bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quantitative bias analysis to estimate measurement error-related attenuation of the association between self-reported physical activity and colorectal cancer risk
Authors: Mahmood Shahid , Nguyen Nga H , Bassett Julie K , MacInnis Robert J , Karahalios Amalia , Owen Neville , Bruinsma Fiona J , Milne Roger L , Giles Graham G , English Dallas R , Lynch Brigid M 
Published: September 2019

Abstract

Background
Self-reported physical activity is inaccurate, yet few investigators attempt to adjust for measurement error when estimating risks for health outcomes. We estimated what the association between self-reported physical activity and colorectal cancer risk would be if physical activity had been assessed using accelerometry instead.

Methods
We conducted a validation study in which 235 Australian adults completed a telephone-administered International Physical Activity Questionnaire (IPAQ), and wore an accelerometer (Actigraph GT3X+) for 7 days. Using accelerometer-assessed physical activity as the criterion measure, we calculated validity coefficients and attenuation factors using a structural equation model adjusted for age, sex, education and body mass index. We then used a regression calibration approach to apply the attenuation factors to data from the Melbourne Collaborative Cohort Study (MCCS) to compute bias-adjusted hazard ratios (HR) and 95% confidence intervals (CI).

Results
Average daily minutes of physical activity from the short form of the International Physical Activity Questionnaire (IPAQ-short) were substantially higher than accelerometer-measured duration (55 versus 32 min). The validity coefficient (0.32; 95% CI: 0.20, 0.43) and attenuation factor (0.20; 95% CI: 0.12, 0.28) were low. The HRs for colorectal cancer risk for high (75th percentile; 411 min/week) versus low (25th percentile; 62 min/week) levels of self-reported physical activity were 0.95 (95% CI: 0.87, 1.05) before and 0.78 (95% CI: 0.47, 1.28) after bias adjustment.

Conclusions
Over-estimation of physical activity by the IPAQ-short substantially attenuates the association between physical activity and colorectal cancer risk, suggesting that the protective effect of physical activity has been previously underestimated.
Phospho-Ser727 triggers a multistep inactivation of STAT3 by rapid dissociation of pY705–SH2 through C-terminal tail modulation
Authors: Yang Junhao , Kunimoto Hiroyuki , Katayama Bumpei , Zhao Hong , Shiromizu Takashi , Wang Lingyu , Ozawa Toshiyuki , Tomonaga Takeshi , Tsuruta Daisuke , Nakajima Koichi 
Published: September 2019

Abstract
Signal transducer and activator of transcription 3 (STAT3) is involved in many biological processes, including immunity and cancer. STAT3 becomes phosphorylated at Tyr705 and Ser727 on IL-6 stimulation. Phospho-Tyr705 (pY705) stabilizes the STAT3 dimer with reciprocal interactions between pY705 and the SH2 of the other molecule and phospho-Ser727 (pS727) accelerates pY705 dephosphorylation. We study how pS727 regulates STAT3 in both structural and biological perspectives. Using STAT3 reconstituted in HepG2-stat3-knockout cells, we show that pS727, together with a handshake N-terminal domain (NTD) interaction, causes rapid inactivation of STAT3 for pY705 dephosphorylation and a chromosome region maintenance 1 (CRM1)-independent nuclear export, which is critical for faithful STAT3 response to the cellular signals. The various N-terminal tags, GFP-related Ruby and FLAG, rendered the export CRM1-dependent and especially FLAG-tag caused nuclear accumulation of STAT3, indicating the presence of conformational changes in inactivation. Impaired reactivation of STAT3 by S727A or FLAG-tag delayed or inhibited the IL-6-induced saa1 mRNA expression, respectively. The detailed analysis of the pY705–SH2 structure identified the C-terminal tail (CTT) from L706 to P715 as a key regulator of the CTT–CTT intermolecular and the CTT–SH2 intramolecular interactions that support pY705–SH2 association. The functional studies using multiple STAT3 mutants indicated that the degree of the two interactions determines the stability of pY705–SH2 interaction. Importantly, Pro715 was critical for the pS727's destabilizing activity and the known phosphorylation and acetylation at the CTT structurally inhibited the pY705–SH2 interaction. Thus, pS727 triggers pY705–SH2 dissociation by weakening the supportive interactions likely through CTT modulation, inducing rapid cycles of STAT3 activation–inactivation for proper function of STAT3.
Effect of 20-Hydroxyecdysone, a Phytoecdysteroid, on Development, Digestive, and Detoxification Enzyme Activities of Tribolium castaneum (Coleoptera: Tenebrionidae)
Authors: Ajaha Ayoub , Bouayad Noureddin , Aarab Ahmed , Rharrabe Kacem 
Published: September 2019

AbstractPlants present a delimited reservoir of biologically active compounds. Many plants synthesize several compounds of secondary metabolism, such as alkaloids, terpenoids, phenolics, steroids, etc. Such compounds are generally thought to be involved in plant–insect interactions. Phytoecdysteroids are a class of chemicals that plants synthesize; these compounds are analogues of molting hormones produced by insects. In this work, the effect of the 20-hydroxyecdysone, which is a molecule that belongs to the family of phytoecdysteroids, was tested on an insect pest, Tribolium castaneum (Herbst). Firstly, the effect of this molecule on post-embryonic development parameters was tested after ingestion at 300, 600, 900, and 1,200 ppm. Secondly, the effect of the 20-hydroxyecdysone was also tested on the biological parameters (proteins, alpha-amylase, detoxification enzymes). The results of the post-embryonic parameters test showed an important induction of larval mortality and a significant reduction of pupation and adult emergence rates. On the other hand, the test on the biological parameters showed that the 20-hydroxyecdysone caused a significant decrease in the levels of soluble proteins in treated larvae. In addition, the alpha-amylase activity was significantly inhibited by the ingestion of the phytoecdysteroid. And there was also a disruption of detoxification enzymes. The whole of the disturbances recorded in this work prove that phytoecdysteroids are thought to have potential value on T. castaneum control.
Moving to Keep Fit: Feeding Behavior and Movement of Helicoverpa armigera (Lepidoptera: Noctuidae) on Artificial Diet With Different Protein: Carbohydrate Ratios
Authors: Wang Peng , Furlong Michael J , Walsh Thomas K , Zalucki Myron P 
Published: September 2019

AbstractInsect herbivores can modify their foraging behavior to obtain a balanced food intake, and they tend to move between food sources with different nutrient values. We investigated this movement in early instar larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) using a putative optimal artificial diet (OP) and high protein (HP) and high carbohydrate (HC) artificial diets based on protein (p) and carbohydrate (c) ratios. Larvae were allowed to choose between the same kind of diet cubes (effectively no-choice), or diet cubes with different p: c ratios. In no-choice tests, we found that first instar larvae remained longest on OP diet and spent the least time on HC diet, while third instar larvae remained longest on HC diet and spent least time on OP diet. First instar larvae moved the most when provided with HC diet, while third instar larvae moved most when provided with OP diet. However, both stages moved the least when allowed to choose between diet cubes with different p: c ratios. The relative growth rate decreased when larvae increased their movement, but this influence was not evident when larvae fed on HC diet. Larvae that fed only on HC diet had the highest relative growth rate, followed by larvae with access to all diets simultaneously, indicating a behavior to mix nutrient intake. We relate these findings to behavior of this major pest species under field conditions.
Mitotic Index Thresholds Do Not Predict Clinical Outcome for IDH-Mutant Astrocytoma
Authors: Yoda Rebecca A , Marxen Troy , Longo Lauren , Ene Chibawanye , Wirsching Hans-Georg , Keene C Dirk , Holland Eric C , Cimino Patrick J 
Published: September 2019

Abstract
Current histological grading recommendations for isocitrate dehydrogenase (IDH)-mutant astrocytoma are imprecise and not reliably predictive of patient outcome, while somatic copy number alterations are emerging as important prognostic biomarkers. One explanation for this relative underperformance of histological grading is that current criteria to distinguish World Health Organization (WHO) grade III anaplastic astrocytomas from lower-grade diffuse astrocytomas (WHO grade II) are vague (“increased mitotic activity”). This qualitative approach ensures diagnostic uncertainty and a broad “gray zone” where both diffuse and anaplastic designations can reasonably be assigned. Thus, we hypothesized that interobserver variability and lack of defined mitotic thresholds for IDH-mutant astrocytomas underlies poor predictive accuracy of current histologic grading approaches. To test this hypothesis, we quantified total mitotic figures and maximum mitotic activity per 10 high-powered fields in an institutional cohort of IDH-mutant astrocytomas. In our cohort, there was no mitotic activity threshold that was reflective of progression-free or overall survival (OS). Furthermore, in a multivariate Cox regression model consisting of mitotic activity, molecular markers, and clinical characteristics, only CDKN2A homozygous deletion was identified as a relevant variant for poor OS. We conclude that lack of defined mitotic figure thresholds may not contribute to underperformance of histological grading for IDH-mutant astrocytomas.
The ethylene receptors CpETR1A and CpETR2B cooperate in the control of sex determination in Cucurbita pepo
Authors: García Alicia , Aguado Encarnación , Martínez Cecilia , Loska Damian , Beltrán Sergi , Valenzuela Juan Luis , Garrido Dolores , Jamilena Manuel 
Published: September 2019

Abstract
High-throughput screening of an ethyl methanesulfonate-generated mutant collection of Cucurbita pepo using the ethylene triple-response test resulted in the identification of two semi-dominant ethylene-insensitive mutants: etr1a and etr2b. Both mutations altered sex determination mechanisms, promoting conversion of female into bisexual or hermaphrodite flowers, and monoecy into andromonoecy, thereby delaying the transition to female flowering and reducing the number of pistillate flowers per plant. The mutations also altered the growth rate and maturity of petals and carpels in pistillate flowers, lengthening the time required for flowers to reach anthesis, as well as stimulating the growth rate of ovaries and the parthenocarpic development of fruits. Whole-genome sequencing allowed identification of the causal mutation of the phenotypes as two missense mutations in the coding region of CpETR1A and CpETR2B, each one corresponding to one of the duplicates of ethylene receptor genes highly homologous to Arabidopsis ETR1 and ETR2. The phenotypes of homozygous and heterozygous single- and double-mutant plants indicated that the two ethylene receptors cooperate in the control of the ethylene response. The level of ethylene insensitivity, which was determined by the strength of each mutant allele and the dose of wild-type and mutant etr1a and etr2b alleles, correlated with the degree of phenotypic changes in the mutants.
Combined transcriptome and metabolome analysis identifies defence responses in spider mite-infested pepper (Capsicum annuum)
Authors: Zhang Yuanyuan , Bouwmeester Harro J , Kappers Iris F 
Published: September 2019

Abstract
Plants regulate responses towards herbivory through fine-tuning of defence-related hormone production, expression of defence genes, and production of secondary metabolites. Jasmonic acid (JA) plays a key role in plant–herbivorous arthropod interactions. To understand how pepper (Capsicum annuum) responds to herbivory, leaf transcriptomes and metabolomes of two genotypes different in their susceptibility to spider mites were studied. Mites induced both JA and salicylic acid (SA) signalling. However, mite infestation and exogenous JA resulted in distinct transcriptome profiles. Compared with JA, mites induced fewer differentially expressed genes involved in metabolic processes (except for genes involved in the phenylpropanoid pathway) and lipid metabolic processes. Furthermore, pathogen-related defence responses including WRKY transcription factors were more strongly induced upon mite infestation, probably as a result of induced SA signalling. Untargeted analysis of secondary metabolites confirmed that JA treatment induced larger changes in metabolism than spider mite infestation, resulting in higher terpenoid and flavonoid production. The more resistant genotype exhibited a larger increase in endogenous JA and volatile and non-volatile secondary metabolites upon infestation, which could explain its stronger defence. Reasoning that in JA–SA antagonizing crosstalk, SA defences are prioritized over JA defences, we hypothesize that lack of SA-mediated repression of JA-induced defences could result in gain of resistance towards spider mites in pepper.
Atmospheric scintillation noise in ground-based exoplanet photometry
Authors: Föhring D , Wilson R W , Osborn J , Dhillon V S 
Published: September 2019

ABSTRACT
Atmospheric scintillation caused by optical turbulence in the Earth’s atmosphere can be the dominant source of noise in ground-based photometric observations of bright targets, which is a particular concern for ground-based exoplanet transit photometry. We demonstrate the implications of atmospheric scintillation for exoplanet transit photometry through contemporaneous turbulence profiling and transit observations. We find a strong correlation between measured intensity variations and scintillation determined through optical turbulence profiling. This correlation indicates that turbulence profiling can be used to accurately model the amount of scintillation noise present in photometric observations on another telescope at the same site. We examine the conditions under which scintillation correction would be beneficial for transit photometry through turbulence profiling, and find that for the atmosphere of La Palma, scintillation dominates for bright targets of magnitude above V ∼ 10.1 mag for a 0.5 m telescope, and at V ∼ 11.7 mag for a 4.2 m telescope under median atmospheric conditions. Through Markov-chain Monte Carlo methods we examine the effect of scintillation noise on the uncertainty of the measured exoplanet parameters, and determine the regimes where scintillation correction is especially beneficial. The ability to model the amount of noise in observations due to scintillation, given an understanding of the atmosphere, is a crucial test for our understanding of scintillation and the overall noise budget of our observations.
Relaxation of spherical stellar systems
Authors: Lau Jun Yan , Binney James 
Published: September 2019

ABSTRACTA total of 10 000 simulations of 1000 particle realizations of the same cluster are computed by direct force summation. After three crossing times self-gravity has amplified the original Poisson noise more than tenfold on large scales, and the amplification is still far from complete. The cluster’s fundamental dipole mode is strongly excited by Poisson noise, and this mode makes a major contribution to driving diffusion of stars in energy. The diffusive flow through action space is computed for the simulations and compared with the predictions of both Chandrasekhar’s local-scattering theory and the Balescu–Lenard (BL) equation. The predictions of local-scattering theory are qualitatively wrong because the latter neglects self-gravity. These results imply that local-scattering theory can account for only a fraction of a cluster’s relaxation. Future work on cluster evolution should employ either N-body simulation or the BL equation. However, significant code development will be required to make use of the BL equation practicable and the way forward may be to merge BL theory with local scattering theory so fluctuations of every scale are efficiently handled.
Transit timing variations in the WASP-4 planetary system
Authors: Southworth John , Dominik M , Jørgensen U G , Andersen M I , Bozza V , Burgdorf M J , D’Ago G , Dib S , Figuera Jaimes R , Fujii Y I , Gill S , Haikala L K , Hinse T C , Hundertmark M , Khalouei E , Korhonen H , Longa-Peña P , Mancini L , Peixinho N , Rabus M , Rahvar S , Sajadian S , Skottfelt J , Snodgrass C , Spyratos P , Tregloan-Reed J , Unda-Sanzana E , von Essen C 
Published: September 2019

ABSTRACT
Transits in the planetary system WASP-4 were recently found to occur 80 s earlier than expected in observations from the TESS satellite. We present 22 new times of mid-transit that confirm the existence of transit timing variations, and are well fitted by a quadratic ephemeris with period decay dP/dt = −9.2 ± 1.1 ms yr−1. We rule out instrumental issues, stellar activity, and the Applegate mechanism as possible causes. The light-time effect is also not favoured due to the non-detection of changes in the systemic velocity. Orbital decay and apsidal precession are plausible but unproven. WASP-4 b is only the third hot Jupiter known to show transit timing variations to high confidence. We discuss a variety of observations of this and other planetary systems that would be useful in improving our understanding of WASP-4 in particular and orbital decay in general.
Aero-resonant migration
Authors: Storch Natalia I , Batygin Konstantin 
Published: September 2019

ABSTRACTThe process of planet conglomeration, which primarily unfolds in a geometrically thin disc of gas and dust, is often accompanied by dynamical excitation of the forming planets and planetesimals. The ensuing orbital crossing can lead to large-scale collisional fragmentation, populating the system with icy and rocky debris. In a gaseous nebula, such leftover solid matter tends to spiral down towards the host star due to aerodynamic drag. Along the way, the inward drifting debris can encounter planets and gravitationally couple to them via mean-motion resonances, sapping them of their orbital energy and causing them to migrate. Here, we develop a simple theory for this migration mechanism, which we call ‘aero-resonant migration’ (ARM), in which small planetesimals (10 m ≲ s ≲ 10 km) undergo orbital decay due to aerodynamic drag and resonantly shepherd planets ahead of them. Using a combination of analytical calculations and numerical experiments, we show that ARM is a robust migration mechanism, able to significantly transport planets on time-scales ≲1 Myr, and present simple formulae for the ARM rate.
Red and dead CANDELS: massive passive galaxies at the dawn of the Universe
Authors: Merlin E , Fortuni F , Torelli M , Santini P , Castellano M , Fontana A , Grazian A , Pentericci L , Pilo S , Schmidt K B 
Published: September 2019

ABSTRACT
We search the five CANDELS fields (COSMOS, EGS, GOODS-North, GOODS-South, and UDS) for passively evolving a.k.a. ‘red and dead’ massive galaxies in the first 2 Gyr after the big bang, integrating and updating the work on GOODS-South presented in a previous paper. We perform SED-fitting on photometric data, with top-hat star-formation histories to model an early and abrupt quenching, and using a probabilistic approach to select only robust candidates. Using libraries without (with) spectral lines emission, starting from a total of more than 20 000 z > 3 sources we end up with 102 (40) candidates, including one at z = 6.7. This implies a minimal number density of 1.73 ± 0.17 × 10−5 (6.69 ± 1.08 × 10−6) Mpc−3 for 3 < z < 5; applying a correction factor to account for incompleteness yields 2.30 ± 0.20 × 10−5. We compare these values with those from five recent hydrodynamical cosmological simulations, finding a reasonable agreement at z < 4; tensions arise at earlier epochs. Finally, we use the star-formation histories from the best-fitting models to estimate the contribution of the high-redshift passive galaxies to the global star formation rate density during their phase of activity, finding that they account for ∼5–10 per cent of the total star formation at 3 < z < 8, despite being only $\sim 0.5{{\ \rm per\ cent}}$ of the total in number. The resulting picture is that early and strong star formation activity, building massive galaxies on short time-scales and followed by a quick and abrupt quenching, is a rare but crucial phenomenon in the early Universe: the evolution of the cosmos must be heavily influenced by the short but powerful activity of these pristine monsters.
The role of the H2 adiabatic index in the formation of the first stars
Authors: Sharda Piyush , Krumholz Mark R , Federrath Christoph 
Published: September 2019

ABSTRACT
The adiabatic index of H$_2\,$ ($\gamma _{\mathrm{H_2}}$) is non-constant at temperatures between $100{\,\rm{and}\,}10^4\, \mathrm{K}$ due to the large energy spacing between its rotational and vibrational modes. For the formation of the first stars at redshifts 20 and above, this variation can be significant because primordial molecular clouds are in this temperature range due to the absence of efficient cooling by dust and metals. We study the possible importance of variations in $\gamma _{\mathrm{H_2}}$ for the primordial initial mass function by carrying out 80 3D gravitohydrodynamic simulations of collapsing clouds with different random turbulent velocity fields, half using fixed $\gamma _{\rm H_2} = 7/5$ in the limit of classical diatomic gas (used in earlier works) and half using an accurate quantum mechanical treatment of $\gamma _{\mathrm{H_2}}$. We use the adaptive mesh refinement code flash with the primordial chemistry network from KROME for this study. The simulation suite produces almost 400 stars, with masses from 0.02 to 50 M⊙ (mean mass ${\sim}10.5\, \mathrm{M_{\odot }}$ and mean multiplicity fraction ∼0.4). While the results of individual simulations do differ when we change our treatment of $\gamma _{\mathrm{H_2}}$, we find no statistically significant differences in the overall mass or multiplicity distributions of the stars formed in the two sets of runs. We conclude that, at least prior to the onset of radiation feedback, approximating H2 as a classical diatomic gas with $\gamma _{\rm H_2} = 7/5$ does not induce significant errors in simulations of the fragmentation of primordial gas. None the less, we recommend using the accurate formulation of the H$_2\,$ adiabatic index in primordial star formation studies since it is not computationally more expensive and provides a better treatment of the thermodynamics.
A toy model for the dynamical discrepancies on galactic scales
Authors: Petersen Jonas , Rosenlyst Martin 
Published: September 2019

ABSTRACTIn this study a simple toy model solution to the missing gravity problem on galactic scales is reverse engineered from galactic data via imposing broad assumptions. It is shown that the toy model solution can be written in terms of baryonic quantities, is highly similar to pseudo-isothermal dark matter on galactic scales and can accommodate the same observations. In this way, the toy model solution is similar to MOND modified gravity in the Bekenstein–Milgrom formulation. However, it differs in the similarity to pseudo-isothermal dark matter and in the functional form. In loose terms, it is shown that pseudo-isothermal dark matter can be written in terms of baryonic quantities. The required form suggests that it may be worth looking into a mechanism that can increase the magnitude of the post-Newtonian correction from general relativity for low accelerations.