bluuebunny/crossref_metadata_2025 huggingface dataset:
Swimming behavior of crucian carp in an open channel with sudden expansion
Authors: Zha Wei , Huang Minghai , Zeng Yuhong
Published: July 2019

The sudden‐expansion effect created by natural and man‐made structures such as unsubmerged boulders, spur dikes, and culvert structures is common in open channels. Migratory fishes may use the heterogeneous flow generated by sudden expansion to their benefit, to select habitats for balancing energy expenditure or for maximizing predation opportunities. This study explores the swimming behavior of three size classes of crucian carp in response to hydrodynamic characteristics in an experimental open channel with sudden expansion. The flow field was characterized using particle image velocimetry (PIV) measurements and featured a recirculation zone in the vicinity of the expansion. Based on the classification of the swimming trajectory, four specific swimming behaviours (SSBs) were utilized by crucian carp during migration. With increasing flow velocity, fish spent more time in the recirculation zone. Residence time in the recirculation zone was inversely correlated with fish body length. Due to the advantage in providing shelter from challenging heterogeneous hydraulic conditions, the recirculation zone was preferred by crucian carp, especially the smaller ones, indicating the importance of energy conservation in habitat occupation. These findings confirm that the recirculation zone generated by sudden expansion may be beneficial to the upstream passage of fish and in habitat restoration.
A sparse Gaussian sigmoid basis function approximation of hyperspectral data for detection of solids
Authors: Lanker Cory , Smith Milton O.
Published: July 2019

We define a new characterization of emissivity and reflectance curves for compositional exploitation of hyperspectral data. Our method decomposes each spectrum into a sparse set of Gaussian sigmoid components using penalized regression. Detection is based on the combination of Gaussian sigmoid components unique to a target material. Focusing on the presence of spectral upslopes and downslopes rather than spectral correlations makes detection more robust to both target variation and spectral variability from atmosphere and background encountered during the collection process. We present simulation studies that demonstrate the potential to reduce false positive rates without compromising sensitivity. Characterization of long‐wave infrared (LWIR) experimental data validates our method using minerals of different particle sizes, measurement angles, and collection conditions.
ZnS/C/MoS2 Nanocomposite Derived from Metal–Organic Framework for High‐Performance Photo‐Electrochemical Immunosensing of Carcinoembryonic Antigen
Authors: Wei Qiuxi , Wang Chen , Li Ping , Wu Tsunghsueh , Yang Nianjun , Wang Xing , Wang Yanying , Li Chunya
Published: July 2019

A hexafluorophosphate ionic liquid is used as a functional monomer to prepare a metal–organic framework (Zn‐MOF). Zn‐MOF is used as a template for MoS2 nanosheets synthesis and further carbonized to yield light‐responsive ZnS/C/MoS2 nanocomposites. Zn‐MOF, carbonized‐Zn‐MOF, and ZnS/C/MoS2 nanocomposites are characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, X‐ray diffraction pattern, scanning electron microscopy (SEM), element mapping, Raman spectroscopy, X‐ray photoelectron spectroscopy, fluorescence, and nitrogen‐adsorption analysis. Carcinoembryonic antigen (CEA) is selected as a model to construct an immunosensing platform to evaluate the photo‐electrochemical (PEC) performances of ZnS/C/MoS2 nanocomposites. A sandwich‐type PEC immunosensor is fabricated by immobilizing CEA antibody (Ab1) onto the ZnS/C/MoS2/GCE surface, subsequently binding CEA and the alkaline phosphatase‐gold nanoparticle labeled CEA antibody (ALP‐Au‐Ab2). The catalytic conversion of vitamin C magnesium phosphate produces ascorbic acid (AA). Upon being illuminated, AA can react with photogenerated holes from ZnS/C/MoS2 nanocomposites to generate a photocurrent for quantitative assay. Under optimized experimental conditions, the PEC immunosensor exhibits excellent analytical characteristics with a linear range from 2.0 pg mL−1 to 10.0 ng mL−1 and a detection limit of 1.30 pg mL−1 (S/N = 3). The outstanding practicability of this PEC immunosensor is demonstrated by accurate assaying of CEA in clinical serum samples.
A physiological data‐driven model for learners' cognitive load detection using HRV‐PRV feature fusion and optimized XGBoost classification
Authors: Guo Junqi , Dai Yazhu , Wang Chixiang , Wu Hao , Xu Tianyou , Lin Kai
Published: July 2019

Due to the increasing attention to online learning, cognitive load has been recently considered as a crucial indicator for judging teenagers' learning state so as to improve both learning and teaching effects. However, some traditional cognitive load measurement methods such as subjective measurement are easily influenced by subjective sensation deviation of subjects. None of them can reflect the cognitive load of learners more precisely. Recently, machine learning–based data modeling has gained more importance in the scenarios of various smart wearables and Internet of things applications. Meanwhile, physiological signals have proven to contribute much to human health assessment. On the basis of the above considerations, this paper proposes a physiological data‐driven model for learners' cognitive load detection under the application of smart wearables. The model consists of four modules: physiological signal acquisition, signal preprocessing, heart rate variability and pulse rate variability feature fusion, and cognitive load classification through an optimized extreme gradient boosting classifier in which hyperparameters are adaptively tuned with sequential model–based optimization. Furthermore, we design an experimental paradigm for signal acquisition in a learning environment, and the experimental results demonstrate that the proposed model for cognitive load detection outperforms conventional approaches that only employ either heart rate variability or pulse rate variability for modeling. We also compare the effects of different feature fusion algorithms combined with different classification algorithms, which demonstrates that the proposed model achieves the highest accuracy of cognitive load detection due to its optimal combination of feature fusion and classification.
Internationalization of services: The case of intra‐multinational enterprise trade
Authors: Rao P. M. , Vinod Hrishikesh D.
Published: July 2019

Increased tradability of services, made possible by the information and communications technology (ICT) revolution, has been at the heart of the internationalization of services. Although rapid growth of the services trade between parents of multinational enterprises (MNEs) and their overseas subsidiaries has contributed to the internationalization of services, empirical studies examining the determinants of intra‐MNE trade in services are few. This article, using the ownership, location, and internalization (OLI) framework, attempts to explain intra‐MNE trade in services. The results provide strong support for the OLI perspective, and posit a complementary relationship between manufacturing foreign direct investment and intra‐MNE services trade. The results also suggest the importance of subsidiaries' absorptive capacity and breadth of global connectedness for intra‐MNE trade.
Cross‐country study on food consumption patterns and rice away from home: The case of Bangladesh
Authors: Hassan Nazmul , Md. Irfan Nafis , Roy Sanjit , Shaheen Nazma
Published: July 2019

As with most Asian countries, rice dominates Bangladesh in terms of food production and consumption. However, with sustained increase in income, persistent commendable GDP growth, urbanization, and significant reduction in poverty, people tend to consume more diversified food, ready to eat food, and food away from home. The findings from this study, based on data from Bangladesh Bureau of Statistics, lend support to this consumption propensity and indicate that with time rice is becoming cheaper and animal and plant foods are getting dearer and expensive. This implies that the national agricultural policy of Bangladesh must recast to match the future food demand of people and to meet the increasing challenge of reversing the rising prices of non‐staples including animal foods. Nested studies on “rice and food away from home” and estimation of demand elasticity and formulation of food demand equations to determine dietary choices and to find nutritional implications of movements in relative food prices and other exogenous variables, to this effect, will have important policy implications for Bangladesh agriculture–food and health paradigm.
Doubling farmer's income: The case of India
Authors: Singh Rohit
Published: July 2019

Agriculture, in most of the developing and under‐developed countries, is the primary sector responsible for employment and livelihood of the majority of population, especially rural. This sector is entrusted with the responsibility of poverty alleviation in rural areas and contribution to overall economic growth. Hence, designing optimal policy and setting objectives have always been a concern area for the policy‐makers. In the last fiscal year, policy objective of doubling farmer income by the year 2022 was announced by the government. This paper analyzes the historical aspects of doubling of farmer's income using the National Sample Survey Office's situation assessment survey and draws projection for the future at degenerate level across land holding and states. This paper reviews the optimal mix of policies that should be adopted by the government to successful double the farmer’s income. The paper also presents a comparative analysis with such policy objective being successfully achieved in Chinese economy.
On scalaron decay via the trace of energy-momentum tensor
Authors: Kamada Ayuki
Published: July 2019

Abstract

In some inflation scenarios such as R
2 inflation, a gravitational scalar degrees of freedom called scalaron is identified as inflaton. Scalaron linearly couples to matter via the trace of energy-momentum tensor. We study scenarios with a sequestered matter sector, where the trace of energy-momentum tensor predominantly determines the scalaron coupling to matter. In a sequestered setup, heavy degrees of freedom are expected to decouple from low-energy dynamics. On the other hand, it is non-trivial to see the decoupling since scalaron couples to a mass term of heavy degrees of freedom. Actually, when heavy degrees of freedom carry some gauge charge, the amplitude of scalaron decay to two gauge bosons does not vanish in the heavy mass limit. Here a quantum contribution to the trace of energy-momentum tensor plays an essential role. This quantum contribution is known as trace anomaly or Weyl anomaly. The trace anomaly contribution from heavy degrees of freedom cancels with the contribution from the classical scalaron coupling to a mass term of heavy degrees of freedom. We see how trace anomaly appears both in the Fujikawa method and in dimensional renormalization. In dimensional renormalization, one can evaluate the scalaron decay amplitude in principle at all orders, while it is unclear how to process it beyond the one-loop level in the Fujikawa method. We consider scalaron decay to two gauge bosons via the trace of energy-momentum tensor in quantum electrodynamics with scalars and fermions. We evaluate the decay amplitude at the leading order to demonstrate the decoupling of heavy degrees of freedom.
Effect of glochidia infection on growth of fish: freshwater pearl mussel Margaritifera margaritifera and brown trout Salmo trutta
Authors: Chowdhury M. Motiur R. , Marjomäki Timo J. , Taskinen Jouni
Published: July 2019

Effect of freshwater mussels’ (Unionoida) glochidia on the growth of fish host has remained poorly studied. We compared the specific growth rate of the juvenile, PIT-marked brown trout (Salmo trutta) between uninfected controls to those experimentally infected (average initial intensity of infection 8000 fish−1) withMargaritifera margaritiferaglochidia, kept in high and low feeding. Growth and mortality of fish were monitored for 10 months. Our hypothesis was that glochidiosis would impair the growth of fish. According to our hypothesis, infected fish gained statistically significantly less weight than the control fish throughout the experiment. A proportional increase in weight of control individuals was 11% higher than that of the infected fish. However, neither the feeding regime (high, low) nor the period (September–November, November–March, March–May), had a significant effect on the growth difference between control and infected fish. As the effect of infection on the growth of fish was subtle and no effect on host mortality was detected either, this may turn public opinion favorable forM. margaritiferaconservation even if the salmonid host population is important for commercial or recreational fishing.
Assessment of executive function in bilingual adults with history of mild traumatic brain injury
Authors: Ratiu Ileana , Azuma Tamiko
Published: July 2019

Background and objective:

Adults with a history of traumatic brain injury (TBI) often show deficits in executive function (EF), including the ability to inhibit, switch, and attend to task relevant information. Although performances differences between bilinguals and monolinguals have been observed in EF tasks, there is little research on the effect of TBI on EF in bilinguals. In this study, an ecologically valid standardized measure and experimental computerized tasks of EF were administered to Spanish-English bilingual adults with and without history of mild traumatic brain injury (mTBI).

Method:

Twenty-two bilinguals with a history of mTBI [mean age=20.1 years, SD=3.7; education=13.4 years, SD=0.7] and 20 control bilinguals [mean age=20.8 years, SD=3.6; education=13.7 years, SD=1.1], matched for age and education, completed language proficiency questionnaires, the Functional Assessment of Verbal Reasoning and Executive Strategies (FAVRES), English and Spanish language assessments, and a Flanker task (a test of inhibition).

Results:

Performance was analyzed using analyses of covariance. The results revealed that bilinguals with a history of mTBI performed worse on both the standardized assessment (FAVRES) and inhibition task. Interestingly, self-reported EF deficits were consistent with performance on these measures.

Conclusion:

The findings of this study provide useful information regarding assessment of EF deficits in bilinguals with a history mTBI. Computerized experimental tasks of EF may also prove useful in the assessment of EF in individuals with mTBI.
How is quality of cardiopulmonary resuscitation being assessed? A national survey of Canadian emergency medicine physicians
Authors: Wright Natasha , Lin Yiqun , Cheng Adam
Published: July 2019

Background

High-quality cardiopulmonary resuscitation (CPR) is a fundamental intervention for cardiac arrest, yet health care providers rarely adhere to recommended guidelines. Real-time feedback improves CPR performance. It is currently unknown how Canadian emergency physicians assess CPR quality during cardiac arrest and if they use feedback devices. Our aim was to describe how emergency physicians assess CPR quality and to describe eventual barriers to implementation of feedback technology.

Methods

This was a cross-sectional survey that was distributed to attending and resident emergency physicians through the Canadian Association of Emergency Physicians. Responses were summarized and analyzed using descriptive statistics.

Results

The response rate was 19% (323/1735). Visual observation was the most common method of assessing CPR quality (41.2%), with leaders standing at the foot of the bed (67.4%). This was followed by real-time pulse check (29.7%) and end-tidal CO2 values (21.7%). Only 12% of physicians utilized CPR feedback technology. The most common perceived barrier to utilization was unavailability, inexperience with devices and lack of guidelines/evidence for their use.

Conclusion

Most Canadian emergency physicians that responded to our survey, assess quality of CPR by standing at the foot of the bed and utilize visual observation and palpation methods which are known to be inaccurate. A minority utilize objective measurements such as ETCO2 or feedback devices, with the greatest barrier being lack of availability.
Designing for Accelerated Translation (DART) of emerging innovations in health
Authors: Ramsey Alex T. , Proctor Enola K. , Chambers David A. , Garbutt Jane M. , Malone Sara , Powderly William G. , Bierut Laura J.
Published: July 2019

Accelerating innovation translation is a priority for improving healthcare and health. Although dissemination and implementation (D&I) research has made significant advances over the past decade, it has attended primarily to the implementation of long-standing, well-established practices and policies. We present a conceptual architecture for speeding translation of promising innovations as candidates for iterative testing in practice. Our framework to Design for Accelerated Translation (DART) aims to clarify whether, when, and how to act on evolving evidence to improve healthcare. We view translation of evidence to practice as a dynamic process and argue that much evidence can be acted upon even when uncertainty is moderately high, recognizing that this evidence is evolving and subject to frequent reevaluation. The DART framework proposes that additional factors – demand, risk, and cost, in addition to the evolving evidence base – should influence the pace of translation over time. Attention to these underemphasized factors may lead to more dynamic decision-making about whether or not to adopt an emerging innovation or de-implement a suboptimal intervention. Finally, the DART framework outlines key actions that will speed movement from evidence to practice, including forming meaningful stakeholder partnerships, designing innovations for D&I, and engaging in a learning health system.
TheN-star network evolution model
Authors: Fazekas István , Noszály Csaba , Perecsényi Attila
Published: July 2019

A new network evolution model is introduced in this paper. The model is based on cooperations ofNunits. The units are the nodes of the network and the cooperations are indicated by directed links. At each evolution stepNunits cooperate, which formally means that they form a directedN-star subgraph. At each step either a new unit joins the network and it cooperates withN− 1 old units, orNold units cooperate. During the evolution both preferential attachment and uniform choice are applied. Asymptotic power law distributions are obtained both for in-degrees and for out-degrees.
Comparison results for M/G/1 queues with waiting and sojourn time deadlines
Authors: Inoue Yoshiaki
Published: July 2019

This paper considers two variants of M/G/1 queues with impatient customers, which are denoted by M/G/1+Gw and M/G/1+Gs. In the M/G/1+Gw queue customers have deadlines for their waiting times, and they leave the system immediately if their services do not start before the expiration of their deadlines. On the other hand, in the M/G/1+Gs queue customers have deadlines for their sojourn times, where customers in service also immediately leave the system when their deadlines expire. In this paper we derive comparison results for performance measures of these models. In particular, we show that if the service time distribution is new better than used in expectation, then the loss probability in the M/G/1+Gs queue is greater than that in the M/G/1+Gw queue.
On the rate of convergence for the length of the longest common subsequences in hidden Markov models
Authors: Houdré C. , Kerchev G.
Published: July 2019

Let (X, Y) = (Xn, Yn)n≥1 be the output process generated by a hidden chain Z = (Zn)n≥1, where Z is a finite-state, aperiodic, time homogeneous, and irreducible Markov chain. Let LCn be the length of the longest common subsequences of X1,..., Xn and Y1,..., Yn. Under a mixing hypothesis, a rate of convergence result is obtained for E[LCn]/n.
First passage percolation on sparse random graphs with boundary weights
Authors: Leskelä Lasse , Ngo Hoa
Published: July 2019

A large and sparse random graph with independent exponentially distributed link weights can be used to model the propagation of messages or diseases in a network with an unknown connectivity structure. In this article we study an extended setting where, in addition, the nodes of the graph are equipped with nonnegative random weights which are used to model the effect of boundary delays across paths in the network. Our main results provide approximative formulas for typical first passage times, typical flooding times, and maximum flooding times in the extended setting, over a time scale logarithmic with respect to the network size.
The De Vylder–Goovaerts conjecture holds within the diffusion limit
Authors: Ankirchner Stefan , Blanchet-Scalliet Christophette , Kazi-Tani Nabil
Published: July 2019

The De Vylder and Goovaerts conjecture is an open problem in risk theory, stating that the finite-time ruin probability in a standard risk model is greater than or equal to the corresponding ruin probability evaluated in an associated model with equalized claim amounts. Equalized means here that the jump sizes of the associated model are equal to the average jump in the initial model between 0 and a terminal time T.In this paper, we consider the diffusion approximations of both the standard risk model and its associated risk model. We prove that the associated model, when conveniently renormalized, converges in distribution to a Gaussian process satisfying a simple SDE. We then compute the probability that this diffusion hits the level 0 before time T and compare it with the same probability for the diffusion approximation for the standard risk model. We conclude that the De Vylder and Goovaerts conjecture holds for the diffusion limits.
A martingale view of Blackwell’s renewal theorem and its extensions to a general counting process
Authors: Daley Daryl J. , Miyazawa Masakiyo
Published: July 2019

Martingales constitute a basic tool in stochastic analysis; this paper considers their application to counting processes. We use this tool to revisit a renewal theorem and give extensions for various counting processes. We first consider a renewal process as a pilot example, deriving a new semimartingale representation that differs from the standard decomposition via the stochastic intensity function. We then revisit Blackwell’s renewal theorem, its refinements and extensions. Based on these observations, we extend the semimartingale representation to a general counting process, and give conditions under which asymptotic behaviour similar to Blackwell’s renewal theorem holds.
On association and other forms of positive dependence for Feller processes
Authors: Tu Eddie
Published: July 2019

We characterize various forms of positive dependence, such as association, positive supermodular association and dependence, and positive orthant dependence, for jump-Feller processes. Such jump processes can be studied through their state-space dependent Lévy measures. It is through these Lévy measures that we will provide our characterization. Finally, we present applications of these results to stochastically monotone Feller processes, including Lévy processes, the Ornstein–Uhlenbeck process, pseudo-Poisson processes, and subordinated Feller processes.
The limit distribution of the maximum probability nearest-neighbour ball
Authors: Györfi László , Henze Norbert , Walk Harro
Published: July 2019

Let X1, …, Xn be independent random points drawn from an absolutely continuous probability measure with density f in ℝd. Under mild conditions on f, wederive a Poisson limit theorem for the number of large probability nearest-neighbour balls. Denoting by Pn the maximum probability measure of nearest-neighbour balls, this limit theorem implies a Gumbel extreme value distribution for nPn − ln n as n → ∞. Moreover, we derive a tight upper bound on the upper tail of the distribution of nPn − ln n, which does not depend on f.
MicroRNAs in acquired sensorineural hearing loss
Authors: Chen H H R , Wijesinghe P , Nunez D A
Published: July 2019

Objective

This review summarises the current literature on the role of microRNAs in presbyacusis (age-related hearing loss) and sudden sensorineural hearing loss.

Methods

Medline, PubMed, Web of Science and Embase databases were searched for primary English-language studies, published between 2000 and 2017, which investigated the role of microRNAs in the pathogenesis of presbyacusis or sudden sensorineural hearing loss. Quality of evidence was assessed using the National Institutes of Health quality assessment tool.

Results

Nine of 207 identified articles, 6 of good quality, satisfied the review's inclusion criteria. In presbyacusis, microRNAs in pro-apoptotic and autophagy pathways are upregulated, while microRNAs in proliferative and differentiation pathways are downregulated. Evidence for microRNAs having an aetiological role in sudden hearing loss is limited.

Conclusion

A shift in microRNA expression, leading to reduced cellular activity and impaired inner-ear homeostasis, may contribute to the pathogenesis of presbyacusis.
Testing the deficient processing account of the spacing effect in second language vocabulary learning: Evidence from eye tracking
Authors: Koval Natalie G.
Published: July 2019

The spacing effect refers to the learning benefit that comes from separating repeated study of target items by time or by other items. A prominent proposed explanation for this effect states that repeated exposures that occur closely together may not engage full attentional processing due to residual activation of the previous exposure and also, in an intentional learning context, due to a sense of familiarity that may result in strategic allocation of less study time to an item in massed repetitions. The present study used eye-tracking methodology to investigate the effects of temporal distribution of repeated exposures to novel second language words on attentional processing and learning of these words under intentional learning instructions. Adult native speakers of English read Finnish words embedded in English sentence contexts under massed and spaced conditions. The results showed that (a) massed repeated exposures received less attentional processing than spaced repeated exposures; (b) target words were better remembered in the spaced condition; and (c) attention was a significant mediator of the obtained spacing effect, in line with the predictions of the deficient processing account of the spacing effect. Implications for vocabulary learning are discussed.
Facilitating contemporary music in projects in schools – a qualitative study in Germany
Authors: Wieneke Julia
Published: July 2019

Since the late nineties, composition projects inviting artists and contemporary composers into schools and communities became more established and written about in German speaking countries (see for instance Henze, 1998; Schneider, Bösze & Stangl, 2000; Schneider, 2000; Schatt, 2009; Schlothfeldt, 2009; Schneider, 2012). Additionally, music education researchers have provided theoretical and didactical analysis of contemporary music teaching and learning in schools (Winkler, 2002; Weber, 2003). In this qualitative study, expert interviews were analysed using Grounded Theory Methodology to investigate structures and processes of current practises in collaborative composition projects. Apart from illustrating the seven structural factors and three main project sections that emerged, the article also discusses the main categoryfostering creative processes.
Caractéristiques environnementales favorisant la participation sociale: une enquête auprès d’aînés québécois
Authors: Naud Daniel , Hamel Mélanie , Caron Mélyna , Cardin Virginie , Roux Marie-Hélène D. , Levasseur Mélanie
Published: July 2019

We document and compare the environmental characteristics potentially associated with social participation of older Quebecers, according to the level of rurality. A survey was carried out among older Quebecers aged 65 and over recruited by different senior groups and through social media. The Questionnaire their potential for social participation, developed from a systematic literature review, was completed by respondents. According to the 515 older participants, 71.5 years old on average, environmental characteristics linked to social participation, as well as user-friendliness of the city and neighborhood, are more favorably perceived in metropolitan and urban areas than rural areas. However, access to public transportation and the welcoming and openness of local residents are more appreciated by rural respondents. These results support the presence of inequalities in social participation according to level of rurality and offer some leads for action.
Strain variations in cone wavelength peaksin situduring zebrafish development
Authors: Nelson Ralph F. , Balraj Annika , Suresh Tara , Torvund Meaghan , Patterson Sara S.
Published: July 2019

There are four cone morphologies in zebrafish, corresponding to UV (U), blue (B), green (G), and red (R)-sensing types; yet genetically, eight cone opsins are expressed. How eight opsins are physiologically siloed in four cone types is not well understood, and in larvae, cone physiological spectral peaks are unstudied. We use a spectral model to infer cone wavelength peaks, semisaturation irradiances, and saturation amplitudes from electroretinogram (ERG) datasets composed of multi-wavelength, multi-irradiance, aspartate-isolated, cone-PIII signals, as compiled from many 5- to 12-day larvae and 8- to 18-month-old adult eyes isolated from wild-type (WT) orroy orbison(roy) strains. Analysis suggests (in nm) a seven-cone, U-360/B1-427/B2-440/G1-460/G3-476/R1-575/R2-556, spectral physiology in WT larvae but a six-cone, U-349/B1-414/G3-483/G4-495/R1-572/R2-556, structure in WT adults. In roy larvae, there is a five-cone structure: U-373/B2-440/G1-460/R1-575/R2-556; in roy adults, there is a four-cone structure, B1-410/G3-482/R1-571/R2-556. Existence of multiple B, G, and R types is inferred from shifts in peaks with red or blue backgrounds. Cones were either high or low semisaturation types. The more sensitive, low semisaturation types included U, B1, and G1 cones [3.0–3.6 log(quanta·μm−2·s−1)]. The less sensitive, high semisaturation types were B2, G3, G4, R1, and R2 types [4.3-4.7 log(quanta·μm−2·s−1)]. In both WT and roy, U- and B- cone saturation amplitudes were greater in larvae than in adults, while G-cone saturation levels were greater in adults. R-cone saturation amplitudes were the largest (50–60% of maximal dataset amplitudes) and constant throughout development. WT and roy larvae differed in cone signal levels, with lesser UV- and greater G-cone amplitudes occurring in roy, indicating strain variation in physiological development of cone signals. These physiological measures of cone types suggest chromatic processing in zebrafish involves at least four to seven spectral signal processing pools.
Beyond Moral Efficiency: Effective Altruism and Theorizing about Effectiveness
Authors: Zuolo Federico
Published: July 2019

In this article I provide a conceptual analysis of an underexplored issue in the debate about effective altruism: its theory of effectiveness. First, I distinguish effectiveness from efficiency and claim that effective altruism understands effectiveness through the lens of efficiency. Then, I discuss the limitations of this approach in particular with respect to the charge that it is incapable of supporting structural change. Finally, I propose an expansion of the notion of effectiveness of effective altruism by referring to the debate in political philosophy about realism and the practical challenge of normative theories. I argue that effective altruism, both as a social movement and as a conceptual paradigm, would benefit from clarifying its ideal, taking into account the role of institutions, and expanding its idea of feasibility.
Dry permafrost over ice-cemented ground at Elephant Head, Ellsworth Land, Antarctica
Authors: McKay Christopher P. , Balaban Edward , Abrahams Simon , Lewis Nick
Published: July 2019

Dry permafrost - ground with temperature always below 0°C and containing negligible ice - overlying ice-cemented ground has been reported in the Dry Valleys of Antarctica and on Mars. Here we report on a new site (79°49.213'S, 83°18.860'W, 718 m elevation) located on the side of Mount Dolence in Ellsworth Land, Antarctica. Year-round temperature and humidity measurements indicate that dry permafrost is present between depths of 13.5 and 49.0 cm - the location of ice-cemented ground. The mean annual frost point of the ice-cemented ground is -17.0 ± 0.2°C and the mean annual frost point of the atmosphere is -22.7 ± 1°C. The corresponding mean annual temperatures are -19.2°C and -20.3°C. Neither the temperature of the ice-cemented ground nor the air rise above freezing. Both the dry permafrost and the ice table may be habitable. In the dry soil at 3 cm depth there are 80 hours in the summer when temperature exceeds -5°C and water activity exceeds 0.8. At the ice table, temperature exceeds -10°C and water activity exceeds 0.8 for 35 hours in the year. The ice table and the dry permafrost above it would be considered a ‘Special Region’ on Mars. Further microbial investigation of this site is indicated.
The Effect of Binding Commitments on Services Trade
Authors: Ciuriak Dan , Dadkhah Ali , Lysenko Dmitry
Published: July 2019

It has long been established in theory that uncertainty impacts on firm behaviour. However, the empirical basis for quantifying the uncertainty-reducing effects of trade agreements has not been firmly established. In this paper, we develop estimates of the effect of reducing uncertainty regarding regulation of foreign services markets by making commitments that are bound under a trade agreement. Specifically, we identify the effect on services trade of services trade restrictions, as measured by the OECD's Services Trade Restrictiveness Index (STRI), and the separate effect of ‘water’ in binding commitments, as assessed by the difference between countries’ commitments under the General Agreement on Trade in Services (GATS) or free trade agreements (FTAs) and applied levels of market access, as captured by STRI scores. Using a gravity model, we find that services trade responds positively but inelastically to reductions in services trade barriers, as measured by the STRI and, in our preferred regression, the response to actual restrictions is more than twice – specifically 2.4 times – as strong as the response to comparable reductions in uncertainty, as measured by water. Moving from GATS commitments to FTA commitments leads to a 4.7% increase in services trade because of the reduction in uncertainty.
Hydrographic and Biological Survey of a Surface‐Intensified Anticyclonic Eddy in the Caribbean Sea
Authors: van der Boog C. G. , de Jong M. F. , Scheidat M. , Leopold M. F. , Geelhoed S. C. V. , Schulz K. , Dijkstra H. A. , Pietrzak J. D. , Katsman C. A.
Published: July 2019

In the Caribbean Sea, mesoscale anticyclonic ocean eddies impact the local ecosystem by mixing of low salinity river outflow with the nutrient‐rich waters upwelling along the Venezuelan and Colombian coast. To gain insight into the physics and the ecological impact of these anticyclones, we performed a combined hydrographic and biological survey of one Caribbean anticyclone in February 2018. We found that the anticyclone had a radius of 90 km and was surface intensified with the strongest velocities (0.72 m/s) in the upper 150 m of the water column. Below, isopycnal displacements were found down to 700 dbar. The core of the anticyclone entrained waters from the Orinoco River plume and contained slightly elevated chlorophyll concentrations compared to the surroundings. At the edge of the anticyclone we observed higher densities of flying fish but not higher densities of predators like seabirds and cetaceans. Below the surface, a strong temperature inversion (0.98 °C) was present within a barrier layer. In addition, we found thermohaline staircases that originated from double diffusion processes within Tropical Atlantic Central Water.
High Thermal Inertia Zones on Ceres From Dawn Data
Authors: Rognini E. , Capria M. T. , Tosi F. , De Sanctis M. C. , Ciarniello M. , Longobardo A. , Carrozzo F. G. , Raponi A. , Frigeri A. , Palomba E. , Fonte S. , Giardino M. , Ammannito E. , Raymond C. A. , Russell C. T.
Published: July 2019

Thermal inertia is a key information to quantify the physical status of a planetary surface. We derive the thermal inertia of the surface of Ceres using spatially resolved data from the Dawn mission. For each location, this quantity can be constrained by comparing theoretical and observed diurnal temperature profiles from retrieved temperatures. We calculated Ceres's surface theoretical temperatures with a thermophysical model that provides temperature as a function of thermal conductivity and roughness, and we determined the values of those parameters for which the best fit with the observed data is obtained. Our results suggest that the area of crater Haulani displays thermal inertia values (up to 130–140 J·m−2·s−½·K−1) substantially higher than the very low to low values (from 1–15 to 50–60 J·m−2·s−½·K−1) derived for the overall surface of Ceres. The results are more ambiguous for the bright faculae located in the floor of crater Occator.
A New Planetary Boundary Layer Scheme Based on LES: Application to the XPIA Campaign
Authors: Senel Cem Berk , Temel Orkun , Porchetta Sara , Muñoz‐Esparza Domingo , van Beeck Jeroen
Published: July 2019

We present a new planetary boundary layer scheme based on large‐eddy simulations for different atmospheric stability classes. Large‐eddy simulations results are compared with the wind speed measurements from the meteorological mast at the Test Centre for Large Wind Turbines at Høvsøre, Denmark. A generic formulation for the determination of mixing length scale is proposed and incorporated with the updated closure coefficients derived under realizability constraints by Temel et al. (2018, https://doi.org/10.1016/j.jweia.2018.01.002). The new planetary boundary layer scheme is implemented into the Weather Research and Forecasting model to perform mesoscale simulations for the Høvsøre test site as an idealized case as well as for a real‐data case at the eXperimental Planetary boundary layer Instrumentation Assessment campaign. Results of the idealized case reveal that the proposed scheme, VKI01, well represents the potential temperature and wind speed characteristics. It decreases mean absolute errors for most of the stability levels despite a slight overestimation for near‐neutral stable and very stable conditions. Regarding the real‐data case, a significant improvement has been achieved by the VKI01 for both turbulence kinetic energy and its dissipation rate in comparison to sonic anemometer measurements for a 2‐day period during the eXperimental Planetary boundary layer Instrumentation Assessment campaign.
Temporally Variable Stream Width and Surface Area Distributions in a Headwater Catchment
Authors: Barefoot Eric , Pavelsky Tamlin M. , Allen George H. , Zimmer Margaret A. , McGlynn Brian L.
Published: July 2019

Headwater stream networks expand and contract in response to event‐driven and seasonal catchment wetness conditions. This dynamic behavior drives variability in the width, length, and surface area of streams, important parameters for constraining a range of ecological and biogeochemical processes, such as atmospheric gas exchange. While the longitudinal expansion and contraction of streams has been studied for some time, variability in stream widths remains poorly understood. Recent studies have found that stream widths at average baseflow conditions follow a log‐normal frequency distribution across diverse physiographies. To examine how the distribution of widths varies with flow conditions, we surveyed stream widths 12 times across a 48.4‐ha research watershed, located in the Duke Forest in central North Carolina, USA. Here, we show that as runoff increased from the 37th to 99th percentiles of flow, flowing streams widened across the network (“lateral expansion”) and streamflow simultaneously extended upstream to reactivate dry channels (“longitudinal expansion”). In general, as runoff increased, the marginal increase in stream surface area was equally divided between longitudinal and lateral expansion. Even so, the median stream width widens on average with increasing runoff, suggesting that longitudinal and lateral expansion affect the distribution of stream width differently. We find that the form of the relationship between stream width and runoff is a power law, which can be used to refine models for surface area estimation.
Factors Controlling Short‐Range Methane Migration of Gas Hydrate Accumulations in Thin Coarse‐Grained Layers
Authors: Wei Li , Cook Ann , Daigle Hugh , Malinverno Alberto , Nole Michael , You Kehua
Published: July 2019

Natural gas hydrate is often found in marine sediment in heterogeneous distributions in different sediment types. Diffusion may be a dominant mechanism for methane migration and affect hydrate distribution. We use a 1‐D advection‐diffusion‐reaction model to understand hydrate distribution in and surrounding thin coarse‐grained layers to examine the sensitivity of four controlling factors in a diffusion‐dominant gas hydrate system. These factors are the particulate organic carbon content at seafloor, the microbial reaction rate constant, the sediment grading pattern, and the cementation factor of the coarse‐grained layer. We use available data at Walker Ridge 313 in the northern Gulf of Mexico where two ~3‐m‐thick hydrate‐bearing coarse‐grained layers were observed at different depths. The results show that the hydrate volume and the total amount of methane within thin, coarse‐grained layers are most sensitive to the particulate organic carbon of fine‐grained sediments when deposited at the seafloor. The thickness of fine‐grained hydrate free zones surrounding the coarse‐grained layers is most sensitive to the microbial reaction rate constant. Moreover, it may be possible to estimate microbial reaction rate constants at other locations by studying the thickness of the hydrate free zones using the Damköhler number. In addition, we note that sediment grading patterns have a strong influence on gas hydrate occurrence within coarse‐grained layers.
Skillful Prediction of Monthly Major Hurricane Activity in the North Atlantic with Two‐way Nesting
Authors: Gao Kun , Chen Jan‐Huey , Harris Lucas , Sun Yongqiang , Lin Shian‐Jiann
Published: July 2019

We investigate the monthly prediction of North Atlantic hurricane and especially major hurricane activity based on the Geophysical Fluid Dynamics Laboratory High‐Resolution Atmospheric Model (HiRAM). We compare the performance of two grid configurations: a globally uniform 25‐km grid and the other with an 8‐km interactive nest over the tropical North Atlantic. Both grid configurations show skills in predicting anomalous monthly hurricane frequency and accumulated cyclone energy. Particularly, the 8‐km nested model shows improved skills in predicting major hurricane frequency and accumulated cyclone energy. The skill in anomalous monthly hurricane occurrence prediction arises from the accurate prediction of zonal wind shear anomalies in the Main Development Region, which in turn arises from the sea surface temperature anomalies persisted from the initialization time. The enhanced resolution on the nested grid permits a better representation of hurricanes and especially intense hurricanes, thereby showing the ability and the potential for prediction of major hurricanes on subseasonal timescales.
Microscale Characterization of Fracture Growth and Associated Energy in Granite and Sandstone Analogs: Insights Using the Discrete Element Method
Authors: Vora Harsh B. , Morgan Julia K.
Published: July 2019

We employ the Discrete Element Method to analyze the micromechanical response of numerical analogs of sandstone and granite to unstable failure. Calibrated particle‐based models of sandstone and granite are subjected to biaxial experiments under confining pressures of 0–50 MPa, leading to the development of shear fractures through interactions of microcracks occurring in shear and tensile modes. We document the mode and energy associated with emergent microcracks to analyze fracture growth patterns and quantify fracture energy. Shear fracture growth in our sandstone analog occurs through cooperative interaction between shear and tensile microcracks, with shear microcracks accounting 4–44% of total microcracks and 31–92% of fracture energy. Shear microcracking increases with confining pressure resulting in an increase in fracture energy, and a transition from dilatant to compactant fracture zones in our sandstone models. Shear fracture growth in our granite analog occurs through coalescence of tensile microcracks, which account for 96–98% of total microcracks and 87–93% of fracture energy. Tensile microcracking increases with confining pressure, resulting in an increase in fracture energy and formation of dilatant fracture zones in our granite models. Our simulations show that fracture energy increases with confining pressure, accounting for 10–15% of the total input mechanical energy in sandstone versus 16–47% in granite. We estimate that the work done against friction from intergranular and fracture sliding accounts for 69–86% of total input energy in our sandstone analogs and 46–81% in our granite analogs. Our results indicate that frictional deformation during fracture is a significant component of the energy budget.
Constraining the Early History of Mercury and Its Core Dynamo by Studying the Crustal Magnetic Field
Authors: Oliveira Joana S. , Hood Lon L. , Langlais Benoit
Published: July 2019

Low‐altitude magnetic field data acquired by MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) over a small portion of Mercury's surface revealed weak crustal magnetic field signatures. Here we study the crustal magnetic anomalies associated with impact craters on Mercury. We assume that the sources of these anomalies consist of impact melt, enriched in impactor iron. We assume that the subsurfaces of Mercury's impact craters have cooled in the presence of a constant global magnetic field, thus becoming thermoremanently magnetized. We invert for the crustal magnetization direction within five craters using a unidirectional magnetization model which assumes that the melt impact rocks recorded the constant core magnetic field present when the crater was formed and that the crater's magnetization has not been altered since its formation. From the best fitting magnetization direction we then obtain the corresponding north magnetic paleopole position assuming a centered core dipolar field. Results show that all five magnetic paleopoles lie in the southern hemisphere but are not required to be located near the present‐day magnetic pole, which lies near the south geographic pole. Accounting for the uncertainties, we show that our results all agree in a common small region that excludes the current magnetic pole. This strongly suggests that the dynamo has evolved with time. Our results represent valuable information for understanding the evolution of Mercury and emphasize the importance of including more anomaly analyses to complete and refine our conclusions.