bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroconversion of Waste Cooking Oil into Bio-Jet Fuel over NiMo/SBUY-MCM-41
Authors: Zhang Zongwei , Wang Qingfa , Zhang Xiangwen
Published: May 2019

A hierarchical SBUY-MCM-41 catalyst was prepared by sacrificing USY (a microporous molecular sieve) to synthesize the MCM-41 zeolite via a hydrothermal method. The hydroconversion of waste cooking oil into hydrocarbon fuel over a NiMo/SBUY-MCM-41 catalyst was investigated. The micropores of the Y building units were inherited by the SBUY-MCM-41 zeolite, in which a special hierarchical structure was formed and the accessibility of reactants to the micropore active sites was improved. The hierarchical SBUY-MCM-41 showed high acidity and hydrothermal stability. Compared with mesoporous Al-MCM-41 and microporous USY zeolites, the SBUY-MCM-41-supported NiMo catalyst significantly enhanced the selective cracking of waste cooking oil for the production of jet-fuel-range hydrocarbons (37.3%), with the highest selectivity for the formation of C10–C14 hydrocarbons and a satisfactory selectivity for the formation of jet-fuel-range aromatics (7.6%), as well as a few cyclic compounds. The improved selectivity is the result of the special hierarchical structure and acid distribution of SBUY-MCM-41. This work provides a new strategy to synthesize a hierarchical catalyst for producing alternative jet fuel from waste cooking oil and vegetable oils.
High Cell Density Conversion of Hydrolysed Waste Cooking Oil Fatty Acids Into Medium Chain Length Polyhydroxyalkanoate Using Pseudomonas putida KT2440
Authors: Ruiz Carolina , Kenny Shane T. , Babu P Ramesh , Walsh Meg , Narancic Tanja , O’Connor Kevin E.
Published: May 2019

Waste cooking oil (WCO) is a major pollutant, primarily managed through incineration. The high cell density bioprocess developed here allows for better use of this valuable resource since it allows the conversion of WCO into biodegradable polymer polyhydroxyalkanoate (PHA). WCO was chemically hydrolysed to give rise to a mixture of fatty acids identical to the fatty acid composition of waste cooking oil. A feed strategy was developed to delay the stationary phase, and therefore achieve higher final biomass and biopolymer (PHA) productivity. In fed batch (pulse feeding) experiments Pseudomonas putida KT2440 achieved a PHA titre of 58 g/l (36.4% of CDW as PHA), a PHA volumetric productivity of 1.93 g/l/h, a cell density of 159.4 g/l, and a biomass yield of 0.76 g/g with hydrolysed waste cooking oil fatty acids (HWCOFA) as the sole substrate. This is up to 33-fold higher PHA productivity compared to previous reports using saponified palm oil. The polymer (PHA) was sticky and amorphous, most likely due to the long chain monomers acting as internal plasticisers. High cell density cultivation is essential for the majority of industrial processes, and this bioprocess represents an excellent basis for the industrial conversion of WCO into PHA.
Role of MHC-I Expression on Spinal Motoneuron Survival and Glial Reactions Following Ventral Root Crush in Mice
Authors: Cartarozzi Luciana Politti , Perez Matheus , Kirchhoff Frank , Oliveira Alexandre Leite Rodrigues de
Published: May 2019

Lesions to the CNS/PNS interface are especially severe, leading to elevated neuronal degeneration. In the present work, we establish the ventral root crush model for mice, and demonstrate the potential of such an approach, by analyzing injury evoked motoneuron loss, changes of synaptic coverage and concomitant glial responses in β2-microglobulin knockout mice (β2m KO). Young adult (8–12 weeks old) C57BL/6J (WT) and β2m KO mice were submitted to a L4–L6 ventral roots crush. Neuronal survival revealed a time-dependent motoneuron-like cell loss, both in WT and β2m KO mice. Along with neuronal loss, astrogliosis increased in WT mice, which was not observed in β2m KO mice. Microglial responses were more pronounced during the acute phase after lesion and decreased over time, in WT and KO mice. At 7 days after lesion β2m KO mice showed stronger Iba-1+ cell reaction. The synaptic inputs were reduced over time, but in β2m KO, the synaptic loss was more prominent between 7 and 28 days after lesion. Taken together, the results herein demonstrate that ventral root crushing in mice provides robust data regarding neuronal loss and glial reaction. The retrograde reactions after injury were altered in the absence of functional MHC-I surface expression.
Climate Data to Undertake Hygrothermal and Whole Building Simulations Under Projected Climate Change Influences for 11 Canadian Cities
Authors: Gaur Abhishek , Lacasse Michael , Armstrong Marianne
Published: May 2019

Buildings and homes in Canada will be exposed to unprecedented climatic conditions in the future as a consequence of global climate change. To improve the climate resiliency of existing and new buildings, it is important to evaluate their performance over current and projected future climates. Hygrothermal and whole building simulation models, which are important tools for assessing performance, require continuous climate records at high temporal frequencies of a wide range of climate variables for input into the kinds of models that relate to solar radiation, cloud-cover, wind, humidity, rainfall, temperature, and snow-cover. In this study, climate data that can be used to assess the performance of building envelopes under current and projected future climates, concurrent with 2 °C and 3.5 °C increases in global temperatures, are generated for 11 major Canadian cities. The datasets capture the internal variability of the climate as they are comprised of 15 realizations of the future climate generated by dynamically downscaling future projections from the CanESM2 global climate model and thereafter bias-corrected with reference to observations. An assessment of the bias-corrected projections suggests, as a consequence of global warming, future increases in the temperatures and precipitation, and decreases in the snow-cover and wind-speed for all cities.
Pitfalls of Two-Step Testing for Changes in the Error Variance and Coefficients of a Linear Regression Model
Authors: Perron Pierre , Yamamoto Yohei
Published: May 2019

In empirical applications based on linear regression models, structural changes often occur in both the error variance and regression coefficients, possibly at different dates. A commonly applied method is to first test for changes in the coefficients (or in the error variance) and, conditional on the break dates found, test for changes in the variance (or in the coefficients). In this note, we provide evidence that such procedures have poor finite sample properties when the changes in the first step are not correctly accounted for. In doing so, we show that testing for changes in the coefficients (or in the variance) ignoring changes in the variance (or in the coefficients) induces size distortions and loss of power. Our results illustrate a need for a joint approach to test for structural changes in both the coefficients and the variance of the errors. We provide some evidence that the procedures suggested by Perron et al. (2019) provide tests with good size and power.
Low-Power, Subthreshold Reference Circuits for the Space Environment: Evaluated with γ-rays, X-rays, Protons and Heavy Ions
Authors: Andreou Charalambos M. , González-Castaño Diego Miguel , Gerardin Simone , Bagatin Marta , Gómez Rodriguez Faustino , Paccagnella Alessandro , Prokofiev Alexander V. , Javanainen Arto , Virtanen Ari , Liberali Valentino , Calligaro Cristiano , Nahmad Daniel , Georgiou Julius
Published: May 2019

The radiation tolerance of subthreshold reference circuits for space microelectronics is presented. The assessment is supported by measured results of total ionization dose and single event transient radiation-induced effects under γ -rays, X-rays, protons and heavy ions (silicon, krypton and xenon). A high total irradiation dose with different radiation sources was used to evaluate the proposed topologies for a wide range of applications operating in harsh environments similar to the space environment. The proposed custom designed integrated circuits (IC) circuits utilize only CMOS transistors, operating in the subthreshold regime, and poly-silicon resistors without using any external components such as compensation capacitors. The circuits are radiation hardened by design (RHBD) and they were fabricated using TowerJazz Semiconductor’s 0.18 μm standard CMOS technology. The proposed voltage references are shown to be suitable for high-precision and low-power space applications. It is demonstrated that radiation hardened microelectronics operating in subthreshold regime are promising candidates for significantly reducing the size and cost of space missions due to reduced energy requirements.
Identifying the Drivers of Wind Capacity Additions: The Case of Spain. A Multiequational Approach
Authors: Quintana-Rojo Consolación , Callejas-Albiñana Fernando E. , Tarancón Miguel-Angel , del Río Pablo
Published: May 2019

An abundant volume of literature has been devoted to the analysis of the drivers of renewable electricity capacity additions in general and wind energy in particular. Nevertheless, whereas the direct influence of several explanatory variables has been considered, indirect effects, which refer to impacts of explanatory variables on another explanatory variable which, in turn, influence capacity additions, have been neglected. However, those effects need to be taken into account in order to properly grasp the full influence of the explanatory variables in general, and the policy variable in particular, on capacity additions (whether in wind energy generation or other energy systems). The aim of this paper is to identify the drivers of wind energy capacity additions. Based on data over the 1998–2015 period for Spain, a country with a substantial deployed wind capacity, we estimate a three-stage least squares multiecuational econometric model, which allows the analysis of direct and indirect effects as mediated by their influence on intermediate variables. Our results show that, as expected, wind capacity additions are positively and significantly driven by renewable energy support and negatively driven by the material costs of wind energy. Other variables are related to capacity additions in an indirect manner, i.e., through their influence on intermediate variables, i.e., electricity demand and electricity prices. This includes the positive impact of GDP, wind share, capacity load and price of oil. Others have a negative impact (tax share in the electricity price and electricity transport costs). Finally, no statistically significant relationship can be observed for the risk premium, interest rates and the price of gas. Our findings suggest that the success of renewable energy policy instruments might be contingent upon the level of other variables and, particularly, electricity consumption.
Effect of Breed and Gender on Meat Quality of M. longissimus thoracis et lumborum Muscle from Crossbred Beef Bulls and Steers
Authors: Cafferky Jamie , Hamill Ruth M. , Allen Paul , O’Doherty John V. , Cromie Andrew , Sweeney Torres
Published: May 2019

The objective of this study was to determine whether sire breed and/or castration had an effect on meat quality of M. longissimus thoracis et lumborum (LTL) muscle from crossbred bulls and steers and to investigate the relationship amongst the traits examined. Warner–Bratzler shear force (WBSF), intramuscular fat (IMF)%, cook-loss%, drip-loss%, colour (L*, a*, b*) and ultimate pH (upH) were determined in the LTL muscle from eight beef sire breeds representative of the Irish herd (Aberdeen Angus, Belgian Blue, Charolais, Hereford, Limousin, Parthenaise, Salers and Simmental). The results indicate that IMF%, cook-loss% and drip-loss% were associated with breed (p < 0.05); while WBSF, IMF% and cook-loss% differ between genders (p < 0.05). Steer LTL had a greater IMF% and exhibited reduced WBSF and cook-loss% in comparison to the bull LTL (p < 0.05). This study provides greater insight into how quality traits in beef are influenced by breed and gender and will support the industry to produce beef with consistent eating quality.
Permafrost Degradation within Eastern Chukotka CALM Sites in the 21st Century Based on CMIP5 Climate Models
Authors: Maslakov Alexey , Shabanova Natalia , Zamolodchikov Dmitry , Volobuev Vasili , Kraev Gleb
Published: May 2019

Permafrost degradation caused by contemporary climate change significantly affects arctic regions. Active layer thickening combined with the thaw subsidence of ice-rich sediments leads to irreversible transformation of permafrost conditions and activation of exogenous processes, such as active layer detachment, thermokarst and thermal erosion. Climatic and permafrost models combined with a field monitoring dataset enable the provision of predicted estimations of the active layer and permafrost characteristics. In this paper, we present the projections of active layer thickness and thaw subsidence values for two Circumpolar Active Layer Monitoring (CALM) sites of Eastern Chukotka coastal plains. The calculated parameters were used for estimation of permafrost degradation rates in this region for the 21st century under various IPCC climate change scenarios. According to the studies, by the end of the century, the active layer will be 6–13% thicker than current values under the RCP (Representative Concentration Pathway) 2.6 climate scenario and 43–87% under RCP 8.5. This process will be accompanied by thaw subsidence with the rates of 0.4–3.7 cm∙a−1. Summarized surface level lowering will have reached up to 5 times more than current active layer thickness. Total permafrost table lowering by the end of the century will be from 150 to 310 cm; however, it will not lead to non-merging permafrost formation.
Potential Instability of Gas Hydrates along the Chilean Margin Due to Ocean Warming
Authors: Alessandrini Giulia , Tinivella Umberta , Giustiniani Michela , de la Cruz Vargas-Cordero Iván , Castellaro Silvia
Published: May 2019

In the last few years, interest in the offshore Chilean margin has increased rapidly due to the presence of gas hydrates. We have modelled the gas hydrate stability zone off Chilean shores (from 33° S to 46° S) using a steady state approach to evaluate the effects of climate change on gas hydrate stability. Present day conditions were modelled using published literature and compared with available measurements. Then, we simulated the effects of climate change on gas hydrate stability in 50 and 100 years on the basis of Intergovernmental Panel on Climate Change and National Aeronautics and Space Administration forecasts. An increase in temperature might cause the dissociation of gas hydrate that could strongly affect gas hydrate stability. Moreover, we found that the high seismicity of this area could have a strong effect on gas hydrate stability. Clearly, the Chilean margin should be considered as a natural laboratory for understanding the relationship between gas hydrate systems and complex natural phenomena, such as climate change, slope stability and earthquakes.
An Assessment of Woody Plant Water Source Studies from across the Globe: What Do We Know after 30 Years of Research and Where Do We Go from Here?
Authors: Sohel Md. , Salam Mohammed , Herbohn John
Published: May 2019

In the face of global climate change, water availability and its impact on forest productivity is becoming an increasingly important issue. It is therefore necessary to evaluate the advancement of research in this field and to set new research priorities. A systematic literature review was performed to evaluate the spatiotemporal dynamics of global research on woody plant water sources and to determine a future research agenda. Most of the reviewed studies were from the United States, followed by China and Australia. The research indicates that there is a clear variation in woody plant water sources in forests due to season, climate, leaf phenology, and method of measurement. Much of the research focus has been on identifying plant water sources using a single isotope approach. Much less focus has been given to the nexus between water source and tree size, tree growth, drought, water use efficiency, agroforestry systems, groundwater interactions, and many other topics. Therefore, a new set of research priorities has been proposed that will address these gaps under different vegetation and climate conditions. Once these issues are resolved, the research can inform forest process studies in new ways.
Reduced Expression of CbUFO Is Associated with the Phenotype of a Flower-Defective Cosmos bipinnatus
Authors: Li Fei , Lan Wu , Zhou Qin , Liu Baojun , Chen Feng , Zhang Sisi , Bao Manzhu , Liu Guofeng
Published: May 2019

LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) homologous genes have been reported to play key roles in promoting the initiation of floral meristems in raceme- and cyme-type plants. Asteraceae, a large family of plants with more than 23,000 species, has a unique head-like inflorescence termed capitulum. Here, we report a floral defective plant of the garden cosmos named green head (gh), which shows homogeneous inflorescence, indistinguishable inflorescence periphery and center, and the replacement of flower meristems by indeterminate inflorescence meristems, coupled with iterative production of bract-like organs and higher order of inflorescences. A comparison of the LFY- and UFO-like genes (CbFLY and CbUFO) isolated from both the wild-type and gh cosmos revealed that CbUFO may play an important role in inflorescence differentiation into different structures and promotion of flower initiation, and the reduced expression of CbUFO in the gh cosmos could be associated with the phenotypes of the flower-defective plants. Further expression analysis indicated that CbUFO may promote the conversion of inflorescence meristem into floral meristem in early ray flower formation, but does not play a role in its later growth period.
Approximation-Free Output-Feedback Non-Backstepping Controller for Uncertain SISO Nonautonomous Nonlinear Pure-Feedback Systems
Authors: Park Jang-Hyun , Park Tae-Sik , Kim Seong-Hwan
Published: May 2019

A novel differentiator-based approximation-free output-feedback controller for uncertain nonautonomous nonlinear pure-feedback systems is proposed. Using high-order sliding mode observer, which is a finite-time exact differentiator, the time-derivatives of the signal generated using tracking error and filtered input are directly estimated. As a result, the proposed non-backstepping control law and stability analysis are drastically simple. The tracking error vector is guaranteed to be exponentially stable in finite time regardless of the nonautonomous property in the considered system. It does not require neural networks or fuzzy logic systems, which are typically adopted to capture unstructured uncertainties intrinsic in the controlled system. As far as the authors know, there are no research results on the output-feedback controller for the uncertain nonautonomous pure-feedback nonlinear systems. The results of the simulation show clearly the performance and compactness of the control scheme proposed.
A New Subclass of Analytic Functions Defined by Using Salagean q-Differential Operator
Authors: Naeem Muhammad , Hussain Saqib , Mahmood Tahir , Khan Shahid , Darus Maslina
Published: May 2019

In our present investigation, we use the technique of convolution and quantum calculus to study the Salagean q-differential operator. By using this operator and the concept of the Janowski function, we define certain new classes of analytic functions. Some properties of these classes are discussed, and numerous sharp results such as coefficient estimates, distortion theorem, radii of star-likeness, convexity, close-to-convexity, extreme points, and integral mean inequalities of functions belonging to these classes are obtained and studied.
Reduced Serum Vitamin D Levels Are Associated with Insulin Resistance in Patients with Obstructive Sleep Apnea Syndrome
Authors: Archontogeorgis Kostas , Papanas Nikolaos , Rizos Evangelos C. , Nena Evangelia , Zissimopoulos Athanasios , Tsigalou Christina , Voulgaris Athanasios , Mikhailidis Dimitri P. , Elisaf Moses S. , Froudarakis Marios E. , Steiropoulos Paschalis
Published: May 2019

Background and objectives: Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular and metabolic risk factors, such as insulin resistance. Furthermore, OSAS has been associated with decreased levels of vitamin D (Vit D). The aim of the study was to assess the association between Vit D levels (expressed as 25(OH)D serum levels) and insulin resistance in patients with OSAS. Materials and Methods: Serum 25(OH)D levels were measured in consecutive subjects who had undergone polysomnography and pulmonary function testing. OSAS patients were divided into those with (homeostatic model assessment [HOMA-IR] ≥ 2) and without insulin resistance (HOMA-IR < 2). Results: Overall, 92 patients (81 males) were included in the study. OSAS patients with insulin resistance significantly differed from those without insulin resistance in terms of the body-mass index (BMI) (36.3 ± 5.8 compared to 32 ± 5.6 kg/m2, respectively, p = 0.001), apnoea-hypopnoea index (AHI) (57.4 ± 28.9 compared to 40.9 ± 27.9 events/h, respectively, p = 0.009) and indices of hypoxia during sleep. Patients with OSAS and insulin resistance had lower levels of serum 25 (OH) D compared with OSAS but without insulin resistance (19.3 ± 11.5 vs 26.7 ± 12.2 ng/mL, respectively, p = 0.005). Regression analysis demonstrated a negative association of 25(OH)D levels (β = −0.048, odds ratio [OR]: 0.953, 95% confidence interval [CI]: 0.913–0.995, p = 0.030) and a positive association of BMI (β = 0.110, OR: 1.116, 95% CI: 1.007–1.237, p = 0.036) with insulin resistance. Conclusions: Vit D insufficiency was significantly more frequent among OSAS patients with insulin resistance. Both low 25(OH)D levels and high BMI were associated with the risk of insulin resistance in this population.
Is Bilateral Facial Paralysis an Indicator of Respiratory Outcome in Guillain–Barré Syndrome?
Authors: Güngör Serdal , Kılıç Betül
Published: May 2019

Background and objectives: Bilateral facial paralysis is a rare and specific clinical manifestation of various neurological disorders. Bilateral facial paralysis has been reported as an essential feature of Guillain–Barré syndrome (GBS) for many years. We aim to describe the incidence of bilateral facial paralysis and prognosis in our GBS patients. Materials and Methods: A retrospective chart review of all patients with GBS and bilateral facial paralysis who were treated at the Inönü University Medical Faculty was performed. Results: A total of 45 cases of GBS were reviewed. Four out of 45 patients (8.8%) had associated bilateral facial paralysis. Only one of the patients also had acute multiple cranial neuropathies. All patients experienced sudden deterioration and respiratory distress. In one of our patients who had multiple cranial neuropathies, serum antiganglioside antibody assay was performed, and anti-GQ1b IgG antibody positivity was observed. The cerebrospinal fluid had albuminocytological dissociation in all patients, and axonal involvement was present in nerve conduction studies (NCS). Three patients improved with immunotherapy; one patient died due to cardiac arrest after resistant hypotension. Conclusion: Bilateral facial paralysis is a rare condition in children. We wanted to emphasize bilateral facial involvement and poor prognosis in our GBS patients.
Near Infrared Spectroscopy Based Clinical Algorithm Applicability During Spinal Neurosurgery and Postoperative Cognitive Disturbances
Authors: Murniece Sniedze , Soehle Martin , Vanags Indulis , Mamaja Biruta
Published: May 2019

Background and Objectives: Postoperative cognitive disturbances (POCD) can significantly alter postoperative recovery. Inadequate intraoperative cerebral oxygen supply is one of the inciting causes of POCD. Near-infrared spectroscopy (NIRS) devices monitor cerebral oxygen saturation continuously and can help to guide intraoperative patient management. The aim of the study was to evaluate the applicability of the NIRS-based clinical algorithm during spinal neurosurgery and to find out whether it can influence postoperative cognitive performance. Materials and Methods: Thirty four patients scheduled for spinal neurosurgery were randomized into a study group (n = 23) and a control group (n = 11). We monitored regional cerebral oxygen saturation (rScO2) throughout surgery, using a NIRS device (INVOS 4100). If rScO2 dropped bilaterally or unilaterally by more than 20% from baseline values, or under an absolute value of 50%, the NIRS-based algorithm was initiated in the study group. In the control group, rScO2 was monitored blindly. To evaluate cognitive function, Montreal-Cognitive Assessment (MoCA) scale was used in both groups before and after the surgery. Results: In the study group, rScO2 dropped below the threshold in three patients and the NIRS-based algorithm was activated. Firstly, we verified correct positioning of the head; secondly, we increased mean systemic arterial pressure in the three patients by injecting repeated intravenous bolus doses of Ephedrine, ultimately resulting in an rScO2 increase above the approved threshold level. None of the three patients showed POCD. In the control group, one patient showed a drop in rScO2 of 34% from baseline and presented with a POCD. RScO2 drop occurred with other stable intraoperative measurements. Conclusions: A significant rScO2 drop may occur during spinal surgery in prone position despite other intraoperative measurements remaining stable, allowing it to stay otherwise unrecognized. Use of the NIRS-based clinical algorithm can help to avoid POCD in patients after spinal surgery.
Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams
Authors: Zhang Litian , Yu Gang , Tian Chongxin , He Xiuli , Li Shaoxia
Published: May 2019

The microstructure of hypereutectic immiscible Cu-50Cr alloy (wt%) was effectively refined and homogenized by a high power density Nd:YAG continuous laser beam (power density 104–105 MW/m2). The average grain size of Cr was effectively refined from ~100 μm to ~1 μm, and some of the Cr particles even decreased to a few hundred nanometers. The high cooling rate (7.29 × 106 K/s) effectively inhibited the coarsening effect on Cr particles during liquid phase separation (LPS). The spherical Cr particles were preferably dispersed in the melt layer, and the thickness of the layer was up to ~150 μm. The refinement and dispersion of the Cr phase contributed to improving the interruption capability of the Cu-Cr contacts. Compared with the untreated samples, the arc duration and the withstanding voltage of the laser surface melting (LSM) treated contacts with refined microstructure increased to 21% and 33%, respectively. The results demonstrated that the LSM method was an effective approach to optimize the microstructure of Cu-Cr alloy, which made it a promising modification method for Cu-Cr vacuum contact applications.
A Prediction Model for Internal Cracks during Slab Continuous Casting
Authors: Kong Yiwen , Chen Dengfu , Liu Qiang , Long Mujun
Published: May 2019

Slab continuous casting internal cracking is a common quality defect in the production process. The ability to predict the quality of each continuous casting product and assess whether it is suitable for hot delivery or needs to be cleaned down will greatly increase the rolled product rate and reduce the scrap rate and production management cost. According to the quality defects of internal cracks during slab continuous casting and based on the solidification and heat transfer simulations, stress and strain calculations and theoretical analysis of metallurgical processes related to continuous casting combined with an abnormal casting event expert system, the internal crack generation index of the slice unit is used to predict the crack occurrence rating of each sized slab. Moreover, the internal crack prediction model for the slab is successfully developed and applied in a domestic steel mill. The accuracy of the model prediction reached 86.85%. This method achieved the organic combination of theoretical analysis and an expert system and provides an important theoretical tool for the prediction of crack quality defects in slab continuous casting; the method can be applied in slab continuous casting production.
On the Hydration of Heavy Rare Earth Ions: Ho3+, Er3+, Tm3+, Yb3+ and Lu3+—A Raman Study
Authors: Rudolph Wolfram , Irmer Gert
Published: May 2019

Raman spectra of aqueous Ho3+, Er3+, Tm3+, Yb3+, and Lu3+-perchlorate solutions were measured over a large wavenumber range from 50–4180 cm−1. In the low wavenumber range (terahertz region), strongly polarized Raman bands were detected at 387 cm−1, 389 cm−1, 391 cm−1, 394 cm−1, and 396 cm−1, respectively, which are fairly broad (full widths at half height at ~52 cm−1). These isotropic Raman bands were assigned to the breathing modes, ν1 Ln–O of the heavy rare earth (HRE) octaaqua ions, [Ln(H2O)8]3+. The strong polarization of these bands (depolarization degree ~0) reveals their totally symmetric character. The vibrational isotope effect was measured in Yb(ClO4)3 solutions in H2O and D2O and the shift of the ν1 mode in changing from H2O to D2O further supports the character of the band. The Ln–O bond distances of these HRE ions (Ho3+, Er3+, Tm3+, Yb3+, and Lu3+) follow the order of Ho–O > Er–O > Tm–O > Yb–O > Lu–O which correlates inversely with the band positions of the breathing modes of their corresponding octaaqua ions [Ln(OH2)8]3+. Furthermore, the force constants, kLn–O, were calculated for these symmetric stretching modes. Ytterbium perchlorate solutions were measured over a broad concentration range, from 0.240 mol·L−1 to 2.423 mol·L−1, and it was shown that with increasing solute concentration outer-sphere ion pairs and contact ion pairs were formed. At the dilute solution state (~0.3 mol·L−1), the fully hydrated ions [Yb(H2O)8]3+ exist, while at higher concentrations (CT > 2 mol·L−1), ion pairs are formed. The concentration behavior of Yb(ClO4)3 (aq) shows similar behavior to the one observed for La(ClO4)3(aq), Ce(ClO4)3(aq) and Lu(ClO4)3(aq) solutions. In ytterbium chloride solutions in water and heavy water, representative for the behavior of the other HRE ions, 1:1 chloro-complex formation was detected over the concentration range from 0.422–3.224 mol·L−1. The 1:1 chloro-complex in YbCl3(aq) is very weak, diminishing rapidly with dilution and vanishing at a concentration < 0.4 mol·L−1.
Effect of Clove and Thyme Essential Oils on Candida Biofilm Formation and the Oil Distribution in Yeast Cells
Authors: Rajkowska Katarzyna , Nowicka-Krawczyk Paulina , Kunicka-Styczyńska Alina
Published: May 2019

Candida biofilm structure is particularly difficult to eradicate, since biofilm is much more resistant to antifungal agents than planktonic cells. In this context, a more effective strategy seems to be the prevention of biofilm formation than its eradication. The aim of the study was to examine whether the process of initial colonization of materials (glass, polyethylene terephthalate, polypropylene) by food-borne Candida sp. can be impeded by clove and thyme essential oils, used at their minimal inhibitory concentrations. In the presence of clove oil, 68.4–84.2% of the yeast tested showed a statistically significant reduction in biofilm formation, depending on the material. After treatment with thyme oil, statistically significant decrease in biofilm cell numbers was observed for 63.2–73.7% of yeasts. Confocal laser scanning microscopy showed diverse compounds of clove and thyme oils that were disparately located in C. albicans cell, on a cell wall and a cell membrane, in cytoplasm, and in vacuoles, depicting the multidirectional action of essential oils. However, essential oils that were used in sub-inhibitory concentration were sequestrated in the yeast vacuoles, which indicate the activation of Candida defense mechanisms by cell detoxification. Clove and thyme essential oils due to their anti-biofilm activity can be efficiently used in the prevention of the tested abiotic surfaces colonization by Candida sp.
Technologies for the Selection, Culture and Metabolic Profiling of Unique Rhizosphere Microorganisms for Natural Product Discovery
Authors: Gurusinghe Saliya , Brooks Tabin L. , Barrow Russell A. , Zhu Xiaocheng , Thotagamuwa Agasthya , Dennis Paul G. , Gupta Vadakattu V. S. R. , Vanniasinkam Thiru , Weston Leslie A.
Published: May 2019

Small molecule discovery has benefitted from the development of technologies that have aided in the culture and identification of soil microorganisms and the subsequent analysis of their respective metabolomes. We report herein on the use of both culture dependent and independent approaches for evaluation of soil microbial diversity in the rhizosphere of canola, a crop known to support a diverse microbiome, including plant growth promoting rhizobacteria. Initial screening of rhizosphere soils showed that microbial diversity, particularly bacterial, was greatest at crop maturity; therefore organismal recovery was attempted with soil collected at canola harvest. Two standard media (Mueller Hinton and gellan gum) were evaluated following inoculation with soil aqueous suspensions and compared with a novel “rhizochip” prototype buried in a living canola crop rhizosphere for microbial culture in situ. Following successful recovery and identification of 375 rhizosphere microbiota of interest from all culture methods, isolates were identified by Sanger sequencing and/or characterization using morphological and biochemical traits. Three bacterial isolates of interest were randomly selected as case studies for intensive metabolic profiling. After successful culture in liquid media and solvent extraction, individual extracts were subjected to evaluation by UHPLC-DAD-QToF-MS, resulting in the rapid characterization of metabolites of interest from cultures of two isolates. After evaluation of key molecular features, unique or unusual bacterial metabolites were annotated and are reported herein.
Theoretical Study on the Difference in Electron Conductivity of a One-Dimensional Penta-Nickel(II) Complex between Anti-Ferromagnetic and Ferromagnetic States—Possibility of Molecular Switch with Open-Shell Molecules
Authors: Kitagawa Yasutaka , Tada Hayato , Era Iori , Fujii Takuya , Ikenaga Kazuki , Nakano Masayoshi
Published: May 2019

The electron conductivity of an extended metal atom chain (EMAC) that consisted of penta-nickel(II) ions bridged by oligo-α-pyridylamino ligands was examined by density functional theory (DFT) and elastic scattering Green’s functions (ESGF) calculations. The calculated results revealed that an intramolecular ferromagnetic (FM) coupling state showed a higher conductivity in comparison with an anti-ferromagnetic (AFM) coupling state. The present results suggest the potential of the complex as a molecular switch as well as a molecular wire.
Promoting Contemplative Culture through Media Arts
Authors: Wu Jiayue
Published: May 2019

This paper presents the practice of designing mediation technologies as artistic tools to expand the creative repertoire to promote contemplative cultural practice. Three art–science collaborations—Mandala, Imagining the Universe, and Resonance of the Heart—are elaborated on as proof-of-concept case studies. Scientifically, the empirical research examines the mappings from (bodily) action to (sound/visual) perception in technology-mediated performing art. Theoretically, the author synthesizes media arts practices on a level of defining general design principles and post-human artistic identities. Technically, the author implements machine learning techniques, digital audio/visual signal processing, and sensing technology to explore post-human artistic identities and give voice to underrepresented groups. Realized by a group of multinational media artists, computer engineers, audio engineers, and cognitive neuroscientists, this work preserves, promotes, and further explores contemplative culture with emerging technologies.
A Sensitive Piezoresistive Tactile Sensor Combining Two Microstructures
Authors: Sun Xuguang , Sun Jianhai , Zheng Shuaikang , Wang Chunkai , Tan Wenshuo , Zhang Jingong , Liu Chunxiu , Liu Chang , Li Tong , Qi Zhimei , Xue Ning
Published: May 2019

A tactile sensor is an indispensable component for electronic skin, mimicking the sensing function of organism skin. Various sensing materials and microstructures have been adopted in the fabrication of tactile sensors. Herein, we propose a highly sensitive flexible tactile sensor composed of nanocomposites with pyramid and irregularly rough microstructures and implement a comparison of piezoresistive properties of nanocomposites with varying weight proportions of multi-wall nanotubes and carbon black particles. In addition to the simple and low-cost fabrication method, the tactile sensor can reach high sensitivity of 3.2 kPa−1 in the range of <1 kPa and fast dynamic response of 217 ms (loading) and 81 ms (recovery) at 40 kPa pressure. Moreover, body movement monitoring applications have been carried out utilizing the flexible tactile sensor. A sound monitoring application further indicates the potential for applications in electronic skin, human–computer interaction, and physiological detection.
Demographics and Epidemiology of Hepatitis B in the State of Qatar: A Five-Year Surveillance-Based Incidence Study
Authors: Al Romaihi Hamad E. , Ganesan Nandakumar , Farag Elmoubasher A. , Smatti Maria K. , Nasrallah Gheyath K. , Himatt Sayed M. , Derbala Moutaz F. , Alshamali Maha , Mahadoon Lylu K. , Khogali Hayat S. , Sallam Mohamed , Al Thani Asmaa A. , Al Thani Mohammed , Al Kaabi Saad , Yassine Hadi M.
Published: May 2019

Background: Expatriates represent >80% of Qatar’s population, mostly arriving from countries in Africa and Asia that are endemic with many diseases. This increases the risk for introducing new pathogens into the country and provides a platform for maintenance of endemic pathogen circulation. Here, we report on the incidence and epidemiological characteristics of hepatitis B in Qatar between 2010 and 2014. Methods: We performed a retrospective epidemiological data analysis using the data available at the surveillance system of the Ministry of Public Health (MOPH) in Qatar. Data were collected from distinctive public and private incorporates around the nation. Reported cases of hepatitis B patients represent those who met the stringent case definition as per World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) guidelines and eventually reported to MOPH. Results: The annual incidence rates of hepatitis B cases were 30.0, 34.2, 30.5, 39.4, and 19.8 per 100,000 population in 2010, 2011, 2012, 2013, and 2014, respectively. There was no specific trend or seasonality for the reported cases. The incidence rates were higher in females compared to males between 2010 and 2012, but similar in 2013 and 2014. The highest incidence rates were reported among individuals between 25 and 34 years of age. No cases were reported in children younger than five years in 2013 and 2014. Rates of hepatitis B cases declined dramatically in 2014, in both Qataris and non-Qataris, as compared to the previous years. Conclusion: Our results indicate a dramatic decline of hepatitis B cases in Qatar but mandate improved surveillance and vaccination efforts in expatriates in the nation.
Fungal-Bacterial Interactions in Health and Disease
Authors: Krüger Wibke , Vielreicher Sarah , Kapitan Mario , Jacobsen Ilse , Niemiec Maria
Published: May 2019

Fungi and bacteria encounter each other in various niches of the human body. There, they interact directly with one another or indirectly via the host response. In both cases, interactions can affect host health and disease. In the present review, we summarized current knowledge on fungal-bacterial interactions during their commensal and pathogenic lifestyle. We focus on distinct mucosal niches: the oral cavity, lung, gut, and vagina. In addition, we describe interactions during bloodstream and wound infections and the possible consequences for the human host.
Predicting Host Immune Cell Dynamics and Key Disease-Associated Genes Using Tissue Transcriptional Profiles
Authors: Wang Muying , Fukuyama Satoshi , Kawaoka Yoshihiro , Shoemaker Jason E.
Published: May 2019

Motivation: Immune cell dynamics is a critical factor of disease-associated pathology (immunopathology) that also impacts the levels of mRNAs in diseased tissue. Deconvolution algorithms attempt to infer cell quantities in a tissue/organ sample based on gene expression profiles and are often evaluated using artificial, non-complex samples. Their accuracy on estimating cell counts given temporal tissue gene expression data remains not well characterized and has never been characterized when using diseased lung. Further, how to remove the effects of cell migration on transcript counts to improve discovery of disease factors is an open question. Results: Four cell count inference (i.e., deconvolution) tools are evaluated using microarray data from influenza-infected lung sampled at several time points post-infection. The analysis finds that inferred cell quantities are accurate only for select cell types and there is a tendency for algorithms to have a good relative fit (R 2 ) but a poor absolute fit (normalized mean squared error; NMSE), which suggests systemic biases exist. Nonetheless, using cell fraction estimates to adjust gene expression data, we show that genes associated with influenza virus replication and increased infection pathology are more likely to be identified as significant than when applying traditional statistical tests.
Determination of the Acidity of Waste Cooking Oils by Near Infrared Spectroscopy
Authors: García Martín Juan Francisco , López Barrera María del Carmen , Torres García Miguel , Zhang Qing-An , Álvarez Mateos Paloma
Published: May 2019

Waste cooking oils (WCO) recycling companies usually have economic losses for buying WCO not suitable for biodiesel production, e.g., WCO with high free acidity (FA). For this reason, the determination of FA of WCO by near infrared (NIR) spectroscopy was studied in this work to assess its potential for in situ application. To do this, FA of 45 WCO was measured by the classical titration method, which ranged between 0.15 and 3.77%. Then, the NIR spectra from 800 to 2200 nm of these WCO were acquired, and a partial least squares model was built, relating the NIR spectra to FA values. The accuracy of the model was quite high, providing r2 of 0.970 and a ratio of performance to deviation (RPD) of 4.05. Subsequently, a model using an NIR range similar to that provided by portable NIR spectrometers (950–1650 nm) was built. The performance was lower (r2 = 0.905; RPD = 2.66), but even so, with good accuracy, which demonstrates the potential of NIR spectroscopy for the in situ determination of FA of WCO.
American Options on High Dividend Securities: A Numerical Investigation
Authors: Rotondi Francesco
Published: May 2019

I document a sizeable bias that might arise when valuing out of the money American options via the Least Square Method proposed by Longstaff and Schwartz (2001). The key point of this algorithm is the regression-based estimate of the continuation value of an American option. If this regression is ill-posed, the procedure might deliver biased results. The price of the American option might even fall below the price of its European counterpart. For call options, this is likely to occur when the dividend yield of the underlying is high. This distortion is documented within the standard Black–Scholes–Merton model as well as within its most common extensions (the jump-diffusion, the stochastic volatility and the stochastic interest rates models). Finally, I propose two easy and effective workarounds that fix this distortion.
Detecting Axial Ratio of Microwave Field with High Resolution Using NV Centers in Diamond
Authors: Li Cui-Hong , Li Deng-Feng , Zheng Yu , Sun Fang-Wen , Du A. M. , Ge Ya-Song
Published: May 2019

Polarization property characterization of the microwave (MW) field with high speed and resolution is vitally beneficial as the circularly-polarized MW field plays an important role in the development of quantum technologies and satellite communication technologies. In this work, we propose a scheme to detect the axial ratio of the MW field with optical diffraction limit resolution with a nitrogen vacancy (NV) center in diamond. Firstly, the idea of polarization selective detection of the MW magnetic field is carried out using a single NV center implanted in a type-IIa CVD diamond with a confocal microscope system achieving a sensitivity of 1.7 μT/Hz. Then, high speed wide-field characterization of the MW magnetic field at the submillimeter scale is realized by combining wide-field microscopy and ensemble NV centers inherent in a general CVD diamond. The precision axial ratio can be detected by measuring the magnitudes of two counter-rotating circularly-polarized MW magnetic fields. The wide-field detection of the axial ratio and strength parameters of microwave fields enables high speed testing of small-scale microwave devices.
Nitrate Supplementation Combined with a Running Training Program Improved Time-Trial Performance in Recreationally Trained Runners
Authors: Santana Jeferson , Madureira Diana , de França Elias , Rossi Fabricio , Rodrigues Bruno , Fukushima André , Billaut François , Lira Fabio , Caperuto Erico
Published: May 2019

Our purpose was to verify the effects of inorganic nitrate combined to a short training program on 10-km running time-trial (TT) performance, maximum and average power on a Wingate test, and lactate concentration ([La−]) in recreational runners. Sixteen healthy participants were divided randomly into two groups: Nitrate (n = 8) and placebo (n = 8). The experimental group ingested 750 mg/day (~12 mmol) of nitrate plus 5 g of resistant starch, and the control group ingested 6 g of resistant starch, for 30 days. All variables were assessed at baseline and weekly over 30 days. Training took place 3x/week. The time on a 10-km TT decreased significantly (p < 0.001) in all timepoints compared to baseline in both groups, but only the nitrate group was faster in week 2 compared to 1. There was a significant group × time interaction (p < 0.001) with lower [La] in the nitrate group at week 2 (p = 0.032), week 3 (p = 0.002), and week 4 (p = 0.003). There was a significant group time interaction (p = 0.028) for Wingate average power and a main effect of time for maximum power (p < 0.001) and [La−] for the 60-s Wingate test. In conclusion, nitrate ingestion during a four-week running program improved 10-km TT performance and kept blood [La−] steady when compared to placebo in recreational runners.