bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Cyclodextrins (β and γ) and l-Arginine on Stability and Functional Properties of Mucoadhesive Buccal Films Loaded with Omeprazole for Pediatric Patients
Authors: Khan Sajjad , Boateng Joshua
Published: February 2018

Omeprazole (OME) is employed for treating ulcer in children, but is unstable and exhibits first pass metabolism via the oral route. This study aimed to stabilize OME within mucoadhesive metolose (MET) films by combining cyclodextrins (CD) and l-arginine (l-arg) as stabilizing excipients and functionally characterizing for potential delivery via the buccal mucosa of paediatric patients. Polymeric solutions at a concentration of 1% w/w were obtained by dispersing the required weight of metolose in 20% v/v ethanol as solvent at a temperature of 40 °C using polyethylene glycol (PEG 400) (0.5% w/w) as plasticizer. The films were obtained by drying the resulting polymer solutions at in an oven at 40 °C. Textural (tensile and mucoadhesion) properties, physical form (differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy), residual moisture content (thermogravimetric analysis (TGA)) and surface morphology (scanning electron microscopy (SEM)) were investigated. Optimized formulations containing OME, CDs (β or γ) and l-arg (1:1:1) were selected to investigate the stabilization of the drug. The DSC, XRD, and FTIR showed possible molecular dispersion of OME in metolose film matrix. Plasticized MET films containing OME:βCD:l-arg 1:1:1 were optimum in terms of transparency and ease of handling and therefore further functionally characterized (hydration, mucoadhesion, in vitro drug dissolution and long term stability studies). The optimized formulation showed sustained drug release that was modelled by Korsmeyer–Peppas equation, while the OME showed stability under ambient temperature conditions for 28 days. The optimized OME loaded MET films stabilized with βCD and l-arg have potential for use as paediatric mucoadhesive buccal delivery system, which avoids degradation in the stomach acid as well as first pass metabolism in the liver.
Effect of Chain Transfer to Polymer in Conventional and Living Emulsion Polymerization Process
Authors: Tobita Hidetaka
Published: February 2018

Emulsion polymerization process provides a unique polymerization locus that has a confined tiny space with a higher polymer concentration, compared with the corresponding bulk polymerization, especially for the ab initio emulsion polymerization. Assuming the ideal polymerization kinetics and a constant polymer/monomer ratio, the effect of such a unique reaction environment is explored for both conventional and living free-radical polymerization (FRP), which involves chain transfer to the polymer, forming polymers with long-chain branches. Monte Carlo simulation is applied to investigate detailed branched polymer architecture, including the mean-square radius of gyration of each polymer molecule, 0. The conventional FRP shows a very broad molecular weight distribution (MWD), with the high molecular weight region conforming to the power law distribution. The MWD is much broader than the random branched polymers, having the same primary chain length distribution. The expected 0 for a given MW is much smaller than the random branched polymers. On the other hand, the living FRP shows a much narrower MWD compared with the corresponding random branched polymers. Interestingly, the expected 0 for a given MW is essentially the same as that for the random branched polymers. Emulsion polymerization process affects branched polymer architecture quite differently for the conventional and living FRP.
IoT-Forensics Meets Privacy: Towards Cooperative Digital Investigations
Authors: Nieto Ana , Rios Ruben , Lopez Javier
Published: February 2018

IoT-Forensics is a novel paradigm for the acquisition of electronic evidence whose operation is conditioned by the peculiarities of the Internet of Things (IoT) context. As a branch of computer forensics, this discipline respects the most basic forensic principles of preservation, traceability, documentation, and authorization. The digital witness approach also promotes such principles in the context of the IoT while allowing personal devices to cooperate in digital investigations by voluntarily providing electronic evidence to the authorities. However, this solution is highly dependent on the willingness of citizens to collaborate and they may be reluctant to do so if the sensitive information within their personal devices is not sufficiently protected when shared with the investigators. In this paper, we provide the digital witness approach with a methodology that enables citizens to share their data with some privacy guarantees. We apply the PRoFIT methodology, originally defined for IoT-Forensics environments, to the digital witness approach in order to unleash its full potential. Finally, we show the feasibility of a PRoFIT-compliant digital witness with two use cases.
Measurement of Axial Rigidity and Postural Instability Using Wearable Sensors
Authors: Phan Dung , Horne Malcolm , Pathirana Pubudu , Farzanehfar Parisa
Published: February 2018

Axial Bradykinesia is an important feature of advanced Parkinson’s disease (PD). The purpose of this study is to quantify axial bradykinesia using wearable sensors with the long-term aim of quantifying these movements, while the subject performs routine domestic activities. We measured back movements during common daily activities such as pouring, pointing, walking straight and walking around a chair with a test system engaging a minimal number of Inertial Measurement (IM) based wearable sensors. Participants included controls and PD patients whose rotation and flexion of the back was captured by the time delay between motion signals from sensors attached to the upper and lower back. PD subjects could be distinguished from controls using only two sensors. These findings suggest that a small number of sensors and similar analyses could distinguish between variations in bradykinesia in subjects with measurements performed outside of the laboratory. The subjects could engage in routine activities leading to progressive assessments of therapeutic outcomes.
Determining Biogenic Content of Biogas by Measuring Stable Isotopologues 12CH4, 13CH4, and CH3D with a Mid-Infrared Direct Absorption Laser Spectrometer
Authors: Kääriäinen Teemu , Richmond Craig , Manninen Albert
Published: February 2018

A tunable laser absorption spectrometer (TLAS) was developed for the simultaneous measurement of δ13C and δD values of methane (CH4). A mid-infrared interband cascade laser (ICL) emitting around 3.27 µm was used to measure the absorption of the three most abundant isotopologues in CH4 with a single, mode-hop free current sweep. The instrument was validated against methane samples of fossil and biogenic origin with known isotopic composition. Three blended mixtures with varied biogenic content were prepared volumetrically, and their δ13C and δD values were determined. Analysis demonstrated that, provided the isotopic composition of the source materials was known, the δ13C and δD values alone were sufficient to determine the biogenic content of the blended samples to within 1.5%.
Acoustic Sensors for Air and Surface Navigation Applications
Authors: Kapoor Rohan , Ramasamy Subramanian , Gardi Alessandro , Schyndel Ron , Sabatini Roberto
Published: February 2018

This paper presents the state-of-the-art and reviews the state-of-research of acoustic sensors used for a variety of navigation and guidance applications on air and surface vehicles. In particular, this paper focuses on echolocation, which is widely utilized in nature by certain mammals (e.g., cetaceans and bats). Although acoustic sensors have been extensively adopted in various engineering applications, their use in navigation and guidance systems is yet to be fully exploited. This technology has clear potential for applications in air and surface navigation/guidance for intelligent transport systems (ITS), especially considering air and surface operations indoors and in other environments where satellite positioning is not available. Propagation of sound in the atmosphere is discussed in detail, with all potential attenuation sources taken into account. The errors introduced in echolocation measurements due to Doppler, multipath and atmospheric effects are discussed, and an uncertainty analysis method is presented for ranging error budget prediction in acoustic navigation applications. Considering the design challenges associated with monostatic and multi-static sensor implementations and looking at the performance predictions for different possible configurations, acoustic sensors show clear promises in navigation, proximity sensing, as well as obstacle detection and tracking. The integration of acoustic sensors in multi-sensor navigation systems is also considered towards the end of the paper and a low Size, Weight and Power, and Cost (SWaP-C) sensor integration architecture is presented for possible introduction in air and surface navigation systems.
A Glider-Assisted Link Disruption Restoration Mechanism in Underwater Acoustic Sensor Networks
Authors: Jin Zhigang , Wang Ning , Su Yishan , Yang Qiuling
Published: February 2018

Underwater acoustic sensor networks (UASNs) have become a hot research topic. In UASNs, nodes can be affected by ocean currents and external forces, which could result in sudden link disruption. Therefore, designing a flexible and efficient link disruption restoration mechanism to ensure the network connectivity is a challenge. In the paper, we propose a glider-assisted restoration mechanism which includes link disruption recognition and related link restoring mechanism. In the link disruption recognition mechanism, the cluster heads collect the link disruption information and then schedule gliders acting as relay nodes to restore the disrupted link. Considering the glider’s sawtooth motion, we design a relay location optimization algorithm with a consideration of both the glider’s trajectory and acoustic channel attenuation model. The utility function is established by minimizing the channel attenuation and the optimal location of glider is solved by a multiplier method. The glider-assisted restoration mechanism can greatly improve the packet delivery rate and reduce the communication energy consumption and it is more general for the restoration of different link disruption scenarios. The simulation results show that glider-assisted restoration mechanism can improve the delivery rate of data packets by 15–33% compared with cooperative opportunistic routing (OVAR), the hop-by-hop vector-based forwarding (HH-VBF) and the vector based forward (VBF) methods, and reduce communication energy consumption by 20–58% for a typical network’s setting.
Predicting Long-Term Stability of Precise Oscillators under Influence of Frequency Drift
Authors: Cheng Weiwei , Nie Guigen
Published: February 2018

High-performance oscillators, atomic clocks for instance, are important in modern industries, finance and scientific research. In this paper, the authors study the estimation and prediction of long-term stability based on convex optimization techniques and compressive sensing. To take frequency drift into account, its influence on Allan and modified Allan variances is formulated. Meanwhile, expressions for the expectation and variance of discrete-time Hadamard variance are derived. Methods that reduce the computational complexity of these expressions are also introduced. Tests against GPS precise clock data show that the method can correctly predict one-week frequency stability from 14-day measured data.
Wearable Driver Distraction Identification On-The-Road via Continuous Decomposition of Galvanic Skin Responses
Authors: Dehzangi Omid , Rajendra Vikas , Taherisadr Mojtaba
Published: February 2018

One of the main reasons for fatal accidents on the road is distracted driving. The continuous attention of an individual driver is a necessity for the task of driving. While driving, certain levels of distraction can cause drivers to lose their attention, which might lead to an accident. Thus, the number of accidents can be reduced by early detection of distraction. Many studies have been conducted to automatically detect driver distraction. Although camera-based techniques have been successfully employed to characterize driver distraction, the risk of privacy violation is high. On the other hand, physiological signals have shown to be a privacy preserving and reliable indicator of driver state, while the acquisition technology might be intrusive to drivers in practical implementation. In this study, we investigate a continuous measure of phasic Galvanic Skin Responses (GSR) using a wristband wearable to identify distraction of drivers during a driving experiment on-the-road. We first decompose the raw GSR signal into its phasic and tonic components using Continuous Decomposition Analysis (CDA), and then the continuous phasic component containing relevant characteristics of the skin conductance signals is investigated for further analysis. We generated a high resolution spectro-temporal transformation of the GSR signals for non-distracted and distracted (calling and texting) scenarios to visualize the associated behavior of the decomposed phasic GSR signal in correlation with distracted scenarios. According to the spectrogram observations, we extract relevant spectral and temporal features to capture the patterns associated with the distracted scenarios at the physiological level. We then performed feature selection using support vector machine recursive feature elimination (SVM-RFE) in order to: (1) generate a rank of the distinguishing features among the subject population, and (2) create a reduced feature subset toward more efficient distraction identification on the edge at the generalization phase. We employed support vector machine (SVM) to generate the 10-fold cross validation (10-CV) identification performance measures. Our experimental results demonstrated cross-validation accuracy of 94.81% using all the features and the accuracy of 93.01% using reduced feature space. The SVM-RFE selected set of features generated a marginal decrease in accuracy while reducing the redundancy in the input feature space toward shorter response time necessary for early notification of distracted state of the driver.
Prevalence and Determinants of Sinus Problems in Farm and Non-Farm Populations of Rural Saskatchewan, Canada
Authors: Kajiwara-Morita Ayami , Karunanayake Chandima , Dosman James , Lawson Joshua , Kirychuk Shelley , Rennie Donna , Dyck Roland , Koehncke Niels , Senthilselvan Ambikaipakan , Pahwa Punam ,   Saskatchewan Rural Health Study Research Team
Published: February 2018

Although sinus problems have long been recognized as the most common respiratory symptoms associated with agricultural work, there is a scarcity of recent studies and/or reliable estimates as to the true prevalence or risk factors of sinus problems related to farming. The aim of this study was to determine the prevalence of sinus problems in farming and non-farming rural populations and further investigate the association of individual (for example life-style, occupational), contextual (e.g., environmental), and important covariates (e.g., age, sex) with sinus problems. A large-scale cross-sectional study was conducted in farm and non-farm residents of rural Saskatchewan, Canada. A logistic regression model based on a generalized estimating equations approach were fitted to investigate the risk factors of sinus problems. Sinus problems were reported by 2755 (34.0%) of the 8101 subjects. Farm residents were more likely to spend their first year of life on farm compared with non-farm residents, and indicated a significantly lower risk of sinus problems. Meanwhile, occupational exposure to solvent and mold were associated with an increased risk of sinus problems. Some health conditions such as allergy and stomach acidity/reflux, family history, and female sex were also related to a higher risk of sinus problems. Farm residents had a significantly lower risk of sinus problems than non-farm residents, likely due to the exposure to farm specific environments in their early life.
Land Use and Cover Change during the Rapid Economic Growth Period from 1990 to 2010: A Case Study of Shanghai
Authors: Shi Ge , Jiang Nan , Yao Lianqiu
Published: February 2018

China has experienced a period of rapid economic growth during the past few decades especially in Shanghai. The rapid urbanization has caused great change for land use and cover change (LUCC), which is a prominent feature of global change. This paper focuses on land use history and the driving forces of LUCC in Shanghai from 1990 to 2010. We evaluated the LUCC of Shanghai based on three period Landsat images using the land use transition matrix model, the land use dynamic degree model, and the land use degree model. Then we analyzed the potential driving forces from different dimensions. The results show that the most obvious pattern of LUCC is the increase of built-up area and the decrease of arable land. The land use change dynamic from 2000 to 2010 is much greater than that from 1990 to 2010. The main driving forces of LUCC are human activity and social economic development.
Back to the Future: The Potential of Intergenerational Justice for the Achievement of the Sustainable Development Goals
Authors: Vasconcellos Oliveira Rita
Published: February 2018

The establishment of the UN Sustainable Development Goals (SDGs) bolstered momentum to achieve a sustainable future. Undeniably, the welfare of future generations is a fundamental value of sustainable development since the publication of the Brundtland report. Nevertheless, SDGs and their targets are meagre on intergenerational justice concerns. The 15-year target horizon of the SDGs might be beneficial for implementation reasons. However, such a short-term perspective is far from innocuous in justice terms. It jeopardises the establishment of long-term goals, which protect both present and future people. This article advocates for clearer stances on intergenerational justice. What type of distributive principles could and should dictate the present socio-economic development? Looking at intragenerational justice principles contained in SDGs does not provide a full answer since they express conflicting visions of what constitutes a fair development. Furthermore, a fair distribution of the development benefits and burdens among present and near future people does not necessarily guarantee the wellbeing of more distant generations. I propose an intergenerational sufficientarian perspective as a way of extending the beneficial impacts of SDGs to both close and distant future generations. Hopefully, it facilitates the translation of the SDGs into policies that promote fairer implementation strategies.
Deliberation in Multi-Stakeholder Participation: A Heuristic Framework Applied to the Committee on World Food Security
Authors: Alves Zanella Matheus , Goetz Ariane , Rist Stephan , Schmidt Oscar , Weigelt Jes
Published: February 2018

Multi-stakeholder participation (MSP) has become a central feature in several institutions and processes of global governance. Those who promote them trust that these arrangements can advance the deliberative quality of international institutions, and thereby improve the democratic quality, legitimacy and effectiveness of both the institutional landscape, as well as decisions made within it. This paper employs a heuristic framework to analyze the deliberative quality of MSP. Specifically, it applies Dryzek’s deliberative systems framework to the case of the Committee on World Food Security (CFS). The assessment shows that the CFS improves the deliberative quality of food security governance by including and facilitating the transmission of discourses from the public to the empowered spaces. However, the deliberative quality of CFS could be higher with stronger accountability mechanisms in place, more meta-deliberation and adoption of CFS outcomes at national and local levels. Reflecting on the limitations of using this heuristic framework to assess MSP, we conclude that the analysis would benefit from more explicit consideration of different forms of power that are part of the social relations between actors involved in such settings. By proposing this analytical approach, we expect to advance a heuristic framework for assessing deliberation in an international context of the growing importance of MSP in sustainability and global governance.
Sustainable Sport Scheduling Approach Considering Team Equity for the Korean Professional Baseball League
Authors: Ko Young , Jung Seung , Kim Sung , Lee Sung
Published: February 2018

Since the Korea Baseball League (KBL) had nine teams, an odd number, in the 2013 season, one team was unable to compete at certain times in the rotation while the other eight teams played games. Therefore, it was necessary to consider several elements to generate an annual match schedule in terms of team equity. However, the annual match schedule created by the conventional method could not fully reflect the elements regarding team equity, and there were a great many complaints from teams and fans. As a result, applying an optimization technique was decided upon to derive an efficient annual match schedule for the 2014 season. All the required conditions for scheduling are formulated as one or more equations and several parameter values concerning team equity are calculated with the related equations. Due to the complicated scheduling conditions, a sequential solution approach is applied by dividing the overall planning horizon in three parts. The derived annual match schedule was used for the 2014 season after some modifications, and the staff of the KBL was satisfied with the performance of the proposed scheduling methodology. Currently, this sustainable scheduling methodology is still in use to generate an efficient annual match schedule for the KBL.
Brand Equity of a Tourist Destination
Authors: Kim Hwa-Kyung , Lee Timothy
Published: February 2018

In the current climate of severe competition among tourist destinations, the importance of brand equity in tourism marketing is increasing. This study looks at the impact of branding in relation to the largest group of inbound overseas tourists to South Korea, the Chinese. Data for the current study were obtained from a survey of tourists visiting Seoul from the Greater China region, including Mainland China, Hong Kong, Macao, Taiwan, and the Chinese living in Southeast Asia. The survey was conducted in popular sightseeing spots, four and five-star hotels in the Seoul Metropolitan Area, and the Incheon International Airport. The respondents were selected randomly, with effort expended to avoid any potential bias in the composition of the sample. Out of a total of 385 distributed questionnaires, 350 (China 191, Hong Kong 71, Taiwan 68, others 20) were selected as valid and finally used in the analysis. The results of this study suggest that price and word of mouth have beneficial effects on perceived quality, publicity, and brand awareness, and advertisement has beneficial effects on brand image. We also found that brand awareness and perceived quality have impacts on brand image, and brand image is related to brand loyalty. This is a pioneering study on the relationships between influencing factors, destination brand equity and its elements, and brand loyalty, with respect to Seoul, South Korea, as a tourism destination for tourists from China.
Greenway Implementation Influence on Agricultural Heritage Sites (AHS): The Case of Liantang Village of Zengcheng District, Guangzhou City, China
Authors: Zhao Fei , Nie Rui , Zhang Jia’en
Published: February 2018

As environment-friendly recreational facilities, greenways can bring ecological, social, and economic benefits to the residents of agricultural heritage sites (AHS). Zengcheng District of Guangzhou City first implemented the recreational greenway in China in 2008. Liantang Village is the tourist center of the Liantang Spring segment of Zeng River Greenway system. This village has always been an important planting region of black olive and lychee from ancient times, with more than 1800 large old trees until today. Taking Liantang as a case, participant observations, in-depth interviews, and questionnaires (n = 140) are performed to collect relevant data. This study explores the economic and sociocultural influences of greenway implementation on AHS. Findings reveal that greenway tourism and agricultural heritage conservation form a mutually beneficial relationship. The greenway implementation successfully prompts the emergence and rapid development of tourism which significantly improves the economy of the heritage area and effectively increases the income of the villagers in AHS. The sources of their income mainly include agritainment businesses, agricultural product sales, tourist-related business wages, land leases, and house rentals. Most villagers greatly improve their quality of life because of the continuous infrastructure improvements. However, the daily lives and production orders of villagers are disturbed to some extent. The villagers have a highly sober cognition of the value of old trees, and their protection consciousness is enhanced. The difference in the source of economic income affects the judgment of the villagers, and three groups of villagers exhibit some cognitive differences with the influence of tourism. Results indicate that multi-dimensional values of agricultural heritage can be achieved, and a mutually beneficial relationship will then be formed between tourism and agricultural heritage conservation as soon as the correct eco-tourism is developed in AHS.
Cross-Scale Baroclinic Simulation of the Effect of Channel Dredging in an Estuarine Setting
Authors: Ye Fei , Zhang Yinglong , Wang Harry , Huang Hai , Wang Zhengui , Liu Zhuo , Li Xiaonan
Published: February 2018

Holistic simulation approaches are often required to assess human impacts on a river-estuary-coastal system, due to the intrinsically linked processes of contrasting spatial scales. In this paper, a Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM) is applied in quantifying the impact of a proposed hydraulic engineering project on the estuarine hydrodynamics. The project involves channel dredging and land expansion that traverse several spatial scales on an ocean-estuary-river-tributary axis. SCHISM is suitable for this undertaking due to its flexible horizontal and vertical grid design and, more importantly, its efficient high-order implicit schemes applied in both the momentum and transport calculations. These techniques and their advantages are briefly described along with the model setup. The model features a mixed horizontal grid with quadrangles following the shipping channels and triangles resolving complex geometries elsewhere. The grid resolution ranges from ~6.3 km in the coastal ocean to 15 m in the project area. Even with this kind of extreme scale contrast, the baroclinic model still runs stably and accurately at a time step of 2 min, courtesy of the implicit schemes. We highlight that the implicit transport solver alone reduces the total computational cost by 82%, as compared to its explicit counterpart. The base model is shown to be well calibrated, then it is applied in simulating the proposed project scenario. The project-induced modifications on salinity intrusion, gravitational circulation, and transient events are quantified and analyzed.
Increased healthcare utilisation among atopic children in a general practice database: a nested index-control study
Authors: Pols David HJ , Nielen Mark MJ , Bohnen Arthur M , Korevaar Joke C , Bindels Patrick JE
Published: February 2018

Background

Atopic eczema, asthma, and allergic rhinitis (AR) create a serious burden on general practice resources.

Aim

To investigate the use of general practice resources (that is, consultation visits, telephone contacts, and home visits) in children with physician-diagnosed atopic disorders (ADs).

Design & setting

In a nested index-control study design, all children (here defined as individuals aged 2–18 years) listed in a representative general practice database were selected in 2014.

Method

Children diagnosed with ADs were matched on age and sex with non-atopic controls within the same practice. For all the different groups, the number and frequency of children contacting the GP were calculated.

Results

Of the children with atopic eczema (n= 15 202), 80% consulted the GP in 2014 (controls = 67%). Of the children with asthma (n= 7754), 80% consulted the GP (controls = 65%), and for children with AR (n= 6710), this was 82% (controls = 66%). Of the children with all three ADs, 91% consulted the GP (controls = 68%). On average, a child with atopic eczema contacted the GP 2.8 times/year (controls = 1.9); for children with asthma, the contact frequency was 3.0 (controls = 1.9); and for AR, 3.2 (controls = 1.9). For children with all three ADs, the contact frequency was 4.3 (controls = 2.0). Consultations related to the ADs investigated only explain a smaller part of the increased healthcare utilisation in atopic children.

Conclusion

Atopic children use more general practice resources compared to non-atopic children, yet frequently for morbidity or other health-related questions not related to one of the ADs.
Contre-offre versus acceptation modifiée
Authors: Alonso-Pérez Maria-Teresa
Published: February 2018

Quand le destinataire d’une offre propose des modifications au contenu de la dite offre, on peut réglementer que c’est une contre-offre et qu’elle doit être acceptée par l’originaire offrant pour conclure le contrat (BGB, proposition de modification du Code civil français, -rapport Catala-). Néanmoins, on peut affirmer que l’acceptation introduisant des modifications non substantielles au contenu de l’offre émise est efficace (Proposition espagnole de modification du Code civil, art. 2 : 208 PECL, art. II. 4 : 208 : DCFR etc.). Les textes qui envisagent la possibilité de l’efficacité de l’acceptation modifiée veulent protéger les attentes du contrat que l’offre a pu susciter chez le bénéficiaire de cette dernière, en favorisant la conclusion du contrat lorsque les divergences sont insignifiantes ou accessoires. Toutefois, les réticences à porter aux dernières conséquences de cette position sont dans l’origine de l’ajout de quelques exceptions qui frustrent l’objectif.
On the Role of Dissolved Gases in the Atmosphere Retention of Low-mass Low-density Planets
Authors: Chachan Yayaati , Stevenson David J.
Published: February 2018

Low-mass low-density planets discovered by Kepler in the super-Earth mass regime typically have large radii for their inferred masses, implying the presence of H2–He atmospheres. These planets are vulnerable to atmospheric mass loss due to heating by the parent star’s XUV flux. Models coupling atmospheric mass loss with thermal evolution predicted a bimodal distribution of planetary radii, which has gained observational support. However, a key component that has been ignored in previous studies is the dissolution of these gases into the molten core of rock and iron that constitute most of their mass. Such planets have high temperatures (>2000 K) and pressures (∼kbars) at the core-envelope boundary, ensuring a molten surface and a subsurface reservoir of hydrogen that can be 5–10 times larger than the atmosphere. This study bridges this gap by coupling the thermal evolution of the planet and the mass loss of the atmosphere with the thermodynamic equilibrium between the dissolved H2 and the atmospheric H2 (Henry’s law). Dissolution in the interior allows a planet to build a larger hydrogen repository during the planet formation stage. We show that the dissolved hydrogen outgasses to buffer atmospheric mass loss. The slow cooling of the planet also leads to outgassing because solubility decreases with decreasing temperature. Dissolution of hydrogen in the interior therefore increases the atmosphere retention ability of super-Earths. The study highlights the importance of including the temperature- and pressure-dependent solubility of gases in magma oceans and coupling outgassing to planetary evolution models.
Spectra of Earth-like Planets through Geological Evolution around FGKM Stars
Authors: Rugheimer S. , Kaltenegger L.
Published: February 2018

Future observations of terrestrial exoplanet atmospheres will occur for planets at different stages of geological evolution. We expect to observe a wide variety of atmospheres and planets with alternative evolutionary paths, with some planets resembling Earth at different epochs. For an Earth-like atmospheric time trajectory, we simulate planets from the prebiotic to the current atmosphere based on geological data. We use a stellar grid F0V to M8V (

–2400 K) to model four geological epochs of Earth's history corresponding to a prebiotic world (3.9 Ga), the rise of oxygen at 2.0 Ga and at 0.8 Ga, and the modern Earth. We show the VIS–IR spectral features, with a focus on biosignatures through geological time for this grid of Sun-like host stars and the effect of clouds on their spectra. We find that the observability of biosignature gases reduces with increasing cloud cover and increases with planetary age. The observability of the visible O2 feature for lower concentrations will partly depend on clouds, which, while slightly reducing the feature, increase the overall reflectivity, and thus the detectable flux of a planet. The depth of the IR ozone feature contributes substantially to the opacity at lower oxygen concentrations, especially for the high near-UV stellar environments around F stars. Our results are a grid of model spectra for atmospheres representative of Earth's geological history to inform future observations and instrument design and are available online at http://carlsaganinstitute.org/data/.
On the Appearance of Thresholds in the Dynamical Model of Star Formation
Authors: Elmegreen Bruce G.
Published: February 2018

The Kennicutt–Schmidt (KS) relationship between the surface density of the star formation rate (SFR) and the gas surface density has three distinct power laws that may result from one model in which gas collapses at a fixed fraction of the dynamical rate. The power-law slope is 1 when the observed gas has a characteristic density for detection, 1.5 for total gas when the thickness is about constant as in the main disks of galaxies, and 2 for total gas when the thickness is regulated by self-gravity and the velocity dispersion is about constant, as in the outer parts of spirals, dwarf irregulars, and giant molecular clouds. The observed scaling of the star formation efficiency (SFR per unit CO) with the dense gas fraction (HCN/CO) is derived from the KS relationship when one tracer (HCN) is on the linear part and the other (CO) is on the 1.5 part. Observations of a threshold density or column density with a constant SFR per unit gas mass above the threshold are proposed to be selection effects, as are observations of star formation in only the dense parts of clouds. The model allows a derivation of all three KS relations using the probability distribution function of density with no thresholds for star formation. Failed galaxies and systems with sub-KS SFRs are predicted to have gas that is dominated by an equilibrium warm phase where the thermal Jeans length exceeds the Toomre length. A squared relation is predicted for molecular gas-dominated young galaxies.
Probing Episodic Accretion in Very Low Luminosity Objects
Authors: Hsieh Tien-Hao , Murillo Nadia M. , Belloche Arnaud , Hirano Naomi , Walsh Catherine , Dishoeck Ewine F. van , Lai Shih-Ping
Published: February 2018

Episodic accretion has been proposed as a solution to the long-standing luminosity problem in star formation; however, the process remains poorly understood. We present observations of line emission from N2H+ and CO isotopologues using the Atacama Large Millimeter/submillimeter Array (ALMA) in the envelopes of eight very low luminosity objects (VeLLOs). In five of the sources the spatial distribution of emission from N2H+ and CO isotopologues shows a clear anticorrelation. It is proposed that this is tracing the CO snow line in the envelopes: N2H+ emission is depleted toward the center of these sources, in contrast to the CO isotopologue emission, which exhibits a peak. The positions of the CO snow lines traced by the N2H+ emission are located at much larger radii than those calculated using the current luminosities of the central sources. This implies that these five sources have experienced a recent accretion burst because the CO snow line would have been pushed outward during the burst because of the increased luminosity of the central star. The N2H+ and CO isotopologue emission from DCE161, one of the other three sources, is most likely tracing a transition disk at a later evolutionary stage. Excluding DCE161, five out of seven sources (i.e., ∼70%) show signatures of a recent accretion burst. This fraction is larger than that of the Class 0/I sources studied by Jørgensen et al. and Frimann et al., suggesting that the interval between accretion episodes in VeLLOs is shorter than that in Class 0/I sources.
Modeling CO, CO2, and H2O Ice Abundances in the Envelopes of Young Stellar Objects in the Magellanic Clouds
Authors: Pauly Tyler , Garrod Robin T.
Published: February 2018

Massive young stellar objects (MYSOs) in the Magellanic Clouds show infrared absorption features corresponding to significant abundances of CO, CO2, and H2O ice along the line of sight, with the relative abundances of these ices differing between the Magellanic Clouds and the Milky Way. CO ice is not detected toward sources in the Small Magellanic Cloud, and upper limits put its relative abundance well below sources in the Large Magellanic Cloud and the Milky Way. We use our gas-grain chemical code MAGICKAL, with multiple grain sizes and grain temperatures, and further expand it with a treatment for increased interstellar radiation field intensity to model the elevated dust temperatures observed in the MCs. We also adjust the elemental abundances used in the chemical models, guided by observations of H ii regions in these metal-poor satellite galaxies. With a grid of models, we are able to reproduce the relative ice fractions observed in MC MYSOs, indicating that metal depletion and elevated grain temperature are important drivers of the MYSO envelope ice composition. Magellanic Cloud elemental abundances have a subgalactic C/O ratio, increasing H2O ice abundances relative to the other ices; elevated grain temperatures favor CO2 production over H2O and CO. The observed shortfall in CO in the Small Magellanic Cloud can be explained by a combination of reduced carbon abundance and increased grain temperatures. The models indicate that a large variation in radiation field strength is required to match the range of observed LMC abundances. CH3OH abundance is found to be enhanced in low-metallicity models, providing seed material for complex organic molecule formation in the Magellanic Clouds.
On the Anisotropy in the Arrival Directions of Ultra-high-energy Cosmic Rays
Authors: Wittkowski David , Kampert Karl-Heinz
Published: February 2018

We present results of elaborate four-dimensional simulations of the propagation of ultra-high-energy cosmic rays (UHECRs), which are based on a realistic astrophysical scenario. The distribution of the arrival directions of the UHECRs is found to have a pronounced dipolar anisotropy and rather weak higher-order contributions to the angular power spectrum. This finding agrees well with the recent observation of a dipolar anisotropy for UHECRs with arrival energies above

by the Pierre Auger Observatory and constitutes an important prediction for other energy ranges and higher-order angular contributions for which sufficient experimental data are not yet available. Since our astrophysical scenario enables simulations that are completely consistent with the available data, this scenario will be a very useful basis for related future studies.
Using Spin to Understand the Formation of LIGO and Virgo’s Black Holes
Authors: Farr Ben , Holz Daniel E. , Farr Will M.
Published: February 2018

With the growing number of binary black hole (BBH) mergers detected by the Advanced LIGO and Virgo detectors, it is becoming possible to constrain the properties of the underlying population and better understand the formation of these systems. Black hole (BH) spin orientations are one of the cleanest discriminators of formation history, with BHs in dynamically formed binaries in dense stellar environments expected to have spins distributed isotropically, in contrast to isolated populations where stellar evolution is expected to induce spins preferentially aligned with the orbital angular momentum. In this work, we propose a simple, model-agnostic approach to characterizing the spin properties of LIGO/Virgo’s BBH population. Using measurements of the effective spin of the binaries, we introduce a simple parameter to quantify the fraction of the population that is isotropically distributed, regardless of the spin magnitude distribution of the population. Once the orientation characteristics of the population have been determined, we show how measurements of effective spin can be used to directly constrain the BH spin magnitude distribution. We find that most effective spin measurements are too small to be informative, with the first four events showing a slight preference for a population with alignment, with an odds ratio of 1.2. We argue that it will be possible to distinguish symmetric and anti-symmetric populations at high confidence with tens of additional detections, although mixed populations may take significantly longer to disentangle. We also derive BH spin magnitude distributions from LIGO’s first four BBHs under the assumption of aligned or isotropic populations.
A New Relativistic Component of the Accretion Disk Wind in PDS 456
Authors: Reeves J. N. , Braito V. , Nardini E. , Lobban A. P. , Matzeu G. A. , Costa M. T.
Published: February 2018

Past X-ray observations of the nearby luminous quasar PDS 456 (at z = 0.184) have revealed a wide angle accretion disk wind, with an outflow velocity of ∼−0.25c. Here, we unveil a new, relativistic component of the wind through hard X-ray observations with NuSTAR and XMM-Newton, obtained in 2017 March when the quasar was in a low-flux state. This very fast wind component, with an outflow velocity of −0.46 ± 0.02c, is detected in the iron K band, in addition to the −0.25c wind zone. The relativistic component may arise from the innermost disk wind, launched from close to the black hole at a radius of ∼10 gravitational radii. The opacity of the fast wind also increases during a possible obscuration event lasting for 50 ks. We suggest that the very fast wind may only be apparent during the lowest X-ray flux states of PDS 456, becoming overly ionized as the luminosity increases. Overall, the total wind power may even approach the Eddington value.
Fishburguers de tilapia-do-nilo (Oreochromis niloticus) com e sem adição de fumaça líquida
Authors: Vaz Duarte Christiane , Porto Vieira Rafael , Marcolino Gherardi Sandra Regina
Published: February 2018

Objetivou-se elaborar duas formulações de fishburguer a base de filé de tilápia-do-nilo (Oreochromis niloticus) com e sem adição de fumaça líquida. As tilápias foram obtidas do Setor de Piscicultura do IF Goiano e, após o abate, foram filetadas manualmente, sendo os filés pesados (com pele) e congelados. Para a elaboração dos fishburguers, os filés foram descongelados e moídos sem pele. Os ingredientes das duas formulações foram pesados e misturados manualmente, sendo os fishburguers moldados em uma modeladora de hamburguers, embalados em sacos de polietileno e posteriormente congelados. As determinações físico-químicas foram realizadas em triplicata, onde se analisou: umidade, pH, proteína, cinzas e lipídeos. Também foram realizadas as análises para presença de estafilococos coagulase-positiva, coliformes a 45 °C e Salmonella spp. O rendimento dos filés foi de 25,5 %. As análises físico-químicas resultaram nos seguintes valores para a formulação A (com adição de fumaça líquida) e B (sem adição de fumaça líquida), respectivamente: umidade: 60,5 e 62,9 %; pH: 6,1 e 6,4; proteína: 51,3 e 49,0 %; cinzas: 3,5 e 3,4 % e lipídeos 3,9 e3,7%. Os resultados microbiológicos não estavam em conformidade com os limites previstos pela RDC nº 12 de 01 de janeiro de 2001, do Ministério da Saúde, não sendo possível a realização de análise sensorial dos fishburguers, ainda assim, o produto obtido foi considerado um potencial tecnológico da carne de tilápia para a elaboração de produtos, em particular o fishburguer.
Desperdício de alimentos em um restaurante comercial de Salvador (BA): características, avaliação e intervenção sobre as principais causas
Authors: González Adrian Rui Angela , Bezerra Priscilla Quênia Muniz Bezerra , Matos Márcia Filgueiras Rebelo de
Published: February 2018

O controle de sobras avalia a adequação da quantidade preparada em relação às necessidades, à porção distribuída e à aceitação do cardápio. O objetivo do estudo foi avaliar o desperdício de alimentos de uma UAN localizada em um shopping center de Salvador (BA). Para isso, a coleta dos dados foi dividida em duas etapas, pesando-se os alimentos produzidos, as sobras do balcão de distribuição e as sobras limpas, realizando-se intervenção após a primeira etapa. Verificou-se que a unidade estudada atende durante o almoço, em média, 136 comensais/dia. Na primeira etapa, a média de sobras da unidade foi de 28,4%, sendo 18,1% sobra limpa e 10,3% sobra suja. Após a intervenção, percebeu-se uma redução considerável, de acordo com o que foi produzido na média de sobras da unidade (20,2%), sendo 14,8% sobra limpa e 5,4% sobra suja, ratificando o melhor gerenciamento e controle de produção após intervenção. Sugere-se a realização de intervenções continuadas pela unidade, estabelecendo metas e incentivos para melhor gerenciar os recursos.
Narrativas, políticas y resultados del desarrollo alternativo en la región andina
Authors: Campodónico Humberto , Carbonnier Gilles , Tezanos Vázquez Sergio
Published: February 2018

Desde principios del 2000, muchos países latinoamericanos alcanzaron un notable crecimiento económico acompañado de la reducción de la pobreza y la desigualdad, debido en gran parte a la persistente aplicación del patrón secular de exportación de materias primas. El fin del superciclo de los precios de los las materias primas en 2014 puso en riesgo algunas de estas ganancias en materia de desarrollo, lo que aumentó la ansiedad entre las clases medias emergentes, temerosas de regresar a la pobreza. Los líderes de América Latina, basándose en un rico legado intelectual, han diseñado enfoques novedosos en la búsqueda del desarrollo sostenible. Las narrativas sobre desarrollo alternativo presentadas por los gobiernos de izquierda han puesto énfasis en nociones como el «buen vivir», posiblemente la propuesta más influyente y revolucionaria originada en la región desde las diferentes variantes de la teoría de la dependencia. Menos claro es hasta qué punto las ideologías y las narrativas en competencia se han traducido en resultados divergentes, ya sea respecto al (neo)extractivismo, la sostenibilidad ecológica o los derechos y la identidad cultural de los pueblos indígenas, o sencillamente en términos de diversificación económica. Este capítulo introduce el número temático de International Development Policy que aborda las innovaciones paradigmáticas y las experiencias de desarrollo recientes en América Latina, con un interés particular en la región andina.