bluuebunny/crossref_metadata_2025 huggingface dataset:
Antitumor immunity of low-dose cyclophosphamide: changes in T cells and cytokines TGF-beta and IL-10 in mice with colon-cancer liver metastasis
Authors: Huang Xiao-Ming , Zhang Nan-Rong , Lin Xu-Tao , Zhu Cai-Yan , Zou Yi-Feng , Wu Xiao-Jian , He Xiao-Sheng , He Xiao-Wen , Wan Yun-Le , Lan Ping
Published: November 2019

Background

The tumor immune microenvironment is one of the most important prognostic factors in liver metastasis from colorectal cancer. Low-dose cyclophosphamide (CTX) is widely believed to be involved in the modulation of the immune system. However, the underlying mechanism of low-dose CTX remains unknown. This study aimed to investigate the antitumor immunity of low-dose CTX in the treatment of colon-cancer liver metastasis.

Methods

Thirty mice were randomly divided into five groups. After liver metastasis was established in colon-cancer models, mice in the treatment groups were injected with low-dose CTX (20 mg/kg) at different time points. Liver and spleen tissues were examined for T-cell markers via flow cytometry. Interleukin (IL)-10 and transforming growth factor (TGF)-β1 expression levels in liver tissues were analysed by immunohistochemistry. Serum interferon (IFN)-γ and IL-10 levels were detected by enzyme-linked immunosorbent assay. An additional 20 mice were randomly allocated into two groups and the survival times were recorded.

Results

The expression levels of CD4+ T cells, CD8+ T cells, and IFN-γ were down-regulated, whereas those of IL-10 and TGF-β1 were up-regulated in liver metastasis from colon cancer in mice. Furthermore, the local and systemic microenvironments of the liver were altered, which led to reduced antitumor immune responses and subsequently liver metastasis. However, treatment with low-dose CTX reversed these effects. The survival times of mice treated with low-dose CTX were significantly longer than those of the other groups.

Conclusions

Low-dose CTX exerts its antitumor activity by changing the systemic and local immune microenvironments and enhancing immune regulation in mice. CTX could be used as a drug to prevent and treat liver metastasis from colon cancer.
Orienting and locating ocean-bottom seismometers from ship noise analysis
Authors: Trabattoni A , Barruol G , Dreo R , Boudraa A O , Fontaine F R
Published: November 2019

Breakthroughs in understanding the structure and dynamics of our planet will strongly depend upon instrumenting deep oceans. Progress has been made these last decades in ocean-bottom seismic observations, but ocean-bottom seismometer (OBS) temporary deployments are still challenging and face set-up limitations. Launched from oceanographic vessels, OBSs fall freely and may slightly drift laterally, dragged by currents. Therefore, their actual orientation and location on the landing sites are hard to assess precisely. Numerous techniques have been developed to retrieve this key information, but most of them are costly, time-consuming or inaccurate. In this work, we show how ship noise can be used as an acoustic source of opportunity to retrieve both the orientation and the location of OBSs on the ocean floor. To retrieve the OBS orientation, we developed a first method based on a combination of seismic and pressure data through the use of the acoustic intensity. This latter can be used to quantify the OBS orientation from the ship noise direction of arrival (DOA), which can then be compared with known ship trajectories obtained from the automatic identification system (AIS). To accurately relocate OBSs, we also developed a second method based on the hydrophone data which computes distances of acoustical sources by measuring time differences of arrival (TDOA) between direct and reverberated phases. The OBS location is then retrieved by fitting measured ship distances with known ship trajectories. In this study, a full network of OBSs deployed in the SW Indian Ocean was reoriented and a test station was relocated. We demonstrate that our new methods may quantify the OBS orientation with an accuracy of about one degree, and its location with an accuracy of a few tens of metres, depending on the number of ships used in the analysis.
Gaussian process models—I. A framework for probabilistic continuous inverse theory
Authors: Valentine Andrew P , Sambridge Malcolm
Published: November 2019

We develop a theoretical framework for framing and solving probabilistic linear(ized) inverse problems in function spaces. This is built on the statistical theory of Gaussian Processes, and allows results to be obtained independent of any basis, avoiding any difficulties associated with the fidelity of representation that can be achieved. We show that the results of Backus–Gilbert theory can be fully understood within our framework, although there is not an exact equivalence due to fundamental differences of philosophy between the two approaches. Nevertheless, our work can be seen to unify several strands of linear inverse theory, and connects it to a large body of work in machine learning. We illustrate the application of our theory using a simple example, involving determination of Earth’s radial density structure.
Predicting lithology using neural networks from downhole data of a gas hydrate reservoir in the Krishna–Godavari basin, eastern Indian offshore
Authors: Singh Amrita , Ojha Maheswar , Sain Kalachand
Published: November 2019

We use the unsupervised and supervised neural network methods together to predict lithology of a gas hydrate reservoir from downhole data in the Krishna–Godavari (KG) offshore basin, India. In this study, we successfully identify the host litho-units of gas hydrate and show its effects in the identification of lithology using neural network techniques, which is not reported earlier. We use well log data acquired at three holes (10A, 03A and 04A) in 2006 during the first expedition of the Indian National Gas Hydrate Program (NGHP-01). Five different logging while drilling data (e.g. density, neutron porosity, gamma ray, resistivity and sonic) are considered for the mapping of lithology and gas hydrate. In the presence of gas hydrate, the resistivity and sonic velocity of the host sediments increase significantly, whereas density, neutron porosity and gamma ray are negligibly affected. Therefore, we calculate resistivity and sonic velocity for water-saturated sediment (without gas hydrate) theoretically to remove the effects of gas hydrate. At first, we apply the seven unsupervised classification methods (i.e. elbow, dendrogram, K-means, 3-D clustering, principal component analysis, Devies–Bouldin index and self-organizing map) to the data with gas hydrate (e.g. observed) and without gas hydrate (i.e. water-saturated/theoretical) to assess the data dimensionality and the number of clusters/litho-units. Each of the unsupervised schemes has its own pros and cons, and may provide different number of cluster/litho-units; sometimes, it is difficult to interpret from only one method. However, all seven methods provide same number of clusters in our study. Then, we apply the supervised classification method (i.e. Bayesian neural networks optimized by hybrid Monte Carlo searching technique) to the training data to refine the defined litho-units and map them with depth. Our approach identifies four types of litho-units and illustrates that the lithology in this area is dominated by clay (∼64 per cent) with some amount of silty clay, silt and minor sand. Gas hydrate is found in clay, silty clay and silt and not in sand. Results also show that, if gas hydrate is not considered as a separate unit, it is distributed as lithology in its hosts (i.e. clay, silty clay and silt). The method is very stable up to ∼15 per cent of random noise added to the data and results are well matched with the analysis of recovered core data. Identified lithologies at three wells correlate very well with seismic section crossing the wells. Very low permeability (<0.1 mD) estimated at three wells also indicates the clay-dominated lithology in our study area.
Reliability evaluation of volcanic tremor source location determination using cross-correlation functions
Authors: Permana Theodorus , Nishimura Takeshi , Nakahara Hisashi , Fujita Eisuke , Ueda Hideki
Published: November 2019

Source location determination of volcanic tremor has been a challenge in seismology due to the waveform complexity and difficulties in reading P- and S-wave arrival times. We present a method for locating volcanic tremor recorded at a seismic network distributed around a volcano. The method combines the source-scanning algorithm and cross-correlation analysis. Tremor records are processed using a technique adopted from ambient seismic interferometry to obtain stacked cross-correlation functions (CCFs) for all station pairs, which are expected to show high amplitudes at the lag time that corresponds to the travel time difference between the stations. The best seismic source location is determined from the maximum of the sum of envelope amplitudes of CCFs at predicted travel time differences between all pairs of stations. This method does not compute theoretical amplitudes, assume an initial hypocenter location, or measure the arrival times. To quantitatively evaluate the accuracy of the location determination, we examine the method by using the vertical component seismic data of volcano-tectonic (VT) earthquakes recorded at six seismic stations at Izu-Oshima volcano. The VTs have been previously located by using arrival times of P- and S-waves, and the hypocenters are used as the reference for evaluation and error estimation of the method. The results show that the misfit, which is the distance between our estimated sources and the references, is about 2 km or less when using CCFs at the frequency band of 4–16 Hz which contains the dominant frequencies of direct S-waves. To test whether the method can be used for volcanic tremor, we simulate the tremors by combining the observed VTs that occurred randomly in time in a localized region. The simulated tremors are determined with location errors of approximately 1 km or less, when the sources of VTs are located within a distance of 1 km and CCFs are calculated for a minimum data length of about 2 minutes. The volcanic tremor location method we present here can be used as an alternative tool for volcano monitoring, especially to locate tremors and seismic events with no clear phase arrival.
A novel method for computing the vertical gradients of the potential field: Application to downward continuation
Authors: Tran Kha Van , Nguyen Trung Nhu
Published: November 2019

Downward continuation is a very useful technique in the interpretation of potential field data. It would enhance the short wavelength of the gravity anomalies or accentuate the details of the source distribution. Taylor series expansion method has been proposed to be one of the best downward continued methods. However, the method using high-order vertical derivatives leads to low accuracy and instability results in many cases. In this paper, we propose a new method using a combination of Taylor series expansion and upward continuation for computing vertical derivatives. This method has been tested on the gravitational anomaly of infinite horizontal cylinder in both cases with and without random noise for higher accurate and stable than Hilbert transform method and Laplace equation method, especially in the case of noise input data. This vertical derivative method is applied successfully to calculate the downward continuation according to Taylor series expansion method. The downward continuation is also tested on both complex synthetic models and real data in the East Vietnam Sea (South China Sea). The results reveal that by calculating this new vertical derivative, the downward continuation method gave higher accurate and stable than the previous downward continuation methods.
A process evaluation of the Communication for Healthy Communities adolescent health program in Uganda
Authors: Nalukwago Judith , Alaii Jane , van den Borne Bart , Bukuluki Paul Mukisa , Kimbowa Musa , Bockh Emily , Coutinho Sheila Marunga , Crutzen Rik
Published: November 2019

This study is a process evaluation of an adolescent-focused intervention of the USAID Communication for Healthy Communities program, in Uganda. We used mixed methods including observation, consultations and review of program documents to collect data on program coverage, reach and factors influencing implementation. Findings show that program activities were successfully implemented through collaborative partnerships with service partners and the community. Interpersonal communication complemented by mass-media messaging was effective in reaching and empowering adolescents with health information to make informed choices for behavior change. The program used theoretical frameworks to guide targeted interventions through audience segmentation and community empowerment. Targeted mass-media messaging and placement was found to be pertinent for program reach. Working through existing community structures is important for an effective reach of health promotion programs. Lessons identified for scaling-up adolescent health programs include the need to harmonize training and deployment of community champions by development partners, recruit audience-specific influential champions and link income-generating activities to health education interventions. There is thus need to collaboratively develop and institutionalize effective monitoring and evaluation strategies during program inception and design phases for appropriate accountability, ownership and a continuation of gains.
Acoustic classification in multifrequency echosounder data using deep convolutional neural networks
Authors: Brautaset Olav , Waldeland Anders Ueland , Johnsen Espen , Malde Ketil , Eikvil Line , Salberg Arnt-Børre , Handegard Nils Olav
Published: November 2019

Acoustic target classification is the process of assigning observed acoustic backscattering intensity to an acoustic category. A deep learning strategy for acoustic target classification using a convolutional network is developed, consisting of an encoder and a decoder, which allow the network to use pixel information and more abstract features. The network can learn features directly from data, and the learned feature space may include both frequency response and school morphology. We tested the method on multifrequency data collected between 2007 and 2018 during the Norwegian sandeel survey. The network was able to distinguish between sandeel schools, schools of other species, and background pixels (including seabed) in new survey data with an F1 score of 0.87 when tested against manually labelled schools. The network separated schools of sandeel and schools of other species with an F1 score of 0.94. A traditional school classification algorithm obtained substantially lower F1 scores (0.77 and 0.82) when tested against the manually labelled schools. To train the network, it was necessary to develop sampling and preprocessing strategies to account for unbalanced classes, inaccurate annotations, and biases in the training data. This is a step towards a method to be applied across a range of acoustic trawl surveys.
A comparison of surgical pulmonary embolectomy and catheter-directed lysis for life-threatening pulmonary emboli
Authors: Winters Amalia A , McDaniel Michael J , Binongo Jose N , Moon Rena C , Jaber Wissam A , Rajani Ravi R , Liberman Henry A , Lattouf Omar M , Halkos Michael E , Stouffer Chadwick W , Keeling W Brent
Published: November 2019

OBJECTIVES

Patients with life-threatening pulmonary emboli (PE) have traditionally been treated with anticoagulation alone, yet emerging data suggest that more aggressive therapy may improve short-term outcomes. The purpose of this study was to compare postoperative outcomes between catheter-directed thrombolysis (CDL) and surgical pulmonary embolectomy (SPE) in the treatment of life-threatening PE.

METHODS

A retrospective single-centre observational study was conducted for patients who underwent SPE or CDL at a single US academic centre. Preprocedural and postprocedural echocardiographic data were collected. Unadjusted regression models were constructed to assess the significance of the between-group postoperative differences.

RESULTS

A total of 126 patients suffered a life-threatening PE during the study period [60 SPE (47.6%), 66 CDL 52.4%]. Ten (24.4%) SPE patients and 10 (15.2%) CDL patients had massive PEs marked by preprocedural hypotension. Six (10.0%) SPE patients and 4 (6.0%) CDL patients suffered a preprocedure cardiac arrest (P = 0.41). In-hospital mortality rate was 3.3% (2) for SPE, and 3.0% (2) for CDL (P = 0.99). SPE patients were more likely to require prolonged ventilation (15.0% vs 1.5%, P = 0.01). No significant differences were found in other major complications. At baseline echocardiography, 76.9% of SPE patients and 56.9% of CDL patients had moderate or severe right ventricular (RV) dysfunction. Both treatment groups showed marked and durable improvement in echocardiographic markers of RV function from baseline at midterm follow-up.

CONCLUSIONS

Both SPE and CDL can be applied to well-selected high-risk patients with low rates of morbidity and mortality. Further research is necessary to delineate which patients would benefit most from either SPE or CDL following a life-threatening PE.
Reflection on modern methods: five myths about measurement error in epidemiological research
Authors: van Smeden Maarten , Lash Timothy L , Groenwold Rolf H H
Published: November 2019

Epidemiologists are often confronted with datasets to analyse which contain measurement error due to, for instance, mistaken data entries, inaccurate recordings and measurement instrument or procedural errors. If the effect of measurement error is misjudged, the data analyses are hampered and the validity of the study’s inferences may be affected. In this paper, we describe five myths that contribute to misjudgments about measurement error, regarding expected structure, impact and solutions to mitigate the problems resulting from mismeasurements. The aim is to clarify these measurement error misconceptions. We show that the influence of measurement error in an epidemiological data analysis can play out in ways that go beyond simple heuristics, such as heuristics about whether or not to expect attenuation of the effect estimates. Whereas we encourage epidemiologists to deliberate about the structure and potential impact of measurement error in their analyses, we also recommend exercising restraint when making claims about the magnitude or even direction of effect of measurement error if not accompanied by statistical measurement error corrections or quantitative bias analysis. Suggestions for alleviating the problems or investigating the structure and magnitude of measurement error are given.
Quasi-optimal and pressure-robust discretizations of the Stokes equations by new augmented Lagrangian formulations
Authors: Kreuzer Christian , Zanotti Pietro
Published: November 2019

We approximate the solution of the stationary Stokes equations with various conforming and nonconforming inf-sup stable pairs of finite element spaces on simplicial meshes. Based on each pair, we design a discretization that is quasi-optimal and pressure-robust, in the sense that the velocity $H^1$-error is proportional to the best velocity $H^1$-error. This shows that such a property can be achieved without using conforming and divergence-free pairs. We also bound the pressure $L^2$-error, only in terms of the best velocity $H^1$-error and the best pressure $L^2$-error. Our construction can be summarized as follows. First, a linear operator acts on discrete velocity test functions, before the application of the load functional, and maps the discrete kernel into the analytical one. Second, in order to enforce consistency, we employ a new augmented Lagrangian formulation, inspired by discontinuous Galerkin methods.
Linear second-order IMEX-type integrator for the (eddy current) Landau–Lifshitz–Gilbert equation
Authors: Di Fratta Giovanni , Pfeiler Carl-Martin , Praetorius Dirk , Ruggeri Michele , Stiftner Bernhard
Published: November 2019

Combining ideas from Alouges et al. (2014, A convergent and precise finite element scheme for Landau–Lifschitz–Gilbert equation. Numer. Math., 128, 407–430) and Praetorius et al. (2018, Convergence of an implicit-explicit midpoint scheme for computational micromagnetics. Comput. Math. Appl., 75, 1719–1738) we propose a numerical algorithm for the integration of the nonlinear and time-dependent Landau–Lifshitz–Gilbert (LLG) equation, which is unconditionally convergent, formally (almost) second-order in time, and requires the solution of only one linear system per time step. Only the exchange contribution is integrated implicitly in time, while the lower-order contributions like the computationally expensive stray field are treated explicitly in time. Then we extend the scheme to the coupled system of the LLG equation with the eddy current approximation of Maxwell equations. Unlike existing schemes for this system, the new integrator is unconditionally convergent, (almost) second-order in time, and requires the solution of only two linear systems per time step.
A problem in control of elastodynamics with piezoelectric effects
Authors: Antil Harbir , Brown Thomas S , Sayas Francisco-Javier
Published: November 2019

We consider an optimal control problem where the state equations are a coupled hyperbolic–elliptic system. This system arises in elastodynamics with piezoelectric effects—the elastic stress tensor is a function of elastic displacement and electric potential. The electric flux acts as the control variable and bound constraints on the control are considered. We develop a complete analysis for the state equations and the control problem. The requisite regularity on the control, to show the well-posedness of the state equations, is enforced using the cost functional. We rigorously derive the first-order necessary and sufficient conditions using adjoint equations and further study their well-posedness. For spatially discrete (time-continuous) problems, we show the convergence of our numerical scheme. Three-dimensional numerical experiments are provided showing convergence properties of a fully discrete method and the practical applicability of our approach.
Tensor Algebras in Finite Tensor Categories
Authors: Etingof Pavel , Kinser Ryan , Walton Chelsea
Published: November 2019

This paper introduces methods for classifying actions of finite-dimensional Hopf algebras on path algebras of quivers and more generally on tensor algebras $T_B(V)$ where $B$ is semisimple. We work within the broader framework of finite (multi-)tensor categories $\mathcal{C}$, classifying tensor algebras in $\mathcal{C}$ in terms of $\mathcal{C}$-module categories. We obtain two classification results for actions of semisimple Hopf algebras: the first for actions that preserve the ascending filtration on tensor algebras and the second for actions that preserve the descending filtration on completed tensor algebras. Extending to more general fusion categories, we illustrate our classification result for tensor algebras in the pointed fusion categories $\textsf{Vec}_{G}^{\omega }$ and in group-theoretical fusion categories, especially for the representation category of the Kac–Paljutkin Hopf algebra.
Single Hepatocyte Hepatitis B Virus Transcriptional Landscape in HIV Coinfection
Authors: Balagopal Ashwin , Hwang Hyon S , Grudda Tanner , Quinn Jeffrey , Sterling Richard K , Sulkowski Mark S , Thio Chloe L
Published: November 2019

Background

Hepatitis B virus (HBV) is a leading cause of liver failure and hepatocellular carcinoma. Approximately 10% of people with HIV also have HBV and are at higher risk of liver disease progression than in HBV monoinfection. Antivirals, common to HIV and HBV, suppress HBV DNA levels but do not eradicate virus because the transcriptional template, covalently closed circular DNA (cccDNA), is long lived in infected hepatocytes.

Methods

Using single-cell laser capture microdissection, we isolated >1100 hepatocytes from 5 HIV/HBV coinfected persons with increasing exposure to HBV antivirals (HB1–HB5; no exposure to >7 years exposure), quantifying cccDNA and pregenomic RNA (pgRNA) in each cell using droplet digital polymerase chain reaction.

Results

The proportion of infected hepatocytes decreased with antiviral exposure from 96.4% (HB1) to 29.8% (HB5). Upper cccDNA range and median pgRNA decreased from HB1 to HB5 (P < .05 for both). The amount of pgRNA transcribed per cccDNA also decreased from HB1 to HB5 (P < .05). Cells with inactive pgRNA transcription were enriched from 0% (HB1) to 14.3% (HB5) of infected hepatocytes.

Conclusions

cccDNA transcription is reduced in HIV/HBV coinfected people with longer antiviral duration. Understanding HBV transcriptional regulation may be critical to develop a functional cure.
Functional Diversity of Evolutionary Novelties: Insights from Waterfall-Climbing Kinematics and Performance of Juvenile Gobiid Fishes
Authors: Blob R W , Lagarde R , Diamond K M , Keeffe R M , Bertram R S , Ponton D , Schoenfuss H L
Published: November 2019

Synopsis

The evolution of novel functional traits can contribute substantially to the diversification of lineages. Older functional traits might show greater variation than more recently evolved novelties, due to the accrual of evolutionary changes through time. However, functional complexity and many-to-one mapping of structure to function could complicate such expectations. In this context, we compared kinematics and performance across juveniles from multiple species for two styles of waterfall-climbing that are novel to gobiid fishes: ancestral “powerburst” climbing, and more recently evolved “inching”, which has been confirmed only among species of a single genus that is nested within the clade of powerburst climbers. Similar net climbing speeds across inching species seem, at first, to indicate that this more recently evolved mode of climbing exhibits less functional diversity. However, these similar net speeds arise through different pathways: Sicyopterus stimpsoni from Hawai’i move more slowly than S. lagocephalus from La Réunion, but may also spend more time moving. The production of similar performance between multiple functional pathways reflects a situation that resembles the phenomenon of many-to-one mapping of structure to function. Such similarity has the potential to mask appropriate interpretations of relative functional diversity between lineages, unless the mechanisms underlying performance are explored. More specifically, similarity in net performance between “powerburst” and “inching” styles indicates that selection on climbing performance was likely a limited factor in promoting the evolution of inching as a new mode of climbing. In this context, other processes (e.g., exaptation) might be implicated in the origin of this functional novelty.
Into the Woods…
Authors: Cooper Martin
Published: November 2019

The demand for web services is driving a proliferation of data centre building. These feed off electricity, which means the internet is contributing to global warming. Martin Cooper MBCS visits a green data centre to explore a small scale answer - in the last place you’d expect.
How Sustainable is the 4th Industrial Revolution?
Authors: Lanyon-Hogg R N
Published: November 2019

Professor R. N. Lanyon-Hogg CEng FBCS CITP reveals how the 4th industrial revolution has a key role to play in the journey towards a zero-carbon future, but sounds a cautious note about the many challenges ahead – and that there is little time to address these problems
Three Years of Change and More to Come…
Authors: Kinnear Andy
Published: November 2019

As Andy Kinnear, Chair of BCS Health and Care Executive, steps down from the role, he reflects on what has been achieved during his time in office and what the future holds.
New £50 Celebrates Turing’s Achievements
Authors: Hamilton Johanna
Published: November 2019

Johanna Hamilton interviews Sarah John, Chief Cashier of the Bank of England, about the decision to feature Alan Turing, the father of computer science, on the new £50 note.
Changes in Security at BCS
Authors: Fish Ian
Published: November 2019

Ian Fish FBCS and Chair of the Information Security Specialist Group, invites members to get in touch with the reformed Security and Privacy Executive.
Digital Badging: Is it Worth IT?
Authors: Jagger Paul D
Published: November 2019

With different standards in digital credentialing now evolving, Paul D. Jagger FBCS asks how we can assess the relative value and merit of badges.
Potential Economic Impacts of the Asian Longhorned Beetle (Coleoptera: Cerambycidae) in Eastern Canada
Authors: Pedlar John H , McKenney Daniel W , Yemshanov Denys , Hope Emily S
Published: November 2019

The Asian longhorned beetle (Anoplophora glabripennis Motschulsky) continues to pose a significant risk to deciduous forests around the world. We assess Asian longhorned beetle-related risks in eastern Canada by generating current and future climate suitability maps, import-based likelihood of introduction estimates for each urban center in our study area, and potential economic impacts in both urban and natural settings. For the current period, climatic suitability for Asian longhorned beetle was highest in southern Ontario, but was projected to expand significantly northward and eastward by midcentury. High likelihood of Asian longhorned beetle introduction was associated with large urban centers, but also smaller centers with high levels of pest-associated imports. Potential costs for the removal and replacement of Asian longhorned beetle-impacted street trees ranged from CDN$8.6 to $12.2 billion, with the exact amount and city-level ranking depending on the method used to calculate risk. Potential losses of merchantable maple (Acer) timber were estimated at CDN$1.6 billion using provincial stumpage fees and CDN$431 million annually when calculated using a combination of economic and forestry product statistics. The gross value of edible maple products, which could potentially be affected by Asian longhorned beetle, was estimated at CDN$358 million annually. These values can help inform the scale of early detection surveys, potential eradication efforts, and research budgets in the event of future Asian longhorned beetle introductions.
Mining correlated high-utility itemsets using various measures
Authors: Fournier-Viger Philippe , Zhang Yimin , Lin Jerry Chun-Wei , Dinh Duy-Tai , Bac Le Hoai
Published: November 2019

Discovering high-utility itemsets (HUIs) consists of finding sets of items that yield a high profit in customer transaction databases. An important limitation of traditional high-utility itemset mining (HUIM) is that only the utility measure is used for assessing the interestingness of patterns. This leads to finding several itemsets that have a high profit but contain items that are weakly correlated. To address this issue, this paper proposes to integrate the concept of correlation in HUIM to find profitable itemsets that are highly correlated, using the all-confidence and bond measures. An efficient algorithm named FCHM (fast correlated high-utility itemset miner) is proposed to efficiently discover correlated high-utility itemsets (CHIs). Two versions of the algorithm are proposed: FCHM$_{all\text{-}confidence}$ and FCHM$_{bond}$, which are based on the all-confidence and bond measures, respectively. An experimental evaluation was done using four real-life benchmark datasets from the HUIM literature: mushroom, retail, kosarak and foodmart. Results show that FCHM is efficient and can prune a huge amount of weakly CHIs.
Gain-of-function mutations: key tools for modifying or designing novel proteins in plant molecular engineering
Authors: Zhu Li , Qian Qian
Published: November 2019

This article comments on:

Deng WJ, Li RQ, Xu YW, Mao RY, Chen SF, Chen LB, Chen LT, Liu YG, Chen YL. 2020. A lipid transfer protein variant with a mutant eight-cysteine motif causes photoperiod- and temperature-sensitive dwarfism in rice. Journal of Experimental Botany 71, 1294–1305.
GABA negatively regulates adventitious root development in poplar
Authors: Xie Tiantian , Ji Jing , Chen Wei , Yue Jianyun , Du Changjian , Sun Jiacheng , Chen Lanzhen , Jiang Zeping , Shi Shengqing
Published: November 2019

γ-Aminobutyric acid (GABA) influences plant growth, but little is known about how this metabolite regulates adventitious root (AR) development. Here, we investigate the effects of GABA on ARs using poplar lines overexpressing glutamate decarboxilase 2 (GAD2) and by treating poplar stem cuttings with exogenous GABA or vigabatrin (VGB; a specific GABA transaminase inhibitor). Endogenous GABA accumulation not only inhibited AR growth, but it also suppressed or delayed AR formation. Anatomical observations revealed that the GABA and VGB treatments resulted in a 1 d delay in the formation of AR primordia and the appearance of ARs. This delay coincided with changes in primary metabolism, including transient increases in hexose and amino acid levels. GABA-dependent changes in the expression of genes related to hormone synthesis and signalling, as well as analysis of hormone levels revealed that ethylene-dependent pathways were decreased at the earliest stage of AR formation. In contrast, auxin and abscisic acid were increased at 1–5 d as well as GA4 over a 5 d period of AR formation. These results demonstrate that GABA plays a crucial role in AR development. Evidence is presented demonstrating that GABA can interact with hormone-related pathways as well as carbon/nitrogen metabolism. These findings also elucidate the functions of GABA in plant development.
The role of P-type IIA and P-type IIB Ca2+-ATPases in plant development and growth
Authors: García Bossi Julián , Kumar Krishna , Barberini María Laura , Domínguez Gabriela Díaz , Rondón Guerrero Yossmayer Del Carmen , Marino-Buslje Cristina , Obertello Mariana , Muschietti Jorge P , Estevez José M
Published: November 2019

As sessile organisms, plants have evolved mechanisms to adapt to variable and rapidly fluctuating environmental conditions. Calcium (Ca2+) in plant cells is a versatile intracellular second messenger that is essential for stimulating short- and long-term responses to environmental stresses through changes in its concentration in the cytosol ([Ca2+]cyt). Increases in [Ca2+]cyt direct the strength and length of these stimuli. In order to terminate them, the cells must then remove the cytosolic Ca2+ against a concentration gradient, either taking it away from the cell or storing it in organelles such as the endoplasmic reticulum (ER) and/or vacuoles. Here, we review current knowledge about the biological roles of plant P-type Ca2+-ATPases as potential actors in the regulation of this cytosolic Ca2+ efflux, with a focus the IIA ER-type Ca2+-ATPases (ECAs) and the IIB autoinhibited Ca2+-ATPases (ACAs). While ECAs are analogous proteins to animal sarcoplasmic-endoplasmic reticulum Ca2+-ATPases (SERCAs), ACAs are equivalent to animal plasma membrane-type ATPases (PMCAs). We examine their expression patterns in cells exhibiting polar growth and consider their appearance during the evolution of the plant lineage. Full details of the functions and coordination of ECAs and ACAs during plant growth and development have not yet been elucidated. Our current understanding of the regulation of fluctuations in Ca2+ gradients in the cytoplasm and organelles during growth is in its infancy, but recent technological advances in Ca2+ imaging are expected to shed light on this subject.
HD 213885b: a transiting 1-d-period super-Earth with an Earth-like composition around a bright (V = 7.9) star unveiled by TESS
Authors: Espinoza Néstor , Brahm Rafael , Henning Thomas , Jordán Andrés , Dorn Caroline , Rojas Felipe , Sarkis Paula , Kossakowski Diana , Schlecker Martin , Díaz Matías R , Jenkins James S , Aguilera-Gomez Claudia , Jenkins Jon M , Twicken Joseph D , Collins Karen A , Lissauer Jack , Armstrong David J , Adibekyan Vardan , Barrado David , Barros Susana C C , Battley Matthew , Bayliss Daniel , Bouchy François , Bryant Edward M , Cooke Benjamin F , Demangeon Olivier D S , Dumusque Xavier , Figueira Pedro , Giles Helen , Lillo-Box Jorge , Lovis Christophe , Nielsen Louise D , Pepe Francesco , Pollacco Don , Santos Nuno C , Sousa Sergio G , Udry Stéphane , Wheatley Peter J , Turner Oliver , Marmier Maxime , Ségransan Damien , Ricker George , Latham David , Seager Sara , Winn Joshua N , Kielkopf John F , Hart Rhodes , Wingham Geof , Jensen Eric L N , Hełminiak Krzysztof G , Tokovinin A , Briceño C , Ziegler Carl , Law Nicholas M , Mann Andrew W , Daylan Tansu , Doty John P , Guerrero Natalia , Boyd Patricia , Crossfield Ian , Morris Robert L , Henze Christopher E , Chacon Aaron Dean
Published: November 2019

We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b) orbiting the bright (V = 7.9) star HD 213885 (TOI-141, TIC 403224672), detected using photometry from the recently launched TESS mission. Using FEROS, HARPS, and CORALIE radial velocities, we measure a precise mass of 8.8 ± 0.6 M⊕ for this 1.74 ± 0.05 R⊕ exoplanet, which provides enough information to constrain its bulk composition – similar to Earth’s but enriched in iron. The radius, mass, and stellar irradiation of HD 213885b are, given our data, very similar to 55 Cancri e, making this exoplanet a good target to perform comparative exoplanetology of short period, highly irradiated super-Earths. Our precise radial velocities reveal an additional 4.78-d signal which we interpret as arising from a second, non-transiting planet in the system, HD 213885c, whose minimum mass of 19.9 ± 1.4 M⊕ makes it consistent with being a Neptune-mass exoplanet. The HD 213885 system is very interesting from the perspective of future atmospheric characterization, being the second brightest star to host an USP transiting super-Earth (with the brightest star being, in fact, 55 Cancri). Prospects for characterization with present and future observatories are discussed.
Gravitational waves from dynamical tides in white dwarf binaries
Authors: McNeill L O , Mardling R A , Müller B
Published: November 2019

We study the effect of tidal forcing on gravitational wave signals from tidally relaxed white dwarf pairs in the LISA, DECIGO and BBO frequency band (0.1 − 100 mHz). We show that for stars not in hydrostatic equilibrium (in their own rotating frames), tidal forcing will result in energy and angular momentum exchange between the orbit and the stars, thereby deforming the orbit and producing gravitational wave power in harmonics not excited in perfectly circular synchronous binaries. This effect is not present in the usual orbit-averaged treatment of the equilibrium tide, and is analogous to transit timing variations in multiplanet systems. It should be present for all LISA white dwarf pairs since gravitational waves carry away angular momentum faster than tidal torques can act to synchronize the spins, and when mass transfer occurs as it does for at least eight LISA verification binaries. With the strain amplitudes of the excited harmonics depending directly on the density profiles of the stars, gravitational wave astronomy offers the possibility of studying the internal structure of white dwarfs, complimenting information obtained from asteroseismology of pulsating white dwarfs. Since the vast majority of white-dwarf pairs in this frequency band are expected to be in the quasi-circular state, we focus here on these binaries, providing general analytic expressions for the dependence of the induced eccentricity and strain amplitudes on the stellar apsidal motion constants and their radius and mass ratios. Tidal dissipation and gravitation wave damping will affect the results presented here and will be considered elsewhere.
Stellar dynamos with solar and antisolar differential rotations: Implications to magnetic cycles of slowly rotating stars
Authors: Karak Bidya Binay , Tomar Aparna , Vashishth Vindya
Published: November 2019

Simulations of magnetohydrodynamics convection in slowly rotating stars predict antisolar differential rotation (DR) in which the equator rotates slower than poles. This antisolar DR in the usual αΩ dynamo model does not produce polarity reversal. Thus, the features of large-scale magnetic fields in slowly rotating stars are expected to be different than stars having solar-like DR. In this study, we perform mean-field kinematic dynamo modelling of different stars at different rotation periods. We consider antisolar DR for the stars having rotation period larger than 30 d and solar-like DR otherwise. We show that with particular α profiles, the dynamo model produces magnetic cycles with polarity reversals even with the antisolar DR provided, the DR is quenched when the toroidal field grows considerably high and there is a sufficiently strong α for the generation of toroidal field. Due to the antisolar DR, the model produces an abrupt increase of magnetic field exactly when the DR profile is changed from solar-like to antisolar. This enhancement of magnetic field is in good agreement with the stellar observational data as well as some global convection simulations. In the solar-like DR branch, with the decreasing rotation period, we find the magnetic field strength increases while the cycle period shortens. Both of these trends are in general agreement with observations. Our study provides additional support for the possible existence of antisolar DR in slowly rotating stars and the presence of unusually enhanced magnetic fields and possibly cycles that are prone to production of superflare.
Type IIb supernovae by the grazing envelope evolution
Authors: Naiman Binyamin V , Sabach Efrat , Gilkis Avishai , Soker Noam
Published: November 2019

We simulate the evolution of binary systems with a massive primary star of 15M⊙ where we introduce an enhanced mass loss due to jets that the secondary star might launch, and find that in many cases the enhanced mass loss brings the binary system to experience the grazing envelope evolution (GEE) and form a progenitor of Type IIb supernova (SN IIb). The jets, the Roche lobe overflow (RLOF), and a final stellar wind remove most of the hydrogen-rich envelope, leaving a blue-compact SN IIb progenitor. In many cases without this jet-driven mass loss the system enters a common envelope evolution (CEE) and does not form a SN IIb progenitor. We use the stellar evolutionary code MESA binary and mimic the jet-driven mass loss with a simple prescription and some free parameters. Our results show that the jet-driven mass loss, that some systems have during the GEE, increases the parameter space for stellar binary systems to form SN IIb progenitors. We estimate that the binary evolution channel with GEE contributes about a quarter of all SNe IIb, about equal to the contribution of each of the other three channels, binary evolution without a GEE, fatal CEE (where the secondary star merges with the core of the giant primary star), and the single star channel.
Exact joint likelihood of pseudo-Cℓ estimates from correlated Gaussian cosmological fields
Authors: Upham Robin E , Whittaker Lee , Brown Michael L
Published: November 2019

We present the exact joint likelihood of pseudo-Cℓ power spectrum estimates measured from an arbitrary number of Gaussian cosmological fields. Our method is applicable to both spin-0 fields and spin-2 fields, including a mixture of the two, and is relevant to cosmic microwave background (CMB), weak lensing, and galaxy clustering analyses. We show that Gaussian cosmological fields are mixed by a mask in such a way that retains their Gaussianity and derive exact expressions for the covariance of the cut-sky spherical harmonic coefficients, the pseudo-aℓms, without making any assumptions about the mask geometry. We then show that each auto or cross-pseudo-Cℓ estimator can be written as a quadratic form, and apply the known joint distribution of quadratic forms to obtain the exact joint likelihood of a set of pseudo-Cℓ estimates in the presence of an arbitrary mask. We show that the same formalism can be applied to obtain the exact joint likelihood of quadratic maximum likelihood power spectrum estimates. Considering the polarization of the CMB as an example, we show using simulations that our likelihood recovers the full, exact multivariate distribution of EE, BB, and EB pseudo-Cℓ power spectra. Our method provides a route to robust cosmological constraints from future CMB and large-scale structure surveys in an era of ever-increasing statistical precision.
The connection between merging double compact objects and the Ultraluminous X-ray Sources
Authors: Mondal Samaresh , Belczyński Krzysztof , Wiktorowicz Grzegorz , Lasota Jean-Pierre , King Andrew R
Published: November 2019

We explore the different formation channels of merging double compact objects (DCOs: BH-BH/BH-NS/NS-NS) that went through a ultraluminous X-ray phase (ULX: X-ray sources with apparent luminosity exceeding $10^{39}\rm {\ erg\ s^{-1}}$). There are many evolutionary scenarios which can naturally explain the formation of merging DCO systems: isolated binary evolution, dynamical evolution inside dense clusters and chemically homogeneous evolution of field binaries. It is not clear which scenario is responsible for the majority of LIGO/Virgo sources. Finding connections between ULXs and DCOs can potentially point to the origin of merging DCOs as more and more ULXs are discovered. We use the StarTrack population synthesis code to show how many ULXs will form merging DCOs in the framework of isolated binary evolution. Our merger rate calculation shows that in the local Universe typically $50\%$ of merging BH-BH progenitor binaries have evolved through a ULX phase. This indicates that ULXs can be used to study the origin of LIGO/Virgo sources. We have also estimated that the fraction of observed ULXs that will form merging DCOs in future varies between $5\%$ to $40\%$ depending on common envelope model and metallicity.
Fade to grey: systematic variation of galaxy attenuation curves with galaxy properties in the eagle simulations
Authors: Trayford James W , Lagos Claudia del P , Robotham Aaron S G , Obreschkow Danail
Published: November 2019

We present a simple model for galaxy attenuation by fitting skirt radiative transfer calculations for ∼10 000 eagle galaxies at redshifts z = 2 − 0. Our model adapts the two-component screen model of Charlot & Fall, parametrizing the optical depth and slope of the interstellar medium screen using the average dust surface density, Σdust. We recover relatively tight relations between these parameters for the eagle sample, but also provide the scatter in these parameters owing to the morphological variation and orientation of galaxies. We also find that these relations are nearly independent of redshift in the eagle model. By pairing our model with an empirical prescription for birth clouds below the resolution scale of the simulation, we reproduce the observed relation between attenuation slope and optical depth for the first time in a cosmological simulation. We demonstrate that this result is remarkably independent of the attenuation properties assumed for the birth cloud screen, merely requiring a boosted attenuation for infant stars. We present this model with a view to interpreting observations, as well as processing semi-analytic models and other hydrodynamic simulations.