bluuebunny/crossref_metadata_2025 huggingface dataset:
Redox Condition, Nature and Tectono-magmatic Environment of Granitoids and Granite gneisses from the Karbi Anglong Hills, Northeast India: Constraints from Magnetic Susceptibility and Biotite Geochemistry
Authors: Anettsungla  , Rino Vikoleno , Kumar Santosh
Published: May 2018

The Karbi Anglong hills (erstwhile Mikir hills) in northeast India are detached and separated from the Meghalaya plateau by a NW-SE trending Kopili rift. The Karbi Anglong hills granitoids (KAHG) and its granite gneissic variants belong to Cambrian plutons formed during Pan-African orogenic cycle, which commonly intrude the basement granite gneisses and Shillong Group metasediments. The KAHG can be broadly classified into three major granitoid facies viz., coarse grained porphyritic granitoid, medium grained massive non-porphyritic granitoid, and granite gneiss, which share a common mineral assemblage of plagioclase-K-feldspar-quartz-biotite±hornblende-apatite-titanite-zircon-magnetite but differ greatly in mineral proportion and texture. Modal mineralogy of KAHG, granite gneiss and basement granite gneiss largely represents monzogranite and syenogranite. The magnetic susceptibility (MS) of the KAHG, granite gneiss and basement granite gneiss varies widely between 0.11×10−3 and 43.144×10−3 SI units, corresponding to ilmenite series (<3×10−3 SI; reduced type) and magnetite series (>3×10−3 SI; oxidized type) of granitoids respectively. The observed MS variations are most likely intrinsic to heterogeneous source regions, modal variations of orthomagnetic and ferromagnetic minerals, and tectonothermal and deformational processes that acted upon these rocks. The primary and re-equilibrated compositions of biotites from the KAHG, granite gneiss and basement granite gneiss suggest calc-alkaline, metaluminous (I-type) nature of felsic host magma formed in a subduction or post-collisional to peraluminous (S-type) host magma originated in syn-collisional tectonic settings, which were evolved and stabilized between FMQ and NNO buffers typically corresponding to reducing and oxidising magma environments respectively.
Influence of Geo-environmental and Chemical Factors on Thermotolerant Coliforms and E. coli in the Groundwater of Central Kerala
Authors: Sreekala M. S. , Sareen Sarah John , Sivalingam Rajathi
Published: May 2018

Geo-environmental studies in parts of Ernakulam district (Kerala, India) were carried out. The study area comprises of sedimentary (Limestone, sandstone, Clay and Lignite) and crystalline (Charnockite and gneisses) rocks. The sedimentary terrain is characterized by confined and unconfined aquifers. In hard crystalline formations groundwater occurs under phreatic conditions in the shallow weathered portions and under semi confined to confined conditions in the deep-seated fractures. The study area is demarcated into five areas based on soil types. Climate is hot humid to hot summer with heavily raining monsoon. Two major rivers Periyar and Muvattupuzha drain through the area. Agricultural and industrial activities are prevalent in Ernakulam district. The major cause of pollution in the study area is due to the presence of coliforms. Detailed investigations carried out to identify the coliforms indicated spatial and seasonal changes in the distribution pattern. Monsoon and post monsoon showed significantly high total coliforms compared to pre-monsoon. Thermo-tolerant coliforms is high during monsoon season. This seasonal change could be due to the effect of rainfall, overland flow, nutrient load and temperature change. Wide variations in the coliform counts are observed in wells situated near rivers, canals, paddy fields and in water bodies lying close to pilgrimage center, fertilizer industry, and public places. It is noticed that the chemical characteristics of the groundwater influence the coliform survival. pH, nitrite, bicarbonate, hardness, and alkalinity play a significant role in controlling coliform count. At the outset, the study highlighted the impact of anthropogenic activities on ground water in a coastal district of Kerala state.
ASTER Spectral Analysis for Host Rock Associated with Porphyry Copper-molybdenum Mineralization
Authors: Sabbaghi Hamid , Moradzadeh Ali
Published: May 2018

This study is an attempt to understand the application of spectral image processing methods to ASTER data for mapping host rock associated with porphyry copper-molybdenum mineralization. The application of remote sensing in identifying variations in surface mineralogy, structural elements, and lithologic contacts can help in identifying such relations. Signatures collected from the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) data is used to map the host rock of Zafarqand area. The study area is located in the central segment of the Urumieh–Dokhtar volcanic belt of Iran. The Urumieh-Dokhtar is a potential zone for exploration of new porphyry copper deposits. Band ratio, band math, false colour composites and principal component analysis techniques are used to refine the different lithologic units in the area. These methods showed the discrimination of acidic igneous rock from intermediate igneous rock and the boundary between igneous rocks using the shortwave infrared bands (SWIR) of ASTER at regional scale. Results have proven to be effective and in accordance with the results of field observations, ore microscopy examination and with reference geological map. In conclusion, the image processing methods used can provide cost-effective information to discover possible locations of porphyry copper and epithermal gold mineralization prior to detailed and costly ground investigations. The extraction of spectral information from ASTER data can produce comprehensive and accurate information for copper and gold resource investigations around the world, including those yet to be discovered.
Mir‐483 inhibits colon cancer cell proliferation and migration by targeting TRAF1
Authors: Niu Zi‐Yu , Li Wen‐Li , Jiang Da‐Lei , Li Yan‐Song , Xie Xiang‐Jun
Published: May 2018

MicroRNAs are important regulators during human growth and development. Emerging evidence indicates that microRNAs play important roles in colorectal cancer. The aim of this study is to reveal the biological function and direct target gene of miR‐483 in colorectal cancer. The biological function of miR‐483 on the proliferation and migration of colon cancer cells was then examined by Edu assay and transwell assay, respectively. Our findings revealed that miR‐483 mimic could significantly inhibit cell proliferation and migration. The target gene of miR‐483 was predicted by target scan software and identified by a dual fluorescence reporter system which showed that TRAF1 was a direct target gene of miR‐483 in SW480 cell line. These data suggest that miR‐483 is a colorectal cancer suppressor which could inhibit cell proliferation and migration, possibly via targeting TRAF1. The miR‐483 could be a potential treatment target for colorectal cancer.
An autopsy case of small vessel, childhood, primary angiitis of the central nervous system (SVcPACNS): suggestions for establishing specific histologic criteria for diagnosis
Authors: Dunham C.
Published: May 2018

SVcPACNS is a rare inflammatory/immune disorder that typically affects the small blood vessels of the brain. SVcPACNS differs from most adult forms of PACNS by being predominantly lymphocytic, non-granulomatous and non-necrotizing. Previously healthy children are typically affected by range of signs and symptoms, including: seizures, headache, cognitive decline, behavior/personality change, focal neurological deficits and potentially a decreased level of consciousness. Treatment protocols featuring induction (steroids and cyclophosphamide) and subsequent maintenance phases (e.g., mycophenolate mofetil) have been demonstrated to yield favorable outcomes. Since SVcPACNS is characteristically angiography negative, the diagnostic gold standard is brain biopsy. Interpretation of these biopsies is often challenging given the histologic overlap between SVcPACNS and encephalitis. Distinguishing the foregoing is critical since the treatment of these entities is significantly different.

Herein, a rare autopsy case of SVcPACNS in a 4 year old male is presented. This case provides a unique opportunity to review the Alrawi criteria for the histologic diagnosis of PACNS and establish/refine criteria specific to SVcPACNS. Generally, such criteria should feature: 1) an intramural and lymphocyte predominant infiltrate devoid of multinucleated giant cells; 2) structural vessel alterations lacking fibrinoid necrosis; 3) perivascular pathology supportive of an angiocentric process; 4) the absence of encephalitis; and, 5) the absence of a concurrent systemic or rheumatic illness that could account for the CNS findings.
Chronic traumatic encephalopathy in contact sports: The Canadian experience
Authors: Hazrati L.N.
Published: May 2018

Chronic traumatic encephalopathy (CTE) is suggested to be a progressive neurodegenerative disease, characterized by tau deposits in the depth of cortical sulci in neurons and in glioneuronal complexes around blood vessels. Few studies have suggested that it is caused by multiple concussions or subconcussive brain injuries. A recent publication showed that most American football players whose brain were donated to the Boston University concussion center had CTE (Mez et al. 2017). Over the last 6 years, with the help of neuropathologist colleagues across Canada, we have collected the brains of 33 high level professional and amateur athletes. These include 5 National hockey league (NHL) players, 15 Canadian football league (CFL) players, 3 College football players, 3 College hockey players, 2 professional boxers, 1 professional bull rider, 1 BMX champion, 1 rugby player and 2 skiers. All were male and the ages ranging from 15 to 87 years. Our results indicate that only a small portion of cases have CTE. Moreover, most cases are low stage (stage 1 or 2) and this pathology is mainly seen in some of the younger players. Older players either have no pathological findings or have other neurodegenerative diseases such as Alzheimer’s disease. The disparity of results between the 2 groups will be discussed.
The role of ATP and P2X purinoreceptor 7 in the pathogenesis of cerebral tau
Authors: Gao A.F. , Hazrati L.N.
Published: May 2018

The tauopathies are a group of neurodegenerative diseases characterized by abnormal deposition of hyperphosphorylated-tau. The pathogenesis of these changes remains uncertain. In chronic traumatic encephalopathy, tauopathy is hypothesized to occur after repeated mild traumatic brain injury (TBI). Post-traumatic extracellular ATP release and signalling via the P2X purinoceptor 7 (P2RX7) has been shown to be important in mediating pathological changes in TBI. We hypothesized that ATP-P2RX7 is involved in the development of tauopathy.

We injected ATP analogue bzATP or vehicle intraventricularly into C57BL/6 mice, pre-treated with either intraperitoneal P2RX7 antagonist Brilliant Blue G (BBG) or vehicle. At 2 weeks and 3 months, behavioural change was assessed with the tail suspension test, accelerating rotatrod, and fear conditioning; mice were then sacrificed for immunohistochemistry and western blot.

We observed increased immobile time in the tail suspension test for mice treated with bzATP at 3 months. Similarly, for rotarod, mice treated with bzATP showed poorer performance at 3 months. These effects were diminished by BBG pre-treatment. Fear conditioning, however, did not demonstrate a significant difference between groups. Immunohistochemical staining for GFAP showed increased intensity at both 2 weeks and 3 months for bzATP-treated mice compared to those pre-treated with BBG. Levels of phosphorylated tau (AT8) were increased in bzATP-treated mice compared to controls.

In summary, ATP-P2RX7-mediated mechanisms may play a role in the development of behavioural deficits and tauopathy.
Influence of permeable beds on hydraulically macro-rough flow
Authors: Fang Hongwei , Han Xu , He Guojian , Dey Subhasish
Published: May 2018

In this study, macro-rough flows over beds with different permeability values are simulated using the large-eddy simulation, and the results are analysed by applying the double-averaging (DA) methodology. Spheres of different sizes and arrangements were used to form the beds, which are deemed to be permeable granular beds. The influence of bed permeability on the turbulence dynamics and structure is investigated. It was observed that the scales of the spanwise vortical structures over more permeable beds are larger than those over less permeable beds. This is attributed to large-scale spanwise-alternate strips of varying Reynolds shear stress (RSS), emerging from the surface of macro-rough elements for the permeable beds. The DA stress balance suggests that the time-averaged spanwise vortical structure leads to a damping in DA RSS and an unusual peak of the form-induced stress in the main flow. In the streamwise direction, both large turbulent structures that originate from the Kelvin–Helmholtz-type instability and small turbulent structures that are associated with the turbulent transport across the gaps of the roughness elements are more prevalent over highly permeable beds. Near the bed, the relative magnitude of turbulent events shows a transition from a ejections-dominating to sweeps-dominating zone with vertical distance. Further, several hydrodynamic characteristics normalized by inner scales (kinematic viscosity to shear velocity ratio) show a greater dependency on permeability Reynolds number than those normalized by sediment size. The study provides an insight into the mechanism of mass transfer near the fluid–particle interface, which is vital to benthic and aquatic ecology.
Experimental investigation of in-line flow-induced vibration of a rotating circular cylinder
Authors: Zhao J. , Lo Jacono D. , Sheridan J. , Hourigan K. , Thompson M. C.
Published: May 2018

This study experimentally investigates the in-line flow-induced vibration (FIV) of an elastically mounted circular cylinder under forced axial rotation in a free stream. The present experiments characterise the structural vibration, fluid forces and wake structure of the fluid–structure system at a low mass ratio (the ratio of the total mass to the displaced fluid mass) over a wide parameter space spanning the reduced velocity range $5\leqslant U^{\ast }\leqslant 32$ and the rotation rate range $0\leqslant \unicode[STIX]{x1D6FC}\leqslant 3.5$, where $U^{\ast }=U/(\,f_{nw}D)$ and $\unicode[STIX]{x1D6FC}=|\unicode[STIX]{x1D6FA}|D/(2U)$, with $U$ the free-stream velocity, $D$ the cylinder outer diameter, $f_{nw}$ the natural frequency of the system in quiescent water and $|\unicode[STIX]{x1D6FA}|$ the angular velocity of the cylinder rotation. The corresponding Reynolds number (defined by $Re=UD/\unicode[STIX]{x1D708}$, with $\unicode[STIX]{x1D708}$ the kinematic viscosity of the fluid) was varied over the interval $1349\leqslant Re\leqslant 8624$, where it is expected that the FIV response is likely to be relatively insensitive to the Reynolds number. The fluid–structure system was modelled using a low-friction air-bearing system in conjunction with a free-surface water-channel facility. Three vibration regions that exhibited vortex-induced vibration (VIV) synchronisation, rotation-induced galloping and desynchronised responses were observed. In both the VIV synchronisation and rotation-induced galloping regions, significant cylinder vibration was found to be correlated with wake–body synchronisation within the rotation rate range $2.20\lesssim \unicode[STIX]{x1D6FC}\lesssim 3.15$. Of significant interest, the frequency of the streamwise fluid force could be modulated by the imposed rotation to match that of the transverse lift force, resulting in harmonic synchronisation. Measurements using the particle image velocimetry (PIV) technique were performed to identify the wake structure. Interestingly, the imposed rotation can cause regular vortex shedding in in-line FIV at rotation rates that see suppression of the Bénard–von-Kármán vortex shedding in the case of a rigidly mounted cylinder ($\unicode[STIX]{x1D6FC}\gtrsim 1.75$). There is a monotonic increase in the drag coefficient with rotation rate beyond $\unicode[STIX]{x1D6FC}=2$ for a non-oscillating rotating cylinder. This suggests that the mechanism for sustaining the large rotation-induced galloping oscillations at higher $\unicode[STIX]{x1D6FC}$ is due to a combination of aerodynamic forcing from the locked induced vortex shedding associated with the oscillations, assisted by aerodynamic forcing, evaluated using quasi-steady theory.
Capillary waves with surface viscosity
Authors: Shen Li , Denner Fabian , Morgan Neal , van Wachem Berend , Dini Daniele
Published: May 2018

Experiments over the last 50 years have suggested a tentative correlation between the surface (shear) viscosity and the stability of a foam or emulsion. We examine this link theoretically using small-amplitude capillary waves in the presence of a surfactant solution of dilute concentration, where the associated Marangoni and surface viscosity effects are modelled via the Boussinesq–Scriven formulation. The resulting integro-differential initial value problem is solved analytically, and surface viscosity is found to contribute an overall damping effect to the amplitude of the capillary wave with varying degree depending on the length scale of the system. Numerically, we find that the critical damping wavelength increases for increasing surface concentration but the rate of increase remains different for both the surface viscosity and the Marangoni effect.
Early riser, late bloomer: Contextualizing Turkish health achievements in the last 50 yearsvis-à-visChina and the global picture of development
Authors: Özen İlhan Can
Published: May 2018

Where does Turkey’s performance in the health dimension of the Preston Curve stand with regard to comparable countries on the development ladder? When one observes the chronological progression of health and wealth values embedded in the Preston Curve for developing countries, one sees a near monotonic increase across the board, with only a very small number of downwardly mobile countries. In the face of this near-universal increase in health and wealth values, it is necessary to adopt a more comparative perspective in order to situate the Turkish state’s choices and performance within the general story playing out for developing countries in the second half of the 20th century. Utilizing just such a comparative framework, this article uses China’s experience between 1960 and 2010 as an alternative through which to understand Turkey’s development experience.
Eroding the symbolic significance of veiling? The Islamic fashion magazineÂlâ, consumerism, and the challenged boundaries of the “Islamic neighborhood”
Authors: Sayan-Cengiz Feyda
Published: May 2018

Islamic fashion and lifestyle magazines enable the global circulation and consumption of newly emerging images of, narratives about, and discourses on Muslim women across the globe. Such magazines also trigger debates by making visible the language of commodification and consumerism that is increasingly shaping Muslim subjectivities. In particular,Âlâ—the pioneering Islamic fashion magazine in Turkey—has been the target of extensive criticism by Islamic intellectuals and columnists. This study contextualizes these criticisms within the broader debate on veiling fashion and Islamic consumerism in the context of 2010s Turkey, a context in which the Islamic bourgeoisie has been strengthened and class cleavages among veiled women have been further sharpened. The study analyzes the opinion columns focusing onÂlâpublished in the Islamic, pro-government newspaperYeni Şafak, as well as the responses ofÂlâ’s editors and producers to such criticisms. The findings demonstrate that the magazine is criticized for making visible the surge of consumerism among the Islamic bourgeoisie, for blurring the boundaries between Islamic and secular identities, and for fragmenting an idealized imagination of Islamic collectivity by emphasizing class cleavages among veiled women. I argue that these criticisms ofÂlâin Islamic circles reflect a concern with the erosion of the symbolic connotations of veiling in Turkey, particularly in terms of marking the boundaries that define the imagination of an Islamic collectivity.
A conceptual model for the interpretation of aeolian sediments from a semiarid high-mountain environment since the late glacial
Authors: Stauch Georg
Published: May 2018

Different interpretations of accumulation and preservation of aeolian sediments lead to divergent and sometimes contradictory palaeoclimate reconstructions. Although aeolian transport mainly occurs during dry climate, the preservation of the aeolian sediment is a critical factor in many environments in determining the nature of the aeolian sedimentary archive. Analysis of more than 200 optically stimulated luminescence ages for aeolian sands from Tibet shows four different aeolian phases of accumulation. Strong aeolian activity occurred during the last glacial maximum, but hardly any aeolian sediments are preserved. Consequently, the period with the highest aeolian activity is not recorded in the sedimentary record. A phase of aeolian accumulation occurred in the late glacial and the early Holocene. The duration of deposition for this phase is a consequence of the complex topography and an increase in moisture. This phase was punctuated by exceptionally strong accumulation during the Younger Dryas stade. The mid-Holocene is characterised by weak aeolian accumulation and fluvial erosion caused by greater precipitation during the maximum height of the Asian summer monsoon. Aeolian activity resumed in the late Holocene because of drier conditions. The conceptual model provides an approach that can be applied to other mountain and desert margin regions that have limited sediment availability.
Neglect as effacement: the multiple lives of the Jardin Ralaimongo, Mahajanga, Madagascar
Authors: Rijke-Epstein Tasha
Published: May 2018

By considering the lifespan of a garden, this article investigates the myriad spatial practices of forgetting and remembering the colonial and postcolonial pasts that people apply to their urban surroundings in Mahajanga, Madagascar. In the heart of an ancient residential and commercial neighbourhood in this multi-ethnic Indian Ocean port city sits the Jardin Ralaimongo. Drawing on ethnographic and archival research, I explore the trajectory of the garden to elucidate the ways in which different socio-political groups have drawn on this site to negotiate differences, frame collective memories, and stake their claims to the urban landscape. I show how, as city inhabitants have reworked the spaces of the garden, so too has the park itself – its layout, material artefacts and location within the city – constrained the possibilities of what can be remembered and silenced, and who can be bound to one another, in contemporary times. Over its hundred-year history, this site has been founded, forgotten and reincarnated as a memorial to a succession of revered leaders, thus serving as a kind of spatial register of the historical socio-political changes that have given rise to the city. This article suggests that the deterioration of colonial-era architectural forms through long-standing neglect and abandonment may be understood as an active spatial practice of effacing some dimensions of the past, while the subsequent recuperation of deserted public spaces by certain groups is an effort to position themselves as legitimate residents and express their attachment to the city.
Dietary arginine affects growth, gut morphology, oxidation resistance and immunity of hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂) juveniles
Authors: Wu Mingjuan , Wu Xiaoyi , Lu Senda , Gao Yujie , Yao Wei , Li Xiaojun , Dong Yu , Jin Zibo
Published: May 2018

An 8-week growth trial was conducted to evaluate the effects of dietary arginine (Arg) levels on growth, gut morphology, oxidation resistance and immunity of hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂) juveniles. Seven isoenergetic (1465 kJ (350 kcal)/100-g DM), isoproteic (53·5 % of DM) and isolipidic (7 % of DM) experimental diets were formulated to contain graded Arg levels ranging from 1·9 to 4·7 % (dry weight) at approximately 0·5 % increments. Each diet was randomly assigned to triplicate groups of 16 juvenile fish (average initial body weight: 11·7 (sd0·1) g) and was administered twice daily (08.00 and 16.00 hours). After the growth trial, all remaining fish were fed their prescribed diets for 2 d and then exposed to 4·5 mg Cu2+/l water for 36 h. Results showed that growth performance and feed utilisation of experimental fish were significantly affected by different dietary Arg levels. Weight gain % (WG%) of fish was increased as dietary Arg increased, reaching a peak value at 3·8 % dietary Arg level, and when dietary Arg level increased to 4·7 % WG% was reduced. Fish fed 1·9 and 2·2 % dietary Arg levels had higher daily feed intake compared with fish fed other dietary Arg levels. Feed conversion ratios in fish fed 1·9, 2·2, 2·7 and 4·7 % dietary Arg levels were higher than those in fish fed 3·1, 3·8 and 4·1 % dietary Arg levels. Protein efficiency ratio and protein productive value (PPV) increased with an increase in dietary Arg, up to a peak value at 3·8 % dietary Arg level, above which these parameters declined. On the basis of quadratic regression analysis of weight gain % (WG%) or PPV against dietary Arg levels, the optimal dietary Arg requirement for hybrid grouper was estimated to be 3·65 %. Fish fed 3·8 % dietary Arg had higher whole-body and muscle protein contents compared with fish fed other dietary Arg levels. Fish fed 3·8 and 4·1 % dietary Arg levels had higher levels of mRNA for insulin-like growth factor-I and target of rapamycin in the liver compared with fish fed other dietary Arg levels. Hepatic S6 kinase 1 mRNA expression in fish fed 3·8 % dietary Arg level was higher than that in fish fed any of the other dietary Arg levels. Gut morphology, hepatic antioxidant indices and immune indices in serum and head kidney were significantly influenced by dietary Arg levels. In conclusion, the optimal dietary Arg requirement for hybrid grouper was estimated to be 3·65 %, and suitable dietary Arg supplementations improved gut morphology and oxidation resistance of hybrid grouper.
HETEROSKEDASTICITY AUTOCORRELATION ROBUST INFERENCE IN TIME SERIES REGRESSIONS WITH MISSING DATA
Authors: Rho Seung-Hwa , Vogelsang Timothy J.
Published: May 2018

In this article, we investigate the properties of heteroskedasticity and autocorrelation robust (HAR) test statistics in time series regression settings when observations are missing. We primarily focus on the nonrandom missing process case where we treat the missing locations to be fixed asT→ ∞ by mapping the missing and observed cutoff dates into points on [0,1] based on the proportion of time periods in the sample that occur up to those cutoff dates. We consider two models, the amplitude modulated series (Parzen, 1963) regression model, which amounts to plugging in zeros for missing observations, and the equal space regression model, which simply ignores the missing observations. When the amplitude modulated series regression model is used, the fixed-blimits of the HAR test statistics depend on the locations of missing observations but are otherwise pivotal. When the equal space regression model is used, the fixed-blimits of the HAR test statistics have the standard fixed-blimits as in Kiefer and Vogelsang (2005). We discuss methods for obtaining fixed-bcritical values with a focus on bootstrap methods and find the naivei.i.d.bootstrap with missing dates fixed to be an effective and practical way to obtain the fixed-bcritical values.
Two remarks on Wall's D2 problem
Authors: HAMBLETON IAN
Published: May 2018

If a finite group G is isomorphic to a subgroup of SO(3), then G has the D2-property. Let X be a finite complex satisfying Wall's D2-conditions. If π1(X) = G is finite, and χ(X) ≥ 1 − def(G), then X ∨ S2 is simple homotopy equivalent to a finite 2-complex, whose simple homotopy type depends only on G and χ(X).
Magnetic properties and crystal structure of Ga2−xFexO3
Authors: Yan Hui , Huang Yuanqi , Cui Wei , Zhi Yusong , Guo Daoyou , Wu Zhenping , Chen Zhengwei , Tang Weihua
Published: May 2018

Ga2−xFexO3 (GFO) bulks with x from 0.7 to 1.3 have been fabricated using the classic solid-state route. The structural, optical, and magnetic properties have been investigated systematically. X-ray diffraction spectra and FULLPROF profile fitting indicate that GFO bulks belong to the orthorhombic structure with the space group Pc21n. Phase separation appears at the Fe content of x = 1.3. The optical bandgap decreases almost linearly with the increase of iron content, which means that the bandgap of GFO bulks can be controlled by adjusting the Fe content in the samples. The magnetic property measurements suggest that GFO is ferromagnetic, and the magnetic properties are enhanced compared with other reported works, exhibiting the application in ferromagnetic semiconductors devices.
Improvement of the developmental competence of canine oocyte using caffeine supplementation during IVM at different maturation time
Authors: Fathi Mohamed , Salama A. , Badr Magdy R.
Published: May 2018

The aim of the current study was to investigate the effect of caffeine supplementation duringin vitromaturation (IVM) for different maturation times on the developmental potential of canine oocytes recovered from ovariohysterectomized bitches. The recovered cumulus–oocytes complexes werein vitromatured for 72 h. Here, 10 mM caffeine was added to the maturation medium for different incubation times (caffeine from 0–72 h maturation, caffeine for the first 24 h of maturation only, caffeine addition from 24 to 48 h maturation time, caffeine addition from 48 to 72 h maturation or in caffeine-free medium, control group). The matured oocytes werein vitrofertilized using frozen–thawed spermatozoa. The presumptive zygotes werein vitrocultured in synthetic oviductal fluid medium for 5 days. The results showed that both maturation and fertilization rates were significantly higher (P˂ 0.05) using caffeine-treated medium for the first 24 h of maturation compared with the control and other two groups of caffeine treatment (from 24 to 48 h and from 48 to 72 h), whereas use of caffeine-treated medium for a 0–72 h incubation time did not affect these rates (P> 0.05). Interestingly, the matured oocytes in caffeine-supplemented medium for the first 24 h or from 0–72 h showed a significant (P˂ 0.05) increase in the total number of cleaved embryos compared with the control group. In conclusion, supplementation of the maturation medium with 10 mM caffeine for the first 24 h of maturation or during the whole maturation time (0–72 h) improved nuclear maturation and subsequent embryo development preimplantation followingin vitrofertilization.
Seasonal and Interannual Mixed‐Layer Heat Budget Variability in the Western Tropical Atlantic From Argo Floats (2007–2012)
Authors: Nogueira Neto A. V. , Giordani H. , Caniaux G. , Araujo M.
Published: May 2018

Oceanic and atmospheric processes were investigated in order to explore the causes of seasonal and interannual variability of sea surface temperatures (SST) in the western tropical Atlantic (WTA; 20°S–20°N, 15°W–60°W). A mixed‐layer (ML) heat budget was performed by using Argo profiles and supplementary data sets based on satellite and atmospheric products during the period 2007–2012. The WTA is divided into four boxes which represent the main temporal and spatial heterogeneities of this region. An analysis of error of each term pointed out that the mean net surface heat fluxes are systematically underestimated by 20 W m−2. A correction of this term provides realistic estimates of the vertical mixing which was obtained as residual term. In agreement with previous studies, the results show that surface flux is the most important process that governs the seasonal cycle of the heat content. Changes in shortwave radiation and latent heat fluxes dictate the oceanic response to the meridional migration of the ITCZ. Along the equator, surface fluxes modulate the annual cycle of ML temperature, but are strongly balanced by horizontal advection. The entrainment term proves a small contribution to the cooling of the ML. On an interannual time scale, the strong positive (negative) SST anomalies observed in 2010 (2012) were generated during the previous winter in both years, mainly north of 10°N, during which the wind anomalies were at the origin of intense heat loss anomalies. Horizontal advection may contributes to the maintaining of these SST anomalies in the equatorial zone and south Atlantic.
Mercury Inputs to Chinese Marginal Seas: Impact of Industrialization and Development of China
Authors: Yin Runsheng , Guo Zhigang , Hu Limin , Liu Wenchuan , Hurley James P. , Lepak Ryan F. , Lin Tian , Feng Xinbin , Li Xiangdong
Published: May 2018

In the past decades, China has experienced substantial economic growth and industrialization. However, the effects of vast development of China on Hg input to the nearby oceans are still unclear. In this study, the influx and isotopic compositions of Hg in four 210Pb‐dated sediment cores were examined to investigate changes in Hg deposition to the marginal seas off China over a century. Nearshore cores had higher Hg influxes than offshore cores. Increases of Hg influxes started since the 1950s, which coincides with China's economic development. Dramatic historical changes in Hg isotopic composition were observed in the cores (δ202Hg: −2.01‰ to −0.69‰; Δ199Hg: −0.16‰ to 0.31‰; n = 106). δ202Hg increased from the deep to the surface layers of the cores. The offshore cores mainly showed positive Δ199Hg values, but the pre‐1950 samples had more positive Δ199Hg values than the younger samples. The nearshore cores mainly showed negative Δ199Hg values in the pre‐1950s samples, but the younger samples showed Δ199Hg values close to zero. A triple‐mixing isotope model, used to quantify the contribution of potential Hg inputs (e.g., direct discharge of industrial Hg, soil Hg, and precipitation‐derived Hg), showed clear evidence of enhanced industrial Hg inputs to the ocean margin, but slightly decreased watershed soil Hg inputs in the last few decades. The variations of watershed‐derived Hg were likely caused by the construction of impoundments in major rivers of China. This study demonstrates that mercury inputs to Chinese marginal seas have been largely altered due to the industrialization and economic development of China.
Statistical Downscaling of GRACE‐Derived Groundwater Storage Using ET Data in the North China Plain
Authors: Yin Wenjie , Hu Litang , Zhang Menglin , Wang Jingrui , Han Shin‐Chan
Published: May 2018

Due to coarse spatial resolution, the application of Gravity Recovery and Climate Experiment (GRACE) data in local groundwater resource management has been limited. To overcome this issue, a downscaling approach is presented to improve the spatial resolution of GRACE‐derived groundwater storage anomalies using evapotranspiration (ET) data. The statistical downscaling method is only applied in areas where there is a strong relationship between GRACE‐derived groundwater storage (GWS) and ET, and the relationship can be established under different spatial resolutions. In this study, GWS anomalies are downscaled from 110 km to 2 km in the North China Plain, capturing subgrid heterogeneity in groundwater storage changes. The downscaled results are further validated using data from 111 observation wells from 2003 to 2014 in the Beijing Plain. The results show that the in situ groundwater levels agree with the Gravity Recovery and Climate Experiment (GRACE) downscaled results for the Beijing Plain in both interannual and monthly scales, with the correlation coefficient of 0.94 and 0.80, respectively. The correlation coefficients vary from 0.63 to 0.78, in 10 of the 13 Beijing Plain administrative regions. The regional downscaling approach employed in this study may be readily integrated into local water resources planning activities.
The Dynamics of Channel Slope, Width, and Sediment in Actively Eroding Bedrock River Systems
Authors: Yanites Brian J.
Published: May 2018

The evolution of rivers in eroding landscapes plays a key role in determining landscape relief and modulating climate‐tectonic interactions. A common approach to quantifying river system evolution uses a one‐dimensional, detachment‐limited stream power equation. One potential drawback of this model is that it does not incorporate the effects of changes in channel width or the role of sediment transport dynamics. Here I present a new method for modeling the influence of channel width on river dynamics to explore how variable width and sediment transport impact river profile evolution. With this approach, vertical river erosion can operate based on any number of river erosion models, such as a simple shear stress model (e.g., detachment limited), sediment cover‐shear stress hybrid models, or mechanistic saltation‐abrasion models. I explore the sensitivity of these three models to increases in rock‐uplift rate (i.e., 2, 3, 5, 10, and 20× increase). Generally, the results show that incorporating channel width adjustment or sediment transport dynamics lowers the sensitivity of a river profile to rock‐uplift rate. For the sediment transport‐dependent models, the degree of sensitivity depends on whether the system is limited by bedrock exposure or erosion potential (i.e., detachment potential). The approach produces transient responses that reveal distinct patterns of width and slope, which may provide valuable insight into the limiting physical mechanisms of bedrock erosion in a region. The implications of the work are broad and include the potential to distinguish underlying erosion controls from field observations of width and slope as well as understanding climate‐tectonic interactions.
Study of Relative Performance of Different Navigational Satellite Constellations Under Adverse Ionospheric Conditions
Authors: Goswami S. , Paul A. , Haldar S.
Published: May 2018

Detrimental effects of satellite signal outages during periods of intense equatorial ionospheric scintillations could be mitigated using multiconstellation satellites if provisions for interoperability of these satellite signals exist. In view of the sharp spatial gradient of ionization occurring in the equatorial region, comparison of satellite signal fluctuations from different constellations should be performed over limited spatial volume. This could be effective for maintaining and improving the performance of satellite‐based communication and navigation without compromising the accuracy and integrity. This paper presents a comparative study of robustness of GPS, GLONASS, and GALILEO satellites over a common ionospheric volume during periods of ionospheric scintillations for the equinoctial months of 2014 and March 2016 from Calcutta (22.58°N 88.38°E geographic; 32°N magnetic dip) and for September 2016 from Siliguri (26.72°N, 88.39°E; 39.49°N magnetic dip), located near the northern crest of equatorial ionization anomaly in the Indian longitude sector. It is found that for all the cases, carrier‐to‐noise ratio fluctuations over limited ionospheric volume from satellites of different constellations are comparable, thereby rendering them interoperable.
Observations of a Submesoscale Cyclonic Filament in the Marginal Ice Zone
Authors: von Appen Wilken‐Jon , Wekerle Claudia , Hehemann Laura , Schourup‐Kristensen Vibe , Konrad Christian , Iversen Morten H.
Published: May 2018

Submesoscale flows are energetic motions on scales of several kilometers that may lead to substantial vertical motions. Here we present satellite and ship radar as well as underway conductivity‐temperature‐depth and Acoustic Doppler Current Profiler observations of a cyclonic submesoscale filament in the marginal ice zone of Fram Strait. The filament created a 500‐m thin and 50‐km long sea ice streak and extends to >250‐m depth with a negative/positive density anomaly within/below the halocline. The frontal jets of 0.5 m/s are in turbulent thermal wind balance while the ageostrophic secondary circulation in places appears to subduct Atlantic Water at >50 m/day. Our study reveals the submesoscale dynamics related to sea ice shapes that can be sensed remotely and shows how submesoscale dynamics contribute to shaping the marginal ice zone. It also demonstrates the co‐occurrence and mixing of water masses over short horizontal scales, which has implications for ocean and sea ice models and understanding of patch formation of planktonic organisms.
Ongoing River Capture in the Amazon
Authors: Stokes Maya F. , Goldberg Samuel L. , Perron J. Taylor
Published: May 2018

River capture is thought to trigger abrupt changes in evolving continental drainage systems, but it is almost always inferred rather than observed, and the mechanisms that lead to capture are unclear. We shed light on these mechanisms by documenting an ongoing capture involving major South American rivers. The Rio Casiquiare is a distributary of the Rio Orinoco and a tributary of the Rio Negro; it forms a perennial water connection between the drainage basins of the Amazon and Orinoco, the largest and fourth‐largest rivers on Earth by discharge. This unusual configuration is the result of an incomplete and ongoing river capture, in which the Rio Negro is capturing the upper Rio Orinoco. We describe a positive feedback between diversion of water into the capturing channel and sedimentation within the channel being captured, a mechanism that could drive river capture in the Amazon and elsewhere.
Reconstruction of Tidal Discharges in the St. Lawrence Fluvial Estuary: The Method of Cubature Revisited
Authors: Matte Pascal , Secretan Yves , Morin Jean
Published: May 2018

Knowledge of tidal flows in rivers and estuaries is often scarce yet vital in determining flushing properties and sediment transport rates. While many rivers still remain ungauged, methodological difficulties often arise in gauged systems, resulting in short flow records compared to historical water level data. Notwithstanding, discharge reconstructions in estuaries are possible using indirect methods based on long‐term tidal data. In this paper, we revisit the method of cubature, integrating the continuity equation for discharges at different sections. The method consists in computing temporal changes in water volume from simultaneous tidal heights readings along the river and storage width estimations. These water balance estimates remain challenging to produce, because they require spatial interpolation of gappy tidal records and an accurate representation of inundated areas over time. Improvements on the method are made by using a 1‐D nonstationary tidal harmonic model that provides continuous tidal data along the estuary, with no temporal or spatial gaps. Second, a 2‐D finite element discretization is used to compute the time‐varying wetted surface area, relying on detailed topographic data over intertidal flats. The method is applied to the St. Lawrence fluvial estuary (SLFE) and validated against discharge data collected along nine cross sections of the river, reaching relative RMSE below 4% of the diurnal tidal discharge range at downstream locations and below 9% upstream. One year reconstructions conducted in the SLFE also show the potential of the method to reproduce the tidal discharge variability along the tidal‐river continuum, for a wide range of temporal scales.
The HESPERIA HORIZON 2020 Project and Book on Solar Particle Radiation Storms Forecasting and Analysis
Authors: Malandraki Olga E. , Crosby Norma B.
Published: May 2018

This article presents the High Energy Solar Particle Events forecasting and Analysis (HESPERIA) project, supported by the HORIZON 2020 programme of the European Union (Project 637324) as well as the resultant recently published book entitled Solar Particle Radiation Storms Forecasting and Analysis, The HESPERIA HORIZON 2020 Project and Beyond, edited by Malandraki and Crosby, Springer, Astrophysics and Space Sciences Library, 2018, ISBN 978‐3‐319‐60051‐2. The book reviews the results of the HESPERIA project as well as our current understanding of solar energetic particle physics.
What Is Nuisance Flooding? Defining and Monitoring an Emerging Challenge
Authors: Moftakhari Hamed R. , AghaKouchak Amir , Sanders Brett F. , Allaire Maura , Matthew Richard A.
Published: May 2018

Nuisance flooding (NF) refers to low levels of inundation that do not pose significant threats to public safety or cause major property damage, but can disrupt routine day‐to‐day activities, put added strain on infrastructure systems such as roadways and sewers, and cause minor property damage. NF has received some attention in the context of low‐lying coastal cities exposed to increasingly higher high tides, a consequence of sea level rise, which exceeds the heights of coastal topography. However, low levels of flooding are widespread and deserve greater attention. Here a simple, quantitative definition of NF is proposed based on established flood intensity thresholds for flood consequences (e.g., pedestrian safety, property damage, and health risks). Based on a wide range of literature including hydrology, transportation, public health risk, and safety impacts, we define NF based on depth >3 cm and <10 cm, regardless of the source. This definition of NF is not limited to high tide flooding but rather is inclusive of all possible flood drivers including pluvial, fluvial, and oceanic and can capture trends in NF resulting from trends in, and compounding effects of, flood drivers. Furthermore, we also distinguish between NF as a process and NF as an event, which is important for linking NF to societal impacts and developing effective policy interventions and mitigation strategies. Potential applications and implications of NF monitoring are also presented.
Correction: Publisher Correction: Wave kinetics of random fibre lasers
Authors: Churkin D. V. , Kolokolov I. V. , Podivilov E. V. , Vatnik I. D. , Nikulin M. A. , Vergeles S. S. , Terekhov I. S. , Lebedev V. V. , Falkovich G. , Babin S. A. , Turitsyn S. K.
Published: May 2018

Nature Communications 6: Article number: 6214 (2015); Published 3 February 2015; Updated 25 May 2018 The original HTML version of this Article had an incorrect volume number of 2; it should have been 6. This has now been corrected in the HTML; the PDF version of the Article was correct from the timeof publication.