bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal allocation of wind capacity considering the impact of generation uncertainty based on zonotope limited security regions
Authors: Gao Jianing , Han Bei , Zhang Lijun , Xu Chenbo , Li Guojie , Feng Lin , Wang Keyou
Published: June 2019

The increasing wind capacity integration brings new challenges to power system planning and operation, due to the intermittency and uncertainty of its power generations. This paper determines the optimal allocation of wind capacity with considerations of the impact of uncertainty in wind generation using the zonotope‐based method, for the sack of reducing the possible violations of operation limits caused by wind power fluctuations. The uncertain variations of wind power are bounded by a zonotope and then propagated through a linearised power flow to get another zonotope, which captures all possible values of the system state variables. The state‐bounding zonotope is then added to the optimal model to quantify and assess the impact of generation uncertainty on system static performance. The proposed method is applied to IEEE 33‐bus system, the results prove the validity of the method and show that the zonotope based set‐theoretic method is more efficient than probabilistic methods when focusing on the operation limits with considerations of the uncertainty of multiple renewable energy sources.
Experimental and theoretical lifetimes and transition probabilities for spectral lines in Nb II
Authors: Nilsson H. , Engström L. , Lundberg H. , Hartman H. , Palmeri P. , Quinet P.
Published: June 2019

Aims. We have measured and calculated lifetimes of high lying levels in Nb II, and derived absolute transition probabilities by combining the lifetimes with experimental branching fractions.

Methods. The lifetimes were measured using time-resolved laser-induced fluorescence in a two-photon and two-step excitation scheme. The branching fractions were measured in intensity calibrated spectra from a hollow cathode discharge, recorded with a Fourier transform spectrometer. The calculations were performed with the relativistic Hartree–Fock method including core polarization.

Results. We report experimental lifetimes of 13 levels in the 4d3(4F)5d and 4d3(4F)6s subconfigurations, at an energy around 70 000 cm−1. By combining the lifetimes with experimental branching fractions absolute transition probabilities of 59 lines are derived. The experimental results are compared with calculated values.
PageRank: An alarming index of probable earthquake occurrence
Authors: Rezaei Soghra , Moghaddasi Hanieh , Darooneh Amir Hossein
Published: June 2019

Here, we introduce PageRank (PR) in a seismic network as an appropriate alarming clue before the occurrence of the event to be worthwhile in hazard probabilistic evaluation of earthquakes. Studying PR changes of two main shocks in Iran and Italy by means of temporal and spatial windows reveals that their PR values increase drastically before the event, while there is no trend for other considered locations and/or other time intervals. Therefore, the PR value seems to be an appropriate index of a place induction by previous events and its susceptibility for having a new earthquake. Moreover, summing over the PRs of areas close to the Italy event location and tracking this newly defined PR behavior show an increasing trend before the main shock implying that the close regions are influenced and become highly connected before the event as well as the earthquake location itself. It is also indicated that PR behavior is not necessarily correlated to the number of occurring earthquakes and is inherently the result of points connectivity and interactions.
Thermal-field and photoemission from meso- and micro-scale features: Effects of screening and roughness on characterization and simulation
Authors: Jensen Kevin L. , McDonald Michael , Chubenko Oksana , Harris John R. , Shiffler Donald A. , Moody Nathan A. , Petillo John J. , Jensen Aaron J.
Published: June 2019

A methodology of modeling nonplanar surfaces, in which the microscale features of the emission sites can be orders of magnitude smaller than the mesoscale features defining the active emission area, has been developed and applied to both ordered arrays of identical emitters and random variations characteristic of a roughened surface. The methodology combines a general thermal-field-photoemission model for electron emission, a point charge model for the evaluation of field enhancement factors and surface geometry, and a Ballistic-Impulse model to account for the trajectories of electrons close to the cathode surface. How microscale and mesoscale features can both undermine the estimation of thermal-field emission parameters, such as characteristic field enhancement and total current predictions, as well as give rise to changes in the distribution of transverse velocity components used to estimate beam quality features such as emittance that are important to photocathodes, is quantified. The methodology is designed to enable both the proper characterization of emitters based on experimental current-voltage data and the development of a unit cell model of emission regions that will ease the emission model demands in beam optics codes.
Global precipitation varies with sea-surface temperature at different timescales
Authors: Bandari Anashe
Published: June 2019

Researchers gain insights on global climate phenomena by studying the effects of sea-surface temperature on precipitation patterns at varying timescales.
New design for on-chip integrated photonic circuits proposed
Authors: Larter Raima
Published: June 2019

New types of on-chip integrated photonic circuits using heterostructures involving hexagonal boron nitride could have large impact in communications technology.
Zinc-Containing Coordination Polymer as a Suitable Precursor for Solid State Synthesis of ZnO
Authors: Mohammadikish Maryam , Zafari Zohreh , Torabi Susan
Published: June 2019

Uniform zinc-containing infinite coordination polymer (ICP) nanoparticles were achieved via a straightforward and rapid precipitation method in 5min, from a bi-thioglycolate functionalized salpn ligand (salpn=N,N′-bis(salicylidene)-1,3-propanediamine) as linker and zinc acetate. Characterization of the resulting product was performed by CHN elemental analysis, inductively coupled plasma–optical emission spectroscopy, FT-IR spectroscopy, thermogravimetric analysis, electron microscopies (FE-SEM and HR-TEM), and photoluminescence spectroscopy. Elemental analyses verified the proposed structure for the ICP with a 1:2 ratio of the salpn type ligand and Zn2+ ion. FE-SEM, TEM, and AFM analyses unveiled the existence of nanoparticles with diameters of ~30nm. PL spectroscopy showed a blue shift in emission peak of the ICP with regards to the organic ligand. The obtained ICP was utilized as a precursor to synthesize ZnO nanoparticles with wurtzite structure. An increase in bandgap of the prepared ZnO nanoparticles was observed in comparison with bulk ZnO as a result of quantum confinement of photogenerated electron–hole pairs. This method can be exploited for the synthesis of other coordination polymer micro/nanostructures.
How to resolve a phonon-associated property into contributions of basic phonon modes
Authors: Cheng Long , Zhang Chenmu , Liu Yuanyue
Published: June 2019

Many properties of materials are associated with phonons. To better understand the phonon-property relation, it is a common practice to decompose the phonon-associated property into the contributions of basic phonon/vibration modes (e.g. longitudinal/transverse acoustic/optical mode), and identify the mode(s) that dominate(s) the property. The existing methods rely on labelling the phonon into one of the basic modes (BMs), however, the vibration characteristics of many phonons are different from the definitions of BMs, indicating these methods may give wrong decomposition results. Here we present a new method based on treating the phonon as a mixture of the BMs. By aligning the wave vectors and then projecting the phonon eigenvector onto the eigenvectors of the BMs, we can obtain the weights of the BMs on the given phonon, which can be used to quantify the contribution of each BM to the property. As an example, we apply this method to unravel the phonon modes that dominate the scattering of the electrons at the conduction band edge in two-dimensional antimony, an emerging semiconductor that has attracted great interest for electronics, but its mobility-limiting factors remain unclear. We find that the electron scattering is dominated by the out-of-plane acoustic phonon mode followed by the longitudinal acoustic mode, which are different from the results of other methods. Our method is generally applicable to different kinds of phonon-related properties and to all crystal materials.
Correspondence principle in plane and axisymmetric mixed boundary-value problems of elasticity
Authors: Antipov Y. , Mkhitaryan S.
Published: June 2019

This paper advances the relations by A. Ja. Aleksandrov between axisymmetric and plane strain states to the case of mixed boundary-value problems. We revise two models of a strip-shaped and a circular stamp indented into a half-plane and a half-space, respectively, when the normal and tangential traction components are unknown a priori. Also, two models of a strip-shaped and a penny-shaped interfacial crack are considered. By using the theory of Abelian integral operators and the Riemann-Hilbert problem on a segment we derive the solutions to the model problems and establish the relations between the governing systems of integral equations associated with the four models and their solutions. These relations can be interpreted as mappings between (i) plane and axisymmetric contact problems, (ii) plane and axisymmetric fracture models, (iii) plane contact and fracture problems, and (iv) axisymmetric contact and fracture problems. The mappings enable us to write down the governing systems of integral equations and the solutions to any three models by making use of the governing system and the solution to the fourth problem. The transformations are specified in the scalar cases when there is no friction in the contact zone and when a crack is in a homogeneous elastic medium. By considering the contact frictionless problem of an annulus stamp it is shown that, although an exact solution to the plane strain frictionless contact problem of two stamps is available, a transformation of the plane to the axisymmetric solution in this case is not possible to obtain, and derivation of a closed-form solution to the annulus stamp model is still an open mathematical problem.
Depressive Symptoms Assessed Near the End of Pregnancy Predict Differential Response to Postpartum Smoking Relapse Prevention Intervention
Authors: Levine Michele D , Emery Rebecca L , Kolko Conlon Rachel P , Marcus Marsha D , Germeroth Lisa J , Salk Rachel H , Cheng Yu
Published: June 2019

Background

Depressive symptoms are prevalent during pregnancy and the postpartum period and affect risk for smoking relapse. Whether and how depression affects response to postpartum interventions designed to sustain smoking abstinence is unknown.

Purpose

We examined end-of-pregnancy depressive symptoms as a moderator of response to two postpartum-adapted smoking relapse prevention interventions.

Methods

Women (N = 300) who quit smoking during pregnancy were randomized to receive either a postpartum intervention focused on psychosocial factors linked to postpartum smoking (Strategies to Avoid Returning to Smoking [STARTS]) or an attention-controlled comparison intervention (SUPPORT). Women completed the Edinburgh Postnatal Depression Scale at the end of pregnancy. Smoking status was biochemically assessed at the end of pregnancy and at 12, 24, and 52 weeks postpartum.

Results

End-of-pregnancy depressive symptoms moderated response to postpartum smoking relapse prevention interventions (χ2 = 10.18, p = .001). After controlling for variables previously linked to postpartum smoking relapse, women with clinically significant end-of-pregnancy depressive symptoms (20%) were more likely to sustain abstinence through 52 weeks postpartum if they received STARTS. In contrast, women with few end-of-pregnancy depressive symptoms were more likely to sustain abstinence through 52 weeks postpartum if they received SUPPORT. Changes in the psychosocial factors addressed in the STARTS intervention did not mediate this moderation effect.

Conclusion

Assessment of end-of-pregnancy depressive symptoms may help determine success following postpartum smoking relapse prevention interventions. Women with elevated end-of-pregnancy depressive symptoms benefited from postpartum relapse prevention intervention tailored to their psychosocial needs, while those with few symptoms were more successful in postpartum intervention that used standard behavioral components.

Clinical Trial Registration

NCT00757068.
The Right to Food in the United States: The Role of the Supplemental Nutrition Assistance Program (SNAP)
Authors: Gundersen Craig
Published: June 2019

The “right to food” has been formally implemented in some countries and, in other contexts, it is used as an exhortation for governments or other entities to take actions to reduce food insecurity. Central to any comprehensive set of policies to reduce food insecurity are food assistance programs directed towards vulnerable households. One example of such a food assistance program is in the United States, the Supplemental Nutrition Assistance Program (SNAP, formerly known as the Food Stamp Program). I begin by discussing one measure of a right to food, namely, to be free from food insecurity and then turn to a consideration the role of SNAP in meeting this goal. To do so, I cover five components that would seem to be essential to any definition of a right to food and how SNAP does and does not meet these components.
Trends in Blood Pressure and High-Sensitivity Cardiac Troponin-T With Cardiovascular Disease: The Cardiovascular Health Study
Authors: Tehrani David M , Fan Wenjun , Nambi Vijay , Gardin Julius , Hirsch Calvin H , Amsterdam Ezra , deFilippi Christopher R , Polonsky Tamar , Wong Nathan D
Published: June 2019

Background

High-sensitivity cardiac troponin T (hs-cTnT) is individually associated with incident hypertension (HTN) and cardiovascular disease (CVD) events. We hypothesize that the increases in hs-cTnT with increases in blood pressure will be related to higher incidence of CVD.

METHODS

The Cardiovascular Health Study is a longitudinal cohort of older adults. Those with hs-cTnT data and CVD risk factors at baseline and follow-up (2–3 years later) were stratified based on systolic blood pressure (SBP; optimal: <120 mm Hg, intermediate: 120–139 mm Hg, elevated: ≥140 mm Hg) and hs-cTnT (undetectable: <5 ng/l, detectable: 5–13 ng/l, elevated: ≥14 ng/l) categories. SBP and hs-cTnT were classified as increased or decreased if they changed categories between exams, and stable if they did not. Cox regression evaluated incident CVD events over an average 9-year follow-up.

RESULTS

Among 2,219 adults, 510 (23.0 %) had decreased hs-cTnT, 1,279 (57.6 %) had stable hs-cTnT, and 430 (19.4 %) had increased hs-cTnT. Those with increased hs-cTnT had a higher CVD risk with stable SBP (hazard ratio [HR]: 1.28 [1.04–1.57], P = 0.02) or decreased SBP (HR: 1.57 [1.08–2.28], P = 0.02) compared to those within the same SBP group but a stable hs-cTnT. In those with lower SBP at follow-up, there was an inverse relation between diastolic blood pressure (DBP) and risk of CVD events in those with increased hs-cTnT (HR: 0.44 per 10 mm Hg increase, P < 0.01).

CONCLUSION

An increase in hs-cTnT over time is associated with a higher risk of CVD even when the blood pressure is stable or decreases over time.
Pygenprop: a Python library for programmatic exploration and comparison of organism genome properties
Authors: Bergstrand Lee H , Neufeld Josh D , Doxey Andrew C
Published: June 2019

A critical step in comparative genomics is the identification of differences in the presence/absence of encoded biochemical pathways among organisms. Our library, Pygenprop, facilitates these comparisons using data from the Genome Properties database. Pygenprop is written in Python and, unlike existing libraries, it is compatible with a variety of tools in the Python data science ecosystem, such as Jupyter Notebooks for interactive analyses and scikit-learn for machine learning. Pygenprop assigns YES, NO, or PARTIAL support for each property based on InterProScan annotations of open reading frames from an organism’s genome. The library contains classes for representing the Genome Properties database as a whole and methods for detecting differences in property assignments between organisms. As the Genome Properties database grows, we anticipate widespread adoption of Pygenprop for routine genome analyses and integration within third-party bioinformatics software.

Availability and implementation

Pygenprop is written in Python and is compatible with versions 3.6 or higher. Source code is available under Apache Licence Version 2 at https://github.com/Micromeda/pygenprop. The package can be installed from both PyPi (https://pypi.org/project/pygenprop) and Anaconda (https://anaconda.org/lbergstrand/pygenprop). Documentation is available on Read the Docs (http://pygenprop.rtfd.io/).
Water turbidity affects melanin-based coloration in the gudgeon: a reciprocal transplant experiment
Authors: Côte Jessica , Pilisi Camille , Morisseau Océane , Veyssière Charlotte , Perrault Annie , Jean Séverine , Blanchet Simon , Jacquin Lisa
Published: June 2019

Human activities cause rapid eutrophication and increased water turbidity in aquatic ecosystems, but their effects on fish communication and colour signals remain of debate. In particular, melanin-based coloration in fish has been understudied, because it was believed to be less costly to display than carotenoid-based colours. Here, we measured the phenotypic divergence of melanin-based coloration in 17 populations of gudgeon (Gobio occitaniae) along a turbidity gradient. We also tested the short-term plasticity of coloration using a reciprocal transplant experiment. We found strong variability in melanin-based coloration along the turbidity gradient: interpopulation divergence in coloration was higher than predicted by genetic drift, and fish were paler with increasing levels of turbidity. Finally, a reciprocal transplant experiment revealed that fish transplanted into more turbid habitats expressed a paler melanin-based coloration, suggesting that melanin-based coloration was highly plastic in the short term. Overall, our results suggest that eutrophication in human-altered rivers can rapidly alter melanin-based coloration, with potential consequences for fish visual communication and sexual selection.
Accounting for unobserved covariates with varying degrees of estimability in high-dimensional biological data
Authors: McKennan Chris , Nicolae Dan
Published: June 2019

An important phenomenon in high-throughput biological data is the presence of unobserved covariates that can have a significant impact on the measured response. When these covariates are also correlated with the covariate of interest, ignoring or improperly estimating them can lead to inaccurate estimates of and spurious inference on the corresponding coefficients of interest in a multivariate linear model. We first prove that existing methods to account for these unobserved covariates often inflate Type I error for the null hypothesis that a given coefficient of interest is zero. We then provide alternative estimators for the coefficients of interest that correct the inflation, and prove that our estimators are asymptotically equivalent to the ordinary least squares estimators obtained when every covariate is observed. Lastly, we use previously published DNA methylation data to show that our method can more accurately estimate the direct effect of asthma on DNA methylation levels compared to existing methods, the latter of which likely fail to recover and account for latent cell type heterogeneity.
Vocal individuality and rhythm in male and female duet contributions of a nonhuman primate
Authors: Clink Dena J , Tasirin Johny S , Klinck Holger
Published: June 2019

Duetting, or the stereotypical, repeated and often coordinated vocalizations between 2 individuals arose independently multiple times in the Order Primates. Across primate species, there exists substantial variation in terms of timing, degree of overlap, and sex-specificity of duet contributions. There is increasing evidence that primates can modify the timing of their duet contributions relative to their partner, and this vocal flexibility may have been an important precursor to the evolution of human language. Here, we present the results of a fine-scale analysis of Gursky’s spectral tarsier Tarsius spectrumgurskyae duet phrases recorded in North Sulawesi, Indonesia. Specifically, we aimed to investigate individual-level variation in the female and male contributions to the duet, quantify individual- and pair-level differences in duet timing, and measure temporal precision of duetting individuals relative to their partner. We were able to classify female duet phrases to the correct individual with an 80% accuracy using support vector machines, whereas our classification accuracy for males was lower at 64%. Females were more variable than males in terms of timing between notes. All tarsier phrases exhibited some degree of overlap between callers, and tarsiers exhibited high temporal precision in their note output relative to their partners. We provide evidence that duetting tarsier individuals can modify their note output relative to their duetting partner, and these results support the idea that flexibility in vocal exchanges—a precursor to human language—evolved early in the primate lineage and long before the emergence of modern humans.
Compatible Taper and Stem Volume Equations for Five Pine Species in Mixed-Species Forests in Mexico
Authors: Quiñonez-Barraza Gerónimo , Zhao Dehai , De los Santos-Posadas Héctor Manuel
Published: June 2019

Ten systems of compatible taper and outside-bark volume equations derived from upper-height-based volume ratio equations were compared with a used segmented-stem system of compatible taper and volume equations. All the systems were simultaneously fitted to cumulative volume data and taper data for Arizona pine, Aztec pine, Durango pine, Mexican white pine, and Smooth-leaved pine species in naturally regenerated mixed-species forests in Mexico. The systems derived from volume ratio equations performed better than the segmented-stem system for most species. The resultant top systems might be easier to implement than the segmented-stem system for predicting upper-stem height, upper-stem diameter, merchantable volume, and total stem volume for considered species.
Sternotomy wound healing disorders due to neoplasia: a diagnostic challenge
Authors: Colombier Sébastien , Delay Dominique , Niclauss Lars
Published: June 2019

Localized neoplastic infiltration of the post-sternotomy scar is a rare late healing disorder. We present 2 patients admitted with the suspicion of chronic osteomyelitis, 1 and 5 years after cardiac surgery. Microbiological analyses were negative. Histopathology revealed sternal metastatic lesions of a hepatocellular carcinoma in 1 patient and of an oesophagogastric carcinoma in the other. In cases of an existing primary tumour, which was unknown in both patients, the sternal healing process may promote secondary seeding of tumour cells, due to the inflammatory and hyper-metabolic trauma. Special attention should be therefore payed to atypical post-sternotomy lesions, which require histopathological analysis and imaging assessment.
Maternal pre-pregnancy obesity and timing of puberty in sons and daughters: a population-based cohort study
Authors: Brix Nis , Ernst Andreas , Lauridsen Lea L B , Arah Onyebuchi A , Nohr Ellen A , Olsen Jørn , Henriksen Tine Brink , Ramlau-Hansen Cecilia Høst
Published: June 2019

Background

In many countries, an increased prevalence of obesity in pregnancy has coincided with a declining pubertal age. We aimed to explore the potential effect of maternal pre-pregnancy overweight and obesity on timing of puberty in sons and daughters.

Methods

Between 2012 and 2018, 15 819 of 22 439 invited children from the Danish National Birth Cohort, born 2000–03, provided half-yearly information from the age of 11 years on the pubertal milestones: Tanner stages, voice break, first ejaculation, menarche, acne and axillary hair. We estimated adjusted mean monthly differences (with 95% confidence intervals) in age at attaining the pubertal milestones for children exposed to maternal pre-pregnancy obesity [body mass index (BMI) ≥30.0 kg/m2] or overweight (BMI 25.0 to 29.9 kg/m2) with normal weight (BMI 18.5 to 24.9 kg/m2) as reference. In mediation analysis, we explored whether childhood BMI at age 7 years mediated the associations.

Results

Maternal pre-pregnancy obesity was associated with earlier age at attaining most pubertal milestones in sons, and pre-pregnancy overweight and obesity were associated with earlier age at attaining all pubertal milestones in daughters. When combining all pubertal milestones, pre-pregnancy obesity [sons: −1.5 (−2.5, −0.4) months; daughters: −3.2 (−4.2, −2.1) months] and overweight [daughters only: −2.6 (−3.3, −1.8) months] were associated with earlier timing of puberty. The associations in sons were completely mediated by higher childhood BMI and partly so in daughters.

Conclusions

Maternal pre-pregnancy obesity appears to lower timing of puberty through childhood obesity in sons and mainly through other mechanisms in daughters.
How Mediated Opinion Polls Influence Political Parties: Revisiting the Arena Framework
Authors: Oleskog Tryggvason Per
Published: June 2019

One key question in research on the mediatization of politics concerns how political actors are influenced by the news media. Using a unique dataset of more than 2,400 Swedish politicians, this study bridges two literatures—the arena framework of strategic party behavior, and research on elite perceptions of media power—by investigating how politicians assess the influence of mediás publication of opinion polls. The results show that published opinion polls are seen as highly influential, but that perceptions of influence vary between the internal, electoral, media, and parliamentary arenas on which political parties act. Furthermore, on the electoral and media arena, the perceived influence of published opinion polls is found to be a function of how the politician’s party has performed on the polls. More specifically, politicians who believe their party to have either increased or decreased their poll support since the previous election deem polls as more influential compared to politicians who perceive that their party has not moved in the polls.
Asynchronous repetitive control of switched systems via periodic event-based dynamic output feedback
Authors: Ma Guoqi , Liu Xinghua , Pagilla Prabhakar R , Sam Ge Shuzhi
Published: June 2019

This paper develops an asynchronous mode-dependent repetitive control strategy with periodic event-based dynamic output feedback for periodic trajectory tracking of continuous-time switched systems subject to time-varying switching delays between system modes and controllers and limited communication capacity in the feedback channel. By employing the input delay approach, the overall system is modelled as an augmented closed-loop switched system with both constant and time-varying state delays. A co-design framework is proposed for simultaneously designing the controller, event-triggering mechanism and mode switching signal. Under the co-design framework, using piecewise Lyapunov functional, free-weighting matrices and average dwell time technique, sufficient conditions are derived for ensuring the augmented closed-loop system to be exponentially stable with a prescribed $H_{\infty }$ attenuation level $\gamma $ for an exogenous disturbance input. The performance of the proposed controller design scheme is verified via numerical simulation results on a switched RLC series circuit system.
Genomic Epidemiology as a Public Health Tool to Combat Mosquito-Borne Virus Outbreaks
Authors: Pollett S , Fauver J R , Maljkovic Berry Irina , Melendrez M , Morrison A , Gillis L D , Johansson M A , Jarman R G , Grubaugh N D
Published: June 2019

Next-generation sequencing technologies, exponential increases in the availability of virus genomic data, and ongoing advances in phylogenomic methods have made genomic epidemiology an increasingly powerful tool for public health response to a range of mosquito-borne virus outbreaks. In this review, we offer a brief primer on the scope and methods of phylogenomic analyses that can answer key epidemiological questions during mosquito-borne virus public health emergencies. We then focus on case examples of outbreaks, including those caused by dengue, Zika, yellow fever, West Nile, and chikungunya viruses, to demonstrate the utility of genomic epidemiology to support the prevention and control of mosquito-borne virus threats. We extend these case studies with operational perspectives on how to best incorporate genomic epidemiology into structured surveillance and response programs for mosquito-borne virus control. Many tools for genomic epidemiology already exist, but so do technical and nontechnical challenges to advancing their use. Frameworks to support the rapid sharing of multidimensional data and increased cross-sector partnerships, networks, and collaborations can support advancement on all scales, from research and development to implementation by public health agencies.
Hyperandrogenism in POMCa-deficient zebrafish enhances somatic growth without increasing adiposity
Authors: Shi Chuang , Lu Yao , Zhai Gang , Huang Jianfei , Shang Guohui , Lou Qiyong , Li Dongliang , Jin Xia , He Jiangyan , Du Zhenyu , Gui Jianfang , Yin Zhan
Published: June 2019

The endocrine regulatory roles of the hypothalamic–pituitary–adrenocortical axis on anxiety-like behavior and metabolic status have been found throughout animal taxa. However, the precise effects of the balancing adrenal corticosteroid biosynthesis under the influence of adrenocorticotrophic hormone (ACTH), a pro-opiomelanocortin (POMC)-derived peptide, on animal energy expenditure and somatic growth remain unknown. POMC has also been identified as one of the candidate loci for polycystic ovary syndrome, which features hyperandrogenism and some prevalence of obesity in patients. Here we show that zebrafish lacking functional POMCa exhibit similar phenotypes of stress response and body weight gain but not obesity as observed in mammalian models. In contrast with the impaired anorexigenic signaling cascade of melanocyte-stimulating hormones and leptin, which are responsible for their obesity-prone weight gain observed in various pomc mutant mammals, analyses with our pomca mutant series indicate that ACTH is the key regulator for the phenotype with enhanced somatic growth without obesity in pomca-deficient zebrafish. Hypocortisolism associated with hyperandrogenism has been observed in the pomca-deficient zebrafish, with enhanced activation of mammalian target of rapamycin complex 1; reutilization of amino acids and fatty acid β-oxidation are observed in the muscle tissue of the pomca-deficient fish. After reducing hyperandrogenism by crossing our pomca mutant fish with a cyp17a1-deficient background, the phenotype of enhanced somatic growth in pomca-deficient fish was no longer observed. Thus, our work also demonstrated that the role of POMCa in stress response seems to be conserved in vertebrates, whereas its effect on adipostasis is unique to teleosts.
How protein - protein interactions contribute to pyrenoid formation in Chlamydomonas
Authors: Mukherjee Ananya , Moroney James V
Published: June 2019

This article comments on:

Atkinson N, Velanis CN, Wunder T, Clarke DJ, Mueller-Cajar O, McCormick AJ. 2019. The pyrenoidal linker protein EPYC1 phase separates with hybrid Arabidopsis-Chlamydomonas Rubisco through interactions with the algal Rubisco small subunit. Journal of Experimental Botany, 70, 5271–5285.
The Reduction of Necessity to Essence
Authors: Ditter Andreas
Published: June 2019

In ‘Essence and Modality’, Kit Fine (1994) proposes that for a proposition to be metaphysically necessary is for it to be true in virtue of the nature of all objects. Call this view Fine’s Thesis. This paper is a study of Fine’s Thesis in the context of Fine’s logic of essence (LE). Fine himself has offered his most elaborate defence of the thesis in the context of LE. His defence rests on the widely shared assumption that metaphysical necessity obeys the laws of the modal logic S5. In order to get S5 for metaphysical necessity, he assumes a controversial principle about the nature of all objects. I will show that the addition of this principle to his original system E5 leads to inconsistency with an independently plausible principle about essence. In response, I develop a theory that avoids this inconsistency while allowing us to maintain S5 for metaphysical necessity. However, I conclude that our investigation of Fine’s Thesis in the context of LE motivates the revisionary conclusion that metaphysical necessity obeys the principles of the modal logic S4, but not those of S5. I argue that this constitutes a distinctively essentialist challenge to the received view that the logic of metaphysical necessity is S5.
A public relativistic transfer function model for X-ray reverberation mapping of accreting black holes
Authors: Ingram Adam , Mastroserio Guglielmo , Dauser Thomas , Hovenkamp Pieter , van der Klis Michiel , García Javier A
Published: June 2019

We present the publicly available model reltrans that calculates the light-crossing delays and energy shifts experienced by X-ray photons originally emitted close to the black hole when they reflect from the accretion disc and are scattered into our line of sight, accounting for all general relativistic effects. Our model is fast and flexible enough to be simultaneously fit to the observed energy-dependent cross-spectrum for a large range of Fourier frequencies, as well as to the time-averaged spectrum. This not only enables better geometric constraints than only modelling the relativistically broadened reflection features in the time-averaged spectrum, but additionally enables constraints on the mass of supermassive black holes in active galactic nuclei and stellar-mass black holes in X-ray binaries. We include a self-consistently calculated radial profile of the disc ionization parameter and properly account for the effect that the telescope response has on the predicted time lags. We find that a number of previous spectral analyses have measured artificially low source heights due to not accounting for the former effect and that timing analyses have been affected by the latter. In particular, the magnitude of the soft lags in active galactic nuclei may have been underestimated, and the magnitude of lags attributed to thermal reverberation in X-ray binaries may have been overestimated. We fit reltrans to the lag-energy spectrum of the Seyfert galaxy Mrk 335, resulting in a best-fitting black hole mass that is smaller than previous optical reverberation measurements (∼7 million compared with ∼14–26 million M⊙).
Constraining astrophysical observables of galaxy and supermassive black hole binary mergers using pulsar timing arrays
Authors: Chen Siyuan , Sesana Alberto , Conselice Christopher J
Published: June 2019

We present an analytic model to describe the supermassive black hole binary (SMBHB) merger rate in the Universe with astrophysical observables: galaxy stellar mass function, pair fraction, merger time-scale, and black hole–host galaxy relations. We construct observational priors and compute the allowed range of the characteristic spectrum hc of the gravitational wave background (GWB) to be 10−16 < hc < 10−15 at a frequency of f = 1 yr−1. We exploit our parametrization to tackle the problem of astrophysical inference from pulsar timing array (PTA) observations. We simulate a series of upper limits and detections and use a nested sampling algorithm to explore the parameter space. Corroborating previous results, we find that the current PTA non-detection does not place significant constraints on any observables; however, either future upper limits or detections will significantly enhance our knowledge of the SMBHB population. If a GWB is not detected at a level of hc(f = 1 yr−1) = 10−17, our current understanding of galaxy and SMBHB mergers is disfavoured at a 5σ level, indicating a combination of severe binary stalling, overestimating of the SMBH–host galaxy relations, and extreme dynamical properties of merging SMBHBs. Conversely, future detections of a Square Kilometre Array (SKA)-type instrument will allow to constrain the normalization of the SMBHB merger rate in the Universe, the time between galaxy pairing and SMBHB merging, the normalization of the SMBH–host galaxy relations and the dynamical binary properties, including their eccentricity and density of stellar environment.
shiva: a dust destruction model
Authors: Murga M S , Wiebe D S , Sivkova E E , Akimkin V V
Published: June 2019

We present a numerical tool, shiva, designed to simulate the dust destruction in warm neutral, warm ionized and hot ionized media under the influence of photo-processing, sputtering and shattering. The tool is designed primarily to study the evolution of hydrogenated amorphous carbons (HACs), but options to simulate polycyclic aromatic hydrocarbons (PAHs), silicate and graphite grains are also implemented. HAC grain photo-processing includes both dehydrogenation and carbon atom loss. Dehydrogenation leads to material transformation from aliphatic to aromatic structure. Simultaneously, some other physical properties (band-gap energy, optical properties, etc.) of the material change as well. The shiva tool allows calculation of the time-dependent evolution of the dust size distribution depending on hydrogen, helium and carbon number densities and ionization state, gas temperature, radiation flux, relative gas–dust and grain–grain velocities. For HAC grains the evolution of band-gap energy distribution is also computed. We describe a dust evolution model, on which the tool relies, and present evolutionary time-scales for dust grains of different sizes depending on external conditions. This allows the user to estimate quickly the lifetime of a specific dust grain under relevant conditions. As an example of the tool usage, we demonstrate how grain properties and corresponding infrared spectra evolve in photo-dissociation regions, H ii regions and supernova remnant shocks.
Symbiosis, Selection, and Novelty: Freshwater Adaptation in the Unique Sponges of Lake Baikal
Authors: Kenny Nathan J , Plese Bruna , Riesgo Ana , Itskovich Valeria B
Published: June 2019

Freshwater sponges (Spongillida) are a unique lineage of demosponges that secondarily colonized lakes and rivers and are now found ubiquitously in these ecosystems. They developed specific adaptations to freshwater systems, including the ability to survive extreme thermal ranges, long-lasting dessication, anoxia, and resistance to a variety of pollutants. Although spongillids have colonized all freshwater systems, the family Lubomirskiidae is endemic to Lake Baikal and plays a range of key roles in this ecosystem. Our work compares the genomic content and microbiome of individuals of three species of the Lubomirskiidae, providing hypotheses for how molecular evolution has allowed them to adapt to their unique environments. We have sequenced deep (>92% of the metazoan “Benchmarking Universal Single-Copy Orthologs” [BUSCO] set) transcriptomes from three species of Lubomirskiidae and a draft genome resource for Lubomirskia baikalensis. We note Baikal sponges contain unicellular algal and bacterial symbionts, as well as the dinoflagellate Gyrodinium. We investigated molecular evolution, gene duplication, and novelty in freshwater sponges compared with marine lineages. Sixty one orthogroups have consilient evidence of positive selection. Transporters (e.g., zinc transporter-2), transcription factors (aristaless-related homeobox), and structural proteins (e.g. actin-3), alongside other genes, are under strong evolutionary pressure in freshwater, with duplication driving novelty across the Spongillida, but especially in the Lubomirskiidae. This addition to knowledge of freshwater sponge genetics provides a range of tools for understanding the molecular biology and, in the future, the ecology (e.g., colonization and migration patterns) of these key species.
Bioinspired hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers
Authors: Gao Huai-Ling , Zhao Ran , Cui Chen , Zhu Yin-Bo , Chen Si-Ming , Pan Zhao , Meng Yu-Feng , Wen Shao-Meng , Liu Chuang , Wu Heng-An , Yu Shu-Hong
Published: June 2019

Bio-sourced nanocellulosic materials are promising candidates for spinning high-performance sustainable macrofibers for advanced applications. Various strategies have been pursued to gain nanocellulose-based macrofibers with improved strength. However, nearly all of them have been achieved at the expense of their elongation and toughness. Inspired by the widely existed hierarchical helical and nanocomposite structural features in biosynthesized fibers exhibiting exceptional combinations of strength and toughness, we report a design strategy to make nanocellulose-based macrofibers with similar characteristics. By combining a facile wet-spinning process with a subsequent multiple wet-twisting procedure, we successfully obtain biomimetic hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers, realizing impressive improvement in their tensile strength, elongation and toughness simultaneously. The achievement certifies the validity of the bioinspired hierarchical helical and nanocomposite structural design proposed here. This bioinspired design strategy provides a potential platform for further optimizing or creating many more strong and tough nanocomposite fiber materials for diverse applications.
Criminal Law Basics and the Willful Ignorance Doctrine
Authors: Sarch Alexander
Published: June 2019

Chapter 1 sets the stage. The author’s starting point is the willful ignorance doctrine, since it is the source from which the author will eventually extract his general theory of equal culpability mental state imputation. After explaining core criminal law concepts (particularly the mens rea concepts), the author introduces the willful ignorance doctrine, its history, and the normative claim it is premised on—namely, the equal culpability thesis. Situating this doctrine in the broader criminal law context reveals the questions to be tackled in the book, and the chapter ends by indicating the sorts of answers the author will go on to develop.
Toward a Normative Theory of Equal Culpability Imputation
Authors: Sarch Alexander
Published: June 2019

This chapter aims to defend a general theory of equal-culpability-based imputation of mental states in the criminal law. The willful ignorance doctrine is one example of an equal culpability mens rea imputation principle. After all, what grounds imputing knowledge to a willfully ignorant actor is that her conduct is as culpable as the analogous knowing conduct. Chapters 3 and 4 examined the scope of this imputation principle. But deeper worries linger. Even if equal culpability is necessary for this mode of imputing knowledge to the willfully ignorant, does it provide sufficient justification for such imputation? This chapter confronts two of the deeper objections that remain. One is pressing for practitioners within an existing legal framework (courts and litigants). But it admits of straightforward answers. The other is a harder normative problem for those who make law. Why should lawmakers take equal culpability to be a legitimate basis for imputing missing mental states? Answering this challenge requires a general theory of equal culpability imputation, which it is the aim of this chapter to provide. This theory will then serve as the basis for the remaining chapters in the book.
Substituting Willful Ignorance for Purpose?
Authors: Sarch Alexander
Published: June 2019

Chapter 6 argued for moving beyond the existing willful ignorance doctrine by allowing some forms of nonwillful ignorance to substitute for knowledge. But where does it end? Chapter 7 considers moving beyond the willful ignorance doctrine in a different direction—by allowing willful ignorance to substitute for purpose—but argues that this doctrinal expansion is not justified. Acting with purpose to bring about a bad state of affairs will, all else equal, always be more culpable (or culpable in a different way) than doing so in willful ignorance of whether this state of affairs will result. This precludes willful ignorance of a proposition from substituting for purpose to make it true. Thus, this chapter aims to get clearer on the limits of equal culpability imputation.
The Tritone Paradox
Authors: Deutsch Diana
Published: June 2019

Chapter 5 explores the tritone paradox—a musical illusion that was discovered by the author. Its basic pattern consists of two computer-generated tones that are related by a half-octave (i.e., a tritone). These tones are well defined in pitch class (note name) but ambiguous in pitch height. When one of these tone pairs is played in succession, some people hear an ascending pattern, yet other people hear a descending one. Indeed, a group of people will disagree completely among themselves as to whether such a pair of tones is moving up or down in pitch. Furthermore, any one person hears one of these tone pairs as ascending or descending depending on their note names (such as C–F♯, or G♯–D). How people hear the tritone paradox varies with the geographic location in which they grew up—and so with their native language or dialect. Native English-speaking Californians hear this pattern differently from natives of the south of England. People who are natives of Vietnam hear the pattern quite differently from native English-speaking Californians. The tritone paradox shows, therefore, that the way we perceive music is related to our language, and generally reveals strong effects of our memories and expectations on how we hear music. It also has important implications for absolute pitch (or “perfect pitch”)—the rare ability to name a musical note that is presented in isolation. People make orderly judgments of the tritone paradox, even though they cannot name the notes that they are judging, so they must have an implicit form of absolute pitch.
Being With Others
Authors: Blustein David L.
Published: June 2019

This chapter reviews the relational aspects of work, exploring how work functions to provide people with an opportunity to connect to others and, at times, to evoke distress in the workplace. Beginning with a review of the relational revolution in psychology, vignettes from the Boston College Working Project participants explicate how relationships function within the workplace, underscoring both adaptive and aversive aspects of relational influences, power differentials at work, work–family balance, and the internalization process. The chapter includes a review of recent contributions on attachment, social support, mentoring, and social networks, which reflect important new directions for understanding the ways in which being with others at work enhances aliveness and well-being. Policy implications pertaining to the need for people to have access to decent work that affirms relational strivings conclude the chapter.