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Abstract Background The great diversity in plant genome size and chromosome number is partly due to polyploidization (i.e. genome doubling events). The differences in genome size and chromosome number among diploid plant species can be a window into the intriguing phenomenon of past genome doubling that may be obscured through time by the process of diploidization. The genus Hibiscus L. (Malvaceae) has a wide diversity of chromosome numbers and a complex genomic history. Hibiscus is ideal for exploring past genomic events because although two ancient genome duplication events have been identified, more are likely to be found due to its diversity of chromosome numbers. To reappraise the history of whole-genome duplication events in Hibiscus, we tested three alternative scenarios describing different polyploidization events. Results Using target sequence capture, we designed a new probe set for Hibiscus and generated 87 orthologous genes from four diploid species. We detected paralogues in > 54% putative single-copy genes. 34 of these genes were selected for testing three different genome duplication scenarios using gene counting. All species of Hibiscus sampled shared one genome duplication with H. syriacus, and one whole genome duplication occurred along the branch leading to H. syriacus. Conclusions Here, we corroborated the independent genome doubling previously found in the lineage leading to H. syriacus and a shared genome doubling of this lineage and the remainder of Hibiscus. Additionally, we found a previously undiscovered genome duplication shared by the /Pavonia and /Malvaviscus clades (both nested within Hibiscus) with the occurrences of two copies in what were otherwise single-copy genes. Our results highlight the complexity of genomic diversity in some plant groups, which makes orthology assessment and accurate phylogenomic inference difficult.

PRDM9 is a PR domain containing histone methyl transferase which expression is normally restricted to the germline that has also been linked to a number of somatic cancers. Here the authors describe the identification of a small molecule that selectivity inhibits the methyltransferase activity of PRDM9 in biochemical and cellular assays

The Colorado Learning Attitudes about Science Survey (CLASS) is a widely used instrument designed to measure student attitudes toward physics and learning physics. Previous research revealed a fairly complex factor structure. In this study, exploratory and confirmatory factor analyses were conducted on data from an undergraduate introductory physics course (n=3844) to determine whether a more parsimonious factor structure exists. Exploratory factor analysis results indicate that many of the items from the original CLASS have poor psychometric properties and could not be used in a revised factor structure. The cross validation showed acceptable fit statistics for a three factor model found in the exploratory factor analysis. This research suggests that a more optimum measurement of students’ attitudes about physics and learning physics is obtained with a 15-item instrument, which describes the factors of personal application, personal effort, and problem solving. The proposed revised version of the CLASS offers researchers the opportunity to test a shortened version of the instrument that may be able to provide information about students’ attitudes in the areas of personal application of physics, personal effort in a physics course, and approaches to problem solving.

Low voltage-activated persistent inward calcium currents (Ca PICs) occur in rat motoneurons and are mediated by Cav1.3 L-type calcium channels (L-Ca current). The objectives of this paper were to determine whether this L-Ca current activates a sustained calcium-activated potassium current (SK current) and examine how such SK currents change with spinal injury. For comparison, the SK current that produces the postspike afterhyperpolarization (mAHP) was also quantified. Intracellular recordings were made from motoneurons of adult acute and chronic spinal rats while the whole sacrocaudal spinal cord was maintained in vitro. Spikes/AHPs were evoked with current injection or ventral root stimulation. Application of the SK channel blocker apamin completely eliminated the mAHP, which was not significantly different in chronic and acute spinal rats. The Ca PICs were measured with slow voltage ramps (or steps) with TTX to block sodium currents. In chronic spinal rats, the PICs were activated at -58.6 +/- 6.0 mV and were 2.2 +/- 1.2 nA in amplitude, significantly larger than in acute spinal rats. Apamin significantly increased the PIC, indicating that there was an SK current activated by L-Ca currents (SK(L) current), which ultimately reduced the net PIC. This SK(L) current was not different in acute and chronic spinal rats. The SK(AHP) and the SK(L) currents were activated by different calcium currents because the mAHP/SK(AHP) was blocked by the N, P-type calcium channel blocker omega-conotoxin MVIIC and was resistant to the L-type calcium channel blocker nimodipine, whereas the L-Ca and SK(L) currents were blocked by nimodipine. Furthermore, the SK(AHP) current activated within 10 ms of the spike, whereas the SK(L) current was delayed approximately 100 ms after the onset of the L-Ca current, suggesting that the SK(L) currents were not as spatially close to the L-Ca currents. Finally, the SK(L) and the L-Ca currents were poorly space clamped, with oscillations at their onset and hysteresis in their activation and deactivation voltages, consistent with currents of dendritic origin. The impact of these dendritic currents was especially pronounced in 15% of motoneurons, where apamin led to uncontrollable L-Ca currents that could not be deactivated, even with large hyperpolarizations of the soma. Thus, although the SK(L) currents are fairly small, they play a critical role in terminating the dendritic L-Ca currents. [ABSTRACT FROM AUTHOR]

The aim of this study was to review MRI findings of clinically suspected posterolateral corner knee injuries and their associated internal derangements. Sixteen knees in 15 patients who had evidence of a posterolateral corner knee injury on the physical exam underwent MRI to evaluate the posterolateral corner of the knee and to look for associated injuries. Two musculoskeletal radiologists reviewed the scans. Surgery was performed on 10 of the knees. Tibial plateau fractures were present in 6 knees; 5 of the fractures were anteromedial rim tibial plateau fractures. The popliteus muscle was injured in 13 knees and the biceps femoris in 6 knees. The lateral collateral ligament was ruptured in 12 knees. The posterior cruciate ligament was completely ruptured in 7 knees and avulsed from its tibial attachment in 1 knee. Eleven knees had a complete anterior cruciate ligament rupture. The anterior cruciate ligament was edematous without complete disruption of all fibers in 3 knees. There was excellent correlation between the MRI results and operative results in regard to the presence of a posterolateral corner injury of the knee (9 of the 10 knees had a posterolateral corner injury). In our study MRI readily detected posterolateral corner injuries. Posterolateral corner injuries of the knee are frequently associated with a variety of significant injuries, including cruciate ligament tears, meniscus tears, and fractures. Fractures of the peripheral anteromedial tibial plateau are not common; however, given their relatively common occurrence in this study, they may be an indicator of a posterolateral corner injury to the knee. [ABSTRACT FROM AUTHOR]

The high-magnification microlensing event MACHO-97-BLG-28 was previously determined to be a binary system composed of either two M dwarfs or an M dwarf and a brown dwarf. We present a revised light-curve model using additional data from the Mt. Stromlo 74″ telescope, model estimates of stellar limb darkening, and fitting of the blend separately for each telescope and passband. We find a lensing system with a larger mass ratio, q = 0.28 ± 0.01, and smaller projected separation, s = 0.61 ± 0.01, than those presented in the original study. We revise the estimate of the lens–source relative proper motion to μrel = 2.8 ± 0.5 mas yr−1, which indicates that 16.07 yr after the event maximum the lens and source should have separated by 46 ± 8 mas. We revise the radius of the source star using more recent reddening maps and angular diameter–color relations to R* = (10.3 ± 1.9) R⊙. K- and J-band adaptive optics images of the field taken at this epoch using the NIRC2 imager on the Keck telescope show that the source and lens are still blended, consistent with our light-curve model. With no statistically significant excess flux detection we constrain the mass, , and distance, DL = 7.0 ± 1.0 kpc, of the lensing system. This supports the interpretation of this event as a stellar binary in the Galactic bulge. This lens mass gives a companion mass of , close to the boundary between being a star and a brown dwarf. [ABSTRACT FROM AUTHOR]

We present the analysis of the binary-microlensing event OGLE-2014-BLG-0289. The event light curve exhibits five very unusual peaks, four of which were produced by caustic crossings and the other by a cusp approach. It is found that the quintuple-peak features of the light curve provide tight constraints on the source trajectory, enabling us to precisely and accurately measure the microlensing parallax . Furthermore, the three resolved caustics allow us to measure the angular Einstein radius . From the combination of and , the physical lens parameters are uniquely determined. It is found that the lens is a binary composed of two M dwarfs with masses and separated in projection by . The lens is located in the disk with a distance of . The reason for the absence of a lensing signal in the Spitzer data is that the time of observation corresponds to the flat region of the light curve. [ABSTRACT FROM AUTHOR]

We present the analysis of the binary gravitational microlensing event MOA-2015-BLG-020. The event has a fairly long timescale (∼63 days) and thus the light curve deviates significantly from the lensing model that is based on the rectilinear lens-source relative motion. This enables us to measure the microlensing parallax through the annual parallax effect. The microlensing parallax parameters constrained by the ground-based data are confirmed by the Spitzer observations through the satellite parallax method. By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing, the physical parameters of the lens are determined. It is found that the binary lens is composed of two dwarf stars with masses and in the Galactic disk. Assuming that the source star is at the same distance as the bulge red clump stars, we find the lens is at a distance . We also provide a summary and short discussion of all of the published microlensing events in which the annual parallax effect is confirmed by other independent observations. [ABSTRACT FROM AUTHOR]

We report the results of the statistical analysis of planetary signals discovered in MOA-II microlensing survey alert system events from 2007 to 2012. We determine the survey sensitivity as a function of planet–star mass ratio, q, and projected planet–star separation, s, in Einstein radius units. We find that the mass-ratio function is not a single power law, but has a change in slope at q ∼ 10−4, corresponding to ∼20 M⊕ for the median host-star mass of ∼0.6 . We find significant planetary signals in 23 of the 1474 alert events that are well-characterized by the MOA-II survey data alone. Data from other groups are used only to characterize planetary signals that have been identified in the MOA data alone. The distribution of mass ratios and separations of the planets found in our sample are well fit by a broken power-law model of the form for q > qbr and for q < qbr, where qbr is the mass ratio of the break. We also combine this analysis with the previous analyses of Gould et al. and Cassan et al., bringing the total sample to 30 planets. This combined analysis yields , n = −0.93 ± 0.13, , and for qbr ≡ 1.7 × 10−4. The unbroken power-law model is disfavored with a p-value of 0.0022, which corresponds to a Bayes factor of 27 favoring the broken power-law model. These results imply that cold Neptunes are likely to be the most common type of planets beyond the snow line. [ABSTRACT FROM AUTHOR]

We present the discovery of the first Neptune analog exoplanet or super-Earth with a Neptune-like orbit, MOA-2013-BLG-605Lb. This planet has a mass similar to that of Neptune or a super-Earth and it orbits at 9 ∼ 14 times the expected position of the snow line, asnow, which is similar to Neptune's separation of 11 asnow from the Sun. The planet/host-star mass ratio is q = (3.6 ± 0.7) × 10−4 and the projected separation normalized by the Einstein radius is s = 2.39 ± 0.05. There are three degenerate physical solutions and two of these are due to a new type of degeneracy in the microlensing parallax parameters, which we designate “the wide degeneracy.” The three models have (i) a Neptune-mass planet with a mass of orbiting a low-mass M-dwarf with a mass of , (ii) a mini-Neptune with orbiting a brown dwarf host with , and (iii) a super-Earth with orbiting a low-mass brown dwarf host with , which is slightly favored. The 3D planet–host separations are au, au, and au, which are , , or times larger than asnow for these models, respectively. Keck adaptive optics observations confirm that the lens is faint. This discovery suggests that low-mass planets with Neptune-like orbits are common. Therefore processes similar to the one that formed Neptune in our own solar system or cold super-Earths may be common in other solar systems. [ABSTRACT FROM AUTHOR]

Two cold gas giant planets orbiting a G-type main-sequence star in the galactic disk were previously discovered in the high-magnification microlensing event OGLE-2012-BLG-0026. Here, we present revised host star flux measurements and a refined model for the two-planet system using additional light curve data. We performed high angular resolution adaptive optics imaging with the Keck and Subaru telescopes at two epochs while the source star was still amplified. We detected the lens flux, H = 16.39 ± 0.08. The lens, a disk star, is brighter than predicted from the modeling in the original study. We revisited the light curve modeling using additional photometric data from the B&C telescope in New Zealand and CTIO 1.3 m H-band light curve. We then include the Keck and Subaru adaptive optic observation constraints. The system is composed of a ∼4–9 Gyr lens star of Mlens = 1.06 ± 0.05 M⊙ at a distance of Dlens = 4.0 ± 0.3 kpc, orbited by two giant planets of 0.145 ± 0.008 MJup and 0.86 ± 0.06 MJup, with projected separations of 4.0 ± 0.5 au and 4.8 ± 0.7 au, respectively. Because the lens is brighter than the source star by 16 ± 8% in H, with no other blend within one arcsec, it will be possible to estimate its metallicity using subsequent IR spectroscopy with 8–10 m class telescopes. By adding a constraint on the metallicity it will be possible to refine the age of the system. [ABSTRACT FROM AUTHOR]

We report the discovery of a planet by the microlensing method, OGLE-2012-BLG-0724Lb. Although the duration of the planetary signal for this event was one of the shortest seen for a planetary event, the anomaly was well covered thanks to high-cadence observations taken by the survey groups OGLE and MOA. By analyzing the light curve, this planetary system is found to have a mass ratio . By conducting a Bayesian analysis, we estimate that the host star is an M dwarf with a mass of located at away from the Earth and the companion’s mass is . The projected planet–host separation is . Because the lens–source relative proper motion is relatively high, future high-resolution images would detect the lens host star and determine the lens properties uniquely. This system is likely a Saturn-mass exoplanet around an M dwarf, and such systems are commonly detected by gravitational microlensing. This adds another example of a possible pileup of sub-Jupiters in contrast to a lack of Jupiters () around M dwarfs, supporting the prediction by core accretion models that Jupiter-mass or more massive planets are unlikely to form around M dwarfs. [ABSTRACT FROM AUTHOR]

We present the discovery of a Neptune-mass planet orbiting a star in the Galactic bulge. The planet manifested itself during the microlensing event MOA-2011-BLG-028/OGLE-2011-BLG-0203 as a low-mass companion to the lens star. The analysis of the light curve provides the measurement of the mass ratio , which indicates that the mass of the planet is 12–60 Earth masses. The lensing system is located at 7.3 ± 0.7 kpc away from the Earth near the direction of Baade’s Window. The projected separation of the planet at the time of the microlensing event was 3.1–5.2 au. Although the microlens parallax effect is not detected in the light curve of this event, preventing the actual mass measurement, the uncertainties of mass and distance estimation are narrowed by the measurement of the source star proper motion on the OGLE-III images spanning eight years, and by the low amount of blended light seen, proving that the host star cannot be too bright and massive. We also discuss the inclusion of undetected parallax and orbital motion effects into the models and their influence onto the final physical parameters estimates. [ABSTRACT FROM AUTHOR]