9 research outputs found
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The ecology and evolution of parental care in the microhylid frogs of New Guinea
I studied the evolutionary relationships and parental care behaviors of an assemblage of 19 species of microhylid frogs from a mid-elevation site in Papua New Guinea. The microhylid frogs of New Guinea are an exceptionally diverse radiation of frogs (\u3e150 species in \u3e20 Genera) on the largest tropical island. Two novel parental care behaviors for male frogs (froglet attendance and froglet transport) are described and quantified and six ecological guilds are defined to better understand variation in parental care behaviors across species. Patterns of parental care behaviors found in ecological guilds of the assemblage were studied in the field with experiments and observations. I discuss the functions and importance of parental care in adaptive suites at the guild level. Results from adult removal experiments for clutches of two species (one terrestrial and one arboreal breeder) confirm that attendance significantly increases offspring survivorship. I show how the proximate causes of mortality in unattended clutches most likely reflect diverse selective pressures acting on species in different microhabitats. Desiccation appears to be a major selective force molding the parental care behaviors of the arboreal frog, Oreophryne sp. rattler whereas predation appears to be the major selective pressure accounting for the parental care behaviors exhibited by the terrestrial frog, Hylophorbus rufescens .I sequenced DNA (1381 base pairs from the 18S and 16S rRNA genes) and coded 36 behavioral characters to hypothesize the phylogeny of Papuan microhylid frogs. Results of phylogenetic analyses suggest that (1) both of the currently recognized Papuan subfamilies, the Genyophryninae and the Asterophryinae are artificial taxa and should be combined into the Asterophryinae (Gunther, 1858), (2) currently recognized genera Austrochaperina, Cophixalus , and Oreophryne are polyphyletic, (3) the previously proposed phylogenetic hypotheses of Wu (1994), the monophyly of both the subfamilies and genera of these microhylid frogs are refuted. I discuss how specific parental care behaviors evolved in these frogs relative to ecological guilds in my preferred hypothesis of phylogeny
Breeding in bamboo: a novel anuran reproductive strategy discovered in Rhacophorid frogs of the Western Ghats, India
Amphibians exhibit extraordinarily diverse sets of reproductive strategies among vertebrates. Understanding life history strategies in an evolutionary framework is lacking for many amphibian species in the tropics. Here, we report a novel reproductive mode where adult frogs enter hollow internodes of bamboo via a small opening, deposit direct developing eggs, and provide parental care. This behaviour is observed in two species of the frog genus Raorchestes. The first description of this unique life history and details of nest site characteristics and embryo development are provided along with ecological comparisons. Evolution of novel reproductive modes and parental care are discussed in context of natural selection. Dearth of natural history information on amphibians in the Western Ghats and much of the South-East Asian region is highlighted with suggestions for further studies.(c) 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114, 1-11
Quantifying the role of online news in linking conservation research to Facebook and Twitter
Conservation Biology293825-83
Breeding in bamboo: a novel anuran reproductive strategy discovered in Rhacophorid frogs of the Western Ghats, India
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Evaluation of Ultra Clean Fuels from Natural Gas
ConocoPhillips, in conjunction with Nexant Inc., Penn State University, and Cummins Engine Co., joined with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) in a cooperative agreement to perform a comprehensive study of new ultra clean fuels (UCFs) produced from remote sources of natural gas. The project study consists of three primary tasks: an environmental Life Cycle Assessment (LCA), a Market Study, and a series of Engine Tests to evaluate the potential markets for Ultra Clean Fuels. The overall objective of DOE's Ultra Clean Transportation Fuels Initiative is to develop and deploy technologies that will produce ultra-clean burning transportation fuels for the 21st century from both petroleum and non-petroleum resources. These fuels will: (1) Enable vehicles to comply with future emission requirements; (2) Be compatible with the existing liquid fuels infrastructure; (3) Enable vehicle efficiencies to be significantly increased, with concomitantly reduced CO{sub 2} emissions; (4) Be obtainable from a fossil resource, alone or in combination with other hydrocarbon materials such as refinery wastes, municipal wastes, biomass, and coal; and (5) Be competitive with current petroleum fuels. The objectives of the ConocoPhillips Ultra Clean Fuels Project are to perform a comprehensive life cycle analysis and to conduct a market study on ultra clean fuels of commercial interest produced from natural gas, and, in addition, perform engine tests for Fisher-Tropsch diesel and methanol in neat, blended or special formulations to obtain data on emissions. This resulting data will be used to optimize fuel compositions and engine operation in order to minimize the release of atmospheric pollutants resulting from the fuel combustion. Development and testing of both direct and indirect methanol fuel cells was to be conducted and the optimum properties of a suitable fuel-grade methanol was to be defined. The results of the study are also applicable to coal-derived FT liquid fuels. After different gas clean up processes steps, the coal-derived syngas will produce FT liquid fuels that have similar properties to natural gas derived FT liquids
Top 100 questions for biodiversity conservation in Southeast Asia
Southeast (SE) Asia holds high regional biodiversity and endemism levels but is also one of the world's most threatened regions. Local, regional and global threats could have severe consequences for the future survival of many species and the provision of ecosystem services.In the face of myriad pressing environmental problems, we carried out a research prioritisation exercise involving 64 experts whose research relates to conservation biology and sustainability in SE Asia. Experts proposed the most pressing research questions which, if answered, would advance the goals of biodiversity conservation and sustainable development in SE Asia. We received a total of 333 questions through three rounds of elicitation, ranked them (by votes) following a workshop and grouped them into themes.The top 100 questions depict SE Asia as a region where strong pressures on biodiversity interact in complex and poorly understood ways. They point to a lack of information about multiple facets of the environment, while exposing the many threats to biodiversity and human wellbeing. The themes that emerged indicate the need to evaluate specific drivers of biodiversity loss (wildlife harvesting, agricultural expansion, climate change, infrastructure development, pollution) and even to identify which species and habitats are most at risk. They also suggest the need to study the effectiveness of practice-based solutions (protected areas, ecological restoration), the human dimension (social interventions, organisational systems and processes and, the impacts of biodiversity loss and conservation interventions on people). Finally, they highlight gaps in fundamental knowledge of ecosystem function. These 100 questions should help prioritise and coordinate research, conservation, education and outreach activities and the distribution of scarce conservation resources in SE Asia
Memory scrutinized through electrical brain stimulation: A review of 80 years of experiential phenomena
International audienceElectrical brain stimulations (EBS) sometimes induce reminiscences, but it is largely unknown what type of memories they can trigger. We reviewed 80 years of literature on reminiscences induced by EBS and added our own database. We classified them according to modern conceptions of memory. We observed a surprisingly large variety of reminiscences covering all aspects of declarative memory. However, most were poorly detailed and only a few were episodic. This result does not support theories of a highly stable and detailed memory, as initially postulated, and still widely believed as true by the general public. Moreover, memory networks could only be activated by some of their nodes: 94.1% of EBS were temporal, although the parietal and frontal lobes, also involved in memory networks, were stimulated. The qualitative nature of memories largely depended on the site of stimulation: EBS to rhinal cortex mostly induced personal semantic reminiscences, while only hippocampal EBS induced episodic memories. This result supports the view that EBS can activate memory in predictable ways in humans
Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element
The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5′ ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains