17 research outputs found

    Undergraduate Biology Education Research Gordon Research Conference: A Meeting Report

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    The 2019 Undergraduate Biology Education Research Gordon Research Conference (UBER GRC), titled “Achieving Widespread Improvement in Undergraduate Education,” brought together a diverse group of researchers and practitioners working to identify, promote, and understand widespread adoption of evidence-based teaching, learning, and success strategies in undergraduate biology. Graduate students and postdocs had the additional opportunity to present and discuss research during a Gordon Research Seminar (GRS) that preceded the GRC. This report provides a broad overview of the UBER GRC and GRS and highlights major themes that cut across invited talks, poster presentations, and informal discussions. Such themes include the importance of working in teams at multiple levels to achieve instructional improvement, the potential to use big data and analytics to inform instructional change, the need to customize change initiatives, and the importance of psychosocial supports in improving undergraduate student well-being and academic success. The report also discusses the future of the UBER GRC as an established meeting and describes aspects of the conference that make it unique, both in terms of facilitating dissemination of research and providing a welcoming environment for conferees

    BioSentinel: Monitoring DNA Damage Repair Beyond Low Earth Orbit on a 6U Nanosatellite

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    We are designing and developing a 6U nanosatellite as a secondary payload to fly aboard NASAs Space Launch System (SLS) Exploration Mission (EM) 1, scheduled for launch in late 2017. For the first time in over forty years, direct experimental data from biological studies beyond low Earth orbit (LEO) will be obtained during BioSentinels 12- to 18-month mission. BioSentinel will measure the damage and repair of DNA in a biological organism and allow us to compare that to information from onboard physical radiation sensors. This data will be available for validation of existing models and for extrapolation to humans.The BioSentinel experiment will use the organism Saccharomyces cerevisiae (yeast) to report DNA double-strand-break (DSB) events that result from space radiation. DSB repair exhibits striking conservation of repair proteins from yeast to humans. The flight strain will include engineered genetic defects that prevent growth and division until a radiation-induced DSB activates the yeasts DNA repair mechanisms. The triggered culture growth and metabolic activity directly indicate a DSB and its repair. The yeast will be carried in the dry state in independent microwells with support electronics. The measurement subsystem will sequentially activate and monitor wells, optically tracking cell growth and metabolism. BioSentinel will also include TimePix radiation sensors implemented by JSCs RadWorks group. Dose and Linear Energy Transfer (LET) data will be compared directly to the rate of DSB-and-repair events measured by the S. cerevisiae biosentinels. BioSentinel will mature nanosatellite technologies to include: deep space communications and navigation, autonomous attitude control and momentum management, and micropropulsion systems to provide an adaptable nanosatellite platform for deep space uses

    Microsatellite DNA Analysis Shows that Greater Sage Grouse Leks Are Not Kin Groups

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    The spectacular social courtship displays of lekking birds are thought to evolve via sexual selection, but this view does not easily explain the participation of many males that apparently fail to mate. One of several proposed solutions to this ‘lek skew paradox’ is that kin selection favors low-ranking males joining leks to increase the fitness of closely related breeders. We investigated the potential for kin selection to operate in leks of the greater sage grouse, Centrocercus urophasianus, by estimating relatedness between lekking males using microsatellite DNA markers. We also calibrated these estimates using data from known families. Mean relatedness within leks was statistically indistinguishable from zero. We also found no evidence for local clustering of kin during lek display, although males tended to range closer to kin when off the lek. These results make kin selection an unlikely solution to the lek skew paradox in sage grouse. Together with other recent studies, they also raise the question of why kin selection apparently promotes social courtship in some lekking species, but not in others

    Morphometric differentiation between two murid rodents, Praomys tullbergi (Thomas, 1894) and Praomys rostratus (Miller, 1900), in west Africa.

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    International audienceMorphometric differentiation between the two species of the genus Praomys Thomas (1915) inhabiting West Africa was investigated using univariate and multivariate statistics on external, cranial and dental measurements. One hundred and seventy six adult specimens (78 P. tullbergi and 98 P. rostratus) from fifteen localities throughout the Upper Guinean rainforest were analyzed. All specimens had been previously identified to species level by molecular analyses (16S rRNA and/or cytochrome b gene sequencing). Sexual dimorphism was observed in both species, but was more significant in P. rostratus than in P. tullbergi. Body weight was significantly lower in P. tullbergi than in P. rostratus. Moreover, males of P. tullbergi had a significantly smaller head and body length than males of P. rostratus. Specimens of P. tullbergi of both sexes were on average smaller than males of P. rostratus regarding all cranial and dental measurements, and smaller than females of P. rostratus with regard to most measurements. However, none of the cranial or dental measurements treated in our study could be used alone to separate P. rostratus and P. tullbergi, because of considerable overlap in the ranges of each variable. A good discrimination between the two species was obtained by means of craniometrical multivariate statistics, several rostrum measurements being significantly lower in P. tullbergi than in P. rostratus. Discrepancies between our results and former published studies are hypothesized to be due to differences between the variables used and/or the geographical areas covered

    Morphometric differentiation between two murid rodents, Praomys tullbergi (Thomas, 1894) and Praomys rostratus (Miller, 1900), in west Africa.

    No full text
    International audienceMorphometric differentiation between the two species of the genus Praomys Thomas (1915) inhabiting West Africa was investigated using univariate and multivariate statistics on external, cranial and dental measurements. One hundred and seventy six adult specimens (78 P. tullbergi and 98 P. rostratus) from fifteen localities throughout the Upper Guinean rainforest were analyzed. All specimens had been previously identified to species level by molecular analyses (16S rRNA and/or cytochrome b gene sequencing). Sexual dimorphism was observed in both species, but was more significant in P. rostratus than in P. tullbergi. Body weight was significantly lower in P. tullbergi than in P. rostratus. Moreover, males of P. tullbergi had a significantly smaller head and body length than males of P. rostratus. Specimens of P. tullbergi of both sexes were on average smaller than males of P. rostratus regarding all cranial and dental measurements, and smaller than females of P. rostratus with regard to most measurements. However, none of the cranial or dental measurements treated in our study could be used alone to separate P. rostratus and P. tullbergi, because of considerable overlap in the ranges of each variable. A good discrimination between the two species was obtained by means of craniometrical multivariate statistics, several rostrum measurements being significantly lower in P. tullbergi than in P. rostratus. Discrepancies between our results and former published studies are hypothesized to be due to differences between the variables used and/or the geographical areas covered

    A molecular diagnostic for identifying central Africa forest artiodactyls from faecal pellets.

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    International audienceSmall to medium-sized central African forest artiodactyls constitute a diverse yet heavily hunted group composed primarily of species within the genera Cephalophus, Neotragus, Tragelaphus and Hyemoschus. Of these genera, Cephalophus is the richest with as many as seven sympatric species known to occur in central African forests. However, differentiating species from their faeces or from tissue where the whole carcass is unavailable is very difficult. In order to develop a robust molecular diagnostic for species identification, a database of mitochondrial cytochrome b (553 bp) and control region (675 bp) sequences was compiled from all forest Cephalophus species and other similarly sized, sympatric Tragelaphus, Neotragus and Hyemoschus species. Reference phylogenies from each marker were then used to recover the identity of sequences obtained from unknown faecal samples collected in the field. Results were then compared to determine which region best recovered species identity with the highest statistical support. Restriction fragment length polymorphisms (RFLPs) were also assessed as an alternative method for rapid species identification. Of themethods examined, tree-based analyses built on a geographically comprehensive database of control region sequences was the best means of reliably recovering species identity from central African duikers. However, three sister taxa appear indistinguishable (Cephalophus callipygus, Cephalophus ogilbyi and Cephalophus weynsi) and not all species were monophyletic. This lack of monophyly may be due to incomplete lineage sorting commonly observed in recently derived taxa, hybridization or the presence of nuclear translocated copies of mitochondrial DNA. The high level of intra-specific variation and lack of robust species-specific diagnostic sites made an RFLP-based approach to duiker species identification difficult to implement. The tree-based control region diagnostic presented here has many important applications including fine-scale mapping of species distributions, identification of confiscated tissue and environmental impact assessments

    BioSentinel: Mission Development of a Radiation Biosensor to Gauge DNA Damage and Repair Beyond Low Earth Orbit on a 6U Nanosatellite

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    We are designing and developing a "6U" (10 x 22 x 34 cm; 14 kg) nanosatellite as a secondary payload to fly aboard NASA's Space Launch System (SLS) Exploration Mission (EM) 1, scheduled for launch in late 2017. For the first time in over forty years, direct experimental data from biological studies beyond low Earth orbit (LEO) will be obtained during BioSentinel's 12- to 18- month mission. BioSentinel will measure the damage and repair of DNA in a biological organism and allow us to compare that to information from onboard physical radiation sensors. In order to understand the relative contributions of the space environment's two dominant biological perturbations, reduced gravity and ionizing radiation, results from deep space will be directly compared to data obtained in LEO (on ISS) and on Earth. These data points will be available for validation of existing biological radiation damage and repair models, and for extrapolation to humans, to assist in mitigating risks during future long-term exploration missions beyond LEO. The BioSentinel Payload occupies 4U of the spacecraft and will utilize the monocellular eukaryotic organism Saccharomyces cerevisiae (yeast) to report DNA double-strand-break (DSB) events that result from ambient space radiation. DSB repair exhibits striking conservation of repair proteins from yeast to humans. Yeast was selected because of 1) its similarity to cells in higher organisms, 2) the well-established history of strains engineered to measure DSB repair, 3) its spaceflight heritage, and 4) the wealth of available ground and flight reference data. The S. cerevisiae flight strain will include engineered genetic defects to prevent growth and division until a radiation-induced DSB activates the yeast's DNA repair mechanisms. The triggered culture growth and metabolic activity directly indicate a DSB and its successful repair. The yeast will be carried in the dry state within the 1-atm P/L container in 18 separate fluidics cards with each card having 16 independent culture microwells, with integral microchannels and filters to supply nutrients and reagents, confine the yeast to the wells, and enable optical measurement. The measurement subsystem will monitor each subgroup of culture wells continuously for several weeks, optically tracking DSBtriggered cell growth and metabolism. BioSentinel will also include physical radiation sensors based on the TimePix sensor, as implemented by JSC's RadWorks group, which record individual radiation events including estimates of their linear-energytransfer (LET) values. Radiation-dose and LET data will be compared directly to the rate of DSB-and-repair events measured by the S. cerevisiae biosentinels. The spacecraft bus will operate in a deep space environment with functions that include command and data handling, communications, power generation (via deployable solar panels) and storage, and attitude determination-and-control system with micropropulsion. Development of the BioSentinel spacecraft will mature and prove multiple nanosatellite advances in order to function well beyond LEO: Communications from distances of 500,000 km; Autonomous attitude control, momentum management, and safe mode of nanosatellites in deep space; Shielding-, hardening-, design-, and software-derived radiation tolerance for electronics; Reliable functionality for 12 - 18 months of key subsystems for biofluidics, memory, communications, power, etc.; Close integration of living biological radiation event monitors with miniature physical radiation spectrometers; Biological measurement of solar particle events beyond Earth orbit In addition to providing the first biological results from beyond LEO in over 4 decades, BioSentinel will provide an adaptable small-satellite instrument platform to perform a range of human-exploration-relevant measurements that characterize the biological consequences of multiple outer space environments. BioSentinel is being developed under NASA's Advanced Exploration Systems program

    BioSentinel: Monitoring DNA Damage Repair Beyond Low Earth Orbit on a 6U Nanosatellite

    Get PDF
    We are designing and developing a “6U” nanosatellite as a secondary payload to fly aboard NASA’s Space Launch System (SLS) Exploration Mission (EM) 1, scheduled for launch in late 2017. For the first time in over forty years, direct experimental data from biological studies beyond low Earth orbit (LEO) will be obtained during BioSentinel’s 12 to 18-month mission. BioSentinel will measure the damage and repair of DNA in a biological organism and compare that to information from onboard physical radiation sensors. This data will be available for validation of existing models and for extrapolation to humans. The BioSentinel experiment will use the organism Saccharomyces cerevisiae (yeast) to report DNA double-strand-break (DSB) events that result from space radiation. DSB repair exhibits striking conservation of repair proteins from yeast to humans. The flight strain will include engineered genetic defects that prevent growth and division until a radiation-induced DSB activates the yeast’s DNA repair mechanisms. The triggered culture growth and metabolic activity directly indicate a DSB and its repair. The yeast will be carried in the dry state in independent microwells with support electronics. The measurement subsystem will sequentially activate and monitor wells, optically tracking cell growth and metabolism. BioSentinel will also include TimePix radiation sensors implemented by JSC’s RadWorks group. Dose and Linear Energy Transfer (LET) data will be compared directly to the rate of DSB-and-repair events measured by the S. cerevisiae biosentinels. BioSentinel will mature nanosatellite technologies to include: deep space communications and navigation, autonomous attitude control and momentum management, and micropropulsion systems to provide an adaptable nanosatellite platform for deep space uses
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