bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating spatiotemporal variation in water chemistry of the upper Colorado River using longitudinal profiling
Authors: Hensley Robert T. , Spangler Margaret J. , DeVito Lauren F. , Decker Paul H. , Cohen Matthew J. , Gooseff Michael N.
Published: December 2019

Stream water chemistry is traditionally measured as variation over time at fixed sites, with sparse sites providing a crude understanding of spatial heterogeneity. An alternative Lagrangian reference frame measures changes with respect to both space and time as water travels through a network. Here, we collected sensor‐based measurements of water chemistry at high spatial resolution along nearly 500 km of the Upper Colorado River. Our objective was to understand sources of spatiotemporal heterogeneity across different solutes and determine whether longitudinal change manifests as smooth gradients as suggested by the River Continuum Concept (RCC) or as abrupt changes as suggested by the Serial Discontinuity Concept (SDC). Our results demonstrate that Lagrangian sampling integrates spatiotemporal variation, and profiles reflect processes that vary in both space and time and over different scales. Over each day of sampling, water temperature (T) and dissolved oxygen (DO) varied strongly in response to diel solar cycles, with most of the variation driven by sampling time rather than sampling location. Equilibration of T and DO with the atmosphere limited small scale spatial heterogeneity, with variation at the entire profile scale driven by regional climate gradients. As such, T and DO profiles more closely approximated the smooth gradients of the RCC (though including temporal sampling artefacts). Conversely, variation in specific conductance and nitrate (NO3‐N) was largely driven by spatial patterns of lateral inflows such as tributaries and groundwater. This resulted in discrete shifts in the profiles at or downstream of discontinuities, appearing as the profiles expected with the SDC. The concatenation of spatiotemporal variation that produces observed Lagrangian profiles presents interpretive challenges but also augments our understanding of where, how, and critically why water chemistry changes in time and space as it moves through river networks.
Potential high‐quality growing tea regions in Ecuador: an alternative cash crop for Ecuadorian small landholders
Authors: Rivera‐Parra José L , Peña‐Loyola Paula J
Published: December 2019

BACKGROUND

Agriculture is the main means of subsistence for most of the population in developing countries. Crops that can increase their value with in situ processing have a big impact on the small landholder's economics. Moreover, crops such as coffee and cocoa beans have been very important for Ecuadorian farmers. In this study, we wanted to analyze if the climatic conditions exist for growing high‐quality tea in Ecuador and determine the areas that will be less affected by global climate change in the future.

RESULTS

We used a GIS (geographic information systems) based analysis, together with ecological niche modeling to determine areas in Ecuador where Ceylon and Nilgiris tea varieties could be grown, which will maintain similar ecological conditions in the future, and have a high agricultural aptitude. In total, there are more than 150 000 ha in Ecuador that could be converted to high‐quality tea plantations, most of them in the coastal provinces, with some specific areas in the Andean foothills.

CONCLUSION

Ecuador has a significant amount of land with the potential to grow high‐quality tea, with no significant ecological niche modifications due to climate change in the long‐term future. Tea is a viable and potentially highly profitable crop for small landholders and should be considered by local stakeholders. © 2019 Society of Chemical Industry
The Association Between Ultrasound Features and Biological Properties of Invasive Breast Carcinoma Is Modified by Age, Tumor Size, and the Preoperative Axilla Status
Authors: Tong Yu‐yang , Sun Pei‐xuan , Zhou Jin , Shi Zhao‐ting , Chang Cai , Li Jia‐wei
Published: December 2019

Objectives

To investigate the value of ultrasound (US) feature‐based models in predicting the proliferation and invasiveness of invasive breast cancer (IBC) and to compare the performance of models based solely on US features with models that combined US features, patient age, tumor size, and axilla status from US.

Methods

With ethical approval, 746 patients with a pathologic diagnosis of IBC were reviewed for preoperative clinical, US, and postoperative pathologic data. The proliferation and invasiveness properties of the IBC included the histologic grade and Ki‐67 status and lymphovascular invasion (LVI) and axillary lymph node metastasis (ALNM), respectively. Logistic regression analyses were used to identify independent risk factors for tumor proliferation and invasiveness.

Results

Posterior echo enhancement, calcification, a tumor size larger than 2 cm, and suspicion of ALNM from axillary US were independent risk factors for a high histologic grade and high Ki‐67 expression of IBC (P < .05). A posterior echo shadow, patient age younger than 45 years, and suspicious findings on axillary US imaging were independent variables for predicting the presence of LVI and ALNM in IBC (P < .05). Calcification was the independent factor for predicting LVI (P = .013). The predictive performance of the combined models was improved compared with the US feature‐based models, with a higher accuracy rate and negative predictive value. The area under curve of the combined models was also significantly higher than that of the single models (P < .05).

Conclusions

Compared with the US feature‐based models, the combined models yielded better predictive performance. This may provide a more robust model to predict the tumor biological properties of IBC before surgery.
Numerical method for generalized time fractional KdV‐type equation
Authors: Kong Desong , Xu Yufeng , Zheng Zhoushun
Published: December 2019

In this article, an efficient numerical method for linearized and nonlinear generalized time‐fractional KdV‐type equations is proposed by combining the finite difference scheme and Petrov–Galerkin spectral method. The scale and weight functions involved in generalized fractional derivative cause too much difficulty in discretization and numerical analysis. Fortunately, motivated by finite difference method for fractional differential equation on graded mesh, the stability and convergence of the constructed method are established rigorously. It is proved that the full discretization schemes of generalized time‐fractional KdV‐type equation is unconditionally stable in linear case. While for nonlinear case, it is stable under a CFL condition and for not small ϵ, coefficient of the high‐order spatial differential term. In addition, the full discretization schemes with respect to linear and nonlinear cases respectively converge to the associated exact solutions with orders and , where τ, α, N and m accordingly indicate the time step size, the order of the fractional derivative, polynomial degree, and regularity of the exact solution. Numerical experiments are carried out to support the theoretical results.
MALDI–HRMS imaging and HPLC–HRESI–MSn characterisation of kaurane diterpenes in the fruits of Xylopia aethiopica (Dunal) A. Rich (Annonaceae)
Authors: Kyekyeku James Oppong , Asare‐Nkansah Samuel , Bekoe Samuel Oppong , Sezgin Selahaddin , Adosraku Reimmel Kwame , Spiteller Michael
Published: December 2019

Introduction

Kaurane diterpenes, notably xylopic acid, have demonstrated important biological activities including analgesia, anti‐oxidant, antimicrobial and cytotoxicity. The fruits of Xylopia aethiopica have been reported to be a rich source of kaurane diterpenes.

Objective

An analytical approach for detailed imaging and characterisation of selected kaurane diterpenes was developed using matrix‐assisted laser desorption/ionisation high‐resolution mass spectrometry (MALDI‐HRMS) imaging techniques and high‐performance liquid chromatography‐high resolution electrospray ionisation‐tandem mass spectrometry (HPLC‐HRESI‐MSn) studies, respectively.

Methods

The images of the compounds were constructed based on selected ions from their HRESI–MS spectra. The matrix employed comprised a solution of α–cyano–4–hydroxycinnamic acid (HCCA) in acetonitrile–water with trifluoroacetic acid (TFA). HPLC–HRESI–MSn measurements were conducted on an LTQ–Orbitrap spectrometer equipped with a heated electrospray ionisation (HESI)–II source.

Results

The analytical strategy adopted showed the spatial distribution of the compounds in the fruits of X. aethiopica based on the dominant ions at m/z 301.2163 [M + H – HOCOCH3]+ and m/z 399.1932 [M + K]+ for xylopic acid, m/z 317.2111 [M + H]+ and m/z 355.1670 [M + K]+ for 15–oxo–ent–kaur–16–en–19–oic acid and m/z 303.2319 [M + H]+ for ent–kaur–16–en–19–oic acid. The fragmentation patterns of the compounds were proposed based on the HRESI–MSn measurements.

Conclusions

The study revealed the spatial variability, differential behaviours and specificity of the selected kaurane diterpenes in the fruit, seed and pericarp. The compounds under study were predominantly restricted to the pericarp of the fruit with trace amounts in the seed.
Fetal cardiac intervention—Perspectives from a single center
Authors: Guseh Stephanie H. , Friedman Kevin G. , Wilkins‐Haug Louise E.
Published: December 2019

Fetal cardiac intervention was first proposed in the early 1990s to impact cardiac development and survival of fetuses with fetal aortic stenosis and evolving hypoplastic left heart syndrome (HLHS). Although initial attempts of fetal aortic valvuloplasty were unsuccessful and carried a high rate of morbidity and mortality, our collaborative group at the Brigham and Women's Hospital and Boston Children's Hospital have reinvigorated the procedure using improvements in imaging, anesthesia, balloon catheters, and surgical techniques. Two decades of experience have now allowed us to document the safety of in utero intervention and to achieve a better understanding of the impact of midgestation intervention on developing HLHS. Research into underlying genetics, predictive biomarkers, and ways to incorporate stem cell technology will hopefully allow us to further refine the procedure to most benefit children with this historically lethal disease.
Impact of first trimester determination of abnormal cord insertion on twin‐to‐twin transfusion syndrome and other adverse outcomes in monochorionic diamniotic twins: A retrospective cohort study
Authors: Saito Mizue , Tokunaka Mayumi , Takita Hiroko , Goto Minako , Machi Maya , Sekiya Bunbu , Arakaki Tatsuya , Hamada Shoko , Oba Tomohiro , Matsuoka Ryu , Sekizawa Akihiko
Published: December 2019

Objective

To assess the influence of abnormal cord insertion (CI) detected by first trimester ultrasonography on the development of twin‐to‐twin transfusion syndrome (TTTS) in monochorionic diamniotic (MCDA) twins.

Method

In this retrospective cohort study, consecutive patients with MCDA twins who underwent fetal ultrasound screening in the first trimester between January 2011 and January 2017 were enrolled. The CI sites were evaluated between 11 + 0 and 13 + 6 weeks' gestation. All twin pairs were assigned to the abnormal CI group (twin pair with velamentous cord insertion (VCI) and/or marginal cord insertion (MCI) in one or both twins) or the normal CI group (twin pair with both normal CI). The relationships of adverse outcomes in two groups were analyzed.

Results

A total of 109 MCDA twin pairs were examined; 15 cases were classified into the abnormal CI group and 94 cases into the normal CI group. The incidence of TTTS was significantly higher in the abnormal than in the normal CI group (26.7% vs 7.45%, P = .04). In patients who developed TTTS, all donors had VCI.

Conclusion

Ultrasound evaluation of abnormal CI at 11 + 0 to 13 + 6 weeks' gestation in MCDA twins is valuable in the assessment of the risk for TTTS.
Click chemistry‐type crosslinking of a low‐conductivity polyethylene copolymer ternary blend for power cable insulation
Authors: Mauri Massimiliano , Hofmann Anna I , Gómez‐Heincke Diana , Kumara Sarath , Amir Masoud Pourrahimi  , Ouyang Yingwei , Hagstrand Per‐Ola , Gkourmpis Thomas , Xu Xiangdong , Prieto Oscar , Müller Christian
Published: December 2019

High‐voltage direct‐current power cables are vital for the efficient transport of electricity derived from renewable sources of energy. The most widely used material for high‐voltage power cable insulation – low‐density polyethylene (LDPE) – is usually crosslinked with peroxides, a process that releases unwanted by‐products. Hence, by‐product‐free crosslinking concepts that mitigate the associated increase in electrical conductivity are in high demand. Click chemistry‐type crosslinking of polyethylene copolymer mixtures that contain glycidyl methacrylate and acrylic acid co‐monomers is a promising alternative, provided that the curing reaction can be controlled. Here, we demonstrate that the rate of the curing reaction can be adjusted by tuning the number of epoxy and carboxyl groups. Both dilution of copolymer mixtures with neat LDPE and the selection of copolymers with a lower co‐monomer content have an equivalent effect on the curing speed. Ternary blends that contain 50 wt% of neat LDPE feature an extended extrusion window of up to 170 °C. Instead, at 200 °C rapid curing is possible, leading to thermosets with a low direct‐current electrical conductivity of about 10−16 S cm−1 at an electric field of 20 kV mm−1 and 70 °C. The conductivity of the blends explored here is comparable to or even lower than values measured for both ultraclean LDPE and a peroxide‐cured commercial crosslinked polyethylene grade. Hence, click chemistry curing represents a promising alternative to radical crosslinking with peroxides. © 2019 Society of Chemical Industry
Totally laparoscopic and totally robotic surgery in patients with left‐sided colonic diverticulitis
Authors: Bilgin Ismail Ahmet , Bas Mustafa , Benlice Cigdem , Esen Eren , Ozben Volkan , Aytac Erman , Baca Bilgi , Hamzaoglu Ismail , Karahasanoglu Tayfun
Published: December 2019

Background

Introduction of the da Vinci Xi system has facilitated the use of robotics in colorectal surgery. Nevertheless, data on the outcomes of robotic surgery for the treatment of colonic diverticulitis have remained scarce.

Methods

Patient demographics, clinical characteristics, and perioperative outcomes of the patients undergoing totally robotic with the da Vinci Xi system or laparoscopic surgery for left‐sided colonic diverticulitis (LCD) were compared.

Results

Laparoscopic and robotic groups included 22 and 20 patients, respectively. There were no significant differences between the two groups in terms of patient demographics, clinical characteristics, operative time, and postoperative complications. There were three conversions in the laparoscopy group and no conversion in the robotic group (P = 0.23). Conversion to open surgery was associated with postoperative morbidity (P = 0.02).

Conclusion

Robotic surgery is an applicable alternative for the treatment of LCD. Robotic approach may potentially lower the risk of operative morbidity by reducing the requirement of conversion.
Research on the accuracy of three‐dimensional localization and navigation in robot‐assisted spine surgery
Authors: Chen Long , Zhang Fengfeng , Zhan Wei , Gan Minfeng , Sun Lining
Published: December 2019

Background

Compared with traditional surgical methods, which only rely on doctors' experience, three‐dimensional robot‐assisted navigation technology could locate the lesion more accurately.

Methods

The transformation principle of three‐dimensional navigation system was analyzed. The surgical path was planned on the reconstructed three‐dimensional model. The experimental data of positioning position and posture were used as two important parameters to evaluate the accuracy of the robot‐assisted spine surgery navigation system.

Results

The final experimental results show that the accuracy of the positioning and navigation position of the robot‐assisted surgical navigation system was 2.54 ± 0.15mm (range 2.25‐2.76 mm). The accuracy of positioning and navigation posture was 2.55 °  ± 0.49°(range 1.92°‐3.21°).

Conclusion

It could be seen the three‐dimensional positioning and navigation system proposed in this study had a high accuracy and could basically meet the basic accuracy requirements of spine surgery.
Dam reverse flow events influence limnological variables and fish assemblages of a downstream tributary in a Neotropical floodplain
Authors: Ferreira Karina , Lopes Taise Miranda , Affonso Igor de Paiva , Agostinho Angelo Antonio , Gomes Luiz Carlos
Published: December 2019

We used a dam‐free tributary (the Baía River) in the upper Paraná River floodplain downstream of a major dam in the Paraná River, Brazil to investigate the effects of dam‐regulated reverse flow on limnological variables and fish. We tested the hypotheses that limnological variables in tributaries change based on flow direction and that fish assemblages respond to this variation. Sampling sites were determined considering flow direction (normal or reverse) and position (near or far from the river mouth). Limnological variables showed higher values for transparency, oxygen, pH, and electrical conductivity at sites near the mouth of the Baía River during reverse flow. Species richness and evenness differed significantly in relation to position, with higher values closer to the Paraná River. The average standard length of fish species was higher near the mouth of the Baía River and during the reverse flow period. No significant differences in species abundance were found. Reverse flow into the Baía River brought nutrient‐poor water from the dammed Paraná River, thereby altering the limnological variables. This flow condition impelled the entry of species with higher average standard lengths. However, increased species richness and low evenness were due to the increase in species dispersal rates under all flow conditions. Our results emphasize that the effects of dams can extend several kilometres into the floodplain, provide basic knowledge on the effects of major dams on downstream pristine tributaries, and highlight the need for further studies to understand the wider influences.
Impact of prospective measurement of outflow tracts in prediction of coarctation of the aorta
Authors: Vigneswaran T. V. , Zidere V. , Chivers S. , Charakida M. , Akolekar R. , Simpson J. M.
Published: December 2019

Objectives

Prenatal diagnosis of coarctation of the aorta (CoA) is associated with reduced mortality and morbidity, however, accurate prenatal prediction remains challenging. To date, studies have used retrospective measurements of the outflow tracts to evaluate their potential to predict CoA. Our primary objective was to evaluate prospectively acquired measurements of the outflow tracts in fetuses with prenatally suspected CoA. A secondary aim was to report the postnatal prevalence of bicuspid aortic valve in this cohort.

Methods

Pregnancies with suspicion of isolated CoA and with a minimum of 6 months' postnatal follow‐up available were identified from the cardiac database of a tertiary fetal cardiology center in the UK, between January 2002 and December 2017. Measurement of the aortic valve, pulmonary valve, distal transverse aortic arch (DTAA) and arterial duct (AD) diameters were undertaken routinely in fetuses with suspected CoA during the study period. Z‐scores were computed using published reference ranges based on > 7000 fetuses from our own unit.

Results

Of 149 pregnancies with prenatally suspected CoA included in the study, CoA was confirmed within 6 months after birth in 77/149 (51.7%) cases. DTAA diameter Z‐score and the Z‐score of second‐trimester DTAA/AD diameter ratio were smaller in fetuses with postnatally confirmed CoA than those in false‐positive cases (–2.8 vs –1.9; P = 0.039 and –3.13 vs –2.61; P = 0.005, respectively). Multiple regression analysis demonstrated that the Z‐scores of DTAA and AD diameters were the only significant predictors of postnatal CoA (P = 0.001). Bicuspid aortic valve was identified in 30% of the false‐positive cases.

Conclusions

Measurement of DTAA and AD diameter Z‐scores can be used to ascertain risk for postnatal CoA in a selected cohort. The high incidence of bicuspid aortic valve in false‐positive cases merits further study with respect to both etiology and longer‐term significance. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Imaging in gynecological disease (18): clinical and ultrasound characteristics of urinary bladder malignancies
Authors: Knez J. , Nardelli F. , van den Bosch T. , Sladkevicius P. , Valentin L. , Jurkovic D.
Published: December 2019

Objective

To describe the clinical and ultrasound characteristics of urinary bladder malignancies diagnosed on transvaginal ultrasound in women presenting with suspected gynecological problems.

Methods

This was a multicenter retrospective study of women with a histological diagnosis of urinary bladder malignancy that was suspected on transvaginal ultrasound examination. The cases were collected from three centers that specialize in the use of pelvic ultrasound and had been examined between January 2007 and October 2018. Clinical data were obtained from the computer databases and all tumor images were assessed by two of the authors (D.J. and J.K.) to identify characteristic sonographic patterns. We compared the characteristics of tumors between women presenting with symptoms suspicious of urinary bladder malignancy and those without such symptoms.

Results

Thirty women with a confirmed diagnosis of urinary bladder malignancy on histological examination were included. Median age at diagnosis was 70.5 (range 36–88) years. The most common presenting symptom was postmenopausal bleeding, which was recorded in 18 (60%) women. Ten (33%) women had symptoms suspicious of bladder malignancy, of whom six had unexplained visible hematuria, three had unexplained recurrent urinary tract infections and one had dysuria and microhematuria. On histological examination, 23 (77%) women were diagnosed with primary bladder malignancy whilst seven (23%) had metastases in the bladder from other primary tumors. Out of 23 primary tumors, 21 (91%) were of urothelial origin (12 low grade and nine high grade). Most low‐grade urothelial carcinomas appeared on ultrasound as irregular papillary growth (11/12, 92%) and were moderately to highly vascular on color Doppler examination (8/12, 67%). The ultrasound appearances of primary non‐urothelial and metastatic tumors varied, without a clear common morphological tumor pattern. The tumors found in women with symptoms suggestive of bladder malignancy did not differ unequivocally from those detected in other women in terms of size, ultrasound morphology, vascularity or histological type.

Conclusion

Urinary bladder malignancies can be detected in patients undergoing transvaginal ultrasound examination for suspected gynecological problems. Primary urothelial cancers have a relatively uniform morphological pattern, whilst the appearances of other bladder malignancies are more variable. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Relative Timing of Nightside and Dayside Plasmapause Motion: Two Events in June 2001
Authors: Goldstein J. , Sandel B. R.
Published: December 2019

We examine the relative timing of dayside and nightside plasmapause motion following southward interplanetary magnetic field turnings on 2 and 9 June 2001. For both events the delay between the dayside and nightside plasmapause response is less than the temporal resolution of Imager for Magnetopause‐to‐Aurora Global Exploration extreme ultraviolet observations (10 min). Our result thus establishes a possible upper limit (
10 min) on the day‐to‐night onset delay. From analysis of the extreme ultraviolet‐observed plasmapause motion we find on 2 June the time‐averaged plasmapause
field was (in mV/m) 0.61 near noon magnetic local time, 0.35 near midnight magnetic local time, and 0.44 overall. The normalized plasmapause speed data (both dayside and nightside) are fitted to the curve
, consistent with a spatially uniform and time‐constant dawn‐dusk penetration
field that is 9% of the solar wind field. On 9 June the time‐averaged
field values (mV/m) were 0.24 (dayside), 0.28 (nightside), and 0.26 (overall); the plasmapause motion was consistent with a penetration
field 10% of the solar wind field. Plasmasphere erosion is a fundamental element of the dynamic magnetospheric response to solar wind driving. This study yields an important observational constraint on the day‐to‐night timing of the plasmapause response. The result also has implications for the two main models for the cause of erosion (convection and interchange).
Evolution of a Long‐Duration Coronal Mass Ejection and Its Sheath Region Between Mercury and Earth on 9–14 July 2013
Authors: Lugaz N. , Winslow R. M. , Farrugia C. J.
Published: December 2019

Using in situ measurements and remote‐sensing observations, we study a coronal mass ejection (CME) that left the Sun on 9 July 2013 and impacted both Mercury and Earth while the planets were in radial alignment (within
). The CME had an initial speed as measured by coronagraphs of 580 
 20 km/s, an inferred speed at Mercury of 580 
 30 km/s, and a measured maximum speed at Earth of 530 km/s, indicating that it did not decelerate substantially in the inner heliosphere. The magnetic field measurements made by MESSENGER and Wind reveal a very similar magnetic ejecta at both planets. We consider the CME expansion as measured by the ejecta duration and the decrease of the magnetic field strength between Mercury and Earth and the velocity profile measured in situ by Wind. The long‐duration magnetic ejecta (20 and 42 hr at Mercury and Earth, respectively) is found to be associated with a relatively slowly expanding ejecta at 1 AU, revealing that the large size of the ejecta is due to the CME itself or its expansion in the corona or innermost heliosphere and not due to a rapid expansion between Mercury at 0.45 AU and Earth at 1 AU. We also find evidence that the CME sheath is composed of compressed material accumulated before the shock formed, as well as more recently shocked material.
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets
Authors: Jofré E. , Almenara J. M. , Petrucci R. , Díaz R. F. , Gómez Maqueo Chew Y. , Martioli E. , Ramírez I. , García L. , Saffe C. , Canul E. F. , Buccino A. , Gómez M. , Moreno Hilario E.
Published: December 2019

Aims. Kepler-278 and Kepler-391 are two of the three evolved stars known to date on the red giant branch (RGB) to host multiple short-period transiting planets. Moreover, the planets orbiting Kepler-278 and Kepler-391 are among the smallest discovered around RGB stars. Here we present a detailed stellar and planetary characterization of these remarkable systems.

Methods. Based on high-quality spectra from Gemini-GRACES for Kepler-278 and Kepler-391, we obtained refined stellar parameters and precise chemical abundances for 25 elements. Nine of these elements and the carbon isotopic ratios, 12C∕13C, had not previously been measured. Also, combining our new stellar parameters with a photodynamical analysis of the Kepler light curves, we determined accurate planetary properties of both systems.

Results. Our revised stellar parameters agree reasonably well with most of the previous results, although we find that Kepler-278 is ~15% less massive than previously reported. The abundances of C, N, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, and Ce, in both stars, are consistent with those of nearby evolved thin disk stars. Kepler-391 presents a relatively high abundance of lithium (A(Li)NLTE = 1.29 ± 0.09 dex), which is likely a remnant from the main-sequence phase. The precise spectroscopic parameters of Kepler-278 and Kepler-391, along with their high 12C∕13C ratios, show that both stars are just starting their ascent on the RGB. The planets Kepler-278b, Kepler-278c, and Kepler-391c are warm sub-Neptunes, whilst Kepler-391b is a hot sub-Neptune that falls in the hot super-Earth desert and, therefore, it might be undergoing photoevaporation of its outer envelope. The high-precision obtained in the transit times allowed us not only to confirm Kepler-278c’s TTV signal, but also to find evidence of a previously undetected TTV signal for the inner planet Kepler-278b. From the presence of gravitational interaction between these bodies we constrain, for the first time, the mass of Kepler-278b (Mp = 56 −13+37 M⊕) and Kepler-278c (Mp = 35 −21+9.9 M⊕). The mass limits, coupled with our precise determinations of the planetary radii, suggest that their bulk compositions are consistent with a significant amount of water content and the presence of H2 gaseous envelopes. Finally, our photodynamical analysis also shows that the orbits of both planets around Kepler-278 are highly eccentric (e ~ 0.7) and, surprisingly, coplanar. Further observations (e.g., precise radial velocities) of this system are needed to confirm the eccentricity values presented here.
Exploring the latitude and depth dependence of solar Rossby waves using ring-diagram analysis
Authors: Proxauf B. , Gizon L. , Löptien B. , Schou J. , Birch A. C. , Bogart R. S.
Published: December 2019

Context. Global-scale equatorial Rossby waves have recently been unambiguously identified on the Sun. Like solar acoustic modes, Rossby waves are probes of the solar interior.

Aims. We study the latitude and depth dependence of the Rossby wave eigenfunctions.

Methods. By applying helioseismic ring-diagram analysis and granulation tracking to observations by HMI aboard SDO, we computed maps of the radial vorticity of flows in the upper solar convection zone (down to depths of more than 16 Mm). The horizontal sampling of the ring-diagram maps is approximately 90 Mm (∼7.5°) and the temporal sampling is roughly 27 hr. We used a Fourier transform in longitude to separate the different azimuthal orders m in the range 3 ≤ m ≤ 15. At each m we obtained the phase and amplitude of the Rossby waves as functions of depth using the helioseismic data. At each m we also measured the latitude dependence of the eigenfunctions by calculating the covariance between the equator and other latitudes.

Results. We conducted a study of the horizontal and radial dependences of the radial vorticity eigenfunctions. The horizontal eigenfunctions are complex. As observed previously, the real part peaks at the equator and switches sign near ±30°, thus the eigenfunctions show significant non-sectoral contributions. The imaginary part is smaller than the real part. The phase of the radial eigenfunctions varies by only ±5° over the top 15 Mm. The amplitude of the radial eigenfunctions decreases by about 10% from the surface down to 8 Mm (the region in which ring-diagram analysis is most reliable, as seen by comparing with the rotation rate measured by global-mode seismology).

Conclusions. The radial dependence of the radial vorticity eigenfunctions deduced from ring-diagram analysis is consistent with a power law down to 8 Mm and is unreliable at larger depths. However, the observations provide only weak constraints on the power-law exponents. For the real part, the latitude dependence of the eigenfunctions is consistent with previous work (using granulation tracking). The imaginary part is smaller than the real part but significantly nonzero.
Triphenylene adsorption on Cu(111) and relevant graphene self-assembly*
Authors: Chen Qiao-Yue , Song Jun-Jie , Jing Liwei , Huang Kaikai , He Pimo , Zhang Hanjie
Published: December 2019

Investigations on adsorption behavior of triphenylene (TP) and subsequent graphene self-assembly on Cu(111) were carried out mainly by using scanning tunneling microscopy (STM). At monolayer coverage, TP molecules formed a long-range ordered adsorption structure on Cu(111) with an uniform orientation. Graphene self-assembly on the Cu(111) substrate with TP molecules as precursor was achieved by annealing the sample, and a large-scale graphene overlayer was successfully captured after the sample annealing up to 1000 K. Three different Moiré patterns generated from relative rotational disorders between the graphene overlayer and the Cu(111) substrate were observed, one with 4° rotation between the graphene overlayer and the Cu(111) substrate with a periodicity of 2.93 nm, another with 7° rotation and 2.15 nm of the size of the Moiré supercell, and the third with 10° rotation with a periodicity of 1.35 nm.
Influence of the Earth’s rotation on measurement of gravitational constant G with the time-of-swing method*
Authors: Luo Jie , Dong Tao , Shao Cheng-Gang , Tan Yu-Jie , Zhang Hui-Jie
Published: December 2019

In the measurement of the Newtonian gravitational constant G with the time-of-swing method, the influence of the Earth’s rotation has been roughly estimated before, which is far beyond the current experimental precision. Here, we present a more complete theoretical modeling and assessment process. To figure out this effect, we use the relativistic Lagrangian expression to derive the motion equations of the torsion pendulum. With the correlation method and typical parameters, we estimate that the influence of the Earth’s rotation on G measurement is far less than 1 ppm, which may need to be considered in the future high-accuracy experiments of determining the gravitational constant G.
Re effects in model Ni-based superalloys investigated with first-principles calculations and atom probe tomography*
Authors: Wang Dianwu , Wang Chongyu , Yu Tao , Liu Wenqing
Published: December 2019

The phase partition and site preference of Re atoms in a ternary Ni–Al–Re model alloy, including the electronic structure of different Re configurations, are investigated with first-principles calculations and atom probe tomography. The Re distribution of single, nearest neighbor (NN), next-nearest neighbor (NNN), and cluster configurations are respectively designed in the models with γ and γ′ phases. The results show that the Re atoms tend to entering γ′ phase and the Re atoms prefer to occupy the Al sites in γ′ phase. The Re cluster with a combination of NN and NNN Re–Re pair configuration is not preferred than the isolated Re atom in the Ni-based superalloys, and the configuration with isolated Re atom is more preferred in the system. Especially, the electronic states are analyzed and the energetic parameters are calculated. The electronic structure analyses show there exists strong Ni–Re electronic interaction and it is mainly contributed by the d–d hybridization. The characteristic features of the electronic states of the Re doping effects are also given. It is also found that Re atoms prefer the Al sites in γ′ side at the interface. The density of states at or near the Fermi level and the d–d hybridizations of NN Ni–Re are found to be important in the systems.
Somatosensory System Organization in Mammals and Response to Spinal Injury
Authors: Darian-Smith Corinna , Fisher Karen
Published: December 2019

Spinal cord injury (SCI) affects well over a million people in the United States alone, and its personal and societal costs are huge. This article provides a current overview of the organization of somatosensory and motor pathways, in the context of hand/paw function in nonhuman primate and rodent models of SCI. Despite decades of basic research and clinical trials, therapeutic options remain limited. This is largely due to the fact that (i) spinal cord structure and function is very complex and still poorly understood, (ii) there are many species differences which can make translation from the rodent to primate difficult, and (iii) we are still some way from determining the detailed multilevel pathway responses affecting recovery. There has also been little focus, until recently, on the sensory pathways involved in SCI and recovery, which are so critical to hand function and the recovery process. The potential for recovery in any individual depends on many factors, including the location and size of the injury, the extent of sparing of fiber tracts, and the post-injury inflammatory response. There is also a progression of change over the first weeks and months that must be taken into account when assessing recovery. There are currently no good biomarkers of recovery, and while axon terminal sprouting is frequently used in the experimental setting as an indicator of circuit remodeling and “recovery,” the correlation between sprouting and functional recovery deserves scrutiny.
Intelligence
Authors: Sternberg Robert J.
Published: December 2019

Intelligence is commonly viewed as the ability to learn from experience as well as to adapt to the surrounding environment. There are several approaches to understanding intelligence, including the psychometric, cognitive, biological, cultural/contextual, and systems approaches. Each approach places an emphasis on different psychological aspects of intelligence as well as on different ways of investigating it. The psychometric approach is largely based on statistical methods, especially factor analysis. The cognitive approach studies mental representations and processes. The biological approach is largely brain based. The cultural/contextual approach emphasizes the role of culture in defining what constitutes intelligence in a given cultural setting. And the systems approach looks at intelligence in terms of complex systemic interactions. Two systems theories are Howard Gardner’s theory of multiple intelligences and Robert Sternberg’s theory of successful intelligence. Gardner’s theory argues that there are eight distinctive intelligences, whereas Sternberg’s theory argues that intelligence comprises creative, analytical, practical, and even wisdom-based skills.

Intelligence appears to be at least somewhat malleable. A number of programs have had modest to moderate success in helping people to improve their intelligence. These programs work best if they are sustained. They work less well if used only for short periods of time. Schooling is one way of increasing intelligence.

The Flynn effect shows modifiability of intelligence across secular time. During the 20th century, IQs rose roughly 30 points worldwide, or 10 points per decade. These results suggest that environment can have a powerful effect, at least on IQ and over a generational time span. However, the increases experienced in the 20th century are not being experienced worldwide in the 21st century.
Distinct responses of neurons and astrocytes to TDP-43 proteinopathy in amyotrophic lateral sclerosis
Authors: Smethurst Phillip , Risse Emmanuel , Tyzack Giulia E , Mitchell Jamie S , Taha Doaa M , Chen Yun-Ru , Newcombe Jia , Collinge John , Sidle Katie , Patani Rickie
Published: December 2019

Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease caused by motor neuron loss, resulting in muscle wasting, paralysis and eventual death. A key pathological feature of ALS is cytoplasmically mislocalized and aggregated TDP-43 protein in >95% of cases, which is considered to have prion-like properties. Historical studies have predominantly focused on genetic forms of ALS, which represent ∼10% of cases, leaving the remaining 90% of sporadic ALS relatively understudied. Additionally, the role of astrocytes in ALS and their relationship with TDP-43 pathology is also not currently well understood. We have therefore used highly enriched human induced pluripotent stem cell (iPSC)-derived motor neurons and astrocytes to model early cell type-specific features of sporadic ALS. We first demonstrate seeded aggregation of TDP-43 by exposing human iPSC-derived motor neurons to serially passaged sporadic ALS post-mortem tissue (spALS) extracts. Next, we show that human iPSC-derived motor neurons are more vulnerable to TDP-43 aggregation and toxicity compared with their astrocyte counterparts. We demonstrate that these TDP-43 aggregates can more readily propagate from motor neurons into astrocytes in co-culture paradigms. We next found that astrocytes are neuroprotective to seeded aggregation within motor neurons by reducing (mislocalized) cytoplasmic TDP-43, TDP-43 aggregation and cell toxicity. Furthermore, we detected TDP-43 oligomers in these spALS spinal cord extracts, and as such demonstrated that highly purified recombinant TDP-43 oligomers can reproduce this observed cell-type specific toxicity, providing further support to a protein oligomer-mediated toxicity hypothesis in ALS. In summary, we have developed a human, clinically relevant, and cell-type specific modelling platform that recapitulates key aspects of sporadic ALS and uncovers both an initial neuroprotective role for astrocytes and the cell type-specific toxic effect of TDP-43 oligomers.
Cooperation in the Face of Transboundary Crisis: A Framework for Analysis
Authors: Blondin Donald , Boin Arjen
Published: December 2019

The nation state is discovering the limits of its crisis management capacities. The Ebola and Zika outbreaks, the financial crisis, the downing of flight MH17 over Ukraine, sinking ships overfilled with refugees, cyber-attacks, urban terrorism and existential environmental threats serve as strong reminders of the complex origins and transboundary dimensions of many contemporary crises and disasters. As these transboundary aspects of modern crises become increasingly manifest, the need for international, collaborative responses appears ever clearer. But that collaboration does not always emerge in time (or at all). Even in the European Union, which has various transboundary crisis management mechanisms in place, the willingness to initiate joint crisis responses varies. This observation prompted our research question: Why do states collaborate in response to some transboundary crises but not others? We bring together the crisis and collective action literatures to formulate a theoretical framework that can help answer this question. This article identifies crucial factors that facilitate a possible pathway toward a joint response.
The null identities for boundary operators in the (2, 2p + 1) minimal gravity
Authors: Ishiki Goro , Muraki Hisayoshi , Rim Chaiho
Published: December 2019

By using the matrix model representation, we show that correlation numbers of boundary-changing operators (BCOs) in $(2,2p+1)$ minimal Liouville gravity satisfy some identities, which we call the null identities. These identities enable us to express the correlation numbers of BCOs in terms of those of boundary-preserving operators. We also discuss a physical implication of the null identities as the manifestation of the boundary interaction.
Comment on ‘Optimal Policy for Multi-Alternative Decisions’
Authors: Marshall James A. R.
Published: December 2019

Abstract

Optimality analysis has recently been proposed for value-based decision-making, in which decision agents are rewarded by the value of the selected option. This contrasts with psychophysics where decision agents are typically rewarded only if they choose the ‘correct’ or best option. The analysis of optimal policies for value-based decisions raises interesting and surprising parallels with decision rules proposed for accuracy-based decisions in binary and multi-alternative cases, and explains experimentally-observed deviations from rationality. However, the analysis assumes that decision agents should treat time as a linear cost, and thus optimise their Bayes Risk from decisions. A more naturalistic assumption is that future rewards are geometrically discounted, since they are less likely to be realised in an uncertain world. Changing the way in which time is costed leads to substantive changes in the resulting optimal policies, explains empirical data that previously could not be explained, and makes falsifiable predictions for future experiments.
Drumming motor sequence training induces apparent myelin remodelling in Huntington’s disease: a longitudinal diffusion MRI and quantitative magnetization transfer study
Authors: Casella Chiara , Bourbon-Teles Jose , Bells Sonya , Coulthard Elizabeth , Parker Greg D. , Rosser Anne , Jones Derek K. , Metzler-Baddeley Claudia
Published: December 2019

1.

Background

Impaired myelination may contribute to Huntington’s disease (HD) pathogenesis. This study assessed differences in white matter (WM) microstructure between HD patients and controls, and tested whether drumming training stimulates WM remodelling in HD. Furthermore, it examined whether training-induced microstructural changes are related to improvements in motor and cognitive function.

Methods

Participants undertook two months of drumming exercises. Working memory and executive function were assessed before and after training. Changes in WM microstructure were investigated with diffusion tensor magnetic resonance imaging (DT-MRI)-based metrics, the restricted diffusion signal fraction (Fr) from the composite hindered and restricted model of diffusion (CHARMED) and the macromolecular proton fraction (MPF) from quantitative magnetization transfer (qMT) imaging. WM pathways linking the putamen and the supplementary motor area (SMA-Putamen), and three segments of the corpus callosum (CCI, CCII, CCIII) were studied using deterministic tractography. Baseline MPF differences between patients and controls were assessed with tract-based spatial statistics (TBSS).

Results

MPF was reduced in HD patients compared to controls in the mid-section of the CC in HD subjects at baseline, while a significantly greater change in MPF was detected in HD patients relative to controls in the CCII, CCIII, and the right SMA-putamen post-training. Further, although patients improved their drumming and executive function performance, such improvements did not correlate with microstructural changes.

Conclusions

Increased MPF suggests training-induced myelin changes in HD. Tailored behavioural stimulation may lead to neural benefits in early HD that could be exploited for delaying disease progression.
FilterDCA: interpretable supervised contact prediction using inter-domain coevolution
Authors: Muscat Maureen , Croce Giancarlo , Sarti Edoardo , Weigt Martin
Published: December 2019

Predicting three-dimensional protein structure and assembling protein complexes using sequence information belongs to the most prominent tasks in computational biology. Recently substantial progress has been obtained in the case of single proteins using a combination of unsupervised coevolutionary sequence analysis with structurally supervised deep learning. While reaching impressive accuracies in predicting residue-residue contacts, deep learning has a number of disadvantages. The need for large structural training sets limits the applicability to multi-protein complexes; and their deep architecture makes the interpretability of the convolutional neural networks intrinsically hard. Here we introduce FilterDCA, a simpler supervised predictor for inter-domain and inter-protein contacts. It is based on the fact that contact maps of proteins show typical contact patterns, which results from secondary structure and are reflected by patterns in coevolutionary analysis. We explicitly integrate averaged contacts patterns with coevolutionary scores derived by Direct Coupling Analysis, reaching results comparable to more complex deep-learning approaches, while remaining fully transparent and interpretable. The FilterDCA code is available athttp://gitlab.lcqb.upmc.fr/muscat/FilterDCA.

Author summary

Thede novoprediction of tertiary and quaternary protein structures has recently seen important advances, by combining unsupervised, purely sequence-based coevolutionary analyses with structure-based supervision using deep learning for contact-map prediction. While showing impressive performance, deep-learning methods require large training sets and pose severe obstacles for their interpretability. Here we construct a simple, transparent and therefore fully interpretable inter-domain contact predictor, which uses the results of coevolutionary Direct Coupling Analysis in combination with explicitly constructed filters reflecting typical contact patterns in a training set of known protein structures, and which improves the accuracy of predicted contacts significantly. Our approach thereby sheds light on the question how contact information is encoded in coevolutionary signals.