bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating secondary production of Uca uruguayensis (Decapoda, Brachyura, Ocypodidae) from Samborombón Bay, Argentina
Authors: Armendáriz LC , César II
Published: August 2017

Specimens of Uca uruguayensis were collected (n = 1200, 216 megalopae, 984 undifferentiated and adults), counted and classified as males, females or undifferentiated individuals. Each was measured (total carapace width, CW) and weighed (dry weight, DW). The crabs were analyzed and separated into cohorts by the conversion of polymodal width-frequency distributions into normal curves. Six cohorts were recruited during the study period. Two cohorts coexisted in September and December 2001, and April and October 2002, and three in March and June 2001, December 2002, and February 2003. Ovigerous females were captured in December 2001 and 2002, and February 2003; on this last date, megalopal settlement was registered at all the sampling sites. The correlation between CW and DW was analyzed and the growth pattern was modelled by applying the power function (DW = a CWb). Males, females and undifferentiated individuals were examined separately and all together as a group. The data were fitted, indicating a positive allometry for DW, males showing the highest allometric values. To estimate the annual production we used a size-frequency method. Mature individuals, in particular those included in the 10–11.99 mm size class, contributed most to production. On the other hand, few individuals belonged to the size class prior to puberty. Total biomass (expressed in DW) varied between 20 and 611 mg m–2 and the highest values were recorded during summer.
Produzindo o Desfile de uma Escola de Samba: Contribuições da Epistemologia de Schatzki
Authors: Júlio Ana Carolina
Published: August 2017

O objetivo deste ensaio teórico é analisar as contribuições da epistemologia de Schatzki  na compreensão das escolas de samba e da produção do desfile carnavalesco. Essas agremiações são organizações tipicamente brasileiras, cujo objetivo principal é desfilar no carnaval. Em um sentido amplo, o carnaval não significa apenas um festejo, mas toda sua preparação. Assim, a produção de um desfile é um conjunto de práticas que ganha forma na avenida. Esse entendimento está alinhado com a “virada” da prática, sendo Schatzki um dos principais autores contemporâneos desse campo. Ao assumir que as organizações são fenômenos sociais que precisam ser analisados como um acontecimento, encontrando-se em constante estado de (re)constituição, a perspectiva da prática pode contribuir para a análise da escola de samba para além da performance do desfile, assim como para a compreensão da produção do carnaval como um conjunto organizado de práticas. Apesar de relevantes, esses temas ainda não foram muito explorados pelos estudos organizacionais.
Acceleration of radiation belt electrons and the role of the average interplanetary magnetic field Bz component in high‐speed streams
Authors: Souza V. M. , Lopez R. E. , Jauer P. R. , Sibeck D. G. , Pham K. , Da Silva L. A. , Marchezi J. P. , Alves L. R. , Koga D. , Medeiros C. , Rockenbach M. , Gonzalez W. D.
Published: August 2017

In this study we examine the recovery of relativistic radiation belt electrons on 15–16 November 2014, after a previous reduction in the electron flux resulting from the passage of a corotating interaction region (CIR). Following the CIR, there was a period of high‐speed streams characterized by large, nonlinear fluctuations in the interplanetary magnetic field (IMF) components. However, the outer radiation belt electron flux remained at a low level for several days before it increased in two major steps. The first increase is associated with the IMF background field turning from slightly northward on average to slightly southward on average. The second major increase is associated with an increase in the solar wind velocity during a period of southward average IMF background field. We present evidence that when the IMF Bz is negative on average, the whistler mode chorus wave power is enhanced in the outer radiation belt, and the amplification of magnetic integrated power spectral density in the ULF frequency range, in the nightside magnetosphere, is more efficient as compared to cases in which the mean IMF Bz is positive. Preliminary analysis of the time evolution of phase space density radial profiles did not provide conclusive evidence on which electron acceleration mechanism is the dominant. We argue that the acceleration of radiation belt electrons requires (i) a seed population of keV electrons injected into the inner magnetosphere by substorms and both (ii) enhanced whistler mode chorus waves activity as well as (iii) large‐amplitude MHD waves.
Insights into the causal relationship between slow slip and tectonic tremor in Guerrero, Mexico
Authors: Villafuerte Carlos , Cruz‐Atienza Víctor M.
Published: August 2017

Similar to other subduction zones, tectonic tremors (TTs) and slow‐slip events (SSEs) take place in the deep segment of the plate interface in Guerrero, Mexico. However, their spatial correlation in this region is not as clear as the episodic tremor and slip observed in Cascadia and Japan. In this study we provide insights into the causal relationship between TTs and SSEs in Guerrero by analyzing the evolution of the deformation fields induced by the long‐term 2006 SSE together with new locations of TTs and low‐frequency earthquakes (LFEs). Unlike previous studies we find that the SSE slip rate modulates the TT and LFE activity in the whole tremor region. This means that the causal relationship between the SSE and the TT activity directly depends on the stressing rate history of the tremor asperities that is modulated by the surrounding slip rate. We estimated that the frictional strength of the asperities producing tremor downdip in the sweet spot is around 3.2 kPa, which is ~2.3 times smaller than the corresponding value updip in the transient zone, partly explaining the overwhelming tremor activity of the sweet spot despite that the slow slip there is smaller. Based on the LFE occurrence‐rate history during the interlong‐term SSE period, we determined that the short‐term SSEs in Guerrero take place further downdip (about 35 km) than previously estimated, with maximum slip of about 8 mm in the sweet spot. This new model features a continuum of slow slip extending across the entire tremor region of Guerrero.
Assimilation of coastal acoustic tomography data using an unstructured triangular grid ocean model for water with complex coastlines and islands
Authors: Zhu Ze‐Nan , Zhu Xiao‐Hua , Guo Xinyu , Fan Xiaopeng , Zhang Chuanzheng
Published: August 2017

For the first time, we present the application of an unstructured triangular grid to the Finite‐Volume Community Ocean Model using the ensemble Kalman filter scheme, to assimilate coastal acoustic tomography (CAT) data. The fine horizontal and vertical current field structures around the island inside the observation region were both reproduced well. The assimilated depth‐averaged velocities had better agreement with the independent acoustic Doppler current profiler (ADCP) data than the velocities obtained by inversion and simulation. The root‐mean‐square difference (RMSD) between depth‐averaged current velocities obtained by data assimilation and those obtained by ADCPs was 0.07 m s−1, which was less than the corresponding difference obtained by inversion and simulation (0.12 and 0.17 m s−1, respectively). The assimilated vertical layer velocities also exhibited better agreement with ADCP than the velocities obtained by simulation. RMSDs between assimilated and ADCP data in vertical layers ranged from 0.02 to 0.14 m s−1, while RMSDs between simulation and ADCP data ranged from 0.08 to 0.27 m s−1. These results indicate that assimilation had the highest accuracy. Sensitivity experiments involving the elimination of sound transmission lines showed that missing data had less impact on assimilation than on inversion. Sensitivity experiments involving the elimination of CAT stations showed that the assimilation with four CAT stations was the relatively economical and reasonable procedure in this experiment. These results indicate that, compared with inversion and simulation, data assimilation of CAT data with an unstructured triangular grid is more effective in reconstructing the current field.
The equilibrium alluvial river under variable flow and its channel‐forming discharge
Authors: Blom Astrid , Arkesteijn Liselot , Chavarrías Víctor , Viparelli Enrica
Published: August 2017

When the water discharge, sediment supply, and base level vary around stable values, an alluvial river evolves toward a mean equilibrium or graded state with small fluctuations around this mean state (i.e., a dynamic or statistical equilibrium state). Here we present analytical relations describing the mean equilibrium geometry of an alluvial river under variable flow by linking channel slope, width, and bed surface texture. The solution holds in river normal flow zones (or outside both the hydrograph boundary layer and the backwater zone) and accounts for grain size selective transport and particle abrasion. We consider the variable flow rate as a series of continuously changing yet steady water discharges (here termed an alternating steady discharge). The analysis also provides a solution to the channel‐forming water discharge, which is here defined as the steady water discharge that, given the mean sediment supply, provides the same equilibrium channel slope as the natural long‐term hydrograph. The channel‐forming water discharge for the gravel load is larger than the one associated with the sand load. The analysis illustrates how the load is distributed over the range of water discharge in the river normal flow zone, which we term the “normal flow load distribution”. The fact that the distribution of the (imposed) sediment supply spatially adapts to this normal flow load distribution is the origin of the hydrograph boundary layer. The results quantify the findings by Wolman and Miller (1960) regarding the relevance of both magnitude and frequency of the flow rate with respect to channel geometry.
Experimental Reference Data for Hexafluorinated Propanol by Exploring an Unusual Intermolecular Torsional Balance
Authors: Oswald Sönke , Suhm Martin A.
Published: August 2017

The hydrogen‐bonded dimer of 1,1,1,3,3,3‐hexafluoro‐2‐propanol forms an intermolecular −OH⋅⋅⋅O− torsional balance, in which the acceptor OH group can point away from or towards the fluorine atoms of the donor. It prefers the former arrangement in the free dimer, but dinitrogen coordination of the acceptor OH favors the latter, as FTIR spectroscopy in supersonic jets suggests. A multi‐step divide‐and‐conquer strategy was employed to rule out density functional and other inexpensive quantum chemical methods within the harmonic approximation. Among 20 exploratory single determinant calculations, only those based on the B3LYP‐D3 functional provide a satisfactory description of six carefully assessed experimental constraints for this fluorous hydrogen bond competition. Low barrier intermolecular torsion balances are proposed more generally as non‐covalent conformational energy benchmarking tools.
Coadministration of isomalto‐oligosaccharides augments metabolic health benefits of cinnamaldehyde in high fat diet fed mice
Authors: Singh Dhirendra Pratap , Khare Pragyanshu , Bijalwan Vandana , Baboota Ritesh Kumar , Singh Jagdeep , Kondepudi Kanthi Kiran , Chopra Kanwaljit , Bishnoi Mahendra
Published: August 2017

Bacteriostatic properties of a potential anti‐obesity agent cinnamaldehyde (CMN) may present untoward effects on the resident gut microbiota. Here, we evaluated whether the combination of Isomalto‐oligosaccharides (IMOs) with CMN prevents unwanted effects of CMN on gut microbiota and associated metabolic outcomes in HFD‐fed mice. Male Swiss albino mice divided into four groups (n = 10), were fed on normal chow, or HFD (58% fat kcal), HFD + CMN (10 mg kg−1) and HFD + CMN (10 mg kg−1) + IMOs (1 g kg−1) for 12 weeks. Effects on HFD‐induced biochemical, histological, inflammatory and genomic changes in the gastrointestinal tract, liver, and visceral white adipose tissue were studied. Cosupplementation of CMN with IMOs potentiates its preventive action against HFD‐induced increase in serum LPS and abundances of selected LPS producing bacteria (Enterobacteriaceae, Escherichia Coli, Cronobacter sp, Citrobacter sp., Klebsiella sp., Salmonella sp.). CMN and IMOs co‐administration prevented HFD‐induced decrease in selected beneficial gut bacterial abundances (Bifidobacteria, Roseburia sp., Akkermansia muciniphila, Feacalibacterium sp.). CMN's effects against HFD‐induced increase in gut permeability, histological and inflammatory changes in the colon were further augmented by cosupplementation of IMOs. Similar effects were observed in hepatic inflammatory markers. Cosupplementation of CMN with IMOs and CMN alone administration prevented HFD‐induced changes in peripheral hormones and lipid metabolism‐related parameters. This study provides evidence that coadministration of IMOs with CMN potentiates its anti‐obesity effect and limits the side effects of CMN on gastrointestinal flora. Further, this study gives us important direction for the development of a concept‐based novel class of functional foods/nutraceuticals for improved metabolic health. © BioFactors, 43(6):821–835, 2017
The psycholegal factors for juvenile transfer and reverse transfer evaluations
Authors: King Christopher M.
Published: August 2017

It remains unclear whether forensic mental health assessments for juvenile reverse transfer (to juvenile court) are distinct from those for juvenile transfer (to adult court). This survey consisted of an updated review of transfer and reverse transfer laws (in jurisdictions that have both mechanisms) in light of the generally accepted three‐factor model of functional legal capacities involved in transfer evaluations (i.e., risk, sophistication–maturity, and treatment amenability). Results indicated that a majority of states' reverse transfer statutes refer explicitly or implicitly to the same three psycholegal constructs identified as central for transfer. Given the legal similarity between transfer and reverse transfer, potential practice implications and directions for future research are discussed.
Effect of Boron Doping On Graphene Oxide for Ammonia Adsorption
Authors: Yang Heena , Züttel Andreas , Kim Shindong , Ko Youngdon , Kim Whajung
Published: August 2017

Boron doped graphene oxide (B‐GO) is a highly effective adsorbent for ammonia due to the high density of strong Lewis acid sites arising from the boron. GO was doped by various amounts of boron described as xB‐GO (x=1.0, 3.0, and 5.0). B‐GO was successfully synthesized and the boron doping was confirmed by X‐ray diffraction, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. The adsorption characteristics of B‐GO were investigated by adsorption isotherm and thermal desorption spectroscopy. The adsorption isotherm shows an increase of ammonia adsorption with increasing concentration of boron such as 12.03 mol kg−1, 16.30 mol kg−1 and 15.58 mol kg−1. It is confirmed that the amount of ammonia adsorbed on the boron sites is limited to a certain amount due to the reduction of Lewis acid sites by B−O bonds. Boron doped into GO significantly enhances the adsorption capacity for ammonia.
Pharmacokinetics and Bioequivalence of Branded and Generic Formulations of Dofetilide 0.5‐mg Capsules After Single‐Dose Administration in Healthy Subjects
Authors: VanderLugt James T. , Bon Charles , Knuth Dean , Schreiber Rhonda , Ruff Michael D.
Published: August 2017

Class III antiarrhythmics are preferred therapy for managing atrial fibrillation/flutter. Dofetilide 0.5‐mg capsules were US Food and Drug Administration (FDA) approved in 1999 to treat atrial fibrillation/flutter. Bioequivalence of generic dofetilide is important for treating arrhythmias because drug concentrations must be consistent to maintain normal sinus rhythm. Generic dofetilide 0.5‐mg capsule pharmacokinetics were compared with branded product in 2 open‐label, 2‐way crossover, single‐dose studies — 1 study each in fasted and fed healthy subjects. Blood samples were collected before and up to 48 hours after dosing. Safety was assessed by tabulating adverse events and vital signs. Seventy‐three subjects were enrolled; 59 completed the studies. In fasted subjects, the 90% confidence intervals (CIs) for generic dofetilide 0.5 mg versus the reference formulation were 0.996–1.026 for the area under the plasma concentration–time curve from 0 to infinity (AUC) and 0.974–1.066 for the maximum observed concentration (Cmax). In fed subjects, the 90%CIs for AUC and Cmax were 0.988–1.015 and 0.928–0.992, respectively. All ratios were within the FDA‐established bioequivalence range. Twenty‐six subjects experienced 37 adverse events (generic, 15; reference, 22); all but 1 were mild or moderate in severity. Generic dofetilide 0.5‐mg capsules can be considered bioequivalent to the reference product.
Relative Bioavailability of Fixed‐Dose Combinations of Tamsulosin and Dutasteride: Results From 2 Randomized Trials in Healthy Male Volunteers
Authors: Burns Olivia , Zhu John , Manyak Michael J , Ravindranath Ramiya , Koosha Fariba , Haque Nazneen , Chung Sally
Published: August 2017

The relative bioavailabilities of dutasteride/tamsulosin hydrochloride 0.5 mg/0.2 mg fixed‐dose combination (FDC) capsules compared with coadministered reference products (1 dutasteride 0.5‐mg capsule [Avodart®] + 1 tamsulosin hydrochloride 0.2‐mg orally disintegrating tablet [Harnal D®]) were investigated in 2 clinical trials under fasted and fed conditions (ClinicalTrials.gov NCT02184585 and NCT02509104). Both trials were open‐label, randomized, single‐dose, crossover studies in healthy male adults aged 18‐65 years. Trial 1 evaluated 2 formulations (FDC1 and FDC2), and trial 2 evaluated a third formulation (FDC3). The primary end points were dutasteride area under the concentration‐time curve from time 0 to t (AUC(0‐t)) and peak plasma concentration (Cmax) and tamsulosin AUC(0‐∞), AUC(0‐t), and Cmax. The formulations were considered to be bioequivalent if the 90%CIs for the geometric mean ratios for each end point were within the range of 0.80‐1.25. For FDC1 in trial 1, bioequivalence criteria were not met for dutasteride Cmax or AUC in the fasted state or for tamsulosin Cmax in the fasted or fed states. For FDC2 in trial 1, all bioequivalence criteria were met except for tamsulosin Cmax in the fasted state. For FDC3 in trial 2, bioequivalence criteria were met for all dutasteride and tamsulosin end points in both the fed and fasted states. Safety profiles were similar for all FDC formulations and combination treatments.
Quantitative Dextran Trafficking to the Coxiella burnetii Parasitophorous Vacuole
Authors: Winfree Seth , Gilk Stacey D.
Published: August 2017

The gram‐negative bacterium Coxiella burnetii causes human Q fever, a disease characterized by a debilitating flu‐like illness in acute cases and endocarditis in chronic patients. An obligate intracellular pathogen, Coxiella burnetii survives within a large, lysosome‐like vacuole inside the host cell. A unique feature of the Coxiella parasitophorous vacuole (PV) is high levels of fusion with the host endocytic pathway, with PV‐endosome fusion critical for Coxiella survival within the host cell. This unit describes quantitating PV‐endosome fusion by measuring delivery of the fluid phase endosome marker dextran to the PV using live cell imaging. To study the effect of host cell proteins involved in PV‐endosome fusion, details are provided for using siRNA knockdown host cells. This method is a powerful tool for understanding mechanisms underlying Coxiella’s ability to manipulate host cell trafficking pathways. © 2017 by John Wiley & Sons, Inc.
Epigenetic Analysis of SV40 Minichromosomes
Authors: Balakrishnan Lata , Milavetz Barry
Published: August 2017

Simian virus 40 (SV40) is one of the best‐characterized members of the polyomavirus family of small DNA tumor viruses. It has a small genome of 5243 bp and utilizes cellular proteins for its molecular biology, with the exception of the T‐antigen protein, which is coded by the virus and is involved in regulating transcription and directing replication. Importantly, SV40 exists as chromatin in both the virus particle and intracellular minichromosomes. These facts, combined with high yields of virus and minichromosomes following infection and ease of manipulation, have made SV40 an extremely useful model to study all aspects of eukaryotic molecular biology. This unit describes procedures for working with SV40 and preparing SV40 chromatin from infected cells and virus particles, as well as procedures for using SV40 chromatin to study epigenetic regulation. © 2017 by John Wiley & Sons, Inc.
THz radiation generation via the interaction of two‐colour ultra‐short laser pulses with SO2 and NH3 gases
Authors: Soltani Gishini M. S. , Ganjovi A.
Published: August 2017

In this work, using a two‐dimensional particle‐in‐cell Monte Carlo collision computation method, terahertz (THz) radiation generation via the interaction of two‐colour, ultra‐short, high‐power laser pulses with the polyatomic molecular gases sulphur dioxide (SO2) and ammonia (NH3) is examined. The influence of SO2 and NH3 pressures and two‐colour laser pulse parameters, i.e., pulse shape, pulse duration, and beam waist, on the THz radiation generation is studied. It is shown that the THz signal generation from SO2 and NH3 increases with the background gas pressure. It is seen that the THz emission intensity for both gases at higher laser pulse durations is higher. Moreover, for these polyatomic gases, the plasma current density increases with increase in the laser pulse beam waist. A more powerful THz radiation intensity with a larger time to peak of the plasma current density is observed for SO2 compared to NH3. In addition, many THz signals with small intensities are observed for both polyatomic gases. It is seen that for both SO2 and NH3 the generated THz spectral intensity is higher at higher gas pressures.
Kinetic study of instability growth rate in a helicon plasma discharge source
Authors: Jaafarian Rokhsare , Ganjovi Alireza , Etaati Gholam Reza
Published: August 2017

In this work, a kinetic model is developed to study the effects of the radio frequency antenna wavenumber, helicon plasma electron density, as well as their drift velocity and temperature on the instability increment rate of the helicon wave in both longitudinal and transverse directions. The ion acoustic (IA) wave frequencies and wavenumbers of the helicon waves are obtained when the maximum wave energy is deposited on the plasma ions. Moreover, it is shown that, at the IA wavenumber and frequencies, while the longitudinal instability increment rates for both the helicon and IA waves are ignorable, the transverse instability increment rate for both the helicon and IA wave increases. Besides, the longitudinal instability increment rate for the helicon or IA wave has non‐zero resonant frequencies. On the other hand, the transverse instability increment rate of helicon or IA wave can be neglected. Furthermore, it is observed that, while both the imaginary part of longitudinal permittivity and longitudinal instability increment rate are not influenced by the electron temperature, their transverse component increases linearly with the electron temperature. In addition, the imaginary part of transverse permittivity increases almost linearly with the drift velocity of the plasma electrons.
Misbehavior analysis of IEEE 802.11 MAC layer in mobile ad hoc network using stochastic reward nets
Authors: Yadollahzadeh Tabari Meisam , Pouyan Ali A.
Published: August 2017

In this paper, we present a Petri net model for performance evaluation of IEEE 802.11 distributed coordination function as a popular media access control layer protocol in mobile ad hoc network. The goal of this evaluation is to examine this protocol under the existing of misbehavior nodes that selfishly try to grasp common channel in a neighbor area. The presented model consists of 2 separate models based on stochastic reward net (SRN), as a variation of stochastic Petri net. The first model, which is called one node operation model, is supposed for presenting all distributed coordination function operations in a single node such as collision avoidance, request to send/clear to send (RTS/CTS) handshake, and backoff mechanism. The next SRN model, all node operation model, is used for modeling nodes competition for occupying channel in a neighbor area. The models could be adjusted to a dynamic network with any number of nodes, dimension scale, and nodes' speed. For evaluation purpose, 4 distinct attack types implemented by modifying associated transitions in SRN models. The proposed SRN model has been quantified by deriving 2 performances metrics as Throughput and Delay. Both metrics are also compared to the value obtained from NS‐2 in terms of different number of nodes and 3 packet generation rates. Three additional metrics measuring the channel usage are also quantified in terms of different attack strategies using only presented SRN model.
Small Scaffolds, Big Potential: Developing Miniature Proteins as Therapeutic Agents
Authors: Holub Justin M.
Published: August 2017

Preclinical Research

Miniature proteins are a class of oligopeptide characterized by their short sequence lengths and ability to adopt well‐folded, three‐dimensional structures. Because of their biomimetic nature and synthetic tractability, miniature proteins have been used to study a range of biochemical processes including fast protein folding, signal transduction, catalysis and molecular transport. Recently, miniature proteins have been gaining traction as potential therapeutic agents because their small size and ability to fold into defined tertiary structures facilitates their development as protein‐based drugs. This research overview discusses emerging developments involving the use of miniature proteins as scaffolds to design novel therapeutics for the treatment and study of human disease. Specifically, this review will explore strategies to: (i) stabilize miniature protein tertiary structure; (ii) optimize biomolecular recognition by grafting functional epitopes onto miniature protein scaffolds; and (iii) enhance cytosolic delivery of miniature proteins through the use of cationic motifs that facilitate endosomal escape. These objectives are discussed not only to address challenges in developing effective miniature protein‐based drugs, but also to highlight the tremendous potential miniature proteins hold for combating and understanding human disease. Drug Dev Res 78 : 268–282, 2017. © 2017 Wiley Periodicals, Inc.
Development and field validation of a regional, management‐scale habitat model: A koala Phascolarctos cinereus case study
Authors: Law Bradley , Caccamo Gabriele , Roe Paul , Truskinger Anthony , Brassil Traecey , Gonsalves Leroy , McConville Anna , Stanton Matthew
Published: August 2017

Species distribution models have great potential to efficiently guide management for threatened species, especially for those that are rare or cryptic. We used MaxEnt to develop a regional‐scale model for the koala Phascolarctos cinereus at a resolution (250 m) that could be used to guide management. To ensure the model was fit for purpose, we placed emphasis on validating the model using independently‐collected field data. We reduced substantial spatial clustering of records in coastal urban areas using a 2‐km spatial filter and by modeling separately two subregions separated by the 500‐m elevational contour. A bias file was prepared that accounted for variable survey effort. Frequency of wildfire, soil type, floristics and elevation had the highest relative contribution to the model, while a number of other variables made minor contributions. The model was effective in discriminating different habitat suitability classes when compared with koala records not used in modeling. We validated the MaxEnt model at 65 ground‐truth sites using independent data on koala occupancy (acoustic sampling) and habitat quality (browse tree availability). Koala bellows (n = 276) were analyzed in an occupancy modeling framework, while site habitat quality was indexed based on browse trees. Field validation demonstrated a linear increase in koala occupancy with higher modeled habitat suitability at ground‐truth sites. Similarly, a site habitat quality index at ground‐truth sites was correlated positively with modeled habitat suitability. The MaxEnt model provided a better fit to estimated koala occupancy than the site‐based habitat quality index, probably because many variables were considered simultaneously by the model rather than just browse species. The positive relationship of the model with both site occupancy and habitat quality indicates that the model is fit for application at relevant management scales. Field‐validated models of similar resolution would assist in guiding management of conservation‐dependent species.
Simultaneous Determination of Peroxide Hydrogen and Ascorbic Acid by Capillary Electrophoresis with Platinum Nanoparticles Modified Micro‐disk Electrode
Authors: Wang J. , Zhou M. , Dong R. , Cong X. , Zhang R. , Wang X.
Published: August 2017

In this study, the first application of a capillary zone electrophoresis‐electrochemical detection (CE‐ECD) method for concurrent determination of hydrogen peroxide (H2O2) and ascorbic acid (AA), was developed using the Pt nanoparticles (PtNPs) modified Pt micro‐disk electrode (PtME). The electrocatalytic activity of the modified electrode for H2O2 and AA was characterized by cyclic voltammetry. Under optimized experimental conditions, highly linear calibration plots were observed for both H2O2 and AA, with concentration linear ranges of 0.8 μM to 0.8 mM and 1.0 μM to 0.8 mM. Detection limits of 0.2 μM H2O2 and 0.5 μM AA were determined on the basis of the signal‐to‐noise characteristics (S/N=3) of an electropherogram. Compared with the unmodified PtME, the sensitivity was promoted in that PtNPs/PtME provided an increased effective electrode surface and high catalytic activity toward H2O2 and AA. Using this method, the added H2O2 and AA in Mizone, a kind of functional drink, were detected, and the concentration of AA was found to be 2.33 mM (n=3). The recovery rates were 95.3 % for H2O2 and 98.7 % for AA. The novel approach provided a wide linear range, low detection limit, good reproducibility and stability. It will provide a new insight into the balance of reactive oxygen species and antioxidant in biological systems.
Effects of chronic cadmium exposure on metamorphosis, skeletal development, and thyroid endocrine disruption in Chinese toad Bufo gargarizans tadpoles
Authors: Sun Nailiang , Wang Hongyuan , Ju Zongqi , Zhao Hongfeng
Published: August 2017

The present study examined the effects of chronic cadmium (Cd) exposure on metamorphosis, body size, thyroid gland, and skeletal development of Chinese toad (Bufo gargarizans) tadpoles. Tadpoles were exposed to Cd concentrations at 0, 5, 10, 50, 100, and 500 μg/L from Gosner stages 26 to 46 of completion of metamorphosis. Our results showed that 100 and 500 μg/L of Cd concentrations increased mortality and decelerated metamorphosis rate. In addition, significant body size reduction at Gosner stage 42 was observed at 100 and 500 μg/L of Cd treatments (p < 0.01). Average body length and hind-limb length were significantly decreased in the 500 μg/L of Cd group (p < 0.05) but body mass was not significantly different at Gosner stage 46. Moreover, bone formation was delayed in high Cd concentration treatments (50, 100, and 500 μg/L) at both Gosner stage 42 and 46. Histopathological changes of the thyroid gland showed that follicular cell hyperplasia and malformation were induced by high Cd concentrations (50, 100, and 500 μg/L). Furthermore, real-time polymerase chain reaction analysis suggested that the larvae exposed to high-dose Cd exhibited a significant decrease in deiodinase (Dio2) and thyroid hormone receptor (TRβ) mRNA levels at Gosner stage 42 and 46. Our investigation indicated that high-dose Cd caused metamorphic deceleration, body size reduction, and delayed skeletal development through disrupting the thyroid system in B. gargarizans larvae. Environ Toxicol Chem 2018;37:213–223. © 2017 SETAC
Combining a root exclusion technique with continuous chamber and porous tube measurements for a pin‐point separation of ecosystem respiration in croplands
Authors: Hoffmann Mathias , Wirth Stephan J. , Beßler Holger , Engels Christof , Jochheim Hubert , Sommer Michael , Augustin Jürgen
Published: August 2017

To better assess ecosystem C budgets of croplands and understand their potential response to climate and management changes, detailed information on the mechanisms and environmental controls driving the individual C flux components are needed. This accounts in particular for the ecosystem respiration (Reco) and its components, the autotrophic (Ra) and heterotrophic respiration (Rh) which vary tremendously in time and space. This study presents a method to separate Reco into Ra [as the sum of Ra (shoot) and Ra (root)] and Rh in order to detect temporal and small‐scale spatial dynamics within their relative contribution to overall Reco. Thus, predominant environmental drivers and underlying mechanisms can be revealed. Reco was derived during nighttime by automatic chamber CO2 flux measurements on plant covered plots. Rh was derived from CO2 efflux measurements, which were performed in parallel to Reco measurements on a fallow plot using CO2 sampling tubes in 10 cm soil depth. Ra (root) was calculated as the difference between sampling tube CO2 efflux measurements on a plant covered plot and Rh. Ra (shoot) was calculated as Reco – Ra (root) – Rh. Measurements were carried out for winter wheat (Triticum aestivum L.) during the crop season 2015 at an experimental plot located in the hummocky ground moraine landscape of NE Germany. Reco varied seasonally from < 1 to 9.5 g C m−2 d−1, and was higher in adult (a) and reproductive (r) than juvenile (j) stands (g C m−2 d−1: j = 1.2, a = 4.6, r = 5.3). Observed Ra and Rh were in general smaller compared to the independently measured Reco, contributing in average 58% and 42% to Reco. However, both varied strongly regarding their environmental drivers and particular contribution throughout the study period, following the seasonal development of soil temperature and moisture (Rh) as well as crop development (Ra). Thus, our results consistently revealed temporal dynamics regarding the relative contribution of Ra (root) and Ra (shoot) to Ra, as well as of Ra and Rh to Reco. Based on the observed results, implications for partitioning of Reco in croplands are given.
Combining evidence from multiple electronic health care databases: performances of one‐stage and two‐stage meta‐analysis in matched case‐control studies
Authors: La Gamba Fabiola , Corrao Giovanni , Romio Silvana , Sturkenboom Miriam , Trifirò Gianluca , Schink Tania , de Ridder Maria
Published: August 2017

Purpose

Clustering of patients in databases is usually ignored in one‐stage meta‐analysis of multi‐database studies using matched case‐control data. The aim of this study was to compare bias and efficiency of such a one‐stage meta‐analysis with a two‐stage meta‐analysis.

Methods

First, we compared the approaches by generating matched case‐control data under 5 simulated scenarios, built by varying: (1) the exposure‐outcome association; (2) its variability among databases; (3) the confounding strength of one covariate on this association; (4) its variability; and (5) the (heterogeneous) confounding strength of two covariates. Second, we made the same comparison using empirical data from the ARITMO project, a multiple database study investigating the risk of ventricular arrhythmia following the use of medications with arrhythmogenic potential. In our study, we specifically investigated the effect of current use of promethazine.

Results

Bias increased for one‐stage meta‐analysis with increasing (1) between‐database variance of exposure effect and (2) heterogeneous confounding generated by two covariates. The efficiency of one‐stage meta‐analysis was slightly lower than that of two‐stage meta‐analysis for the majority of investigated scenarios. Based on ARITMO data, there were no evident differences between one‐stage (OR = 1.50, CI = [1.08; 2.08]) and two‐stage (OR = 1.55, CI = [1.12; 2.16]) approaches.

Conclusions

When the effect of interest is heterogeneous, a one‐stage meta‐analysis ignoring clustering gives biased estimates. Two‐stage meta‐analysis generates estimates at least as accurate and precise as one‐stage meta‐analysis. However, in a study using small databases and rare exposures and/or outcomes, a correct one‐stage meta‐analysis becomes essential.
Solution properties, unperturbed dimensions, and chain flexibility of poly(1‐adamantyl acrylate)
Authors: Lu Wei , Yin Panchao , Osa Masashi , Wang Weiyu , Kang Nam‐Goo , Hong Kunlun , Mays Jimmy W.
Published: August 2017

Poly(1‐adamantyl acrylate) (PAdA) exhibits much higher glass transition and degradation temperatures than other polyacrylates. However, the quantitative evaluation of the stiffness of this polymer chain has not been reported previously. In this study, the dilute solution properties and conformational characteristics of PAdA were evaluated using viscometry and scattering techniques. The unperturbed dimensions of this polymer were evaluated using the Burchard–Stockmayer–Fixman extrapolation and the touched‐bead wormlike chain model. The PAdA chain has a comparable persistence length, diameter per bead and characteristic ratio to poly(methyl methacrylate) and polystyrene. All these results indicate that PAdA is less flexible than common polyacrylates. In addition, the second virial coefficients (A2) of PAdA in different solvents obtained by static light scattering were compared. Among the solvents investigated, tetrahydrofuran is a moderate solvent. Radius of gyration of a polymer sample in the various solvents ranged from 16.8 to 30.3 nm. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1526–1531
The molecular mechanism behind resistance of the kinase FLT3 to the inhibitor quizartinib
Authors: Friedman Ran
Published: August 2017

Fms‐like tyrosine kinase 3 (FLT3) is a receptor tyrosine kinase that is a drug target for leukemias. Several potent inhibitors of FLT3 exist, and bind to the inactive form of the enzyme. Unfortunately, resistance due to mutations in the kinase domain of FLT3 limits the therapeutic effects of these inhibitors. As in many other cases, it is not straightforward to explain why certain mutations lead to drug resistance. Extensive fully atomistic molecular dynamics (MD) simulations of FLT3 were carried out with an inhibited form (FLT‐quizartinib complex), a free (apo) form, and an active conformation. In all cases, both the wild type (wt) proteins and two resistant mutants (D835F and Y842H) were studied. Analysis of the simulations revealed that impairment of protein‐drug interactions cannot explain the resistance mutations in question. Rather, it appears that the active state of the mutant forms is perturbed by the mutations. It is therefore likely that perturbation of deactivation of the protein (which is necessary for drug binding) is responsible for the reduced affinity of the drug to the mutants. Importantly, this study suggests that it is possible to explain the source of resistance by mutations in FLT3 by an analysis of unbiased MD simulations.
Extracellular vesicles: nature's nanoparticles for improving gene transfer with adeno‐associated virus vectors
Authors: György Bence , Maguire Casey A.
Published: August 2017

Gene therapy, the ability to treat a disease at the level of nucleic acid, has journeyed from science fiction, to hard lessons learned from early clinical trials, to improved technologies with efficacy in patients for several diseases. Adeno‐associated virus (AAV) vectors are currently a leader for direct in vivo gene therapy. To date, AAV is safe in patients, with clinical benefit in trials to treat blindness, hemophilia, and a lipid disorder, with many more trials underway. Despite this remarkable progress, barriers exist for AAV vectors to be effective gene transfer vehicles in all organ/cell targets, as well as patient subpopulations. Extracellular vesicles (EVs, e.g., exosomes, microvesicles) are natural lipid particles released by many cell types. They have been reported to mediate cell to cell communication via transferred contents including proteins, nucleic acids, and metabolites. These properties of EV attracted our attention to help solve certain gene transfer issues encountered by AAV vectors. We made the initial discovery that a subpopulation of AAV vectors isolated from media directly interacted with EVs [referred to as exosome‐associated AAV (exo‐AAV)]. In following reports, we have demonstrated that exo‐AAV has advantages over the conventional AAV vector in areas such as anti‐AAV antibody evasion and transduction of cells of the eye and cochlea in preclinical models. The work of others using EVs as therapeutics as well as our continued development of the exo‐AAV platform may advance the field towards useful clinical applications.

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Emerging Technologies

Biology-Inspired Nanomaterials > Lipid‐Based Structures

Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease
Effectiveness of a bounty program for reducing wild pig densities
Authors: Ditchkoff Stephen S. , Holtfreter Robert W. , Williams Brian L.
Published: August 2017

Bounty programs have been historically implemented as a means of controlling invasive or pest species. Although bounty programs are generally considered to be ineffective, they are still proposed as management tools in situations where other management strategies have been unsuccessful. The wild pig (Sus scrofa) is an invasive large mammal in North America and most management strategies have proven to be ineffective at reducing or eliminating its populations, resulting in population expansion in recent decades. Fort Benning Army Infantry Training Center, Georgia, USA, had been inhabited by wild pigs since the mid‐1900s. In response to increasing negative impacts on flora, fauna, and military training activities and equipment, Fort Benning began offering a bounty on pigs in June 2007 to reduce the population and eventually eradicate wild pigs from the installation. To gauge the effectiveness of the program, we evaluated the population response of wild pigs within 2 study areas on the installation from June 2007 to February 2008. During the study, 1,138 pigs were harvested throughout the installation at a total cost (bounties paid and administration) of US$57,296. Surveys indicated that pig density and occupancy rates increased 23–130% and 12–19%, respectively, during the course of the bounty program. Additionally, sounder size and number of juveniles per adult female increased 144–233% and 191–219%, respectively. These data suggest that the wild pig population was increasing during the period when the bounty program was in effect. We hypothesize that this was due to increased food availability and reproduction associated with baiting wild pigs during the program, and because efforts of program participants were focused on eliminating the segment of the pig population that would maximize return on effort and “trophy” quality of animals rather than on the segment of the population that would most greatly influence population growth. © 2017 The Wildlife Society.
Vitamin B6 is essential for serine de novo biosynthesis
Authors: Ramos Rúben J. , Pras‐Raves Mia L. , Gerrits Johan , van der Ham Maria , Willemsen Marcel , Prinsen Hubertus , Burgering Boudewijn , Jans Judith J. , Verhoeven‐Duif Nanda M.
Published: August 2017

Pyridoxal 5′‐phosphate (PLP), the metabolically active form of vitamin B6, plays an essential role in brain metabolism as a cofactor in numerous enzyme reactions. PLP deficiency in brain, either genetic or acquired, results in severe drug‐resistant seizures that respond to vitamin B6 supplementation. The pathogenesis of vitamin B6 deficiency is largely unknown. To shed more light on the metabolic consequences of vitamin B6 deficiency in brain, we performed untargeted metabolomics in vitamin B6‐deprived Neuro‐2a cells. Significant alterations were observed in a range of metabolites. The most surprising observation was a decrease of serine and glycine, two amino acids that are known to be elevated in the plasma of vitamin B6 deficient patients. To investigate the cause of the low concentrations of serine and glycine, a metabolic flux analysis on serine biosynthesis was performed. The metabolic flux results showed that the de novo synthesis of serine was significantly reduced in vitamin B6‐deprived cells. In addition, formation of glycine and 5‐methyltetrahydrofolate was decreased. Thus, vitamin B6 is essential for serine de novo biosynthesis in neuronal cells, and serine de novo synthesis is critical to maintain intracellular serine and glycine. These findings suggest that serine and glycine concentrations in brain may be deficient in patients with vitamin B6 responsive epilepsy. The low intracellular 5‐mTHF concentrations observed in vitro may explain the favourable but so far unexplained response of some patients with pyridoxine‐dependent epilepsy to folinic acid supplementation.
Reliability and Availability Engineering
Authors: Trivedi Kishor S. , Bobbio Andrea
Published: August 2017

Do you need to know what technique to use to evaluate the reliability of an engineered system? This self-contained guide provides comprehensive coverage of all the analytical and modeling techniques currently in use, from classical non-state and state space approaches, to newer and more advanced methods such as binary decision diagrams, dynamic fault trees, Bayesian belief networks, stochastic Petri nets, non-homogeneous Markov chains, semi-Markov processes, and phase type expansions. Readers will quickly understand the relative pros and cons of each technique, as well as how to combine different models together to address complex, real-world modeling scenarios. Numerous examples, case studies and problems provided throughout help readers put knowledge into practice, and a solutions manual and Powerpoint slides for instructors accompany the book online. This is the ideal self-study guide for students, researchers and practitioners in engineering and computer science.
Financial Enterprise Risk Management
Authors: Sweeting Paul
Published: August 2017

This comprehensive, yet accessible, guide to enterprise risk management for financial institutions contains all the tools needed to build and maintain an ERM framework. It discusses the internal and external contexts with which risk management must be carried out, and it covers a range of qualitative and quantitative techniques that can be used to identify, model and measure risks. This new edition has been thoroughly updated to reflect new legislation and the creation of the Financial Conduct Authority and the Prudential Regulation Authority. It includes new content on Bayesian networks, expanded coverage of Basel III, a revised treatment of operational risk and a fully revised index. Over 100 diagrams are used to illustrate the range of approaches available, and risk management issues are highlighted with numerous case studies. This book also forms part of the core reading for the UK actuarial profession's specialist technical examination in enterprise risk management, ST9.