding African Americans and domestic violence, many questions remain about African American perceptions of domestic violence. This article explores African American women's perceptions about domestic violence through three focus groups held at a New York social services agency.…

  14. African American Educational Leadership in the School Superintendency

    ERIC Educational Resources Information Center

    Smith, Eva C.

    2013-01-01

    African American educational leadership has long been part of American education and African American activism to resist oppression. However, the field of educational leadership has rarely included the contributions of African American leaders, particularly women leaders, into mainstream leadership theory and practices. This omission is difficult…

  15. Some Growth Points in African Child Development Research

    ERIC Educational Resources Information Center

    Serpell, Robert; Marfo, Kofi

    2014-01-01

    We reflect on ways in which research presented in earlier chapters responds to challenges of generating an African child development field and identify additional issues calling for the field's attention. The chapters collectively display a variety of African contexts and reflexive evidence of the authors' African cultural roots. Connecting…

  16. 77 FR 5375 - National African American History Month, 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... Documents#0;#0; ] Proclamation 8776 of January 31, 2012 National African American History Month, 2012 By the... for the better. During National African American History Month, we celebrate the rich legacy of... African American women are not limited to those recorded and retold in our history books. Their impact...

  17. 76 FR 6519 - National African American History Month, 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ... February 4, 2011 Part II The President Proclamation 8627--National African American History Month, 2011 #0..., 2011 National African American History Month, 2011 By the President of the United States of America A... breaking down barriers. During National African American History Month, we celebrate the vast...

  18. From Crisis to Empowerment: African American Women in Community Colleges

    ERIC Educational Resources Information Center

    Bates, Marcie Ann

    2012-01-01

    Social challenges tear at the fabric of the African American family, revealing complexities that identify a de facto leader, the African American woman. She exists in a chasm of overt circumstances which heavily influences her successes. The purpose of this study is to identify factors that motivated seven female African American community college…

  19. The African Storybook and Language Teacher Identity in Digital Times

    ERIC Educational Resources Information Center

    Stranger--Johannessen, Espen; Norton, Bonny

    2017-01-01

    The African Storybook (ASb) is a digital initiative that promotes multilingual literacy for African children by providing openly licenced children's stories in multiple African languages, as well as English, French, and Portuguese. Based on Darvin and Norton's (2015) model of identity and investment, and drawing on the Douglas Fir Group's (2016)…

  20. Barriers to Hospice Use among African Americans: A Systematic Review

    ERIC Educational Resources Information Center

    Washington, Karla T.; Bickel-Swenson, Denise; Stephens, Nathan

    2008-01-01

    The present review was undertaken to explore recent evidence in the professional literature pertaining to use of hospice services by African Americans. The article addresses the research methods that have been used to study African American hospice use, obstacles to African American participation in hospice that have been identified, and…

  1. Persistence among African American Males in the Honors College

    ERIC Educational Resources Information Center

    Anderson Goins, Johnell Roxann

    2014-01-01

    Retaining African American students, specifically African American males, is an issue that plagues the American higher education system. Research shows that African American male students are the lowest represented group in the gifted studies programs (Ford, 2010). Lockie and Burke (1999); Chen and DeJardins (2010) and Bell (2010a) found that…

  2. African American Males in Counseling: Who's Pulling the Trigger Now?

    ERIC Educational Resources Information Center

    Bethea-Whitfield, Patricia

    African American males face numerous challenges to their physical and psychological well-being. This project is a survey of the literature and trends relative to African American males from 1987 to the present. In reviewing the fifteen years since Parham and McDavis published their now famous article on African American men as an endangered…

  3. Student-Centered Designs of Pan-African Literature Courses

    ERIC Educational Resources Information Center

    M'Baye, Babacar

    2010-01-01

    A student-centered teaching methodology is an essential ingredient of a successful Pan-African literary course. In this article, the author defines Pan-Africanism and how to go about designing a Pan-African literature course. The author combines reading assignments with journals, film presentations, and lectures in a productive learning…

  4. Representing African American Women in U.S. History Textbooks

    ERIC Educational Resources Information Center

    Schocker, Jessica B.; Woyshner, Christine

    2013-01-01

    This article addresses the dearth of African American women in high school U.S. history textbooks. The authors conducted a content analysis of the images in an African American history textbook and found that black women are underrepresented. Women are found in less than 15 percent of the images in the African American history text, while they…

  5. Empowerment Groups for Urban African American Girls: A Response

    ERIC Educational Resources Information Center

    Holcomb-McCoy, Cheryl C.

    2005-01-01

    Although the author wanted to read Bemak, Chung, and Siroskey-Sabdo's article in an objective sense, her response to their article is most likely influenced by her own experiences as an African American female and mother of an African American daughter. To her, the paramount issue facing African American females is the double and sometimes triple…

  6. Women of African Descent: Persistence in Completing Doctorates

    ERIC Educational Resources Information Center

    Iddrisu, Vannetta Bailey

    2010-01-01

    This study examines the educational persistence of women of African descent (WOAD) in pursuit of a doctorate degree at universities in the southeastern United States. WOAD are women of African ancestry born outside the African continent. These women are heirs to an inner dogged determination and spirit to survive despite all odds (Pulliam, 2003,…

  7. Against the Wind: Five South Africans Follow Their Dreams.

    ERIC Educational Resources Information Center

    Lewis, Lesley

    This book for beginning readers tells the story of five South Africans who, though not very famous, all did things that no black South African had ever done before. They include: Simon Mkhize who, year after year, ran the Comrades Marathon unofficially, ignoring its racial bans; Magema M. Fuze, who was the first black South African to publish a…

  8. An Exploration of African American Students' Attitudes toward Online Learning

    ERIC Educational Resources Information Center

    Okwumabua, Theresa M.; Walker, Kristin M.; Hu, Xiangen; Watson, Andrea

    2011-01-01

    The current work presents exploratory research findings concerning African American students' attitudes toward online learning. The Online Tutoring Attitudes Scale (OTAS; Graff, 2003) was administered to 124 African American students in a positive youth development program. Findings suggest that African American students' attitudes toward…

  9. Perceived Attractiveness, Facial Features, and African Self-Consciousness.

    ERIC Educational Resources Information Center

    Chambers, John W., Jr.; And Others

    1994-01-01

    Investigated relationships between perceived attractiveness, facial features, and African self-consciousness (ASC) among 149 African American college students. As predicted, high ASC subjects used more positive adjectives in descriptions of strong African facial features than did medium or low ASC subjects. Results are discussed in the context of…

  10. African Education Research. Part One: Issues and Patterns.

    ERIC Educational Resources Information Center

    Bigelow, Ross Edgar

    This study of 416 African Education Research (AER) projects was conducted to: (a) provide information on current studies by Africans on African education; (b) provide a framework for critical analysis of research based on a classification of the issues; and (c) provide a listing and discussion of continuing research resources which would aid…

  11. Diversity and origin of South African chickens.

    PubMed

    Mtileni, B J; Muchadeyi, F C; Maiwashe, A; Chimonyo, M; Groeneveld, E; Weigend, S; Dzama, K

    2011-10-01

    The objectives of this study were to analyze the genetic diversity and structure of South African conserved and field chicken populations and to investigate the maternal lineages of these chicken populations. Four South African conserved chicken populations (n = 89), namely, Venda (VD_C), Ovambo, Naked Neck, and Potchefstroom Koekoek from the Animal Production Institute of the Agricultural Research Council, and 2 field populations, the Venda and Ovambo (OV_F), from which the Ovambo and the Venda conservation flocks were assumed to have been sampled, were genotyped for 460 bp of the mitochondrial DNA (mtDNA) D-loop sequence. Haplotypes of these chickens were aligned to 7 Japanese and 9 Chinese and Eurasian chicken mtDNA D-loop sequences taken from GenBank and reflecting populations from presumed centers of domestication. Sequence analysis revealed 48 polymorphic sites that defined 13 haplotypes in the South African chicken populations. All 6 South African conserved and field chicken populations observed were found to be polymorphic, with the number of haplotypes ranging from 3 for VD_C to 8 for OV_F. The lowest haplotype diversity, 0.54 ± 0.08, was observed in VD_C chickens, whereas the highest value, 0.88 ± 0.05, was observed in OV_F chickens. Genetic diversity between the 4 South African conserved and 2 field chicken populations constituted 12.34% of the total genetic variation, whereas within-population diversity constituted 87.66% of the total variation. The median network analysis of the mtDNA D-loop haplotypes observed in the South African conserved and field populations and the reference set resulted in 5 main clades. All 6 South African chickens were equally represented in the major clade, E, which is presumed to be of Indian subcontinent maternal origin and may have its roots in Southeast Asia. The results showed multiple maternal lineages of South African chickens. Conservation flocks and field chicken populations shared the major haplotypes A, D and E

  12. Mammary gland tumors in captive African hedgehogs.

    PubMed

    Raymond, J T; Gerner, M

    2000-04-01

    From December 1995 to July 1999, eight mammary gland tumors were diagnosed in eight adult captive female African hedgehogs (Atelerix albiventris). The tumors presented as single or multiple subcutaneous masses along the cranial or caudal abdomen that varied in size for each hedgehog. Histologically, seven of eight (88%) mammary gland tumors were malignant. Tumors were classified as solid (4 cases), tubular (2 cases), and papillary (2 cases). Seven tumors had infiltrated into the surrounding stroma and three tumors had histologic evidence of neoplastic vascular invasion. Three hedgehogs had concurrent neoplasms. These are believed to be the first reported cases of mammary gland tumors in African hedgehogs.

  13. E-Voting: A South African Perspective

    NASA Astrophysics Data System (ADS)

    Swanepoel, E.; Thomson, K.; van Niekerk, J. F.

    The South African democracy, despite being worthy of admiration, is in its infancy. As such its electoral processes still needs to be nurtured and protected. Since 1994 there has been four national elections. All of these have been declared "free and fair" by the Independent Electoral Commission. However, there has been some problems and growing pains. This paper firstly discusses the current electoral system in South Africa. It then examines E-voting systems and discusses the feasibility of such a voting system for use in the South African context.

  14. Navigational Strategies of Migrating Monarch Butterflies

    DTIC Science & Technology

    2014-11-10

    of navigational mechanisms in migrating insects has been presented (7). Archival publications (published) during reporting period: 1...navigational mechanisms in migratory insects . Curr Opin Neurobiol 22:353-361. Changes in research objectives, if any: None Change in AFOSR

  15. President, Prime Minister, or Constitutional Monarch?

    DTIC Science & Technology

    1989-10-01

    however, without test cases, and the President has always been an important initiator of test cases. 6 EUGENE V. RosTOw This paper is divided into...Judge Gerhard A. Gesell in the trial of Oliver North confirms, those two issues do not raise either constitutional or significant statutory questions...expired after sixty or ninety days if congress did nothing. Section 6 of the 1973 act was never tested , but it was generally thought to be unworkable. The

  16. The African VLBI network project

    NASA Astrophysics Data System (ADS)

    Loots, Anita

    2015-01-01

    larger teams in science, engineering and technology issues and collaborate with the broader global science community to develop new African radio astronomy science communities.

  17. Epidemiology of human African trypanosomiasis

    PubMed Central

    Franco, Jose R; Simarro, Pere P; Diarra, Abdoulaye; Jannin, Jean G

    2014-01-01

    Human African trypanosomiasis (HAT), or sleeping sickness, is caused by Trypanosoma brucei gambiense, which is a chronic form of the disease present in western and central Africa, and by Trypanosoma brucei rhodesiense, which is an acute disease located in eastern and southern Africa. The rhodesiense form is a zoonosis, with the occasional infection of humans, but in the gambiense form, the human being is regarded as the main reservoir that plays a key role in the transmission cycle of the disease. The gambiense form currently assumes that 98% of the cases are declared; the Democratic Republic of the Congo is the most affected country, with more than 75% of the gambiense cases declared. The epidemiology of the disease is mediated by the interaction of the parasite (trypanosome) with the vectors (tsetse flies), as well as with the human and animal hosts within a particular environment. Related to these interactions, the disease is confined in spatially limited areas called “foci”, which are located in Sub-Saharan Africa, mainly in remote rural areas. The risk of contracting HAT is, therefore, determined by the possibility of contact of a human being with an infected tsetse fly. Epidemics of HAT were described at the beginning of the 20th century; intensive activities have been set up to confront the disease, and it was under control in the 1960s, with fewer than 5,000 cases reported in the whole continent. The disease resurged at the end of the 1990s, but renewed efforts from endemic countries, cooperation agencies, and nongovernmental organizations led by the World Health Organization succeeded to raise awareness and resources, while reinforcing national programs, reversing the trend of the cases reported, and bringing the disease under control again. In this context, sustainable elimination of the gambiense HAT, defined as the interruption of the transmission of the disease, was considered as a feasible target for 2030. Since rhodesiense HAT is a zoonosis

  18. "Brothers Gonna Work It Out:" Understanding the Pedagogic Performance of African American Male Teachers Working with African American Male Students

    ERIC Educational Resources Information Center

    Brown, Anthony L.

    2009-01-01

    Drawing from ethnographic data, this paper explores how African American male teachers working with African American male students performed their pedagogy. This paper highlights how teachers' understanding of African American males social and educational needs shaped their pedagogical performance. Interestingly however, teachers' performance was…

  19. "Now the African reigns supreme": the rise of African boxing on the Witwatersrand, 1924-1959.

    PubMed

    Fleming, Tyler

    2011-01-01

    This essay explores the growth of boxing among the African populations on the Witwatersrand region of South Africa between 1924 and 1959. It details how the sport's jump in popularity with Africans paralleled migration to Johannesburg. Africans increasingly saw boxing as an activity and skill conducive with survival in this new environment, and thus the sport grew in popularity, stature, and skill-level amongst this emergent urban population. The essay further explores the various ways that the sport was disseminated and popularized during the era, thus detailing how the sport reached both the African masses and petit-bourgeois educated elite. As their presence in Johannesburg became more and more permanent, boxing came to encompass various meanings and ideals, such as notions of discipline, independence and civility, to these urban populations.

  20. The African Renaissance and its relation to the geosciences: a South African perspective

    NASA Astrophysics Data System (ADS)

    Mtimkulu, M. N.; Motloung, M.; Graham, I. T.; Eriksson, P. G.; Bumby, A. J.

    2001-08-01

    Implicit in the African Renaissance is the synergy between government, the private sector, the educated minority and the disadvantaged majority. For this concept to work, belief and commitment must arise first from the African individual, whatever his or her potential contribution may be. The geosciences in South Africa provide a currently vibrant example of such cooperation, which has the potential to contribute significantly to the upliftment of the country and its neighbouring states. Based largely on personal interviews with various role players, from the Presidency of South Africa, through ministerial levels, the corporate sector and down to the individual, we present a spectrum of viewpoints and initiatives which are starting to result in practical implementation of the African revival. An end to conflict and xenophobia, the entrenchment of democratic government and corporate expression of the entrepreneurial spirit are essential to provide the framework within which the individual African can become a "Renaissance Man or Woman".

  1. African-American mitochondrial DNAs often match mtDNAs found in multiple African ethnic groups

    PubMed Central

    Ely, Bert; Wilson, Jamie Lee; Jackson, Fatimah; Jackson, Bruce A

    2006-01-01

    Background Mitochondrial DNA (mtDNA) haplotypes have become popular tools for tracing maternal ancestry, and several companies offer this service to the general public. Numerous studies have demonstrated that human mtDNA haplotypes can be used with confidence to identify the continent where the haplotype originated. Ideally, mtDNA haplotypes could also be used to identify a particular country or ethnic group from which the maternal ancestor emanated. However, the geographic distribution of mtDNA haplotypes is greatly influenced by the movement of both individuals and population groups. Consequently, common mtDNA haplotypes are shared among multiple ethnic groups. We have studied the distribution of mtDNA haplotypes among West African ethnic groups to determine how often mtDNA haplotypes can be used to reconnect Americans of African descent to a country or ethnic group of a maternal African ancestor. The nucleotide sequence of the mtDNA hypervariable segment I (HVS-I) usually provides sufficient information to assign a particular mtDNA to the proper haplogroup, and it contains most of the variation that is available to distinguish a particular mtDNA haplotype from closely related haplotypes. In this study, samples of general African-American and specific Gullah/Geechee HVS-I haplotypes were compared with two databases of HVS-I haplotypes from sub-Saharan Africa, and the incidence of perfect matches recorded for each sample. Results When two independent African-American samples were analyzed, more than half of the sampled HVS-I mtDNA haplotypes exactly matched common haplotypes that were shared among multiple African ethnic groups. Another 40% did not match any sequence in the database, and fewer than 10% were an exact match to a sequence from a single African ethnic group. Differences in the regional distribution of haplotypes were observed in the African database, and the African-American haplotypes were more likely to match haplotypes found in ethnic groups from

  2. African-American women and abortion: a neglected history.

    PubMed

    Ross, L J

    1992-01-01

    The history of African-American women's efforts to control their fertility is largely unknown. From slavery to the present, the growth rate of the African-American population has been cut in half. Demographers and historians frequently attribute this change to external factors such as poverty, disease, and coerced birth control, rather than the deliberate agency of African-American women. This essay assembles a brief historical record of the ways African-American women have sought to control their fertility through the use of abortion and birth control. It also examines the activism of African-American women in the establishment of family planning clinics and in defense of abortion rights.

  3. An Exploration of African Students in Malaysia

    ERIC Educational Resources Information Center

    Lian, Irene Tan Ai

    2011-01-01

    The exploratory study is an attempt to understand the reasons that prompted African students to study in Malaysia, the challenges encountered and the coping strategies used. The research on such topics among international students is well documented, but studies on international students in Malaysia are scarce. The sample included 155 African…

  4. Dissecting the genetic diversity in African rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    African cultivated rice, Oryza glaberrima, and its progenitor, O. barthii are excellent sources of important genes for rice improvement because they exhibit tolerance to several abiotic and biotic stresses. Development of advance backcross (ABC) populations between an unadapted donor parent and ada...

  5. Toward Understanding Korean and African American Relations.

    ERIC Educational Resources Information Center

    Chang, Edward Taehan

    1996-01-01

    Presents a lesson plan that examines the economic, cultural, and ideological factors that influence Korean and African American relations. Discusses how the two groups perceive each other and situates the role of race and class in this relationship. Includes informational handouts and discussion questions. (MJP)

  6. Art exhibit focuses on African astronomy

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-07-01

    Connections between Africans and astronomy are the focus of a new exhibition in the National Museum of African Art in Washington, D. C. "African Cosmos: Stellar Arts," which includes artwork, cultural items, and scientific displays from ancient to contemporary times, is the first major exhibit "that brings together arts and science focused on Africa's contribution to keen observations of the heavens over time," curator Christine Mullen Kreamer said at a 20 June news briefing. Among the exhibit's nearly 100 objects are an ancient Egyptian mummy board that includes a representation of the sky goddess Nut, sculptures by the Dogon people of Mali depicting figures in relation to the cosmos, a video that uses data from two square degrees of the Hubble Space Telescope Cosmic Evolution Survey, and a nearly floor-to-ceiling "Rainbow Serpent" constructed of plastic containers by Benin artist Hazoume. An untitled acrylic painting (Figure 1) by South African Gavin Jantjes evokes a myth of the Khoi San people of southern Africa, as it portrays a girl throwing evening fire embers into the night sky, where they remained as the Milky Way.

  7. In Pursuit of African Scholarship: Unpacking Engagement

    ERIC Educational Resources Information Center

    O'Brien, Frances

    2009-01-01

    Engagement between higher education and other societal sectors is a key theme in higher education discourse in South Africa, as it is in other countries. In South Africa, however, engagement has gained additional status as an appropriate strategy for pursuing African Scholarship. On the ground, however, inequitable power relationships and erratic…

  8. French-African Cultures: A Resource Unit.

    ERIC Educational Resources Information Center

    Forbes, Barbara

    This resource unit concerns French-African cultures and their influence on other cultures. The materials may be incorporated into Levels 3, 4, and 5 French classes. Topics in the outline include environmental aspects; historical background; and cultural differences expressed in Senegal, Guinee, Mali, Cote d'Ivoire, Haute Volta, Togo, Dahomey,…

  9. Liberty in African and Western Thought.

    ERIC Educational Resources Information Center

    Mudimbe, V. Y.

    The theoretical African mode of thinking about liberty seems to stand in contrast to the view of liberty that has dominated Western philosophy. Western philosophy accepts as its starting point the notion of an unconstrained and uncontextualized "I" that is defined in relation to the self and its inner being. Greek, Cartesian, and…

  10. Contemporary Sexism in the South African Navy

    ERIC Educational Resources Information Center

    Van Wijk, Charles H.

    2011-01-01

    The military traditionally embraces highly sexist attitudes. Over the past decade, the South African Navy (SAN) has been exposed to an increasingly progressive political environment. This study investigated contemporary expressions of sexism in the SAN. A representative sample of 476 sailors completed the Ambivalent Sexism Inventory, Modern Sexism…

  11. African and Pacific Literature: A Comparative Study.

    ERIC Educational Resources Information Center

    Martin, Kristine L.

    Literary writing in Africa and the Pacific addresses themes that reflect colonial experience and the struggles of newly independent nations to cope with change and conflicts between traditional and modern existence. The novels of Chinua Achebe of Nigeria and Ngugi Wa Thiong'o of Kenya illustrate many dominant themes of African literature. Achebe…

  12. City Children in African Children's Literature.

    ERIC Educational Resources Information Center

    Kuntz, Patricia S.

    A descriptive study identified titles and features of children's books set in an African city. Data were collected from various reviews of children's literature for titles published since 1980. In addition, the Cooperative Children's Book Center's log list of acquired titles for Africa from 1990 to 1996 was reviewed. Results showed that authors…

  13. One African Male in Higher Education

    ERIC Educational Resources Information Center

    Nichols, Robert L.

    2016-01-01

    Many predominantly White universities and colleges are seeking ways to both recruit and retain Black students (Simmons, J., Lowery-Hart, R., Wahl, S. T., & McBride, M. C. (2013). "Understanding the African-American student experience in higher education through a relational dialectics perspective." "Communication…

  14. Allocation of Students in North African Universities.

    ERIC Educational Resources Information Center

    Jones, Marie Thourson

    1981-01-01

    Student bodies at public universities in Morocco, Algeria, and Tunisia have grown rapidly, outside the direct control of university authorities. How the three North African nations differ in their policies regulating which students may study which subjects, and the implications of these policies for the goals of higher education are discussed.…

  15. African-American Axioms and Maxims.

    ERIC Educational Resources Information Center

    Zulu, Itibari M.

    1998-01-01

    Examines and describes 30 African-American centered quotation and motivational books, all but one of which were published between 1993 and 1997. The books articulate a diversity of genres and themes. Annotations are divided into: (1) general quotation; (2) daily words and meditation/motivation sources; (3) religion and theology; and (4)…

  16. Gravimetric maps of the Central African Republic

    NASA Technical Reports Server (NTRS)

    Albouy, J.; Godivier, R. (Principal Investigator)

    1982-01-01

    Gravimetric maps of the Central African Republic are described including a map of Bouguer anomalies at 1/1,000,000 in two sections (eastern sheet, western sheet) and a map, in color, of Bouguer anomalies at 1/2,000,000. Instrumentation, data acquisition, calibration, and data correction procedures are discussed.

  17. Reconceptualization of African American Self-Concept.

    ERIC Educational Resources Information Center

    Braithwaite, Harold, Jr.; And Others

    1994-01-01

    Focuses on how African American students define self-concept, and whether there is a specific black self-concept. Questionnaires completed by 60 undergraduates at a historically black college provide insight into student self-esteem and support the existence of a specific black self-concept. (SLD)

  18. African American's Perceptions of Psychotherapy and Psychotherapists.

    ERIC Educational Resources Information Center

    Thompson, Vetta L. Sanders; Akbar, Maysa D.; Bazile, Anita

    The attitudes and beliefs about utilization of mental health services of 201 African Americans, 18 years and older, are explored. One hundred and thirty-four females and 66 males participated in mixed sex focus groups conducted in an urban, Midwestern city. Discussion probes addressed participant perceptions of psychotherapists and psychotherapy,…

  19. Growing Up African American in Catholic Schools.

    ERIC Educational Resources Information Center

    Irvine, Jacqueline Jordan, Ed.; Foster, Michele, Ed.

    Contributors to this volume use their own stories to demonstrate success of one institution, the Catholic school system, in educating many African Americans who have gone on to make important contributions to the community. Their own experiences are the starting points for their reflections on the historical and sociological treatment of the…

  20. Colorectal Cancer in African Americans: An Update

    PubMed Central

    Williams, Renee; White, Pascale; Nieto, Jose; Vieira, Dorice; Francois, Fritz; Hamilton, Frank

    2016-01-01

    This review is an update to the American College of Gastroenterology (ACG) Committee on Minority Affairs and Cultural Diversity's paper on colorectal cancer (CRC) in African Americans published in 2005. Over the past 10 years, the incidence and mortality rates of CRC in the United States has steadily declined. However, reductions have been strikingly much slower among African Americans who continue to have the highest rate of mortality and lowest survival when compared with all other racial groups. The reasons for the health disparities are multifactorial and encompass physician and patient barriers. Patient factors that contribute to disparities include poor knowledge of benefits of CRC screening, limited access to health care, insurance status along with fear and anxiety. Physician factors include lack of knowledge of screening guidelines along with disparate recommendations for screening. Earlier screening has been recommended as an effective strategy to decrease observed disparities; currently the ACG and American Society of Gastrointestinal Endoscopists recommend CRC screening in African Americans to begin at age 45. Despite the decline in CRC deaths in all racial and ethnic groups, there still exists a significant burden of CRC in African Americans, thus other strategies including educational outreach for health care providers and patients and the utilization of patient navigation systems emphasizing the importance of screening are necessary. These strategies have been piloted in both local communities and Statewide resulting in notable significant decreases in observed disparities. PMID:27467183

  1. African Socialism and Educational Practice. Draft.

    ERIC Educational Resources Information Center

    Draisma, Tom

    The relationship between the secondary education system and wider political, economic, and sociocultural developments in Africa is examined. Special emphasis is given to the problems of political ideology and education in Zambia; but as Zambian socialist ideology and educational history show similarities to other African nations, the author's…

  2. Wages and Labor Management in African Manufacturing

    ERIC Educational Resources Information Center

    Fafchamps, Marcel; Soderbom, Mans

    2006-01-01

    Using matched employer-employee data from ten African countries, we examine the relationship between wages, worker supervision, and labor productivity in manufacturing. Wages increase with firm size for both production workers and supervisors. We develop a two-tier model of supervision that can account for this stylized fact and we fit the…

  3. African Universities Tackle the Continent's Agricultural Crisis

    ERIC Educational Resources Information Center

    Lindow, Megan

    2009-01-01

    Pests, population growth, and depleted soil have wreaked havoc on agriculture in Africa, so universities across the continent are rethinking how they teach the topic. Some African universities have been building their own networks and pooling their limited resources to train more agricultural scientists and improve their responsiveness to the…

  4. African rainforests: past, present and future

    PubMed Central

    Malhi, Yadvinder; Adu-Bredu, Stephen; Asare, Rebecca A.; Lewis, Simon L.; Mayaux, Philippe

    2013-01-01

    The rainforests are the great green heart of Africa, and present a unique combination of ecological, climatic and human interactions. In this synthesis paper, we review the past and present state processes of change in African rainforests, and explore the challenges and opportunities for maintaining a viable future for these biomes. We draw in particular on the insights and new analyses emerging from the Theme Issue on ‘African rainforests: past, present and future’ of Philosophical Transactions of the Royal Society B. A combination of features characterize the African rainforest biome, including a history of climate variation; forest expansion and retreat; a long history of human interaction with the biome; a relatively low plant species diversity but large tree biomass; a historically exceptionally high animal biomass that is now being severely hunted down; the dominance of selective logging; small-scale farming and bushmeat hunting as the major forms of direct human pressure; and, in Central Africa, the particular context of mineral- and oil-driven economies that have resulted in unusually low rates of deforestation and agricultural activity. We conclude by discussing how this combination of factors influences the prospects for African forests in the twenty-first century. PMID:23878339

  5. West African Folktales [and] Instructor's Manual.

    ERIC Educational Resources Information Center

    Gale, Steven H.

    Traditionally, an important function of folktales in West Africa has been to educate, as the older generation imparts knowledge to younger members of the family, tribe, societal unit, or ethnic group both informally in everyday life and more formally within the context of the bush schools. This anthology of West African folk literature offers more…

  6. African American College Women's Suicide Buffers.

    ERIC Educational Resources Information Center

    Marion, Michelle S.; Range, Lillian M.

    2003-01-01

    To examine the relationships buffers may have with suicide ideation, 300 African American female college students completed measures of suicide ideation and buffers. Three variables accounted for a significant and unique portion of the variance in suicide ideation: family support, a view that suicide is unacceptable, and a collaborative religious…

  7. The African Heritage in Spanish Caribbean Literature.

    ERIC Educational Resources Information Center

    Smart, Ian I.

    1981-01-01

    Uses Fanon's concept of the Manichean colonial situation and his Dialectical Theory of Identification to explore images of African heritage in the works of two mulatto Cuban poets, Gabriel de la Concepcion Valdez (1809-1844) and Nicolas Guillen (born 1902). (GC)

  8. Competency Development of Southern African Housing Officers

    ERIC Educational Resources Information Center

    Dunn, Munita; Dunkel, Norbert W.

    2013-01-01

    The Report on the Ministerial Committee for the Review of the Provision of Student Housing at South African Universities (Department of Higher Education and Training, 2011) has provided a comprehensive review of residences across several housing functional areas. In one of the residence management and administration recommendations it stated,…

  9. Intertextuality in EAP: An African Context

    ERIC Educational Resources Information Center

    Holmes, John

    2004-01-01

    This paper focuses on the development of EAP methodology within an African EAP context. I describe the setting up and implementation of an EAP study skills programme at the University of Asmara, Eritrea, over the period 1994-1998 and its subsequent development up to 2002. The unique social and political context of the EAP programme served as a…

  10. African Theatre and the University of Leeds

    ERIC Educational Resources Information Center

    Banham, Martin; Plastow, Jane

    2006-01-01

    This paper discusses the impact that teaching and research on African theatre in the Workshop Theatre of the University of Leeds' School of English may have had in Africa and elsewhere. After surveying the productivity and influence of the Workshop Theatre to the present, the authors ask if they have contributed meaningfully to the development,…

  11. African American Women Counselors, Wellness, and Spirituality

    ERIC Educational Resources Information Center

    Knowles, Debora; Bryant, Rhonda M.

    2011-01-01

    Given their tremendous professional responsibilities, professional counselors face daunting challenges to remaining healthy and avoiding role stress and overload. This article explores the intersection of race, gender, wellness, and spirituality in the self-care of African American women counselors. The authors give particular attention to…

  12. 2000 African American History Month Celebration Luncheon

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Early Space Exploration Conference Center at the KSC Visitor Complex, Dr. Julian M. Earls (left), deputy director for Operations, Glenn Research Center, receives a plaque from astronaut Joan Higginbotham (right) during the 2000 African American History Month Celebration Luncheon. Dr. Earls was guest speaker at the luncheon.

  13. 2000 African American History Month Celebration Luncheon

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Early Space Exploration Conference Center at the KSC Visitor Complex, the planning committee for the 2000 African American History Month Celebration Luncheon gather in the lobby. At the far left is Mack McKinney, chief, Programs Resources Management, who was chairperson for the event.

  14. 2000 African American History Month Celebration Luncheon

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Mack McKinney (left), chief, Programs Resources Management, and Delores Abraham (right), with the Astronaut office, flank one of the posters decorating the Early Space Exploration Conference Center at the KSC Visitor Complex for the 2000 African American History Month Celebration Luncheon. McKinney is chairperson for the event.

  15. African Higher Education: An International Reference Handbook.

    ERIC Educational Resources Information Center

    Teferra, Damtew, Ed.; Altbach, Philip G., Ed.

    This book is a comprehensive survey of all aspects and dimensions of higher education in Africa. It includes a historical overview of higher education, descriptions of the higher education systems in each African country, and analyses of current and timely topics in higher education. Part 1, "Themes," contains 13 essays on trends in…

  16. Violent Behaviors among African-American Adolescents.

    ERIC Educational Resources Information Center

    Garrett, Darhyl

    1995-01-01

    Explores the development of behaviors by using Erik Erikson's psychosocial developmental theory, with emphasis on adolescents. Examines factors, such as identity versus identity diffusion, that may be contributing to increasing acts of violence by African American adolescents. Other factors are examined that may contribute to increased violence.…

  17. African American Female Superintendents: Resilient School Leaders

    ERIC Educational Resources Information Center

    Johnson, Bernadeia H.

    2012-01-01

    Six African American female superintendents who had served as superintendents in at least 2 school districts were interviewed to understand ways in which they responded to barriers and adversity in their roles, with a particular emphasis on issues related to sexism and racism. Study participants shared that they work to engage the community and…

  18. African-American Males: Education or Incarceration.

    ERIC Educational Resources Information Center

    Green, Robert L.

    This paper analyzes the relationship between levels of educational attainment and outcomes for African American males, in particular the likelihood of conflict with the criminal justice system. The analysis begins with a look at society's belief system and political and economic forces, and argues that these have combined to promote failure among…

  19. Adult Illiteracy: The Root of African Underdevelopment

    ERIC Educational Resources Information Center

    Jogwu, C. N. O.

    2010-01-01

    All African Nations belong to the category of third world underdeveloped countries of the world. UNDP Human Development Index uses factors like per capita income, health of the people, and educational attainment to classify countries. Adult literacy and gross enrolment ratios are indicators of education status. This paper uses Nigeria, a typical…

  20. Promotive Parenting Practices among African American Mothers

    ERIC Educational Resources Information Center

    Williams-Wheeler, Meeshay

    2011-01-01

    The purpose of this study was to examine communication/reasoning, behavioral control, and trust as predictors of resourcefulness among African American children during middle childhood (6-12 years of age). Mothers who practice promotive socialization strategies are more likely to rear children who are socially competent and well adjusted. Multiple…

  1. Five Types of African-American Marriages.

    ERIC Educational Resources Information Center

    Allen, William D.; Olson, David H.

    2001-01-01

    Developed a marital typology based on a nonrandom, national sample of 415 African American couples who took the Enriching Relationship Issues, Communication and Happiness (ENRICH) marital assessment inventory. Five marriage types were labeled as vitalized; harmonious; traditional; conflicted; and devitalized. Results were similar to findings in…

  2. African Drum and Steel Pan Ensembles.

    ERIC Educational Resources Information Center

    Sunkett, Mark E.

    2000-01-01

    Discusses how to develop both African drum and steel pan ensembles providing information on teacher preparation, instrument choice, beginning the ensemble, and lesson planning. Includes additional information for the drum ensembles. Lists references and instructional materials, sources of drums and pans, and common note layout/range for steel pan…

  3. The African Experience with Higher Education.

    ERIC Educational Resources Information Center

    Ajayi, J. F. Ade; And Others

    This book covers the history and politics of higher education in Africa south of the Sahara, as well as contemporary issues, problems, and weaknesses of African universities. The need for a new look at the mission of the university in the 21st century is also addressed. Chapters cover the following topics: (1) higher education in Africa before…

  4. African American Homeschooling Practices: Empirical Evidence

    ERIC Educational Resources Information Center

    Mazama, Ama

    2016-01-01

    Despite a significant increase in scholarly interest for homeschooling, some of its most critical aspects, such as instructional daily practices, remain grossly understudied. This essay thus seeks to fill that void by presenting empirical evidence regarding the homeschooling practices of a specific group, African Americans. Most specifically, the…

  5. The landscape of recombination in African Americans

    PubMed Central

    Hinch, Anjali G.; Tandon, Arti; Patterson, Nick; Song, Yunli; Rohland, Nadin; Palmer, Cameron D.; Chen, Gary K.; Wang, Kai; Buxbaum, Sarah G.; Akylbekova, Meggie; Aldrich, Melinda C.; Ambrosone, Christine B.; Amos, Christopher; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; Blot, William J.; Bock, Cathryn H.; Boerwinkle, Eric; Cai, Qiuyin; Caporaso, Neil; Casey, Graham; Cupples, L. Adrienne; Deming, Sandra L.; Diver, W. Ryan; Divers, Jasmin; Fornage, Myriam; Gillanders, Elizabeth M.; Glessner, Joseph; Harris, Curtis C.; Hu, Jennifer J.; Ingles, Sue A.; Isaacs, Williams; John, Esther M.; Kao, W. H. Linda; Keating, Brendan; Kittles, Rick A.; Kolonel, Laurence N.; Larkin, Emma; Le Marchand, Loic; McNeill, Lorna H.; Millikan, Robert C.; Murphy, Adam; Musani, Solomon; Neslund-Dudas, Christine; Nyante, Sarah; Papanicolaou, George J.; Press, Michael F.; Psaty, Bruce M.; Reiner, Alex P.; Rich, Stephen S.; Rodriguez-Gil, Jorge L.; Rotter, Jerome I.; Rybicki, Benjamin A.; Schwartz, Ann G.; Signorello, Lisa B.; Spitz, Margaret; Strom, Sara S.; Thun, Michael J.; Tucker, Margaret A.; Wang, Zhaoming; Wiencke, John K.; Witte, John S.; Wrensch, Margaret; Wu, Xifeng; Yamamura, Yuko; Zanetti, Krista A.; Zheng, Wei; Ziegler, Regina G.; Zhu, Xiaofeng; Redline, Susan; Hirschhorn, Joel N.; Henderson, Brian E.; Taylor, Herman A.; Price, Alkes L.; Hakonarson, Hakon; Chanock, Stephen J.; Haiman, Christopher A.; Wilson, James G.; Reich, David; Myers, Simon R.

    2011-01-01

    Recombination, together with mutation, is the ultimate source of genetic variation in populations. We leverage the recent mixture of people of African and European ancestry in the Americas to build a genetic map measuring the probability of crossing-over at each position in the genome, based on about 2.1 million crossovers in 30,000 unrelated African Americans. At intervals of more than three megabases it is nearly identical to a map built in Europeans. At finer scales it differs significantly, and we identify about 2,500 recombination hotspots that are active in people of West African ancestry but nearly inactive in Europeans. The probability of a crossover at these hotspots is almost fully controlled by the alleles an individual carries at PRDM9 (P<10−245). We identify a 17 base pair DNA sequence motif that is enriched in these hotspots, and is an excellent match to the predicted binding target of African-enriched alleles of PRDM9. PMID:21775986

  6. Tuberculosis Detection by Giant African Pouched Rats

    ERIC Educational Resources Information Center

    Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

    2011-01-01

    In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

  7. Prostate Cancer Genetics in African Americans

    DTIC Science & Technology

    2014-09-01

    receiving appropriate education, genetic counseling , and/or referral. During each interview the research coordinator identifies at risk family members...AD_________________ Award Number: W81XWH-11-1-0566 TITLE: Prostate Cancer Genetics in African...ADDRESS. 1. REPORT DATE 2. REPORT TYPE Annual 3. DATES COVERED 15 Aug 2013 – 14 Aug 2014 4. TITLE AND SUBTITLE Prostate Cancer Genetics in

  8. Caring School Leadership: A South African Study

    ERIC Educational Resources Information Center

    van der Vyver, Cornelius P.; van der Westhuizen, Philip C.; Meyer, L. W.

    2014-01-01

    The research pivoted on the question whether South African school principals fulfilled their caring role towards teachers. The aims of the study were threefold. First, to determine how principals rated their care-giving, secondly to determine whether significant discrepancies existed between principals' rating of their care-giving and teachers'…

  9. Endometrial polyps in 2 African pygmy hedgehogs.

    PubMed

    Phillips, Irene D; Taylor, Jacqueline J; Allen, Andrew L

    2005-06-01

    Reports of spontaneously occurring endometrial polyps in animals are rare and have only involved a few species. This report is intended to advise veterinarians that older African pygmy hedgehogs may develop endometrial polyps and that these lesions can be a cause of bloody vaginal discharge, sometimes interpreted as hematuria.

  10. African Trypanosomes Find a Fat Haven

    PubMed Central

    Beverley, Stephen M.

    2016-01-01

    The African trypanosome was thought to primarily develop in the bloodstream and interstitial spaces of its mammalian host. In this issue of Cell Host & Microbe, Trindade et al. (2016) report the surprising finding that during ongoing persistent infections in mice, a major fraction of the parasites reside within fatty tissues. PMID:27281564

  11. African Linguistics. Working Papers in Linguistics 19.

    ERIC Educational Resources Information Center

    University of Trondheim Working Papers in Linguistics, 1993

    1993-01-01

    Five papers on African linguistics are presented. "Observations on Some Derivational Affixes in Kiswahili Predicate Items" (Assibi Apatewon Amidu) examines the few morphemes recognized in the Swahili derivational affix system and suggests changes in the rules of vowel harmony and in presentation and representation of the affixes in use.…

  12. Legacy of a Pioneer African American Educator

    ERIC Educational Resources Information Center

    Cazers, Gunars; Curtner-Smith, Matthew

    2013-01-01

    Purpose: The purpose was to reconstruct the historical and legendary contribution of one exemplary African American physical education teacher educator who lived and worked in the Deep South prior to and immediately following the 1954 Brown v. Board of Education court case. The following questions guided data collection and analysis: To what…

  13. African Women in the Visual Arts.

    ERIC Educational Resources Information Center

    Aronson, Lisa

    1991-01-01

    Explores recent studies in anthropology, art history, and archeology on African women's art from a feminist theoretical perspective. Relates women's arts to several sociological and economic factors and suggests new avenues of exploration, especially in the face of urbanization and modernization. (CJS)

  14. The landscape of recombination in African Americans.

    PubMed

    Hinch, Anjali G; Tandon, Arti; Patterson, Nick; Song, Yunli; Rohland, Nadin; Palmer, Cameron D; Chen, Gary K; Wang, Kai; Buxbaum, Sarah G; Akylbekova, Ermeg L; Aldrich, Melinda C; Ambrosone, Christine B; Amos, Christopher; Bandera, Elisa V; Berndt, Sonja I; Bernstein, Leslie; Blot, William J; Bock, Cathryn H; Boerwinkle, Eric; Cai, Qiuyin; Caporaso, Neil; Casey, Graham; Cupples, L Adrienne; Deming, Sandra L; Diver, W Ryan; Divers, Jasmin; Fornage, Myriam; Gillanders, Elizabeth M; Glessner, Joseph; Harris, Curtis C; Hu, Jennifer J; Ingles, Sue A; Isaacs, William; John, Esther M; Kao, W H Linda; Keating, Brendan; Kittles, Rick A; Kolonel, Laurence N; Larkin, Emma; Le Marchand, Loic; McNeill, Lorna H; Millikan, Robert C; Murphy, Adam; Musani, Solomon; Neslund-Dudas, Christine; Nyante, Sarah; Papanicolaou, George J; Press, Michael F; Psaty, Bruce M; Reiner, Alex P; Rich, Stephen S; Rodriguez-Gil, Jorge L; Rotter, Jerome I; Rybicki, Benjamin A; Schwartz, Ann G; Signorello, Lisa B; Spitz, Margaret; Strom, Sara S; Thun, Michael J; Tucker, Margaret A; Wang, Zhaoming; Wiencke, John K; Witte, John S; Wrensch, Margaret; Wu, Xifeng; Yamamura, Yuko; Zanetti, Krista A; Zheng, Wei; Ziegler, Regina G; Zhu, Xiaofeng; Redline, Susan; Hirschhorn, Joel N; Henderson, Brian E; Taylor, Herman A; Price, Alkes L; Hakonarson, Hakon; Chanock, Stephen J; Haiman, Christopher A; Wilson, James G; Reich, David; Myers, Simon R

    2011-07-20

    Recombination, together with mutation, gives rise to genetic variation in populations. Here we leverage the recent mixture of people of African and European ancestry in the Americas to build a genetic map measuring the probability of crossing over at each position in the genome, based on about 2.1 million crossovers in 30,000 unrelated African Americans. At intervals of more than three megabases it is nearly identical to a map built in Europeans. At finer scales it differs significantly, and we identify about 2,500 recombination hotspots that are active in people of West African ancestry but nearly inactive in Europeans. The probability of a crossover at these hotspots is almost fully controlled by the alleles an individual carries at PRDM9 (P value < 10(-245)). We identify a 17-base-pair DNA sequence motif that is enriched in these hotspots, and is an excellent match to the predicted binding target of PRDM9 alleles common in West Africans and rare in Europeans. Sites of this motif are predicted to be risk loci for disease-causing genomic rearrangements in individuals carrying these alleles. More generally, this map provides a resource for research in human genetic variation and evolution.

  15. Prevalence of Stuttering in African American Preschoolers

    ERIC Educational Resources Information Center

    Proctor, Adele; Yairi, Ehud; Duff, Melissa C.; Zhang, Jie

    2008-01-01

    Purpose: In this study, the authors sought to determine the prevalence of stuttering in African American (AA) 2- to 5-year-olds as compared with same-age European Americans (EAs). Method: A total of 3,164 children participated: 2,223 AAs and 941 EAs. Data were collected using a 3-pronged approach that included investigators' individual…

  16. Myths in African Concept of Reality

    ERIC Educational Resources Information Center

    Jaja, Jones M.

    2014-01-01

    Myths are accounts of the origin of societies and institutions not subject to rationalization but often used by historians and philosophers in their quest to study African history; for it is only thus that we can comprehend the various aspects of the continent's history and culture. This paper examines the critical understanding of African…

  17. Cataloging the Pan-African Experience

    ERIC Educational Resources Information Center

    Hayes, Dianne

    2012-01-01

    Of all the honors and accolades bibliophile and noted authority on the Underground Railroad Charles Blockson has received, being bequeathed recently with some of Harriet Tubman's personal items by her great-niece is one of the most significant experiences of his life. A longtime collector of books and rare items by and about African-Americans,…

  18. African American Biographies: A Collection Development Challenge.

    ERIC Educational Resources Information Center

    Woody, Donna

    2000-01-01

    Discusses the lack of African American biographies for elementary school libraries and reports the results of a study that surveyed publishers from the Children's Book Council. Examines book reviews, discusses the number of sports figures included, and considers problems with a lack of appropriate materials to support the curriculum. (LRW)

  19. Language and the African American Child

    ERIC Educational Resources Information Center

    Green, Lisa J.

    2011-01-01

    How do children acquire African American English? How do they develop the specific language patterns of their communities? Drawing on spontaneous speech samples and data from structured elicitation tasks, this book explains the developmental trends in the children's language. It examines topics such as the development of tense/aspect marking,…

  20. The Persistence of African American College Men

    ERIC Educational Resources Information Center

    Beale, Tyson J.

    2010-01-01

    This study explored the family dynamics of persistent African American college men. These students were typical Black males, not those pre-categorized as high-achieving or unprepared for college. The stories of participants revealed their strength, ambition, and intentions to successfully gain a baccalaureate degree. In general Black males are…

  1. Dictionaries of African Sign Languages: An Overview

    ERIC Educational Resources Information Center

    Schmaling, Constanze H.

    2012-01-01

    This article gives an overview of dictionaries of African sign languages that have been published to date most of which have not been widely distributed. After an introduction into the field of sign language lexicography and a discussion of some of the obstacles that authors of sign language dictionaries face in general, I will show problems…

  2. Regenerating African Decayed Land: Can Reading Contribute?

    ERIC Educational Resources Information Center

    Biniakunu, Dianzungu Dia

    1991-01-01

    Relates how the publication of a book (written in Kikongo, an African native language) designed to raise peasants' awareness in Lower Zaire about desertification and other serious environmental issues had dramatic and surprising implications not only for the environment, but also regarding peasant literacy and the power of reading. (SR)

  3. Fat, fibre and cancer risk in African Americans and rural Africans.

    PubMed

    O'Keefe, Stephen J D; Li, Jia V; Lahti, Leo; Ou, Junhai; Carbonero, Franck; Mohammed, Khaled; Posma, Joram M; Kinross, James; Wahl, Elaine; Ruder, Elizabeth; Vipperla, Kishore; Naidoo, Vasudevan; Mtshali, Lungile; Tims, Sebastian; Puylaert, Philippe G B; DeLany, James; Krasinskas, Alyssa; Benefiel, Ann C; Kaseb, Hatem O; Newton, Keith; Nicholson, Jeremy K; de Vos, Willem M; Gaskins, H Rex; Zoetendal, Erwin G

    2015-04-28

    Rates of colon cancer are much higher in African Americans (65:100,000) than in rural South Africans (<5:100,000). The higher rates are associated with higher animal protein and fat, and lower fibre consumption, higher colonic secondary bile acids, lower colonic short-chain fatty acid quantities and higher mucosal proliferative biomarkers of cancer risk in otherwise healthy middle-aged volunteers. Here we investigate further the role of fat and fibre in this association. We performed 2-week food exchanges in subjects from the same populations, where African Americans were fed a high-fibre, low-fat African-style diet and rural Africans a high-fat, low-fibre western-style diet, under close supervision. In comparison with their usual diets, the food changes resulted in remarkable reciprocal changes in mucosal biomarkers of cancer risk and in aspects of the microbiota and metabolome known to affect cancer risk, best illustrated by increased saccharolytic fermentation and butyrogenesis, and suppressed secondary bile acid synthesis in the African Americans.

  4. Fat, Fiber and Cancer Risk in African Americans and Rural Africans

    PubMed Central

    O'Keefe, Stephen J.D.; Li, Jia V.; Lahti, Leo; Ou, Junhai; Carbonero, Franck; Mohammed, Khaled; Posma, Joram M; Kinross, James; Wahl, Elaine; Ruder, Elizabeth; Vipperla, Kishore; Naidoo, Vasudevan; Mtshali, Lungile; Tims, Sebastian; Puylaert, Philippe G.B.; DeLany, James; Krasinskas, Alyssa; Benefiel, Ann C.; Kaseb, Hatem O.; Newton, Keith; Nicholson, Jeremy K.; de Vos, Willem M.; Gaskins, H. Rex; Zoetendal, Erwin G.

    2015-01-01

    Rates of colon cancer are much higher in African Americans (65:100,000) than in rural South Africans (<5:100,000). The higher rates are associated with higher animal protein and fat and lower fiber consumption, higher colonic secondary bile acids, lower colonic short chain fatty acid quantities and higher mucosal proliferative biomarkers of cancer risk in otherwise healthy middle aged volunteers. Here we investigate further the role of fat and fiber in this association. We performed two-week food exchanges in subjects from the same populations, where African Americans were fed a high-fiber, lowfat African-style diet, and rural Africans a high-fat low-fiber western-style diet under close supervision. In comparison to their usual diets, the food changes resulted in remarkable reciprocal changes in mucosal biomarkers of cancer risk and in aspects of the microbiota and metabolome known to affect cancer risk, best illustrated by increased saccharolytic fermentation and butyrogenesis and suppressed secondary bile acid synthesis in the African Americans. PMID:25919227

  5. Managing the hair and skin of African American pediatric patients.

    PubMed

    Smith, W; Burns, C

    1999-01-01

    In Africa, the ancestral home of most African Americans, hair is viewed as the epitome of beauty. However, when Africans were brought to America as slaves, they were unable to care for their hair and skin adequately and were exposed to the predominant white culture, which valued straight hair and light skin. As a result, many African Americans lost self-esteem because of the characteristics of their hair and skin. In this article we examine the anatomic and physiologic features of African American hair and skin and typical African American hair and skin care practices. Common African American hair and skin disorders and their management are discussed. The goal of this article is to help primary care providers understand the special hair and skin care required for African American children (as well as other dark-skinned patients). With good patient education, understanding one's own hair and skin characteristics can also support positive self-esteem.

  6. Informing cancer prevention strategies for African Americans: the relationship of African American acculturation to fruit, vegetable, and fat intake.

    PubMed

    Ard, Jamy D; Skinner, Celette Sugg; Chen, Chuhe; Aickin, Mikel; Svetkey, Laura P

    2005-06-01

    Acculturation has been associated with health-related behaviors in African Americans. We sought to determine if there is a relationship between acculturation and dietary intake in African Americans. African Americans in the PREMIER trial completed the African American Acculturation Scale (AAAS) and 2 nonconsecutive 24-h dietary recalls (n = 238). Analysis of variance (ANOVA) and canonical correlation were used to assess relationships between acculturation and dietary intakes. Canonical correlation (p = 0.05) showed that traditional African Americans had lower intakes of fruits/vegetables and milk/dairy with higher intakes of fats, meat, and nuts. This pattern was supported by differences in the ANOVA. African American acculturation is related to dietary intake. These findings have implications for the design of cancer-related public health messages targeted to African Americans.

  7. Population affinities of African Colombians to Sub-Saharan Africans based on dental morphology.

    PubMed

    Delgado-Burbano, M E

    2007-01-01

    The Atlantic slave trade moved more than 13 million Africans to American lands between the 15th and 19th centuries. Previous historical, linguistic, and social-cultural studies suggested a Western-Central Bantu African origin for the Colombian slaves; however, their precise provenance remains unclear. The present study investigates the variation of the epigenetic dental traits in the deciduous and permanent dentition and phenotypic affinities of a contemporary Afro-Colombian community (n=178) in an attempt to identify their possible African ancestors. The results of a multivariate analysis of principal components show that Afro-descendents from Guapi have strong phenotypic relationships with several Bantu-speakers groups of Western and Western-Central Africa (Sub-Saharan region), specifically from Gabon, Congo, Pygmies, Nigeria, Cameroon, Togo and Benin. In concordance with recent mtDNA studies, this research suggests a distant but important relationship between Afro-Colombians and Eastern and South-Eastern African populations. This analysis also shows a marked dental divergence with North African samples. The dental information is not very different from the cultural, linguistic and historic data; however, it is more in agreement with studies based on molecular variation. In addition, this study reveals that African-Americans from North America, Central America-Caribbean and South America have high biological variation essentially identical to their several Sub-Saharan sources. Although a microevolutionary model, based on differential rates of gene flow with Native American and European-American groups and little selective pressures influence, better explains the phenotypic variation observed, more African-American dental samples must be analyzed from a regional perspective.

  8. Pan-African genetic structure in the African buffalo (Syncerus caffer): investigating intraspecific divergence.

    PubMed

    Smitz, Nathalie; Berthouly, Cécile; Cornélis, Daniel; Heller, Rasmus; Van Hooft, Pim; Chardonnet, Philippe; Caron, Alexandre; Prins, Herbert; van Vuuren, Bettine Jansen; De Iongh, Hans; Michaux, Johan

    2013-01-01

    The African buffalo (Syncerus caffer) exhibits extreme morphological variability, which has led to controversies about the validity and taxonomic status of the various recognized subspecies. The present study aims to clarify these by inferring the pan-African spatial distribution of genetic diversity, using a comprehensive set of mitochondrial D-loop sequences from across the entire range of the species. All analyses converged on the existence of two distinct lineages, corresponding to a group encompassing West and Central African populations and a group encompassing East and Southern African populations. The former is currently assigned to two to three subspecies (S. c. nanus, S. c. brachyceros, S. c. aequinoctialis) and the latter to a separate subspecies (S. c. caffer). Forty-two per cent of the total amount of genetic diversity is explained by the between-lineage component, with one to seventeen female migrants per generation inferred as consistent with the isolation-with-migration model. The two lineages diverged between 145 000 to 449 000 years ago, with strong indications for a population expansion in both lineages, as revealed by coalescent-based analyses, summary statistics and a star-like topology of the haplotype network for the S. c. caffer lineage. A Bayesian analysis identified the most probable historical migration routes, with the Cape buffalo undertaking successive colonization events from Eastern toward Southern Africa. Furthermore, our analyses indicate that, in the West-Central African lineage, the forest ecophenotype may be a derived form of the savanna ecophenotype and not vice versa, as has previously been proposed. The African buffalo most likely expanded and diverged in the late to middle Pleistocene from an ancestral population located around the current-day Central African Republic, adapting morphologically to colonize new habitats, hence developing the variety of ecophenotypes observed today.

  9. Pan-African Genetic Structure in the African Buffalo (Syncerus caffer): Investigating Intraspecific Divergence

    PubMed Central

    Smitz, Nathalie; Berthouly, Cécile; Cornélis, Daniel; Heller, Rasmus; Van Hooft, Pim; Chardonnet, Philippe; Caron, Alexandre; Prins, Herbert; van Vuuren, Bettine Jansen; De Iongh, Hans; Michaux, Johan

    2013-01-01

    The African buffalo (Syncerus caffer) exhibits extreme morphological variability, which has led to controversies about the validity and taxonomic status of the various recognized subspecies. The present study aims to clarify these by inferring the pan-African spatial distribution of genetic diversity, using a comprehensive set of mitochondrial D-loop sequences from across the entire range of the species. All analyses converged on the existence of two distinct lineages, corresponding to a group encompassing West and Central African populations and a group encompassing East and Southern African populations. The former is currently assigned to two to three subspecies (S. c. nanus, S. c. brachyceros, S. c. aequinoctialis) and the latter to a separate subspecies (S. c. caffer). Forty-two per cent of the total amount of genetic diversity is explained by the between-lineage component, with one to seventeen female migrants per generation inferred as consistent with the isolation-with-migration model. The two lineages diverged between 145 000 to 449 000 years ago, with strong indications for a population expansion in both lineages, as revealed by coalescent-based analyses, summary statistics and a star-like topology of the haplotype network for the S. c. caffer lineage. A Bayesian analysis identified the most probable historical migration routes, with the Cape buffalo undertaking successive colonization events from Eastern toward Southern Africa. Furthermore, our analyses indicate that, in the West-Central African lineage, the forest ecophenotype may be a derived form of the savanna ecophenotype and not vice versa, as has previously been proposed. The African buffalo most likely expanded and diverged in the late to middle Pleistocene from an ancestral population located around the current-day Central African Republic, adapting morphologically to colonize new habitats, hence developing the variety of ecophenotypes observed today. PMID:23437100

  10. SADCC: challenging the "South African connection.".

    PubMed

    Liebenow, J G

    1982-01-01

    The Southern African Development Coordination Conference (SADCC) which unites 9 states with a combined population of 60 million, has as its objective the task of promoting economic development and realizing economic independence. In many respects the strain of neocolonialism that Southern Africa faces at this time is even more virulent than that facing West, Central, and East Africa. In the latter regions the surrender of political authority by colonial administrators frequently left the commercial, agricultural, and industrial interests of the European powers in continued control of the economies of the former colonies. The fate of economic development plans was determined by situations and decisions made in places distant from the African continent. In the case of Southern Africa, the withdrawal or expulsion of European colonialists has found whites in neighboring South Africa most eager to step into the economic breech. For most of the Southern African states this variant strain of the neocolonial virus creates a dual problem: the independent states acting separately have been no match for South Africa; and the acquiescence of independent African states in forging economic links with South Africa has impeded the liberation efforts of Africans in Namibia and the Republic of South Africa. Discussion focus turns to the challenges that confront SADCC; transport as the most significant factor accounting for the dependency of SADCC states upon South Africa; the role of minerals in dependency; other aspects of dependency; South Africa's proposed Constellation of States; the origins and objectives of SADCC; and dollars and donors. SADCC planning for economic liberation has been conducted against the background of a counterproposal advanced by South Africa's government, which put the Republic at the center of an expanded network of economic linkages within the entire southern African region. While being formally rejected, the Constellation of States scheme does have

  11. Ectomycorrhizal symbiosis of tropical African trees.

    PubMed

    Bâ, Amadou M; Duponnois, Robin; Moyersoen, Bernard; Diédhiou, Abdala G

    2012-01-01

    The diversity, ecology and function of ectomycorrhizal (EM) fungi and ectomycorrhizas (ECMs) on tropical African tree species are reviewed here. While ECMs are the most frequent mycorrhizal type in temperate and boreal forests, they concern an economically and ecologically important minority of plants in African tropical forests. In these African tropical forests, ECMs are found mainly on caesalpionioid legumes, Sarcolaenaceae, Dipterocarpaceae, Asterpeiaceae, Phyllantaceae, Sapotaceae, Papilionoideae, Gnetaceae and Proteaceae, and distributed in open, gallery and rainforests of the Guineo-Congolian basin, Zambezian Miombo woodlands of East and South-Central Africa and Sudanian savannah woodlands of the sub-sahara. Overall, EM status was confirmed in 93 (26%) among 354 tree species belonging to EM genera. In addition, 195 fungal taxa were identified using morphological descriptions and sequencing of the ML5/ML6 fragment of sporocarps and ECMs from West Africa. Analyses of the belowground EM fungal communities mostly based on fungal internal transcribed spacer sequences of ECMs from Continental Africa, Madagascar and the Seychelles also revealed more than 350 putative species of EM fungi belonging mainly to 18 phylogenetic lineages. As in temperate forests, the /russula-lactarius and /tomentella-thelephora lineages dominated EM fungal flora in tropical Africa. A low level of host preference and dominance of multi-host fungal taxa on different African adult tree species and their seedlings were revealed, suggesting a potential for the formation of common ectomycorrhizal networks. Moreover, the EM inoculum potential in terms of types and density of propagules (spores, sclerotia, EM root fragments and fragments of mycelia strands) in the soil allowed opportunistic root colonisation as well as long-term survival in the soil during the dry season. These are important characteristics when choosing an EM fungus for field application. In this respect, Thelephoroid fungal sp

  12. A plea to better feed African soils

    NASA Astrophysics Data System (ADS)

    Stroosnijder, Leo

    2014-05-01

    Most African cropping system are rainfed. Rain is distributed at the soil surface over infiltration and runoff. The infiltrated water is stored in the rootable soil layer and the excess drains below that layer into the groundwater. The stored water is partly lost as evaporation to the atmosphere and partly used as transpiration for plant growth. In African cropping system the green water use efficiency (GWUE: fraction transpiration over rainfall) is as low as 15%. This low value is due to the often poor soil quality (physical, chemical and biological) of African soils. The poor physical state causes a weak soil structure resulting in crust formation with low infiltration and high runoff as consequences. The water holding capacity of the rootable soil layer is also poor, causing quite some water lost into deeper layers. African soils are poor due to long time soil mining. Soil life depends on soil organic matter (SOM) which is decreasing everywhere at an average rate of 2% per year. It is common sense that an improved soil quality is essential for improved food security. The key that triggers a sustainable improvement in soil quality is a system's approach that focus on the management of organic resources. Soil is a living organism, and it feeds on SOM. This feed is continuously consumed but a living soil makes new SOM out of fresh organic matter. In order to keep our soils alive we need cropping systems that feed our soils with fresh organic matter in the form of crop residues in the right mix of quality and quantity. The tendency to breed crops with a high harvest index (hence low straw) and the many other uses of crop residues (competing claims) with it recent use for bio-ethanol fabrication is disastrous for our living soils. If we continue to allow SOM to decrease, soil crusting and hard setting will increase with less end less water available for the production of green biomass. Lower available water will trigger a negative spiral with lower food security and

  13. Range and Frequency of Africanized Honey Bees in California (USA)

    PubMed Central

    Kono, Yoshiaki; Kohn, Joshua R.

    2015-01-01

    Africanized honey bees entered California in 1994 but few accounts of their northward expansion or their frequency relative to European honey bees have been published. We used mitochondrial markers and morphometric analyses to determine the prevalence of Africanized honeybees in San Diego County and their current northward progress in California west of the Sierra Nevada crest. The northernmost African mitotypes detected were approximately 40 km south of Sacramento in California’s central valley. In San Diego County, 65% of foraging honey bee workers carry African mitochondria and the estimated percentage of Africanized workers using morphological measurements is similar (61%). There was no correlation between mitotype and morphology in San Diego County suggesting Africanized bees result from bidirectional hybridization. Seventy percent of feral hives, but only 13% of managed hives, sampled in San Diego County carried the African mitotype indicating that a large fraction of foraging workers in both urban and rural San Diego County are feral. We also found a single nucleotide polymorphism at the DNA barcode locus COI that distinguishes European and African mitotypes. The utility of this marker was confirmed using 401 georeferenced honey bee sequences from the worldwide Barcode of Life Database. Future censuses can determine whether the current range of the Africanized form is stable, patterns of introgression at nuclear loci, and the environmental factors that may limit the northern range of the Africanized honey bee. PMID:26361047

  14. In vitro permeation of platinum through African and Caucasian skin.

    PubMed

    Franken, A; Eloff, F C; du Plessis, J; Badenhorst, C J; Du Plessis, J L

    2015-02-03

    The majority of the South African workforce are Africans, therefore potential racial differences should be considered in risk and exposure assessments in the workplace. Literature suggests African skin to be a superior barrier against permeation and irritants. Previous in vitro studies on metals only included skin from Caucasian donors, whereas this study compared the permeation of platinum through African and Caucasian skin. A donor solution of 0.3 mg/ml of potassium tetrachloroplatinate (K₂PtCl₄) dissolved in synthetic sweat was applied to the vertical Franz diffusion cells with full thickness abdominal skin. Skin from three female African and three female Caucasian donors were included (n=21). The receptor solution was removed at various intervals during the 24 h experiment, and analysed with high resolution inductively coupled plasma-mass spectrometry (ICP-MS). Skin was digested and analysed by inductively coupled plasma-optical emission spectrometry (ICP-OES). Significantly higher permeation of platinum through intact African skin (p=0.044), as well as a significantly higher mass of platinum retention in African skin in comparison with Caucasian skin (p=0.002) occurred. Significant inter-donor variation was found in both racial groups (p<0.02). Results indicate that African workers have increased risk of dermal permeation and therefore possible sensitisation caused by dermal exposure to platinum salts. These results are contradictory to limited literature suggesting a superior barrier in African skin and further investigation is necessary to explain the higher permeation through African skin.

  15. Range and Frequency of Africanized Honey Bees in California (USA).

    PubMed

    Kono, Yoshiaki; Kohn, Joshua R

    2015-01-01

    Africanized honey bees entered California in 1994 but few accounts of their northward expansion or their frequency relative to European honey bees have been published. We used mitochondrial markers and morphometric analyses to determine the prevalence of Africanized honeybees in San Diego County and their current northward progress in California west of the Sierra Nevada crest. The northernmost African mitotypes detected were approximately 40 km south of Sacramento in California's central valley. In San Diego County, 65% of foraging honey bee workers carry African mitochondria and the estimated percentage of Africanized workers using morphological measurements is similar (61%). There was no correlation between mitotype and morphology in San Diego County suggesting Africanized bees result from bidirectional hybridization. Seventy percent of feral hives, but only 13% of managed hives, sampled in San Diego County carried the African mitotype indicating that a large fraction of foraging workers in both urban and rural San Diego County are feral. We also found a single nucleotide polymorphism at the DNA barcode locus COI that distinguishes European and African mitotypes. The utility of this marker was confirmed using 401 georeferenced honey bee sequences from the worldwide Barcode of Life Database. Future censuses can determine whether the current range of the Africanized form is stable, patterns of introgression at nuclear loci, and the environmental factors that may limit the northern range of the Africanized honey bee.

  16. Distinguishing African and European honeybee matrilines using amplified mitochondrial DNA.

    PubMed Central

    Hall, H G; Smith, D R

    1991-01-01

    Previous DNA studies have revealed that feral neotropical African bees have largely retained an African genetic integrity. Additional DNA testing is needed to confirm these findings, to understand the processes responsible, and to follow African bee spread into the temperate United States. To facilitate surveys, the polymerase chain reaction was utilized. African and European honeybee mitochondrial DNA (mtDNA) was identified through amplified segments that carry informative restriction site and length polymorphisms. The ability to discriminate among honeybee subspecies was established by testing a total of 129 colonies from Africa and Europe. Matriline identities could thus be determined for imported New World bees. Among 41 managed and feral colonies in the United States and north Mexico, two European lineages (west and east) were distinguished. From neotropical regions, 72 feral colonies had African mtDNA and 4 had European mtDNA. The results support earlier conclusions that neotropical African bees have spread as unbroken African maternal lineages. Old and New World African honeybee populations exhibit different frequencies of a mtDNA length polymorphism. Through standard analyses, a north African mtDNA type that may have been imported previously from Spain or Portugal was not detected among neotropical African bees. Images PMID:1674608

  17. Hematopoietic SCT for the Black African and non-Black African variants of sickle cell anemia.

    PubMed

    Lucarelli, G; Isgrò, A; Sodani, P; Marziali, M; Gaziev, J; Paciaroni, K; Gallucci, C; Cardarelli, L; Ribersani, M; Alfieri, C; De Angelis, G; Armiento, D; Andreani, M; Testi, M; Amato, A; Akinyanju, O O; Wakama, T T

    2014-11-01

    Sickle cell anemia (SCA) remains associated with high risks of morbidity and early death. Allogeneic hematopoietic SCT (HSCT) is the only curative treatment for SCA. We report our experience with transplantation in a group of patients with the non-Black African variant and the Black African variant of SCA. This study included 40 consecutive SCA patients (13 patients with the non-Black African variant and 27 with the Black African variant) who underwent BM transplantation from HLA-identical sibling donors between June 2004 and May 2013, following a myeloablative-conditioning regimen. All patients obtained sustained engraftment. One patient (non-Black African variant) became a stable mixed chimera with 25% donor cells more than 6 years after transplantation. The probabilities of survival, SCA-free survival and TRM at 5 years after transplant were 91%, 91% and 9%, respectively. All surviving patients remained free of any SCA-related events after transplantation. Our results confirm that it is possible to offer a greater than 90% chance of cure to children with SCA. HSCT should be considered the standard of care for who have an HLA-identical donor, before complications result from the sickling of RBC.

  18. The evolution of cardenolide-resistant forms of Na⁺,K⁺ -ATPase in Danainae butterflies.

    PubMed

    Aardema, Matthew L; Zhen, Ying; Andolfatto, Peter

    2012-01-01

    Cardenolides are a class of plant secondary compounds that inhibit the proper functioning of the Na(+) , K(+) -ATPase enzyme in susceptible animals. Nonetheless, many insect species are able to sequester cardenolides for their own defence. These include butterflies in the subfamily Danainae (Family: Nymphalidae) such as the monarch (Danaus plexippus). Previous studies demonstrated that monarchs harbour an asparagine (N) to histidine (H) substitution (N122H) in the α subunit of Na(+) , K(+) -ATPase (ATPα) that reduces this enzyme's sensitivity to cardenolides. More recently, it has been suggested that at ATPα position 111, monarchs may also harbour a leucine (L)/glutamine (Q) polymorphism. This later amino acid could also contribute to cardenolide insensitivity. However, here we find that incorrect annotation of the initially reported DNA sequence for ATPα has led to several erroneous conclusions. Using a population genetic and phylogenetic analysis of monarchs and their close relatives, we show that an ancient Q111L substitution occurred prior to the radiation of all Danainae, followed by a second substitution at the same site to valine (V), which arose before the diversification of the Danaus genus. In contrast, N122H appears to be a recent substitution specific to monarchs. Surprisingly, examination of a broader insect phylogeny reveals that the same progression of amino acid substitutions (Q111L → L111V + N122H) has also occurred in Chyrsochus beetles (Family: Chrysomelidae, Subfamily: Eumolpinae) that feed on cardenolide-containing host plants. The parallel pattern of amino acid substitution in these two distantly related lineages is consistent with an adaptive role for these substitutions in reducing cardenolide sensitivity and suggests that their temporal order may be limited by epistatic interactions.

  19. Young Africans Tackle Their Continent's Environmental Issues

    NASA Astrophysics Data System (ADS)

    Olwoch, Jane Mukarugwiza

    2008-11-01

    Young African Scientists Session at the Fourth International Geosphere-Biosphere Programme Congress; Cape Town, South Africa, 7 May 2008; Africa is often described as a unique and diverse continent. This is reflected in its biodiversity, economic and social circumstances, and diversity in culture and environment. The Young African Scientists (YAS) session at the International Geosphere-Biosphere Programme Congress was one of the congress's highlights. Global environmental change research in Africa was presented to an audience that included visiting international and national scientists, policy makers, and a group of schoolchildren. From the uniqueness of Africa's paleoclimate to the diversity and complexity of current and future impacts of environmental change on Africa, the session not only provided an overview of current projects but also highlighted the problems that are intertwined with poverty. This session was sponsored by the Global Change System for Analysis, Research, and Training (START).

  20. Bushmeat hunting changes regeneration of African rainforests

    PubMed Central

    Effiom, Edu O.; Nuñez-Iturri, Gabriela; Smith, Henrik G.; Ottosson, Ulf; Olsson, Ola

    2013-01-01

    To assess ecological consequences of bushmeat hunting in African lowland rainforests, we compared paired sites, with high and low hunting pressure, in three areas of southeastern Nigeria. In hunted sites, populations of important seed dispersers—both small and large primates (including the Cross River gorilla, Gorilla gorilla diehli)—were drastically reduced. Large rodents were more abundant in hunted sites, even though they are hunted. Hunted and protected sites had similar mature tree communities dominated by primate-dispersed species. In protected sites, seedling communities were similar in composition to the mature trees, but in hunted sites species with other dispersal modes dominated among seedlings. Seedlings emerging 1 year after clearing of all vegetation in experimental plots showed a similar pattern to the standing seedlings. This study thus verifies the transforming effects of bushmeat hunting on plant communities of tropical forests and is one of the first studies to do so for the African continent. PMID:23516245

  1. Heat flow from the West African shield

    SciTech Connect

    Brigaud, F.; Lucazeau, F.; Ly, S.; Sauvage, J.F.

    1985-09-01

    The heat flow over Precambrian shields is generally lower than over other continental provinces. Previous observations at 9 sites of the West African shield have shown that heat flow ranges from 20 mW m/sup -2/ in Niger to 38-42 mW m/sup -2/ in Liberia, Ghana and Nigeria. Since some of these values are lower than expected for Precambrian shields, it is important to find out whether or not they are representative of the entire shield before trying to derive its thermal structure. In this paper, we present new heat flow determinations from seven sites of the West African shield. These indicate that the surface heat flow is comparable with that of other Precambrian shields in the world.

  2. Postpartum depression among African-American women.

    PubMed

    Amankwaa, Linda Clark

    2003-01-01

    The purpose of this qualitative study was to describe the nature of postpartum depression (PPD) among African-American women. Twelve women, who had experienced PPD within the last three years, were interviewed for approximately one hour at two intervals. Nudist-4 software and the constant comparative method were used to analyze the data. Five themes "Stressing Out," "Feeling Down," "Losing It," "Seeking Help," and "Feeling Better" represented aspects of PPD as experienced by the participants. The last theme, "Dealing with It," represented the cultural ways in which African-American mothers managed their depression. These included Keeping the Faith, Trying to Be a Strong Black Woman, Living with Myths, and Keeping Secrets. Suggestions for future directions in nursing research are included.

  3. A Regime Legitimacy Explanation of African Peacekeeping

    DTIC Science & Technology

    2011-09-01

    peacekeeping in a U-shaped curve, meaning that states attempting to increase their legitimacy participate at a higher-than-expected level. Likewise, the...distribution is unlimited A REGIME LEGITIMACY EXPLANATION OF AFRICAN PEACEKEEPING Matthew Ross Second Lieutenant, United States Air Force...B.S., Political Science, United States Air Force Academy, 2010 Submitted in partial fulfillment of the requirements for the degree of

  4. Prostate Cancer Genetics in African Americans

    DTIC Science & Technology

    2013-09-01

    grant from the U.S. Department of Defense to study the role heredity plays in prostate cancer among African Americans. "Prostate cancer is the...visit our website at: www.creighton.edu. Creighton gets grant to study heredity -cancer link - Houston Chronicle Coogle offers Google Offers Deals on...traffic Nahan & world Politics Health News bizarre Deaths Hurncanes Creighton gets grant to study heredity -cancer link Published 04 :40a.m., Monday

  5. Seasonal distribution of African savanna fires

    NASA Technical Reports Server (NTRS)

    Cahoon, Donald R., Jr.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; O'Neill, Katherine P.

    1992-01-01

    The temporal and spatial distribution of savanna fires over the entire African continent, as determined from nighttime satellite imagery, is described. It is found that, contrary to expectations, most fires are left to burn uncontrolled, so that there is no strong diurnal cycle in the fire frequency. The knowledge gained from this study regarding the distribution and variability of fires is helpful in the monitoring of climatically important trace gases emitted from burning biomass.

  6. African swine fever: an epidemiological update.

    PubMed

    Sánchez-Vizcaíno, J M; Mur, L; Martínez-López, B

    2012-03-01

    African swine fever (ASF) is one of the most important swine diseases, mainly because of its significant sanitary and socioeconomic consequences. This review gives an update on the epidemiology of the disease and reviews key issues and strategies to improve control of the disease and promote its eradication. Several characteristics of ASF virus (ASFV) make its control and eradication difficult, including the absence of available vaccines, marked virus resistance in infected material and contaminated animal products, and a complex epidemiology and transmission involving tick reservoir virus interactions. The incidence of ASF has not only increased on the African continent over the last 15 years, so that it now affects West African countries, Mauritius and Madagascar, but it has also reached new areas, such as the Caucasus region in 2007. In fact, the rapid spread of the disease on the European continent and the uncontrolled situation in the Russian Federation places all countries at great risk as a result of intense global trade. The proximity of some affected areas to the European Union (EU) borders (<150 km) has increased concerns about the potential economic consequences of an ASF incursion into the EU pig sector. Establishing effective surveillance, control and eradication programmes that implicate all actors (veterinarians, farmers, and policy makers) is essential for controlling ASF. African swine fever -free countries should be aware of the potential risk of ASF incursion and implement risk reduction measures such as trade controls and other sanitary measures. This review will discuss lessons learnt so far about ASF control, current challenges to its control and future studies needed to support global efforts at prevention and control.

  7. Africans in the American Labor Market.

    PubMed

    Elo, Irma T; Frankenberg, Elizabeth; Gansey, Romeo; Thomas, Duncan

    2015-10-01

    The number of migrants to the United States from Africa has grown exponentially since the 1930s. For the first time in America's history, migrants born in Africa are growing at a faster rate than migrants from any other continent. The composition of African-origin migrants has also changed dramatically: in the mid-twentieth century, the majority were white and came from only three countries; but today, about one-fifth are white, and African-origin migrants hail from across the entire continent. Little is known about the implications of these changes for their labor market outcomes in the United States. Using the 2000-2011 waves of the American Community Survey, we present a picture of enormous heterogeneity in labor market participation, sectoral choice, and hourly earnings of male and female migrants by country of birth, race, age at arrival in the United States, and human capital. For example, controlling a rich set of human capital and demographic characteristics, some migrants-such as those from South Africa/Zimbabwe and Cape Verde, who typically enter on employment visas-earn substantial premiums relative to other African-origin migrants. These premiums are especially large among males who arrived after age 18. In contrast, other migrants-such as those from Sudan/Somalia, who arrived more recently, mostly as refugees-earn substantially less than migrants from other African countries. Understanding the mechanisms generating the heterogeneity in these outcomes-including levels of socioeconomic development, language, culture, and quality of education in countries of origin, as well as selectivity of those who migrate-figures prominently among important unresolved research questions.

  8. Africans in the American Labor Market

    PubMed Central

    Elo, Irma T.; Frankenberg, Elizabeth; Gansey, Romeo; Thomas, Duncan

    2015-01-01

    The number of migrants to the United States from Africa has grown exponentially since the 1930s. For the first time in America’s history, migrants born in Africa are growing at a faster rate than migrants from any other continent. The composition of African-origin migrants has also changed dramatically: in the mid-twentieth century, the majority were white and came from only three countries; but today, about one-fifth are white, and African-origin migrants hail from across the entire continent. Little is known about the implications of these changes for their labor market outcomes in the United States. Using the 2000–2011 waves of the American Community Survey, we present a picture of enormous heterogeneity in labor market participation, sectoral choice, and hourly earnings of male and female migrants by country of birth, race, age at arrival in the United States, and human capital. For example, controlling a rich set of human capital and demographic characteristics, some migrants—such as those from South Africa/Zimbabwe and Cape Verde, who typically enter on employment visas—earn substantial premiums relative to other African-origin migrants. These premiums are especially large among males who arrived after age 18. In contrast, other migrants—such as those from Sudan/Somalia, who arrived more recently, mostly as refugees—earn substantially less than migrants from other African countries. Understanding the mechanisms generating the heterogeneity in these outcomes—including levels of socioeconomic development, language, culture, and quality of education in countries of origin, as well as selectivity of those who migrate—remain important unresolved research questions. PMID:26304845

  9. Intraspinal tumours in the Kenya African.

    PubMed

    Ruberti, R F; Carmagnani, A L

    1976-06-01

    Thirty-one cases of intraspinal tumours in the African have been described, with age, sex incidence, frequency, site and histopathology shown. Intraspinal tumours in this series are compared with the larger series. Extradural and intramedullary tumours together with cervical spine tumours appear to be more frequent in this series. There is a high incidence of dumbell tumours in the neurinomas. Sarcomas are the most common type of tumours and mainly affect the thoracic spine.

  10. Malignant lymphoma in african lions (panthera leo).

    PubMed

    Harrison, T M; McKnight, C A; Sikarskie, J G; Kitchell, B E; Garner, M M; Raymond, J T; Fitzgerald, S D; Valli, V E; Agnew, D; Kiupel, M

    2010-09-01

    Malignant lymphoma has become an increasingly recognized problem in African lions (Panthera leo). Eleven African lions (9 male and 2 female) with clinical signs and gross and microscopic lesions of malignant lymphoma were evaluated in this study. All animals were older adults, ranging in age from 14 to 19 years. Immunohistochemically, 10 of the 11 lions had T-cell lymphomas (CD3(+), CD79a(-)), and 1 lion was diagnosed with a B-cell lymphoma (CD3(-), CD79a(+)). The spleen appeared to be the primary site of neoplastic growth in all T-cell lymphomas, with involvement of the liver (6/11) and regional lymph nodes (5/11) also commonly observed. The B-cell lymphoma affected the peripheral lymph nodes, liver, and spleen. According to the current veterinary and human World Health Organization classification of hematopoietic neoplasms, T-cell lymphoma subtypes included peripheral T-cell lymphoma (4/11), precursor (acute) T-cell lymphoblastic lymphoma/leukemia (2/11), chronic T-cell lymphocytic lymphoma/leukemia (3/11), and T-zone lymphoma (1/11). The single B-cell lymphoma subtype was consistent with diffuse large B-cell lymphoma. Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) testing by immunohistochemistry on sections of malignant lymphoma was negative for all 11 lions. One lion was seropositive for FeLV. In contrast to domestic and exotic cats, in which B-cell lymphomas are more common than T-cell lymphomas, African lions in this study had malignant lymphomas that were primarily of T-cell origin. Neither FeLV nor FIV, important causes of malignant lymphoma in domestic cats, seems to be significant in the pathogenesis of malignant lymphoma in African lions.

  11. Exploration of Depressive Symptoms in African American Cancer Patients

    PubMed Central

    Zhang, Amy Y.; Gary, Faye; Zhu, Hui

    2016-01-01

    Background Accurately assessing depression in African American cancer patients is difficult because of the similarities of physical symptoms observed in cancer and depression. Aim To identify universal and distinctive depressive symptoms in African American cancer patients. Methods Seventy-four cancer patients (34 depressed and 23 nondepressed African Americans, and 17 depressed Whites) were interviewed. Qualitative and quantitative analyses were conducted. Results Compared to nondepressed African Americans, depressed African Americans reported irritability, social isolation, insomnia, fatigue, and crying (p ≤ .05) more frequently over time. Compared to depressed Whites, they reported sadness, frustration, and intrusive thoughts less frequently (p ≤ .05), but insomnia and fatigue more frequently (p ≤ .05) during cancer treatment. There was little racial difference at the time of interview. Conclusion Depressed African American cancer patients may benefit from more culturally sensitive depression measures that consider symptoms of irritability, social isolation, and altered expressions of depressive mood. PMID:25564890

  12. Variables affecting racial-identity salience among African Americans.

    PubMed

    Thompson, V L

    1999-12-01

    The author clarified the African American racial-group identification process by addressing the issue of salience and its relationship to racial-group attitudes. A sample of 409 African American adults responded to surveys pertaining to their racial-group salience, racial-group attitudes, racial socialization, racial-group interaction, political activism, experiences of discrimination, and demographic data (e.g., sex, age, and income). The author tested 3 hypotheses: (a) Racial socialization and interaction with other African Americans are predictive of African American racial-identity salience; (b) discriminatory experiences are predictive of African American racial-identity salience; and (c) racial-identity salience is a stronger predictor of African American racial-group identification than are previously identified predictive variables (D. H. Demo & H. Hughes, 1990; V. L. Thompson Sanders, 1991, 1995). The results supported the 1st and 3rd hypotheses.

  13. Some growth points in African child development research.

    PubMed

    Serpell, Robert; Marfo, Kofi

    2014-01-01

    We reflect on ways in which research presented in earlier chapters responds to challenges of generating an African child development field and identify additional issues calling for the field's attention. The chapters collectively display a variety of African contexts and reflexive evidence of the authors' African cultural roots. Connecting research with African audiences demands cooperative communication between educational practitioners and parents with low literacy, and cross-sector communication among professionals. Intracultural exploration of factors influencing the pattern of human development has begun to document the potential of indigenous African cultures as a fund of resources for enhancing child development. Priority topics for future African developmental research include multilingualism, musical performance, socially distributed caregiving, and the relation between adolescence and economic activity. Integration of multiple disciplines in the application of research-based principles to service delivery in the fields of community-based (re)habilitation and early childhood care and education calls for researcher collaboration with practitioners.

  14. The topology of African exports: Emerging patterns on spanning trees

    NASA Astrophysics Data System (ADS)

    Araújo, Tanya; Ferreira, Manuel Ennes

    2016-11-01

    This paper is a contribution to interweaving two lines of research that have progressed in separate ways: network analysis of international trade and the literature on African trade and development. Gathering empirical data on African countries has important limitations and so does the space occupied by African countries in the analysis of trade networks. Here, these limitations are dealt with by the definition of two independent bipartite networks: a destination share network and a commodity share network. These networks-together with their corresponding minimal spanning trees-allow to uncover some ordering emerging from African exports in the broader context of international trade. The emerging patterns help to understand important characteristics of African exports and its binding relations to other economic, geographic and organizational concerns as the recent literature on African trade, development and growth has shown.

  15. Nutritional consequences of the African diaspora.

    PubMed

    Luke, A; Cooper, R S; Prewitt, T E; Adeyemo, A A; Forrester, T E

    2001-01-01

    Along with their foods and dietary customs, Africans were carried into diaspora throughout the Americas as a result of the European slave trade. Their descendants represent populations at varying stages of the nutrition transition. West Africans are in the early stage, where undernutrition and nutrient deficiencies are prevalent. Many Caribbean populations represent the middle stages, with undernutrition and obesity coexisting. African-Americans and black populations in the United Kingdom suffer from the consequences of caloric excess and diets high in fat and animal products. Obesity, non-insulin-dependent diabetes mellitus, hypertension, coronary heart disease, and certain cancers all follow an east-to-west gradient of increasing prevalence. Public health efforts must focus not only on eradicating undernutrition in West Africa and the Caribbean but also on preventing obesity, hypercholesterolemia, and their consequences. Fortunately, a coherent and well-supported set of recommendations exists to promote better nutrition. Implementation of it founders primarily as a result of the influence of commercial and political interests.

  16. African American teen mothers' perceptions of parenting.

    PubMed

    Wayland, J; Rawlins, R

    1997-02-01

    The purpose of this study was to describe the childbearing African American teens' perceptions of parenting based on their own experiences. Focus group discussions were held with 17 teens in their school setting for 50 minutes each week. Group discussions were audiotaped, tapes were transcribed, and then analyzed for common themes. The unmarried teens ranged in age from 15 to 18 years. Findings indicated that the teens depended on grandmothers to provide child care and for information about parenting. The teens identified parenting problems including crying, discipline, and conflicts dealing with grandmothers and the child's father. Teens wanted more information about breastfeeding and minor childhood diseases. The researchers identified that teens lacked information about their children's growth and development and safety issues. Findings have implications for nurses who care for childbearing teens and their children; and those involved in planning and implementing parent education programs for African American teen mothers and their families. Further research is indicated with larger samples of African American teens; and to explore the context of family relationships in which teen mothers and grandmothers share parenting for the teens' children.

  17. Rethinking "relevance": South African psychology in context.

    PubMed

    Long, Wahbie

    2013-02-01

    This article examines the phenomenon known as the "relevance debate" in South African psychology. It begins with a historical overview of the contours of the discipline in that country before describing the controversy's international dimensions, namely, the revolutionary politics of 1960s higher education and the subsequent emergence of cognate versions of the debate in American, European, and "Third World" psychology. The article then details how South Africa's "relevance" project enjoyed a special affinity with an assortment of ethnic-cultural, national, and continental myths and metaphors, all of which served the interests of the political formations of the day. It discusses how, in present-day South Africa, the intelligentsia has become an important catalyst for the so-called African Renaissance, which seeks to provide "relevant" solutions for the regeneration of African society. However, the global hegemony of what began in the 1970s as a "second academic revolution," aided by the lifting of the academic boycott of South Africa, has blunted the once critical edge of "relevance" discourse. A new mode of knowledge production now holds sway, the outcome of a dramatic reformulation of the capitalist manifesto in which the values of the "May 68" generation have been hijacked by a managerialist rationality. In light of the capitalization of the knowledge-production enterprise, it is concluded that the idiom of "relevance" has outlived its usefulness.

  18. Neuropsychological screening tests in African Americans.

    PubMed Central

    Lampley-Dallas, V. T.

    2001-01-01

    Neuropsychological tests are instruments used to diagnose a variety of cognitive conditions. This article will review a few of the brief scales commonly used in screening for dementia. It will also discuss the properties of and problems with some of the brief scales that are commonly used to screen African Americans for dementia, highlighting the various biases. The Mini-Mental State Examination (MMSE) is the most widely known and utilized cognitive impairment instrument in the United States. Whether or not it is biased to race after adjusting the scores for educational attainment remains controversial. The Blessed Information-Memory-Concentration Test (BIMC), Blessed Orientation-Memory-Concentration Test (BOMC), Short Portable Mental Status Questionnaire (SPMSQ), and Neurobehavioral Cognitive Status Examination (NCSE) are other screening tests used to diagnose dementia. Some of these tests have been found to misclassify many more African Americans as demented compared to the proportion of whites that are misclassified. The Cambridge Cognitive Examination (CAMCOG) is the only brief neuropsychological scale designed to actually diagnose early dementia, but it is not known if it is biased for African Americans. PMID:11560287

  19. Epidemiology of African swine fever virus.

    PubMed

    Costard, S; Mur, L; Lubroth, J; Sanchez-Vizcaino, J M; Pfeiffer, D U

    2013-04-01

    African swine fever virus used to occur primarily in Africa. There had been occasional incursions into Europe or America which apart from the endemic situation on the island of Sardinia always had been successfully controlled. But following an introduction of the virus in 2007, it now has expanded its geographical distribution into Caucasus and Eastern Europe where it has not been controlled, to date. African swine fever affects domestic and wild pig species, and can involve tick vectors. The ability of the virus to survive within a particular ecosystem is defined by the ecology of its wild host populations and the characteristics of livestock production systems, which influence host and vector species densities and interrelationships. African swine fever has high morbidity in naïve pig populations and can result in very high mortality. There is no vaccine or treatment available. Apart from stamping out and movement control, there are no control measures, thereby potentially resulting in extreme losses for producers. Prevention and control of the infection requires good understanding of its epidemiology, so that targeted measures can be instigated.

  20. Seasonal Distribution of African Savanna Fires

    NASA Technical Reports Server (NTRS)

    Cahoon, Donald R.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; O'Neill, Katherine P.

    1992-01-01

    Savannas consist of a continuous layer of grass interspersed with scattered trees or shrubs, and cover approx. 10 million square kilometers of tropical Africa. African savanna fires, almost all resulting from human activities, may produce as much as a third of the total global emissions from biomass burning. Little is known, however, about the frequency and location of these fires, and the area burned each year. Emissions from African savanna burning are known to be transported over the mid-Atlantic, south Pacific and Indian oceans; but to study fully the transport of regional savanna burning and the seasonality of the atmospheric circulation must be considered simultaneously. Here we describe the temporal and spatial distribution of savanna fires over the entire African continent, as determined from night-time satellite imagery. We find that, contrary to expectations, most fires are left to burn uncontrolled, so that there is no strong diurnal cycle in the fire frequency. The knowledge gained from this study regarding the distribution and variability of fires will aid monitoring of the climatically important trace gases emitted from burning biomass.

  1. Acquired immunodeficiency syndrome in older African Americans.

    PubMed

    Funnyé, Allen S; Akhtar, Abbasi J; Biamby, Gisele

    2002-04-01

    The purpose of this study was to determine if older African Americans are disproportionately affected by acquired immunodeficiency syndrome (AIDS), and to review the clinical impact of AIDS and the importance of prevention and treatment efforts. A review of the literature and statistics was obtained using Medline and the AIDS Public Information Data Set offered by the Centers for Disease Control and Prevention. Twenty-seven percent of the U.S. population is above the age of 50, and the number of AIDS cases in this group is growing, with African Americans accounting for the highest proportion of cases and deaths. Testing for HIV may be delayed and symptoms attributed to other illnesses. Though 5% of new cases occur in those over 50, prevention programs, testing, and the perception of risk by providers may be insufficient. There are few research studies on HIV treatment in older patients and no specific guidelines for antiretroviral treatments available. Although death rates for AIDS has been declining, adults over 50 still have the highest mortality rate. Co-morbid conditions, such as heart disease and hypertension, may require taking multiple drugs, which may complicate treatment. Increasing heterosexual transmission rates and a lack of information on HIV reinforces the need for specific prevention programs targeted toward older African Americans.

  2. The Lived Experience of African American Caregivers Caring for Adult African American Patients With Heart Failure.

    PubMed

    Hamilton, Heather

    2016-04-01

    Assistance from informal caregivers such as family members, friends, or neighbors is crucial to adequately managing the complex care of heart failure (HF) patients. This study examined the lived experience of African American caregivers caring for African American patients with HF. Purposive sampling was used to recruit 10 participants who were formally interviewed. The interviews, analyzed using Colaizzi's steps, revealed six themes: layers of support, realization of self-neglect, experiencing the "blues," connecting with healthcare providers, unmet financial needs, and perception of nonadherence. The information regarding the experience of African American caregivers of HF patients obtained through this research will inform the delivery of culturally competent support to caregivers, thereby improving quality of life for both the HF patients and their caregivers.

  3. KSC kicks off African-American History Month

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Michelle Amos, mistress of ceremonies for the kick-off of African-American History Month, works with the audience to assist them in the pronunciation of a few token words in native Swahili. The theme for this year's observation is 'Heritage and Horizons: The African-American Legacy and the Challenges of the 21st Century.' February is designated each year as a time to celebrate the achievements and contributions of African Americans to Kennedy Space Center, NASA and the nation.

  4. African rice (Oryza glaberrima): History and future potential

    PubMed Central

    Linares, Olga F.

    2002-01-01

    The African species of rice (Oryza glaberrima) was cultivated long before Europeans arrived in the continent. At present, O. glaberrima is being replaced by the introduced Asian species of rice, Oryza sativa. Some West African farmers, including the Jola of southern Senegal, still grow African rice for use in ritual contexts. The two species of rice have recently been crossed, producing a promising hybrid. PMID:12461173

  5. Genetic African Ancestry and Markers of Mineral Metabolism in CKD

    PubMed Central

    Parsa, Afshin; Isakova, Tamara; Scialla, Julia J.; Chen, Jing; Flack, John M.; Nessel, Lisa C.; Gupta, Jayanta; Bellovich, Keith A.; Steigerwalt, Susan; Sondheimer, James H.; Wright, Jackson T.; Feldman, Harold I.; Kusek, John W.; Lash, James P.; Wolf, Myles

    2016-01-01

    Background and objectives Disorders of mineral metabolism are more common in African Americans with CKD than in European Americans with CKD. Previous studies have focused on the differences in mineral metabolism by self-reported race, making it difficult to delineate the importance of environmental compared with biologic factors. Design, setting, participants, & measurements In a cross-sectional analysis of 3013 participants of the Chronic Renal Insufficiency Cohort study with complete data, we compared markers of mineral metabolism (phosphorus, calcium, alkaline phosphatase, parathyroid hormone, fibroblast growth factor 23, and urine calcium and phosphorus excretion) in European Americans versus African Americans and separately, across quartiles of genetic African ancestry in African Americans (n=1490). Results Compared with European Americans, African Americans had higher blood concentrations of phosphorus, alkaline phosphatase, fibroblast growth factor 23, and parathyroid hormone, lower 24-hour urinary excretion of calcium and phosphorus, and lower urinary fractional excretion of calcium and phosphorus at baseline (P<0.001 for all). Among African Americans, a higher percentage of African ancestry was associated with lower 24-hour urinary excretion of phosphorus (Ptrend<0.01) in unadjusted analyses. In linear regression models adjusted for socio-demographic characteristics, kidney function, serum phosphorus, and dietary phosphorus intake, higher percentage of African ancestry was significantly associated with lower 24-hour urinary phosphorus excretion (each 10% higher African ancestry was associated with 39.6 mg lower 24-hour urinary phosphorus, P<0.001) and fractional excretion of phosphorus (each 10% higher African ancestry was associated with an absolute 1.1% lower fractional excretion of phosphorus, P=0.01). Conclusions A higher percentage of African ancestry was independently associated with lower 24-hour urinary phosphorus excretion and lower fractional

  6. BRCA1 and BRCA2 Mutations in African Americans

    DTIC Science & Technology

    2000-10-01

    cancer syndromes that are prevalent among African Americans? Little information exists about other familial cancer syndromes unique to African...Americans but two African-American families with Cowden’s syndrome have been reported (Fackenthal et al, 2000). The same germline p53 coding mutation and...familial syndromes based on pedigree analysis, calculation of risk estimates, and effective communication of risk status at a level that the patient can

  7. Y Chromosome Lineages in Men of West African Descent

    PubMed Central

    Keita, Shomarka O. Y.; Kittles, Rick A.

    2012-01-01

    The early African experience in the Americas is marked by the transatlantic slave trade from ∼1619 to 1850 and the rise of the plantation system. The origins of enslaved Africans were largely dependent on European preferences as well as the availability of potential laborers within Africa. Rice production was a key industry of many colonial South Carolina low country plantations. Accordingly, rice plantations owners within South Carolina often requested enslaved Africans from the so-called “Grain Coast” of western Africa (Senegal to Sierra Leone). Studies on the African origins of the enslaved within other regions of the Americas have been limited. To address the issue of origins of people of African descent within the Americas and understand more about the genetic heterogeneity present within Africa and the African Diaspora, we typed Y chromosome specific markers in 1,319 men consisting of 508 west and central Africans (from 12 populations), 188 Caribbeans (from 2 islands), 532 African Americans (AAs from Washington, DC and Columbia, SC), and 91 European Americans. Principal component and admixture analyses provide support for significant Grain Coast ancestry among African American men in South Carolina. AA men from DC and the Caribbean showed a closer affinity to populations from the Bight of Biafra. Furthermore, 30–40% of the paternal lineages in African descent populations in the Americas are of European ancestry. Diverse west African ancestries and sex-biased gene flow from EAs has contributed greatly to the genetic heterogeneity of African populations throughout the Americas and has significant implications for gene mapping efforts in these populations. PMID:22295064

  8. African Genetic Ancestry is Associated with Sleep Depth in Older African Americans

    PubMed Central

    Halder, Indrani; Matthews, Karen A.; Buysse, Daniel J.; Strollo, Patrick J.; Causer, Victoria; Reis, Steven E.; Hall, Martica H.

    2015-01-01

    Study Objectives: The mechanisms that underlie differences in sleep characteristics between European Americans (EA) and African Americans (AA) are not fully known. Although social and psychological processes that differ by race are possible mediators, the substantial heritability of sleep characteristics also suggests genetic underpinnings of race differences. We hypothesized that racial differences in sleep phenotypes would show an association with objectively measured individual genetic ancestry in AAs. Design: Cross sectional. Setting: Community-based study. Participants: Seventy AA adults (mean age 59.5 ± 6.7 y; 62% female) and 101 EAs (mean age 60.5 ± 7 y, 39% female). Measurements and Results: Multivariate tests were used to compare the Pittsburgh Sleep Quality Index (PSQI) and in-home polysomnographic measures of sleep duration, sleep efficiency, apnea-hypopnea index (AHI), and indices of sleep depth including percent visually scored slow wave sleep (SWS) and delta EEG power of EAs and AAs. Sleep duration, efficiency, and sleep depth differed significantly by race. Individual % African ancestry (%AF) was measured in AA subjects using a panel of 1698 ancestry informative genetic markers and ranged from 10% to 88% (mean 67%). Hierarchical linear regression showed that higher %AF was associated with lower percent SWS in AAs (β (standard error) = −4.6 (1.5); P = 0.002), and explained 11% of the variation in SWS after covariate adjustment. A similar association was observed for delta power. No association was observed for sleep duration and efficiency. Conclusion: African genetic ancestry is associated with indices of sleep depth in African Americans. Such an association suggests that part of the racial differences in slow-wave sleep may have genetic underpinnings. Citation: Halder I, Matthews KA, Buysse DJ, Strollo PJ, Causer V, Reis SE, Hall MH. African genetic ancestry is associated with sleep depth in older African Americans. SLEEP 2015;38(8):1185–1193

  9. 76 FR 43649 - Board of Directors Meeting; African Development Foundation, Board of Directors Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ...; ] AFRICAN DEVELOPMENT FOUNDATION Board of Directors Meeting; African Development Foundation, Board of Directors Meeting Time: Tuesday, August 2, 2011, 9 a.m. to 12 p.m. Place: African Development...

  10. The myth of meritocracy and African American health.

    PubMed

    Kwate, Naa Oyo A; Meyer, Ilan H

    2010-10-01

    Recent theoretical and empirical studies of the social determinants of health inequities have shown that economic deprivation, multiple levels of racism, and neighborhood context limit African American health chances and that African Americans' poor health status is predicated on unequal opportunity to achieve the American Dream. President Obama's election has been touted as a demonstration of American meritocracy-the belief that all may obtain the American Dream-and has instilled hope in African Americans. However, we argue that in the context of racism and other barriers to success, meritocratic ideology may act as a negative health determinant for African Americans.

  11. Challenges in internet study recruitment of African American cancer patients.

    PubMed

    Bender, Melinda; Clark, Maresha; Guevara, Enrique; Chee, Wonshik; Im, Eun-Ok

    2006-01-01

    Health care inequities continue to plague African Americans. For African American cancer patients these inequities include access to health care, availability of treatment modalities, support groups, and participation in nursing cancer research. A support group setting is better for recruitment than a clinical setting. Referrals to the researcher from individuals who personally know the African American cancer patients generated the best response rates. If the researcher has no previous connection with the potential participant, interest in the study may be generated but recruitment is minimal or absent. Ethnically sensitive recruitment of African American cancer patients is therefore essential to improving participatory responses in cancer nursing research.

  12. Critical social theory and the domination of African American Women.

    PubMed

    Davis, S P

    1995-01-01

    This historical reconstruction of the experiences of African American women in America from slavery to the present exposes the prevailing and enduring system of White male domination. From White men having control of their reproductive choices, to conspiracy to withhold the right to vote, African American women were victims of both sexism and racism. Later, as a result of the myth conceived by White sociologists of the super African American woman, further divisiveness became apparent in the African American home. As African American women took advantage of educational opportunities only to find that there was a dearth of similarly educated African American males to marry, increasing numbers of African American men were reported as parties to violent acts, drugs or illness. All of these variables are conjectured as impacting on the African American woman's experience. Lastly, data were presented depicting the increasing trend of African American women marrying White men, and the emergence of a more diverse workforce. It was concluded that economics serve as a catalyst for this change in human relations.

  13. African American legislators' perceptions of firearm violence prevention legislation.

    PubMed

    Payton, Erica; Thompson, Amy; Price, James H; Sheu, Jiunn-Jye; Dake, Joseph A

    2015-06-01

    Firearm mortality is the leading cause of death for young African American males, however, few studies have focused on racial/ethnic minority populations and firearm violence. The National Black Caucus of State Legislators advocates for legislation that promotes the health of African Americans. Thus, the purpose of this study was to collect baseline data on African American legislators' perceptions regarding firearm violence in the African American community. A cross-sectional study of African American legislators (n = 612) was conducted to investigate the research questions. Of the 612 questionnaires mailed, 12 were not deliverable, and 170 were returned (28%). Utilizing a three wave mailing process, African American legislators were invited to participate in the study. The majority (88%) of respondents perceived firearm violence to be very serious among African Americans. Few (10%) legislators perceived that addressing legislative issues would be an effective strategy in reducing firearm violence among African Americans. The majority (72%) of legislators perceived the most effective strategy to reducing firearm violence in the African American community should focus on addressing societal issues (e.g. crime and poverty). After adjusting for the number of perceived barriers, the number of perceived benefits was a significant predictor of legislators' perceived effectiveness of firearm violence prevention legislation for 8 of the 24 potential firearm violence prevention legislative bills.

  14. Black and Blue: Depression and African American Men.

    PubMed

    Plowden, Keith O; Thompson Adams, Linda; Wiley, Dana

    2016-10-01

    Depression is a common mental disorder affecting individuals. Although many strides have been made in the area of depression, little is known about depression in special populations, especially African American men. African American men often differ in their presentation of depression and are often misdiagnosed. African American men are at greater risk for depression, but they are less likely to participate in mental health care. This article explores depression in African American by looking at environmental factors, sigma, role, and other unique to this populations, such as John Henryism. Interventions to encourage early screening and participation in care are also discussed.

  15. Novel recurrently mutated genes in African American colon cancers

    PubMed Central

    Guda, Kishore; Veigl, Martina L.; Varadan, Vinay; Nosrati, Arman; Ravi, Lakshmeswari; Lutterbaugh, James; Beard, Lydia; Willson, James K. V.; Sedwick, W. David; Wang, Zhenghe John; Molyneaux, Neil; Miron, Alexander; Adams, Mark D.; Elston, Robert C.; Markowitz, Sanford D.; Willis, Joseph E.

    2015-01-01

    We used whole-exome and targeted sequencing to characterize somatic mutations in 103 colorectal cancers (CRC) from African Americans, identifying 20 new genes as significantly mutated in CRC. Resequencing 129 Caucasian derived CRCs confirmed a 15-gene set as a preferential target for mutations in African American CRCs. Two predominant genes, ephrin type A receptor 6 (EPHA6) and folliculin (FLCN), with mutations exclusive to African American CRCs, are by genetic and biological criteria highly likely African American CRC driver genes. These previously unsuspected differences in the mutational landscapes of CRCs arising among individuals of different ethnicities have potential to impact on broader disparities in cancer behaviors. PMID:25583493

  16. African Ancestry is a Risk Factor for Asthma and High Total IgE Levels in African Admixed Populations

    PubMed Central

    Vergara, Candelaria; Murray, Tanda; Rafaels, Nicholas; Lewis, Rachel; Campbell, Monica; Foster, Cassandra; Gao, Li; Faruque, Mezbah; Oliveira, Ricardo Riccio; Carvalho, Edgar; Araujo, Maria Ilma; Cruz, Alvaro A.; Watson, Harold; Mercado, Dilia; Knight-Madden, Jennifer; Ruczinski, Ingo; Dunston, Georgia; Ford, Jean; Caraballo, Luis; Beaty, Terri H.; Mathias, Rasika A.; Barnes, Kathleen C.

    2014-01-01

    Characterization of genetic admixture of populations in the Americas and the Caribbean is of interest for anthropological, epidemiological, and historical reasons. Asthma has a higher prevalence and is more severe in populations with a high African component. Association of African ancestry with asthma has been demonstrated. We estimated admixture proportions of samples from six trihybrid populations of African descent and determined the relationship between African ancestry and asthma and total serum IgE levels (tIgE). We genotyped 237 ancestry informative markers in asthmatics and nonasthmatic controls from Barbados (190/277), Jamaica (177/529), Brazil (40/220), Colombia (508/625), African Americans from New York (207/171), and African Americans from Baltimore/Washington, D.C. (625/757). We estimated individual ancestries and evaluated genetic stratification using Structure and principal component analysis. Association of African ancestry and asthma and tIgE was evaluated by regression analysis. Mean SD African ancestry ranged from 0.76 ± 0.10 among Barbadians to 0.33 ± 0.13 in Colombians. The European component varied from 0.14 ± 0.05 among Jamaicans and Barbadians to 0.26 ± 0.08 among Colombians. African ancestry was associated with risk for asthma in Colombians (odds ratio (OR) = 4.5, P = 0.001) Brazilians (OR = 136.5, P = 0.003), and African Americans of New York (OR: 4.7; P = 0.040). African ancestry was also associated with higher tIgE levels among Colombians (β = 1.3, P = 0.04), Barbadians (β = 3.8, P = 0.03), and Brazilians (β = 1.6, P = 0.03). Our findings indicate that African ancestry can account for, at least in part, the association between asthma and its associated trait, tIgE levels. PMID:23554133

  17. Seasonal changes in sleep duration in African American and African college students living in Washington, D.C.

    PubMed

    Volkov, Janna; Rohan, Kelly J; Yousufi, Samina M; Nguyen, Minh-Chau; Jackson, Michael A; Thrower, Courtney M; Postolache, Teodor T

    2007-06-12

    Duration of nocturnal melatonin secretion, a marker of "biological night" that relates to sleep duration, is longer in winter than in summer in patients with seasonal affective disorder (SAD), but not in healthy controls. In this study of African and African American college students, we hypothesized that students who met criteria for winter SAD or subsyndromal SAD (S-SAD) would report sleeping longer in winter than in summer. In addition, based on our previous observation that Africans report more "problems" with change in seasons than African Americans, we expected that the seasonal changes in sleep duration would be greater in African students than in African American students. Based on Seasonal Pattern Assessment Questionnaire (SPAQ) responses, African American and African college students in Washington, D.C. (N = 575) were grouped into a winter SAD/S-SAD group or a no winter diagnosis group, and winter and summer sleep length were determined. We conducted a 2 (season) x 2 (sex) x 2 (ethnicity) x 2 (winter diagnosis group) ANCOVA on reported sleep duration, controlling for age. Contrary to our hypothesis, we found that African and African American students with winter SAD/S-SAD report sleeping longer in the summer than in the winter. No differences in seasonality of sleep were found between African and African American students. Students with winter SAD or S-SAD may need to sacrifice sleep duration in the winter, when their academic functioning/efficiency may be impaired by syndromal or subsyndromal depression, in order to meet seasonally increased academic demands.

  18. A Comparison of African and Mainstream Culture on African-American Students in Public Elementary Schools

    ERIC Educational Resources Information Center

    Green-Gibson, Andrea

    2011-01-01

    This mixed, causal-comparative study was an investigation of culture infusion methods and AYP of two different public schools in Chicago, a school that infuses African culture and a school that does not. The purpose of the study was to identify if there was a significant causative relationship between culture infusion methods and Adequate Yearly…

  19. Assessment of the Status of African-Americans. Volume III: The Education of African-Americans.

    ERIC Educational Resources Information Center

    Willie, Charles V., Ed.; Garibaldi, Antoine M., Ed.; Reed, Wornie L., Ed.

    In 1987 a project was undertaken to assess the status of African Americans in the United States in the topical areas to be addressed by the National Research Council's Study Committee on the Status of Black Americans: education, employment, income and occupations, political participation and the administration of justice, social and cultural…

  20. Key Copyright Issues in African Distance Education: A South African Case Study

    ERIC Educational Resources Information Center

    Ncube, Caroline B.

    2011-01-01

    This report draws primarily on the results of the recently concluded African Copyright and Access to Knowledge (ACA2K) Project, which investigated copyright and access to learning materials in face-to-face, distance education (DE), and dual-mode tertiary educational institutions in Egypt, Ghana, Kenya, Morocco, Mozambique, Senegal, South Africa,…