Morphological and digestive adjustments buffer performance:How staging shorebirds cope with severe food declines

Organisms cope with environmental stressors by behavioral, morphological, and physiological adjustments. Documentation of such adjustments in the wild provides information on the response space in nature and the extent to which behavioral and bodily adjustments lead to appropriate performance effects. Here we studied the morphological and digestive adjustments in a staging population of migrating Great Knots Calidris tenuirostris in response to stark declines in food abundance and quality at the Yalu Jiang estuarine wetland (northern Yellow Sea, China). At Yalu Jiang, from 2011 to 2017 the densities of intertidal mollusks, the food of Great Knots, declined 15‐fold. The staple prey of Great Knots shifted from the relatively soft‐shelled bivalve Potamocorbula laevis in 2011–2012 to harder‐shelled mollusks such as the gastropod Umbonium thomasi in 2016–2017. The crushing of the mollusks in the gizzard would require a threefold to 11‐fold increase in break force. This was partially resolved by a 15% increase in gizzard mass which would yield a 32% increase in shell processing capacity. The consumption of harder‐shelled mollusks was also accompanied by reliance on regurgitates to excrete unbreakable parts of prey, rather than the usual intestinal voidance of shell fragments as feces. Despite the changes in digestive morphology and strategy, there was still an 85% reduction in intake rate in 2016–2017 compared with 2011–2012. With these morphological and digestive adjustments, the Great Knots remaining faithful to the staging site to a certain extent buffered the disadvantageous effects of dramatic food declines. However, compensation was not complete. Locally, birds will have had to extend foraging time and use a greater daily foraging range. This study offers a perspective on how individual animals may mitigate the effects of environmental change by morphological and digestive strategies and the limits to the response space of long‐distance migrating shorebirds in the wild

Nicotine Enhances Staphylococcus epidermidis Biofilm Formation by Altering the Bacterial Autolysis, Extracellular DNA Releasing, and Polysaccharide Intercellular Adhesin Production

Staphylococcus epidermidis is a common bacterial colonizer of human skin and mucous membranes, yet it has emerged as an important nosocomial pathogen largely due to its ability to form biofilms. Tobacco smoke has been demonstrated as a contributor to various infection diseases by improving the biofilm formation of multiple bacterial species; however, the association between tobacco smoke and S. epidermidis biofilm is still unclear. In this study, we tested the effect of nicotine, one of the most active components of tobacco, on S. epidermidis biofilm formation, and we studied the underlying mechanisms. Our results showed that nicotine promoted the biofilm formation of S. epidermidis 1457 strain (SE1457) and enhanced its initial attachment to a polyethylene surface as well as polysaccharide intercellular adhesin (PIA) production. In addition, an increased extracellular DNA release and a higher autolysis rate of SE1457 was detected after nicotine treatment, which was consistent with the increased ratio of dead cells in nicotine-treated SE1457 biofilm observed with confocal laser-scanning microscopy. Furthermore, the effect of nicotine on several autolysis-related and biofilm-related gene knockout mutants of SE1457 was tested. It showed that in ΔsaeRS, ΔlytSR, and ΔsceD, nicotine induced increase in biofilm formation was similar to that in SE1457; but in ΔarlRS, ΔatlE, and ΔicaC, the effect was obviously impaired. Consistently, the increase of the bacterial autolysis rate in ΔarlRS and ΔatlE induced by nicotine was not as significant as that in SE1457. Meanwhile, the growth inhibition of nicotine on SE1457 was observed, and it was much less on ΔarlRS and restored by the arlRS complementation. The arlRS transcription in SE1457 was inhibited by nicotine during cultivation as indicated by a promoter reporter assay using green fluoresent protein. Taken together, our study indicates that nicotine improves S. epidermidis biofilm formation by promoting its initial attachment and intercellular accumulation; the arlRS, atlE, and ica genes mediating bacterial autolysis and PIA production play an important role in this process

Rapid assessment of knowledge, attitudes, practices, and risk perception related to the prevention and control of Ebola virus disease in three communities of Sierra Leone

Questionnaire on Ebola knowledge, attitudes, practices, and risk perception in three communities of Sierra Leone, 2015. (DOCX 34 kb

Hierarchical domain structure and extremely large wall current in epitaxial BiFeO3 thin films

Funding: J.F.S. acknowledges the financial support of the Strategic Priority Research Program of the Chinese Academy of Sciences (grant number XDB07030200).Erasable electrical conductive domain walls in an insulating ferroelectric matrix provide novel functionalities for applications in logic and memory devices. The crux of such success requires sufficiently high wall currents to drive high‐speed and high‐power nanodevices. This work provides an appealing strategy to increase the current by two orders of magnitude through the careful selection of current flowing paths along the charged walls. The dense walls come into form through the hierarchical evolution of the 71°, 109°, and 180° domains of epitaxial BiFeO3 films in a planar‐geometry ferroelectric resistance‐switching memory cell. The engineered films grown on SrTiO3 and GdScO3 substrates allow the observation of detailed local configurations and the evolution of the different domain types using vector piezo‐force microscopy. The higher local electrical conductivity near the charged domain walls is identified by conductive atomic‐force microscopy. It is shown that 180° domain reversal proceeds by three‐step 71° rotations of the pristine domains. Surprisingly, a maximum current of ≈300 nA is observed for current paths along charge‐uncompensated head‐to‐head hierarchical domain walls connecting the two electrodes on the film surface. Furthermore, the achievable current level can be conveniently controlled by varying the relative directions of the initial polarization and the applied field.PostprintPeer reviewe

Temporary formation of highly conducting domain walls for non-destructive read-out of ferroelectric domain-wall resistance switching memories

Funding: Strategic Priority Research Program of the Chinese Academy of Sciences (grant number XDB07030200) (JFS).Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO3 thin films formed in mesa-geometry structures. Partially switched domains, which enable the formation of conductive walls during the read operation, spontaneously retract when the read voltage is removed, reducing the accumulation of mobile defects at the domain walls and potentially improving the device stability. Three-terminal memory devices produced 14 nA read currents at an operating voltage of 5 V, and operated up to T = 85 °C. The gap length can also be smaller than the film thickness, allowing the realization of ferroelectric memories with device dimensions far below 100 nm.PostprintPostprintPeer reviewe

The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

Data Provenance and Data Management in eScience

eScience allows scientific research to be carried out in highly distributed environments. The complex nature of the interactions in an eScience infrastructure, which often involves a range of instruments, data, models, applications, people and computational facilities, suggests there is a need for data provenance and data management (DPDM). The W3C Provenance Working Group defines the provenance of a resource as a “record that describes entities and processes involved in producing and delivering or otherwise influencing that resource”. It has been widely recognised that provenance is a critical issue to enable sharing, trust, authentication and reproducibility of eScience process.   Data Provenance and Data Management in eScience identifies the gaps between DPDM foundations and their practice within eScience domains including clinical trials, bioinformatics and radio astronomy. The book covers important aspects of fundamental research in DPDM including provenance representation and querying. It also explores topics that go beyond the fundamentals including applications. This book is a unique reference for DPDM with broad appeal to anyone interested in the practical issues of DPDM in eScience domains

Accuracy and reproducibility of IOLMaster versus contact ultrasound biometry

AIM: To compare biometry results of IOLMaster and contact ultrasound(US)anterior segment parameters, and to evaluate the calculation accuracy and repeatability of intraocular lens power in both.METHODS: Preoperative measurement of anterior segment parameters were prospectively obtained in 137 eyes of 121 subjects with the IOLMaster compared with the US. Postoperative best corrected visual acuity(BCVA)and the actual diopter were measured.RESULTS: There was an excellent correlation between IOLMaster and US measurements for the ACD(r=0.823, Pr=0.996, PPCONCLUSION: Partial coherence biometry using the IOLMaster provides the more accurate and reliable anterior segment parameters measurement values. A high degree of agreement between US and IOLMaster is noted. The IOLMaster not only has the advantage of performing noncontact examinations, but also produces various additional data simultaneously and may thus obviate the need for multiple examinations