mir-RNAs play a role in regulating bone homeostasis. In this study we assessed the functional role of mir-RNA 150 in bone homeostasis. We also assess the effects of miR-150 deficiency on osteoblast ...and osteoclast differentiation and function using in vivo and in vitro approaches.
Wild type (WT) (C57BL/6J) and miR-150 KO mice were compared for a variety of parameters. Micro-CT imaging was conducted to quantify trabecular bone mass inferior to the distal growth plate of the femur. Von Kossa staining was performed for osteoblast culture mineralization. RT-qPCR, biochemical analysis and bone histomorphometry were utilized for quantification of relevant genes and serum protein measurements. Differentiation and function of osteoblasts and osteoclasts was performed using primarily cultures and assessed the cell autonomous response of mir-RNA-150 on cell differentiation and function.
Mir-150 exhibited expression in a variety of tissues and increases progressively with age. Through micro-CT imaging, we found that KO mice presented reduced bone mass at 4, 8, and 16 weeks of age compared to WT mice. Furthermore, histomorphometric analysis revealed increased trabecular separation, decreased bone thickness, and decreased osteoblast number in KO compared to WT mice. Mir-150 deficiency also correlated with higher bone resorption, accompanied with significant increases in CTX-1 serum levels, and a decrease in cell apoptotic rate ex vivo. Additionally, miR-150 KO mice showed increased osteoblast differentiation and decreased osteoclastogenesis ex vivo. Luciferase assay showed increased Osteoactivin/GPNMB expression in miR-150 KO osteoblasts compared to WT cells.
Our data suggests that miR-150 influences osteoblast and osteoclast functionality and differentiation; specifically, miR-150 serves as a negative regulator for osteoblasts and a positive regulator for osteoclasts by regulating, at least in part, Osteoactivin/GPNMB expression.
•Below is the corrected info. MicroRNAs (miRs) influence osteoblast and osteoclast functionality and differentiation•Mir-150 serves as a negative regulator for osteoblastogenesis and a positive regulator for osteoclastogenesis•There is an inverse relationship between Osteoactivin/GPNMB and miR-150 during osteoblast differentiation in vitro•miR-150 can act for therapeutic strategies to either enhance/reduce bone formation in pathologic conditions
Abstract The nearby LHS 1678 (TOI-696) system contains two confirmed planets and a wide-orbit, likely brown-dwarf companion, which orbit an M2 dwarf with a unique evolutionary history. The host star ...occupies a narrow “gap” in the Hertzsprung–Russell diagram lower main sequence, associated with the M dwarf fully convective boundary and long-term luminosity fluctuations. This system is one of only about a dozen M dwarf multiplanet systems to date that hosts an ultra-short-period planet (USP). Here we validate and characterize a third planet in the LHS 1678 system using TESS Cycle 1 and 3 data and a new ensemble of ground-based light curves. LHS 1678 d is a 0.98 ± 0.07 R ⊕ planet in a 4.97 day orbit, with an insolation flux of 9.1 − 0.8 + 0.9 S ⊕ . These properties place it near 4:3 mean motion resonance with LHS 1678 c and in company with LHS 1678 c in the Venus zone. LHS 1678 c and d are also twins in size and predicted mass, making them a powerful duo for comparative exoplanet studies. LHS 1678 d joins its siblings as another compelling candidate for atmospheric measurements with the JWST and mass measurements using high-precision radial velocity techniques. Additionally, USP LHS 1678 b breaks the “peas-in-a-pod” trend in this system although additional planets could fill in the “pod” beyond its orbit. LHS 1678's unique combination of system properties and their relative rarity among the ubiquity of compact multiplanet systems around M dwarfs makes the system a valuable benchmark for testing theories of planet formation and evolution.
One of the most scrutinized contemporary techniques for geospatial data collection and production is crowdsourcing. This inverts the traditional top-down geospatial data production and distribution ...methods by emphasizing on the participation of the end user or community. The technique has been shown to be particularly useful in the domain of accessibility mapping, where it can augment traditional mapping methods and systems by providing information about transitory obstacles in the built environment. This research paper presents details of techniques and applications of crowdsourcing and related methods for improving the presence of transitory obstacles in accessibility mapping systems. The obstacles are very difficult to incorporate with any other traditional mapping workflow, since they typically appear in an unplanned manner and disappear just as quickly. Nevertheless, these obstacles present a major impediment to navigating an unfamiliar environment. Fortunately, these obstacles can be reported, defined, and captured through a variety of crowdsourcing techniques, including gazetteer-based geoparsing and active social media harvesting, and then referenced in a crowdsourced mapping system. These techniques are presented, along with context from research in tactile cartography and geo-enabled accessibility systems.
The tibial tubercle-trochlear groove measurement (TT-TG), which measures the lateral offset of the tibial tubercle relative to the trochlear groove of the femur, has been utilized as an ...intraoperative tool to help establish maximum patellofemoral congruency in patients who suffer from patellar instability. We have previously published our approach of establishing how far to transfer the tibial tubercle using intraoperative femoral nerve stimulation in order to achieve congruency from 0-30° of flexion. The technique and clinical outcomes have previously been published in this journal and elsewhere. Here we describe the use of the TT-TG distance to determine how far to transfer the tibial tubercle to achieve our goals and have found that it varies according to the clinical exam features.
We intended to determine the effectiveness of using the preoperatively established TT-TG to predict the degree of intraoperative me- dialization of the tibial tubercle to achieve our goal of establishing dynamic congruency of the patella in the trochlear groove when using the previously described femoral nerve stimulation method of estimating dynamic tracking of the patella.
From the study group of patients used in other publications, we examined 20 knees in 18 patients who had a history of recurrent lateral dislocations and underwent a Fulkerson tibial tubercle transfer. Each knee was dynamically assessed preoperatively by obtaining an MRI at 30° of flexion and complete hyperextension while voluntarily contracting their quadriceps. These were then compared to the intraoperative transfer of the tibial tubercle required to achieve maximum congruency when the femoral nerve was stimulated. We then looked at the preoperative TT-TG measurement to determine its role in predicting what was required at achieving congruency in the context of the quad active MRI findings.
Thirteen knees preoperatively demonstrated a positive J-sign defined as the patella subluxated greater than or equal to 5 mm lateral in full extension compared to 30° of flexion. In these patients, the TT-TG was accurate if the distance medialized was 1:1 with the measured TT-TG. In 7 out of the 20 knees, the patella demonstrated a false negative J-sign where the patella was radio- graphically subluxated at 30° of flexion as well as at hyperextension. In this group, the TT-TG underestimated the transfer required for congruency on average 5mm even when using the 1:1 ratio.
The preoperative use of the J-sign is of value when determining the role of the TT-TG measurement and estimating the distance required to intraoperatively achieve congruency when using the femoral nerve stimulation technique. Those that demonstrated a positive J-sign of 5mm or greater, a 1:1 ratio of TT-TG to medialization is most reliable at establishing congruency of the patellofemoral joint. Whereas, those that demonstrated a false negative J-sign even the 1:1 ratio remains inadequate at producing congruency and more medialization is required.
Level III, Retrospective Observational/Comparative Study.
Abstract
The future of exoplanet science is bright, as
Transiting Exoplanet Survey Satellite
(
TESS
) once again demonstrates with the discovery of its longest-period confirmed planet to date. We ...hereby present HD 21749b (TOI 186.01), a sub-Neptune in a 36 day orbit around a bright (
V
= 8.1) nearby (16 pc) K4.5 dwarf.
TESS
measures HD 21749b to be
R
⊕
, and combined archival and follow-up precision radial velocity data put the mass of the planet at
M
⊕
. HD 21749b contributes to the
TESS
Level 1 Science Requirement of providing 50 transiting planets smaller than 4
R
⊕
with measured masses. Furthermore, we report the discovery of HD 21749c (TOI 186.02), the first Earth-sized (
) planet from
TESS
. The HD 21749 system is a prime target for comparative studies of planetary composition and architecture in multi-planet systems.
The goal is to introduce a reproducible exam technique that allows clinical diagnosis of symptomatic plical bands and associated synovium about the knee. We then aimed to assess the accuracy of the ...exam technique through arthroscopic confirmation of these tissues. Lastly, we hope to determine whether arthroscopic plicectomy and partial synovectomy is an effective treatment for alleviating the pain associated with symptomatic plica.
This retrospective study evaluated 80 consecutive symptomatic knees under the care of a single physician diagnosed with symptomatic plica and associated painful synovium from 2001-2011. These patients underwent diagnostic and therapeutic arthroscopy to verify the presence of a plica and painful synovium with plicectomy and partial synovectomy if necessary. Statistical analysis was performed to determine the sensitivity and positive predictive value of the exam.
The medial parapatellar region was the most common location for symptomatic plica and associated synovial tissue. The exam technique described in this study had a sensitivity of 83.8% with a positive predictive value of 98.6% in the specific patient population described.
This study suggests that while the medial plical band is the most common, there is frequently sensitive synovial tissue found in multiple locations about the knee. This study also suggests that a thorough exam technique can accurately diagnose both the plical bands as well as the sensitive synovial tissue.
Level II, Diagnostic Study. See the Guidelines for Authors for a complete description of levels of evidence.
Phase-curve measurements provide a global view of the composition, thermal structure, and dynamics of exoplanet atmospheres. Although most of the dozens of phase-curve measurements made to date are ...of large, massive hot Jupiters, there is considerable interest in probing the atmospheres of the smaller planets that are the more typical endproduct of the planet formation process. One such planet that is favorable for these studies is the ultrahot Neptune LTT 9779b, a rare denizen of the Neptune desert. A companion paper presents the planet's secondary eclipses and dayside thermal emission spectrum; in this work we describe the planet's optical and infrared phase curves, characterized using a combination of Spitzer and Transiting Exoplanet Survey Satellite (TESS) photometry. We detect LTT 9779b's thermal phase variations at 4.5 m, finding a phase amplitude of 358 106 ppm and no significant phase offset, with a longitude of peak emission occurring −10° 21° east of the substellar point. Combined with our secondary eclipse observations, these phase-curve measurements imply a 4.5 m dayside brightness temperature of 1800 120 K, a nightside brightness temperature of 700 430 K (<1350 K at 2 confidence), and a day-night brightness temperature contrast of 1110 460 K. We compare our data to the predictions of 3D general circulation models calculated at multiple metallicity levels and to similar observations of hot Jupiters experiencing similar levels of stellar irradiation. Though not conclusive, our measurement of its small 4.5 m phase offset, the relatively large amplitude of the phase variation, and the qualitative differences between our target's dayside emission spectrum and those of hot Jupiters of similar temperatures all suggest a supersolar atmospheric metallicity for LTT 9779b, as might be expected given its size and mass. Finally, we measure the planet's transits at both 3.6 m and 4.5 m, providing a refined ephemeris (P = 0.79207022 0.00000069 days, T0 = 2458783.51636 0.00027, BJDTDB) that will enable efficient scheduling of future observations to further characterize the atmosphere of this intriguing planet.
Abstract
Studies of close-in planets orbiting M dwarfs have suggested that the M-dwarf radius valley may be well explained by distinct formation timescales between enveloped terrestrials and rocky ...planets that form at late times in a gas-depleted environment. This scenario is at odds with the picture that close-in rocky planets form with a primordial gaseous envelope that is subsequently stripped away by some thermally driven mass-loss process. These two physical scenarios make unique predictions of the rocky/enveloped transition’s dependence on orbital separation such that studying the compositions of planets within the M-dwarf radius valley may be able to establish the dominant physics. Here, we present the discovery of one such keystone planet: the ultra-short-period planet TOI-1634 b (
P
= 0.989 days,
F
=
121
F
⊕
,
r
p
=
1.790
−
0.081
+
0.080
R
⊕
) orbiting a nearby M2 dwarf (
K
s
= 8.7,
R
s
= 0.450
R
⊙
,
M
s
= 0.502
M
⊙
) and whose size and orbital period sit within the M-dwarf radius valley. We confirm the TESS-discovered planet candidate using extensive ground-based follow-up campaigns, including a set of 32 precise radial velocity measurements from HARPS-N. We measure a planetary mass of
4.91
−
0.70
+
0.68
M
⊕
, which makes TOI-1634 b inconsistent with an Earth-like composition at
5.9
σ
and thus requires either an extended gaseous envelope, a large volatile-rich layer, or a rocky composition that is not dominated by iron and silicates to explain its mass and radius. The discovery that the bulk composition of TOI-1634 b is inconsistent with that of Earth supports the gas-depleted formation mechanism to explain the emergence of the radius valley around M dwarfs with
M
s
≲
0.5
M
⊙
.
Abstract
TOI-216 hosts a pair of warm, large exoplanets discovered by the TESS mission. These planets were found to be in or near the 2:1 resonance, and both of them exhibit transit timing variations ...(TTVs). Precise characterization of the planets’ masses and radii, orbital properties, and resonant behavior can test theories for the origins of planets orbiting close to their stars. Previous characterization of the system using the first six sectors of TESS data suffered from a degeneracy between planet mass and orbital eccentricity. Radial-velocity measurements using HARPS, FEROS, and the Planet Finder Spectrograph break that degeneracy, and an expanded TTV baseline from TESS and an ongoing ground-based transit observing campaign increase the precision of the mass and eccentricity measurements. We determine that TOI-216c is a warm Jupiter, TOI-216b is an eccentric warm Neptune, and that they librate in 2:1 resonance with a moderate libration amplitude of
deg, a small but significant free eccentricity of
for TOI-216b, and a small but significant mutual inclination of 1.°2–3.°9 (95% confidence interval). The libration amplitude, free eccentricity, and mutual inclination imply a disturbance of TOI-216b before or after resonance capture, perhaps by an undetected third planet.
ABSTRACT
We present TOI-1259Ab, a 1.0RJup gas giant planet transiting a 0.71R⊙ K-dwarf on a 3.48 d orbit. The system also contains a bound white dwarf companion TOI-1259B with a projected distance of ...∼1600 au from the planet host. Transits are observed in nine TESS sectors and are 2.7 per cent deep – among the deepest known – making TOI-1259Ab a promising target for atmospheric characterization. Our follow-up radial velocity measurements indicate a variability of semiamplitude $K=71\, \rm m\, s^{-1}$, implying a planet mass of 0.44MJup. By fitting the spectral energy distribution of the white dwarf, we derive a total age of $4.08^{+1.21}_{-0.53}$ Gyr for the system. The K dwarf’s light curve reveals rotational variability with a period of 28 d, which implies a gyrochronology age broadly consistent with the white dwarf’s total age.
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