Real-time phase-contrast x-ray imaging: a new technique for the study of animal form and function

BACKGROUND: Despite advances in imaging techniques, real-time visualization of the structure and dynamics of tissues and organs inside small living animals has remained elusive. Recently, we have been using synchrotron x-rays to visualize the internal anatomy of millimeter-sized opaque, living animals. This technique takes advantage of partially-coherent x-rays and diffraction to enable clear visualization of internal soft tissue not viewable via conventional absorption radiography. However, because higher quality images require greater x-ray fluxes, there exists an inherent tradeoff between image quality and tissue damage. RESULTS: We evaluated the tradeoff between image quality and harm to the animal by determining the impact of targeted synchrotron x-rays on insect physiology, behavior and survival. Using 25 keV x-rays at a flux density of 80 μW/mm(-2), high quality video-rate images can be obtained without major detrimental effects on the insects for multiple minutes, a duration sufficient for many physiological studies. At this setting, insects do not heat up. Additionally, we demonstrate the range of uses of synchrotron phase-contrast imaging by showing high-resolution images of internal anatomy and observations of labeled food movement during ingestion and digestion. CONCLUSION: Synchrotron x-ray phase contrast imaging has the potential to revolutionize the study of physiology and internal biomechanics in small animals. This is the only generally applicable technique that has the necessary spatial and temporal resolutions, penetrating power, and sensitivity to soft tissue that is required to visualize the internal physiology of living animals on the scale from millimeters to microns

Addressing human-tiger conflict using socio-ecological information on tolerance and risk

Tigers are critically endangered due to deforestation and persecution. Yet in places, Sumatran tigers (Panthera tigris sumatrae) continue to coexist with people, offering insights for managing wildlife elsewhere. Here, we couple spatial models of encounter risk with information on tolerance from 2,386 Sumatrans to reveal drivers of human-tiger conflict. Risk of encountering tigers was greater around populated villages that neighbored forest or rivers connecting tiger habitat; geographic profiles refined these predictions to three core areas. People’s tolerance for tigers was related to underlying attitudes, emotions, norms and spiritual beliefs. Combining this information into socio-ecological models yielded predictions of tolerance that were 32 times better than models based on social predictors alone. Pre-emptive intervention based on these socio-ecological predictions could have averted up to 51% of attacks on livestock and people, saving 15 tigers from the wild. Our work provides further evidence of the benefits of interdisciplinary research on conservation conflicts

Genome-wide analysis identifies 12 loci influencing human reproductive behavior.

The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits

Multi-dimensional carbon nanofibers for supercapacitor electrodes

Four different types of porous carbon nanofibers (CNFs), plain, hollow, multi-channel (MC), and hollowed MC, were fabricated using coaxial electrospinning and thermal treatment for supercapacitor electrodes. The influence of the porosity on the specific surface area (SSA), pore volumes, and electrochemical propoerties of porous CNFs were investigated. The comparisons of their properties are a valuable work with same methods, becuase electrochemical performances are depending on the measurement conditions. Among them, the hollowed MC CNF structure was indicated the highest SSA and pore volumes. In addition, their hybrid structures with multi-walled carbon nanotubes (MWCNTs) were analyzed in therms of their porosity, SSA, and electrochemical properties for supercapacitors (specific capacitance and long-term cycling). These hybrid structures can improve overall porosity and electrochemical propoerties due to the extra mesoporous structures formed by entangling MWCNTs. In conclusion, these porous CNFs have a promising potential for various fields which need high porosity and SSA, and can be used as the platforms for catalysts, sensors, or energy devices.clos

More than $1 billion needed annually to secure Africa's protected areas with lions

Protected areas (PAs) play an important role in conserving biodiversity and providing ecosystem services, yet their effectiveness is undermined by funding shortfalls. Using lions (Panthera leo) as a proxy for PA health, we assessed available funding relative to budget requirements for PAs in Africa’s savannahs. We compiled a dataset of 2015 funding for 282 state-owned PAs with lions. We applied three methods to estimate the minimum funding required for effective conservation of lions, and calculated deficits. We estimated minimum required funding as $978/km2 per year based on the cost of effectively managing lions in nine reserves by the African Parks Network;$1,271/km2 based on modeled costs of managing lions at ≥50% carrying capacity across diverse conditions in 115 PAs; and $2,030/km2 based on Packer et al.’s [Packer et al. (2013) Ecol Lett 16:635–641] cost of managing lions in 22 unfenced PAs. PAs with lions require a total of$1.2 to $2.4 billion annually, or ∼$1,000 to 2,000/km2, yet received only $381 million annually, or a median of$200/km2. Ninety-six percent of range countries had funding deficits in at least one PA, with 88 to 94% of PAs with lions funded insufficiently. In funding-deficit PAs, available funding satisfied just 10 to 20% of PA requirements on average, and deficits total $0.9 to$2.1 billion. African governments and the international community need to increase the funding available for management by three to six times if PAs are to effectively conserve lions and other species and provide vital ecological and economic benefits to neighboring communities.Griffith Sciences, Environmental Futures Research InstituteFull Tex