bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical composition of Rosmarinus officinalis (Lamiaceae) essential oils and evaluation of their toxicity against Bruchus rufimanus (Coleoptera: Chrysomelidae: Bruchinae) in Morocco
Authors: Hannour Karima , Boughdad Ahmed , Maataoui Abdelwahed , Bouchelta Aziz
Published: May 2018

Control methods used to limit field losses caused byBruchus rufimanusBoheman, 1833 consist of synthetic insecticides that pose health risks to farmers, consumers and the environment. In an attempt to find safer alternatives, we screened essential oils from the leaves ofRosmarinus officinaliscollected in the Middle Atlas and Loukkos regions of Morocco in the laboratory as natural fumigants againstB. rufimanus.These essential oils were extracted by steam distillation using a Clevenger distiller, characterised chemically by coupled gas chromatography–mass spectrometry (GC/MS) and tested at five concentrations (0, 10, 20, 40, 80 µl/l air). The essential oils ofR. officinalismainly comprised oxygenated monoterpenes (Middle Atlas: 79.4%; Loukkos: 48.78%) and terpenes (Middle Atlas: 14.71%; Loukkos: 32.33%). The lethal concentrations (LC50) of Middle Atlas and Loukkos essential oils against male beetles ranged from, respectively, 46.53 to 1.19 µl/l air and 58.85 to 11.57 µl/l air. Similarly, doses ofR. officinalisessential oils from Middle Atlas and Loukkos lethal to females, ranged from 44.6 to 2.08 µl/l air and from 53.00 to 5.38 µl/l air, respectively. Additionally, the lethal time (LT50and LT99) of exposed adults ranged from 1–8 and from 2–13 days for different concentrations ofR. officinalisessential oils from Middle Atlas and Loukkos, respectively. With no mortality recorded in the control groups, these findings demonstrate the fumigant potential of these oils against this bruchid under the storage conditions.
Androgens Modulate Brain Responses to Sexual Stimuli in Female-to-Male Transsexuals
Authors: Ye Zheng , Mohammadi Bahram , Kopyciok Robert , Heldmann Marcus , Samii Amir , F. Münte Thomas
Published: May 2018

Abstract. Interpersonal and intrapersonal differences in brain responses to sexual stimuli have been linked with individuals’ testosterone levels. However, it remains unclear how hormones modulate brain functions underlying sexual arousal. In order to assess the effects of chronic hormonal treatment, we used functional magnetic resonance imaging in a group of female-to-male transsexuals before and during androgen therapy while they watched a set of pictures representing dressed or nude (erotic content) men or women (sex information). A broad network of cortical and subcortical regions were activated during the processing of erotic stimuli (nude vs. dressed), including the insula, amygdala, and hypothalamus. The insula activity in response to erotic male stimuli decreased over the initial 4 months of hormonal therapy. In the following 8 months, the insula response to erotic female stimuli increased. In other words, long-term androgen administration makes the brain more “male” by reducing the sexual arousal caused by male stimuli and amplifying that caused by female stimuli.
Praxis der Unterrichtsplanung
Authors: Schewior-Popp Susanne
Published: May 2018

Zusammenfassung. Unterrichtsplanung gehört für Lehrerinnen und Lehrer zum „Tagesgeschäft“. Von ihrer Qualität hängt viel für das Gelingen des Unterrichts ab. Dieser Beitrag will grundlegende Strukturelemente einer professionellen Unterrichtsplanung aufzeigen.
Forschungsbasiertes Lernen mit Schülern
Authors: Fischer Renate
Published: May 2018

Zusammenfassung. Wie können die Themen Pflegewissenschaft und Pflegeforschung im Unterricht interessant und praxisrelevant gestaltet werden? Könnte man mit Pflegeschülern echte Forschungsprojekte durchführen, um sie für dieses Thema zu motivieren und die Bedeutung einer wissenschaftlichen Denkweise im Alltag greifbar zu machen? Die Ergebnisse eines Unterrichtsprojektes an der Schule für Gesundheits- und Krankenpflege am Katholischen Klinikum Koblenz-Montabaur zeigen: Wenn eine echte Fragestellung vorliegt und die Ergebnisse auch praktische Relevanz haben, dann können Forschungsprojekte ein Weg sein, Schüler der Gesundheits- und Krankenpflege für Wissenschaft und Forschung zu begeistern.
Das Lernen unterstützen – Lerncoaching an der Krankenpflegeschule
Authors: Pelikan Silvia
Published: May 2018

Zusammenfassung. Immer mehr Lernende benötigen professionelle Begleitung, um erfolgreich lernen zu können. Am Bildungscampus Koblenz (BicK) wird aus diesem Grund seit einem Jahr Lernunterstützung in Form eines Lerncoachings angeboten. Die hier beschriebene Methode kann problemlos in den Schulalltag integriert werden.
Potentiale erkennen und Fehlerkultur in der Ausbildung fördern
Authors: Messer Misak Karin , Mircic Eva
Published: May 2018

Zusammenfassung. Qualität zu sichern und Fehlerbewusstsein bereits in der Ausbildung von diplomierten Gesundheits- und Pflegepersonal zu stärken ist eine Voraussetzung, um die internationalen Standards im Gesundheitsbereich auf einem hohen wissenschaftlichen Niveau weiter zu entwickeln. Die Nutzung von speziell adaptierten CIRS (Critical Incident Reporting System) bietet die Möglichkeit eine Basis für eine entsprechende Fehlerkultur im späteren Berufsleben zu schaffen.
A Finite Difference Time Domain Investigation of Electric Field Enhancements Along Ocean‐Continent Boundaries During Space Weather Events
Authors: Pokhrel Santosh , Nguyen Bach , Rodriguez Miguel , Bernabeu Emanuel , Simpson Jamesina J.
Published: May 2018

Geomagnetic disturbances caused by solar storms have the potential to create large‐scale geomagnetically induced currents in long conductors at the Earth's surface. These may disrupt the operation of electric power grids and cause blackouts. Ocean‐continent boundary regions are of particular concern because of the sharp contrast between the higher ocean electrical conductivity compared to the lower continental conductivity. This contrast may generate high‐amplitude geoelectric fields and cause power grids in coastal regions to be more vulnerable to space weather hazards. Previously, analytical calculations were used to estimate geomagnetically induced currents at ocean‐continent boundaries. However, for the analytical equations to be solvable, the physics and geometries of the problem were simplified. As a result of these simplifications and due to a lack of published measurements examining this issue in coastal regions, it is difficult to know for sure whether there are unique hazards to electric power grids at ocean‐continent boundaries. In this paper, a grid‐based, time domain modeling approach is used to solve the complete Maxwell's equations, which permits accommodation of (1) the complete physics of the propagating electromagnetic fields from disturbed ionospheric currents through the air and into the lithosphere and even into the ocean via the skin effect and (2) more realistic coastal geometries. Using this more robust approach, in the variety of scenarios studied in this paper, only a local enhancement of the electric fields was observed, which are expected to only pose potential hazards to power grids only a local scale near ocean‐continent boundaries.
Spacecraft‐Charging Mitigation of a High‐Power Electron Beam Emitted by a Magnetospheric Spacecraft: Simple Theoretical Model for the Transient of the Spacecraft Potential
Authors: Lucco Castello F. , Delzanno G. L. , Borovsky J. E. , Miars G. , Leon O. , Gilchrist B. E.
Published: May 2018

A spacecraft‐charging mitigation scheme necessary for the operation of a high‐power electron beam in the low‐density magnetosphere is analyzed. The scheme is based on a plasma contactor, that is, a high‐density charge‐neutral plasma emitted prior to and during beam emission and its ability to emit high ion currents without strong space‐charge limitations. A simple theoretical model for the transient of the spacecraft potential and contactor expansion during beam emission is presented. The model focuses on the contactor ion dynamics and is valid in the limit when the ion contactor current is equal to the beam current. The model is found in very good agreement with particle‐in‐cell simulations over a large parametric study that varies the initial expansion time of the contactor, the contactor current, and the ion mass. The model highlights the physics of the spacecraft‐charging mitigation scheme, indicating that the most important part of the dynamics is the evolution of the outermost ion front, which is pushed away by the charge accumulated in the system by the beam. The model can be also used to estimate the long‐time evolution of the spacecraft potential. For a short contactor expansion (0.3‐ or 0.6‐ms helium plasma or 0.8‐ms argon plasma, both with 1‐mA current) it yields a peak spacecraft potential of the order of 1–3 kV. This implies that a 1‐mA relativistic electron beam would be easily emitted by the spacecraft.
Frontal Dynamics of a Buoyancy‐Driven Coastal Current: Quantifying Buoyancy, Wind, and Isopycnal Tilting Influence on the Nova Scotia Current
Authors: Dever Mathieu , Skagseth Øystein , Drinkwater Ken , Hebert David
Published: May 2018

The focus of this study is on the relative roles of winds and buoyancy in driving the Nova Scotia Current (NSC) utilizing detailed hydrographic glider transects along the Halifax Line. We define a Hydrographic Wind Index (HWI) using a simplistic two‐layer model to represent the NSC and its frontal system. The HWI is based on local characteristics of the density front extracted from the glider data (e.g., frontal slope). The impact of wind‐driven isopycnal tilting on the frontal slope is estimated and corrected for to accurately scale the buoyancy‐driven component of the NSC. Observations from independent current profilers deployed across the NSC confirm that the HWI captures the low‐frequency variability of the NSC. The monthly wind‐driven flow is estimated to represent between 1.0% (±0.1%) and 48% (±1%) of the total alongshore currents, with a yearly mean of about 36% (±1%). We demonstrate that using local conditions is more appropriate to the study of buoyancy‐driven currents ranging over distances on the order of
(100 km), compared to the traditional approach based on upstream conditions. Contrary to the traditional approach, the HWI is not affected by the advective time lag associated with the downshelf propagation of the buoyant water coming from the upstream source. However, the HWI approach requires high‐resolution data sets, as errors on the estimates of the buoyancy‐ and wind‐driven flows become large as the sampling resolution decreases. Despite being data intensive, we argue that the HWI is also applicable to multisource currents, where upstream conditions are difficult to define.
Seasonal Variability and Generation Mechanisms of Nonlinear Internal Waves in the Strait of Georgia
Authors: Li Lan , Pawlowicz Richard , Wang Caixia
Published: May 2018

Seasonal variability and generation mechanisms of large nonlinear internal waves are reported, based on an analysis of 9 years of continuous observational data collected at nodes of the Ocean Networks Canada coastal observatory in the Strait of Georgia, Canada. About one thousand large nonlinear internal wave packets were identified. The timing of these packets suggests a very strong correlation with daily tides and fortnightly cycles. More waves are seen during the stronger tides of the fortnightly cycle but overall waves are seen in less than 40% of all days. Other wave characteristics show seasonal variations. In winter, when the pycnocline is weaker, both the spatial and temporal scales of internal waves are several times larger than summertime waves and wave amplitudes can approach 30 m. These waves are large enough vertically but small enough horizontally that standard acoustic Doppler current profiler (ADCP) processing algorithms present a strongly distorted view of wave shape and features. A specialized reprocessing of the beam velocities is used to correctly measure the wave velocity field and to determine wave propagation speed and direction. In addition to the previously known northward‐propagating waves in the Strait, we also found waves propagating in other directions and a noticeable correlation with winds, which may be a proxy for spatial variations in density and/or velocity shear. By considering wave propagation direction, relationship with tidal phase, and relationship with wind, three generation mechanisms were found. Two particularly interesting generation mechanisms involve waves radiating from the Sand Heads area.
Upper Ocean Cooling in a Coupled Climate Model Due to Light Attenuation by Yellowing Materials
Authors: Kim Grace E. , Gnanadesikan Anand , Del Castillo Carlos E. , Pradal Marie‐Aude
Published: May 2018

Colored detrital matter consists of dissolved organic molecules and detrital materials that impart a yellow shift to the ocean's color. These materials reduce light penetration, concentrating heating by sunlight closer to the surface. We ran two climate model simulations: one of an ocean including colored detrital matter (Yellow Ocean) and one without (Green Ocean). Due to the decreased water clarity in the Yellow Ocean, upper ocean heat content was lower and temperatures were colder compared to the Green Ocean. The difference between these simulations is opposite to the ocean warming that has been observed in recent decades. Increasing precipitation in high‐latitude regions has also been observed, with greater inputs of terrestrial organic materials to the ocean. We suggest that an increase in these yellowing materials behaves as a buffer that mitigates some effects of a warming climate. Future studies should investigate this link between the atmosphere, land, and ocean systems.
What Causes Radiation Belt Enhancements: A Survey of the Van Allen Probes Era
Authors: Boyd A. J. , Turner D. L. , Reeves G. D. , Spence H. E. , Baker D. N. , Blake J. B.
Published: May 2018

We survey radiation belt enhancement events during the Van Allen Probes era to determine what mechanism is the dominant cause of enhancements and where it is most effective. Two primary mechanisms have been proposed: (1) betatron/Fermi acceleration due to the Earthward radial transport of electrons, which produces monotonic gradients in phase space density (PSD), and (2) “local acceleration” due to gyro/Landau resonant interaction with electromagnetic waves, which produces radially localized growing peaks in PSD. To differentiate between these processes, we examine radial profiles of PSD in adiabatic coordinates using data from the Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms satellites for 80 outer belt enhancement events from October 2012 to April 2017 This study shows that local acceleration is the dominant acceleration mechanism for MeV electrons in the outer belt, with 87% of the enhancement events exhibiting growing peaks. The strong correlation of the location of these with geomagnetic activity further supports this conclusion.
Global Aurora on Mars During the September 2017 Space Weather Event
Authors: Schneider N. M. , Jain S. K. , Deighan J. , Nasr C. R. , Brain D. A. , Larson D. , Lillis R. , Rahmati Ali , Halekas J. S. , Lee C. O. , Chaffin M. S. , Stiepen A. , Crismani M. , Evans J. S. , Stevens M. H. , Lo D. Y. , McClintock W. E. , Stewart A. I. F. , Yelle R. V. , Clarke J. T. , Holsclaw G. M. , Lefevre F. , Montmessin F. , Jakosky B. M.
Published: May 2018

We report the detection of bright aurora spanning Mars' nightside during the space weather event occurring in September 2017. The phenomenon was similar to diffuse aurora detected previously at Mars, but 25 times brighter and detectable over the entire visible nightside. The observations were made with the Imaging UltraViolet Spectrograph, a remote sensing instrument on the Mars Atmosphere and Volatile EvolutioN spacecraft orbiting Mars. Images show that the emission was brightest around the limb of the planet, with a fairly uniform faint glow against the disk itself. Spectra identified four molecular emissions associated with aurora, and limb scans show the emission originated from an altitude of ~60 km in the atmosphere. Both are consistent with very high energy particle precipitation. The auroral brightening peaked around 13 September, when the flux of solar energetic electrons and protons both peaked. During the declining phase of the event, faint but statistically significant auroral emissions briefly appeared against the disk of the planet in the form of narrow wisps and small patches. These features are approximately aligned with predicted open field lines in the region of strong crustal magnetic fields in Mars' southern hemisphere.
Effects of Iron Spin Transition on the Structure and Stability of Large Primordial Reservoirs in Earth's Lower Mantle
Authors: Li Yang , Vilella Kenny , Deschamps Frédéric , Zhao Liang , J. Tackley Paul
Published: May 2018

Experimental and theoretical studies have shown that the iron spin transition alters the properties of lower mantle minerals. This may have important implications for mantle dynamics. In particular, the vigor of convection is enhanced, which in turn may impact the stability of large primordial reservoirs at the base of the lower mantle. Here we performed numerical experiments of thermochemical convection in 2‐D annulus geometry including the change of density induced by iron spin transition. Our results show that this density change only slightly affects mantle dynamics by increasing the convection vigor. This, in turn, slightly increases the entrainment of primordial dense materials by plumes and leads to smaller reservoirs with sharper edges. However, this effect is small compared to those of the intrinsic density contrast between the dense primordial and regular mantle materials, which is the dominant parameter controlling the long‐term stability of the large primordial reservoirs.
Control of ITCZ Width by Low‐Level Radiative Heating From Upper‐Level Clouds in Aquaplanet Simulations
Authors: Dixit Vishal , Geoffroy Olivier , Sherwood Steven C.
Published: May 2018

Atmospheric cloud radiative effects (ACRE) narrow the Intertropical Convergence Zones (ITCZs) in climate models. Some studies have attributed this to the upper tropospheric heating by deep clouds. We report two types of idealized aquaplanet experiments, one where ACRE in specific altitude ranges is removed and another where the ACRE associated with clouds in specific altitude ranges is removed. Lower tropospheric heating due to upper tropospheric clouds in the deep tropics exerts the greatest impact on the ITCZ width and meridional overturning, even though the heating is weaker than in the upper troposphere. It is argued that this is because radiatively driven changes in the shallow circulation drive a feedback via net import of MSE and make the ITCZ more unstable in its core, thereby forcing the ITCZ to contract. The radiative effects of clouds in the subsiding subtropics are found to be of secondary importance in driving the necessary circulation changes.
An Explanation of Episodic Tremor and Slow Slip Constrained by Crack‐Seal Veins and Viscous Shear in Subduction Mélange
Authors: Ujiie Kohtaro , Saishu Hanae , Fagereng Åke , Nishiyama Naoki , Otsubo Makoto , Masuyama Haruna , Kagi Hiroyuki
Published: May 2018

Episodic tremor and slow slip (ETS) occurs in the transition zone between the locked seismogenic zone and the deeper, stably sliding zone. Actual mechanisms of ETS are enigmatic, caused by lack of geological observations and limited spatial resolution of geophysical information from the ETS source. We report that quartz‐filled, crack‐seal shear and extension veins in subduction mélange record repeated low‐angle thrust‐sense frictional sliding and tensile fracturing at near‐lithostatic fluid pressures. Crack‐seal veins were coeval with viscous shear zones that accommodated deformation by pressure solution creep. The minimum time interval between thrusting events, determined from a kinetic model of quartz precipitation in shear veins, was less than a few years. This short recurrence time of low‐angle brittle thrusting at near‐lithostatic fluid overpressures within viscous shear zones may be explained by frequent release of accumulated strain by ETS.
Injection‐Induced Moment Release Can Also Be Aseismic
Authors: McGarr A. , Barbour Andrew J.
Published: May 2018

The cumulative seismic moment is a robust measure of the earthquake response to fluid injection for injection volumes ranging from 3,100 to about 12 million m3. Over this range, the moment release is limited to twice the product of the shear modulus and the volume of injected fluid. This relation also applies at the much smaller injection volumes of the field experiment in France reported by Guglielmi et al. (2015, https://doi.org/10.1126/science.aab0476) and laboratory experiments to simulate hydraulic fracturing described by Goodfellow et al. (2015, https://doi.org/10.1002/2015GL063093). In both of these studies, the relevant moment release for comparison with the fluid injection was aseismic and consistent with the scaling that applies to the much larger volumes associated with injection‐induced earthquakes with magnitudes extending up to 5.8. Neither the microearthquakes, at the site in France, nor the acoustic emission in the laboratory samples contributed significantly to the deformation due to fluid injection.
From Slab Coupling to Slab Pull: Stress Segmentation in the Subducting Nazca Plate
Authors: Bloch Wasja , Schurr Bernd , Kummerow Jörn , Salazar Pablo , Shapiro Serge A.
Published: May 2018

We investigate the stress field that the Nazca slab experiences during subduction beneath the South American plate by determining the focal mechanisms of moderate subduction‐related earthquakes continuously from 20‐ to 120‐km depth and inverting for the stress directions of four slab regions. Our results show the sharp termination of the coupling zone, which is characterized by compressional stresses, uplift of the overlying mountain range, and likely the activation of preexisting slab structures. Beyond and below this zone slab pull is the dominant stress. Near the slab surface, we also find signatures of the activation of inherited structures. Deeper in the slab, fault orientations are more likely controlled by the stress field alone. Along the subduction pathway, we find indication for an increase of the absolute slab pull component of the stress field that correlates with an increase in event rate and the occurrence possibility of M > 7 intermediate depth earthquakes.
Spreading of the South Pacific Tropical Water and Antarctic Intermediate Water Over the Maritime Continent
Authors: Yang Lina , Zhou Lei , Li Shujiang , Wei Zexun
Published: May 2018

The three‐dimensional climatological spreading of South Pacific waters over the Maritime Continent is examined using eddy‐resolving simulations and a passive tracer method. Four pathways are summarized for the South Pacific Tropical Water and the Antarctic Intermediate Water through the Maritime Continent, including two direct pathways, namely, the Eastern Path and the Torres Strait Path, and two indirect pathways, namely, the Western Path and the South China Sea Path. Among them, according to tracer concentration distribution, the former two contribute most of the volume transport of the Indonesian Throughflow (ITF) originating from the South Pacific. The latter two experience two retroflections (i.e., the South Equatorial Current‐Equatorial Undercurrent and the North Equatorial Countercurrent‐North Equatorial Current) before entering the Indonesian Seas. The vertical distributions of the South Pacific waters along each path throughout the Indonesian Seas are also analyzed, revealing that the South Pacific salinity extrema greatly affect the intermediate and deep layers of the Indonesian Seas and ITF as well as the upper thermocline. Vertical fluxes, especially vertical advection, are vital to these Indo‐Pacific water exchange processes. Sensitivity tests are conducted for the vertical diffusion coefficient and initial conditions, the results of which are robust. According to current study, the South Pacific has substantial impacts on the water properties throughout the Maritime Continent and the mass‐energy exchanges between the Pacific and Indian Oceans.
Uncertainties in the Impact of Urbanization on Heavy Rainfall: Case Study of a Rainfall Event in Beijing on 7 August 2015
Authors: Yu Miao , Miao Shiguang , Zhang Hanbin
Published: May 2018

The impact of urbanization on precipitation was investigated using a regional model with different artificial scenarios, which included unavoidable errors resulting from uncertainties related to the initial value and boundary conditions. We studied a typical summer rainfall event that occurred in Beijing on 7 August 2015 to determine whether the uncertainty in parameterization schemes and the initial field affected the urban impact on rainfall. We also quantitatively analyzed the uncertainty in the impact of urban land use on heavy rainfall caused by the initial field and parameterization schemes. The results showed that the microphysics scheme had higher levels of uncertainty than the planetary boundary layer scheme in forecasting precipitation. Urban land use led to an increase in precipitation in the downwind suburban area, consistent with the results of a previous case study. The magnitude of the impact of urban land use on precipitation was about 8 mm, much smaller than the 20 mm reported in the earlier case study. We suggest that the case study probably overestimated the impact of urban land use on rainfall by about 100% because of model uncertainties. Ensemble forecasting is valuable for studies of the impact of urban land use because there is a positive correlation with precipitation and its spread. The ensemble mean analysis increased the significance of the spatial distribution of the impact of urban land use relative to the earlier case study, although the magnitude of the impact was reduced.
Lateral Continuity of Layering in the Mars South Polar Layered Deposits From SHARAD Sounding Data
Authors: Whitten Jennifer L. , Campbell Bruce A.
Published: May 2018

The south polar layered deposits (SPLD) are composed of alternating layers of ice and dust in varying proportions. The accumulation of the layers is driven by orbital forcings, and the cadence and structure of these layers preserve a record of the past Martian climate. We use SHARAD data to examine the radar properties of SPLD reflectors and to infer their spatial correlations. Crossing orbit tracks are incoherently stacked to improve the echo signal‐to‐noise ratio and extend the delineation of reflectors, laterally and vertically, into areas where they are not evident in individual SHARAD traces. Three distinct radar reflection “facies” are identified: (a) shallow layers that are generally well focused in processed radargrams, (b) less densely spaced layers that occur over much of the depth of the SPLD but are blurred to varying degrees, and (c) low reflectivity zones. A pattern of diffuse echoes termed fog, which originates from an uncertain surface or volume scattering mechanism, extends to varying round‐trip delay times and is often correlated with blurring of subsurface reflections. The fog signature is pervasive, being present in some form over 64% of the SPLD. Unconformities are observed in stacks of reflectors that both intersect the surface and are confined to the subsurface. Only one major deviation from near‐horizontality of the reflectors, located to the east of Australe Mensa, was identified. There is no evidence for major unconformities that suggest multiple depositional centers that later merged into the SPLD. Instead, SHARAD data suggest that the materials of the SPLD were deposited regionally, superposing materials from previous depositional episodes.
CD24 regulates sorafenib resistance via activating autophagy in hepatocellular carcinoma
Authors: Lu Shuai , Yao Yao , Xu Guolong , Zhou Chao , Zhang Yuan , Sun Jie , Jiang Runqiu , Shao Qing , Chen Yun
Published: May 2018

Hepatocellular carcinoma is one of most common solid cancers worldwide. Sorafenib is indicated as a treatment for advanced hepatocellular carcinoma (HCC). However, the clinical efficacy of sorafenib has been severely compromised by the development of drug resistance, and the precise mechanisms of drug resistance remain largely unknown. Here we found that a cell surface molecule, CD24, is overexpressed in tumor tissues and sorafenib-resistant hepatocellular carcinoma cell lines. Moreover, there is a positive correlation between CD24 expression levels and sorafenib resistance. In sorafenib-resistant HCC cell lines, depletion of CD24 caused a notable increase of sorafenib sensitivity. In addition, we found that CD24-related sorafenib resistance was accompanied by the activation of autophagy and can be blocked by the inhibition of autophagy using either pharmacological inhibitors or essential autophagy gene knockdown. In further research, we found that CD24 overexpression also leads to an increase in PP2A protein production and induces the deactivation of the mTOR/AKT pathway, which enhances the level of autophagy. These results demonstrate that CD24 regulates sorafenib resistance via activating autophagy in HCC. This is the first report to describe the relationships among CD24, autophagy, and sorafenib resistance. In conclusion, the combination of autophagy modulation and CD24 targeted therapy is a promising therapeutic strategy in the treatment of HCC.
FSTL1 interacts with VIM and promotes colorectal cancer metastasis via activating the focal adhesion signalling pathway
Authors: Gu Chuansha , Wang Xiaoyan , Long Ting , Wang Xia , Zhong Yan , Ma Yidan , Hu Zhiyan , Li Zuguo
Published: May 2018

Follistatin-like protein 1 (FSTL1) has been reported to have both tumour-promoting and tumour-suppressive characters. However, the role of FSTL1 in colorectal cancer (CRC) remains unclear. Here we showed that FSTL1 expression was significantly up-regulated in CRC tissues compared with the paired normal tissues. In addition, the higher FSTL1 expression was associated with the infiltrating depth, lymph node metastasis and poor prognosis of CRC. Enhanced expression of FSTL1 distinctly increased cell migration and invasion in vitro, as well as promoting liver metastasis of CRC in vivo. Conversely, knockdown of FSTL1 expression significantly repressed invasion and metastasis of CRC. Mechanically, transcription factor Smad3 was involved in FSTL1 protein expression inducing by TGFβ1-Smad2/3 signalling. Furthermore, this effect of FSTL1 in promoting CRC progression was actualised via activating focal adhesions signalling pathway and regulating cytoskeleton rearrangement. We identified VIM, as an interactive protein of FSTL1, participated in FSTL1-mediated aggressive phenotype. We showed the role of FSTL1 in CRC and explored its transcription regulation and downstream signalling molecular mechanisms. In conclusion, our findings suggested that FSTL1 promoted CRC progression and metastasis, making it a novel target for diagnosis and prognostic evaluation of CRC.
Tolerance to ambiguous uncertainty predicts prosocial behavior
Authors: Vives Marc-Lluís , FeldmanHall Oriel
Published: May 2018

Uncertainty is a fundamental feature of human life that can be fractioned into two distinct psychological constructs: risk (known probabilistic outcomes) and ambiguity (unknown probabilistic outcomes). Although risk and ambiguity are known to powerfully bias nonsocial decision-making, their influence on prosocial behavior remains largely unexplored. Here we show that ambiguity attitudes, but not risk attitudes, predict prosocial behavior: the greater an individual’s ambiguity tolerance, the more they engage in costly prosocial behaviors, both during decisions to cooperate (experiments 1 and 3) and choices to trust (experiment 2). Once the ambiguity associated with another’s actions is sufficiently resolved, this relationship between ambiguity tolerance and prosocial choice is eliminated (experiment 3). Taken together, these results provide converging evidence that attitudes toward ambiguity are a robust predictor of one’s willingness to engage in costly social behavior, which suggests a mechanism for the underlying motivations of prosocial action.
Venom proteomics and antivenom neutralization for the Chinese eastern Russell’s viper, Daboia siamensis from Guangxi and Taiwan
Authors: Tan Kae Yi , Tan Nget Hong , Tan Choo Hock
Published: May 2018

The eastern Russell’s viper (Daboia siamensis) causes primarily hemotoxic envenomation. Applying shotgun proteomic approach, the present study unveiled the protein complexity and geographical variation of eastern D. siamensis venoms originated from Guangxi and Taiwan. The snake venoms from the two geographical locales shared comparable expression of major proteins notwithstanding variability in their toxin proteoforms. More than 90% of total venom proteins belong to the toxin families of Kunitz-type serine protease inhibitor, phospholipase A2, C-type lectin/lectin-like protein, serine protease and metalloproteinase. Daboiasiamensis Monovalent Antivenom produced in Taiwan (DsMAV-Taiwan) was immunoreactive toward the Guangxi D. siamensis venom, and effectively neutralized the venom lethality at a potency of 1.41 mg venom per ml antivenom. This was corroborated by the antivenom effective neutralization against the venom procoagulant (ED = 0.044 ± 0.002 µl, 2.03 ± 0.12 mg/ml) and hemorrhagic (ED50 = 0.871 ± 0.159 µl, 7.85 ± 3.70 mg/ml) effects. The hetero-specific Chinese pit viper antivenoms i.e. Deinagkistrodon acutus Monovalent Antivenom and Gloydius brevicaudus Monovalent Antivenom showed negligible immunoreactivity and poor neutralization against the Guangxi D. siamensis venom. The findings suggest the need for improving treatment of D. siamensis envenomation in the region through the production and the use of appropriate antivenom.
Subgenual anterior cingulate cortex controls sadness-induced modulations of cognitive and emotional network hubs
Authors: Ramirez-Mahaluf Juan P. , Perramon Joan , Otal Begonya , Villoslada Pablo , Compte Albert
Published: May 2018

The regulation of cognitive and emotional processes is critical for proper executive functions and social behavior, but its specific mechanisms remain unknown. Here, we addressed this issue by studying with functional magnetic resonance imaging the changes in network topology that underlie competitive interactions between emotional and cognitive networks in healthy participants. Our behavioral paradigm contrasted periods with high emotional and cognitive demands by including a sadness provocation task followed by a spatial working memory task. The sharp contrast between successive tasks was designed to enhance the separability of emotional and cognitive networks and reveal areas that regulate the flow of information between them (hubs). By applying graph analysis methods on functional connectivity between 20 regions of interest in 22 participants we identified two main brain network modules, one dorsal and one ventral, and their hub areas: the left dorsolateral prefrontal cortex (dlPFC) and the left medial frontal pole (mFP). These hub areas did not modulate their mutual functional connectivity following sadness but they did so through an interposed area, the subgenual anterior cingulate cortex (sACC). Our results identify dlPFC and mFP as areas regulating interactions between emotional and cognitive networks, and suggest that their modulation by sadness experience is mediated by sACC.
Application of confocal surface wave microscope to self-calibrated attenuation coefficient measurement by Goos-Hänchen phase shift modulation
Authors: Pechprasarn Suejit , Chow Terry W. K. , Somekh Michael G.
Published: May 2018

In this paper, we present a direct method to measure surface wave attenuation arising from both ohmic and coupling losses using our recently developed phase spatial light modulator (phase-SLM) based confocal surface plasmon microscope. The measurement is carried out in the far-field using a phase-SLM to impose an artificial surface wave phase profile in the back focal plane (BFP) of a microscope objective. In other words, we effectively provide an artificially engineered backward surface wave by modulating the Goos Hänchen (GH) phase shift of the surface wave. Such waves with opposing phase and group velocities are well known in acoustics and electromagnetic metamaterials but usually require structured or layered surfaces, here the effective wave is produced externally in the microscope illumination path. Key features of the technique developed here are that it (i) is self-calibrating and (ii) can distinguish between attenuation arising from ohmic loss (k″
Ω
) and coupling (reradiation) loss (k″
c
). This latter feature has not been achieved with existing methods. In addition to providing a unique measurement the measurement occurs of over a localized region of a few microns. The results were then validated against the surface plasmons (SP) dip measurement in the BFP and a theoretical model based on a simplified Green’s function.
A meta-analysis of the greenhouse gas abatement of bioenergy factoring in land use changes
Authors: El Akkari M. , Réchauchère O. , Bispo A. , Gabrielle B. , Makowski D.
Published: May 2018

Non-food biomass production is developing rapidly to fuel the bioenergy sector and substitute dwindling fossil resources, which is likely to impact land-use patterns worldwide. Recent publications attempting to factor this effect into the climate mitigation potential of bioenergy chains have come to widely variable conclusions depending on their scope, data sources or methodology. Here, we conducted a first of its kind, systematic review of scientific literature on this topic and derived quantitative trends through a meta-analysis. We showed that second-generation biofuels and bioelectricity have a larger greenhouse gas (GHG) abatement potential than first generation biofuels, and stand the best chances (with a 80 to 90% probability range) of achieving a 50% reduction compared to fossil fuels. Conversely, directly converting forest ecosystems to produce bioenergy feedstock appeared as the worst-case scenario, systematically leading to negative GHG savings. On the other hand, converting grassland appeared to be a better option and entailed a 60% chance of halving GHG emissions compared to fossil energy sources. Since most climate mitigation scenarios assume still larger savings, it is critical to gain better insight into land-use change effects to provide a more realistic estimate of the mitigation potential associated with bioenergy.
Sensations from a single M-cone depend on the activity of surrounding S-cones
Authors: Schmidt Brian P. , Sabesan Ramkumar , Tuten William S. , Neitz Jay , Roorda Austin
Published: May 2018

Color vision requires the activity of cone photoreceptors to be compared in post-receptoral circuitry. Decades of psychophysical measurements have quantified the nature of these comparative interactions on a coarse scale. How such findings generalize to a cellular scale remains unclear. To answer that question, we quantified the influence of surrounding light on the appearance of spots targeted to individual cones. The eye’s aberrations were corrected with adaptive optics and retinal position was precisely tracked in real-time to compensate for natural movement. Subjects reported the color appearance of each spot. A majority of L-and M-cones consistently gave rise to the sensation of white, while a smaller group repeatedly elicited hue sensations. When blue sensations were reported they were more likely mediated by M- than L-cones. Blue sensations were elicited from M-cones against a short-wavelength light that preferentially elevated the quantal catch in surrounding S-cones, while stimulation of the same cones against a white background elicited green sensations. In one of two subjects, proximity to S-cones increased the probability of blue reports when M-cones were probed. We propose that M-cone increments excited both green and blue opponent pathways, but the relative activity of neighboring cones favored one pathway over the other.
Luteolin attenuates Wnt signaling via upregulation of FZD6 to suppress prostate cancer stemness revealed by comparative proteomics
Authors: Han Kun , Lang Tingyuan , Zhang Zhiqi , Zhang Yi , Sun Yongning , Shen Zan , Beuerman Roger W. , Zhou Lei , Min Daliu
Published: May 2018

The mechanisms underlying luteolin-induced inhibition of prostate cancer (PCa) stemness have remained elusive. Here, we report that luteolin suppresses PCa stemness through Wnt signaling by upregulation of FZD6 (frizzled class receptor 6). Luteolin inhibits PCa cell proliferation, migration, self-renewal as well as the expression of prostate cancer stem cell markers in vitro. Through iTRAQ-based quantitative proteomics study, we identified 208 differentially expressed proteins in luteolin-treated PC-3 cells. Subsequent mechanistic analysis revealed that luteolin inhibits Wnt signaling by transcriptional upregulation of FZD6, and thereby suppressing the stemness of PCa cells. Furthermore, we identified FZD6 as a tumor suppressor that can abolish PCa stemness. In summary, our findings demonstrate that suppression of Wnt signaling by upregulation of FZD6 is a mechanism underlying luteolin-induced inhibition of PCa stemness. Our work suggests a new therapeutic strategy against human prostate cancer caused by aberrant activation of Wnt signaling.
BrainFilm, a novel technique for physical compression of 3D brain slices for efficient image acquisition and post-processing
Authors: Kim Joo Yeon , Kim Hyun Jung , Jang Min Jee , Kim June Hoan , Lee Ju-Hyun , Lee Eunsoo , Park Kyerl , Kim Hyuncheol , Lee Jaedong , Kwag Jeehyun , Kim Namhee , Song Mi-Ryoung , Kim Hyun , Sun Woong
Published: May 2018

Tissue clearing enables us to observe thick tissue at a single cell resolution by reducing light scattering and refractive index matching. However, imaging of a large volume of tissue for 3D reconstruction requires a great deal of time, cost, and efforts. Few methods have been developed to transcend these limitations by mechanical compression or isotropic tissue shrinkage. Tissue shrinkage significantly lessens the imaging burden; however, there is an inevitable trade-off with image resolution. Here, we have developed the “BrainFilm” technique to compress cleared tissue at Z-axis by dehydration, without alteration of the XY-axis. The Z-axis compression was approximately 90%, and resulted in substantial reduction in image acquisition time and data size. The BrainFilm technique was successfully used to trace and characterize the morphology of thick biocytin-labelled neurons following electrophysiological recording and trace the GFP-labelled long nerve projections in irregular tissues such as the limb of mouse embryo. Thus, BrainFilm is a versatile tool that can be applied in diverse studies of 3D tissues in which spatial information of the Z-axis is dispensable.
The effect of stimulation interval on plasticity following repeated blocks of intermittent theta burst stimulation
Authors: Tse Nga Yan , Goldsworthy Mitchell R. , Ridding Michael C. , Coxon James P. , Fitzgerald Paul B. , Fornito Alex , Rogasch Nigel C.
Published: May 2018

This study assessed the effect of interval duration on the direction and magnitude of changes in cortical excitability and inhibition when applying repeated blocks of intermittent theta burst stimulation (iTBS) over motor cortex. 15 participants received three different iTBS conditions on separate days: single iTBS; repeated iTBS with a 5 minute interval (iTBS-5-iTBS); and with a 15 minute interval (iTBS-15-iTBS). Changes in cortical excitability and short-interval cortical inhibition (SICI) were assessed via motor-evoked potentials (MEPs) before and up to 60 mins following stimulation. iTBS-15-iTBS increased MEP amplitude for up to 60 mins post stimulation, whereas iTBS-5-iTBS decreased MEP amplitude. In contrast, MEP amplitude was not altered by single iTBS. Despite the group level findings, only 53% of individuals showed facilitated MEPs following iTBS-15-iTBS, and only 40% inhibited MEPs following iTBS-5-iTBS. Modulation of SICI did not differ between conditions. These results suggest interval duration between spaced iTBS plays an important role in determining the direction of plasticity on excitatory, but not inhibitory circuits in human motor cortex. While repeated iTBS can increase the magnitude of MEP facilitation/inhibition in some individuals compared to single iTBS, the response to repeated iTBS appears variable between individuals in this small sample.
Non-linearity correction in NIR absorption spectra by grouping modeling according to the content of analyte
Authors: Liu Ai , Li Gang , Fu Zhigang , Guan Yang , Lin Ling
Published: May 2018

To correct the non-linearity caused by light scattering in quantitative analysis with near infrared absorption spectra, a new modeling analysis method was proposed: grouping modeling according to the content of analyte. In this study, we tested the proposed method for non-invasive detection of human hemoglobin (Hb) based on dynamic spectrum (DS). We compared the prediction performance of the proposed method with non-grouping modeling method. Experimental results showed that the root mean square error of the prediction set (RMSEP) by the proposed method was reduced by 9.96% and relative standard deviation of the prediction set (RSDP) was reduced by 4.73%. The results demonstrated that the proposed method could reduce the effects of non-linearity on the composition analysis by spectroscopy. This research provides a new method for correcting the non-linearity stemming from light scattering. And the proposed method will accelerate the pace of non-invasive detection of blood components into clinical application.
Microfluidic preparation of monodisperse polymeric microspheres coated with silica nanoparticles
Authors: Kim Dong-Yeong , Jin Si Hyung , Jeong Seong-Geun , Lee Byungjin , Kang Kyoung-Ku , Lee Chang-Soo
Published: May 2018

The synthesis of organic-inorganic hybrid particles with highly controlled particle sizes in the micrometer range is a major challenge in many areas of research. Conventional methods are limited for nanometer-scale fabrication because of the difficulty in controlling the size. In this study, we present a microfluidic method for the preparation of organic-inorganic hybrid microparticles with poly (1,10-decanediol dimethacrylate-co-trimethoxysillyl propyl methacrylate) (P (DDMA-co-TPM)) as the core and silica nanoparticles as the shell. In this approach, the droplet-based microfluidic method combined with in situ photopolymerization produces highly monodisperse organic microparticles of P (DDMA-co-TPM) in a simple manner, and the silica nanoparticles gradually grow on the surface of the microparticles prepared via hydrolysis and condensation of tetraethoxysilane (TEOS) in a basic ammonium hydroxide medium without additional surface treatment. This approach leads to a reduction in the number of processes and allows drastically improved size uniformity compared to conventional methods. The morphology, composition, and structure of the hybrid microparticles are analyzed by SEM, TEM, FT-IR, EDS, and XPS, respectively. The results indicate the inorganic shell of the hybrid particles consists of SiO2 nanoparticles of approximately 60 nm. Finally, we experimentally describe the formation mechanism of a silica-coating layer on the organic surface of polymeric core particles.
Quantitative analysis of DNA with single-molecule sequencing
Authors: Ohshiro Takahito , Tsutsui Makusu , Yokota Kazumichi , Taniguchi Masateru
Published: May 2018

Cancer can be diagnosed by identifying DNA and microRNA base sequences that have the same base length yet differ in a few base sequences, if the abundance ratios of these slightly deviant base sequences can be determined. However, such quantitative analyses cannot be performed using the current DNA sequencers. Here we determine entire base sequences of four types of DNA corresponding to the let-7 microRNA, which is a 22-base cancer marker. We record the single-molecule conductances of the base molecules using current-tunneling measurements. In addition, we count the numbers of molecules in a solution to determine the abundance ratios of two DNA strands that differ by a single base sequence.