bluuebunny/crossref_metadata_2025 huggingface dataset:
Personality, mental health and demographic correlates of hoarding behaviours in a midlife sample
Authors: Spittlehouse Janet K. , Vierck Esther , Pearson John F. , Joyce Peter R.
Published: December 2016

We describe the Temperament and Character Inventory personality traits, demographic features, physical and mental health variables associated with hoarding behaviour in a random community sample of midlife participants in New Zealand. A sample of 404 midlife participants was recruited to a study of ageing. To assess hoarding behaviours participants completed the Savings Inventory-Revised (SI-R), personality was assessed by the Temperament and Character Inventory and self-reported health was measured by the Short Form-36v2 (SF-36v2). Other measures were used to assess socio-demographic variables and current mental disorders. Participants were split into four groups by SI-R total score (scores: 0–4, 5–30, 31–41 and >41). Those who scored >41 on the SI-R were classified as having pathological hoarding. Trend tests were calculated across the four hoarding groups for socio-demographic, personality, mental and physical health variables. SI-R scores ranged from 0 to 58. The prevalence of pathological hoarding was 2.5% and a further 4% reported sub-clinical symptoms of hoarding. Higher hoarding behaviour scores were related to higher Temperament and Character Inventory scores for Harm Avoidance and lower scores for Self-directedness. Persistence and Cooperativeness scores were lower too but to a lesser extent. Trend analysis revealed that those with higher hoarding behaviour scores were more likely to be single, female, unemployed, receive income support, have a lower socio-economic status, lower household income and have poorer self-reported mental health scores. Current depression rates were considerably higher in the pathological hoarding group. Increasing SI-R hoarding behaviour scores were associated with higher scores of negative affect (Harm Avoidance) and lower scores of autonomy (Self-directedness). Those with pathological hoarding or sub-clinical symptoms of hoarding also reported widespread mental and socio-economic problems. In this study it is clear to see the physical, mental and socio-economic problems experienced by those achieving the highest hoarding scores. The prevalence of pathological hoarding was 2.5%, similar to the prevalence reported by other studies. The personality traits associated with hoarding behaviours are discussed.
Culturable bioaerosols along an urban waterfront are primarily associated with coarse particles
Authors: Montero Angel , Dueker M. Elias , O’Mullan Gregory D.
Published: December 2016

The source, characteristics and transport of viable microbial aerosols in urban centers are topics of significant environmental and public health concern. Recent studies have identified adjacent waterways, and especially polluted waterways, as an important source of microbial aerosols to urban air. The size of these aerosols influences how far they travel, their resistance to environmental stress, and their inhalation potential. In this study, we utilize a cascade impactor and aerosol particle monitor to characterize the size distribution of particles and culturable bacterial and fungal aerosols along the waterfront of a New York City embayment. We seek to address the potential contribution of bacterial aerosols from local sources and to determine how their number, size distribution, and taxonomic identity are affected by wind speed and wind direction (onshore vs. offshore). Total culturable microbial counts were higher under offshore winds (average of 778 CFU/m3± 67), with bacteria comprising the majority of colonies (58.5%), as compared to onshore winds (580 CFU/m3± 110) where fungi were dominant (87.7%). The majority of cultured bacteria and fungi sampled during both offshore winds (88%) and onshore winds (72%) were associated with coarse aerosols (>2.1 µm), indicative of production from local sources. There was a significant correlation (p < 0.05) of wind speed with both total and coarse culturable microbial aerosol concentrations. Taxonomic analysis, based on DNA sequencing, showed that Actinobacteria was the dominant phylum among aerosol isolates. In particular,StreptomycesandBacillus, both spore forming genera that are often soil-associated, were abundant under both offshore and onshore wind conditions. Comparisons of bacterial communities present in the bioaerosol sequence libraries revealed that particle size played an important role in microbial aerosol taxonomy. Onshore and offshore coarse libraries were found to be most similar. This study demonstrates that the majority of culturable bacterial aerosols along a New York City waterfront were associated with coarse aerosol particles, highlighting the importance of local sources, and that the taxonomy of culturable aerosol bacteria differed by size fraction and wind direction.
SPCZ zonal events and downstream influence on surface ocean conditions in the Indonesian Throughflow region
Authors: Linsley Braddock K. , Wu Henry C. , Rixen Tim , Charles Christopher D. , Gordon Arnold L. , Moore Michael D.
Published: December 2016

Seasonal surface freshening of the Makassar Strait, the main conduit of the Indonesian Throughflow (ITF), is a key factor controlling the ITF. Here we present a 262 year reconstruction of seasonal sea‐surface‐salinity variability from 1742 to 2004 Common Era by using coral δ18O records from the central Makassar Strait. Our record reveals persistent seasonal freshening and also years with significant truncations of seasonal freshening that correlate exactly with South Pacific Convergence Zone (SPCZ) zonal events >4000 km to the east. During these events, the SPCZ dramatically rotates ~15° north to near the equator and stronger westward flowing South Pacific boundary currents force higher‐salinity water through the Makassar Strait in February–May halting the normal seasonal freshening in the strait. By these teleconnections, our Makassar coral δ18O series provides the first record of the recurrence interval of these zonal SPCZ events and demonstrates that they have occurred on a semiregular basis since the mid‐1700s.
Collapse of the North American ice saddle 14,500 years ago caused widespread cooling and reduced ocean overturning circulation
Authors: Ivanovic Ruza F. , Gregoire Lauren J. , Wickert Andrew D. , Valdes Paul J. , Burke Andrea
Published: December 2016

Collapse of ice sheets can cause significant sea level rise and widespread climate change. We examine the climatic response to meltwater generated by the collapse of the Cordilleran‐Laurentide ice saddle (North America) ~14.5 thousand years ago (ka) using a high‐resolution drainage model coupled to an ocean‐atmosphere‐vegetation general circulation model. Equivalent to 7.26 m global mean sea level rise in 340 years, the meltwater caused a 6 sverdrup weakening of Atlantic Meridional Overturning Circulation (AMOC) and widespread Northern Hemisphere cooling of 1–5°C. The greatest cooling is in the Atlantic sector high latitudes during Boreal winter (by 5–10°C), but there is also strong summer warming of 1–3°C over eastern North America. Following recent suggestions that the saddle collapse was triggered by the Bølling warming event at ~14.7–14.5 ka, we conclude that this robust submillennial mechanism may have initiated the end of the warming and/or the Older Dryas cooling through a forced AMOC weakening.
Imaging the structure of the low K‐corona
Authors: Kim I. S. , Nasonova L. P. , Lisin D. V. , Popov V. V. , Krusanova N. L.
Published: December 2016

The first 2‐D distributions of the polarization angle and of the relative color index for the K‐corona of 29 March 2006 are presented. The distributions illustrate the efficiency of the total solar eclipse approach for high‐precision measurements of the K‐corona continuum in the range < 1.4 R⊙. Natural ground and space total solar eclipses caused by external occulting the bright solar‐disk light by the Moon or Earth group planets are discussed. Calculations of the eclipse magnitude m are carried out to show ideal conditions for total solar eclipse observations in space from Lagrange point L2 for Mars (m ≈ 1.025). The illumination in Mars' shadow is estimated to equal 5.6 × 10−11 for the wavelength of 550 nm. No internal or external occulting coronagraphs are needed. Partial solar eclipses with m > 0.91 can be observed from Lagrange points L2 for Mercury, Venus, and Earth.
Magnetospheric response and reconfiguration times following IMF By reversals
Authors: Tenfjord P. , Østgaard N. , Strangeway R. , Haaland S. , Snekvik K. , Laundal K. M. , Reistad J. P. , Milan S. E.
Published: December 2016

The interaction between the interplanetary magnetic field (IMF) and the geomagnetic field at the dayside magnetopause leads to transfer of momentum and energy which changes the magnetospheric configuration, but only after a certain time. In this study we quantify this time, to advance our understanding of the causes for the delayed response of the magnetosphere. We study the response and reconfiguration time of the inner magnetosphere to IMF By reversals. A superposed epoch analysis of magnetic field measurements from four Geostationary Operational Environmental Satellite spacecraft at different local times both for negative to positive IMF By reversals and for positive to negative reversals is presented. The magnetospheric response time at geosynchronous orbit to the sudden change of IMF By is less than 15 (∼10) min from the bow shock (magnetopause) arrival time, while the reconfiguration time is less than 46 (∼41) min. These results are consistent with a By component induced on closed magnetic field lines due to the asymmetric loading of flux following asymmetric dayside reconnection when IMF By≠0. Our results also confirm our earlier studies that nightside reconnection is not required for generating a By component on closed field lines.
A new methodology for the development of high‐latitude ionospheric climatologies and empirical models
Authors: Chisham G.
Published: December 2016

Many empirical models and climatologies of high‐latitude ionospheric processes, such as convection, have been developed over the last 40 years. One common feature in the development of these models is that measurements from different times are combined and averaged on fixed coordinate grids. This methodology ignores the reality that high‐latitude ionospheric features are organized relative to the location of the ionospheric footprint of the boundary between open and closed geomagnetic field lines (OCB). This boundary is in continual motion, and the polar cap that it encloses is continually expanding and contracting in response to changes in the rates of magnetic reconnection at the Earth's magnetopause and in the magnetotail. As a consequence, models that are developed by combining and averaging data in fixed coordinate grids heavily smooth the variations that occur near the boundary location. Here we propose that the development of future models should consider the location of the OCB in order to more accurately model the variations in this region. We present a methodology which involves identifying the OCB from spacecraft auroral images and then organizing measurements in a grid where the bins are placed relative to the OCB location. We demonstrate the plausibility of this methodology using ionospheric vorticity measurements made by the Super Dual Auroral Radar Network radars and OCB measurements from the IMAGE spacecraft FUV auroral imagers. This demonstration shows that this new methodology results in sharpening and clarifying features of climatological maps near the OCB location. We discuss the potential impact of this methodology on space weather applications.
Turbulent and numerical mixing in a salt wedge estuary: Dependence on grid resolution, bottom roughness, and turbulence closure
Authors: Ralston David K. , Cowles Geoffrey W. , Geyer W. Rockwell , Holleman Rusty C.
Published: December 2016

The Connecticut River is a tidal salt wedge estuary, where advection of sharp salinity gradients through channel constrictions and over steeply sloping bathymetry leads to spatially heterogeneous stratification and mixing. A 3‐D unstructured grid finite‐volume hydrodynamic model (FVCOM) was evaluated against shipboard and moored observations, and mixing by both the turbulent closure and numerical diffusion were calculated. Excessive numerical mixing in regions with strong velocities, sharp salinity gradients, and steep bathymetry reduced model skill for salinity. Model calibration was improved by optimizing both the bottom roughness (z0), based on comparison with the barotropic tidal propagation, and the mixing threshold in the turbulence closure (steady state Richardson number, Rist), based on comparison with salinity. Whereas a large body of evidence supports a value of Rist ∼ 0.25, model skill for salinity improved with Rist ∼ 0.1. With Rist = 0.25, numerical mixing contributed about 1/2 the total mixing, while with Rist = 0.10 it accounted for ∼2/3, but salinity structure was more accurately reproduced. The combined contributions of numerical and turbulent mixing were quantitatively consistent with high‐resolution measurements of turbulent mixing. A coarser grid had increased numerical mixing, requiring further reductions in turbulent mixing and greater bed friction to optimize skill. The optimal Rist for the fine grid case was closer to 0.25 than for the coarse grid, suggesting that additional grid refinement might correspond with Rist approaching the theoretical limit. Numerical mixing is rarely assessed in realistic models, but comparisons with high‐resolution observations in this study suggest it is an important factor.
Monitoring remote ocean waves using P‐wave microseisms
Authors: Neale Jennifer , Harmon Nicholas , Srokosz Meric
Published: December 2016

Oceanic microseisms are generated by the interaction of opposing ocean waves and subsequent coupling with the seabed, so microseisms should contain information on the ocean conditions that generated them. This leads to the possibility of using seismic records as a proxy for the ocean gravity wavefield. Here we investigate the P‐wave component of microseisms, which has previously been linked to areas of high wave interaction intensity in mid‐ocean regions. We compare modeled P‐wave microseismic sources with those observed at an array in California, and also investigate the relationship between observed sources and significant wave height. We found that the time‐varying location of microseism sources in the North Pacific, mapped from beamforming and backprojection of seismic data, was accurate to ≤10° in 90% of cases. The modeled sources were found to dominate at ∼0.2 Hz which was also reflected in the seismic observations. An empirical relationship between observed beampower and modeled source power allowed sources during an independent data period to be estimated with a correlation coefficient of 0.63. Likewise, significant wave height was also estimated with a correlation coefficient of 0.63. Our findings suggest that with improvements in resolution and amplitude retrieval from beamforming, correlations up to 0.78 should be possible between observed P‐wave microseisms and significant wave height in remote ocean regions.
Nitrogen fixation in the eastern Atlantic reaches similar levels in the Southern and Northern Hemisphere
Authors: Fonseca‐Batista Debany , Dehairs Frank , Riou Virginie , Fripiat François , Elskens Marc , Deman Florian , Brion Natacha , Quéroué Fabien , Bode Maya , Auel Holger
Published: December 2016

Euphotic layer dinitrogen (N2) fixation and primary production (PP) were measured in the eastern Atlantic Ocean (38°N–21°S) using 15N2 and 13C bicarbonate tracer incubations. This region is influenced by Saharan dust deposition and waters with low nitrogen to phosphorus (N/P) ratios originating from the Subantarctic and the Benguela upwelling system. Depth‐integrated rates of N2 fixation in the north (0°N–38°N) ranged from 59 to 370 µmol N m−2 d−1, with the maximal value at 19°N under the influence of the northwest African upwelling. Diazotrophic activity in the south (0°S–21°S), though slightly lower, was surprisingly close to observations in the north, with values ranging from 47 to 119 µmol N m−2 d−1. Our North Atlantic N2 fixation rates correlate well with dust deposition, while those in the South Atlantic correlate strongly with excess phosphate relative to nitrate. There, the necessary iron is assumed to be supplied from the Benguela upwelling system. When converting N2 fixation to carbon uptake using a Redfield ratio (6.6), we find that N2 fixation may support up to 9% of PP in the subtropical North Atlantic (20°N–38°N), 5% in the tropical North Atlantic (0°N–20°N), and 1% of PP in the South Atlantic (0°S–21°S). Combining our data with published data sets, we estimate an annual N input of 27.6 ± 10 Tg N yr−1 over the open Atlantic Ocean, 11% of which enters the region between 20°N and 50°N, 71% between 20°N and 10°S, and 18% between 10°N and 45°S.
Interannual variability of tropical Pacific sea level from 1993 to 2014
Authors: Zhu Xiaoting , Greatbatch Richard J. , Claus Martin
Published: December 2016

A multimode, linear reduced‐gravity model, driven by ERA‐Interim monthly mean wind stress anomalies, is used to investigate interannual variability in tropical Pacific sea level as seen in satellite altimeter data. The model output is fitted to the altimeter data along the equator, in order to derive the vertical profile for the model forcing, showing that a signature from modes higher than mode 6 cannot be extracted from the altimeter data. It is shown that the model has considerable skill at capturing interannual sea level variability both on and off the equator. The correlation between modeled and satellite‐derived sea level data exceeds 0.8 over a wide range of longitudes along the equator and readily captures the observed ENSO events. Overall, the combination of the first, second, third, and fifth modes can provide a robust estimate of the interannual sea level variability, the second mode being dominant. A remarkable feature of both the model and the altimeter data is the presence of a pivot point in the western Pacific on the equator. We show that the westward displacement of the pivot point from the center of the basin is strongly influenced by the fact that most of the wind stress variance is found in the western part of the basin. We also show that the Sverdrup transport is not fundamental to the dynamics of the recharge/discharge mechanism in our model, although the spatial structure of the wind forcing does play a role in setting the amplitude of the “warm water volume.”
Using remotely sensed data from AIRS to estimate the vapor flux on the Greenland ice sheet: Comparisons with observations and a regional climate model
Authors: Boisvert Linette N. , Lee Jae N. , Lenaerts Jan T. M. , Noël Brice , van den Broeke Michiel R. , Nolin Anne W.
Published: December 2016

Mass loss from the Greenland ice sheet (GrIS) in recent years has been dominated by runoff from surface melt. It is currently being studied extensively, while little interest has been given to the smallest component of surface mass balance (SMB): the vapor flux. Although poorly understood, it is not negligible and could potentially play a larger role in SMB in a warming climate where temperature, relative humidity, and precipitation changes remain uncertain. Here we present an innovative approach to estimate the vapor flux using the Atmospheric Infrared Sounder (AIRS) version 6 data and a modified vapor flux model (BMF13) over the GrIS between 2003 and 2014. One modification to the BMF13 model includes a new Multiangle Imaging SpectroRadiometer surface aerodynamic roughness product, which likely produces more accurate estimates of the drag coefficient on the ice sheet. When comparing AIRS data with GC‐Net and Programme for Monitoring of the Greenland Ice Sheet automatic weather station observations of skin temperature, near‐surface air temperature, and humidity, they agree within 2 K, 2.68 K, and 0.34 g kg−1. Largest differences occur in the ablation zone where there is significant subgrid heterogeneity. Overall, the average vapor flux from the GrIS between 2003 and 2014 was found to be 14.6 ± 3.6 Gt yr−1. No statistically significant trends were found during the data record. This data set is compared to the Regional Atmospheric Climate Model (RACMO2.3) vapor flux, and BMF13 produced smaller vapor fluxes in the summer (~0.05 Gt d−1) and slightly more deposition in the winter (~9.4 × 10−3 Gt d−1). Annually, differences between BMF13 and RACMO2.3 were only 30 ± 15%.
Can MODIS cloud fraction fully represent the diurnal and seasonal variations at DOE ARM SGP and Manus sites?
Authors: Wang Yang , Zhao Chuanfeng
Published: December 2016

Though cloud fraction (CF) from Moderate Resolution Imaging Spectroradiometer (MODIS) has been widely used, it remains unclear whether it can fully represent the diurnal variations. This study evaluates the time representation (i.e., satellite passes' mean value per day to represent daily average value) error in MODIS CF by using daytime‐only total sky cover and continuous day‐and‐night radar/lidar CF (Active Remote Sensing of Clouds product, ARSCL) from 2000 to 2010 for two Atmospheric Radiation Measurement (ARM) program climate regime sites of Southern Great Plains (SGP) and Manus. By comparing the daily averaged CFs from ARSCL between using all hourly and using the MODIS‐passing‐time observations, it shows a correlation coefficient of 0.93 (0.88) and root mean square deviation (RMSD) of 12.68% (13.27%) over SGP (Manus) site for daily averaged CFs. Differently, it shows a better correlation coefficient of 0.97 (0.97) and smaller RMSD of 2.98% (3.97%) over SGP (Manus) site for monthly averaged CFs. These suggest that considerable errors could be introduced while using the MODIS CF observed at several fixed time points a day to represent average CF at different time scales. Monthly time representation errors have also been evaluated for daytime only and nighttime only, which show even larger values. A further analysis shows that uncertainties caused by the time representation account for about 23% (21%) of the total differences between surface and MODIS CFs over SGP (Manus) site at monthly time scale.
Development of a discrete‐continuum VDFST‐CFP numerical model for simulating seawater intrusion to a coastal karst aquifer with a conduit system
Authors: Xu Zexuan , Hu Bill X.
Published: December 2016

A hybrid discrete‐continuum numerical model, Variable‐Density Flow and Solute Transport—Conduit Flow Process (VDFST‐CFP), is developed to simulate seawater intrusion to a coastal karst aquifer with a conduit network. The Darcy‐Weisbach equation is applied to simulate the nonlaminar groundwater flow in the conduit system that is conceptualized as pipes, while the Darcy equation is used for laminar groundwater flow in the continuum porous medium. Density‐dependent groundwater flow with appropriate additional density terms in the conduit is analytically derived. The flow and transport equations are coupled, and numerically solved by the finite difference method with an implicit iteration procedure. Two synthetic benchmarks are developed to compare the VDFST‐CFP model results with other numerical models, such as the variable‐density SEAWAT, constant‐density continuum MODFLOW/MT3DMS, and constant‐density discrete‐continuum CFPv2/UMT3D models. The VDFST‐CFP model compares reasonably well with the other model results in both conduit and porous medium domains, and well describes water and salt exchange between the two systems. Under turbulent flow conditions within the conduit, the Darcy‐Weisbach equation calculates the flow rate more accurately without overestimation by the Darcy equation. Sensitivity analysis indicates that conduit diameter, friction factor, matrix hydraulic conductivity, and effective medium porosity are important parameters in the VDFST‐CFP model. The pros and cons of the VDFST‐CFP model are discussed, including the model assumptions and simplifications, limitations of the discrete‐continuum modeling method, and the convergence criteria. In general, the newly developed VDFST‐CFP model provides a new numerical modeling method for simulating seawater intrusion in a coastal karst aquifer with conduits.
Mixed populations and annual flood frequency estimates in the western United States: The role of atmospheric rivers
Authors: Barth Nancy A. , Villarini Gabriele , Nayak Munir A. , White Kathleen
Published: December 2016

The Bulletin 17B framework assumes that the annual peak flow data included in a flood frequency analysis are from a homogeneous population. However, flood frequency analysis over the western United States is complicated by annual peak flow records that frequently contain annual flows generated from distinctly different flood generating mechanisms. These flood series contain multiple zero flows and/or potentially influential low floods (PILFs) that substantially deviate from the overall pattern in the data. Moreover, they often also contain extreme flood events representing different hydrometeorologic agents. Among the different flood generating mechanisms, atmospheric rivers (ARs) are responsible for large, regional‐scale floods. The spatial and fractional contribution of ARs in annual peak flow data is examined based on 1375 long‐term U.S. Geological Survey (USGS) streamgage sites with at least 30 years of data. Six main areas in which flooding is impacted by ARs at varying degrees were found throughout the western United States. The Pacific Northwest and the northern California coast have the highest fraction of AR‐generated peaks (∼80–100%), while eastern Montana, Wyoming, Utah, Colorado, and New Mexico have nearly no impacts from ARs. The individual regions of the central Columbia River Basin in the Pacific Northwest, the Sierra Nevada, the central and southern California coast, and central Arizona all show a mixture of 30–70% AR‐generated flood peaks. Analyses related to the largest flood peaks on record and to the estimated annual exceedance probabilities highlight the strong impact of ARs on flood hydrology in this region, together with marked regional differences.
The moving‐boundary approach for modeling gravity‐driven stable and unstable flow in soils
Authors: Brindt Naaran , Wallach Rony
Published: December 2016

The Richards equation is unsuccessful at describing gravity‐driven unstable flow with nonmonotonic water content distribution. This shortcoming is resolved in the current study by introducing the moving‐boundary approach. Following this approach, the flow domain is divided into two subdomains with a sharp change in fluid saturation between them (moving boundary). The upper subdomain consists of water and air, whose relationship varies with space and time following the imposed boundary condition at the soil surface calculated by the Richards equation. The lower subdomain consists of an initially dry soil that remains constant. The location of the boundary between the two subdomains is part of the solution, rendering the problem nonlinear. The moving boundary solution was used after verification to demonstrate the effect of contact angle, soil characteristic curves and incoming flux on the dynamic water‐entry pressure of the soil, which depends on the soil's wettability, incoming flux at the soil surface and the wetting front's propagation rate. Lower soil wettability hinders spontaneous invasion of the dry pores and, together with a higher input flux, induces water accumulation behind the wetting front (saturation overshoot). The wetting front starts to propagate once the pressure building up behind it exceeds the dynamic water‐entry pressure. To conclude, the physically based novel moving‐boundary approach for solving stable and gravity‐driven unstable flow in soils was developed and verified. It supports the conjecture that saturation overshoot is a prerequisite for gravity‐driven fingering.
Statistical distributions for monthly aggregations of precipitation and streamflow in drought indicator applications
Authors: Svensson Cecilia , Hannaford Jamie , Prosdocimi Ilaria
Published: December 2016

Drought indicators are used as triggers for action and so are the foundation of drought monitoring and early warning. The computation of drought indicators like the standardized precipitation index (SPI) and standardized streamflow index (SSI) require a statistical probability distribution to be fitted to the observed data. Both precipitation and streamflow have a lower bound at zero, and their empirical distributions tend to have positive skewness. For deriving the SPI, the Gamma distribution has therefore often been a natural choice. The concept of the SSI is newer and there is no consensus regarding distribution. In the present study, twelve different probability distributions are fitted to streamflow and catchment average precipitation for four durations (1, 3, 6, and 12 months), for 121 catchments throughout the UK. The more flexible three‐ and four‐parameter distributions generally do not have a lower bound at zero, and hence may attach some probability to values below zero. As a result, there is a censoring of the possible values of the calculated SPIs and SSIs. This can be avoided by using one of the bounded distributions, such as the reasonably flexible three‐parameter Tweedie distribution, which has a lower bound (and potentially mass) at zero. The Tweedie distribution has only recently been applied to precipitation data, and only for a few sites. We find it fits both precipitation and streamflow data nearly as well as the best of the traditionally used three‐parameter distributions, and should improve the accuracy of drought indices used for monitoring and early warning.
Nonlinear advection‐aridity method for landscape evaporation and its application during the growing season in the southern Loess Plateau of the Yellow River basin
Authors: Brutsaert Wilfried , Li Wei , Takahashi Atsuhiro , Hiyama Tetsuya , Zhang Lu , Liu Wenzhao
Published: December 2016

The advection‐aridity approach to estimate actual evaporation from natural land surfaces is one of the better known implementations of Bouchet's complementary principle. Detailed measurements at 2, 12, and 32 m above the ground surface during the growing seasons of 2004–2007 allowed validation of a generalized nonlinear form of this approach above the highly variable terrain in Changwu County in the southern Loess Plateau of the Yellow River basin in China. The obtained values of the parameters were found to lie well within the ranges to be expected on physical grounds or from previous measurements by different experimental means; calibration on the basis of any one year of data allowed predictions within roughly 5% on average. Relative to the corresponding observed turbulent vapor fluxes, the evaporation rates calculated with measurements at the highest level of 32 m displayed the least scatter but only slightly less than those calculated with measurements at the lower level of 12 m; however, those based on measurements at the lowest level of 2 m displayed considerably more scatter than those derived at the two higher levels. This is consistent with the existence of a blending height at higher elevations above the ground, where the effects of surface variability tend to fade away.
Precipitation of Long‐Period Stacking Ordered Structure in Mg–Gd–Zn–Mn Alloy
Authors: Li Jiehua , Albu Mihaela , Wu Yujuan , Peng Liming , Dienstleder Martina , Kothleitner Gerald , Hofer Ferdinand , Schumacher Peter
Published: December 2016

Precipitation of long‐period stacking ordered (LPSO) structure in Mg–15Gd–0.8Zn–0.8Mn (wt%) alloy after solution treatment at 520 °C for 1 000 h has been investigated using high angle annular dark field scanning transmission electron microscopy (HAADF‐STEM). The stacking periodicity of the LPSO phase is lengthened 14‐fold along the c‐axis and the LPSO phase consists of Gd‐ and Zn‐enriched solute clustering. Detailed HAADF‐STEM imaging shows a clear evidence of a co‐segregation of Gd and Zn within a LPSO phase. This paper provides a better understanding of the interaction between Gd and Zn, which can, therefore, provide useful guidelines to develop high performance Mg alloys.
Sulfide and Sulfonyl Chloride as Sulfonylating Precursors for the Synthesis of Sulfone‐Containing Isoquinolinonediones
Authors: Xia Xiao‐Feng , Zhu Su‐Li , Wang Dawei , Liang Yong‐Min
Published: December 2016

An efficient method for the synthesis of sulfone‐containing isoquinolinonediones has been achieved via radical cascade addition/cyclization of acrylamide with sulfide or sulfonyl chloride under silver‐catalysis or visible light‐induced conditions. On the basis of this newly developed strategy, a wide range of isoquinolinonedione derivatives with a variety of functional groups can be effectively synthesized.

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Elusive Thiyl Radical Migration in a Visible Light Induced Chemoselective Rearrangement of γ‐Keto Acrylate Thioesters: Synthesis of Substituted Butenolides
Authors: Naskar Sandip , Das Indrajit
Published: December 2016

The first metal/photocatalyst‐free, visible light induced chemoselective rearrangement of γ‐keto acrylate thioesters via elusive thiyl radical migration is described. Thioesters bearing at least one alkyl substitution undergo 1,2‐thiyl radical migration, whereas 1,4‐migration has been observed when the substrate is substituted by aromatics only. The reactions show excellent functional group tolerance and are proposed to proceed through the trans‐cis isomerization/intramolecular lactonization/thiyl radical capture pathway. This atom‐economical process constitutes an efficient and practical method for the formation of substituted butenolides.

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Naphthalene‐based polyimide electrolytes for lithium‐ion battery applications
Authors: Toker Öztürk Raife D. , Uğur Mustafa H. , Gungor Atilla , Kayaman‐Apohan Nilhan
Published: December 2016

The preparation of 2,6‐Bis(m‐amino phenoxy) benzoyl naphthalene‐based polyimides for solid polymer electrolytes was reported. Li‐salt and PEO bearing polyimide membranes were prepared. Thermo‐gravimetric analysis results reveal that the PI/PEO/LiCF3SO3 polymer electrolyte membranes are thermally stable up to 500°C. The “Tg” values are in the range 167–221.5°C according to dynamic mechanical analysis (DMA). The conductivities of Li‐salt and PEO containing PI membranes are in the range of 10−7–10−5 S/cm. The conductivity increases with incorporation of PEO and Li+ concentration. The linear sweep voltammetry experiments showed that no peaks were observed between 1.75 and 4.5 V.
Acceleration of Inward Ring Opening of 3‐Phosphorylcyclobutenes
Authors: Ishida Naoki , Yano Takaaki , Murakami Masahiro
Published: December 2016

3‐Phosphorylcyclobutenes undergo a 4π‐electrocyclic ring opening reaction faster than cyclobutene itself, and afford the corresponding 1,3‐dienes with the cis isomer predominating. The accelerating effect and the inward preference of the phosphonate substituents are ascribed to the orbital interaction between the breaking C−C σ‐orbital of the cyclobutene backbone with the P−O σ* orbitals at the transition state.
Fluid dipping technology of chimpanzees in Comoé National Park, Ivory Coast
Authors: Lapuente Juan , Hicks Thurston C. , Linsenmair K. Eduard
Published: December 2016

Over a 6 month period during the dry season, from the end of October 2014 to the beginning of May 2015, we studied tool use behavior of previously unstudied and non‐habituated savanna chimpanzees (Pan troglodytes verus) living in the Comoé National Park, Ivory Coast (CI). We analyzed all the stick tools and leaf‐sponges found that the chimpanzees used to forage for ants, termites, honey, and water. We found a particular behavior to be widespread across different chimpanzee communities in the park, namely, dipping for water from tree holes using sticks with especially long brush‐tip modifications, using camera traps, we recorded adults, juveniles, and infants of three communities displaying this behavior. We compared water dipping and honey dipping tools used by Comoé chimpanzees and found significant differences in the total length, diameter, and brush length of the different types of fluid‐dipping tools used. We found that water dipping tools had consistently longer and thicker brush‐tips than honey dipping tools. Although this behavior was observed only during the late dry season, the chimpanzees always had alternative water sources available, like pools and rivers, in which they drank without the use of a tool. It remains unclear whether the use of a tool increases efficient access to water. This is the first time that water dipping behavior with sticks has been found as a widespread and well‐established behavior across different age and sex classes and communities, suggesting the possibility of cultural transmission. It is crucial that we conserve this population of chimpanzees, not only because they may represent the second largest population in the country, but also because of their unique behavioral repertoire.
N,P‐Heterocyclic Germylene/B(C6F5)3 Adducts: A Lewis Pair with Multi‐reactive Sites
Authors: Del Rio Natalia , Lopez‐Reyes Morelia , Baceiredo Antoine , Saffon‐Merceron Nathalie , Lutters Dennis , Müller Thomas , Kato Tsuyoshi
Published: December 2016

An N,P‐heterocyclic germylene/B(C6F5)3 Lewis adduct 2 presenting multi‐reactive sites (P/B Lewis pair, germylene, Ge=P π‐bond) is reported. In contrast to classical frustrated Lewis pairs or divalent Group 14 element species, 2 is able to activate two small molecules simultaneously. Of particular interest, 2 reacts with silanes leading to the formation of original cationic germylenes 3, and can be used as a metal‐free catalyst for selective CO2‐hydrosilylation to H2C(OSiEt3)2.
Selective Metal‐free HB(C6F5)2 Catalyzed Allene Cyclotrimerization: Formation of 1,3,5‐Trimethylenecyclohexane and Its Tris‐hydroboration Product
Authors: Tao Xin , Kehr Gerald , Daniliuc Constantin G. , Erker Gerhard
Published: December 2016

Allene is cyclotrimerized under metal‐free conditions with the borane HB(C6F5)2 catalyst to selectively give 1,3,5‐trimethylenecyclohexane (3 a). Three‐fold hydroboration of the 1,3,5‐cyclotrimer with Piers’ borane gives the all‐cis 1,3,5‐CH2B(C6F5)2 substituted cyclohexane product 14.
Beryllium‐Phosphan‐Komplexe: Synthese, Eigenschaften und Reaktivität von (PMe3)2BeCl2 und (Ph2PC3H6PPh2)BeCl2
Authors: Buchner Magnus R. , Müller Matthias , Rudel Stefan S.
Published: December 2016

Es wird über die gezielte Synthese, die spektroskopischen Eigenschaften und die Reaktivität von Bis(trimethylphosphan)berylliumdichlorid (1) und Bisdiphenylphosphinopropanberylliumdichlorid (2), inklusive der Kristallstruktur von (PMe3)2BeCl2 (1) berichtet. Diese vierfach koordinierten Berylliumverbindungen können mit nButyllithium (nBuLi) zu dreifach koordiniertem (Ph2PC3H6PPh2)BenBu2 (3) und (PMe3)BenBu2 (4) alkyliert werden. PMe3 kann im Vakuum aus (PMe3)BenBu2 (4) entfernt werden, um [nBu2Be]2 (5) zu erhalten. Zum ersten Mal wurde die seit Dekaden postulierte Dimerisierung von [nBu2Be]2 in Lösung spektroskopisch beobachtet. Diese neuartige, etherfreie Syntheseroute ermöglicht den Zugang zu Berylliumdialkylen, unter völligem Ausschluss sauerstoffatomhaltiger Reagenzien und Lösungsmittel. Diese “Sauerstofffreiheit” ist entscheidend für Halbleiteranwendungen, bei denen Sauerstoff oft unerwünscht ist und um jeden Preis vermieden werden muss.
1,1,3,3‐Tetratriflylpropene (TTP): A Strong, Allylic C–H Acid for Brønsted and Lewis Acid Catalysis
Authors: Höfler Denis , van Gemmeren Manuel , Wedemann Petra , Kaupmees Karl , Leito Ivo , Leutzsch Markus , Lingnau Julia B. , List Benjamin
Published: December 2016

Tetratrifylpropene (TTP) has been developed as a highly acidic, allylic C–H acid for Brønsted and Lewis acid catalysis. It can readily be obtained in two steps and consistently shows exceptional catalytic activities for Mukaiyama aldol, Hosomi–Sakurai, and Friedel–Crafts acylation reactions. X‐ray analyses of TTP and its salts confirm its designed, allylic structure, in which the negative charge is delocalized over four triflyl groups. NMR experiments, acidity measurements, and theoretical investigations provide further insights to rationalize the remarkable reactivity of TTP.
Energetic and Frictional Effects in the Transport of Ions in a Cyclic Peptide Nanotube
Authors: Seo Yongil , Song Yeonho , Schatz George C. , Hwang Hyonseok
Published: December 2016

The effects of geometric restraints and frictional parameters on the energetics and dynamics of ion transport through a synthetic ion channel are investigated using molecular dynamics (MD) simulations for several different ions. To do so, potential of mean force profiles and position‐dependent diffusion coefficients for Na+, K+, Ca2+, and Cl− transport through a simple cyclic peptide nanotube, which is composed of 4× cyclo[−(D‐Ala‐Glu‐D‐Ala‐Gln)2−] rings, are calculated via an adaptive biasing force MD simulation method and a Baysian inference/Monte Carlo algorithm. Among the restraints and parameters examined in this work, the radius parameter used in the flat‐bottom half‐harmonic restraint at the entrance and exit to channel has a great effect on the energetics of ion transport through the variation of entropy in the outside of the channel. The diffusivity profiles for the ions show a strong dependence on the damping coefficient, but the dependence on the coefficient becomes minimal inside the channel, indicating that the most important factor which affects the diffusivity of ions inside the channel is local interactions of ions with the structured channel water molecules through confinement.
Self‐assembling Helical Rod–Coil Peptoid Amphiphiles
Authors: Lee Yen Jea , Chung Solchan , Ahn Young Deok , Kang Boyeong , Lee Jae Young , Seo Jiwon
Published: December 2016

A helical rod–coil motif was employed to design water‐soluble peptoid amphiphiles. Prior to this study, this approach was rarely exploited in the construction of amphiphilic peptoids. The helical rod–coil motif enabled complete dissolution of the peptoids 1 and 2 in water. The critical micelle concentration (CMC) of the water‐soluble peptoids was measured. Circular dichroism (CD) analysis of each peptoid was performed to confirm the helical secondary structure in solution. Scanning electron microscopy (SEM) revealed the surface morphology of the self‐assembled peptoid structures. Water‐soluble peptoids comprised helical rod–coil structures provide a variety of self‐assembled architectures in aqueous solutions.
Ordered CaSi2 Microwall Arrays on Si Substrates Induced by the Kirkendall Effect
Authors: Meng Xiang , Ueki Akiko , Tatsuoka Hirokazu , Itahara Hiroshi
Published: December 2016

We have specified the synthetic conditions to obtain one‐directionally ordered CaSi2 microwall arrays vertically grown on a Si substrate. Our basic concept is based on the utilization of the Kirkendall effect for reactive deposition epitaxy (RDE). We found for the first time that: 1) a much larger Ca vapor supply on the Si substrate than the conventional RDE, 2) the adoption of a two‐step heating process, and 3) the selection of the crystal axis of the Si surface are the keys to control the microstructures of CaSi2 on the Si substrate. The CaSi phase was first formed on Si, then the CaSi2 phase was formed at the CaSi/Si interface. Based on the Kirkendall effect, the interdiffusion of Ca and Si was enhanced in the vertical direction rather than in the parallel direction to the Si surface. CaSi2 tends to grow along four equivalent Si{111} planes, however, the specific orientation of the Si surface resulted in CaSi2 microwalls grown along its Si(11
) plane, the only plane directing nearly vertical to the surface among the Si{111} planes. These results suggest that the Kirkendall effect under asymmetric growth of target materials would be a rational strategy to obtain their ordered microstructures.
Structural and Mechanistic Insights into Development of Chemical Tools to Control Individual and Inter‐Related Pathological Features in Alzheimer's Disease
Authors: Lee Hyuck Jin , Korshavn Kyle J. , Nam Younwoo , Kang Juhye , Paul Thomas J. , Kerr Richard A. , Youn Il Seung , Ozbil Mehmet , Kim Kwang S. , Ruotolo Brandon T. , Prabhakar Rajeev , Ramamoorthy Ayyalusamy , Lim Mi Hee
Published: December 2016

To elucidate the involvement of individual and inter‐related pathological factors [i.e., amyloid‐β (Aβ), metals, and oxidative stress] in the pathogenesis of Alzheimer's disease (AD), chemical tools have been developed. Characteristics required for such tool construction, however, have not been clearly identified; thus, the optimization of available tools or new design has been limited. Here, key structural properties and mechanisms that can determine tools’ regulatory reactivities with multiple pathogenic features found in AD are reported. A series of small molecules was built up through rational structural selection and variations onto the framework of a tool useful for in vitro and in vivo metal–Aβ investigation. Variations include: (i) location and number of an Aβ interacting moiety; (ii) metal binding site; and (iii) denticity and structural flexibility. Detailed biochemical, biophysical, and computational studies were able to provide a foundation of how to originate molecular formulas to devise chemical tools capable of controlling the reactivities of various pathological components through distinct mechanisms. Overall, this multidisciplinary investigation illustrates a structure–mechanism‐based strategy of tool invention for such a complicated brain disease.
Charge‐sharing read port with bitline pre‐charging and sensing scheme for low‐power SRAMs
Authors: Maroof Naeem , Sohail Muhammad , Shin Hyunchul
Published: December 2016

In this paper, we present our decoupled differential read (DDR) port and bitline (BL) pre‐charging scheme. The proposed scheme allows the charge sharing between bitlines during the read operation. DDR port isolates the internal nodes, thus improves the read static noise margin and allows the subthreshold operation. BLs are not pre‐charged to full VDD. Read port is designed such that for the read ‘1’ operation, BL shares its charge with BLB, and for read ‘0’ operation, BL is charged toward VDD and BLB is discharged to the ground. The proposed non‐VDD BL pre‐charging and the charge‐sharing mechanism provide substantial read power savings. Virtual power rail is used to suppress the BL leakages. A dynamic voltage level shifting pre‐amplifier is used that shifts both BLs to the middle voltage and amplifies the voltage difference. Single‐ended write driver is also presented that only conditionally charges the write BL. The proposed 10‐transistor static random access memory cell using DDR provides more than 2 times read static noise margin, ~72% read power savings, and ~40% write power savings compared with the conventional six‐transistor static random access memory. Copyright © 2016 John Wiley & Sons, Ltd.
Cobalt(II)/TPPMS‐Catalyzed Dehydrative Nucleophilic Substitution of Alcohols in Water
Authors: Hikawa Hidemasa , Ijichi Yukiko , Kikkawa Shoko , Azumaya Isao
Published: December 2016

A green and sustainable direct dehydrative amination of alcohols, catalyzed by cobalt(II)/TPPMS (sodium diphenylphosphinobenzene‐3‐sulfonate) in water, is described. Earth‐abundant cobalt is used in form of Co(hfac)2·xH2O (hfac: hexafluoroacetylacetone), which acts as a highly efficient Lewis acidic catalyst. This simple atom‐economical protocol features mild conditions without the need for a base or other additives and affords the corresponding benzylic and allylic anilines along with water as the only coproduct. Mechanistic studies suggest that this system is driven by direct nucleophilic substitution of alcohols.